Preparation method of water-based pigment type nanoscale color paste

Abstract

The invention relates to the technical field of color paste, in particular to a preparation method of water-based pigment type nanoscale color paste, which comprises the following steps: mixing 192 grams of dispersing agent 1, 48 grams of dispersing agent 2 and 360 grams of deionized water, and heating in a drying oven at 60 DEG C for 1 hour to prepare 600 grams of mixed dispersing agent with 40% of effective component for later use; the self-developed surface synergist is introduced to anchor the surface of the pigment and is matched with the two dispersants to generate a coordination effect. The acrylic acid and carboxylic acid polymer synergist, the block polymerization amide hyperdispersant and the high-molecular polyether polymer are proportioned according to a certain proportion, so that the color development is effectively improved, and meanwhile, the heat storage stability in the formula is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of color pastes, and in particular to a method for preparing a water-based pigment nano-scale color paste. Background Art

[0002] Digital inkjet printing inks are a crucial component of inkjet printing. Currently, digital inkjet printing inks can be categorized into dye inks and pigment inks. Compared to dye inks, pigment inks offer the following advantages: 1. Versatility across different fibers. Different fibers require different dye inks, while pigment inks are suitable for a wide range of fiber fabrics. 2. Simple application process. Pigment inks for textile inkjet printing do not require complex pre- and post-processing processes; the fabric can be directly inkjet printed and then simply baked. 3. No wastewater is discharged, contributing to environmental protection. After inkjet printing, the pigments undergo a color fixation process, preventing floating color on the fabric. Therefore, washing to remove floating color is unnecessary, as is the case with dye inks. 4. Excellent lightfastness. After being sprayed onto fabric, pigment inks are deposited as tiny particles on the fibers, making them less susceptible to light dispersion. Even if the outer molecules of the particles are broken down by light, the inner layers retain their color. Dye inks, on the other hand, are deposited as molecules or loose aggregates upon application, making them easily decomposed by light.

[0003] Compared to dye inks, pigment inks are more technically difficult. On the one hand, this is limited by the immature technology for stabilizing and controlling nanoparticle size, and on the other hand, it is also limited by the performance of domestic raw materials, such as resins, pigments, and dispersants. The materials for pigment inks cannot be domestically produced, making it difficult to reduce material costs, and the technology for controlling nanoparticle size is also difficult. Water-based nano-colorants are a technical difficulty in the research, development, and preparation of pigment inks. The difficulty mainly lies in controlling the colorant particle size, particle size distribution span, storage stability, and color saturation. The smaller the particle size of the pigment particles, the more difficult it is to stabilize the pigment particle size, and the higher the performance requirements for the dispersant. Currently, the main material is still imported nano-dispersants. Different dispersants have different anchoring groups for pigments, so it is necessary to select a suitable dispersant to match them in order to improve the storage stability and color saturation of the colorant. Different colors of pigment inks have different performance requirements, and the range of particle size needs to be controlled. For example, white inkjet printing requires good covering power. Under the premise of ensuring smooth printing, it is necessary to get as close to the maximum allowable particle size as possible, narrow the particle size distribution span, and reduce the sedimentation caused by large particle size. This places extremely high demands on particle size control technology. There are very few domestic companies that have mastered this technology. Based on this, the present invention further improves it. Summary of the Invention

[0004] In view of the defects of the prior art, the purpose of the present invention is to provide a method for preparing a water-based pigment nano-scale color paste to solve the problems raised in the above background technology.

