JP2006055781A - Emulsifier, emulsion composition, capsulated toner composition, image forming method, process cartridge and electrograph device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an emulsion composition having a small diameter and uniform emulsion particles and to provide a capsulated toner composition having a small diameter and an excellent stability of electricity. <P>SOLUTION: The emulsion composition has a polymer obtained by emulsion for polymerizing a polymeric unsaturated monomer in the presence of an emulsifier containing a block polymer having a hydrophilic block segment, a main chain structure of which is a polyalkenyl ether structure, and a hydrophobic block segment. The capsulated toner composition has the emulsion composition and a pigment which is coated with the emulsion composition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an emulsifier for emulsion polymerization, an emulsion composition, a microencapsulated toner composition, an image forming method, a process cartridge, and an electrophotographic apparatus.

  To disperse another liquid that does not dissolve in a predetermined liquid as fine particles, a predetermined emulsifier is conventionally added to the system in order to obtain a stable emulsion. Such an emulsifier is generally recognized as a so-called surface-active substance having a structure containing both a hydrophilic group and a hydrophobic group in the molecule, and is used as a detergent, a dyeing assistant, and a dispersant for disperse dyes. In addition to industrial uses such as deinking agents, water-repellent softeners, agricultural chemicals, precipitating flocculants and photosensitive emulsions, they have been widely used in pharmaceutical emulsified preparations and the like.

  The emulsifiers used for these various applications are generally appropriately selected from surfactants, such as alkali soaps, organic amine soaps, higher alcohol sulfate nonionic surfactants, proteins, vegetable gums, alginates. , Low molecular surfactants such as carboxymethyl cellulose, fatty acid monoglycerides, sorbitan fatty acid esters, and fatty acid esters of sucrose.

  One industrial application of such emulsifiers is in emulsion polymerization. Specifically, when the unsaturated monomer insoluble in water is polymerized, the above-mentioned emulsifier and the like are used to uniformly disperse the unsaturated monomer in water and to polymerize using a water-soluble polymerization catalyst. Even after polymerization, the resulting polymer is obtained as an emulsion composition dispersed in water, and is usually used as such an emulsion composition or by washing with an aqueous solution.

However, in addition to these low molecular weight emulsifiers themselves becoming impurities in the resulting polymer, the molecular weight of the resulting polymer is much larger than the molecular weight of the emulsifier, and there is affinity or compatibility between them. There is almost no. Therefore, when the emulsion composition formed with the low molecular weight emulsifier is used in various applications, the physical properties may be adversely affected by the presence of the emulsifier. For example, emulsion polymerization toners (see Patent Documents 1 and 2 and Non-Patent Document 1) are increasingly used as electrophotographic developers for the purpose of improving image quality. In some cases, it may not be possible to obtain a uniform small particle size due to problems such as emulsion particle stability and problems such as emulsion particle stability, and further improvements to toner charging stability, small particle size and uniform particle size Is required.
JP-A-7-146585 JP 7-261453 A “Fuji Xerox Technical Report” No. 14, 2002

  The present invention is a block polymer having a polyalkenyl ether structure as a main chain structure, and by carrying out emulsion polymerization using an emulsifier having at least both a hydrophilic block segment and a hydrophobic block segment, a small particle size and uniform An emulsion composition containing emulsion particles is provided.

The present invention also provides an encapsulated toner composition having a small particle size and excellent charge stability using the emulsion composition.
The present invention also provides an image forming method and an electrophotographic apparatus that can stably obtain a high image density and a high-definition image quality by using the encapsulated toner composition.

As a result of intensive studies on the background art and problems, the present inventors have completed the present invention shown below.
The first of the present invention is an emulsifier characterized by containing a block polymer having a hydrophilic block segment having a polyalkenyl ether structure as a main chain structure and a hydrophobic block segment.

The second of the present invention is an emulsion composition characterized by containing a polymer obtained by emulsion polymerization of a polymerizable unsaturated monomer in the presence of the emulsifier.
A third aspect of the present invention is an encapsulated toner composition comprising the emulsion composition and a pigment, wherein the pigment is coated with the emulsion composition.

  And a step of obtaining an encapsulated toner precursor in which the emulsion composition is adsorbed on the surface of toner base particles, and a step of heating the encapsulated toner precursor to a temperature equal to or higher than a glass transition temperature of an emulsifier contained in the emulsion composition. It is a manufacturing method of the encapsulated toner composition characterized by having.

  According to a fourth aspect of the present invention, a charging step of charging the latent image carrier by applying a voltage to the charging member from the outside, a step of forming a charge image on the charged latent image carrier, and charging the charge image to the latent image carrier. A developing process for developing a toner image on an electrostatic latent image carrier by developing with an image developing toner, a transfer process for transferring the toner image on the latent image carrier to a recording material, and a toner image on the recording material. An image forming method comprising at least the encapsulated toner composition according to claim 4, wherein the image forming method includes at least a fixing step of heat fixing.

  A fifth aspect of the present invention is an electrophotographic photosensitive member, a charging means for charging the electrophotographic photosensitive member, an exposure means for exposing the charged electrophotographic photosensitive member to form a latent image, and an electrophotographic image having a latent image formed thereon. A developing means for developing the photoreceptor with the encapsulated toner composition according to claim 4 and a cleaning means for recovering the toner according to claim 4 remaining on the electrophotographic photoreceptor after the transfer step. A process cartridge which is integrally supported with at least one means and is detachable from an electrophotographic apparatus main body.

