JP2011107366A - Toner and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core-shell type toner improved in charging properties and durability while preventing the shell layer from dropping from the core surface. <P>SOLUTION: The toner for dry electrostatic charge image development contains at least a binder resin, a coloring material and a release agent, wherein the toner has a core-shell structure, the core comprises a resin having a polyester skeleton, and the shell layer comprises a styrene-acrylic resin and an acrylic resin. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a toner for developing a dry electrostatic image for developing an electrostatic latent image formed by electrophotography, electrostatic recording, and electrostatic printing.

Conventionally, research and development on electrophotography has been carried out by various creative ideas and technical approaches. In electrophotography, an electrostatic latent image formed by charging and exposing the surface of a photoconductor is developed with a colored toner to form a toner image, and the toner image is transferred to a transfer material such as transfer paper. An image is formed by fixing with a heat roll or the like. As a toner fixing method, a contact heating fixing method such as a heat roll fixing method is widely adopted. A fixing device used for a heat roll fixing method includes a heating roll and a pressure roll, and passes a recording sheet carrying a toner image through a pressure contact portion (nip portion) between the heating roll and the pressure roll. As a result, the toner image is melted and fixed on the recording sheet.

  In the above-mentioned contact heating fixing method, energy is saved by lowering the heating temperature as much as possible. Therefore, the toner resin is preferably one that melts at a low temperature. However, in the electrophotographic process, there is a process in which mechanical or thermal stress is applied to the toner. Therefore, in order not to cause a problem such as so-called blocking, a thermal characteristic restriction such as a glass transition point or a toner crack is generated. There are restrictions on molecular weight so as not to occur, and the resin is required to satisfy these characteristics. Therefore, the above two points are in a so-called trade-off relationship, and it is important to balance them. From this point of view, a so-called core / shell type toner in which a resin advantageous for heat fixing is used inside the toner and the outside thereof is covered with a resin advantageous for blocking or the like is already known (for example, Patent Document 1 and Patent Document). 2).

  However, when a conventional styrene resin or styrene-acrylic resin alone is used as the shell, when the core is a polyester resin, the compatibility between the shell and the core is low, and the core is completely covered with the shell. Cannot be used, or due to the low compatibility between the shell and the core, separation of the shell layer may occur, resulting in WAX on the core surface or the detached shell layer. ” was there.

  The present invention has been made in view of the above, and an object of the present invention is to provide a toner having improved chargeability and durability by preventing separation of the shell layer from the core surface.

The present inventors use not only a styrene-acrylic resin having a high chargeability in the shell but a low adhesion to the core but also an acrylic resin having a high adhesion to the core as a binding medium. A member (developing roller, regulation) by WAX exposed on the surface of the release shell layer and the core, which gives high chargeability to the toner while maintaining the adhesion with the core by the acrylic component of the acrylic resin and the acrylic resin. Blade) It was found that the contamination can be prevented and the charging property and durability can be improved.

That is, the present invention relates to a dry electrostatic image developing toner, a developer using the same, an image forming apparatus, and a process cartridge as described below.
(1) In a dry electrostatic image developing toner containing at least a binder resin, a colorant, and a release agent, the toner has a core-shell structure, the core is made of a resin having a polyester skeleton, and the shell is A dry electrostatic image developing toner comprising a styrene-acrylic resin and an acrylic resin.
(2) The styrene-acrylic resin is characterized in that the styrene monomer is 85 to 65% by weight, the acrylic monomer is 15 to 35% by weight, and the total of the styrene monomer and the acrylic monomer is 90 to 100% by weight. The toner for developing a dry electrostatic image according to (1).
(3) The dry electrostatic charge according to (1) or (2), wherein the core contains a modified polyester resin having a urethane or / and urea group in addition to the resin having a polyester skeleton. Toner for image development.
(4) The dry static electricity according to any one of (1) to (3), wherein when the core contains an organic solvent, a shell-forming resin is added and a continuous layer of the core and shell is formed by dissolution / precipitation. Toner for charge image development (5) The release agent contains one or more selected from paraffins, synthetic esters, polyolefins, carnauba wax, or rice wax ( The toner for developing an electrostatic charge image according to any one of 1) to (4).
(6) A toner container filled with the dry electrostatic image developing toner according to any one of (1) to (5).
(7) A developer containing the dry electrostatic image developing toner according to any one of (1) to (5).
(8) A developer carrying member for carrying the developer supplied to the latent image carrying member on the surface, a developer supply member for supplying the developer to the surface of the developer carrying member, and a developer container for containing the developer. The developing device is characterized in that the developer according to (7) is stored in a developer container.
(9) In a process cartridge in which a latent image carrier and a developing device that develops at least a latent image on the latent image carrier with a developer are integrated and detachable from an image forming apparatus, 8. A process cartridge which is the developing device according to 8).
(10) A latent image carrier that carries a latent image, a charging unit that uniformly charges the surface of the latent image carrier, and the surface of the charged latent image carrier is exposed based on image data, and electrostatic latent An exposure unit for writing an image, a developing unit for supplying toner to the electrostatic latent image formed on the surface of the latent image carrier to make it visible, and a visible image on the surface of the latent image carrier are transferred to the transfer target An image forming apparatus comprising: a transfer unit; and a fixing unit that fixes a visible image on a transfer target, wherein the developing unit is the developing device according to (8). .

  The shell is mixed with a styrene-acrylic resin that has a high charge-providing property and an acrylic resin that is known to have high adhesion to the core layer from experiments, and the acrylic resin is mixed with the core and the styrene-acrylic resin. By suppressing the detachment of the shell and improving the charging property and durability and suppressing the blade fixing, it is possible to provide a good toner free from image noise such as filming and background fogging. As a result, a high-quality image can be provided.

3 is a SEM photograph of toner for electrostatic charge development having a core-shell structure of Example 1. 4 is a SEM photograph of electrostatic charge developing toner having a core-shell structure of Comparative Example 2. 4 is an SEM photograph of toner for electrostatic charge development having a core-shell structure of Comparative Example 3. FIG. 3 is an explanatory diagram illustrating a main part of an embodiment of an image forming apparatus in which the electrostatic image developing toner of the present invention is used. FIG. 3 is an explanatory diagram illustrating a configuration of a fixing device used in an image forming apparatus in which the electrostatic charge image developing toner of the present invention is used. It is explanatory drawing which shows the other example of the image forming apparatus in which the toner for electrostatic image development of this invention is used. It is explanatory drawing which shows the other example of the image forming apparatus in which the toner for electrostatic image development of this invention is used. It is explanatory drawing which shows the process cartridge using the toner for electrostatic image development of this invention.

As a result of intensive studies, the present inventors have mixed a styrene-acrylic resin having a high charging property to the shell and an acrylic resin having high adhesiveness with the core layer, and the acrylic resin is used as the core. It has been found that separation of the shell can be suppressed by using a binding medium with a styrene-acrylic resin.
The toner according to the present invention contains at least a resin and a colorant, and the resin contains a non-crosslinked resin and / or a crosslinked resin, and is a layered inorganic mineral, a release agent, a fluorine compound, and other suitable toners. You may contain a component.

<About core-shell structure>
The method for producing a toner for developing an electrostatic charge image according to the present invention comprises dissolving or dispersing at least a hybrid resin or a polyester resin, a colorant and a release agent in an organic solvent, and then dissolving the dispersion or dispersion in an aqueous medium. A toner for electrostatic charge image development comprising at least a step of granulating core particles by dispersing in water and a step of adding an aqueous dispersion in which at least vinyl copolymer resin fine particles are dispersed to coat the core particles with the fine particles In the production method, the organic solvent is removed from the core particle dispersion and the vinyl copolymer resin fine particles are added, or the vinyl copolymer resin fine particles are added to the core particle dispersion in the presence of the organic solvent. According to the present invention, the low-temperature fixability and the heat-resistant storage stability are compatible, the offset resistance is excellent, and the toner structure can be controlled. An ability, the charge amount is provided good toner for developing electrostatic images without contaminating the developing device or the like.