[0005] The present invention solves the technical problem by adopting the following technical solutions: The present invention provides a method for preparing a water-based pigment nano-scale color paste, comprising the following steps: (1) Mix 192 g of dispersant 1, 48 g of dispersant 2, and 360 g of deionized water, and heat in a 60°C oven for 1 h to prepare 600 g of a mixed dispersant with a 40% effective content for later use; The mixed dispersant in (2) was added with 30 g of surfactant and mixed evenly to obtain dispersion 2; (3) Add 150 g of deionized water to dispersion 2, and slowly mix dispersion 2 and 6 g of wetting agent using a dispersing mixer at a low speed of 300-500 RPM to prepare 780 g of dispersion 3; (4) Using a dispersing mixer at a speed of 1000-1500 RPM, add 300 g of nano carbon black pigment and 1920 g of deionized water to the dispersion 3 prepared in step 3, and disperse at 2000-2500 RPM for 30 min to obtain 3 kg of 10% pigment content nano black slurry to be ground; (5) Turn on the power of the 5L horizontal sand mill, vacuum machine and refrigerator, add 1.2kg of 0.2-0.3mm zirconium beads into the grinding cylinder of the sand mill at 500RPM, add 3kg of slurry to be ground into the dispersion cylinder of the sand mill, and turn on the feed pump and feed valve; (6) The particle size D99 of the color paste was tested by Bettersize 2600 laser particle size analyzer and was less than 300 nm. When the peak value of the particle size was 50-60 nm, grinding was stopped and the material was discharged to obtain 3 kg of nano black paste with a pigment content of 10%.

[0006] Preferably, the dispersant 1 is polyamide; the dispersant 2 is polyoxyethylene ether; The synergist is Lubrizol 12000S synergist; The wetting agent is selected from one of Hyperlev F420, Hyperlev F104, Hyperlev F465, and Hyperlev F440; The defoaming agent is one of Defomaster WS1, Defomaster WS2 and Defomaster M3X.

[0007] Preferably, the nano carbon black pigment is further modified, and the specific modification method is: Add nanocarbon black pigment to 5% chitosan solution in a weight ratio of 2:5 and stir evenly to obtain nanocarbon black solution; 1-3 parts of silane coupling agent KH560, 2-5 parts of lanthanum oxide, and 5-8 parts of sodium carboxymethyl cellulose solution are fully mixed to obtain a modified solution; The nano carbon black liquid and the modified liquid are stirred and modified in a weight ratio of 4:7. After the stirring is completed, the mixture is filtered and dried.

[0008] Preferably, the stirring temperature of the stirring modification treatment is 55-60° C., the stirring speed is 450-500 r / min, and the stirring is carried out for 1 hour.

[0009] Preferably, the preparation method of sodium carboxymethyl cellulose solution is: 2-5 parts of sodium carboxymethyl cellulose, 1-3 parts of nano-silica sol, 5-8 parts of silicon carbide fiber and 8-12 parts of sodium dodecylbenzenesulfonate solution are fully blended to obtain sodium carboxymethyl cellulose solution.

[0010] Preferably, the mass fraction of the sodium dodecylbenzenesulfonate solution is 2-5%.

[0011] Preferably, after the feed pump and the feed valve are turned on in step (5), the main engine speed is adjusted to 2900 RPM and grinding is carried out for 180 minutes.

[0012] Different from the nano-color paste currently on the market that only uses a single dispersant to anchor the pigment, and the method of increasing the amount of dispersant added to improve the particle size stability, the present invention adopts multi-layer coating technology on the pigment surface, using surface enhancers and multiple dispersants to produce a synergistic effect to anchor and disperse the pigment particles. The nano-color paste produced by this method has high grinding efficiency, excellent stability and color development.

[0013] The core chemical wetting agent is one of the acetylene glycol surfactants Hyperlev F420, Hyperlev F104, Hyperlev F465, and Hyperlev F440, which are non-ionic gemini surfactants with hydrophobic properties. They reduce the occurrence of bubbles and floating color and effectively improve the fluidity and leveling of the slurry.

[0014] The core chemical defoamer is a modified siloxane polymer selected from Defomaster WS1, Defomaster WS2, and Defomaster M3X, which has the ability to quickly break bubbles, improve grinding efficiency, and has good stability.

