JP2007065630A - Method for manufacturing image-forming particles, and the image-forming particles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily manufacture image-forming particles having an always stable volume average grain size and a sharp grain size distribution without waste, and to provide the image forming particles suitable for a fixing device capable of achieving energy saving and capable of forming high-definition images with developability that is satisfactory over a long period, and to provide a method for manufacturing the same. <P>SOLUTION: The method comprises manufacturing the image forming particles by dissolving or dispersing a polymer and a colorant into at least an organic solvent to obtain an organic solvent liquid and subjecting the organic solvent liquid to dispersion in an aqueous medium, to obtain an aqueous dispersion liquid containing the liquid drops of the organic solvent, then removing the organic solvent from the aqueous dispersion liquid, thence subjecting the liquid to washing and drying, in which the dispersion of the organic solvent liquid in the aqueous medium is continuous, and the aqueous dispersion liquid discharged after the dispersion is stored under stirring, until the liquid is subjected to the removal of at least the organic solvent; and the liquid does not again undergo the dispersion process. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention uses a method for producing image-forming particles, an image-forming particle, an image-forming particle container, and the image-forming particles that visualize an electrostatic charge image formed on the surface of a photoreceptor in electrophotography and electrostatic recording. The present invention relates to an image forming apparatus and a process cartridge.

  In an electrophotographic apparatus, an electrostatic recording apparatus, or the like, an electrical or magnetic latent image is visualized with toner. For example, in electrophotography, an electrostatic charge image (latent image) is formed on a photoreceptor, and then the latent image is developed with toner to form a toner image. The toner image is usually transferred onto a transfer material such as paper and then fixed by a method such as heating. The toner used for electrostatic image development is generally colored particles in which a binder, a colorant, a charge control agent, and other additives are contained in a binder resin, and its production method is a pulverization method (thermoplastic resin). The colorant, charge control agent, anti-offset agent, and the like are melt-mixed therein and uniformly dispersed, and the resulting composition is pulverized and classified). According to the pulverization method, a toner having some excellent characteristics can be produced, but there is a limitation in the selection of the toner material. For example, the composition obtained by melt mixing must be capable of being pulverized and classified by economically usable equipment. From this requirement, the melt-mixed composition must be made sufficiently brittle. Therefore, when the above composition is actually pulverized into particles, a high-range particle size distribution is likely to be formed, and when attempting to obtain a copy image with good resolution and gradation, for example, the particle size There is a disadvantage that the fine powder of 5 μm or less and the coarse powder of 20 μm or more must be removed by classification, resulting in a very low yield. Further, considering the average particle size in the toner particle size distribution from the viewpoint of yield, productivity and cost, it is a very big problem for the pulverized toner to make the particle size small, particularly 6 μm or less. In addition, the chargeability of the irregular shaped toner prepared by pulverization is different for each toner particle because the adhesion area to the developing roll in a one-component developer and the adhesion area to a carrier in a two-component developer are different for each toner particle. The adhesion to the carrier is different and the ease of development is also different. Since toners having different particle diameters have different charge amounts, the ease of development is also different. Due to these differences, easily developable toner is selectively developed, and difficultly developed toner remains in the developing device, and developability changes with time.

  Similarly, when transferring to recording paper, there are toners that are easily transferred and toners that are difficult to transfer, and therefore image quality deterioration such as toner scattering is likely to occur. Further, when a toner is produced by internally adding a release agent such as wax, the release agent may be exposed on the toner surface by combination with a thermoplastic resin. In particular, in a combination of a resin imparted with elasticity by a high molecular weight component and slightly pulverized resin and a brittle wax such as polypropylene, the exposure of the wax is often observed on the toner surface. The exposure of the release agent is advantageous for releasability at the time of fixing and cleaning of the toner remaining on the photoconductor after transfer, but since the fluidizing agent on the toner surface is easily moved by mechanical force, This easily causes wax contamination of the photoreceptor and carrier, leading to a decrease in reliability of the image forming apparatus.

  In recent years, suspension polymerization methods (Patent Documents 1 and 2) and emulsion polymerization methods (Patent Document 3) have been proposed in order to overcome the problems in these pulverization methods. However, the toner particles obtained by the suspension polymerization method have a problem that the low-temperature fixability is insufficient and the energy required for fixing increases. This problem is particularly noticeable with full-color toners. Further, since the viscosity difference between the release material and the monomer is large and incompatible, it is very difficult to finely disperse at this stage. As a result, a large number of particles in which the wax is not present in the resin are generated, causing uneven distribution between the toner particles and causing a problem of unstable toner charging. In addition, the toner particles obtained by the emulsion polymerization method have a large amount of surfactant remaining not only on the surface but also inside the particles even after a water washing step, impairing the environmental stability of toner charging, and charging. The amount distribution is widened, and the background stain of the obtained image becomes poor. In addition, the remaining surfactant contaminates the photoconductor, the charging roller, the developing roller, and the like, so that the original charging ability cannot be exhibited.

  Also, a method for producing toner particles by dispersing and suspending a toner composition mixed solution obtained by dissolving / dispersing a toner composition in an organic solvent in an aqueous medium has been proposed (Patent Document 4). A toner having sufficient properties cannot be obtained. This is because a high molecular weight resin for exhibiting hot offset resistance has a limit in dissolving in an organic solvent, and it is very difficult to form a fine dispersion.

  As a method for solving the above problems, an aqueous medium is obtained by dispersing an organic solvent containing active hydrogen and a modified polyester resin capable of reacting with active hydrogen groups in a binder resin in the form of droplets in the aqueous medium. Among them, methods for granulating toner particles (Patent Documents 5 and 6) have been proposed. With this method, it is possible to obtain a low-temperature fixing / charge-stable toner that is free from the problems in the polymerization method described above.

  However, toner produced by the toner particle granulation method has disadvantages in terms of productivity. That is, although the uniform droplet diameter is maintained immediately after dispersion of the organic solvent in the aqueous medium, the particle stability is lower than in the case of other polymerization toners. For example, a method commonly used for dispersion of polymerization methods, “a method of storing droplets and granulating droplets with a good particle size distribution by circulating a part of the dispersion through a high-speed stirrer” ( If Patent Document 7: FIG. 1) is applied to the toner particle granulation method, the particles tend to start to coalesce and aggregate while the dispersion is stored or while flowing through the piping. It can be seen. Further, once coalesced and aggregated particles cannot be easily dispersed even if a shearing force is applied later, even if dispersed, particles having a narrow particle size distribution cannot be obtained.

This phenomenon is not seen with known polymerization / granulation dispersions. The reason why such a phenomenon occurs is not clear at present, but other polymerization methods / structures are produced when the organic solvent phase containing the modified polyester capable of reacting with active hydrogen is dispersed in an aqueous medium. It is thought that this is because the viscosity increases so rapidly as to be incomparable with the grain method (particularly in the initial stage of dispersion).
That is, in the toner particle granulation method, it is necessary to apply a shearing force required for a short time to the dispersion, and in that respect, the batch system can be said to be a very effective production facility. However, the batch type is difficult to maintain uniformity when the production scale is increased, and it cannot be said that the production efficiency is good.

JP-A-8-44111 JP-A-8-286416 Japanese Patent No. 2537503 JP 2001-255695 A Japanese Patent Laid-Open No. 11-133665 JP-A-11-133666 JP 2001-356523 A

  Accordingly, the object of the present invention is to easily and efficiently produce image-forming particles having a stable volume average particle size and a sharp particle size distribution in view of the current problems as described above. It is an object of the present invention to provide an image forming particle suitable for a fixing device capable of achieving a high resolution, capable of forming a high-quality image with good developability in the long term, and a method for producing the same.

  As a result of intensive studies by the present inventors to solve such problems, at least a polymer and a colorant are dissolved or dispersed in an organic solvent, and the organic solvent liquid is dispersed in an aqueous medium. In the method of producing an image-forming particle by removing the organic solvent from the aqueous dispersion, washing and drying after obtaining an aqueous dispersion containing droplets of the organic solvent in the aqueous medium The dispersion of the organic solvent liquid is continuous, and the aqueous dispersion discharged by the dispersion is stored while being stirred at least until it is subjected to the removal of the organic solvent, and does not enter the dispersion step again. However, it has been found that granulation having a sharp particle size distribution can be efficiently produced.

  Dispersion of the organic solvent liquid in the aqueous medium is continuous, and the aqueous dispersion discharged by the dispersion does not enter the dispersion step again. It is possible to control the shearing force applied to the water-based dispersion liquid at the periphery so that the distribution becomes small. In the method in which the aqueous dispersion is stored and a part of the aqueous dispersion is circulated through a high-speed stirrer, the shear force applied to the aqueous dispersion per unit time for a relatively long time can be controlled. The shearing force applied to the aqueous dispersion per unit time in time will vary. As a result, image forming particles (typically toner) caused by coalescence of the droplets of the organic solvent liquid and aggregation of the polymer contained in the organic solvent liquid, which are not seen in general polymerization toners. This leads to disturbance of the particle size distribution and instability of granulation.

  As one of the methods for embodying the image forming particle manufacturing method based on the above knowledge, a non-release tank type container having at least two openings and a disperser capable of applying a high shear force is prepared. To do. Then, the organic solvent in which the polymer and the colorant are dissolved or dispersed and the aqueous medium are allowed to flow into the container from at least one opening, and the container is uniformly distributed using a disperser capable of applying a high shearing force. It can be dispersed.

  Furthermore, the tank-type container is formed in a tank whose interior is at least partially divided into two or more areas, and the divided areas of the tank are openings that allow the dispersion to flow in one direction. If they are communicated with each other, short paths are less likely to occur, and the shearing force applied to the dispersion per unit time can be made more uniform.

The polymer contains a modified polyester (i) having a site capable of reacting with a compound having an active hydrogen group, and the organic solvent liquid may contain a compound having an active hydrogen group. desirable. The active hydrogen group-containing compound and the polyester having a site capable of reacting with the active hydrogen group-containing compound are reacted in the aqueous medium to produce a resin component (polymer), whereby image-forming particles are in the form of particles. Is obtained. The obtained image-forming particles are easy to adjust the molecular weight of the polymer component, and as a result, are excellent in low-temperature fixability, releasability and blocking resistance.