  The sixth aspect of the present invention is an electrophotographic photosensitive member, a charging means for charging the electrophotographic photosensitive member, an exposure means for exposing the charged electrophotographic photosensitive member to form a latent image, and an electrophotographic image having a latent image formed thereon. An electrophotographic apparatus comprising: a developing unit that develops the encapsulated toner composition according to claim 4 on a photoconductor; and a transfer unit that transfers a toner image on the electrophotographic photoconductor onto a transfer material.

  The present invention is a block polymer having a polyalkenyl ether structure as a main chain structure, and by carrying out emulsion polymerization using an emulsifier having at least both a hydrophilic block segment and a hydrophobic block segment, a small particle size and uniform An emulsion composition containing emulsion particles can be provided.

In addition, the present invention can provide an encapsulated toner composition having a small particle size and excellent charge stability using the emulsion composition.
In addition, the present invention can provide an image forming method and an electrophotographic apparatus that can stably obtain a high image density and a high-definition image quality by using the encapsulated toner composition.

Hereinafter, the present invention will be described in detail.
The first of the present invention is a block polymer having a polyalkenyl ether structure as a main chain structure, and is an emulsifier for emulsion polymerization characterized by having at least both a hydrophilic block segment and a hydrophobic block segment. The number of block segments to be formed is preferably 3 or more.

  In the present invention, the hydrophobic block segment means a block segment that does not harmonize with water molecules, and the hydrophilic block segment means a block segment that harmonizes with water molecules. The side chain of the hydrophobic segment preferably contains an aromatic ring such as a phenyl group, a methylphenyl group, or a biphenyl group. Examples of the hydrophilic segment include an alkylene oxide chain, a carboxylic acid group, a hydroxyl group, and a carboxylate.

  Specific examples of the repeating unit of a block segment having a specific hydrophobic block include the following structures, but the present invention is not limited to these structures.

(R represents a hydrogen atom or an alkyl group.)
Specific examples of the repeating unit of the block segment having a specific hydrophilic block include the following structures, but the present invention is not limited to these structures.

(R represents a hydrogen atom or an alkyl group.)
In addition, the block polymer in this invention means the polymer compound comprised by the block segment which has a 2 or more different structure.

  The most preferred structure of the block polymer used in the present invention has 3 or more block segments, has an aromatic hydrocarbon as a side chain of the hydrophobic segment, and an alkylene oxide as a side chain of the hydrophilic segment. A structure having a chain, a carboxylic acid or a carboxylate. In addition, when it has carboxylate as a substituent, it will have a counter cation. The counter cation used in the present invention is not a problem as long as it can form a charge pair with a carboxylate anion, and specific examples include lithium ion, sodium ion, potassium ion, calcium ion, and rubidium ion.

  Next, a living polymerization method of a block polymer containing a polyalkenyl ether structure that is preferably produced in the present invention will be described. A number of methods for synthesizing polymers containing a polyvinyl ether structure have been reported (for example, JP-A-11-080221), but the method by Aoshima et al. (Polymer Bulletin, 15, 417-423 (1986), JP-A-11-322294. Japanese Patent Laid-Open No. 11-322866) is representative. By synthesizing high molecular compounds by the method of Aoshima et al., The length (molecular weight) of various polymers such as homopolymers, copolymers composed of two or more monomers, block polymers, and graft polymers can be accurately measured. It can be synthesized to match.

The second of the present invention is an emulsion composition obtained by emulsion polymerization of monomers in the presence of the emulsifier.
Monomers used in the present invention include acrylic acid, methacrylic acid esters, styrene, fatty acid vinyl esters, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, 2-carboxyethyl acrylate (βCEA), and the like. However, the present invention is not limited to these.

  As a general emulsification method, it is desirable to stir the monomers in an aqueous solution in the presence of an emulsifier. In the present invention, the emulsion composition is prepared by vigorously stirring the monomers in the presence of the emulsifier in an organic solvent, and preferably 1 part by weight or more of water with respect to 10 parts by weight of the organic solvent. Alternatively, a manufacturing method in which an aqueous solution is added to perform strong stirring, or a method in which the monomers are dispersed in water or an aqueous solution in the absence of the emulsifier, and then the emulsifier dissolved in a small amount of an organic solvent is added, followed by further strong stirring. Is preferred. The strong stirring in the present invention means that stirring is performed at a peripheral speed of 15 m / second or more, preferably 60 m / second or more using a colloid mill or a homogenizer. However, if stirring is continued for a sufficiently long time, the stirring speed may be 15 m / sec or less.

  Specific examples of the organic solvent used in the present invention include methanol, ethanol, n-propanol, diethyl ether, tetrahydrofuran, dioxane, toluene, xylene and the like, but the present invention is not limited thereto. Water may be dissolved in an organic solvent or dispersed or emulsified. The organic solvent used for the emulsification may be removed by distillation under reduced pressure, dialysis, ultrafiltration or the like.

Emulsification is generally performed at a temperature of about 5 to about 40 ° C., but emulsions are formed at higher temperatures.
Furthermore, it is desirable to add a chain transfer agent to the monomer emulsion in order to adjust the molecular weight of the polymer produced. Specific examples of the chain transfer agent include dodecanethiol, butanethiol, isooctyl 3-mercaptopropionate (IOMP), 2-methyl-5-tert-butylthiophenol, carbon tetrachloride, carbon tetrabromide and the like. However, the chain transfer agent used in the present invention is not limited thereto. The chain transfer agent is used in an effective amount, for example from about 0.1 to about 10% by weight of the monomer in the monomer emulsion. This monomer emulsion is used to produce an emulsion polymer.

