KR100453150B1 - Compositions and method of producing particles suitable for production of high resolution toner by way of dispersion comminution - Google Patents

Abstract

The present invention relates to a particulate resin composition for producing a high-resolution toner for electrostatic latent image development, and to a method for manufacturing the same, the production method comprising a resin having a functional group suitable for interacting with a dye, a processing aid, and optionally a charge control agent. Preparing a resin mixture in a molten state; dispersing the resin mixture in a state where a surfactant is added to an organic medium insoluble to the resin; and heating the resin by heating and shearing in the organic medium. Pulverizing the mixture into resin fine particles, evaporating and removing the processing aid by heating the pulverized resin fine particle dispersion, and separating and recovering the particulate resin composition from the organic medium. , The particulate resin composition prepared in this manner The high particle size smaller is useful for the manufacture of a high resolution color toner showing excellent characteristics in electrophotographic imaging systems.

Description

Composition of particulate resin for high resolution toner production using solvent pulverization method and its preparation method {Compositions and method of producing particles suitable for production of high resolution toner by way of dispersion comminution}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particulate resin composition used for producing a toner for electrostatic latent image development, such as electrophotographic, electrostatic lock, and electrostatic printing, and a method for producing the same. More specifically, the present invention relates to a method for producing a particulate resin composition of a suitable size for use in high resolution color electrophotographic, electrostatic rock, electrostatic printing in such a way that the resin mixture is subjected to shearing and grinding in a solvent. The resin is preferably an amorphous polyester resin and a styrene / acrylate copolymer.

The present invention can be said to be a more improved method of US patent application Ser. No. 09 / 571,772, which is currently pending.

Methods of developing and forming images on the surface of photoconductive materials by electrostatic methods are well known. Basic electrophotographic imaging (US Pat. No. 2,297,691) induces a uniform electrostatic charge on a photoconductive insulating layer, also known as a photoconductor or photoreceptor, exposes the photoreceptor to light and then masks the image from the light to light the photoreceptor. After dissipating the charge in the portion that has been exposed to, developing the electrostatic latent image produced by depositing a finely divided electroscopic toner material on the image. These toners are usually attracted to the portion that holds the charge of the photoreceptor, forming a toner image corresponding to the electrostatic latent image. The developed image is transferred to a substrate such as paper. The shifted image is then permanently fixed to the substrate via a combination of heating, pressurization, heat pressurization or other suitable fixation methods such as solvent treatment or protective coating treatment.

Also known is the technique of developing such electrostatic images. The developer is a carrier in which charged color toner particles are dispersed. The photoreceptor containing the electrostatic latent image is in contact with the developer. Charged toner particles in the developer are moved to the charged region of the photoreceptor through the contact to develop a latent image. The photoreceptor is then developed as the charged color particles adhere to the latent image in the form of an image. The developed image is typically transferred to a suitable substrate, such as paper, transparent film, and can optionally be fixed to the substrate by heating, pressing or other suitable method.

Electrostatic images formed on electrophotographic photoconductors and electrostatic green media generally comprise (i) a single component type comprising a colorant, such as a dye or pigment, and a resin in which the colorant is dispersed, and a toner to which a charge control agent has been added, if necessary. It is developed using a dry developer or (ii) a two-component dry developer comprising the toner and solid carrier particles. Toner and developer compositions comprising colored particles are well known. In this regard, reference may be made to U.S. Pat. . Conventional compositions typically include toner particles composed of colorants and synthetic resins, waxes or polyolefins, charge control agents, rheology enhancers and other additives. Typical toner compositions include about 90-95 weight percent resin, about 2-10 weight percent colorant, 0-about 6 weight percent wax, 0-3 weight percent charge control agent, and about 0.25-1 weight percent fluidity. Enhancer and 0 to about 1 weight percent of other additives. The main resins used are styrene-acrylic copolymers, styrene butadiene copolymers and polyesters. The colorant is generally selected from cyan dyes or pigments, magenta dyes or pigments, yellow dyes or pigments and mixtures thereof.

Conventional color toners are produced, for example, by the milling method described in US Pat. No. 5,102,761 described above. In this process, the polyacrylate resin is mixed in a melt mixer with pigments, charge control agents and optionally waxes. The polymer is milled mechanically and then milled into small particles. Conventional toner particles typically exhibit irregular shapes and a wide particle size distribution. In order to achieve the optimal resolution of the image and color, the smaller the particle size, the better the performance. Thus, for example, when the average particle diameter is 7 microns or more, it is difficult to obtain a resolution of about 600 dots / inch or more. The particle size must be less than 5 microns for the printed image to achieve a resolution of 1200 dots / inch. Since energy is consumed to produce small particles, conventional methods have a narrow and uniform size distribution, and it is difficult to produce particles having a size of 7 to 10 microns or less.