Further, the polymer contains a polyester resin (ii) that is not modified together with the modified polyester resin (i), and the weight ratio ((i) / (ii) of the resin (i) to the resin (ii). )) Of 5/95 to 25/75, the adhesiveness to the fixing heating medium can be suppressed while maintaining high fluidity and transparency in the fixing temperature range.
In addition, it is desirable that the step of removing the solvent of the dispersion is performed at least under reduced pressure and / or heating conditions. Thereby, a solvent removal process is performed efficiently.
The present invention has been found and the present invention has been completed.

That is, the above-mentioned problem is (1) of the present invention “at least, a polymer and a colorant are dissolved or dispersed in an organic solvent to obtain an organic solvent liquid, and the organic solvent liquid is dispersed in an aqueous medium. In the method of producing an image-forming particle by removing the organic solvent from the aqueous dispersion, washing and drying after obtaining an aqueous dispersion containing organic solvent droplets in the aqueous medium The dispersion of the organic solvent liquid in is continuous, and the aqueous dispersion discharged after the dispersion is stored while being stirred at least until it is subjected to the removal of the organic solvent, and again enters the dispersion step. A process for producing image-forming particles characterized by having no ",
(2) “Dispersion of the organic solvent liquid in the aqueous medium is performed in a tank whose interior is at least partially divided into two or more regions. The method for producing image-forming particles as described in (1) above, characterized in that there is a disperser that communicates with an opening that can flow and that performs the dispersion step in at least one region.
(3) “The polymer contains a modified polyester (i) having a site capable of reacting with a compound having an active hydrogen group, and the organic solvent liquid contains a compound having an active hydrogen group. The method for producing image-forming particles according to item (1) or (2), wherein:
(4) “The polymer contains the unmodified polyester resin (ii) together with the modified polyester resin (i), and the weight ratio of the resin (i) to the resin (ii) ((i) / (Ii)) is 5/95 to 25/75, wherein the method for producing image-forming particles according to item (3),
(5) The method according to any one of (1) to (4), wherein the step of removing the organic solvent from the aqueous dispersion is performed at least under reduced pressure and / or heating conditions. This is achieved by the “method for producing image-forming particles”.
In addition, the above-described object is achieved by (6) “image-forming particles produced by the production method according to any one of items (1) to (5)” of the present invention.
In addition, the above-mentioned problem is solved by (7) “image-forming particle container filled with image-forming particles produced by the production method according to any one of (1) to (5)” of the present invention. Achieved.
In addition, the above-mentioned problem is achieved by using the image-forming particles produced by the manufacturing method according to any one of (8) and “(1) to (5)” of the present invention. apparatus",
(9) A heating body including a heating element, a film in contact with the heating body, and a pressure member in pressure contact with the heating body through the film, and between the film and the pressure member The image forming apparatus according to item (8), further comprising a fixing unit that heats and fixes a recording material on which an unfixed image is formed,
(10) An image forming apparatus according to item (8), which has an image carrier, and an alternating electric field is applied when developing a latent image on the image carrier. Is done.
In addition, the above-described problem may be solved by the image forming apparatus according to (11) of the present invention, “having the image carrier and the developing unit, and integrally supporting at least one unit selected from the charging unit and the cleaning unit. In the process cartridge which is detachably attached to the main body, the developing means holds image forming particles, and the image forming particles are produced by the manufacturing method according to any one of the items (1) to (5). This is achieved by a process cartridge characterized by being image-forming particles.

According to the present invention, when the organic solvent liquid in which at least the polymer and the colorant are dissolved or dispersed is dispersed in the aqueous medium, the dispersion of the organic solvent liquid in the aqueous medium is continuous, and The aqueous dispersion discharged by the dispersion is stored while being stirred at least until it is subjected to the removal of the organic solvent, and by not entering the dispersion step again, the organic solvent droplets are coalesced. Can prevent coalescence and aggregation of the generated toner particles, and can efficiently produce image-forming particles having a sharp particle size distribution,
Further, the active hydrogen group-containing compound in the organic solvent liquid and a polymer having a site capable of reacting with the active hydrogen group are reacted in the aqueous medium to produce a resin component, and the molecular weight of the polymer component It is possible to obtain image-forming particles that are easy to adjust. In addition, although it is a continuous type, the shearing force applied to the dispersion per unit time for a short time can be controlled to reduce the distribution, resulting in low-temperature fixability, releasability, and blocking resistance. Image forming particles having a stable volume average particle diameter and a sharp particle size distribution can be produced stably and continuously. It is carried out in a tank that is at least partially divided into two or more areas, the divided areas of the tank communicate with each other through an opening through which the dispersion can flow in one direction, and at least one area When there is a disperser responsible for the dispersion process in the aqueous medium, short-passing is reduced, and the shearing force applied to the dispersion per unit time can be made more uniform, and as a result always stable Image forming particles having a high volume average particle diameter and a sharp particle size distribution can be produced more stably and continuously, and the image forming particles containing a polyester resin are obtained. From the above, while maintaining high fluidity and transparency in the fixing temperature range, it is possible to suppress adhesion to the fixing heating medium, and the polymer, together with the modified polyester resin (i), Containing a non-modified polyester resin (ii) and having a weight ratio of (i) to (ii) of 5/95 to 25/75, high fluidity and transparency in the fixing temperature range; Image forming particles having well-balanced properties satisfying the respective adhesive properties to the heating medium for fixing are obtained, and the step of removing the solvent of the particle-containing solution or dispersion includes at least reduced pressure and / or heating. conditions Be performed by, it is possible to efficiently perform the solvent removal step, exhibits an extremely excellent effect that contributes to the improvement production efficiency.
Further, the image forming particles produced by the production method of the present invention can be expected to improve the performance and productivity of the image forming particles.

  That is, as is clear from the following detailed and specific description, according to the present invention, it is possible to easily and easily produce image-forming particles having a stable volume average particle size and a sharp particle size distribution, and as a result, Suitable for a fixing device capable of achieving energy saving, and having an extremely excellent effect of providing image forming particles capable of forming a high-quality image with good developability in the long term and a method for producing the same. It is.

The present invention is described in detail below.
(Urea-modified polyester)
In the present invention, the image-forming particle (toner) binder resin was obtained by reacting a polyester resin capable of reacting with active hydrogen groups with a crosslinking agent and / or an extender (compound containing active hydrogen groups). Modified polyester resin (i) is preferable, and modified polyester resin (i) is preferably polyester (i) modified with a urea bond.
Examples of the polyester (i) modified with a urea bond include a reaction product of a polyester prepolymer (A) having an isocyanate group and an amine (B). Examples of the polyester prepolymer (A) having an isocyanate group include a polycondensate of a polyol (1) and a polycarboxylic acid (2) and a polyester having an active hydrogen group further reacted with a polyisocyanate (3). Can be mentioned. Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred.

  Examples of the polyol (1) include a diol (1-1) and a tri- or higher valent polyol (1-2). (1-1) alone or (1-1) and a small amount of (1-2) Mixtures are preferred. Diol (1-1) includes alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide phenol compound (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyol (1-2) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2). (2-1) alone and (2-1) with a small amount of ( The mixture of 2-2) is preferred. Dicarboxylic acid (2-1) includes alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, and the like). In addition, as polycarboxylic acid (2), you may make it react with polyol (1) using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.

  The ratio of the polyol (1) to the polycarboxylic acid (2) is usually 2/1 to 1/1, preferably 1. as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 5/1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  Examples of the polyisocyanate (3) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; polyisocyanates such as phenol derivatives, oximes, caprolactams, etc. And a combination of two or more of these.

  The ratio of the polyisocyanate (3) is usually 5/1 to 1/1, preferably 4 /, as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester will be low, and the hot offset resistance will deteriorate. The content of the polyisocyanate (3) component in the prepolymer (A) having an isocyanate group at the terminal is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.

  The number of isocyanate groups contained per molecule in the prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

  As amines (B), diamine (B1), triamine or higher polyamine (B2), amino alcohol (B3), amino mercaptan (B4), amino acid (B5), and amino groups of (B1) to (B5) (B6) etc. that are blocked. Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine etc.) and the like. Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. As (B6) which blocked the amino group of (B1) to (B5), ketimine compounds obtained from the amines and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) of (B1) to (B5), Examples include oxazoline compounds. Among these amines (B), preferred are (B1) and a mixture of (B1) and a small amount of (B2). Moreover, amines (B) can be used as a crosslinking agent and an extender.

Furthermore, if necessary, the molecular weight of the urea-modified polyester can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
The ratio of amines (B) is the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). The ratio is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] exceeds 2 or less than 1/2, the molecular weight of the urea-modified polyester (i) becomes low, and the hot offset resistance deteriorates. In the present invention, the polyester (i) modified with a urea bond may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

  The urea-modified polyester (i) of the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the urea-modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.

(Unmodified polyester)
In the present invention, not only the polyester (i) modified with a urea bond but also the polyester (ii) not modified can be included as a toner binder component together with the (i). By using (ii) in combination, the low-temperature fixability and glossiness when used in a full-color apparatus are improved, which is preferable to single use. Examples of (ii) include the same polycondensates of polyol (1) and polycarboxylic acid (2) as in the polyester component (i) above, and preferred ones are also the same as (i). (Ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example. It is preferable that (i) and (ii) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the weight ratio of (i) to (ii) is usually 5/95 to 25/75, preferably 8/92 to 25/75, particularly preferably 8/92 to 22/78. is there. When the weight ratio of (i) is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.
Moreover, the peak molecular weight of (ii) is 1000-30000 normally, Preferably it is 1500-10000, More preferably, it is 2000-8000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate.

