阅读说明：本技术 一种彩色聚合墨粉的制备方法 (Preparation method of color polymerized ink powder ) 是由 刘志军 曹方敏 王密 孟鸿 黄维 羊辉 于 2019-11-25 设计创作，主要内容包括：本发明公开了彩色聚合墨粉的制备方法,具体为：制备带正电非水溶性单体油相；将其和水性分散液共混,悬浮造粒后,转移至反应器中,通过第一次聚合反应使单体油滴粒子完全转化为聚合物颗粒,得到软性核粒子；将高Tg壳单体和带正电非水溶性单体加至去离子水中,通过高速剪切或超声形成细乳液后,加至软性核粒子中,并加入水溶性引发剂再次进行聚合反应,得核壳结构的聚合物微球；将聚合物微球进行清洗、过滤、干燥后,添加二氧化硅处理,得具有核壳结构的彩色聚合墨粉。由于带正电非水溶性单体具有高的带正电性及良好的疏水性,以及硅烷偶联剂对墨粉粒子表面的极性物质进行疏水改性,因而在高温高湿环境下具有优良的环境稳定性及优异的图像品质。(The invention discloses a preparation method of a colorful polymerized ink powder, which comprises the following steps: preparing a positively charged water-insoluble monomer oil phase; mixing the monomer oil droplets with aqueous dispersion, suspending and granulating, transferring to a reactor, and completely converting the monomer oil droplets into polymer particles through a first polymerization reaction to obtain soft core particles; adding a high-Tg shell monomer and a positively charged water-insoluble monomer into deionized water, forming miniemulsion through high-speed shearing or ultrasonic, adding the miniemulsion into soft core particles, adding a water-soluble initiator, and carrying out polymerization reaction again to obtain polymer microspheres with a core-shell structure; and cleaning, filtering and drying the polymer microspheres, and then adding silicon dioxide for treatment to obtain the colored polymerized ink powder with the core-shell structure. The positively-charged water-insoluble monomer has high positively-charged properties and good hydrophobicity, and the silane coupling agent hydrophobically modifies the polar substance on the surface of the toner particles, so that the toner particles have excellent environmental stability and excellent image quality in a high-temperature and high-humidity environment.)

1. The preparation method of the color polymerized ink powder is characterized by comprising the following steps:

step 1, preparing a positively charged water-insoluble monomer oil phase;

step 2, blending the positively charged water-insoluble monomer oil phase and the aqueous dispersion liquid obtained in the step 1, carrying out high-speed shearing suspension granulation, transferring the mixture into a reactor, and completely converting monomer oil drop particles into polymer particles through a first polymerization reaction to obtain soft core particles;

step 3, adding the high Tg shell monomer and the positively charged water-insoluble monomer into deionized water, forming miniemulsion through high-speed shearing or ultrasound, adding the miniemulsion into the soft core particles obtained in the step 2, adding a water-soluble initiator, and carrying out polymerization reaction again to obtain the polymer microsphere with the core-shell structure;

and 4, cleaning the polymer microspheres obtained in the step 3, adding a coupling agent for hydrophobic modification, filtering and drying, and adding an external additive to obtain the color polymerized ink powder with the core-shell structure.

2. The method for preparing a color polymerized toner according to claim 1, wherein the method for preparing the positively charged water-insoluble monomer oil phase in step 1 is:

adding a coloring agent into a soft core resin monomer, uniformly grinding and dispersing by a sand mill, and adding a positively charged water-insoluble monomer, wax, a cross-linking agent, a molecular weight regulator and an initiator to obtain a monomer oil phase;

wherein the soft core resin monomer is selected from a monovinyl monomer; the positively charged water-insoluble monomer comprises a tertiary amine vinyl monomer and a quaternary ammonium salt vinyl monomer with hydrophobicity; the colorant comprises at least one material of black, yellow, cyan or magenta pigment; the cross-linking agent is a monomer containing two or more unsaturated ethylene groups; the initiator is an oil-soluble initiator.

3. The method for producing a color polymerized toner according to claim 2 wherein the aqueous dispersion in step 2 is a suspension dispersant.

4. The method for producing a color polymerized toner according to any one of claims 1 to 3, wherein the positively charged water-insoluble monomer oil phase and the aqueous dispersion are blended in step 2 and suspension granulated by high-speed shearing, specifically: mixing and stirring a monomer oil phase and an aqueous dispersion liquid according to the mass ratio of oil to water of 1:2-1:10 to form primary oil drop particles, and then suspending, shearing and granulating the oil-water mixed liquid at the temperature of 20-60 ℃ by using a high-speed emulsifier or a high-shear emulsifying pump to obtain oil drop particles with the particle size distribution range of 1-20 mu m; wherein the rotation speed range of suspension shearing granulation is 6000-25000rpm, and the high-speed shearing linear speed range is 15-40 m/s.

5. The method for preparing color polymerized toner according to claim 4, wherein in step 2, the oil droplet particles are transferred to a reactor, the stirring speed is kept at 50-1000rpm, nitrogen is introduced to remove oxygen, the polymerization is carried out for 2-20 hours after the temperature is raised to 60-95 ℃, and the oil droplet ions are completely converted into polymer particles to form soft core particles.

6. The method of claim 5 wherein the high Tg shell monomer of step 3 is selected from one or more of styrene, methacrylate/butyl acrylate, butyl methacrylate and other monomers that form polymers with glass transition temperatures in excess of 80 ℃. The dosage of the soft core ion is 2-10 wt% of the soft core ion.

7. The method for producing a color polymerized toner according to claim 6, wherein the positively charged water-insoluble monomer in the step 3 comprises a hydrophobic tertiary amine vinyl monomer and a quaternary ammonium vinyl monomer in an amount of 1 to 20 wt% based on the weight of the soft core ion.

8. The method for producing a color polymerized toner according to claim 1 wherein the temperature at which the polymerization reaction is carried out again in step 3 is 60 to 95 ℃ and the polymerization time is 2 to 10 hours.

9. The method for producing a colored polymerized toner according to claim 8, wherein the step 4 is carried out by adjusting the pH of the polymer microspheres to not more than 6 before washing the polymer microspheres, and then adding an inorganic compound colloid as a dispersion stabilizer.

10. The method for producing a color polymerized toner according to claim 9, wherein the washing in the step 4 is performed until the filtrate has an electric conductivity of 50 μ S/cm and the drying temperature is not higher than 50 ℃.

Technical Field

The invention belongs to the technical field of color ink powder, and particularly relates to a preparation method of color ink powder.

Background

In recent years, with the development of computers and multimedia, there has been an increasing demand for high-definition full-color image laser printers, and there has been an increasing demand for color toners having high performance requirements such as environmental stability, low-temperature fixability, development durability and storage stability, and member contamination.

