JP4866280B2 - Image forming toner and process cartridge filled with the toner - Google Patents

Description

  The present invention relates to a toner used as a developer for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like, and a process cartridge that holds the toner. More specifically, the present invention relates to an image forming toner and a process cartridge used for a copying machine, a laser printer, a plain paper fax machine, and the like using a direct or indirect electrophotographic developing system.

  In recent years, the strong demand for higher image quality from the market has spurred the development of an electrophotographic apparatus suitable for it and a toner developer used therefor. As a toner corresponding to high image quality, it is essential that the toner has a small particle size and a uniform particle size. When the toner particle size is uniform and the particle size distribution becomes sharp, the behavior of individual toner particles during development is aligned, and the reproducibility of minute dots is remarkably improved. In recent years, a polymerized toner method has attracted attention as a method for producing a toner having a uniform particle diameter. As the polymerized toner method, there are an emulsion polymerization method and a dissolution suspension method, which are relatively easy to be modified, in addition to suspension polymerization. That is, conventionally, pulverized toner has been used as the toner, and the technology for making the pulverized toner spherical by heat treatment is disclosed in Japanese Patent Publication No. 4-27897 (Patent Document 2) and JP-A-6-317928 (Patent Document 3). ) Etc. In addition, in order to improve the image quality of formed images and improve transferability, technologies for reducing the diameter and spheroidization of toners have been developed. In addition to suspension polymerization, emulsification weight is relatively easy to modify. A technique for producing a spherical toner in a wet method such as a combination method or a dissolution suspension method has been proposed in Japanese Patent Application Laid-Open No. 1-257857 (Patent Document 1).

When the toner particle size is uniform and the particle size distribution is sharp, the behavior of individual toner particles during development is uniform, and the reproducibility of minute dots is remarkably improved. However, in a toner having a small particle size and a uniform particle size, a cleaning failure is likely to occur from a gap near the edge of the cleaning blade at the nip portion between the cleaning blade and the surface of the image carrier (photosensitive member).
In view of this, various methods have been proposed for improving the cleaning property by devising the toner. One of them is a method of changing the toner from a spherical shape to a different shape. By changing the shape of the toner, the powder fluidity of the toner is lowered, and it is easy to stop by blade cleaning. However, if the degree of toner irregularity is too large, the behavior of the toner becomes unstable during development and the like, and the fine dot reproducibility deteriorates. In addition, when the shape of the toner is uneven, contamination of the photoconductor by the toner is caused by weak adhesion of the silica added as a fluidizing agent to the recesses or movement of the silica to the recesses in use. And the problem of toner adhesion to the fixing roller are likely to occur.

  In addition, by changing the shape of the toner, the reliability of the toner with respect to cleaning is improved, but on the other hand, a problem occurs in terms of fixing. In other words, when the shape of the toner is changed, the toner filling density in the toner layer on the transfer material before fixing is reduced, the thermal conductivity in the toner layer is lowered during fixing, and the low-temperature fixability is deteriorated. Resulting in. In particular, when the pressure at the time of fixing is smaller than the conventional pressure, the thermal conductivity is further deteriorated and the low-temperature fixing is hindered. Japanese Patent Application Laid-Open No. 11-133665 (Patent Document 4) proposes a toner made of polyester having a Wadell practical sphericity of 0.90 to 1.00. The problem of toner cleaning properties has not been solved.

In terms of the low-temperature fixing of toner, an attempt has been made to use a polyester resin having excellent low-temperature fixability and relatively good heat-resistant storage, in place of styrene-acrylic resins that have been frequently used. However, for further low-temperature fixing, it is necessary to control the thermal characteristics of the resin itself. However, if the glass transition temperature (Tg) is lowered too much, the heat-resistant storage stability is deteriorated or the molecular weight is decreased. If the softening temperature [T (F1 / 2)] of the resin is lowered too much, there are problems such as lowering the hot offset occurrence temperature. For this reason, even a polyester resin excellent in low-temperature fixability has not yet obtained a toner having excellent low-temperature fixability and high hot offset occurrence temperature by controlling the thermal characteristics of the resin itself.
In addition, as a result of controlling the thermal characteristics, the developer in the copying machine is stirred for a long time due to long-time image output, so the release agent and low-melting-point polyester component in the toner adheres to the carrier and increases the charging ability of the carrier. There is a strong tendency for the developer charge amount to decrease.

  In the above-mentioned dissolution suspension method, there is a merit that a polyester resin capable of low-temperature fixing can be used, but in order to achieve oil-less fixing, polymer control and coloration are performed in the production and polymer control for widening the mold release width. Since the high molecular weight component is added in the step of dissolving or dispersing the agent in the solvent, the viscosity of the liquid rises and productivity problems are likely to occur. And those problems are not solved yet. In particular, in the solution suspension method, JP-A-9-15903 (Patent Document 5) proposes to improve the cleaning by making the toner surface shape spherical and uneven, but the regularity In fact, it is not a regular toner, so it is difficult to obtain a toner with satisfactory quality because it has not been designed with a high molecular weight to ensure basic durability and releasability. .

JP-A-1-257857 Japanese Patent Publication No. 4-27897 JP-A-6-317928 Japanese Patent Laid-Open No. 11-133665 JP 9-15903 A

  The present invention has been made in view of the above-described problems of the prior art. The first object of the present invention is to provide a small particle size and sharpness capable of obtaining a high-quality image with excellent microdot reproducibility. It is to provide an image forming toner having a proper particle size distribution. A second object is to provide an image forming toner which is excellent in cleaning property and low temperature fixing property, and has little adhesion of a toner component to a carrier even in long-term use, and does not deteriorate charging ability. A third object is to provide a process cartridge using the image forming toner.

Said subject is solved by invention of following (1)-(6).
(1) An image forming toner containing at least a binder resin, a colorant, a release agent and an inorganic filler, wherein the release agent is a paraffin wax having a melting point of 60 to 90 ° C., and the inorganic filler is montmorillonite or The endothermic peak of the endothermic peak derived from the release agent in the DSC measurement of the toner is in the range of 3.0 to 6.0 J / g, and the average circularity of the toner is 0.94 or more. In addition, the toner powder phase is preliminarily brought into a compacted state by a compacting means, and then the conical rotor is intruded into the compacted toner powder phase while rotating the conical rotor having a groove on the surface. In a toner evaluation method for evaluating the fluidity of toner by measuring the torque generated when moving inside, the toner put into a cylindrical container having an inner diameter of 60 mm and compacted for 60 seconds with a compaction load of 585 g Body phase, apex angle rotation speed 1rpm the conical rotor of 60 °, the torque obtained while 20mm penetrate the powder phase at an entry speed 5 mm / min is 1.4～2.0MNm,
An image forming toner characterized by the above.
(2) In the toner, a toner material solution in which a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, a release agent, and an inorganic filler is dissolved or dispersed in at least an organic solvent is used as an aqueous medium. The toner has a shape factor SF-1 in the range of 130 to 160 and a shape factor SF-2 in the range of 110 to 140. The image forming toner according to (1) above.
(3) The toner has a weight average particle diameter (D4) of 3 to 8 μm and a ratio (D4 / Dn) of the weight average particle diameter (D4) to the number average particle diameter (Dn) of 1.00 to 1.n. The toner for image formation as described in (1) or (2) above, which is in the range of 30.
(4) The toner for image formation as described in any one of (1) to (3) above, wherein the toner has a glass transition point of 40 to 60 ° C.
(5) The toner for image formation as described in any one of (1) to (4) above, wherein 1 to 10% by number of particles of 2 μm or less of the toner is included.
(6) Image carrier, charging means for charging the surface of the image carrier, exposure means for writing a latent image by exposing the image carrier, and latent image written on the image carrier with toner At least an image carrier among developing means for developing, transfer means for transferring the developed toner image to an intermediate transfer body or printing paper, and cleaning means for cleaning the transfer residual toner on the image carrier that has not been completely transferred A process cartridge having the developing unit, wherein the developing unit is filled with a toner or a developer composed of a toner and a carrier, and the toner forms the image according to any one of the above (1) to (5). A process cartridge characterized by being a toner for use.