In the present invention, the glass transition point (Tg) of the image-forming particles is usually 40 to 70 ° C., preferably 50 to 65 ° C. If it is less than 40 ° C., the heat-resistant storage stability of the image-forming particles deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of the urea-modified polyester resin, the image-forming particles of the present invention tend to have good heat-resistant storage stability even when the glass transition point is low, as compared with known polyester toners. As the storage elastic modulus of the image-forming particles, the temperature (TG ′) at which 10000 dyne / cm ² is obtained at a measurement frequency of 20 Hz is usually 100 ° C. or higher, preferably 110 to 200 ° C. If it is less than 100 ° C., the resistance to hot offset deteriorates. As the viscosity of the image-forming particles, the temperature (Tη) at 1000 poise at a measurement frequency of 20 Hz is usually 180 ° C. or lower, preferably 80 to 160 ° C. If it exceeds 180 ° C., the low-temperature fixability deteriorates. That is, from the viewpoint of achieving both low-temperature fixability and hot offset resistance, (TG ′) is preferably higher than (Tη). In other words, the difference between (TG ′) and (Tη) ((TG ′) − (Tη)) is preferably 0 ° C. or more. More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more. The upper limit of the difference is not particularly limited. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between (Tη) and (TG) is preferably 0 to 100 ° C. More preferably, it is 10-90 degreeC, Most preferably, it is 20-80 degreeC. Further, it is important that the outflow start temperature (Tfb) as the image-forming particles after the reaction is 80 to 170 ° C. as a condition that the image-forming particles can obtain both low-temperature fixability and offset resistance.

(Dv / Dn (ratio of volume average particle diameter / number average particle diameter))
In the present invention, the volume average particle diameter (Dv) of the image forming particles is preferably 3 to 7 μm, and the ratio (Dv / Dn) to the number average particle diameter (Dn) is preferably 1.25 or less, more preferably 1. With image forming particles of 05 to 1.20, it is excellent in all of heat-resistant storage stability, low-temperature fixability, and hot offset resistance, especially when used in a full-color copying machine, etc. In the developer, even if the image forming particle balance is performed over a long period of time, the fluctuation of the image forming particle diameter in the developer is reduced, and good and stable developability can be obtained even with long-term stirring in the developing device. . In addition, even when used as a one-component developer, even if the balance of the image forming particles is performed, the fluctuation of the image forming particle diameter is reduced, and the filming of the image forming particles on the developing roller and the image forming particles are reduced. The image forming particles were not fused to a member such as a blade for thinning the film, and good and stable developability and images were obtained even in the long-term use (stirring) of the developing device.

In general, it is said that the smaller the particle diameter of the image-forming particles, the more advantageous it is to obtain a high-resolution and high-quality image. It is disadvantageous. Further, when the volume average particle diameter is smaller than the range of the present invention, in the two-component developer, the image-forming particles are fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier is reduced. When used as a component developer, filming of image forming particles to the developing roller and fusing of image forming particles to a member such as a blade for thinning the image forming particles are likely to occur.
Further, these phenomena are the same for image forming particles having a fine powder content higher than the above range of the present invention.

Conversely, when the particle diameter of the image-forming particles is larger than the above range of the present invention, it becomes difficult to obtain a high-resolution and high-quality image, and the balance of the image-forming particles in the developer is performed. In many cases, the variation in the particle diameter of the image-forming particles increases. It was also clarified that the same is true when the volume average particle diameter / number average particle diameter (Dv / Dn) is larger than 1.25.
In addition, when the volume average particle size / number average particle size (Dv / Dn) is smaller than 1.05, there are preferable aspects from the viewpoint of stabilizing the behavior of the image forming particles and uniforming the charge amount. In some cases, the formed particles cannot be sufficiently charged or the cleaning property is deteriorated.

(Image forming particle shape)
In the present invention, it is necessary that at least the image-forming particles have a circularity of 0.92 to 0.99 and have spherical surfaces having a plurality of depressions on the surface. If it is less than 0.92, the transferability and image quality are adversely affected, and if it exceeds 0.99, the cleaning property is deteriorated. Preferably, the circularity of the image-forming particles that sufficiently satisfy transferability, image quality, and cleaning properties is set to 0.94 to 0.97. Further, when the plurality of indentations on the surface of the image forming particle are measured with a scanning electron microscope (SEM image), the major axis of the indentation is ½ or less of the particle diameter of the image forming particle, and the major axis of the indentation on the particle surface is 1. It is desired that the depth is 0.0 to 5.0 μm, and the depth of the indentation is at least 1/10 or more, preferably 1/8 or more of the major axis. Such image-forming particles have a plurality of dents on the surface to compensate for the difficulty of cleaning the spherical shape, and improve transferability and stability of charging as compared with the irregular-shaped image-forming particles. In general, particles on irregularities made by pulverized toner or emulsion polymerization tend to accumulate silica in the recesses to improve fluidity, and when the additives are stirred and mixed with a high-speed mixer, the silica is fixed. Although the silica fine particles are difficult to fix and the silica particles are liberated and the photoconductor is contaminated or adheres to the carrier, the dents on the surface of the image-forming particles this time are gently concave and the major axis is 1 μm or more. This is presumed to be the reason why the accumulation and movement of the additive silica and the liberation in the immobilization of the silica, which were likely to be a problem in the past, do not occur.

(Both fixing and transparency / gloss)
In addition to heat-resistant storage stability, low-temperature fixability, and offset resistance, image forming particles are required to have characteristics such as color reproducibility, transparency, and glossiness, particularly for full-color toners. As a general method for achieving both low-temperature fixability and offset resistance, for example, a method using a binder resin having a wide molecular weight distribution, a high molecular weight component having a molecular weight of hundreds of thousands to several million, and a molecular weight of There is a method in which a resin having at least two molecular weight peaks of thousands to tens of thousands of low molecular weight components is mixed and used, and the mechanism of each component is separated. When the high molecular weight component has a cross-linked structure or is in a gel state, it is more effective for hot offset.
On the other hand, in order to achieve transparency, glossiness, etc., it is preferable that the molecular weight is as small as possible and the molecular weight distribution is sharp, and it is difficult to achieve both of these contradictory characteristics only by the above method. .

In the molecular weight distribution of the THF-soluble component of the polyester resin contained in the image-forming particles, the image-forming particles of the present invention have a molecular weight peak of 1000 to 30000, 30000 or more components of 1 wt% or more, and a number average Since the molecular weight is 2000 to 15000, both low-temperature fixability and offset resistance are achieved. The reason why the content of the high molecular weight component is relatively small is that the modified group in the modified polyester (part of the bonded group other than the ester bond) has a strong cohesive force such as a hydrogen bond. Resin properties that cannot be controlled by molecular weight or degree of crosslinking can be controlled by the cohesive force of the modifying group.
Further, in the molecular weight distribution of the THF-soluble component of the polyester-based resin contained in the image-forming particles, it is preferable that the component having a molecular weight of 1000 or less is 0.1 to 5.0 wt%. When the component having a molecular weight of 1,000 or less is 5.0 wt% or more, it is not preferable for the offset property. If the component having a molecular weight of 1000 or less is 0.1 wt% or less, the cost increases due to problems in the production of raw materials and the manufacturing process.
Furthermore, when the THF-insoluble content of the high molecular weight component that is effective for hot offset, that is, the polyester resin contained in the image forming particles is 1 to 15 wt%, the transparency and glossiness are not hindered. Sufficient offset resistance can be imparted.

(Fine particles)
In the present invention, in order to obtain an image-forming particle size in which the chargeability and particle size distribution of the image-forming particles are uniform, fine particles may be dispersed in an aqueous medium in which the image-forming particle composition is dispersed. The fine particles are present in a solid state hardly soluble in water in an aqueous medium, and those having an average particle size of 0.01 to 1 μm are preferable.

Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. More preferably, tricalcium phosphate, calcium carbonate, colloidal titanium oxide, colloidal silica, hydroxyapatite and the like can also be used. In particular, hydroxyapatite synthesized by reacting sodium phosphate and calcium chloride in water under a basic condition is preferable. In addition, organic fine particles include microcrystals of low molecular weight organic compounds.
The relationship between the fine particles and the size of the fine particles fixed on the surface thereof is as follows. When the particle diameter of the image forming particles is R and the particle diameter of the fine particles is Rs, at least the relationship between the two satisfies 5 ≦ R / Rs ≦ 2000. Preferably, it is desirable that 20 ≦ R / Rs ≦ 200 is satisfied. It has been found that when the relationship between the two is out of this range, the effect of controlling the particle size by the fine particles is remarkably reduced. The amount of fine particles to be fixed on the surface of the resin particles should be selected in accordance with the purpose within the range of 0.1 to 20 wt%, preferably 1 to 10 wt% with respect to the resin particles.

From the viewpoint of particle size control, at least resin fine particles satisfying 5 ≦ Dv ≦ 500, desirably resin fine particles satisfying 50 ≦ Dv ≦ 200 (volume average particle size: Dv [nm]) are desirable. In order to control the particle size, it is required that the particle size distribution of the added fine particles should be narrow (Dv / Dn of resin fine particles: less than 1.25). Is easy to obtain.
The resin fine particles are obtained by soap-free emulsion polymerization, suspension polymerization, dispersion polymerization or the like, and may be a thermoplastic resin or a thermosetting resin. For example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate resin, silicone resin, benzoguanamine resin, nylon resin Etc. As the resin fine particles, two or more of the above resins may be used in combination. Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles is easily obtained.
Examples of the vinyl resin include polystyrene copolymerized with a monomer having a carboxyl group such as methacrylic acid, a methacrylic acid ester and an acrylic acid ester copolymer. From the viewpoint of emulsifiability, it is preferable to use a surfactant having radical polymerizability as a reaction initiator.

The resin fine particles have a glass transition point (Tg) of 40 to 100 ° C. and a weight average molecular weight of 9000 to 200,000. As described above, the glass transition point (Tg) is less than 40 ° C. When the weight average molecular weight is less than 9,000, the storage stability of the image-forming particles is deteriorated, and blocking occurs during storage and in the developing machine. When the glass transition point (Tg) is 100 ° C. or higher and / or the weight average molecular weight is 200,000 or higher, the resin fine particles inhibit the adhesiveness to the fixing paper, and the minimum fixing temperature increases.
It is necessary that the residual ratio with respect to the image-forming particles is 0.5 to 5.0 wt%. When the residual ratio is less than 0.5 wt%, the storage stability of the image-forming particles deteriorates, and blocking occurs during storage and in the developing machine, and when the residual amount is 5.0 wt% or more, the resin The fine particles inhibit the exudation of the wax, and the effect of releasing the wax cannot be obtained, and the occurrence of offset is observed.
The residual rate of the resin fine particles can be measured by analyzing a substance caused by the resin fine particles not by the image forming particles by a pyrolysis gas chromatograph mass spectrometer, and calculating from the peak area. The detector is preferably a mass spectrometer, but is not particularly limited.

