JP4542986B2 - Electrophotographic toner, developer, image forming apparatus using the developer, and process cartridge - Google Patents

Description

  The present invention relates to a toner used as a developer for developing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing, and the like, a manufacturing method thereof, and an image forming method using the toner. Further, the present invention relates to an electrophotographic toner used in an electrophotographic developing apparatus such as a copying machine, a laser printer, and a plain paper fax machine using a direct or indirect electrophotographic developing system, and an image forming method. Furthermore, the present invention relates to an electrophotographic toner used in an electrophotographic developing apparatus such as a full-color copying machine, a full-color laser printer, a full-color plain paper fax machine or the like using a direct or indirect electrophotographic multicolor image developing system, and an image forming method.

  Conventionally, a latent image formed electrically or magnetically in an electrophotographic apparatus, an electrostatic recording apparatus or the like has been visualized with toner. For example, in electrophotography, an electrostatic charge image (latent image) is formed on a photoreceptor, and then the latent image is developed with toner to form a toner image. The toner image is usually transferred onto a transfer material such as paper, and then fixed onto the transfer material such as paper by a method such as heating. Further, the photosensitive member is cleaned by a cleaning member in order to form a latent image again.

  The toner used for developing an electrostatic image is generally colored particles containing a colorant, a charge control agent, and other additives in a toner binder. There is chemical toner.

  In recent years, there has been an increasing demand for chemical toners in order to obtain high-quality and high-quality images. The chemical toner manufacturing method can make the shape of the particles uniform, such as a spherical shape, and can have a small particle size and a sharp particle size distribution, and is excellent in image reproducibility and granularity. In particular, by making the particle shape spherical, the transfer efficiency can be improved, the toner consumption can be reduced to obtain a high-quality image without missing images, and the running cost can be reduced. If the transfer efficiency is very good, there is no need for a cleaning unit for removing untransferred toner from the photoreceptor or transfer medium, which has the advantages of reducing the size and cost of the equipment and eliminating waste toner. Because. At present, various chemical toner production methods have been devised. For example, a toner production method using a suspension polymerization method, an emulsion polymerization aggregation method, or a polymer dissolution suspension method is being studied.

  On the other hand, in a fixing process in which a toner image developed on a latent image carrier is heated and fixed on a transfer paper, a heating roller fixing method is widely used because of its energy efficiency. In such a heat fixing system, a part of the toner image adheres to the surface of the heat roller at the time of fixing, and this is liable to cause a so-called offset phenomenon in which the toner image is transferred onto the copy paper and causes scumming. Therefore, in order to prevent the occurrence of the offset phenomenon, a method of adding a wax as a releasing agent to the toner is known. For example, solid silicon varnish, higher fatty acid, higher alcohol, various waxes and the like are used as the releasing agent. Addition is proposed (for example, refer patent documents 1-4).

  However, since wax has a small molecular weight and is softer than the binder resin, a so-called filming phenomenon that shifts to a carrier, a photoreceptor, or a developing sleeve is likely to occur. When the filming (this is called spent) phenomenon on the carrier occurs, the toner cannot be appropriately triboelectrically charged. As a result, charging failure occurs, which causes background stains and the like. In addition, when a photoconductor filming phenomenon occurs, an abnormal image with a white band appears on a halftone image, or the effect of developing bias decreases depending on the filming state of the sleeve, resulting in an abnormal image in which the image density decreases. Occurs. These defects are gradually aggravated by the repetition of the copying process, and become worse and it becomes difficult to maintain the state of the initial image.

  Accordingly, in order to obtain a stable image quality over a long period of time when using a toner containing a wax, an improvement measure focusing on the dispersion state of the wax, the binder resin, and the wax has been required.

  The wax itself is compatible with the binder resin, and if it exists in an extremely finely dispersed state in the toner, it cannot exhibit the releasability, which is the original function, and therefore may exist as incompatible domain particles. It is said that it is necessary. However, if there is no appropriate compatibility, the seepage of the wax is hindered by the binder resin at the time of heat fixing, and the releasing effect does not work between the fixing roller and the toner instantaneously.

  In order to appropriately control the wax dispersion, it is known to use a wax dispersion aid (see, for example, Patent Documents 5 and 6), but the exudation of wax during heat fixing is suppressed, The separation between the fixing roller and the fixed image is deteriorated. In addition, as a technique for suppressing wax filming, a technique in which the domain diameter and shape of the wax in the toner cross section are defined (for example, refer to Patent Documents 7 and 8), and a technique using low molecular weight polypropylene wax as the wax ( For example, see Patent Document 9). However, the exudation of wax was never good.

  On the other hand, by using carnauba wax and nonpolar paraffin as the wax and regulating the acid value of the binder resin, the wax exuding from the binder resin is improved (for example, see Patent Document 10). However, the wax filming was not suppressed.

JP 51-143333 A JP-A-57-148752 JP 58-97056 A JP 60-247250 A JP 2001-255690 A JP 2001-249485 A JP 2004-219964 A JP 2004-287185 A Japanese Patent No. 3375881 JP 2004-287231 A

  In an electrophotographic toner containing a release agent, in order to suppress so-called wax filming (or wax spent) in which the release agent migrates onto a carrier, a photoreceptor, or a developing sleeve, Have been improved. However, at the time of heat fixing, the binder resin does not solve the problem of hindering the exudation of wax, so that sufficient release effect cannot be exhibited at low temperature fixing, and cold offset occurs or fixing to the fixing roller. There was a problem that paper was wound around.

  Conventional chemical toners (water-based granulated toners) can achieve high image quality by achieving a sharp particle size distribution and a small particle size. However, the physical properties of the toner, that is, the toner composition (resin or resin) The index of hardness and softness that the (wax) constitutes was insufficient as compared with the pulverized toner. For this reason, each part related to the electrophotographic process in the image forming apparatus is in a state where it has been adapted to the pulverized toner and evolved. Therefore, even if this chemical toner is used as a developer, sufficient developer performance is achieved. I couldn't.

  The object of the present invention is to suppress wax filming, and at the time of heat-fixing, the wax exudes instantaneously with a little heat energy, has excellent fixing roller separation, and has both low-temperature fixability and hot offset resistance. It is to provide a photographic toner. Another object of the present invention is to provide a developer, an image forming apparatus, and a process cartridge using the electrophotographic toner.

  As a result of studying the above problems, the present inventors have adjusted the crosslink density, crystallinity, or molecular mobility of the toner to an appropriate range, so that the wax and the binder resin maintain appropriate compatibility, As a result, it was found that wax filming can be suppressed. In addition, it is possible to provide a toner that exhibits good exudation of wax with a binder resin during heat fixing and can instantly exhibit excellent releasability even in a low temperature fixing system.

That is, the problems of the present invention are solved by the following technical means and methods.
(1) For an electrophotographic toner obtained by dispersing a toner composition comprising at least a binder resin, a release agent, and a colorant in an aqueous medium, a free induction decay curve obtained by a pulse NMR method When the electrophotographic toner is separated into three curves derived from the hard component, the soft component, and the interface component between the hard component and the soft component, the spin-spin relaxation time of the curve derived from the hard component ( An electrophotographic toner, wherein T ₂ s) is 35 to 90 μs, and a proton ratio (Hs) of the hard component is 0.2 to 0.6.
(2) In the electrophotographic toner described in (1), the ratio T ₂ s / the spin-spin relaxation time (T ₂ s) of the curve derived from the hard component and the proton ratio (Hs) of the hard component The toner for electrophotography, wherein Hs is 110 to 145.
(3) In the electrophotographic toner according to (1) or (2), the spin-spin relaxation time (T ₂ l) of the curve derived from the soft component is 1.5 to 3.5 ms. A toner for electrophotography, wherein the proton ratio (Hl) of the component is 0.1 to 0.2.
(4) The electrophotographic toner according to any one of (1) to (3), wherein the binder resin contains a polyester resin.
(5) In the electrophotographic toner according to any one of (1) to (4), a compound having an active hydrogen group and a moiety having a site capable of reacting with the active hydrogen group in an organic solvent. The polymer and the colorant are dissolved or dispersed to form a solution or dispersion, the solution or dispersion is dispersed in the aqueous medium, and then the compound having an active hydrogen group and the polymer are reacted. An electrophotographic toner obtained by removing the organic solvent after or while reacting.
(6) In the electrophotographic toner according to any one of (1) to (5), a spin-spin relaxation time (T ₂ m) of a curve derived from an interface component between the hard component and the soft component is 0. An electrophotographic toner characterized by being 2 to 0.6 ms.
(7) The electrophotographic toner according to any one of (1) to (6), wherein the releasing agent is a carbonyl group-containing wax.
(8) A two-component developer comprising the electrophotographic toner according to any one of (1) to (7) and a carrier made of magnetic particles.
(9) An electrostatic charge image carrier, a charging means for charging the electrostatic charge image carrier, an exposure means for forming an electrostatic charge image on the charged electrostatic charge image carrier, and the electrostatic charge image carrier. A developing unit that forms a toner image with the developer according to claim 8, a transfer unit that electrostatically transfers the toner image to a transfer material, and a fixing unit that heat-fixes the toner image on the transfer material. And an image forming apparatus.
(10) In the image forming apparatus according to (9), the charging unit performs charging by bringing a charging member into contact with the electrostatic image carrier and applying a voltage to the charging member. The image forming apparatus is characterized.
(11) The image forming apparatus according to (9) or (10), wherein the electrostatic image carrier is an amorphous silicon electrostatic image carrier.
(12) In the image forming apparatus according to any one of (9) to (11), the fixing unit includes a heating body including a heating element, a film in contact with the heating body, and the film through the film. An image forming apparatus, comprising: a pressure member that is in pressure contact with a heating body; and passing the transfer material onto which the toner image is transferred between the film and the pressure member to heat and fix the toner image. Be a device.
(13) In the image forming apparatus according to any one of (9) to (11), the fixing unit is formed of a magnetic metal and heated by electromagnetic induction, and is arranged in parallel with the heating roller. A fixing roller, an endless belt-shaped toner heating medium that is stretched between the heating roller and the fixing roller, heated by the heating roller and rotated by the rollers, and the fixing via the toner heating medium A pressure roller that is in pressure contact with the roller and rotates to form a fixing nip, and passes the transfer material onto which the toner image has been transferred between the toner heating medium and the pressure roller, and the toner An image forming apparatus that heat-fixes an image.
(14) In the image forming apparatus according to any one of (9) to (13), the developing unit applies an electric field for applying an alternating electric field when developing the electrostatic image on the electrostatic image carrier. An image forming apparatus having a printing unit.
(15) In a process cartridge in which at least the electrostatic charge image carrier and the developing unit are integrally supported and detachable from the main body of the image forming apparatus, the developing unit is any one of (1) to (7) A process cartridge which holds the electrophotographic toner described in 1.

  According to the electrophotographic toner of the present invention, the wax filming on the photoreceptor and the carrier is suppressed, and at the time of heat fixing, the wax exudes instantly with a small amount of heat energy, excellent in fixing roller separation property, and low temperature. The fixing property and the hot offset resistance can be combined. Further, it is possible to sufficiently match the image forming apparatus as described above, and to fully exhibit the potential of the toner.

  Next, the embodiment of the present invention will be described in detail. Here, the toner, the manufacturing method and material of the developer, and the overall system relating to the electrophotographic process that are used in the present invention can be used as long as the conditions are satisfied.

<Pulse NMR>
The present invention defines the molecular mobility of the polymer material constituting the toner as measured by pulse NMR. Details will be described below.
The pulse NMR method is used when analyzing the molecular mobility of a polymer material, and is an effective means for evaluating the molecular mobility and heterogeneity of a heterogeneous composite polymer material such as a toner. When a polymer material is irradiated with a pulsed electromagnetic wave in a magnetic field, the spin energy of hydrogen nuclei in the polymer material transitions to a high energy state, and then follows a relaxation process in which the hydrogen nuclei return to the original energy state again. Pulsed NMR observes this relaxation process, and a relaxation curve in which magnetization decays with respect to time is obtained. Here, this relaxation curve is called a free induction decay curve (FID: Free Induction Decay), and the relaxation time obtained from this is the spin-spin relaxation time (T ₂ ). The free induction decay curve is a superposition of relaxation curves derived from three components: a hard component with low molecular mobility, a soft component with high molecular mobility, and an interface component between the hard component and the soft component. By analyzing by the non-linear least square method, it is possible to separate into three relaxation curves derived from the three components. FIG. 1 shows an example of a free induction decay curve obtained by measuring the electrophotographic toner of the present invention by a pulse NMR method, and a hard component, a soft component, and an interface between the hard component and the soft component obtained by decomposing the curve. Three relaxation curves of the components are shown.

