JP2005301011A - toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide excellent developability not only in a normal temperature and normal humidity environment but also in a high temperature and high humidity environment and a low temperature and low humidity environment. In addition, a uniform and good image quality can be obtained in a halftone image. It is an object to provide a toner imparted with durability that can be maintained over a long period of time.
SOLUTION: In a toner having toner particles and inorganic fine powder mixed with the toner particles, the toner particles are a binder resin, a colorant, a wax, and styrene or a styrene derivative satisfying the following conditions, (meth) acrylic. A resin (resin A) comprising a vinyl monomer containing an acid ester and a sulfonic acid group is contained.
(1) The relationship between the acid value [AV (s)] obtained from the content of a vinyl monomer containing a sulfonic acid group and the total acid value of [AV (r)] in the resin (A) is
AV (s) ≦ AV (r) ≦ AV (s) × 1.2
(2) Glass transition temperature of 80 ° C or higher [Selection figure] None

Description

  The present invention relates to a toner used in a recording method using an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or the like.

  Conventionally, a number of methods are known as electrophotographic methods, but general electrophotographic methods utilize a photoconductive substance, and an electrostatic charge image carrier (hereinafter also referred to as a photoreceptor) by various means. An electric latent image is formed thereon, and then the latent image is developed with toner to form a visible image. If necessary, the toner image is transferred to a transfer material such as paper, and then transferred to the transfer material by heat, pressure, or the like. A toner image is fixed on top to obtain a copy.

  As a method of visualizing an electric latent image with toner, a cascade development method, a magnetic brush development method, a pressure development method, a magnetic brush development method using a two-component developer composed of a carrier and a toner, a toner carrier is a photoreceptor. Non-contact one-component development method that causes toner to fly from the toner carrier to the photoreceptor without contact with the toner, contact one-component development method in which the toner carrier is pressed against the photoreceptor and the toner is transferred by an electric field, and a jumping method using magnetic toner Are also used.

  In recent years, the resolution of electrophotographic apparatuses such as printer apparatuses has been increasing as a technical direction. That is, what was conventionally 300 and 600 dpi has become 1200 and 2400 dpi. Therefore, higher definition is also required for the development method. In addition, copying machines are becoming more sophisticated, and therefore, digitization is progressing. The method of digitally forming an image is mainly a method of forming an electrostatic charge image with a laser. Since digitalization promotes further development in the direction of higher resolution, high-resolution and high-definition image formation is required here as well as a printer.

  Furthermore, colorization is progressing rapidly in the field of electrophotography. Since a color image is formed by appropriately overlapping and developing four color toners of yellow, magenta, cyan, and black, each color toner is required to have higher development characteristics than those of a single color. That is, there is a need for a toner that can faithfully develop an electrostatic charge image, reliably transfer to a transfer material without scattering, and easily fix to a transfer material such as paper.

  Therefore, it has become important to control the toner charge amount and charge amount distribution (hereinafter referred to as chargeability) as uniformly as possible.

  There are two charge control agents that are usually used to control the chargeability of the toner: a compound having a complex structure in which a ligand component is coordinated to a central metal, and a polymer compound containing a polar functional group serving as a charging site. Broadly divided into types. Since the compound having a complex structure has crystallinity, the compatibility with the binder resin is poor, and the method for producing the toner is limited in order to uniformly disperse it in the toner particles. On the other hand, the polymer compound type has high compatibility with the resin and is easily dispersed uniformly in the toner, so that there are few restrictions on the selection of the manufacturing method, materials used together, and the like.

  As a polymer compound type charge control agent, a resin containing a polymerizable monomer having a specific structure has been proposed (for example, see Patent Document 1).

  On the other hand, the toner image formed on the photoconductor in the development process is transferred to a recording material in the transfer process, but the transfer residual toner in the image area and the fog toner in the non-image area remaining on the photoconductor are cleaned in the cleaning process. And stored in a waste toner container. For this cleaning process, blade cleaning, fur brush cleaning, roller cleaning and the like have been conventionally performed. From the standpoint of the apparatus, since the apparatus is inevitably enlarged in order to have such a cleaning apparatus, it has become a bottleneck when aiming to make the apparatus compact. Furthermore, from the viewpoint of ecology, a system with less waste toner is desired, and a toner with high transfer efficiency and low fog is required.

  In recent years, there has been an increasing demand for high image quality, and in particular, an image quality such as a silver salt photograph and printed matter has been required at intermediate density. In an electrophotographic system, it is necessary to narrow the toner charge amount distribution more than ever in order to maintain the uniformity in the density of the intermediate range regardless of the usage environment until the end of the life of the cartridge or the developing device. is there. If the charge amount distribution is narrowed, the development efficiency and the transfer efficiency are increased.

  Development efficiency and transfer efficiency are related to toner charge amount, charge amount distribution, toner circularity (or sphericity), and the like.

  If the charge amount of the toner is within an appropriate range and the distribution thereof is narrow, the development efficiency and the transfer efficiency are increased.

  Also, if the circularity of the toner is low, i) the area where the toner and the drum are in contact with each other is large, so that the unevenness of the toner surface is large, and charge concentration tends to occur on the edge portion. Since the generated image force is increased, the releasability from the drum is lowered. The same thing occurs between the toner and the toner carrier or carrier. That is, in order to improve development efficiency and transfer efficiency, it is necessary to increase the circularity of the toner.

  In order to increase the circularity of the toner, the achievement method differs depending on the toner manufacturing method. The toner production method is roughly classified into a pulverization method and a polymerization method. In the pulverization method, a binder resin, a colorant and the like are melt-mixed, and other components are dispersed in the binder resin, and then pulverized by a fine pulverizer and classified by a classifier to have a desired particle size. Toner is obtained. In the toner obtained by the pulverization method, the fracture surface generated by the pulverization becomes the surface of the toner, so that the toner surface has irregularities. For this reason, the degree of circularity cannot be sufficiently increased only by pulverization, and it becomes necessary to form a sphere by a surface modification treatment such as mechanical impact or heat treatment as a post-treatment step. In addition, the polymerization method includes an association aggregation method in which resin particles, a colorant, a release agent, and the like are associated and aggregated to a desired particle size in an aqueous medium containing emulsion-polymerized resin particles as a binder resin component. A polymerizable monomer composition in which a colorant, a release agent, a polymerization initiator, and the like are dispersed and dissolved in a polymerizable monomer serving as a resin component is a droplet having a desired particle size by shearing force in an aqueous medium. There are two types of production processes, suspension polymerization, in which suspension polymerization is carried out. Since the aggregation toner also has irregularities on the surface due to the production method thereof, in order to increase the circularity, the toner after aggregation is heated as a post-treatment step or a new polymerizable monomer composition is used. Needs to be surface-modified by a post-process such as seed polymerization by adding. Since the suspension polymerization toner is obtained by polymerizing a polymerizable monomer in a monomer composition in a droplet state, the shape thereof is close to a true sphere compared to other production methods, and unevenness is also caused. Since the amount of the toner is small, it is possible to obtain a toner having a high degree of circularity without requiring a post-processing step (for example, see Patent Document 2).

  That is, it is possible to obtain a toner that is uniformly charged and has high transfer efficiency by producing it by suspension polymerization using a polymer compound type charge control agent (see, for example, Patent Document 3).

  Further, it is known that the molecular weight of the charge control agent is related to controlling the chargeability of the toner (see, for example, Patent Documents 4 and 5).

JP 63-184762 A JP 2001-343788 A JP 2000-056518 A JP 63-184762 A JP 11-288129 A

  As described above, the toner chargeability is improved by controlling the shape of the toner particles and designing the material of the charge control agent. However, by simply combining these technologies, it is possible to simultaneously satisfy both development durability and toner scattering in the apparatus, which can provide high image quality including halftone image uniformity over a long period of time. I can't. That is, in the prior art, the physical properties for effectively expressing the function of the charge control agent designed to satisfy the chargeability as a toner have not been fully grasped.