(Release agent)
Further, a wax may be contained together with the toner binder and the colorant. Known waxes can be used as the wax of the present invention, such as polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax, sasol wax, etc.); carbonyl group-containing wax, etc. It is done. Of these, carbonyl group-containing waxes are preferred. Carbonyl group-containing waxes include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18 -Octadecanediol distearate, etc.); polyalkanol esters (tristearyl trimellitic acid, distearyl maleate, etc.); polyalkanoic acid amides (ethylene diamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred. The melting point of the wax of the present invention is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature. Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability.
The wax content in the image-forming particles is usually less than 40 wt%, preferably 3 to 30 wt%.

(Coloring agent)
As the colorant of the present invention, known dyes and pigments can be appropriately used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide , Ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow ( 5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red , Fais red, parachlorol Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake , Thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazolone , Polyazo red, chrome vermillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal free phthalocyanine blue, phthalocyanine blue, fast sky blue, in Dunslen Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake Phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used.
The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the image-forming particles.

The colorant used in the present invention can also be used as a resin colorant complex combined with a resin.
There are methods for producing resin colorant composites, such as dissolution in a solvent, dissolution / dispersion in a small amount of solvent or liquid polymer, high viscosity solution, stirring and shearing, etc., but the strongest method is available. Mixing and kneading in which force can be applied is more desirable. For mixing and kneading, a high shear dispersion device such as a three-roll mill is preferably used.
A resin colorant composite (hereinafter referred to as a master batch) obtained by mixing and kneading can be obtained by mixing and kneading a resin for a master batch and a colorant under high shearing force to obtain a master batch. At this time, an organic solvent can be used in order to enhance the interaction between the colorant and the resin. Also, a so-called flushing method called watering paste containing water of a colorant is mixed and kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture and organic solvent components. Since it can be used as it is, it does not need to be dried and is preferably used.

The binder resin kneaded with the master batch includes styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and substituted polymers thereof; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene. -Vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer Styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl Methyl ketone copolymer Styrene copolymers such as styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl Methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic fork Can be used alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax and the like. Further, by adding the modified polyester resin, or the modified polyester resin and the unmodified polyester resin, the dispersion of the colorant can be further strengthened.
The content of the colorant in the resin colorant complex is usually 80 wt% or less, preferably 30 to 60 wt%.

(Charge control agent)
The image-forming particles of the present invention may contain a charge control agent as necessary. Known charge control agents can be used as appropriate. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified) Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of a phenol-based condensate (manufactured by Orient Chemical Industry Co., Ltd.), TP-302 of a quaternary ammonium salt molybdenum complex, TP-415 (manufactured by Hodogaya Chemical Industry Co., Ltd.), quaternary ammonium Copy charge PSY VP2038 of salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone Azo pigments, sulfonate group, carboxyl group, and polymer compounds having a functional group such as a quaternary ammonium salt.

  In the present invention, the amount of charge control agent used is determined uniquely by the type of binder resin, the presence or absence of additives used as required, and the method for producing image-forming particles including the dispersion method. Although not intended, it is preferably used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the image forming particles is too high, the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, the image The concentration is lowered. These charge control agents can be dissolved and dispersed after being melt-kneaded with a masterbatch and resin, or of course, may be added when directly dissolving or dispersing in an organic solvent, or after the image-forming particles are formed on the surface of the image-forming particles. It may be fixed.

(Metal oxide and metal oxide solvent dispersion)
The image-forming particles of the present invention may contain a metal oxide and a metal oxide solvent dispersion as necessary. As the metal oxide (solvent dispersion), for example, a hydrogel dispersion of a linear / ring-shaped metal oxide synthesized by a wet method (hydrothermal synthesis method, sol-gel method, etc.) is subjected to a hydrophobization treatment to obtain a dispersion solvent. There is a method of substituting with an arbitrary solvent.

  Examples of metal oxides synthesized by a wet method include, for example, silicon dioxide (silica), titanium dioxide (titania), aluminum oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide Zinc oxide, tin oxide, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, parium sulfate, barium carbonate, calcium carbonate, and the like. Among these, silicon dioxide (silica), titanium dioxide (titania), aluminum oxide, particularly silica are preferable.

Further, as a method of hydrophobizing treatment, a surface treating agent is often used, and it is necessary to optimize the hydrophilicity / hydrophobicity balance on the surface of the metal oxide. For example, the following coupling agent (Q) x-Si (P) y- (A) z (wherein Q represents a hydrolyzable group such as a halogen atom, an amino group or an alkoxy group, and A represents Represents an alkyl group or an aryl group, and the organic functional group P represents —BOOC (R ′) C═CH ₂ , —BNHR ″ or —BNH ₂ (R ′ represents an alkyl group, R ″ represents an alkyl group or an aryl group) B represents an alkylene group or an alkylene group containing —O—, —NH—, —CO—, x and y are integers of 1 or more, z is an integer of 0 or more, and x + y + z = 4 Specifically, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxy Propyltrimethoxysilane [γ-glycidoxypropyltrimethoxysilane], 3-glycidoxypropylmethyldiethoxysilane [γ-glycidoxypropylmethyldimethoxysilane], 3-glycidoxypropyltriethoxysilane, p -Styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane [γ-methacryloxypropyltrimethoxysilane], 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltri Ethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane [γ- (2-aminoethyl) aminopropylmethyldimethoxysilane], N-2 (aminoethyl) 3) 3-aminopropyltrimethoxysilane [γ- (2-aminoethyl) aminopropyltrimethoxysilane], N-2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- Aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane [γ-anilinopropyltrimethoxysilane], N— (Vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride [N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride], octadecyldimethyl (3- ( Trimethoxysilyl) propyl) ammonium chloride, 3-u Idpropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane (γ-mercaptopropyltrimethoxysilane), bis (triethoxysilylpropyl) tetrasulfide, 3 -Isocyanatopropyltriethoxysilane. The effect can also be obtained by using a silylating agent, a silane coupling agent having an alkyl fluoride group, an organic titanate coupling agent, an aluminum coupling agent, or a silicone oil as a hydrophobizing agent.

As a solvent for dispersing the metal oxide, for example, methanol, ethanol, 1-pentanol, n-butanol, isopropanol, 2-methoxyethanol, isobutanol, methyl ethyl ketone, methyl isobutyl ketone, 2-methyl tetrahydrofuran, cyclohexanone, formaldehyde, dioxane , Dimethylformamide, ethyl acetate, n-butyl acetate, methyl methacrylate, diisopropyl ether, dibutyl ether, benzene, toluene and the like, and a mixture of two or more of these can also be used. It is desirable that the SP value δ _{MS of the} solvent used in the metal oxide solvent dispersion and the SP value δ _PS of the solvent when the metal oxide solvent dispersion is removed are as close as possible, δ _MS and δ _PS needs to satisfy at least −2.0 <δ _MS −δ _PS <4.0, and preferably −0.5 <δ _MS −δ _PS <1.0. Most preferably, it is in the range of −0.1 <δ _MS −δ _PS <0.3. For example, as a solvent in which a polymer, a colorant, and a release agent are dissolved or dispersed in ethyl acetate and a metal oxide added to the ethyl acetate solution [dispersion] is dispersed, ethyl acetate and methyl ethyl ketone are most preferable.

  The primary particles in the solvent are desirable because the dispersibility of the metal oxide is good until the formation of the image forming particles and the effect of changing the shape of the image forming particles is greater. Dispersibility, stability over time, and production From the viewpoint of properties, it is more desirable to use an organosilica sol as the metal oxide solvent dispersion. The organosilica sol refers to a state in which colloidal silica in which some silanol groups on the particle surface are silylated is dispersed in an organic solvent in a stable state or a solution thereof. For a detailed description and production method of the organosilica sol, refer to JP-A-11-43319.

  The pH of dilution with water is measured as follows. First, a metal oxide solvent dispersion is dispersed uniformly. If it is already a sol, it is easy to disperse, but if it is a wet gel, it is crushed with a disper as required. The mixture is diluted with an equal amount of ion-exchanged water and stirred for 3 minutes at a homomixer 2000 rotation, and the pH is measured.

The added amount of the metal oxide may be 0.05 to 50 wt%, preferably 0.25 to 10 wt% with respect to the image forming particles. If it is smaller than this range, the absolute amount of the metal oxide on the surface of the image forming particle is insufficient, and it is difficult to obtain a sufficient improvement effect on the shape change of the image forming particle. Since the amount of oxide becomes excessive and the metal oxide acts as a fixing inhibitor, the minimum fixing temperature is increased and the low temperature fixing property is impaired. Moreover, the average particle diameter of the primary particle of inorganic fine particles is 5-200 nm, More preferably, it is 10-180 nm. If it is smaller than this range, separation from the organic solvent to the aqueous medium is likely to occur, and it is difficult to obtain a sufficient improvement effect on the shape change of the image forming particle. If it is larger than this range, a gap is generated between the metal oxides, The effect on the shape change of the image forming particle is reduced. As the shape of the inorganic fine particles, spherical particles, irregular particles, linear types, network types, and the like can be used, and they are properly used depending on the dispersion state in the organic solvent.
These inorganic fine particles may be used alone or in combination of two or more.
The average particle diameter here is a number average particle diameter. The particle size of the inorganic fine particles used in the present invention can be measured by a particle size distribution measuring device using dynamic light scattering, for example, DLS-700 manufactured by Otsuka Electronics Co., Ltd. or Coulter N4 manufactured by Coulter Electronics. However, since it is difficult to dissociate the secondary aggregation of the particles after the silicone oil treatment, it is preferable to directly determine the particle diameter from a photograph obtained by a scanning electron microscope or a transmission electron microscope. In this case, at least 100 or more inorganic fine particles are observed, and the average value of the major axis is obtained.