  The hard component having low molecular mobility is generally a component derived from a hard material having high crosslinkability and crystallinity, and conversely, the soft component having high molecular mobility is derived from a soft material. On the other hand, it is known that the spin-spin relaxation time is shorter as the molecular mobility is lower and longer as the molecular mobility is higher.

Accordingly, the relaxation curve having the shortest spin-spin relaxation time (T ₂ s) among the three separated relaxation curves is the hard component, and the relaxation having the longest spin-spin relaxation time (T ₂ l). The curve is the soft component. The remaining component is an interface component between the hard component and the soft component, and the spin-spin relaxation time of this component is represented by T ₂ m.

  The proton ratio of each component is obtained from each relaxation curve, and the hard component, the soft component, and the interface component between the hard component and the soft component are represented by Hs, Hl, and Hm (Hs + Hl + Hm = 1), respectively.

The T ₂ s of the toner in the present invention is 35 to 90 μs, preferably 55 to 85 μs, more preferably 60 to 80 μs. The smaller T ₂ s, the lower the molecular mobility of the toner and the higher the degree of crosslinking and crystallinity. In addition, T ₂ s is supposed to be small even when the material has high heterogeneity.

The relationship between T ₂ s and wax filming or wax exudation is not completely elucidated, but when T ₂ s is within this range, the molecular mobility of the binder resin and wax in the toner The compatibility is most appropriate, and the wax tends to flow in the binder resin at the time of heat-fixing. Further, since the binder resin and the wax are appropriately compatible, it is considered that the wax existing on the toner surface does not easily move to the carrier, the photoreceptor, and the developing sleeve, and the wax filming can be suppressed. If it is larger than this range, the wax is too compatible with the binder resin or the domain diameter becomes too small, and the original releasability cannot be obtained. On the other hand, when it is small, the exuding property of the wax is poor, and filming due to the wax existing on the toner surface occurs.

  On the other hand, the proton ratio Hs of the hard component is preferably 0.2 to 0.6, and preferably 0.3 to 0.4. When it was larger than this range, the hard component hindered the fixing property, and the low-temperature fixing property deteriorated. On the other hand, when it is small, hot offset is likely to occur during high-temperature fixing, and sufficient releasability is not exhibited.

The ratio of T ₂ s to Hs (T ₂ s / Hs) may be 110 to 145, preferably 125 to 135. The ratio of T ₂ s to Hs is a characteristic value suitable for showing the balance between the hardness of the hard component or the inhomogeneity in the toner and the amount of the component. The smaller the value, the more the hard component exists. The larger the numerical value, the less the soft component tends to exist. If the hard component is excessively hard and excessively present in the toner, the low-temperature fixability deteriorates. Conversely, if the hard component is soft and the abundance is small, the low-temperature fixability is relatively good. Hot offset resistance and heat-resistant storage stability deteriorate. Accordingly, there is an optimum amount of hardness and amount of the hard component. By setting the hardness within the above range, a toner having both low-temperature fixability, hot offset resistance, and heat-preserving stability can be obtained.

T ₂ l is preferably 1.5 to 3.5 ms, more preferably 2.0 to 3.0 ms, and particularly preferably 2.2 to 2.7 ms. When T ₂ l becomes too large, the toner storage stability tends to be poor, and when T ₂ l becomes small, the low-temperature fixability tends to be inhibited. Therefore, the above range is preferable.
The proton ratio Hl of the soft component is preferably 0.1 to 0.2, more preferably 0.15 to 0.2. This range is the range where the low temperature fixability and the hot offset resistance are most compatible, and the low temperature fixability was particularly good.

Furthermore, the relaxation time T ₂ m of the interface component between the hard component and the soft component has characteristics close to that of the hard component. T ₂ m is preferably 0.2 to 0.6 ms, and preferably 0.2 to 0.35 ms. When it is within this range, it has been found that the suppression of wax filming and the exuding property of the wax, which are the main effects of the present invention, become better.

  Although the pulse NMR apparatus is not particularly limited, in the present invention, using JNM-MU25 (manufactured by JEOL Ltd.), by the solid echo method (90 ° -τ-90 ° -τ pulse), Measurement was performed under the conditions of measurement temperature: 100 ° C., 90 ° pulse width: 2.2 μs, delay time: 8.0 μs, repetition time: 2.0 s, and number of integrations: 32 times.

<Toner>
The toner used in the present invention is an electrophotographic toner obtained by dispersing a toner composition comprising at least a binder resin, a release agent, and a colorant in an aqueous medium, a so-called chemical toner. As long as the conditions are satisfied, all known ones can be used and are not particularly limited. For example, a method of dissolving and / or dispersing at least a binder resin, a release agent, and a colorant in an organic solvent (solvent) and dispersing and dissolving the solution / dispersion in an aqueous medium (dissolution suspension), A method in which a release agent and a colorant are dissolved and / or dispersed in a polymerizable monomer which is a precursor of a resin and the solution / dispersion is dispersed in an aqueous medium and polymerized and granulated (suspension polymerization, dispersion). Polymerization), a primary monomer fine particle is produced by emulsifying and polymerizing a polymerizable monomer that is a precursor of a binder resin in an aqueous medium, and a primary fine particle of a release agent and a colorant that are other toner materials. It includes those obtained by agglomeration in an aqueous medium and granulation as toner particles (emulsion aggregation).

  On the other hand, the toner by the conventional pulverization method is easily broken at the interface between the binder resin and the wax when pulverizing the bulk toner, so that the wax is easily exposed on the toner surface and the dispersibility of the wax is also poor. For this reason, it is easy to perform wax filming, and it is not preferable from the viewpoint of the exuding property of wax.

  Further, from the viewpoint of low temperature fixability, the binder resin used is preferably a polyester resin. In the present invention, a toner dissolves or disperses a polymer having a site capable of reacting with a compound having an active hydrogen group, a release agent, and a colorant in at least an organic solvent, and the solution or the dispersion is used as an aqueous medium. Electrophotographic film characterized in that the organic solvent is removed, washed and dried after or while reacting a polymer having a site capable of reacting with the compound having an active hydrogen group. Toner was used.

  In the method for producing the polymerized toner, a polyester resin having high resin selectivity and high low-temperature fixability can be used. Moreover, it is excellent in granulation property and it is easy to control the particle size, particle size distribution, and shape. Furthermore, since the toner composition is dispersed in an organic solvent, it is excellent in material dispersibility and controllability, so that the toner is preferably produced by the above production method.

Further, the molecular mobility of the toner is determined by several factors such as the molecular structure, molecular weight, viscoelasticity, crystallinity, and crosslinking degree of the binder resin and wax. In the present invention, the control means is It is not particularly limited. However, the above-described toner production method is preferable because the degree of crosslinking of the resin can be easily controlled by the heating temperature in the heating step after granulation and the elongation terminator. Specific means will be described in the embodiments described later.
Details of the toner manufacturing method and materials used in the present invention will be described below.

[Organic solvent phase]
~ Organic solvent ~
The organic solvent used for forming the organic solvent phase in the present invention can be used without particular limitation as long as it can dissolve at least the functional group-containing polyester resin described later. In particular, since the organic solvent needs to be distilled off after the dispersion step of the organic solvent phase in the aqueous medium phase described later, the boiling point is less than 150 ° C. in order to facilitate the distillation step. It is preferable to use a volatile organic solvent. Specific examples of the organic solvent used in the present invention include, for example, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, acetic acid. Examples thereof include methyl, ethyl acetate, methyl ethyl ketone, acetone, tetrahydrofuran and the like, and these can be used singly or in combination of two or more. Among these, non-halogen solvents are particularly preferable, and methyl acetate and ethyl acetate are preferable from the viewpoint of safety. The amount of solvent used relative to 100 parts of the toner composition is usually 40 to 300 parts, preferably 60 to 140 parts, and more preferably 80 to 120 parts.

-Functional group-containing polyester resin-
The functional group-containing polyester resin used in the present invention is dissolved in the organic solvent and, as will be described later, undergoes an extension reaction and / or a crosslinking reaction with an active hydrogen-containing compound to be described later in an aqueous medium, resulting in a higher molecular weight toner. It is a component that forms a binder (binder resin).

  Examples of the functional group-containing polyester resin include a polyester prepolymer having a functional group that reacts with active hydrogen such as an isocyanate group. The polyester prepolymer preferably used in the present invention is the polyester prepolymer (A) having this isocyanate group. This polyester prepolymer (A) is produced by reacting a polyisocyanate (PIC) with a polyester having a polycondensate of a polyol (PO) and a polycarboxylic acid (PC) and having an active hydrogen group. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable. Examples of the polyol include diol (DIO) and trivalent or higher polyol (TO), and DIO alone or a mixture of DIO and a small amount of TO is preferable. Diols include alkylene glycols (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, etc.) Alkylene oxide glycol (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.), alicyclic diol (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.), bisphenol (Bisphenol A, bisphenol F, bisphenol S, etc.), alkylene oxides of the alicyclic diols (ethylene oxide, propylene oxide, butylene) Kisaido etc.) adducts, alkylene oxide (ethylene oxide of the bisphenols, propylene oxide, butylene oxide, etc.) adducts. Among these, alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols are preferable. Particularly preferred are alkylene oxide adducts of bisphenols and combinations thereof with alkylene glycols having 2 to 12 carbon atoms. Examples of the trivalent or higher polyols include 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.), and trivalent or higher phenols (trisphenol PA, Phenol novolac, cresol novolac, etc.), and alkylene oxide adducts of the above trivalent polyphenols. Examples of the polycarboxylic acid (PC) include dicarboxylic acid (DIC) and trivalent or higher polycarboxylic acid (TC), and DIC alone or a combination of DIC and a small amount of TC is preferable. Dicarboxylic acids include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.), alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.), aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.) ) And the like. Among these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polycarboxylic acid include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). The polycarboxylic acid may be subjected to a condensation reaction with a polyol as the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) described above.

  In order to prepare a polyester having an alcoholic hydroxyl group at the terminal by a polycondensation reaction, the polyol component and the polycarboxylic acid component are used in an equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Usually, it is 2/1 to 1/1, preferably 1.5 / 1 to 1/1, and more preferably 1.3 / 1 to 1.02 / 1.

  Examples of the polyisocyanate (PIC) used to prepare the polyester prepolymer (A) by reacting with the alcoholic hydroxyl group of the polyester include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-di-). Isocyanatomethyl caproate, etc.), alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.), aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.), araliphatic diisocyanates (α, α, α ', α') -Tetramethylxylylene diisocyanate, etc.), isocyanurates; those obtained by blocking the polyisocyanate with a phenol derivative, oxime, caprolactam, etc. Combinations of two or more of these and the like.

  The use ratio of the polyisocyanate is usually 5/1 to 1/1, preferably 4/1, as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. To 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. If the equivalent ratio is too high, the low-temperature fixability of the obtained toner may be deteriorated. On the other hand, if the equivalent ratio is too low, the urea bond content in the reaction product with amines will be low, and the resulting toner will be resistant to hot offset. This is not preferable because the properties may deteriorate.

  The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

  In the present invention, as described above, the polyester prepolymer (A) is used by being dissolved in the organic solvent phase. The amount used and the amount of the polyester prepolymer (A) is 10 to 55% by weight as the content in the toner base. , Preferably 10 to 40% by weight, more preferably 15 to 30% by weight.

  In the present invention, the polyester modified with a urea bond may contain a urethane bond (—O (CO) NH—) together with a urea bond (—NH (CO) NH—). The molar ratio between the urea bond content and the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

-Combination of non-reactive low molecular weight polyester-
In the present invention, as a toner binder component, not only the elongation reaction and / or crosslinking reaction product of the functional group-containing polyester resin and the active hydrogen compound described below, but also non-reactive polyester (PE) is contained in the organic solvent phase. It can be dissolved and used together. By using this PE in combination, the low-temperature fixability of the toner of the present invention and the glossiness when used in a full-color apparatus are improved, which is preferable to the case where the elongation reaction and / or crosslinking reaction product is used alone. Examples of PE include a polycondensate of a polyol and a polycarboxylic acid similar to the polyester used for the reaction with the polyisocyanate (PIC), and preferable ones are also the same as described above.

