KR100852785B1 - Toner and Method of Preparing the Same - Google Patents

Abstract

The manufacturing method of the toner of the present invention comprises agglomerating a colorant dispersion with a polymer latex having a bi-modal particle size distribution containing wax. The present invention provides a method for producing a toner having a uniform particle shape and particle size distribution by controlling the speed of the aggregation process more quickly and uniformly.

Toner composition, bi-modal polymer latex, flocculation, particle size distribution, emulsion polymerization

Description

Toner and its manufacturing method {Toner and Method of Preparing the Same}

Field of invention

The present invention relates to a toner and a manufacturing method thereof. More specifically, the present invention applies a polymer latex having a bi-modal particle size distribution containing wax, thereby controlling the speed of the agglomeration process more quickly and uniformly, and a toner having a uniform particle shape and particle size distribution and its preparation It is about a method.

Background of the Invention

In the electrophotographic image forming apparatus, the size and particle size distribution of the toner particles affect the resolution of the final printed image. The more uniform and spherical the particle size distribution of the toner particles is and the smaller the particle size is, the higher the resolution of the final printed image can be realized. Recently, there is a growing interest in manufacturing a toner capable of realizing high resolution according to demands of consumers and industries requiring high resolution images.

In general, a method for producing an electrophotographic developing toner for an image forming apparatus can be roughly divided into a pulverization method and a polymerization method, and the polymerization method can be further divided into a suspension polymerization method and an emulsion polymerization method. Since the pulverization method tends to form colored particles having a relatively large particle size distribution, in order to obtain satisfactory developing characteristics, it is necessary to classify the pulverized toner particles so as to have a narrow particle size distribution.

In addition, the pulverization method applies a kneading / grinding process when preparing toner particles, which is difficult to precisely control the shape, particle size, and particle size distribution of the toner particles. It has the disadvantage that the yield is greatly reduced. In addition, there is a problem that the change and adjustment of the toner design for adjusting the charging and fixing characteristics is limited.

Therefore, recently, polymerized toners have been attracting attention because it is easy to control the shape and particle size of particles and obtain a toner having a uniform particle size distribution even without a separate classification step even at a small particle size.

As a method of preparing a toner by suspension polymerization, US Patent No. 6,033,822 discloses a polymerized toner having a core comprising a polymer particle colored in a molecule by suspension polymerization and a shell surrounding the core. However, the toner by the suspension polymerization method is difficult to control its shape, and it is difficult to control the particle size due to the limitation of suspension, and there is a problem that the particle size distribution is wide.

As a method for preparing toner by emulsion polymerization method, US Patent No. 6,120,967 and US Patent No. 5,863,696 first prepare an emulsion of components of a toner having a sub-micron size, that is, a binder resin, a colorant, a release agent, and the like. A method of producing spherical particles through primary agglomeration by agglomeration of 1 to 3 μm and then secondary agglomeration or melting after primary agglomeration is disclosed. However, the manufacturing method of the above is difficult to control the particle size and spherical particles due to the complicated process of agglomeration or melting. In particular, the melting process has to go through a heating process of at least 2 to 4 hours, there is a disadvantage that the entire process is long.

Therefore, the present inventors use bimodal particle diameter of the polymer latex particles to solve the above problems, and increase the resolution by controlling the speed of the aggregation process more quickly and uniformly, and easily control the size and shape of the particles and produce them. It is possible to reduce the cost and to shorten the manufacturing time of the toner particles, and to develop an effective toner production method in terms of production.

An object of the present invention is to provide a method for producing a toner having a simple manufacturing process since no emulsifier is used in the aggregation process.

Another object of the present invention is to provide a method for producing a toner having uniform particle formation and particle size distribution by controlling the speed of the aggregation process faster and more uniformly by using a bimodal particle diameter of the polymer latex particles.

Still another object of the present invention is to provide a method for producing a toner, in which the size and shape of the particles can be easily controlled.

Still another object of the present invention is to provide a method for producing toner, which is effective in terms of production by shortening the process time for producing toner particles.

Still another object of the present invention is to provide a toner capable of realizing high resolution by producing a toner having a uniform particle size distribution and a spherical shape, and a method of manufacturing the same.

The above and other objects of the present invention can be achieved by the present invention described below.

Summary of the Invention

The present invention relates to a method of producing a toner, which comprises agglomerating a colorant dispersion with a polymer latex having a bi-modal particle size distribution containing wax.