  The toner for image formation of the present invention is excellent in cleaning properties and low-temperature fixability, has little toner component adhesion to the carrier even during long-term use, and does not deteriorate the charging ability. It is done. In particular, even if the toner has a spherical shape with a small particle size and is granulated in water, it can be used in an image forming apparatus or a process cartridge that can be sufficiently cleaned.

The present invention is described in further detail below.
The image forming toner of the present invention contains at least a binder resin, a colorant, a release agent, and an inorganic filler.

[Binder resin]
As the binder resin, known resins can be used, for example, styrene resin, vinyl chloride resin, rosin modified maleic acid resin, phenol resin, epoxy resin, saturated polyester resin, unsaturated polyester resin, low molecular weight polyethylene, low molecular weight. Examples include polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, and polyvinyl butyral resin. These resins may be used alone or in combination. The binder resin used in the present invention is preferably a resin obtained by crosslinking or elongation reaction in an aqueous medium described later.
In the present invention, the glass transition point (Tg) of the binder resin is usually 40 to 70 ° C, preferably 40 to 60 ° C. If it is less than 40 ° C., the heat resistance of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of a modified polyester such as a urea-modified polyester resin to be described later, the toner of the present invention tends to have good heat-resistant storage stability even when the glass transition point is low, as compared with a known polyester-based toner.

[Colorant]
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by mass, preferably 3 to 10% by mass with respect to the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded together with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene or the like, or a copolymer of these and a vinyl compound, 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, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

  The masterbatch can be obtained by mixing and kneading a masterbatch resin and a colorant under high shear. In this case, 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 a 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 shear dispersion device such as a three-roll mill is preferably used.

〔Release agent〕
As the release agent, paraffin wax having a melting point of 60 to 90 ° C. is used. Paraffin wax effectively acts as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface, thereby preventing high temperature offset resistance without applying a release agent such as oil to the fixing roller. The effect is shown. The melting point of the paraffin wax in the present invention is the maximum endothermic peak by DSC (differential scanning calorimeter). If the content of the paraffin wax is too small, the toner releasing action is poor, which is a problem.
Further, the toner of the present invention needs to have an endothermic amount of an endothermic peak derived from a release agent (paraffin wax) in the DSC measurement of the toner in a range of 3.0 to 6.0 J / g.

[Inorganic filler]
Examples of the inorganic filler for controlling the toner shape include silica, alumina, and titania. Preferably, montmorillonite or an organic modified product thereof (Clayton APA) is used. The function of the inorganic filler is to form irregularities on the toner surface, and the mechanism is as follows. That is, in the toner manufacturing method in which the toner of the present invention emulsifies the toner material liquid in an aqueous medium in the presence of a surfactant and resin fine particles, the inorganic filler in the toner material liquid is an interface between the organic solvent and the aqueous solvent at the time of emulsification. And gather in the surface shape of the emulsified dispersion (reactant). Next, in the step of removing the organic solvent from the emulsified dispersion (reactant), washing and drying, the inorganic filler present on the surface forms irregularities on the surface of the reaction product.
Therefore, in obtaining such a shape, the amount of the inorganic filler can be controlled and changed in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the binder resin, and the amount of the inorganic filler is large. As the values of SF-1 and SF-2 become larger, they are deformed.

  The toner of the present invention can contain a charge control agent as required, and an external additive can be externally added as necessary.

[Charge control agent]
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salt or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSYVP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (manufactured by Nippon Carlit) ), Copper phthalocyanine, perylene, quinacridone, azo face And other polymeric compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.
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 not limited uniquely. However, it is preferably used in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the binder resin. Preferably, the range of 0.2-5 mass parts is good. When the amount exceeds 10 parts by mass, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the developer fluidity is lowered, and the image density is lowered. Invite.

(External additive)
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 mμ to 3 μm, particularly preferably 5 to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 100-500 m < ² > / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5% by mass of the toner, and particularly preferably 0.01 to 2.0% by mass.

Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
In addition, polymer fine particles, such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, methacrylic acid ester, acrylic acid ester copolymer, polycondensation system such as silicone, benzoguanamine, nylon, thermosetting Examples thereof include polymer particles made of a resin.

  Such external additives can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. . In particular, it is preferable to use hydrophobic silica and hydrophobic titanium oxide obtained by subjecting silica and titanium oxide to the above surface treatment.

  The toner of the present invention can also be produced by mixing and melting a binder resin, a release agent (paraffin wax), a charge control agent and the like, then pulverizing and classifying the mixture, and adding an external additive thereto. However, the toner preferably contains a toner material solution in which a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, a release agent, and an inorganic filler are dissolved or dispersed in at least an organic solvent. It can be produced by crosslinking and / or elongation reaction in a medium.

The method for producing the toner in water will be described as follows.
Specifically, this toner is formed by dissolving or dispersing a toner component consisting of a binder component (binder resin) composed of a modified polyester resin capable of reacting at least with active hydrogen and a colorant in an organic solvent. Alternatively, it is produced by reacting the dispersion with a crosslinking agent and / or an extender in a hydrogen medium containing a dispersant and removing the solvent from the obtained dispersion.

[Modified polyester resin]
The toner of the present invention contains a modified polyester (i) as a binder component. The modified polyester (i) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound.

  Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with. 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.

The urea-modified polyester is produced as follows.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. As trihydric or higher polyhydric alcohol (TO), trihydric or higher polyhydric aliphatic alcohol (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) and a small amount of (TC) Mixtures are preferred.
Divalent carboxylic acids (DIC) 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) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms.
Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) ); Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; phenol derivatives, oximes, polyisocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.

  The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40% by mass, preferably 1 to 30% by mass, more preferably 2 to 20% by mass. %. If it is less than 0.5% by mass, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40% by mass, the low-temperature fixability deteriorates.
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 is lowered, and the hot offset resistance is deteriorated.

Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acids B1 to B5 blocked (B6).
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.).
Examples of the trivalent or higher polyvalent amine compound (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 compound (B6) obtained by blocking the amino group of B1 to B5 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 mixture of B1 and a small amount of B2.

  The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.

  The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

The modified polyester (i) used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1000 to 10000. When the molecular weight is less than 1000, the elongation reaction hardly occurs, the elasticity of the toner is small, and as a result, the resistance to hot offset deteriorates. On the other hand, if it exceeds 10,000, the problem in production becomes high in the case where the fixing property is lowered, the particles are formed or pulverized.
The number average molecular weight of the modified polyester (i) is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.

  In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (i), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those blocked (ketimine compounds).

[Unmodified polyester]
In the present invention, not only the modified polyester (i) is used alone, but also the unmodified polyester (ii) can be contained as a binder resin component together with the (i). By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to the single use.
Examples of the unmodified polyester (ii) include polycondensates of a polyhydric alcohol (PO) and a polycarboxylic acid (PC) similar to the polyester component (i), and preferred ones include (i) It is the same. Further, (ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, for example, may be modified with a urethane bond. It is preferable that (i) and (ii)) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (i) and the unmodified polyester component (ii) preferably have similar compositions. In the case of containing (ii), the weight ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. If the weight ratio of (i) is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight of unmodified polyester (ii) is usually 1000 to 10000, preferably 2000 to 8000, and more preferably 2000 to 5000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. As for the acid value of (ii), 1-5 are preferable, More preferably, it is 2-4. Since a high acid value wax is used for the wax, the binder resin easily matches a toner used for a two-component developer because a low acid value binder leads to charging and high volume resistance.