  Specific examples of the initiator used in the emulsion production process of the present invention include ammonium persulfate, potassium persulfate, sodium persulfate, ammonium persulfite, potassium persulfite, sodium persulfite, ammonium bisulfate, sodium bisulfate, 1,1. Examples include, but are not limited to, '-azobis (sodium 1-methylbutyronitrile-3-sulfonate), 4,4'-azobis (4-cyanovaleric acid), and the like. Desirable initiators are persulfate initiators such as ammonium persulfate, potassium persulfate, sodium persulfate and the like.

  The initiator is usually added as an aqueous solution. The amount of initiator used to form the emulsion polymer is typically about 0.1 to about 10 weight percent of the monomer to be polymerized. 5-100% by weight, preferably 30-100% by weight, of the total amount of initiator used to prepare the emulsion polymer is added in the seed polymerization stage.

In the production of the seed polymer, emulsion polymerization is usually performed at a temperature of about 35 to about 125 ° C.
Initiators are generally added to the emulsion very slowly to maintain system stability. For example, the initiator is preferably added over 5 minutes, more preferably over 10 minutes. Next, the monomer is added to the seed polymer to complete the polymerization. This emulsion polymerization is usually carried out at a temperature of about 35 to about 125 ° C. The additional monomer is generally added to the composition over an effective time, for example 0.5 to 10 hours, desirably 2 to 6 hours. The additional monomer may be in the form of a monomer emulsion. That is, this monomer is the remainder of the monomer emulsion that was partially used to produce the seed polymer. Furthermore, an additional initiator may be added after the seed polymerization. If an initiator is added during this reaction stage, the initiator may or may not be the same type used to produce the seed polymer. In either case, however, the initiator is desirably a free radical initiator.

  Initiators useful in this step include hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, p-methane hydroperoxide, benzoyl peroxide, tert-butyl peroxide, cumyl peroxide, in addition to the initiators described above. 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis Isobutylamide dihydrate, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (5-methyl-2-imidazoline-2) -Yl) propane] dihydrochloride and the like, but are not limited thereto.

  Specific examples of the emulsion polymer produced by the production method of the present invention include a styrene-butadiene copolymer, a methyl methacrylate-butadiene copolymer, an ethyl methacrylate-butadiene copolymer, a propyl methacrylate-butadiene copolymer, Butyl methacrylate-butadiene copolymer, methyl acrylate-butadiene copolymer, ethyl acrylate-butadiene copolymer, propyl acrylate-butadiene copolymer, butyl acrylate-butadiene copolymer, styrene-isoprene copolymer Polymer, methylstyrene-isoprene copolymer, methyl methacrylate-isoprene copolymer, ethyl methacrylate-isoprene copolymer, propyl methacrylate-isoprene copolymer, butyl methacrylate-isoprene copolymer, methyl acrylate- Isoprene Polymer, ethyl acrylate-isoprene copolymer, propyl acrylate-isoprene copolymer, butyl acrylate-isoprene copolymer, styrene-butyl acrylate copolymer, styrene-butyl methacrylate copolymer, styrene-acrylic Acid butyl-acrylic acid copolymer, styrene-butadiene-acrylic acid copolymer, styrene-isoprene-acrylic acid copolymer, styrene-butyl methacrylate-acrylic acid copolymer, butyl methacrylate-butyl acrylate copolymer Examples of the polymers include known polymers such as a polymer, a butyl methacrylate-acrylic acid copolymer, a styrene-butyl acrylate-acrylonitrile-acrylic acid copolymer, and an acrylonitrile-butyl acrylate-acrylic acid copolymer. It is not limited.

  The emulsion composition contains at least an emulsion polymer, an emulsifier, and water. The content of the emulsion polymer is 1 to 99% by mass, preferably 10 to 90% by mass, and the content of the emulsifier is 1 to 99% by mass, preferably 10 to 90% by mass.

  A third aspect of the present invention is an encapsulated toner composition, wherein a pigment is coated with the emulsion composition, and the emulsion composition is adsorbed on the surface of toner base particles as a polymer coating layer. An encapsulated toner obtained by heating the encapsulated toner precursor above the glass transition temperature of the emulsifier is contained.

  The method for producing the encapsulated toner composition in the present invention includes a composition containing a colorant, preferably a colorant dispersion, and more preferably a pigment such as carbon black, phthalocyanine, quinacridone, or rhodamin B®. Mixing the emulsion composition with the flocculant and / or charge additive, if necessary, and the resulting mixture at a temperature below the glass transition point of the emulsifier, preferably about Tg of the emulsifier. The toner is formed by heating at a temperature of 25 to about 1 ° C. to form toner-sized agglomerates, heating at the Tg of the emulsion polymer or higher to coalesce or coalesce to obtain toner particles, filtration and the like. The product is removed and then the toner particles are washed as necessary, followed by oven, fluid bed dryer, freeze dryer Preferably contains a step of drying or spray dryer, but the present invention is not limited to this method.

  The average particle size / dispersity index of the emulsion composition suitable for the production method of the present invention is the value measured using dynamic light scattering (DLS) under the conditions of a polymer concentration of 20% by mass and 0.01% by mass. However, other measurement methods, specifically, laser diffraction method, laser Doppler method, centrifugal sedimentation method, field-flow fractionation method, electrical detector method, etc. It only has to be corrected to the value measured in.

  The average particle size of the emulsion polymer in the emulsion composition is 10 to 500 nm, preferably 20 to 300 nm. Further, the dispersity index is 0.05 to 0.30, preferably 0.08 to 0.20.

