JP4965905B2 - Toner, method for producing the same, and image forming method - Google Patents

Description

  The present invention relates to a toner suitably used in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like, a manufacturing method thereof, and an image forming method using the toner.

  In general, an electrophotographic method is an electrostatic latent image forming step in which an electrostatic latent image is formed on a photoreceptor layer using a photoconductive material by using various means, and a toner image is developed using toner. A developing process for forming, a transferring process for transferring the toner image to a recording material such as paper, a fixing process for fixing the toner image transferred to the recording material to the recording material by heating, pressure, thermal pressure, solvent vapor, or the like; This includes a cleaning process for removing toner remaining on the body layer.

The toner used in the electrophotographic method is required to be manufactured by a method that saves energy and has little influence on the environment. As a current toner production method, a melt-kneading pulverization method is conventionally known.
In the toner production method by the melt pulverization method, in order to ensure the uniformity of the shape of the obtained toner, it is important how to uniformly disperse and pulverize each constituent material. Basically, the shape of the pulverized toner is indefinite, and the pulverized cross section is random. Therefore, it is very difficult to control the shape and structure. In addition, when a large number of coloring materials, release agents, charge control agents, and the like are added, during the pulverization step, these added materials are easily exposed on the surface side by cleaving at the crystal plane, and within each particle. There is a problem that quality deterioration is likely to occur, such as toner characteristics such as fluidity and charging performance, such as uneven charging property.

  For this reason, in recent years, there have been methods for producing toners by chemical methods in liquid solvents (for example, polymerization methods such as emulsion polymerization, suspension polymerization, dispersion polymerization, dissolution suspension, and dissolution suspension extension). It is becoming mainstream.

The suspension polymerization method is a method for producing a toner by dispersing a toner material containing a monomer, a polymerization initiator and the like in an aqueous medium to form oil droplets, and then performing a polymerization reaction by raising the temperature. .
The emulsification dispersion method is a method of producing a toner by mixing a toner material containing a polymer and the like with an aqueous medium and emulsifying or dispersing to form oil droplets (see Patent Documents 1 and 2). . The dissolution suspension method is described in, for example, Patent Document 3.

  The chemical toner produced by such a chemical method (polymerization method) effectively expresses the desired function as expressed by the names of capsule toner and core-shell toner from the viewpoint of environmental issues in recent years. What has a possible form is provided.

  In the method for producing the polymerization toner, although it is possible to produce a spherical toner having a small particle size and a narrow particle size distribution as compared with the pulverization method, it is difficult to form arbitrary droplets in the dispersion medium, Problems such as a narrow selection range of materials to be used and uneven distribution of charging performance due to unevenness of toner constituent materials arise. Further, delicate emulsification control for each color toner is also required, which is a cause of poor robustness in toner production.

Furthermore, since toner granulation is performed in water or in a hydrophilic solvent, the toner surface becomes hydrophilic, resulting in deterioration of charging property, deterioration of stability over time, and destabilization of environmental characteristics. There is a risk of causing problems such as toner scattering and image quality degradation.
In addition, the polymerized toner has a problem of waste liquid treatment that occurs at the time of manufacture and a constructional restriction such as requiring heat energy for drying, and has the potential to increase costs. ing. In addition, from the viewpoint of water resources and the viewpoint of CO ₂ generation, it is desired to provide a toner manufacturing method with a low global environmental load.

As a method for producing a toner using a supercritical fluid, for example, Patent Document 4 proposes a method for granulating toner particles using a Rapid Expansion of Supercritical Solutions (RESS) method. However, this proposed method can use only a resin that is soluble in a supercritical fluid, and the selection range of the resin that can be used is small. For example, for high molecular weight components (gels) called H-forms required in toners and supercritical fluids such as styrene-acrylic resins and polyester resins that are inexpensive and have high performance generally used in the toner field. The solubility is extremely low, and there is a problem that it cannot usually be used as it is.
In order to improve the above-mentioned problem, for example, in Patent Document 5, Patent Document 6, and Patent Document 7, instead of dissolving a resin in a supercritical fluid, a colored resin that has been previously melt-kneaded is used in an insoluble state. It proposes a method of using and applying a shearing force to form particles. However, these methods have a disadvantage that the range of material selection is widened, but the particle size distribution is widened. In particular, in order to obtain a high-definition image required by recent toners, the particle size distribution is wide. Is a fatal drawback.

  Therefore, it has a sharp particle size distribution, good toner characteristics such as chargeability, environmental properties, stability over time, no waste liquid, no residual monomer, no drying process, low As for the production method of toner, the toner produced by the production method of the toner, and the image forming method using the toner, there are currently no products having sufficiently satisfactory performance.

JP-A-5-66600 JP-A-8-21655 Japanese Patent No. 3141784 JP 2001-312098 A JP 2004-161824 A JP 2004-144778 A JP-A-2005-107405

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention has a sharp particle size distribution by producing a chemical toner (polymerized toner) in at least one of a supercritical fluid and a subcritical fluid, and has a charging property, environmental property, stability over time, etc. The toner has good toner characteristics, is low in cost, does not generate waste liquid, does not require a drying step, does not contain residual monomers, and has a low environmental impact, and is manufactured by the toner manufacturing method. It is an object of the present invention to provide a toner to be used and an image forming method capable of improving image quality using the toner.

In view of the above problems, the present inventors have made extensive studies on a toner production method that has good toner characteristics, does not generate waste water, and requires almost no drying energy. Instead of the above, a chemical toner (polymerized toner) obtained by polymerizing at least a polymerizable monomer in at least one of a supercritical fluid and a subcritical fluid has a chargeability, environmental property, stability over time, etc. It was found that the toner characteristics are good, low cost and low environmental load. In addition, supercritical carbon dioxide is nonflammable and highly safe, and since it is a non-aqueous solvent, a polymerized toner with a hydrophobic surface is obtained. It was found that the obtained toner does not need to be dried.
In the present invention, polymerization is performed using a radical polymerizable monomer as a raw material in at least one of a supercritical fluid and a subcritical fluid, and the resulting polymer (resin) is insoluble in the supercritical fluid. It was found that by performing granulation while skillfully using the toner, it is possible to obtain a toner having a considerably narrow particle size distribution in a high yield as compared with the conventional case and to obtain a high-definition image. Furthermore, in the present invention, since a radical polymerizable monomer is used as a starting material instead of a resin, it has also been found that the cost can be significantly reduced due to the raw material cost and labor saving of the manufacturing process.

The present invention is based on the above findings of the present inventors, and means for solving the above problems are as follows. That is,
<1> A method for producing a toner comprising granulating a toner by polymerizing at least a radical polymerizable monomer in at least one of a supercritical fluid and a subcritical fluid,
A method for producing a toner, wherein the polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and subcritical fluid.
<2> A method for producing a toner comprising granulating a toner by dispersing and polymerizing at least a radical polymerizable monomer in at least one of a supercritical fluid and a subcritical fluid,
In the toner production method, the dispersion polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and the subcritical fluid.
<3> A method for producing a toner comprising granulating a toner by suspension polymerization of at least a radical polymerizable monomer in at least one of a supercritical fluid and a subcritical fluid,
In the toner production method, the suspension polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and the subcritical fluid.
<4> A toner manufacturing method in which at least one of radically polymerizable monomers is polymerized in at least one of a supercritical fluid and a subcritical fluid, and the resulting resin fine particles are aggregated or associated to form a granule. ,
In the toner production method, the resin fine particles are insoluble in at least one of the supercritical fluid and the subcritical fluid.
<5> The toner production method according to any one of <1> to <4>, wherein the radical polymerizable monomer is soluble in at least one of the supercritical fluid and the subcritical fluid.
<6> The method for producing a toner according to any one of <1> to <5>, wherein at least one of the supercritical fluid and the subcritical fluid contains at least carbon dioxide.
<7> The method for producing a toner according to any one of <1> to <6>, wherein a surfactant is contained in at least one of the supercritical fluid and the subcritical fluid.
<8> The method for producing a toner according to <7>, wherein the surfactant is at least one selected from a fluorine-containing compound and a silicon-containing compound.
<9> The method for producing a toner according to any one of <1> to <8>, wherein a dispersant is contained in at least one of the supercritical fluid and the subcritical fluid.
<10> The method for producing a toner according to <9>, wherein the dispersant contains one of inorganic fine particles and organic fine particles.
<11> The method for producing a toner according to any one of <1> to <10>, wherein at least one of the supercritical fluid and the subcritical fluid includes an entrainer.
<12> The toner production method according to <11>, wherein the content of the entrainer is 0.1 to 10% by mass.
<13> The toner production method according to any one of <11> to <12>, wherein the entrainer is a poor solvent for the toner binder resin under normal temperature and normal pressure (25 ° C., 0.1 MPa). is there.
<14> The toner production method according to any one of <11> to <13>, wherein the entrainer is a lower alcohol selected from methanol, ethanol, and propanol.
<15> A toner produced by the toner production method according to any one of <1> to <14>.
<16> The weight average particle diameter is 3 to 10 μm, and the ratio of the weight average particle diameter to the number average particle diameter (weight average particle diameter / number average particle diameter) is 1.00 to 1.25. The toner according to <15>.
<17> A developer comprising the toner according to any one of <15> to <16>.
<18> The developer according to <17>, which is one of a one-component developer and a two-component developer.
<19> A toner-containing container filled with the toner according to any one of <15> to <16>.
<20> An electrostatic latent image carrier and an electrostatic latent image formed on the electrostatic latent image carrier are developed with the toner according to any one of <15> to <16> to be a visible image And a developing means for forming the process cartridge.
<21> An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image according to <15> to <16> Developing means for developing a visible image by developing using any of the toners, Transfer means for transferring the visible image to a recording medium, and Fixing means for fixing the transferred image transferred to the recording medium And an image forming apparatus characterized by comprising:
<22> An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image using the toner according to any one of <15> to <16> The image forming apparatus includes at least a developing step for developing to form a visible image, a transferring step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium. An image forming method.

The toner production method of the present invention, in the first embodiment, granulates the toner by polymerizing at least a radical polymerizable monomer in at least one of a supercritical fluid and a subcritical fluid,
The polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and subcritical fluid.
In the second aspect of the method for producing a toner of the present invention, in at least one of a supercritical fluid and a subcritical fluid, at least a radical polymerizable monomer is dispersed and polymerized to granulate the toner,
The dispersion polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and subcritical fluid.
In the third aspect of the method for producing a toner of the present invention, at least one of radically polymerizable monomers is suspension-polymerized in at least one of a supercritical fluid and a subcritical fluid, and the toner is granulated.
The suspension polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and subcritical fluid.
In the fourth aspect of the toner manufacturing method of the present invention, at least one of radically polymerizable monomers is polymerized in at least one of a supercritical fluid and a subcritical fluid, and the resulting resin fine particles are aggregated or associated. The resin fine particles are insoluble in at least one of the supercritical fluid and subcritical fluid.
In the toner production method according to any one of the first to fourth embodiments, at least one of a supercritical fluid and a subcritical fluid is used instead of the aqueous medium, and at least one of the supercritical fluid and the subcritical fluid is used. Among them, radical polymerization monomer polymerization and toner granulation have sharp particle size distribution, good toner characteristics such as charging performance, low cost, low environmental impact Can be produced efficiently.

  Since the toner of the present invention is produced by the toner production method according to any one of the first to fourth aspects of the present invention, it has a sharp particle size distribution, and is charged, environmentally friendly, and stable over time. The toner characteristics such as are good.

  The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and the electrostatic latent image is developed using the toner of the present invention to be visible. It includes at least a developing step for forming an image, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium. In the image forming method of the present invention, an electrostatic latent image is formed on the electrostatic latent image carrier in the electrostatic latent image forming step. In the developing step, the electrostatic latent image is developed using the toner of the present invention to form a visible image. In the transfer step, the visible image is transferred to a recording medium. In the fixing step, the transferred image transferred to the recording medium is fixed. As a result, a high quality image with high image density and high sharpness can be obtained.

  According to the present invention, various problems in the prior art can be solved, the toner has a sharp particle size distribution, good toner characteristics such as charging property, environmental property, stability over time, low cost, and low environmental load. It is possible to provide a method for producing toner and an image forming method capable of improving image quality using the toner produced by the toner production method.