The content of the large particle size latex particles in the bimodal polymer latex is characterized in that more than 50% by volume.

In the embodiment of the present invention, the average particle diameter ratio of the large particle size / small particle particle size in the bimodal polymer latex is 2 to 10.

The toner prepared by the above method has a particle size of 2 to 20 탆. In addition, the toner produced by the method of the present invention has a particle size distribution ratio D50 / D16 or D84 / D50 of 1.4 or less.

The present invention also includes an image forming method and an image forming apparatus using the above toner.

Detailed Description of the Invention

The toner of the present invention is prepared by agglomerating a colorant dispersion with a polymer latex having a bi-modal particle size distribution containing wax.

Polymer latex with bi-modal particle size distribution

The polymer latex of the present invention consists of large particle size latex particles having a particle size of 0.4 µm or more and 1 µm or less and small particle size latex particles having a particle size of 0.05 µm or more and less than 0.4 µm.

In one preferred embodiment of the present invention, the polymer latex having the bimodal particle size distribution has a content of large particle size latex particles of 50% by volume or more. If the content of the large particle latex particles in the total polymer latex is less than 50% by volume, it may be difficult to control the particle size and the particle size distribution due to the fast aggregation rate appearing in the small particle size latex. In addition, if the agglomeration rate is deliberately lowered for smooth control of the particle size, when the content of the small particle latex is high, a large number of latexes must be agglomerated to produce a toner having a target particle size, which may increase the process time. The more preferable large particle size latex content is 70 volume% or more.

The average particle diameter ratio of the polymer latex having the bimodal particle size distribution is characterized in that the average particle size ratio of the large particle size / small particle size is 2 to 10. If the average particle size ratio of the large particle size / small particle size is less than 2 in the above, the difference in particle size is not so large that the synergistic effect of the aggregation rate and the fusion rate is not obtained. On the other hand, when the average particle diameter ratio of the large particle size / small particle size of the polymer latex is 10 or more, the difference in the aggregation rate due to the difference in particle size becomes too large and uniform aggregation and fusion may not occur. Therefore, it is preferable to use a mixture of large particle size latex and small particle size latex in an appropriate content ratio in the above average particle diameter ratio.

The large-size polymer latex and the small-size polymer latex may be prepared separately and mixed, or the polymerization conditions are controlled to have a bi-modal particle size distribution in the process of preparing the polymer latex by emulsion polymerization. It may be manufactured in one-step. In terms of simplification and shortening of time, it is more preferable to prepare and use bimodal polymer latex particles by one-step emulsion polymerization.

The polymer latex having the bimodal distribution is prepared by polymerizing a toner composition including a macromonomer, a polymerizable monomer and a wax.

The toner composition comprises 0.5 to 10% by weight macromonomer, 70 to 90% by weight polymerizable monomer and 0.1 to 20% by weight wax.

In the present invention, the macromonomer is an amphiphilic material having both a hydrophilic group and a hydrophobic group and has at least one reactive functional group at its end. The macromonomers have a polymer or oligomeric form. The hydrophilic group of the macromonomer chemically bonded to the particle surface increases the long term stability of the particles by steric stabilization, and can control the particle size of the latex according to the amount or molecular weight of the macromonomer injected. Hydrophobic groups of the macromonomer may be present on the surface of the toner particles to promote the emulsion polymerization reaction. The macromonomer may be combined with the polymerizable monomer contained in the composition in various forms such as grafting, branching, or crosslinking to form a copolymer.

The amphoteric macromonomers can act not only as comonomers but also as stabilizers. Initial reaction of radicals with monomers produces oligomeric radicals and exhibits an in situ stabilizing effect. Thermally degraded initiators generate radicals and react with monomeric units in aqueous solutions to form oligomeric radicals and increase hydrophobicity. The hydrophobic nature of such oligomer radicals facilitates diffusion into the micelles and promotes reaction with the polymerizable monomers, with which copolymerization with the macromonomers can proceed.

Due to this hydrophilic nature of the macromonomer, the copolymerization reaction can occur more easily near the surface of the toner particles. The hydrophilic portion of the macromonomer located on the particle surface enhances the stability of the toner particles by steric stabilization, and can adjust the size of the particles according to the content or molecular weight of the macromonomer to be introduced. In addition, the functional group reacting on the particle surface can improve the triboelectric properties of the toner.