  The glass transition point (Tg) of the binder resin in the present invention is usually 35 to 70 ° C, preferably 55 to 65 ° C. If the temperature is lower than 35 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show.

The toner of the present invention has an average circularity of 0.94 or more.
(Measurement method of circularity)
The circularity of the toner is
Circularity = defined by the circumference of a circle having the same area as the projected area of the particle / the contour length of the projected particle image. As a method for measuring the circularity, an engineering detection method is suitable in which a suspension containing particles is passed through an imaging region suspension zone on a flat plate, and a particle image is optically detected and analyzed by a CCD camera.

Further, in the toner of the present invention, after the toner powder phase is preliminarily compacted by a compacting means, the conical rotor is intruded into the compacted toner powder phase while rotating the conical rotor having grooves cut on the surface. In a toner evaluation method for evaluating the fluidity of a toner by measuring the torque generated when the toner moves in the powder phase, the toner powder phase is put into a cylindrical container having an inner diameter of 60 mm and compacted for 60 seconds with a compaction load of 585 g. Further, when a conical rotor having an apex angle of 60 ° is caused to penetrate 20 mm into the powder phase at a rotation speed of 1 rpm and a penetration speed of 5 mm / min , the torque is 1.4 to 2.0 mNm.
When the torque is less than 1.4 mNm or exceeds 2.0 mNm, the charging ability of the carrier is easily lowered.

Further, as a problem that has not been found so far, in the process of charging and developing the toner, the surface area of the toner is smoother, and the smaller the torque evaluated by the previous torque evaluation method, the smaller the contact area between the toner and the carrier. The smaller the contact area between the toner and the developing sleeve (one component developing system), the more the toner and the carrier or the developing sleeve are in point contact at the same time. Since it is easy to roll, low melting point wax, resin component, etc. are easily fixed on the carrier. For this reason, it is easy to reduce the charging ability of the carrier. In particular, when the torque evaluated by this torque evaluation method is less than 1.2 mNm, this problem becomes remarkable.
In addition, the toner has a rougher surface shape, more irregularities, and the larger the torque evaluated by this torque evaluation method, the more the toner, the carrier, and the developing sleeve are in surface contact. Although it is difficult to roll, at the same time, since the contact area between the toner and the carrier is large, wax having a low melting point, a resin component, and the like are easily fixed on the carrier. For this reason, this problem becomes prominent because the charging ability of the carrier is easily lowered. This tendency becomes remarkable when the torque evaluated by this torque evaluation method exceeds 2.0 mNm. For this reason, the torque evaluated by this torque evaluation method has an optimal range, and the value is 1.2 mNm to 2.0 mNm, and particularly preferably 1.4 mNm to 2.0 mNm.

  When the toner of the present invention is produced by crosslinking and / or elongation reaction in the aqueous medium, the toner has a shape factor SF-1 in the range of 130 to 160 and a shape factor SF-2 of 110 to 110. Preferably it is in the range of 140. The shape factor SF-1 indicates the ratio of the roundness of the toner shape, and the shape factor SF-2 indicates the ratio of the unevenness of the toner shape.

As described above, a toner having a small particle size and a uniform particle size is difficult to clean. Therefore, in the present invention, the values of the shape factors SF-1 and SF-2 of the toner are defined.
Here, the relationship between toner shape and transferability will be described first. When using a full-color copier that transfers images with multi-color development, the amount of toner on the photoconductor increases compared to the case of one-color black toner used in black-and-white copiers. It is difficult to improve transfer efficiency. In addition, when ordinary irregular toner is used, a shearing force or friction between the photosensitive member and the cleaning member, between the intermediate transfer member and the cleaning member, and / or between the photosensitive member and the intermediate transfer member. Due to the force, toner fusing or filming occurs on the surface of the photoreceptor or the intermediate transfer member, and transfer efficiency tends to deteriorate. When generating a full-color image, it is difficult to transfer the four-color toner images uniformly. Furthermore, when an intermediate transfer member is used, problems are likely to occur in terms of color unevenness and color balance, and high-quality full-color images are stabilized. Output is not easy.

From the viewpoint of the balance between blade cleaning and transfer efficiency, the toner shape factor SF-1 is 130 to 160, which achieves both cleaning and transferability. Cleaning and transferability are greatly related to the material of the blade and how to apply the blade, and transfer is also different depending on the process conditions. Therefore, the design according to the process can be performed within the range of SF-1. However, when SF-1 falls below 130, cleaning with a blade becomes difficult. On the other hand, when SF-1 exceeds 160, the aforementioned transferability is deteriorated. This phenomenon is caused by the shape of the toner being deformed and the movement of toner during transfer (photosensitive member surface to transfer paper, photosensitive member surface to intermediate transfer belt, first intermediate transfer belt to second intermediate transfer belt, etc.) Since the toner particles are not smooth and the behavior of the toner particles varies, uniform and high transfer efficiency cannot be obtained. In addition, unstable charging and brittleness of particles begin to appear. Furthermore, it becomes a fine phenomenon in the developer, which causes a decrease in the durability of the developer.
The shape of the toner is preferably a spindle shape with a shape factor SF-1 in the range of 130 to 160. The spindle shape has excellent transferability after the spherical shape because there are few large irregularities on the surface. The cleaning property, which is in a trade-off relationship with the transfer property, is also good, and it can be said that the shape is very balanced.

  In the case of the pulverized toner, the toner is indefinite shape (a shape that is not a specific and well-rounded shape) and the toner has a shape factor SF-1 exceeding 140. However, since the particle size distribution of the toner is generally broad, In order to make D4 / Dn 1.30 or less, this is an inefficient method. When a toner is obtained by a polymerization method, for example, suspension polymerization or emulsion polymerization makes it difficult to make a polyester toner, and it cannot cope with further low-temperature fixing. In a dry toner comprising a toner binder obtained by subjecting an isocyanate group-containing prepolymer to an extension reaction and / or a crosslinking reaction in JP-A Nos. 11-149180 and 2000-292981, and a colorant, the dry toner comprises the prepolymer ( A dry toner characterized by comprising particles formed by elongation reaction and / or cross-linking reaction with amines (B) in an aqueous medium of A) has been proposed, and the toner shape of the present invention is proposed. Therefore, transferability and cleaning performance cannot be achieved at the same time.

  The toner of the present invention has a weight average particle diameter (D4) of 3 to 8 μm and a ratio (D4 / Dn) of the weight average particle diameter (D4) to the number average particle diameter (Dn) of 1.00 to 1.30. In this range, it is possible to obtain a high-resolution and high-quality toner. Furthermore, in the case of a two-component developer, even if a long-term balance of the toner is performed, fluctuations in the particle size of the toner in the developer are reduced, and good and stable developability even with long-term stirring in the developing device. Is possible. If D4 / Dn exceeds 1.30, the particle size variation of individual toner particles is large, and the behavior of the toner varies during development, and the reproducibility of minute dots is impaired. Therefore, a high-quality image cannot be obtained. More preferably, D4 / Dn is in the range of 1.00 to 1.20, and a better image can be obtained.

