JP2007148225A - Image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stable image forming method causing no unevenness image density even if a toner of which the particles have been formed in an aqueous medium is used. <P>SOLUTION: In the image forming method, a toner image is formed by bearing a toner, of which the moisture content becomes 0.5-3.0 mass% by the Karl Fischer's method after standing in an environment at 30°C and 85% RH for 24 h, on a toner carrier having a coating layer of which the contact angle to water becomes 90-120°. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic image forming method for forming a toner image via a toner carrier such as a developing roller.

  2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus such as a copying machine or a printer, a non-magnetic one-component developer (hereinafter also referred to as non-magnetic one-component toner) is supplied to a photosensitive drum carrying a latent image. There is a development method for converting the formed latent image into a visible image.

  In the developing method using a non-magnetic one-component developer, a developing roller (hereinafter also referred to as a toner carrier) carrying a toner as a non-magnetic one-component developer is used to carry a latent image carrier such as a photosensitive drum. The toner is attached to the latent image on the latent image carrier and developed. In addition, since image formation using a non-magnetic one-component developer does not require a carrier, the apparatus can be simplified and downsized, and a full-color toner image can be easily created.

  By the way, in recent years, so-called polymerized toners that produce toner through a process of aggregating resin particles in an aqueous medium have been remarkably developed, and it is possible to produce a toner having a small particle size and a uniform shape and particle size distribution ( For example, see Patent Document 1). While the polymerized toner contributes to high image quality of the toner image for the above reasons, the feature is that the production process is in an aqueous medium and the saturated water content is high due to the use of a resin having an acid value. is there. The saturated water content in the toner has an effect on the rise of the charging property of the toner. By having a certain amount of saturated water, the charge rise of the toner can be improved. However, if the saturated water content of the toner becomes excessive, the toner itself will easily adsorb moisture, causing charge leakage in a high-temperature and high-humidity environment, resulting in a decrease in charge amount. In particular, a friction charging carrier is used. In a one-component developer that does not, the toner charge charged by frictional charging leaks, and insufficiently charged toner is mixed.

  On the other hand, toner with a large amount of saturated moisture tends to increase adhesion due to a decrease in the glass transition temperature of the contained binder resin due to the influence of moisture, so that toner adheres to the surface of the developing roller, so-called toner fill. Had a problem with ming.

Further, the surface of the developing roller has many polar groups for imparting charge to the toner. For this reason, there is a problem that toner adhesion is high, toner filming occurs on the surface of the developing roller, or toner is not delivered to the latent image carrier, resulting in insufficient developability. In order to solve such a problem, there is a technique for reducing the adhesion force with the toner by setting the contact angle of water on the surface of the developing roller to a specific range and reducing the influence of water molecules on the developing roller (for example, , See Patent Document 2). However, this method is concerned that the toner cannot obtain sufficient chargeability, and does not suggest that a good toner image is formed. Furthermore, the above patent document did not describe a saturated water content of the toner or a polymerized toner that forms a toner by aggregating resin particles in an aqueous medium.
JP 2000-214629 A JP-A-8-44192

  The present invention provides a stable toner image that does not cause unevenness in image density due to environmental fluctuations even when a non-magnetic one-component developer containing toner produced through particle formation in an aqueous medium is used. An object of the present invention is to provide an image forming method capable of forming images.

  It has been confirmed that the present invention is realized by any of the configurations described below.

1. In an image forming method for forming a toner image by conveying a toner containing at least a resin and a colorant to a development region via a toner carrier,
The toner carrier has a coating layer on the surface having a contact angle with water of 90 to 120 °,
An image forming method, wherein the water content of the toner left in an environment of 30 ° C. and 85% RH for 24 hours is 0.5 to 3.0% by mass by the Karl Fischer method.

  2. 2. The image forming method according to 1, wherein the toner is formed through a step of aggregating resin particles in an aqueous medium.

  3. 3. The image forming method according to 1 or 2, wherein the coating layer contains a siloxane-modified urethane resin.

  According to the present invention, when an image is formed using a non-magnetic one-component developer containing a toner produced through particle formation in an aqueous medium, stable image formation without unevenness in image density can be performed. It became so.

  Further, according to the present invention, it is possible to stably provide a full-color image having a beautiful finish without unevenness by using a toner produced through particle formation in an aqueous medium as a non-magnetic one-component developer. Became.

  The present inventor has found that a polymerized toner formed through a process of agglomerating resin particles in an aqueous medium has a high saturated water content, and the glass transition temperature is lowered by the influence of water in such a high water content toner. It was noted that the adhesion strength was high because it was easy, while the charge rising tendency had a good tendency. Then, by controlling the contact angle on the surface of the developing roller 32 and controlling the adhesion force of the toner, an image forming method that maintains the charge rising performance of the toner and solves the problem of toner filming has been developed. It was.

  Hereinafter, the present invention will be described in detail.

  First, the image forming apparatus used in the present invention will be described. FIG. 1 is a structural sectional view of a full-color image forming apparatus capable of performing the image forming method according to the present invention.

  In the full-color image forming apparatus shown in FIG. 1, a charging brush 11 that uniformly charges the surface of the photosensitive drum 10 to a predetermined potential around the photosensitive drum 10 that is rotationally driven, and the photosensitive drum 10 on the photosensitive drum 10. A cleaner 12 for scraping off the remaining toner is provided.

  Also provided is a laser scanning optical system 20 that scans and exposes the photosensitive drum 10 charged by the charging brush 11 with a laser beam. The laser scanning optical system 20 includes a laser diode, a polygon mirror, and an fθ optical element. The print data for each of cyan, magenta, yellow, and black is transferred from the host computer to the control unit. The laser scanning optical system 20 sequentially outputs the laser beam as a laser beam based on the print data for each color, scans and exposes the photosensitive drum 10, and thereby electrostatic charges of the respective colors are formed on the photosensitive drum 10. The latent images are sequentially formed.

  Further, the full-color developing device 30 that supplies full-color development to the photosensitive drum 10 on which the electrostatic latent image is formed in this way, develops full-color, around cyan, magenta, yellow, and black around the support shaft 33. Four color-developing units 30C, 30M, 30Y, and 30Bk each containing a non-magnetic one-component toner are provided. The developing units 30C, 30M, 30Y, and 30Bk rotate around the support shaft 33. It is guided to a position facing the photosensitive drum 10.

  In each of the developing devices 30C, 30M, 30Y, and 30Bk in the full-color developing device 30, a toner regulating member 35 is pressed against the outer peripheral surface of a toner carrier (developing roller) 32 that rotates and conveys toner. The toner regulating member 35 regulates the amount of toner conveyed by the developing roller 32 and charges the conveyed toner. In the full color developing device 30, two toner regulating members may be provided in order to appropriately regulate and charge the toner conveyed by the developing roller 32.

  Then, whenever the electrostatic latent image of each color is formed on the photosensitive drum 10 by the laser scanning optical system 20 as described above, the full-color developing device 30 is rotated around the support shaft 33 as described above. Then, the developing devices 30C, 30M, 30Y, and 30Bk containing the corresponding color toners are sequentially guided to positions facing the photosensitive drum 10, and the developing rollers 32 in the developing devices 30C, 30M, 30Y, and 30Bk are moved. The development is carried out by sequentially supplying charged toners of the respective colors onto the photosensitive drum 10 in which the electrostatic latent images of the respective colors are sequentially formed as described above in contact with the photosensitive drum 10. It has become.

  Further, an endless intermediate transfer belt 40 that is rotationally driven is provided as an intermediate transfer body 40 at a position downstream of the full-color developing device 30 in the rotation direction of the photosensitive drum 10. Is driven to rotate in synchronization with the photosensitive drum 10. The intermediate transfer belt 40 is pressed by a rotatable primary transfer roller 41 so as to come into contact with the photosensitive drum 10, and a portion of a support roller 42 that supports the intermediate transfer belt 40 includes: A secondary transfer roller 43 is rotatably provided, and the recording material S such as recording paper is pressed against the intermediate transfer belt 40 by the secondary transfer roller 43.

  Further, a cleaner 50 that scrapes off the toner remaining on the intermediate transfer belt 40 is provided in a space between the full-color developing device 30 and the intermediate transfer belt 40 so as to be able to contact with and separate from the intermediate transfer belt 40. ing.

  Further, the paper feeding means 60 that guides the recording material S such as plain paper to the intermediate transfer belt 40 includes a paper feeding tray 61 that accommodates the recording material S and the recording material S that is accommodated in the paper feeding tray 61 one by one. The recording material S fed in synchronization with the paper feed roller 62 for feeding paper and the image formed on the intermediate transfer belt 40 is sent between the intermediate transfer belt 40 and the secondary transfer roller 43. The recording material S sent between the intermediate transfer belt 40 and the secondary transfer roller 43 in this way is pressed against the intermediate transfer belt 40 by the secondary transfer roller 43. The recording material S presses and transfers the toner image from the intermediate transfer belt 40.

  On the other hand, the recording material S on which the toner image is pressed and transferred as described above is guided to the fixing device 70 by the conveying means 66 constituted by an air suction belt or the like, and is transferred by the fixing device 70. The toner image is fixed on the recording material S, and then the recording material S is discharged onto the upper surface of the apparatus main body 1 through the vertical conveyance path 80.

  Next, the operation of forming a full color image using this full color image forming apparatus will be specifically described.

  First, the photosensitive drum 10 and the intermediate transfer belt 40 are rotationally driven in the respective directions at the same peripheral speed, and the photosensitive drum 10 is charged to a predetermined potential by the charging brush 11.

