Preparation method of high-stability water-soluble cationic colorant

Abstract

The invention relates to the field of fine chemical engineering, and discloses a preparation method of a high-stability water-soluble cationic colorant, which comprises the following steps: firstly synthesizing a novel efficient and high-stability cationic macromolecular RAFT (reversible addition-fragmentation chain transfer) reagent, and then carrying out soap-free RAFT emulsion polymerization on the novel efficient and high-stability cationic macromolecular RAFT reagent, an acrylate monomer and an organic pigment to obtain the high-stability water-soluble cationic colorant. The cationic colorant prepared by the method has water solubility and self-dispersion effect, and can keep high dispersion stability in water for a long time without using a dispersing agent. In addition, the high-stability water-soluble cationic coloring agent disclosed by the invention can be better combined with a fabric through an adsorption effect, so that the color fastness and the washing resistance of the fabric are remarkably improved. The method has the advantages of mild reaction conditions and simple process, can realize clean production, and can meet the conditions of industrial large-scale production.

Description

Technical Field

[0001] The invention relates to the field of fine chemicals, and in particular to a method for preparing a highly stable water-soluble cationic colorant. Background Art

[0002] Pigments can be divided into two types according to their chemical composition, one is organic pigments and the other is inorganic pigments. Compared with inorganic pigments, organic pigments are more diverse, have a wide color spectrum, high tinting strength, low toxicity, and good water resistance. Therefore, organic pigments have important uses in printing, coatings, plastics, rubber and other industries.

[0003] The primary particle size of organic pigments is 0.1-0.5mm. Under the action of van der Waals force and intermolecular force, they are very easy to agglomerate into large particles. To disperse them, the attraction between molecules must be overcome, and after dispersion, the fine particles must maintain stability to avoid reagglomeration. Therefore, when using organic pigments, it is usually necessary to grind the organic pigments into powder first, and then use surfactants or dispersants to disperse the organic pigments. However, traditional surfactants or dispersants cannot maintain the stability of pigments for a long time, and it is difficult to prepare stable, high-concentration dye solutions, inks, etc. Moreover, when the amount of surfactants or dispersants is too much, it will also affect the film-forming properties of organic pigments, thereby adversely affecting the performance of organic pigments.

[0004] In order to improve the dispersibility of the pigment, the pigment can be modified. The commonly used modification methods are core encapsulation, coating and surface modification technology. Among them: the core encapsulation method is mainly that inorganic materials use adsorption to adsorb organic pigments and combine them into composite pigments with better performance. Publication No. CN105524486A discloses a preparation method of core-encapsulated modified pigment red 170. Through the modification of inorganic materials and the optimization of reaction conditions, the bonding strength between the inorganic core and the coating layer pigment is effectively improved, thereby improving the heat resistance and weather resistance of pigment red 170. The prepared core-encapsulated modified pigment red 170 has bright color and excellent comprehensive performance. The coating method is to use a specific polymer to wrap the surface of the pigment so that a layer of film is formed on its surface. The formed film can protect the pigment from the influence of the external environment. Publication No. CN102532939A uses a polymer containing hydrophilic and hydrophobic segments to coat and modify the organic pigment by spray drying. The coated organic pigment has good self-dispersibility in the aqueous phase, a simple production process and stable product quality. Surface modification technology is to modify the surface of the pigment by surfactants, modifiers, polymer compounds, coupling agents, etc. to enhance the polarity of the pigment surface, enhance the interaction between the pigment and the contact medium, improve the wettability and dispersibility of the pigment, and reduce the particle agglomeration phenomenon. Publication No. CN111675938A discloses a phthalocyanine pigment paste and its preparation method and application. The phthalocyanine pigment paste is obtained by mixing and adjusting the pH value of surfactants, moisturizers, mildew-proof fungicides and water, and then mixing and filtering with surface-modified phthalocyanine pigments. The end of the surface-modified phthalocyanine pigment is a hydrophilic carboxyl group, which enhances the dispersibility and stability of the paste in water, and the use of a surfactant with a special structure makes the paste have a low critical micelle concentration, high surface activity, good hydrophilicity, wettability and low foaming.