(About Shell)
<About acrylic resin shell>
The inventors' experiments have shown that the surface of the acrylic resin shell can be coated relatively uniformly (see FIG. 1-2, which is an SEM image of the toner of Comparative Example 2 described later).
On the other hand, in consideration of chargeability, it is preferable to use a styrene resin or a styrene-acrylic resin as a shell agent. The compatibility was low and there was a problem in terms of detachment of the shell layer (see FIG. 1-3 which is an SEM image of the toner of Comparative Example 3 described later). Therefore, as a result of extensive studies, it was invented to form a shell layer using an acrylic resin as a binding medium by mixing an acrylic resin and a styrene-acrylic resin (SEM image of the toner of Example 1). FIG. 1-1).

<Polyester resin>
Examples of the polyester resin used in the present invention include the following polycondensates of polyol (1) and polycarboxylic acid (2), and any of them can be used. May be used.

(Polyol)
Examples of the polyol (1) 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, Ethylene 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, 4,4′-dihydroxybiphenyls such as bisphenol S, 3,3′-difluoro-4,4′-dihydroxybiphenyl, etc .; bis (3-fluoro-4-hydroxyphenyl) Nyl) methane, 1-phenyl-1,1-bis (3-fluoro-4-hydroxyphenyl) ethane, 2,2-bis (3-fluoro-4-hydroxyphenyl) propane, 2,2-bis (3 Bis (5-difluoro-4-hydroxyphenyl) propane (also known as: tetrafluorobisphenol A), 2,2-bis (3-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane, etc. Hydroxyphenyl) alkanes; bis (4-hydroxyphenyl) ethers such as bis (3-fluoro-4-hydroxyphenyl) ether); alkylene oxides of the above alicyclic diols (ethylene oxide, propylene oxide, butylene oxide, etc.) Adducts; alkylene oxides of the above bisphenols (ethylene oxide) De, propylene oxide, and the like butylene oxide, etc.) adducts.

  Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use.

  In addition, trihydric or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (trisphenol PA, phenol novolac, cresol novolac, etc.) ); Alkylene oxide adducts of the above trihydric or higher polyphenols.

In addition, the said polyol can be used individually by 1 type or in combination of 2 or more types, It is not limited to the above.
(Polycarboxylic acid)
Examples of the polycarboxylic acid (2) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, Naphthalenedicarboxylic acid, 3-fluoroisophthalic acid, 2-fluoroisophthalic acid, 2-fluoroterephthalic acid, 2,4,5,6-tetrafluoroisophthalic acid, 2,3,5,6-tetrafluoroterephthalic acid, 5- Trifluoromethylisophthalic acid, 2,2-bis (4-carboxyphenyl) hexafluoropropane, 2,2-bis (4-carboxyphenyl) hexafluoropropane, 2,2-bis (3-carboxyphenyl) hexafluoropropane 2,2′-bis (trifluoromethyl) -4,4′- Phenyldicarboxylic acid, 3,3′-bis (trifluoromethyl) -4,4′-biphenyldicarboxylic acid, 2,2′-bis (trifluoromethyl) -3,3′-biphenyldicarboxylic acid, hexafluoroisopropylidene Dendiphthalic anhydride, etc.).

Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Further, polyvalent polycarboxylic acids having 3 or more valences are aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, etc.), and acid anhydrides or lower alkyl esters (methyl esters, ethyl esters) described above. , Isopropyl ester, etc.) may be used to react with polyol (1).
In addition, the said polycarboxylic acid can be used individually by 1 type or in combination of 2 or more types, It is not limited to the above.

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

(Molecular weight of polyester resin)
The peak molecular weight of the polyester resin is usually 1000 to 30000, preferably 1500 to 10000, and more preferably 2000 to 8000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 30000, low-temperature fixability will deteriorate.

<Modified polyester resin>
The binder resin used in the present invention may contain a modified polyester resin having urethane or / and urea groups (hereinafter referred to as “modified polyester resin”) in order to adjust viscoelasticity. The content of the modified polyester resin having urethane or / and urea groups is preferably 20% or less, more preferably 15% or less, and still more preferably 10% or less in the binder resin. When the content ratio exceeds 20%, the low-temperature fixability is deteriorated. The modified polyester resin having urethane or / and urea groups may be directly mixed with the binder resin, but from the viewpoint of manufacturability, a relatively low molecular weight modified polyester resin having an isocyanate group at the terminal (hereinafter referred to as prepolymer). And an amine that reacts with the binder resin is mixed with a binder resin, and during the granulation / after granulation, chain extension or / and cross-linking reaction to modify the urethane or / and urea group A polyester resin is preferred. By doing so, it becomes easy to contain a relatively high molecular weight modified polyester resin for adjusting the viscoelasticity.

(Prepolymer)
Examples of the prepolymer having an isocyanate group include a polycondensate of the polyol (1) and the polycarboxylic acid (2) and a polyester having an active hydrogen group that is further reacted with a polyisocyanate (3). . Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred.

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

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

(Number of isocyanate groups in the prepolymer)
The number of isocyanate groups contained per molecule in the prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is. When the number is less than 1 per molecule, the molecular weight of the modified polyester after chain extension and / or crosslinking becomes low, and offset resistance deteriorates.

(Chain extension and / or cross-linking agent)
In the present invention, amines can be used as chain extenders and / or crosslinkers. As amines (B), diamine (B1), trivalent or higher polyamine (B2), aminoalcohol (B3), aminomercaptan (B4), amino acid (B5), and amino acids B1-B5 blocked (B6) etc. are mentioned.

Examples of the diamine (B1) include the following.
Aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, tetrafluoro-p-xylylenediamine, tetrafluoro-p-phenylenediamine, etc.);
Alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, isophoronediamine, etc.);
And aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, dodecafluorohexylenediamine, tetracosafluorododecylenediamine, etc.).

Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine.
Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline.
Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.

Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.
Examples of the B1 to B5 amino group blocked (B6) include ketimine compounds and oxazoline compounds obtained from the B1 to B5 amines and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.).

(Stopper)
Furthermore, if necessary, the molecular extension of the modified polyester after completion of the reaction can be adjusted by using a terminator for the chain extension and / or crosslinking reaction. Examples of the terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those blocked (ketimine compounds).

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

<Colorant>
As the coloring agent of the present invention, 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, Lead Red, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red , Fais red, parachlorol Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake , Thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazolone , Polyazo red, chrome vermillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, in Dunslen Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake Phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by mass, preferably 3 to 10% by mass with respect to the toner.

<Release agent>
As the release agent used in the present invention, known ones can be used, for example, polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax, Fischer-Tropsch wax, sazol wax, etc.); carbonyl group Examples thereof include waxes. Carbonyl group-containing waxes include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1, 18-octadecanediol distearate etc.); polyalkanol esters (tristearyl trimellitic acid, distearyl maleate etc.); polyalkanoic acid amides (ethylenediamine dibehenyl amide etc.); polyalkylamides (trimellitic acid tristearyl amide etc.) ); And dialkyl ketones (such as distearyl ketone). Synthetic esters and rice wax are also preferably used. Of these, polyolefin waxes and long-chain hydrocarbons are preferred because of their low polarity and low melt viscosity, and paraffin wax and Fischer-Tropsch wax are particularly preferred.

[External additive]
(Inorganic fine particles)
As the external additive for assisting the fluidity, developability and chargeability of the colored particles obtained in the present invention, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 nm to 2 μm, and particularly preferably 5 nm to 500 nm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The 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, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

(Polymer fine particles)
Other polymer fine particles such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization and dispersion polymerization, methacrylic acid ester and acrylic acid ester copolymer, polycondensation system such as silicon, benzoguanamine and nylon, and thermosetting resin Examples include polymer particles.

(Surface treatment of external additives)
Such a fluidizing agent 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. .

(Cleaning aid)
Examples of the cleaning property improver for removing the developer after transfer remaining on the photoreceptor or the primary transfer medium include, for example, zinc stearate, calcium stearate, fatty acid metal salts such as stearic acid, such as polymethyl methacrylate fine particles, polystyrene fine particles, etc. And polymer fine particles produced by soap-free emulsion polymerization. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

[Polymerization of shell resin]
<Styrene-acrylic resin>
Examples of the styrene-acrylic polymer include polymers obtained by copolymerizing two or more styrene-based and acrylic monomers at an arbitrary ratio, for example, styrene- (meth) acrylic acid. Examples thereof include an ester copolymer, a styrene- (meth) acrylic acid copolymer, a styrene- (meth) acrylic acid, a divinylbenzene copolymer, and a styrene-styrenesulfonic acid- (meth) acrylic acid ester copolymer.

