High-brightness water-based pigment ink-jet color paste and preparation method thereof

Abstract

The invention discloses high-brightness water-based pigment ink-jet color paste, and relates to the technical field of pigments. The water-based ink is prepared from the following materials in parts: 200 to 1000 parts of organic pigment, 100 to 900 parts of inorganic pigment, 1 to 500 parts of water-based dispersant, 50 to 300 parts of humectant, 10 to 600 parts of surfactant, 1 to 100 parts of mildew-proof bactericide, 1 to 200 parts of fluorescent whitening agent, 1 to 500 parts of pearlescent pigment, 1 to 200 parts of ultraviolet absorbent and 2 to 120 parts of antioxidant. The invention also discloses a preparation method of the high-brightness water-based pigment ink-jet color paste. By adding the fluorescent whitening agent, the pearlescent pigment, the ultraviolet light absorber and the antioxidant, the color is fuller and brighter, the color paste is endowed with a pearlescent gloss effect, rich and diversified decorative effects are achieved, the requirements of different customers for personalized and creative product appearances are met, and the color paste has a good market prospect in an outdoor environment with strong illumination. A good color state can still be kept, the color durability is prolonged, and the color brightness and durability of the color paste are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pigments, and particularly to a high-brightness water-based pigment inkjet colorant and a preparation method thereof. Background Art

[0002] With the rapid development of modern printing technology and the digital printing field, people's requirements for printing quality, especially in terms of color performance, are increasing day by day. As a convenient, efficient, and personalized printing method, inkjet printing has been widely used in many fields, such as advertising, digital printing, art creation and reproduction, office and home printing. In these application scenarios, the characteristics of color vividness, brightness, and durability have become the key indicators for measuring the printing effect, which has promoted the continuous development of inkjet colorant technology towards high performance.

[0003] Traditional water-based pigment inkjet colorants often have difficulty achieving high brightness while ensuring color accuracy. Many existing colorant products have relatively dull colors for the patterns or texts ejected due to limitations in pigment selection, dispersion process, and additive compatibility factors, and cannot meet the requirements of scenarios with high color visual impact, such as high-end advertising displays and high-quality reproduction of artworks. Moreover, under the influence of long-term light and humid environmental factors, the pigments are prone to fading and discoloration, resulting in poor color durability of the printed products. For this reason, we propose a high-brightness water-based pigment inkjet colorant and a preparation method thereof. Summary of the Invention

[0004] To solve the above technical problems, a high-brightness water-based pigment inkjet colorant and a preparation method thereof are provided, and this technical solution solves the problems of dull color brightness and poor durability.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: A high-brightness water-based pigment inkjet colorant is prepared from the following parts by weight of materials: 200 - 1000 parts of organic pigment, 100 - 900 parts of inorganic pigment, 1 - 500 parts of water-based dispersant, 50 - 300 parts of humectant, 10 - 600 parts of surfactant, 1 - 100 parts of mildew and bactericide, 1 - 200 parts of fluorescent whitening agent, 1 - 500 parts of pearlescent pigment, 1 - 200 parts of ultraviolet absorber, and 2 - 120 parts of antioxidant.

[0006] Preferably, it is specifically prepared from the following parts by weight of materials: 500 parts of organic pigment, 450 parts of inorganic pigment, 90 parts of water-based dispersant, 150 parts of humectant, 80 parts of surfactant, 50 parts of mildew and bactericide, 55 parts of fluorescent whitening agent, 15 parts of pearlescent pigment, 25 parts of ultraviolet absorber, and 10 parts of antioxidant.

[0007] Preferably, the organic pigment includes one of phthalocyanine pigments, azo pigments, and quinacridone pigments; the inorganic pigment is one of titanium dioxide and carbon black.

[0008] Preferably, the aqueous dispersant is one of acrylate copolymer dispersants, polymer dispersants, and anionic polyelectrolyte dispersants; the humectant is one or more of propylene glycol and glycerol.

[0009] Preferably, the surfactant is one of polyoxyethylene ether surfactants and sodium alkylbenzene sulfonate; the mildew and bactericide is one or more of isothiazolinone compounds and benzisothiazolinone.