  In the toner of the present invention, the weight average particle diameter D4 is preferably 3 to 8 μm. In general, it is said that the smaller the particle size of the toner, the more advantageous it is to obtain a high-resolution and high-quality image, but it is disadvantageous for transferability and cleaning properties. is there. In addition, when the weight average particle diameter is smaller than the above range, in the case of a two-component developer, the toner is fused to the surface of the carrier during long-term agitation in the developing device, and the charging ability of the carrier is reduced. When it is used, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur. In addition, these phenomena are greatly related to the content of fine powder. In particular, when the particle size of 2 μm or less exceeds 10%, it becomes an obstacle to the adhesion to the carrier and the stability of charging at a high level. Conversely, when the toner particle size is larger than the above range, it becomes difficult to obtain a high-resolution and high-quality image, and the toner particle size when the balance of the toner in the developer is performed. In many cases, fluctuations of It was also clarified that the same was true when the weight average particle diameter / number average particle diameter was larger than 1.30.

  The toner of the present invention preferably has a glass transition point (Tg) of 40 to 60 ° C. If it is less than 40 ° C., the heat resistance of the toner deteriorates, and if it exceeds 60 ° C., the low-temperature fixability is insufficient. Due to the coexistence of a modified polyester such as a urea-modified polyester resin, the dry toner of the present invention tends to have good heat-resistant storage stability even when the glass transition point is low, as compared with a known polyester-based toner.

  The toner of the present invention preferably contains 1 to 10% by number of particles of 2 μm or less. As a result, the cleaning property is improved and a clear image can be obtained.

  The toner of the present invention can contain a charge control agent as necessary, and an external additive is used as needed to assist fluidity, developability, chargeability, and environmental stability. It has been.

[Charge control agent]
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salt or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSYVP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (manufactured by Nippon Carlit) ), Copper phthalocyanine, perylene, quinacridone, azo face And other polymeric compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.
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 not limited uniquely. However, it is preferably used in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the binder resin. Preferably, the range of 0.2-5 mass parts is good. When the amount exceeds 10 parts by mass, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the developer fluidity is lowered, and the image density is lowered. Invite.

(External additive)
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 mμ to 3 μm, particularly preferably 5 to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 100-500 m < ² > / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5% by mass of the toner, and particularly preferably 0.01 to 2.0% by mass.

Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
In addition, polymer fine particles, such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, methacrylic acid ester, acrylic acid ester copolymer, polycondensation system such as silicone, benzoguanamine, nylon, thermosetting Examples thereof include polymer particles made of a resin.

  Such external additives can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. . In particular, it is preferable to use hydrophobic silica and hydrophobic titanium oxide obtained by subjecting silica and titanium oxide to the above surface treatment.

  Next, a measurement method relating to the properties and the like of the toner of the present invention will be shown.

(Melting point)
The melting point of the paraffin wax is determined by, for example, using a differential scanning calorimeter (“DSC-60”; manufactured by Shimadzu Corporation, etc.) at a rate of 10 ° C./min to 20 to 150 ° C. After cooling to 0 ° C. at 10 ° C./min and then measuring at a rate of temperature increase of 10 ° C./min, the endothermic peak temperature at the second temperature increase can be calculated.

(Endothermic peak endotherm derived from release agent by DSC)
Using Shimadzu TA-60WS and DSC-60 as measuring devices, the measurement was performed under the following measurement conditions.
Measurement condition:
Sample container: Aluminum sample pan (with lid)
Sample amount: 5mg
Reference: Aluminum sample pan (alumina 10mg)
Atmosphere: Nitrogen (flow rate 50 ml / min)
Temperature conditions:
Starting temperature: 20 ° C
Temperature increase rate: 10 ° C / min
End temperature: 150 ° C
Holding time: None Temperature drop: 10 ° C / min
End temperature: 20 ° C
Holding time: None Temperature increase rate: 10 ° C / min
End temperature: 150 ° C
The measurement results were analyzed using the data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation. In the analysis method, in the DrDSC curve, which is the DSC differential curve of the second temperature increase, specify two locations on the low-temperature side and high-temperature side of the endothermic peak corresponding to the endotherm when the release agent melts. The peak endotherm is obtained using the peak analysis function. The endothermic peak corresponding to the endotherm at the time of melting of the release agent is an endothermic peak obtained by performing DSC measurement of the release agent alone by the above procedure.

(Particle size distribution)
Examples of the measuring device for the particle size distribution of toner particles by the Coulter counter method include Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. Volume distribution and number distribution are calculated. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter of the toner can be obtained.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm. In addition, a flow type particle image analyzer (“FPIA-2100”; manufactured by Sysmex Corporation) is used for measurement of ultrafine toner of 2 μm or less, and analysis software (FPIA-2100 Data Processing Program for FPIA version 00-10) is used. Analysis.

  Specifically, 0.1 to 0.5 ml of 10 wt% surfactant (alkylbenzene sulfonate Neogen SC-A; Daiichi Kogyo Seiyaku) is added to a glass 100 ml beaker, and each toner 0.1 to 0 is added. 0.5 g was added and stirred with a microspatel, and then 80 ml of ion-exchanged water was added. The obtained dispersion was subjected to a dispersion treatment for 3 minutes with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.). The shape and distribution of the toner were measured using the FPIA-2100 until the density of the dispersion was 5000 to 15000 / μl. In this measurement method, it is important that the concentration of the dispersion liquid is 5000 to 15000 / μl from the viewpoint of measurement reproducibility of the average circularity. In order to obtain the dispersion concentration, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant to be added and the amount of toner. The amount of the surfactant varies depending on the hydrophobicity of the toner as in the measurement of the toner particle diameter described above. If it is added in a large amount, noise due to bubbles is generated. If the amount is too small, the toner cannot be sufficiently wetted. It becomes insufficient. Further, the toner addition amount differs from the particle size, and it is necessary to decrease the small particle size and increase the large particle size. When the toner particle size is 3 to 7 μm, the toner amount is 0.1 to 0. By adding 0.5 g, the dispersion concentration can be adjusted to 5000 to 15000 / μl.

(torque)
As a publicly known document disclosing a technique for evaluating a toner for developing an electrostatic image and an electrophotographic developer, Japanese Patent Application Laid-Open No. 2004-177371 describes the fluidity of a powder toner composed of at least a resin and a pigment. A method of measuring a conical rotor by rotating the conical rotor while rotating and measuring a torque or a load generated when the conical rotor moves in the powder phase. ) / Technology that measures the torque or load under the condition that the rotational speed (rpm) of the conical rotor is 2/1 to 20/1 is described, Japanese Patent Application Laid-Open No. 2004-177850 describes An apparatus for measuring by measuring a torque or a load generated when a conical rotor is rotated into a body phase and the conical rotor moves in a powder phase. A technique is described in which the powder is rotated in advance and then entered into the powder phase. Japanese Patent Application Laid-Open No. 2006-78257 discloses that the technique of these patent documents is further improved. As described above, a method suitable for evaluating the difference between toners has been proposed in which the torque is small even when measuring a material having good fluidity, and it is strongly influenced by measurement variations.

The inventors of the present invention precisely evaluated the fluidity of the toner by the torque evaluation method, and found that the torque evaluated by the torque evaluation method has a close correlation with the cleaning characteristics. In the toner having a large torque evaluated by this torque evaluation method, the interaction force between the toner particles under the compacting condition is large, and in the process of clogging (cleaning) the transfer residual toner on the photoreceptor with a cleaning blade or the like. The toner blocked by the blade is likely to aggregate and form a toner layer. Accordingly, the transfer residual toner is blocked not only by the blade but also by the toner layer blocked by the blade, and the amount of toner passing through the cleaning blade is reduced, so that a good cleaning property can be obtained.
When the torque evaluated by this torque evaluation method is less than 1.2 mNm, the cleaning performance deteriorates. On the other hand, when the torque evaluated by this torque evaluation method exceeds 2.0 mNm, fluidity is low in processes other than cleaning. Problems, such as the occurrence of toner clogging in the piping, are particularly noticeable. For this reason, there is an optimum range for the torque evaluated by this torque evaluation method, and the value is 1.2 mNm to 2,0 mNm, particularly preferably 1.4 mNm to 2.0 mNm.