  Moreover, PE may be modified not only with unmodified polyester but also with a chemical bond other than a urea bond, for example, with a urethane bond. When formed into a toner, it is preferable in terms of low-temperature fixability and hot offset resistance that the elongation reaction and / or crosslinking reaction product and PE are at least partially compatible. Therefore, the polyester prepolymer (A) and PE preferably have similar compositions.

  In the present invention, when PE is contained in the organic solvent phase, the blending amount is 10/90 to 55/45, preferably 10/90 to 40 / as the weight ratio of the polyester prepolymer (A) and PE. 60, more preferably 15/85 to 30/70. When the weight ratio of the polyester prepolymer (A) is too low, hot offset resistance is deteriorated and it is difficult to achieve both heat-resistant storage stability and low-temperature fixability.

  In the present invention, the peak molecular weight of the weight average molecular weight measured by GPC (gel permeation chromatography) of PE is 5000 to 25000, preferably 8000 to 20000, and more preferably 13,000 to 18000. If the molecular weight is too low, the heat-resistant storage stability is deteriorated, whereas if it is too high, the low-temperature fixability is deteriorated.

  In the present invention, the acid value of PE is 15 to 45 mgKOH / g, preferably 20 to 35 mgKOH / g. Thus, by using a medium to high acid value PE resin, the low-temperature fixability can be improved without impairing the hot offset resistance. If the acid value is lower than this range, improvement in low-temperature fixability cannot be expected so much. On the other hand, if the acid value is too high, the reaction between the active hydrogen and the prepolymer tends to be inhibited, and the granulation property is lowered or the negative chargeability is reduced. It tends to be too strong and is not preferred.

  Moreover, it is preferable that the hydroxyl value of PE is 5 or more, More preferably, it is 10-120, Most preferably, it is 20-80. If the hydroxyl value is too low, it is difficult to achieve both heat-resistant storage stability and low-temperature fixability.

  The organic solvent phase may further contain a toner binder other than those described above, for example, a conventionally known toner binder such as styrene resin, acrylic resin, epoxy resin, styrene-acrylic acid ester copolymer.

~ Active hydrogen-containing compounds ~
As will be described later, the above-mentioned polyester prepolymer (A) having an isocyanate group is made to have a higher molecular weight by an extension reaction and / or a crosslinking reaction with an active hydrogen compound.

  As the active hydrogen compound used in the present invention, amines (B) are preferably used, and a urea-modified polyester resin (UMPE) can be obtained by reaction with the isocyanate group of the polyester prepolymer (A). This has excellent performance as a toner binder.

  As the amines (B), the diamine (B1), trivalent or higher polyamine (B2), amino alcohol (B3), amino mercaptan (B4), amino acid (B5), and amino groups of B1 to B5 were blocked. (B6) etc. are mentioned. Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.), alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexylmethane, diamino). Cyclohexane, isophorone diamine, etc.), and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.). Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the B1 to B5 amino group blocked (B6) include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a combination of B1 and a small amount of B2.

  The use ratio of the amines (B) is equivalent to the isocyanate group [NCO] in the prepolymer (A) having an isocyanate group and the amino group [NHx] (x is 1 or 2) in the amines (B). The ratio [NCO] / [NHx] is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. . If the equivalent ratio is too high or too low, the molecular weight of the urea-modified polyester becomes low, and the hot offset resistance of the resulting toner deteriorates.

~ Extension terminator ~
If necessary, the molecular mobility of the toner can be controlled by adjusting the molecular weight and the degree of crosslinking of the modified polyester such as urea-modified polyester using an elongation terminator. As elongation terminators, monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those blocked (ketimine compounds), monoalcohols (methyl alcohol, ethyl alcohol, n-propyl alcohol, n-butyl alcohol) , Isobutyl alcohol, n-pentyl alcohol, isopentyl alcohol, n-hexyl alcohol, n-octyl alcohol, n-decyl alcohol, cyclopentanol, cyclohexanol, benzyl alcohol, diphenyl alcohol, triphenyl alcohol and the like. Among these, particularly preferred are n-butyl alcohol, isobutyl alcohol, n-pentyl alcohol, isopentyl alcohol, n-hexyl alcohol and the like. These exhibit the most suitable reactivity as an elongation terminator acting on an isocyanate group in the present invention. Furthermore, since the boiling point is around 100 ° C., it is easy to remove the unreacted elongation terminator monomer, and it is preferable because it shows a property that it is difficult to dissolve in an aqueous medium during emulsification.

  The use ratio of the elongation terminator depends on the compound used, but if it is a monoalcohol, the equivalent ratio of the isocyanate group [NCO] and the monoalcohol [OH] in the prepolymer (A) having an isocyanate group [ NCO] / [OH] is usually changed to 1 / 0.01 to 1/1, preferably 1 / 0.1 to 1 / 0.8 to adjust the degree of crosslinking of the prepolymer.

  In the present invention, the elongation terminator is used by being dispersed in an oil phase, but is not particularly limited, and may be dispersed in an aqueous phase in advance or charged into an emulsified dispersion. It may be used.

-Property of toner binder-
In the present invention, as described above, a urea-modified polyester resin obtained by reaction of the polyester prepolymer (A) and the amines (B) is used as a toner binder, and a non-reactive polyester or the like is used. Other components (including resins used in the preparation of the colorant master batch described later) are also used in combination.

  In the present invention, the glass transition point (Tg) of the toner binder is 50 to 70 ° C., preferably 55 to 65 ° C. If Tg is too low, the heat-resistant storage stability of the toner is deteriorated. Conversely, if Tg is too high, the low-temperature fixability becomes insufficient. In the dry toner of the present invention, the use of a urea-modified polyester resin or the like tends to have good heat-resistant storage stability even when the glass transition point is low as compared with known polyester toners. As the storage elastic modulus of the toner binder, the temperature (TG ′) at which the measurement frequency is 20 Hz becomes 1000 Pa is usually 100 ° C. or higher, preferably 110 to 200 ° C. When the TG ′ is too low, the hot offset resistance is deteriorated. As the viscosity of the toner binder, the temperature (Tη) at which the measurement frequency is 20 Hz becomes 100 Pa · s is usually 180 ° C. or less, preferably 90 to 160 ° C. If the Tη is too high, the low-temperature fixability deteriorates. That is, TG ′ is preferably higher than Tη from the viewpoint of achieving both low temperature fixability and hot offset resistance. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or more. More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more. The upper limit of the difference is not particularly limited. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 to 100 ° C. More preferably, it is 10-90 degreeC, Most preferably, it is 20-80 degreeC.

~Release agent~
As the release agent used in the toner of the present invention, known ones can be used, for example, polyolefin wax (polyethylene wax, polypropylene wax, etc.), long chain hydrocarbon (paraffin wax, sasol wax, etc.), carbonyl group-containing wax, etc. Is mentioned. Of these, carbonyl group-containing waxes are preferred. Examples of the carbonyl group-containing wax include polyhydric alcohol carboxylates (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1 , 18-octadecanediol distearate, etc.), polyvalent carboxylic esters (tristearyl trimellitic acid, distearyl maleate, etc.), polyvalent amine carboxylic acid amides (ethylenediamine dibehenyl amide, etc.), polyvalent carboxylic acid amides (tri Meritic acid tristearyl amide, etc.) and dialkyl ketones (distearyl ketone, etc.). Among these carbonyl group-containing waxes, polyhydric alcohol carboxylic acid esters such as pentaerythritol tetrabehenate are preferable. The melting point of the wax used in the present invention is usually 40 to 160 ° C, preferably 50 to 100 ° C, and more preferably 50 to 70 ° C. A wax having a melting point that is too low adversely affects heat-resistant storage stability. Conversely, a wax having a melting point that is too high tends to cause a cold offset during fixing at a low temperature. The melt viscosity of the wax is preferably 5 to 1000 mPa · s, more preferably 10 to 100 mPa · s, as a measured value at a temperature 20 ° C. higher than the melting point. The wax having a too high melt viscosity has a poor effect of improving hot offset resistance and low-temperature fixability.
The amount of the wax used is usually 0 to 40% by weight, preferably 3 to 30% by weight, particularly preferably 3 to 10% by weight as the content in the toner base of the present invention. .
The wax can be dissolved or dispersed in the organic solvent phase, but is not limited thereto.

~ Colorant ~
As the colorant used in the present invention, all known dyes and pigments can be used. Examples of organic pigments or dyes include carbon black, nigrosine dye, naphthol yellow S, Hansa yellow (10G, 5G, G), polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), and pigment yellow. L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Anthrazan Yellow BGL, Isoindolinone Yellow, Flavanthrone Yellow, Tartrazine Lake, Quinoline Yellow Lake, Permanent Red 4R , Para 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, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Red, Toluidine Maroon, Permanent Bordeaux F2K Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Thioindigo Red B, Thio Indigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Anzanthrone Red, Diketopyrrolopyrrole, Dianthraquinolyl Red, Perinone Red, Perylene Maroon, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Benji Orange, perinone orange, oil orange, pyrazolone orange, metal-free phthalocyanine blue, indanthrene blue (RS, BC), indigo, anthraquinone blue, alkali blue lake, peacock blue lake, Victoria blue lake, metal phthalocyanine blue, fast Sky Blue, Fast Violet B, Methyl Violet Lake, Dioxane Violet, Anthraquinone Violet, Quinacridone Violet, Quinacridone Magenta, Thioindigo Magenta, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green and mixtures thereof can be used. Examples of inorganic pigments include iron black, cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, Bengala, red lead, lead vermilion, cadmium red, cadmium mercury red, and antimony vermilion. Chrome vermilion, cobalt blue, cerulean blue, ultramarine, bitumen, cobalt violet, manganese violet, chrome green, chromium oxide, titanium oxide, zinc white, zinc green, pyridian, emerald green, lithopone and mixtures thereof. The amount of the colorant used is usually 1 to 15% by weight, preferably 3 to 10% by weight as the content in the toner of the present invention.

  The colorant used in the present invention can also be used as a master batch combined with a resin. Examples of the binder resin to be kneaded with the production of the master batch or the master batch include, for example, styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and its substitutes in addition to the urea-modified polyester resin and non-reactive polyester resin. Polymers of: styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-acrylic acid Ethyl copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, Styrene-α-Chlor Methyl tacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid Styrene copolymers such as copolymers and styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane Polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. These can be used singly or in combination of two or more.

  This master batch can be obtained by mixing and kneading a resin for a master batch and a colorant under a high shear force. At this time, an organic solvent can be used in order to enhance the interaction between the colorant and the resin. In addition, a so-called flushing method, which is a wet cake of colorant, is a method of mixing and kneading an aqueous paste containing water of a colorant together with a resin and an organic solvent, transferring the colorant to the resin side, and removing moisture and organic solvent components. Since it can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shearing dispersion device such as a three-roll mill is preferably used. The colorant or masterbatch can be dissolved or dispersed in the organic solvent phase, but is not limited thereto.

[Aqueous medium phase]
~ Aqueous medium ~
In the present invention, the aqueous medium in which the resin fine particles described later are dispersed to form the aqueous medium phase may be water alone, or a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohols (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like. These can be used singly or in combination of two or more.

  Furthermore, in order to reduce the viscosity when the resin component contained in the organic solvent phase is dispersed in an aqueous medium, a solvent in which the polyester prepolymer (A) is soluble can be used in combination. It is preferable to use the solvent in that the particle size distribution of the toner particles becomes sharp. The solvent is preferably volatile with a boiling point of less than 100 ° C. because it can be easily distilled off. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Examples thereof include methyl ethyl ketone and methyl isobutyl ketone, and these can be used singly or in combination of two or more. Particularly preferred are aromatic solvents such as toluene and xylene; halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride; and methyl acetate and ethyl acetate. The usage-amount of the solvent with respect to 100 parts of prepolymers (A) is 0-300 parts normally, Preferably it is 0-100 parts, More preferably, it is 25-70 parts. When the solvent is used, after the urea-modified polyester is formed, it is distilled off by heating under normal pressure or reduced pressure like other organic solvents.

~ Resin fine particles ~
In the present invention, the average particle size of the resin fine particles dispersed and used in the aqueous medium is 5 to 200 nm, preferably 20 to 300 nm. The resin fine particles are components that function as an external additive that binds to the surface or surface layer of the dispersed particles formed by dispersing the organic medium in the aqueous medium phase and coats the formed toner particles. .