[0015] Dispersant 1 is a polyamide nonionic dispersant from the core chemical Disuper S9100, Disuper S19, Disuper E199, and Disuper S90. It has a wetting and dispersing effect and is particularly good at stabilizing phthalocyanine blue and acidic carbon black, showing excellent thermal stability and viscosity reduction properties.

[0016] Dispersant 2 is a polyoxyethylene ether nonionic dispersant from the core chemical Disuper S21, Disuper S31, Disuper S760, and Disuper S100. It has a synergistic effect with dispersant 1 to improve the versatility and stability of nano color paste.

[0017] The principle is to utilize the polar groups on Lubrizol 12000S surfactant to form van der Waals forces with inert / polar anchoring receptors on the pigment surface, allowing the surfactant to be well anchored on the surface of the pigment particles. Then, through block polymerization of high molecular weight polyamide dispersant 1 (HLB value 12-14) and polyoxyethylene ether dispersant 2 (HLB value 15-17, molecular weight 6000-10000), the pigment particles and the synergist anchored on the pigment surface are wrapped in multiple layers, forming an HLB gradient on the surface of the pigment particles. The surface of the pigment particles is anchored by hydrogen bonds and other receptor groups, producing a synergistic effect with the surfactant, allowing the solid pigment particles to form a continuous phase in liquid water. The excellent steric hindrance effect greatly reduces pigment particle collisions and particle size changes, making the pigment particles extremely stable in water.

[0018] Most commercially available pigment inks are made from imported pigment powders. Drying of the pigment powder can lead to the formation of large amounts of pigment aggregates and rearranged crystal forms, affecting the pigment's tinting strength, hue, gloss, and dispersion stability. The present invention utilizes domestically produced organic pigment filter cakes, whose particle size, distribution, and shape are essentially identical to those of the pigments produced. This eliminates dust pollution and offers high tinting strength and gloss, along with excellent dispersibility and stability.

[0019] Due to the large differences in the activity and HLB values ​​of the various materials in the formula, gelation is likely to occur between the materials during the preparation of the color paste, especially the polishing aid and the surface enhancer. Gelation is very likely to occur when the two are directly mixed.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The present invention addresses the problem that existing nano-color pastes are prone to coarsening and sedimentation after storage, and have poor stability, which in turn leads to clogging of the print head. A self-developed surface enhancer is introduced to anchor the pigment surface, and a synergistic effect is produced in combination with two dispersants. Acrylic acid polymer enhancers, block polymer amide hyperdispersants, and high molecular weight polyether polymers are mixed in a certain proportion to effectively improve the color development while having the characteristics of thermal storage stability in the formula. By wrapping the surface of the pigment particles with a gradient HLB, a continuous phase is formed between the pigment surface and the solvent medium, increasing the affinity for water and reducing mutual collisions between pigments. The introduction of hydrogen bonds in the polyamide dispersant reduces the mutual attraction and sedimentation caused by the collision of pigment particles, further improving stability. According to the anchoring groups and the number of the pigment structure characteristics, the ratio of the synergist and the dispersant is adjusted. The invention can be used to prepare nano-color pastes of almost all organic pigments and carbon black pigments. At the same time, the carbon black is modified. During the modification, the modification liquid is optimized and improved, and the silane coupling agent KH560, lanthanum oxide, and sodium carboxymethyl cellulose are blended and blended to prepare the product. The carboxymethyl cellulose liquid is fully blended with sodium carboxymethyl cellulose, nano-silica sol, silicon carbide fiber, and sodium dodecylbenzenesulfonate solution to obtain sodium carboxymethyl cellulose liquid. By combining the needle-like structure of the silicon carbide fiber with the raw materials in the sodium carboxymethyl cellulose liquid to achieve synergistic effects, the performance of the product is further improved, and the applicability is wide. The wetting ability of the acetylene alcohol wetting agent and the combined dispersant can provide good pigment surface defoaming and low dynamic surface tension, improve grinding efficiency, color paste fluidity and filterability, and the grinding aid effectively shortens the grinding time during color paste production, narrows the particle size band, reduces the particle size span, and can stably coexist with the synergist. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the particle size distribution diagram of the core nano-color paste; Figure 2 This is the particle size distribution of the core nano-color paste after 30 days of heat storage at 70°C; Figure 3 This is the particle size distribution diagram of commercially available nano-color paste; Figure 4 This is a test image of the transfer paper substrate; Figure 5 This is a test image of white cardboard substrate; Figure 6 This is a test chart for coated paper substrate. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] The method for preparing a water-based pigment nano-scale color paste of this embodiment includes the following steps: (1) Mix 192 g of dispersant 1, 48 g of dispersant 2, and 360 g of deionized water, and heat in a 60°C oven for 1 h to prepare 600 g of a mixed dispersant with a 40% effective content for later use; The mixed dispersant in (2) was added with 30 g of surfactant and mixed evenly to obtain dispersion 2; (3) Add 150 g of deionized water to dispersion 2, and slowly mix dispersion 2 and 6 g of wetting agent using a dispersing mixer at a low speed of 300-500 RPM to prepare 780 g of dispersion 3; (4) Using a dispersing mixer at a speed of 1000-1500 RPM, add 300 g of nano carbon black pigment and 1920 g of deionized water to the dispersion 3 prepared in step 3, and disperse at 2000-2500 RPM for 30 min to obtain 3 kg of 10% pigment content nano black slurry to be ground; (5) Turn on the power of the 5L horizontal sand mill, vacuum machine and refrigerator, add 1.2kg of 0.2-0.3mm zirconium beads into the grinding cylinder of the sand mill at 500RPM, add 3kg of slurry to be ground into the dispersion cylinder of the sand mill, and turn on the feed pump and feed valve; (6) The particle size D99 of the color paste was tested by Bettersize 2600 laser particle size analyzer and was less than 300 nm. When the peak value of the particle size was 50-60 nm, grinding was stopped and the material was discharged to obtain 3 kg of nano black paste with a pigment content of 10%.