  This torque evaluation method is described in the aforementioned Japanese Patent Application Laid-Open No. 2006-78257. While rotating the conical rotor in the powder phase, the torque evaluation method is allowed to enter (lower) or withdraw (up). The torque and load applied to the container containing the conical rotor and the toner powder phase are sometimes measured, and the fluidity is evaluated based on the relationship between the torque and the load. A cone rotor having a cone apex angle of 60 ° is suitable. The length of the conical rotor needs to be long enough so that the conical rotor surface is continuously present in the toner powder phase. In the present invention, the conical rotor has a length of 30 mm. Further, the conical rotor surface should have grooves. Rather than measuring the friction component between the material surface of the conical rotor and the toner particles, it is better to measure the friction component between the toner particles and the toner particles. For this purpose, when the conical rotor rotates and enters the toner powder phase, the toner particles enter the grooves cut on the surface of the conical rotor, and the toner particles and the surrounding toner enter. It is more appropriate to measure the state of friction with the particles. The shape of the groove is not limited, but it is necessary to devise so that the contact between the material surface of the conical rotor and the toner particles becomes small.

FIG. 2 shows the shape of the conical rotor in the present invention. This is obtained by cutting a groove straight from the apex of the cone in the direction of the base, and the cross section of the groove has a sawtooth shape having triangular irregularities. In this case, the contact between the conical rotor material surface and the toner particles is only at the tip of the crest of the triangular groove. Most of the contact is between the toner particles that have entered the groove and the surrounding toner particles. Any material can be used for the conical rotor, but a material that is easy to process, has a hard surface, and does not change quality is preferable. A material that is not charged is suitable. In the present invention, those made of Cu were used.
The torque and load of the toner powder vary depending on the rotational speed of the conical rotor and the penetration speed of the conical rotor. In this measurement, in order to increase the accuracy of the measurement, the rotation speed and the penetration speed of the conical rotor are reduced so that the delicate contact state between the toner particles can be measured. Therefore, the measurement conditions in the present invention are as follows.
・ Rotation speed of conical rotor: 1 rpm
・ Intrusion speed of conical rotor: 5 mm / min

  The outline of the apparatus configuration in the present invention is, for example, as shown in FIG. 1, and a conical rotor is attached to the tip of a shaft and fixed to a torque meter. The torque meter can be moved up and down by an elevator, a container filled with toner is placed in the center of the stage, and the conical rotor is lowered so that the conical rotor enters the center of the container while rotating. To do. Torque applied to the conical rotor is detected by a torque meter at the top, and a load applied to a container containing toner is detected by a load cell below the container. The amount of movement of the conical rotor is determined by a position detector. This configuration is an example, and other configurations such as moving a container containing toner up and down by an elevator are also possible. FIG. 4 shows another example of the outline of the apparatus configuration in the present invention.

FIG. 3 shows an example of changes in the cross-sectional shape and cone apex angle of the conical rotor in the present invention. The material of the container is not limited, but a conductive material is suitable so as not to be affected by charging with the powder. In addition, since the measurement is performed while changing the powder, the surface is preferably close to a mirror surface in order to reduce contamination. The size of the container is important, and it is necessary to select a larger (diameter) size with respect to the diameter of the conical rotor so that there is no influence of the container wall when the conical rotor enters while rotating, An aluminum cylindrical container having an inner diameter of 60 mm and a height of 30 mm was used.
The torque meter is preferably a high-sensitivity type, and a non-contact type is suitable. A load cell with a wide load range and high resolution is suitable. The position detector returns the position information detected by monitoring the current position to the motor drive circuit of the elevator via the encoder as a control signal for control to eliminate the deviation between the current position and the planned position. There are linear scales and displacement sensors that use light, but specifications of 0.1 mm or less are suitable for accuracy. The elevator can be driven with high accuracy using a servo motor or a stepping motor.

  FIG. 4 shows an example of an apparatus provided with a consolidation function. The device consists of a consolidation zone and a measurement zone. The compaction zone is a container for powder (inner diameter 60 mm, aluminum cylindrical container 30 mm in height), an elevating stage for moving the container up and down, a piston for compaction, and a weight for applying a load to the piston (60 mm diameter with a weight of 585 g) Columnar weight). In this configuration, a fixed amount of toner (so that the toner phase height is 23 mm) is charged into the container and set in the apparatus. Next, the sample container containing the powder is raised, brought into contact with the compacting piston, and further lifted so that the weight is lifted from the support plate so that all the weight load is applied to the piston. Leave for 60 seconds. Thereafter, the lifting stage on which the container containing the powder is placed is lowered to separate the piston from the powder surface.

  The piston may be made of any material, but the surface on which the powder is pressed needs to be smooth. Therefore, a material that is easy to process, has a hard surface, and does not change quality is preferable. Further, it is necessary to prevent the powder from adhering due to charging, and a conductive material is suitable. In this apparatus, a Cu type material was used. The measurement zone includes a powder container, an elevating stage for moving the container up and down, a load cell for measuring a load on the stage, a torque meter for measuring the torque of the powder, and the like.

When entering the torque and load measurement, it is performed at the determined rotation speed and penetration speed. The rotational direction of the conical rotor is arbitrary. If the penetration distance of the conical rotor is shallow, the values of torque and load are small, which causes problems in data reproducibility and the like. Therefore, it is better to penetrate the conical rotor deeply into a region where the data is reproducible. In the examination results in the present invention, the torque when 20 mm is penetrated is taken as the measured value.
The measurement modes are as follows.
[1] Fill a container with toner.
[2] Pressurize the toner powder phase to create a compacted state.
[3] The conical rotor is rotated while entering, and the torque at that time is measured.
[4] When the conical rotor enters from the toner surface layer to a preset depth, the intrusion operation is stopped.
[5] The operation of pulling out the conical rotor is started.
[6] When the tip of the conical rotor comes off the surface of the toner powder phase and becomes completely free
At the second position just above the toner phase surface, the conical rotor is pulled out and stopped.
Measurement is performed by repeating the operations [1] to [6].

(SF-1, SF-2)
FIGS. 1 and 2 are diagrams schematically showing the shape of the toner in order to explain the shape factor SF-1 and the shape factor SF-2. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases.
The shape factor SF-2 indicates the ratio of the unevenness of the toner shape, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner on the two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-2 = {(PERI) ² / AREA} × (100π / 4) Expression (2)
When the value of SF-2 is 100, there is no unevenness on the toner surface, and as the value of SF-2 increases, the unevenness of the toner surface becomes more prominent.
Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.) and introducing it into an image analyzer (LUSEX3: manufactured by Nireco). 100 pieces were analyzed and calculated.
When a toner having a D / S of 15 to 40% and (L / M)> 2 is expressed by SF-1 and SF-2, SF-1 is in a range of 130 to 160, and a shape factor SF-2 is 110 to 110. In the range of 140

(FPIA)
For the measurement of the average circularity, the above-mentioned flow type particle image analyzer (“FPIA-2100”; manufactured by Sysmex Corporation) is used for measurement, and the analysis software (FPIA-2100 Data Processing Program for FPIA version 00-10) is used. And analyzed. As an analysis condition, an average circularity obtained by analyzing a measurement target particle size limit of 2 to 400 μm is used, and a toner having a D / S of 15 to 40% and (L / M)> 2 is expressed by an average circularity. In the range of 0.94 to 0.98.