  The resin fine particles preferably have a glass transition point (Tg) of 40 to 90 ° C, and more preferably in the range of 50 to 70 ° C. If the Tg is too low, toner storage stability is deteriorated, and blocking occurs during storage and in the developing machine. On the other hand, if it is too high, the resin fine particles (B) inhibit the adhesiveness to the fixing paper, and the minimum fixing temperature rises, so that a sufficient fixing temperature range cannot be secured. Inconveniences such as being unable to be removed or being peeled off when the fixed image is rubbed occur.

  The weight average molecular weight is preferably 200,000 or less, more preferably 50,000 or less. The lower limit is usually 4000. If the weight average molecular weight is too high, the resin fine particles inhibit the adhesion to the fixing paper, and the minimum fixing temperature is increased.

  The resin fine particles may be any resin as long as it can form a dispersion in an aqueous medium, and may be a thermoplastic resin or a thermosetting resin. For example, vinyl resin, polyurethane resin, epoxy resin, polyester Examples thereof include resins, polyamide resins, polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins. These can be used singly or in combination of two or more. Among these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, or combinations thereof are preferable because an aqueous dispersion of fine spherical resin particles is easily obtained. Vinyl resins are polymers obtained by homopolymerization or copolymerization of vinyl monomers, such as styrene- (meth) acrylic acid ester copolymers, styrene-butadiene copolymers, (meth) acrylic acid-acrylic acid ester copolymers. Examples thereof include a polymer, a styrene-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and a styrene- (meth) acrylic acid copolymer.

  The dispersion / blending amount of the resin fine particles in the aqueous medium is preferably 0.5 to 10 wt% with respect to the organic solvent phase. If it is not within this range, emulsification failure occurs and granulation cannot be performed. More preferably, it is 1 to 3 wt%.

  As described above, the resin fine particles are used for the purpose of controlling (aligning) the toner shape (circularity, particle size distribution, etc.), and are mainly distributed on the surface of the toner particles to be formed. The surface coverage by the resin fine particles with respect to the toner particles is preferably in the range of 1 to 90%, more preferably in the range of 5 to 80%. If the surface coverage is too high, the surface of the toner particles is almost completely covered with resin fine particles, and bleeding out of the release agent inside the toner particles to the toner particle surface is inhibited, and a releasing effect is obtained. Therefore, there is a problem that an offset to the fixing roller occurs. Conversely, if the surface coverage is too low, the adhesion between the toner particles tends to work, and the toner tends to aggregate. Therefore, the fluidity of the toner is deteriorated, which is not preferable.

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

  In the present invention, the amount of charge control agent used is determined by the toner production method including the type of binder resin, the presence or absence of additives used as necessary, and the dispersion method, and is uniquely limited. However, it is preferably used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline. These charge control agents can be dissolved and dispersed after being melt-kneaded with a masterbatch or resin, and of course, they may be added when dissolved or dispersed directly in an organic solvent. It is preferable to make it.

[Preparation of toner particles]
The toner particles in the present invention can be prepared by the following method.
-Dispersion and reaction of organic solvent phase-
As described above, in the toner particles, the organic solvent phase containing the polyester prepolymer (A) is dispersed in the aqueous medium phase together with the amines (B), and an elongation reaction and / or a crosslinking reaction is performed in the aqueous medium phase. To form a urea-modified polyester.

  In addition to the polyester prepolymer (A) and the non-reactive polyester, the colorant or colorant masterbatch, the release agent and the charge control agent may be dissolved or dispersed in advance in the organic solvent phase. Although most preferable for controlling the ratio, the colorant or the colorant masterbatch, the release agent and the charge control agent may be mixed when the organic solvent phase is dispersed in the aqueous medium. In the present invention, the colorant or the colorant master batch and the charge control agent may be added and blended after the toner particles are formed. For example, the charge control agent is preferably driven after the toner particles are formed, and after the toner particles not containing the colorant are formed, the colorant can be added by a known dyeing method.

  The surface pigment abundance ratio can be easily controlled in the above-described mixing / dispersing step of the colorant and the non-reactive polyester as the binder resin. In the present invention, the colorant masterbatch in which the colorant is sufficiently finely dispersed and the non-reactive polyester are dispersed together with a mixed solvent of ethyl acetate and MEK (methyl ethyl ketone) (ethyl acetate: MEK = 4: 1). The dispersion method is not particularly limited, and for example, all known methods such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. As the dispersion is more uniform and finely dispersed, the surface pigment abundance ratio tends to decrease. When the dispersion is not well performed, the pigment can move relatively freely in the binder resin, and the pigment is unevenly distributed by moving to the water phase side by oil-water distribution at the stage of the emulsification process. It is considered a thing. On the contrary, it is considered that when sufficient dispersion is achieved, the filler effect due to the pigment works, the structural viscosity of the binder resin increases, and it becomes difficult to move to the aqueous phase side during emulsification. The selection of the solvent to be mixed together is also important because the mobility of the pigment is greatly affected by the speed and amount of the solvent that moves in the binder resin to the aqueous phase side during emulsification.

  Mixing of the polyester prepolymer (A) in the organic solvent phase with the amines (B) (especially blocked ketimine) and the elongation terminator may be carried out before dispersion in the aqueous medium. When a blocked ketimine or the like is used as the amine (B), the block is removed in the aqueous medium, and the elongation and / or crosslinking reaction with the polyester prepolymer (A) can be performed. Furthermore, when an elongation terminator is used, the degree of crosslinking and the molecular weight can be adjusted according to the type and amount. Further, after dispersing the organic solvent phase in the aqueous medium, amines (B) or an elongation terminator may be added. When the amines (B) are added after the dispersion of the organic solvent phase, the reaction starts from the dispersed particle interface, urea-modified polyester is preferentially generated from the surface of the toner particles to be prepared, and a concentration gradient may be provided inside the particles. it can. On the contrary, when the elongation terminator is added after the dispersion of the organic solvent phase, it is possible to reduce the degree of crosslinking of the toner particle surface.

Examples of a method for stably forming a dispersion of an organic solvent phase, an amine (B), and an elongation terminator in an aqueous medium include a method in which a shearing force is applied to the dispersion.
The dispersion method is not particularly limited, and known methods such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. The particle size of the dispersion is preferably 2 to 20 μm, and for this purpose, it is preferable to use a high-speed shearing method. When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 1000 to 30,000 rpm, preferably 5000 to 20,000 rpm. The dispersion time depends on the processing amount and is not particularly limited. However, in the case of a batch method, it is usually about 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C. It is preferable that the temperature during dispersion is high because the viscosity of the polyester prepolymer (A) and the like contained in the organic solvent dispersed phase can be lowered and the dispersion is easy.

  The usage-amount of the aqueous medium (except resin fine particles) with respect to 100 parts of solid content contained in an organic solvent phase is 50-2000 weight part normally, Preferably it is 100-1000 weight part. If the amount used is too small, the dispersed state of the organic solvent phase becomes non-uniform, and toner particles having a predetermined particle diameter cannot be obtained. On the other hand, if the amount is too large, there is no particular effect and the cost is disadvantageous. And not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

  When the dispersant is used, examples of the dispersant include anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, and phosphate esters; alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, Cationic surfactants of amine salt type such as imidazoline, and quaternary ammonium salt type such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride Nonionic surfactants such as fatty acid amide derivatives and polyhydric alcohol derivatives; amphoteric boundaries such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine Active agents.

  Further, by using a surfactant having a fluoroalkyl group, a dispersion effect can be exhibited with a very small amount of use. Preferred examples of the anionic surfactant having a fluoroalkyl group include a fluoroalkylcarboxylic acid having 2 to 10 carbon atoms and a metal salt thereof, disodium perfluorooctanesulfonylglutamate, 3- [ω-fluoroalkyl ( C6-C11) oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11- C20) Carboxylic acid and its metal salt, Perfluoroalkylcarboxylic acid (C7 to C13) and its metal salt, Perfluoroalkyl (C4 to C12) sulfonic acid and its metal salt, Perfluorooctanesulfonic acid diethanolamide, N-propyl -N- (2hydroxy Ciethyl) perfluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphoric acid Examples include esters. As a trade name, Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.); Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.); Unidyne DS-101 DS-102 (manufactured by Taikin Kogyo Co., Ltd.); Megafac F-l10, F-120, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.); Xtop EF- 102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products); and Fagents F-100, F150 (manufactured by Neos). Further, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary amine, secondary amine or secondary amine acid having a fluoroalkyl group, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, etc. Salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, and the like. Trade names include Surflon S-121 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.); Unidyne DS-202 (Daikin Industries Co., Ltd.); Xetop EF-132 (manufactured by Tochem Products); Footage F-300 (manufactured by Neos) and the like. Further, calcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite and the like can also be used as inorganic compound-based dispersants that are hardly soluble in water. Further, the dispersed droplets may be stabilized using a polymer protective colloid. For example, acids such as acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride; (meth) acrylic monomer containing hydroxyl group Bodies such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, acrylic acid 3 -Chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N-methyl Roll acrylamide, N-methylol methacrylamide, etc .; Vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc .; Esters of compounds containing vinyl alcohol and carboxyl groups, such as, for example, Pinyl acetate, vinyl propionate, vinyl butyrate, etc .; acrylamide, methacrylamide, diacetone acrylamide or methylol compounds thereof; acid chlorides such as acrylic acid chloride, methacrylic acid chloride; pinylviridine, vinylpyrrolidone, vinylimidazole, ethyleneimine Homopolymers or copolymers of vinyl monomers such as those having a nitrogen atom such as the above or a heterocyclic ring thereof can be used. Also, polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxy Polyoxyethylenes such as ethylene stearyl phenyl ester and polyoxyethylene nonylphenyl ester; celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can also be used. In addition, when using an acid or alkali soluble material such as calcium phosphate salt as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and then washing with water. To do. In addition, it can be removed by an operation such as enzymatic degradation. When a dispersant is used, the dispersant can remain on the surface of the toner particles, but the elongation and / or crosslinking reaction between the polyester prepolymer (A) and the amines (B) is completed. Thereafter, removal by washing or the like is preferable from the viewpoint of the charging characteristics of the toner of the present invention.

~ Toner particle molding ~
In order to remove the organic solvent from the obtained dispersion liquid, a method of gradually elevating the temperature of the entire system and completely evaporating and removing the organic solvent in the droplets can be employed. Alternatively, the dispersion liquid can be sprayed into a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner particles, and the aqueous dispersant can be removed by evaporation together. As the dry atmosphere, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, particularly various air streams heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. Sufficient target quality can be obtained by short-time treatment using a spray dryer, belt dryer, rotary kiln or the like.

~ Application of external additives ~
The toner particles (base material) obtained by the operations and processes as described above are further treated on the surface with an external additive to obtain the toner of the present invention with improved fluidity, developability, chargeability and the like. . As the external additive for assisting, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 nm to 2 μm, and particularly preferably 5 nm to 500 nm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight, particularly 0.01 to 2.0% by weight, based on the toner particles.

  Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, Examples thereof include diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. These can be used singly or in combination of two or more.

  Other than inorganic fine particles, polymer fine particles, such as polystyrene, methacrylic ester-based or acrylate-based copolymers obtained by soap-free emulsion polymerization suspension polymerization or dispersion polymerization, silicon resins, benzoguanamine resins, polyamides Polymer particles such as a polycondensation system such as a thermosetting resin can be used.

  The external additive used for improving fluidization and the like is subjected to surface treatment in advance to make it hydrophobic, thereby preventing deterioration of the toner flow characteristics and charging characteristics even under high humidity. be able to. Examples of the surface treatment agent include a silane coupling agent, a silylating agent, a silane coupling agent having a fluorinated alkyl group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and modified silicone oil. Etc. are preferably exemplified.

  Further, for the purpose of improving the cleaning property when removing the developer after transfer remaining on the photosensitive member and the primary transfer medium, toner particles (base material) are made of, for example, zinc stearate, calcium stearate, stearic acid, etc. Fatty acid metal salt; for example, it can be treated with polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles. The polymer fine particles used preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

<Two-component developer>
When the toner of the present invention is used for a two-component developer, it may be used by mixing with a magnetic carrier, and the content ratio of the carrier and the toner in the developer is 1 to 10 wt. Part is preferable, and the range of 5 to 10 parts by weight is more preferable.

  As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used.

  Examples of the coating material for the magnetic carrier include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin; urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins; polystyrene resins such as polystyrene resins and styrene acrylic copolymer resins; Halogenated olefin resins such as vinyl chloride; polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin: polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexa Fluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride Fluoro such as terpolymers of emission and non-fluoride monomers including, and silicone resins.