  The photosensitive drum 10 thus charged is exposed to a cyan image by the laser scanning optical system 20 to form an electrostatic latent image of the cyan image on the photosensitive drum 10. The cyan toner charged by the toner regulating member as described above is supplied from the developing device 30C in which the cyan toner is accommodated in the photosensitive drum 10 to develop the cyan image, and the cyan toner image is thus formed. The intermediate transfer belt 40 is pressed against the body drum 10 by the primary transfer roller 41, and the cyan toner image formed on the photosensitive drum 10 is primarily transferred to the intermediate transfer belt 40.

  After the cyan toner image is transferred to the intermediate transfer belt 40 in this way, the full-color developing device 30 is rotated around the support shaft 33 as described above, and the developing device 30M containing magenta toner is moved. As in the case of the cyan image described above, the magenta image is exposed to the photosensitive drum 10 charged by the laser scanning optical system 20 to form an electrostatic latent image. The electrostatic latent image is developed by a developing device 30M containing magenta toner, and the developed magenta toner image is primarily transferred from the photosensitive drum 10 to the intermediate transfer belt 40, and similarly, a yellow image And black image exposure, development, and primary transfer in sequence, and cyan, magenta, yellow, and black toner images are sequentially superimposed on the intermediate transfer belt 40. To form a full color toner image.

  When the final black toner image is primarily transferred onto the intermediate transfer belt 40, the recording material S is fed between the secondary transfer roller 43 and the intermediate transfer belt 40 by the timing roller 63, and the secondary transfer roller. The recording material S is pressed against the intermediate transfer belt 40 by 43, and the full color toner image formed on the intermediate transfer belt 40 is secondarily transferred onto the recording material S.

  When the full-color toner image is secondarily transferred onto the recording material S in this way, the recording material S is guided to the fixing device 70 by the conveying means 66, and the full-color toner transferred by the fixing device 70 is transferred. The image is fixed on the recording material S, and then the recording material S is discharged onto the upper surface of the apparatus main body 1 through the vertical conveyance path 80.

  Next, the developing device 30 will be further described.

  FIG. 2 is a schematic diagram showing one developing device 30C of the developing device 30 of the full-color image forming apparatus shown in FIG. 1, and the other developing devices 30M, 30Y, and 30Bk have the same configuration, and thus description thereof is omitted.

  In FIG. 2, 10 is a drum-shaped photoconductor, 30C is a developing device, 32 is a developing roller corresponding to a toner carrier, 34 is a supply roller, 35 is a toner regulating member, 36 is an agitator, 37 is a bias power source, and 38 is a bias power source. A hopper 39 indicates a main body case. The developing device 30C is configured by disposing members such as a developing roller 32, a supply roller 34, a toner regulating member 35, an agitator 36 and the like in a main body case 39 at predetermined positions. When installed at a predetermined position in the apparatus, the developing roller 32 faces or contacts the photosensitive member 10 with a predetermined gap.

  The new toner T in the developing device 30C is agitated by the agitator 36 and conveyed to the developing roller 32 by the supply roller 34. The developing roller 32 is composed of a conductive substrate, and the surface thereof is resin-coated. Therefore, the toner T is adsorbed on the surface of the developing roller 32, and the toner layer Ts is formed. The toner layer Ts is thinned by the toner regulating member 35 and is triboelectrically charged. The toner T on the surface of the developing roller 32 that has been frictionally charged is electrically transferred and adhered to the electrostatic latent image on the surface of the photoconductor 10, whereby the electrostatic latent image is developed.

  The contact pressure between the toner regulating member 35 and the developing roller 32 is 3 to 250 N / m, preferably 5 to 12 N / m, as the line pressure in the sleeve bus direction. By setting the contact pressure to 3 to 250 N / m, the toner charge amount distribution becomes sharp and the occurrence of fogging and scattering can be avoided. In addition, since no load is applied to the toner during image formation, toner deterioration and aggregation are avoided, and a large torque is not required for driving the developing roller 32. As described above, by adjusting the contact pressure to 3 to 250 N / m, it is possible to effectively loosen the aggregation of the toner of the present invention, and it is possible to instantaneously increase the toner charge amount. Become.

  The toner regulating member 35 is preferably an elastic blade, an elastic roller, or the like, and is made of a friction charging material suitable for charging the toner to a desired polarity.

  In the present invention, metal plates such as SUS and phosphor bronze, silicone rubber, urethane rubber, styrene-butadiene rubber and the like are suitable. Furthermore, an organic resin layer such as polyamide, polyimide, nylon, melamine, melamine cross-linked nylon, phenol resin, fluorine resin, silicone resin, polyester resin, urethane resin, styrene resin may be provided. In addition, conductive rubber, conductive resin, etc. are used, or fillers such as metal oxide, carbon black, inorganic whisker, inorganic fiber, and charge control agent are dispersed in the blade rubber and resin. It is preferable because it imparts charge imparting properties and can charge the toner appropriately.

  The developing roller 32 that is a toner carrier will be further described.

  FIG. 3 is a cross-sectional view showing an example of the developing roller in the present invention. As shown in FIG. 3, the developing roller is formed on a shaft body 321 that is a core metal, a base rubber layer 322 formed along the outer peripheral surface of the shaft body 321, and an outer periphery of the base rubber layer 322. The intermediate layer 323 and the surface layer 324 formed on the outer periphery of the intermediate layer 323 are provided.

  The shaft body 321 is not particularly limited, and for example, a metal hollow body or solid body is used. Examples of the material include stainless steel and aluminum. In order to enhance the adhesiveness of the base rubber layer, an adhesive agent, a primer, etc. may be applied to the outer peripheral surface of the shaft body 321 as necessary. The adhesive agent, the primer, etc. are electrically conductive as necessary. May be used.

  The base rubber layer 322 formed on the outer peripheral surface of the shaft body 321 is formed of, for example, ethylene-propylene-diene rubber (EPDM), styrene-butadiene rubber (SBR), silicone rubber, polyurethane elastomer, or the like. Especially, as a forming material of the said base rubber layer 4, it is preferable to use an electroconductive silicone rubber from the point that the fatigue strength with respect to the elastic deformation with low hardness is high. Various additives such as a conductive agent and silicone oil are appropriately blended with this material. Examples of the conductive agent include carbon black, graphite, potassium titanate, iron oxide, and the like. Examples of the silicone oil include various types such as dimethyl silicone oil.

  An intermediate layer 323 is formed on the outer peripheral surface of the base rubber layer 322. As the intermediate layer forming material, for example, EPDM, SBR, nitrile rubber, acryl-nitrile rubber (NBR), hydrogenated nitrile rubber, polyurethane elastomer, polyester, N-methoxymethylated nylon and the like are used. In addition to the above components, a conductive agent such as carbon black, metal oxide, quaternary ammonium salt, and borate may be appropriately added as necessary.

  The layer forming material is dissolved in an organic solvent and used as a coating liquid. Examples of the organic solvent include methyl ethyl ketone (MEK), methanol, toluene, isopropyl alcohol, methyl cellosolve, dimethylformamide and the like. These may be used alone or in combination of two or more. In particular, it is preferable to use methyl ethyl ketone from the viewpoint of solubility in the layer forming material.

  The material for forming the surface layer 324 formed on the outer periphery of the intermediate layer 323 is not particularly limited, and examples thereof include urethane resin, polyamide resin, acrylic resin, acrylic silicone resin, butyral resin (PVB), and the like. These may be used alone or in combination of two or more. Of these, urethane resins are preferably used in terms of wear resistance. In addition to the above components, a conductive agent, a charge control agent and the like may be appropriately added as necessary.

  The material for forming the surface layer 40 is also dissolved in an organic solvent and used as a coating liquid, like the material for forming the intermediate layer 30. Tetrahydrofuran (THF), MEK or the like is used as the organic solvent.

  The developing roller according to the present invention can be produced, for example, as follows.

[Production of base roll]
The material (compound) for forming the base rubber layer is prepared by kneading and stirring each component for forming the base rubber layer using an apparatus such as a kneader or a mixer. Next, a cylindrical mold and a shaft body for forming the base layer are prepared. Then, a wax-based release agent is applied to the inner peripheral surface of the cylindrical mold, and an adhesive, a primer, or the like is applied to the outer peripheral surface of the shaft body as necessary. Subsequently, the shaft body is installed on the central axis of the cylindrical mold having the lower lid fitted thereon, and a gap between the shaft body and the cylindrical mold is filled with a base layer forming material (compound). After that, an upper lid is fitted on the cylindrical mold. Subsequently, the entire cylindrical mold fitted with the lower lid and the upper lid is placed in an oven and heated to vulcanize the base layer forming material (compound) to form a base rubber layer on the outer periphery of the shaft body. . And it demolds after that. Secondary vulcanization may be performed after demolding. Thus, what the base rubber layer 322 was formed in the outer peripheral surface of a shaft body is called a base roll.

[Preparation of intermediate layer and surface layer forming solution]
The intermediate layer and surface layer forming material (coating solution) is prepared by dispersing each component forming the main component material using an appropriate disperser (ball mill, sand mill, homomixer, etc.), and further adding an organic solvent. And stir to prepare.

  Examples of the organic solvent include methyl ethyl ketone, cyclohexanone, methanol, toluene, isopropyl alcohol, methyl cellosolve, dimethylformamide, tetrahydrofuran, and ethyl acetate. These may be used alone or in combination of two or more.

