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CN-121975348-A - Preparation method and application of nano organic pigment with different crystal forms

CN121975348ACN 121975348 ACN121975348 ACN 121975348ACN-121975348-A

Abstract

The invention relates to the field of organic pigments, and discloses a preparation method and application of nano organic pigments with different crystal forms. The preparation method comprises the steps of 1) dissolving a crude product of an organic pigment in a good solvent, adding inorganic salt for activation, 2) dripping a poor solvent at a gradient rate, adding a crystal form guiding agent, and inducing nucleation, wherein the alpha crystal form guiding agent is magnesium stearate, the beta crystal form guiding agent is dibutyl phthalate, the gamma crystal form guiding agent is polyethylene glycol, the gradient rate is initially 0.5-1mL/min, the gradient rate is increased by 0.2-0.3mL/min every 8-12min, 3) ultrasonic treatment, 4) cooling, adding a surface modifier for surface modification, and 5) post treatment to obtain the target crystal form organic pigment. The nano organic pigment of the target crystal form can be accurately obtained through process regulation, and has the characteristics of uniform particle size distribution, good dispersibility, good heat resistance stability, high color intensity, flocculation resistance stability and good weather resistance after a coating is formed.

Inventors

  • FENG MENGLONG
  • LUO DELIANG
  • WANG JIANJUN
  • TAO MING
  • LI JIAWEI
  • XIA HEYUN
  • QI DONGMING

Assignees

  • 杭州百合辉柏赫颜料有限公司
  • 浙江理工大学

Dates

Publication Date
20260505
Application Date
20251231

Claims (10)

  1. 1. The preparation method of the nanometer organic pigment with different crystal forms is characterized by comprising the following steps: 1) Dissolving the crude organic pigment in a good solvent, and adding inorganic salt for activation, wherein the organic pigment is phthalocyanine pigment, azo pigment or quinacridone pigment; 2) Dripping poor solvent at gradient rate, adding crystal form guiding agent to induce nucleation, wherein the alpha crystal form guiding agent is magnesium stearate, the beta crystal form guiding agent is dibutyl phthalate, the gamma crystal form guiding agent is polyethylene glycol, and the gradient rate is 0.5-1mL/min initially, and the gradient rate is increased by 0.2-0.3mL/min every 8-12 min; 3) Performing ultrasonic treatment; 4) Cooling, and adding a surface modifier for surface modification, wherein the surface modifier is selected from silane coupling agents and polyether modified polysiloxane; 5) Post-treatment to obtain the target crystal form organic pigment, wherein the average grain diameter is 100-250nm, and the grain diameter distribution PDI is 0.1-0.25.
  2. 2. The method according to claim 1, wherein in step 1), the crude organic pigment is 10-20 parts by weight, the good solvent is 50-80 parts by weight, and the inorganic salt is 0.1-1 part by weight.
  3. 3. The process according to claim 1 or 2, wherein in step 1), The good solvent is selected from N, N-dimethylformamide, dimethyl sulfoxide and dichloromethane; the inorganic salt is selected from sodium chloride, potassium chloride, sodium sulfate and calcium chloride; the dissolution temperature is 40-60 ℃.
  4. 4. The method according to claim 2, wherein in the step 2), the crystal form guiding agent is 0.5-3 parts, and the volume ratio of the good solvent to the poor solvent is 1-1.5:1.
  5. 5. The method according to claim 1 or 4, wherein in step 2), the poor solvent is selected from the group consisting of deionized water, ethanol and ethyl acetate.
  6. 6. The method according to claim 1, wherein in the step 3), the ultrasonic treatment is performed at a power of 150 to 300W and a frequency of 20 to 40kHz for 30 to 90 minutes.
  7. 7. The method according to claim 4, wherein in the step 4), the surface modifier is 1 to 5 parts.
  8. 8. The preparation method according to claim 1 or 7, characterized in that: in the step 4), the temperature is reduced to 30-40 ℃, and the surface modification condition is that the stirring speed is 800-1000r/min and the time is 20-40min; In the step 5), the post-treatment comprises suction filtration, washing and vacuum drying.
  9. 9. Use of the nano-organic pigment obtained by the preparation method according to any one of claims 1-8 in paints, inkjet inks, printing inks, plastic colorants, textile printing dyes.
  10. 10. The method according to claim 9, wherein the nano-organic pigment is added in an amount of 5-20wt% of the paint, the ink-jet ink is added in an amount of 3-15 wt%, the plastic colorant is added in an amount of 0.8-5wt%, the printing ink is added in an amount of 2-8wt%, and the fabric printing dye is added in an amount of 8-20wt%.