  Moreover, you may make conductive powder etc. contain in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.

  The toner of the present invention can also be used as a one-component magnetic toner that does not use a carrier, or a non-magnetic toner.

<Image forming apparatus>
Hereinafter, an image forming apparatus using the electrophotographic toner of the present invention or a two-component developer composed of the toner and a carrier will be described. Note that the image forming apparatus of the present invention is not limited to the one described below, and any image forming apparatus can be used as long as the conditions shown in the claims are satisfied.

-Tandem type color image forming device-
An embodiment of a tandem color image forming apparatus of the present invention will be described.
As shown in FIG. 2, the tandem type electrophotographic apparatus employs a direct transfer system in which an image on each photoconductor 1 is sequentially transferred onto a sheet (transfer material) s conveyed by a sheet conveying belt 3 by a transfer device 2. As shown in FIG. 3, the images on the respective photoreceptors 1 are sequentially transferred to the intermediate transfer member 4 by the primary transfer device 2, and then the images on the intermediate transfer member 4 are transferred to the secondary transfer device 5. Indirect transfer system that performs batch transfer to the sheet s. The transfer device 5 is a transfer conveyance belt, but there are also roller shapes and methods.

  Comparing the direct transfer type and the indirect transfer type, the former arranges the sheet feeding device 6 on the upstream side of the tandem image forming apparatus T on which the photoconductors 1 are arranged, and the fixing device 7 on the downstream side. There is a drawback in that the size increases in the sheet conveying direction. On the other hand, the latter can set the secondary transfer position relatively freely. The sheet feeding device 6 and the fixing device 7 can be arranged so as to overlap with the tandem image forming apparatus T, and there is an advantage that downsizing is possible.

In the former, in order not to increase the size in the sheet conveying direction, the fixing device 7 is disposed close to the tandem type image forming apparatus T. For this reason, the fixing device 7 cannot be disposed with a sufficient margin that allows the sheet s to bend, and an impact when the leading edge of the sheet s enters the fixing device 7 (particularly with a thick sheet) or fixing. Due to the difference in speed between the sheet conveyance speed when passing through the apparatus 7 and the sheet conveyance speed by the transfer conveyance belt, there is a drawback that the fixing device 7 tends to affect image formation on the upstream side. On the other hand, in the latter case, the fixing device 7 can be disposed with a sufficient margin that the sheet s can be bent, so that the fixing device 7 hardly affects the image formation.
In view of the above, recently, an indirect transfer type of tandem type electrophotographic apparatus has attracted attention.

  In this type of color electrophotographic apparatus, as shown in FIG. 3, the transfer residual toner remaining on the photoconductor 1 after the primary transfer is removed by the photoconductor cleaning device 8 to clean the surface of the photoconductor 1. In preparation for another image formation. Further, the transfer residual toner remaining on the intermediate transfer body 4 after the secondary transfer is removed by the intermediate transfer body cleaning device 9 to clean the surface of the intermediate transfer body 4 to prepare for image formation again.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 4 shows an embodiment of the present invention, which is a tandem indirect transfer type electrophotographic apparatus. In the figure, reference numeral 100 is a copying apparatus main body, 200 is a paper feed table on which it is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) further mounted thereon. The copying machine main body 100 is provided with an endless belt-shaped intermediate transfer member 10 at the center.

Then, as shown in FIG. 4, in the illustrated example, it is wound around three support rollers 14, 15, and 16 so that it can be rotated and conveyed clockwise in the figure.
In this illustrated example, an intermediate transfer body cleaning device 17 for removing residual toner remaining on the intermediate transfer body 10 after image transfer is provided on the left of the second support roller 15 among the three.

  Further, among the three images, four images of yellow, cyan, magenta, and black are arranged on the intermediate transfer member 10 stretched between the first support roller 14 and the second support roller 15 along the conveyance direction. The tandem image forming apparatus 20 is configured by arranging the forming units 18 side by side.

  An exposure device 21 is further provided on the tandem image forming apparatus 20 as shown in FIG. On the other hand, a secondary transfer device 22 is provided on the side opposite to the tandem image forming apparatus 20 with the intermediate transfer body 10 interposed therebetween. In the illustrated example, the secondary transfer device 22 is configured by spanning a secondary transfer belt 24, which is an endless belt, between two rollers 23, and is pressed against the third support roller 16 via the intermediate transfer body 10. The image on the intermediate transfer body 10 is transferred to a sheet.

A fixing device 25 for fixing the transfer image on the sheet is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.
The secondary transfer device 22 described above is also provided with a sheet transport function for transporting the image-transferred sheet to the fixing device 25. Of course, a transfer roller or a non-contact charger may be disposed as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveyance function together.

  In the illustrated example, a sheet reversing device 28 for reversing the sheet so as to record an image on both sides of the sheet is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. Is provided.

  Now, when making a copy using this color electrophotographic apparatus, a document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed and pressed by it.

  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 other contact glass 32. At that time, the scanner 300 is immediately driven to travel the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34 and is reflected by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  When a start switch (not shown) is pressed, one of the support rollers 14, 15 and 16 is rotationally driven by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer body 10 is rotated and conveyed. To do. At the same time, the individual image forming means 18 rotates the photoconductor 140 to form black, yellow, magenta, and cyan monochrome images on the photoconductor 140, respectively. Then, along with the conveyance of the intermediate transfer member 10, the single color images are sequentially transferred to form a composite color image on the intermediate transfer member 10.

  On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, the sheet is fed out from one of the paper cassettes 44 provided in the paper bank 43 in multiple stages, and the separation roller 45 Then, the sheets are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped.

  Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, 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.

  Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer member 10, the sheet is fed between the intermediate transfer member 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. A color image is recorded on the sheet.

  The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge roller. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.

  On the other hand, the intermediate transfer body 10 after the image transfer is removed by the intermediate transfer body cleaning device 17 to remove residual toner remaining on the intermediate transfer body 10 after the image transfer, so that the tandem image forming apparatus 20 can prepare for another image formation.

  Here, the registration roller 49 is generally used while being grounded, but it is also possible to apply a bias for removing paper dust from the sheet.

  In the tandem image forming apparatus 20 described above, the individual image forming means 18 includes, for example, a charging device 160, a developing device 61, and a primary transfer device around a drum-shaped photoconductor 140 as shown in FIG. 62, a photoconductor cleaning device 63, a charge removal device 64, and the like. The reference numerals shown in FIG. 5 will be described. 65 is a developer on the developing sleeve, 68 is a stirring paddle, 69 is a partition plate, 71 is a toner density sensor, 72 is a developing sleeve, 73 is a doctor, 75 is a cleaning blade, and 76 is A cleaning brush, 77 is a cleaning roller, 78 is a cleaning blade, 79 is a toner discharge auger, and 80 is a driving device.

~ Charging device ~
FIG. 6 shows a schematic configuration of an example of an image forming apparatus using a contact-type charging device. The photosensitive member 140 serving as a member to be charged and an image carrier is rotationally driven in the direction of the arrow at a predetermined speed (process speed). The charging device (charging roller) 160, which is a charging member brought into contact with the drum of the photoreceptor 140, has a basic configuration of a cored bar 161 and a conductive rubber layer 162 formed concentrically on the outer periphery of the cored bar. Both ends of the gold 161 are rotatably held by a bearing member (not shown) and the like, and the photosensitive member 140 is pressed with a predetermined pressure by a pressing means (not shown). Reference numeral 160 denotes a rotation driven by the rotation of the photosensitive drum. The charging device 160 is formed to a diameter of 16 mm by coating a medium resistance rubber layer of about 100,000 Ω · cm on a core metal having a diameter of 9 mm.

  The metal core 161 of the charging device 160 and the illustrated power source E are electrically connected, and a predetermined bias is applied to the charging device 160 by the power source E. As a result, the peripheral surface of the photoreceptor 140 is uniformly charged to a predetermined polarity and potential.

  The charging device 160 used in the present invention may take any form such as a magnetic brush or a fur brush in addition to a roller, and can be selected according to the specifications and form of the electrophotographic apparatus. In the case of using a magnetic brush, the magnetic brush is composed of various ferrite particles such as Zn—Cu ferrite as a charging member, a non-magnetic conductive sleeve for supporting it, and a magnet roll included therein. In addition, when using a fur brush, for example, as a material of the fur brush, a fur treated with carbon, copper sulfide, metal or metal oxide is used, and this is wound around a metal or other conductive core metal. By charging or pasting, it becomes a charger.

  Of course, the charging device used in the present invention is not limited to the contact type charging device as described above, but an image forming apparatus in which ozone generated from the charging device is reduced can be obtained. Is preferably used.

-Photoconductor-
As an electrophotographic photoreceptor used in the present invention, a conductive support is heated to 50 ° C. to 400 ° C., and a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD method, a photo CVD is applied on the support. An amorphous silicon photoconductor (hereinafter referred to as “a-Si photoconductor”) having a photoconductive layer made of a-Si can be used by a film forming method such as a plasma CVD method. Among them, a plasma CVD method, that is, a method in which a source gas is decomposed by direct current, high frequency or microwave glow discharge to form an a-Si deposited film on a support is preferably used.

  The layer structure of the amorphous silicon photoconductor is, for example, as follows. FIG. 7 is a schematic configuration diagram for explaining a layer configuration. In the electrophotographic photoreceptor 500 shown in FIG. 7A, a photoconductive layer 502 made of a-Si: H, X and having photoconductivity is provided on a support 501. An electrophotographic photoreceptor 500 shown in FIG. 7B includes a photoconductive layer 502 made of a-Si: H, X and having photoconductivity, and an amorphous silicon-based surface layer 503 on a support 501. It is configured. An electrophotographic photoreceptor 500 shown in FIG. 7C has an amorphous silicon-based charge injection blocking layer 504 and a photoconductive layer 502 made of a-Si: H, X and having photoconductivity on a support 501. And an amorphous silicon-based surface layer 503. In the electrophotographic photoreceptor 500 shown in FIG. 7D, a photoconductive layer 502 is provided on a support 501. The photoconductive layer 502 includes a charge generation layer 505 made of a-Si: H, X and a charge transport layer 506, and an amorphous silicon-based surface layer 503 is provided thereon.

  The support 501 for the photoconductor may be conductive or electrically insulating. Examples of the conductive support include metals such as Al, Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys thereof such as stainless steel. Also, at least the surface on the side where the photosensitive layer is to be formed of an electrically insulating support such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, polyamide or other synthetic resin film or sheet, glass or ceramic. A conductively treated support can also be used.

  The shape of the support 501 can be a smooth surface, a cylindrical or plate-like surface having an uneven surface, or an endless belt, and the thickness thereof is appropriately determined so that a desired photoreceptor for an image forming apparatus can be formed. However, when flexibility as a photoreceptor for an image forming apparatus is required, it can be made as thin as possible within a range in which the function as a support can be sufficiently exhibited. However, the support is usually 10 μm or more from the viewpoints of manufacturing and handling, such as mechanical strength.

  In the amorphous silicon photosensitive member that can be used in the present invention, a charge injection blocking layer 504 that functions to prevent charge injection from the conductive support side between the conductive support and the photoconductive layer, if necessary. It is more effective to provide (Fig. 7 (c)). That is, the charge injection blocking layer 504 has a function of blocking charge injection from the support side to the photoconductive layer side when the photosensitive layer is subjected to a charging process with a constant polarity on its free surface. Such a function is not exhibited when the charging process is performed, and so-called polarity dependency is exhibited. In order to provide such a function, the charge injection blocking layer 504 contains a relatively large number of atoms for controlling conductivity as compared with the photoconductive layer.

  The thickness of the charge injection blocking layer 504 is preferably 0.1 to 5 μm, more preferably 0.3 to 4 μm, and most preferably 0.5 from the viewpoints of obtaining desired electrophotographic characteristics and economic effects. It is desirable that the thickness be ˜3 μm.

  The photoconductive layer 502 is formed on the undercoat layer as necessary, and the layer thickness of the photoconductive layer 502 is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects, etc. Is preferably 1 to 100 μm, more preferably 20 to 50 μm, and most preferably 23 to 45 μm.

  The charge transport layer 506 is a layer mainly having a function of transporting charges when the photoconductive layer 502 is functionally separated. The charge transport layer 506 includes at least silicon atoms, carbon atoms, and fluorine atoms as constituent elements, and is formed of a-SiC (H, F, O) including hydrogen atoms and oxygen atoms as required. Photoconductive properties, particularly charge retention properties, charge generation properties, and charge transport properties. In the present invention, it is particularly preferable to contain an oxygen atom.