Here, the styrene monomer refers to an aromatic compound having a vinyl polymerizable functional group. Examples of the polymerizable functional group include a vinyl group, an isopropenyl group, an allyl group, an acryloyl group, and a methacryloyl group.
Specific examples of the styrene monomer include styrene, α-methylstyrene, 4-methylstyrene, 4-ethylstyrene, 4-tert-butylstyrene, 4-methoxystyrene, 4-ethoxystyrene, 4-carboxystyrene, and metal salts thereof. 4-styrenesulfonic acid or a metal salt thereof, 1-vinylnaphthalene, 2-vinylnaphthalene, allylbenzene, phenoxyalkylene glycol acrylate, phenoxyalkylene glycol methacrylate, phenoxy polyalkylene glycol acrylate, phenoxy polyalkylene glycol methacrylate, and the like.
Of these, it is preferable to mainly use styrene which is easily available, has excellent reactivity and high chargeability.

  Specific examples of (meth) acrylic monomers include acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and acrylic. Acrylic acid such as n-octyl acid, dodecyl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, tetrahydrofurfuryl acrylate; methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, And methacrylic acids such as n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, stearyl methacrylate, 2-ethylhexyl methacrylate, and tetrahydrofurfuryl methacrylate.

  Particularly desirable is a monomer ratio in the polymerization of 85 to 65% by mass of styrene, preferably 15 to 35% by mass of acrylic monomer, particularly preferably 90 to 80% by mass of styrene and 10 to 20% by mass of monomer.

<Acrylic resin>
Specific examples of (meth) acrylic monomers include acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and acrylic. Acrylic acid such as n-octyl acid, dodecyl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, tetrahydrofurfuryl acrylate; methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, And methacrylic acids such as n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, stearyl methacrylate, 2-ethylhexyl methacrylate, and tetrahydrofurfuryl methacrylate.
These (meth) acrylic monomers may be used alone or in combination of two or more.

Of the (meth) acrylic monomers exemplified above, methyl methacrylate is more preferred.
<Toner production method>
The method for producing the toner of the present invention is exemplified below, but the present invention is not limited thereto. In the toner production method of the present invention, a resin having at least a polyester skeleton and a release agent are dissolved or dispersed in an organic solvent, and then the melt or dispersion is suspended in an aqueous medium to form core particles. After the formation, the styrene-acrylic resin fine particles and the resin dispersion of the acrylic resin fine particles are added, or the styrene-acrylic resin fine particles are added while adding / adding the acrylic resin fine particle dispersion. It is characterized in that it is obtained by removing the organic solvent after forming the layer.

More specifically, it is as follows.
<Core particle granulation process>
(Organic solvent)
The organic solvent used for granulation is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal of the solvent later. Examples of such organic solvents include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, Ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. Particularly preferred are ester solvents such as methyl acetate and ethyl acetate, aromatic solvents such as toluene and xylene, and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride. The polyester resin and the colorant may be dissolved or dispersed at the same time, but are usually dissolved or dispersed individually, and the organic solvents used at that time may be different or the same, but considering the subsequent solvent treatment The same is preferable. Moreover, when the solvent (single or mixed) which melt | dissolves a polyester-type resin suitably is selected, the mold release agent used preferably by this invention will hardly melt | dissolve from the difference in the solubility.

(Dissolution or dispersion of polyester resin)
The polyester resin is preferably dissolved or dispersed in a resin concentration of about 40% to 80%. If the concentration is too high, it will be difficult to dissolve or disperse, and the viscosity will be too high to handle. On the other hand, if the concentration is too low, the amount of fine particles produced decreases and the amount of solvent to be removed increases. When mixing a polyester resin with a modified polyester resin having an isocyanate group at the terminal, it may be mixed in the same solution or dispersion, or separately dissolved or dispersed, but the respective solubility In view of the viscosity, it is preferable to prepare separate solutions or dispersions.

<Aqueous medium>
As an aqueous medium to be used, water alone may be used, but a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methylcellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like. The usage-amount of the aqueous medium with respect to 100 mass parts of resin fine particles is 50-2000 mass parts normally, Preferably it is 100-1000 mass parts.

<Inorganic dispersant and organic resin fine particles>
When the dissolved or dispersed solution of the polyester resin and the release agent is dispersed in the aqueous medium, the particle size distribution is sharpened by dispersing the inorganic dispersant or the organic resin fine particles in the aqueous medium in advance. And is preferable in that the dispersion is stable. As the inorganic dispersant, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite and the like are used. As the resin forming the organic resin fine particles, any resin can be used as long as it can form an aqueous dispersion, and it may be a thermoplastic resin or a thermosetting resin. Includes vinyl resins, polyurethane resins, epoxy resins, polyester resins, polyamide resins, polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, polycarbonate resins, and the like. These resins may be used in combination of two or more. Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferable from the viewpoint that an aqueous dispersion of fine spherical resin particles is easily obtained.

<Surfactant>
Moreover, when manufacturing the said resin fine particle, surfactant etc. can also be used as needed. 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 salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol 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. It is.

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Examples of the anionic surfactant having a fluoroalkyl group preferably used include fluoroalkylcarboxylic acids having 2 to 10 carbon atoms, and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6 -C11) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) ) Carboxylic acid and metal salt, perfluoroalkyl carboxylic acid (C7 to C13) and its metal salt, perfluoroalkyl (C4 to C12) sulfonic acid and its metal salt, perfluorooctane sulfonic acid diethanolamide, N-propyl-N -(2-hydroxyethyl) par Fluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned. In addition, examples of the cationic surfactant include aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, and perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts. Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt and the like.

<Protective colloid>
Further, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-acrylate Chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N -Of methyl alcohol 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 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 , Homopolymers or copolymers such as those having a nitrogen atom such as ethyleneimine or its heterocyclic ring, polyoxyethylene, polyoxypropylene, Oxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl Polyoxyethylenes such as esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used. In addition, when an acid such as calcium phosphate salt or an alkali-soluble substance is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. To do. It can also be removed by operations such as enzymatic degradation. When a dispersant is used, the dispersant can remain on the surface of the toner particles, but it is preferable to remove it by washing from the charged surface of the toner.

<Method of dispersion>
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. 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 temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 20 to 80 ° C.

<Desolation>
In order to remove the organic solvent from the obtained emulsified dispersion, a known method can be used. For example, a method can be employed in which the entire system is gradually heated under normal pressure or reduced pressure to completely evaporate and remove the organic solvent in the droplets.

<Extension or / and cross-linking reaction>
For the purpose of introducing a modified polyester resin having a urethane or / and urea group, when a modified polyester resin having an isocyanate group at the terminal and an amine capable of reacting with the polyester resin are added, the toner composition is placed in an aqueous medium. Before dispersion, amines may be mixed in the oil phase, or amines may be added to the aqueous medium. The time required for the above reaction is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer and the added amines, but is usually 1 minute to 40 hours, preferably 1 to 24 hours. The reaction temperature is usually 0 to 150 ° C., preferably 20 to 98 ° C.

[Shell formation process]
The obtained core particle dispersion can keep core particle droplets stably while stirring. In this state, the above-mentioned vinyl copolymer resin fine particle dispersion is introduced and adhered onto the core particles. The vinyl copolymer resin fine particle dispersion is preferably charged over 30 seconds. If the charging is performed in less than 30 seconds, it is not preferable because aggregated particles are generated due to abrupt changes in the dispersion system and adhesion of vinyl copolymer resin fine particles becomes uneven. On the other hand, it is not preferable from the viewpoint of production efficiency to add to the dark cloud for a long time, for example, exceeding 60 minutes.

  The vinyl copolymer resin fine particle dispersion may be diluted or concentrated to adjust the concentration as appropriate before being added to the core particle dispersion. The concentration of the vinyl copolymer resin fine particle dispersion is preferably 5 to 30% by weight, and more preferably 8 to 20% by weight. If it is less than 5%, the change in the concentration of the organic solvent accompanying the introduction of the dispersion is large, and the adhesion of the resin fine particles becomes insufficient. Further, if it exceeds 30% by weight, the resin fine particles are likely to be unevenly distributed in the core particle dispersion, and as a result, the adhesion of the resin fine particles becomes non-uniform.

