JP5338462B2 - Method for producing toner for developing electrostatic image, toner for developing electrostatic image, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a toner for electrostatic charge image development which is reduced in production of fine powders from particle aggregates, has constant chargeability even under a low temperature and low humidity environment, and also has good cleaning properties; and to provide a toner for electrostatic charge image development, and an image forming method. <P>SOLUTION: The method for producing the toner for electrostatic charge image development includes forming colored particles by aggregating/fusing from a dispersion liquid containing at least resin particles and colorant particles, wherein a compound expressed by general formula (1) is added in a step of stopping aggregation or in the succeeding steps. In formula (1), R<SB>1</SB>and R<SB>2</SB>each represent a methyl group; R<SB>3</SB>and R<SB>4</SB>each represent a 1-20C alkyl or alkenyl group, phenyl group or benzyl group; and X represents a halogen atom. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for producing an electrostatic charge image developing toner, an electrostatic charge image developing toner produced by the production method, and an image forming method using the electrostatic charge image developing toner.

  Recently, in the field of image forming technology using electrophotography such as copying machines and printers, with the progress of digital technology, a minute dot image of 1200 dpi (dpi; the number of dots per 2.54 cm) level is accurately reproduced. Image forming technology has been demanded.

  In order to accurately reproduce such a minute dot image, it has been studied to reduce the diameter of an electrostatic charge image developing toner (hereinafter sometimes simply referred to as toner), and various controls can be added in the manufacturing process. So-called polymerized toners have attracted attention.

  However, these small-diameter toners are more susceptible to external environmental fluctuations such as temperature and humidity because they have a larger surface area than their volume. In order to improve this point, paying attention to the charge amount of the toner that affects the dot reproducibility, a toner having a small charge amount variation in a low-temperature and low-humidity environment where the dot reproducibility varies greatly due to excessive charging has been proposed. (For example, Patent Document 1). However, although a toner having a small charge amount variation was produced, it has been found that in the production method, the particle size of the particle aggregate is not stable, and fine particles are generated from the aggregate to deteriorate the cleaning property. .

  On the other hand, in order to solve the above problems, a proposal for stabilizing the particle size of the particle aggregate has been made (for example, Patent Document 2). However, it is insufficient in terms of controlling the particle size of the particle aggregate.

JP 2008-224713 A JP 2008-304874 A

  The present invention has been made in view of the above-mentioned background, and an object of the present invention is to reduce the generation of fine powder from particle aggregates, to have a constant chargeability even in a low temperature and low humidity environment, and to have a good cleaning property. An electrostatic charge image developing toner manufacturing method, and an electrostatic charge image developing toner and an image forming method are provided.

  The present inventor paid attention to the process of stopping the aggregation of the particle aggregates, and in particular, studied to find a method for easily controlling the particle diameter of the particle aggregates and making the particle diameter constant.

  As a result, it has been found that the object of the present invention is achieved by adopting the following configuration.

(1)
In the method for producing a toner for developing an electrostatic charge image by agglomerating / fusing from a dispersion containing at least resin particles and colorant particles to form colored particles, the compound c shown below after the step of stopping aggregation A method for producing a toner for developing an electrostatic charge image, wherein one of the compounds d, f and f is added all at once to a dispersion kept at the same temperature as in the aggregation step .

( 2 )
An electrostatic image developing toner produced by the method for producing an electrostatic image developing toner described in (1 ) .

( 3 )
The electrostatic latent image formed on the electrophotographic photosensitive member is developed using the electrostatic image developing toner described in ( 2 ) to form a toner image, which is contact-heat-fixed after being transferred to a recording material. An image forming method.

  According to the present invention, a method for producing a toner for developing an electrostatic charge image with reduced generation of fine powder from particle aggregates, a constant chargeability even in a low-temperature and low-humidity environment, and a good cleaning property, and for electrostatic image development A toner and an image forming method can be provided.

FIG. 3 is a cross-sectional view illustrating an example of a color image forming apparatus. The block diagram for description of a cleaning apparatus. The block diagram for description of a cleaning apparatus. The block diagram for description of a cleaning apparatus.

  The present invention relates to a method for producing a toner for developing an electrostatic charge image, in which a dispersion containing at least resin particles and colorant particles and, if necessary, an additive is aggregated / fused. The electrostatic charge image developing toner produced by the production method in which the compound represented by the general formula (1) is added after the step of stopping the aggregation has a fine powder from the particle aggregate before becoming the toner particles by fusing. The inventors have found that a toner having a good cleaning property can be obtained by preventing the toner from being generated.

  The reason why the effect of the present invention has been achieved by adding the compound represented by the general formula (1) after the step of stopping the aggregation is not necessarily clear. However, the configuration of the present invention has been achieved as a result of the following estimation and investigation.

  In the invention described in Patent Document 1, NaOH is used to stop further aggregation of the particle aggregate. Presumably, NaOH imparts an electrostatic repulsion force on the surface of the particle aggregate, so that aggregation between the particle aggregates can be stopped. However, since NaOH is three-dimensionally small, it penetrates into the inside of the particle aggregate, and an electrostatic repulsive force is generated inside the particle aggregate, thereby releasing a part of the particle aggregate. And a part of particle aggregate isolate | separates and a fine powder generate | occur | produces. From this, it was considered desirable to apply a three-dimensional repulsive force in order to stop aggregation without applying an electrostatic repulsive force. Based on this idea, a compound that adsorbs on the surface of the particle aggregate and can be expected to have steric hindrance was found, and it was found that the compound represented by the general formula (1) was extremely effective.

  On the other hand, in the cited document 2, in order to stop the aggregation of the particle aggregate, a dispersant (preferably an emulsifier) is added while increasing the temperature as an aggregation stopper. However, if it is added while raising the temperature in this way, the particle aggregates may coalesce and re-grow, which is insufficient in terms of controlling the particle size of the particle aggregates. Therefore, it is considered that it is more preferable to add the coagulation terminator at the same temperature as the coagulation step, and it is easy to obtain a preferable result. In addition, the same temperature as the aggregation process means that the temperature is not intentionally increased or decreased, and the batch addition is not intentionally added over time or dividedly. Meaning. Further, “aggregation and fusion” will be described later.

  Hereinafter, the present invention will be described in detail.

  The toner in the present invention contains at least a resin, a colorant, and other additives as constituent components. Among these, the resin and the colorant have been used in the toner so far as described later. Can be used. In addition, other additives that have been conventionally used in many cases can also be used in the present invention. Therefore, the compound represented by the general formula (1) used only in the present invention will be described in detail.

[Compound represented by the general formula (1)]
Specific examples of the compound represented by the general formula (1) to be added to the toner are listed in the following “Chemical Formula 2”.

  The compound of the general formula (1) can be synthesized by a general quaternary amine synthesis method.

  For example, a tertiary amine having a corresponding structure is used as a starting material, and a quaternary alkylating reagent having a corresponding structure is used at a molar ratio of 1: 0.95 to 1: 3, preferably 1: 1 to 1: 2. Make contact. Although the reaction can be carried out without using a solvent, it is preferable to use a solvent, and alcohols such as methanol, ethanol, propanol, isopropanol, butanol or isobutanol, ethers such as tetrahydrofuran or ethylene glycol dimethyl ether and dichloromethane, Preference is given to using anhydrous solvents selected from halogenated hydrocarbons such as dichloroethane or chloroform. Halogenated hydrocarbons are preferred.