  The layer thickness of the charge transport layer 506 is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects. The charge transport layer 506 is preferably 5 to 50 μm, more preferably 10 to 10 μm. It is desirable that the thickness is 40 μm, optimally 20 to 30 μm.

  The charge generation layer 505 is a layer mainly having a function of generating charges when the photoconductive layer 502 is functionally separated. This charge generation layer 505 is composed of a-Si: H containing at least silicon atoms as components and substantially not containing carbon atoms, and if necessary containing hydrogen atoms, and has desired photoconductive properties, particularly charge generation. Characteristics and charge transport characteristics.

  The layer thickness of the charge generation layer 505 is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects, etc., preferably 0.5 to 15 μm, more preferably 1 to 10 μm, optimally 1 to 5 μm.

  The amorphous silicon photoreceptor that can be used in the present invention can be further provided with a surface layer 503 on the photoconductive layer 502 formed on the support 501 as described above, if necessary. It is preferable to form a silicon-based surface layer. The surface layer 503 has a free surface and is provided to achieve the object of the present invention mainly in moisture resistance, continuous repeated use characteristics, electrical pressure resistance, use environment characteristics, and durability.

  The thickness of the surface layer 503 in the present invention is usually 0.01 to 3 μm, preferably 0.05 to 2 μm, and most preferably 0.1 to 1 μm. If the layer thickness is less than 0.01 μm, the surface layer is lost due to wear or the like during use of the photoreceptor, and if it exceeds 3 μm, electrophotographic characteristics such as an increase in residual potential are observed.

  Amorphous silicon photoconductor 500 has high surface hardness, high sensitivity to long-wavelength light such as a semiconductor laser (770 to 800 nm) and the like, and almost no deterioration due to repeated use. It is used as an electrophotographic photoreceptor such as a printer (LBP).

-Fixing device (surf fixing device)-
As the fixing device of the present invention, a so-called surf fixing device that rotates and fixes the fixing film 260 as shown in FIG. 8 may be used. More specifically, the fixing film 260 is an endless belt-like heat-resistant film, and is held by a driving roller 261 and a driven roller 262 that are support rotating members of the film, and a heater support provided below the rollers. The heating body 263 is disposed so as to be fixedly supported.

  The driven roller 262 also serves as a tension roller for the fixing film 260. The fixing film 260 is rotationally driven in the clockwise direction by the rotational driving of the driving roller in the clockwise direction in the drawing. The rotational driving speed is adjusted to a speed at which the speeds of the transfer material s and the fixing film 260 become equal in the fixing nip region L where the pressure roller 270 and the fixing film 260 are in contact with each other.

  Here, the pressure roller 270 is a roller having a rubber elastic layer having good releasability, such as silicon rubber, and applies a total pressure of 4 to 10 kgf to the fixing nip region L while rotating counterclockwise. It is pressed with contact pressure.

  The fixing film 260 preferably has excellent heat resistance, releasability and durability, and a thin film having a total thickness of 100 μm or less, preferably 40 μm or less is used. For example, at least an image of a single layer film of a heat-resistant resin such as polyimide, polyetherimide, PES (polyether sulfide), PFA (tetrafluoroethylene bar fluoroalkyl vinyl ether copolymer resin), or a composite layer film, for example, a 20 μm thick film The contact surface is coated with a release coating layer of PTFE (tetrafluoroethylene resin), PFA or other fluororesin added with a conductive material to a thickness of 10 μm, or an elastic layer such as fluororubber or silicon rubber. It is a thing.

In FIG. 8, the heating body 263 of this embodiment is composed of a flat substrate 263b and a fixing heater 263h, and the flat substrate 263b is made of a material having high thermal conductivity and high electrical resistivity, such as alumina. On the surface in contact with the fixing film 260, a fixing heater 263h made of a resistance heating element is provided in the longitudinal direction. The fixing heater 263h is obtained by coating an electric resistance material such as Ag / Pd or Ta ₂ N in a linear or belt shape by screen printing or the like. In addition, electrodes (not shown) are formed at both ends of the fixing heater 263h, and the resistance heating element generates heat when energized between the electrodes. Further, a fixing temperature sensor 263s formed of a thermistor is provided on the surface of the substrate 263b opposite to the surface provided with the fixing heater 263h.

  The temperature information of the substrate 263b detected by the fixing temperature sensor 263s is sent to a control means (not shown), the amount of electric power supplied to the fixing heater 263h is controlled by the control means, and the heating body 263 is controlled to a predetermined temperature. .

  Of course, the fixing device 250 used in the present invention is not limited to the surf fixing device as described above, but a fixing device that is excellent in color reproducibility and color developability, has high efficiency, and can shorten the rise time is used. Since an image forming apparatus can be obtained, it is preferable to use a surf fixing device.

-Fixing device (electromagnetic induction heating method (IH fixing device))-
In the fixing device according to the present invention, as shown in FIG. 9A, the heating device generates Joule heat by eddy current generated in the magnetic metal member by the alternating magnetic field, and the heating body including the metal member is heated by electromagnetic induction. A so-called electromagnetic induction heating type fixing device (IH fixing device) may be used.

  The fixing device 350 shown in FIG. 9A includes a heating roller 361 that is heated by electromagnetic induction of the induction heating unit 364, a fixing roller 362 that is arranged in parallel with the heating roller 361, a heating roller 361, and a fixing roller 362. And an endless belt-like heat-resistant belt (toner heating medium) 360 that is heated by a heating roller 361 and rotated in the direction of arrow A by at least one of these rollers, and is fixed via the belt 360. The pressure roller 370 is in pressure contact with the roller 362 and rotates in the forward direction with respect to the belt 360. The heating roller 361 is made of a hollow cylindrical magnetic metal member such as iron, cobalt, nickel, or an alloy of these metals, and has a low heat capacity and a high temperature rise. The fixing roller 362 includes a metal core 362a made of, for example, stainless steel, and an elastic member 362b covered with a core metal 362a in a solid or foamed heat-resistant silicone rubber. In order to form a contact portion having a predetermined width between the pressure roller 370 and the fixing roller 362 by the pressing force from the pressure roller 370, the outer diameter is made larger than that of the heating roller 361.

  With this configuration, the heat capacity of the heating roller 361 becomes smaller than the heat capacity of the fixing roller 362, the heating roller 361 is rapidly heated, and the warm-up time is shortened. The belt 360 stretched between the heating roller 361 and the fixing roller 362 is heated at a contact portion W1 with the heating roller 361 heated by the induction heating unit 364. Then, the inner surface of the belt 360 is continuously heated by the rotation of the rollers 361 and 362, and as a result, the entire belt is heated. The pressure roller 370 includes, for example, a core metal 370a made of a metal cylindrical member having high thermal conductivity such as copper or aluminum, and an elastic member having high heat resistance and toner releasability provided on the surface of the core metal 370a. 370b. In addition to the above metal, SUS may be used for the core metal 370a. The pressure roller 370 presses the fixing roller 362 via the belt 360 to form the fixing nip portion N, but in this embodiment, the pressure roller 370 is harder than the fixing roller 362. As a result, the pressure roller 370 bites into the fixing roller 362 (and the belt 360), and this biting causes the recording material s to follow the circumferential shape of the surface of the pressure roller 370, so that the recording material s separates from the surface of the belt 360. Has the effect of facilitating.

  As shown in FIGS. 9A and 9B, the induction heating means 364 for heating the heating roller 361 by electromagnetic induction includes an excitation coil 365 that is a magnetic field generation means, and an excitation coil 365. The coil guide plate 366 is wound around. The coil guide plate 366 has a semi-cylindrical shape that is disposed close to the outer peripheral surface of the heating roller 361. As shown in FIG. 9B, the excitation coil 365 is composed of a single long excitation coil wire. The heating roller 361 is wound alternately along the plate 366 in the axial direction. The exciting coil 365 is connected to a driving power source (not shown) whose oscillation circuit has a variable frequency. Outside the excitation coil 365, a semi-cylindrical excitation coil core 367 made of a ferromagnetic material such as ferrite is fixed to the excitation coil core support member 368 and is disposed close to the excitation coil 365. In this embodiment, the exciting coil core 365 having a relative permeability of 2500 is used. A high frequency alternating current of 10 kHz to 1 MHz, preferably a high frequency alternating current of 20 kHz to 800 kHz is supplied to the exciting coil 365 from a driving power source, thereby generating an alternating magnetic field. The alternating magnetic field acts on the heat generating layer of the heating roller 361 and the belt 360 in the contact area W1 between the heating roller 361 and the heat-resistant belt 360 and in the vicinity thereof, and in the direction B that prevents the change of the alternating magnetic field inside these. Eddy current I flows. This eddy current I generates Joule heat according to the resistance of the heat generating layer of the heating roller 361 and the belt 360, and the belt having the heating roller 361 and the heat generating layer mainly in the contact area between the heating roller 361 and the belt 360 and its vicinity. 360 is heated by electromagnetic induction.

  The belt 360 heated in this way is detected by a temperature detecting means 363 comprising a temperature sensitive element such as a thermistor disposed in contact with the inner surface of the belt 360 in the vicinity of the inlet side of the fixing nip N. The belt inner surface temperature is detected.

  Of course, the fixing device used in the present invention is not limited to the above-mentioned IH fixing device, but a high-quality image having particularly excellent color reproducibility and color developability can be obtained, and a heat roller system can be used. It is preferable to use an IH fixing device because the heat transfer efficiency is higher than that of the fixing device, the warm-up time can be shortened, and an image forming apparatus using a fixing device capable of quick start and energy saving can be obtained.

-Developer-
In the developing device used in the embodiment of the present invention, during development, a vibration bias voltage obtained by superimposing an AC voltage on a DC voltage is applied to the developing sleeve as a developing bias by a power source. The background portion potential and the image portion potential are located between the maximum value and the minimum value of the vibration bias potential. As a result, an alternating electric field whose direction changes alternately is formed in the developing portion. In this alternating electric field, the developer toner and carrier vibrate vigorously, and the toner flies off the electrostatic binding force on the developing sleeve and carrier and flies to the photosensitive drum, and adheres corresponding to the latent image on the photosensitive drum. To do.

  The difference between the maximum value and the minimum value of the vibration bias voltage (voltage between peaks) is preferably 0.5 to 5 KV, and the frequency is preferably 1 to 10 KHz. As the waveform of the vibration bias voltage, a rectangular wave, a sine wave, a triangular wave, or the like can be used. As described above, the DC voltage component of the vibration bias is a value between the background part potential and the image part potential, but the value closer to the background part potential than the image part potential is more likely to cover the background part potential region. Or, it is preferable for preventing toner adhesion.

  When the vibration bias voltage waveform is a rectangular wave, the duty ratio is preferably 50% or less. Here, the duty ratio is a ratio of time during which the toner is directed to the photosensitive member during one period of the vibration bias. By doing so, the difference between the peak value at which the toner is directed to the photoreceptor and the time average value of the bias can be increased, so that the movement of the toner is further activated and the potential of the latent image surface is increased. It can adhere to the distribution and improve the roughness and resolution. In addition, since the difference between the peak value of the carrier having a charge opposite to that of the toner and the time average value of the bias toward the photosensitive member can be reduced, the movement of the carrier is reduced, and the background portion of the latent image is reduced. The probability of carriers adhering to the substrate can be greatly reduced.

  Of course, the applied bias of the developing device used in the present invention is not limited as described above. However, in order to obtain a high-definition image without roughness, it is preferable to take the above-described form.

~ Process cartridge ~
FIG. 10 shows a schematic configuration of an image forming apparatus having a process cartridge used in the embodiment of the present invention. In the drawing, a represents the entire process cartridge, b represents a photoreceptor, c represents a charging unit, d represents a developing unit, and e represents a cleaning unit.

  In the present invention, at least the photosensitive member b and the developing unit d are integrally combined as a process cartridge among the above-described components such as the photosensitive member b, the charging device unit c, the developing unit d, and the cleaning unit e. The process cartridge is configured to be detachable from a main body of an image forming apparatus such as a copying machine or a printer.