[0005] Although the above methods can improve the dispersibility of pigments to a certain extent, it is still difficult to maintain long-term dispersion stability during storage and transportation after the pigment is prepared into an oil film. The reasons are as follows: the core encapsulation method is adsorbed by electrostatic, physical or chemical adsorption, which is easy to fall off and unstable when stored for a long time, resulting in poor dispersion stability; the film formed by pigment coating modification may be affected by external factors during long-term storage and transportation, and the coating layer may not be uniform. If the coating layer is too thick, it will increase the steric hindrance of the pigment particles, resulting in a decrease in the dispersion stability of the pigment; surface modification is to combine with the charge characteristics of the pigment surface through electrostatic adsorption, hydrogen bonding, chemical bonding, etc., thereby changing the polarity of the pigment to improve the performance of the pigment. However, the use of surfactants may cause changes in the surface charge characteristics of the pigment, thereby affecting the stability of the pigment in the dispersion medium. Summary of the invention

[0006] In order to solve the technical problem of unstable dispersion of organic pigments during the use of traditional dispersants, the present invention provides a method for preparing a highly stable water-soluble cationic colorant. The cationic colorant prepared by the method of the present invention has water solubility and self-dispersion effect, and can maintain high dispersion stability in water for a long time without using a dispersant. In addition, the highly stable water-soluble cationic colorant of the present invention can be better combined with fabrics through adsorption, thereby significantly improving the color fastness and water washing resistance of the fabric.

[0007] The specific technical scheme of the present invention is: In a first aspect, the present invention provides a method for preparing a highly stable water-soluble cationic colorant, comprising: 1) An acrylate monomer, 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid (CDPA) and an initiator are reacted in a solvent to obtain a macromolecular RAFT agent.

[0008] 2) Emulsifying the acrylic acid ester monomer, the macromolecular RAFT agent, the initiator and the organic pigment in a solvent to obtain a fine emulsion; heating the reaction, adding a crosslinking agent to continue the reaction, removing the solvent, and vacuum drying to obtain a highly stable water-soluble cationic colorant.

[0009] As described in the background technology section, in the prior art, whether adding a dispersant or modifying the organic pigment (core encapsulation method, coating method and surface modification), it is impossible to keep the dispersion stability of the organic pigment for a long time. Therefore, the present invention provides a cationic colorant with high stable water solubility. Specifically: In step 1), the present invention uses acrylate monomer and 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid as main raw materials to synthesize a macromolecular RAFT agent.

[0010] In step 2), the present invention uses acrylate monomers, macromolecular RAFT agents and organic pigments as main raw materials, first emulsifies to obtain a mini-emulsion, then heats the mixture for reaction, and then adds a crosslinking agent for crosslinking reaction.

[0011] The specific reaction process of the above method of the present invention is as follows: The cationic colorant designed by the present invention forms a thick hydration film layer on the surface of the pigment, thereby increasing the hydrophilicity of the pigment surface, thereby improving the dispersibility and stability of the pigment in the aqueous system. In addition, the hydration film layer can also increase the charge properties of the pigment surface, further enhancing the interaction between the pigment and the colorant. Therefore, the cationic colorant prepared by the method of the present invention has water solubility and self-dispersion effect, and can maintain high dispersion stability in water for a long time without using a dispersant.

[0012] In addition, the highly stable water-soluble cationic colorant of the present invention can be better combined with anionic fabrics (such as cotton fabrics) through electrostatic adsorption, thereby significantly improving the color fastness and water washability of the fabrics.

[0013] Preferably, in step 1), the mass of the acrylic acid ester monomer is 90-105wt% of the solvent; the mass of the 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid is 1-5wt% of the solvent. w t%.

[0014] The present invention finds that in order to further improve the effect, in the process of synthesizing the macromolecular RAFT agent, the ratio of the acrylate monomer and the 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid will affect the polymerization degree of the macromolecular RAFT agent. If the polymerization degree is too high, it will affect the solubility of the macromolecular RAFT agent and reduce the dispersion effect; conversely, if the polymerization degree is too low, it will lead to fewer adsorbed and dispersed particles, thereby affecting its dispersion performance.

[0015] Preferably, in step 1), the acrylate monomer is one or more of dimethylaminoethyl methacrylate (DMAEMA), polyethylene glycol methyl ether methacrylate (PEGMA), butyl methacrylate (BMA), methyl methacrylate (MMA), isobornyl methacrylate (IBOMA), n-butyl acrylate (n-BA), methyl acrylate (MA) and n-propyl acrylate (PA).

[0016] Preferably, in step 1), the molecular weight of the macromolecular RAFT agent is in the range of 6000-12000.