The printer operates substantially as follows: exposing the uniformly charged surface of the photosensitive drum to form an electrostatic latent image; the toner which is frictionally charged by the developing roller and the scraper develops the electrostatic latent image on the surface of the photosensitive drum to form an image; the image on the surface of the photosensitive drum is transferred to the paper by attraction of the opposite charges on the surface of the paper, and then is fixed by a heating roller and a pressure roller, so that the required printed image is obtained. As can be seen from the above printing process, the developing roller and the doctor blade charge the toner, the toner surface acquires an electric charge, the charged toner can be developed into a pattern to be printed on the surface of the photosensitive drum, and in order to make the toner have good chargeability, a Charge Control Agent (CCA) is required to be dispersed as uniformly as possible on the toner particle surface; the toner is required to be continuously kept in a charged state before being transferred from the photosensitive drum to the paper; if the charging characteristics and charge retention ability of the toner are not good, it is difficult to easily perform development or transfer, and it is difficult to obtain an image with a desirable printing effect.

Similarly, the toner is required to have other properties such as excellent transferability, low-temperature fixability and storage stability. The toner with good sphericity has high transfer efficiency, can be easily transferred from the photosensitive drum to paper, and reduces or avoids the residual of the toner on the photosensitive drum. In order to reduce the environmental load, the toner is required to be fixed to paper at as low a temperature as possible, and at the same time, the toner is required to have good preservability without melt blocking even when exposed to high temperature conditions at the time of use or transportation. The core-shell structured toner is improved in fixability by a core having a low glass transition temperature (low Tg) and improved in blocking resistance by a shell having a high glass transition temperature (high Tg), and can satisfy both low-temperature fixation and storage stability by adopting such a layer structure.

In various environments with different temperatures and humidities, a high-definition full-color image output device that can be used for a long time is required, and therefore, the color toner needs to satisfy the requirement that a high-definition full-color image can be output even if it is used for a long time in different temperature and humidity environments; thus, there is a need to reduce fluctuation in the charge amount of toner and variation in surface properties of toner caused by changes in the temperature and humidity of the environment.

Toner is conventionally mechanically pulverized by melt-blending a resin, a Charge Control Agent (CCA), a pigment, a wax and the like, pulverizing and classifying. Since the mechanically pulverized toner has an irregular shape, the pressure applied to each toner particle by the doctor blade varies, and at the same time, CCA tends to form a phase separated from the binder resin, and the electric CCA particles exposed on the toner surface easily peel off, the mechanically pulverized toner is not uniformly charged and the charge distribution is wide.

Compared with the traditional mechanically pulverized toner, the conventional suspension polymerization toner is obtained by uniformly dispersing CCA, wax, pigment and other components in a monomer, and polymerizing after high-speed shearing granulation. The CCA among the toner particles is dispersed more uniformly and the particles have better sphericity, thereby having better charge distribution uniformity and transfer efficiency. This method still has a significant amount of charge control distributed in the center region of the toner particles. Since the charging of the toner is generated by the friction between the doctor blade and the CCA located on the toner surface, however, the CCA distributed in the central area of the toner particle does not participate in the frictional charging of the toner, resulting in inefficient use of CCA, resulting in high cost of material use of CCA, and there is a need to develop an effective method for increasing the charge density on the toner surface.

Disclosure of Invention

In order to solve the above problems, the present invention provides a method for preparing a color polymerized toner having excellent environmental stability and excellent image quality under a high-temperature and high-humidity environment.

The technical scheme adopted by the invention is as follows:

the preparation method of the color polymerized ink powder is implemented according to the following steps:

step 1, preparing a positively charged water-insoluble monomer oil phase;

step 2, blending the positively charged water-insoluble monomer oil phase and the aqueous dispersion liquid obtained in the step 1, carrying out high-speed shearing suspension granulation, transferring the mixture into a reactor, and completely converting monomer oil drop particles into polymer particles through a first polymerization reaction to obtain soft core particles;

step 3, adding the high Tg shell monomer and the positively charged water-insoluble monomer into deionized water, forming miniemulsion through high-speed shearing or ultrasound, adding the miniemulsion into the soft core particles obtained in the step 2, adding a water-soluble initiator, and carrying out polymerization reaction again to obtain the polymer microsphere with the core-shell structure;

and 4, cleaning the polymer microspheres obtained in the step 3, adding a coupling agent for hydrophobic modification, filtering and drying, and adding an external additive to obtain the color polymerized ink powder with the core-shell structure.

Preferably, the preparation method of the positively charged water-insoluble monomer oil phase in step 1 is as follows:

adding a coloring agent into a soft core resin monomer, uniformly grinding and dispersing by a sand mill, and adding a positively charged water-insoluble monomer, wax, a cross-linking agent, a molecular weight regulator and an initiator to obtain a monomer oil phase;

wherein the soft core resin monomer is selected from a monovinyl monomer; the positively charged water-insoluble monomer comprises a tertiary amine vinyl monomer and a quaternary ammonium salt vinyl monomer with hydrophobicity; the colorant comprises at least one material of black, yellow, cyan or magenta pigment; the cross-linking agent is a monomer containing two or more unsaturated ethylene groups; the initiator is an oil-soluble initiator.

Preferably, the aqueous dispersion in the step 2 adopts a suspension dispersant.

Preferably, in the step 2, the positively charged water-insoluble monomer oil phase and the aqueous dispersion are blended and granulated by high-speed shearing suspension, specifically:

mixing and stirring a monomer oil phase and an aqueous dispersion liquid according to the mass ratio of oil to water of 1:2-1:10 to form primary oil drop particles, and then suspending, shearing and granulating the oil-water mixed liquid at the temperature of 20-60 ℃ by using a high-speed emulsifier or a high-shear emulsifying pump to obtain oil drop particles with the particle size distribution range of 1-20 mu m;

wherein the rotation speed range of suspension shearing granulation is 6000-25000rpm, and the high-speed shearing linear speed range is 15-40 m/s.

Preferably, in the step 2, the oil droplet particles are transferred into a reactor, the stirring speed is kept at 50-1000rpm, nitrogen is introduced to remove oxygen, the temperature is raised to 60-95 ℃, polymerization is carried out for 2-20 hours, and the oil droplet ions are completely converted into polymer particles to form soft core particles.

Preferably, the high Tg shell monomer in step 3 is selected from one or more materials of styrene, methacrylate/butyl acrylate, butyl methacrylate and the like monomers capable of forming a polymer with a glass transition temperature of more than 80 ℃. The dosage of the soft core ion is 2-10 wt% of the soft core ion.

Preferably, the positively charged water-insoluble monomer in step 3 includes a tertiary amine type vinyl monomer and a quaternary ammonium type vinyl monomer having hydrophobicity, and the amount thereof is 1 to 20 wt% based on the weight of the soft core ion.

Preferably, the temperature for carrying out the polymerization reaction again in the step 3 is 60-95 ℃, and the polymerization time is 2-10 hours.

Preferably, in the step 4, before the polymer microspheres are washed, the pH of the polymer microspheres is adjusted to be not more than 6, and then inorganic compound colloid is added as a dispersion stabilizer.

Preferably, the polymer microspheres are washed in the step 4 until the conductivity of the filtrate is 50 μ S/cm and the drying temperature is not higher than 50 ℃.