As macromonomers, for example, polyethylene glycol (PEG) -methacrylate, polyethylene glycol (PEG) -ethyl ether methacrylate, polyethylene glycol (PEG) -dimethacrylate, polyethylene glycol (PEG) -modified urethane , Polyethylene glycol (PEG) -modified polyester, polyacrylamide (PAM), polyethylene glycol (PEG) -hydroxyethyl methacrylate, hexafunctional polyester acrylate, dendritic polyester acrylate, carboxy polyester It is preferably one selected from the group consisting of acrylates, fatty acid modified epoxy acrylates, and polyester methacrylates, but is not necessarily limited thereto.

The macromonomer has a weight average molecular weight of 100 to 100,000, preferably 1,000 to 10,000. When using a macromonomer having a weight average molecular weight of less than 100, the physical properties of the finished toner may not be improved or a role as a stabilizer may not be preferable, and when using a macromonomer exceeding 100,000, the reaction conversion may be lowered. Not desirable

In the present invention, the macromonomer is 0.5 to 10% by weight based on 100 parts by weight of the total content of the toner composition. If it is less than 0.5% by weight, the dispersion stability of the particles is lowered, which is not preferable. If it exceeds 10% by weight, it is not preferable because the physical properties of the toner deteriorate.

In the present invention, the polymerizable monomer is selected from a vinyl monomer, a polar monomer having a carboxyl group, a monomer having an unsaturated polyester group, and a monomer having a fatty acid group, and one or two or more thereof may be mixed and used.

Examples of the polymerizable monomer include styrene monomers of styrene, vinyltoluene and α-methylstyrene; Acrylic acid, methacrylic acid; Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, dimethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate Derivatives of (meth) acrylic acid of dimethylaminoethyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, and methacrylamide; Ethylenically unsaturated monoolefins of ethylene, propylene, butylene; Vinyl halides of vinyl chloride, vinylidene chloride and vinyl fluoride; Vinyl esters of vinyl acetate and vinyl propionate; Vinyl ethers of vinyl methyl ether and vinyl ethyl ether; Vinyl ketones of vinyl methyl ketone and methyl isopropenyl ketone; 2-vinylpyridine, 4-vinylpyridine, N-vinylpyrrolidone nitrogen-containing vinyl compound, and the like, but is not necessarily limited thereto. The polymerizable monomer of the present invention can be used by mixing one or two or more of these.

The content of the polymerizable monomer is preferably 70 to 90% by weight based on 100 parts by weight of the total content of the toner composition. When the amount is less than 70% by weight based on 100 parts by weight of the toner composition, the yield is lowered, which is not preferable, and when it exceeds 90% by weight, the stability is lowered, which is not preferable.

Such waxes are well known by those skilled in the art to which the present invention pertains, and are readily available for commercial purchase. Types of the wax include polyethylene wax, polypropylene wax, silicone wax, paraffin wax, ester wax, carbau wax, and metallocene wax, but are not necessarily limited thereto. Preferably the melting point of the wax used in the present invention is about 50 to about 150 ° C. The wax component is in physical contact with the toner particles but does not covalently bond with the toner particles. Wax allows the toner to settle at a low fixing temperature on the final image receptor and exhibit excellent final image durability and wear resistance.

In a preferred embodiment of the present invention, the organic phase solution in which the macromolecular monomer, the polymerizable monomer, and the wax are mixed in the reactor purged with water and nitrogen gas is introduced into the reactor and heated with stirring. In this case, an electrolyte such as NaCl or an inorganic salt may be added to control the ionic strength of the reaction medium. When the temperature inside the reactor reaches an appropriate value, an initiator solution is added to carry out a polymerization reaction.

One or more polymerizable monomers are then introduced into the reactor in a semi-continuous manner, preferably with a chain transfer agent. Type and content of the chain transfer agent can be easily carried out by those skilled in the art to which the present invention belongs.

At this time, in order to control the reaction rate and degree of dispersion, the supply of the polymerizable monomer is performed slowly in a starved condition process. After the polymerization reaction proceeds, the timing of adding the wax is determined in consideration of the reaction rate and the conversion rate. After the reaction proceeded to some extent, the dispersion liquid in which the wax was dispersed in the mixed liquid of the monomer was introduced into the reactor, and an additional initiator was added to continue the reaction. The polymerization time is determined by the temperature and the experimental conditions from 6 hours to 12 hours, and is determined by measuring the reaction rate and the conversion rate. In order to control the durability or other physical properties of the toner after the reaction, the monomer may be added to prepare polymer latex particles.