Attempts have been made to obtain particles that are small in size and narrow in distribution. For example, the aforementioned U.S. Patent Nos. 5,352,521, 5,470,687, and 5,500,321 disclose methods for producing toner particles by dispersion polymerization. These methods combine monomers (primarily styrene and acrylates) and additives such as pigments, CCA and waxes to form a dispersion. After this dispersion is dispersed in an aqueous or non-aqueous solvent, the monomers are reacted to form toner particles. The advantage of this method over other methods is that small diameter spherical toner particles can be produced in a single process. However, during the polymerization process, the volume of the material decreases, which causes dispersant to be included in the toner particles. In addition, since it is difficult to completely terminate the polymerization, a large amount of monomer remains in the toner particles. Residual monomers and the dispersed solvent included are difficult to separate from the particles. In addition, the polarities of the polymeric materials change rapidly during the polymerization process and additives ooze out of the particle mass and tend to concentrate on the surface. In addition, it is very difficult to remove them from the toner particles when the dispersing stabilizer, the surface active agent, and the like, which lower the charge characteristics and the stability of the toner particles, remain on the surface of the toner particles.

US patent application Ser. No. 09 / 571,772, which is currently pending, describes a method for preparing toner particles by pulverizing resin particles composed of colorants and charge control agents into fine particles in a solvent insoluble in the resin.

However, this method is limited to toner resins having a relatively small molecular weight, and high temperatures and strong shearing forces are generally required for atomization of more effective toner particles. In addition, the toner particles produced by the above method generally have a smooth surface so that they cannot have important fast charging characteristics in the one-component electrophotographic developing system.

Korean Patent Application No. 2001-32682, which is currently pending, is a spherical toner having a small particle diameter distribution by dispersing a polymer resin including colorants, processing aids and other additives in a dispersion medium containing a surfactant while applying shear force. An improved dispersion method for producing high resolution color toner particles that exhibits excellent properties in electrophotographic imaging systems by forming particles is described.

This method is viable at significantly lower temperatures and has the advantage of using high molecular weight resins to produce toner particles as compared to the method described in the aforementioned pending US patent application Ser. No. 09 / 571,772. Furthermore, the toner particles produced by this method have a narrow particle size distribution and can also have fast charging characteristics by having the toner particles have a rough surface.

The patents cited above refer to the method of preparing toner particles in general by milling, polymerizing or atomizing after mixing all the components constituting the toner composition.

However, the present invention is characterized by having a method of first preparing a particulate resin composition and then adding a colorant or another toner additive to the resin composition. Related inventions are described in US Pat. No. 6,001,524, which is incorporated herein by reference. This patent describes a method for preparing polyester toner particles by combining dyes and charge control agents with polyester resin particles. . Resin particles are prepared by dispersion polymerization of a suitable monomer in a non-aqueous solvent, which has the advantage of making spherical toner particles having a small particle size.

However, the volume of the material decreases during the polymerization process, which results in the inclusion of the dispersion solvent in the toner particles. Such residual dispersing solvents are difficult to separate from the particles and create hazy shapes in printing. In addition, the toner particles produced by this method have a smooth surface. Smooth surfaces and residual dispersion solvents make the toner produced by this method unsuitable for one-component electrophotographic systems that require fast charging properties.

Another engagement for the toner particle composition is the narrow particle size distribution. This narrow particle distribution generally causes the toner to have a uniform charge distribution, which not only reduces the mottled background but also increases the line resolution of the printed shape. Conventional milling methods for producing toner particles are generally ineffective in producing narrow particle distributions. Therefore, a classification process is required to remove too small or too large particles from the toner composition.

Narrow particle distribution can be expressed as 80% span value. The span value is defined as the ratio of the particle size range at 80% of the volume occupied by the particle to the medium size. A more detailed definition of the span value will be described later in this patent. Narrow span means a narrow particle distribution. Typical span values of toner particles produced by the aforementioned commercialized method are about 1.2. Therefore, it is highly desirable to produce particles with a span value less than 1.2 without classification.

Accordingly, it is an object of the present invention to provide a mixture of a resin in a molten state comprising a resin, a processing aid, and optionally a charge control agent, suitable for interacting with the dye, in which the surfactant is added to an organic medium insoluble to the resin. After dispersing in a state, the latent electrostatic image which separates and recovers the particulate resin composition from the organic medium by pulverizing the resin mixture into fine resin particles by heating and shearing in the organic medium and vaporizing and removing the processing aid. It is to provide a method for producing a particulate resin composition for producing a developing toner.

Yet another object of the present invention is an improved dispersion atomization method for producing particulate resin compositions for toners that are viable at low temperatures.

Another object of the present invention is to provide a dispersion atomization method for producing fine particles of resin by rapidly atomizing a substantial high molecular weight polymer resin.

It is another object of the present invention to provide a process for producing spherical resin particulates comprising a polymer resin and optionally a suitable charge control agent and having a narrow particle size distribution as well as sizes ranging from about 1 to 10 μm.

Other objects and advantages of the present invention will become apparent from the following description and examples.

In order to achieve the above object, the present invention provides a process for preparing a resin mixture in a molten state comprising a) a resin having a functional group suitable for interacting with a dye, a processing aid, and optionally a charge control agent, and b) the resin. Dispersing the mixture in the presence of a surfactant in an organic medium insoluble to the resin, c) pulverizing the resin mixture into fine particles of resin by heating and shearing in the organic medium, d) Evaporating and removing the processing aid by heating the pulverized resin particulate dispersion; and e) separating the particulate resin composition from the organic medium, thereby preparing a particulate resin composition for preparing an electrostatic latent image toner. Provide a method.