Compared with the prior art, the low-Tg monomer oil phase for forming the ink powder core particles is mixed with the aqueous dispersion liquid, and the monomer oil drop particles are converted into polymer particles through heating polymerization reaction after suspension granulation to obtain the soft ink powder core particles; emulsifying a high Tg shell monomer and an electropositive water-insoluble monomer which form a rigid shell layer, adding the emulsified monomers into a suspension dispersion liquid of soft ink powder core particles, mixing, performing secondary polymerization, cleaning, performing hydrophobic modification by using a silane coupling agent, filtering, drying, performing external addition treatment, and removing coarse particles. The positively-charged water-insoluble monomer has high positively-charged properties and good hydrophobicity, and the silane coupling agent hydrophobically modifies the polar substance on the surface of the toner particles, so that the toner particles have excellent environmental stability and excellent image quality in a high-temperature and high-humidity environment.

Drawings

FIG. 1 is a flowchart for providing a method of producing a color polymerized toner according to an embodiment of the invention;

FIG. 2 is an electron micrograph of a black toner prepared in example 1 of the present invention;

FIG. 3 is an electron micrograph of a yellow toner prepared in example 2 of the present invention;

FIG. 4 is an electron micrograph of a magenta toner prepared in example 3 of the present invention;

FIG. 5 is an electron micrograph of a cyan toner prepared in example 4 of the present invention;

FIG. 6 is a graph showing a glass transition temperature test of a black toner prepared in example 1 of the present invention;

FIG. 7 is a softening temperature test chart of toners produced in example 1 and example 2 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The embodiment of the invention provides a preparation method of a color polymerized toner, which is implemented according to the following steps as shown in figure 1:

step 1, preparing a positively charged water-insoluble monomer oil phase; the method specifically comprises the following steps: adding a coloring agent into a soft core resin monomer, uniformly grinding and dispersing by a sand mill, and adding a positively charged water-insoluble monomer, wax, a cross-linking agent, a molecular weight regulator and an initiator to obtain a monomer oil phase;

the soft core resin monomer is mainly selected from a monovinyl monomer and comprises one or more than one of the following materials: aromatic vinyl monomers such as styrene, methylstyrene or α -methylstyrene; acrylic monomers such as (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl methacrylate, glycidyl (meth) acrylate, and lauryl (meth) acrylate. The resin component in the toner accounts for 60-90%, which has a decisive influence on the fixing property of the toner;

in the preparation process, if the glass transition temperature (Tg) of the toner core resin is too low, the toner can adhere to a heating roller during printing, and a thermal offset problem is generated; when the toner core resin glass transition (Tg) is too high, it is not sufficiently melted during printing, and the fixing fastness of the toner on paper is poor. The toner core resin glass transition temperature (Tg) is therefore preferably from 40 to 60 ℃;

the positively charged water-insoluble monomer mainly comprises a tertiary amine vinyl monomer with stronger hydrophobicity and a quaternary ammonium salt vinyl monomer, preferably one or more materials of oleyl dimethyl tertiary amine, oleic acid amide propyl dimethyl tertiary amine (PKO-O), erucic acid amide propyl dimethyl tertiary amine (PKO-E) and oleyl dimethyl benzyl ammonium chloride, and the dosage of the positively charged water-insoluble monomer is 1-10 wt%, preferably 1-5 wt% of the weight of the soft core resin monomer;

the colorant comprises at least one material of black, yellow, cyan or magenta pigments: the black pigment is mainly selected from pigment carbon blacks having a primary particle diameter of 20 to 40nm, such as MA-100 (Mitsubishi chemical corporation), #44 (Mitsubishi chemical corporation), #52 (Mitsubishi chemical corporation), REGAL300R (Cambot corporation), REGAL330R (Cambot corporation), REGAL400R (Cambot corporation), and MOGULL (Cambot corporation); the cyan pigment is selected from copper phthalocyanine compounds and derivatives thereof, such as C.I. PigmentBlue15, 15:1, 15:2, 15:3, 15:4, etc.; the magenta pigment is selected from azo-based pigments such as c.i. pigment red31, 48, 57, 58, 63, 68, 114, 122, 146, 150, 163, 187, and 206, etc.; the yellow pigment is mainly selected from azo pigments such as c.i. pigment yellow3, 12, 13, 17, 65, 74, 83, 97, 155, 180, 185, 186, and the like. The above pigments are generally used in an amount of 1 to 30% by weight, preferably 3 to 15% by weight, based on the weight of the soft core resin monomer;

the release agent used in the invention is mainly selected from one or more than one of low molecular weight polyolefin wax and grease synthetic wax: polyolefin waxes include polyethylene wax (PE wax) and polypropylene wax (PP wax); the oil and fat synthetic wax comprises pentaerythritol tetrastearate, pentaerythritol tetra behenate, dipentaerythritol hexapalmitate, dipentaerythritol hexamyristate or dipentaerythritol hexalaurate, preferably oil and fat synthetic wax or polyolefin wax with hydroxyl value less than 5mgKOH/g and acid value less than 1mgKOH/g, and has melting point of 50-100 deg.C, preferably 60-80 deg.C. The release agent is generally used in an amount of 1 to 40% by weight, preferably 5 to 20% by weight, based on the weight of the soft core resin monomer;

the cross-linking agent is a monomer containing two or more unsaturated ethylene groups, and comprises one or more of the following: divinylbenzene, divinylsulfone, ethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, 1, 4-butanediol dimethacrylate, 1, 6-hexanediol dimethacrylate, allyl methacrylate or pentaerythritol triacrylate; the cross-linking agent and the monovinyl monomer are used together, so that the high-temperature offset resistance of the ink powder can be effectively improved, the dosage of the cross-linking agent accounts for 0.1-1 wt% of the weight of the soft core resin monomer, and the fixing fastness of the ink powder can be reduced when the dosage is too high;

the molecular weight regulator in the invention comprises one or more than one of the following materials: n-dodecyl mercaptan, t-dodecyl mercaptan, carbon tetrachloride or carbon tetrabromide, etc., are used in an amount of generally 0.1 to 5% by weight, preferably 0.5 to 3% by weight, based on the weight of the soft core resin monomer. The molecular weight regulator (chain transfer agent) of the present invention can preferably improve the fixing fastness of the toner, and when the amount is too high, the high temperature offset resistance and the storability of the toner may be deteriorated;

step 2, blending the positively charged water-insoluble monomer oil phase and the aqueous dispersion liquid obtained in the step 1, carrying out high-speed shearing suspension granulation, transferring the mixture into a reactor, and completely converting monomer oil drop particles into polymer particles through a first polymerization reaction to obtain soft core particles; the method specifically comprises the following steps:

firstly, blending and stirring a monomer oil phase and an aqueous dispersion liquid according to the mass ratio of oil to water of 1:2-1:10 to form primary oil drop particles, and then suspending, shearing and granulating the oil-water mixed liquid at the temperature of 20-60 ℃ by using a high-speed emulsifier or a high-shear emulsifying pump to obtain oil drop particles with the particle size distribution range of 1-20 mu m; wherein the rotation speed range of suspension shearing granulation is 6000-25000rpm, and the high-speed shearing linear speed range is 15-40 m/s;

transferring the oil drop particles into a reactor, keeping the stirring speed at 50-1000rpm, introducing nitrogen to remove oxygen, heating to 60-95 ℃, polymerizing for 2-20 hours, and completely converting the oil drop ions into polymer particles to form soft core particles;