As said initiator, a water-soluble free radical initiator is preferable. Specifically, persulfates, such as potassium persulfate and ammonium persulfate; 4,4-azobis (4-cyanoylacetic acid), dimethyl-2,2'-azobis (2-methylpropionate), 2,2-azobis (2-amidinopropane) dihydrochloride, 2, 2-azobis-2-methyl-N-1,1-bis (hydroxymethyl) -2-hydroxyethylpropioamide, 2,2'-azobis (2,4-dimethylvaleronitrile), 2 Azo compounds such as 2'-azobisisobutyronitrile and 1,1'-azobis (1-cyclohexanecarbonitrile); Methylethylperoxide, di-t-butylperoxide, acetylperoxide, dicumylperoxide, lauroylperoxide, benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, di-isopropylper Peroxides, such as an oxydicarbonate and di-t- butylperoxy isophthalate, etc. can be illustrated, It is not necessarily limited to this. Moreover, the oxidation-reduction initiator which combined these polymerization initiators and a reducing agent is mentioned.

The toner composition of the present invention may optionally include a release agent. The release agent is suitably used to protect the photoconductor and to prevent deterioration of development characteristics to obtain a high quality image. In one embodiment of the present invention, the release agent may use a high purity solid fatty acid ester-based material. For example, low molecular weight polyolefins, such as low molecular weight polyethylene, low molecular weight polypropylene, and low molecular weight polybutylene; Paraffin wax; And polyfunctional ester compounds. As a mold release agent used by this invention, the polyfunctional ester compound manufactured from trifunctional or more than trifunctional alcohol and carboxylic acid is preferable.

As said trifunctional or more than polyfunctional alcohol, For example, aliphatic alcohols, such as glycerin, pentaerythritol, pentaglycerol; Alicyclic alcohols such as chloroglycitol, xelitol, and inositol; Aromatic alcohols such as tris (hydroxymethyl) benzene; Sugars such as D-erythroose, L-arabinose, D-mannose, D-galactose, D-fructose, L-lamunoose, saccharose, maltose and lactose; Sugar alcohols such as erythrite, D-trate, L-arabit, adnit, and kissitrite; and the like.

Examples of the carboxylic acid include acetic acid, butyric acid, caproic acid, enanthic acid, capuric acid, perargonic acid, capuric acid, undecanoic acid, lauric acid, myristic acid, stearic acid, margaric acid, arachidic acid, and cellotine. Aliphatic carboxylic acids such as acid, mericic acid, elikaic acid, bursidic acid, sorbic acid, linoleic acid, linolenic acid, beheric acid, tetrolic acid, and chisimenic acid; Alicyclic carboxylic acids such as cyclohexanecarboxylic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, and 3,4,5,6-tetrahydrophthalic acid; Aromatic carboxylic acids, such as benzoic acid, a true acid, a cumic acid, a phthalic acid, an isophthalic acid, a terephthalic acid, a trimesic acid, trimellitic acid, a hemimelic acid, etc. are mentioned.

The toner composition of the present invention may further include a charge control agent. The charge control agent is preferably selected from the group consisting of metal-containing salicylic acid compounds such as zinc or aluminum, boron complexes of bis diphenyl glycolic acid, and silicates. More specifically, zinc disalicylic acid, borobis (1,1-diphenyl-1-oxo-acetyl potassium salt) {boro bis (1,1-diphenyl-1-oxo-acetyl potassium salt)}, etc. may be used. have.

Colorant dispersion

In the case of the black and white toner as the colorant according to the present invention, carbon black or aniline black may be used, and the nonmagnetic toner according to the present invention is easy to produce color toner. In addition, in the case of the color toner, black of the colorant uses carbon black, and the color further includes yellow, magenta, and cyanide blue colorants.

As said yellow colorant, a condensed nitrogen compound, an isoindolinone compound, an atlakin compound, an azo metal complex, or an allyl imide compound is used. Specifically C.I. Pigment Yellow 12, 13, 14, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180 and the like can be used.