(External additive)
As the external additive for assisting the fluidity, developability and chargeability of the colored particles obtained in the present invention, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 mμ to 2 μm, and particularly preferably 5 mμ to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5 wt%, particularly preferably 0.01 to 2.0 wt% of the image forming particles. Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

  In addition, polymer fine particles such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization and dispersion polymerization, methacrylic acid ester and acrylic acid ester copolymer, silicone resin, benzoguanamine resin, nylon and other polycondensation systems, heat Examples thereof include polymer particles made of a curable resin.

Such a fluidizing agent performs surface treatment to increase hydrophobicity, and can prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having a fluoroalkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .
Further, it is more preferable that the inorganic fine particles used as the external additive are the same type as the inorganic fine particles added in the organic solvent.
A cleaning property improver for removing the developer after transfer remaining on the photoreceptor or the primary transfer medium may be added. Examples of the cleaning property improver include fatty acids such as zinc stearate, calcium stearate, stearic acid, and the like. Mention may be made, for example, of polymer salts produced by soap-free emulsion polymerization of metal salts such as polymethyl methacrylate fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

(Production method)
The weight body added to the organic solvent can be produced by the following method. The polyol (1) and the polycarboxylic acid (2) are heated to 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and the generated water is distilled off as necessary. Thus, a polyester having a hydroxyl group is obtained. Next, this is reacted with polyisocyanate (3) at 40 to 140 ° C. to obtain a prepolymer (A) having an isocyanate group. Further, (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a polyester modified with a urea bond. When (3) is reacted and (A) and (B) are reacted, a solvent can be used as necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to the isocyanate (3), such as tetrahydrofuran (such as tetrahydrofuran). When polyester (ii) not modified with urea bond is used in combination, (ii) is produced by the same method as polyester having a hydroxyl group, and this is dissolved in the solution after completion of the reaction of (i) and mixed. To do. However, when the used components such as the prepolymer and the compound containing an active hydrogen group are liquid, they can be used in place of the organic solvent in the present invention. In any case, the organic solvent liquid in the present invention can be rephrased as an oil phase dispersed in an aqueous medium.
The image-forming particles of the present invention can be produced by the following method, but are not limited thereto.

(Method for producing image-forming particles in aqueous medium)
The aqueous medium used in the present invention may be water alone, or a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like.

  The image-forming particles are prepared by dissolving or dispersing a polymer and a colorant in an organic solvent, dispersing the organic solvent liquid in an aqueous medium, removing the organic solvent, washing and drying. Further, a dispersion composed of a prepolymer (A) having an isocyanate group in an aqueous medium may be formed by reacting with (B), or a urea-modified polyester (i) produced in advance may be used. As a method for stably forming a dispersion comprising urea-modified polyester (i) or prepolymer (A) in an aqueous medium, urea-modified polyester (i), prepolymer (A), or resin colorant is used in an aqueous medium. Examples thereof include a method of adding a composition of raw material for image forming particles composed of a composite and dispersing it by shearing force. The prepolymer (A) and other image-forming particle composition (hereinafter referred to as image-forming particle raw material) release agent, charge control agent, unmodified polyester resin, etc. are used when forming a dispersion in an aqueous medium. It is preferable to mix the raw material for image forming particles in advance, and then add and disperse the mixture in an aqueous medium. In the present invention, other image forming particle raw materials such as a release agent and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium, but after the particles are formed. , May be added. For example, after forming particles that do not contain a charge control agent, the charge control agent can be immobilized on the surface of the image-forming particles by a known method.

The dispersion method is not particularly limited, and known facilities such as a medium speed shearing method, a high speed shearing method, a friction method, a high pressure jet method, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferable.
The amount of the aqueous medium used is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight based on 100 parts by weight of the image-forming particle composition (organic solvent liquid) containing the urea-modified polyester (i) and the prepolymer (A). is there. If it is less than 50 parts by weight, the image-forming particle composition is not well dispersed, and image-forming particles having a predetermined particle size cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

In the step of synthesizing the urea-modified polyester (i) and the prepolymer (A), the amine (B) may be added and reacted before the image forming particle composition is dispersed in the aqueous medium. After dispersion, amines (B) may be added to cause a reaction from the particle interface. In this case, urea-modified polyester is preferentially produced on the surface of the image-forming particles to be produced, and a concentration gradient can be provided inside the particles.
As a dispersant for emulsifying and dispersing the oily phase (organic solvent liquid) in which the image-forming particle composition is dispersed in a liquid containing water, alkylbenzene sulfonate, α-olefin sulfonate, phosphate ester, etc. Anionic surfactants, alkylamine salts, aminoalcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisocyanates Quaternary ammonium salt type cationic surfactants such as norinium salt and benzethonium chloride, nonionic surfactants such as fatty acid amide derivatives and polyhydric alcohol derivatives, such as alanine, dodecyldi (aminoethyl) glycine, di (octylamino) ethyl) Lysine and N- alkyl -N, amphoteric surfactants such as N- dimethyl ammonium betaine and the like.

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-hydroxyethyl) -Fluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Is mentioned.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Taikin Kogyo Co., Ltd.), Mega-Fac F-ll0, F-120, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), Xtop EF- 102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fagento F-100, F150 (manufactured by Neos).

Examples of cationic surfactants include aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, aliphatic quaternary ammonium salts such as perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, benza Luconium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass), Florard FC-135 (Sumitomo 3M), Unidyne DS-202 (Daikin Industries) , Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products Co., Ltd.), Footgent F-300 (Neos Co., Ltd.), and the like.
Moreover, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, etc. can be used as an inorganic compound dispersant which is hardly soluble in water.

Further, the dispersed droplets may be stabilized by a polymer protective colloid.
For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-acrylate Chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N -Methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc., or esters of compounds containing vinyl alcohol and carboxyl groups, such as Vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethylene imine, etc. Homopolymers or copolymers such as those having a nitrogen atom or a heterocyclic ring thereof, polyoxyethylene, polyoxypropylene, Oxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl Polyoxyethylenes such as esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

In addition, when an acid such as calcium phosphate salt or an alkali-soluble one is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as washing with water after dissolving the calcium phosphate salt with an acid such as hydrochloric acid. To do. It can also be removed by operations such as enzymatic degradation.
When a dispersant is used, the dispersant may remain on the surface of the image-forming particles. However, it is preferable from the charged surface of the image-forming particles to wash away after the elongation and / or crosslinking reaction.

  Furthermore, in order to reduce the viscosity of the image-forming particle composition, a solvent in which the urea-modified polyester (i) or the prepolymer (A) is soluble can be used. The use of a solvent is preferable in that the particle size distribution becomes sharp. The solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of the solvent with respect to 100 weight part of prepolymers (A) is 0-300 weight part normally, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after elongation and / or crosslinking reaction.

  The elongation and / or cross-linking reaction time is selected depending on the reactivity of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. is there. The reaction temperature is usually 0 to 150 ° C., preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

  The method for producing a liquid (hereinafter referred to as particle-containing slurry) in which a polymer and a colorant are dissolved or dispersed in an organic solvent and the solution or dispersion is dispersed in an aqueous medium is continuous and the aqueous medium. It is necessary that the particle-containing solution or dispersion discharged by dispersion in the liquid does not enter the dispersion step in the aqueous medium again. For example, a non-open tank-type container having at least two openings and a disperser capable of applying a high shearing force is prepared. Then, the organic solvent liquid in which the polymer and the colorant are dissolved or dispersed and the aqueous medium are allowed to flow into the container from at least one opening, and the container is uniformly distributed using a disperser that can apply a high shearing force. To be dispersed. At this time, the organic solvent liquid and the aqueous medium may be allowed to flow together (FIG. 2) or separately (FIG. 3). There is also a method in which the organic solvent liquid and the aqueous medium are lightly mixed in advance. The tank in this case indicates a structure having a space for storing the liquid dispersed by the disperser and having an opening through which the dispersed liquid is discharged, and the shape is not particularly limited, but preferably It is desirable that the internal structure is such that convection is generated by the disperser and there is no portion where the dispersion is not reachable, more preferably a cylindrical shape, a spindle shape, or a spherical shape. Further, as a flow of the liquid to be dispersed, it is desirable that the organic solvent liquid and the aqueous medium flow in from below and be discharged from above.

  In order to increase the shearing force of dispersion, there is also a method in which the dispersion steps are arranged in series, and the absolute amount of the shearing force is increased with little variation in the shearing force applied to the dispersion (FIG. 4). As a form in which this idea is advanced, the inside is generally a tank-type container divided into two or more regions, and the divided regions have an opening through which a dispersion can flow (FIG. 5). ), The short pass is reduced, the shear force applied to the dispersion per unit time can be made more uniform, and the distance between the dispersers can be shortened as much as possible. Further, if the dividing plate (shaded portion in the figure) that divides the interior is not fixed to the inner wall of the tank (FIG. 6), in addition to obtaining the above effects, there is a feature that cleaning and maintenance are simplified.

  When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 4000-20000 rpm, preferably 6000-14000 rpm. The feed amount varies depending on the amount and type of the polymer and colorant contained in the organic solvent, but is 0.5 to 20 kg / min. Is preferred. Moreover, as temperature at the time of dispersion | distribution, it is at least 0-40 degreeC, Preferably it is 10-30 degreeC, More preferably, it is 15-25 degreeC. In addition, since a large amount of heat is generated by shearing during dispersion, it is desirable to provide a device for cooling the inside of the system.

  As described in Japanese Patent Application Laid-Open Nos. 2003-316074 and 2003-316075, there are devices that define manufacturing apparatuses. The differences from the present invention will be clarified below. In the present invention, an organic solvent liquid containing a polymer and a colorant is dispersed in an aqueous medium. However, in Japanese Patent Application Laid-Open Nos. 2003-316074 and 2003-316075, vinyl-based polymerization monomers are used. It is different in that it is. However, the biggest difference is the idea of the dispersion process. The dispersion step as referred to in the present invention has already been carried out in the form of “adjustment of preliminary dispersion” in JP-A Nos. 2003-316074 and 2003-316075. For this reason, in the present invention, it is desired that the rotation speed and temperature of the dispersion step be 6000 to 14000 rpm, a high peripheral speed and at least 40 ° C. or lower, whereas Japanese Patent Laid-Open No. 2003-316074 In 2003-316075, heating is performed at 60 to 80 ° C. in order to carry out the polymerization process at a low peripheral speed of 30 rpm (Example of JP-A-2003-316074). Therefore, it can be seen that the aim, intention and effect of the present invention are completely different from those of JP-A Nos. 2003-316074 and 2003-316075.