(Toner and toner production method)
The toner production method of the present invention, in the first embodiment, further includes a step of granulating the toner by polymerizing at least a radical polymerizable monomer in at least one of a supercritical fluid and a subcritical fluid. Depending on the other steps,
The polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and subcritical fluid.
In a second embodiment, the method for producing a toner of the present invention includes a step of granulating the toner by dispersing and polymerizing at least a radical polymerizable monomer in at least one of a supercritical fluid and a subcritical fluid. It includes other processes as necessary,
The dispersion polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and subcritical fluid.
In the third embodiment, the method for producing a toner of the present invention includes a step of granulating a toner by suspension polymerization of at least a radical polymerizable monomer in at least one of a supercritical fluid and a subcritical fluid, In addition, other steps are included as necessary,
The suspension polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and subcritical fluid.
In the fourth aspect of the toner manufacturing method of the present invention, at least one of radically polymerizable monomers is polymerized in at least one of a supercritical fluid and a subcritical fluid, and the resulting resin fine particles are aggregated or associated. And granulating, and further comprising other steps as necessary,
The resin fine particles (polymer) are insoluble in at least one of the supercritical fluid and subcritical fluid.
In the toner production method according to any one of the first to fourth aspects, it is preferable that the radical polymerizable monomer is soluble in at least one of the supercritical fluid and the subcritical fluid.
The toner of the present invention is produced by the toner production method according to any one of the first to fourth aspects of the present invention.
Hereinafter, the details of the toner of the present invention will be clarified through the description of the toner production method of the present invention.

Here, the radical polymerizable monomer is soluble (compatible) in at least one of the supercritical fluid and subcritical fluid in a high-pressure vessel (with an internal volume of 50 ml) with an observation window. 1 g of a radical polymerizable monomer as a test material was added, and at least one of a supercritical fluid and a subcritical fluid was mixed. After a certain time (for example, 30 minutes) with stirring, the inside of the high-pressure vessel was visually observed. Sometimes it means a uniform state with no cloudiness or phase separation.
The polymer is insoluble (incompatible) in at least one of the supercritical fluid and subcritical fluid. 1 g of polymer as a test material is placed in a high-pressure vessel (50 ml) with an observation window. It is impregnated and mixed with at least one of a supercritical fluid and a subcritical fluid. After a certain time (for example, 30 minutes) has elapsed, when the inside of the high-pressure vessel is visually observed, it means a state of white turbidity or phase separation.

<Step of granulating toner>
The step of polymerizing and granulating the radically polymerizable monomer includes at least radical polymerization monomer polymerization, dispersion polymerization, suspension polymerization, or polymerization in at least one of a supercritical fluid and a subcritical fluid. This is a step of agglomerating or associating the fine resin particles obtained in this way to granulate.

  The radical polymerizable monomer is not particularly limited as long as the polymer component obtained by polymerization is a resin used for forming an image as a binder resin for toner, and may be appropriately selected according to the purpose. For example, polymerizable monomers having an unsaturated double bond represented by vinyl monomers, styrene monomers, and the like can be mentioned, and a wide variety of them are commercially available.

-Supercritical fluid and subcritical fluid-
The supercritical fluid has an intermediate property between gas and liquid, and has properties such as fast mass transfer and heat transfer and low viscosity, and its density and dielectric constant by changing temperature and pressure. Means a fluid capable of continuously changing the solubility parameter, the free volume, etc. Furthermore, since the supercritical fluid has an extremely small interfacial tension as compared with an organic solvent, even a small undulation (surface) can follow and be wet with the supercritical fluid.
The supercritical fluid exists as a non-condensable high-density fluid in a temperature and pressure range that exceeds the limit (critical point) where gas and liquid can coexist, does not cause condensation even when compressed, and exceeds the critical temperature. And, as long as it is a fluid in a state equal to or higher than the critical pressure, there is no particular limitation and can be appropriately selected according to the purpose, but those having a low critical temperature and critical pressure are preferable, and the subcritical fluid is As long as it exists as a high-pressure liquid in the temperature and pressure region near the critical point, there is no particular limitation, and it can be appropriately selected according to the purpose.

Examples of the supercritical fluid or subcritical fluid include carbon monoxide, carbon dioxide, ammonia, nitrogen, water, methanol, ethanol, ethane, propane, 2,3-dimethylbutane, benzene, chlorotrifluoromethane, and dimethyl ether. Are preferable. Among these, carbon dioxide can easily create a supercritical state with a critical pressure of 7.3 MPa and a critical temperature of 31 ° C., and is non-flammable and highly safe. As a non-aqueous solvent, a polymerized toner having a hydrophobic surface can be obtained. Further, it is particularly preferable in that it is easily recovered and reused because it is gasified only by returning to normal pressure, and the obtained toner does not need to be dried, no waste liquid is generated, and no residual monomer is contained.
The supercritical fluid or the subcritical fluid may be used alone or as a mixture of two or more.

  The critical temperature and critical pressure of the supercritical fluid are not particularly limited and may be appropriately selected depending on the intended purpose. However, the critical temperature is preferably −273 to 300 ° C., more preferably 0 to 200 ° C. preferable. The lower the critical pressure, the more advantageous, for example, in terms of apparatus load, equipment cost, operating energy, etc., but in practice, 1-100 MPa is preferable, and 1-50 MPa is more preferable.

  In the present invention, toner can be granulated by positively utilizing the properties of the supercritical fluid or the subcritical fluid and polymerizing at least a radical polymerizable monomer. In addition, since the supercritical fluid can be easily separated from the target product and can be recovered and reused, it is possible to realize a revolutionary toner production method with low environmental impact that does not use conventional water or organic solvents.

It is preferable that at least one of the supercritical fluid and the subcritical fluid contains a surfactant.
The surfactant is not particularly limited as long as it has an affinity moiety for the supercritical fluid and an affinity moiety for the radical polymerizable monomer in the same molecule, and can be appropriately selected according to the purpose. For example, in the case of supercritical CO ₂ , a compound having a bulky group such as a fluorine group, a silicon group, a carbonyl group, a short hydrocarbon group, or propylene oxide acts as a parent CO ₂ group. Among these, fluorine-containing compounds, silicon-containing compounds, and carbonyl group-containing compounds are particularly preferable.

  The fluorine-containing compound is not particularly limited as long as it is a compound having a perfluoroalkyl group having 1 to 30 carbon atoms, and may be a low molecular compound or a high molecular compound. Among these, a high molecular compound is preferable from the viewpoints of surface activity, charging performance and durability when toner is used.

Examples of the fluorine-containing polymer compound include compounds represented by the following structural formula (A) and structural formula (B). These may be compounds such as a homopolymer, a block copolymer, and a random copolymer in consideration of the affinity with the radical polymerizable monomer.
However, the structural formula (A), _{R 1} represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, a represents an integer of 0 to 4, Rf is par number from 1 to 30 carbon Represents a fluoroalkyl group and a perfluoroalkenyl group.
In the structural formula (B), R ₁ represents a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms, and Rf represents a perfluoroalkyl group or perfluoroalkenyl group having 1 to 30 carbon atoms. .

  In addition, many compound raw materials similar to the compound having a perfluoroalkyl group are commercially available (for example, catalog of AMAX Co.), and various fluorine-containing compounds can be obtained by using them.

The silicon-containing compound is not particularly limited as long as it is a compound having a siloxane bond, and may be a low molecular compound or a high molecular compound. Among these, a compound containing polydimethylsiloxane (PDMS) represented by the following structural formula (C) is preferable. These may be compounds such as a homopolymer, a block copolymer, and a random copolymer in consideration of the affinity with the radical polymerizable monomer.
However, the structural formula (C), _{R 1} represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, n represents the number of repeated, _{R 2} is a hydrogen atom, a hydroxyl group, a carbon number 1 to Represents 10 alkyl groups.
A large number of compound raw materials similar to these polydimethylsiloxanes are also commercially available (for example, catalog of AMAX Co.), and various surfactants can be obtained by using them.

  The method for producing these fluorine-containing compounds and silicon-containing compounds can be obtained by polymerizing a vinyl polymerizable monomer as a raw material thereof, in a supercritical fluid other than conventional solvents (especially supercritical carbon dioxide is preferred). But it can be polymerized.

  The carbonyl group-containing compound is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aliphatic polyesters and polyacrylates.

  0.01-30 mass% is preferable and, as for content in the composition containing the radically polymerizable monomer of the said surfactant at least, 0.1-20 mass% is more preferable.

A dispersing agent may be contained in at least one of the supercritical fluid and the subcritical fluid.
The dispersant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include organic fine particles and inorganic fine particles. Among these, silicone-modified inorganic fine particles, fluorine-modified inorganic fine particles, fluorine-containing organic fine particles, and silicone-based organic fine particles are preferable.

Examples of the organic fine particles include silicone-modified products and fluorine-modified products of acrylic fine particles that are insoluble in a supercritical fluid.
Examples of the inorganic fine particles include inorganic metals such as calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate and other polyvalent metal phosphates, carbonates such as calcium carbonate and magnesium carbonate, calcium metasuccinate, calcium sulfate and barium sulfate. Examples thereof include inorganic oxides such as salt, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, titanium oxide, bentonite, and alumina. Among these, silica is particularly preferable.

Specific examples of the silane coupling agent containing the fluorine atom are shown below.
(1) CF ₃ (CH ₂ ) ₂ SiCl ₃
(2) CF ₃ (CF ₂ ) ₅ SiCl ₃
(3) CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ SiCl ₃
(4) CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ SiCl ₃
(5) CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃
(6) CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (CH ₃ ) C 1 ₂
(7) CF ₃ (CH ₂ ) ₂ Si (OCH ₃ ) ₃
(8) CF ₃ (CH ₂ ) ₂ Si (CH ₃ ) (OCH ₃ ) ₂
(9) CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ Si (OCH ₃ ) ₃
(10) CF ₃ (CF ₂ ) ₅ CONH (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃
(11) CF ₃ (CF ₂ ) ₄ COO (CH ₂ ) ₂ Si (OCH ₃ ) ₃
(12) CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OCH ₃ ) ₃
(13) CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (CH ₃ ) (OCH ₃ ) ₂
(14) CF ₃ (CF ₂ ) ₇ SO ₂ NH (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃
(15) CF ₃ (CF ₂ ) ₈ (CH ₂ ) ₂ Si (OCH ₃ ) ₃

  0.1-30 mass% is preferable and, as for content in the composition containing the radically polymerizable monomer of the said dispersing agent at least, 0.2-20 mass% is more preferable. Further, the dispersant is preferably used alone, but a surfactant may be used in combination in consideration of control of the toner particle diameter and toner charging performance.

In addition to the supercritical fluid and the subcritical fluid, other fluids can be used in combination. The other fluid is preferably one that can easily control the solubility of the toner material. Specifically, methane, ethane, propane, ethylene, and the like are preferable.
In addition to the supercritical fluid and the subcritical fluid, an entrainer (azeotropic agent) may be added. By the addition of the entrainer, polymerization of the polymerizable monomer is more easily performed. There is no restriction | limiting in particular as said entrainer, Although it can select suitably according to the objective, A polar organic solvent is preferable. Examples of the polar organic solvent include methanol, ethanol, propanol, butanol, hexane, toluene, ethyl acetate, chloroform, dichloromethane, ammonia, melamine, urea, thioethylene glycol, and the like. Among these, a lower alcohol solvent which is a poor solvent for the toner binder resin at normal temperature (25 ° C.) and normal pressure (0.1 MPa) is preferable. Here, the poor solvent means that the solubility of the resin in 1 L of the solvent is 0.1 g or less.

Examples of the entrainer include those in which the granulated resin fine particles do not dissolve or those that cause slight swelling, specifically, the difference between the solubility parameter [SP value] and the [SP value] of the resin fine particles used. Is preferably 1.0 or more, more preferably 2.0 or more. For example, for styrene-acrylic resins, use alcohols such as methanol, ethanol, and n-propanol with high [SP value], or n-hexane, n-heptane, etc. with low [SP value]. Is preferred. If the difference in [SP value] is large, wetting with respect to the resin fine particles is deteriorated and good dispersion of the resin fine particles cannot be obtained. Therefore, the optimum [SP value] difference is preferably 2 to 5.
Moreover, 0.1-10 mass% is preferable and, as for content of the entrainer in the mixed fluid of at least any one of the said supercritical fluid and a subcritical fluid, and an entrainer, 0.5-5 mass% is more preferable. When the content is less than 0.1% by mass, it may be difficult to obtain the effect as an entrainer. When the content exceeds 10% by mass, the properties of the entrainer as a liquid become too strong, and supercritical or May make it difficult to obtain a subcritical state.