  Examples of the colorant used in the present invention include pigments, dyes, and mixtures of pigments and dyes. A toner composition in which a color material is used for the pigment of the present invention is preferably used as a toner composition. Specific examples of organic pigments and inorganic pigments used in the toner composition are shown below.

  The pigment used in the ink is preferably a black pigment and three primary color pigments of cyan, magenta, and yellow. Color pigments other than those described above, colorless, white or light color pigments, pigments having an absorption spectrum in the infrared or ultraviolet wavelength region, metallic luster pigments, and the like may be used. In the present invention, a commercially available pigment may be used, or a newly synthesized pigment may be used.

The following are examples of commercially available pigments for black, cyan, magenta, and yellow.
Examples of black pigments include Raven 1060 (trade name, manufactured by Colombian Carbon), MOGUL-L (trade name, manufactured by Cabot), Color Black FW1 (trade name, manufactured by Degussa), MA100 (trade name, Mitsubishi Chemical). However, it is not limited to these.

  Examples of cyan pigments include C.I. I. Pigment Blue-15: 3, C.I. I. Pigment Blue-15: 4, C.I. I. Pigment Blue-16, and the like, but are not limited thereto.

  Examples of magenta pigments include C.I. I. Pigment Red-122, C.I. I. Pigment Red-123, C.I. I. Pigment Red-146 and the like, but are not limited thereto.

  Examples of yellow pigments include C.I. I. Pigment Yellow-74, C.I. I. Pigment Yellow-128, C.I. I. Pigment Yellow-129 and the like, but are not limited thereto.

The dyes and pigments as described above may be used alone, or may be arbitrarily mixed and used in order to obtain a desired toner color tone.
The content of the colorant in the toner can be widely changed according to a desired coloring effect. Usually, in order to obtain the best toner characteristics, that is, when considering the coloring power of printing, toner shape stability, toner scattering, etc., these colorants are usually used with respect to 100 parts by mass of the emulsion composition. And 0.1 to 60 parts by mass, preferably about 0.5 to 20 parts by mass.

  A cationic surfactant may be used in the preparation of the encapsulated toner according to the present invention, specifically, in the color material dispersion step. Examples of the cationic surfactant selected for the toner and the production method of the present invention include, for example, dialkylbenzene alkyl ammonium chloride, caprylamine (1-octylamine), caprylamine (1-decylamine), laurylamine (1- Dodecylamine), myristylamine (1-tetradecylamine), palmitylamine (cetylamine or 1-hexadecylamine), stearylamine (1-octadecylamine), oleylamine (1-octadecenylamine), arachidylamine ( 1-eicosylamine), behenylamine (1-docosylamine), dilaurylamine (di-n-dodecylamine), lauryldimethylamine (n-dodecyldimethylamine), dioctadecylamine, ditetradecylamine, trioctadecylamine , Lauryltrimethylammonium chloride, alkylbenzylmethylammonium chloride, alkylbenzyldimethylammonium bromide, benzalkonium chloride, C12, C15 and C17 trimethylammonium bromides, lauryl pyridinium chloride, lauryl pyridinium bromide, lauryl pyridinium bisulfate, ralyl pyridinium -5-chloro-2-mercaptobenzothiazole, laurylpicolinium-p-toluenesulfonate, tetradecylpyridinium bromide, cetylpyridinium chloride, cetylpyridinium bromide, 4-alkylmercaptopyridine, poly (vinylpyridine), poly (vinylmethylpyridinium Bromide), poly (vinylpyridine) Dodecyl bromide, dodecyl benzyl triethyl ammonium chloride, MIRAPOL and ALKAQUAT (trade name) obtained from Alkaril Chemical Company, there is SANIZOL (benzalkonium chloride) etc. and mixtures thereof resulting from Kao.

  The surfactant is utilized in various effective amounts, for example from about 0.01 to about 5 parts by weight per 1.0 part by weight of water. Preferably, the molar ratio of the cationic surfactant used for flocculation to the anionic surfactant used to make the emulsion ranges from about 0.5 to about 4, preferably from about 0.5 to about 2. is there.

  In the encapsulated toner of the present invention, in addition to the binder resin and the colorant component described above, the following compounds may be contained as waxes within a range that does not adversely affect the effects of the present invention. For example, silicone resin, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin such as low molecular weight polyethylene or low molecular weight polypropylene, aromatic Petroleum resin, chlorinated paraffin, paraffin wax and the like. Specific examples of the waxes preferably used include low molecular weight polypropylene and its by-products, low molecular weight polyesters and ester waxes, and aliphatic derivatives. Of these waxes, waxes obtained by fractionating waxes by molecular weight by various methods are also preferably used in the present invention. Further, after the fractionation, acid value, block copolymerization, or graft modification may be performed. The waxes contained in the present invention are not limited to these compounds.

  In the encapsulated toner of the present invention, as a charge control agent, for example, an azo dye metal complex, a metal complex of an aromatic dicarboxylic acid, a negative charge control agent such as a salicylic acid derivative, or a positive charge control agent, a nigrosine dye, You may contain organotin compounds, such as phenylmethane type dye and various quaternary ammonium salt dibutyltin oxide. The charge control agent contained in the present invention is not limited to these compounds.

The average particle size of the encapsulated toner in the encapsulated toner composition of the present invention is 10 μm or less, preferably 5 μm or less.
The encapsulated toner composition of the present invention can be used not only in electrophotographic copying machines but also widely in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, laser plate making, and facsimiles. it can.