[0024] Dispersant 1 in this embodiment is polyamide; dispersant 2 is polyoxyethylene ether; The synergist is Lubrizol 12000S synergist; The wetting agent is selected from one of Hyperlev F420, Hyperlev F104, Hyperlev F465, and Hyperlev F440; The defoaming agent is one of Defomaster WS1, Defomaster WS2 and Defomaster M3X.

[0025] The nano carbon black pigment of this embodiment is further subjected to modification treatment, and the specific modification method is as follows: Add nanocarbon black pigment to 5% chitosan solution in a weight ratio of 2:5 and stir evenly to obtain nanocarbon black solution; 1-3 parts of silane coupling agent KH560, 2-5 parts of lanthanum oxide, and 5-8 parts of sodium carboxymethyl cellulose solution are fully mixed to obtain a modified solution; The nano carbon black liquid and the modified liquid are stirred and modified in a weight ratio of 4:7. After the stirring is completed, the mixture is filtered and dried.

[0026] The stirring temperature of the stirring modification treatment in this embodiment is 55-60° C., the stirring speed is 450-500 r / min, and the stirring is carried out for 1 hour.

[0027] The preparation method of the sodium carboxymethyl cellulose solution of the present embodiment is: 2-5 parts of sodium carboxymethyl cellulose, 1-3 parts of nano-silica sol, 5-8 parts of silicon carbide fiber and 8-12 parts of sodium dodecylbenzenesulfonate solution are fully blended to obtain sodium carboxymethyl cellulose solution.

[0028] The mass fraction of the sodium dodecylbenzenesulfonate solution in this embodiment is 2-5%.

[0029] In step (5) of this embodiment, after the feed pump and the feed valve are turned on, the main engine speed is adjusted to 2900 RPM and grinding is carried out for 180 minutes.