  The amount of the solvent is such that the concentration of the compound represented by the general formula (1) is 3 to 99.9% by mass, preferably 5 to 30% by mass with respect to the mass of the solution or dispersion when the reaction product is brought into contact. Select The reaction is generally carried out at a temperature of 0 to 130 ° C., preferably 30 to 80 ° C., under atmospheric pressure, until the reactants (possibly the lesser reactants) are completely consumed. A quaternary amine of the present invention can be obtained by performing a post-treatment according to a conventional method of organic synthesis.

[Toner according to the present invention]
Next, the particle size and shape of the small particle toner according to the present invention will be described.

  The volume-based median diameter (volume D50% diameter) of the toner according to the present invention is preferably 2.0 to 8.0 μm. More preferably, it is 3.0-7.0 micrometers. Here, the volume-based median diameter (volume D50% diameter) is a count number (cumulative value) corresponding to 50% of the total number of particles when a certain volume of toner is counted in order of increasing or decreasing particle diameter. The toner has a particle size.

  The toner according to the present invention preferably has a coefficient of variation (hereinafter also referred to as CV value) of 20% or less in the volume-based particle size distribution of the toner constituting the toner. It is preferable to form a high-definition character image with a toner having a variation coefficient of 20% or less and a sharp particle size distribution. The coefficient of variation in the toner volume-based particle size distribution is calculated from the following equation.

Coefficient of variation (CV value) (%) = (S2 / Dn) × 100
(In the formula, S2 represents the standard deviation in the volume-based particle size distribution, and Dn represents the volume-based median diameter (volume D50% diameter; μm).)
The volume-based median diameter (volume D50% diameter) and coefficient of variation (CV value) of the toner according to the present invention are determined by the Coulter Multisizer 3 (Beckman Coulter) and the computer system for data processing (Beckman Coulter, Inc.). ) Can be used for measurement and calculation.

  As a measurement procedure, 0.02 g of toner is blended with 20 ml of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing the toner). After that, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion. Pipet this toner dispersion into a beaker containing the electrolyte “ISOTONII” (manufactured by Beckman Coulter) in the sample stand until the measured concentration reaches 8%, and set the measuring machine count to 2500. To measure. The aperture diameter of the Coulter Multisizer is 50 μm.

  The toner according to the present invention preferably has an average circularity of 0.916 to 0.955. Here, the circularity of the toner is calculated from the following equation.

Circularity = (perimeter of a circle having the same projection area as the particle image) / (perimeter of the particle projection image)
The average circularity is a value calculated by dividing the sum of the circularity of individual toner particles by the total number of particles.

  As an apparatus for measuring the circularity of the toner, for example, “FPIA-2100 (manufactured by Sysmex)” can be mentioned. In the measurement using FPIA-2100, the toner is blended with an aqueous solution containing a surfactant, and after ultrasonic dispersion treatment is performed for 1 minute to disperse the toner, the measurement is performed using FPIA-2100. Measurement conditions are set to the HPF (high magnification imaging) mode and the number of HPF detections is set to an appropriate density of 3000 to 10,000.

  The toner according to the present invention is mainly used as a black toner, but can also be used as a color toner. That is, in the case of forming an image using color toner, it is possible to reduce the environmental dependence of color reproducibility and to always provide a stable color image.

  In the present invention, it is preferable to use a toner manufacturing method for obtaining particle aggregates from a dispersion containing polymer primary particles.

[Toner Production Method]
Next, a toner manufacturing method according to the present invention will be described.
(1) Step of producing colored particle dispersion containing resin and colorant (2) Step of cooling colored particle dispersion (3) Colored particles are solid-liquid separated from the cooled colored particle dispersion, and colored particles (4) The step of drying the washed colored particles (5) The step of adding an external additive to the dried colored particles First, (1) “Producing particles containing resin and colorant Will be described. This step is a step of agglomerating and fusing the polymer primary particles and the colorant particles in an aqueous medium to produce particles containing a resin and a colorant, and includes the following steps. That is,
(A) A step of dissolving a wax in the radical polymerizable monomer as needed to prepare a monomer solution (b) A polymerization step of polymerizing the radical polymerizable monomer solution to produce polymer primary particles (c) polymerization It comprises a step of agglomerating and fusing the polymer primary particles and colorant particles obtained in the step to form particles.

  The polymerization reaction for producing the polymer primary particles is performed, for example, by the following procedure. A monomer solution in which wax is dissolved is added to an aqueous medium (an aqueous solution of a surfactant and a radical polymerization initiator) containing a surfactant having a critical micelle concentration (CMC) or less, and mechanical energy is added to the monomer solution. Droplets are formed. Next, a water-soluble radical polymerization initiator is added to advance the polymerization reaction in the droplets. It is also possible to carry out the polymerization by containing an oil-soluble polymerization initiator in the monomer droplet. Examples of the mechanical energy applying means for forming droplets of the monomer solution include a homomixer, a manton gourin, and an ultrasonic vibration device.

  The wax that can be used for the production of polymer primary particles in this step is not particularly limited, and if not necessary, it may not be added. Specifically, long-chains such as low molecular weight polyethylene and polypropylene, olefin waxes such as copolymers of polyethylene and other olefin polymers, paraffin wax, behenyl behenate and montanate esters, glycerin esters and stearyl stearate Ester waxes having aliphatic groups, plant waxes such as hydrogenated castor oil and carnauba wax, ketone waxes having long chain alkyl groups such as distearyl ketone, silicone waxes having alkyl groups, and higher grades such as stearic acid Fatty acid wax, long chain fatty acid alcohol wax, long chain fatty acid polyhydric alcohol wax such as pentaerythritol and its partial ester wax, higher fatty acid amide wax such as oleic acid amide and stearic acid amide, etc. . Among these, good fixability is obtained by using a wax having a melting point of 100 ° C. or less, more preferably 40 to 90 ° C., and particularly preferably 50 to 80 ° C.

  In addition, known cationic surfactants, anionic surfactants, nonionic surfactants, and amphoteric surfactants are used as emulsifiers used when preparing droplets of the monomer solution. Two or more types can be used in combination.

  Examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide and the like.

  Examples of the anionic surfactant include aliphatic soaps such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and sodium laurate.

  Further, examples of the nonionic surfactant include dodecyl polyoxyethylene ether, hexadecyl polyoxyethylene ether, nonylphenyl polyoxyethylene ether, lauryl polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, monodecanoyl Sucrose etc. are mentioned.

  Examples of amphoteric surfactants include N-alkylnitrilotriacetic acid, N-alkyldimethyl N oxide, α-trimethylammonio fatty acid, N-alkyl-β-aminopropionate, N-alkyl-β-iminopropionate, N -Alkyl-oxymethyl-N, N-diethyl N oxide, N-alkyl-N, N-diaminoethylglycine hydrochloride, 2-alkyl imidazoline derivatives, aminoethyl imidazoline organic acid salt, N-alkyl sulfo N oxide, N- Alkyl taurine salts can be mentioned.

  Next, the monomer used for production of polymer primary particles will be described. In the present invention, a polymer primary particle containing a wax is prepared by adding a monomer having a polar group and another monomer to advance the polymerization. When producing polymer primary particles using a plurality of types of monomers, the monomers may be added separately, or a plurality of monomers may be added in advance after mixing. Further, it is possible to change the monomer composition during the monomer addition.

  In producing the polymer primary particles, a certain amount of emulsifier can be added in order to allow the polymerization reaction to proceed more reliably. Further, the timing for adding the polymerization initiator may be before the monomer addition, at the same time as the monomer addition, after the monomer addition, or by an addition method combining these.

  It is also possible to add components other than wax, such as colorants and charge control agents, to produce polymer primary particles containing these components. After the colorant is dissolved in the monomer or wax, the polymerization reaction It is also possible to perform.