the aqueous dispersion adopts suspension dispersant, and is selected from one or more of calcium phosphate, magnesium hydroxide, calcium carbonate, polyvinyl alcohol, and hydroxypropyl methylcellulose. A dispersion stabilizer preferably containing a hardly water-soluble inorganic magnesium hydroxide colloid, which can give a narrow particle size distribution of polymer particles, has a small residue after washing, and can reproduce a clear image;

specifically, the preparation process of the magnesium hydroxide colloid comprises the following steps: preparing a magnesium chloride solution and a sodium hydroxide solution by using deionized water respectively; then slowly adding sodium hydroxide solution into the liquid magnesium chloride solution, and carrying out high-speed shearing emulsification by using a high-speed emulsifying machine or a pipeline type emulsifying pump or the combination of the high-speed emulsifying machine and the pipeline type emulsifying pump, wherein the high-speed shearing linear speed is 25-45m/s, the high-speed shearing time is 0.1-1h, and the ultrasonic aging time is 1-5h, so that the prepared magnesium hydroxide has the particle diameter D50: 0.3 to 0.5 μm;

in the above process, the apparatus for shear dispersion comprises a shear dispersion apparatus selected from the group consisting of a batch UltratalaxT50 (manufactured by IKA corporation), ClearmixClM-0.8S (manufactured by M-Technique corporation); continuous processspot 2000 (manufactured by IKA corporation) and the like, which meet the required average particle size by controlling the shear rotation speed. The rotation speed range of suspension shearing granulation is 6000-25000rpm, and the high-speed shearing linear speed range is 15-40 m/s.

The concentration of the dispersant in the aqueous dispersion is preferably 0.5 to 5 wt% of the water by mass or the amount of the dispersant in the dispersion is 1 to 20 wt% of the low Tg monomer oil phase. The concentration of the dispersing agent is too low or the dosage of the dispersing agent is too small, the dispersing system is unstable, coalescence is easy to occur among oil drop particles, and the particle size distribution is widened; too high concentration of the dispersing agent or too much consumption of the dispersing agent can easily generate a large amount of too fine latex particles during high-speed shearing, and can easily cause pollution to a developing roller and too low image concentration during printing, thereby seriously affecting the image quality;

step 3, adding the high Tg shell monomer and the positively charged water-insoluble monomer into deionized water, forming miniemulsion through high-speed shearing or ultrasound, adding the miniemulsion into the soft core particles obtained in the step 2, adding a water-soluble initiator, and carrying out polymerization reaction again to obtain the polymer microsphere with the core-shell structure;

the high Tg monomer forming the rigid shell layer is one or more than one of styrene, methacrylate/butyl acrylate, butyl methacrylate and other monomers capable of forming polymers with the glass transition temperature of more than 80 ℃. The amount used is generally 2 to 10% by weight, preferably 3 to 6% by weight, based on the weight of the soft core resin monomer. Within this ratio range, both the toner storage stability and the low-temperature fixing property can be achieved.

The positively charged water-insoluble monomer mainly comprises a tertiary amine vinyl monomer with stronger hydrophobicity and a quaternary ammonium salt vinyl monomer, preferably one or more than one of oleyl dimethyl tertiary amine, oleamide propyl dimethyl tertiary amine (PKO-O), erucamide propyl dimethyl tertiary amine (PKO-E) and oleyl dimethyl benzyl ammonium chloride, and the dosage of the positively charged water-insoluble monomer is 1-20 wt%, preferably 3-15 wt% of the weight of the shell resin monomer.

As the polymerization initiator for polymerizing the rigid shell monomer of the toner, a water-soluble initiator is preferable. This is because the radicals of the water-soluble initiator easily move to the vicinity of the surface of the toner soft core particles adsorbed by the rigid shell monomer, and toner particles having a core-shell structure are easily obtained. The water-soluble initiator used in the invention is one or more materials selected from potassium persulfate, ammonium persulfate, 2-bis (2-methyl-N- (2-hydroxyethyl) propionamide) and 2, 2-azo-bis (2-methyl-N- (1, 1-bis (hydroxymethyl) -2-hydroxyethyl) propionamide). The amount of the aqueous initiator is 2 to 30 wt%, preferably 5 to 20 wt% of the rigid shell monomer.

During the second polymerization reaction, the polymerization temperature of the shell is preferably 60-95 ℃, and the polymerization time is 2-10 hours, preferably 3-8 hours;

step 4, cleaning, filtering and drying the polymer microspheres obtained in the step 3, and then adding silicon dioxide to treat the polymer microspheres to obtain the color polymerized ink powder with the core-shell structure;

when an inorganic compound colloid is used as the dispersion stabilizer, it is preferable that the pH of the toner particle suspension obtained by polymerization is set to 6 or less after adding an acid, and the inorganic compound colloid which is hardly soluble in water is dissolved. As the additive acid, inorganic acids such as sulfuric acid, hydrochloric acid and nitric acid can be used, and sulfuric acid is preferred. Then, the filtration may be performed by washing and filtration repeatedly by a large amount of deionized water, and may be performed by a centrifugal filtration method, a vacuum filtration method, a pressure filtration method, or the like.

When the filtrate is washed until the conductivity is 50. mu.S/cm or less, the residual amount of impurities adhering to the toner ions is reduced, and when the filtrate is washed until the conductivity is 10. mu.S/cm or less, the residual amount of impurities adhering to the toner ions is further reduced. The conductivity of the filtrate is usually measured with a conductivity meter.

As the water for washing, deionized water having an electric conductivity of 20. mu.S/cm or less, preferably 1. mu.S/cm or less is used for the filtrate.

Since a certain amount of polar group remains in the initiation reaction of the water-soluble initiator and a small amount of salt ions remains on the toner surface even if the toner is washed with a large amount of deionized water, the charge amount is liable to decrease in a high-temperature and high-humidity environment.

And cleaning a product formed by the second polymerization reaction until the conductivity of the filtrate is less than or equal to 10 mu S/cm, adding a certain amount of hydrolyzed silane coupling agent, stirring and mixing for 1-2h, and carrying out hydrophobic modification.

The silane coupling agent is preferably one or more of anilino triethoxysilane, 3-aminopropyl triethoxysilane, N- (2 aminoethyl) -3-aminopropyl trimethoxysilane, dodecyl trimethoxysilane and phenyl trimethoxysilane. The amount is generally from 0.1 to 5% by weight, preferably from 0.5 to 2% by weight, based on the weight of the polymeric microspheres;

the toner particles subjected to the washing process are subjected to a drying process. As the dryer used for the toner drying process, a vacuum freeze dryer, a reduced pressure dryer, a fluidized bed dryer, and the like are included. In order to prevent toner particles from blocking, the drying temperature is preferably below 50 ℃;

the process is to add external additives into the dried toner particles.

The external additive is attached to or buried in the surface of the toner particles, whereby the chargeability, flowability, storage stability, and the like of the particles can be adjusted. The external additive for the ink powder is one or more than one of inorganic particles such as silicon dioxide, aluminum oxide, titanium oxide and the like, preferably hydrophobically modified silicon dioxide and titanium dioxide particles, and the using amount of the external additive is 0.5-5 wt% of the weight of the ink powder. As a device for adding the external additive, various known mixing devices such as henschel mixer can be used.