[Production roller development]
After the intermediate layer and surface layer forming material (coating liquid) is applied on the base rubber layer 322 in the base roll, drying and heat treatment are performed to form a coating film on the base rubber layer.

  Examples of the coating method include, but are not limited to, dip coating, roll coating, and spray coating. The coating film on the base rubber layer may be a single layer or a plurality of layers of two or more layers, and is not particularly limited. In this way, the developing roller can be produced.

  The thickness of the base rubber layer is not particularly limited, and is preferably set in the range of 0.1 to 10 mm, particularly preferably 0.2 to 3 mm. Moreover, the thickness of an intermediate | middle layer and a surface layer is not specifically limited, It is preferable to set to the range of 1-30 micrometers, Especially preferably, it is 5-20 micrometers. The thicknesses of the base rubber layer, the intermediate layer, and the surface layer can be obtained by taking a cross-sectional sample from the toner carrier and measuring this micrograph.

  In the above embodiment, the base rubber layer, the intermediate layer, and the surface layer are sequentially formed on the outer periphery of the shaft body, but the inner peripheral surface of each base rubber layer, each layer, and the layer adjacent to the outer peripheral surface of the surface layer. A layer having the same function or a different function may be interposed. For example, the intermediate layer forming solution is dip coated and dried as the intermediate layer 323, and the surface layer forming solution is dip coated and dried as the surface layer 324 on the outer peripheral surface of the intermediate layer 323, as shown in FIG. A developing roller having such a three-layer structure is produced.

  It is also possible to form a layer containing a siloxane-modified urethane resin on the developing roller 32. Hereinafter, the siloxane-modified urethane resin that can be contained in the coating layer of the developing roller 32 will be described.

  The siloxane-modified urethane resin is, for example, a polyurethane resin (1) obtained from a polyol, an isocyanate and a chain extender and having a functional group reactive with an epoxy group, and an epoxy compound (A) having one hydroxyl group per molecule (A ) (Hereinafter simply abbreviated as epoxy compound (A)) and an alkoxy group obtained by reacting an alkoxy group-containing alkoxysilane partial condensate (2) obtained by a dealcoholization reaction between the alkoxysilane partial condensate (B). Although a containing silane modified polyurethane resin can be used, it is not limited to this.

  The polyol is not particularly limited, and various known ones such as polyester polyol, polycarbonate polyol, polyether polyol, and polyolefin polyol can be used. The polyol preferably has a hydroxyl group at the molecular end. In consideration of the mechanical properties of the cured product, the polyol is preferably in the range of 1000 to 6000. Moreover, polyester polyol and / or polycarbonate polyol are particularly suitable among the above-mentioned polymer polyols from the viewpoint of various resistances such as high-temperature durability of the finally obtained polyurethane-silica hybrid.

  Examples of the polyester polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, and pentanediol. Various known low-molecular glycols such as 3-methyl-1,5-pentanediol, 1,6-hexanediol, octanediol, 1,4-butynediol, dipropylene glycol and the like, or n-butyl Alkyl glycidyl ethers such as glycidyl ether and 2-ethylhexyl glycidyl ether, monocarboxylic acid glycidyl esters such as versatic acid glycidyl ester, adipic acid, maleic acid, fumaric acid, phthalic anhydride, Dibasic acids such as phosphoric acid, terephthalic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, suberic acid, etc. or their corresponding acid anhydrides, dimer acid, castor oil and fatty acids thereof And the like, and polyester polyols obtained by ring-opening polymerization of cyclic ester compounds. In the case of a polymer polyol obtained from a low molecular glycol and a dibasic acid, up to 5 mol% of the glycols can be substituted with the following various polyols. Examples thereof include glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, sorbitol, pentaerythritol and the like.

  Polycarbonate polyol is generally obtained by a known reaction such as a demethanol condensation reaction of polyhydric alcohol and dimethyl carbonate, a deurethane condensation reaction of polyhydric alcohol and diphenyl carbonate, or a deethylene glycol condensation reaction of polyhydric alcohol and ethylene carbonate. It is done. Polyhydric alcohols used in these reactions include 1,6-hexanediol, diethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1, Various known low molecular weight glycols such as 5-pentanediol, octanediol, 1,4-butynediol and dipropylene glycol, 1,4-cyclohexanediglycol, 1,4-cyclohexanedimethanol, etc. An alicyclic glycol etc. are mentioned.

  Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polyoxytetramethylene glycol and the like obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran and the like.

  Examples of polyolefin polyols include polybutadiene polyols and polyisoprene polyols having a hydroxyl group at the terminal, or hydrogenated products thereof.

  As the diisocyanate compound which is a constituent component of the polyurethane resin (1), various known diisocyanates which are aromatic, aliphatic or alicyclic can be used.

  For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3- Phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4- Trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate , Hydrogenated xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate and dimer acid carboxyl A typical example is dimerized isocyanate obtained by converting a group into an isocyanate group.

  Examples of the chain extender used in the polyurethane resin (1) include glycols having a carboxyl group in the molecule such as low-molecular glycols, dimethylolpropionic acid and dimethylolbutanoic acid described in the section of the polyester polyol, Polyamines such as ethylenediamine, propylenediamine, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, dimeramine obtained by converting the carboxyl group of dimer acid into an amino group, L-lysine And polyamines having a carboxyl group in the molecule such as L-arginine.

  In addition, a polymerization terminator can be used for the polyurethane resin in order to adjust the molecular weight. Examples of the polymerization terminator include alkyl monoamines such as di-n-butylamine and n-butylamine, monoamines having a carboxyl group in the molecule such as D-alanine and D-glutamic acid, and alcohols such as ethanol and isopropyl alcohol. And alcohols having a carboxyl group in the molecule such as glycolic acid.

As a method for producing the polyurethane resin (1),
(A) a one-stage method in which at least one of a polymer polyol and a diisocyanate compound and a chain extender and a polymerization terminator are reacted at once in a suitable solvent;
(B) A polymer polyol and a diisocyanate compound are reacted under an excess of isocyanate group to prepare a prepolymer having an isocyanate group at the terminal of the polymer polyol, and then this is added to a chain extender and a necessary in an appropriate solvent. Depending on the case, a two-stage method of reacting with a polymerization terminator may be used. Of these, the two-stage method is preferred for obtaining a uniform polymer solution. In these production methods, the solvent used is usually an aromatic solvent such as benzene, toluene or xylene; an ester solvent such as ethyl acetate or butyl acetate; methanol, ethanol, isopropanol, n-butanol, diacetone alcohol or the like. Alcohol solvents; acetone solvents such as methyl ethyl ketone and methyl isobutyl ketone; and other solvents such as dimethylformamide, dimethylacetamide, ethylene glycol dimethyl ether, tetrahydrofuran and cyclohexanone can be used alone or in combination.

  The functional group having reactivity with the epoxy group in the polyurethane resin (1) may be present at either the terminal or the main chain of the polyurethane resin (1). Such epoxy group reactive functional groups include carboxyl groups, sulfone groups, phosphoric acid groups and other acidic groups, amino groups, hydroxyl groups, mercapto groups, etc. From the viewpoint of ease, an acidic group and an amino group are preferable. Although there is no limitation on the method for imparting an acidic group to the polyurethane resin (1), for example, among the chain extenders and polymerization terminators described above, a carboxyl group can be easily imparted.

  Moreover, although there is no limitation in the method to provide an amino group to a polyurethane resin (1), what is necessary is just to make polyamines react so that an amino group may become excess with respect to the terminal isocyanate group of a prepolymer, for example. The amount of the epoxy group-reactive functional group in the polyurethane resin (1) is not particularly limited, but it is usually preferably 0.1 to 20 KOHmg / g. When it is less than 0.1 KOHmg / g, the flexibility and heat resistance of the obtained polyurethane resin-silica hybrid are lowered, and when it exceeds 20 KOHmg / g, the water resistance of the polyurethane resin-silica hybrid tends to be lowered.

  Next, the epoxy group-containing alkoxysilane partial condensate (2) is obtained by a dealcoholization reaction between the epoxy compound (A) and the alkoxysilane partial condensate (B) as described above.

  As the epoxy compound (A), the number of epoxy groups is not particularly limited as long as it is an epoxy compound having one hydroxyl group in one molecule. In addition, as the epoxy compound (A), the smaller the molecular weight, the better the compatibility with the alkoxysilane partial condensate (B), and the higher the heat resistance and adhesion imparting effect. Is preferred. Specific examples include monoglycidyl ethers having one hydroxyl group at the molecular end obtained by reacting epichlorohydrin with water, dihydric alcohol or phenol; epichlorohydrin and glycerin, pentaerythritol, etc. Polyglycidyl ethers having one hydroxyl group at the molecular end obtained by reacting with a trihydric or higher polyhydric alcohol of the above; one hydroxyl group at the molecular end obtained by reacting epichlorohydrin and amino monoalcohol Examples thereof include alicyclic hydrocarbon monoepoxides having one hydroxyl group in the molecule (for example, epoxidized tetrahydrobenzyl alcohol). Among these epoxy compounds, glycidol is most suitable in terms of heat resistance imparting effect, and is also optimal because of its high reactivity with the alkoxysilane partial condensate (2).

  The alkoxysilane partial condensate (B) is obtained by hydrolyzing a hydrolyzable alkoxysilane monomer represented by the following general formula (a) in the presence of an acid or alkaline water and partially condensing it. Things are used.