  Examples of the monomer having an acidic polar group include monomers having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and cinnamic acid, and monomers having a sulfonic acid group such as sulfonated styrene. It is done.

  Examples of the monomer having a basic polar group include monomers containing nitrogen-containing heterocycles such as aminostyrene and quaternary salts thereof, vinylpyridine and vinylpyrrolidone, dimethylaminoethyl acrylate, diethylaminoethyl methacrylate and the like. (Meth) acrylic acid ester monomers having amino groups, and (meth) acrylic acid ester monomers having quaternized ammonium salts of these amino groups, acrylamide, N-propylacrylamide, N, N-dimethylacrylamide, N , N-dipropylacrylamide, N, N-dibutylacrylamide, acrylic acid amide and the like.

  Furthermore, as other monomers, styrenes such as styrene, methylstyrene, chlorostyrene, dichlorostyrene, p-tert-butylstyrene, pn-butylstyrene, pn-nonylstyrene, methyl acrylate, acrylic acid Examples include (meth) acrylic acid esters such as ethyl, propyl acrylate, n-butyl acrylate, isobutyl methacrylate, hydroxyethyl methacrylate, and ethylhexyl methacrylate.

  In the present invention, methacrylic acid is suitably used as the monomer having a polar group, and styrene, acrylic acid ester, and methacrylic acid ester are suitably used as other monomers.

  These monomers can be used alone or in combination, but it is preferable to select the monomers so that the glass transition temperature of the polymer is 40 to 80 ° C. By setting the glass transition temperature of the polymer within the above range, the storage stability of the toner can be ensured and the fixing temperature can be set widely.

  As polymerization initiators, persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate, redox initiators combining these persulfates as a component with a reducing agent such as acidic sodium sulfite, hydrogen peroxide, Water-soluble polymerization initiators such as 4,4'-azobiscyanovaleric acid, t-butyl hydroperoxide, cumene hydroperoxide, etc., and reducing agents such as ferrous salts with these water-soluble polymerization initiators as one component The combined redox initiator, benzoyl peroxide, 2,2'-azobisisobutyronitrile and the like can be mentioned.

  Moreover, a chain transfer agent can also be used when producing the said polymer primary particle. Examples of the chain transfer agent include t-dodecyl mercaptan, n-octyl mercaptan, 2-mercaptoethanol, diisopropylxanthogen and the like. The chain transfer agents can be used alone or in combination of two or more. Further, the addition amount of the chain transfer agent is preferably 5% by mass or less with respect to the total monomer amount.

  The size of the polymer primary particles is in the range of 50 to 3000 nm as an average particle size, preferably 100 to 1000 nm, and particularly preferably 100 to 500 nm. As a result, it becomes easy to control the agglomeration speed at the time of toner production, and it becomes easy to produce a uniform toner. Further, when the size of the polymer primary particles is within the above range, a small-diameter toner is easily obtained, and high-resolution image formation is promoted. The size of the polymer primary particles can be measured using a particle size distribution measuring device as in the case of the wax particle measurement described above. For example, the microtrack particle size distribution measuring device UPA using a laser diffraction scattering method can be used. Examples include commercially available particle size distribution measuring devices such as Nikkiso Co., Ltd.

  In the particle formation step subsequent to the polymerization step, particles are formed by agglomerating and fusing the polymer primary particles and the colorant particles. One of the typical methods for forming particles by agglomeration and fusion is “salting out / fusion”. In this method, polymer primary particles obtained by polymerizing monomers to form polymer primary particles are aggregated using colorant particles and metal salts to grow particles. And when it grows to the desired particle diameter, an aggregation stop agent is added to stop the particle growth, and further, heating for controlling the particle shape is continued as necessary. In the present invention, particle growth is performed by mixing polymer primary particles having different polarities and colored particles, instead of the “salting out / fusion method” using a metal salt. And when it grows to a desired particle diameter, an aggregation terminator is added to stop the particle growth, and further, heating for controlling the particle shape is continued as necessary.

  Further, in the particle forming step, in addition to the polymer primary particles and the colorant particles, internal additives such as waxes and charge control agents can also be aggregated and fused.

  The “aqueous medium” in the particle forming step refers to a material whose main component (50% by mass or more) is water. Examples of components other than water include organic solvents that dissolve in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran.

  The colorant particles can be prepared by dispersing the colorant in an aqueous medium. The dispersion treatment of the colorant is performed in a state where the surfactant concentration is set to a critical micelle concentration (CMC) or more in water. The disperser used for the dispersion treatment of the colorant is not particularly limited, but preferably an ultrasonic disperser, a mechanical homogenizer, a pressure disperser such as a manton gorin or a pressure homogenizer, a sand grinder, a Getzmann mill, a diamond fine mill, or the like. Examples thereof include a medium type disperser. Further, examples of the usable surfactant include the same surfactants as those used for forming the fine resin particles described above, but it is preferable to use an amphoteric surfactant. In the present invention, the colorant (fine particles) may be surface-modified. In the surface modification method of the colorant, the colorant is dispersed in a solvent, the surface modifier is added to the molecular weight solution, and the system is reacted by raising the temperature. After completion of the reaction, the colorant is separated by filtration, washed and filtered with the same solvent, and dried to obtain a colorant (pigment) treated with the surface modifier.

  In the agglomeration / fusion method, an acid such as hydrochloric acid is added to water in which polymer primary particles and colorant particles are present under basic conditions, and the pH is adjusted to the acid side. Next, it is a step of fusing at the same time as agglomeration is advanced by heating to a temperature above the glass transition point of the resin particles. When the desired particle size is reached, the growth of particles is stopped by adding the aggregation terminator of the above general formula (1). And the shape of particle | grains is controlled by performing heating continuously as needed.

  Next, the “step of cooling the colored particle dispersion” (2) will be described. This step is a step of cooling the dispersion of colored particles produced in the above-described step, and a rapid cooling treatment is performed at a cooling rate of 1 to 20 ° C./min. Examples of the cooling treatment method used in this step include a method of cooling by introducing a refrigerant from the outside of the reaction vessel, and a method of cooling by directly introducing cold water into the reaction system.

  Next, (3) “step of solid-liquid separation of colored particles from the cooled colored particle dispersion and washing the colored particles” will be described. In this solid-liquid separation / washing process, the colored particles dispersed from the colored particle dispersion that has been cooled to a predetermined temperature in the above-described process are solid-liquid separated, and the solid colored liquid aggregate called a toner cake is washed by solid-liquid separation. The process consists of a process. By washing the toner cake, deposits such as surfactants and flocculants adhering to the surface of the colored particles are removed.

  Examples of the solid-liquid separation method for the colored particle dispersion include a centrifugal separation method, a vacuum filtration method using Nutsche and the like, a filtration method using a filter press and the like. In addition, by repeatedly performing the solid-liquid separation / washing process a plurality of times, the deposits on the surface of the colored particles can be more reliably removed.

  Next, (4) “step of drying washed colored particles” will be described. This step is a step of drying the toner cake that has undergone the final cleaning process. Specific drying devices used in this process include spray dryer, vacuum freeze dryer, vacuum dryer, stationary shelf dryer, mobile shelf dryer, fluidized bed dryer, rotary dryer And a stirring type dryer.

  The water content of the colored particles after the drying treatment is 5% by mass or less, preferably 2% by mass or less, as measured by the Karl Fischer method. Examples of the moisture measuring device by the Karl Fischer method include an automatic moisture measuring device “AQS-724” (manufactured by Hiranuma Sangyo Co., Ltd.). The conditions for measuring the moisture content are, for example, a vaporization temperature of 110 ° C., and a vaporization time. Set to 25 seconds and measure.