[0017] The present invention finds that as the degree of polymerization of the hydrophilic block PDMA increases, the molecular weight increases, and the average particle size decreases accordingly, and the smaller the particle size of the pigment particles, the faster the diffusion speed in the fiber, the stronger the adsorption capacity, the higher the dyeing rate, the stronger the pigment hiding power, and the higher the color depth. However, if the molecular weight of the RAFT agent is too large, curling will occur on the pigment surface, affecting the charge properties and dispersion stability of the pigment surface, and further affecting the performance of the pigment in the coating or ink.

[0018] Preferably, in step 1), the reaction temperature is 55-75° C. and the reaction time is 20-30 h.

[0019] Preferably, in step 1), after the reaction is completed, the product is purified with petroleum ether and dried to obtain a macromolecular RAFT agent.

[0020] Preferably, in step 2), the amount of the acrylate monomer is 10-25 wt % of the solvent; the amount of the macromolecular RAFT agent is 1-10 wt % of the solvent. wt%; the amount of the organic pigment is 0.1-0.5 of the solvent w t%.

[0021] The present invention finds that the ratio of acrylate monomer, macromolecular RAFT agent and organic pigment has an important influence on the performance of the colorant. As the degree of polymerization of the hydrophilic block PDMA increases, the average particle size decreases accordingly; while as the polymer of the hydrophobic block PBzMA increases, the average particle size increases. When the hydrophobic block is fixed, the average degree of polymerization of the hydrophilic block increases, and the nanoparticle strength-average hydrodynamic diameter decreases. The smaller the particle size of the pigment particles, the faster the diffusion speed in the fiber, the stronger the adsorption capacity, the higher the dyeing rate, the stronger the pigment hiding power, and the higher the color depth.

[0022] Preferably, in step 2), the amount of the cross-linking agent used is 1-5 wt % of the solvent.

[0023] The present invention also found that the amount of crosslinking agent will also affect the performance of the colorant to a certain extent. Too much crosslinking agent may reduce the levelness of the fabric, affect the feel and air permeability, while too little crosslinking agent may reduce the water resistance and friction resistance of the fabric.

[0024] Preferably, in step 2), the acrylate monomer is selected from one or more of benzyl methacrylate (BzMA), dimethylaminoethyl methacrylate (DMAEMA), polyethylene glycol methyl ether methacrylate (PEGMA), butyl methacrylate (BMA), methyl methacrylate (MMA), isobornyl methacrylate (IBOMA), n-butyl acrylate (n-BA), methyl acrylate (MA) and n-propyl acrylate (PA).

[0025] Preferably, in step 2), the crosslinking agent is selected from one or more of hexylene glycol dimethacrylate (1,6-HDDMA), trimethylolpropane trimethacrylate (TMPTMA), 1,4-butanediol dimethacrylate (1,4-BDDMA) and ethylene glycol diacrylate (EGDMA).

[0026] Preferably, in step 2), the organic pigment is selected from one or more of phthalocyanine blue, fuchsin, carbon black, titanium white and pigment red 170.

[0027] Preferably, in step 2), the heating reaction temperature is 65-75°C and the time is 10-15h; the continued reaction time is 8-12h.

[0028] Preferably, in steps 1) and 2), the initiator is one or more of 4,4'-azobis(4-cyanovaleric acid) (ACVA), azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN), dimethyl azobisisobutyrate (AIBME), lauroyl peroxide (LPO) and potassium persulfate (KPS).

[0029] More preferably, in steps 1) and 2), the amount of the initiator used is 0.02-0.2 wt % of the solvent mass.

[0030] Preferably, in steps 1) and 2), the solvent is selected from one or more of tetrahydrofuran, anhydrous ethanol, 1,4-dioxane, N,N-dimethylformamide and ethyl acetate.

[0031] In a second aspect, the present invention provides the use of the highly stable water-soluble cationic colorant obtained by the above preparation method in fabric dyeing: the highly stable water-soluble cationic colorant is directly dissolved in water to form a dye solution, and then the fabric is directly immersed in the dye solution for dyeing.

[0032] Preferably, the fabric is a cotton fabric. After dyeing, the fabric is first dried at 75-85° C. for 3-10 min, and then baked at 140-160° C. for 2-5 min.

[0033] Compared with the prior art, the beneficial effects of the present invention are: (1) The present invention first synthesizes a novel, highly efficient and stable cationic macromolecular RAFT agent, and then obtains a highly stable water-soluble cationic colorant through soap-free RAFT emulsion polymerization with an acrylate monomer and an organic pigment. The cationic colorant prepared by the method of the present invention has water solubility and self-dispersion effect, and can maintain high dispersion stability in water for a long time without using a dispersant.