  The vinyl copolymer resin fine particles adhere to the core particles with sufficient strength by the method of the present invention because the core particles freely deform when the vinyl copolymer resin fine particles adhere to the core particle droplets. The vinyl copolymer resin fine particle interface and the contact surface are sufficiently formed, and the vinyl copolymer resin fine particle is swollen or dissolved by the organic solvent, and the vinyl copolymer resin fine particle and the resin in the core particle are It seems that the situation will be easy to adhere. Therefore, in this state, the organic solvent needs to be sufficiently present in the system. Specifically, in the state of the core particle dispersion, it is 50 wt% to 150 wt%, preferably 70 wt% based on the solid content (resin, colorant, and if necessary, release agent, charge control agent, etc.). It should be in the range of% to 125% by weight. If it exceeds 150% by weight, the amount of colored resin particles obtained in a single production process is reduced and the production efficiency is low, and if there is a large amount of organic solvent, the dispersion stability is lowered and stable production becomes difficult. .

The temperature at which the vinyl copolymer resin fine particles are adhered to the core particles is 10 to 60 ° C, preferably 20 to 45 ° C. If the temperature exceeds 60 ° C, the energy required for production increases and the production environmental load increases. In addition, low acid value vinyl copolymer resin particles may be present on the droplet surface, resulting in unstable dispersion. And coarse particles may be generated. On the other hand, when the temperature is lower than 10 ° C., the viscosity of the dispersion is increased, and adhesion of resin fine particles becomes insufficient, which is not preferable.
<Washing and drying process>
A known technique is used for washing and drying the toner particles dispersed in the aqueous medium.

  That is, after solid-liquid separation with a centrifuge, a filter press, etc., the obtained toner cake is redispersed in ion exchange water at about room temperature to about 40 ° C., and after adjusting the pH with acid or alkali as necessary, After removing the impurities and surfactants by repeating the process of solid-liquid separation again and again, the toner powder is obtained by drying with an air dryer, circulating dryer, vacuum dryer, vibration fluid dryer, etc. . At this time, the fine particle component of the toner may be removed by centrifugation or the like, and a desired particle size distribution can be obtained using a known classifier after drying, if necessary.

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

[Image Forming Method, Image Forming Apparatus, Process Cartridge]
<Image forming apparatus, process cartridge>
The image forming apparatus of the present invention forms an image using the toner of the present invention. The toner of the present invention can be used as either a one-component developer or a two-component developer, but is preferably used as a one-component developer. The image forming apparatus of the present invention preferably has an endless intermediate transfer unit. Furthermore, the image forming apparatus of the present invention preferably includes a photosensitive member and a cleaning unit that cleans the toner remaining on the photosensitive member and / or the intermediate transfer unit. At this time, the cleaning means may or may not have a cleaning blade. The image forming apparatus of the present invention preferably includes a fixing unit that fixes an image using a roller having a heating device or a belt having a heating device. Further, the image forming apparatus of the present invention preferably has a fixing unit that does not require oil application to the fixing member. Furthermore, it is preferable to include other means appropriately selected as necessary, for example, static elimination means, recycling means, control means, and the like.

  In the image forming apparatus of the present invention, the photosensitive member and the constituent elements such as the developing unit and the cleaning unit may be configured as a process cartridge, and the process cartridge may be configured to be detachable from the image forming apparatus main body. Further, at least one of a charging unit, an exposure unit, a developing unit, a transfer unit, a separating unit, and a cleaning unit is supported together with a photosensitive member to form a process cartridge, and a single unit that is detachable from the main body of the image forming apparatus. It is good also as a structure which can be attached or detached using guide means, such as a rail of a forming apparatus main body.

  FIG. 2 shows an example of the image forming apparatus of the present invention. In this image forming apparatus, a latent image carrier (1) that is driven to rotate in the clockwise direction in FIG. 2 is housed in a main body housing (not shown), and around the latent image carrier (1). In addition, a charging device (2), an exposure device (3), a developing device (4) having the electrostatic image developing toner (T) of the present invention, a cleaning unit (5), an intermediate transfer member (6), a support roller ( 7), a transfer roller (8), a charge eliminating means (not shown), and the like.

  The image forming apparatus includes a paper feed cassette (not shown) that stores a plurality of recording papers (P) as an example of a recording medium, and the recording paper (P) in the paper feed cassette is a paper feed (not shown). After the timing is adjusted by a pair of registration rollers (not shown) one by one by a roller, the sheet is fed between a transfer roller (8) as a transfer means and an intermediate transfer body (6).

  In this image forming apparatus, the latent image carrier (1) is rotated clockwise in FIG. 2 to uniformly charge the latent image carrier (1) with the charging device (2), and then the exposure device ( 3) to irradiate the laser modulated with the image data to form an electrostatic latent image on the latent image carrier (1), and to the developing device (4) on the latent image carrier (1) on which the electrostatic latent image is formed. ) To attach toner and develop. Next, a transfer bias is applied from the latent image carrier (1) on which the toner image is formed by the developing device (4) to the intermediate transfer member (6) to transfer the toner image onto the intermediate transfer member (6). By transferring the recording paper (P) between the intermediate transfer body (6) and the transfer roller (8), the toner image is transferred to the recording paper (P). Further, the recording paper (P) on which the toner image is transferred is conveyed to a fixing means (not shown).

  The fixing unit includes a fixing roller heated to a predetermined fixing temperature by a built-in heater and a pressure roller pressed against the fixing roller with a predetermined pressure, and heats the recording paper conveyed from the transfer roller (8). After pressurizing and fixing the toner image on the recording paper on the recording paper, it is discharged onto a paper discharge tray (not shown).

  On the other hand, the image forming apparatus further rotates the latent image carrier (1) on which the toner image is transferred onto the recording paper by the transfer roller (8), and the cleaning unit (5) applies the surface to the surface of the latent image carrier (1). After the remaining toner is scraped off and removed, the charge is removed by a charge removal device (not shown). The image forming apparatus uniformly charges the latent image carrier (1) neutralized by the static eliminator with the charging device (2), and then performs the next image formation in the same manner as described above.

Hereinafter, each member suitably used for the image forming apparatus of the present invention will be described in detail.
The material, shape, structure, size and the like of the latent image carrier (1) are not particularly limited and may be appropriately selected from known ones. The shape may be a drum shape or a belt shape. Examples of the material include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors such as polysilane and phthalopolymethine. Among these, amorphous silicon and organic photoreceptors are preferable from the viewpoint of long life.

  The electrostatic latent image can be formed on the latent image carrier (1) by, for example, charging the surface of the latent image carrier (1) and then exposing it like an image. It can be performed by latent image forming means. The electrostatic latent image forming means includes, for example, a charging device (2) for charging the surface of the latent image carrier (1) and an exposure device (3) for exposing the surface of the latent image carrier (1) imagewise. At least.

The charging can be performed, for example, by applying a voltage to the surface of the latent image carrier (1) using the charging device (2).
The charging device (2) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the charging device (2) includes a conductive or semiconductive roller, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotron and scorotron.

The shape of the charging device (2) may be a magnetic brush, a fur brush or the like in addition to the roller, and can be selected according to the specifications and form of the electrophotographic apparatus. In the case of using a magnetic brush, the magnetic brush is composed of, for example, various ferrite particles such as Zn-Cu ferrite as a charging member, and a non-magnetic conductive sleeve for supporting the same, and a magnet roll included therein. . In addition, when using a brush, for example, as a material of the fur brush, a fur treated with carbon, copper sulfide, metal or metal oxide is used, and this is wound around a metal or other conductive core. It is configured by pasting.
The charging device (2) is not limited to the contact type charger as described above, but an image forming apparatus in which ozone generated from the charger is reduced is obtained. Therefore, a contact type charger is used. It is preferable.

  The exposure can be performed, for example, by exposing the surface of the photoreceptor imagewise using the exposure apparatus (3). The exposure device (3) is not particularly limited as long as the surface of the latent image carrier (1) charged by the charging device (2) can be exposed like an image to be formed. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system may be used.