(Toner density)
In a full-color molding apparatus, the toner concentration in the developer is often used in a toner concentration range of 3 to 12 wt%. The image density is controlled in consideration of the particle size of the toner and the carrier in the developer, that is, the surface area, and the occupied area of the toner to be tightened to the carrier surface area is controlled to be 100% or less. This is a measure for maintaining contact and preventing insufficient charging of the toner due to poor contact between the toner and the carrier. Here, in the developer having a high toner concentration, there is a problem that a low melting point wax, a resin or the like in the toner is fixed on the carrier surface and the charging ability of the carrier is lowered.

(2μm or less grain size)
The particle ratio of 2 μm or less and the circularity of the toner of the present invention can be measured by a flow type particle image analyzer FPIA-2000 (manufactured by Toa Medical Electronics Co., Ltd.). As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance, and further measurement is performed. Add about 0.1-0.5g of sample. The suspension in which the sample is dispersed is obtained by performing dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl. .

(Molecular weight)
The molecular weight according to the present invention is measured by GPC (gel permeation chromatography) as follows. Stabilize the column in a heat chamber at 40 ° C., flow THF at a flow rate of 1 ml / min through the column at this temperature, and prepare a THF sample solution of resin prepared at a sample concentration of 0.05 to 0.6% by weight. Is measured by injecting 50 to 200 μl. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the prepared calibration curve and the count using several types of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Or molecular weight made by Toyo Soda Industry Co., Ltd. is 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9. It is suitable to use x10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

(Acid value)
Measurement is performed under the following conditions in accordance with the measurement method described in JIS K0070-1992.
Sample preparation: 0.5 g of polyester (0.3 g for ethyl acetate-soluble component) is added to 120 ml of toluene and dissolved by stirring at room temperature (23 ° C.) for about 10 hours. Further, 30 ml of ethanol is added to prepare a sample solution.
The measurement can be calculated by the apparatus described above, but specifically, the calculation is performed as follows.
Titrate with a pre-standardized N / 10 caustic potash to alcohol solution, and determine the acid value from the consumption of the alcohol potash solution by the following calculation.
Acid value = KOH (ml) x N x 56.1 / sample weight
(N is a factor of N / 10KOH)

(Hydroxyl value)
Weigh accurately 0.5 g of sample into a 100 ml volumetric flask and add 5 ml of acetylating reagent correctly. Then, it is immersed in a bath at 100 ° C. ± 5 ° C. and heated. After 1-2 hours, the flask is removed from the bath, allowed to cool, water is added and shaken to decompose acetic anhydride. Furthermore, in order to complete the decomposition, the flask is again heated in a bath for 10 minutes or more and allowed to cool, and then the wall of the flask is thoroughly washed with an organic solvent. This solution is subjected to potentiometric titration with an N / 2 potassium hydroxide ethyl alcohol solution using the electrode to determine the OH value (according to JISK0070-1966).

(Glass transition point)
The temperature is measured with a Rigaku THRMOFLEX TG8110 manufactured by Rigaku Denki Co. under the condition of a heating rate of 10 ° C./min.
A method for measuring Tg will be outlined. As an apparatus for measuring Tg, a TG-DSC system TAS-100 manufactured by Rigaku Corporation was used.
First, about 10 mg of a sample is placed in an aluminum sample container, which is placed on a holder unit and set in an electric furnace. First, after heating from room temperature to 150 ° C. at a temperature rising rate of 10 ° C./min, the sample was allowed to stand at 150 ° C. for 10 min, the sample was cooled to room temperature and left for 10 min, and the temperature rising rate was again increased to 150 ° C. under a nitrogen atmosphere. DSC measurement was performed by heating at min. Tg was calculated from the tangent of the endothermic curve near the Tg and the base line using the analysis system in the TAS-100 system.

  Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.

[Binder resin production method]
The binder resin can be produced by the following method. Polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) are heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc., and water generated while reducing the pressure as necessary. Distill off to obtain a polyester having a hydroxyl group. Subsequently, at 40-140 degreeC, this is made to react with a polyvalent isocyanate compound (PIC), and the prepolymer (A) which has an isocyanate group is obtained. Further, (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a polyester modified with a urea bond.
Inactive to the polyvalent isocyanate compound (PIC) such as (reacted with (PIC)).
When the unmodified polyester (ii) is used in combination, (ii) is produced in the same manner as the polyester having a hydroxyl group, and this is dissolved and mixed in the solution after the completion of the reaction (i).

[Toner Production Method]
(1) A toner material liquid is prepared by dispersing a colorant, unmodified polyester (i), a polyester prepolymer (A) having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride are preferred.
The usage-amount of an organic solvent is 0-300 mass parts normally with respect to 100 mass parts of polyester prepolymers, Preferably it is 0-100 mass parts, More preferably, it is 25-70 mass parts.

(2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.
The amount of the aqueous medium used relative to 100 parts by mass of the toner material liquid is usually 50 to 2000 parts by mass, preferably 100 to 1000 parts by mass. If the amount is less than 50 parts by mass, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by mass, it is not economical.

  The glass transition point (Tg) of the resin fine particles dispersed in the aqueous medium is preferably 50 to 110 ° C., more preferably 50 to 90 ° C. When the glass transition point (Tg) is less than 50 ° C., toner storage stability is obtained. Or the probability of fixing and aggregation in the toner recovery path during recycling increases. When the glass transition point (Tg) is higher than 110 ° C., the resin fine particles hinder the adhesion to the fixing paper, and the fixing minimum temperature is increased. A more preferred range is a range of 50 to 70 ° C. The weight average molecular weight is desirably 100,000 or less. Preferably it is 50,000 or less. The lower limit is usually 4000. When the weight average molecular weight exceeds 100,000, the resin fine particles inhibit the adhesiveness with the fixing paper, and the minimum fixing temperature increases.

As the resin fine particles, known resins can be used as long as they can form an aqueous dispersion, and thermoplastic resins or thermosetting resins may be used. Examples thereof include vinyl resins, polyurethane resins, epoxy resins, and polyester resins. It is done. As the resin fine particles, two or more of the above resins may be used in combination. Among these, those made of a vinyl resin, a polyurethane resin, an epoxy resin, a polyester resin, or a combination resin 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-acrylic acid ester resins, styrene-methacrylic acid ester resins, styrene-butadiene copolymers, acrylic acid-acrylic acid ester polymers. Methacrylic acid-acrylic acid ester polymer, styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, and the like.
In the resin fine particles, the volume average particle diameter is a value measured with a light scattering photometer (manufactured by Otsuka Electronics), and is 10 to 200 nm, preferably 20 to 80 nm.

Further, a surfactant can be appropriately added in order to improve the dispersion in the aqueous medium.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, fatty acid amide derivatives, polyhydric alcohols Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkylcarboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6- C11) Sodium oxy] -1-alkyl (C3-C4) sulfonate, sodium 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonate, fluoroalkyl (C11-C20) Carboxylic acid and metal salt, perfluoroalkyl carboxylic acid (C7 to C13) and metal salt thereof, perfluoroalkyl (C4 to C12) sulfonic acid and metal salt thereof, perfluorooctane sulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl) perf Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Moreover, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt which has a right fluoroalkyl group is used. Salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, trade names include Surflon S-121 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Daikin Industries) Smoke), Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footage F-300 (Neos), and the like.

The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium or to prevent the wax from being exposed to the outermost surface of the toner. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao Corporation), SGP (manufactured by Soken Co., Ltd.), Techno Examples include polymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), and micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.).
In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

  As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole , Nitrogen-containing compounds such as ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, polyoxypro Len, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene Polyoxyethylenes such as nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment 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. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

(3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.
This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

(4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

(5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.
The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like. Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape between the true spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.

  The process cartridge according to the present invention is such that the toner for image formation is filled in the toner storage portion of the developing means.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In addition, the part here is a mass part.