The present invention also provides a particulate resin composition which is spherical in shape and has a volume average diameter of 1 to 10 microns and a span value of 1.0 or less, wherein the average weight molecular weight of the resin is about 100,000 g / mol or less.

First look at each component of the present invention in detail as follows.

1) Polymer resin

The resin used in the present invention is generally an amorphous resin having a glass transition temperature in the range of about 40 ° C. to about 90 ° C., with polyester resins and styrene copolymer resins being particularly preferred. When the processing aid is used, the molecular weight range of the polymer resin available for toner production can be increased, and the molecular weight of the polymer resin usable is in the range of 3000 g / mol to 100,000 g / mol. The polymer resin may optionally include a functional group to improve the compatibility of the portion of the polymer chain with the colorant.

Examples of such resins include polyamides, polyolefins, styrene acrylates, styrene methacrylates, styrene butadienes, styrene polymers with crosslinked structures, ethylene-cycloolefin copolymers, epoxides, polyurethanes, single components or two or more vinyl monomers. Vinyl resins including copolymers, and the like, and polyesters obtained through esterification of dicarboxylic acids with diols of diphenols as exemplified in US Pat. No. 3,590,000 and similar patents. Of these resins, polyester copolymers and styrene copolymers are particularly preferred.

The resin is selected from the group consisting of hydroxy group, alkoxy group, phosphonic group or phosphonic derivative, phosphonic group or phosphonic derivative group, thiol group, amine group, alkylamine group, quaternary amine group and mixtures thereof, It may have a functional group suitable for interacting with the dye.

The weight average molecular weight of the resin has a value in the range of 3,000 g / mol to 100,000 g / mol as measured by gel permeation chromatography (GPC), and more preferably has a value within 5,000 g / mol to 20,000 g / mol. Do. The molecular weight distribution (Mw / Mn) of the linear polymer generally has a value in the range of 1.5 to 6, but preferably has a value of 2 to 4. The temperature at which the glass transition temperature of the linear polymer measured by the calorimetry (DSC) starts is generally in the range of 50 ° C to 90 ° C, but is preferably in the range of 50 ° C to 70 ° C.

2) Processing aid

The processing aid, which can be said to be a component of the present invention, is selected from organic solvents having a boiling point of 200 ° C. or less that can be easily absorbed by the polymer resin component. The use of processing aids lowers the melting temperature of the resin mixture, allowing the entire manufacturing process to be carried out at a lower temperature than without processing aids. The processing aid is preferably insoluble in the organic solvent component used in the dispersion process, and examples thereof include acetone, dimethylformamide, cyclohexane, dimethyl sulfoxide, chlorobenzene and the like.

3) Charge control agent

Positive or negative charge control agents suitable for the present invention may be added, which may generally be infused at a rate of 0% to 10% by weight, but more preferably from 1% to 3%. Examples using alkyl pyridinium halide, alkyl pyridinium compounds are illustrated in US Pat. No. 4,298,672, and organic sulfate, sulfonate compounds are illustrated in US Pat. No. 4,338,390. In addition, US Pat. No. 5,114,821 describes various examples, in which bisulfonate, ammonium sulfate, distearyldimethyl ammonium bisulfate, and the like are used, such as cetyl pyridinium, tetrafluoroborate, and distearyl dimethyl. When using aluminum salts such as ammonium methyl sulphate, BONTRON E-84 or E-88 and when mixing a known charge control agent such as distearyl dimethylammonium bisulfate or ammonium sulfate as an agent to improve the properties of the charge Included. Effective internal or external charge control agents can be selected and used from those described in the foregoing patent specification.

4) Other additives-wax or fumed silica

The toner composition of the present invention may be added an additive such as wax or fumed silica.

Wax helps toner toner and removes ghost image. Ghost image refers to a phenomenon in which a toner is fused in an unwanted place when printed on a substrate. The process in which the toner is printed on the paper is first shown in the present specification, and the toner is first transferred onto the opc drum, and the transferred toner is again moved by the electrostatic attraction on the paper. At this stage, the toner is only physically on the paper. Therefore, the position of the toner may change when a physical force is applied. The toner is fixed on the paper while passing through a hot fusing roll. At this time, in the process of toner melting on paper, some toner may cause unwanted reverse transition to the fusion roll. It is a ghost image that the toner reversed to the fusion roll appears in another position while rotating. When using a toner in which wax is added, the reverse transition may be suppressed by the releasing property of the wax.

Generally, low molecular weight waxes such as polypropylene and polyethylene can be added, and such materials can be purchased and used commercially from EPOLENE N-15 ^™ or Eastman Chemical Products. The molecular weight of commercially available polyethylenes ranges from 1,000 g / mol to 1500 g / mol, but the molecular weight of polypropylenes that can be used in the present invention can range from 4,000 g / mol to 7,000 g / mol.