[0010] Preferably, the fluorescent whitening agent is one or more of stilbene type, coumarin type, and pyrazoline type; the pearlescent pigment is one or more of natural mica-based pearlescent pigments, synthetic mica-based pearlescent pigments, glass flake-based pearlescent pigments, and flaky alumina-based pearlescent pigments; the ultraviolet absorber is one or more of benzophenone type, benzotriazole type, salicylate type, and cyanoacrylate type; the antioxidant is one or more of hindered phenol antioxidants, aromatic amine antioxidants, thiodipropionate antioxidants, and phosphite antioxidants.

[0011] A preparation method of a high-brightness aqueous pigment inkjet color paste, the preparation steps are as follows:

[0012] S1. Prepare materials, including: 200 - 1000 parts of organic pigment, 100 - 900 parts of inorganic pigment, 1 - 500 parts of aqueous dispersant, 50 - 300 parts of humectant, 10 - 600 parts of surfactant, 1 - 100 parts of mildew and bactericide, 1 - 200 parts of fluorescent whitening agent, 1 - 500 parts of pearlescent pigment, 1 - 200 parts of ultraviolet absorber, and 2 - 120 parts of antioxidant;

[0013] S2. Disperse the pigments. Place the weighed organic pigment and inorganic pigment in a high-speed disperser, start stirring, stir at 300 - 500 r / min for 5 - 10 min to mix the two pigments evenly to form a pigment mixture;

[0014] S3. Add partial dispersant. Add the aqueous dispersant to the pigment mixture, increase the stirring speed to 800 - 1200 r / min, and continuously stir for 15 - 30 min to make the dispersant contact with the pigments and start to wrap on the surface of the pigment particles, reducing the agglomeration tendency of the pigment particles;

[0015] S4. Fine grinding. Put the pigment mixture into a sand mill for grinding and dispersing;

[0016] S5. Additive mixing: Add a humectant, a surfactant, a mold and mildew fungicide, a fluorescent brightener, a pearlescent pigment, an ultraviolet absorber, and an antioxidant in sequence, and stir for 5 - 10 min.

[0017] S6. Performance adjustment: Perform performance testing on the color paste system after adding all additives, and measure the viscosity, surface tension, and pH value of the color paste. Adjust the performance of the color paste according to the test results.

[0018] S7. Filtration and impurity removal: Filter the color paste with adjusted performance through a filtration device to remove large particles that are not fully dispersed, impurities, and residues generated during the grinding process in the color paste, and obtain the color paste.

[0019] Preferably, in step S2, the operator judges whether the stirring meets the requirements by observing the overall state of the pigments in the dispersion tank and the change in color uniformity. When the color presents a unique color that combines the characteristics of the two pigments, and the entire mixture shows a stable and uniform state in the disperser, without obvious pigment agglomeration or excessive local color difference, it indicates that the two pigments have been successfully mixed evenly.

[0020] Preferably, in step S4 during the grinding process, the operator understands the grinding condition by observing the monitoring instrument on the sand mill. The grinding time is 1.5 h. Samples are taken from the sand mill every 15 - 30 min to check the grinding effect.

[0021] Preferably, in step S6, for viscosity detection, start the viscometer, set the corresponding measurement parameters according to the operating procedures, and measure the viscosity. During the measurement process, the viscometer calculates the viscosity value of the color paste based on the resistance received by the rotor when rotating in the color paste. After the measurement is completed, record the viscosity value displayed at this time to judge whether the current viscosity of the color paste meets the standard; for surface tension detection, start the surface tension meter, and measure the surface tension value of the color paste through the built-in measurement principle of the instrument, and record the measured data. The surface tension of the high - light water - based pigment inkjet color paste is 30 - 50 mN / m; for pH index detection, use a pH meter for detection. The pH value of the color paste that meets the standard is within 7 - 9.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] By adding fluorescent brighteners, pearlescent pigments, ultraviolet absorbers and antioxidants, the present invention makes the colors more saturated and bright, endows the color paste with a pearl-like luster effect, realizes rich and diverse decorative effects, and meets the needs of different customers for the appearance of personalized and creative products. The ultraviolet absorber can absorb the ultraviolet part in sunlight and release the absorbed energy in the form of low-energy heat, thereby reducing the destructive effect of ultraviolet rays on pigment molecules, maintaining the chemical structure stability of the pigments, ensuring that the color paste can still maintain a good color state during long-term use, especially in an environment with strong outdoor light, extending the durability of the color, and effectively improving the color brightness and durability of the color paste. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of the preparation steps of the high-brightness water-based pigment inkjet color paste of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations.

