JP2011221269A - Toner for electrostatic charge latent image development, image forming method and apparatus using the same, and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner which is excellent in charging characteristics and duration stability, and capable of providing an image without scumming while maintaining fixability, and an image forming apparatus and an image forming method which use the toner.SOLUTION: A core-shell structure toner which contains at least a binder resin and a coloring material and has a core material granulated in a water-based medium and a shell material covering the core material is used in an image forming apparatus and an image forming method, or for electrostatic image development. The shell material comprises a hybrid resin containing a polyester unit and a vinyl unit.

Description

  The present invention relates to an electrostatic charge image developing toner for developing an electrostatic latent image formed in electrophotography, electrostatic recording method, and electrostatic printing method, and an image forming method, an image forming apparatus, and a process using the same. It relates to the cartridge.

  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. The 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 hot 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.

  Examples of the resin used in the toner include a vinyl polymer resin and a resin having a polyester skeleton. These resins have advantages and disadvantages with respect to the fluid properties, mobility, chargeability, fixability, image properties, etc., which are the functional properties of the toner. Recently, both resins have been used in combination. So-called hybrid type resins having the following skeleton are also used. In addition to the so-called kneading and pulverization methods that exist conventionally, toner production methods include suspension methods and emulsification methods using organic solvents and aqueous solvents, and suspensions in which polymerized monomer droplets are controlled to obtain toner particles directly. A so-called wet granulation or chemical toner method such as a polymerization method or an aggregation method in which emulsified fine particles are produced and then aggregated to obtain toner particles is known.

  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.

In the past, efforts have been made to improve the stress resistance of the toner by designing the resin of the toner. By adding a high molecular weight and low molecular weight molecular weight distribution of the resin, the mechanical strength and resistance of the toner are improved. A method of balancing the blocking property and the fixing property is common.
Further, a so-called core / shell type toner in which the toner has a core / shell structure to achieve functional separation, a resin advantageous for heat fixing is used inside the toner, and the outside is covered with a resin advantageous for blocking or the like. In addition, a design method in which the core portion mainly improves low-temperature fixing performance and the shell portion improves mechanical strength and blocking resistance is also widely known.

  When manufacturing a core / shell structure type toner, the shell material cannot be adhered to the core part if the shell material particles are designed to have a high molecular weight or have a cross-linked molecular structure in order to obtain mechanical strength. However, there has been a problem that the fusion / film formation does not proceed well, resulting in a toner whose capsule structure is easily broken.

  Various approaches have been made so far to deal with such problems, and Patent Document 1 proposes a core-shell structure type toner for the purpose of achieving both low-temperature fixability and storage stability. Proposal of dry material adhesion method using mechanical shearing force such as mechanochemical, wet method utilizing the properties of surfactants, and adhesion of shell material particles to smooth the toner surface with a solvent Has been. However, in the dry shelling process, the surface is not smooth, that is, the surface becomes non-uniform, and sufficient mechanical strength cannot be obtained.

In Patent Document 2, the resin of the core material and the resin of the shell material are specified to achieve both low-temperature fixability and storage stability, but the adhesive strength is weakened due to the difference in the material of the core and the shell. The binding force is weak, the durability is not stable, peeling and chipping occur, member contamination due to the peeled shell material and core material is caused, and image defects occur.
Patent Document 3 discloses an electrostatic charge image developing toner having a core-shell structure in which a shell is provided on the surface of core particles containing a binder resin containing a crystalline polyester resin and an amorphous polyester resin, and a colorant. A toner for developing an electrostatic charge image is described, wherein the core particle includes a composite resin in which a styrene resin and a polyester resin are bonded. Since the toner described in Patent Document 8 contains a hybrid resin in the core particles, a large amount of the hybrid resin must be added to improve the adhesion between the core and the shell, and fixing at low temperature is not possible.

  The present invention has been made in view of the above-described problems, and is an electrostatic charge image developing toner capable of obtaining an image excellent in charging characteristics and durability stability and free from background stains while maintaining fixability, and a method for producing the same, It is another object of the present invention to provide a developer, a toner container, a process cartridge, and an image forming apparatus using the toner.

The present inventors have found that the above-described problem is in a core-shell structure type toner having at least a binder resin and a colorant, and having a core material granulated with an aqueous medium and a shell material covering the core material. The present invention was completed by finding that the shell material can be solved by using a hybrid resin composed of a polyester unit and a vinyl unit.
That is, the present invention relates to an electrostatic charge image developing toner and an image forming method, an image forming apparatus, and a process cartridge using the same as described below.