The use of silica is as follows. In general, the smaller the size of the powder is, the more physical agglomeration occurs, which is due to van der Waals forces formed between the powders. The best way to control this is to maintain a constant distance between the powders. When very small particles, such as silica, are coated around the toner particles, the silica particles physically adhere to the particles by van der Waals forces, thereby maintaining a constant distance between the toners. In addition, since the silica particles are generally spherical, they have a good rolling property such as bearings. For this reason, silica coated toners have fluid-like fluidity, which is a representative example of the fluidity improver described below.

5) organic medium

Effective dispersion and production of particles are made possible when using organic solvents that do not dissolve the resin. More specifically, it is easy to apply that the difference between the solubility index of the solvent and the solubility index of the resin particles is 1 or more, and more preferably 2 or more. Any organic medium may be used as long as it does not dissolve the resin component. Particularly preferred are solvents containing paraffinic solvents and poly (ethylene glycol). For example, it is preferable to use a nonpolar solvent having a low solubility index such as paraffin, paraffin ester, paraffin amide, and paraffin ether together with the polyester particles. . On the other hand, when a solvent having a relatively high polarity such as water, methanol, propanol and acetone is selected as the solvent of the dyeing process, coalescence of particles occurs remarkably. On the other hand, when a nonpolar resin, such as a styrene copolymer, is dispersed, it is preferable to use a polar organic solvent such as polyethylene glycol having a number average molecular weight of less than 1,000. When nonpolar solvents such as paraffin, paraffin ester, paraffin amide, and paraffin ether are used in the dispersion process of the styrene copolymer, a remarkable coalescence phenomenon occurs.

6) surfactant

Surfactants are used in the dispersion process together with the aforementioned organic solvents and serve two important functions for the successful production of small particles. Firstly, the surfactant prevents the resin particles from coalescing during the process. The dispersion process in the course of the invention is generally carried out at or near the glass transition temperature of the resin. Thus, in the absence of a surfactant, molten particles tend to coalesce, thereby forming dyed particles unsuitable for high resolution toner. Second, the size of the particles is determined by the relative amount of the surfactant with respect to the resin particles. Surfactants accumulate at the interface between insoluble solvents and molten particles due to their chemical structure. Thus, large amounts of surfactants can be applied to produce small sized particles, while small amounts of surfactants can be applied to produce large particles. The surfactant can be anionic, cationic or nonionic.

Nonionic surfactants can be made using ethylene oxide or propylene oxide. Preference is given to polymer surfactants comprising polyvinyl pyrrolidone, alkylated maleic acid copolymers, polymers comprising ethylene oxide functional groups and copolymers of polymers comprising propylene oxide functional groups. The surfactant may be present in the solvent at 0.2 to 15% by weight, but typically includes 1 to 10% by weight.

7) Fluidity improver

Toner fine particles can be coated with a suitable fluidity enhancer. Flow improvers help to improve the flow of particles to be used as color toners. Suitable fluidity improvers include finely classified hydrophobic silica, titanium oxide, zinc stearate, magnesium stearate and the like. These fluidity improvers are coated on the particles by dry mixing, solvent mixing or the like. In general, fumed silica (available under the trade name Cab-O-Sil from Cabot, Tusco, Illinois) under a hydrophobic material such as hexamethylsilazene in a tμmble mixer for 10 to 60 minutes. Mixed with particles coated with CCA.

Definition of Terms

1) volume average particle size

The term "volume average particle size (L)" as used herein is defined in pages 3 to 13 of the Power Technology Handbook (K. Gotoh et al., 2nd edition, Marcell Dekker Publications, 1997).

In the particulate toner composition of the present invention, it is preferable that at least about 80% by weight of the total resin particles use particles having a particle size distribution in the range of 0.5 × L to 1.5 × L. This provides toner particles containing a uniform amount of charge in each toner particle, in which resin particles having a narrow particle size distribution are uniformly dyed, and also provide a high quality copy image, and facilitate charge control at a developing site. Because it makes you.

In the present invention, particle size distribution is measured using a commercial Coulter LS particle size analyzer (Coulter Electronics Co., Ltd., St. Pittsburgh, FL).

2) span value

As an index defining the size distribution of particles, a span value was defined and used as follows. In the size distribution chart, the diameter of the particles corresponding to the volume of 10% was defined as d10, the diameter of the particles corresponding to 90%, d90, and the particle diameter of the 50% distribution corresponding to the average value was defined as d50. The span value obtained using the above three values can be expressed as below.

As can be seen from the definition, the span value is smaller, and the index value indicates the narrower particle distribution, and the larger value, the wider particle distribution.

The surface area of the microsphere resin is obtained from the BET isothermal curve. BET isothermal experiments are measured using a commercially available Automatic Vol μm tric Sorption Analyzer (Model No. ASAP2000, Micromeritics Instr μment Corporation, Norcross, Georgia). The measurement is made in such a way as to determine the amount of nitrogen adsorbed on the particle surface under reduced pressure, the surface area being determined from the plot of pressure and adsorption amount. A detailed description of this is found in the BET isothermal curve section on pages 615-631 of Physical Physics of Surfaces (New York John Wiley and Sons, A. W. Adamson and A. P. Cast (1997), 6th edition).