-Resin fine particles-
The resin fine particles (toner base particles) are not particularly limited as long as they are resin fine particles used for image formation, and can be appropriately selected according to the purpose. For example, a resin obtained by a pulverization method or a polymerization method Examples include fine particles. There is no restriction | limiting in particular as this polymerization method, According to the objective, it can select suitably, For example, a suspension method, an emulsification method, a dispersion method etc. are mentioned.
The toner may be produced by a microencapsulation method (spray drying method, coacervation method, etc.), etc., in addition to the pulverization method and polymerization method.
As the resin fine particles, those appropriately synthesized may be used, or commercially available products may be used.

  The pulverization method is, for example, a method for producing the resin fine particles (base particles of toner) by melting and kneading a material containing at least a binder resin, pulverizing, classifying, and the like. In the case of the pulverization method, the shape may be controlled by applying a mechanical impact force to the obtained toner base particles in order to increase the average circularity of the toner. In this case, the mechanical impact force can be applied to the toner base particles using a device such as a hybridizer or mechanofusion.

The resin fine particles by the polymerization method are not particularly limited and can be appropriately selected from known resins according to the purpose. For example, vinyl resins, polyurethane resins, epoxy resins, polyester resins, polyamide resins, polyimide resins , Silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate resin, and the like. The vinyl resin is a polymer obtained by homopolymerizing or copolymerizing a vinyl monomer. For example, styrene- (meth) acrylic acid ester resin, styrene-butadiene copolymer, (meth) acrylic acid-acrylic acid ester polymer. Styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, styrene- (meth) acrylic acid copolymer, and the like.
In addition, polycondensation resins such as polystyrene, methacrylic acid ester, acrylic acid ester copolymer, silicone resin, benzoguanamine, nylon obtained by soap-free emulsion polymerization method, suspension polymerization method, dispersion polymerization method, thermosetting resin, The resin fine particles formed by the above method are preferable because of their sharp particle size distribution. Among these, the resin fine particles obtained by the dispersion polymerization method are preferable because they have a sharper particle size. Further, if the toner is imparted with a low temperature fixability, resin fine particles made of a polyester resin or a polyol resin can be selected. That is, the resin can be selected in accordance with the target toner design.

Here, the dispersion polymerization method will be specifically described.
First, a polymer compound dispersant that dissolves in the hydrophilic organic liquid is added to the hydrophilic organic liquid, and the polymer is dissolved in the hydrophilic liquid, but the resulting polymer is swollen by the hydrophilic liquid. Or hardly dissolve. One or more vinyl monomers are added to this to form particles. A reaction in which a polymer having a particle size distribution smaller than the target particle diameter but having a narrow particle size distribution is used in advance is also included. The monomer used for the growth reaction may be the same as that used to produce the seed particles, or may be another monomer, but the polymer must not be dissolved in the hydrophilic organic liquid.

  As the hydrophilic organic liquid, a liquid that dissolves the vinyl monomer to be used and does not dissolve the obtained resin fine particles (polymer particles) is used. Examples of the liquid include methyl alcohol, ethyl alcohol, modified ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, sec-butyl alcohol, tert-amyl alcohol, 3-pentanol and octyl alcohol. , Alcohols such as benzyl alcohol, cyclohexanol, furfuryl alcohol, ethylene glycol, glycerin, diethylene glycol; methyl cellosolve, cellosolve, isopropyl cellosolve, butyl cellosolve, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl And ether alcohols such as ether That. These organic liquids can be used alone or in combination of two or more. In addition, by using together with the above-mentioned alcohols and ether alcohols in organic liquids other than alcohols and ether alcohols, various SPs can be used under conditions that do not give solubility to the produced polymer particles of the organic liquid. By changing the value and changing the polymerization conditions, it is possible to suppress the size of the generated particles, the coalescence of the particles, and the generation of new particles.

Examples of the organic liquid include hydrocarbons such as hexane, octane, petroleum ether, cyclohexane, benzene, toluene, and xylene; halogenated hydrocarbons such as carbon tetrachloride, trichloroethylene, and tetrabromoethane; ethyl ether, dimethyl Ethers such as glycol, trioxane and tetrahydrofuran; acetals such as methylal and diethyl acetal; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexa; esters such as butyl formate, butyl acetate, ethyl propionate and cellosolve acetate Acids such as formic acid, acetic acid and propionic acid; sulfur and nitrogen-containing organic compounds such as nitropropene, nitrobenzene and dimethylamine; and water.
Polymerization in the presence of SO ₄ ²⁻ , NO ₂ ⁻ , PO ₄ ³⁻ , Cl ⁻ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ , and other inorganic ions in the solvent mainly composed of the hydrophilic organic liquid May be performed. In addition, the average particle size, particle size distribution, drying conditions, and the like of the polymer particles can be adjusted by changing the type and composition of the mixed solvent at the start of polymerization, during polymerization, and at the end of polymerization.

  The polymer compound dispersant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid Acids such as fumaric acid, maleic acid or maleic anhydride; acrylic monomers; vinyl alcohol or ethers of vinyl alcohol; esters of vinyl alcohol and compounds containing a carboxyl group; acrylamide, methacrylamide, di Acetone acrylamide, or methylol compounds thereof; acid chlorides such as acrylic acid chloride and methacrylic acid chloride; compounds having a heterocyclic ring; homopolymers of various monomers such as; or copolymers thereof; polyoxyethylene resins , Celluloses, and the like.

  The polymer compound dispersant is appropriately selected depending on the hydrophilic organic liquid to be used, the target polymer particle seed and the seed particle manufacturing or the growth particle manufacturing. In view of sterically preventing the polymer particles, those having high affinity and adsorbability to the polymer particle surface and high affinity and solubility to the hydrophilic organic liquid are selected. Further, in order to enhance the repulsion between particles in a three-dimensional manner, a molecular chain having a certain length, particularly a molecular weight of 10,000 or more is preferable. However, if the molecular weight is too high, the viscosity of the liquid is remarkably increased, the operability and the stirrability are deteriorated, and the precipitation probability of the produced polymer on the particle surface varies. In addition, it is effective for stabilization to allow the monomer of the polymer compound dispersant mentioned above to coexist with the monomer constituting the intended polymer particle.

  In general, the amount of the polymer compound dispersant used in the production of seed particles varies depending on the type of monomer for forming the polymer particles, but is 0.1 to 10% by mass with respect to the hydrophilic organic liquid. Preferably, 1-5 mass% is more preferable. When the concentration of the polymer compound dispersant is low, the produced polymer particles have a relatively large diameter, and when the concentration is high, small particles are obtained. Is less effective in reducing the diameter.

  In addition, the use of inorganic compound fine powders and surfactants in combination with these polymer compound dispersants can further improve the stabilization of the produced polymer particles and the improvement of the particle size distribution. Polymerization may be carried out in the presence of these materials in a vinyl monomer solution or a seed particle dispersion added for the purpose of preventing coalescence of particles. Initially generated particles are stabilized by a distributed polymer dispersant that is equilibrated in the hydrophilic organic liquid and on the polymer particle surface, but significant amounts of unreacted vinyl monomer are present in the hydrophilic organic liquid. In some cases, it will be somewhat swollen and sticky and will agglomerate over the steric repulsion of the polymeric dispersion stabilizer.

  Furthermore, in the case where the amount of monomer is extremely large relative to the hydrophilic organic liquid, it does not precipitate unless the polymerization that completely dissolves the produced polymer proceeds to some extent. The state of precipitation in this case takes the form of forming a highly sticky lump. Therefore, the amount of the monomer with respect to the hydrophilic organic liquid when producing the fine resin particles is not particularly limited, and is somewhat different depending on the kind of the hydrophilic organic liquid, but is preferably 100% by mass or less, and more preferably 50% by mass or less.

As the polymerization initiator, a normal radical initiator soluble in the solvent to be used is used. Examples of the polymerization initiator include azo polymerization initiators such as 2,2′-azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile); lauryl peroxide, benzoyl Peroxide-based polymerization initiators such as oxide, tert-butyl peroctoate, potassium persulfate, etc., or a system in which sodium thiosulfate, amine, etc. are used in combination therewith are used.
As for the addition amount of the said polymerization initiator, 0.1-10 mass parts is preferable with respect to 100 mass parts of vinyl monomers. Polymerization is performed by completely dissolving the polymer dispersant in the hydrophilic organic liquid, and then adding one or more vinyl monomers, a polymerization initiator, etc., and stirring at a speed that makes the flow in the reaction vessel uniform. However, it is carried out by heating to a temperature corresponding to the dispersion rate of the polymerization initiator used. In addition, since the temperature at the initial stage of polymerization has a large influence on the particle size to be generated, it is preferable to increase the temperature to the polymerization temperature after adding the monomer and dissolve the polymerization initiator in a small amount of solvent.

  In the polymerization, it is preferable that oxygen in the reaction vessel is sufficiently expelled with an inert gas such as nitrogen gas or argon gas. If the oxygen purge is insufficient, fine particles may be easily generated.

  In order to perform the polymerization in a high polymerization rate region, a polymerization time of 5 to 40 hours is preferable. The polymerization rate can be increased by stopping the polymerization in a desired particle size and particle size distribution state, sequentially adding a polymerization initiator, or performing a reaction under high pressure.

  Alternatively, the polymerization may be carried out in the presence of a compound having a large chain transfer constant for the purpose of adjusting the average molecular weight of the resin fine particles. Examples of the compound having a large chain transfer constant include a low molecular compound having a mercapto group, carbon tetrachloride, carbon tetrabromide, and the like.

The suspension polymerization method is an oil-soluble polymerization initiator, emulsification described later in an aqueous medium in which a colorant, a release agent, and the like are dispersed in a polymerizable monomer and a surfactant and other solid dispersant are contained. Emulsified and dispersed by the method. Thereafter, a polymerization reaction is performed to form particles, and then wet processing for attaching inorganic fine particles to the toner particle surfaces in the present invention may be performed. At that time, it is preferable to treat the resin fine particles from which excess surfactant and the like are removed by washing.
Examples of the polymerizable monomer include acids such as acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride; acrylamide, By using a part of acrylate or methacrylate having amino group such as methacrylamide, diacetone acrylamide or their methylol compounds, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, dimethylaminoethyl methacrylate, etc. Functional groups can be introduced. Further, by selecting a dispersant having an acid group or a basic group as the dispersant to be used, the dispersant can be adsorbed and left on the surface of the resin fine particles, and a functional group can be introduced.

  As the emulsion polymerization method, a water-soluble polymerization initiator and a polymerizable monomer are emulsified in water using a surfactant, and a latex is synthesized by a usual emulsion polymerization method. Separately, a dispersion in which a colorant, a release agent and the like are dispersed in an aqueous medium is prepared, and after mixing, the toner is aggregated to a toner size and heat-fused to obtain a toner. Thereafter, wet processing of inorganic fine particles described later may be performed. A functional group can be introduced on the surface of the resin fine particles by using the same monomer as the latex that can be used in the suspension polymerization method.

Examples of the dissolution suspension extension method include dissolving or dispersing an active hydrogen group-containing compound and a toner material containing a polymer capable of reacting with the active hydrogen group-containing compound, a colorant, and a release agent in an organic solvent. After preparing the toner solution, the toner solution is emulsified or dispersed in an aqueous medium to prepare a dispersion, and the active hydrogen group-containing compound and the active hydrogen group-containing compound can react in the aqueous medium. A toner can be obtained by reacting with a polymer to form an adhesive substrate in the form of particles and removing the organic solvent.
Examples of the toner material include an adhesive base obtained by reacting an active hydrogen group-containing compound, a polymer capable of reacting with the active hydrogen group-containing compound, a binder resin, a release agent, and a colorant. And the like, and further containing other components such as resin fine particles and a charge control agent as necessary.