  In the image forming apparatus having the process cartridge using the electrophotographic toner of the present invention, the photosensitive member is rotationally driven at a predetermined peripheral speed. In the rotation process, the photosensitive member is uniformly charged with a positive or negative predetermined potential on its peripheral surface by the charging unit, and then receives image exposure light from an image exposing unit such as slit exposure or laser beam scanning exposure. An electrostatic image is sequentially formed on the peripheral surface of the body, and the formed electrostatic image is then developed with toner by a developing unit, and the developed toner image is exposed between the photosensitive member and the transfer unit from the paper feeding unit. The transfer material is sequentially transferred to the transfer material fed in synchronization with the rotation of the body. The transfer material that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means, and fixed on the image, and printed out as a copy (copy). The surface of the photoconductor after the image transfer is cleaned by removing toner remaining after transfer by a cleaning unit, and after further static elimination, it is repeatedly used for image formation.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited only to these examples. In the following examples, “parts” and “%” are based on weight unless otherwise specified.

Example 1
~ Preparation of aqueous phase ~
The following components were mixed and stirred to obtain a milky white liquid. This is called [Aqueous phase].
・ Water: 950 parts ・ Aqueous dispersion of vinyl resin (styrene salt copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate) (manufactured by Sanyo Chemical Industries): 20 parts 48.5% aqueous solution of sodium diphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries): 16 parts, 3.0% aqueous solution of polymer protective colloid carboxymethylcellulose (Serogen BSH, manufactured by Sanyo Chemical Industries): 12 parts Ethyl acetate: 130 parts

~ Synthesis of ketimine ~
170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged into a reaction vessel equipped with a stirrer and a thermometer, and reacted at 50 ° C. for 5 hours to obtain a blocked amine. This is referred to as [ketimine compound]. The amine value of this [ketimine compound] was 418.

~ Preparation of masterbatch ~
Add 1200 parts of water, 50 parts of carbon black (Cabot Corp., Regal 400R), 50 parts of polyester resin (Sanyo Chemical Industries, RS801), add 30 parts of water, and mix with a Henschel mixer (Mitsui Mining Co., Ltd.). The mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain a carbon black masterbatch. This is designated as [Bk master batch].

~ Preparation of oil phase ~
A container equipped with a stir bar and a thermometer was charged with 500 parts of a polyester resin (manufactured by Sanyo Chemical Co., Ltd., RS801), 30 parts of carnauba wax, and 850 parts of ethyl acetate. After maintaining the time, it was cooled to 30 ° C. over 1 hour, and using a bead mill (Ultra Visco Mill, manufactured by IMEX), liquid feeding speed: 1.2 Kg / hr, disk peripheral speed: 8 m / second, 0 The wax was dispersed under the conditions of 5 mm zirconia bead filling amount: 80% by volume and pass number: 3 times.
Next, 110 parts of [Bk masterbatch] and 500 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain a dissolved product. Thereafter, 240 parts of ethyl acetate was further added, and using the above-mentioned bead mill, liquid feeding speed: 1.2 Kg / hr, disk peripheral speed: 8 m / sec, 0.5 mm zirconia bead filling amount: 80 vol%, number of passes: A dispersion was obtained under three conditions.
This is designated as [Bk pigment / wax dispersion].

~ Emulsification ~
[Bk pigment / wax dispersion] 1780 parts, 50% ethyl acetate solution of prepolymer (manufactured by Sanyo Chemical Co., Ltd., number average molecular weight 3800, weight average molecular weight 15000, Tg 60 ° C., acid value 0.5, hydroxyl value 51, and free isocyanate Content is 1.57% by weight) 100 parts, isobutyl alcohol 15 parts, and [ketimine compound] 7.5 parts are put in a container and TK rpm is used at 6,000 rpm for 1 minute. After mixing, 1200 parts of [Aqueous Phase] was added to the container and mixed with a TK homomixer at a rotational speed of 7,500 rpm for 20 minutes to obtain an aqueous medium dispersion. This is designated as [Bk emulsified slurry].

-Deorganic solvent, washing, drying-
[Bk emulsified slurry] is put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 12 hours, aging is carried out at 45 ° C. for 8 hours to obtain a dispersion in which the organic solvent is distilled off. It was. After 100 parts of this dispersion was filtered under reduced pressure, the operation was performed according to the following procedure.
(S1) 200 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (10 minutes at a rotation speed of 12000 rpm), and then filtered.
(S2) 100 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of Step S1, mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(S3) 100 parts of 10% hydrochloric acid was added to the filter cake of Step S2, mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered.
(S4) 500 parts of ion-exchanged water was added to the filter cake of Step S3, mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered twice to obtain a filter cake.
This filter cake was dried at 45 ° C. for 48 hours in a circulating drier and sieved with a mesh having a mesh size of 75 μm to obtain toner base particles. This is referred to as [Bk toner base].

~ Mixing of external additives ~
100 parts by weight of the [Bk toner base] obtained above, 1.2 parts by weight of hydrophobic silica (manufactured by Clariant Japan) as an external additive, and 0.5 parts by weight of hydrophobic titanium oxide (manufactured by Teica) are added to Henschel. The toner was obtained by mixing with a mixer and passing through a sieve having an aperture of 38 μm to remove aggregates. This is black toner [Bk toner].

The ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. ¹ H relaxation time and ¹ H abundance ratio were measured using a solid echo method (90 ° -τ-90 ° -τ pulse) using JNM-MU25 (manufactured by JEOL Ltd.), measuring temperature: 100 ° C. Measurement was performed under the conditions of 90 ° pulse width: 2.2 μs, delay time: 8.0 μs, repetition time: 2.0 s, and number of integrations: 32 times. The volume average particle size (Dv) was measured using COULTER TA-II (manufactured by COULTER ELECTRONICS, INC). At this time, the aperture diameter was 100 μm.

  Next, using the toner, a developer was prepared by the method shown in <Create two-component developer> below.

<Creation of two-component developer>
As the carrier used for the two-component developer, a ferrite carrier having an average particle diameter of 35 μm coated with a silicon resin with an average thickness of 0.5 μm is used, and 7 parts by weight of toner is contained in 100 parts by weight of the carrier. A developer was prepared by uniformly mixing and charging using a tumbler mixer of the type that is rolled and stirred.

The carrier was prepared as follows.
As a core material, 5000 parts of Mn ferrite particles (weight average diameter: 35 μm), and as a coating material, 450 parts of toluene, 450 parts of silicon resin SR2400 (made by Toray Dow Corning Silicon, nonvolatile content 50%), aminosilane SH6020 ( Using a coating solution prepared by dispersing 10 parts of Toray Dow Corning Silicon) and 10 parts of carbon black with a stirrer for 10 minutes, the core material, the coating liquid, and a rotating bottom plate disk in a fluidized bed The coating liquid was applied to the core material by applying the coating liquid while forming a swirling flow provided with stirring blades. The obtained coated material was baked in an electric furnace at 250 ° C. for 2 hours to obtain the carrier.

  The obtained two-component developer was subjected to image formation with a copy image quality evaluation machine, and the image quality of the copy image was evaluated based on the following <evaluation items>. As the image quality evaluation machine used, a full-color laser printer with a four-color developing unit that develops each color sequentially onto a belt photoreceptor, sequentially transfers it to an intermediate transfer member, and transfers all four colors onto paper or the like at once. Using an Ipsio 8000 (manufactured by Ricoh Co., Ltd.) (Evaluator A), the same developer was added to each of the four color developing sections, and the image quality and the like were evaluated in a single color mode.

<Evaluation items>
(1) Image granularity and sharpness 10,000 photo images were output in a single color mode, and the degree of granularity and sharpness was visually evaluated. In Table 1, the degree is ◎ when the level is equivalent to offset printing, ◯ when it is slightly worse than offset printing, and △ when it is slightly better than the conventional electrophotographic image. In the case of grade, it was indicated by ×, and in the case of worse than the conventional electrophotographic image, it was indicated by ××.

(2) Fine line reproducibility After running 30,000 image charts with 50% image area in monochrome mode, a 600 dpi thin line image is output to Ricoh type 6000 paper, and the degree of fine line bleeding is compared with a step sample. did. Evaluation is made in five stages of ranks 1 to 5, rank 5 is the best in fine line reproducibility, and rank 1 is the worst. In Table 1, it is ◎ when it is rank 5, ◯ when it is rank 4, △ when it is rank 3, x when it is rank 2, and xx when it is rank 1. Displayed.

(3) White section of character part After running 30,000 image charts with 50% image area in single color mode, the character part image is output to the OHP sheet of type DX made by Ricoh, and the inside of the line image of the character part The toner untransferred frequency at which the toner drops out was compared with the stage sample, and was evaluated in five stages of ranks 1-5. Also, rank 5 has the least white spots and rank 1 has the most white spots. In Table 1, it is ◎ when it is rank 5, ◯ when it is rank 4, △ when it is rank 3, x when it is rank 2, and xx when it is rank 1. Displayed.

(4) Low-temperature fixability / hot offset resistance Solid with a toner adhesion amount of 0.85 ± 0.1 mg / cm ^{2 on} plain paper and thick paper transfer paper (Ricoh Type 6200 and NBS Ricoh Copy Printing Paper <135>) An image was prepared, a fixing test was performed by changing the temperature of the fixing belt, and an upper limit temperature at which hot offset did not occur on plain paper was defined as an upper limit fixing temperature. Further, the solid image was created on a plain paper at a position 3.0 cm from the front end in the paper passing direction. Further, the minimum fixing temperature was measured with a thick paper. The lower limit fixing temperature was obtained by drawing the obtained fixed image with a load of 50 g using a drawing tester, and setting the fixing roller temperature at which the image was hardly scraped as the lower limit fixing temperature. Table 1 shows the low temperature fixability when the fixing lower limit temperature is 130 ° C. or less, ◯ when 131 to 140 ° C., △ when 141 to 155 ° C., × when 161 to 155 ° C., 161 ° C. In the above case, it is indicated by xx. As for hot offset resistance, ◎ when the upper limit fixing temperature is 220 ° C. or higher, ○ when 200 to 219 ° C., Δ when 180 to 199 ° C., × when 170 to 179 ° C., 169 ° C. or lower. In the case of, it is indicated by xx.

(5) Fixing releasability A solid image with a toner adhesion amount of 0.85 ± 0.1 mg / cm ² is created on plain paper (Ricoh type 6200 Y), and a fixing test is performed by changing the temperature of the fixing belt. The releasability was evaluated by the upper limit temperature at which no wrapping occurred on plain paper. Further, the solid image was created on a plain paper at a position of 3.0 mm from the front end in the paper passing direction. Here, winding refers to a phenomenon in which a fixed image is wound without being separated from the fixing roller at the time of heat-fixing, and winding is less likely to occur as the wax exudes better in the toner. In Table 1, when the winding temperature is 180 ° C. or higher, ◎, when 165 to 179 ° C., ◯ when 150 to 164 ° C., × when 140 to 149 ° C., × when 139 ° C. or lower Displayed with ×.

(6) Photoreceptor filming property After running 10,000 sheets of a solid image chart with a 100% image area in the monochromatic mode, the degree of filming on the photoconductor is compared with the step sample, and ranks 1 to 5 are provided. It was evaluated with. Further, it was confirmed in advance using an FT-IR (Fourier transform infrared spectroscopic) apparatus SpectrumOne (manufactured by Perkin Elmer) that the filming material on the photoconductor was a wax. Rank 5 has the least filming, almost no filming is seen, and rank 1 has the most filming. In Table 1, it is ◎ when it is rank 5, ◯ when it is rank 4, △ when it is rank 3, x when it is rank 2, and xx when it is rank 1. Displayed.

(7) Carrier spent property Developer is extracted after running 30,000 image charts with 50% image area in single color mode, and an appropriate amount of developer is placed in a gauge with a mesh with a mesh opening of 32μm. To separate the toner and the carrier. 1.0 g of the obtained carrier was put in a 50 ml glass bottle, 10 ml of chloroform was added, and the mixture was shaken 50 times and allowed to stand for 10 minutes. Thereafter, the supernatant chloroform solution was placed in a glass cell, and the transmittance of the chloroform solution was measured using a turbidimeter. In Table 1, when the transmittance is 95% or more, ◎, when it is 90 to 94%, ◯, when it is 80 to 89%, △, when it is 70 to 79%, ×, and When it is 69% or less, it is indicated by xx.