  Next, (5) “step of adding an external additive to the dried colored particles” will be described. In this step, an external additive is added to the dried colored particles as necessary to make the colored particles a toner that can be used for image formation. Examples of the apparatus for adding and mixing the external additive include mechanical mixing apparatuses such as a Henschel mixer and a coffee mill.

  Next, constituent materials of the toner according to the present invention will be described.

  The binder resin used in the toner according to the present invention is not particularly limited, and known ones are used. Specifically, a copolymer of styrene such as polystyrene and polyvinyltoluene and a substituted product thereof; styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid. Acid ester copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene Styrene copolymers such as copolymers, styrene-acrylonitrile-indene copolymers; phenol resins, natural modified phenolic resins, natural resin modified maleic resins, acrylic resins, methacrylic resins, polyvinyl acetate resins, silicone resins, polyesters resin, Polyurethane resins, polyamide resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral resins, terpene resins, coumarone-indene resins, and petroleum resins. Of these, polyester resins and styrene copolymer resins are particularly preferably used.

  In addition, as a monomer combined with the styrene monomer of the styrenic copolymer, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate , Monocarboxylic acids having a double bond such as methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide or the like; maleic acid, butyl maleate, malee Dicarboxylic acids having a double bond such as methyl acid and dimethyl maleate or substituted products thereof; vinyl esters such as vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene and butene; Ketone, vinyl ketones such as vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, vinyl ethers such as vinyl isobutyl ether. In the case of forming a styrene copolymer, these vinyl monomers are used alone or in combination of two or more.

  In addition, the toner binder resin may be a mixture of two or more of the above-described resins, or may form a crosslinked structure via a crosslinking agent. As the crosslinking agent, a compound having two or more polymerizable double bonds is used. Specifically, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid ester compounds having two or more double bonds such as ethylene glycol dimethacrylate, ethylene glycol diacrylate, and 1,3-butanediol dimethacrylate Divinyl aniline, divinyl ether, divinyl sulfide, divinyl sulfone and other divinyl compounds; compounds having three or more vinyl groups, and the like. These can be used alone or in combination of two or more.

  Examples of the colorant that can be used in the toner according to the present invention include the following.

  As the black colorant, for example, carbon black such as furnace black, channel black, acetylene black, thermal black, lamp black, or a magnetic material such as magnetite or ferrite can be used.

  Examples of the colorant for magenta or red 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 colorant for orange or yellow include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.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 pigments for green or cyan 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 15; 4, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. Pigment blue 62, C.I. I. Pigment blue 66, C.I. I pigment green 7 etc. are mentioned.

  These colorants can be used alone or in combination of two or more as required. The addition amount of the colorant is set in the range of 1 to 30% by mass, preferably 2 to 20% by mass with respect to the whole toner.

  A charge control agent can be added to the toner according to the present invention as necessary. Specific examples of charge control agents include nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, benzylic acid derivative metal salts or metal complexes thereof, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, Examples include salicylic acid metal salts and metal complexes thereof. Examples of the contained metal include Al, B, Ti, Fe, Co, and Ni. Among these, a metal complex compound of a benzylic acid derivative is particularly preferable.

  The addition amount of the charge control agent is preferably set in a range of 0.1 to 20.0% by mass with respect to the whole toner.

  A so-called external additive can be added to the toner according to the present invention for the purpose of improving fluidity, chargeability, and cleaning property. These external additives are not particularly limited, and various inorganic fine particles, organic fine particles, and lubricants can be used.

  As inorganic fine particles, for example, silica, titania, alumina, strontium titanate fine particles and the like can be preferably used. These inorganic fine particles may be hydrophobized as necessary. Specific examples of the silica fine particles include commercially available products R-805, R-976, R-974, R-972, R-812, R-809 manufactured by Nippon Aerosil Co., Ltd., HVK-2150, H- manufactured by Hoechst. 200, commercial products TS-720, TS-530, TS-610, H-5, MS-5 and the like manufactured by Cabot Corporation.

  As titania fine particles, for example, commercially available products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., commercially available products MT-100S, MT-100B, MT-500BS, MT-600, MT-600SS, 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, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm can be used. Specifically, homopolymers such as styrene and methyl methacrylate and copolymers thereof can be used.

  The addition amount of these external additives is preferably 0.1 to 10.0% by mass with respect to the whole toner. As a method for adding the external additive, various known mixing apparatuses such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer can be used.

  The toner according to the present invention may be used with a lubricant added for the purpose of improving the cleaning property and the transfer property, if necessary. Examples of lubricants include, for example, salts of zinc stearate, aluminum, copper, magnesium, calcium, zinc oleate, salts of manganese, iron, copper, magnesium, etc., zinc palmitate, copper, magnesium, calcium, etc. And salts of higher fatty acids such as salts, zinc of linoleic acid, salts of calcium, etc., zinc of ricinoleic acid, salts of calcium, etc.

  The addition amount of these lubricants is preferably 0.1 to 10.0% by mass with respect to the whole toner. As a method for adding the lubricant, various known mixing apparatuses such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer can be used.

[Developer according to the present invention]
The toner according to the present invention can be used as a one-component developer or a two-component developer. When used as a one-component developer, a non-magnetic one-component developer or a magnetic one-component developer containing about 0.1 to 0.5 μm of magnetic particles in the toner can be used. be able to. However, the effect of the present invention can be sufficiently exerted and the minute dot reproducibility can be stably exhibited over a long period of time when the toner is mixed with a carrier and used as a two-component developer.

  In this case, conventionally known materials typified by iron-containing magnetic particles such as iron, ferrite, and magnetite can be used as the magnetic particles of the carrier, but ferrite particles or magnetite particles are particularly preferable. The magnetic particles preferably have a volume average particle diameter of 15 to 100 μm, more preferably 20 to 80 μm.

  The volume average particle diameter of the carrier can be measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by Sympathetic).

  The carrier is preferably a coating carrier in which magnetic particles are further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited, and for example, olefin resin, styrene resin, styrene-acrylic resin, silicone resin, ester resin, or fluorine-containing polymer resin is used. The resin for constituting the resin-dispersed carrier is not particularly limited, and known resins can be used. For example, styrene-acrylic resin, polyester resin, fluorine resin, phenol resin, etc. are used. be able to.

  The mixing ratio of the carrier and the toner is preferably in the range of carrier: toner = 1: 1 to 50: 1 by mass ratio.

[Image Forming Method and Image Forming Apparatus]
The toner of the present invention may be used by being loaded into a black and white image forming apparatus or a color image forming apparatus in which toner remaining on any of the photosensitive member, the intermediate transfer member, and the secondary transfer member is cleaned by a cleaning blade. it can.

  Here, the remaining toner refers to transfer residual toner on the photosensitive member, transfer residual toner on the intermediate transfer belt, and patch image toner on the secondary transfer member.

  In a color image forming device, a patch image is formed on an intermediate transfer body for each fixed print, the reflection density of this patch image is measured by a detection sensor, and charging and developing conditions are controlled so that the density becomes a prescribed value. High quality print images are continuously obtained.

  Specifically, the patch image formed on the photosensitive member is transferred as it is to the intermediate transfer member, and the reflection density of the patch image is measured by a detection sensor installed on the periphery of the intermediate transfer member. The charging conditions and the development conditions are controlled by the reflection density of the patch image measured by the detection sensor, and a stable high-quality print image can be continuously obtained.