That is, the present invention relates to a toner having toner particles and inorganic fine powder mixed with the toner particles, wherein the toner particles include a binder resin, a colorant, a wax, and styrene or a styrene derivative satisfying the following conditions: The present invention relates to a toner comprising a resin (resin A) comprising a (meth) acrylic acid ester and a vinyl monomer containing a sulfonic acid group.
(1) The relationship between the acid value [AV (s)] obtained from the content of a vinyl monomer containing a sulfonic acid group and the total acid value of [AV (r)] in the resin (A) is
AV (s) ≦ AV (r) ≦ AV (s) × 1.2
(2) Glass transition temperature is 80 ° C or higher

  According to the present invention, it is excellent in developability not only in a normal temperature and normal humidity environment, but also in a high temperature and high humidity environment and a low temperature and low humidity environment, and a uniform and good image quality can be obtained in a halftone image. Thus, it is possible to provide a toner imparted with durability capable of maintaining the toner for a long time.

  As a result of intensive studies, the present inventors have found that the ratio of the total acid value of the resin composed of a vinyl monomer containing a sulfonic acid group and the acid value derived from the sulfonic acid group is within a certain range. It has been found that there is an effect of further improving the uniformity of the charge amount distribution. As a result, it has reached a toner that exhibits good developability and high transferability without being affected by various environments in which the toner is used, and can maintain high image quality over a long period of time.

  In the present invention, the ratio between the acid value AV (r) of the resin A and the acid value AV (s) derived from the vinyl monomer containing the sulfonic acid group contained in the resin A is controlled within a certain range. It is characterized in that the above effects can be obtained. As a reason why the effect of the present invention can be obtained by controlling within this range, the present inventors consider as follows. AV (r) of the present invention refers to the entire acid value of the resin A, and AV (s) is calculated from the amount of sulfur atoms constituting the sulfonic acid group. There is a high possibility that it is a carboxylic acid produced by decomposition of a (meth) acrylic ester during production. If these acid components are present in the vicinity of the sulfonic acid, it is considered that the charge amount distribution becomes wide due to charge leakage due to the interaction. More specifically, sulfonic acid has a higher acidity than carboxylic acid, which is presumed to be the main component of the acid component that is the difference in acid value between AV (r) and AV (s), and therefore stores electric charge. Although the ability is high, the inventors consider that charge leaks through carboxylic acid with high polarity and low resistance in the process of delocalizing the localized charge as entropy increases Yes. Furthermore, in the study by the present inventors, since the leakage becomes significant when the amount of the functional group of the carboxylic acid exceeds a certain amount (0.2 times) with respect to the amount of the functional group of the sulfonic acid, AV (s) ≦ It was concluded that the range of AV (r) ≦ AV (s) × 1.2 is essential.

  Furthermore, in order to achieve the uniformity of the halftone image, which is one of the objects of the present invention, the acid value of the resin A is preferably 5 or more and 24 or less. If it is less than 5, uniformity in a high-temperature and high-humidity environment is lost, and if it exceeds 24, gradation in a low-temperature and low-humidity environment is lost, so that the stability of a halftone image tends to be lost.

  In the present invention, the acid value AV (r) of the resin A was measured according to JIS K0070: 1992.

  The acid value AV (s) derived from the vinyl-based monomer containing a sulfonic acid group contained in the resin A is a fluorescent X-ray analyzer (in which a calibration curve is created using a sample whose sulfur content is known by elemental analysis) ( RIX3000) was used on the assumption that all sulfur amounts obtained by quantitative analysis were derived from sulfonic acid.

  Further, the resin A preferably has a weight average molecular weight (Mw) of 25000 to 50000. When the weight average molecular weight (Mw) is less than 25000, the fluidity of the toner under high temperature and high humidity deteriorates and the halftone uniformity decreases. If it exceeds 50000, in addition to taking time to dissolve in the monomer, the oozing out of the wax becomes slow, the winding offset at the time of fixing deteriorates, and the charge amount distribution in a low-temperature and low-humidity environment widens. Resulting in.

  The number average molecular weight of the resin A is preferably 5000 or more and 20000 or less. The reason is that if it is less than 5000, the amount of the oligomer component of the toner increases, and the fluidity of the toner under high temperature and high humidity deteriorates. If it exceeds 20000, the compatibility with the binder resin decreases, so the charge amount distribution is reduced. This is because they tend to be broad.

  The peak molecular weight of the resin A is preferably 18000 or more and 30000 or less. The reason is that if it is less than 18000, the amount of the oligomer component of the toner increases and the fluidity of the toner under high temperature and high humidity deteriorates, and if it exceeds 30000, the fixability tends to be adversely affected.

  Measurement of the molecular weight of the resin component soluble in THF by GPC of resin A of the present invention was performed as follows.

A solution obtained by allowing the toner to stand in THF at room temperature for 24 hours and dissolving it is filtered through a solvent-resistant membrane filter having a pore diameter of 0.2 μm to obtain a sample solution, and measurement is performed under the following conditions. In addition, sample preparation adjusts the quantity of THF so that the density | concentration of the component soluble in THF may be 0.4-0.6 mass%.
Equipment: High-speed GPC “HLC8120 GPC” (manufactured by Tosoh Corporation)
Column: Seven columns of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko)
Eluent: THF
Flow rate: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection volume: 0.10 ml

  In calculating the molecular weight of the sample, standard polystyrene resin (TSO standard polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F- manufactured by Tosoh Corporation) was used. 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500).

  In the toner of the present invention, it is advantageous that the resin A is present on the surface most involved in the charging of the toner in order to maximize the effect.

  In the toner of the present invention, the content of carbon element present on the toner surface (A: atomic number%) and the content of sulfur element present on the toner surface (E: atomic number%) measured by X-ray photoelectron spectroscopy analysis. ) (E / A) is preferably in the range of 0.0010 to 0.0050. This ratio can be controlled within a suitable range by the amount of the polymer having a vinyl monomer containing a sulfonic acid group to be used. If it is less than 0.0010, it becomes difficult to obtain a sufficient charge amount under high temperature and high humidity, resulting in loss of uniformity of the halftone image, and if it exceeds 0.0050, the stability of the charge amount against humidity change is reduced. As a result, the overall image quality tends to deteriorate.

  The ratio (E / A) of the sulfur element content (E) to the carbon element content (A) present on the toner particle surface is determined by surface composition analysis by ESCA (X-ray photoelectron spectroscopy) as follows. It can be measured by doing.

In the present invention, the ESCA apparatus and measurement conditions are as follows.
Equipment used: 1600S type X-ray photoelectron spectrometer manufactured by PHI Measurement conditions: X-ray source MgKα (400 W)
Spectral region 800μmφ

  In calculating the surface atom concentration, the peak top intensity existing at a binding energy of 160 to 172 eV for sulfur atoms and a binding energy of 280 to 290 eV for carbon atoms was used.

  In the present invention, the surface atomic concentration was calculated from the measured peak intensity of each element using a relative sensitivity factor provided by PHI.

  In this measurement, it is preferable that the toner is ultrasonically washed and the external additive adhering to the toner particle surface is removed by a method such as decantation, filtration, and centrifugation, and then dried and measured.

  As the sulfur-containing monomer for producing the resin A according to the present invention, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamide-2-methylpropanesulfonic acid, vinylsulfonic acid, There are methacrylsulfonic acid and the like, or maleic acid amide derivatives, maleimide derivatives, and styrene derivatives having the following structures.

  The resin A according to the present invention may be a homopolymer of the above monomer, but may be a copolymer of the above monomer and another monomer. As a monomer that forms a copolymer with the above monomer, there is a vinyl polymerizable monomer, and a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

  Of the above monomers, sulfonic acid group-containing (meth) acrylamide is more preferable in obtaining the chargeability suitable for the toner of the present invention.

  The amount of the vinyl monomer containing a sulfonic acid group used when polymerizing the resin A of the present invention is in the range of 2 to 8% by mass, achieving a suitable charge amount in the toner, and improving the image quality of the halftone image. It is preferable for stable supply without being affected by the environment.