  The image forming method used in the present invention includes at least a charging step in which a voltage is applied to the charging member from the outside to charge the electrostatic latent image carrier, and an electrostatic charge is applied to the charged electrostatic latent image carrier. Forming an image, developing the electrostatic image with toner to form a toner image on the electrostatic latent image carrier, and transferring the toner image on the electrostatic latent image carrier to a recording material An image forming method including a transfer step and a heat fixing step for heat fixing a toner image on a recording material, or the transfer step transfers the toner image on the electrostatic latent image carrier to an intermediate transfer member. It is particularly preferable to apply to an image forming method including a first transfer step and a second transfer step of transferring a toner image on the intermediate transfer member to a recording material.

  Next, the process cartridge and the electrophotographic apparatus of the present invention will be described. FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention. In the figure, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate about a shaft 2 in the direction of an arrow at a predetermined peripheral speed. In the rotation process, the photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the primary charging unit 3, and then exposure light from an exposure unit (not shown) such as slit exposure or laser beam scanning exposure. Receive 4. In this way, electrostatic latent images are sequentially formed on the peripheral surface of the photoreceptor 1. The formed electrostatic latent image is then developed with toner by the developing unit 5, and the developed toner developed image is rotated between the photosensitive member 1 and the transfer unit 6 from a sheet feeding unit (not shown). The image is sequentially transferred by the transfer means 6 to the transfer material 7 fed in synchronization. The transfer material 7 that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means 8, and subjected to image fixing, thereby being printed out as a copy (copy). After the image transfer, the surface of the photoreceptor 1 is cleaned by removing the transfer residual toner by the cleaning unit 9, and is further subjected to charge removal processing by the pre-exposure light 10 from the pre-exposure unit (not shown). Used repeatedly for image formation. Since the primary charging means 3 is a contact charging means using a charging roller as shown in the figure, pre-exposure is not always necessary.

  In the present invention, a plurality of components such as the photosensitive member 1, the primary charging unit 3, the developing unit 5 and the cleaning unit 9 described above are integrally supported as a process cartridge, and the process cartridge is copied. You may comprise so that attachment or detachment is possible with respect to electrophotographic apparatus main bodies, such as a machine and a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported with the photosensitive member 1 to form a cartridge, and the process cartridge can be attached to and detached from the apparatus main body using a guide unit 12 such as a rail of the apparatus main body. 11 can be used.

  Further, when the electrophotographic apparatus is a copying machine or a printer, the exposure light 4 uses reflected light or transmitted light from the original, or reads the original with a sensor, converts it into a signal, and performs a laser beam performed according to this signal. Light emitted by scanning, LED array driving, liquid crystal shutter array driving, and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples. First, a synthesis example is shown as an example of a block polymer. In addition, “%” and “part” shown below mean “% by mass” and “part by mass”, respectively.

Synthesis example 1
Synthesis Examples of emulsifiers consisting of triblock polymer compound <isobutyl vinyl ether and _{CH 2 = CHOCH 2 CH 2 OPhPh} : and: (IBVE-r-BPhOVE A block), 2-methoxyethyl ether: and (MOVE B block), 4 Synthesis of Triblock Polymer Compound / Poly [(IBVE-r-BPhOVE) -b- (MOVE) -b- (EBVE)] Composed of (2-Vinyloxy) benzoic Acid (BBVE: C Block)> (Here , R is a random polymer, and b is a block polymer compound.

  The inside of the glass container fitted with the three-way stopcock was purged with nitrogen, and then heated to 250 ° C. under a nitrogen gas stream to remove adsorbed water. After returning the system to room temperature, IBVE 6 mmol (mmol), BPhOVE 6 mmol, ethyl acetate 16 mmol, 1-isobutoxyethyl acetate 0.1 mmol, and toluene 11 ml were added, and the reaction system was cooled while stirring. When the system temperature reached 0 ° C., 0.2 mmol of ethylaluminum sesquichloride (an equimolar mixture of diethylaluminum chloride and ethylaluminum dichloride) was added to initiate polymerization. The molecular weight was monitored in a time-sharing manner using molecular sieve column chromatography (GPC) to confirm the completion of polymerization of the A block.

Next, 12 mmol of MOVE was added as a B block component, and monitoring was performed using GPC to confirm the completion of polymerization of the B block.
After completion of polymerization of B block, 3.6 mmol of EBVE toluene solution was added, and after 24 hours, the polymerization reaction was stopped by adding 0.3 mass% ammonia / methanol aqueous solution to obtain a toluene solution of block polymer precursor. It was. After the toluene solution was washed with 0.6 mol / l dilute hydrochloric acid and pure water, the toluene was removed with an evaporator and purified by reprecipitation using methanol to obtain a block polymer precursor. Next, after the block polymer precursor was dissolved in dimethylformamide, 18.0 mmol of sodium hydroxide was added, and the mixture was stirred at room temperature for 72 hours to deprotect C-block ethylbenzoic acid. After completion of the reaction, dimethylformamide was removed by an evaporator, and the resulting solid was dissolved in chloroform. Then, the chloroform solution was washed with 0.6 mol / l dilute hydrochloric acid and water. After washing, the target triblock polymer compound was obtained by removing chloroform with an evaporator. The compound was identified using ¹ H-NMR and GPC. Mn = 23000 and Mw / Mn = 1.44. The polymerization ratio was A: B: C = 100: 100: 30, and the polymerization ratio of the two monomers in the A block was 1: 1.