3) Roughness Index

The surface roughness index used in the present invention has a volume average particle size and is defined as the ratio of the surface area of 1 g of a full spherical particle to the surface area obtained from the BET isothermal curve. The surface roughness index is expressed by the following equation.

Surface roughness index = (1/6) r * d * A _exp ,

Where r is the polymer density and d is the diameter of the polymer microspheres. The coefficient defined in this way indicates how rough the surface is. The optical density of the printed image was measured using a light density meter (commercially available from Macbeth Company, New Windsor, NY).

Hereinafter, a method of manufacturing the particulate resin composition of the present invention for producing a toner will be described in detail step by step.

As described above, the process for preparing the particulate resin composition of the present invention comprises the steps of: a) preparing a resin mixture in a molten state comprising a resin having a functional group suitable for interacting with the dye, a processing aid, and optionally a charge control agent. And b) dispersing the resin mixture in the state in which the surfactant is added to an organic medium insoluble to the resin, and c) pulverizing the resin mixture into fine resin particles by heating and shearing in the organic medium. D) evaporating and removing the processing aid by heating the pulverized resin particulate dispersion, and e) separating the particulate resin composition from the organic medium.

The step a) of preparing a resin mixture of the present invention consists of melt kneading a resin having a functional group suitable for interacting with the dye, a processing aid, and optionally a charge control agent. In this case, in order to effectively mix the resin, the colorant and the charge control agent, a method of melting and mixing in a reactor equipped with a stirrer, a melt kneader method of mixing in a sealed kneader, and a method of melt mixing in a twin screw extruder may be used. Can be.

The amount of the processing aid may vary but is generally used within the range of 5% to 50% by weight, more preferably 10% to 30% by weight. The melting temperature of the first resin composition is determined by adjusting the amount of the processing aid included, but the resin composition is preferably prepared at a low temperature.

(B) dispersing the resin mixture of the present invention in a state where a surfactant is added to an organic medium insoluble to the resin, and generally the content of the surfactant is about 0.2 to about 15 based on the amount of solvent present. Weight percent, with about 1 to about 10 weight percent being preferred based on the amount of solvent present.

At this time, the step of dispersing the resin mixture in the organic medium may be performed in the following two ways. One method is carried out by introducing the resin mixture while stirring the organic medium at a temperature above the flow temperature of the resin mixture, and another method is agitating the vessel containing the melt of the resin mixture. It is carried out by introducing the organic medium into. At this time, a suitable mixing device may be used in this step, for example, an impeller type stirrer and a device capable of heating the reactant.

The organic medium is kept warm during the dispersing of the resin mixture, which temperature can be freely selected in a range satisfying the following two conditions. In other words, the resin mixture may be high enough to have fluidity and low enough to prevent evaporation of the processing aid contained in the resin mixture. Accordingly, the dispersion process of the present invention is generally carried out at or near the glass transition temperature of the resin. Although the operating temperature varies depending on the type and amount of processing aid, a temperature in the range of about 30 ° C to 200 ° C is preferred. In addition, the operating temperature does not necessarily need to be equal to the dispersion temperature. The dispersing process continues until the mixture shows milky white, since milky white means that the resin composition is pulverized into small particles.

(C) The step of pulverizing the first resin composition by the temperature raising and shearing action in the organic medium to form the resin fine particles are as follows.

The shearing action causes the dispersed resin particles to be pulverized into fine particles, and the surfactant covers the surface of the crushed particles to prevent the pulverized particles from agglomerating back into larger particles. The grinding process into fine particles is continued until the size of the particles reaches an equilibrium value determined by the relative amount of the surfactant and the total resin. When the processing aid is added, the shear force applied in the present invention is significantly smaller than in the case where the processing aid is not used. If the impeller-type stirring device having a radius of 10 cm is stirred at a speed of 100 rpm, effective production is possible, and the process generally proceeds for about 30 minutes to 10 hours.

The step of vaporizing and removing the processing aid of the present invention takes place at a temperature higher than or similar to the boiling point of the processing aid. At this time, the processing aid is evaporated from the resin fine particles and removed from the reactor. This process can be done more efficiently if the processing aids do not mix with the organic medium. The removal step is stopped when the processing aid is no longer mixed with the vapor from the reactor.

The step of separating and recovering the prepared particulate resin composition of the present invention is performed while cooling the reactor to a temperature lower than the glass transition temperature of the resin composition. The solid particles are then filtered from the organic medium, and various suitable filtration devices can be used. After washing the filtered particles with an organic solvent having a low boiling point such as isohexane, the solvent is dried at a temperature lower than the glass transition temperature of the resin composition to obtain final dried particles.

The dispersing, particulate preparation and processing aid removal steps may be carried out discontinuously in the same reactor respectively or may be carried out in superimposition in one reactor.

The present invention will be described in more detail through the following examples. However, since the embodiments are only intended to illustrate the invention, the scope of the present invention should not be construed as limited to the examples.