  Monofunctional polymerizable monomers include styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butyl. Styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p -Styrene derivatives such as phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2 -Ethylhexyl acrylate , Acrylic polymerizable monomers such as n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl Methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate Methacrylic polymerizable monomers such as dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl methyl ether Vinyl ether such as vinyl ethyl ether and vinyl isobutyl ether; vinyl ketone such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  As polyfunctional polymerizable monomers, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol Diacrylate, polypropylene glycol diacrylate, 2,2′-bis (4- (acryloxydiethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4- (methacryloxy-diethoxy) phenyl) propane, 2,2′-bis (4-methacryloxy / polyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether, and the like.

  In the resin A, as a monomer that can be used in combination with a vinyl monomer containing a sulfonic acid group, the above-described monomers can be used, but styrene or a styrene derivative is an essential monomer. This is because it is indispensable for controlling the charge amount of the resin A in order to stably maintain the image quality of the halftone image. Furthermore, (meth) acrylic acid ester must exist as an essential component in controlling the glass transition temperature described later.

  The production method of the resin A includes bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, ionic polymerization, etc., but solution polymerization is preferable from the viewpoint of operability.

As resin A, the polymer which has a sulfonic acid group which has the following structure can also be illustrated.
X (SO ₃ ⁻ ) n · mY ^{k +}
(X represents a polymer site derived from the polymerizable monomer, Y ^{k +} represents a counter ion, k is a valence of the counter ion, m and n are integers, and n = k × m is there.)

  In this case, the counter ions are preferably hydrogen ions, sodium ions, potassium ions, calcium ions, ammonium ions, and the like.

  The resin A is preferably contained in an amount of 0.5 to 10 parts by mass per 100 parts by mass of the binder resin. 1 to 8 parts by mass is preferable.

  When the content of the resin A is less than 0.5 parts by mass, it is difficult to obtain a sufficient charge control action as mentioned in the present invention. It tends to cause deterioration of transferability and transferability.

  The content of the resin A in the toner can be measured using a capillary electrophoresis method or the like.

  The resin A must have a glass transition point (Tg) of 80 ° C. or higher, and preferably 100 ° C. or lower. When the glass transition point is less than 80 ° C., it tends to be difficult to stably output a halftone image at a high temperature. If the glass transition temperature is less than 80 ° C., the external charge can easily be embedded in the charge control agent portion present on the surface, so that the triboelectric chargeability is lowered. On the other hand, when the glass transition point exceeds 100 ° C., the charge-up in a low-temperature and low-humidity environment tends to deteriorate, and the fixability at the time of an image having a high toner printing rate is poor.

  The glass transition temperature Tg was measured according to ASTM D3418-82 using a differential thermal analysis measuring device (DSC measuring device), DSC-7 (manufactured by PerkinElmer).

  The sample to be measured is precisely weighed 5 to 20 mg, preferably 10 mg.

  This is put in an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rise rate of 10 ° C./min at room temperature and normal humidity within a measurement temperature range of 30 to 200 ° C.

  An endothermic peak of the main peak is obtained in this temperature rising process.

  At this time, the point of intersection between the base line midpoint before and after the endothermic peak and the differential heat curve is defined as the glass transition temperature Tg in the present invention.

  Resin A preferably has a volatile content of 0.01 to 2.0%. In order to reduce the volatile content to less than 0.01%, the volatile content removal process becomes complicated, and when the volatile content exceeds 2.0%, charging under high temperature and high humidity, especially charging after standing. It tends to be inferior. The polymer volatile content is the ratio of the weight that decreases when heated at high temperature (135 ° C.) for 1 hour.

  In the measurement of the molecular weight and glass transition point of the resin A, when the resin is extracted from the toner, the extraction method is not particularly limited, and any method can be used.

  The average circularity, which is a preferred embodiment of the toner of the present invention, will be described below.

  The toner of the present invention preferably has an average circularity of 0.960 to 0.995. A toner having an average circularity of 0.960 or more has excellent transferability. This is because the contact area between the toner particles and the photoconductor is small, and the adhesion force of the toner particles to the photoconductor due to mirror image force, van der Waals force, or the like is reduced. Therefore, when such toner is used, the transfer efficiency is high, which contributes to a reduction in toner consumption.

  Furthermore, toner particles having an average circularity of 0.960 or more have few edge portions on the surface, and therefore, the charge distribution in one particle is difficult to occur, so that the charge amount distribution tends to be narrow, and the latent image Developed faithfully. Therefore, 0.960 or more is preferable. However, even if the average circularity is high, the effect may be insufficient if the circularity of the existing particles is low. In order to obtain the above effect, the mode circularity described later is particularly 0.99. The above is preferable.

  On the other hand, since the toner circularity composed of toner having an average circularity exceeding 0.995 is very high, it is difficult to obtain the effect of suppressing cleaning failure, which is an effect of the present invention.

  The average circularity in the present invention is used as a simple method for quantitatively expressing the shape of the particles. In the present invention, the average circularity is measured using a flow type particle image analyzer “FPIA-1000” manufactured by Toa Medical Electronics. The circularity degree (ai) of each particle measured for a particle group having a circle-equivalent diameter of 3 μm or more was determined by the following equation (1), and the total particle size measured by the following equation (2) A value obtained by dividing the sum of the circularity by the total number of particles (m) is defined as the average circularity (a).

  Further, the mode circularity means that the circularity is divided into 61 parts every 0.01 from 0.40 to 1.00, and the measured circularity of each particle is assigned to each divided range, and the frequency value in the circularity frequency distribution. Is the maximum circularity of the peak.

  In addition, “FPIA-1000”, which is a measuring apparatus used in the present invention, calculates the circularity of each particle, and then calculates the average circularity and the mode circularity. A calculation method is used in which 0.40 to 1.00 is divided into 61 classes, and the average circularity and mode circularity are calculated using the center value and frequency of the dividing points. However, the error of the average circularity obtained from the calculation formula that directly uses the average circularity value calculated by this calculation method and the circularity of each particle described above is very small and can be substantially ignored. is there. Therefore, in the present invention, for the reason of handling data such as shortening the calculation time and simplifying the calculation formula, the concept of the calculation method that directly uses the circularity of each particle described above is used, and some changes are made. Such a calculation formula may be used.

  Measuring means are as follows. A dispersion is prepared by dispersing 5 mg of toner in 10 ml of water in which about 0.1 mg of a surfactant is dissolved, and ultrasonic waves (20 kHz, 50 W) are irradiated to the dispersion for 5 minutes, and the dispersion concentration is set to 5000 to 2 The number of particles / μl is measured by the above apparatus, and the average circularity and mode circularity of a particle group having an equivalent circle diameter of 3 μm or more are obtained.

  The average circularity in the present invention is an index of the degree of unevenness of the developer, and is 1.000 when the developer is a perfect sphere, and the circularity becomes smaller as the surface shape becomes more complicated.

  In this measurement, the reason for measuring the circularity only for the particle group having an equivalent circle diameter of 3 μm or more is as follows. The particle group having an equivalent circle diameter of less than 3 μm includes a large number of particle groups of external additives that exist independently of the toner particles. Therefore, when the object to be measured is expanded to less than 3 μm, the effect of the toner particles This is because the circularity of the group cannot be estimated accurately.

  Next, the particle size of the toner will be described.

  The toner of the present invention preferably has a weight average particle diameter of 4 to 8 [mu] m in order to faithfully develop finer latent image dots for higher image quality. In a toner having a weight average particle diameter of less than 4 μm, the transfer residual toner on the photoreceptor increases due to a decrease in transfer efficiency. In such a case, it is difficult to suppress the photoconductor scraping and toner fusion in the contact charging step. Furthermore, in addition to an increase in the entire surface area of the toner, the fluidity and agitation as a powder decrease, and it becomes difficult to uniformly charge individual toner particles, so fog and transferability tend to deteriorate, This is not preferable for the toner used in the present invention because it tends to cause non-uniform image unevenness other than scraping and fusion. When the weight average particle diameter of the toner exceeds 8 μm, the characters and line images are likely to be scattered and it is difficult to obtain high resolution.