Example 1
Preparation of emulsion composition (1) Styrene 74 parts Butyl acrylate 26 parts Acrylic acid 1 part Dodecyl mercaptan 1.2 parts (above Wako Pure Chemical Industries, Ltd.)
50 parts of the emulsifier is dissolved to form an oil layer, and added to and dispersed in a 70 ° C. aqueous sodium hydroxide solution in which sodium hydroxide is dissolved in 120 parts of ion-exchanged water to adjust the pH to 12, After adding 50 parts of ion-exchanged water in which 1.0 part of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved and replacing with nitrogen, the flask was stirred and heated in an oil bath until the contents reached 70 ° C. The emulsion polymerization was continued for 6 hours. Then, this reaction liquid was cooled to room temperature, and an emulsion composition (1) having an average particle diameter of 0.49 μm and a dispersity index of 0.097 was obtained. The average particle diameter was measured using DLS-7000 (manufactured by Otsuka Electronics Co., Ltd.). Next, a part of the emulsion composition (1) was left on an oven at 80 ° C. to remove moisture, and the properties of the resin as a residue were measured. As a result, Tg was 51 ° C.

Example 2
Preparation of emulsion composition (2) Styrene 75 parts Butyl acrylate 25 parts Acrylic acid 1 part Dodecyl mercaptan 2.2 parts (above Wako Pure Chemical Industries, Ltd.)
Decanediol diacrylate 0.3 parts
(Shin Nakamura Chemical Co., Ltd.)
50 parts of the emulsifier is dissolved to form an oil layer, and added to and dispersed in a 70 ° C. aqueous sodium hydroxide solution in which sodium hydroxide is dissolved in 120 parts of ion-exchanged water to adjust the pH to 12, After adding 50 parts of ion-exchanged water in which 1.0 part of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved and replacing with nitrogen, the flask was stirred and heated in an oil bath until the contents reached 70 ° C. The emulsion polymerization was continued for 6 hours. Then, this reaction liquid was cooled to room temperature, and an emulsion composition (2) having an average particle diameter of 0.52 μm and a dispersity index of 0.098 was obtained. Subsequently, when a part of the emulsion composition (2) was left on an oven at 80 ° C. to remove moisture and the properties of the resin as a residue were measured, Mw was 30000 and Tg was 49 ° C. .

Example 3
Preparation of Emulsion Composition (3) Styrene 75 parts Butyl acrylate 25 parts Acrylic acid 1 part Dodecyl mercaptan 1.0 part Divinylbenzene 0.2 part (manufactured by Wako Pure Chemical Industries, Ltd.)
Dissolve 50 parts of emulsifier to make an oil layer, dissolve sodium hydroxide in 120 parts of ion-exchanged water, add and disperse the oil layer contained in the flask to a 70 ° C sodium hydroxide aqueous solution adjusted to pH 12. While slowly mixing for 10 minutes, 50 parts of ion-exchanged water in which 1.0 part of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved was added and purged with nitrogen. The mixture was heated in an oil bath until it reached 0 ° C., and emulsion polymerization was continued for 6 hours. Then, this reaction liquid was cooled to room temperature, and an emulsion composition (3) having an average particle size of 0.55 μm and a dispersity index of 0.096 was obtained. Subsequently, when a part of the emulsion composition (3) was left on an oven at 80 ° C. to remove moisture and the characteristics of the resin as a residue were measured, the Mw was 63000 and the Tg was 53 ° C. .

Example 4
Preparation of emulsion composition (4) Styrene 77 parts Butyl acrylate 23 parts Acrylic acid 1 part Dodecyl mercaptan 1.5 parts Divinyl adipate 0.3 part Benzoyl peroxide 0.1 part (manufactured by Wako Pure Chemical Industries, Ltd.)
50 parts of the emulsifier is dissolved to form an oil layer, and added to and dispersed in a 70 ° C. aqueous sodium hydroxide solution in which sodium hydroxide is dissolved in 120 parts of ion-exchanged water to adjust the pH to 12, After adding 50 parts of ion-exchanged water in which 1.0 part of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved and replacing with nitrogen, the flask was stirred and heated in an oil bath until the contents reached 70 ° C. The emulsion polymerization was continued for 6 hours. Thereafter, the reaction solution was cooled to room temperature, and an emulsion composition (4) having an average particle size of 0.55 μm and a dispersity index of 0.101 was obtained. Subsequently, when a part of the emulsion composition (4) was left on an oven at 80 ° C. to remove moisture and the properties of the resin as a residue were measured, the Mw was 42000 and the Tg was 52 ° C. .

Example 5
Preparation of emulsion composition (5) Styrene 72 parts Sodium parastyrene sulfonate 3 parts Butyl acrylate 25 parts Acrylic acid 1 part Dodecyl mercaptan 1.2 parts Pyrrole 0.2 part (manufactured by Wako Pure Chemical Industries, Ltd.)
50 parts of the emulsifier is dissolved to form an oil layer, and added to and dispersed in a 70 ° C. aqueous sodium hydroxide solution in which sodium hydroxide is dissolved in 120 parts of ion-exchanged water to adjust the pH to 12, After adding 50 parts of ion-exchanged water in which 1.0 part of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved and replacing with nitrogen, the flask was stirred and heated in an oil bath until the contents reached 70 ° C. The emulsion polymerization was continued for 6 hours. Thereafter, the reaction solution was cooled to room temperature to obtain an emulsion composition (5) having an average particle size of 0.49 μm and a dispersity index of 0.100. Subsequently, when a part of the emulsion composition (5) was left on an oven at 80 ° C. to remove moisture and the characteristics of the resin as a residue were measured, Mw was 46000 and Tg was 55 ° C. .