The method for forming the resin fine particles (toner base particles) is not particularly limited as long as at least a radical polymerizable monomer is polymerized in at least one of the supercritical fluid and the subcritical fluid. It can be appropriately selected depending on the case.
Here, the apparatus used for forming the resin fine particles (toner base particles) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a composition containing at least a radical polymerizable monomer A device including a pressure vessel for polymerizing the toner and granulating the toner, and a pressure pump for supplying the supercritical fluid is preferable. As a processing method using the apparatus, first, a composition containing at least the radical polymerizable monomer is charged into the pressure vessel, and the supercritical fluid is supplied into the pressure vessel by a pressure pump, The supercritical fluid is brought into contact with a composition containing a radical polymerizable monomer to granulate resin fine particles. Then, when the supercritical fluid is returned to room temperature (25 ° C.) and normal pressure (0.1 MPa), the supercritical fluid becomes a gas, so that removal of the solvent is not necessary and conventionally required. Waste water generated by cleaning the surface of the fine resin particles is no longer necessary, and the burden on the environment is reduced.

The temperature at which the composition containing the radical polymerizable monomer is polymerized is not particularly limited as long as it is equal to or higher than the critical temperature of the supercritical fluid or the subcritical fluid to be used, and is appropriately selected according to the purpose. However, the upper limit of the critical temperature is preferably lower than the melting point of the substance forming the resin fine particles, and more preferably a temperature at which aggregation such as adhesion between the resin fine particles does not occur. The lower limit of the critical temperature is preferably a temperature at which the other fluid that can be added to the supercritical fluid can exist as a gas.
Specifically, the temperature at which the resin coating layer is formed is preferably 0 to 100 ° C, and more preferably 20 to 80 ° C. When the temperature exceeds 60 ° C., resin fine particles may be dissolved.

  The pressure at which the polymerization is performed is not particularly limited as long as it is equal to or higher than the critical pressure of the supercritical fluid or the subcritical fluid to be used, and can be appropriately selected according to the purpose, but is preferably 1 to 60 MPa.

Here, a method for forming resin fine particles using the polymerization granulator will be described. In the polymerization granulator shown in FIG. 1, a reactor vessel 9 having a volume of 1,000 cm ³ was used. In FIG. 1, 2 is an entrainer tank, 4 is a pressure pump, 6 is a temperature sensor, 113 is an injection nozzle, and 114 is a pressure sensor.
Carbon dioxide (CO ₂ ) was used as a gas for the supercritical fluid. A composition containing at least a radical polymerizable monomer was charged into the reaction vessel 9.

Next, carbon dioxide gas was supplied from the gas cylinder 1, pressurized by the pressurizing pump 3, and introduced into the reaction vessel 9 through the valve 7. At this time, the valve 5 is closed, and carbon dioxide gas is not introduced into the ejection container 112 side. Here, the pressure reducing valve 8 for discharging and ejecting remains closed, and the pressure in the reaction vessel 9 rises due to the introduction of high-pressure carbon dioxide. In addition, the temperature inside the reaction vessel 9 was adjusted to 320 K with the heater 117.
When the pressure in the reaction vessel 9 is 7.3 MPa or more, the reaction vessel 9 is in a supercritical state. Moreover, each valve | bulb 5 and 7 was adjusted, the pressure in reaction container 9 was set to 20 Mpa, and it set to the state in which the composition in the reaction container 9 containing at least a radically polymerizable monomer was dissolved. In this state, the valves 5 and 7 were closed, the dissolved state in the reaction vessel 9 was maintained for 120 minutes, and the supercritical fluid was sufficiently diffused and circulated. Thereafter, the valve 7 was opened, the pressure in the reaction vessel was adjusted to 10 MPa, and maintained for 60 minutes. Thereafter, carbon dioxide gas was introduced again from the high-pressure pump side, and introduction of carbon dioxide was continued while maintaining the pressure in the reaction vessel at 10 MPa. At this time, the composition containing the supercritical fluid carbon dioxide contained in the mixed solution and at least the radical polymerizable monomer dissolved in the supercritical carbon dioxide is recovered by a recovery mechanism (not shown). They are separated from each other into carbon dioxide and a composition containing at least a radically polymerizable monomer by a separation device (not shown) and reused.

  By continuing the introduction of supercritical carbon dioxide, all the composition containing at least the radical polymerizable monomer dissolved in the reaction vessel 9 was discharged out of the vessel and granulated in the reaction vessel 9. Only resin fine particles and supercritical carbon dioxide fluid. Thereafter, the valve is opened, and the supercritical carbon dioxide fluid is vaporized to produce resin fine particles.

The number average molecular weight (Mn) of the resin fine particles (toner base particles) is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1,000 to 500,000, and the weight average molecular weight (Mw) is 2,000 to 1,000,000 is preferable.
Here, the molecular weight of the resin fine particles can be measured by GPC (gel permeation chromatography) under the following conditions.
・ Apparatus: GPC-150C (manufactured by Waters)
Column: KF801-807 (manufactured by Shodex)
・ Temperature: 40 ℃
・ Solvent: THF (tetrahydrofuran)
・ Flow rate: 1.0 mL / min ・ Sample: 0.1 mL injection of a sample having a concentration of 0.05 to 0.6 mass% A molecular weight calibration curve prepared by a monodisperse polystyrene standard sample from the molecular weight distribution of the resin measured under the above conditions Was used as the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the resin fine particles.

  The obtained resin fine particles are suitably used as toner base particles, and preferably contain a colorant, a charge control agent, a release agent, and other components.

  The charge control agent is not particularly limited and may be appropriately selected from known ones according to the purpose. However, since a color tone may change when a colored material is used, a colorless or nearly white material may be used. Preferably, for example, nigrosine dye, triphenylmethane dye, chromium-containing metal complex dye, molybdate chelate pigment, rhodamine dye, alkoxy amine, quaternary ammonium salt (including fluorine-modified quaternary ammonium salt), alkylamide And a simple substance of phosphorus or a compound thereof, a simple substance of tungsten or a compound thereof, a fluorine-based activator, a metal salt of salicylic acid, a metal salt of a salicylic acid derivative, and the like. Among these, salicylic acid metal salts and metal salts of salicylic acid derivatives are preferred. These may be used individually by 1 type and may use 2 or more types together. There is no restriction | limiting in particular as said metal, According to the objective, it can select suitably, For example, aluminum, zinc, titanium, strontium, boron, silicon, nickel, iron, chromium, zirconium etc. are mentioned.

  Commercially available products may be used as the charge control agent. Examples of the commercially available products include quaternary ammonium salt Bontron P-51, oxynaphthoic acid metal complex E-82, and salicylic acid metal complex. E-84, E-89 of phenol-based condensate (both manufactured by Orient Chemical Co., Ltd.); TP-302, TP-415 of quaternary ammonium salt molybdenum complex (both manufactured by Hodogaya Chemical Co., Ltd.) ); Quaternary ammonium salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (both manufactured by Hoechst); LRA-901, LR-147 which is a boron complex (manufactured by Nippon Carlit Co., Ltd.); quinacridone; azo type Pigments; polymer compounds having functional groups such as sulfonic acid groups and carboxyl groups.

  The addition amount of the charge control agent is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.5 to 5 parts by mass, and 1 to 3 parts by mass with respect to 100 parts by mass of the resin fine particles. More preferred. When the addition amount is less than 0.5 parts by mass, the charging characteristics of the toner may be deteriorated. When the addition amount exceeds 5 parts by mass, the chargeability of the toner becomes too large, and the effect of the main charge control agent is reduced. The electrostatic attraction force with the developing roller is increased, and the fluidity of the developer and the image density may be reduced.

There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably from well-known things, For example, waxes etc. are mentioned suitably.
Examples of the waxes include low molecular weight polyolefin waxes, synthetic hydrocarbon waxes, natural waxes, petroleum waxes, higher fatty acids and metal salts thereof, higher fatty acid amides, and various modified waxes thereof. These may be used individually by 1 type and may use 2 or more types together.
Examples of the low molecular weight polyolefin wax include low molecular weight polyethylene wax and low molecular weight polypropylene wax.
Examples of the synthetic hydrocarbon wax include Fischer-Tropsch wax.
Examples of the natural waxes include beeswax, carnauba wax, candelilla wax, rice wax, and montan wax.
Examples of the petroleum waxes include paraffin wax and microcrystalline wax.
Examples of the higher fatty acid include stearic acid, palmitic acid, myristic acid, and the like.

There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 40-160 degreeC is preferable, 50-120 degreeC is more preferable, 60-90 degreeC is especially preferable.
If the melting point is less than 40 ° C., the wax may adversely affect the heat-resistant storage stability. If the melting point exceeds 160 ° C., it may easily cause a cold offset when fixing at a low temperature. May occur.

  There is no restriction | limiting in particular in the addition amount of the said mold release agent, Although it can select suitably according to the objective, 1-20 mass parts is preferable with respect to 100 mass parts of said resin fine particles, and 3-15 mass parts is more preferable. .

  The colorant is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. 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, Lead Red, Lead Red, Cadmium Red, Cad Muum Mercury Red, Antimon Zhu, Permanent Red 4R, PA Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Bordeaux 5B, Toluidine 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, Oh Lured, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene 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, Oxidation Chrome, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Ash Examples include degreen lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, and lithobon. These may be used individually by 1 type and may use 2 or more types together.

There is no restriction | limiting in particular as said dye, According to the objective, it can select suitably, For example, C.I. I. SOLVENT YELLOW (6, 9, 17, 31, 35, 100, 102, 103, 105), C.I. I. SOLVENT ORANGE (2, 7, 13, 14, 66), C.I. I. SOLVENT RED (5, 16, 17, 18, 19, 22, 23, 143.145, 146, 149, 150, 151, 157, 158), C.I. I. SOLVENT VIOLET (31, 32, 33, 37), C.I. I. SOLVEN BLUE (22, 63, 78, 83-86, 191, 194, 195, 104), C.I. I. SOLVEN GREEN (24, 25), C.I. I. SOLVEN BROWN (3, 9) and the like.
Moreover, there is no restriction | limiting in particular as a commercially available dye, According to the objective, it can select suitably, For example, Hodogaya Chemical Co., Ltd. Aizen SOT dye Yellow-1,3,4, Orange-1,2,3, Scallet-1, Red-1,2,3, Brown-2, Blue-1,2, Violet-1, Green-1,2,3, Black-1,4,6,8; Sudan dye manufactured by BASF Yellow-146, 150, Orange-220, Red-290, 380, 460, Blue-670; Dialresin Yellow-3G, F, H2G, HG, HC, HL, Orange-HS, G, Red, manufactured by Mitsubishi Kasei Co., Ltd. -GG, S, HS, A, K, H5B, Violet-D, Blue-J, G, N, K, P, H3G, 4G, Green C, Brown-A; Oil color YEllow-3G, GG-S, # 105, Orange-PS, PR, # 201, Scarlet- # 308, Red-5B, Brown-GR, # 416, manufactured by Orient Chemical Industries, Ltd. , Green-BG, # 502, Blue-BOS, IIN, Black-HBB, # 803, EB, EX; Sumiplast Blue GP, OR, Red FB, 3B, Yellow FL7G, GC manufactured by Sumitomo Chemical Co., Ltd .; Japan Kayalon Polyester Black EX-SF300, Kaya Set Red-B, Blue A-2R, etc. manufactured by Kayaku Co., Ltd. can be used.

  There is no restriction | limiting in particular in the addition amount of the said coloring agent, Although it can select suitably according to a coloring degree, 1-50 mass parts is preferable with respect to 100 mass parts of said resin fine particles.

The fluidity improver, which is the other component, means a material that can be surface-treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, a silane coupling agent Silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils, and the like.
The cleaning property improving agent is added to the resin fine particles in order to remove the developer after transfer remaining on the photosensitive member or the primary transfer medium, for example, zinc stearate, calcium stearate, stearic acid, polymethyl methacrylate fine particles, Examples thereof include polymer fine particles produced by soap-free emulsion polymerization such as polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 to 1 μm are suitable.

  The resin particles may contain additives such as the charge control agent, the release agent, and the colorant. The resin particles and various additives may be mixed and then kneaded, a supercritical fluid, and a subcritical fluid. And a method of kneading after mixing the resin particles and various additives is particularly preferable.