Example 1
(Synthesis of organic fine particle emulsion)
In a reaction vessel in which a stir bar and a thermometer were set, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 83 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate and 1 part of ammonium persulfate were charged and stirred at 3800 rpm for 30 minutes, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 4 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 6 hours, and then an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion [fine particle dispersion 1] was obtained. The volume average particle size of the [fine particle dispersion 1] measured with a laser diffraction / scattering particle size distribution analyzer (LA-920: manufactured by Horiba, Ltd.) was 110 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The Tg of the resin was 58 ° C., and the weight average molecular weight was 130,000.

(Adjustment of aqueous phase)
990 parts of water, 83 parts of [fine particle dispersion 1], 37 parts of a 48.3% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries) and 90 parts of ethyl acetate were mixed and stirred to give a milky white liquid. Got. This is designated [Aqueous Phase 1].

(Synthesis of low molecular weight polyester 1)
Into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 724 parts of bisphenol A ethylene oxide 2-mole adduct and 276 parts of terephthalic acid were placed, polycondensed at 230 ° C. for 7 hours under normal pressure, and further 10-15 mmHg Was reacted for 5 hours under reduced pressure to obtain [Low molecular weight polyester 1]. [Low molecular polyester 1] had a number average molecular weight of 2300, a weight average molecular weight of 6700, a peak molecular weight of 3800, a Tg of 43 ° C., and an acid value of 4.

(Synthesis of intermediate polyester)
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2 mol adduct, 81 parts of bisphenol A propylene oxide 2 mol adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. under normal pressure for 7 hours, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2200, a weight average molecular weight of 9700, a peak molecular weight of 3000, a Tg of 54 ° C., an acid value of 0.5, and a hydroxyl value of 52.
Next, 410 parts of [Intermediate Polyester 1], 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Polymer 1] was obtained. [Prepolymer 1] had a free isocyanate mass% of 1.53%.

(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 4 and a half hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 417.

(Synthesis of master batch)
1200 parts of water, 540 parts of carbon black (Printex35: manufactured by Dexa) [DBP oil absorption = 42 ml / 100 mg, pH = 9.5] and 1200 parts of polyester resin are added and mixed with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). Was kneaded at 130 ° C. for 1 hour using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch 1].

(Production of oil phase)
In a container equipped with a stir bar and a thermometer, 378 parts of [Low molecular weight polyester 1], 100 parts of paraffin wax (melting point 70 ° C.), and 947 parts of ethyl acetate are charged, and the temperature is raised to 80 ° C. with stirring, and remains at 80 ° C. After holding for 5 hours, it was cooled to 30 ° C. in 1 hour. Next, 500 parts of [Masterbatch 1], 30 parts of organically modified montmorillonite and 500 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution 1].

  [Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill: manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads are 80 vol%. Carbon black and wax were dispersed under conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] was added, and the mixture was subjected to two passes by the bead mill under the above conditions to obtain [Pigment / Wax Dispersion 1]. The solid content concentration of [Pigment / Wax Dispersion 1] was 50%.

(Emulsification to solvent removal)
[Pigment / Wax Dispersion 1] 749 parts, [Prepolymer 1] 115 parts, [Ketimine Compound 1] 2.9 parts in a container, and TK homomixer (manufactured by Tokushu Kika) at 5,000 rpm for 2 minutes After mixing, 1200 parts of [Aqueous phase 1] was added to the container, and mixed with a TK homomixer at 13,000 rpm for 25 minutes to obtain [Emulsion slurry 1].
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 7 hours, aging was carried out at 45 ° C. for 7 hours to obtain [Dispersion slurry 1].

(Washing-drying)
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
I: 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
II: 100 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of I and mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), followed by filtration under reduced pressure.
100 parts of 10% hydrochloric acid was added to the filter cake of III: II, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
To the filter cake of IV: III, 300 parts of ion-exchanged water was added, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes) and then filtered twice to obtain [Filter cake 1].
[Filter cake 1] 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 1]. Thereafter, 100 parts of [toner base particle 1] were mixed with 1 part of hydrophobic silica and 1 part of hydrophobic titanium oxide by a Henschel mixer to obtain the toner of Example 1.

(Comparative Example 1)
A toner of Comparative Example 1 was obtained in the same manner as in Example 1 except that 30 parts of the organically modified montmorillonite was changed to 0 part.

(Comparative Example 2)
A toner of Comparative Example 2 was obtained in the same manner as in Example 1 except that 100 parts of paraffin wax (melting point: 70 ° C.) as a release agent was changed to 100 parts of carnauba wax (melting point: 70 ° C.).

(Comparative Example 3)
The toner of Comparative Example 3 was prepared in the same manner as in Example 1 except that 30 parts of organically modified montmorillonite was changed to 0 part, and 100 parts of paraffin wax (melting point: 70 ° C.) was changed to 100 parts as a release agent. Obtained.

(Comparative Example 4)
Toner of Comparative Example 4 in the same manner as in Example 1 except that 30 parts of organically modified montmorillonite was changed to 0 part and 100 parts of paraffin wax (melting point 70 ° C.) as a release agent was changed to 100 parts of carnauba wax (melting point 70 ° C.). Got.

(Example 2)
A toner of Example 2 was obtained in the same manner as in Example 1 except that 30 parts of the organically modified montmorillonite was changed to 48 parts.

(Example 3)
A toner of Example 3 was obtained in the same manner as in Example 1 except that 30 parts of the organically modified montmorillonite was changed to 12 parts.

(Example 4)
A toner of Example 4 was obtained in the same manner as in Example 1 except that 100 parts of paraffin wax (melting point: 70 ° C.) as a release agent was changed to 150 parts.

(Example 5)
A toner of Example 5 was obtained in the same manner as in Example 1 except that 100 parts of paraffin wax (melting point: 70 ° C.) as a release agent was changed to 75 parts.

(Example 6)
A toner of Example 6 was obtained in the same manner as in Example 1 except that the low molecular weight polyester 1 was changed to the following low molecular weight polyester 2.
(Synthesis of low molecular weight polyester 2)
690 parts of bisphenol A ethylene oxide 2-mole adduct and 335 parts of terephthalic acid are charged into a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and condensed at 210 ° C. for 10 hours under a normal pressure nitrogen stream. Reacted. Next, the reaction was continued for 5 hours while dehydrating under a reduced pressure of 10 to 15 mmHg, followed by cooling to obtain a low molecular weight polyester 2. The obtained low molecular weight polyester 2 had a weight average molecular weight of 6,000, an acid value of 20 KOHmg / g, and a glass transition point of 55 ° C.

(Example 7)
A toner of Example 7 was obtained in the same manner as in Example 1 except that the rotation speed of stirring in the TK homomixer was increased to make the particle size smaller than in Example 1.

Table 1 shows the properties of the toners obtained in the examples and comparative examples.

(Example of production of two-component developer)
The toners of the above production examples and comparative examples and the carrier of the following production method were mixed for 10 minutes with a turbuler mixer at a maximum stirring intensity of 1 kg of toner and carrier so that the toner concentration was 3 wt% and 12 wt%. It was used for the evaluation described in 1.