[0034] (2) The present invention can further improve the performance of the colorant by adjusting the raw material ratio and reaction conditions.

[0035] (3) The highly stable water-soluble cationic colorant of the present invention can be better combined with the fabric through adsorption, thereby significantly improving the color fastness and water washability of the fabric.

[0036] (4) The present invention adopts RAFT polymerization, which has mild reaction conditions and simple process, can achieve clean production, and can meet the conditions for industrial large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the NMR characterization of the macromolecular RAFT agent and block copolymer synthesized in Example 1.

[0038] Figure 2The gel permeation chromatograms (b) of the macromolecular RAFT agent (a) and the block copolymer in each example.

[0039] Figure 3 Graph showing particle size distribution of the cationic colorants synthesized in each example.

[0040] Figure 4 TEM images of the cationic colorants synthesized in each example.

[0041] Figure 5 This is a transmission electron microscope image of the nanoparticles synthesized in Comparative Example 1. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the embodiments.

[0043] Overall embodiment A method for preparing a highly stable water-soluble cationic colorant comprises the following steps: 1) An acrylate monomer, 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid (CDPA) and an initiator are reacted in a solvent to obtain a macromolecular RAFT agent.

[0044] In some specific implementation cases, the mass of the acrylic acid ester monomer is 90-105 wt % of the solvent; the mass of the 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid is 1-5 wt % of the solvent. w t%.

[0045] In some specific implementation cases, the acrylate monomer is one or more of dimethylaminoethyl methacrylate (DMAEMA), polyethylene glycol methyl ether methacrylate (PEGMA), butyl methacrylate (BMA), methyl methacrylate (MMA), isobornyl methacrylate (IBOMA), n-butyl acrylate (n-BA), methyl acrylate (MA) and n-propyl acrylate (PA).

[0046] In some specific implementation cases, the molecular weight of the macromolecular RAFT agent is in the range of 6000-12000.

[0047] In some specific implementation cases, the reaction temperature is 55-75° C., and the reaction time is 20-30 h.

[0048] In some specific implementation cases, after the reaction is completed, the product is purified with petroleum ether and dried to obtain a macromolecular RAFT agent.

[0049] 2) Emulsifying the acrylic acid ester monomer, the macromolecular RAFT agent, the initiator and the organic pigment in a solvent to obtain a fine emulsion; heating the reaction, adding a crosslinking agent to continue the reaction, removing the solvent, and vacuum drying to obtain a highly stable water-soluble cationic colorant.

[0050] In some specific implementation cases, the amount of the acrylate monomer is 10-25wt% of the solvent; the amount of the macromolecular RAFT agent is 1-10wt% of the solvent. w t%; the amount of the organic pigment is 0.1-0.5 of the solvent w t%.

[0051] In some specific implementation cases, the acrylate monomer is selected from one or more of benzyl methacrylate (BzMA), dimethylaminoethyl methacrylate (DMAEMA), polyethylene glycol methyl ether methacrylate (PEGMA), butyl methacrylate (BMA), methyl methacrylate (MMA), isobornyl methacrylate (IBOMA), n-butyl acrylate (n-BA), methyl acrylate (MA) and n-propyl acrylate (PA).

[0052] In some specific implementation cases, the organic pigment is selected from one or more of phthalocyanine blue, magenta, carbon black, titanium white and pigment red 170.

[0053] In some specific implementation cases, the amount of the cross-linking agent is 1-5 wt % of the solvent.

[0054] In some specific implementation cases, the crosslinking agent is selected from one or more of hexylene glycol dimethacrylate (1,6-HDDMA), trimethylolpropane trimethacrylate (TMPTMA), 1,4-butanediol dimethacrylate (1,4-BDDMA) and ethylene glycol diacrylate (EGDMA).

[0055] In some specific implementation cases, the temperature of the heating reaction is 65-75°C, and the time is 10-15 hours; the time of the continued reaction is 8-12 hours.

[0056] In some specific implementation cases, in steps 1) and 2), the initiator is one or more of 4,4'-azobis(4-cyanovaleric acid) (ACVA), azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN), dimethyl azobisisobutyrate (AIBME), lauroyl peroxide (LPO) and potassium persulfate (KPS). Further preferably, in steps 1) and 2), the amount of the initiator is 0.02-0.2 of the mass of the solvent. w t%.