  After the reflection density of the patch image is measured, the patch image toner on the intermediate transfer member is cleaned by the intermediate transfer member cleaning means described below, or transferred from the intermediate transfer member to the secondary transfer member. Thereafter, the secondary transfer member is cleaned by a cleaning means.

  Hereinafter, a color image forming method and an image forming apparatus in which the toner of the present invention is preferably used will be described.

  FIG. 1 is a schematic cross-sectional view showing an example of a color image forming apparatus using the toner of the present invention.

  First, an outline of an image forming apparatus for color electrophotography equipped with a detection sensor and a secondary transfer device will be described.

  The image forming apparatus GS is called a tandem type color image forming apparatus, and arranges image forming units that form yellow, magenta, cyan, and black color toner images along the moving direction of the intermediate transfer member. The color toner image formed on the image carrier of the image forming unit is transferred onto the intermediate transfer member by multiple transfer, and then transferred onto the transfer material at a time.

  In FIG. 1, a document image placed on an image reading device SC disposed at a position occupying the upper portion of the image forming device GS is scanned and exposed by an optical system, read into a line image sensor CCD, and line image sensor CCD. The analog signal photoelectrically converted by the above is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the image processing section, and then sent to the exposure optical system 3 as image writing means. .

  The intermediate transfer member includes a drum type and an endless belt type, both of which have similar functions. However, in the following description, the intermediate transfer member refers to the endless belt-like intermediate transfer 6. I will decide.

  In FIG. 1, four sets of process units 100 are formed on the peripheral edge of the intermediate transfer member 6 for image formation for each color of yellow (Y), magenta (M), cyan (C), and black (K). Is provided. The process unit 100 is arranged in a vertical line along the intermediate transfer body 6 as a color toner image forming unit along the intermediate transfer body 6 with respect to the rotation direction of the vertical intermediate transfer body 6 indicated by the arrows in the drawing. , K in this order.

  Each of the four sets of process units 100 has a common structure, and each includes a photosensitive drum 1, a charger 2 as a charging unit, an exposure optical system 3 as an image writing unit, a developing device 4, and an image. It comprises a photoconductor cleaning device 190 as a carrier cleaning means.

  In the photosensitive drum 1, a photosensitive layer having a layer thickness (film thickness) of about 20 to 40 μm is formed on the outer periphery of a cylindrical substrate formed of a metallic member such as aluminum having an outer diameter of about 40 to 100 mm. Is. The photosensitive drum 1 is rotated in the direction of the arrow in a state where the substrate is grounded by power from a driving source (not shown), for example, at a linear velocity of about 80 to 280 mm / s, preferably 220 mm / s.

  Around the photosensitive drum 1, an image forming unit including a charger 2 as a charging unit, an exposure optical system 3 as an image writing unit, and a developing device 4 is set as a photosensitive drum indicated by an arrow in the figure. 1 with respect to the rotation direction.

  The charger 2 as a charging unit is attached in close proximity to the photosensitive drum 1 in a direction parallel to the rotation axis of the photosensitive drum 1. The charger 2 includes a discharge wire as a corona discharge electrode that applies a predetermined potential to the photosensitive layer of the photosensitive drum 1, and performs a charging action (negative charging in the present embodiment) by corona discharge having the same polarity as the toner. A uniform potential is applied to the photosensitive drum 1.

  An exposure optical system 3 serving as an image writing means rotationally scans laser light emitted from a semiconductor laser (LD) light source (not shown) in a main scanning direction by a rotating polygon mirror (no symbol), and an fθ lens (no symbol). ), A reflection mirror (without a symbol), etc., the photosensitive drum 1 is exposed to an electrical signal corresponding to an image signal (image writing), and an electrostatic latent image corresponding to a document image is formed on the photosensitive layer of the photosensitive drum 1. Form an image.

  The developing device 4 as a developing unit is configured to supply a two-component developer of each color of yellow (Y), magenta (M), cyan (C), and black (K) charged to the same polarity as the charging polarity of the photosensitive drum 1. A developing roller 4a, which is a developer carrier formed of a cylindrical nonmagnetic stainless steel or aluminum material having a thickness of 0.5 to 1 mm and an outer diameter of 15 to 25 mm, for example, is provided. The developing roller 4a is kept in contact with the photosensitive drum 1 with a predetermined gap (for example, 100 to 1000 μm) by an abutting roller (not shown), and rotates in the same direction as the rotational direction of the photosensitive drum 1. At the time of development, a photoconductor drum is applied by applying to the developing roller 4a a DC voltage having the same polarity as the toner (negative polarity in the present embodiment) or a developing bias voltage that superimposes an AC voltage on the DC voltage. The reversal development is performed on the upper exposed portion.

The intermediate transfer member 6 has a volume resistivity of about 1.0 × 10 ^{7 to} 1.0 × 10 ⁹ Ω · cm and a surface resistivity of about 1.0 × 10 ^{10 to} 1.0 × 10 ¹² Ω / □. A semiconductive endless (seamless) resin belt is used. Specifically, the resin belt has a thickness of 0.05 to 0.5 mm in which a conductive material is dispersed in engineering plastics such as modified polyimide, thermosetting polyimide, ethylene tetrafluoroethylene copolymer, polyvinylidene fluoride, and nylon alloy. A semiconductive resin film can be used. In addition to this, a semiconductive rubber belt having a thickness of 0.5 to 2.0 mm in which a conductive material is dispersed in silicone rubber, urethane rubber or the like can also be used as the intermediate transfer member 6. The intermediate transfer member 6 is wound around a plurality of roller members including a tension roller 6a and a backup roller 6B facing the secondary transfer member, and is supported so as to be rotatable in the vertical direction.

  The primary transfer roller 7 as a first transfer unit for each color is made of a roller-like conductive member using foamed rubber such as silicone or urethane, for example, and the photosensitive drum 1 for each color with the intermediate transfer body 6 interposed therebetween. The transfer area is formed between the photosensitive drum 1 and the back surface of the intermediate transfer body 6 by pressing the back surface thereof. A DC constant current having a polarity opposite to that of the toner (positive polarity in the present embodiment) is applied to the primary transfer roller 7 by constant current control, and a toner image on the photosensitive drum 1 is formed by a transfer electric field formed in the transfer area. Transferred onto the intermediate transfer body 6.

  The toner image transferred onto the intermediate transfer body 6 is transferred onto the transfer material P. A detection sensor 8 for measuring the density of the patch image toner is installed on the periphery of the intermediate transfer member 6.

  In order to clean the residual toner on the intermediate transfer member 6, a cleaning device 190A is provided.

  Further, a secondary transfer device 70 is provided for cleaning the patch image toner on the secondary transfer member 7A.

  Next, an image forming process (image forming process) will be described.

  When the image recording is started, the photosensitive drum drive motor (not shown) is rotated to rotate the Y photosensitive drum 1 in the direction indicated by the arrow in the figure, and a potential is applied to the Y photosensitive drum 1 by the Y charger 2. . After the Y photosensitive drum 1 is applied with a potential, the Y exposure optical system 3 performs exposure (image writing) with an electrical signal corresponding to the first color signal, that is, the Y image data. An electrostatic latent image corresponding to a yellow (Y) image is formed on the body drum 1. The latent image is reversely developed by the Y developing device 4 to form a toner image made of yellow (Y) toner on the Y photosensitive drum 1. The Y toner image formed on the Y photosensitive drum 1 is transferred onto the intermediate transfer member 6 by a primary transfer roller 7 as a primary transfer means.