Formula _{^{(a): R 1 p Si}} (OR 2) 4-p
(In the formula, p represents 0 or 1. R ¹ represents a lower alkyl group, aryl group or unsaturated aliphatic residue which may have a functional group directly connected to a carbon atom. R ² represents a methyl group. Or an ethyl group, and R ² may be the same or different.
Specific examples of such hydrolyzable alkoxysilane monomers include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyl Trialkoxysilanes such as tripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, Can be mentioned. In addition, as these alkoxysilane partial condensates (B), those exemplified above can be used without particular limitation. However, when two or more of these examples are used in combination, tetramethoxysilane is replaced with alkoxysilane. What was synthesized using 70 mol% or more of all alkoxysilane monomers constituting the partial condensate (B) is preferable.

  The alkoxysilane partial condensate (B) is represented by, for example, the following general formula (b) or (c).

(In the formula, R ^1, .R ² showing a lower alkyl group which may have a functional group directly bonded to a carbon atom, an aryl group or an unsaturated aliphatic residue represents a methyl group or an ethyl group, R ² Each may be the same or different.)

(In the general formula (c), R ² is Formula (b) the same as R ² in.)
The structural portion represented by the general formula (b) or (c) can be referred to as a typical silane skeleton.

  Examples of the method for forming the resin layer include dipping, spraying, roll coating, and brush coating depending on the viscosity of the resin component constituting the resin layer.

  Next, a method for measuring the contact angle on the surface of the developing roller 32 will be described. In the present invention, the developing roller (toner carrying member) 32 provided in the developing device preferably has a coating layer on the surface having a contact angle with water of 90 to 120 °, particularly preferably 100 to 110 °.

  The contact angle of the developing roller 32 with respect to water is typically measured by a droplet method. In addition to the droplet method, the falling method (a method of calculating the advancing angle, the receding angle, and the falling angle when the fixed sample is tilted and the droplet starts to slide), the tilt method (a measuring body is set up in the test solution) The contact angle can be calculated by, for example, a method in which the contact angle is the angle when the meniscus formed between the measurement body and the liquid surface disappears.

Specific examples of conditions of the developing roller surface contact angle measuring method capable of measuring the contact angle of the developing roller 32 with water are shown below.
<Development roller surface contact angle measurement method>
Device name: Fully automatic contact angle meter CA-W roll special model [manufactured by Kyowa Interface Science Co., Ltd.]
Measuring method: Droplet method (θ / 2 method by automatic image analysis)
Measurement range: 0 to 180 °
Reading accuracy: 0.1 °
Measurement accuracy: ± 1 °
Measurement temperature: normal temperature (23 ° C)
Amount of liquid landing: 2.0 ± 0.1 ml
Setting: 2 (Key-in when setting conditions)
Control: Standard (Creating liquid: Automatic, Liquid movement: Automatic, Sample stage movement: Automatic)
Image processing-Algorithm: Automatic-Image mode: Frame-Threshold level: Automatic Sample stage movement interval: 30 mm
Number of repetitions: 7 times (repetition of the above sample stage movement interval of 30 mm)
The average value of 7 points of 30 mm pitch is obtained.

  Next, the toner used in the image forming method according to the present invention will be described. The toner used in the present invention contains at least a resin and a colorant, and a so-called polymerized toner formed through a process of aggregating resin particles in an aqueous medium can be used.

  FIG. 4 is a schematic diagram showing a typical structure of the toner used in the present invention. The toner used in the present invention contains a resin and a colorant, and has a typical structure of a toner containing a resin and a colorant. The toner particles shown in FIG. 4 have a so-called sea-island structure in which an isolated phase (island) of the colorant is present in the continuous phase (sea) of the resin.

  The structure of the toner particles is confirmed by a cross-sectional photograph taken with a transmission electron microscope. That is, it is possible to confirm by the transmission electron microscope that there are granular islands (colorant phases) having different luminances in the continuous phase of the resin (binder resin phase).

  Examples of the transmission electron microscope apparatus for observing the toner structure include “LEM-2000 type (manufactured by Topcon Corporation)”.

  For example, toner particles can be photographed with a transmission electron microscope after the toner is sufficiently dispersed in a room temperature curable epoxy resin, embedded and cured, and then dispersed in a styrene fine powder having a particle size of about 100 nm. Press molding. At this time, if necessary, the obtained block can be dyed with ruthenium tetroxide or osmium tetroxide. After the pressure molding, a flaky sample is cut out using a microtome equipped with diamond teeth and loaded into a transmission electron microscope (TEM) to photograph a tomographic form of the toner.

  The toner used in the present invention is left in a high-temperature and high-humidity environment at 30 ° C. and 85% RH for 24 hours, and its water content is measured by the Karl Fischer method to be 0.5 to 3.0% by mass. Is preferable, and 1.0 to 2.0% by mass is particularly preferable.

  Here, the Karl Fischer method is a method for measuring the amount of water using a reagent called Karl Fischer reagent composed of solvents such as iodine, sulfur dioxide, base, and alcohol, and selection with water shown below The amount of water can be quantified by a typical reaction.

I ₂ + SO ₂ + 3BASE + ROH + H ₂ O → 2Base · HI + Base · HSO ₄ R
There are two methods of titration of moisture by the Karl Fischer method: a coulometric titration method and a volumetric titration method.

In the coulometric titration method, a sample is added to an electrolytic solution mainly composed of a solvent such as iodide ion, carbon dioxide, base, and alcohol, and electrolytic oxidation is performed to generate iodine. Is to be calculated. That is, in the electrolytic oxidation, an iodine production reaction represented by 2I ⁻ -2e → I ₂ occurs. Since the generated iodine is generated in proportion to the amount of electricity based on Faraday's law, the amount of water can be obtained immediately from the amount of electricity required for electrolytic oxidation (from 1 mg of water = 10.71 coulombs). ). In the coulometric titration method, two types of electrolytic solutions are used: an anolyte (hereinafter also referred to as a generating solution) placed on the anode side of an electrolytic cell and a catholyte (hereinafter also referred to as a counter electrode solution) placed on the cathode side.

On the other hand, in the volumetric titration method, a dehydrating solvent suitable for a sample is put in a titration flask, and the sample is added after making it anhydrous with a titrant. Then, a titration using a titrant which has been orientation previously titer (mgH ₂ O / ml), determine the water content in the sample from the titration (ml). Note that the constant current polarization potential difference method is adopted for end point detection.

Coulometric titration is usually suitable 10μgH ₂ O~99mgH ₂ O (number ppm~ number% by weight) level moisture content measurements, whereas, volumetric titration is usually, 0.1mgH ₂ O~500mgH ₂ O (number (10 ppm to 100 mass%) Suitable for water content measurement. Therefore, the coulometric titration method is preferable for measuring the water content of the toner used in the present invention.

  As a specific water content measuring apparatus of the Karl Fischer method using the coulometric titration method, for example, an automatic heating vaporization water measuring system “AQS-724” (manufactured by Hiranuma Sangyo Co., Ltd.) can be mentioned. Here, as an example of the measurement of the moisture content of the toner, the measurement of the moisture content of the toner using the automatic heating and vaporization moisture measurement system “AQS-724” will be described.

  The automatic heating and vaporization moisture measuring system “AQS-724” has a configuration as shown in FIG. 5, and the moisture content of the toner used in the present invention is measured under the following conditions, for example.

Measurement conditions Carrier gas: Nitrogen gas Input pressure: 9.8 × 10 ⁴ Pa (1.0 kgf / cm ² )
Flow rate: 150 ml / min Desiccant: One silica gel column and one zeolite column Electrolyte Generation solution (anolyte): Hydranal Aqualite RS
Counter electrode solution (catholyte): Aqualite CN
Set heating temperature: 110 ° C
Sample container: Use the one attached to the device (capacity 20 ml, with packing and screw cap).

The measurement procedure is as follows.
(1) Weighing sample: Using a chemical balance, 0.5 g of toner to be measured is sampled and weighed in a sample container. The chemical balance is preferably one that can be weighed to 5 digits after the decimal point.
(2) In order to remove moisture in the piping in the measurement system, one empty sample container without a sample is set on the turntable of the measurement apparatus.
(3) Next, in order to subtract the moisture in the measurement sample container as a blank test value, two use containers for the blank test are set on the turntable of the measurement apparatus.
(4) Next, the above-mentioned five weighed sample containers are set on the turntable of the apparatus.
(5) Total the number of the above-mentioned moisture removal sample containers and the number of blank test measurements, and set.
(6) Enter the mass of each sample collected.
(7) Turn on the start switch of the device.

Hereinafter, (8) to (13) are automatically performed by the apparatus.
(8) The background of the carrier gas is measured, and after stabilization, the background is held and the turntable rotates one step.
(9) The heating of the sample is started by the temperature rise of the heating furnace.
(10) The needle is lowered to penetrate the packing of the sample container, and the moisture evaporated by heating is transferred by the carrier gas.
(11) Simultaneously with the needle lowering, the carrier gas flow path is switched to the sample measurement line, and measurement is started.
(12) Output the measurement result to the printer.
(13) Each sample container set on the turntable is measured, and the process is terminated when the stop pin is advanced.

  The water content in the toner is calculated from the following equation.

Water content (H ₂ O%) = (H ₂ O [μg] −Blank [μg]) / toner mass (g)
The water content of the toner used in the present invention can be controlled by controlling the toner particle drying method disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2004-184810 and 2004-251965. It is. Hereinafter, the toner drying process by the air dryer disclosed in Japanese Patent Application Laid-Open No. 2004-184810 will be described.