[0030] Example 1. The method for preparing a water-based pigment nano-scale color paste of this embodiment includes the following steps: (1) Mix 192 g of dispersant 1, 48 g of dispersant 2, and 360 g of deionized water and heat in a 60°C oven for 1 h to prepare 600 g of a 40% effective content mixed dispersant for later use; The mixed dispersant in (2) was added with 30 g of surfactant and mixed evenly to obtain dispersion 2; (3) Add 150 g of deionized water to dispersion 2, and slowly mix dispersion 2 and 6 g of wetting agent using a dispersing mixer at a low speed of 300-500 RPM to prepare 780 g of dispersion 3; (4) Using a dispersing mixer at a speed of 1000-1500 RPM, add 300 g of nano carbon black pigment and 1920 g of deionized water to the dispersion 3 prepared in step 3, and disperse at 2000-2500 RPM for 30 min to obtain 3 kg of 10% pigment content nano black slurry to be ground; (5) Turn on the power of the 5L horizontal sand mill, vacuum machine and refrigerator, add 1.2kg of 0.2-0.3mm zirconium beads into the grinding cylinder of the sand mill at 500RPM, add 3kg of slurry to be ground into the dispersion cylinder of the sand mill, and turn on the feed pump and feed valve; (6) The particle size D99 of the color paste was tested by Bettersize 2600 laser particle size analyzer and was less than 300 nm. When the peak value of the particle size was 50-60 nm, grinding was stopped and the material was discharged to obtain 3 kg of nano black paste with a pigment content of 10%.

[0031] Dispersant 1 in this embodiment is polyamide; dispersant 2 is polyoxyethylene ether; The synergist is Lubrizol 12000S synergist; The wetting agent is selected from one of Hyperlev F420, Hyperlev F104, Hyperlev F465, and Hyperlev F440; The defoaming agent is one of Defomaster WS1, Defomaster WS2 and Defomaster M3X.

[0032] The nano carbon black pigment of this embodiment is further subjected to modification treatment, and the specific modification method is as follows: Add nanocarbon black pigment to 5% chitosan solution in a weight ratio of 2:5 and stir evenly to obtain nanocarbon black solution; 1-3 parts of silane coupling agent KH560, 2-5 parts of lanthanum oxide, and 5-8 parts of sodium carboxymethyl cellulose solution are fully mixed to obtain a modified solution; The nano carbon black liquid and the modified liquid are stirred and modified in a weight ratio of 4:7. After the stirring is completed, the mixture is filtered and dried.

[0033] The stirring temperature of the stirring modification treatment in this embodiment is 55-60° C., the stirring speed is 450-500 r / min, and the stirring is carried out for 1 hour.

[0034] The preparation method of the sodium carboxymethyl cellulose solution of the present embodiment is: 2-5 parts of sodium carboxymethyl cellulose, 1-3 parts of nano-silica sol, 5-8 parts of silicon carbide fiber and 8-12 parts of sodium dodecylbenzenesulfonate solution are fully blended to obtain sodium carboxymethyl cellulose solution.

[0035] The mass fraction of the sodium dodecylbenzenesulfonate solution in this embodiment is 2-5%.

[0036] In step (5) of this embodiment, after the feed pump and the feed valve are turned on, the main engine speed is adjusted to 2900 RPM and grinding is carried out for 180 minutes.

[0037] Example 2. The method for preparing a water-based pigment nano-scale color paste of this embodiment includes the following steps: (1) Mix 192 g of dispersant 1, 48 g of dispersant 2, and 360 g of deionized water, and heat in a 60°C oven for 1 h to prepare 600 g of a mixed dispersant with a 40% effective content for later use; The mixed dispersant in (2) was added with 30 g of surfactant and mixed evenly to obtain dispersion 2; (3) Add 150 g of deionized water to dispersion 2, and slowly mix dispersion 2 and 6 g of wetting agent using a dispersing mixer at a low speed of 300-500 RPM to prepare 780 g of dispersion 3; (4) Using a dispersing mixer at a speed of 1000-1500 RPM, add 300 g of nano carbon black pigment and 1920 g of deionized water to the dispersion 3 prepared in step 3, and disperse at 2000-2500 RPM for 30 min to obtain 3 kg of 10% pigment content nano black slurry to be ground; (5) Turn on the power of the 5L horizontal sand mill, vacuum machine and refrigerator, add 1.2kg of 0.2-0.3mm zirconium beads into the grinding cylinder of the sand mill at 500RPM, add 3kg of slurry to be ground into the dispersion cylinder of the sand mill, and turn on the feed pump and feed valve; (6) The particle size D99 of the color paste was tested by Bettersize 2600 laser particle size analyzer and was less than 300 nm. When the peak value of the particle size was 50-60 nm, grinding was stopped and the material was discharged to obtain 3 kg of nano black paste with a pigment content of 10%.