Description

Preparation method and application of nano organic pigment with different crystal forms Technical Field The invention relates to the field of organic pigments, in particular to a preparation method and application of nano organic pigments with different crystal forms. Background Organic pigments are widely used in the fields of paint, ink, plastic, printing and dyeing, etc. because of bright color, strong tinting strength and low toxicity. However, the traditional organic pigment has certain technical defects such as single and unstable crystal form, poor dispersion performance and low surface activity. The existing preparation method of the organic pigment mainly comprises a ball milling method, a kneading method, a solvent treatment method, surface modification and the like. Although the methods are widely used, the problems that the pigment prepared by a ball milling or kneading method is unstable in crystal form, easy to return, uneven in particle size distribution, poor in dispersibility and unstable in coloring strength, the solvent recrystallization method depends on a large amount of organic solvents, is unfavorable for environmental protection and industrialization, is poor in crystal form controllability, has high requirements on conditions such as solvents, temperature and concentration, and the like, and can improve the dispersibility by surface treatment, but has limited contribution to crystal form transformation of a pigment body, and cannot radically change a lattice structure, and a coating layer can influence the coloring performance and durability of the pigment. Patent CN113683905 discloses a method for controlling the crystal form of nano pigment, which comprises the steps of pre-dispersing pigment by a kneader, adding specific water-based photosensitive resin, and dispersing by a sand mill, thereby realizing the preparation of the crystal form pigment. However, special equipment is required, and the cost of the aqueous photosensitive resin is high. Patent CN111621168a discloses a mixed crystal method of quinacridone pigment, the crude pigment produced by the mixed crystal method is placed in a closed reaction kettle to complete crystal transformation and curing, and then the surface modification can be carried out according to the requirement. However, this approach is only directed to quinacridone pigments and does not allow for modulation of the target crystal form. Therefore, a new preparation method is urgently needed, which can realize low energy consumption, stably and efficiently produce the organic pigment with target crystal forms and good particle size distribution, so as to improve the performances of dispersibility, color intensity, stability and the like. Disclosure of Invention In order to solve the technical problems, the invention provides a preparation method and application of different crystal forms of nano organic pigment. The nano organic pigment of the target crystal form can be accurately obtained through process regulation, and has the characteristics of uniform particle size distribution, good dispersibility, good heat resistance stability, high color intensity, flocculation resistance stability and good weather resistance after a coating is formed. The specific technical scheme of the invention comprises the following steps: in a first aspect, the present invention provides a method for preparing different crystal forms of nano organic pigment, comprising the steps of: 1) And (3) pretreatment, namely dissolving the crude organic pigment in a good solvent of the organic pigment, adding inorganic salt for activation to form a homogeneous solution, wherein the organic pigment is phthalocyanine pigment, azo pigment or quinacridone pigment. In the step 1), inorganic salt is used as an activator, and collides with organic pigment under the action of shearing force in the mixing and activating process, and salt crystals 'centralize' and transmit mechanical energy to organic pigment particles at the moment of collision, so that the salt crystals overcome lattice potential energy barriers, and are converted from a metastable crystal form with high internal energy to a crystal form with low internal energy, and meanwhile, the grain size is reduced, defects are increased, and the surface activity is improved. 2) The gradient solvent is mixed, namely, a poor solvent of the organic pigment is dripped at a gradient dripping rate, a crystal form guiding agent is added to induce nucleation, wherein the alpha crystal form guiding agent is magnesium stearate, the beta crystal form guiding agent is dibutyl phthalate, the gamma crystal form guiding agent is polyethylene glycol, and the gradient dripping rate is initially 0.5-1mL/min, and the gradient dripping rate is increased by 0.2-0.3mL/min every 8-12 min. In the step 2), firstly, the invention discovers that aiming at specific organic pigments of phthalocyanine pigments, azo pigments and quinacridone pigments, when magnesium