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CN-121182290-B - Composite microcapsule color-changing pigment and preparation method thereof

CN121182290BCN 121182290 BCN121182290 BCN 121182290BCN-121182290-B

Abstract

The invention relates to the technical field of pigment preparation, in particular to a composite microcapsule color-changing pigment and a preparation method thereof. The intelligent microcapsule adopts a multi-compartment structure, the core is a thermochromic microcapsule, and the surface is fixed with a plurality of spice releasing sub-capsules with different thermal response thresholds through chemical bonding, so that the selective aroma release based on temperature gradient is realized. The thermochromic compound consists of crystal violet lactone, bisphenol A and a specific solvent, so that excellent thermochromic performance is ensured. The design realizes the multifunctional integration of the pigment, has the functions of temperature response color change and staged fragrance release, is widely applicable to the fields of intelligent paint and sensory materials, and has remarkable innovation and practical value.

Inventors

  • CHEN SHUANGZI
  • Chen Shuangnan
  • CHEN HUILING

Assignees

  • 深圳市添金利新材料科技有限公司

Dates

Publication Date
20260508
Application Date
20251104

Claims (7)

  1. 1. A composite microcapsule color-changing pigment is characterized by comprising, by mass, 30-50 parts of intelligent microcapsules, 40-60 parts of aqueous acrylic resin, 2-3 parts of film-forming auxiliary agents and 0.5-1 part of thickening agents; The intelligent microcapsule has a multi-compartment structure, and comprises a thermochromic microcapsule serving as a core and at least one perfume releasing sub-capsule fixed on the surface of the thermochromic microcapsule through chemical bonding; wherein the core material of the thermochromic microcapsule comprises a thermochromic compound, the core material of the perfume releasing sub-capsule comprises perfume, and the wall materials of different perfume releasing sub-capsules have different thermal response thresholds so as to realize selective perfume release based on temperature gradient; the perfume releasing sub-capsules comprise low-temperature perfume releasing sub-capsules, medium Wen Shixiang sub-capsules and high Wen Shixiang sub-capsules; the wall material of the low Wen Shixiang sub-capsule is gelatin-acacia compound, the core material of the low Wen Shixiang sub-capsule is menthol, and the trigger release temperature is 25-34 ℃; the wall material of the Wen Shixiang sub-capsule is ethyl cellulose, the core material of the Wen Shixiang sub-capsule is lavender oil, and the trigger release temperature is 35-45 ℃; the wall material of the Gao Wenshi perfume capsule is polystyrene-acrylic acid copolymer, the core material is citral, and the trigger release temperature is above 46 ℃; the intelligent microcapsule is prepared by the following steps: s11, coating the thermochromic composite serving as a core material by using polyacrylate-styrene copolymer resin serving as a wall material through an interfacial polymerization method to obtain thermochromic microcapsules; S12, coating the perfume serving as a core material by one of a complex coacervation method, a solvent volatilization method and an interfacial polymerization method, and adding groups capable of reacting with the surface functional groups of the thermochromic microcapsule on the surface of the perfume releasing microcapsule wall material in a chemical modification mode in the coating process to obtain a perfume releasing microcapsule; S13, mixing the thermochromic microcapsule obtained in the step S11 with the spice releasing sub-capsule obtained in the step S12, stirring and reacting for 4-12 hours at 20-60 ℃ to enable the spice releasing sub-capsule to be fixed on the surface of the thermochromic microcapsule through chemical bonding, and washing and drying to obtain the intelligent microcapsule; In step S12, when the perfume delivery sub-capsule comprises a low temperature perfume delivery sub-capsule, the low Wen Shixiang sub-capsule is prepared by a complex coacervation method; when the perfume delivery sub-capsule comprises a medium Wen Shixiang sub-capsule, the medium Wen Shixiang sub-capsule is prepared by a solvent evaporation method; when the perfume delivery sub-capsule comprises a high Wen Shixiang sub-capsule, the Gao Wenshi perfume sub-capsule is prepared by interfacial polymerization; the specific method for chemical modification comprises the following steps: When the complex coacervation method is adopted, glutaraldehyde is added into the wall material, the addition amount is 1.5-2.0% of the weight of the wall material, sodium chloroacetate is added for carboxymethylation modification, the addition amount of sodium chloroacetate is 2-4% of the weight of the wall material, the carboxymethylation reaction condition is that the temperature is 50-60 ℃, the time is 2-3h, the pH value is 10-11, then thionyl chloride is used under the ice bath condition of 0-5 ℃, the addition amount is 1.2-1.5 times of the molar amount of carboxymethyl, and chloridization reaction is carried out, so that chloralkane side chains are finally generated on the surface of the wall material; When a solvent volatilization method is adopted, 1-chlorododecane is doped in an organic phase of a wall material, the addition amount of the 1-chlorododecane is 5-10% of the total weight of the wall material, the emulsification process is carried out for 15-25min under high-speed shearing of 8000-12000 rpm, the temperature in the solvent volatilization stage is controlled at 35-40 ℃, the stirring speed is 250-350 rpm, the volatilization time is 4-6h, and the chloroalkane groups are stably exposed on the surface of the sub-capsule through blending emulsification; When the interfacial polymerization method is adopted, 4-chloromethyl styrene is added into the oil phase, the addition amount is 0.5% -5% of the weight of the wall material monomer, the chloralkane is embedded into the wall material polymer chain through the polymerization reaction, the polymerization reaction temperature is maintained at 70-80 ℃, the reaction time is 4-6h, the pH value of the system is adjusted to 8-9, and the stirring speed is controlled at 800-1200 rpm.
  2. 2. The composite microcapsule color-changing pigment according to claim 1, wherein the thermochromic composite consists of an electron donor, an electron acceptor and a solvent in a mass ratio of (0.08-0.1): (0.4-0.5): (3-6), wherein the electron donor is crystal violet lactone, the electron acceptor is bisphenol a, and the solvent is one or more of tetradecanol and hexadecanol.
  3. 3. The composite microcapsule color-changing pigment according to claim 1, wherein the wall material of the thermochromic microcapsule is polyacrylate-styrene copolymer resin, and the chemical bond is a covalent bond formed between an imidazole ring on the surface of the wall material of the thermochromic microcapsule and a reactive group on the surface of the wall material of the perfume releaser capsule.
  4. 4. A composite microcapsule color changing pigment according to claim 1, characterized in that the thermochromic microcapsules have a particle size in the range of 1-20 μm and the perfume releaser capsules have a particle size in the range of 100-800nm.
  5. 5. The composite microcapsule color-changing pigment according to claim 1, wherein in the step S11, the reaction condition of the interfacial polymerization method is that the pH value of the aqueous phase is adjusted to 4-5, the reaction temperature is 55-65 ℃, the stirring rotation speed is 1000-1200 rpm, and the reaction time is 1.5-2 h.
  6. 6. The composite microcapsule color-changing pigment according to claim 1, wherein in step S13, the mass ratio of the thermochromic microcapsule to the flavor-releasing sub-capsule is 1:2-6.
  7. 7. A method for preparing a composite microcapsule color-changing pigment, for preparing the composite microcapsule color-changing pigment according to any one of claims 1 to 6, comprising the steps of: s1, adding the intelligent microcapsule into water-based acrylic resin according to the mass parts, and stirring at 200-300rpm for 15-20min; s2, sequentially adding a thickening agent and a film forming additive according to the mass parts, stirring at 200-300rpm for 20-30min, defoaming for 20-30min under the vacuum degree of 0-5MPa, and removing the aggregates through a 400-mesh screen to obtain the composite microcapsule color-changing pigment.