  The development can be performed, for example, by developing the electrostatic latent image using the toner of the present invention, and can be performed by the developing device (4). The developing device (4) is not particularly limited as long as it can be developed using the toner of the present invention, for example, and can be appropriately selected from known ones. For example, the developing device (4) contains the toner of the present invention, Preferable examples include those having at least a developing unit that can apply toner to the electrostatic latent image in a contact or non-contact manner.

  The developing device (4) carries toner on its peripheral surface, rotates in contact with the latent image carrier (1), and supplies toner to the electrostatic latent image formed on the latent image carrier (1). The developing roller (40) that performs development and a thin layer forming member (41) that contacts the peripheral surface of the developing roller (40) and thins the toner on the developing roller (40) are preferable.

  As the developing roller (40), either a metal roller or an elastic roller is preferably used. There is no restriction | limiting in particular as a metal roller, Although it can select suitably according to the objective, For example, an aluminum roller etc. are mentioned. By performing a blasting process on the metal roller, it is possible to produce the developing roller (40) having an arbitrary surface friction coefficient relatively easily. Specifically, by treating the aluminum roller with glass bead blasting, the roller surface can be roughened, and an appropriate toner adhesion amount can be obtained on the developing roller.

As the elastic roller, a roller coated with an elastic rubber layer is used, and a surface coat layer made of a material that is easily charged to a polarity opposite to that of the toner is provided on the surface. The elastic rubber layer is set to a hardness of 60 degrees or less according to JIS-A in order to prevent toner deterioration due to pressure concentration at the contact portion with the thin layer forming member (41). The surface roughness (Ra) is set to 0.3 to 2.0 μm, and a necessary amount of toner is held on the surface. Further, since the developing roller (40) is applied with a developing bias for forming an electric field with the latent image carrier (1), the elastic rubber layer has a resistance value of 10 ³ to 10 ¹⁰ Ω. Is set. The developing roller (40) rotates in the clockwise direction, and conveys the toner held on the surface to a position facing the thin layer forming member (41) and the latent image carrier (1).

  The thin layer forming member (41) is provided at a position lower than the contact position between the supply roller (42) and the developing roller (40). The thin layer forming member (41) is made of a metal leaf spring material such as stainless steel (SUS) or phosphor bronze, and the free end is brought into contact with the surface of the developing roller (40) with a pressing force of 10 to 40 N / m. Therefore, the toner that has passed under the pressure is thinned and charged by frictional charging. Further, a regulating bias having a value offset in the same direction as the charging polarity of the toner with respect to the developing bias is applied to the thin layer forming member (41) in order to assist frictional charging.

There is no restriction | limiting in particular as a rubber elastic body which comprises the surface of a developing roller (40), Although it can select suitably according to the objective, For example, a styrene-butadiene-type copolymer rubber, an acrylonitrile-butadiene-type copolymer weight Examples include coalesced rubber, acrylic rubber, epichlorohydrin rubber, urethane rubber, silicone rubber, or a blend of two or more thereof. Among these, a blend rubber of epichlorohydrin rubber and acrylonitrile-butadiene copolymer rubber is particularly preferable.
The developing roller (40) is manufactured, for example, by covering the outer periphery of the conductive shaft with a rubber elastic body. The conductive shaft is made of a metal such as stainless steel (SUS), for example.

  The transfer can be performed, for example, by charging the latent image carrier (1), and can be performed by a transfer roller. The transfer roller includes a primary transfer unit that transfers a toner image onto an intermediate transfer member (6) to form a transfer image, and a secondary transfer unit (transfer) that transfers the transfer image onto a recording paper (P). An embodiment having a roller (8) is preferred. At this time, two or more colors, preferably full color toners are used as toners, and a primary transfer means for forming a composite transfer image by transferring the toner image onto the intermediate transfer member (6), and recording the composite transfer image An embodiment having secondary transfer means for transferring onto the paper (P) is more preferable.

The intermediate transfer member (6) is not particularly limited, and can be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.
The transfer means (primary transfer means, secondary transfer means) preferably has at least a transfer device that peels and charges the toner image formed on the latent image carrier (1) to the recording paper (P) side. . There may be one transfer means, or two or more transfer means. Examples of the transfer means include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.

  The recording paper (P) is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. A PET base for OHP can also be used.

For example, the fixing can be performed on the toner image transferred to the recording paper (P) by using a fixing unit, and is performed each time the toner image of each color is transferred to the recording paper (P). Alternatively, it may be performed at the same time in a state where toner images of respective colors are laminated.
The fixing unit is not particularly limited and may be appropriately selected depending on the intended purpose. However, a known heating and pressing unit is preferable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt. In addition, as for the heating temperature by a heating-pressing means, 80-200 degreeC is preferable.

It may be a soft roller type fixing device having a fluorine surface layer composition as shown in FIG. This is because the heating roller (9) has an elastic body layer (11) made of silicone rubber and a PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) surface layer (12) on an aluminum core bar (10). The heater (13) is provided inside the aluminum cored bar. The pressure roller (14) has an elastic layer (16) made of silicone rubber and a PFA surface layer (17) on an aluminum cored bar (15). The recording paper (P) on which the unfixed image (18) is printed is passed as shown.
In the present invention, for example, a known optical fixing device may be used together with or instead of the fixing unit depending on the purpose.

  The neutralization can be performed, for example, by applying a neutralization bias to the latent image carrier, and can be suitably performed by a neutralization unit. The neutralizing means is not particularly limited as long as it can apply a neutralizing bias to the latent image carrier, and can be appropriately selected from known static eliminators. For example, a neutralizing lamp is preferable. It is done.

  Cleaning can be suitably performed, for example, by removing the toner remaining on the photoreceptor by a cleaning means. The cleaning means is not particularly limited and may be any one selected from known cleaners as long as it can remove the toner remaining on the photosensitive member. For example, a magnetic brush cleaner, an electrostatic brush cleaner, or a magnetic roller can be selected. A cleaner, a blade cleaner, a brush cleaner, a web cleaner and the like are preferable.

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

Control can be suitably performed by controlling each means by a control means, for example. The control means is not particularly limited as long as each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.
According to the image forming apparatus, the image forming method, and the process cartridge of the present invention, an excellent image can be obtained by using the electrostatic latent image developing toner that has excellent fixability and does not deteriorate due to stress in the developing process. Can be provided.

<Multicolor image forming apparatus>
FIG. 4 is a schematic view showing an example of a multicolor image forming apparatus to which the present invention is applied. FIG. 4 shows a tandem type full-color image forming apparatus.

  In FIG. 4, the image forming apparatus stores a latent image carrier (1) that is driven to rotate in the clockwise direction in FIG. 4 in a main body housing (not shown), and around the latent image carrier (1). A charging device (2), an exposure device (3), a developing device (4), an intermediate transfer member (6), a support roller (7), a transfer roller (8) and the like are arranged. Although not shown, the image forming apparatus includes a paper feeding cassette that stores a plurality of recording papers. The recording paper (P) in the paper feeding cassette is fed to a pair of registration rollers (not shown) one by one by a paper feeding roller (not shown). After the timing adjustment, the sheet is fed between the intermediate transfer member (6) and the transfer roller (8) and fixed by the fixing means (19).

  The image forming apparatus rotates the latent image carrier (1) clockwise in FIG. 4 to uniformly charge the latent image carrier (1) with the charging device (2), and then exposes the exposure device (3). The electrostatic image is formed on the latent image carrier (1) by irradiating the laser modulated with the image data, and the developing device (4) forms the latent image carrier (1) on which the electrostatic latent image is formed. Develop with toner attached. The image forming apparatus transfers the toner image formed by attaching the toner to the latent image carrier with the developing device (4) from the latent image carrier (1) to the intermediate transfer member. This is performed for each of the four colors of cyan (C), magenta (M), yellow (Y), and black (K) to form a full-color toner image.

  Next, FIG. 5 is a schematic diagram illustrating an example of a revolver type full-color image forming apparatus. In this image forming apparatus, a plurality of color toners are sequentially developed on one latent image carrier (1) by switching the operation of the developing device. Then, the color toner image on the intermediate transfer body (6) is transferred to the recording paper (P) by the transfer roller (8), the recording paper (P) to which the toner image is transferred is conveyed to the fixing unit, and the fixed image is transferred. obtain.