As the magenta colorant, a condensed nitrogen compound, anthrakin, quinacridone compound, a base dye late compound, a naphthol compound, a benzo imidazole compound, a thioindigo compound, or a perylene compound is used. Specifically C.I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, or 254 may be used.

As the cyanide blue colorant, a copper phthalocyanine compound and a derivative thereof, an anthrakin compound, a basic dye rate compound and the like are used. Specifically C.I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 or the like can be used.

Such colorants may be used alone or in admixture of two or more thereof, and are selected in consideration of color, saturation, lightness, weather resistance, dispersibility in toner, and the like. The content of the colorant is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the polymerizable monomer in the binder resin. The content of the colorant may be any amount sufficient to color the toner, and if the amount of the colorant is less than 0.1 part by weight based on 100 parts by weight of the polymerizable monomer, the coloring effect is not sufficient. Since the production cost of is increased, sufficient triboelectric charge cannot be obtained, which is undesirable.

Flocculation stage

It can be prepared by adjusting the size and shape of the toner particles through agglomeration process of the polymer latex particles having a bi-modal particle size distribution and the colorant dispersion.

In the present invention, by preparing a polymerized toner without using an emulsifier in the flocculation process, the manufacturing process can be simplified and the production cost can be reduced.

In the coagulation process, the rate of coagulation can be controlled by adjusting the pH of the reaction medium and the concentration of the electrolyte (or inorganic salt), but in order to obtain toner particles of appropriate size, the coagulation time depends on the particle size and particle size distribution of the latex used initially. There is a big difference in. For example, when the particle size of the polymer latex particles is too small, the surface area becomes large and the aggregation rate tends to be increased. When the aggregation rate is too high, the particle size distribution is widened and it is often difficult to control the desired particle size. On the other hand, if the particle size of the polymer latex particles is too large, the aggregation rate is slow, and since the surface area of the latex particles is small, it may take a long time to sufficiently fusion at the interface.

Therefore, in order to solve the above problems, in the present invention, by controlling the particle diameter of the polymer latex particles used in the agglomeration process by bi-modal, the reaction time is appropriately controlled to reduce the reaction time, thereby reducing the reaction time between particles. Provided is a method of improving fusion to produce uniform spherical toner particles.

In the present invention, without using an emulsifier at all, the aggregation process is performed to agglomerate the latex already containing wax together with the colorant dispersion at a temperature above the glass transition temperature (Tg). The rate of aggregation can be controlled by adjusting the pH of the reaction medium and the concentration of the electrolyte (or inorganic salt).

The medium which can be used in the flocculation process according to the present invention may be an aqueous solution, an organic solvent, or a mixture thereof.

In general, the particle size of the latex particles by emulsion polymerization has a size of about 0.05 to 1 μm, and the particle size of the suitable toner after the particle aggregation is 2 to 20 μm. The more preferable toner has a particle size of 5 to 10 탆, and in order to produce toner particles of this size, a large number of sub-micron sized latex particles must be agglomerated.

In the present invention, toner may be prepared by performing aggregation and coalescence processes at a temperature of Tg or more by controlling the concentration of pH, electrolyte solution, or inorganic salt together with the colorant dispersion using the latex-containing polymer latex particles. have. The size and shape of the toner particles are adjusted using temperature, heating time, and stirring speed.

In the initial stage of aggregation, pH may be adjusted or inorganic salts such as NaCl or MgCl ₂ may be added to aggregate latex particles containing colorants and waxes. As the pH is increased by the addition of alkali, the surface of the particles changes to negative charge or takes up relatively less positive charge. These particle surfaces are mainly due to the presence of large monomer chains chemically bound to the surface, to sulfate groups of initiators such as potassium persulfate (KPS), and to acid groups used as comonomers.

The method may further include adjusting the ionic strength by adding an electrolyte solution or an inorganic salt in the step of agglomerating the polymer latex particles. In the aggregation process, the size of the particles increases due to ionic strength and collision between the particles.

According to the present invention, the polymer latex can be aggregated by heating to a temperature of Tg or more. This increases the Gibbs free energy of the latex polymer chain at a temperature higher than the latex Tg, allowing free movement of the latex polymer chain, thereby creating a smooth surface toner particle shape. It is possible to adjust the shape of the particles depending on the temperature conditions.

The morphological differences of toner particles are due to the interfacial force and rheology of the particles. After the desired size and shape have been obtained, the mixture is cooled to below Tg, filtered and separated from the toner particles and dried. The dried toner is externally treated with silica or the like, and the toner for the final laser printer can be manufactured by adjusting the charge amount.