(1) In a core-shell structure type toner including at least a binder resin and a colorant and having a core material granulated with an aqueous medium and a shell material covering the core material, the shell material includes a polyester unit and A toner for developing electrostatic images, wherein a hybrid resin comprising a vinyl unit is used.
(2) A toner obtained through a granulation process by emulsifying or dispersing an oil phase containing at least a binder resin and / or a binder resin precursor and a colorant in an aqueous medium (1) The toner for developing an electrostatic image according to (1).
(3) The electrostatic image developing toner according to (1) or (2), wherein the binder resin contains a polyester resin having a glass transition temperature of 40 ° C. or higher and 80 ° C. or lower.
(4) The electrostatic image developing toner according to any one of (1) to (3), wherein the binder resin contains a modified polyester resin.
(5) The electrostatic image developing toner according to any one of (1) to (4), wherein the modified polyester resin has a urethane group and / or a urea group.
(6) The binder resin according to any one of (1) to (5), wherein the binder resin contains a resin obtained by reacting an amine with a polyester resin having an isocyanate group at a terminal. Toner for charge image development.
(7) A developer comprising the electrostatic image developing toner according to any one of (1) to (6).
(8) The developer according to (7), which is used in a non-magnetic one-component development method.
(9) A toner-containing container filled with the electrostatic image developing toner according to any one of (1) to (6).
(10) An electrostatic latent image carrier and an electrostatic latent image formed on the electrostatic latent image carrier are developed using the electrostatic image developing toner according to any one of (1) to (6). And at least developing means for forming a visible image.
(11) An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and any one of (1) to (6) Development means for forming a visible image by developing using the electrostatic image developing toner described in claim 1, transfer means for transferring the visible image to a recording medium, and fixing the transferred image transferred to the recording medium An image forming apparatus having at least a fixing unit.
(12) An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image for electrostatic image development according to any one of (1) to (6) At least a developing process for forming a visible image by developing with toner, a transferring process for transferring the visible image to a recording medium, and a fixing process for fixing the transferred image transferred to the recording medium. An image forming method.

  The toner of the present invention employs a core-shell structure type toner, a shell material is blended with a hybrid resin including a polyester (hereinafter also referred to as “Pes”) unit and a vinyl-based unit, and the shell material Pes skeleton and core As the Pes skeleton of the material is intertwined, the shell material is firmly bound to the core material, the contact area is increased, and the shell is made uniform. As a result, it is possible to form a good image having stable development characteristics through durability and without fogging while maintaining fixing.

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.

  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 a layered inorganic mineral, a release agent, a fluorine compound, and other suitable toner compositions. You may contain a thing.

In the present invention, the toner composition means what is finally contained in the toner.
Further, in the present invention, the toner composition precursor is a precursor of the toner composition and constitutes one of the toner compositions through polymerization and the like, specifically, a prepolymer, a monomer, and the like. Means.

  Conventionally, to achieve the core / shell structure, the surface of the core material is covered with a shell material. However, if the coating is not sufficient, cracks and chipping occur due to stress in the developing unit, etc. cause. Moreover, heat-resistant storage stability also deteriorates and causes process member contamination. In the present invention, the shell material Pes skeleton and the core material Pes skeleton are positively entangled and have a strong bond, whereby a toner having excellent stress resistance can be provided.

  The toner having the core-shell structure of the present invention is obtained by adding an aqueous dispersion in which resin fine particles constituting a shell material are dispersed to an aqueous dispersion of core particles, and attaching the resin fine particles to the core particles. It is preferable to form a shell material.

The Pes skeleton ratio of the shell material made of the hybrid resin in the present invention is preferably 5% to 50%. If it is less than 5%, the entanglement with the target core material is weak, and the shell material is detached during the manufacturing process or peeled during durability even if it is made into a shell, resulting in poor image quality and heat-resistant storage. On the other hand, if it is larger than 50%, the ratio of vinyl units having excellent charging performance is lowered, and the effect of improving background stains is diminished.

<About core-shell structure>
The toner for developing an electrostatic charge image having a core / shell structure according to the present invention is obtained by dissolving or dispersing at least a polyester resin, a colorant and a release agent in an organic solvent, and then dissolving the dispersion or dispersion in an aqueous medium. At least a step of granulating core particles and adding an aqueous dispersion in which fine particles of a hybrid resin containing a polyester unit and a vinyl unit are dispersed to coat the core particles with the fine particles. In the method for producing a toner for developing an electrostatic charge image, an organic solvent is removed from the core particle dispersion and the hybrid resin particles are added, or the hybrid resin particles are added to the core particle dispersion in the presence of an organic solvent. Can be manufactured. According to the present invention, an electrostatic charge image developing toner having both low-temperature fixability and heat-resistant storage stability, excellent offset resistance, control of the toner structure, and good charge amount without contaminating the developing device or the like. Is provided.