[0038] Dispersant 1 in this embodiment is polyamide; dispersant 2 is polyoxyethylene ether; The synergist is Lubrizol 12000S synergist; The wetting agent is selected from one of Hyperlev F420, Hyperlev F104, Hyperlev F465, and Hyperlev F440; The defoaming agent is one of Defomaster WS1, Defomaster WS2 and Defomaster M3X.

[0039] The nano carbon black pigment of this embodiment is further subjected to modification treatment, and the specific modification method is as follows: Add nanocarbon black pigment to 5% chitosan solution in a weight ratio of 2:5 and stir evenly to obtain nanocarbon black solution; 1-3 parts of silane coupling agent KH560, 2-5 parts of lanthanum oxide, and 5-8 parts of sodium carboxymethyl cellulose solution are fully mixed to obtain a modified solution; The nano carbon black liquid and the modified liquid are stirred and modified in a weight ratio of 4:7. After the stirring is completed, the mixture is filtered and dried.

[0040] The stirring temperature of the stirring modification treatment in this embodiment is 55-60° C., the stirring speed is 450-500 r / min, and the stirring is carried out for 1 hour.

[0041] The preparation method of the sodium carboxymethyl cellulose solution of the present embodiment is: 2-5 parts of sodium carboxymethyl cellulose, 1-3 parts of nano-silica sol, 5-8 parts of silicon carbide fiber and 8-12 parts of sodium dodecylbenzenesulfonate solution are fully blended to obtain sodium carboxymethyl cellulose solution.

[0042] The mass fraction of the sodium dodecylbenzenesulfonate solution in this embodiment is 2-5%.

[0043] In step (5) of this embodiment, after the feed pump and the feed valve are turned on, the main engine speed is adjusted to 2900 RPM and grinding is carried out for 180 minutes.

[0044] Example 3. The method for preparing a water-based pigment nano-scale color paste of this embodiment includes the following steps: (1) Mix 192 g of dispersant 1, 48 g of dispersant 2, and 360 g of deionized water, and heat in a 60°C oven for 1 h to prepare 600 g of a mixed dispersant with a 40% effective content for later use; The mixed dispersant in (2) was added with 30 g of surfactant and mixed evenly to obtain dispersion 2; (3) Add 150 g of deionized water to dispersion 2, and slowly mix dispersion 2 and 6 g of wetting agent using a dispersing mixer at a low speed of 300-500 RPM to prepare 780 g of dispersion 3; (4) Using a dispersing mixer at a speed of 1000-1500 RPM, add 300 g of nano carbon black pigment and 1920 g of deionized water to the dispersion 3 prepared in step 3, and disperse at 2000-2500 RPM for 30 min to obtain 3 kg of 10% pigment content nano black slurry to be ground; (5) Turn on the power of the 5L horizontal sand mill, vacuum machine and refrigerator, add 1.2kg of 0.2-0.3mm zirconium beads into the grinding cylinder of the sand mill at 500RPM, add 3kg of slurry to be ground into the dispersion cylinder of the sand mill, and turn on the feed pump and feed valve; (6) The particle size D99 of the color paste was tested by Bettersize 2600 laser particle size analyzer and was less than 300 nm. When the peak value of the particle size was 50-60 nm, grinding was stopped and the material was discharged to obtain 3 kg of nano black paste with a pigment content of 10%.