  In the method of kneading after mixing the resin particles and various additives, specifically, the resin particles and a known additive or resin are mixed by a mixer such as a Henschel mixer, and then a batch type two-roll, Banbury. Mixer, continuous twin screw extruder (for example, KTK type twin screw extruder (manufactured by Kobe Steel), TEM type twin screw extruder (manufactured by Toshiba Machine Co., Ltd.), TEX type twin screw extruder (manufactured by Nippon Steel) ), PCM type twin screw extruder (manufactured by Ikegai Iron Works Co., Ltd.), KEX type twin screw extruder (manufactured by Kurimoto Iron Works), continuous type single screw kneader (for example, Ko Neida (manufactured by Buss)), etc. The constituent materials can be incorporated into the resin particles by kneading the constituent materials using a thermal kneader or the like, and depending on the case, forming into pellets or sheets with various injectors and cooling. . If necessary, the resin is roughly crushed using a hammer mill, etc., and further pulverized by a fine pulverizer or mechanical pulverizer using a jet stream, and classified using a classifier using a swirling air stream or the Coanda effect. It can also be classified to a predetermined particle size by a machine.

<Toner>
The toner of the present invention is produced by the toner production method of the present invention, and further contains other components as necessary.

  The shape, size, etc. of the toner is not particularly limited and can be appropriately selected according to the purpose. The image density, average circularity, weight average particle size, weight average particle, and the like are as follows. It is preferable to have a ratio between the diameter and the number average particle diameter (weight average particle diameter / number average particle diameter), glass transition temperature, and the like.

The image density is preferably 1.90 or more, more preferably 2.00 or more, and particularly preferably 2.10 or more, as measured by a spectrometer (X-Light, 938 Spectrodensitometer). preferable.
If the image density is less than 1.90, the image density may be low and high image quality may not be obtained.
The image density is, for example, imagio Neo 450 (manufactured by Ricoh Co., Ltd.), and the amount of developer attached to copy paper (TYPE6000 <70W>, manufactured by Ricoh Co., Ltd.) is 1.00 ± 0.05 mg / cm ^2. The solid roller image was formed at a fixing roller surface temperature of 160 ± 2 ° C., and the image density at any six locations in the solid image obtained was measured using a spectrometer (938 Spectrodensitometer, manufactured by X-Light). It can be measured by measuring and calculating the average value.

The average circularity is a value obtained by dividing the perimeter of an equivalent circle having the same projected shape as the toner shape by the perimeter of the actual particles, and is preferably 0.900 to 0.980, for example, 0.950 to 0 .975 is more preferred. Note that particles having an average circularity of less than 0.94 are preferably 15% or less.
If the average circularity is less than 0.900, satisfactory transferability and a high-quality image free from dust may not be obtained. If the average circularity exceeds 0.980, image formation employing blade cleaning or the like is employed. In the system, defective cleaning occurs on the photoconductor and the transfer belt, and in the case of image formation with a high image area ratio such as a photographic image, an untransferred image is formed due to defective paper feeding, etc. The accumulated toner may become a transfer residual toner on the photoconductor, resulting in background smearing of the image, or it may contaminate the charging roller for charging the photoconductor in contact with the original charging ability. It may become impossible to demonstrate.

Here, the average circularity can be measured by using a flow particle image analyzer (Flow Particle Image Analyzer). For example, it can be measured using a flow type particle image analyzer FPIA-2000 manufactured by Toa Medical Electronics Co., Ltd.
In the measurement, fine dust is removed through a filter, and as a result, in 10 ml of water having 10 or less particles within a measurement range (for example, an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm) in 10 ⁻³ cm ³ of water. Add a few drops of a nonionic surfactant (preferably Contaminone N manufactured by Wako Pure Chemical Industries, Ltd.), add 5 mg of a measurement sample, and 20 kHz, 50 W / 10 cm with an ultrasonic dispersing device (UH-50 manufactured by SMT). ^3. Dispersion treatment for 1 minute under the condition of ³ and further dispersion treatment for a total of 5 minutes, the particle concentration of the measurement sample is 4,000 to 8,000 particles / 10 ⁻³ cm ³ (measurement circle equivalent diameter range particles The particle size distribution of particles having an equivalent-circle diameter of 0.60 μm or more and less than 159.21 μm is measured using the sample dispersion liquid (as an object).
The sample dispersion liquid is passed through a flow path (expanded along the flow direction) of a flat and flat transparent flow cell (thickness: about 200 μm). In order to form an optical path that passes across the thickness of the flow cell, the strobe and the CCD camera are mounted on the flow cell so as to be opposite to each other. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle has a certain range parallel to the flow cell 2. Taken as a dimensional image. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter.
In about 1 minute, the equivalent circle diameter of 1,200 or more particles can be measured, and the number based on the equivalent circle diameter distribution and the ratio (number%) of particles having a prescribed equivalent circle diameter can be measured. The results (frequency% and cumulative%) can be obtained by dividing the range of 0.06 to 400 μm into 226 channels (divided into 30 channels per octave). In actual measurement, particles are measured in the range where the equivalent circle diameter is 0.60 μm or more and less than 159.21 μm.

There is no restriction | limiting in particular as a weight average particle diameter of the said toner, Although it can select suitably according to the objective, For example, 3-10 micrometers is preferable and 3-8 micrometers is more preferable.
When the weight average particle size is less than 3 μm, in a two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be reduced. In the developer, toner filming on the developing roller and toner fusion to a member such as a blade are likely to occur because the toner layer is thinned. It becomes difficult to obtain an image of an image quality, and when the balance of the toner in the developer is performed, the variation in the particle diameter of the toner may increase.

The ratio of the weight average particle diameter to the number average particle diameter (weight average particle diameter / number average particle diameter) in the toner is preferably 1.00 to 1.25, and more preferably 1.00 to 1.10.
When the ratio of the weight average particle diameter to the number average particle diameter (weight average particle diameter / number average particle diameter) exceeds 1.25, the two-component developer can be applied to the surface of the carrier during long-term agitation in the developing device. The toner may be fused to reduce the charging ability of the carrier. In the case of a one-component developer, the toner filming on the developing roller or the toner is thinned so that the toner is fused to a member such as a blade. May occur easily, and it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the fluctuation of the toner particle size may increase. is there.

  The weight average particle diameter and the ratio of the weight average particle diameter to the number average particle diameter (weight average particle diameter / number average particle diameter) are, for example, a particle size measuring device “Coulter Counter TAII” manufactured by Coulter Electronics. Can be measured.

The glass transition temperature of the toner is preferably 40 to 70 ° C. If the glass transition temperature is less than 40 ° C, the heat-resistant storage stability may be insufficient, and if it exceeds 70 ° C, the low-temperature fixability may be adversely affected.
Here, the glass transition temperature (Tg) is specifically determined by the following procedure. Using a Shimadzu TA-60WS and DSC-60 as measurement devices, measurement can be performed under the following measurement conditions.
〔Measurement condition〕
・ Sample container: Aluminum sample pan (with lid)
-Sample amount: 5mg
Reference: Aluminum sample pan (alumina 10 mg)
・ Atmosphere: Nitrogen (flow rate 50ml / min)
・ Temperature condition Start temperature: 20 ℃
Temperature increase rate: 10 ° C / min
End temperature: 150 ° C
Holding time: None Temperature drop: 10 ° C / min
End temperature: 20 ° C
Holding time: None Temperature increase rate: 10 ° C / min
End temperature: 150 ° C
The measurement results were analyzed using the data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation. In the analysis method, the glass transition temperature is obtained from the DrDSC curve which is the DSC differential curve of the second temperature rise using the glass transition point analysis function in the same apparatus. In the present invention, as the glass transition temperature, the temperature of the first shoulder portion where the glass transition starts is defined as the glass transition temperature.

<Developer>
The developer used in the present invention contains at least the toner of the present invention, and contains other components appropriately selected such as a carrier. The developer may be a one-component developer or a two-component developer. However, when it is used for a high-speed printer or the like corresponding to the recent improvement in information processing speed, the life is improved. In view of the above, the two-component developer is preferable.
In the case of the one-component developer using the toner of the present invention, even if the balance of the toner is performed, there is little fluctuation in the particle diameter of the toner, and the filming of the toner on the developing roller or the toner is made thin. Therefore, the toner is not fused to a member such as a blade, and good and stable developability and image can be obtained even when the developing device is used (stirred) for a long time. In addition, in the case of the two-component developer using the toner of the present invention, even if the toner balance for a long time is performed, the fluctuation of the toner diameter in the developer is small, and it is good even for long-term stirring in the developing device. And stable developability can be obtained.

-Career-
There is no restriction | limiting in particular as said carrier, Although it can select suitably according to the objective, What has a core material and the resin layer which coat | covers this core material is preferable.

  There is no restriction | limiting in particular as a material of the said core material, It can select suitably from well-known things, For example, 50-90 emu / g manganese-strontium (Mn-Sr) type material, manganese-magnesium (Mn-) Mg) -based materials and the like are preferable, and highly magnetized materials such as iron powder (100 emu / g or more) and magnetite (75 to 120 emu / g) are preferable in terms of securing image density. In addition, a weakly magnetized material such as a copper-zinc (Cu—Zn) -based (30 to 80 emu / g) is advantageous in that it can weaken the contact with the photoconductor in which the toner is in a spiked state and is advantageous in improving the image quality. Is preferred. These may be used alone or in combination of two or more.

The core material has a volume average particle diameter of preferably 10 to 150 μm, more preferably 40 to 100 μm.
When the average particle diameter (volume average particle diameter (D ₅₀ )) is less than 10 μm, the distribution of carrier particles may increase the number of fine powders, lower the magnetization per particle, and cause carrier scattering. If the thickness exceeds 150 μm, the specific surface area may decrease and toner scattering may occur. In the case of a full color having a large solid portion, the reproduction of the solid portion may be deteriorated.

  The material of the resin layer is not particularly limited and can be appropriately selected from known resins according to the purpose. For example, amino resins, polyvinyl resins, polystyrene resins, halogenated olefin resins, Polyester resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, vinylidene fluoride And a copolymer of vinyl fluoride, a fluoroterpolymer such as a terpolymer of tetrafluoroethylene, vinylidene fluoride, and a non-fluorinated monomer, and a silicone resin. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the amino resins include urea-formaldehyde resins, melamine resins, benzoguanamine resins, urea resins, polyamide resins, and epoxy resins. Examples of the polyvinyl resins include acrylic resins, polymethyl methacrylate resins, and polyacrylonitrile resins. , Polyvinyl acetate resin, polyvinyl alcohol resin, polyvinyl butyral resin and the like. Examples of the polystyrene resin include polystyrene resin and styrene acrylic copolymer resin. Examples of the halogenated olefin resin include polyvinyl chloride. Examples of the polyester resin include polyethylene terephthalate resin and polybutylene terephthalate resin.

  The resin layer may contain conductive powder or the like as necessary. Examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. The average particle diameter of these conductive powders is preferably 1 μm or less. When the average particle diameter exceeds 1 μm, it may be difficult to control electric resistance.

For example, the resin layer is prepared by dissolving the silicone resin or the like in a solvent to prepare a coating solution, and then uniformly coating the coating solution on the surface of the core material by a known coating method, drying, and baking. It can be formed by doing. Examples of the coating method include a dipping method, a spray method, and a brush coating method.
There is no restriction | limiting in particular as said solvent, Although it can select suitably according to the objective, For example, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cellosolve, butyl acetate, etc. are mentioned.
The baking is not particularly limited, and may be an external heating method or an internal heating method. For example, a stationary electric furnace, a fluid electric furnace, a rotary electric furnace, a burner furnace, etc. The method of using, the method of using a microwave, etc. are mentioned.

The amount of the resin layer in the carrier is preferably 0.01 to 5.0% by mass.
When the amount is less than 0.01% by mass, it may not be possible to form the uniform resin layer on the surface of the core material. When the amount exceeds 5.0% by mass, the resin layer becomes too thick. As a result, granulation of carriers occurs, and uniform carrier particles may not be obtained.

  When the developer is the two-component developer, the content of the carrier in the two-component developer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 90 to 98% by mass Is preferable, and 93-97 mass% is more preferable.

Since the developer contains the toner of the present invention, it is possible to stably form a high-quality image with excellent charging performance during image formation.
The developer can be suitably used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, and a two-component development method. It can be particularly suitably used for a process cartridge, an image forming apparatus and an image forming method.