Example 1 Preparation of Cationic Dyeable Polyesters by Melt Condensation

Cationic dyeable polyesters were prepared by melt condensation as follows. Dimethyl terephthalate (941g, 4,85mol), dimethyl isophthalate (970g, 5.0mol), dimethyl 5-sulfoiso in 10 liter glass reactor equipped with paddle type stirrer and 20cm fractional distillation column Sodium salt of phthalate (44.4 g, 0.15 mol) and 1,2-propylene glycol (1520 g, 20 mol) were packed. As a transesterification catalyst, 1.4 g of titanium tetra-isopropoxide and 5.0 g of IRGANOX 1010 (available from Clariant Corporation, East Hanover, NJ) were added. The reactants were filled at room temperature and purged with argon gas for about 1 hour. The reaction mixture was then heated to 150 ° C. while stirring at 50 rpm to make a uniform melt. The reaction mixture was then heated to 150 ° C. to 200 ° C. for 4 hours with argon gas flowing and maintained at 200 ° C. until about 340 mL of distillate came out.

The reaction mixture was then slowly heated to 210 ° C. for 30 minutes and held at this temperature for 1 hour with stirring at 50 rpm. Thereafter, the stirring speed was lowered to 30 rpm and the reactor was allowed to stand for about 1 hour in a vacuum of 0.5 Torr. Subsequently, the vacuum was released using argon gas and the reaction was cooled to about 150 ° C. After that, the reaction was poured into a glass plate and cooled to room temperature. About 2050 g of polyester resin was obtained.

The glass transition temperature of the polyester resin thus produced was 65 ° C. The number average molecular weight of this polyester resin was 5500, the weight average molecular weight was 11200, and the polydispersity was 1.2. The molecular weight was measured by gel permeation chromatography (GPC) using polystyrene as the standard molecular weight.

Example 2 Dispersion Atomization of Polyester Resin

A 1-1 round bottom flask equipped with a condensation column and a stirrer was charged with 300 g of polyester resin of Example 1 and 90 g of N, N-dimethylformamide. The contents were heated to 150 ° C. with reflux and held at this temperature for 20 minutes. When the mixture showed fluidity, 30 g of Bontron E-84 (commercially available from Orient Chemical Company, Springfield, NJ as charge regulator) was added and the stirrer was adjusted to 30 rpm. After raising the stirrer speed to 100rpm and maintained at this speed for 1 hour to completely mix the resin and the additives.

300g of ISOPAR®L 250g and ISOPAR®V (available from Exxon Chemical Company, Houston, TX as paraffin solvent) 1: 1 mixture and 30g Ganex V-220 (New Jersey as nonionic surfactant) Commercially available from ISP Corporation, Wayne, USA) was added to the flask. The contents turned milky white and were maintained at this temperature and stirring speed for 7 hours with partial reflux to the mounted column. The particle size was measured after collecting the resin particle sample. The resin particles had a volume average particle diameter of 4.5 microns and a span value of 0.9. After the contents were cooled to room temperature, 200 g of isohexane was added into the flask and stirred for 1 hour. The resin particles were then separated from the solution by filtration. The resin particles were dispersed again in isohexane and filtered twice. Finally, the resin particles were vacuum dried at 40 ° C. for 10 hours to obtain dried polyester particles.

The volume average particle diameter of the resin particles was 4.7 microns and the span value was 0.85 with a slight decrease. Examining the resin particles by SEM (scanning electron microscopy) method, it was found that the particles are all spherical in shape and have a rough surface.

Example 3 Dispersion Atomization of Polyester Resin Using Mixed Surfactant

In Example 2 a mixture of 24 g of Ganex V-220 and 6 g of Genapol 26-L-1 (commercially available from Clariant Corporation, Charlotte, NC, as a nonionic surfactant) was used instead of 30 g of Ganex V-220. Except that the polyester particle composition was prepared in the same manner as in Example 2.

The volume average particle diameter of the resin particles was 4.7 microns and the span value was 0.85 with a slight decrease. Examining the resin particles by the SEM method, it was found that the particles were all spherical and had a rough surface. The surface roughness index measured by the BET isothermal method was 2.0. This example shows that the size of the particles is related to the amount of surfactant used in the dispersion atomization process.

Example 4 Preparation of Resin Particle Compositions Having Small Average Particle Diameter Using Large Amount of Surfactant

A polyester particle composition was prepared in the same manner as in Example 2, except that 60 g of Ganex V-220 was used instead of 30 g of Ganex V-220 in Example 2. The volume average particle diameter of the resin particles was 3.5 microns and the span value was 0.6. Examining the resin particles by the SEM method, it was found that the particles were all spherical and had a rough surface. The surface roughness index measured by the BET isothermal method was 1.9.

Example 5 Preparation of Resin Particle Compositions Having Large Average Particle Diameter Using Small Amount of Surfactant

A polyester particle composition was prepared in the same manner as in Example 2, except that 15 g of Ganex V-220 was used instead of 30 g of Ganex V-220 in Example 2. The volume average particle diameter of the resin particles was 7.3 microns and the span value was 0.9. Examining the resin particles by the SEM method, it was found that the particles were all spherical and had a rough surface. The surface roughness index measured by the BET isothermal method was 2.1.