[0045] Dispersant 1 in this embodiment is polyamide; dispersant 2 is polyoxyethylene ether; The synergist is Lubrizol 12000S synergist; The wetting agent is selected from one of Hyperlev F420, Hyperlev F104, Hyperlev F465, and Hyperlev F440; The defoaming agent is one of Defomaster WS1, Defomaster WS2 and Defomaster M3X.

[0046] The nano carbon black pigment of this embodiment is further subjected to modification treatment, and the specific modification method is as follows: Add nanocarbon black pigment to 5% chitosan solution in a weight ratio of 2:5 and stir evenly to obtain nanocarbon black solution; 1-3 parts of silane coupling agent KH560, 2-5 parts of lanthanum oxide, and 5-8 parts of sodium carboxymethyl cellulose solution are fully mixed to obtain a modified solution; The nano carbon black liquid and the modified liquid are stirred and modified in a weight ratio of 4:7. After the stirring is completed, the mixture is filtered and dried.

[0047] The stirring temperature of the stirring modification treatment in this embodiment is 55-60° C., the stirring speed is 450-500 r / min, and the stirring is carried out for 1 hour.

[0048] The preparation method of the sodium carboxymethyl cellulose solution of the present embodiment is: 2-5 parts of sodium carboxymethyl cellulose, 1-3 parts of nano-silica sol, 5-8 parts of silicon carbide fiber and 8-12 parts of sodium dodecylbenzenesulfonate solution are fully blended to obtain sodium carboxymethyl cellulose solution.

[0049] The mass fraction of the sodium dodecylbenzenesulfonate solution in this embodiment is 2-5%.

[0050] In step (5) of this embodiment, after the feed pump and the feed valve are turned on, the main engine speed is adjusted to 2900 RPM and grinding is carried out for 180 minutes.

[0051] Results test: Color paste comparison test Step 1): Test and compare the particle size distribution of the above-mentioned nano black paste and the commercially available nano black paste, and the particle size distribution of the color paste after storage at 70°C for 30 days; Step 2): Take 30 grams of the above-mentioned nano black slurry and 30 grams of commercially available nano black slurry respectively, add 50 grams of water-based polyurethane PU110 resin into a 200 ml beaker container and disperse evenly to make ink and scrape on white cardboard, transfer paper, and coated paper for color comparison.

[0052] Thermal stability test: The particle size distribution of the above-mentioned nano black slurry and commercially available nano black slurry was tested by wet method using Bettersize 2600 laser particle size analyzer. The above-mentioned nano black slurry and commercially available nano black slurry were placed in a glass container, stored in an oven at 70° C. for 30 days, and then the particle size distribution was tested again.

[0053] Figure 1 and Figure 3The data show that the particle size distribution span of the nano-black slurry prepared by the present invention is smaller than that of commercial products, the peak is narrower, and the peak value of the particle size is around 100 nanometers. Figure 2 and Figure 3 It can be seen from the data that after the two-color paste is hot-stored at 70 degrees for 30 days, the D99 value particle size of the nano black paste prepared by the present invention migrates by 13 nanometers, with a span change of 0.076, while the D99 value particle size of the commercially available black paste migrates by 325 nanometers, with a span change of 0.590. The nano black paste prepared by the present invention has good stability.

[0054] Color contrast Preparation of scraper: The ink prepared by the nano black slurry prepared by the present invention and the ink prepared by the commercial product are simultaneously applied on white cardboard, transfer paper and coated paper. Figure 5 The ink was scraped with an RDS8# wire rod (wet film thickness 18 microns). After the ink dried, the coating (scraper) was observed and gloss and hue were measured. Gloss was measured using a specular gloss meter at a 60° angle of incidence, and hue was measured using a ZJ-300 standard colorimeter. The experimental results are shown in Table 1.