When the organic solvent liquid (oil phase) and the aqueous medium (aqueous phase) containing the image-forming particle composition are granulated in a continuous manner, it is desirable to supply them to the disperser while maintaining a certain ratio, The allowable width of the ratio is at least less than 15% of the aqueous phase flow ratio, preferably less than 5%, most preferably less than 1.0%. Further, when the oil phase and the water phase are charged into the disperser, it is preferable that the oil phase does not adhere to the wall surface of the pipe. Specifically, the oil phase is charged in a state surrounded by the water phase. It is desirable.
Agitation in the storage tank prevents unnecessary coalescence and aggregation of the image forming particles contained in the dispersion. Depending on the type of resin / colorant contained in the image-forming particles, the composition ratio of the dispersion, and the dispersion conditions, the fine powder may be reduced to a narrow particle size distribution. However, conditions for redispersing the particles in the storage tank, that is, stirring conditions for reducing the volume average particle size must be avoided.

The disperser used in the present invention is not particularly limited. Examples of commercially available products include TK Philmix, TK Homomic Line Flow, TK Pipeline Homo Mixer (made by Tokushu Kika Kogyo Co., Ltd.), Ultra Turrax, Ultra Turrax Inline, and Dispacks Reactor (made by IKA). , Ebara Milder (manufactured by Ebara Manufacturing Co., Ltd.), colloid mill (manufactured by Shinko Pantech Co., Ltd.), slasher, trigonal wet pulverizer (manufactured by Mitsui Miike Chemicals), Cavitron (manufactured by Eurotech), fine flow mill (Pacific Kiko Co., Ltd.) Product), Claremix (Mtechnic Co., Ltd.), etc.
When the particle size distribution during the dispersion step is wide and the washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classification into a desired particle size distribution.
In the classification operation, the fine particle portion can be removed in the liquid by a cyclone, a decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder after drying, but it is preferably performed in a liquid in terms of efficiency. The unnecessary fine particles or coarse particles obtained can be returned to the kneading step and used for the formation of particles. At that time, fine particles or coarse particles may be wet.
The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.

The resulting dried image-forming particle powder is mixed with different types of particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, and mechanical impact force is applied to the mixed powder. As a result, it is possible to prevent the dissociation of the foreign particles from the surface of the composite particle obtained by immobilizing and fusing on the surface.
Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture in a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) has been modified to reduce the pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron Examples include a system (manufactured by Kawasaki Heavy Industries, Ltd.) and an automatic mortar.

(Carrier for two components)
When the image-forming particles of the present invention are used in a two-component developer, they may be used by mixing with a magnetic carrier. The content ratio of the carrier and the image-forming particles in the developer is an image with respect to 100 parts by weight of the carrier. 1 to 10 parts by weight of the formed particles are preferred. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resin such as vinyl chloride, polyester resin such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexa Fluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride Fluoro such as terpolymers of emission and non-fluoride monomers including, and silicone resins. Moreover, you may make conductive powder etc. contain in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.
The image-forming particles of the present invention can also be used as a one-component magnetic toner that does not use a carrier or a non-magnetic toner.

The image forming apparatus of the present invention will be described below with reference to the drawings.
Still another embodiment for carrying out the image forming method of the present invention by an example of the image forming apparatus of the present invention (for example, the image forming apparatus shown in FIGS. 11 to 13) will be described with reference to FIG.
The image forming apparatus (100) of the example shown in FIG. 11 includes a photosensitive drum (10) (hereinafter referred to as “photosensitive member 10”) as an electrostatic latent image carrier, a roller-shaped charging unit (20), and an exposure unit. (30), a developing means (40), an intermediate transfer member (50), a cleaning means (60) having a cleaning blade, and a static elimination lamp as a static elimination means (70).

  The intermediate transfer member (50) is an endless belt, and is designed to be movable in the direction of the arrow by three rollers (51) that are arranged on the inner side and stretch the belt. A part of the three rollers (51) also functions as a transfer bias roller capable of applying a predetermined transfer bias (primary transfer bias) to the intermediate transfer member (50). A cleaning means (90) having a cleaning blade is disposed in the vicinity of the intermediate transfer member (50), and a developed image (image-forming particle image) is transferred to a transfer paper (95) as a final transfer material. Transfer rollers as transfer means (80) to which a transfer bias for (secondary transfer) can be applied are arranged to face each other. Around the intermediate transfer member (50), there is a corona charger (58) for applying a charge to the image-forming particle image on the intermediate transfer member (50) in the rotational direction of the intermediate transfer member (50). It is arranged between the contact portion between the photoconductor (10) and the intermediate transfer member (50) and the contact portion between the intermediate transfer member (50) and the transfer paper (95).

  The developing means (40) includes a developing belt (41) as a developer carrier, a black developing means (unit) (45K) provided around the developing belt (41), a yellow developing means (unit) (45Y), It is composed of a magenta developing means (unit) (45M) and a cyan developing means (unit) (45C). The black developing means (45K) includes a developer accommodating portion (42K), a developer supply roller (43K), and a developing roller (44K). The yellow developing means (45Y) is provided with a developer accommodating portion ( 42Y), a developer supply roller (43Y), and a development roller (44Y). The magenta developing means (45M) includes a developer accommodating portion (42M), a developer supply roller (43M), and a development roller (44M). The cyan developing means (45C) includes a developer container (42C), a developer supply roller (43C), and a developing roller 44C. Further, the developing belt 41 is an endless belt, is rotatably stretched around a plurality of belt rollers, and a part thereof is in contact with the photoreceptor (10).

  In the image forming apparatus (100) shown in FIG. 11, for example, the charging means (20) uniformly charges the photosensitive drum (10). The exposure means (30) exposes the photosensitive drum (10) imagewise to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum (10) is developed by supplying image forming particles from the developing means (40) to form a visible image (image forming particle image). The visible image (image-forming particle image) is transferred (primary transfer) onto the intermediate transfer body (50) by the voltage applied from the roller (51), and further transferred onto the transfer paper (95) (secondary transfer). ) As a result, a transfer image is formed on the transfer paper (95). The residual image forming particles on the photoreceptor (10) are removed by the cleaning means (60), and the charge on the photoreceptor (10) is once removed by the charge eliminating means (charge eliminating lamp) (70).

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. An image forming apparatus (100) shown in FIG. 12 does not include the developing belt (41) in the image forming apparatus (100) shown in FIG. 11, and a black developing means (developing unit) (developing unit) ( 45K), yellow developing means (developing unit) (45Y), magenta developing means (developing unit) (45M) and cyan developing means (developing unit) (45C) are arranged directly opposite to each other, as shown in FIG. The image forming apparatus (100) shown in FIG. In FIG. 12, the same components as those in FIG. 11 are denoted by the same reference numerals.

Still another embodiment for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. A tandem image forming apparatus (120) shown in FIG. 13 is a tandem color image forming apparatus. The tandem image forming apparatus (120) includes a copying apparatus main body (150), a paper feed table (200), a scanner (300), and an automatic document feeder (ADF) (400). The copying machine main body (150) is provided with an endless belt-like intermediate transfer member (50) at the center. The intermediate transfer member (50) is stretched around the support rollers (14), (15), and (16), and can rotate clockwise in FIG. An intermediate transfer body cleaning device (17) for removing residual image forming particles on the intermediate transfer body (50) is disposed in the vicinity of the support roller (15). The intermediate transfer member (50) stretched between the support roller (14) and the support roller (15) has four image forming units (18) of yellow, cyan, magenta, and black along the conveyance direction. A tandem developing means (120) arranged opposite to each other is arranged. An exposure means (21) is disposed in the vicinity of the tandem developing means (120). A secondary transfer unit (22) is disposed on the side of the intermediate transfer member (50) opposite to the side on which the tandem type developing unit (120) is disposed. In the secondary transfer means (22), a secondary transfer belt (24), which is an endless belt, is stretched between a pair of rollers (23), and a transfer sheet conveyed on the secondary transfer belt (24); The intermediate transfer member (50) can contact each other. A fixing means (25) is disposed in the vicinity of the secondary transfer means (22). The fixing means (25) includes a fixing belt (26) that is an endless belt, and a pressure roller (27) that is pressed against the fixing belt (26).
In the tandem image forming apparatus (120), a sheet reversal is performed in the vicinity of the secondary transfer unit (22) and the fixing unit (25) for reversing the transfer paper in order to form an image on both sides of the transfer paper. A device (28) is arranged.

  Next, full color image formation (color copying) using the tandem developing means (120) will be described. That is, first, a document is set on the document table (130) of the automatic document feeder (ADF) (400) or the automatic document feeder (400) is opened and the contact glass (32) of the scanner (300) is opened. A document is set on the document and the automatic document feeder (400) is closed.

  When a start switch (not shown) is pressed, when a document is set on the automatic document feeder (400), the document is transported and moved onto the contact glass (32). ) Immediately after the document is set on the scanner (300), the first traveling body (33) and the second traveling body (34) travel. At this time, light from the light source is irradiated by the first traveling body (33) and reflected light from the document surface is reflected by the mirror in the second traveling body (34), and is read through the imaging lens (35). The color original (color image) is read at (36), and is read as black, yellow, magenta and cyan image information.

  Each image information of black, yellow, magenta and cyan is stored in each image forming means (18) (black image forming means, yellow image forming means, magenta image forming means and cyan) in the tandem developing means (120). Image forming means), and image forming particle images of black, yellow, magenta and cyan are formed in each image forming means. The black image, the yellow image, the magenta image, and the cyan image formed in this way are transferred onto the intermediate transfer member (50) that is rotationally moved by the support rollers (14), (15), and (16) in FIG. The black image formed on the black photoconductor (10K), the yellow image formed on the yellow photoconductor (10Y), the magenta image formed on the magenta photoconductor (10M), and the cyan photoconductor, respectively. The cyan image formed on the body (10C) is sequentially transferred (primary transfer). Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member (50) to form a composite color image (color transfer image).