Comparative Example 1
Preparation of Emulsion Composition (6) The average particle size was 8.92 μm and the dispersity was the same as in Example 1 except that 1.3 parts of abietic acid was added instead of the emulsifier polymerized in Synthesis Example 1. An emulsion composition having an index of 0.117 and a Tg of 52 ° C. was obtained.

Comparative Example 2
Preparation of Emulsion Composition (7) Similar to Example 1, except that 10 parts of an emulsifier mixture (Arakawa Chemical Co., Ltd .: Longis K-25) containing a potassium salt was added instead of the emulsifier polymerized in Synthesis Example 1. By the method, an emulsion composition having an average particle size of 8.73 μm, a dispersity index of 0.124 and a Tg of 52 ° C. was obtained.

Comparative Example 3
Preparation of Emulsion Composition (8) Similar to Example 1 except that 1 part of nonionic surfactant (Nonion P-213, manufactured by NOF Corporation) was added instead of the emulsifier polymerized in Synthesis Example 1. By the method, an emulsion composition having an average particle size of 8.44 μm, a dispersity index of 0.125 and a Tg of 52 ° C. was obtained.

Example 6
Preparation of toner base particles 25 parts of carbon black (Cabot, Regal 330)
12 parts of anionic surfactant (Nippon Yushi Co., Ltd., Diapon S)
150 parts of aqueous sodium hydroxide solution having a pH of 12 After mixing and dissolving the above components, the mixture is dissolved using a homogenizer (manufactured by IKA: Ultra Tarrax), and a colorant dispersion obtained by dispersing a colorant (carbon black) (5) was prepared.

Preparation of release agent particle dispersion 50 parts of polyethylene wax (Toyo Petrolite, polywax 725)
Anionic surfactant 25 parts (SLS, manufactured by Nikko Chemicals)
250 parts of aqueous sodium hydroxide solution with a pH of 12 After mixing and dissolving the above components, the mixture was dispersed using a homogenizer (manufactured by IKA: Ultra Tarrax), and further dispersed with a pressure discharge type homogenizer, and release agent particles A release agent particle dispersion liquid in which (polyethylene wax) is dispersed was prepared.

Preparation of encapsulated toner composition (1) Emulsion composition (1) 145 parts Toner base particles 42 parts Release agent particle dispersion 36 parts Ion-exchanged water 300 parts The above ingredients are contained in a round stainless steel flask, After dispersing using a homogenizer (manufactured by IKA: Ultra Tarrax T50), the pH in the container was adjusted to 11.5 and heated to 45 ° C. with stirring in a heating oil bath. After maintaining at 45 ° C. for 5 minutes, 0.1N hydrochloric acid (manufactured by Wako Pure Chemical Industries, Ltd.) was added to adjust the pH in the container to 7.5, and then 30 parts of the emulsion composition (1) was gently added. Further, the pH was adjusted to 7.4, and the heating and stirring were continued at 48 ° C. for 20 minutes. Next, an aqueous solution obtained by diluting sodium hydroxide to 0.5% by mass is gently added to the above adhering particle dispersion, the pH is adjusted to 10.6, and then heated to 93 ° C. while stirring is continued. And held for 6 hours. Thereafter, the pH in the container is adjusted to 7.1, the reaction product is filtered, washed with 500 parts of ion-exchanged water four times, and then dried using a vacuum drier so that the average particle size is 3.6 μm. Encapsulated toner particles were obtained.

  In addition, a two-component developer was prepared, image evaluation was performed, and a result regarding toner chargeability was obtained. As a carrier, a ferrite carrier (average particle size of 39 μm) coated with 0.5 parts by mass of silicone resin with respect to the carrier core material is used, and a developer is prepared by mixing so that the toner concentration in the developer becomes 6%. Using an electrophotographic copying machine CLC-700 (manufactured by Canon), an original document with an image area ratio of 20% was used in an environment with a temperature of 30 ° C./humidity of 90% RH, and a 10000 sheet printing test was performed. went. As a result, the charge amount of the encapsulated toner from the initial stage to the end of the printing durability test showed a substantially constant value, and a high image density and high definition image quality were stably obtained.

Example 7
Preparation of encapsulated toner composition (2) Encapsulated toner having an average particle diameter of 3.8 μm in the same manner as in Example 6 except that the emulsion composition (2) was used instead of the emulsion composition (1). A composition was prepared. In addition, a two-component developer was prepared in the same manner as in Example 6, and the same image evaluation as in Example 6 was performed to obtain a result regarding the chargeability of the encapsulated toner. As a result, the charge amount of the encapsulated toner from the initial stage to the end of the printing durability test showed a substantially constant value, and a high image density and high definition image quality were stably obtained.

Example 8
Preparation of encapsulated toner composition (3) Encapsulated toner having an average particle size of 3.4 μm in the same manner as in Example 6 except that the emulsion composition (3) was used instead of the emulsion composition (1). A composition was prepared. In addition, a two-component developer was prepared in the same manner as in Example 6, and the same image evaluation as in Example 6 was performed to obtain a result regarding the chargeability of the encapsulated toner. As a result, the charge amount of the encapsulated toner from the initial stage to the end of the printing durability test showed a substantially constant value, and a high image density and high definition image quality were stably obtained.