The toner particles obtained through the particle formation process in the aqueous medium are in the form of a cake-like lump in a water-containing state in the filtration / washing process described later, and the water-containing cake is subjected to a drying process by using an air dryer. . As for the moisture content of the water-containing cake provided to the drying process by an air dryer, 30-60 mass% is preferable normally. Further, the amount of air supplied to the air dryer (air volume) is preferably about 1 to 6 m ³ / min in terms of room temperature when the diameter of the pipe is 5 cm. Moreover, the circulation speed of the air circulated inside the dryer body is preferably about 10 to 40 m / sec.

Furthermore, the dry processing amount per unit air volume is about 5 to 200 g / m ^{3 in} terms of the mass of the toner particles after complete drying, and the dry processing amount per unit time is, for example, in the case of a pipe having a diameter of 5 cm. It is preferably about 5 to 500 g / min in terms of toner mass after drying.

  The temperature (inlet temperature) of the compressed air supplied to the air dryer is preferably 100 to 150 ° C., and the temperature (outlet temperature) of the compressed air discharged from the air dryer is the resin constituting the toner particles. When the glass transition temperature is Tg, it is preferably Tg-10 to Tg + 5 ° C.

  In the drying process by the air dryer, the moisture content of the toner particles discharged from the air dryer is measured, and the water-containing cake in the air dryer is maintained so that the moisture content is maintained below a predetermined value. It is preferable to control the supply amount. The water content of the toner particles during the drying process can also be measured by the Karl Fischer method described above.

  Further, in the drying process by the air dryer, the outlet temperature in the air dryer is always measured, and the water-containing cake-like colorant is supplied to the air dryer so that the outlet temperature is maintained in a certain range. It is preferred to control the amount.

  The water content of the colored particles that have been dried by airflow drying is preferably 5% by mass or less (30 ° C., 85% RH), more preferably 3% by mass or less (30 ° C., 85% RH). The colored particles having a water content exceeding 5% by mass (30 ° C., 85% RH) have incorporated a large amount of water into the colored particles. It is difficult to reduce to 3.0% by mass (30 ° C., 85% RH).

  Toner particles having a water content of 0.5 to 3.0% by mass (30 ° C., 85% RH) may be prepared only by the above drying process (primary drying) using an air dryer. In the drying process (primary drying) by the machine, the water content is once reduced to 5% by mass or less (30 ° C., 85% RH), and then the post-drying process (secondary drying) is performed to reduce the water content to 0.5%. A method of preparing toner particles of ˜3.0% by mass (measurement of a sample stored in a high temperature and high humidity environment) is suitable for stably producing toner particles.

  The vibration fluidized dryer preferably used in the secondary drying is a dryer that performs post-drying treatment on the colored particles that have been primarily dried in an environment of atmospheric pressure, reduced pressure, or vacuum. As a specific example of such a vibration fluidized dryer, a “vibrated fluidized dryer” (manufactured by Chuo Koki Co., Ltd.) can be mentioned. The secondary drying treatment temperature is preferably Tg−10 to Tg + 5 ° C. when the glass transition temperature of the resin constituting the colored particles is (Tg).

  Next, the physical properties of the toner used in the present invention will be described.

  The molecular weight of the resin constituting the toner used in the present invention can be measured by GPC (gel permeation chromatography).

  Tetrahydrofuran was used as a solvent for measuring the molecular weight of the resin by GPC.

  The specific measurement is as follows. Add 1 ml of tetrahydrofuran solvent to 1 mg of measurement resin, stir using a magnetic stirrer at room temperature, dissolve the resin sufficiently, and filter through a membrane filter with a pore size of 0.45 to 0.50 μm. To prepare a sample for GPC measurement. Next, after the GPC measurement column is heated and stabilized at 40 ° C., tetrahydrofuran is flowed at a rate of 1 ml per minute, and 100 μL of a measurement sample having a concentration of 1 mg / ml is injected and measured.

  The measurement column is preferably used in combination with a commercially available polystyrene gel column. For example, a combination of Shodex GPC KF-801, 802, 803, 804, 806, 807 manufactured by Showa Denko KK, a combination of TSKgel G1000H, G2000H, G3000H, G4000H, G5000H, G6000H, G7000H, TSK guard column, etc. manufactured by Tosoh Corporation Can be mentioned. As a detector, a refractive index detector (IR detector) or a UV detector may be used.

  The molecular weight of the resin of the present invention is expressed in terms of styrene resin equivalent molecular weight. The molecular weight in terms of styrene resin is determined from a styrene calibration curve. A styrene calibration curve may be prepared by measuring about 10 monodisperse polystyrene standard resins.

The volume-based median particle diameter (D ₅₀ ) of the toner used in the present invention is from 3.0 to 7.0 μm, preferably from 4.0 to 5.0 μm. By setting this range, a high-quality toner image can be obtained.

Median particle size in volume basis (D ₅₀₎ is the "Coulter Multisizer III" (manufactured by Beckman Coulter), measured with a device connected to the computer system for data processing (manufactured by Beckman Coulter, Inc.), is calculated be able to.

  As a measurement procedure, 0.02 g of toner is blended with 20 g of a surfactant solution (for example, a surfactant solution in which a neutral detergent containing a surfactant component is diluted 10-fold with pure water for the purpose of dispersing the toner). After that, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion. This toner dispersion is poured into a beaker containing “ISOTONII” (manufactured by Beckman Coulter) in a sample stand with a pipette until the measured concentration is 5 to 10%, and the measuring machine count is set to 2500 pieces. taking measurement. The aperture diameter of the Coulter Multisizer was 50 μm.

  Next, a method for producing the toner used in the present invention will be described.

The toner used in the present invention can be formed through a process of aggregating resin particles in an aqueous medium. Specifically, it is produced through steps such as a resin particle forming step, a salting out / fusion step, a filtration / washing step, and a drying step described below. Hereinafter, each process of the toner used in the present invention will be described.
(1) Resin particle forming step In this step, a radical polymerizable monomer solution is added to an aqueous medium containing a surfactant having a critical micelle concentration (CMC) or less, and mechanical energy is added to form droplets. In this step, a radical polymerization initiator is added and a polymerization reaction is performed to form resin particles.

  In this step, resin particles having a particle diameter of 20 to 500 nm in terms of mass average diameter are formed. Resin particles having such a size are produced by a polymerization method such as emulsion polymerization.

  Here, components such as a polymerizable monomer and a colorant used for the resin particles will be described.

<Polymerizable monomer>
Resin particles prepared by emulsion polymerization can be used as the resin particles. As the polymerizable monomer for preparing the resin particles, a radical polymerizable monomer is an essential constituent component, and a crosslinking agent can be used as necessary. Specific radical polymerizable monomer components are not particularly limited, and conventionally known radical polymerizable monomers can be used.

  For example, aromatic vinyl monomers, (meth) acrylic acid ester monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers, halogenated Examples include olefinic monomers.

  Examples of the aromatic vinyl monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, p-ethyl styrene, p. -N-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2, Examples thereof include styrene monomers such as 4-dimethylstyrene and 3,4-dichlorostyrene and derivatives thereof.

  Examples of (meth) acrylic acid ester monomers include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, and methacrylic acid. Methyl, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate Etc.

  Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl benzoate.

  Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.

  Examples of the monoolefin monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.

  Examples of the diolefin monomer include butadiene, isoprene, chloroprene and the like.

  Examples of the halogenated olefin monomer include vinyl chloride, vinylidene chloride, vinyl bromide and the like.

  It is also possible to use a radical polymerizable crosslinking agent as a crosslinking agent in order to improve the properties of the resin particles. Examples of the radical polymerizable crosslinking agent include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diaryl phthalate.

  Moreover, the radically polymerizable monomer which has an acidic group can also be used, for example, a carboxyl group and a sulfone group containing monomer can be used.

  Examples of the carboxylic acid group-containing monomer include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, maleic acid monooctyl ester and the like.

  Examples of the sulfonic acid-containing monomer include styrene sulfonic acid, arylsulfosuccinic acid, octyl arylsulfosuccinate, and the like.

  These may have a structure of an alkali metal salt such as sodium or potassium, or an alkaline earth metal salt such as calcium.

  It is also possible to use a radically polymerizable monomer having a basic group, for example, containing an amine group such as a primary amine, secondary amine, tertiary amine, quaternary ammonium salt or the like. Monomers can be used.

  Examples of the amine group-containing monomer include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary ammonium salts of the above four compounds, 3-dimethylaminophenyl acrylate, 2-hydroxy- 3-methacryloxypropyltrimethylammonium salt, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N-butylmethacrylamide, N-octadecylacrylamide, vinylpyridine, vinylpyrrolidone, vinyl N-methyl Pyridinium chloride, vinyl N-ethylpyridinium chloride, N, N-diarylmethylammonium chloride, N, N- Aryl ethyl chloride, and the like.

<Radical polymerization initiator>
The radical polymerization initiator used for emulsion polymerization can be used as appropriate as long as it is water-soluble. Peroxide compounds such as potassium persulfate persulfate, ammonium persulfate, etc., 4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis (2-amidinopropane) salt, etc. Etc.

  Further, the radical polymerization initiator can be combined with a reducing agent and used as a redox initiator, if necessary. By using a redox initiator, the polymerization activity increases, the polymerization temperature can be lowered, and the polymerization time can be further shortened.

  The polymerization temperature may be any temperature as long as it is equal to or higher than the lowest radical generation temperature of the polymerization initiator, but is preferably in the range of 50 to 90 ° C. However, it is also possible to perform polymerization at room temperature or higher by using a polymerization initiator that starts at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (ascorbic acid or the like).