[0055]

[0056] The data in Table 1 show that the nano black paste prepared by the present invention has better color development and higher gloss than the products on the market, and the color paste has good compatibility with the commonly used polyurethane resins on the market, does not fog or whiten, and can be applied to absorbent substrates and non-absorbent substrates such as white cardboard, transfer paper, and coated paper, and has a wide range of applications.

[0057] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0058] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for preparing a water-based pigment nano-scale color paste, characterized in that: The following steps are involved: (1) Mix 192 g of dispersant 1, 48 g of dispersant 2, and 360 g of deionized water, and heat in a 60°C oven for 1 h to prepare 600 g of a mixed dispersant with a 40% effective content for later use; The mixed dispersant in (2) was added with 30 g of surfactant and mixed evenly to obtain dispersion 2; (3) Add 150 g of deionized water to dispersion 2, and slowly mix dispersion 2 and 6 g of wetting agent using a dispersing mixer at a low speed of 300-500 RPM to prepare 780 g of dispersion 3; (4) Using a dispersing mixer at a speed of 1000-1500 RPM, add 300 g of nano carbon black pigment and 1920 g of deionized water to the dispersion 3 prepared in step 3, and disperse at 2000-2500 RPM for 30 min to obtain 3 kg of 10% pigment content nano black slurry to be ground; (5) Turn on the power of the 5L horizontal sand mill, vacuum machine and refrigerator, add 1.2kg 0.2-0.3mm zirconium beads into the grinding cylinder of the sand mill at 500RPM, add 3kg of slurry to be ground into the dispersion cylinder of the sand mill, and turn on the feed pump and feed valve; (6) The particle size D99 of the color paste was tested by Bettersize 2600 laser particle size analyzer and was less than 300 nm. When the peak value of the particle size was 50-60 nm, grinding was stopped and the material was discharged to obtain 3 kg of nano black paste with a pigment content of 10%.

2. The method for preparing a water-based pigment nano-scale color paste according to claim 1, characterized in that: The dispersant 1 is polyamide; the dispersant 2 is polyoxyethylene ether; The synergist is Lubrizol 12000S synergist; Hyperlev F104 was selected as the wetting agent; The defoaming agent is one of Defomaster WS1, Defomaster WS2 and Defomaster M3X.

3. The method for preparing a water-based pigment nano-scale color paste according to claim 1, characterized in that: Nano carbon black pigments are also modified. The specific modification methods are as follows: Add nanocarbon black pigment to 5% chitosan solution in a weight ratio of 2:5 and stir evenly to obtain nanocarbon black solution; 1-3 parts of silane coupling agent KH560, 2-5 parts of lanthanum oxide, and 5-8 parts of sodium carboxymethyl cellulose solution are fully mixed to obtain a modified solution; The nano carbon black liquid and the modified liquid are stirred and modified in a weight ratio of 4:

7. After the stirring is completed, the mixture is filtered and dried.

4. The method for preparing a water-based pigment nano-scale color paste according to claim 2, characterized in that: The stirring temperature of the modified treatment is 55-60°C, the stirring speed is 450-500 r / min, and the stirring is for 1 hour.

5. The method for preparing a water-based pigment nano-scale color paste according to claim 2, characterized in that: The preparation method of sodium carboxymethyl cellulose solution is: 2-5 parts of sodium carboxymethyl cellulose, 1-3 parts of nano-silica sol, 5-8 parts of silicon carbide fiber and 8-12 parts of sodium dodecylbenzenesulfonate solution are fully blended to obtain sodium carboxymethyl cellulose solution.

6. The method for preparing a water-based pigment nano-scale color paste according to claim 4, characterized in that: The mass fraction of the sodium dodecylbenzenesulfonate solution is 2-5%.

7. The method for preparing a water-based pigment nano-scale color paste according to claim 4, characterized in that: After turning on the feed pump and feed valve in step (5), adjust the main engine speed to 2900 RPM and grind for 180 minutes.

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