<Hybrid resin>
For the shell of the toner of the present invention, a resin in which a polyester unit and a vinyl unit are chemically bonded is used. The glass transition temperature (Tg) is preferably 40 ° C. or higher which can satisfy the heat-resistant storage stability. If it is higher than ℃, the low-temperature fixing performance of the toner cannot be secured.
In the present invention, the hybrid resin reacts with a raw material monomer for a polyester resin, a raw material monomer for a vinyl resin, and a raw material monomer for both resins (a raw material monomer for a polyester resin and a raw material monomer for a vinyl resin). Resins having both polyester units and vinyl units in the molecular skeleton obtained by using a mixture with other monomers and performing the condensation polymerization reaction and radical polymerization reaction in parallel in the same container are also preferably used. Is possible. In addition, the other monomer that reacts with the raw material monomers of both resins is a monomer that can be used in both the condensation polymerization reaction and the radical polymerization reaction. That is, it is a monomer having a carboxy group that can undergo a condensation polymerization reaction and a vinyl group that can undergo a radical polymerization reaction, and examples thereof include fumaric acid, maleic acid, acrylic acid, and methacrylic acid.
Examples of the raw material monomer for the polyester resin include the polyhydric alcohol component and the polyvalent carboxylic acid component described above.

  Examples of the raw material monomer for the vinyl unit include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, p-tert. -Styrene or styrene derivatives such as butylstyrene and p-chlorostyrene; Ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; Methyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n- methacrylate Butyl, isobutyl methacrylate, t-butyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, neopentyl methacrylate, 3- (methyl) butyl methacrylate hexyl methacrylate, octyl methacrylate, methacrylate Alkyl, methacrylic acid alkyl esters such as decyl methacrylate, undecyl methacrylate, dodecyl methacrylate; methyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate Acrylics such as n-pentyl acrylate, isopentyl acrylate, neopentyl acrylate, 3- (methyl) butyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, etc. Acid alkyl esters; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid; acrylonitrile, maleic acid ester, itaconic acid ester, vinyl chloride, vinyl acetate, vinyl benzoate, vinyl Examples include butyl ethyl ketone, vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether. A styrene acrylic resin is preferable as the resin constituting the vinyl unit.

  Examples of the polymerization initiator for polymerizing the raw material monomer of the radical polymerization unit (vinyl resin) include 2,2′-azobis (2,4-dimethylvaleronitrile) and 2,2′-azobisisobutyrate. Rononitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile and other azo or diazo polymerization initiators, benzoyl peroxide And peroxide polymerization initiators such as dicumyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate and lauroyl peroxide.

-Polyester resin-
Examples of the polyester resin used for the core in the present invention include the following polycondensates of polyol (1) and polycarboxylic acid (2), and any of them can be used, and several kinds of polyester resins are mixed. 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 is usually 1000-30000, preferably 1500-10000, more preferably 2000-8000. 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 for adjusting viscoelasticity. The content of the modified polyester resin having a urethane or / and urea group 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 a urethane or / and urea group may be directly mixed with a 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 “polyester resin”) And an amine that reacts with the binder resin is mixed with the binder resin, and during the granulation / after granulation, chain extension or / and cross-linking reaction is carried out to form the urethane or / and urea group. It is preferable to have a modified polyester resin. 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--
As polyisocyanate (3), aliphatic polyisocyanate (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanate (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; 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, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red , Fais red, parachlorol Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake , Thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazolone , Polyazo red, chrome vermillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, in Dunslen Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake Phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by 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)
The fluidizing agent that improves the fluidity of the toner is surface-treated to increase the hydrophobicity, thereby preventing deterioration of the fluidity 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.

  As a method of obtaining a dispersion in which fine particles of a hybrid resin are dispersed (hereinafter referred to as “hybrid resin fine particle dispersion”), a hybrid resin manufactured in advance is used, and the hybrid resin is in a fluid state by containing a solvent. In a water-based medium and finely dispersing oil droplets containing a hybrid resin, and then removing the solvent to obtain a hybrid resin fine particle dispersion, a radically polymerizable vinyl group-containing polyester resin Dissolve or disperse in the raw material monomer solution of the vinyl resin, put the obtained liquid into an aqueous medium and finely disperse, and then in a finely dispersed droplet by polymerizing the radical polymerizable monomer. And a method for producing a hybrid resin.

  Among these, the latter method is preferable because it can obtain fine resin particles having a small particle diameter and can be applied to a high molecular weight hybrid resin. In order to cause the polymerization reaction of the radical polymerizable monomer, it is preferable to generate a radical as a polymerization initiator, and a known polymerization initiator can be used. The polymerization initiator includes an oil-soluble polymerization initiator that dissolves in the raw material monomer solution of the vinyl resin, and a water-soluble polymerization initiator that dissolves in the aqueous medium. If the former, it is dissolved in the radical polymerizable monomer solution in advance. After that, it is dispersed and used to generate radicals by means such as heating to perform so-called suspension polymerization. In the latter case, it is added to an aqueous medium, and radicals are generated by means such as heating or redox reaction. And is preferably used for emulsion polymerization or miniemulsion polymerization. Both methods can be used in combination. Of these, the latter method is preferred because it facilitates molecular weight control.

<Toner production method>
The method for producing the toner of the present invention is exemplified below, but 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, it is obtained by adding a fine particle dispersion containing fine hybrid resin particles to form a shell layer and then removing the organic solvent.
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 for forming the organic resin fine particles, any resin that can form an aqueous dispersion can be used, and it may be a thermoplastic resin or a thermosetting resin. Includes vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate resin 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, when the resin fine particles are produced, 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.