  In order to efficiently develop the effect of the toner of the present invention, the average circularity is 0.960 to 0.995, and the weight average particle diameter (D4) is more preferably 3 to 10 μm. preferable. Further, it is particularly preferable that the mode circularity of the toner is 0.99 or more because the number of particles having the same circularity is increased and the charging property is improved.

  The weight average particle diameter and number average particle diameter of the toner of the present invention can be measured by various methods such as Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter Inc.). Specifically, it can be measured as follows. Using a Coulter Multisizer (manufactured by Coulter), an interface (manufactured by Nikka) and a PC 9801 personal computer (manufactured by NEC) are connected to output the number distribution and volume distribution. As the electrolytic solution, a 1% NaCl aqueous solution prepared using primary sodium chloride can be used. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. The measurement procedure is as follows.

  100 to 150 ml of the electrolytic aqueous solution is added, and 2 to 20 mg of a measurement sample is further added. The electrolyte solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the volume and number of toner particles of 2 μm or more are measured with the Coulter Multisizer using a 100 μm aperture. Calculate the distribution. From this, the weight average particle diameter (D4) and the number average particle diameter (D1) are determined.

  Although the toner according to the present invention can be produced by a pulverization method, the toner particles obtained by this pulverization method are generally indefinite shape, and the average circularity which is a preferable requirement of the toner according to the present invention is high. In order to obtain a physical property of 0.960 to 0.995 (preferably a mode circularity of 0.99 or more), it is necessary to perform mechanical / thermal or some treatment.

  Therefore, in the present invention, it is preferable to produce toner particles by a polymerization method. Examples of the toner production method by polymerization include a direct polymerization method, a suspension polymerization method, an emulsion polymerization method, an emulsion association polymerization method, and a seed polymerization method. Among these, the balance between the particle size and the particle shape is balanced. In view of easiness, it is particularly preferable to produce by suspension polymerization. In this suspension polymerization method, a monomer composition is prepared by uniformly dissolving or dispersing a colorant (and, if necessary, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives) in the polymerizable monomer. Then, the monomer composition is dispersed in a continuous layer containing a dispersion stabilizer (for example, an aqueous phase) by using an appropriate stirrer, and a polymerization reaction is performed to have a desired particle size. Toner is obtained. When the toner is produced by this suspension polymerization method, since the individual toner particle shapes are substantially spherical, the average circularity is 0.960 to 0.995, particularly the mode circularity is 0.99 or more. It is easy to obtain toner that satisfies the requirements, and such toner has high transferability because the distribution of charge amount is relatively uniform.

  Furthermore, a toner having a core / shell structure in which a surface layer is provided by adding a polymerizable monomer and a polymerization initiator to the fine particles obtained by suspension polymerization can be designed as necessary. .

  The toner of the present invention preferably contains 0.5 to 50 parts by mass of a release agent with respect to 100 parts by mass of the binder resin in order to obtain a good fixed image. Examples of the release agent include various waxes.

  As the release agent usable in the toner according to the present invention, petroleum wax such as paraffin wax, microcrystalline wax, petrolactam and derivatives thereof, montan wax and derivatives thereof, hydrocarbon wax and derivatives thereof by Fischer-Tropsch method, Polyolefin waxes represented by polyethylene and derivatives thereof, natural waxes such as carnauba wax and candelilla wax, and derivatives thereof. These derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. Furthermore, higher fatty alcohols, fatty acids such as stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes and the like can be mentioned. Among these waxes, those having an endothermic peak in differential thermal analysis of 40 ° C. to 110 ° C. are preferred, and those having a temperature of 45 ° C. to 90 ° C. are more preferred.

  As content when using a mold release agent, the range of 0.5-50 mass parts is preferable with respect to 100 mass parts of binder resin. If the content is less than 0.5 parts by mass, the effect of suppressing the low temperature offset is poor, and if it exceeds 50 parts by mass, the long-term storage stability is deteriorated and the dispersibility of other toner materials is deteriorated, and the toner fluidity is deteriorated. Leading to a decrease in image quality and image characteristics.

  The maximum endothermic peak temperature of the wax component is measured according to “ASTM D 3418-82”. For the measurement, for example, DSC-7 manufactured by PerkinElmer is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium. An aluminum pan is used as a measurement sample, an empty pan is set as a control, and measurement is performed at a heating rate of 10 ° C./min.

  Further, the glass transition temperature (Tg) of the resin A is based on the DSC curve at the time of the second temperature increase, and the temperature at the intersection between the baseline before the endothermic peak, the baseline between the endothermic peak and the rising curve is Tg. did.

  The toner of the present invention contains a colorant as an essential component in order to impart coloring power. Examples of the organic pigment or dye preferably used in the present invention include the following.

  As an organic pigment or organic dye that can be used as a cyan colorant, a copper phthalocyanine compound and a derivative thereof, an anthraquinone compound, a basic dye lake compound, or the like can be used. Specifically, C.I. I. Pigment blue 1, C.I. I. Pigment blue 7, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 1, 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 60, C.I. I. Pigment blue 62, C.I. I. And CI Pigment Blue 66.

  Organic pigments or organic dyes that can be used as magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds. Is used. Specifically, 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 violet 19, C.I. I. Pigment red 23, C.I. I. Pigment red 48: 2, C.I. I. Pigment red 48: 3, C.I. I. Pigment red 48: 4, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 81: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 144, C.I. I. Pigment red 146, C.I. I. Pigment red 150, C.I. I. Pigment red 166, C.I. I. Pigment red 169, C.I. I. Pigment red 177, C.I. I. Pigment red 184, C.I. I. Pigment red 185, C.I. I. Pigment red 202, C.I. I. Pigment red 206, C.I. I. Pigment red 220, C.I. I. Pigment red 221, C.I. I. And CI Pigment Red 254.

  As the organic pigment or organic dye that can be used as the yellow colorant, compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, 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 62, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 110, C.I. I. Pigment yellow 111, C.I. I. Pigment yellow 120, C.I. I. Pigment yellow 127, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 129, C.I. I. Pigment yellow 147, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 168, C.I. I. Pigment yellow 174, C.I. I. Pigment yellow 175, C.I. I. Pigment yellow 176, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 181, C.I. I. Pigment yellow 191, C.I. I. And CI Pigment Yellow 194.

  These colorants can be used alone or mixed and further used in the form of a solid solution. The colorant used in the toner of the present invention is selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in the toner.

  The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  As the black colorant, carbon black, a magnetic material, and a color toned to black using the yellow / magenta / cyan colorant are used.

  When a magnetic material is used as the black colorant, it is used by adding 30 to 200 parts by mass with respect to 100 parts by mass of the resin, unlike other colorants.

Examples of the magnetic material include metal oxides containing elements such as iron, cobalt, nickel, copper, magnesium, manganese, aluminum, and silicon. Among them, those containing iron oxide as a main component, such as triiron tetroxide and γ-iron oxide, are preferable. Further, from the viewpoint of toner chargeability control, other metal elements such as silicon element or aluminum element may be contained. These magnetic particles, BET specific surface area by nitrogen adsorption method 2~30m ² / g, particularly preferably 3~28m ² / g, further Mohs hardness magnetic powder 5-7 is preferred.

  Magnetic materials include octahedrons, hexahedrons, spheres, needles, scales, and the like. In the present invention, there are few anisotropies such as octahedrons, hexahedrons, spheres, and irregular shapes. Those for increasing the image density are preferable. The average particle size of the magnetic material is preferably 0.05 to 1.0 μm, more preferably 0.1 to 0.6 μm, and further preferably 0.1 to 0.3 μm.

  In the present invention, when a toner is obtained using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and water phase transfer property of the colorant, and preferably a material that does not inhibit surface modification, for example, polymerization inhibition. It is better to apply a hydrophobizing treatment. In particular, since dye-based colorants and carbon black often have polymerization inhibition properties, care must be taken when using them. A preferable method for surface-treating the dye-based colorant includes a method in which a polymerizable monomer is polymerized in the presence of these dyes in advance, and the obtained colored polymer is added to the monomer system.

  Carbon black may be treated with a substance that reacts with the surface functional group of carbon black, such as polyorganosiloxane, in addition to the same treatment as the dye-based colorant.