The toner prepared by the above method is characterized in that the particle size distribution ratios D50 / D16 and D84 / D50 are both 1.4 or less.

The toner manufactured by the method of the present invention is a measure of the fine amount of toner particles, and D50 / D16, which is 50% of the particle size distribution D50 divided by D16, which is 16% particle size distribution, is 1.4 or less, preferably 1.3 It is characterized by the following. Smaller values of D50 / D16 mean less fine particles are distributed than the average particle diameter. The coarse amount of the toner particles is measured by dividing D84, which is 84% of the particle size distribution, by D50, which is 50% of the particle size distribution, and D84 / D50 of 1.4 or less, preferably 1.3 or less. Similarly, smaller D84 / D50 means less particle size distribution than the average particle size.

The toner produced by the present invention can be applied to an image forming method. Specifically, the toner is formed by attaching a toner to a surface of a photosensitive member on which an electrostatic latent image is formed, thereby forming a visible image and transferring the visible image to a transfer material, wherein the toner of the present invention is applied as the toner. Exemplary electrophotographic imaging processes include a series of steps to form an image on a receptor, including charging, exposing, developing, transferring, fixing, cleaning, and antistatic steps.

In the charging step, the photoreceptor is typically covered with a charge of the desired polarity, either negative or positive, by a corona or a charging roller. In the exposing step, an optical system, typically a laser scanner or diode array, selectively discharges the charging surface of the photoreceptor to form a latent image in an imagewise manner corresponding to the desired image formed on the final image receptor. Electromagnetic radiation, which may be referred to as "light", may include, for example, infrared radiation, visible light, and ultraviolet radiation.

In the developing step, toner particles of suitable polarity are generally in contact with the latent image on the photoconductor, using a developer electrically-biased, usually having a potential polarity equal to the toner polarity. Toner particles move to the photoconductor and are selectively attached to the latent image by electrostatic force, forming a toned image on the photoconductor.

In the transfer step, the tone image is transferred from the photoreceptor to the desired final image receptor, sometimes an intermediate transfer element is used to influence the transfer of the tone image from the photoreceptor to the final image receptor with subsequent transfer of the tone image. .

In the fixing step, the tone image on the final image receptor is heated to soften or melt the toner particles, thereby fixing the tone image to the final receptor. Another method of fixing involves fixing the toner to the final receptor under high pressure with or without heat.

In the cleaning step, residual toner remaining on the photoreceptor is removed.

Finally, in the antistatic step, the photoreceptor charge is exposed to light of a specific wavelength band and reduced to a substantially uniformly low value, thereby removing the residue of the original latent image and preparing the photoreceptor for the next image forming cycle.

The present invention includes an image forming apparatus using the toner. The image forming apparatus includes an organophotoreceptor, means for charging the surface of the organophotoreceptor, means for forming an electrostatic latent image on the surface of the organophotoreceptor, means for accommodating toner, and supplying the toner to develop an electrostatic latent image on the surface of the organophotoreceptor to toner Means for developing an image, and means for transferring said toner image from a photosensitive member surface to a transfer material, wherein the toner of the present invention is applied to the toner.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

(a) Preparation of Polymer Latex Particles

2,200 parts by weight of deionized water was added to a reactor of 4L and the temperature was raised to 80 ° C while stirring while purging N ₂ . Thereafter, 390 parts by weight of styrene monomer, 145 parts by weight of butyl methacrylate, 20 parts by weight of methacrylic acid, 20 parts by weight of PEG-ethylether methacrylate, and 40 parts by weight of wax were mixed and stirred to completely dissolve the mixture from the monomer mixture prepared. A mixture of 5% of the total monomers of is first introduced into a heated reactor. Subsequently, an initiator solution in which 16 parts by weight of potassium persulfate was dissolved in 140 parts by weight of deionized water was added thereto, followed by reaction for 10 minutes. When the polymer in the reactor appears cloudy, the remaining 95% of the monomer mixture is added dropwise. The reaction product was added dropwise for 2 hours, and when the monomer addition was completed, the reaction was further proceeded for 4 hours and finished to prepare polymer latex particles.