<Toner container>
The toner-containing container used in the present invention contains the toner or developer of the present invention in a container.
There is no restriction | limiting in particular as said container, It can select suitably from well-known things, For example, what has a container main body and a cap containing a toner etc. are mentioned suitably.
The size, shape, structure, material and the like of the container body containing toner are not particularly limited and can be appropriately selected according to the purpose. For example, the shape is preferably cylindrical. A spiral irregularity is formed on the peripheral surface, and the toner as the contents can be transferred to the discharge port side by rotating, and part or all of the spiral part has a bellows function, etc. Is particularly preferred.
The material of the toner-containing container body is not particularly limited, and those having good dimensional accuracy are preferable. For example, a resin is preferably used. Among them, for example, polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, Preferable examples include vinyl chloride resin, polyacrylic acid, polycarbonate resin, ABS resin, polyacetal resin, and the like.
The container containing toner is easy to store and transport, has excellent handling properties, and can be attached to a process cartridge, an image forming apparatus, etc., which will be described later, detachably and can be suitably used for replenishing toner.

<Process cartridge>
The process cartridge used in the present invention can develop an electrostatic latent image carrier carrying an electrostatic latent image and the electrostatic latent image carried on the electrostatic latent image carrier using a developer. At least developing means for forming a visual image, and other means appropriately selected as necessary.
The developing means includes a developer container that contains the toner or developer of the present invention, and a developer carrier that carries and transports the toner or developer contained in the developer container. And a layer thickness regulating member for regulating the thickness of the toner layer to be carried.

Here, for example, as shown in FIG. 2, the process cartridge includes an electrostatic latent image carrier 101, and includes a charging unit 102, a developing unit 104, a transfer unit 108, and a cleaning unit 107. And other means. In FIG. 2, reference numeral 103 denotes exposure by exposure means, and 105 denotes a recording medium.
Next, the image forming process using the process cartridge shown in FIG. 2 will be described. The electrostatic latent image carrier 101 is rotated by the charging means 102 while rotating in the direction of the arrow, and the exposure 103 by the exposure means (not shown). An electrostatic latent image corresponding to the exposure image is formed on the surface. The electrostatic latent image is developed by the developing unit 104, and the obtained visible image is transferred to the recording medium 105 by the transfer unit 108 and printed out. Next, the surface of the latent electrostatic image bearing member after the image transfer is cleaned by the cleaning unit 107, further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

(Image forming method and image forming apparatus)
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, and a fixing step, and other steps appropriately selected as necessary, for example, a static elimination step, a cleaning step. , Including recycling process, control process, etc.
The image forming apparatus used in the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit. Other selected means include, for example, a static elimination means, a cleaning means, a recycling means, a control means, and the like.

The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
There are no particular restrictions on the material, shape, structure, size, etc. of the latent electrostatic image bearing member (hereinafter sometimes referred to as “electrophotographic photoreceptor” or “photoreceptor”). The shape can be suitably selected from among them, and the shape thereof is preferably a drum shape. Examples of the material include inorganic photoconductors such as amorphous silicon and selenium, and organic photoconductors such as polysilane and phthalopolymethine. Can be mentioned. Among these, amorphous silicon or the like is preferable in terms of long life.

  The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then performing imagewise exposure, and is performed by the electrostatic latent image forming unit. be able to. The electrostatic latent image forming means includes, for example, at least a charger that uniformly charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise. Prepare.

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons and corotrons.

The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device.
The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger so as to form an image to be formed, and is appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image using the toner or the developer of the present invention to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer of the present invention, and can be performed by the developing unit.
The developing unit is not particularly limited as long as it can be developed using, for example, the toner or the developer of the present invention, and can be appropriately selected from known ones. For example, the toner of the present invention Preferably, a developer containing at least a developer and having at least a developer capable of bringing the toner or the developer into contact or non-contact with the electrostatic latent image is provided. Etc. are more preferable.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

  The developer accommodated in the developing device is a developer containing the toner of the present invention, but the developer may be a one-component developer or a two-component developer. The toner contained in the developer is the toner of the present invention.

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the latent electrostatic image bearing member (photoconductor) of the visible image using a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. There may be one transfer means or two or more transfer means.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The heating in the heating and pressing means is usually preferably 80 to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrostatic latent image carrier. Preferably mentioned.

The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited as long as it can remove the electrophotographic toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Suitable examples include brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

The control means is a process for controlling the respective steps, and can be suitably performed by the control means.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as sequencers and computers.

  One mode of carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. An image forming apparatus 100 shown in FIG. 3 includes a photosensitive drum 10 (hereinafter referred to as “photosensitive member 10”) as the electrostatic latent image carrier, a charging roller 20 as the charging unit, and an exposure as the exposure unit. The apparatus 30 includes a developing device 40 as the developing means, an intermediate transfer member 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a static elimination lamp 70 as the static elimination means.

  The intermediate transfer member 50 is an endless belt, and is designed so as to be movable in the direction of the arrow in the figure by three rollers 51 that are arranged on the inner side and stretch the belt. Part of the three rollers 51 also functions as a transfer bias roller that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer member 50. An intermediate transfer member cleaning blade 90 is disposed in the vicinity of the intermediate transfer member 50, and a transfer bias for transferring a visible image (toner image) to the recording medium 95 (secondary transfer) is applied. Possible transfer rollers 80 as the transfer means are arranged to face each other. Around the intermediate transfer member 50, a corona charger 58 for applying a charge to the visible image on the intermediate transfer member 50 is connected to the electrostatic latent image carrier 10 in the rotation direction of the intermediate transfer member 50. The contact portion between the intermediate transfer member 50 and the contact portion between the intermediate transfer member 50 and the recording medium 95 is disposed.

  The developing device 40 includes a developing belt 41 as a developer carrying member, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C provided around the developing belt 41. Yes. The black developing unit 45K includes a developer accommodating portion 42K, a developer supply roller 43K, and a developing roller 44K. The yellow developing unit 45Y includes a developer container 42Y, a developer supply roller 43Y, and a developing roller 44Y. The magenta developing unit 45M includes a developer container 42M, a developer supply roller 43M, and a developing roller 44M. The cyan developing unit 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 by a plurality of belt rollers, and a part thereof is in contact with the electrostatic latent image carrier 10.

  In the image forming apparatus 100 shown in FIG. 3, for example, the charging roller 20 uniformly charges the photosensitive drum 10. The exposure device 30 performs imagewise exposure on the photosensitive drum 10 to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 10 is developed by supplying toner from the developing device 40 to form a visible image (toner image). The visible image (toner image) is transferred (primary transfer) onto the intermediate transfer member 50 by the voltage applied from the roller 51, and further transferred (secondary transfer) onto the transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. The residual toner on the photoconductor 10 is removed by the cleaning device 60, and the charge on the photoconductor 10 is temporarily removed by the charge eliminating lamp 70.

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. The image forming apparatus 100 shown in FIG. 4 does not include the developing belt 41 in the image forming apparatus 100 shown in FIG. 3, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and the like around the photoconductor 10. Except for the fact that the cyan developing unit 45C is arranged directly opposite, it has the same configuration as the image forming apparatus 100 shown in FIG. In FIG. 4, the same components as those in FIG. 3 are denoted by the same reference numerals.

Another mode for carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. The tandem image forming apparatus shown in FIG. 5 is a tandem type color image forming apparatus. The tandem image forming apparatus includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.
The copying apparatus 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 be rotated clockwise in FIG. 5. An intermediate transfer member cleaning device 17 for removing residual toner on the intermediate transfer member 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 is a tandem type in which four image forming units 18 of yellow, cyan, magenta, and black are arranged to face each other along the conveyance direction. A developing device 120 is disposed. An exposure device 21 is disposed in the vicinity of the tandem developing device 120. A secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the transfer paper conveyed on the secondary transfer belt 24 and the intermediate transfer body 50 are in contact with each other. Is possible. A fixing device 25 is disposed in the vicinity of the secondary transfer device 22. The fixing device 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, a sheet reversing device 28 for reversing the transfer paper for image formation on both sides of the transfer paper is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25. .

  Next, formation of a full-color image (color copy) using the tandem developing device 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 document is set on the contact glass 32 of the scanner 300. 400 is closed.

  When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. Immediately after that, the scanner 300 is driven, and 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 received by the reading sensor 36 through the imaging lens 35 to be color. An original (color image) is read and used as black, yellow, magenta, and cyan image information.

  The image information of black, yellow, magenta, and cyan is stored in each image forming unit 18 (black image forming unit, yellow image forming unit, magenta image forming unit, and cyan image) in the tandem developing unit 120. Each of the image forming units forms black, yellow, magenta, and cyan toner images. That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem developing means 120 is a static image as shown in FIG. An electrostatic latent image carrier 10 (black electrostatic latent image carrier 10K, yellow electrostatic latent image carrier 10Y, magenta electrostatic latent image carrier 10M, and cyan electrostatic latent image carrier 10C); The electrostatic latent image bearing member 10 is uniformly charged, and the electrostatic latent image bearing member is exposed (L in FIG. 6) for each color image corresponding to each color image information. An exposure device that forms an electrostatic latent image corresponding to each color image on the electrostatic latent image carrier, and each color toner (black toner, yellow toner, magenta toner, and cyan toner) Develop with A developing device 61 for forming a toner image with each color toner, a transfer charger 62 for transferring the toner image onto the intermediate transfer member 50, a cleaning device 63, and a static eliminator 64, respectively. Each single color image (black image, yellow image, magenta image, and cyan image) can be formed based on the image information of the colors. The black image, the yellow image, the magenta image, and the cyan image formed in this way are respectively transferred to the black electrostatic latent image carrier 10K on the intermediate transfer member 50 that is rotationally moved by the support rollers 14, 15, and 16. Black image formed on top, yellow image formed on electrostatic latent image carrier 10Y for yellow, magenta image formed on electrostatic latent image carrier 10M for magenta, and electrostatic latent image carrier for cyan The cyan image formed on 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 to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Each sheet is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the sheet feed roller 142 is rotated to feed out sheets (recording paper) on the manual feed tray 54, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. . 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 synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member 50, and a sheet (recording paper) is interposed between the intermediate transfer member 50 and the secondary transfer device 22. The secondary color transfer device 22 transfers the composite color image (color transfer image) onto the sheet (recording paper), thereby transferring the color image onto the sheet (recording paper). Is formed. The residual toner on the intermediate transfer member 50 after 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 conveyed by the secondary transfer device 22 and sent to the fixing device 25, where the combined color image (color) is generated by heat and pressure. (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 reversed by the sheet reversing device 28 and transferred again. After being guided to the position and recording an image on the back surface, the image is discharged by the discharge roller 56 and stacked on the discharge tray 57.

  In the image forming method and the image forming apparatus of the present invention, the toner of the present invention having a sharp particle size distribution and good toner characteristics such as chargeability, environmental properties, and stability over time is used. A quality image can be formed.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Synthesis Example 1)
-Synthesis of surfactant 1 (perfluoroacrylate resin)-
30 parts by volume of perfluorooctyl acrylate with respect to 100 parts by volume of the pressure-resistant reaction cell is charged, carbon dioxide as a supercritical fluid is supplied into the reaction cell by a supply cylinder, a pressure pump and a temperature controller To 30 MPa and 80 ° C. To this, 1 part by mass of AIBN (azobisisobutyronitrile) as a polymerization initiator was added with respect to 100 parts by mass of the perfluorooctyl acrylate, and reacted for 24 hours.
After completion of the reaction, using a back pressure valve, supercritical carbon dioxide was flowed to the outside at a flow rate of 5.0 L / min over 6 hours to remove residual monomers, and then normal temperature (25 ° C.), normal pressure (0 .1 MPa) was gradually returned to synthesize “Surfactant 1”. The resulting surfactant 1 had a glass transition temperature (Tg) of 50.5 ° C.

(Synthesis Example 2)
-Synthesis of Surfactant 2-
30 parts by volume of a mixed monomer composed of 30 mol% perfluorooctyl acrylate and 70 mol% of styrene with respect to 100 parts by volume of the pressure-resistant reaction cell, and carbon dioxide as a supercritical fluid is supplied to the reaction cell by a supply cylinder. The pressure was adjusted to 30 MPa and 80 ° C. with a pressure pump and a temperature controller. To this, 1 part by mass of AIBN (azobisisobutyronitrile) as a polymerization initiator was added with respect to 100 parts by mass of the mixed monomer and reacted for 24 hours.
After completion of the reaction, using a back pressure valve, supercritical carbon dioxide was flowed to the outside at a flow rate of 5.0 L / min over 6 hours to remove residual monomers, and then normal temperature (25 ° C.), normal pressure (0 .1 MPa) was gradually returned to synthesize “surfactant 2 (copolymer)”.