  Next, a method for producing the toner of the present invention by suspension polymerization will be described.

  When the toner of the present invention is produced by the suspension polymerization method, examples of the polymerizable monomer constituting the polymerizable monomer system to be used include the following.

Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; methyl acrylate, ethyl acrylate, Acrylic esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate Class: Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenolic methacrylate , Dimethylaminoethyl methacrylate, such as methacrylic acid esters of diethylaminoethyl methacrylate; and other acrylonitrile, methacrylonitrile, and such monomers of acrylamide.

  These polymerizable monomers can be used alone or in combination. Among the polymerizable monomers described above, styrene or a styrene derivative is preferably used alone or in combination with other polymerizable monomers from the viewpoint of developing characteristics and durability of the toner.

  In the production of the suspension polymerization toner according to the present invention, the polymerization may be carried out by adding a resin to the polymerizable monomer system.

  Since monomers containing hydrophilic functional groups such as amino groups, carboxylic acid groups, hydroxyl groups, glycidyl groups, and nitrile groups are water-soluble, they dissolve in an aqueous suspension and cause emulsion polymerization. Cannot be used as a mass. When it is desired to introduce a monomer component containing a hydrophilic functional group into the toner, a random copolymer, a block copolymer or a graft copolymer of these hydrophilic functional group-containing monomer and a vinyl compound such as styrene or ethylene. It can be introduced into the toner in the form of a copolymer such as a polymer, or in the form of a polycondensate such as polyester or polyamide, or a polyaddition polymer such as polyether or polyimine. When such a hydrophilic functional group-containing resin coexists in the toner, the above-mentioned wax component is phase-separated and the encapsulation becomes stronger, and a toner having good offset resistance, blocking resistance, and low-temperature fixability can be obtained. Can do.

  In addition, for the purpose of improving the dispersibility and fixability of the material or image characteristics, a resin may be included in the polymerizable monomer system. Examples of the resin used include styrene such as polystyrene and polyvinyltoluene. And styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-methacrylic acid Acid butyl copolymer, styrene-dimethylaminoethyl methacrylate copolymer Polymer, Styrene-vinyl methyl ether copolymer, Styrene-vinyl ethyl ether copolymer, Styrene-vinyl methyl ketone copolymer, Styrene-butadiene copolymer, Styrene-isoprene copolymer, Styrene-maleic acid copolymer Styrene copolymers such as styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacryl Acid resins, rosins, modified rosins, terpene resins, phenol resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins and the like can be used alone or in combination.

  Among these, a polyester resin is preferable as the resin used by adding to the monomer system.

  The polyester resin used in the present invention, for example, controls one or both of a saturated polyester resin and an unsaturated polyester resin in order to control physical properties such as chargeability, durability, and fixability of toner obtained from toner particles. It is possible to select and use as appropriate. The alcohol component and acid component which comprise the polyester resin used for this invention are illustrated below. As alcohol components, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexane Diol, neopentyl glycol, 2-ethyl-1,3-hexanediol, cyclohexanedimethanol, butenediol, octenediol, cyclohexenedimethanol, hydrogenated bisphenol A, and bisphenol derivatives represented by the following general formula (III):

［式中、Ｒはエチレンまたはプロピレン基であり、ｘ，ｙはそれぞれ１以上の整数であり、かつｘ＋ｙの平均値は２〜１０である。］、あるいは一般式（ＩＩＩ）の化合物の水添物
また、下記一般式（ＩＶ）で示されるジオール、

[Wherein, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10. Or a hydrogenated compound of the compound of the general formula (III), or a diol represented by the following general formula (IV):

  Or the diol of the hydrogenated compound of the compound of Formula (IV), Furthermore, polyhydric alcohol like glycerin, pentaerythritol, sorbit, sorbitan, oxyalkylene ether of a novolak-type phenol resin, etc. are mentioned.

  As the divalent carboxylic acid, benzene dicarboxylic acid such as phthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride or its anhydride, alkyl dicarboxylic acid such as succinic acid, adipic acid, sebacic acid, azelaic acid or its anhydride, Furthermore, succinic acid substituted with an alkyl or alkenyl group having 6 to 18 carbon atoms or anhydride thereof, unsaturated dicarboxylic acid such as fumaric acid, maleic acid, citraconic acid, itaconic acid or anhydride thereof, and further trimellit And polyvalent carboxylic acids such as acid, pyromellitic acid, 1,2,3,4-butanetetracarboxylic acid and benzophenonetetracarboxylic acid, and anhydrides thereof.

  The polyester resin is present on the surface of the toner particles in the production method of the present invention, and the obtained toner particles have an acid value of 0.1 to 50 mg KOH / resin 1 g in order to develop stable chargeability. It is preferable. If the amount is less than 0.1 mg KOH / resin 1 g, the amount existing on the surface of the toner particles may be absolutely insufficient. If the amount exceeds 50 mg KOH / resin 1 g, the chargeability of the toner particles may be adversely affected. Furthermore, in the present invention, the acid value range of 5 to 35 mg KOH / resin 1 g is more preferable.

  As addition amount of these resin, 1-20 mass parts is preferable with respect to 100 mass parts of polymerizable monomers. If it is less than 1 part by mass, the effect of addition is small, while if it exceeds 20 parts by mass, it becomes difficult to design various physical properties of the suspension polymerization toner.

  Furthermore, if a polymer having a molecular weight different from the molecular weight range of the binder resin obtained by polymerizing the polymerizable monomer is dissolved in the monomer and polymerized, the toner has a wide molecular weight distribution and high offset resistance. Can be obtained.

  As the polymerization initiator used in the production of the polymerized toner according to the present invention, a polymerization initiator having a half life of 0.5 to 30 hours at the reaction temperature during the polymerization reaction is preferably used. Moreover, when a polymerization reaction is carried out at an addition amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer, a polymer having a maximum between 10,000 and 100,000 is usually obtained. A toner having strength and melting characteristics can be obtained. Examples of polymerization initiators include 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile) Azo or diazo polymerization initiators such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide, t-butylperoxy 2-ethylhexa Noate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl Peroxide polymerization such as peroxide and lauroyl peroxide Agents.

  When the polymerized toner according to the present invention is produced, a crosslinking agent may be added, and a preferable addition amount is 0.001 to 15 parts by mass with respect to 100 parts by mass of the polymerizable monomer. Examples of the crosslinking agent include divinylbenzene.

  In producing the polymerized toner according to the present invention, a molecular weight modifier can be used. Examples of the molecular weight modifier include mercaptans such as t-dodecyl mercaptan, n-dodecyl mercaptan and n-octyl mercaptan; halogenated hydrocarbons such as carbon tetrachloride and carbon tetrabromide; α-methylstyrene dimer, and the like. Can be mentioned. These molecular weight regulators can be added before the polymerization starts or during the polymerization. The molecular weight modifier is usually used in a proportion of 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  In the method for producing a polymerized toner according to the present invention, a colorant in a polymerizable monomer, and if necessary, a polymer having a sulfur atom, a magnetic powder, a release agent, a plasticizer, a charge control agent, and a crosslinking agent Add organic solvent, high molecular weight polymer, dispersing agent, etc. to reduce the viscosity of the polymer produced by the polymerization reaction, and dissolve uniformly with a disperser such as a homogenizer, ball mill, colloid mill, or ultrasonic disperser Alternatively, it is dispersed to prepare a polymerizable monomer system, which is dropped into an aqueous medium containing a dispersion stabilizer, suspended and granulated. At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to obtain a desired toner particle size at a stretch. As the timing of addition of the polymerization initiator, it may be added simultaneously with the addition of other additives to the polymerizable monomer, or may be added immediately before suspending the polymerizable monomer system in the aqueous medium. . Also, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction.

  After granulation, stirring may be performed using a normal stirrer to such an extent that the particle state is maintained and the particles are prevented from floating and settling.