  Next, a potential is applied to the M photosensitive drum 1 by the M charger 2. After the potential is applied to the M photoconductor drum 1, the M exposure optical system 3 performs exposure (image writing) with an electrical signal corresponding to the first color signal, that is, the M image data, and the M photosensitivity. An electrostatic latent image corresponding to a magenta (M) image is formed on the body drum 1. The latent image is reversely developed by the M developing device 4 to form a toner image made of magenta (M) toner on the M photoconductor drum 1. The M toner image formed on the M photoconductor drum 1 is transferred onto the intermediate transfer body 6 by being superimposed on the Y toner image by a primary transfer roller 7 as a primary transfer unit.

  By a similar process, a toner image made of cyan (C) toner formed on the C photoconductive drum 1 and a toner image made of black (K) toner formed on the K photoconductive drum 1 are obtained. The toner images are sequentially superimposed on the intermediate transfer member 6, and a superimposed color toner image composed of Y, M, C, and K toners is formed on the peripheral surface of the intermediate transfer member 6.

  The toner remaining on the peripheral surface of each photoreceptor drum 1 after the transfer is cleaned by the photoreceptor cleaning device 190.

  On the other hand, the transfer material P as recording paper accommodated in the paper feed cassettes 20A, 20B, and 20C is fed by the feed roller 21 and the paper feed roller 22A provided in the paper feed cassettes 20A, 20B, and 20C, respectively, and conveyed. A secondary transfer member serving as a secondary transfer unit that is transported on the path 22 by transport rollers 22B, 22C, and 22D and to which a voltage having a polarity opposite to that of the toner (plus polarity in the present embodiment) is applied via the registration roller 23. The superposed color toner image (color image) formed on the intermediate transfer body 6 is transferred onto the transfer material P at a time in the transfer area of the secondary transfer member 7A.

  The transfer material P onto which the color image has been transferred is heated and pressed at the fixing nip NA formed by the heating member 17a and the pressure roller 17b of the fixing device 17, and is fixed by the paper discharge roller 24. It is placed on the outer paper discharge tray 25.

  The above describes the state in which image formation is performed on the first surface, which is one side of the transfer material P. In the case of duplex copying, the sheet discharge switching member 26 is switched, the sheet guide portion 26A is opened, and the transfer is performed. The material P is conveyed in the direction of a broken line arrow.

  Further, the transfer material P is transported to the lower transport path 27B by the transport mechanism 27A, switched back by the sheet reversing portion 27C, and the transport path is switched by the branching portion 27D. And is conveyed into the duplex copying paper feed unit 130.

  The transfer material P moves in the paper feeding direction through a conveyance guide 131 provided in the duplex copying paper supply unit 130, and the transfer material P is re-fed by the paper supply roller 132 and guided to the conveyance path 22.

  Then, as described above, the transfer material P is conveyed in the direction of the secondary transfer member 7A, the toner image is transferred to the second surface which is the back surface of the transfer material P, fixed by the fixing device 17, and then the paper discharge tray. 25 is discharged.

  Further, after the color image is transferred onto the transfer material P by the secondary transfer member 7A as the secondary transfer means, the residual toner on the intermediate transfer body 6 that has separated the curvature of the transfer material P becomes the intermediate transfer body cleaning device 190A. Is removed.

  Further, the patch image toner on the secondary transfer member 7 </ b> A is cleaned by the cleaning blade 71 of the secondary transfer device 70.

  Next, the cleaning means for the member to be cleaned will be described.

  FIG. 2 is a schematic view showing an example of a cleaning unit for the photosensitive member.

In FIG. 2, the photoreceptor 1 has a cleaning blade contact angle represented by θ ₁ . Free length L ₁ of the cleaning blade 16 is the length to the tip A 'of the cleaning blade where it is assumed that not deformed from the end portion B of the blade holder 17 (shown by dotted lines in the drawing). h ₁ indicates the thickness of the cleaning blade. The cleaning blade contact angle θ ₁ represents an angle formed between the tangent line X at the contact point A of the photosensitive member and the cleaning blade assumed not to be deformed. The amount of biting a is a radius r ₀ of the outer periphery S ₀ of the photosensitive member and a radius r ₁₁ of a circle S ₁₁ centered on the same central axis C as the photosensitive member having the tip A ′ of the cleaning blade assumed to be undeformed. It is a difference. Contact angle theta ₁ to the photosensitive member of the cleaning blade is preferably 5 to 35 °. By setting the contact angle within the above range, there is no cleaning failure of the transfer residual toner, and no cleaning blade curling occurs (the cleaning blade tip is moved from the counter direction in the same direction as the rotation direction of the photosensitive member). preferable.

  The free length of the cleaning blade is preferably 6 to 15 mm, and the thickness of the cleaning blade is preferably 0.5 to 10 mm.

  As a material of the cleaning blade, urethane rubber, silicone rubber, fluorine rubber, chloroprene rubber, butadiene rubber, or the like can be used. Among these, urethane rubber is preferable in terms of excellent wear characteristics.

  The shape and material of the cleaning blade can be determined as appropriate according to various conditions such as toner characteristics, photoconductor characteristics, cleaning blade contact angle and contact pressure.

  FIG. 3 is a schematic diagram illustrating an example of a cleaning unit for the intermediate transfer member.

  In FIG. 3, reference numeral 601 denotes a casing, which has a housing portion to which the members constituting the cleaning means 190A are attached and the toner removed from the intermediate transfer body 6 is housed.

  Reference numeral 602 denotes a cleaning blade made of an elastic material such as urethane rubber, and is fixed to the blade holder 603 with an adhesive or the like.

  The blade holder 603 is rotatably attached to a support shaft 604 provided in the casing 601.

  A pressing spring 605 urges the blade holder 603 to rotate counterclockwise around the support shaft 604, and the tip of the cleaning blade 602 is in a direction opposite to the rotation direction of the intermediate transfer body 6 (counter direction). In this state, the intermediate transfer member 6 backed up by the backup roller 75 is disposed in pressure contact with the pressure contact position C.

  Reference numeral 608 denotes a toner guide member formed of a sponge roller. The intermediate transfer member 6 is located upstream of the pressure contact position C between the cleaning blade 602 and the intermediate transfer member 6 in the rotational direction indicated by the arrow of the intermediate transfer member 6. It is arrange | positioned so that it may contact | abut.

  The sponge roller 608 is rotated in the same direction as the intermediate transfer body 6 at a contact position with the intermediate transfer body 6 by a rotating means (not shown), and the peripheral speed of the sponge roller 608 is higher than the peripheral speed of the intermediate transfer body 6. It is configured to be faster.

  Reference numeral 609 denotes a toner discharge regulating member made of a polyester resin (PET) sheet. One end of the toner discharge regulating member abuts on the surface of the sponge roller 608 at a position opposite to the contact position between the sponge roller 608 and the intermediate transfer member 6. The other end is fixed to a sheet holding member 610 provided above the sponge roller 608 with a double-sided tape or the like.

  The sheet holding member 610 is fixed to the protrusion 611 of the casing 601 with a screw or the like.

  With such a configuration, the intermediate transfer body 6, the cleaning blade 602, the sponge roller 608, and the toner discharge regulating member 609 form a space S.

  Reference numeral 612 denotes a collection screw provided at the bottom of the casing 601. The toner stored in the bottom of the casing 601 is transported in a direction perpendicular to the paper surface of the drawing and discharged outside the casing 601.

  As shown in the figure, reference numeral 613 denotes a toner receiving sheet made of PET having one end bonded to the bottom of the casing 601 facing the intermediate transfer body 6 and the other end lightly contacting the intermediate transfer body 6, and the toner inside the casing 601. Prevents falling down.