On the other hand, in the paper feed table (200), one of the paper feed rollers (142) is selectively rotated so that the sheet (recording paper) is fed from one of the paper feed cassettes (144) provided in the paper bank (143). ), Separated one by one by the separation roller (145), sent to the paper feed path (146), and conveyed by the conveyance roller (147) to the paper feed path (148) in the copier body (150). Guide and stop against the registration roller (49). Alternatively, the sheet feed roller (142) is rotated to feed out the sheets (recording paper) on the manual feed tray (54), separated one by one by the separation roller (52), and put into the manual feed path (53). Stop against the registration roller (49). The registration roller (49) is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet.
Then, the registration roller (49) is rotated in synchronism with the synthesized color image (color transfer image) in which the respective toners are synthesized on the intermediate transfer member (50), and the intermediate transfer member (50) and the secondary transfer means ( 22), a sheet (recording paper) is sent to the sheet (recording paper), and the composite color image (color transfer image) is transferred (secondary transfer) onto the sheet (recording paper) by the secondary transfer means (22). A color image is transferred and formed on the sheet (recording paper). The residual toner on the intermediate transfer member (50) after the image transfer is cleaned by the intermediate transfer member cleaning device (17).

  The sheet (recording paper) on which the color image has been transferred is transported by the secondary transfer means (22) and sent to the fixing means (25). The fixing means (25) generates heat and pressure. The composite color image (color transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw (55) and discharged by the discharge roller (56) and stacked on the discharge tray (57), or switched by the switching claw (55) and the sheet is reversed. The image is reversed by the device (28) and guided again to the transfer position, and an image is recorded also on the back surface. Then, the image is discharged by the discharge roller (56) and stacked on the discharge tray (57).

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to this. Hereinafter, a part shows a weight part.

~ Synthesis of low molecular weight polyester ~
(Production Example 1)
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 48 parts adipic acid and dibutyl Add 2 parts of tin oxide, react for 8 hours at 230 ° C. under normal pressure, and then react for 6 hours at a reduced pressure of 20 mmHg or less. The reaction yielded [low molecular polyester]. [Low molecular weight polyester] had a number average molecular weight of 2,400, a weight average molecular weight of 6,800, a Tg of 43 ° C., and an acid value of 25.

~ Creation of master batch ~
(Production Example 2)
1200 parts of water, 1000 parts of Pigment Yellow 180 and 1000 parts of [low molecular weight polyester] were mixed with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), and the mixture was kneaded at 150 ° C. for 30 minutes using two rolls, then cooled and pulverized. To obtain a [master batch].

~ Synthesis of intermediate polyester and prepolymer ~
(Production Example 3)
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. under normal pressure for 8 hours, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg to obtain an [intermediate polyester]. The [intermediate polyester] had a number average molecular weight of 2100, a weight average molecular weight of 9600, Tg of 55 ° C., an acid value of 0.5, and a hydroxyl value of 51.
Next, 410 parts of [Intermediate Polyester 1], 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Polymer] was obtained. [Prepolymer] had a free isocyanate weight% of 1.60%. The solid content concentration of [Prepolymer] (calculated from the weight after standing at 150 ° C. for 45 minutes) was 50%.

~ Synthesis of ketimine ~
(Production Example 4)
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound]. The amine value of [ketimine compound] was 423.

~ Creation of oil phase ~
(Production Example 5)
A container equipped with a stir bar and a thermometer was charged with 50 parts of synthetic ester wax WAX, 30 parts of CCA (salicylic acid metal complex E-84: Orient Chemical Industries), 330 parts of ethyl acetate, and heated to 80 ° C. with stirring. After maintaining at 80 ° C. for 5 hours, it was cooled to 30 ° C. over 1 hour. Next, 250 parts of [master batch] were mixed in the container for 1 hour to obtain [raw material solution].
[Raw material solution] 132 parts were transferred to a container and filled with 80% by volume of 0.5 mm zirconia beads using a bead mill (Ultra Visco Mill, manufactured by Imex) with a liquid feed speed of 1 kg / hr, a disk peripheral speed of 6 m / sec. The pigment and WAX were dispersed under conditions of 6 to 24 passes. Next, 200 parts of a 70 wt% ethyl acetate solution of [low molecular weight polyester], 80 parts of ethyl acetate, and 10 parts of water were added, and three passes were performed with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion]. The solid content concentration of the [pigment / WAX dispersion] (calculated from the weight after standing at 150 ° C. for 60 minutes under reduced pressure) was 50%.

~ Synthesis of organic fine particle emulsion ~
(Production Example 6)
In a reaction vessel equipped with a stir bar and a thermometer, 680 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30: manufactured by Sanyo Chemical Industries), 69 parts of styrene, 110 parts of methacrylic acid, When 69 parts of butyl acrylate and 1 part of ammonium persulfate were charged and stirred at 400 rpm for 15 minutes, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous dispersion of a vinyl resin (a copolymer of styrene-methacrylic acid-methacrylic acid ethylene oxide adduct sulfate sodium salt) [fine particles Dispersion] was obtained. The volume average particle diameter of the [fine particle dispersion] measured by LA-920 was 0.11 μm. A part of the [fine particle dispersion] was dried to isolate the resin component. The resin content Tg was 150 ° C.

-Adjustment of aqueous phase-
(Production Example 7)
240 parts of ion exchange water, 13 parts of [fine particle dispersion], 50 parts of 50% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7): Sanyo Chemical Industries, Ltd., 25 parts of ethyl acetate are mixed and stirred. A milky white liquid was obtained. This is referred to as [aqueous phase].

Example 1
-Image forming particle granulation⇒Image forming particle formation-
(Production Example 8-1)
[Prepolymer] and [Pigment / WAX dispersion] are mixed at a ratio of 15/85 to make [Oil phase], and [Oil phase] / [Aqueous phase] = 400/600 Continue to add to the disperser set at 14000 rpm.
A schematic diagram of the dispersion process is shown in FIG. The high-speed stirring device has the structure shown in FIG. 2 (the disperser is a modified TK homomixer). The volume of the high-speed stirrer is 750 ml, and the total amount of [oil phase] and [aqueous phase] charged into the disperser is 300 g / min. It is. The dispersion discharged from the high-speed stirring device was immediately sent to the storage tank and stirred using an anchor type stirring blade. [Oil phase] and [Aqueous phase] were charged for 60 minutes, and the dispersion in the storage tank was further stirred for 2 hours to obtain [Solvent-containing slurry 1]. The solvent was removed at 30 ° C. for 8 hours to obtain [Solvent Removal Slurry 1]. [Solvent removal slurry 1] was aged at 60 ° C. for 10 hours to obtain [Dispersion slurry 1].
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(I): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(II): 300 parts of ion-exchanged water was added to the filter cake of (I), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered twice.
(III): 20 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of (II), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(IV): 300 parts of ion-exchanged water was added to the filter cake of (III), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered twice.
(V): 20 parts of 10% hydrochloric acid was added to the filter cake of (IV), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(VI): 300 parts of ion-exchanged water was added to the filter cake of (V), mixed with a TK homomixer (at 12,000 rpm for 10 minutes), and then filtered twice. The obtained cake was blown off and dried at 45 ° C. for 48 hours in a circulating air dryer, and sieved with an opening of 75 μm mesh to obtain [Image-forming particles 1].

(Example 2)
-Image forming particle granulation⇒Image forming particle formation-
(Production Example 8-2)
[Prepolymer] and [Pigment / WAX dispersion] are mixed at a ratio of 15/85 to make [Oil phase], and [Oil phase] / [Aqueous phase] = 400/600 Continue to add to the disperser set at 14000 rpm.
A schematic diagram of the dispersion process is shown in FIG. The high-speed stirring device has the structure shown in FIG. 4 (the disperser is a modified TK homomixer). The volume of the high-speed stirrer is 750 ml, and the total amount of [oil phase] and [aqueous phase] charged into the disperser is 600 g / min. It is. The dispersion discharged from the high-speed stirring device was immediately sent to the storage tank and stirred using an anchor type stirring blade. [Oil phase] and [Aqueous phase] were charged for 60 minutes, and the dispersion in the storage tank was further stirred for 2 hours to obtain [Solvent-containing slurry 2]. This was desolventized at 30 ° C. for 8 hours to obtain [Solvent Solvent 2]. [Solvent removal slurry 2] was aged at 60 ° C. for 10 hours to obtain [Dispersion slurry 2].
[Dispersion Slurry 2] was filtered and washed in the same manner as [Dispersion Slurry 1] in Production Example 8-1, and the resulting cake was blown off and dried in a circulating air dryer at 45 ° C. for 48 hours. Sieve [Image-forming particles 2] was obtained with an opening of 75 μm mesh.

(Example 3)
-Image forming particle granulation⇒Image forming particle formation-
(Production Example 8-3)
[Prepolymer] and [Pigment / WAX dispersion] are mixed at a ratio of 15/85 to make [Oil phase], and [Oil phase] / [Aqueous phase] = 400/600 Continue to add to the disperser set at 14000 rpm.
A schematic diagram of the dispersion process is shown in FIG. The high-speed agitator has the structure shown in FIG. 5 (the disperser is a modified TK homomixer). The volume of the high-speed stirrer is 750 ml, and the total amount of [oil phase] and [aqueous phase] charged into the disperser is 600 g / min. It is. The dispersion discharged from the high-speed stirring device was immediately sent to the storage tank and stirred using an anchor type stirring blade. [Oil phase] and [Aqueous phase] were charged for 60 minutes, and the dispersion in the storage tank was stirred for 2 hours to obtain [Solvent-containing slurry 3]. This was desolventized at 30 ° C. for 8 hours to obtain [Solvent Removal Slurry 3]. [Solvent removal slurry 3] was aged at 60 ° C. for 10 hours to obtain [Dispersion slurry 3].
[Dispersion Slurry 3] was filtered and washed in the same manner as [Dispersion Slurry 1] in Production Example 8-1, and the resulting cake was blown off and dried at 45 ° C. for 48 hours in a circulating air dryer. Sieve [image-forming particles 3] was obtained with an opening of 75 μm mesh.