Example 1: the embodiment 1 of the invention provides a preparation method of a color polymerized ink powder, which comprises the following specific steps:

80 parts of styrene (hereinafter referred to as "parts" in terms of parts by mass), 20 parts of n-butyl acrylate, and 7 parts of carbon black (NP60, manufactured by Degussa corporation) were dispersed at room temperature by a bead mill to prepare a pigment dispersion (D50:300 nm);

further, 1 part of oleyldimethylbenzylammonium chloride, 0.6 part of divinylbenzene, 2.0 parts of n-dodecylmercaptan, 10 parts of ester wax (WE-4, manufactured by japan oil and fat co., ltd.), and 6 parts of t-butyl peroxy-2-ethylacetate, an oil-soluble initiator, were added thereto, and dissolved and dispersed for 30 minutes;

in addition, 100 parts of deionized water dissolved with 20 parts of magnesium chloride aqueous solution is slowly added into 200 parts of deionized water dissolved with 9 parts of sodium hydroxide aqueous solution, high-speed shearing dispersion is carried out for 1h, and ultrasonic aging is carried out for 4h at room temperature, thus obtaining magnesium hydroxide suspension dispersion liquid (D50:350 nm);

the prepared monomeric oil phase was added to the above magnesium hydroxide suspension dispersion containing a magnesium chloride electrolyte, sheared at 4500rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA) to form primary oil droplet particles having an average particle diameter of 20 μm, and then sheared at 9000rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA). Then transferring the mixture to a reactor protected by nitrogen, heating the mixture to 90 ℃ for polymerization reaction for 5 hours to obtain soft suspended powdered ink core particles with the average particle size of 7.0 mu m;

adding 2 parts of styrene, 3 parts of methyl methacrylate, 0.2 part of butyl acrylate and 0.5 part of oleyl dimethyl benzyl ammonium chloride into 50 parts of deionized water, emulsifying at high speed of 10000rpm for 5min by a high-speed dispersion machine (UltrataxT 50 manufactured by IKA), adding into the suspension dispersion system for dispersing for 30min, dissolving 1 part of potassium persulfate into 10 parts of deionized water, adding into the suspension dispersion system, and carrying out polymerization reaction at 80 ℃ for 5 hours;

removing magnesium hydroxide from the polymerization product by using a sulfuric acid solution, and then repeatedly washing the polymerization product by using a large amount of deionized water until the conductivity is less than or equal to 10 mu S/cm;

the filter cake was stably dispersed in deionized water at 40 ℃ in a ratio of 1:3, 0.5 part of prehydrolyzed 3-aminopropyltriethoxysilane was added and stirred and dispersed for 1 hour, followed by washing with deionized water until the conductivity became less than or equal to 10. mu.S/cm, the filter cake product was dried, and then 1 part of silica R504(12nm, manufactured by Degussa, Ltd.), 1 part of NA50Y (40nm, manufactured by Degussa, Ltd.), and 0.5 part of silica TG-C190(110nm, manufactured by Cabot, Ltd.) were added and treated with a high-speed mixer to obtain the color polymerized toner of the present invention, and the suspension polymerized toner of the present invention having an average particle diameter of 6.9 μm was obtained as shown in FIG. 2.

Example 2: embodiment 2 of the present invention provides a method for preparing a color polymerized toner, which specifically comprises:

80 parts of styrene (hereinafter referred to as "parts" in terms of parts by mass), 20 parts of n-butyl acrylate, and 9 parts of yellow pigment P.Y155 (manufactured by Clariant) were dispersed at room temperature by a bead mill to prepare a pigment dispersion (D50:300 nm);

further, 1 part of oleyldimethylbenzylammonium chloride, 0.6 part of divinylbenzene, 2.0 parts of n-dodecylmercaptan, 10 parts of ester wax (WE-4, manufactured by japan oil and fat co., ltd.), and 6 parts of t-butyl peroxy-2-ethylacetate, an oil-soluble initiator, were added thereto, and dissolved and dispersed for 30 minutes;

in addition, 100 parts of deionized water dissolved with 20 parts of magnesium chloride aqueous solution is slowly added into 200 parts of deionized water dissolved with 9 parts of sodium hydroxide aqueous solution, high-speed shearing dispersion is carried out for 1h, and ultrasonic aging is carried out for 4h at room temperature, thus obtaining magnesium hydroxide suspension dispersion liquid (D50:350 nm);

the prepared monomeric oil phase was added to the above magnesium hydroxide suspension dispersion containing a magnesium chloride electrolyte, sheared at 4500rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA) to form primary oil droplet particles having an average particle diameter of 20 μm, and then sheared at 9000rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA). Then transferring the mixture to a reactor protected by nitrogen, heating the mixture to 90 ℃ for polymerization reaction for 5 hours to obtain soft suspended powdered ink core particles with the average particle size of 7.0 mu m;

adding 2 parts of styrene, 3 parts of methyl methacrylate, 0.2 part of butyl acrylate and 0.5 part of erucamidopropyldimethyl tertiary amine into 50 parts of deionized water, emulsifying at high speed of 10000rpm for 5min by a high-speed dispersion machine (UltratalaxT50 manufactured by IKA), adding into the suspension dispersion system for dispersing for 30min, dissolving 1 part of potassium persulfate into 10 parts of deionized water, adding into the suspension dispersion system, and carrying out polymerization reaction at 80 ℃ for 5 hours;

removing magnesium hydroxide from the polymerization product by using a sulfuric acid solution, and then repeatedly washing the polymerization product by using a large amount of deionized water until the conductivity is less than or equal to 10 mu S/cm;

the filter cake was stably dispersed in deionized water at 40 ℃ in a ratio of 1:3, 0.6 part of anilinotriethoxysilane was added and stirred and dispersed for 1 hour, then washed repeatedly with deionized water until the conductivity became less than or equal to 10. mu.S/cm, the filter cake product was dried, and 1 part of silica R504(12nm, manufactured by Degussa corporation), 1 part of NA50Y (40nm, manufactured by Degussa corporation), and 0.5 part of silica TG-C190(110nm, manufactured by Cabot corporation) were added and treated with a high-speed mixer to obtain the suspension polymerization toner of the present invention, and a color polymerization toner of the present invention having an average particle size of 6.9 μm was obtained as shown in FIG. 3.