[0057] In some specific implementation cases, in steps 1) and 2), the solvent is selected from one or more of tetrahydrofuran, anhydrous ethanol, 1,4-dioxane, N,N-dimethylformamide and ethyl acetate.

[0058] The highly stable water-soluble cationic colorant obtained by the above preparation method is used in fabric dyeing: the highly stable water-soluble cationic colorant is directly dissolved in water to form a dye solution, and then the fabric is directly immersed in the dye solution for dyeing.

[0059] In some specific implementation cases, the fabric is a cotton fabric. After dyeing, the fabric is first dried at 75-85° C. for 3-10 min, and then baked at 140-160° C. for 2-5 min.

[0060] Specific Examples and Comparative Examples Example 1 A method for preparing a highly stable water-soluble cationic colorant comprises the following steps: Weigh 10g of dimethylaminoethyl methacrylate (DMAEMA), 0.3406g of 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid (CDPA), 23.8mg of 4,4'-azobis(4-cyanovaleric acid) (ACVA), and 10g of tetrahydrofuran (THF) in a round-bottom flask, pass nitrogen for 30min, and exclude air. When the water bath temperature reaches 60°C, place the flask in the reaction for 24h. After the reaction is completed, wash and purify with excess petroleum ether 3 times, and place in a vacuum oven to dry to obtain PDMA 72 Homopolymer (Macro RAFT Agent).

[0061] Weigh 1.74g PDMA 72 The homopolymer, 23.5 g of anhydrous ethanol and 0.1 g of phthalocyanine blue were mixed evenly, and then ultrasonic sheared for 20 min using an ultrasonic cell crusher at 270 W to obtain a dispersion containing an organic pigment.

[0062] Weigh 2.5g benzyl methacrylate (BzMA) and 4.7mg azobisisobutyronitrile (AIBN) and mix them with the organic pigment dispersion and pass nitrogen for 30min. Transfer to a 70℃ water bath. The mixture of monomer and initiator is injected by a syringe pump at 0.6ml / h. After that, react for 12h. Add 0.285g ethylene glycol diacrylate (EGDMA) and dissolve in 1.9 g In anhydrous ethanol, oxygen is excluded for 30 minutes and then directly added to the flask, and the reaction is continued for 10 hours. After the reaction is completed, the product is transferred to a rotary evaporator to remove the solvent, and then placed in a vacuum oven at 40°C for drying to obtain a highly stable water-soluble cationic colorant.

[0063] Example 2 A method for preparing a highly stable water-soluble cationic colorant comprises the following steps: Weigh 10g of dimethylaminoethyl methacrylate (DMAEMA), 0.3406g of 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid (CDPA), 23.8mg of 4,4'-azobis(4-cyanovaleric acid) (ACVA), and 10g of tetrahydrofuran (THF) in a round-bottom flask, pass nitrogen for 30min, and exclude air. When the water bath temperature reaches 60°C, place the flask in the reaction for 24h. After the reaction is completed, wash and purify with excess petroleum ether 3 times, and place in a vacuum oven to dry to obtain PDMA 72 Homopolymer (Macro RAFT Agent).

[0064] Weigh 1.17 g PDMA 72 The homopolymer, 23.5 g of anhydrous ethanol and 0.1 g of titanium dioxide were mixed evenly, and then ultrasonic sheared for 20 min using an ultrasonic cell crusher at 270 W to obtain a dispersion containing an organic pigment.

[0065] Weigh 2.5g benzyl methacrylate (BzMA) and 4.7mg azobisisobutyronitrile (AIBN) and mix them with the organic pigment dispersion and pass nitrogen for 30min. Transfer to a 70℃ water bath. The mixture of monomer and initiator is injected by a syringe pump at 0.6ml / h. After that, react for 12h. Add 0.198g ethylene glycol diacrylate (EGDMA) and dissolve in 1.9 g In anhydrous ethanol, oxygen is excluded for 30 minutes and then directly added to the flask, and the reaction is continued for 10 hours. After the reaction is completed, the product is transferred to a rotary evaporator to remove the solvent, and then placed in a vacuum oven at 40°C for drying to obtain a highly stable water-soluble cationic colorant.