  In FIG. 3, the cleaning blade is made of urethane rubber, the hardness is 74 ° (JIS, A rubber hardness), and the contact pressure of the tip of the cleaning blade against the intermediate transfer member is set to 16.0. The free length of the cleaning blade is preferably 6 to 15 mm, and the thickness of the cleaning blade is preferably 0.5 to 10 mm.

  FIG. 4 is a schematic diagram illustrating an example of a cleaning unit for the secondary transfer member.

  The shape of the secondary transfer member of the secondary transfer device 70 is not particularly limited, and either a roller shape or a belt shape can be used.

  FIG. 4A shows a cleaning unit using a secondary transfer roller 7A as a secondary transfer member.

  4A shows a state in which the secondary transfer roller 7A is pressure-bonded to the backup roller 6B and the cleaning blade 71 is pressure-bonded to the secondary transfer roller 7A via the intermediate transfer body 6. FIG.

  The secondary transfer device 70 includes the secondary transfer roller 7A and its cleaning means 71, and the position of the rotating shaft 7C of the secondary transfer roller 7A and the cleaning holding portion 73H of the cleaning blade 71 in the cleaning portion 71. The position of the rotation support shaft 73C and the position of the fixing pin 74P that fixes the other end of the spring 74 that is hooked on one end of the cleaning holding portion 73H are fixed to the casing 72 of the secondary transfer device 70. Has been.

  In the above-described embodiment, the spring 74 is formed as an elastic member, and one end thereof is fixed to the cleaning holding portion 73H and the other end is fixed to the housing 72.

  4B shows a cleaning unit in which the secondary transfer roller 7A shown in FIG. 4A is changed to an endless belt 7D.

  4A and 4B, the cleaning blade 71 is made of urethane rubber, has a free length of 9 mm, a thickness of 2 mm, and a spring force of the spring 74 of 18.3 N / m. The contact pressure against the secondary transfer roller is set to 13.7 N / m.

  The transfer sheet P for holding a toner image formed using the toner according to the present invention is usually called an image support, a transfer material or a transfer paper, and is particularly limited as long as it can form a toner image. It is not a thing. Specific examples include plain paper ranging from thin paper to thick paper, coated printing paper such as art paper and coated paper, commercially available Japanese paper and postcard paper, plastic films for OHP, cloth, and the like.

  Examples of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

[Preparation of colored particles 1]
(1) Preparation of Polymer Primary Particle Dispersion 1 A monomer mixture composed of 175 g of styrene, 60 g of n-butyl acrylate, 15 g of methacrylic acid, and 7 g of n-octyl-3-mercaptopropionate was attached with a stirrer. Into a stainless steel kettle, 100 g of pentaerythritol tetrabehenate was added and heated to 70 ° C. and dissolved to prepare a monomer mixture.

  On the other hand, a surfactant solution obtained by dissolving 2 g of sodium polyoxyethylene (2) dodecyl ether sulfate in 1350 g of ion-exchanged water is heated to 70 ° C., and after adding and mixing the monomer mixture, it has a circulation path. An emulsified dispersion was prepared by dispersing for 30 minutes with a mechanical disperser CLEARMIX (manufactured by M Technique Co., Ltd.).

  Next, an initiator solution in which 7.5 g of potassium persulfate was dissolved in 150 g of ion exchange water was added to this dispersion, and the system was polymerized by heating and stirring at 78 ° C. for 1.5 hours. Produced. A polymerization initiator solution in which 12 g of potassium persulfate was further dissolved in 220 g of ion-exchanged water was added to the resin particles, and under a temperature condition of 80 ° C., 320 g of styrene, 100 g of n-butyl acrylate, 35 g of methacrylic acid, n -A monomer mixture composed of 7.5 g of octyl-3-mercaptopropionate was added dropwise over 1 hour.

  After completion of the dropping, the mixture was heated and stirred for 2 hours to proceed the polymerization, and then cooled to 28 ° C. to obtain a polymer primary particle dispersion. This polymer primary particle dispersion is referred to as “polymer primary particle dispersion 1”.

(2) Production of Colorant Particle Dispersion 1 100 g of lauryldimethylaminoacetic acid betaine was added to 500 g of ion-exchanged water and dissolved by stirring. While stirring this liquid, 80 g of carbon black (Regal 330R (manufactured by Cabot)) is gradually added, and then dispersed by using a mechanical disperser CLEARMIX (manufactured by M Technique Co., Ltd.), thereby coloring. An agent particle dispersion was prepared. This is designated as “colorant particle dispersion 1”. The particle diameter of the colorant particles in “Colorant particle dispersion 1” was 130 nm when measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.).

(3) Preparation of colored particles Into a reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction device, 392 g of the above-mentioned “polymer primary particle dispersion 1” in terms of solid content and 2100 g of ion-exchanged water are added. The pH was adjusted to 10 by adding a 5 mol / liter sodium hydroxide aqueous solution. Thereafter, 100 g of “Colorant Dispersion 1” was added, and a 5 mol / liter aqueous hydrochloric acid solution was added to adjust the pH to 3.

  Then, aggregation reaction was performed by heating up. In this state, the particle size of the aggregated particles was measured using “Coulter Multisizer 3” (manufactured by Beckman Coulter), and when the median diameter on the volume basis became 6.6 μm, the temperature was kept at 5 mol / 180 g of an aqueous solution of the compound d in 1 liter was added all at once to stop the particle growth. Further, the temperature is raised and the mixture is heated and stirred at 90 ° C. to advance particle fusion. Using the above-mentioned FPIA-2100 (the number of detected HPF is 4000), the average circularity is 0.925. When it became, it cooled to 30 degreeC and produced "colored particle dispersion liquid 1". The produced “colored particle dispersion 1” is subjected to solid-liquid separation with a basket-type centrifuge “MARK 3 type (model number 60 × 40) (manufactured by Matsumoto Machinery Co., Ltd.)” to prepare a wet cake of “colored particle 1”. Formed.

  The formed wet cake was washed with ion-exchanged water at 40 ° C. until the electric conductivity of the filtrate reached 5 μS / cm with the basket-type centrifuge, and then the airflow dryer “Flash Jet Dryer (Seishin Co., Ltd.) "Made by a company" and dried until the water content became 0.5 mass% to produce "colored particles 1". The volume-based median diameter (volume D50% diameter) of the obtained “colored particles 1” was 6.5 μm.

[Preparation of colored particles 2]
(1) Preparation of resin particle dispersion for shell In a reactor equipped with a stirrer, cooling tube, nitrogen introduction tube, and temperature sensor, 2948 g of pure water, anionic surfactant “polyoxyethylene (2) sodium dodecyl ether sulfate” 1.55 g was added and dissolved by stirring, and then heated to 80 ° C. under a nitrogen stream. Next, a monomer solution in which 520 g of styrene, 184 g of butyl acrylate, 96 g of methacrylic acid and 22.1 g of n-octyl mercaptan were mixed, and an aqueous polymerization initiator solution in which 10.2 g of potassium persulfate was dissolved in 218 g of pure water were prepared. After the polymerization initiator aqueous solution was charged into the reactor, the monomer mixed solution was dropped over 3 hours, and further polymerized for 1 hour, and then cooled to room temperature to prepare “resin particle dispersion for shell”. . The weight average molecular weight of the shell tree particles was 13,200, and the mass average particle diameter was 98 nm.

(2) Preparation of colored particles Into a reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introducing device, 392 g of the above-mentioned “polymer primary particle dispersion 1” in terms of solid content and 2100 g of ion-exchanged water are added. The pH was adjusted to 10 by adding a 5 mol / liter sodium hydroxide aqueous solution. Thereafter, 100 g of “Colorant Dispersion 1” was added, and a 5 mol / liter aqueous hydrochloric acid solution was added to adjust the pH to 3.