Example 3: embodiment 3 of the present invention provides a method for preparing a color polymerized toner, which specifically comprises:

a pigment dispersion (D50:300nm) was prepared by dispersing 80 parts (hereinafter referred to as "parts" as parts by mass) of styrene, 20 parts of n-butyl acrylate and 7 parts of n-butyl acrylate with 8 parts of a magenta pigment (p.r122, manufactured by clariant corporation) at room temperature by a bead mill;

further, 1 part of oleyldimethylbenzylammonium chloride, 0.4 part of divinylbenzene, 1.5 parts of n-dodecylmercaptan, 10 parts of ester wax (WE-4, manufactured by japan oil and fat co., ltd.), and 6 parts of t-butyl peroxy-2-ethylacetate, an oil-soluble initiator, were added thereto, and dissolved and dispersed for 30 minutes;

in addition, 100 parts of deionized water dissolved with 20 parts of magnesium chloride aqueous solution is slowly added into 200 parts of deionized water dissolved with 9 parts of sodium hydroxide aqueous solution, high-speed shearing dispersion is carried out for 1h, and ultrasonic aging is carried out for 4h at room temperature, thus obtaining magnesium hydroxide suspension dispersion liquid (D50:350 nm);

the prepared monomeric oil phase was added to the above magnesium hydroxide suspension dispersion containing a magnesium chloride electrolyte, sheared at 4500rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA) to form primary oil droplet particles having an average particle diameter of 20 μm, and then sheared at 9000rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA). Then transferring the mixture to a reactor protected by nitrogen, heating the mixture to 90 ℃ for polymerization reaction for 5 hours to obtain soft suspended powdered ink core particles with the average particle size of 7.0 mu m;

adding 2 parts of styrene, 3 parts of methyl methacrylate, 0.2 part of butyl acrylate and 0.8 part of oleic acid amide propyl dimethyl tertiary amine into 50 parts of deionized water, emulsifying at a high speed of 10000rpm for 5min by a high-speed dispersion machine (UltratalaxT50 manufactured by IKA), adding into the suspension dispersion system for dispersing for 30min, dissolving 1 part of potassium persulfate into 10 parts of deionized water, adding into the suspension dispersion system, and carrying out polymerization reaction at 80 ℃ for 5 hours;

removing magnesium hydroxide from the polymerization product by using a sulfuric acid solution, and then repeatedly washing the polymerization product by using a large amount of deionized water until the conductivity is less than or equal to 10 mu S/cm;

the filter cake was stably dispersed in deionized water at 40 ℃ in a ratio of 1:3, 0.3 part of anilinotriethoxysilane and 0.3 part of dodecyltrimethoxysilane were added and stirred and dispersed for 1 hour, then washed repeatedly with deionized water until the conductivity became less than or equal to 10. mu.S/cm, the filter cake product was dried, 1 part of silica R504(12nm, manufactured by Degussa corporation), 1 part of NA50Y (40nm, manufactured by Degussa corporation) and 0.5 part of silica TG-C190(110nm, manufactured by Cabot corporation) were added and treated with a high-speed mixer to obtain the suspension polymerization toner of the present invention having an average particle diameter of 7.2 μm, as shown in FIG. 4.

Example 4: embodiment 4 of the present invention provides a method for preparing a color polymerized toner, which specifically comprises:

a pigment dispersion (D50:300nm) was prepared by dispersing 80 parts of styrene (hereinafter referred to as "parts" in terms of parts by mass), 20 parts of n-butyl acrylate, and 6 parts of phthalocyanine blue p.b15:3 (manufactured by clariant corporation) at room temperature using a bead mill;

further, 1 part of oleyl dimethyl tertiary amine, 0.6 part of divinylbenzene, 2.0 parts of n-dodecyl mercaptan, 10 parts of ester wax (WE-4, manufactured by NOF corporation), 7 parts of tert-butyl peroxy-2-ethyl acetate as an oil-soluble initiator were added and dissolved and dispersed for 30 minutes;

in addition, 100 parts of deionized water dissolved with 20 parts of magnesium chloride aqueous solution is slowly added into 200 parts of deionized water dissolved with 9 parts of sodium hydroxide aqueous solution, high-speed shearing dispersion is carried out for 1h, and ultrasonic aging is carried out for 4h at room temperature, thus obtaining magnesium hydroxide suspension dispersion liquid (D50:350 nm);

the prepared monomeric oil phase was added to the above magnesium hydroxide suspension dispersion containing a magnesium chloride electrolyte, sheared at 4500rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA) to form primary oil droplet particles having an average particle diameter of 20 μm, and then sheared at 9000rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA). Then transferring the mixture to a reactor protected by nitrogen, heating the mixture to 85 ℃ for polymerization reaction for 5 hours to obtain soft suspended powdered ink core particles with the average particle size of 7.0 mu m;

adding 2 parts of styrene, 3 parts of methyl methacrylate, 0.2 part of butyl acrylate and 0.5 part of oleyl dimethyl benzyl ammonium chloride into 50 parts of deionized water, emulsifying at high speed of 10000rpm for 5min by a high-speed dispersion machine (UltrataxT 50 manufactured by IKA), adding into the suspension dispersion system for dispersing for 30min, dissolving 1 part of potassium persulfate into 10 parts of deionized water, adding into the suspension dispersion system, and carrying out polymerization reaction at 80 ℃ for 5 hours;

removing magnesium hydroxide from the polymerization product by using a sulfuric acid solution, and then repeatedly washing the polymerization product by using a large amount of deionized water until the conductivity is less than or equal to 10 mu S/cm;

the filter cake was stably dispersed in deionized water at 40 ℃ in a ratio of 1:3, 0.5 part of prehydrolyzed 3-aminopropyltriethoxysilane was added and stirred and dispersed for 1 hour, followed by washing with deionized water until the conductivity became not more than 10. mu.S/cm, and after drying the filter cake product, 1 part of silica R504(12nm, manufactured by Degussa, Ltd.), 1 part of NA50Y (40nm, manufactured by Degussa, Ltd.), and 0.5 part of silica TG-C190(110nm, manufactured by Cabot, Ltd.) were added and treated with a high-speed mixer to obtain the suspension polymerization toner of the present invention having an average particle diameter of 7.1 μm, as shown in FIG. 5.

Comparative example 1: 80 parts of styrene, 20 parts of n-butyl acrylate and 7 parts of carbon black (NP60, manufactured by Degussa corporation), the above components were dispersed at room temperature by a bead mill to prepare a pigment dispersion (D50:300 nm); further, 2 parts of a positive charge control agent (FCA-201PS), 0.6 part of divinylbenzene, 2.0 parts of n-dodecylmercaptan, 10 parts of an ester wax (WE-4, manufactured by Nippon oil and fat Co., Ltd.), and 6 parts of t-butyl peroxy-2-ethylacetate as an oil-soluble initiator were added thereto, and the mixture was dissolved and dispersed for 30 minutes;

in addition, 100 parts of deionized water dissolved with 20 parts of magnesium chloride aqueous solution is slowly added into 200 parts of deionized water dissolved with 9 parts of sodium hydroxide aqueous solution, high-speed shearing dispersion is carried out for 1h, and ultrasonic aging is carried out for 4h at room temperature, thus obtaining magnesium hydroxide suspension dispersion liquid (D50:350 nm);

the prepared monomeric oil phase was added to the above magnesium hydroxide suspension dispersion containing a magnesium chloride electrolyte, sheared at 4500rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA) to form primary oil droplet particles having an average particle diameter of 20 μm, and then sheared at 9000rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA). Then transferring the mixture to a reactor protected by nitrogen, heating the mixture to 90 ℃ for polymerization reaction for 5 hours to obtain soft suspended powdered ink core particles with the average particle size of 7.2 mu m;

adding 2 parts of styrene, 3 parts of methyl methacrylate, 0.2 part of butyl acrylate and 0.5 part of methacryloxyethyltrimethyl ammonium chloride into 50 parts of deionized water, emulsifying at a high speed of 10000rpm for 5min by a high-speed dispersion machine (UltratalaxT50 manufactured by IKA), adding into the suspension dispersion system for dispersing for 30min, dissolving 1 part of potassium persulfate into 10 parts of deionized water, adding into the suspension dispersion system, and carrying out polymerization reaction at 80 ℃ for 5 hours; removing magnesium hydroxide from the polymerization product by using a sulfuric acid solution, and then repeatedly washing the polymerization product by using a large amount of deionized water until the conductivity is less than or equal to 10 mu S/cm;

after drying the cake product, 1 part of silica R504(12nm, manufactured by Degussa corporation), 1 part of NA50Y (40nm, manufactured by Degussa corporation), and 0.5 part of silica TG-C190(110nm, manufactured by Cabot corporation) were added, and the mixture was treated with a high-speed mixer to obtain the suspension polymerization toner of the present invention; the results of evaluation of the toner characteristics obtained are shown in Table 1.