<Surfactant>
A surfactant is preferably used for the emulsion polymerization of the radically polymerizable monomer. The surfactant that can be used in this case is not particularly limited, but the following anionic or nonionic surfactants can be mentioned as preferable ones.

  As an anionic surfactant, for example, sodium dodecyl benzene sulfonate sulfonate, sodium arylalkyl polyether sulfonate, etc., sodium sulfate dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc. Examples of the fatty acid salts include sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate and the like.

  Examples of the nonionic surfactant include polyethylene oxide, polypropylene oxide, a combination of polyethylene oxide and polypropylene oxide, alkylphenol polyethylene oxide, ester of higher fatty acid and polyethylene glycol, ester of higher fatty acid and polypropylene oxide, sorbitan ester, and the like. I can list them.

  These are mainly used as emulsifiers during emulsion polymerization, but can be used in other processes or for other purposes.

<Colorant>
As the colorant, it is preferable to use an inorganic pigment or an organic pigment.

  Examples of inorganic pigments include conventionally known black pigments and magnetic pigments.

  Examples of the black pigment include carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black.

  These inorganic pigments can be used alone or in combination as required. Further, the amount of the inorganic pigment added is preferably 2 to 20 parts by mass, more preferably 3 to 15 parts by mass with respect to 100 parts by mass of the toner.

  A conventionally well-known organic pigment can be used as an organic pigment. Any organic pigment can be used, but specific organic pigments are listed below.

  Examples of the magenta or red pigment include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of the pigment for orange or yellow include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. And CI Pigment Yellow 138.

  Examples of the pigment for cyan or green include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. And CI Pigment Green 7.

  These organic pigments can be used alone or in combination as required.

<Surface modification of colorant>
It is also possible to use a surface modifier for modifying the surface of the colorant.
As the surface modifier of the colorant, a conventionally known material can be used. Specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent, or the like can be preferably used.

  Examples of the silane coupling agent include alkoxysilanes such as methyltrimethoxysilane, phenyltrimethoxysilane, methylphenyldimethoxysilane, and diphenyldimethoxysilane, siloxanes such as hexamethyldisiloxane, γ-chloropropyltrimethoxysilane, vinyltrimethyl. Chlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-ureido Examples thereof include propyltriethoxysilane.

  As a titanium coupling agent, for example, commercial products made from Ajinomoto Co., Inc. Tact, 9S, 38S, 41B, 46B, 55, 138S, 238S, etc., commercial products A-1, B-1, TOT made by Nippon Soda Co., Ltd. TST, TAA, TAT, TLA, TOG, TBSTA-400, TTS, TOA-30, TSDMA, TTAB, TTOP and the like can be mentioned.

  Examples of the aluminum coupling agent include Plenact AL-M manufactured by Ajinomoto Co., Inc.

  These surface modifiers are preferably added in an amount of 0.01 to 20 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the colorant.

<wax>
The wax contained in the toner used in the present invention includes, for example, acid-modified low molecular weight polyethylene (number average molecular weight = 1,000 to 9,000), acid-modified low molecular weight polypropylene (number average molecular weight). = 1,000 to 9,000), and oxidized wax.

  Examples of the oxidized wax include sasol wax types A1, A2, A3, and A14.

  The wax particles are used in a state dispersed in an aqueous medium. A dispersion of wax particles can be prepared by adding a wax to an aqueous medium in which a surfactant is dissolved, emulsifying and dispersing under heating, and adding an alkali to adjust the hydrogen ion concentration. The heating temperature at the time of emulsification dispersion is preferably higher than the softening point of the wax.

<Additive>
The toner used in the present invention may contain additives capable of imparting various functions in addition to the colorant and wax. Specific examples include charge control agents.

  These additives are added at the stage of emulsion polymerization of the resin particles, added at the same time as the resin particles, the colorant particles and the wax particles in the salting-out / fusion process described later, or added directly to the finished toner. It can be added by various methods. As a preferable method, an additive is added at the stage of emulsion polymerization of the resin particles, and an additive is added at the same time as the resin particles, the colorant particles and the wax particles in the salting-out / fusion process and included in the toner. The method of making it include.

  The charge control agent used as the additive is preferably a known material and can be dispersed in water. Specific examples include nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts, or metal complexes thereof.

The charge control agent preferably has a number average primary particle diameter of about 10 to 500 nm in a dispersed state.
(2) Salting-out / fusion step This step is a step of aggregating resin particles in an aqueous medium, specifically, agglomerating resin particles containing wax or a colorant, or resin particles, a colorant. In this step, toner particles (colored particles) are produced by aggregating particles and wax particles. In this step, a salting-out agent having an alkali metal salt or alkaline earth metal salt or the like is added to water in which particles such as resin particles are dispersed, and then heated above the glass transition point of the resin particles. In this step, the agglomeration (hereinafter also referred to as salting out) is advanced and fusion is performed at the same time. This aggregation process is also referred to as a salting out / fusion process.

  In this step, it is possible to use a technique in which fusion is effectively performed by adding an organic solvent that is infinitely soluble in water and substantially lowering the glass point transition temperature of the resin particles.

  In the toner used in the present invention, the formation and fusion of particles by salting out proceed simultaneously, and toner particles can be prepared. It is assumed that it can be obtained stably.

  Here, examples of alkali metal atoms of alkali metal salts and alkaline earth metal salts that are salting-out agents include metal atoms such as lithium, potassium, and sodium, and examples of alkaline earth metal atoms include magnesium, calcium, strontium, and barium. And metal atoms such as Of these, metal atoms such as potassium, sodium, magnesium, calcium, and barium are preferable.

  Examples of the salts of alkali metal salts and alkaline earth metal salts include chlorine salts, bromine salts, iodine salts, carbonates, sulfates, and the like.

  Furthermore, examples of the organic solvent that is infinitely soluble in water include methanol, ethanol, 1-propanol, 2-propanol, ethylene glycol, glycerin, acetone, and the like, but preferably methanol having 3 or less carbon atoms, ethanol, 1- Alcohols such as propanol and 2-propanol are preferable, and 2-propanol is more preferable.

  When performing salting-out / fusion, it is preferable to make the time allowed to stand after adding the salting-out agent as short as possible. The reason for this is not clear, but if it is left for a long time after salting out, the aggregation state of the particles may change, the particle size distribution may become unstable, or the surface properties of the fused toner may change. appear.

  The temperature for adding the salting-out agent needs to be at least the glass transition temperature of the resin particles. The reason for this is that if the temperature at which the salting-out agent is added is equal to or higher than the glass transition temperature of the resin particles, the salting-out / fusion of the resin particles proceeds rapidly, but it becomes difficult to control the particle size. There arises a problem that particles having a particle size are generated. The range of the addition temperature may be not higher than the glass transition temperature of the resin particles, but is generally 5 to 55 ° C, preferably 10 to 45 ° C.

  It is also possible to add a salting-out agent below the glass transition temperature of the resin particles, then raise the temperature as quickly as possible, and heat it above the glass transition temperature of the resin particles.

The time until this temperature rise is preferably less than 1 hour. Furthermore, it is necessary to quickly raise the temperature, and the rate of temperature rise is preferably 0.25 ° C./min or more and 5 ° C./min or less. The upper limit of the temperature rising rate is not particularly clear, but by setting the temperature rising rate within the above range, the progress of salting out and the control of the particle size can be appropriately performed.
(3) Filtration / Washing Step Toner particles formed by aggregating resin particles in the salting out / fusion step are filtered from an aqueous medium, washed with washing water, Remove impurities such as salting-out agent. The filtration and washing machine used in this step is not particularly limited, and for example, a centrifuge, a Nutsche, a filter press or the like is used.
(4) Drying step The toner particles after filtration and washing are dried. As described above, the toner used in the present invention can be controlled such that the water content at 30 ° C. and 85% RH is 0.5 to 3.0% by mass by controlling the drying process. . In the present invention, the water content of the toner is reduced to 5% by mass or less by primary drying, and then the secondary drying is performed to ensure that the water content of the toner is within the range of 0.5 to 3.0% by mass. Is possible.

When performing the primary drying and the secondary drying, it is preferable to use an air flow dryer for the primary drying and a vibration fluidized dryer for the secondary drying. In addition to the above, drying equipment that can be used for secondary drying includes spray dryers, vacuum dryers, vacuum dryers, stationary shelf dryers, mobile shelf dryers, fluidized bed dryers, and rotary dryers. And an agitating dryer.
(5) Crushing step This step may not be particularly necessary, but the toner particles may be weakly aggregated after drying. In this case, for example, a crushing device such as a jet mill, a Henschel mixer, or a coffee mill. May be used to break up agglomeration of toner particles.
(6) Tonerization step The toner particles obtained through the above steps can be used as they are. For example, in order to improve fluidity, chargeability, and cleaning properties, an external additive described later is added. It is preferable to do. The process of adding an external additive is called a toner process.

  The equipment for adding the external additive is not particularly limited. For example, a known mixer such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, or a V-type mixer can be used.

  The external additive is not particularly limited, and various inorganic fine particles, organic fine particles and a lubricant can be used.

  A conventionally well-known thing can be used as an inorganic fine particle. Specifically, fine particles such as silica, titanium, and alumina are preferable, and hydrophobic silica fine particles are more preferable.

  Examples of the silica fine particles include commercial products R-805, R-809, R-812, R-972, R-974, R-976 manufactured by Nippon Aerosil Co., Ltd., commercial products HVK-2150, H- 200, commercial products TS-530, TS-610, TS-720, H-5, MS-5, etc. manufactured by Cabot Corporation.