[0026] Referring to Figure 1 As shown, a high-brightness water-based pigment inkjet color paste is prepared from the following parts by weight of materials: 200-1000 parts of organic pigment, 100-900 parts of inorganic pigment, 1-500 parts of water-based dispersant, 50-300 parts of humectant, 10-600 parts of surfactant, 1-100 parts of mildew and bactericide, 1-200 parts of fluorescent brightener, 1-500 parts of pearlescent pigment, 1-200 parts of ultraviolet absorber and 2-120 parts of antioxidant.

[0027] Specifically, it is prepared from the following parts by weight of materials: 500 parts of organic pigment, 450 parts of inorganic pigment, 90 parts of water-based dispersant, 150 parts of humectant, 80 parts of surfactant, 50 parts of mildew and bactericide, 55 parts of fluorescent brightener, 15 parts of pearlescent pigment, 25 parts of ultraviolet absorber and 10 parts of antioxidant.

[0028] Water is the main water-based dispersion medium in the water-based dispersant, which has many advantages such as environmental protection, non-toxic, odorless and low cost. As a carrier, it enables pigment particles to be evenly dispersed therein, forming a stable system for inkjet printing. However, pure water sometimes cannot ensure a good dispersion state of the pigments for a long time, so the following substances are usually used in combination:

[0029] Polymeric dispersants, such as acrylate copolymer dispersants, have active groups on their molecular chains that can adsorb on the surface of pigments. Through steric hindrance effects and electrostatic repulsion, they effectively prevent the agglomeration of pigment particles due to mutual attraction, enabling the pigments to be uniformly and stably dispersed in water, ensuring the inkjet performance and color uniformity of the color paste;

[0030] Polyelectrolyte dispersants, like some anionic polyelectrolyte dispersants, dissociate into charged ions in aqueous systems. By interacting with the charges on the surface of pigments, they increase the repulsive force between pigment particles, helping the pigments to disperse better. They are commonly used in various aqueous pigment inkjet color paste formulations to improve the stability of the color paste.

[0031] Humectants are miscible with water. By reducing the evaporation rate of water, they maintain the water content in the color paste, preventing the color paste from thickening and clogging the nozzle due to excessive water loss during storage and use, maintaining the good fluidity and injectability of the color paste, and ensuring the smooth progress of the inkjet process.

[0032] Surfactants can adjust the surface tension of the color paste, making it better compatible with the inkjet print head, ensuring that the ejected ink droplets are of uniform size and regular shape, facilitating accurate and high-quality printing effects. At the same time, they also help the color paste to spread and adhere better on the surface of the substrate;

[0033] Mildew and bactericide have high-efficiency and broad-spectrum bactericidal and mildew-proof effects. They can inhibit the growth of microorganisms in the color paste during storage, avoiding problems such as color paste deterioration, odor, and nozzle clogging caused by microbial reproduction, extending the shelf life of the color paste, and ensuring the stable performance of the color paste for a long time.

[0034] For colored articles or printed materials, fluorescent brighteners do not only act on the white parts. They can also affect the presentation effect of the colored parts by adjusting the optical balance of the entire color system. The blue light emitted by them can increase the brightness and vividness of the color, making the color look more saturated and vivid, enhancing the overall color layering and visual impact.

[0035] Pearlescent pigments are an optical effect pigment. Their internal structure causes light to be reflected and refracted multiple times on the surface and inside of the pigment flakes, producing a soft luster similar to that of pearls. This luster has a unique charm and can make the product present an elegant and noble texture.