Comparative example 2: 80 parts of styrene, 20 parts of n-butyl acrylate and 9 parts of a yellow pigment P.Y155 (manufactured by Claien) were dispersed at room temperature by a bead mill to prepare a pigment dispersion (D50:300 nm); further, 2 parts of a positive charge control agent (FCA-201PS), 0.6 part of divinylbenzene, 2.0 parts of n-dodecylmercaptan, 10 parts of an ester wax (WE-4, manufactured by Nippon oil and fat Co., Ltd.), and 6 parts of t-butyl peroxy-2-ethylacetate as an oil-soluble initiator were added thereto, and the mixture was dissolved and dispersed for 30 minutes;

in addition, 100 parts of deionized water dissolved with 20 parts of magnesium chloride aqueous solution is slowly added into 200 parts of deionized water dissolved with 9 parts of sodium hydroxide aqueous solution, high-speed shearing dispersion is carried out for 1h, and ultrasonic aging is carried out for 4h at room temperature, thus obtaining magnesium hydroxide suspension dispersion liquid (D50:350 nm);

the prepared monomeric oil phase was added to the above magnesium hydroxide suspension dispersion containing a magnesium chloride electrolyte, sheared at 4500rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA) to form primary oil droplet particles having an average particle diameter of 20 μm, and then sheared at 9000rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA). Then transferring the mixture to a reactor protected by nitrogen, heating the mixture to 90 ℃ for polymerization reaction for 5 hours to obtain soft suspended powdered ink core particles with the average particle size of 7.2 mu m;

2 parts of styrene, 3 parts of methyl methacrylate, 0.2 part of butyl acrylate and 0.6 part of diethylaminoethyl methacrylate were added together to 50 parts of deionized water, emulsified at a high speed of 10000rpm for 5 minutes by a high-speed dispersion machine (UltrataxT 50, manufactured by IKA), and added to the above suspension dispersion system to be dispersed for 30 minutes. Dissolving 1 part of potassium persulfate in 10 parts of deionized water, adding the potassium persulfate into the suspension dispersion system, and carrying out polymerization reaction for 5 hours at the temperature of 80 ℃; removing magnesium hydroxide from the polymerization product by using a sulfuric acid solution, and then repeatedly washing the polymerization product by using a large amount of deionized water until the conductivity is less than or equal to 10 mu S/cm;

after drying the cake product, 1 part of silica R504(12nm, manufactured by Degussa corporation), 1 part of NA50Y (40nm, manufactured by Degussa corporation) and 0.5 part of silica TG-C190(110nm, manufactured by Cabot corporation) were added thereto, and the suspension polymerization toner of the present invention was obtained by treating the mixture with a high-speed mixer, and the suspension polymerization toner of the present invention having an average particle diameter of 7.1 μm was obtained, and the evaluation results of the characteristics of the obtained toner are shown in Table 1.

Comparative example 3: 80 parts of styrene, 20 parts of n-butyl acrylate and 8 parts of magenta pigment (P.R122, manufactured by Clariant corporation), and the above components were dispersed at room temperature by a bead mill to prepare a pigment dispersion (D50:300 nm); further, 2 parts of a positive charge control agent (FCA-201PS), 0.4 part of divinylbenzene, 1.5 parts of n-dodecylmercaptan, 10 parts of an ester wax (WE-4, manufactured by Nippon oil and fat Co., Ltd.), and 6 parts of t-butyl peroxy-2-ethylacetate as an oil-soluble initiator were added thereto, and the mixture was dissolved and dispersed for 30 minutes;

in addition, 100 parts of deionized water dissolved with 20 parts of magnesium chloride aqueous solution is slowly added into 200 parts of deionized water dissolved with 9 parts of sodium hydroxide aqueous solution, high-speed shearing dispersion is carried out for 1h, and ultrasonic aging is carried out for 4h at room temperature, thus obtaining magnesium hydroxide suspension dispersion liquid (D50:350 nm);

the prepared monomeric oil phase was added to the above magnesium hydroxide suspension dispersion containing a magnesium chloride electrolyte, sheared at 4500rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA) to form primary oil droplet particles having an average particle diameter of 20 μm, and then sheared at 9000rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA). Then transferring the mixture to a reactor protected by nitrogen, heating the mixture to 90 ℃ for polymerization reaction for 5 hours to obtain soft suspended powdered ink core particles with the average particle size of 7.2 mu m;

2 parts of styrene, 3 parts of methyl methacrylate, 0.2 part of butyl acrylate and 0.8 part of dimethyldiallylammonium chloride were added together to 50 parts of deionized water, emulsified at a high speed of 10000rpm for 5 minutes by a high speed disperser (UltratalaxT50, manufactured by IKA), and added to the above suspension dispersion system to be dispersed for 30 minutes. Dissolving 1 part of potassium persulfate in 10 parts of deionized water, adding the potassium persulfate into the suspension dispersion system, and carrying out polymerization reaction for 5 hours at the temperature of 80 ℃; removing magnesium hydroxide from the polymerization product by using a sulfuric acid solution, and then repeatedly washing the polymerization product by using a large amount of deionized water until the conductivity is less than or equal to 10 mu S/cm;

after drying the cake product, 1 part of silica R504(12nm, manufactured by Degussa corporation), 1 part of NA50Y (40nm, manufactured by Degussa corporation) and 0.5 part of silica TG-C190(110nm, manufactured by Cabot corporation) were added thereto, and the suspension polymerization toner of the present invention was obtained by treating the mixture with a high-speed mixer, and the suspension polymerization toner of the present invention having an average particle diameter of 7.0 μm was obtained, and the evaluation results of the characteristics of the obtained toner are shown in Table 1.