(Distribution method)
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.

(Elongation 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 hybrid resin fine particle dispersion is charged and adhered onto the core particles. The introduction of the hybrid resin fine particle dispersion is preferably performed over 30 seconds. If the charging is performed in less than 30 seconds, it is not preferable because the dispersion system changes suddenly to generate agglomerated particles or non-uniform adhesion of the hybrid resin fine particles. 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 hybrid 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 hybrid resin fine particle dispersion is preferably 5 to 30% by mass, and more preferably 8 to 20% by mass. 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 hybrid resin fine particles becomes insufficient. On the other hand, when it exceeds 30% by mass, the hybrid resin fine particles are likely to be unevenly distributed in the core particle dispersion, and as a result, the adhesion of the hybrid resin fine particles becomes non-uniform and should be avoided.

  In the present invention, the hybrid resin fine particles adhere to the core particles with sufficient strength because when the hybrid resin fine particles adhere to the core particle droplets, the core particles can be freely deformed. The reason seems to be that the contact surface is sufficiently formed and that the hybrid resin fine particles are swollen or dissolved by the organic solvent, and the hybrid resin fine particles and the resin in the core particles are easily bonded. 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% by mass to 150% by mass, preferably 70% by mass with respect to the solid content (resin, colorant, and if necessary, release agent, charge control agent, etc.). It may be in the range of% to 125% by mass. If it exceeds 150% by mass, 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. .

  In the present invention, the hybrid resin fine particles are more firmly attached to the core particles because the polyester unit of the hybrid resin fine particles has high compatibility with the polyester resin of the core. This is probably because it does not come off easily when it comes into contact with the droplets, making it possible to adhere firmly.

  The temperature at which the hybrid resin fine particles adhere to the core particles is 10 to 60 ° C, preferably 20 to 45 ° C. When the temperature exceeds 60 ° C., the energy required for production increases and the production environmental load increases. In addition, low acid value hybrid resin fine particles may be present on the droplet surface, resulting in unstable dispersion and coarseness. This is not preferable because particles may be generated. On the other hand, when the temperature is less than 10 ° C., the viscosity of the dispersion becomes high, and the adhesion of the hybrid resin fine particles becomes insufficient.

[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. 1 shows an example of an 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. 1 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. 1 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.

The fixing device may be a soft roller type fixing device having a fluorine surface layer structure 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. 3 is a schematic diagram showing an example of a multicolor image forming apparatus to which the present invention is applied. FIG. 3 shows a tandem type full-color image forming apparatus.
In FIG. 3, the image forming apparatus houses a latent image carrier (1) that is driven to rotate in the clockwise direction in FIG. 3 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. 3, uniformly charges 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. 4 is a schematic view showing 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. 5, 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. 5, (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.

<Method for measuring physical properties>
(Particle size)
Next, a method for measuring the particle size distribution of toner particles will be described.
As an apparatus for measuring the particle size distribution of toner particles by the Coulter counter method, there are Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of 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 the 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 with an ultrasonic disperser for about 1 to 3 minutes, and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl. .

<Evaluation method>
(Stress resistance evaluation)
Using a Ricoh IPSiO CX2500, a predetermined print pattern having a B / W ratio of 6% was printed continuously in a monochrome mode in an H / H environment (27 ° C., 80%). At this time, the number that can be confirmed as fixed streaks on the regulating blade was confirmed. The judgment ○ or higher is a level where there is no problem in actual use.
◎: 0 pieces ○: Within 5 pieces △: 6-10 pieces ×: 11 pieces or more

(Dirt)
Using a Ricoh IPSiO CX2500, a predetermined print pattern having a B / W ratio of 6% was printed continuously in a monochrome mode in an N / N environment (23 ° C., 50%). As for the background stain on the photoconductor, a colorless transparent tape was applied to the uncleaned portion after development, the background toner on the photoconductor was peeled off, and the density after being applied to a white paper was visually evaluated. All of the evaluation criteria were performed in the following three stages.
〔Evaluation criteria〕
◎: Good ○: No problem in actual use ×: Unusable

(Heat resistant storage stability)
The toner was stored at 50 ° C. for 8 hours, and then sieved with a 42 mesh sieve for 2 minutes. The residual rate on the wire mesh was used as an index for heat resistant storage stability. The heat resistant storage stability was evaluated in the following four stages.
◎: Less than 10% ○: Less than 10-20% △: Less than 20-30% ×: 30% or more

(Fixability)
Toner was put in the modified IPSiO SP C220, and 19 sheets of 50 mm square unfixed solid images were printed on Ricoh's My Recycled Paper 100T eye paper with an adhesion amount set to 11 g / m ² . .
Next, using the modified fixing unit, the system speed was set to 180 mm / sec, and the prepared unfixed solid image was passed through to fix the image. The fixing temperature was tested from 120 ° C to 200 ° C in 10 ° C increments. The fixed image was folded inward, spread again, and then lightly rubbed with an eraser. The lowest temperature at which the crease did not disappear was defined as the minimum fixing temperature.
〔Evaluation criteria〕
A: Fixing lower limit temperature is less than 130 ° C.
○: Fixing lower limit temperature is 130 ° C. or higher and lower than 140 ° C.
Δ: Minimum fixing temperature is 140 ° C. or higher and lower than 150 ° C.
×: Fixing lower limit temperature is 150 ° C. or higher

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. “Parts” means all parts by mass.