Using particle size analyzers using light scattering or light diffraction, the polymer latex particles produced have peaks at 610 nm and between 400 nm and 1,000 nm (specifically, 400 nm ≤ particle ≤ 1,000 nm). It was confirmed that the bi-modal state was composed of the large particle size and the peak appearing at 189 nm and distributed between 50 nm and 400 nm (specifically, 50 nm ≤ particle size <400 nm). In the polymer latex particles, the content of the large particle size distributed between 400 nm and 1,000 nm was 84% by volume, and the content of the small particle size distributed between 50 nm and 400 nm was 16% by volume. Specific examples of the particle size analyzer were Zetasizer Nano Series of Malvern, UK or ELS-8000, Otsuka, Japan.

(b) Black Dispersion Preparation

First, 260 parts by weight of deionized water, 60 parts by weight of carbon black and 10 parts by weight of urethane acrylate are weighed and mixed in a beaker. Thereafter, using a microfluidization device, the dispersion was dispersed until the average particle diameter of the dispersion was 110 ± 20 nm, thereby preparing a black colorant dispersion.

(c) Preparation of Toner Particles

950 parts by weight of the polymer latex prepared above was added to a 3L reactor and then stirred. 920 parts by weight of deionized water, 75 parts by weight of black pigment dispersion and 60 parts by weight of sodium hydroxide (1N) were added thereto, and adjusted for about 1 hour. Thereafter, 30 parts by weight of magnesium chloride hexahydrate and 30 parts by weight of deionized water were added to 60 parts by weight of an electrolyte solution in which mussels were dissolved. The temperature of the reactor was raised to 90 ° C., and the polymer latex and the colorant dispersion were reacted for 4 hours. Then adjust the pH to 11 and then heated to 95 ℃. After heating for about 1 hour to form a particle, cooling and filtration to obtain toner particles.

The volume average size of the finally obtained toner particles was 6.5 µm, and D50 / D16 was measured to be 1.25 and D84 / D50 was measured to be 1.19, which showed uniform particle size distribution.

Comparative Example 1

(a) Preparation of Polymer Latex Particles

2,200 parts by weight of deionized water was added to a 4 L reactor, and the mixture was heated to 80 ° C. while stirring while purging N ₂ . Subsequently, an initiator solution in which 16 parts by weight of potassium persulfate was dissolved in 140 parts by weight of deionized water was added thereto, followed by reaction for 10 minutes. Thereafter, 390 parts by weight of styrene monomer, 145 parts by weight of butyl methacrylate, 20 parts by weight of methacrylic acid, 20 parts by weight of PEG-ethylether methacrylate, and 40 parts by weight of wax were mixed and stirred to completely dissolve the monomer mixture prepared. I was. The reaction was added dropwise for 2 hours, and when the monomer was added, the reaction was continued at 250 rpm for an additional 4 hours, and then polymer latex particles having an average particle size of 650 nm were prepared.

Polymer latex particles were prepared in a similar manner to the above except that potassium persulfate was adjusted to 20 parts by weight. The average particle diameter of the produced particles was 450 nm.

(b) Preparation of Toner Particles

700 parts by weight of the large particle size latex prepared above and 250 parts by weight of the small particle size latex were introduced into a 3L reactor, followed by stirring. 920 parts by weight of deionized water, 75 parts by weight of black pigment dispersion and 60 parts by weight of sodium hydroxide (1N) were added thereto, and adjusted for about 1 hour. Thereafter, 30 parts by weight of magnesium chloride hexahydrate and 30 parts by weight of deionized water were dissolved in 60 parts by weight of an electrolyte solution in which mussels were dissolved. The temperature of the reactor was increased to 90 ° C., and the polymer latex and the colorant dispersion were reacted for 4 hours. Then adjust the pH to 11 and then heated to 95 ℃. After heating for about 1 hour to form a particle, it was cooled and filtered to obtain toner particles.

The volume average size of the toner particles finally obtained was 5.5 μm, and D50 / D16 was measured to be 1.45 and D84 / D50 was measured at 1.38, indicating that particle size growth was slowed and that fine powder was included as compared with Example 1.

In the present invention, since the emulsifier is not used in the flocculation process, the manufacturing process is simple, and the particle shape and the particle size distribution are made uniform by controlling the speed of the flocculation process more quickly and uniformly using the bi-modal particle diameter of the polymer latex particles. It is possible to increase the resolution, to control the size and shape of the particles, to reduce the production cost, and to reduce the processing time required to produce the toner particles. The invention provides an excellent toner and an image forming method and an image forming apparatus using the same.