  Examples of the titanium fine particles include commercial products T-604 and T-805 manufactured by Nippon Aerosil Co., Ltd., commercial products MT-100B, MT-100S, MT-500BS, MT-600, MT-600SS, and JA- 1. Commercial products TA-300SI, TA-500, TAF-130, TAF-510, TAF-510T manufactured by Fuji Titanium Co., Ltd. Commercial products IT-S, IT-OA, IT-OB, IT- manufactured by Idemitsu Kosan Co., Ltd. OC etc. are mentioned.

  Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd. and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

  As the organic fine particles, it is preferable to use spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm. Specific examples include homopolymers such as styrene and methyl methacrylate, and copolymers thereof.

  As the lubricant, for example, a metal salt of a higher fatty acid is preferably used. Specific examples include zinc stearate, such as zinc, aluminum, copper, magnesium, calcium, zinc oleate, manganese, iron, copper, magnesium, etc., zinc palmitate, copper, magnesium, calcium, etc. Salts, salts of zinc linoleic acid, calcium and the like can be mentioned.

  The amount of these external additives added is preferably about 0.1 to 5 parts by mass with respect to 100 parts by mass of the toner.

  The toner used in the present invention is preferably used as a non-magnetic one-component developer, but may be used as a magnetic one-component developer in some cases.

Hereinafter, although an example is given and explained concretely, the embodiment of the present invention is not limited to this. In the following description, “part” and “%” mean “part by mass” and “% by mass” unless otherwise specified.
1. Production of development roller To produce toner carrier (development roller), shaft, base rubber layer forming material (compound), intermediate layer forming material, surface layer forming material (coating solution), and base rubber layer are formed. A cylindrical mold or the like was prepared. As the shaft body 321, a hollow cylinder having a diameter of 15 mm made of SUS303 was prepared.
(1) Adjustment of base rubber layer forming material Base rubber layer forming material (compound) was adjusted by kneading conductive silicone rubber using a kneader.
(2) Preparation of intermediate layer forming material Particles comprising 6 parts of Ketjen Black and acrylic resin having an average particle diameter of 20 μm in a solution in which 20 parts of urethane resin (Nipporan 5199 (manufactured by Nippon Polyurethane)) is dissolved in 100 parts of methyl ethyl ketone 8 parts were dispersed for 2 hours using a sand mill to prepare a coating liquid as an intermediate layer forming material.
(3) Production of alkoxy group-containing silane-modified polyurethane resin (siloxane-modified urethane resin) Polycarbonate diol (Placcel CD220 (manufactured by Daicel Chemical Co., Ltd.)), number average, in a reactor equipped with a stirrer, thermometer and nitrogen gas introduction tube 1000 g of molecular weight 2000) and 278 g of isophorone diisocyanate were added and reacted at 100 ° C. for 6 hours under a nitrogen stream to form a prepolymer having a free isocyanate value of 3.44%. To this, 548 g of methyl ethyl ketone was added to obtain a urethane prepolymer solution.

  Next, 1000 g of the urethane prepolymer solution was added in the presence of a mixture consisting of 1.8 g of isophorone diisocyamine, 4.0 g of di-n-butylamine, 906 g of methyl ethyl ketone and 603 g of isopropyl alcohol, and reacted at 50 ° C. for 3 hours. . The obtained polyurethane resin solution (hereinafter referred to as polyurethane resin 1A) had a resin solid content concentration of 30% and an amine value of 1.2 KOH (mg / g).

  Next, after heating 500 g of the polyurethane resin 1A to 50 ° C. in the same reaction apparatus, 10.95 g of the following epoxy group-containing alkoxysilane partial condensate (2A) was added, and the mixture was heated at 60 ° C. for 4 hours under a nitrogen stream. By reacting, an alkoxy group-containing silane-modified polyurethane resin was obtained.

The epoxy group-containing alkoxysilane partial condensate (2A) has an epoxy group equivalent / polyurethane resin (1A) has an amino group equivalent (equivalent ratio) of 2, and the solid residue in the alkoxy group-containing silane-modified polyurethane resin. The Si content in the minutes was 3.3% in terms of silica mass.
(4) Preparation of surface layer forming material Particles (Pernock CFB100, Dainippon Ink & Chemicals, Inc.) comprising an addition amount of the siloxane-modified urethane resin shown in Table 1, 30 parts of ketjen black, and urethane resin having an average particle diameter of 20 μm 40 parts) were mixed and dispersed to prepare surface layer forming materials 1 to 8.
(5) Formation of base rubber layer The outer peripheral surface of the shaft body coated with an adhesive is set inside a cylindrical mold, and the base is formed in the gap between the shaft body and the inner peripheral surface of the cylindrical mold. After casting a compound as a rubber layer forming material and performing heat vulcanization at 180 ° C. for 1 hour, secondary vulcanization treatment is further performed at 200 ° C. for 4 hours to obtain a thickness on the outer periphery of the shaft body. A 0.5 mm base rubber layer was formed.
(6) Formation of intermediate layer After removing the shaft body with the base rubber layer 3 thus obtained from the mold, the intermediate layer forming material has a thickness of 15 μm on the outer peripheral surface of the base rubber layer. Thus, the intermediate layer was formed.
(7) Formation of surface layer The surface layer (thickness 15 μm) is formed by applying the coating liquid of each surface layer forming material described above to the outer peripheral surface of the intermediate layer, followed by drying and heat treatment to form three layers. The developing rollers 1 to 8 shown in Table 1 composed of rolls having a structure were obtained.

  The contact angles of the produced developing rollers 1 to 8 with respect to water were measured. The measurement was performed under the measurement conditions described above using a fully automatic contact angle meter CA-W roll special model [manufactured by Kyowa Interface Science Co., Ltd.]. Table 1 shows the contact angle of the obtained developing roller with respect to water.

2. Preparation of toner (1) Preparation of colorant particle dispersion 0.90 kg of Adeka Hope LS-90 (sodium n-dodecyl sulfate manufactured by Asahi Denka Co., Ltd.) and 10.0 L of pure water were stirred and dissolved in a resin container with an internal volume of 20 L. To do. To this solution, 1.20 kg of Legal 330R (Carbot Black manufactured by Cabot) is gradually added while stirring, and the mixture is stirred well for 1 hour. Subsequently, it is continuously dispersed for 18 hours using a sand grinder (medium type disperser).

After dispersion, the particle size of the dispersion was measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd. As a result, the particle size was 118 nm in terms of mass average diameter. Further, the solid content concentration of the dispersion measured by a mass method by standing drying was 16.5% by mass. This dispersion was designated as “colorant dispersion 1”.
(2) Preparation of wax particle dispersion 1.05 kg of acid-modified low molecular weight polypropylene (number average molecular weight = 3,000) is added to 2.45 kg of an aqueous solution of a surfactant (nonylphenoxyethanol), and potassium hydroxide is used. Adjust the pH to 9.

  This system is heated to a temperature equal to or higher than the softening point of the acid-modified low molecular weight polypropylene under pressure and is subjected to an emulsification dispersion treatment of the acid-modified low molecular weight polypropylene, thereby releasing a release agent particle having a solid content of 30% by mass. A dispersion is prepared. This dispersion was designated as “release agent particle dispersion 1”.

When the average particle size of the release agent particles in the obtained “release agent particle dispersion 1” was measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., the number average primary particle size was obtained. Was 122 nm.
(3) Preparation of resin particle dispersion 1 56 g of sodium dodecylbenzenesulfonate (manufactured by Kanto Chemical Co., Inc.) is added to a 10 L stainless steel pot, 4.0 L of ion-exchanged water is added, and the mixture is stirred and dissolved at room temperature. This was designated as “anionic surfactant solution A”.

  In a 10 L stainless steel pot, 15 g of New Coal 565C (manufactured by Nippon Emulsifier Co., Ltd.) is added, 4.0 L of ion exchange water is added, and the mixture is dissolved under stirring at room temperature. This was designated as “nonionic surfactant solution B”.

  In a 20 L enamel pot, 226.5 g of potassium persulfate (manufactured by Kanto Chemical Co., Inc.) is added, 12.0 L of ion-exchanged water is added, and the mixture is stirred and dissolved at room temperature. This was designated as “initiator solution C”.

  “Anionic surfactant solution A” and “nonionic surfactant solution B” are placed in a 100 L glass-lined reaction kettle equipped with a temperature sensor, a cooling pipe, and a nitrogen introducing device, and stirring is started. Next, 44.0 L of ion exchange water is added.

  Next, heating is started, and when the liquid temperature reaches 75 ° C., “initiator solution C” is added. Thereafter, while controlling the liquid temperature at 75 ° C. ± 1 ° C., 12.70 kg of styrene, 3.20 kg of n-butyl acrylate, 96 g of methacrylic acid, and 554.1 g of t-dodecyl mercaptan are added.

  Further, the liquid temperature is raised to 78 ° C. ± 1 ° C., and the mixture is heated and stirred for 7 hours.

  Thereafter, the liquid temperature is cooled to 40 ° C. or lower, and stirring is stopped. This liquid was filtered through a pole filter to prepare “resin particle dispersion 1”.