  When the polymerized toner according to the present invention is produced, a known surfactant or organic or inorganic dispersant can be used as a dispersion stabilizer. In particular, when an inorganic dispersant is used, it is difficult to produce ultrafine powder, and since the inorganic dispersant is generally large in size, dispersion stability is obtained due to steric hindrance, so it is stable even when the reaction temperature is changed. It is difficult to lose its properties and is easy to clean. Therefore, an inorganic dispersant can be used more preferably. Examples of such inorganic dispersants include polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate, and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; calcium metaoxalate, calcium sulfate, and sulfuric acid. Inorganic salts such as barium; inorganic oxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite and alumina.

  These inorganic dispersants may be used alone in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer, and 0.001 to 0.1 parts by mass for the purpose of adjusting the particle size distribution. These surfactants may be used in combination. Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

  The inorganic dispersant can be almost completely removed by dissolution with an acid or alkali after the polymerization.

  In the polymerization step, the polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. When the polymerization is carried out in this temperature range, the release agents to be sealed inside are precipitated by phase separation, and encapsulation is more sure. In order to consume the remaining polymerizable monomer, the reaction temperature may be raised to 90 to 150 ° C. at the end of the polymerization reaction. The polymerized toner particles are filtered, washed, and dried by a known method after the polymerization is completed, and the toner can be obtained by mixing and adhering the inorganic fine powder to the surface. Moreover, a classification process may be put into a manufacturing process and coarse powder and fine powder may be cut.

  When the toner of the present invention is produced by a pulverization method, a known method is used. For example, a binder resin, a colorant according to the present invention, and optionally a resin A, magnetic powder, a release agent, a charge control agent. Components necessary for toner and other additives and other additives are thoroughly mixed by a mixer such as a Henschel mixer and a ball mill, and then melt-kneaded using a heat kneader such as a heating roll, kneader, extruder, etc. Disperse or dissolve other toner materials such as magnetic powder in the toner, cool and solidify, pulverize, then classify and surface treatment as necessary to obtain toner particles, if necessary The toner of the present invention can be obtained by adding and mixing fine powder and the like. Either the classification or the surface treatment may be performed first. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency. The pulverization step can be performed by a method using a known pulverizer such as a mechanical impact type or a jet type. In order to obtain a toner having a specific circularity according to the present invention, it is preferable that the toner is further pulverized by heat or subjected to a supplementary mechanical shock treatment. Further, a hot water bath method in which finely pulverized (classified as necessary) toner particles are dispersed in hot water, a method of passing in a hot air stream, or the like may be used.

  Examples of means for applying a mechanical impact force include a method using a mechanical impact pulverizer such as a kryptron system manufactured by Kawasaki Heavy Industries, Ltd. or a turbo mill manufactured by Turbo Industry. Also, like devices such as Hosokawa Micron's Mechano-Fusion System and Nara Machinery's Hybridization System, the toner is pressed against the inside of the casing by centrifugal force with high-speed rotating blades, and the force of compression force, friction force, etc. There is also a method of applying a mechanical impact force to the toner.

  In the case of using the mechanical impact method, it is preferable from the viewpoint of aggregation prevention and productivity to apply a thermomechanical impact to such an extent that the processing temperature becomes a temperature near the glass transition point Tg (Tg ± 10 ° C.) of the toner. . More preferably, it is particularly effective to improve the transfer efficiency to carry out at a processing temperature of the glass transition point Tg ± 5 ° C. of the toner.

  Furthermore, the toner of the present invention may be produced by a method of obtaining a spherical toner by atomizing a molten mixture in air using a disk or a multi-fluid nozzle described in JP-B-56-13945.

  As the binder resin when the toner of the present invention is produced by a pulverization method, polystyrene; homopolymer of substituted styrene such as polyvinyltoluene; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene- Vinyl naphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer Polymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, Styrene-vinyl ethyl ether copolymer Styrene copolymers such as styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate , Polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic Hydrocarbon resins, aromatic petroleum resins, paraffin waxes and carnauba waxes can be used alone or in combination. In particular, a styrene copolymer and a polyester resin are preferable in terms of development characteristics, fixing properties, and the like.

  To the toner of the present invention, inorganic fine powder is added in order to improve the fluidity of the toner and make the charge uniform.

  In the inorganic fine powder, the average primary particle size is preferably 4 to 80 nm.

  When the average primary particle size of the inorganic fine powder is larger than 80 nm, the fluidity of the toner cannot be sufficiently improved, the adhesion to the toner particles tends to be uneven, and the triboelectric charging property under low humidity is low. Since this leads to non-uniformity, problems such as an increase in fog, a decrease in image density, or a decrease in durability are likely to occur. When the average primary particle size of the inorganic fine powder is smaller than 4 nm, the agglomeration property of the inorganic fine particles becomes stronger, and it behaves as an agglomerate with a wide particle size distribution that is not primary particles but has strong agglomeration properties that are difficult to break even by crushing treatment Image defects are likely to occur when the aggregate is developed or the image carrier or the toner carrier is damaged. In order to make the charge amount distribution of the toner particles more uniform, the average primary particle size of the inorganic fine powder is more preferably 6 to 35 nm.

  The average primary particle size of the inorganic fine powder is a photograph of the toner magnified by a scanning electron microscope, and is further mapped by the element contained in the inorganic fine powder by an elemental analysis means such as XMA attached to the scanning electron microscope. It can be measured by measuring 100 or more primary particles of the inorganic fine powder present on the toner surface while adhering to or separating from the toner image, and determining the number average particle diameter.

  Further, the content of the inorganic fine powder can be quantified using a calibration curve prepared from a standard sample using fluorescent X-ray analysis.

  As the inorganic fine powder added to the toner of the present invention, silica, titanium oxide, alumina, or a double oxide thereof can be used.

For example, as the silica, both a so-called dry method produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and so-called wet silica produced from water glass or the like can be used. Dry silica is preferred because it has less silanol groups on the surface and in the silica fine powder and less production residue such as Na ₂ O, SO ₃ ^2- . In dry silica, it is also possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process. Is also included.

  The addition amount of the inorganic fine powder is preferably 0.1 to 4.0 parts by mass with respect to 100 parts by mass of the toner particles, and if the addition amount is less than 0.1 parts by mass, the effect is not sufficient. If it exceeds 0 part by mass, the fixability tends to be lowered.

  The inorganic fine powder is preferably hydrophobized from the viewpoint of improving characteristics in a high humidity environment. When the inorganic fine powder added to the toner absorbs moisture, the charge amount as the toner is remarkably reduced, and the developability and transferability are easily lowered.

  As treatment agents for hydrophobic treatment, treatment agents such as silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, and organic titanium compounds may be used alone or in combination. And may be processed.

  Among these, those treated with silicone oil are preferable, and more preferably, the inorganic fine powder is treated with silicone oil at the same time or after treatment to maintain the charge amount of toner particles high even in a high humidity environment. In view of suppressing selective development, it is preferable.

  The processing conditions of the inorganic fine powder include, for example, a silylation reaction as the first stage reaction to eliminate active hydrogen groups on the surface by chemical bonds, and then a hydrophobic thin film is formed on the surface with silicone oil as the second stage reaction. can do. As a usage-amount of a silylating agent, 5-50 mass parts is preferable with respect to 100 mass parts of inorganic fine powder. If it is less than 5 parts by mass, it is not sufficient to eliminate the active hydrogen groups on the surface of the inorganic fine particles, and if it exceeds 50 parts by mass, the siloxane compound produced by the reaction of the excess silylating agent serves as a paste to serve as the inorganic fine particles. Aggregation occurs and image defects are likely to occur.

The silicone oil preferably has a viscosity at 25 ° C. of 10 to 200,000 mm ² / s, and more preferably 3,000 to 80,000 mm ² / s. If it is less than 10 mm ² / s, the inorganic fine powder is not stable and the image quality tends to deteriorate due to heat and mechanical stress. If it exceeds 200,000 mm ² / s, uniform processing tends to be difficult.

  As a method for treating silicone oil, for example, inorganic fine powder treated with a silane compound and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or a method of spraying silicone oil on inorganic fine powder. May be used. Alternatively, after dissolving or dispersing silicone oil in an appropriate solvent, inorganic fine powder may be added and mixed to remove the solvent. A method using a sprayer is more preferable in that the formation of inorganic fine powder aggregates is relatively small.