<Synthesis of polyester 1>
In a reaction vessel equipped with a condenser and a nitrogen introducing tube, 320 parts of neopentyl glycol, 362 parts of ethylene glycol, 372 parts of dimethyl terephthalate, 372 parts of dimethyl isophthalate, 40 parts of dimethyl fumarate, dimethyl isophthalate 5- 34 parts of sodium sulfonate and 0.5 part of dibutyltin oxide were charged and reacted at 170 ° C. for 5 hours under normal pressure.
Next, it was made to react at 220 degreeC under pressure reduction of 10-15 mmHg for 5 hours, and [Polyester 1] was synthesize | combined. The obtained [Polyester 1] had a number average molecular weight of 2400, a weight average molecular weight of 5800, and a glass transition temperature of 52 ° C.
[Polyester 1] was used as a raw material component for obtaining a hybrid resin.

[Method for producing resin dispersion 1]
In 529 parts of ion-exchanged water, 0.7 part of sodium dodecyl sulfate was added and heated to 70 ° C. for dissolution to obtain an aqueous medium. Separately, 133 parts of styrene monomer, 7 parts of butyl acrylate, 60 parts of [Polyester 1] and 2.7 parts of n-octanethiol were stirred while heating to 70 ° C. in a nitrogen atmosphere to obtain a uniform monomer solution.
The obtained monomer solution was put into an aqueous medium, and ultrasonic irradiation was performed at 90 to 110 W for 10 minutes using an ultrasonic homogenizer VCX750 in a nitrogen atmosphere while maintaining the temperature at 70 ° C. to disperse the monomer solution in the aqueous medium. It was. In the middle, the liquid temperature increased by ultrasonic irradiation, but was adjusted to 65 to 75 ° C. with a water bath or the like. The obtained dispersion was transferred into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, maintained at 70 ° C. with stirring, and 1.8 parts of potassium persulfate was dissolved in 72 parts of ion-exchanged water. The polymerization reaction was carried out for 180 minutes.
Then, it cooled and the white [resin dispersion liquid 1] with a volume average particle diameter of 156 nm was obtained. The obtained dispersion was placed in a 2 ml petri dish and the dried solid obtained by evaporating the dispersion medium was measured. The number average molecular weight was 14,800, the weight average molecular weight was 32900, and Tg was 69 ° C.
Moreover, it was St: Pes = 70: 30.

[Production Method of Resin Dispersion Liquid 2]
In 550 parts of ion-exchanged water, 0.8 part of sodium dodecyl sulfate was added and heated to 70 ° C. for dissolution to obtain an aqueous medium. Separately, 95 parts of styrene monomer, 5 parts of butyl acrylate, 100 parts of [Polyester 1], and 2.8 parts of n-octanethiol were stirred while heating to 70 ° C. in a nitrogen atmosphere to obtain a uniform monomer solution.
The obtained monomer solution was put into an aqueous medium, and ultrasonic irradiation was performed at 90 to 110 W for 10 minutes using an ultrasonic homogenizer VCX750 in a nitrogen atmosphere while maintaining the temperature at 70 ° C. to disperse the monomer solution in the aqueous medium. It was. In the middle, the liquid temperature increased by ultrasonic irradiation, but was adjusted to 65 to 75 ° C. with a water bath or the like. The obtained dispersion was transferred into a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, maintained at 70 ° C. with stirring, and 1.3 parts of potassium persulfate was dissolved in 51 parts of ion-exchanged water. The polymerization reaction was carried out for 180 minutes.
Then, it cooled and the white [resin dispersion 2] with a volume average particle diameter of 138 nm was obtained. The obtained dispersion was placed in a 2 ml petri dish and the dried solid obtained by evaporating the dispersion medium was measured. The number average molecular weight was 13,900, the weight average molecular weight was 33,000, and Tg was 65 ° C.
Moreover, it was St: Pes = 50: 50.