A portion of “Resin Particle Dispersion 1” was taken and the acid value of the resin particles in the dispersion, the peak of the molecular weight distribution by GPC, and the mass average particle diameter were measured. The acid value was 3.9 and the GPC peak position was 12. 800, mass average particle size = 119 nm.
(4) Preparation of resin particle dispersion 2 56 g of sodium dodecylbenzenesulfonate (manufactured by Kanto Chemical Co., Inc.) is added to a new 10 L stainless steel pot, and 4.0 L of ion-exchanged pure water is added and dissolved at room temperature. This was designated as “anionic surfactant solution D”.

  In a 10 L stainless steel pot, 15 g of New Coal 565C (manufactured by Nippon Emulsifier Co., Ltd.) is added, and 4.0 L of ion-exchanged pure water is added and dissolved at room temperature. This was designated as “nonionic surfactant solution E”.

  Add 207.0 g of potassium persulfate (manufactured by Kanto Chemical Co., Inc.) to a 20 L enamel pot, add 12.0 L of ion-exchanged water, and dissolve at room temperature. This was designated as “initiator solution F”.

  Into a 100-liter glass-lined reaction kettle with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a comb baffle (the wing is a Faudler wing), put “anionic surfactant solution D” and “nonionic surfactant solution E”. Start stirring the solution. Next, 44.0 L of ion exchange water is added.

  Next, heating of the solution is started, and when the liquid temperature reaches 70 ° C., “initiator solution F” is added. Thereafter, 13.50 kg of styrene, 2.40 kg of n-butyl acrylate, 100 g of methacrylic acid and 9.26 g of t-dodecyl mercaptan are added in advance.

  Thereafter, the liquid temperature is controlled to 72 ° C. ± 2 ° C., and heating is performed for 6 hours. Further, the liquid temperature is raised to 78 ° C. ± 2 ° C. and heating is performed for 13 hours.

  Then, after cooling the liquid temperature to 40 ° C. or lower, this solution is filtered with a pole filter to produce “resin particle dispersion 2”.

A portion of “Resin Particle Dispersion 2” was taken, and the acid value of the resin particles in the dispersion, the peak of the molecular weight distribution by GPC, and the mass average particle diameter were measured. GPC peak position = 239,700, mass average particle diameter = 115 nm.
(5) Association process 5.36 kg of sodium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) as a salting-out agent and 20.0 L of ion-exchanged water are dissolved in a 35 L stainless steel pot. This was designated as “sodium chloride solution G”.

  Next, 20.0 kg of the “resin particle dispersion 1” prepared above was added to a 100 L stainless steel reaction kettle (the wing is an anchor wing) with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a comb-shaped baffle. Disperse 5.0 kg of “dispersion 2”, 0.4 kg of “colorant dispersion 1”, 6.50 kg of “release agent particle dispersion 1” and 20.0 L of ion-exchanged water, and stir. Next, the mixture is heated to 40 ° C., and 25 kg of “sodium chloride solution G” and 6.00 kg of isopropanol (manufactured by Kanto Chemical Co., Inc.) are added in this order. Then, after leaving to stand for 10 minutes, the temperature rise is started and the temperature is raised to a liquid temperature of 85 ° C. over 60 minutes. The liquid temperature was controlled to 85 ° C. ± 2 ° C., heated for 6 hours, and aggregated / fused to produce “colored particles 1”.

Thereafter, the liquid temperature is cooled to 40 ° C. or lower, and stirring is stopped. Subsequently, the solution was filtered through a sieve having an opening of 45 μm to obtain an “association liquid” containing colored particles.
(6) Washing of colored particles Next, the “association liquid” was filtered using a Nutsche, and “wet cake-like colored particles” were taken out and washed with ion-exchanged water. The colored particles after the washing treatment were again made into a wet cake form. This operation was repeated four times to remove impurities such as a surfactant from the surface of the colored particles.
(7) Drying of colored particles The “hydrous cake” thus obtained is subjected to a drying process (primary drying) using a continuous instantaneous air flow dryer “flash jet dryer, model: 5 cm” (manufactured by Seishin Enterprise Co., Ltd.). ) Here, 120 ° C. The inlet temperature of the continuous instantaneous flash dryer, the outlet temperature of 55 ° C., the air flow 2 Nm ³ / min ( "Nm ^3" are the same.. Or less representative of the volume of the room temperature equivalent) was set to.

  In addition, the water content of the colored particles discharged from the continuous instantaneous air dryer is sequentially measured so that the water content of the colored particles discharged is 5% by mass or less. ”Was controlled in a range of 5 to 20 kg / hour. The time required for this drying treatment (primary drying) was 60 minutes, and when the water content of the colored particles after the drying treatment was measured, it was 5.0% by mass (30 ° C., 85% RH).

  Next, after drying (primary drying), the colored particles having a water content of 5.0% by mass (30 ° C., 85% RH) are post-dried using a “vibrating fluid dryer” (manufactured by Chuo Kako Co., Ltd.). Treatment (secondary drying) was performed. The drying temperature was set to 55 ° C., and colored particles 1 to 8 having water amounts shown in Table 2 were prepared according to the treatment time shown in Table 2.

In addition, the measurement of the said moisture content was performed based on the above-mentioned conditions and procedure using automatic heating vaporization moisture measuring system "AQS-724" (made by Hiranuma Sangyo Co., Ltd.).
(8) Preparation of toner Toners 1 to 8 were prepared by adding 0.8 part of hydrophobic silica having a number average primary particle size of 12 nm to 100 parts of the obtained colored particles.

3. Evaluation Experiment (1) Evaluation Apparatus For the evaluation of Examples 1 to 10 and Comparative Examples 1 to 4, a color printer having the configuration of FIG. 1 was used. That is, the developed developing roller and the toner are incorporated into the developing cartridge used in the developing device of the printer, and the pressure and the protruding amount of the SUS toner regulating member are adjusted so that the toner conveyance amount is 4.5 g / m. ² Next, as a development condition, a bias voltage in which an alternating voltage composed of a rectangular wave having a DC voltage of _VDC of −420 V, a peak value of 1.9 kV and a frequency of 2 kHz is applied is applied, and the duty ratio is adjusted to obtain a solid print density. Was adjusted to about 1.4. The system speed at this time was 140 mm / sec, and the peripheral speed of the developing roller was 210 mm / sec.
(2) Evaluation method First, the print print solid image density was measured under normal temperature and normal humidity environmental conditions (N / N; 23 ° C., 55% RH). Next, the environment was changed to a high temperature and high humidity environment condition (H / H; 30 ° C., 85% RH), and the solid image density of the printed image after 2 hours and 24 hours was measured. Further, a full color image with a printing rate of 15% was intermittently printed for each sheet in the H / H environment, and image defects of the printed images after printing one sheet and after printing 1000 sheets were evaluated. It should be noted that the manuscript used for print creation at the time of image defect evaluation is a character image (3 points, 5 points) with a pixel rate of 7%, a color human face image (dot image including halftone), a solid white image, a reflection density of 0. An original image (A4 size) in which halftone images to be 8 were respectively divided into quarters was used.

  Further, after 1000 sheets were printed, the toner fusing state to the developing roller was visually evaluated.

<Density unevenness>
Fluctuation in solid image density formed on a print created under 23 ° C and 55% RH and a print created under 30 ° C and 85% RH was evaluated with a reflection densitometer (Macbeth reflection densitometer “RD-918”). did. The solid image density fluctuation was evaluated as density fluctuation 1 and density fluctuation 2 defined below.

Density fluctuation 1 = (reflection density after standing for 2 hours at 30 ° C. and 85% RH) − (reflection density under 23 ° C. and 55% RH)
Density fluctuation 2 = (reflection density after standing for 24 hours under 30 ° C. and 85% RH) − (reflection density after standing for 2 hours under 30 ° C. and 85% RH)
A: Density difference is less than 0.05 B: Density difference is 0.05 or more and less than 0.20 X: Density difference is 0.20 or more <Toner Adhesion>
A: No toner adhesion was observed on the developing roller B: A minute toner adhesion was found by observation with a magnifying glass, but there was no problem. X: The toner adhesion was confirmed with the naked eye.

  The results are shown in Table 3.

  As can be seen from Table 3, in Examples 1 to 10 corresponding to the present invention, no toner adheres to the developing roller even after continuous printing of 1000 sheets in a high temperature and high humidity environment. There was no occurrence of density unevenness due to the change of. On the other hand, in the comparative example, it was confirmed that density unevenness occurred with the environmental change, and the result was different from the example.

1 is a cross-sectional view of a full-color image forming apparatus that can be used in an image forming method according to the present invention. FIG. 2 is a schematic view of a developing device used in the full color image forming apparatus of FIG. 1. It is sectional drawing which shows an example of the developing roller in this invention. FIG. 3 is a schematic diagram illustrating the structure of a toner that can be used in the present invention. It is a block diagram of automatic heating vaporization moisture measuring system "AQS-724".

Explanation of symbols

1 Device body 30, 30C, 30M, 30Y, 30Bk Developer 32 Developing roller (toner carrier)
321 Shaft body 322 Base rubber layer 323 Intermediate layer 324 Surface layer

Claims (3)

In an image forming method for forming a toner image by conveying a toner containing at least a resin and a colorant to a development region via a toner carrier,
The toner carrier has a coating layer on the surface having a contact angle with water of 90 to 120 °,
An image forming method, wherein the water content of the toner left in an environment of 30 ° C. and 85% RH for 24 hours is 0.5 to 3.0% by mass by the Karl Fischer method. The image forming method according to claim 1, wherein the toner is formed through a process of aggregating resin particles in an aqueous medium. The image forming method according to claim 1, wherein the coating layer contains a siloxane-modified urethane resin.

Images