  The treatment amount of the silicone oil is 1 to 23 parts by mass, preferably 5 to 20 parts by mass with respect to 100 parts by mass of the inorganic fine powder. If the amount of the silicone oil is too small, good hydrophobicity cannot be obtained, and if it is too large, aggregation of inorganic fine particles tends to occur.

The toner of the present invention preferably has a primary particle size of more than 30 nm (preferably a BET specific surface area of less than 50 m ² / g), more preferably a primary particle size of 50 nm or more (preferably for the purpose of improving cleaning properties, etc. It is preferable to further add inorganic or organic fine particles having a BET specific surface area of less than 30 m ² / g). For example, spherical silica particles, spherical polymethylsilsesquioxane particles, spherical resin particles and the like are preferably used.

  Next, image formation using the toner of the present invention will be described.

  The conditions of the development step in the image forming method to which the toner of the present invention can be applied may be that the toner carrier and the surface of the photosensitive body as the electrostatic latent image carrier are in contact or non-contact. . Here, the case where it contacts is demonstrated.

As the toner carrying member, an elastic roller can be used, and a method can be used in which toner is coated on the surface of the elastic roller or the like and developed by bringing it into contact with the surface of the photoreceptor. As the elastic roller, one having an elastic layer having an ASKER-C hardness of 30 to 60 degrees is preferably used. When the development is performed by bringing the toner carrier into contact with the surface of the photoreceptor, the development is performed by an electric field acting between the photoreceptor and the elastic roller facing the surface of the photoreceptor via the toner. Therefore, the surface of the elastic roller or the vicinity of the surface has an electric potential, and it is necessary to have an electric field in a narrow gap between the surface of the photoreceptor and the toner carrying surface. Therefore, the elastic rubber of the elastic roller is resistance-controlled in the middle resistance region, and the electric field is maintained while preventing conduction with the surface of the photoreceptor, or a thin insulating layer is provided on the surface layer of the conductive roller Can also be used. Further, there is also a configuration in which a conductive layer is provided on the side not facing the photoconductor with a resin-coated conductive sleeve in which the side facing the surface of the photoconductor is coated with an insulating material (resin) on the conductive roller. Is possible. Further, it is possible to employ a configuration in which a rigid roller is used as the toner carrying member and the photosensitive member is a flexible material such as a belt. The resistance of the toner carrier is preferably in the range of 10 ² to 10 ⁹ Ω · cm. If it is lower than 10 ² Ωcm, for example if there is a pinhole or the like on the surface of the photoreceptor, an overcurrent may flow. On the other hand, if it is higher than 10 ⁹ Ωcm, the toner is likely to be charged up by frictional charging, and the image density is likely to be lowered.

  If the surface roughness Ra (μm) of the toner carrier is set to 0.2 to 3.0, both high image quality and high durability can be achieved. The surface roughness Ra correlates with the toner conveying ability and the toner charging ability. When the surface roughness Ra of the toner carrier exceeds 3.0, not only the toner layer on the toner carrier becomes difficult to be thinned but also the toner charging uniformity deteriorates and the halftone uniformity is reduced. We cannot expect improvement of image quality such as deterioration. Since the toner carrying ability on the surface of the toner carrier is suppressed by setting it to 3.0 or less, the toner layer on the toner carrier is thinned, and the number of contact between the toner carrier and the toner increases. Since the chargeability of the toner is also improved, the image quality is synergistically improved. On the other hand, when the surface roughness Ra is smaller than 0.2, it becomes difficult to control the toner coat amount.

The toner coat amount on the toner carrier is preferably 0.1 to 1.5 mg / cm ² . When the amount is less than 0.1 mg / cm ^2, it is difficult to obtain a sufficient image density. When the amount is more than 1.5 mg / cm ^2, it becomes difficult to uniformly charge all of the individual toner particles, causing fogging. Become. Furthermore, 0.2 to 0.9 mg / cm ² is more preferable. In the present invention, the surface roughness Ra of the toner carrier is measured using a surface roughness measuring instrument (Surfcoder SE-30H, manufactured by Kosaka Laboratory Co., Ltd.) based on JIS surface roughness “JIS B 0601”. This corresponds to the centerline average roughness. Specifically, a 2.5 mm portion as the measurement length a is extracted from the roughness curve in the direction of the center line, the center line of this extraction portion is the X axis, the direction of the vertical magnification is the Y axis, and the roughness curve is When expressed by y = f (x), it means a value obtained by the following formula expressed in micrometers (μm).

  In the image forming method used in the present invention, the toner carrier may be rotated in the same direction at the portion facing the photoconductor, or may be rotated in the opposite direction. When both rotations are in the same direction, it is preferable to set the peripheral speed of the toner carrier to be 1.05 to 3.0 times the peripheral speed of the photoreceptor.

When the peripheral speed of the toner carrier is less than 1.05 times the peripheral speed of the photoreceptor, the stirring effect received by the toner on the photoreceptor is insufficient, and good image quality cannot be expected. On the other hand, when the peripheral speed ratio exceeds 3.0, toner deterioration due to mechanical stress and toner adhesion to the toner carrier are generated and promoted, which is not preferable. As the photoreceptor, a photosensitive drum or a photosensitive belt having a photoconductive insulating material layer such as a-Se, CdS, ZnO ₂ , OPC, or a-Si is preferably used.

  The photosensitive layer in the OPC photoreceptor may be a single layer type containing a charge generation material and a material having charge transport performance in the same layer, or a function-separated type photosensitive layer having a charge transport layer and a charge generation layer as components. There may be. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated in this order on a conductive substrate is one preferred example. In addition, the binder resin of the organic photosensitive layer is not particularly limited, but polycarbonate resin, polyester resin, and acrylic resin are particularly excellent in transferability, and the toner can be fused to the photosensitive member and external additives. It is preferable because filming is difficult to occur.

  Next, image formation using the toner of the present invention will be described below with reference to the accompanying drawings.

  In FIG. 1, 100 is a developing device, 109 is a photosensitive member, 105 is a transfer target such as paper, 106 is a transfer member, 107 is a fixing pressure roller, 108 is a fixing heating roller, and 110 is in contact with the photosensitive member 109. A primary charging member that performs direct charging is shown.

  A bias power source 115 is connected to the primary charging member 110 so as to uniformly charge the surface of the photoconductor 109.

  The developing device 100 contains toner 104 and includes a toner carrier 102 that rotates in the direction of an arrow in contact with an electrostatic latent image carrier (photoconductor) 109. Further, a developing blade 101 for regulating the amount of toner and applying a charge, and a coating roller that rotates in the direction of the arrow in order to attach the toner 104 to the toner carrier 102 and to apply a charge to the toner by friction with the toner carrier 102 103. A developing bias power source 117 is connected to the toner carrier 102. A bias power source (not shown) is also connected to the application roller 103, and when negatively charged toner is used, the voltage is more negative than the developing bias, and when positively charged toner is used, the voltage is more positive than the developing bias. Is set.

  A transfer bias power supply 116 having a polarity opposite to that of the photoconductor 109 is connected to the transfer member 106.

  Here, the length in the rotation direction, that is, the so-called development nip width at the contact portion between the photoconductor 109 and the toner carrier 102 is preferably 0.2 to 8.0 mm. If the thickness is less than 0.2 mm, the development amount is insufficient, and it is difficult to obtain a satisfactory image density, and the transfer residual toner tends to be insufficiently collected. If it exceeds 8.0 mm, the toner supply amount becomes excessive, fogging is likely to occur, and wear of the photoconductor tends to be remarkable.

  The toner coating amount is controlled by the developing blade 101, and the developing blade 101 is in contact with the toner carrier 102 through the toner layer. The contact pressure at this time is preferably in the range of 4.9 to 49 N / m (5 to 50 gf / cm). If it is less than 4.9 N / m, in addition to controlling the toner coating amount, uniform frictional charging becomes difficult, causing fogging. On the other hand, if it exceeds 49 N / m, the toner particles are subjected to an excessive load, so that the deformation of the particles and the fusion of the toner to the developing blade or the toner carrier are likely to occur.