[0066] Example 3 A method for preparing a highly stable water-soluble cationic colorant comprises the following steps: Weigh 6.68g of dimethylaminoethyl methacrylate (DMAEMA), 0.3406g of 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid (CDPA), 23.8mg of 4,4'-azobis(4-cyanovaleric acid) (ACVA), and 10g of tetrahydrofuran (THF) in a round-bottom flask, pass nitrogen for 30min, and exclude air. When the water bath temperature reaches 60°C, place the flask in the reaction for 24h. After the reaction is completed, wash and purify with excess petroleum ether 3 times, and place in a vacuum oven to dry to obtain PDMA 50 Homopolymer (Macro RAFT Agent).

[0067] Weigh 1.15g PDMA 50The homopolymer, 23.5 g of anhydrous ethanol and 0.1 g of carbon black were mixed evenly, and then ultrasonic sheared for 20 min using an ultrasonic cell crusher at 270 W to obtain a dispersion containing an organic pigment.

[0068] Weigh 2.5g benzyl methacrylate (BzMA) and 4.7mg azobisisobutyronitrile (AIBN) and mix them with the organic pigment dispersion and pass nitrogen for 30min. Transfer to a 70℃ water bath. The mixture of monomer and initiator is injected by a syringe pump at 0.6ml / h. After that, react for 12h. Add 0.285g ethylene glycol diacrylate (EGDMA) and dissolve in 1.9 g In anhydrous ethanol, oxygen is excluded for 30 minutes and then directly added to the flask, and the reaction is continued for 10 hours. After the reaction is completed, the product is transferred to a rotary evaporator to remove the solvent, and then placed in a vacuum oven at 40°C for drying to obtain a highly stable water-soluble cationic colorant.

[0069] Example 4 A method for preparing a highly stable water-soluble cationic colorant comprises the following steps: Weigh 6.68g of dimethylaminoethyl methacrylate (DMAEMA), 0.3406g of 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid (CDPA), 23.8mg of 4,4'-azobis(4-cyanovaleric acid) (ACVA), and 10g of tetrahydrofuran (THF) in a round-bottom flask, pass nitrogen for 30min, and exclude air. When the water bath temperature reaches 60°C, place the flask in the reaction for 24h. After the reaction is completed, wash and purify with excess petroleum ether 3 times, and place in a vacuum oven to dry to obtain PDMA 50 Homopolymer (Macro RAFT Agent).

[0070] 0.58 g of PDMA50 homopolymer, 23.5 g of anhydrous ethanol, and 0.1 g of Pigment Red 170 were weighed and mixed evenly, and then ultrasonic shearing was performed for 20 min using an ultrasonic cell crusher at 270 W to obtain a dispersion containing an organic pigment.

[0071] Weigh 2.5 g of benzyl methacrylate (BzMA) and 4.7 mg of azobisisobutyronitrile (AIBN), mix them with the organic pigment dispersion, and pass nitrogen for 30 min. Transfer to a 70°C water bath. The mixture of monomer and initiator is injected at 0.6 ml / h through a syringe pump. After that, react for 12 h. Add 0.141 g of ethylene glycol diacrylate (EGDMA) and dissolve it in 1.9 g In anhydrous ethanol, oxygen is excluded for 30 minutes and then directly added to the flask, and the reaction is continued for 10 hours. After the reaction is completed, the product is transferred to a rotary evaporator to remove the solvent, and then placed in a vacuum oven at 40°C for drying to obtain a highly stable water-soluble cationic colorant.

[0072] Example 5 A method for preparing a highly stable water-soluble cationic colorant comprises the following steps: Weigh 6.68g of dimethylaminoethyl methacrylate (DMAEMA), 0.3406g of 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid (CDPA), 23.8mg of 4,4'-azobis(4-cyanovaleric acid) (ACVA), and 10g of tetrahydrofuran (THF) in a round-bottom flask, pass nitrogen for 30min, and exclude air. When the water bath temperature reaches 60°C, place the flask in the reaction for 24h. After the reaction is completed, wash and purify with excess petroleum ether 3 times, and place in a vacuum oven to dry to obtain PDMA 50 Homopolymer (Macro RAFT Agent).

[0073] 0.35 g of PDMA50 homopolymer, 23.5 g of anhydrous ethanol, and 0.1 g of titanium dioxide were weighed and mixed evenly, and then ultrasonic shearing was performed for 20 min using an ultrasonic cell crusher at 270 W to obtain a dispersion containing an organic pigment.