(Synthesis Example 3)
-Synthesis of surfactant 3-
Mono-methacryloxypropyl Terminated Poly Dimethylsiloxane (manufactured by Amax Co., Ltd., MCR-M17) 70 mol%, mixed monomer consisting of 24 mol% styrene and 6 mol% butyl acrylate First, carbon dioxide as a supercritical fluid was supplied into the reaction cell by a supply cylinder, and the pressure was adjusted to 30 MPa and 80 ° C. with a pressure pump and a temperature controller. To this, 1 part by mass of AIBN (azobisisobutyronitrile) as a polymerization initiator was added with respect to 100 parts by mass of the monomer and reacted for 24 hours.
After completion of the reaction, using a back pressure valve, supercritical carbon dioxide was flowed to the outside at a flow rate of 5.0 L / min over 6 hours to remove residual monomers, and then normal temperature (25 ° C.), normal pressure (0 .1 MPa) was gradually returned to synthesize “Surfactant 3”.

(Synthesis Example 4)
-Synthesis of Dispersant 1-
In a round bottom flask equipped with a magnetic stirrer and a trap, 5 parts by mass of titanium oxide (MT-500B, manufactured by Teika Co., Ltd.) dried at 110 ° C. for 24 hours, 150 parts by mass of dehydrated toluene, 1.5 Part by mass of CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ was added, and 0.5 part by mass of acetic acid was further added as a buffer. The resulting suspension was refluxed at 50-60 ° C. for 7 hours, cooled to room temperature, and then filtered with suction. Subsequently, the residue was washed with toluene and dried at 110 ° C. for 4 hours. Thereafter, it was washed with ethanol, dried at 110 ° C. for 4 hours, and pulverized in a menor mortar to synthesize “dispersant 1” as a white powder.

Example 1
-Preparation of polymerizable monomer composition-
A polymerizable monomer composed of 80 parts by mass of styrene and 20 parts by mass of n-butyl acrylate (the glass transition temperature (Tg) of the copolymer obtained = 55 ° C. (calculated value)) and 0.1% of surfactant 1 were added. 5 parts by mass, 0.3 parts by mass of divinylbenzene, and 2 parts by mass of natural gas-based Fischer-Tropsch wax (manufactured by D Shell MS, trade name: FT-100, melting point 92 ° C.) are mixed with high shearing force. Using a possible homomixer (made by Tokki Kako Co., Ltd., TK type), the mixture was stirred and mixed at a rotation speed of 11,000 rpm to perform uniform dispersion. “Polymerizable monomer composition 1 (mixed solution)” Was prepared.

<Supercritical polymerization process>
100 parts by mass of the obtained “polymerizable monomer composition 1”, filled in a pressure-resistant treatment cell, selecting carbon dioxide as a supercritical fluid, supplying the carbon dioxide into the treatment cell by a supply cylinder, The pressure was adjusted to 30 MPa and 80 ° C. with a pressure pump and a temperature controller. To this, 3 parts by mass of AIBN (azobisisobutyronitrile) as a polymerization initiator was added and reacted for 24 hours.
After completion of the reaction, using a back pressure valve, after flowing supercritical carbon dioxide at a flow rate of 5.0 L / min for 6 hours to remove residual monomer, 0.5 mass of oil black HBB (manufactured by Orient Chemical Co., Ltd.) And 0.02 part by mass of Oil Orange 201 (manufactured by Orient Chemical Co., Ltd.) were added and dyeing was performed for 1 hour, and then gradually returned to normal temperature (25 ° C.) and normal pressure (0.1 MPa). Thus, “Toner 1” was produced.

<Solubility in carbon dioxide as a supercritical fluid>
When 1 g of the polymerizable monomer was put into a high-pressure vessel (with an internal volume of 50 ml) with a viewing window, carbon dioxide as a supercritical fluid was mixed, and after 30 minutes had passed, the inside of the high-pressure vessel was visually observed. It was soluble without causing cloudiness or phase separation.
Also, 1 g of the polymerizable monomer polymer is put into a high-pressure vessel (with an internal volume of 50 ml) with a viewing window, carbon dioxide as a supercritical fluid is mixed, and after 30 minutes, When visually observed, it was insoluble due to white turbidity or phase separation.

(Example 2)
-Preparation of polymerizable monomer composition-
A polymerizable monomer composed of 80 parts by mass of styrene and 20 parts by mass of n-butyl acrylate (the glass transition temperature (Tg) of the resulting copolymer (calculated value) = 55 ° C.) and 1 part of surfactant 2 Parts, 0.3 parts by weight of divinylbenzene, 5 parts by weight of carnauba wax (trade name: CWT01, manufactured by Toyo Petrolite Co., Ltd.), C.I. I. 7 parts by mass of Pigment Blue (15: 3) is stirred at a rotation speed of 11,000 rpm with a homomixer that can be mixed with a high shear force (manufactured by Tokki Kako Co., Ltd., TK type) and mixed to be uniformly dispersed And “Polymerizable monomer composition 2 (mixed solution)” was prepared.

<Supercritical polymerization process>
100 parts by mass of the obtained “polymerizable monomer composition 2” and 1 part by mass of silica fine particles (average particle size: 20 nm) as a dispersant were filled in a pressure-resistant treatment cell equipped with the homomixer. Carbon dioxide as a critical fluid is selected, the carbon dioxide is supplied into the processing cell by a supply cylinder, adjusted to 10 MPa and 65 ° C. with a pressure pump and a temperature controller, and stirred at 10000 rpm while being a polymerization initiator. As a result, 5 parts by mass of V-65 (manufactured by Wako Pure Chemical Industries, Ltd., 2,2′-azobis (2,4-dimethylvaleronitrile)) was added and reacted for 24 hours.
After completion of the reaction, using a back pressure valve, flow supercritical carbon dioxide for 5 hours at a flow rate of 5.0 L / min to remove residual monomers, and then to room temperature (25 ° C.) and normal pressure (0.1 MPa). By gradually returning, “Toner 2” was produced.

<Solubility in carbon dioxide as a supercritical fluid>
When 1 g of the polymerizable monomer was put into a high-pressure vessel (with an internal volume of 50 ml) with a viewing window, carbon dioxide as a supercritical fluid was mixed, and after 30 minutes had passed, the inside of the high-pressure vessel was visually observed. It was soluble without causing cloudiness or phase separation.
Also, 1 g of the polymerizable monomer polymer is put into a high-pressure vessel (with an internal volume of 50 ml) with a viewing window, carbon dioxide as a supercritical fluid is mixed, and after 30 minutes, When visually observed, it was insoluble due to white turbidity or phase separation.

(Example 3)
-Preparation of polymerizable monomer composition-
A homomixer that can mix 80 parts by mass of styrene and 20 parts by mass of n-butyl methacrylate, 2 parts by mass of surfactant 3, and 0.3 parts by mass of divinylbenzene with high shearing force ( Stirring at a rotation speed of 11,000 rpm and mixing evenly by Special Machine Chemical Co., Ltd. (TK type) to prepare “Polymerizable monomer composition 3 (mixed solution)”.

-Preparation of supercritical dispersion-
5 parts by mass of synthetic ester wax (Nippon Yushi Co., Ltd., trade name: WEP05), C.I. I. 7 parts by mass of Pigment Blue (15: 3) is filled in a pressure-resistant treatment cell equipped with a homomixer, carbon dioxide is selected as a supercritical fluid, and the carbon dioxide is supplied into the treatment cell by a supply cylinder. The pressure was adjusted to 25 MPa and 80 ° C. using a pressure pump and a temperature controller, and the mixture was sufficiently stirred at 10,000 rpm. The pressure and temperature were adjusted to 25 MPa and 50 ° C. to prepare “Dispersion 1”.

<Supercritical polymerization process>
100 parts by mass of the “polymerizable monomer composition 3” is filled in a pressure-resistant treatment cell equipped with a stirrer, carbon dioxide is selected as a supercritical fluid, and the carbon dioxide is supplied into the treatment cell by a supply cylinder. V-65 (manufactured by Wako Pure Chemical Industries, Ltd., 2,2′-azobis (2,4-dimethylvaleronitrile) while stirring and adjusting to 25 MPa and 80 ° C. with a pressure pump and a temperature controller. ) Was added in an amount of 2 parts by mass and reacted for 24 hours.
After completion of the reaction, using a back pressure valve, flow supercritical carbon dioxide at a flow rate of 5.0 L / min for 6 hours to remove the residual monomer, and then add dispersion 1 at 25 MPa and 50 ° C. for aggregation. To make “Toner 3”.

<Solubility in carbon dioxide as a supercritical fluid>
When 1 g of the polymerizable monomer was put into a high-pressure vessel (with an internal volume of 50 ml) with a viewing window, carbon dioxide as a supercritical fluid was mixed, and after 30 minutes had passed, the inside of the high-pressure vessel was visually observed. It was soluble without causing cloudiness or phase separation.
Also, 1 g of the polymerizable monomer polymer is put into a high-pressure vessel (with an internal volume of 50 ml) with a viewing window, carbon dioxide as a supercritical fluid is mixed, and after 30 minutes, When visually observed, it was insoluble due to white turbidity or phase separation.

Example 4
In Example 2, “Toner 4” was produced in the same manner as in Example 2 except that Dispersant 1 was used instead of silica fine particles.

(Example 5)
100 parts by mass of the “polymerizable monomer composition 1” was filled in a pressure-resistant treatment cell, and as an entrainer, 1% by volume of ethanol was filled with respect to the pressure-resistant vessel volume. Carbon dioxide was selected as a supercritical fluid, the carbon dioxide was supplied into the treatment cell by a supply cylinder, and the pressure was adjusted to 30 MPa and 80 ° C. with a pressure pump and a temperature controller. To this, 3 parts by mass of AIBN (azobisisobutyronitrile) was added as a polymerization initiator and reacted for 24 hours.
After completion of the reaction, using a back pressure valve, after flowing supercritical carbon dioxide at a flow rate of 5.0 L / min for 6 hours to remove residual monomer, 0.5 mass of oil black HBB (manufactured by Orient Chemical Co., Ltd.) Part and oil orange 201 (manufactured by Orient Chemical Co., Ltd.) 0.02 part by mass, and after dyeing for 1 hour, gradually return to room temperature (25 ° C.) and normal pressure (0.1 MPa). Toner 5 "was prepared.

<Solubility in carbon dioxide as a supercritical fluid>
When 1 g of the polymerizable monomer was put into a high-pressure vessel (with an internal volume of 50 ml) with a viewing window, carbon dioxide as a supercritical fluid was mixed, and after 30 minutes had passed, the inside of the high-pressure vessel was visually observed. It was soluble without causing cloudiness or phase separation.
Also, 1 g of the polymerizable monomer polymer is put into a high-pressure vessel (with an internal volume of 50 ml) with a viewing window, carbon dioxide as a supercritical fluid is mixed, and after 30 minutes, When visually observed, it was insoluble due to white turbidity or phase separation.

(Comparative Example 1)
-Preparation of resin fine particles-
A sealable reaction vessel equipped with a stirring blade, a cooling condenser, and a nitrogen gas introduction tube was installed in a constant temperature water bath, and the reaction vessel was charged with the following composition.
-Ethanol-70 parts by weight-Distilled water-30 parts by weight-Polyvinylpyrrolidone-4 parts by weight

Next, the stirring blade was rotated to completely dissolve the polyvinylpyrrolidone. Next, the following composition was charged into the container.
Styrene: 28 parts by mass Ethyl acrylate: 10 parts by mass n-butyl methacrylate: 2 parts by mass Ethylene glycol dimethacrylate: 0.2 parts by mass Carbon tetrachloride: 0. 03 parts by mass ・ Benzoyl peroxide: 0.6 parts by mass

Subsequently, while rotating the stirring blade, nitrogen gas was blown into the container to completely expel oxygen, and then the temperature in the water tank was raised to 50 ± 0.1 ° C. to initiate polymerization. After 2 hours, the temperature in the water tank was raised to 65 ± 0.1 ° C. to increase the reaction rate.
After 12 hours from the start of the reaction, the mixture was cooled to room temperature to obtain a dispersion. As a result of sampling a part and measuring by gas chromatography with an internal standard method, it was confirmed that the polymerization rate exceeded 90%. Thus, “resin fine particle 1” was synthesized.
The obtained “resin fine particles 1” were measured for particle size distribution using a Coulter multisizer (100 μm aperture tube) as follows. The weight average particle size (D4) was 6.83 μm, and the number average particle size (Dn). The ratio (D4 / Dn) was 6.04 μm and 1.13.