[Production Method of Resin Dispersion Liquid 3]
In 511 parts of ion-exchanged water, 0.7 part of sodium dodecyl sulfate was added and dissolved by heating to 70 ° C. to obtain an aqueous medium. Separately, 171 parts of styrene monomer, 9 parts of butyl acrylate, 20 parts of [Polyester 1] and 2 parts of n-octanethiol were stirred while heating to 70 ° C. in a nitrogen atmosphere to obtain a uniform monomer solution.
The obtained monomer solution was put into an aqueous medium, and ultrasonic irradiation was performed at 90 to 110 W for 10 minutes using an ultrasonic homogenizer VCX750 in a nitrogen atmosphere while maintaining the temperature at 70 ° C. to disperse the monomer solution in the aqueous medium. It was. In the middle, the liquid temperature increased by ultrasonic irradiation, but was adjusted to 65 to 75 ° C. with a water bath or the like. The obtained dispersion was transferred into a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, maintained at 70 ° C. with stirring, and 2.3 parts of potassium persulfate was dissolved in 93 parts of ion-exchanged water. The polymerization reaction was carried out for 180 minutes.
Then, it cooled and the white [resin dispersion 3] with a volume average particle diameter of 157 nm was obtained. The obtained dispersion was placed in a 2 ml petri dish and the dried solid obtained by evaporating the dispersion medium was measured. The number average molecular weight was 15,100, the weight average molecular weight was 32300, and Tg was 74 ° C.
Moreover, it was St: Pes = 90: 10.

[Production Method of Resin Dispersion Liquid 4]
Put 1.2 parts of sodium dodecyl sulfate and 492 parts of ion-exchanged water in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, heat to 80 ° C, and then ion-exchange 2.5 parts of potassium persulfate. What was dissolved in 100 parts of water was added, and 15 minutes later, a mixture of 150 parts of styrene monomer, 30 parts of butyl acrylate, 20 parts of methacrylic acid and 3 parts of n-octyl mercaptan was added dropwise over 90 minutes, and then another 60 minutes. Maintained at 80 ° C. Thereafter, the mixture was cooled to obtain [resin dispersion 4]. The average particle size of the fine particles was 80 nm. The dispersion was taken in a small petri dish, and the solid obtained by evaporating the dispersion medium was measured. The number average molecular weight was 14,000, the weight average molecular weight was 29000, and Tg was 69 ° C.

<Manufacture of hybrid resin>
[Resin dispersion 2] obtained in the same manner as in the production method of [Resin dispersion 2] is dried, and the resulting solidified product is arbitrarily crushed with an Auster mixer to obtain powdered [Hybrid resin 1]. Obtained.

<Synthesis of polyester 2>
In a reaction vessel equipped with a condenser, stirrer and nitrogen inlet tube, 553 parts of bisphenol A ethylene oxide 2-mole adduct, 196 parts of bisphenol A propylene oxide 2-mole adduct, 220 parts terephthalic acid, 45 parts adipic acid and dibutyl Add 2 parts of tin oxide, react for 8 hours at 230 ° C. under normal pressure, and react for 5 hours under reduced pressure of 10-15 mmHg, then add 46 parts of trimellitic anhydride to the reaction vessel, and add 2 parts at 180 ° C. under normal pressure. Reaction was performed for a time to obtain [Polyester 2]. [Polyester 2] had a number average molecular weight of 2200, a weight average molecular weight of 5600, a Tg of 43 ° C., and an acid value of 13 mgKOH / g.

<Synthesis of polyester 3>
In a reaction vessel equipped with a cooling tube stirrer and a nitrogen introduction tube, 218 parts of bisphenol A ethylene oxide 2-mole adduct, 460 parts of bisphenol A propylene oxide 2-mole adduct, 140 parts of terephthalic acid, 145 parts of isophthalic acid, and dibutyltin 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 18 mmHg for 6 hours, 24 parts of trimellitic anhydride is added to the reaction vessel and reacted at 180 ° C. for 2 hours under normal pressure to synthesize [Polyester 3]. did. [Polyester 3] obtained had a number average molecular weight of 7,600, a weight average molecular weight of 21,000, a glass transition temperature of 57 ° C., and an acid value of 15 mgKOH / g.

<Synthesis of prepolymer>
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride Then, 2 parts of dibutyltin oxide was added, reacted at 230 ° C. under normal pressure for 8 hours, and further reacted at reduced pressure of 10-15 mmHg for 5 hours to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 49 mgKOH / g.
Next, 411 parts of [Intermediate polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and reacted at 100 ° C. for 5 hours. Polymer 1] was obtained. [Prepolymer 1] had a free isocyanate mass% of 1.53%.

<Synthesis of master batch>
Carbon black (Regal 400R manufactured by Cabot Corporation): 40 parts, Binder resin: Polyester resin (Sanyo Kasei RS-801, acid value 10 mg KOH / g, Mw 20000, 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 mmφ with a pulverizer to obtain [Masterbatch 1].

Example 1
<Preparation of aqueous phase>
963 parts of ion-exchanged water, 88 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) for dispersion stabilization, dodecyl diphenyl ether 80 parts of a 48.5% aqueous solution of sodium disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries) and 113 parts of ethyl acetate were mixed and stirred to obtain a milky white liquid. This is designated as [Aqueous Phase 1].