[0074] Weigh 2.5g benzyl methacrylate (BzMA) and 4.7mg azobisisobutyronitrile (AIBN) and mix them with the organic pigment dispersion and pass nitrogen for 30min. Transfer to a 70℃ water bath. The mixture of monomer and initiator is injected by a syringe pump at 0.6ml / h. After that, react for 12h. Add 0.084g ethylene glycol diacrylate (EGDMA) and dissolve in 1.9 g In anhydrous ethanol, oxygen is excluded for 30 minutes and then directly added to the flask, and the reaction is continued for 10 hours. After the reaction is completed, the product is transferred to a rotary evaporator to remove the solvent, and then placed in a vacuum oven at 40°C for drying to obtain a highly stable water-soluble cationic colorant.

[0075] Example 6 A method for preparing a highly stable water-soluble cationic colorant comprises the following steps: Weigh 4g of dimethylaminoethyl methacrylate (DMAEMA), 0.3406g of 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid (CDPA), 23.8mg of 4,4'-azobis(4-cyanovaleric acid) (ACVA), and 10g of tetrahydrofuran (THF) in a round-bottom flask, pass nitrogen for 30min, and exclude air. When the water bath temperature reaches 60°C, place the flask in the reaction for 24h. After the reaction is completed, wash and purify with excess petroleum ether 3 times, and place in a vacuum oven to dry to obtain PDMA 37 Homopolymer (Macro RAFT Agent).

[0076] Weigh 0.87g PDMA 37The homopolymer, 23.5 g of anhydrous ethanol and 0.1 g of phthalocyanine blue were mixed evenly, and then ultrasonic sheared for 20 min using an ultrasonic cell crusher at 270 W to obtain a dispersion containing an organic pigment.

[0077] Weigh 2.5g benzyl methacrylate (BzMA) and 4.7mg azobisisobutyronitrile (AIBN) and mix them with the organic pigment dispersion and pass nitrogen for 30min. Transfer to a 70℃ water bath. The mixture of monomer and initiator is injected by a syringe pump at 0.6ml / h. After that, react for 12h. Add 0.285g ethylene glycol diacrylate (EGDMA) and dissolve in 1.9 g In anhydrous ethanol, oxygen is excluded for 30 minutes and then directly added to the flask, and the reaction is continued for 10 hours. After the reaction is completed, the product is transferred to a rotary evaporator to remove the solvent, and then placed in a vacuum oven at 40°C for drying to obtain a highly stable water-soluble cationic colorant.

[0078] Comparative Example 1 Weigh 10g of dimethylaminoethyl methacrylate (DMAEMA), 0.3406g of 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid (CDPA), 23.8mg of 4,4'-azobis(4-cyanovaleric acid) (ACVA), and 10g of tetrahydrofuran (THF) in a round-bottom flask, pass nitrogen for 30min, and exclude air. When the water bath temperature reaches 60°C, place the flask in the reaction for 24h. After the reaction is completed, wash and purify with excess petroleum ether 3 times, and place in a vacuum oven to dry to obtain PDMA 72 Homopolymer (Macro RAFT Agent).

[0079] Weigh 1.74g PDMA 72 Homopolymer, 2.5g benzyl methacrylate (BzMA), 4.7mg azobisisobutyronitrile (AIBN) and 20.278g / 3.579g ethanol / water were transferred to a 70°C water bath and reacted for 12h after nitrogen flow for 30min. 0.57g ethylene glycol diacrylate (EGDMA) was added and dissolved in 1.9g anhydrous ethanol. After excluding oxygen for 30min, it was directly added to the flask and reacted for 10h to obtain PISA copolymer nanoparticles.

[0080] 20 ml of water, 0.1 g of Pigment Red 170 and 0.2 g of copolymer nanoparticles were added to a sample bottle, stirred thoroughly with a magnetic stirrer, and sheared with a cell crusher at 270 W before use for dyeing.

[0081] Performance Testing The macromolecular RAFT agent (PDMA) obtained in Example 1 72 Homopolymer) and highly stable water-soluble cationic colorant (block copolymer PDMA 72 -PBzMA100 )'s H NMR spectrum is as follows Figure 1 As shown, the macromolecular RAFT agent PDMA 72 and block copolymer PDMA 72 -PBzMA 100 Successfully synthesized.

[0082] The gel permeation chromatography of the macromolecular RAFT agent and block copolymer synthesized in Examples 1-6 is as follows: Figure 2 As shown. Figure 2 As shown, the molecular weight distribution of the copolymers obtained in various examples is relatively narrow and the polydispersity is relatively low, indicating that the polymerization process is well controlled.