Example 9
Preparation of Encapsulated Toner Composition (4) Encapsulated toner having an average particle size of 3.6 μm in the same manner as in Example 6 except that the emulsion composition (4) was used instead of the emulsion composition (1). A composition was prepared. In addition, a two-component developer was prepared in the same manner as in Example 6, and the same image evaluation as in Example 6 was performed to obtain a result regarding the chargeability of the encapsulated toner. As a result, the charge amount of the encapsulated toner from the initial stage to the end of the printing durability test showed a substantially constant value, and a high image density and high definition image quality were stably obtained.

Example 10
Preparation of encapsulated toner composition (5) Encapsulated toner having an average particle diameter of 3.8 μm in the same manner as in Example 6 except that the emulsion composition (5) was used instead of the emulsion composition (1). A composition was prepared. In addition, a two-component developer was prepared in the same manner as in Example 6, and the same image evaluation as in Example 6 was performed to obtain a result regarding the chargeability of the encapsulated toner. As a result, the charge amount of the encapsulated toner from the initial stage to the end of the printing durability test showed a substantially constant value, and a high image density and high definition image quality were stably obtained.

Comparative Example 4
Preparation of Encapsulated Toner Composition (6) Encapsulated toner having an average particle diameter of 5.2 μm in the same manner as in Example 6 except that the emulsion composition (6) was used instead of the emulsion composition (1). A composition was prepared. In addition, a two-component developer was prepared in the same manner as in Example 6, and the same image evaluation as in Example 6 was performed to obtain a result regarding the chargeability of the encapsulated toner. As a result, the charge amount of the encapsulated toner was unstable from the beginning to the end of the printing durability test, and a decrease in the charging amount was observed in the latter half of the printing durability test. For this reason, high image density and high-definition image quality could not be obtained stably.

Comparative Example 5
Preparation of Encapsulated Toner Composition (7) Encapsulated toner having an average particle diameter of 5.4 μm in the same manner as in Example 6 except that the emulsion composition (7) was used instead of the emulsion composition (1). A composition was prepared. In addition, a two-component developer was prepared in the same manner as in Example 6, and the same image evaluation as in Example 6 was performed to obtain a result regarding the chargeability of the encapsulated toner. As a result, the charge amount of the encapsulated toner was unstable from the initial stage until the end of the printing durability test, and the charging amount decreased as the latter half of the printing durability test was performed. For this reason, high image density and high-definition image quality could not be obtained stably.

Comparative Example 6
Preparation of Encapsulated Toner Composition (8) Encapsulated toner having an average particle size of 5.3 μm in the same manner as in Example 6 except that the emulsion composition (8) was used instead of the emulsion composition (1). A composition was prepared. In addition, a two-component developer was prepared in the same manner as in Example 6, and the same image evaluation as in Example 6 was performed to obtain a result regarding the chargeability of the encapsulated toner. As a result, the charge amount of the encapsulated toner was unstable from the beginning to the end of the printing durability test, and a decrease in the charging amount was observed in the latter half of the printing durability test. For this reason, high image density and high-definition image quality could not be obtained stably.

  By performing emulsion polymerization using the emulsifier of the present invention, it is possible to obtain an emulsion composition containing uniform emulsion particles having a small particle size, and capsules having a small particle size and excellent charge stability from the emulsion composition. The encapsulated toner composition can be obtained, and the encapsulated toner composition can be used in an image forming method and an electrophotographic apparatus that can stably obtain a high image density and a high-definition image quality.

1 is a diagram showing a schematic mechanism of an image recording apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Axis 3 Primary charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Image fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge 12 Guide means

Claims (8)

  An emulsifier comprising a block polymer having a main chain structure having a hydrophilic block segment having a polyalkenyl ether structure and a hydrophobic block segment.   The emulsifier according to claim 1, wherein the number of block segments of the block polymer is 3 or more.   An emulsion composition comprising a polymer obtained by emulsion polymerization of a polymerizable unsaturated monomer in the presence of an emulsifier according to claim 1 or 2.   An encapsulated toner composition comprising the emulsion composition according to claim 3 and a pigment, wherein the pigment is coated with the emulsion composition.   A step of obtaining an encapsulated toner precursor in which the emulsion composition according to claim 3 is adsorbed on the surface of toner base particles, and the encapsulated toner precursor is heated to a glass transition temperature or higher of an emulsifier contained in the emulsion composition. A process for producing an encapsulated toner composition comprising the steps of:   A charging step of applying a voltage to the charging member from the outside to charge the latent image carrier, a step of forming a charge image on the charged latent image carrier, and developing the charge image with a charge image developing toner. A developing step for forming a toner image on the electrostatic latent image carrier, a transfer step for transferring the toner image on the latent image carrier to a recording material, and a fixing step for heating and fixing the toner image on the recording material. An image forming method comprising using at least the encapsulated toner composition according to claim 4.   5. An electrophotographic photosensitive member, charging means for charging the electrophotographic photosensitive member, exposure means for exposing the charged electrophotographic photosensitive member to form a latent image, and an electrophotographic photosensitive member having a latent image formed thereon. 5. A developing means for developing with the encapsulated toner composition of claim 1 and at least one means selected from the group consisting of a cleaning means for recovering the toner remaining on the electrophotographic photosensitive member after the transfer step. A process cartridge which is supported and detachable from an electrophotographic apparatus main body.   5. The electrophotographic photosensitive member, charging means for charging the electrophotographic photosensitive member, exposure means for exposing the charged electrophotographic photosensitive member to form a latent image, and the electrophotographic photosensitive member on which the latent image is formed. An electrophotographic apparatus comprising: developing means for developing with the encapsulated toner composition; and transfer means for transferring a toner image on the electrophotographic photosensitive member onto a transfer material.

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