  Next, 20 parts by mass of ethanol, 30 parts by mass of solvent black were dissolved by heating, and 20 parts by mass of 100 parts by mass of ethanol and 100 parts by mass of “resin fine particles 1” were obtained. It took in the container and stirred at 50 degreeC for 1 hour, and dyeing | staining of resin fine particles was performed. Thereafter, the dyeing solution was cooled to room temperature, centrifuged, the supernatant was removed, and an operation of redispersing in ethanol was performed three times, followed by filtration to prepare “Comparative Toner 1”.

(Comparative Example 2)
-Preparation of resin kneaded material-
Raw materials in a ratio of 178 parts by mass of a styrene-acrylic resin (glass transition temperature = 65 ° C.) and 10 parts by mass of carnauba wax (trade name: CWT01, manufactured by Toyo Petrolite Co., Ltd.) are charged into a Henschel mixer for 10 minutes. The mixed raw material mixture was melt-kneaded at 130 ° C. or lower using a Nidex MOS140-800 manufactured by Mitsui Mining Co., Ltd. and dispersed to obtain a resin kneaded product (P-1).

-Supercritical polymerization process-
150 parts by mass of the resin kneaded product (P-1), 10 parts by mass of surfactant 2, 10 parts by mass of phthalocyanine pigment (CI Pigment Blue (15: 3)), and a charge control agent (aluminum salicylate) ) 1 part by mass is charged into a pressure-resistant reaction cell (1,000 mL) incorporating a stirrer having a comb-shaped blade, a heater, a temperature and pressure monitor, and carbon dioxide is selected as a supercritical fluid. Was supplied to the treatment cell by a supply cylinder, adjusted to 25 MPa and 90 ° C. with a pressure pump and a temperature adjuster, and stirred at 3,000 rpm for 3 hours. After this was cooled to 4 ° C., the pressure reducing valve was gradually opened to produce comparative toner 2.
The obtained comparative toner 2 has a particle size distribution by Coulter Multisizer (100 μm aperture tube) measured as follows, the weight average particle size (D4) is 11.5 μm, and the number average particle size (Dn) is 5. It was 5 μm. In addition, the ratio (D4 / Dn) was very wide as 2.09, and generation of fine powder and coarse powder was also observed.

<Solubility in carbon dioxide as a supercritical fluid>
After putting 1 g of the styrene-acrylic resin in a high-pressure vessel (with an internal volume of 50 ml) with a viewing window, putting carbon dioxide as a supercritical fluid, and stirring for 30 minutes at 25 MPa and 90 ° C., When the inside of the high-pressure vessel was visually observed, phase separation occurred and it was insoluble.

<Measurement of weight average particle size and particle size distribution>
About each obtained toner, the weight average particle diameter and particle size distribution by the Coulter counter method were measured using Coulter counter TA-II or Coulter multisizer II (all are the Coulter company make).
First, 0.1 to 5 ml of a surfactant (alkyl benzene sulfonate) was added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution. Here, the electrolytic solution is prepared by preparing a 1% by mass NaCl aqueous solution using first grade sodium chloride, and for example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample was further added. The electrolyte in which the sample is suspended is subjected to a dispersion treatment for 1 to 3 minutes with an ultrasonic disperser, and the weight and number of toners are measured with the measuring device using a 100 μm aperture as an aperture, The number distribution was calculated. From the obtained distribution, the weight average particle diameter (D4) and number average particle diameter (Dn) of the toner were determined. The results are shown in Table 1.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.

Further, the ratio (D4 / Dn) was determined from the results of the weight average particle diameter (D4) and the number average particle diameter (Dn) of the obtained toner, and the particle size distribution was evaluated according to the following criteria. The results are shown in Table 1.
[Evaluation of particle size distribution (D4 / Dn)]
A: D4 / Dn is less than 1.15 B: D4 / Dn is 1.15 or more and less than 1.25 Δ: D4 / Dn is 1.25 or more and less than 1.50 X: D4 / Dn is 1.50 or more

-Preparation of developer-
To 100 parts by mass of each toner obtained, 0.7 part by mass of hydrophobic silica and 0.3 part by mass of hydrophobic titanium oxide were mixed using a Henschel mixer. Next, “Developers 1 to 7” comprising 5% by mass of each of the toners subjected to the external additive treatment and 95% by mass of a copper-zinc ferrite carrier coated with a silicone resin and having an average particle diameter of 40 μm were prepared. .
The toners used in “Developers 1 to 7” correspond to “Toners 1 to 5” and “Comparative toners 1 and 2”, respectively.

  Next, for the developers of Examples 1 to 5 and Comparative Examples 1 and 2 thus obtained, image density, fusion to a photoconductor, and charge amount were measured as follows. The results are shown in Table 1.

<Image density>
About each obtained developer, the adhesion amount of each developer is 1. on copy paper (TYPE6000 <70W>, manufactured by Ricoh Co., Ltd.) using a tandem color electrophotographic apparatus (image Neo 450, manufactured by Ricoh Co., Ltd.). A solid image of 00 ± 0.05 mg / cm ² was formed. The solid image was repeatedly formed on 8,000 copy sheets. The image density of the obtained solid image was visually observed for the initial stage and after the end of 8,000 sheets and evaluated based on the following criteria. This evaluation corresponds to an embodiment of the image forming method of the present invention.
〔Evaluation criteria〕
◯: There was no change in image density and high image quality was obtained at the initial stage and after endurance of 8,000 sheets.
Δ: The image density was slightly lowered and the image quality was lowered after the endurance of 8,000 sheets.
X: After the endurance of 8,000 sheets, the image density was remarkably lowered and the image quality was greatly lowered.

<Fusion to photoconductor>
After the image formation, the fusion of the toner to the organic photoreceptor (OPC) was visually observed and evaluated based on the following criteria.
〔Evaluation criteria〕
○: No fusion of toner to the photoreceptor was observed.
Δ: Some fusion of toner to the photoreceptor was observed.
X: Fusion of toner to photoreceptor was observed.

<Charge amount>
6 g of each developer was weighed, charged into a metal cylinder that could be sealed, and blown to obtain the charge amount. The toner concentration was adjusted to 4.5 to 5.5% by mass.

<Comprehensive evaluation>
From the above evaluation results, the following criteria were evaluated comprehensively.
〔Evaluation criteria〕
○: Good ×: Bad

From the results of Table 1, Examples 1 to 5 using toner processed with a supercritical fluid have a sharp particle size distribution, excellent charging performance, and high image quality as compared with Comparative Example 1 and Comparative Example 2. It was confirmed that the concentration was obtained.
The toner of Comparative Example 1 has a low image density due to the low colorability of the dye. However, when a supercritical fluid is used, the dye enters the inside of the resin fine particles, so that sufficient dyeing and image density can be obtained. understood.
In the toner of Comparative Example 2, the styrene-acrylic resin is dissolved in the supercritical fluid to precipitate the toner particles. However, since the solubility of the styrene-acrylic resin in the supercritical fluid is low, the particle size distribution is sharp. No toner was obtained.
Further, in the toner production method of the present invention, almost no waste liquid is generated, and a dry polymerization toner can be obtained by simply returning to normal pressure, which is low cost, low environmental load, energy saving, and resource saving. Therefore, it was confirmed that this was an innovative toner production method compared to the conventional method.

  The toner manufactured by the toner manufacturing method of the present invention has a sharp particle size distribution, good toner characteristics such as charging property, environmental property, stability over time, low cost, and no waste liquid. Since no drying process is required, no residual monomer is contained, and the environmental load is small, for example, a laser printer, a direct digital plate making machine, a full color copying machine using a direct or indirect electrophotographic multicolor image developing system, a full color It can be widely used for laser printers and full-color plain paper fax machines.

FIG. 1 is a schematic view showing an example of a polymerization granulator used in the polymerization granulation step of the present invention. FIG. 2 is a schematic explanatory diagram illustrating an example of a process cartridge. FIG. 3 is a schematic explanatory view showing an example of an image forming apparatus used in the image forming method of the present invention. FIG. 4 is a schematic explanatory view showing another example of an image forming apparatus used in the image forming method of the present invention. FIG. 5 is a schematic explanatory view showing an example of an image forming apparatus (tandem color image forming apparatus) used in the image forming method of the present invention. 6 is a partially enlarged schematic explanatory view of the image forming apparatus shown in FIG.

Explanation of symbols

1 Gas cylinder 3 Pressure pump 5, 7, 8 Valve 9 Reaction vessel 10 Photoconductor (photosensitive 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 Manual feed path 54 Manual feed tray 55 Switching claw 56 Discharge roller 57 discharge tray 58 corona charger 60 cleaning device 61 developing device 62 transfer charger 63 photoconductor cleaning device 64 discharger 70 discharger lamp 80 transfer roller 90 cleaning device 95 transfer paper 100 image forming device 101 photoconductor 102 charging means 103 exposure 104 Developing means 105 Recording medium 107 Cleaning means 108 Transfer means 120 Tandem developer 121 Heating roller 122 Fixing roller 123 Fixing belt 124 Pressure roller 125 Heating source 126 Clear Ning roller 127 temperature sensor 130 document table 142 paper feed roller 143 paper bank 144 paper feed cassette 145 separation roller 146 paper feed path 147 transport roller 148 paper feed path 150 copying machine main body 160 charging device 200 paper feed table 300 scanner 400 automatic document transport Equipment (ADF)

Claims (17)

A method for producing a toner comprising granulating a toner by polymerizing at least a radical polymerizable monomer in at least one of a supercritical fluid and a subcritical fluid,
A toner production method, wherein the polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and subcritical fluid. A method for producing a toner comprising granulating a toner by dispersing and polymerizing at least a radical polymerizable monomer in at least one of a supercritical fluid and a subcritical fluid,
A method for producing a toner, wherein the dispersion polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and subcritical fluid. A method for producing a toner comprising granulating a toner by suspension polymerization of at least a radical polymerizable monomer in at least one of a supercritical fluid and a subcritical fluid,
A method for producing a toner, wherein the suspension polymer of the radical polymerizable monomer is insoluble in at least one of the supercritical fluid and subcritical fluid. A method for producing a toner, in which at least one of radically polymerizable monomers is polymerized in at least one of a supercritical fluid and a subcritical fluid, and the resulting resin fine particles are aggregated or associated to form a granule,
A toner manufacturing method, wherein the resin fine particles are insoluble in at least one of the supercritical fluid and subcritical fluid.   The method for producing a toner according to claim 1, wherein the radical polymerizable monomer is soluble in at least one of the supercritical fluid and the subcritical fluid.   The method for producing a toner according to claim 1, wherein at least one of the supercritical fluid and the subcritical fluid contains at least carbon dioxide.   The method for producing a toner according to claim 1, wherein a surfactant is contained in at least one of the supercritical fluid and the subcritical fluid.   The method for producing a toner according to claim 7, wherein the surfactant is at least one selected from a fluorine-containing compound and a silicon-containing compound.   The method for producing a toner according to claim 1, wherein a dispersant is contained in at least one of the supercritical fluid and the subcritical fluid.   The method for producing a toner according to claim 9, wherein the dispersant contains one of inorganic fine particles and organic fine particles.   The method for producing a toner according to claim 1, wherein at least one of the supercritical fluid and the subcritical fluid includes an entrainer.   The toner production method according to claim 11, wherein the content of the entrainer is 0.1 to 10% by mass.   The method for producing a toner according to claim 11, wherein the entrainer is a poor solvent for the toner binder resin under normal temperature and normal pressure (25 ° C., 0.1 MPa).   The method for producing a toner according to claim 11, wherein the entrainer is a lower alcohol selected from methanol, ethanol, and propanol.   A toner manufactured by the toner manufacturing method according to claim 1.   The weight average particle diameter is 3 to 10 µm, and the ratio of the weight average particle diameter to the number average particle diameter (weight average particle diameter / number average particle diameter) is 1.00 to 1.25. Toner. An electrostatic latent image forming step for forming an electrostatic latent image on an electrostatic latent image carrier, and developing the electrostatic latent image with the toner according to any one of claims 15 to 16 to form a visible image An image forming method comprising: a developing step for forming the image; a transfer step for transferring the visible image to a recording medium; and a fixing step for fixing the transferred image transferred to the recording medium.