(Comparative Example 1)
-Image forming particle granulation⇒Image forming particle formation-
(Production Example 8-4)
A schematic diagram of the dispersion process is shown in FIG. The high-speed stirring device has the structure shown in FIG. 2 (the disperser is a modified TK homomixer). First, 1080 g of [prepolymer], 6120 g of [pigment / WAX dispersion], and 10800 g of [aqueous phase] were put into a storage tank, and stirred using an anchor type stirring blade to obtain [storage tank dispersion]. . Immediately [Reservoir dispersion] was added at 300 g / min. Was put into a high-speed stirring apparatus. The volume of the high-speed stirrer was 750 ml, and the rotation speed was set to 14000 rpm. After 20 minutes, the storage tank contains the prepolymer and pigment / WAX dispersion separated from the aqueous phase. Even if the operation of charging the storage tank dispersion into the high-speed agitator is performed for 3 hours, the dispersion is performed. Was not done.

(Comparative Example 2)
-Image forming particle granulation⇒Image forming particle formation-
(Production Example 8-5)
[Prepolymer] and [Pigment / WAX dispersion] are mixed at a ratio of 15/85 to form an [oil phase], where [oil phase] / [aqueous phase] = 400/600 ratio. Continue to add to the disperser set at 14000 rpm.
A schematic diagram of the dispersion process is shown in FIG. The high-speed stirring device has the structure shown in FIG. 2 (the disperser is a modified TK homomixer). The dispersion discharged from the high-speed stirring device was immediately sent to the storage tank and stirred using an anchor type stirring blade. A part of the dispersion liquid sent to the storage tank is dispersed again by the high-speed stirring device.
The volume of the high-speed stirrer is 750 ml, and the [oil phase] and the [aqueous phase] are charged into the disperser for a total amount of 300 g / min only for 1 minute, and then the [oil phase] and [ The total amount of the aqueous phase] is 150 g / min. , The dispersion [storage tank dispersion] contained in the storage tank was 150 g / min. It was assumed that the [oil phase] and [aqueous phase] were charged for 120 minutes by the method of redispersing in step (1). However, the dispersion particles in the storage tank became coarse in about one hour. For this reason, the operation of charging the storage tank dispersion liquid into the high-speed agitator was performed for 3 hours. Contrary to this, the particles were further coarsened and finally separated.

(Comparative Example 3)
-Image forming particle granulation⇒Image forming particle formation-
(Production Example 8-6)
[Prepolymer] and [Pigment / WAX dispersion] are mixed at a ratio of 15/85 to make [Oil phase], and [Oil phase] / [Aqueous phase] = 400/600 Continue to add to the disperser set at 6000 rpm.
A schematic diagram of the dispersion process is shown in FIG. The high-speed stirring device has the structure shown in FIG. 2 (the disperser is a modified TK homomixer). The dispersion discharged from the high-speed stirring device was immediately sent to the storage tank and stirred using an anchor type stirring blade. A part of the dispersion liquid sent to the storage tank is dispersed again by the high-speed stirring device.
The volume of the high-speed stirrer is 750 ml, and the [oil phase] and the [aqueous phase] are charged into the disperser for a total amount of 300 g / min only for 1 minute, and then the [oil phase] and [ The total amount of the aqueous phase] is 150 g / min. , The dispersion [storage tank dispersion] contained in the storage tank was 150 g / min. Disperse again with [Oil phase] and [aqueous phase] were charged for 120 minutes, but the dispersion was insufficient. For this reason, the operation of charging the storage tank dispersion liquid into the high-speed stirring device was performed for 3 hours, but the dispersion was insufficient.

(Evaluation item)
(1) Dispersion Particle Size In Examples 1 to 3 and Comparative Examples 2 to 3, the relationship between the time from the start of dispersion and the volume average particle size of the image forming particles of the dispersion is shown in FIG. Sampling of the dispersion was performed every 5 minutes from the storage tank, and sampling was optionally performed after 1 hour from the start of dispersion. The particle size was measured using a particle size measuring device “Coulter Counter TAII” manufactured by Coulter Electronics Co., Ltd., with an aperture diameter of 100 μm. The volume average particle size was determined by the particle size measuring instrument.

(2) Particle diameter of image forming particle The volume average particle diameter and the number average particle diameter of [Image forming particle 1] to [Image forming particle 3] in Examples 1 to 3 were measured. The particle size was measured using a particle size measuring device “Coulter Counter TAII” manufactured by Coulter Electronics Co., Ltd., with an aperture diameter of 100 μm. The measurement results are shown in Table 1.

(3) Amount of fine particles of image forming particles The amount of fine particles of [Image forming particles 1] to [Image forming particles 3] in Examples 1 to 3 was measured. The measurement results are shown in Table 1.
For the amount of fine powder, a flow type particle image analyzer FPIA-2000 (manufactured by Toa Medical Electronics Co., Ltd.) is used. A surfactant, preferably alkylbenzene sulfonate, is added in an amount of 0.1 to 0.5 ml as a dispersant in 100 to 150 ml of water from which impure solids have been removed in advance. Add about 5g. The suspension in which the sample was dispersed was subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the concentration of the dispersion was set to 3000 to 10,000 particles / μl, and the amount of fine particles of the image forming particles was measured with the above apparatus.

The emulsion granulation system in a prior art (Unexamined-Japanese-Patent No. 2001-356523) is typically shown. It is explanatory drawing inside the high-speed stirring apparatus which bears the dispersion | distribution process in this invention. It is another explanatory drawing inside the high-speed stirring apparatus which bears the dispersion | distribution process in this invention. It is another explanatory drawing inside the high-speed stirring apparatus which bears the dispersion | distribution process in this invention. It is another explanatory drawing inside the high-speed stirring apparatus which bears the dispersion | distribution process in this invention. It is another explanatory drawing inside the high-speed stirring apparatus which bears the dispersion | distribution process in this invention. It is the figure which showed typically the flow of the dispersion liquid in the process from dispersion | distribution in an aqueous medium to storage. It is another figure which showed typically the flow of the dispersion liquid in the process from dispersion | distribution in an aqueous medium to storage. It is another figure which showed typically the flow of the dispersion liquid in the process from dispersion | distribution in an aqueous medium to storage. The relationship between the time from the dispersion | distribution start in Examples 1-3 and Comparative Examples 2-3 and the volume average particle diameter of the dispersion liquid particle in a storage tank is shown. It is a schematic explanatory drawing which shows an example of the image forming apparatus using the image forming particle of this invention. It is a schematic explanatory drawing which shows the other example of the image forming apparatus using the image forming particle of this invention. 1 is a schematic explanatory diagram illustrating an example of an image forming apparatus (tandem color image forming apparatus) using image forming particles of the present invention.

Explanation of symbols

10 Photoconductor (Photoconductor drum)
10K black photoconductor 10Y yellow photoconductor 10M magenta photoconductor 10C cyan photoconductor 14 support roller 15 support roller 16 support roller 17 intermediate transfer cleaning device 18 image forming means 20 charging roller 21 exposure device 22 secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure belt 28 Sheet reversing device 30 Exposure device 32 Contact glass 33 First traveling member 34 Second traveling member 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing belt 42K Developer container 42Y Developer container 42M Developer container 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K Developer roller 44Y Developer roller 44M Developer Roller 44C Developing roller 45K Black developing unit 45Y Yellow developing unit 45M Magenta developing unit 45C Cyan developing unit 49 Registration roller 50 Intermediate transfer member 51 Roller 52 Separating roller 53 Constant current source 55 Switching claw 56 Discharging roller 57 Discharging tray 58 Corona charger 60 Cleaning device 62 Transfer charger 70 Static elimination lamp 80 Transfer roller 90 Cleaning device 95 Transfer paper 100 Image forming device 120 Tandem developer 130 Document table 142 Paper feed roller 143 Paper bank 144 Paper feed cassette 145 Separation roller 146 Feed Paper path 147 Conveying roller 148 Paper feeding path 150 Copier main body 200 Paper feeding table 300 Scanner 400 Automatic document feeder (ADF)

Claims (11)

An aqueous system containing droplets of an organic solvent by dissolving or dispersing a polymer and a colorant in an organic solvent to obtain an organic solvent liquid and dispersing the organic solvent liquid in an aqueous medium In the method of producing the image-forming particles by removing the organic solvent from the aqueous dispersion, washing and drying after obtaining the dispersion, the dispersion of the organic solvent in the aqueous medium is continuous. A method for producing image-forming particles, wherein the aqueous dispersion discharged after the dispersion is stored while being stirred at least until the organic solvent is removed, and does not enter the dispersion step again . The dispersion of the organic solvent liquid in the aqueous medium is performed in a tank at least partially divided into two or more areas, and the dispersion can flow between the divided areas of the tank. 2. The method for producing image-forming particles according to claim 1, wherein there is a disperser that communicates with the opening and that performs the dispersion step in at least one region. The polymer contains a modified polyester (i) having a site capable of reacting with a compound having an active hydrogen group, and the organic solvent liquid contains a compound having an active hydrogen group. The method for producing image-forming particles according to claim 1 or 2. The polymer contains an unmodified polyester resin (ii) together with the modified polyester resin (i), and a weight ratio ((i) / (ii) between the resin (i) and the resin (ii). 4) is 5/95 to 25/75, the method for producing image-forming particles according to claim 3. The method for producing image-forming particles according to any one of claims 1 to 4, wherein the step of removing the organic solvent from the aqueous dispersion is performed at least under reduced pressure and / or heating conditions. Image-forming particles made by the production method according to claim 1. An image forming particle container filled with image forming particles produced by the production method according to claim 1. An image forming apparatus using the image forming particles produced by the production method according to claim 1. A heating body including a heating element, a film in contact with the heating body, and a pressure member in pressure contact with the heating body through the film, and an unfixed image between the film and the pressure member 9. The image forming apparatus according to claim 8, further comprising a fixing unit that heats and fixes the recording material on which the recording material is formed. 9. The image forming apparatus according to claim 8, further comprising an image carrier, wherein an alternating electric field is applied when developing a latent image on the image carrier. In a process cartridge having an image carrier and developing means, and may integrally support at least one means selected from a charging means and a cleaning means, and is detachable from the main body of the image forming apparatus, the developing means A process cartridge characterized in that it holds image-forming particles, and the image-forming particles are image-forming particles produced by the production method according to claim 1.

Images