Example 6 Low Temperature Atomization Using Acetone as Processing Aid

A 1-1 round bottom flask equipped with a condensation column and a stirrer was filled with 300 g of polyester resin of Example 1 and 180 g of acetone. The contents were heated to 50 ° C. with full reflux and held at this temperature for 20 minutes. When the mixture showed fluidity, the stirrer was set to 50 rpm and held for one hour until the resin and additives were thoroughly mixed.

Subsequently, 300 g of ISOPAR®L and 250 g of ISOPAR®V 1: 1 mixture and 30 g of Ganex V-220 were added to the flask. After the contents changed to milky white, the temperature was increased to 65 ° C. and the stirring speed was increased to 300 rpm. Acetone was removed from the atomized polyester particles with partial reflux for 4 hours in a column mounted at this temperature and stirring speed. After the contents were cooled to room temperature, 200 g of isohexane was added into the flask and stirred for 1 hour. The resin particles were then separated from the solution by filtration. The resin particles were dispersed again in isohexane and filtered twice. Finally, the resin particles were vacuum dried at 40 ° C. for 16 hours to obtain dried polyester particles.

The volume average particle diameter of the resin particles was 4.7 micron and the span value was 0.6. Examining the resin particles by the SEM method, it was found that the particles were all spherical and had a rough surface. The surface roughness index measured by the BET isothermal method was 2.0.

Example 7 Atomization Without Processing Aid

A polyester particle composition was prepared in the same manner as in Example 2, except that N, N-dimethylformamide, which was a processing aid, was not used in Example 2. The volume average particle diameter of the resin particles was 5.3 microns and the span value was 2.1. Examination of the resin particles by the SEM method showed that the particles were all spherical and had a smooth surface. The surface roughness index measured by the BET isothermal method was 1.1.

Example 8 Preparation of Styrene / acrylate Copolymer Resins with Acidic Functional Groups

A 2-1 round bottom flask equipped with a condensation column and a stirrer was charged with 738 g of polystyrene resin, 180 g of N-butyl acrylate, 39 g of acrylic acid, and 45 g of 2,2-azobisisobutyl nitryl. The mixture was blown with argon gas for 30 minutes to foam. The temperature was then increased to 69 ° C. while stirring the mixture at 50 rpm. The polymerization was carried out under reflux for 16 hours under argon gas.

After cooling the dispersion to room temperature, the resin particles were separated. The resin particles were then washed three times with a mixture of 80 wt% methanol and 20 wt% water. Then, vacuum drying at 15 ° C. for 16 hours yielded about 700 g of a polymer resin.

This polymer had a number average molecular weight of 16,000 and a weight average molecular weight of 53,000 and a glass transition temperature of 62 ° C.

Example 9 Atomization of Styrene / Acrylate Copolymer Resins with Acidic Functional Groups

In a round bottom flask equipped with a condenser and an impeller type stirrer, 150 g of styrene-acrylate copolymer resin having an acidic functional group of Example 8 and 90 g of tetrahydrofuran were charged as a processing aid at room temperature. The contents were heated to 50 ° C. while stirring to mix the contents and at full reflux. After the mixture showed sufficient fluidity, the resin mixture was held at this temperature for 60 minutes with stirring at 50 rpm.

Next, 150 g of polyethylene oxide as an unmixed solvent and 7.5 g of sodium dodecyl sulfate as a surfactant were filled into a flask containing a resin composition which was stirred at 50 ° C. After filling, the stirring speed was raised to 100 rpm at the same temperature to maintain the mixture under increased shear force. After about 10 minutes the condenser was set to partial reflux as the mixture turned milky. After applying shear force at 50 ° C. for 2 hours, the temperature of the flask contents was raised to 80 ° C. in order to promote evaporation of tetrahydrofuran. The contents were kept under shear force until no tetrahydrofuran appeared in the evaporate. After that, the dispersion was cooled to room temperature. The atomized resin particles were separated from the solvent by filtration. The organic medium contained in the filter cake was washed three times by dispersing the filter cake in water and filtering again. The filtered particles were vacuum dried at 60 ° C. for 10 hours to obtain dried resin particles.

The volume average particle diameter of the resin particles thus obtained was 6.8 micron and the span value was 0.7. Examination of the resin particles by the SEM method showed that the particles were all spherical and had a rough surface. The surface roughness index measured by the BET isothermal method was 2.2.

The particulate resin composition prepared according to the present invention is useful for producing a toner for developing electrostatic latent images through a coloring process. The particulate resin composition for preparing toner of the present invention can be manufactured at low temperature, and may use a polymer resin having a high molecular weight, and because of the roughness of the surface, the charging property is excellent, and thus there is an advantage suitable for producing a high resolution toner.