[0083] The particle size of the copolymers of each embodiment was analyzed by transmission electron microscopy. Figure 3 and Figure 4 As shown, the average polymerization degree of the hydrophobic block PBzMA and the hydrophilic block PDMA were changed respectively, and it was found that when the length of the hydrophobic segment PBzMA was fixed, as the average polymerization degree of the hydrophilic block PDMA increased, the particle size of the final nanoparticles decreased from 62nm to 32nm; when the length of the hydrophilic segment PDMA was fixed, as the hydrophobic segment PBzMA increased, the diameter increased from 50nm to 273nm. The transmission results show that the dispersion performance of Examples 1-6 is good, the distribution is narrow, and the shape is irregular. In comparison, the latter two have better dispersion effects and smaller particle sizes.

[0084] The nanoparticle transmission image obtained in Comparative Example 1 is as follows Figure 5 As shown, it is found that the dispersion effect of Comparative Example 1 is poor, the distribution is uneven, the shape is irregular, and the particle size is relatively larger.

[0085] The raw materials and equipment used in the present invention, unless otherwise specified, are all commonly used raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are all conventional methods in the art.

[0086] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a highly stable water-soluble cationic colorant, characterized in that include: 1) reacting acrylate monomer, 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid and initiator in a solvent to obtain a macromolecular RAFT agent; 2) Emulsifying the acrylic acid ester monomer, macromolecular RAFT agent, initiator and organic pigment in a solvent to obtain a fine emulsion; heating the reaction, adding a crosslinking agent to continue the reaction, and removing the solvent to obtain a highly stable water-soluble cationic colorant.

2. The preparation method according to claim 1, characterized in that: In step 1), The mass of the acrylate monomer is 90-105wt% of the solvent; The mass of the 4-cyano-4-(dodecylsulfonylthiocarbonyl)sulfonylvaleric acid is 1-5wt% of the solvent.

3. The preparation method according to claim 1 or 2, characterized in that: In step 1), the acrylic acid ester monomer is one or more of dimethylaminoethyl methacrylate, polyethylene glycol methyl ether methacrylate, butyl methacrylate, methyl methacrylate, isobornyl methacrylate, n-butyl acrylate, methyl acrylate and n-propyl acrylate.

4. The preparation method according to claim 1 or 2, characterized in that: In step 1), the molecular weight of the macromolecular RAFT agent is 6000-12000.

5. The preparation method according to claim 1 or 2, characterized in that: In step 1), The reaction temperature is 55-75°C and the reaction time is 20-30h; After the reaction is completed, the product is purified by petroleum ether and dried to obtain a macromolecular RAFT agent.

6. The preparation method according to claim 1, characterized in that: In step 2), The amount of the acrylate monomer is 10-25wt% of the solvent; The amount of the macromolecular RAFT agent is 1-10wt% of the solvent; The amount of the organic pigment is 0.1-0.5wt% of the solvent; The amount of the cross-linking agent used is 1-5 wt % of the solvent.

7. The preparation method according to claim 1 or 6, characterized in that: In step 2), The acrylate monomer is selected from one or more of benzyl methacrylate, dimethylaminoethyl methacrylate, polyethylene glycol methyl ether methacrylate, butyl methacrylate, methyl methacrylate, isobornyl methacrylate, n-butyl acrylate, methyl acrylate and n-propyl acrylate; The crosslinking agent is selected from one or more of hexylene glycol dimethacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol dimethacrylate and ethylene glycol diacrylate; The organic pigment is selected from one or more of phthalocyanine blue, fuchsin, carbon black, titanium white and pigment red 170.

8. The preparation method according to claim 1 or 6, characterized in that: In step 2), The heating reaction temperature is 65-75°C and the time is 10-15h; The reaction time is 8-12 hours.

9. The preparation method according to claim 1, characterized in that: In steps 1) and 2), The initiator is one or more of 4,4'-azobis(4-cyanovaleric acid), azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, dodecyl peroxide and potassium persulfate; The solvent is selected from one or more of tetrahydrofuran, anhydrous ethanol, 1,4-dioxane, N,N-dimethylformamide and ethyl acetate.

10. Use of the highly stable water-soluble cationic colorant obtained according to the preparation method according to any one of claims 1 to 9 in fabric dyeing, characterized in that: The highly stable water-soluble cationic colorant is directly dissolved in water to form a dye solution, and then the fabric is directly immersed in the dye solution for dyeing.

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