Description

Composite microcapsule color-changing pigment and preparation method thereof Technical Field The invention relates to the technical field of pigment preparation, in particular to a composite microcapsule color-changing pigment and a preparation method thereof. Background The temperature-sensitive color-changing material can generate remarkable color conversion when the temperature is changed, and is widely applied to the fields of temperature indication, intelligent materials, temperature control devices and the like, and becomes an important direction for researching functional materials. However, the existing temperature-sensitive color-changing material generally has the problems of insufficient stability, limited response sensitivity, higher preparation cost, poor environmental adaptability and the like, and severely restricts the wide popularization and practical application of the material. Particularly, crystal Violet Lactone (CVL) is taken as a typical organic thermosensitive color-changing material, and has obvious thermal phase-change characteristics, but the performance of the material is easily influenced by external factors such as pH value, illumination, humidity and the like, so that the color-changing effect is unstable and the durability is insufficient. The microcapsule technology is widely adopted because the microcapsule technology can effectively protect core active substances from the external environment, and particularly has good application prospect in the aspect of packaging temperature-sensitive color-changing materials. For example, there have been studied a method of coating an organic photochromic material with a polymer material such as polyurethane to realize a multi-color photochromic microcapsule having a strong light response and excellent thermal stability, and a method of compounding a heat-sensitive photochromic material with a water-soluble dye and a phase-change material to prepare a multi-functional microcapsule having a rich color spectrum and reversible color change. However, traditional microcapsules are mostly single-function carriers and generally respond to only a single stimulus, limiting the potential of achieving multi-stimulus, multi-function responses in the field of smart materials. Therefore, development of the composite microcapsule temperature-sensitive color-changing material with novel structure, multi-stimulus response and stable performance becomes a key for improving the application performance of the temperature-sensitive color-changing material and expanding the application range. Disclosure of Invention In order to overcome the defects in the prior art, the invention aims to provide a composite microcapsule color-changing pigment and a preparation method thereof, wherein the pigment consists of intelligent microcapsules, aqueous acrylic resin, a film-forming auxiliary agent and a thickening agent according to a specific proportion. The intelligent microcapsule adopts a multi-compartment structure, the core is a thermochromic microcapsule, and the surface is fixed with a plurality of spice releasing sub-capsules with different thermal response thresholds through chemical bonding, so that the selective aroma release based on temperature gradient is realized. The thermochromic compound consists of crystal violet lactone, bisphenol A and a specific solvent, so that excellent thermochromic performance is ensured. The design realizes the multifunctional integration of the pigment, has the functions of temperature response color change and staged fragrance release, is widely applicable to the fields of intelligent paint and sensory materials, and has remarkable innovation and practical value. In order to achieve the above purpose, the present invention provides the following technical solutions: the composite microcapsule color-changing pigment comprises, by mass, 30-50 parts of intelligent microcapsules, 40-60 parts of aqueous acrylic resin, 2-3 parts of film-forming auxiliary agents and 0.5-1 part of thickening agents; The intelligent microcapsule has a multi-compartment structure, and comprises a thermochromic microcapsule serving as a core and at least one perfume releasing sub-capsule fixed on the surface of the thermochromic microcapsule through chemical bonding; Wherein the core material of the thermochromic microcapsule comprises a thermochromic compound, the core material of the perfume-releasing sub-capsule comprises perfume, and the wall materials of different perfume-releasing sub-capsules have different thermal response thresholds so as to realize selective perfume release based on temperature gradient. Preferably, the thermochromic compound consists of an electron donor, an electron acceptor and a solvent according to the mass ratio of (0.08-0.1) (0.4-0.5) (3-6), wherein the electron donor is crystal violet lactone, the electron acceptor is bisphenol A, and the solvent is one or more of tetradecyl alcohol and hexadecyl alcohol. Preferabl