Claims (36)

a) preparing a resin mixture in a molten state comprising a resin having a functional group suitable for interacting with the dye, a processing aid, and optionally a charge control agent, b) dispersing the resin mixture in the presence of a surfactant in an organic medium insoluble in the resin, c) grinding the resin mixture into fine particles of resin by heating and shearing in the organic medium; d) vaporizing and removing the processing aid by heating the pulverized resin particulate dispersion; e) separating and recovering the particulate resin composition from the organic medium, The particulate resin composition is spherical in shape, has a volume average particle diameter of 1 to 10 µm, and a span value of 1.0 or less. delete The method of claim 1, The volume average particle diameter is 3 to 8 microns, the method for producing a particulate resin composition. The method of claim 1, Said span value is 0.8, The manufacturing method of the fine particle resin composition characterized by the above-mentioned. The method of claim 1, The particulate resin composition has a rough surface structure, and a roughness index defined by the ratio of the surface area of the rough surface tissue particles to the surface area of the smooth surface tissue particles is 1.2 or more. . delete delete The method of claim 1, The resin component suitable for interacting with a dye having a functional group is selected from polyester resins and styrene copolymer resins, Suitable functional groups for interacting with the dyes of the resin component are hydroxyl groups, alkoxy groups, sulfonic or sulfonic derivative groups, sulfonic or sulfonic derivative groups, carboxyl or carboxyl derivatives, phosphonic or phosphoric derivative groups, A method for producing a particulate resin composition, characterized in that it is selected from the group consisting of phosphonic or phosphonic derivative groups, thiol groups, amine groups, alkylamine groups, quaternary amine groups and mixtures thereof. The method of claim 1, The resin component suitable for interacting with a dye having a functional group is selected from polyester resins and styrene copolymer resins, The resin component is an amorphous resin, has a glass transition temperature of 40 ° C to 90 ° C, and has a weight molecular weight in the range of 3,000 g / mol to 100,000 g / mol. The method of claim 1, The boiling point of the said processing aid is 200 degrees C or less, The manufacturing method of the particulate-resin composition characterized by the above-mentioned. It is an organic solvent which can melt | dissolve the said polymer resin in 1 g or more of solubility. delete delete The method of claim 1, The processing aid is kneaded in an amount of 5 to 200% by weight of the polymer resin. The method of claim 13, The processing aid is kneaded in an amount of 10 to 100% by weight of the polymer resin. delete delete The method of claim 1, Dispersing the resin mixture in the organic medium is prepared by introducing the resin mixture while stirring the organic medium while maintaining a temperature higher than the flow temperature of the resin mixture. Way. The method of claim 1, And dispersing the resin mixture in the organic medium is carried out by introducing the organic medium into the container while stirring the container containing the resin mixture. The method of claim 1, The solubility index of the organic solvent component in the said organic medium differs by 1 or more from the solubility index of the resin component. The method of claim 19, The solubility index of the organic solvent component in the said organic medium differs by 2 or more from the solubility index of the resin component. The method of claim 1, The organic medium is composed of a paraffin solvent. The method of claim 1, A method for producing a particulate resin composition, wherein the organic medium is composed of polyethylene glycol. The method of claim 1, The surfactant is selected from nonionic, cationic or anionic surfactants, The surfactant is selected from the group consisting of copolymers of vinylpyrrolidinone, maleic acid copolymers having alkyl groups, polymers containing ethylene oxide residues, polymers containing propylene oxide residues and sodium dodecyl sulfate. The manufacturing method of the fine particle resin composition made into. delete The method of claim 1, Wherein said organic medium comprises an organic solvent and a surfactant and is present in an amount of from 0.2 to 15% by weight of the amount of solvent in which said surfactant is present. The method of claim 25, The surfactant is present in the amount of 1 to 10% by weight of the amount of the organic solvent present. The method of claim 1, And in the step of pulverizing the resin mixture into fine particles, the resin mixture is present in an amount of 10 to 70% by weight of the mixed weight of the resin mixture and the organic medium. The method of claim 27, And in the step of pulverizing the resin mixture into fine particles, the resin mixture is present in an amount of 20 to 50% by weight of the mixed weight of the resin mixture and the organic medium. The method of claim 1, Pulverizing the resin mixture into fine particles, wherein the resin mixture is stirred in a temperature of 30 ° C. to 200 ° C. in the organic medium. delete delete delete The method of claim 1, Preparing the resin mixture, dispersing the resin mixture, pulverizing the resin dispersion into fine particles, and removing the processing aid from the dispersion liquid in a superimposed manner in a single device. Method for producing a resin composition. After preparing a molten resin mixture comprising a resin having a functional group suitable for interacting with the dye, a processing aid, and optionally a charge control agent, the resin mixture is added to an organic medium insoluble to the resin. And disperse the resin mixture into fine particles by heating and shearing in the organic medium, and then warming the dispersed fine resin dispersion to evaporate and remove the processing aid from the organic medium. A particulate resin composition prepared by a method of separating and recovering a particulate resin composition, i) the shape of the particles is spherical, ii) the volume average diameter of the particles is in the range of 1 to 10 μm, i) the span value is 1.0 or less, and i) the weight average molecular weight of the resin component is 100,000 g / mol or less. A particulate resin composition for producing a latent electrostatic latent image developing toner. The method of claim 34, wherein A particulate resin composition for producing an electrostatic latent image toner, wherein the roughness index defined by the ratio of the surface area of the rough surface tissue particles to the surface area of the smooth surface tissue particles is 1.2 or more. The method of claim 34, wherein The particulate resin composition, wherein the resin is a polyester resin or a styrene copolymer.