  On the other hand, the image forming apparatus further rotates the latent image carrier (1) on which the toner image is transferred to the recording paper (P) by the intermediate transfer member (6), and the latent image carrier (1) by the cleaning unit (5). ) The toner remaining on the surface is removed by scraping with a blade, and then the charge is removed by the charge removing unit. The image forming apparatus uniformly charges the latent image carrier (1) neutralized by the neutralization unit with the charging device (2), and then performs the next image formation as described above. The cleaning unit (5) is not limited to scraping off the residual toner on the latent image carrier (1) with a blade. For example, the cleaning unit (5) scrapes off the residual toner on the latent image carrier (1) with a fur brush. It may be a thing.

In the image forming method and the image forming apparatus of the present invention, since the toner of the present invention is used as the developer, a good image can be obtained.
<Process cartridge>
The process cartridge of the present invention can develop an electrostatic latent image carrier carrying an electrostatic latent image and the electrostatic latent image carried on the electrostatic latent image carrier using the toner of the present invention. A developing means for forming a visual image, and further comprising other means such as a charging means, a developing means, a transfer means, a cleaning means, and a static elimination means, which are appropriately selected as necessary. The image forming apparatus main body is detachable.

  The developing means includes a developer container that contains the toner or developer of the present invention, and a developer carrier that carries and transports the toner or developer contained in the developer container. And a layer thickness regulating member for regulating the thickness of the toner layer to be carried. The process cartridge of the present invention can be detachably provided in various electrophotographic apparatuses, facsimiles, and printers, and is preferably detachably provided in the image forming apparatus of the present invention described later.

  For example, as shown in FIG. 6, the process cartridge includes a latent image carrier (1), and includes a charging device (2), a developing device (4), a transfer roller (8), and a cleaning unit (5). In addition, other means are provided as necessary. In FIG. 6, (L) shows exposure from the exposure apparatus, and (P) shows recording paper. As the latent image carrier (1), the same one as the image forming apparatus can be used. An arbitrary charging member is used for the charging device (2).

  Next, the image forming process using the process cartridge shown in the figure will be described. The latent image carrier (1) is charged by the charging device (2) while being rotated in the direction of the arrow, and exposure by the exposure means (not shown) ( L), an electrostatic latent image corresponding to the exposure image is formed on the surface. The electrostatic latent image is developed with toner by the developing device (4), and the toner development is transferred onto the recording paper (P) by the transfer roller (8) and printed out. Next, the surface of the latent image carrier after the image transfer is cleaned by the cleaning unit (5), further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited by these Examples.
Hereinafter, “parts” and “%” indicate parts by mass and mass% unless otherwise specified.
First, analysis and evaluation methods for the toners obtained in Examples and Comparative Examples will be described.
In the following, the case where the toner of the present invention is used as a one-component developer was evaluated. However, the toner of the present invention can be used as a two-component developer by using a suitable external addition process and a suitable carrier. Can be used.

[Preparation of core resin]
<Synthesis of polyester resin>
229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 2-mole adduct, 208 parts of terephthalic acid, 46 parts of adipic acid, and dibutyltin in a reaction vessel equipped with a condenser and a nitrogen introducing tube 2 parts of oxide were charged and reacted at 230 ° C. for 8 hours under normal pressure.
Next, after reacting under reduced pressure of 10 to 15 mmHg for 5 hours, 44 parts of trimellitic anhydride was added to the reaction vessel and reacted at 180 ° C. for 2 hours under normal pressure to synthesize [Polyester 1]. did.
[Polyester 1] obtained had a number average molecular weight of 2500, a weight average molecular weight of 6700, a glass transition temperature of 43 ° C., and an acid value of 25 mgKOH / g.
-Synthesis of isocyanate-modified polyester 1-

<Synthesis of prepolymer>
Into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction pipe, 366 parts of 1,2-propylene glycol, 566 parts of terephthalic acid, 44 parts of trimellitic anhydride and 6 parts of titanium tetrabutoxide are placed at a normal pressure of 230 The mixture was reacted at 0 ° C. for 8 hours, and further reacted at a reduced pressure of 10 to 15 mmHg for 5 hours to obtain [Intermediate Polyester 1]. [Intermediate polyester 1] had a number average molecular weight of 3200, a weight average molecular weight of 12000, and a Tg of 55 ° C.
Next, 420 parts of [Intermediate polyester 1], 80 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, and reacted at 100 ° C. for 5 hours. A [prepolymer] which was polyester was obtained. [Prepolymer] had a free isocyanate mass% of 1.34%.

<Manufacture of master batch 1>
Carbon black (Regal 400R manufactured by Cabot Corporation): 40 parts, Binder resin: Polyester resin (Sanyo Kasei RS-801, acid value 10, Mw 20,000, Tg 64 ° C.): 60 parts, water: 30 parts are mixed in a Henschel mixer. Thus, a mixture in which water was soaked into the pigment aggregate was obtained. This was kneaded for 45 minutes with two rolls set at a roll surface temperature of 130 ° C. and pulverized to a size of 1 mm with a pulverizer to obtain [Masterbatch 1].

<Preparation of pigment / WAX dispersion (oil phase)>
In a container equipped with a stir bar and a thermometer, 545 parts of [Polyester 1], paraffin wax (endothermic peak 73.1 ° C., half-value width 3.9 ° C. in thermal analyzer (DSC)) 85 parts, ethyl acetate 1, 450 parts was charged, the temperature was raised to 80 ° C. with stirring, the temperature was maintained at 80 ° C. for 5 hours, and then cooled to 30 ° C. in 1 hour. Next, 500 parts of [Masterbatch 1] and 100 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution 1].

  [Raw material solution 1] 1,500 parts were transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feed speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads of 80 Carbon black and WAX were dispersed under the conditions of volume% filling and 3 passes. Next, 425 parts of [Polyester L1] and 230 parts of ethyl acetate were added, and one pass was performed with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion 1]. It was adjusted by adding ethyl acetate so that the solid content concentration of [Pigment / WAX Dispersion 1] (130 ° C., 30 minutes) was 50%.

[Production of resin for shell]
<Method for producing resin dispersion 1 (styrene-acrylic)>
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 0.7 part of sodium dodecyl sulfate and 498 parts of ion-exchanged water were added and dissolved by heating to 80 ° C. with stirring, and then potassium persulfate. A solution prepared by dissolving 2.6 parts in 104 parts of ion-exchanged water was added, and 15 minutes later, a monomer mixture of 170 parts of styrene monomer, 30 parts of butyl acrylate and 4.2 parts of n-octanethiol was added for 90 minutes. The mixture was added dropwise, and then kept at 80 ° C. for 60 minutes to cause a polymerization reaction. Then, it cooled and white [resin dispersion 1] with a volume average particle diameter of 118 nm was obtained.

<Method for producing resin dispersion 2 (styrene-acrylic)>
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 0.7 part of sodium dodecyl sulfate and 498 parts of ion-exchanged water were added and dissolved by heating to 80 ° C. with stirring, and then potassium persulfate. A solution prepared by dissolving 2.6 parts in 104 parts of ion-exchanged water was added, and 15 minutes later, a monomer mixture of 180 parts of styrene monomer, 20 parts of butyl acrylate, and 4.2 parts of n-octanethiol was added. The solution was added dropwise over a period of time, and then kept at 80 ° C. for another 60 minutes to cause a polymerization reaction. Then, it cooled and white [resin dispersion 2] with a volume average particle diameter of 135 nm was obtained.

<Method for producing resin dispersion 3 (styrene-acrylic)>
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 0.7 part of sodium dodecyl sulfate and 498 parts of ion-exchanged water were added and dissolved by heating to 80 ° C. with stirring, and then potassium persulfate. A solution prepared by dissolving 2.6 parts in 104 parts of ion-exchanged water was added, and 15 minutes later, 90 parts of a monomer mixture of 140 parts of styrene monomer, 60 parts of butyl acrylate, and 4.2 parts of n-octanethiol was added. The solution was added dropwise over a period of time, and then kept at 80 ° C. for another 60 minutes to cause a polymerization reaction. Then, it cooled and white [resin dispersion 3] with a volume average particle diameter of 133 nm was obtained.