[0036] The molecular structures of pigments and many colored materials are prone to change under the action of ultraviolet light, leading to fading and discoloration. Ultraviolet absorbers prevent the initiation of photochemical reactions of pigment molecules by absorbing ultraviolet light, ensuring that the pigments can maintain their original chemical structure and color characteristics for a long time, and maintaining the vividness and durability of the color.

[0037] Antioxidants can preferentially react with free radicals by providing hydrogen atoms or electrons, converting the free radicals into relatively stable substances, thereby blocking the oxidation chain reaction initiated by free radicals, inhibiting the further development of the oxidation process, and protecting the chemical structure integrity of the material.

[0038] The organic pigment includes one of phthalocyanine pigments, azo pigments, and quinacridone pigments; the inorganic pigment is one of titanium dioxide and carbon black.

[0039] Preferably, the aqueous dispersant is one of acrylate copolymer dispersants, polymer dispersants, and anionic polyelectrolyte dispersants; the humectant is one or more of propylene glycol and glycerol.

[0040] The surfactant is one of polyoxyethylene ether surfactants and sodium alkylbenzenesulfonate; the mildew and bactericide is one or more of isothiazolinone compounds and benzisothiazolinone.

[0041] The fluorescent whitening agent is one or more of stilbene type, coumarin type, and pyrazoline type; the pearlescent pigment is one or more of natural mica-based pearlescent pigments, synthetic mica-based pearlescent pigments, glass flake-based pearlescent pigments, and flaky alumina-based pearlescent pigments; the ultraviolet absorber is one or more of benzophenone type, benzotriazole type, salicylate type, and cyanoacrylate type; the antioxidant is one or more of hindered phenol antioxidants, aromatic amine antioxidants, thiodipropionate antioxidants, and phosphite antioxidants.

[0042] Example 1

[0043] A preparation method of a high-brightness aqueous pigment inkjet color paste, and the preparation steps are as follows:

[0044] S1. Prepare materials, including: 500 parts of organic pigment, 450 parts of inorganic pigment, 90 parts of aqueous dispersant, 150 parts of humectant, 80 parts of surfactant, 50 parts of mildew and bactericide, 55 parts of fluorescent whitening agent, 15 parts of pearlescent pigment, 25 parts of ultraviolet absorber, and 10 parts of antioxidant;

[0045] S2. Disperse the pigments. Place the weighed organic pigment and inorganic pigment in a high-speed disperser, start stirring, stir at 300 - 500 r / min for 5 - 10 min to mix the two pigments evenly to form a pigment mixture;

[0046] S3. Add part of the dispersant. Add the aqueous dispersant to the pigment mixture, increase the stirring speed to 800 - 1200 r / min, and continuously stir for 15 - 30 min to make the dispersant contact with the pigments and start to wrap on the surface of the pigment particles, reducing the agglomeration tendency of the pigment particles;

[0047] S4, fine grinding, putting the pigment mixture into a sand mill for grinding and dispersion;

[0048] S5, mixing additives, adding moisturizer, surfactant, mildew-proof fungicide, fluorescent brightener, pearlescent pigment, ultraviolet absorber and antioxidant in sequence, and stirring for 5-10 minutes;

[0049] S6. Performance adjustment: test the performance of the color paste system after adding all additives, test the viscosity, surface tension, and pH value of the color paste, and fine-tune the performance of the color paste based on the test results;

[0050] S7, filtering and removing impurities, filtering the color paste with adjusted performance through filtering equipment, removing the large particles that are not completely dispersed, impurities and residues produced in the grinding process in the color paste, and obtaining the color paste.

[0051] In step S2, the operator determines whether the stirring meets the requirements by observing the overall state of the pigments in the dispersion tank and the change in color uniformity. When the color presents a unique color that combines the characteristics of the two pigments, and the entire mixture presents a stable and uniform state in the disperser, without obvious pigment agglomeration or excessive local color difference, it indicates that the two pigments have been successfully mixed evenly.

[0052] During the grinding process in step S4, the operator understands the grinding status by observing the monitoring instrument on the sand mill. The grinding time is 1.5 hours. Every 15-30 minutes, samples are taken from the sand mill to check the grinding effect.