Claims (18)

A method of manufacturing a toner, comprising agglomerating a latex containing a polymer and a colorant dispersion having a bi-modal particle size distribution. The method of claim 1, wherein the polymer latex is prepared by polymerizing a toner composition including a macromonomer, a polymerizable monomer and a wax. 3. The macromonomer of claim 2 wherein the macromonomer is polyethylene glycol (PEG) -methacrylate, polyethylene glycol (PEG) -ethylether methacrylate, polyethylene glycol (PEG) -dimethacrylate, polyethylene glycol (PEG) -modified Urethane, polyethylene glycol (PEG) -modified polyester, polyacrylamide (PAM), polyethylene glycol (PEG) -hydroxyethyl methacrylate, hexafunctional polyester acrylate, dendritic polyester acrylate, carboxy poly A process for producing a toner, characterized in that it is selected from the group consisting of ester acrylates, fatty acid modified epoxy acrylates, polyester methacrylates and mixtures thereof. The method of claim 2, wherein the weight average molecular weight of the macromonomer is 100 to 100,000. The method of claim 2, wherein the polymerizable monomer is at least one selected from a vinyl monomer, a polar monomer having a carboxyl group, a monomer having an unsaturated polyester group, and a monomer having a fatty acid group. The method of claim 5, wherein the polymerizable monomer is a styrene monomer of styrene, vinyltoluene, α-methylstyrene; Acrylic acid, methacrylic acid; Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, dimethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate Derivatives of (meth) acrylic acid of dimethylaminoethyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, and methacrylamide; Ethylenically unsaturated monoolefins of ethylene, propylene, butylene; Vinyl halides of vinyl chloride, vinylidene chloride and vinyl fluoride; Vinyl esters of vinyl acetate and vinyl propionate; Vinyl ethers of vinyl methyl ether and vinyl ethyl ether; Vinyl ketones of vinyl methyl ketone and methyl isopropenyl ketone; And at least one selected from nitrogen-containing vinyl compounds of 2-vinylpyridine, 4-vinylpyridine and N-vinylpyrrolidone. The method of claim 2, wherein the toner composition comprises 0.5 to 10 wt% of a macromonomer, 70 to 90 wt% of a polymerizable monomer, and 0.1 to 20 wt% of a wax. 2. The toner of claim 1, wherein the polymer latex having a bimodal particle size distribution is composed of large particle latex particles having a particle size of 0.4 µm or more and 1 µm or less and small particle latex particles having a particle size of 0.05 µm or more and less than 0.4 µm. Way. The method of claim 8, wherein the polymer latex having a bimodal particle size distribution has a content of large particle size latex particles of 50% by volume or more. The method of claim 8, wherein the average particle diameter ratio of the polymer latex having the bimodal particle size distribution is 2 to 10. The method of claim 1, wherein the coagulation rate is controlled by adjusting pH in the step of coagulating the polymer latex and the colorant dispersion. The method of claim 1, further comprising adjusting an ionic strength by adding an electrolyte solution or an inorganic salt in the step of coagulating the polymer latex and the colorant dispersion. 13. The method of claim 12, wherein the inorganic salt comprises NaCl or MgCl ₂ . 2. The method of claim 1, wherein the polymer latex particles are heated to agglomerate at a glass transition temperature (Tg) or higher of the latex particles to agglomerate. The method of claim 2, wherein the toner composition further comprises at least one selected from an initiator, a chain transfer agent, a charge control agent, and a release agent. A toner prepared by the method of any one of claims 1 to 15, having a volume average particle size of 2 to 20 µm and a particle size distribution ratio of D50 / D16 and D84 / D50 of 1.4 or less. An image forming method comprising attaching toner to a surface of a photosensitive member on which an electrostatic latent image is formed to form a visible image, and transferring the visible image to a transfer material, wherein the toner uses the toner of claim 16. Forming method. Means for charging the organophotoreceptor, surface of the organophotoreceptor, means for forming an electrostatic latent image on the surface of the organophotoreceptor, means for accommodating toner, and means for developing a toner image by developing an electrostatic latent image on the surface of the organophotoreceptor by supplying the toner And means for transferring the toner image from the surface of the photoconductor to the transfer material, wherein the toner is the toner of claim 16.