<Preparation of pigment / WAX dispersion (oil phase)>
In a container equipped with a stir bar and a thermometer, 545 parts of [Polyester 2], 181 parts of paraffin wax (HNP9) and 1450 parts of ethyl acetate were charged, heated to 80 ° C. with stirring, and maintained at 80 ° C. for 5 hours. Thereafter, it was 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] 1500 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), liquid feeding speed is 1 kg / hr, disk peripheral speed is 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. Carbon black and WAX were dispersed under conditions of filling and 3 passes. Next, 655 parts of a 65% ethyl acetate solution of [Polyester 2] was 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%.

<Emulsification process>
[Pigment / WAX Dispersion 1] To 967 parts, 6 parts of isophoronediamine as amines and TK homomixer (manufactured by Tokushu Kika) are mixed for 1 minute at 5,000 rpm, and then 137 parts of [Prepolymer 1] are added to TK. After mixing for 1 minute at 5,000 rpm with a homomixer (made by Tokushu Kika), add 1200 parts of [Aqueous Phase 1], and adjust for 20 minutes with a TK homomixer at a rotational speed of 8,000 to 13,000 rpm. By mixing, [Emulsified slurry 1] was obtained.

<Shell material adhesion process>
[Emulsified slurry 1] 20 parts of [resin dispersion 1] was added to a container containing 100 parts of a stirrer and a thermometer, and mixed and stirred for 10 minutes. The temperature was raised to 60 ° C., and further for 60 minutes. The mixture was stirred to obtain [Composite Particle Slurry 1].

<Desolvent>
[Emulsion slurry 2] was put into a container equipped with a stirrer and a thermometer, and the solvent was removed at 30 ° C. for 8 hours to obtain [Dispersion 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 μC / cm or less.
(3): 10% hydrochloric acid was added so that the pH of the reslurry liquid of (2) was 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 μC / cm or less to obtain [Filter Cake 1].

  [Filtration cake 1] was dried at 45 ° C. for 48 hours in a circulating drier and sieved with a mesh of 75 μm to obtain [Toner base 1]. The volume average particle diameter (Dv) was 7.1 μm, the number average particle diameter (Dp) was 6.3 μm, Dv / Dp was 1.13, and the average circularity was 0.978. Subsequently, 100 parts of the base toner was mixed with 1.0 part of hydrophobic silica using a Henschel mixer to obtain [Developer 1] of the present invention.

(Example 2, Example 3)
A developer of Example 2 was obtained in the same manner as in Example 1 except that [Resin Dispersion 1] in the shell material adhesion step was changed to [Resin Dispersion 2]. Further, a developer of Example 3 was obtained in the same manner as in Example 1 except that [resin dispersion 1] in the shell material adhesion step was changed to [resin dispersion 3].

Example 4
<Preparation of aqueous phase>
970 parts of ion-exchanged water, 29 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) for dispersion stabilization, dodecyl diphenyl ether When 95 parts of a 48.5% aqueous solution of sodium disulfonate and 98 parts of ethyl acetate were mixed and stirred, the pH was 6.2. A 10% aqueous sodium hydroxide solution was added dropwise thereto to adjust the pH to 9.1 to obtain [Aqueous Phase 2].

<Preparation of pigment / WAX dispersion (oil phase)>
A container equipped with a stir bar and a thermometer was charged with 175 parts of [Polyester 2], 430 parts of [Polyester 3], 153 parts of [Paraffin wax (HNP9)] and 1450 parts of ethyl acetate, and the temperature was raised to 80 ° C. with stirring. The sample was kept at 80 ° C. for 5 hours and then cooled to 30 ° C. in 1 hour. Next, 410 parts of [Masterbatch 1] and 100 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Material solution 2].
[Raw material solution 2] 1500 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by IMEX), liquid feeding speed is 1 kg / hr, disk peripheral speed is 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. The pigment and WAX were dispersed under the conditions of filling and 3 passes. Next, 470 parts of a 70% ethyl acetate solution of [Polyester 2], 250 parts of a 55% ethyl acetate solution of [Polyester 3], and 95 parts of ethyl acetate were added, followed by one pass with a bead mill under the above conditions, [Pigment / WAX dispersion liquid] 2] was obtained. The solid content of the obtained [Pigment / WAX Dispersion 2] was measured to be 49.3% by mass, and the amount of ethyl acetate based on the solid content was 103% by mass.

<Emulsification process>
[Pigment / WAX Dispersion 2], 976 parts, was mixed for 1 minute at 5,000 rpm with a TK homomixer (made by Tokushu Kika), and then added at 5,000 rpm with a TK homomixer (made by Tokushu Kika). After mixing for 1 minute, 1200 parts of [Aqueous phase 2] was added and mixed for 2 minutes while adjusting at 8,000 to 15,000 rpm with a TK homomixer to obtain [Emulsion slurry 2].

<Shell material adhesion process>
[Emulsified slurry 2] 20 parts of [resin dispersion 1] was added to a container containing 100 parts of a stirrer and a thermometer, mixed and stirred for 10 minutes, the temperature was raised to 60 ° C., and another 60 minutes The mixture was stirred to obtain [Composite Particle Slurry 2].

<Desolvation and washing ⇒ Drying>
A developer of Example 4 was obtained in the same manner except that [Composite Particle Slurry 1] in Example 1 was changed to [Composite Particle Slurry 2].