[0053] In step S6, the viscosity test is performed by starting the viscometer, setting the corresponding measurement parameters according to the operating procedures, and measuring the viscosity. During the measurement, the viscometer calculates the viscosity value of the color paste through the resistance encountered by the rotor when it rotates in the color paste. After the measurement is completed, the viscosity value displayed at this time is recorded to determine whether the current color paste viscosity meets the standard; the surface tension test is performed by starting the surface tension meter, determining the surface tension value of the color paste through the built-in measurement principle of the instrument, and recording the measured data. The surface tension of the high-gloss water-based pigment inkjet color paste is 30-50mN / m; the pH index test is performed by a pH meter, and the pH value of the color paste that meets the standard is within 7-9.

[0054] Comparative Example 1

[0055] The preparation steps of inkjet color paste are as follows:

[0056] A1. Select pigments, dispersants, solvents, defoamers, preservatives and pH adjusters;

[0057] A2. Add pigments, dispersants, solvents and other additives into a suitable container according to a certain formulation ratio, and use stirring equipment for preliminary mixing and stirring;

[0058] A3. Select grinding equipment for grinding treatment;

[0059] A4. Conduct filtration and quality inspection, and perform packaging after passing the inspection.

[0060] The color pastes prepared in Comparative Example 1 often have difficulty achieving high brightness while ensuring color accuracy. For many existing color paste products, due to limitations in pigment selection, dispersion process, and additive compatibility factors, the colors of the sprayed patterns or texts are relatively dull, unable to meet the requirements of scenarios with high color visual impact, such as high-end advertising displays and high-quality reproductions of artworks. However, under the influence of long-term light and humid environmental factors, the pigments are prone to fading and color change, resulting in poor color durability of the printed finished products. In Example 1, by adding fluorescent whitening agents, pearlescent pigments, ultraviolet absorbers, and antioxidants, the color becomes more saturated and bright, endowing the color paste with a pearl-like luster effect, achieving a rich variety of decorative effects, and meeting the needs of different customers for personalized and creative product appearances. The ultraviolet absorber can absorb the ultraviolet part of sunlight and release the absorbed energy in the form of low-energy heat, thereby reducing the destructive effect of ultraviolet rays on pigment molecules, maintaining the chemical structure stability of the pigments, ensuring that the color paste can still maintain a good color state during long-term use, especially in an environment with strong outdoor light, extending the color durability, and effectively improving the color brightness and durability of the color paste.

[0061] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A high-gloss water-based pigment inkjet paste, characterized in that: The invention is prepared from the following materials: 200-1000 parts of organic pigments, 100-900 parts of inorganic pigments, 1-500 parts of aqueous dispersants, 50-300 parts of moisturizers, 10-600 parts of surfactants, 1-100 parts of mildew and fungicides, 1-200 parts of fluorescent brighteners, 1-500 parts of pearlescent pigments, 1-200 parts of ultraviolet absorbers and 2-120 parts of antioxidants.

2. The high-gloss water-based pigment inkjet paste according to claim 1, characterized in that: It is specifically prepared from the following materials: 500 parts of organic pigments, 450 parts of inorganic pigments, 90 parts of aqueous dispersants, 150 parts of moisturizers, 80 parts of surfactants, 50 parts of mildew and fungicides, 55 parts of fluorescent brighteners, 15 parts of pearlescent pigments, 25 parts of ultraviolet absorbers and 10 parts of antioxidants.

3. The high-gloss water-based pigment inkjet paste according to claim 1, characterized in that: The organic pigment includes one of phthalocyanine pigments, azo pigments and quinacridone pigments; the inorganic pigment is one of titanium dioxide and carbon black.

4. The high-gloss water-based pigment inkjet paste according to claim 1, characterized in that: The aqueous dispersant is one of an acrylic copolymer dispersant, a high molecular polymer dispersant and an anionic polyelectrolyte dispersant; the humectant is one or more of propylene glycol and glycerol.

5. The high-gloss water-based pigment inkjet paste according to claim 1, characterized in that: The surfactant is one of polyoxyethylene ether surfactant and sodium alkylbenzene sulfonate; the mildew-proofing and fungicide is one or more of isothiazolinone compounds and benzisothiazolinone.