<Method for producing resin dispersion 4 (styrene-acrylic)>
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 0.7 part of sodium dodecyl sulfate and 498 parts of ion-exchanged water were added and dissolved by heating to 80 ° C. with stirring, and then potassium persulfate. A solution prepared by dissolving 2.6 parts in 104 parts of ion-exchanged water was added, and 15 minutes later, 90 parts of a monomer mixture of 170 parts of styrene monomer, 30 parts of methyl methacrylate, and 4.2 parts of n-octanethiol was added. The solution was added dropwise over a period of time, and then kept at 80 ° C. for another 60 minutes to cause a polymerization reaction. Then, it cooled and white [resin dispersion 4] with a volume average particle diameter of 120 nm was obtained.

<Method for producing resin dispersion 5 (styrene-acrylic)>
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 0.7 part of sodium dodecyl sulfate and 498 parts of ion-exchanged water were added and dissolved by heating to 80 ° C. with stirring, and then potassium persulfate. A solution prepared by dissolving 2.6 parts in 104 parts of ion-exchanged water was added, and 15 minutes later, 140 parts of styrene monomer, 30 parts of butyl acrylate, 30 parts of methyl methacrylate, and 4.2 parts of n-octanethiol were simply added. The monomer mixture was added dropwise over 90 minutes, and then kept at 80 ° C. for 60 minutes to cause a polymerization reaction. Then, it cooled and white [resin dispersion 5] with a volume average particle diameter of 117 nm was obtained.

<Method for producing resin dispersion 6 (acrylic resin)>
To a 1 liter four-necked flask equipped with an introduction tube, 400 parts of ion-exchanged water and 5 parts of ammonium dodecylbenzenesulfonate were added, and after raising the temperature to 85 ° C., ammonium peroxodisulfate (APS) 0.5 Part by weight was added.
Next, while maintaining the temperature at 76 to 78 ° C., 75 parts of methyl methacrylate (MMA), 25 parts of ethylene glycol dimethacrylate, 5 parts of ethylene glycol monostearate with HLB = 2, 1 part of ammonium salt of dodecylbenzenesulfonate, ion exchange An aqueous emulsion solution composed of 40 parts of water was added dropwise for polymerization.
Next, after holding for 30 minutes, the temperature was raised to 85 ° C. and held for 1.5 hours. Then, it cooled and white [resin dispersion 6] with a volume average particle diameter of 100 nm was obtained.

<Method for producing resin dispersion 7 (acrylic resin)>
To a 1 liter four-necked flask equipped with an introduction tube, 400 parts of ion-exchanged water and 5 parts of ammonium dodecylbenzenesulfonate were added, and after raising the temperature to 85 ° C., ammonium peroxodisulfate (APS) 0.5 Parts were added.
Subsequently, an aqueous emulsion comprising 100 parts of methyl methacrylate (MMA), 5 parts of ethylene glycol monostearate with HLB = 2, 1 part of ammonium salt of dodecylbenzenesulfonate, and 40 parts of ion-exchanged water while maintaining the temperature at 76 to 78 ° C. The solution was added dropwise to perform polymerization.
Next, after holding for 30 minutes, the temperature was raised to 85 ° C. and held for 1.5 hours. Then, it cooled and white [resin dispersion 7] with a volume average particle diameter of 100 nm was obtained.

Example 1
<Preparation of aqueous phase>
990 parts of ion-exchanged water, 40 parts of a 25 wt% aqueous dispersion of organic resin fine particles (styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt copolymer) for dispersion stabilization, dodecyl diphenyl ether 145 parts of 48.5% aqueous solution of sodium disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries) and 95 parts of ethyl acetate were mixed and stirred to obtain a pale yellow liquid. This is designated as [Aqueous Phase 1].

<Emulsification process>
[Pigment / WAX Dispersion 1] 975 parts and 2.7 parts of isophoronediamine were mixed for 1 minute at 5,000 rpm with a TK homomixer (manufactured by Tokushu Kika). After mixing for 1 minute at 5,000 rpm (manufactured by Special Machine), add 1,200 parts of [Aqueous Phase 1] for 20 minutes while adjusting with a TK homomixer at a rotational speed of 8,000-13,000 rpm. By mixing, [Emulsified slurry 1] was obtained.

<Formation of shell>
While adjusting [Emulsion slurry 1] with a TK homomixer at a rotational speed of 300 to 500 rpm, a mixture of 2.5 parts of [Resin dispersion 1] and 2.5 parts of [Resin dispersion 6] is dropped. Ten minutes after the dropwise addition, the mixture was diluted 1.4 times with ion-exchanged water to obtain [mixed solution 1].

<Desolvent>
[Mixed liquid 1] was put into a container in which a stirrer and a thermometer were set, and the solvent was removed at 30 ° C. for 8 hours to obtain [Dispersed slurry 1].

<Washing → Drying>
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered.
(2): 900 parts of ion-exchanged water was added to the filter cake of (1), ultrasonic vibration was applied, and the mixture was mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure. This operation was repeated so that the electric conductivity of the reslurry liquid was 10 μS / cm or less.
(3): 10% hydrochloric acid was added so that the reslurry liquid of (2) had a pH of 4, and the mixture was filtered as it was with a three-one motor for 30 minutes.
(4): 100 parts of ion-exchanged water was added to the filter cake of (3), mixed with a TK homomixer (10 minutes at 12,000 rpm) and then filtered. This operation was repeated so that the reslurry liquid had an electric conductivity of 10 μS / cm or less to obtain [Filter Cake 1].
[Filter cake 1] was dried at 42 ° C. for 48 hours in a circulating drier, sieved with a mesh opening of 75 μm, an average circularity of 0.976, and a volume average particle diameter (Dv) of 6.2 μm [Toner Base 1] having an average particle diameter (Dp) of 5.8 μm was obtained.

<Example 2>
A toner base was obtained in the same manner as in Example 1 except that the resin dispersion 2 was used instead of the resin dispersion 1 in Example 1.
<Example 3>
A toner base was obtained in the same manner as in Example 1 except that the resin dispersion 3 was used instead of the resin dispersion 1 in Example 1.
<Example 4>
A toner base was obtained in the same manner as in Example 1 except that the resin dispersion 4 was used instead of the resin dispersion 1 in Example 1.
<Example 5>
A toner base was obtained in the same manner as in Example 1 except that the resin dispersion 5 was used instead of the resin dispersion 1 in Example 1.

<Example 6>
A toner base was obtained in the same manner as in Example 1 except that isophoronediamine and prepolymer were not used in the emulsification step of Example 1.
<Example 7>
A toner base was obtained in the same manner as in Example 1 except that the resin dispersion 7 was used instead of the resin dispersion 6 in Example 1.
<Example 8>
A toner base was obtained in the same manner as in Example 1 except that the resin dispersion 2 was used instead of the resin dispersion 1 and the resin dispersion 7 was used instead of the resin dispersion 6 in Example 1.
<Example 9>
In Example 1, a toner base was obtained in the same manner as in Example 7 except that isophoronediamine and prepolymer were not used in the emulsification step, and the resin dispersion 7 was used instead of the resin dispersion 6.

<Comparative example 1>
A toner base was obtained in the same manner as in Example 1 except that no resin dispersion was used in Example 1.
<Comparative example 2>
A toner base was obtained in the same manner as in Example 1 except that the resin dispersion 1 was not used in Example 1.
<Comparative Example 3>
A toner base was obtained in the same manner as in Example 1 except that the resin dispersion 6 was not used in Example 1.
<Comparative example 4>
In Example 1, a toner base was obtained in the same manner as in Example 1 except that no isophoronediamine and prepolymer were used in the emulsification step, and no resin dispersion was used.

Table 1 shows the evaluation results of the toners of Examples and Comparative Examples.
(Measuring method)
The physical property measurement methods and evaluation methods used in the examples and comparative examples are described below.