Carrier manufacturing method:
Acrylic resin solution (solid content 50 wt%) 21.0 parts Guanamin solution (solid content 70 wt%) 6.4 parts Alumina particles [0.3 μm, specific resistance 10 14 (Ω · cm)] 7.6 parts Silicon resin solution [solid 23wt% min
(SR2410: manufactured by Toray Dow Corning Silicone Co., Ltd.)] 65.0 parts aminosilane [solid content: 100 wt%
(SH6020: manufactured by Toray Dow Corning Silicone Co., Ltd.)] 0.3 parts Toluene 60 parts Butyl cellosolve 60 parts are dispersed with a homomixer for 10 minutes to obtain a blend coating film forming solution of acrylic resin and silicon resin containing alumina particles. It was. A fired ferrite powder [(MgO) _1.8 (MnO) _49.5 (Fe 2 O 3) _48.0 : average particle size; 35 μm] was used as the core material, and the coating film forming solution had a film thickness of 0. It was applied and dried with a Spira coater (Okada Seiko Co., Ltd.) so as to have a thickness of 15 μm. The obtained carrier was baked by standing in an electric furnace at 150 ° C. for 1 hour. After cooling, the ferrite powder bulk was crushed using a sieve having an aperture of 106 μm to obtain [Carrier 1]. The measurement of the binder resin film thickness was performed by observing the cross section of the carrier with a transmission electron microscope so that the coating film covering the carrier surface could be observed.

(Evaluation of toner fluidity)
The fluidity of the toner was evaluated using this evaluation apparatus shown in FIG. 4, and the torque when the conical rotor entered 20 mm from the surface of the toner powder phase compacted for 60 seconds with a compaction load of 585 g was measured. The evaluation conditions for the conical rotor were as follows.
・ Vertical angle of conical rotor: 60 °
・ Rotary speed of conical rotor: 1rpm
・ Invasion speed of conical rotor: 5 mm / min

(Evaluation of cleaning properties)
1. The obtained toner and apparatus were all left in an environmental room at 25 ° C. for 50 days.
2. All toner on the Imageo neo C600 commercial product PCU is removed, leaving only the carrier in the development apparatus.
3. 28 g of black toner serving as a sample is put into a developing device having only a carrier, and 400 g of a developer having a toner concentration of 7% is prepared.
4). A developing device is attached to the main body of Imagio neo C600, and only the developing device is idled for 5 minutes at a developing sleeve linear velocity of 300 mm / s.
5. Both the developing sleeve and the photosensitive member were rotated at 300 mm / s trailing, and the charging potential and the developing bias were adjusted so that the toner on the photosensitive member was 0.6 ± 0.05 mg / cm 2.
6). The cleaning blade was only one cleaning blade mounted on a commercially available Imagio neo C600 PCU, its elastic modulus was 70%, the thickness was 2 mm, and the contact angle with the image carrier at the counter was 20 °.
7). Under the above development conditions, the transfer current is adjusted so that the transfer rate is 96 ± 2%.
8). Using the above set values, 1000 charts (FIG. 7) with a band of 4 cm in the paper passing direction and 25 cm in the paper passing width direction were output.
9. The image output at the end was evaluated for the image quality in the central portion of the printing paper passing direction and the central portion in the width direction, which is a white background portion, and was evaluated based on whether or not an abnormal image was generated due to poor cleaning.
10. For evaluation of the output image, an image ID (X-RITE 938, v-value manufactured by X-RITE) was measured.
11. When the image ID after passing paper is 0.01 or less compared to the image ID of paper that has not passed, the cleaning performance is OK (◯), and when it is more than that, the cleaning performance is NG (×) and rank evaluation did.

(Decrease in charging ability of carrier)
Using a digital full-color copier (imageColor 2800 manufactured by Ricoh), running 30,000 image charts with a 50% image area in a monochrome mode in an environment of temperature 25 ° C and humidity 50%, and then partially sampling the developer Then, the amount of charge was measured by the blow-off method, and the amount of decrease in the charging ability of the carrier was evaluated. When the amount of change in charge amount before and after running 30,000 sheets was less than 5 μc / g, it was evaluated as “◯”, when it was 5 to 10 μc /, Δ when it exceeded 5 to 10 μc /. Further, in this test, the test was performed under two conditions when the toner concentration was 3 wt% and 12 wt%.

(Fixability evaluation)
Ricoh Copier Co., Ltd. using a Teflon (registered trademark) roller as a fixing roller MF2200 Using a machine with a modified fixing unit, an unfixed image was formed on Ricoh type 6200 paper (toner adhesion) A rectangular solid image (amount 1.0 mg / cm 2, 2 cm × 7 cm) was passed through and a fixing test was conducted.
The fixing temperature was changed by 5 ° C., and the cold offset generation temperature and the hot offset generation temperature were obtained. The evaluation conditions for low-temperature fixing are a paper feed linear velocity of 120 mm / sec, a surface pressure of 1.2 kgf / cm ² , a nip width of 3 mm, and the high temperature offset is an evaluation condition of a paper feed linear velocity of 50 mm / sec and a surface pressure. It was set to 2.0 kgf / cm ² and a nip width of 4.5 mm.

Table 2 shows the performance evaluation results of the two-component developers using the toners obtained in Examples 1 to 7 and Comparative Examples 1 to 4.

  As is apparent from the evaluations described in Examples 1 to 7, the use of the toner of the present invention hardly reduces the charging ability of the carrier and is excellent in cleaning properties. A copy of is obtained.

It is a figure which shows an example of the outline | summary of the apparatus structure in this invention. It is a figure which shows an example of the shape of the conical rotor in this invention. It is a figure which shows an example of the cross-sectional shape of a conical rotor in this invention, and a change of a cone apex angle. It is a figure which shows the other example of the outline | summary of the apparatus structure in this invention. It is SF-1 measurement conceptual diagram It is SF-2 measurement conceptual diagram. It is the chart used in the Example

Claims (6)

An image forming toner containing at least a binder resin, a colorant, a release agent and an inorganic filler,
The release agent is a paraffin wax having a melting point of 60 to 90 ° C .;
The inorganic filler is montmorillonite or a modified product thereof,
The endothermic peak of the endothermic peak derived from the release agent in the DSC measurement of the toner is in the range of 3.0 to 6.0 J / g;
The average circularity of the toner is 0.94 or more, and
The toner powder phase is preliminarily brought into a compacted state by a compacting means, and then the conical rotor having grooves cut on the surface is rotated to enter the compacted toner powder phase, and the conical rotor moves through the powder phase. In the toner evaluation method for evaluating the fluidity of the toner by measuring the torque generated at the time, the toner powder phase is put into a cylindrical container having an inner diameter of 60 mm and compacted for 60 seconds with a compaction load of 585 g. The torque when the conical rotor is intruded 20 mm into the powder phase at a rotation speed of 1 rpm and an intrusion speed of 5 mm / min is 1.4 to 2.0 mNm.
An image forming toner characterized by the above.   The toner crosslinks a toner material solution in which a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, a release agent, and an inorganic filler are dissolved or dispersed in an aqueous medium at least in an organic solvent. And / or obtained by an extension reaction, and the shape factor SF-1 of the toner is in the range of 130 to 160, and the shape factor SF-2 is in the range of 110 to 140. Item 2. The image forming toner according to Item 1.   The toner has a weight average particle diameter (D4) of 3 to 8 μm and a ratio (D4 / Dn) of the weight average particle diameter (D4) to the number average particle diameter (Dn) in the range of 1.00 to 1.30. The image forming toner according to claim 1, wherein the toner is for image formation.   The toner for image formation according to any one of claims 1 to 3, wherein the toner has a glass transition point of 40 to 60 ° C.   The image forming toner according to claim 1, wherein 1 to 10% by number of particles of 2 μm or less of the toner is contained.   Image carrier, charging means for charging the surface of the image carrier, exposure means for writing a latent image by exposure on the image carrier, development for developing the latent image written on the image carrier with toner At least the image carrier and the developing means, the transfer means for transferring the developed toner image to the intermediate transfer body or the printing paper, and the cleaning means for cleaning the transfer residual toner on the image carrier that has not been completely transferred. The developing means holds the toner or the developer composed of the toner and the carrier, and the toner is the image forming toner according to any one of claims 1 to 5. Feature process cartridge.

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