6. The high-gloss water-based pigment inkjet paste according to claim 1, characterized in that: The fluorescent brightener is one or more of the diphenylethylene type, coumarin type and pyrazoline type; the pearlescent pigment is one or more of the natural mica-based pearlescent pigment, synthetic mica-based pearlescent pigment, glass flake-based pearlescent pigment and flaky alumina-based pearlescent pigment; the ultraviolet absorber is one or more of the benzophenone type, benzotriazole type, salicylic acid ester type and cyanoacrylate type; the antioxidant is one or more of the hindered phenol antioxidant, aromatic amine antioxidant, thiodipropionate antioxidant and phosphite antioxidant.

7. A method for preparing a high-brightness water-based pigment inkjet paste, characterized in that: The preparation steps are: S1. Prepare materials, including: 200-1000 parts of organic pigments, 100-900 parts of inorganic pigments, 1-500 parts of aqueous dispersants, 50-300 parts of moisturizers, 10-600 parts of surfactants, 1-100 parts of mildew and fungicides, 1-200 parts of fluorescent brighteners, 1-500 parts of pearlescent pigments, 1-200 parts of ultraviolet absorbers, and 2-120 parts of antioxidants; S2. Dispersing the pigments: placing the weighed organic pigments and inorganic pigments in a high-speed disperser, starting stirring, stirring at 300-500 r / min for 5-10 min, and mixing the two pigments evenly to form a pigment mixture; S3, add part of the dispersant, add the aqueous dispersant to the pigment mixture, increase the stirring speed to 800-1200r / min, and continue stirring for 15-30min, so that the dispersant contacts the pigment and begins to wrap around the surface of the pigment particles, reducing the agglomeration tendency of the pigment particles; S4, fine grinding, putting the pigment mixture into a sand mill for grinding and dispersion; S5, mixing additives, adding moisturizer, surfactant, mildew-proof fungicide, fluorescent brightener, pearlescent pigment, ultraviolet absorber and antioxidant in sequence, and stirring for 5-10 minutes; S6. Performance adjustment: test the performance of the color paste system after adding all additives, test the viscosity, surface tension, and pH value of the color paste, and fine-tune the performance of the color paste based on the test results; S7, filtering and removing impurities, filtering the color paste with adjusted performance through filtering equipment, removing the large particles that are not completely dispersed, impurities and residues produced in the grinding process in the color paste, and obtaining the color paste.

8. The method for preparing a high-gloss water-based pigment inkjet paste according to claim 7, characterized in that: In step S2, the operator determines whether the stirring meets the requirements by observing the overall state of the pigments in the dispersion tank and the change in color uniformity. When the color presents a unique color that combines the characteristics of the two pigments, and the entire mixture presents a stable and uniform state in the disperser, without obvious pigment agglomeration or excessive local color difference, it indicates that the two pigments have been successfully mixed evenly.

9. The method for preparing a high-gloss water-based pigment inkjet paste according to claim 7, characterized in that: During the grinding process in step S4, the operator understands the grinding status by observing the monitoring instrument on the sand mill. The grinding time is 1.5 hours. Every 15-30 minutes, samples are taken from the sand mill to check the grinding effect.

10. The method for preparing a high-gloss water-based pigment inkjet paste according to claim 7, characterized in that: In step S6, the viscosity test is performed by starting the viscometer, setting the corresponding measurement parameters according to the operating procedures, and measuring the viscosity. During the measurement process, the viscometer calculates the viscosity value of the color paste by the resistance encountered by the rotor when rotating in the color paste. After the measurement is completed, the viscosity value displayed at this time is recorded to determine whether the current color paste viscosity meets the standard; the surface tension test is performed by starting the surface tension meter, determining the surface tension value of the color paste through the built-in measurement principle of the instrument, and recording the measured data. The surface tension of the high-gloss water-based pigment inkjet color paste is 30-50mN / m; The pH index is tested by a pH meter, and the pH value of the color paste that meets the standard is within 7-9.

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