  Then, aggregation reaction was performed by heating up. The “Coulter Counter 3 (manufactured by Beckman Coulter)” was used as it was, and heating and stirring were continued until the median diameter (D50) based on the number became 5.3 μm.

  When the median diameter (D50) on the basis of the number reaches 5.3 μm, 40 g of “resin particle dispersion for shell” is added in terms of solid content and stirred for 1 hour to fuse the particles for shell to the surface. It was. Furthermore, stirring was continued as it was for 30 minutes, and after the shell was completely formed, the particle size of the aggregated particles was measured using “Coulter Multisizer 3” (manufactured by Beckman Coulter) in this state, When the median diameter reached 6.6 μm, 180 g of a 5 mol / liter aqueous solution of Compound d was added at the same temperature to stop particle growth. Further, the temperature is raised and the mixture is heated and stirred at 90 ° C. to advance particle fusion. Using the above-mentioned FPIA-2100 (the number of detected HPF is 4000), the average circularity is 0.925. When it became, it cooled to 30 degreeC and produced "colored particle dispersion liquid 2." The produced “colored particle dispersion 2” is subjected to solid-liquid separation with a basket-type centrifuge “MARK 3 type (model number 60 × 40) (manufactured by Matsumoto Machinery Co., Ltd.)” to prepare a wet cake of “colored particle 2”. Formed.

  The formed wet cake was washed with ion-exchanged water at 40 ° C. until the electric conductivity of the filtrate reached 5 μS / cm with the basket-type centrifuge, and then the airflow dryer “Flash Jet Dryer (Seishin Co., Ltd.) "Made by a company" and dried until the water content became 0.5 mass% to produce "colored particles 2". The volume-based median diameter (volume D50% diameter) of the obtained “colored particles 2” was 6.5 μm.

[Preparation of colored particles 3]
In the step of “(3) Preparation of colored particles” in Example 1 described above, the aqueous solution of compound d was replaced with a 5 mol / liter sodium hydroxide aqueous solution. The amount added was adjusted to a pH of 5. Otherwise, the same means as in Example 1 were used. This is referred to as “colored particles 3”.

[Preparation of colored particles 4]
In the step of “(3) Preparation of colored particles” in Example 1 described above, the method of adding compound d was changed, and compound d was added “at the same temperature at the same temperature when it reached 6.6 μm”. In contrast, “added dropwise over 40 minutes while gradually raising the temperature from 6.6 μm”. Otherwise, the same means as in Example 1 were used. This is referred to as “colored particles 4”.

[Preparation of colored particles 5]
In the step of “(3) Production of colored particles” in Example 1 described above, Compound d was added in a lump instead of Compound a, and otherwise the same procedure as in Example 1 was used. This is designated as “colored particles 5”.

[Preparation of colored particles 6]
In the step of “(3) Preparation of colored particles” in Example 1 described above, Compound d was added in a batch instead of Compound c, and the other means were the same as in Example 1. This is designated as “colored particles 6”.

[Preparation of colored particles 7]
In the step of “(3) Production of colored particles” in Example 1 described above, Compound d was added in a lump in place of Compound i, and the same procedure as in Example 1 was used except that. This is designated as “colored particles 7”.

[Preparation of colored particles 8]
In the step of “(2) Preparation of colored particles” in Example 2 described above, Compound d was added in a lump in place of Compound f, and otherwise the same procedure as in Example 2 was used. This is designated as “colored particles 8”.

[Preparation of colored particles 9]
In the step of “(2) Preparation of colored particles” in Example 2 described above, the compound d was changed to the compound f, and the compound was added at the same temperature at the time when the compound became 6.6 μm. In contrast, “added dropwise over 40 minutes while gradually raising the temperature from 6.6 μm”. The other means were the same as in Example 2. This is referred to as “colored particles 9”.

[Production of toner and developer]
The obtained “colored particles 1 to 9” were each 1% by weight of hydrophobic silica having a number average primary particle diameter of 12 nm and a hydrophobization degree of 68, and a number average primary particle diameter of 20 nm. Was added so as to be 1% by mass and mixed using a “Henschel Miki mixer (manufactured by Mitsui Miike Chemical Co., Ltd.)”. Thereafter, coarse particles were removed using a sieve having an opening of 45 μm to obtain “Toners 1 to 9”. The produced toners 1 to 9 all had a volume-based median diameter (D50% diameter) of 6.5 μm and an average circularity of 0.925.

  A developer having a toner concentration of 6% was prepared by mixing each of the toners 1 to 9 with a ferrite carrier having a volume average particle diameter of 60 μm coated with a silicone resin.

<Evaluation of cleaning properties>
As an image forming apparatus for evaluation, a commercially available digital printer “bizhub Pro C500 (manufactured by Konica Minolta Business Technologies Co., Ltd.)” has a patch image detection sensor shown in FIG. 1 and a secondary transfer member shown in FIG. A device equipped with a cleaning means for cleaning was prepared.

  The toner and developer prepared above were sequentially loaded into the image forming apparatus, and 400,000 characters were printed on high-quality A4-size paper in a printing environment of 20 ° C. and 50% RH.

  The size of the patch image was 15 mm × 15 mm for all four colors, and the patch image was formed every 1000 sheets printed. The patch image toner was set to be transferred from the intermediate transfer member to the secondary transfer member.

<Cleanability>
The cleaning performance is that after completion of printing on 400,000 sheets, a character image and a patch image with a printing rate of 10% are formed in a printing environment of 20 ° C. and 50% RH, and after cleaning with a cleaning blade, The surface of the next transfer member was visually observed to evaluate the cleaning properties of the patch image toner and the transfer residual toner.

Evaluation criteria A: The surface of the photoconductor, intermediate transfer member, and secondary transfer member is good with no defective cleaning. ○: The surface of the photoconductor, intermediate transfer member, and secondary transfer member is slightly defective in cleaning, but is practically used. No problem x: A cleaning defect occurs on any of the surfaces of the photosensitive member, the intermediate transfer member, and the secondary transfer member, and there is a practical problem.

<< Evaluation of particle size controllability >>
When producing the “colored particle dispersions 1 to 9”, the particle size controllability when the same operation was performed was evaluated.

A: Particle size could be controlled 5 times out of 5 times to 6.5 μm ± 0.2 μm B: Particle size could be controlled 3 times out of 5 times to 6.5 μm ± 0.2 μm X: Particle size 6.5 μm ± 0. The control result could be controlled once in 5 times to 2 μm.

Examples 1 , 2, 4, and 6 and Reference Examples 3 and 5 within the present invention may have any characteristics, but Comparative Examples 1 to 3 outside the present invention have problems with any characteristics.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging device as charging means 3 Exposure optical system as image writing means 4 Developing device as developing means 6 Intermediate transfer member 7A Secondary transfer member 70 Secondary transfer device 100 Process unit 190A Cleaning device

Claims (3)

In the method for producing a toner for developing an electrostatic charge image by agglomerating / fusing from a dispersion containing at least resin particles and colorant particles to form colored particles, the compound c shown below after the step of stopping aggregation A method for producing a toner for developing an electrostatic charge image, wherein one of the compounds d, f and f is added all at once to a dispersion kept at the same temperature as in the aggregation step .

Claim 1 has been toner over the electrostatic image developing you characterized by being manufactured by the manufacturing method of the electrostatic image developing toner according to. The electrostatic latent image developing toner according to claim 2 is used to develop an electrostatic latent image formed on an electrophotographic photosensitive member to form a toner image, which is contact-heat-fixed after being transferred to a recording material. An image forming method .

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