(8) Heat-resistant storage stability After weighing 10 g of toner, put it in a 30 ml glass container (inner diameter 26 mm), close the lid in an environment of temperature 23 ± 2 ° C. and humidity 52 ± 3%, and tapping the glass bottle 150 times. And left in a high-temperature bath adjusted to a temperature of 50 ° C. and a humidity of 80% for 1 hour. Thereafter, the lid was opened in a high-temperature tank and allowed to stand for 24 hours, and then the penetration was measured with a penetration meter. Tapping was performed using a tapping machine (manufactured by Kuramochi Scientific Instruments), and the penetration was measured using a penetration testing machine (manufactured by Nikka Engineering Co., Ltd.) (based on JIS K 2207). In Table 1, from the good ones, it is ◎ for 30 mm or more, ◯ for 20 mm to 29 mm, △ for 15 mm to 19 mm, x for 8 mm to 14 mm, and 7 mm or less. Is indicated by xx.

(Example 2)
In the emulsification step described in Example 1, the amount of isobutyl alcohol was changed from 15 parts to 28 parts, and the aging time after the desolvation step was changed from 8 hours to 6 hours. [Bk toner] was obtained.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

(Example 3)
Example 1 except that in the emulsification process described in Example 1, 17 parts of n-butyl alcohol was used instead of 15 parts of isobutyl alcohol, and the aging time after the solvent removal process was changed from 8 hours to 6 hours. In the same manner as above, [Bk toner] was obtained.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

(Comparative Example 1)
[Bk toner] was obtained in the same manner as in Example 1, except that the isobutyl alcohol was not added in the emulsification step described in Example 1.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

(Comparative Example 2)
In the emulsification step described in Example 1, the amount of the 50% ethyl acetate solution of the prepolymer was changed from 100 parts to 70 parts, 10 parts of n-butyl alcohol instead of 15 parts of isobutyl alcohol, and the quantity of ketimine compound was changed to 7. [Bk Toner] was obtained in the same manner as in Example 1 except that the aging time after the solvent removal step was changed from 5 parts to 5.5 parts from 8 hours to 6 hours.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

(Comparative Example 3)
[Bk toner] was obtained in the same manner as in Example 1 except that the amount of isobutyl alcohol was changed from 15 parts to 32 parts in the emulsification step described in Example 1.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

Example 4
In the emulsification step described in Example 1, the amount of the 50% ethyl acetate solution of the prepolymer was changed from 100 parts to 200 parts, 35 parts of n-pentyl alcohol instead of 15 parts of isobutyl alcohol, and the amount of ketimine compound was changed to 7. [Bk toner] was obtained in the same manner as in Example 1 except that the amount was changed from 5 parts to 9.3 parts.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

(Example 5)
In the emulsification step described in Example 1, the amount of the 50% ethyl acetate solution of the prepolymer was changed from 100 parts to 200 parts, 35 parts of n-pentyl alcohol instead of 15 parts of isobutyl alcohol, and the amount of ketimine compound was changed to 7. [Bk toner] was obtained in the same manner as in Example 1 except that the aging time after the solvent removal step was changed from 5 parts to 9.3 parts from 8 hours to 12 hours.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

(Example 6)
Using the developer of Example 5, image formation was performed by an evaluation machine B shown below, and evaluation was performed.
Evaluation machine B: A contact-type charging device, an amorphous silicon photoreceptor, and an oilless surf fixing device are provided in the evaluation machine A so that a vibration bias voltage in which an AC voltage is superimposed on a DC voltage is applied as a developing bias. Further, the photosensitive member, the charging device, the developing means, and the cleaning device are integrally combined as a process cartridge (FIG. 10), and the same developer is used for each of the four color developing sections. The image quality and the like were evaluated in the single color mode.

(Example 7)
Using the developer of Example 5, image formation was performed by an evaluation machine C shown below, and evaluation was performed.
Evaluation machine C: The fixing device of the evaluation device B was modified to an oilless IH fixing device, and the same developer was put in each of the four color developing sections, and the image quality and the like were evaluated in the single color mode.

(Example 8)
In the emulsification step described in Example 1, the amount of the 50% ethyl acetate solution of the prepolymer was changed from 100 parts to 95 parts, and instead of 15 parts of isobutyl alcohol, 13 parts of n-butyl alcohol, and the amount of ketimine compound was changed to 7. [Bk toner] was obtained in the same manner as in Example 1 except that the amount was changed from 5 parts to 7.0 parts.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

Example 9
In the emulsification step described in Example 1, the amount of the 50% ethyl acetate solution of the prepolymer was changed from 100 parts to 95 parts, 17 parts of n-butyl alcohol instead of 15 parts of isobutyl alcohol, and the quantity of ketimine compound was changed to 7. [Bk toner] was obtained in the same manner as in Example 1 except that the amount was changed from 5 parts to 7.0 parts.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

(Example 10)
In the emulsification step described in Example 1, the amount of 50% ethyl acetate solution of the prepolymer was changed from 100 parts to 95 parts, 10 parts of n-butyl alcohol instead of 15 parts of isobutyl alcohol, and the amount of ketimine compound was changed to 7. [Bk toner] was obtained in the same manner as in Example 1 except that the amount was changed from 5 parts to 7.0 parts.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

(Example 11)
In the emulsification step described in Example 1, the amount of 50% ethyl acetate solution of the prepolymer was changed from 100 parts to 95 parts, n-butyl alcohol 20 parts instead of isobutyl alcohol 15 parts, and the ketimine compound quantity 7. [Bk toner] was obtained in the same manner as in Example 1 except that the amount was changed from 5 parts to 7.0 parts.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

(Example 12)
In the emulsification step described in Example 1, the amount of 50% ethyl acetate solution of the prepolymer was changed from 100 parts to 220 parts, n-pentyl alcohol was used instead of 15 parts of isobutyl alcohol, and the amount of ketimine compound was changed to 7. [Bk toner] was obtained in the same manner as in Example 1, except that the aging time after the solvent removal step was changed from 5 parts to 9.5 parts from 8 hours to 12 hours.
Further, the ¹ H relaxation time, ¹ H abundance ratio, and volume average particle diameter (Dv) of the obtained toner were as shown in Table 1. Furthermore, evaluation was performed in the same manner as in Example 1.

  The above evaluation results are shown in Table 1.

It is a figure which shows the example of the free induction decay curve and three-component separation of the toner for electrophotography measured by the pulse NMR method. 1 is a cross-sectional view illustrating a configuration of a tandem direct transfer system in an electrophotographic image forming apparatus. 1 is a cross-sectional view illustrating a configuration of a tandem type indirect transfer system in an electrophotographic image forming apparatus. 1 is a cross-sectional view illustrating a configuration of an image forming apparatus according to the present invention. It is sectional drawing which shows the structure in an image formation means. It is a schematic block diagram of a roller-type contact charging device. It is explanatory drawing which showed the structural example of the photoconductor. It is a schematic block diagram of a surf fixing device. 1 is a schematic configuration diagram of an IH fixing device. It is a schematic block diagram showing an example of a process cartridge.

Explanation of symbols

1,140,500, b Photoconductor 2,5 Transfer device 3 Sheet conveying belt 4,10 Intermediate transfer body 6 Paper feed device 7, 25, 250, 350 Fixing device 8, 63, e Photoconductor cleaning device (cleaning means)
DESCRIPTION OF SYMBOLS 9 Intermediate transfer body cleaning apparatus 14-16 Support roller 18 Image forming means 20 Tandem image forming apparatus 21 Exposure apparatus 22 Secondary transfer apparatus 23 Roller 24 Secondary transfer belt 26,360 Fixing belt 260 Fixing film 261 Driving roller 262 Driven roller 263 Heating body 263b Flat substrate 263h Fixing heater 263s Fixing temperature sensor 361 Heating roller 362 Fixing roller 364 Dielectric heating means 27, 270, 370 Pressure roller 28 Sheet reversing device 30 Document table 32 Contact glass 33, 34 Traveling body 35 Imaging lens 36 Reading sensor 42, 50 Paper feed roller 43 Paper bank 44 Paper feed cassette 45, 52 Separation roller 46, 48, 53 Paper feed path 47 Transport roller 49 Registration roller 51 Manual feed tray 55 Switching claw 56 Ejection Rollers 57 discharge tray 60, c charging device (charging means)
61, d Developing device (developing means)
62 Primary transfer device 64 Static elimination device 65 Developer on developing sleeve 68 Agitation paddle 69 Partition plate 71 Toner density sensor 72 Developing sleeve 73 Doctor 75 Cleaning blade 76 Cleaning brush 77 Cleaning roller 78 Cleaning blade 79 Toner discharge auger 80 Drive device 100 Copying device Main body 160 Charging roller 161 Core metal 162 Conductive rubber layer 200 Paper feed table 300 Scanner 400 Automatic document feeder 501 Support 502 Photoconductive layer 503 Amorphous silicon surface layer 504 Amorphous silicon charge injection blocking layer 505 Charge generation layer 506 Charge transport Layer a Process cartridge s Sheet (transfer material)

Claims (15)

In an electrophotographic toner obtained by dispersing a toner composition comprising at least a binder resin, a release agent and a colorant in an aqueous medium
When the free induction decay curve obtained by the pulse NMR method is separated into three curves derived from the hard component, the soft component, and the interface component between the hard component and the soft component constituting the electrophotographic toner. The spin-spin relaxation time (T ₂ s) of the curve derived from the hard component is 35 to 90 μs, and the proton ratio (Hs) of the hard component is 0.2 to 0.6. Toner for electrophotography. The ratio T ₂ s / Hs between the spin-spin relaxation time (T ₂ s) of the curve derived from the hard component and the proton ratio (Hs) of the hard component is 110 to 145, The toner for electrophotography according to 1. The spin-spin relaxation time (T ₂ l) of the curve derived from the soft component is 1.5 to 3.5 ms, and the proton ratio (Hl) of the soft component is 0.1 to 0.2. The electrophotographic toner according to claim 1, wherein the toner is an electrophotographic toner.   The electrophotographic toner according to claim 1, wherein the binder resin contains a polyester resin.   In an organic solvent, a compound having an active hydrogen group, a polymer having a site capable of reacting with the compound having an active hydrogen group, and the colorant are dissolved or dispersed to form a solution or dispersion, and the solution or dispersion It is obtained by dispersing the dispersion in the aqueous medium and then removing the organic solvent after reacting or reacting the compound having an active hydrogen group with the polymer. The toner for electrophotography according to any one of claims 1 to 4. According to claim 1, spin relaxation time (T 2 _m) is characterized in that it is a 0.2～0.6Ms - the spin of the curve from the interface component between the hard component and the soft component Toner for electrophotography.   The electrophotographic toner according to claim 1, wherein the release agent is a carbonyl group-containing wax.   A developer comprising the electrophotographic toner according to claim 1 and a carrier made of magnetic particles.   An electrostatic charge image carrier, a charging means for charging the electrostatic charge image carrier, an exposure means for forming an electrostatic charge image on the charged electrostatic charge image carrier, and an electrostatic charge image on the electrostatic charge image carrier. A developing unit that forms a toner image with the developer according to claim 8, a transfer unit that electrostatically transfers the toner image onto a transfer material, and a fixing unit that heat-fixes the toner image on the transfer material. An image forming apparatus.   The image forming apparatus according to claim 9, wherein the charging unit performs charging by bringing a charging member into contact with the electrostatic image carrier and applying a voltage to the charging member.   The image forming apparatus according to claim 9, wherein the electrostatic charge image carrier is an amorphous silicon electrostatic charge image carrier. The fixing unit includes a heating body provided with a heating element, a film in contact with the heating body, and a pressure member in pressure contact with the heating body through the film,
The image forming apparatus according to claim 9, wherein the toner image is heated and fixed by passing a transfer material onto which the toner image is transferred between the film and the pressure member. . The fixing unit includes a heating roller made of magnetic metal and heated by electromagnetic induction, a fixing roller arranged in parallel with the heating roller, and stretched between the heating roller and the fixing roller. An endless belt-shaped toner heating medium that is heated by the roller and rotated by these rollers, and a pressure roller that is pressed against the fixing roller through the toner heating medium and rotates to form a fixing nip portion. ,
12. The image according to claim 9, wherein the toner image is heated and fixed by passing a transfer material onto which the toner image is transferred between the toner heating medium and the pressure roller. Forming equipment.   The image according to any one of claims 9 to 13, wherein the developing unit includes an electric field printing unit for applying an alternating electric field when developing the electrostatic image on the electrostatic image carrier. Forming equipment. In the process cartridge in which at least the electrostatic charge image carrier and the developing unit are integrally supported and are detachable from the image forming apparatus main body.
A process cartridge, wherein the developing means holds the electrophotographic toner according to claim 1.

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