(Comparative Example 1 and Comparative Example 2)
A developer of Comparative Example 1 was obtained in the same manner as in Example 1 except that the shell material attaching step of Example 1 was omitted.
Further, a developer of Comparative Example 2 was obtained in the same manner as in Example 1 except that [Resin Dispersion 1] in the shell material adhering step was changed to [Resin Dispersion 4].

(Comparative Example 3)
<Preparation of pigment / WAX dispersion (oil phase)>
In a container equipped with a stir bar and a thermometer, 545 parts of [Polyester 2], 181 parts of paraffin wax (HNP9) and 1450 parts of ethyl acetate were charged, heated to 80 ° C. with stirring, and maintained at 80 ° C. for 5 hours. Thereafter, it was 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] 1500 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), liquid feeding speed is 1 kg / hr, disk peripheral speed is 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. Carbon black and WAX were dispersed under conditions of filling and 3 passes. Next, 550 parts of a 60% ethyl acetate solution of [Polyester 2] and 105 g of [Hybrid resin 1] were added, and one pass was performed with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion 3]. Ethyl acetate was added to adjust the solid content concentration of [Pigment / WAX Dispersion 3] (130 ° C., 30 minutes) to 50%.
<After emulsification process>
[Pigment / WAX Dispersion 1] was changed to [Pigment / WAX Dispersion 3], and [Resin Dispersion 1] in the shell material adhering step was changed to [Resin Dispersion 4]. The developer of Comparative Example 3 was obtained.

(Comparative Example 4)
<Preparation of pigment / WAX dispersion (oil phase)>
A container equipped with a stir bar and thermometer was charged with 545 parts of [Hybrid resin 1], 181 parts of paraffin wax (HNP9), and 1450 parts of ethyl acetate, heated to 80 ° C. with stirring, and 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 3].
[Raw material solution 3] 1500 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. Carbon black and WAX were dispersed under conditions of filling and 3 passes. Next, 655 parts of a 65% ethyl acetate solution of [Hybrid resin 1] was added, and one pass was performed with a bead mill under the above conditions to obtain [Pigment / WAX dispersion 4]. Ethyl acetate was added and adjusted so that the solid content concentration of [Pigment / WAX Dispersion 4] (130 ° C., 30 minutes) was 50%.
<After emulsification process>
[Pigment / WAX Dispersion 1] was changed to [Pigment / WAX Dispersion 4], and [Resin Dispersion 1] in the shell material adhesion step was changed to [Resin Dispersion 4]. The developer of Comparative Example 4 was obtained.

  According to the above evaluation results, the toners of the examples which are the toners of the present invention have obtained very good results in the entire electrophotographic process. However, the toners of Comparative Examples 1 to 4 did not give satisfactory results in terms of background stains, fixability, and image quality.

  The core-shell structure type toner of the present invention has a stable development characteristic over a long period of time while maintaining fixing since the shell material is firmly bound to the core material and the shell is uniformized. Since a good image without fogging can be formed, it is suitable as a method for producing toner for electrophotography used in copying machines, printers, fax machines, and composite machines based on the electrophotographic recording method.

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-A-9-179336 JP 2007-71965 A JP 2007-93809 A

Claims (12)

In a core-shell structure type toner comprising at least a binder resin and a colorant and having a core material granulated with an aqueous medium and a shell material covering the core material, the shell material includes a polyester unit and a vinyl unit. A toner for developing an electrostatic charge image, which comprises using a hybrid resin. The toner obtained through a step of granulating by emulsifying or dispersing an oil phase containing at least a binder resin and / or a binder resin precursor and a colorant in an aqueous medium. Toner for developing electrostatic images.   The electrostatic image developing toner according to claim 1, wherein the binder resin contains a polyester resin having a glass transition temperature of 40 ° C. or higher and 80 ° C. or lower.   The electrostatic image developing toner according to claim 1, wherein the binder resin contains a modified polyester resin.   The electrostatic image developing toner according to claim 1, wherein the modified polyester resin has a urethane group and / or a urea group.   6. The electrostatic image developing toner according to claim 1, wherein the binder resin contains a resin obtained by reacting an amine group with a polyester resin having an isocyanate group at a terminal. .   A developer comprising the electrostatic image developing toner according to claim 1.   The developer according to claim 7, wherein the developer is used in a nonmagnetic one-component development method.   A toner-containing container filled with the electrostatic image developing toner according to claim 1.   An electrostatic latent image carrier and an electrostatic latent image formed on the electrostatic latent image carrier are developed using the electrostatic image developing toner according to claim 1 to produce a visible image. A process cartridge having at least developing means to be formed.   An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image according to any one of claims 1 to 6. Developing means for developing a visible image by developing with toner for developing a charge image, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium An image forming apparatus comprising at least the image forming apparatus.   An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image using the electrostatic image developing toner according to any one of claims 1 to 6. And forming a visible image, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium. Method.

Images