<Particle size>
Next, a method for measuring the particle size distribution of toner particles will be described.
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 measuring method is as follows.
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 the measurement sample is further added as a solid content. 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, and the measurement device is used to measure the volume and number of toner particles or toner using a 100 μm aperture as an aperture. Volume distribution and number distribution are calculated. From the obtained distribution, the volume average particle diameter (Dv) and the number average particle diameter (Dp) of the toner can be obtained.
As a channel, for example, less than 2.00 to 2.52 μm; less than 2.52 to 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; 6.35 to less than 8.00 μm; 8.00 to less than 10.08 μm; 10.08 to less than 12.70 μm; 12.70 to less than 16.00 μm; 16.00 to less than 20.20 μm; Less than .40 μm; 25.40 to less than 32.00 μm; 13 channels of 32.00 to less than 40.30 μm are used, and particles having a particle size of 2.00 μm to less than 40.30 μm can be targeted.

<Average circularity>
As a method for measuring the shape, an optical detection band method is suitable in which a suspension containing particles is passed through an imaging unit detection band on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. The average circularity is a value obtained by dividing the perimeter of an equivalent circle having the same projected area obtained by this method by the perimeter of the actual particle.
This value is a value measured as an average circularity by a flow type particle image analyzer FPIA-2000. 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 for about 1 to 3 minutes with an ultrasonic disperser and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl. .

<Volume average particle diameter of resin fine particles>
As a measuring method of the volume average particle diameter of the resin fine particles, it can be measured with a nanotrack particle size distribution measuring apparatus UPA-EX150 (manufactured by Nikkiso, dynamic light scattering method / laser Doppler method). As a specific measuring method, the dispersion in which resin fine particles are dispersed is adjusted to a measurement concentration range for measurement. At that time, the background measurement is performed in advance using only the dispersion solvent of the dispersion. By this measurement method, it is possible to measure several tens of nm to several μm, which is the volume average particle size range of the resin fine particles used in the present invention.

<Molecular weight>
The molecular weights of the polyester resin, vinyl copolymer resin, hybrid resin, etc. used were measured under the following conditions by ordinary GPC (gel permeation chromatography).
・ Device: HLC-8220GPC (manufactured by Tosoh Corporation)
Column: TSKgel SuperHZM-M x 3
・ Temperature: 40 ℃
・ Solvent: THF (tetrahydrofuran)
・ Flow rate: 0.35 ml / min ・ Sample: 0.01 ml injection of a sample having a concentration of 0.05 to 0.6% A molecular weight calibration curve prepared by a monodisperse polystyrene standard sample from the molecular weight distribution of the toner resin measured under the above conditions Was used to calculate the weight average molecular weight Mw. As monodisperse polystyrene standard samples, 5.8 × 100, 1.085 × 10000, 5.95 × 10000, 3.2 × 100,000, 2.56 × 1000000, 2.93 × 1000, 2.85 × 10000, Ten points of 1.48 × 100,000, 8.417 × 100,000, 7.5 × 1000000 were used.

<Toner surface shape>
An electron microscope S-4800 manufactured by Hitachi, Ltd. was used. Observation was performed at an acceleration voltage of 5 kV and a magnification of 5000 times, and the photograph of FIG. 1 was taken.

<Photoconductor background dirt>
Using Ricoh's ipsio SP C220, a predetermined print pattern with a printing rate of 6% can be printed in an N / N environment (23 ° C., 45%) at the initial stage (before durability) and after 10,000 continuous copies (after durability). The L * of the background toner was determined by a tape transfer method. The tape transfer method is a method in which a mending tape (manufactured by Sumitomo 3M) is affixed onto the toner existing on the photoconductor to transfer fog toner onto the tape. This is a method of pasting on white paper, measuring the reflection density with X-Rite 939, and determining the difference L * as the reflection density of the background stain.
○: Change rate of L * after initial and endurance is within 2%
Δ: Change rate of L * between the initial stage and after endurance is within 2% to 5%
X: The rate of change in L * after the initial stage and after endurance was 5% or more.

<Adhering to regulation blade>
Using Ricoh's ipsio SP C220, the state of the developing roller of the developer after a predetermined print pattern with a printing rate of 6% was copied continuously after 10,000 sheets in an N / N environment (23 ° C, 45%) (after durability) The copied images were visually observed and evaluated. Judgment criteria are as follows.
○: No streak or unevenness occurred on the developing roller.
Δ: Although some streaks or unevenness occurred on the developing roller, there were no vertical streaks on the copied image, and there was no practical problem.
X: Many streaks or unevenness occurred on the developing roller, and vertical streak-like omission occurred on the copied image, which had a problem in practical use.
“◯” and “△” were accepted.

<Filming>
Using a Ricoh ipsio SP C220, a predetermined print pattern with a printing rate of 6% was continuously printed in an N / N environment (23 ° C., 45%). After continuous printing of 10,000 sheets in an N / N environment (after endurance), the photoreceptor and the intermediate transfer belt were visually observed and evaluated. Judgment criteria are as follows.
○: Filming did not occur on the photosensitive member and the intermediate transfer member, and there was no problem at all.
Δ: Filming was observed on one of the photosensitive member and the intermediate transfer member, but it was not visible on the copied image, and there was no practical problem.
X: Filming occurred on the photoreceptor and / or the intermediate transfer member, which could be confirmed on the image, and there was a problem in practical use.

  Since the toner of the present invention can suppress blade sticking and can provide a high-quality image without causing image noise such as filming and background fogging, the copying machine, printer, and fax machine based on the electrophotographic recording method can be provided. , And a method for producing an electrophotographic toner used in these multifunction devices.

DESCRIPTION OF SYMBOLS 1 Latent image carrier 2 Charging apparatus 3 Exposure apparatus 4 Developing apparatus 40 Developing roller 41 Thin layer forming member 42 Supply roller 5 Cleaning part 6 Intermediate transfer body 7 Support roller 8 Transfer roller 9 Heating roller 10 Aluminum core 11 Elastic body layer 12 PFA surface layer 13 Heater 14 Pressure roller 15 Aluminum core 16 Elastic layer 17 PFA surface layer 18 Unfixed image 19 Fixing means L Exposure P Recording paper T Electrostatic charge image developing toner

JP 2006-285188 A Japanese Patent Laid-Open No. 5-333587

Claims (10)

  In a dry electrostatic image developing toner containing at least a binder resin, a colorant, and a release agent, the toner has a core-shell structure, the core is made of a resin having a polyester skeleton, and the shell is made of styrene-acrylic. A toner for developing a dry electrostatic image, characterized in that the toner is composed of an acrylic resin and an acrylic resin.   The styrene-acrylic resin is characterized in that the styrene monomer is 85 to 65% by weight, the acrylic monomer is 15 to 35% by weight, and the total of the styrene monomer and the acrylic monomer is 90 to 100% by weight. Item 2. The toner for developing a dry electrostatic image according to Item 1.   3. The dry electrostatic charge image developing toner according to claim 1, wherein the core contains a modified polyester resin having a urethane or / and urea group in addition to a resin having a polyester skeleton.   4. The dry electrostatic charge image developing toner according to claim 1, wherein when the core contains an organic solvent, a shell-forming resin is added to form a continuous layer of the core and shell by dissolution / precipitation.   The said mold release agent contains 1 type (s) or 2 or more types selected from paraffins, synthetic esters, polyolefins, carnauba wax, or rice wax in any one of Claims 1-4 characterized by the above-mentioned. The toner for developing an electrostatic image according to the description.   A toner container filled with the dry electrostatic image developing toner according to claim 1.   A developer comprising the dry electrostatic image developing toner according to claim 1.   A developer carrying member for carrying the developer to be supplied to the latent image carrying member on the surface; a developer supplying member for supplying the developer to the surface of the developer carrying member; and a developer container for containing the developer. 8. A developing device according to claim 7, wherein the developer according to claim 7 is stored in a developer container.   In the process cartridge in which the latent image carrier and the developing device for developing at least the latent image on the latent image carrier with the developer are integrated and configured to be detachable from the image forming apparatus, the developing device is claimed in claim 8. A process cartridge according to claim 1.   A latent image carrier for carrying a latent image, a charging means for uniformly charging the surface of the latent image carrier, and exposing the charged surface of the latent image carrier based on image data to write an electrostatic latent image An exposure unit; a developing unit that supplies toner to the electrostatic latent image formed on the surface of the latent image carrier to make it visible; and a transfer unit that transfers the visible image on the surface of the latent image carrier to the transfer target; An image forming apparatus comprising: a fixing unit that fixes a visible image on a transfer target, wherein the developing unit is the developing device according to claim 8.