Comparative example 4: dispersing 80 parts of styrene, 20 parts of n-butyl acrylate and 6 parts of phthalocyanine blue P.B15:3 (manufactured by Clariant) at room temperature by a bead mill to prepare a pigment dispersion (D50:300 nm); further, 2 parts of a positive charge control agent (FCA-201PS), 0.6 part of divinylbenzene, 2.0 parts of n-dodecylmercaptan, 10 parts of ester wax (WE-4, manufactured by Nippon oil and fat Co., Ltd.), and 7 parts of t-butyl 2-ethylhexanoate as an oil-soluble initiator were added and dissolved and dispersed for 30 minutes;

in addition, 100 parts of deionized water dissolved with 20 parts of magnesium chloride aqueous solution is slowly added into 200 parts of deionized water dissolved with 9 parts of sodium hydroxide aqueous solution, high-speed shearing dispersion is carried out for 1h, and ultrasonic aging is carried out for 4h at room temperature, thus obtaining magnesium hydroxide suspension dispersion liquid (D50:350 nm);

the prepared monomeric oil phase was added to the above magnesium hydroxide suspension dispersion containing a magnesium chloride electrolyte, sheared at 4500rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA) to form primary oil droplet particles having an average particle diameter of 20 μm, and then sheared at 9000rpm for 5min with a high speed disperser (UltratalaxT50, manufactured by IKA). Then transferring the mixture to a reactor protected by nitrogen, heating the mixture to 85 ℃ for polymerization reaction for 5 hours to obtain soft suspended powdered ink core particles with the average particle size of 7.2 mu m;

2 parts of styrene, 3 parts of methyl methacrylate, 0.2 part of butyl acrylate and 0.5 part of methacryloxyethyltrimethyl ammonium chloride were added together to 50 parts of deionized water, emulsified at a high speed of 10000rpm for 5 minutes by a high speed disperser (UltratalaxT50, manufactured by IKA), and added to the above-mentioned suspension dispersion system to be dispersed for 30 minutes. Dissolving 1 part of potassium persulfate in 10 parts of deionized water, adding the potassium persulfate into the suspension dispersion system, and carrying out polymerization reaction for 5 hours at the temperature of 80 ℃; removing magnesium hydroxide from the polymerization product by using a sulfuric acid solution, and then repeatedly washing the polymerization product by using a large amount of deionized water until the conductivity is less than or equal to 10 mu S/cm;

after drying the cake product, 1 part of silica R504(12nm, manufactured by Degussa corporation), 1 part of NA50Y (40nm, manufactured by Degussa corporation) and 0.5 part of silica TG-C190(110nm, manufactured by Cabot corporation) were added thereto, and the suspension polymerization toner of the present invention was obtained by treating the mixture with a high-speed mixer, and the suspension polymerization toner of the present invention having an average particle diameter of 7.3 μm was obtained, and the evaluation results of the characteristics of the obtained toner are shown in Table 1.

The evaluation of the toner properties was as follows:

firstly, the particle size distribution of toner particles: the volume average particle diameter of the toner particles constituting the present invention is preferably 5 to 9 μm, and when the volume average particle diameter is in the above range, the transfer efficiency can be improved, and the image quality concerning thin lines, spots, and the like can be improved.

The specific measurement mode is as follows: about 0.1g of toner particles was weighed and measured, and the resulting mixture was placed in a beaker, and 0.01g of sodium dodecylbenzenesulfonate and 30ml of deionized water were added thereto, and the mixture was ultrasonically dispersed in a 60W ultrasonic disperser for 3 minutes using a Coulter counter (Multisizer3, manufactured by Beckmann corporation, USA) at a pore diameter of 100. mu.m, and the number of particles was measured: the volume average particle diameter (Dv) and the particle average particle diameter (Dn) of the toner particles were measured on the condition of 50000 particles, and the particle diameter distribution (Dv)/(Dn) was calculated.

Secondly, average sphericity of toner particles: from the viewpoint of improving transfer efficiency, the average sphericity of the toner particles constituting the present invention is preferably 0.950 to 0.995.

The specific measurement mode is as follows: deionized water is added into a container in advance, 0.02g of surfactant sodium dodecyl benzene sulfonate is added, then 0.02g of powdered ink particles are added, and ultrasonic dispersion is carried out for 3min by a 60W ultrasonic disperser. The concentration of the colorant resin particles at the time of measurement was adjusted to 1000-10000 pieces/. mu.L, and the measurement was performed by using a flow particle image analyzer (FPIA-2100, manufactured by Sysmex). The average sphericity is obtained from the measured values. The sphericity is represented by the following calculation formula I, and the average sphericity is the average value of the sphericity; sphericity is the perimeter of a circle equal to the projected area of the particle/the perimeter of the projected image of the particle.

Thirdly, charge amount: a toner was charged into a developing device of a commercially available color printer HL-3170CDW, and the toner was left for 24 hours in an (N/N) environment at a temperature of 23 ℃ and a humidity of 50% and an (H/H) environment at a temperature of 35 ℃ and a humidity of 80%, respectively, and the toner charge was measured by a Q/M charge meter.

Fourthly, high temperature and high humidity durability: toner was charged into a developing device of a commercially available color printer HL-3170CDW, and printing was continuously performed for 5000 pages at a density of 5% in an (H/H) environment at a temperature of 35 ℃ and a humidity of 80%, wherein full color printing was performed every 500 pages, and an image density and a toner charge amount were measured.

Fifthly, the softening point temperature T of the ink powder_1/2: weighing 1g of ink powder sample, pressing the ink powder sample into a cylinder (the diameter of the cylinder is 10mm, the length of the cylinder is 9-15 mm) on a forming machine, heating the ink powder sample to 160 ℃ from 60 ℃ under the condition that the load pressure is 1.96MP and the heating rate is 6 ℃/min by using a capillary rheometer, so that the ink powder sample is molten and flows out of a nozzle under the pressure of a plunger, and selecting the temperature indicated by a tester when the plunger is descended to 1/2 as the softening point temperature T of the ink powder sample according to a time plunger stroke curve drawn by the tester_1/2。

Sixthly, storage performance: adding about 20g of toner into a closed container, standing at 50 deg.C for 2 weeks, taking out, transferring to a vibrating screen with 60 mesh/200 mesh/300 mesh screen, vibrating for 30 seconds, measuring the weight of toner remaining on the screen, and determining the weight as the weight of the agglomerated toner; the specific gravity of the agglomerated toner with respect to the weight of the toner initially charged in the container was calculated. The average value of 1 sample measured 3 times was used as an index of storability, and the storability of the toner was better when the value of the toner sieving residual rate was small.

TABLE 1

As is apparent from the evaluation results of the electrostatic charge developing toners shown in table 1:

the water-soluble cationic copolymer coated by the toner shell layers in comparative examples 1 to 4 has a high charge amount under a normal temperature and normal humidity environment, but the charge property of the toner greatly fluctuates under the influence of the environment because the used water-soluble cationic monomers such as methacryloxyethyltrimethyl ammonium chloride, diethylaminoethyl methacrylate and the like have strong hydrophilic polarity, and the image quality is not good under an HH environment.

On the other hand, the copolymers of the positively chargeable water-insoluble monomers coated with the toner shell layers in examples 1, 2, 3 and 4 of the present invention have high positively chargeable properties and good hydrophobicity, and the polar substances on the toner particle surfaces are hydrophobically modified by the silane coupling agent, so that they have excellent environmental stability and excellent image quality in a high-temperature and high-humidity environment.

In addition, as can be seen from FIGS. 6 and 7, the toners prepared in examples 1 and 2 both reached glass transition temperature and softening temperature performances.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.