  The free end portion of the regulating member may have any shape as long as it has a preferable NE length (the length from the contact portion of the developing blade to the toner carrying member to the free end). For example, the cross-sectional shape is linear. In addition to those, those having an L shape bent near the tip or those having a shape in which the tip is swelled in a spherical shape are preferably used.

  As the toner coat amount regulating member, a rigid metal blade or the like may be used in addition to the elastic blade for press-fitting toner.

  As the elastic regulating member, it is preferable to select a material of a triboelectric charge series suitable for charging the toner to a desired polarity. A rubber elastic body such as silicone rubber, urethane rubber or NBR, or a synthetic resin such as polyethylene terephthalate. A metal elastic body such as an elastic body, stainless steel, steel, or phosphor bronze can be used. Moreover, those composites may be sufficient.

  Further, when durability is required for the elastic regulating member and the toner carrier, it is preferable that the metal elastic body is bonded or coated with a resin or rubber so as to contact the sleeve contact portion.

  Furthermore, an organic substance or an inorganic substance may be added to the elastic regulating member, and it may be melt-mixed or dispersed. For example, the chargeability of the toner can be controlled by adding a metal oxide, metal powder, ceramics, carbon allotrope, whisker, inorganic fiber, dye, pigment, surfactant or the like. In particular, when the elastic body is a molded body such as rubber or resin, fine metal oxide powders such as silica, alumina, titania, tin oxide, zirconia, and zinc oxide, carbon black, a charge control agent generally used for toners, etc. It is also preferable to contain.

  Furthermore, application of a DC electric field and / or an AC electric field to the regulating member also improves the uniform thin-layer coating property and uniform charging property due to the loosening action on the toner, achieving a sufficient image density and high quality. Images can be obtained.

  As the charging member, there are a non-contact type corona charger and a contact type charging member using a roller or the like, and any of them is used. For efficient uniform charging, simplification, and low ozone generation, a contact type is preferably used.

  In FIG. 1, a contact-type charging member is used.

  The primary charging member 110 used in FIG. 1 is a charging roller having a central core 110b and a conductive elastic layer 110a formed on the outer periphery thereof as a basic configuration. The charging roller 110 is brought into contact with the entire surface of the electrostatic latent image carrier with a pressing force, and is rotated following the rotation of the electrostatic latent image carrier 109.

  As a preferable process condition when the charging roller is used, the contact pressure of the roller is 4.9 to 490 N / m (5 to 500 gf / cm), and a DC voltage superimposed with an AC voltage is used as an applied voltage. Sometimes AC voltage = 0.5-5 kVpp, AC frequency = 50 Hz-5 kHz, DC voltage = ± 0.2- ± 1.5 kV, and when DC voltage is used, DC voltage = ± 0.2- ± 5 kV It is. In addition, since the amount of scraping of the drum can be suppressed, it is more preferable to use only a DC voltage as the applied voltage. Other contact charging means include a method using a charging blade and a method using a conductive brush. These contact charging means are superior to non-contact corona charging in that a high voltage is unnecessary and generation of ozone is reduced. The material of the charging roller and charging blade as the contact charging means is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), and the like are applicable.

  As the description of the image forming apparatus shown in FIG. 1, the contact charging unit has been described. However, in the case of using the contact charging unit in an image forming apparatus having another configuration, the same apparatus and conditions can be used. .

  Following the primary charging step, an electrostatic latent image corresponding to the information signal is formed on the photoconductor 109 by exposure 123 from the light emitting element, and the electrostatic latent image can be developed with toner at a position where it abuts the toner carrier 102. Visualize. Furthermore, in the image forming method of the present invention, particularly in combination with a developing system in which a digital latent image is formed on a photoreceptor, it becomes possible to develop the dot latent image faithfully without disturbing the latent image. . The visible image is transferred to the transfer target 105 by the transfer member 106 and passed between the heating roller 108 and the pressure roller 107 and fixed to obtain a fixed image. In addition to the heat roller system, which includes a heating roller incorporating a heating element such as a halogen heater and an elastic pressure roller pressed against the heating roller with a pressing force as a basic configuration, the heating and pressure fixing means may be provided via a film. A method of fixing by heating with a heater is also used.

  On the other hand, the untransferred toner remaining on the photoconductor 109 without being transferred is collected by a cleaner 138 having a cleaning blade in contact with the surface of the photoconductor 109, and the photoconductor 109 is cleaned.

  Next, an image forming method and an apparatus unit using the toner of the present invention will be described with reference to the drawings.

  2 and 3 are schematic views of an image forming apparatus that collectively transfers multiple toner images onto a recording material using an intermediate transfer member in the image forming method of the present invention.

  The surface of the electrostatic latent image carrier (photosensitive drum) 1 as a latent image carrier is brought into contact with the surface of the photosensitive drum 1 while rotating the charging roller 2 to which a charging bias voltage is applied, and then the surface of the photosensitive drum is primarily charged. Then, a first electrostatic latent image is formed on the photosensitive drum 1 by the laser light E emitted from the light source device L as the exposure means. The formed first electrostatic latent image is developed with the black toner in the black developing device 4Bk as a first developing device provided in the rotatable rotary unit 24 to form a black toner image. The black toner image formed on the photosensitive drum 1 is electrostatically primary transferred onto the intermediate transfer drum 5 by the action of the transfer bias voltage applied to the conductive support of the intermediate transfer drum. Next, a second electrostatic latent image is formed on the surface of the photosensitive drum 1 in the same manner as described above, and the rotary unit 24 is rotated so that the yellow toner in the yellow developing device 4Y as the second developing device is used. Development is performed to form a yellow toner image, and the yellow toner image is electrostatically primary transferred onto the intermediate transfer drum 5 on which the black toner image is primarily transferred. Similarly, a third electrostatic latent image is formed, and the rotary unit 24 is rotated to develop with the magenta toner in the magenta developer 4M as the third developer, and further, the fourth electrostatic latent image is developed. An image is formed, the rotary unit 24 is rotated, and primary transfer is sequentially performed with cyan toner in the cyan developing unit 4C as a fourth developing unit, and each color toner image is primary transferred onto the intermediate transfer drum 5. To do. The multiple toner image primarily transferred onto the intermediate transfer drum 5 is electrostatically applied onto the recording material P by the action of the transfer bias voltage from the second transfer device 8 positioned on the opposite side via the recording material P. Secondary transfer is performed at once. The multiple toner image secondarily transferred onto the recording material P is heated and fixed to the recording material P by a fixing device 9 having a heating roller 9a and a pressure roller 9b. The transfer residual toner remaining on the surface of the photosensitive drum 1 after the transfer is collected by a cleaner 6 having a cleaning blade in contact with the surface of the photosensitive drum 1, and the photosensitive drum 1 is cleaned.

  In the primary transfer from the photosensitive drum 1 to the intermediate transfer drum 5, the toner image is transferred by applying a transfer bias from a power source (not shown) to the conductive support of the intermediate transfer drum 5 as the first transfer device. Done.

  The intermediate transfer drum 5 includes a conductive support 5a that is a rigid body and an elastic layer 5b that covers the surface.

  As the conductive support 5a, a metal or an alloy such as aluminum, iron, copper, and stainless steel, and a conductive resin in which carbon or metal particles are dispersed can be used. The thing which penetrated the axis | shaft in the center, the thing which gave reinforcement to the inside of a cylinder, etc. are mentioned.

  The elastic layer 5b is not particularly limited, but styrene-butadiene rubber, high styrene rubber, butadiene rubber, isoprene rubber, ethylene-propylene copolymer, EPDM (terpolymer of ethylene propylene diene), Elastomer rubbers such as nitrile butadiene rubber (NBR), chloroprene rubber, butyl rubber, silicone rubber, fluorine rubber, nitrile rubber, urethane rubber, acrylic rubber, epichlorohydrin rubber and norbornene rubber are preferably used. A resin such as a polyolefin resin, a silicone resin, a fluorine resin, or a polycarbonate, and a copolymer or a mixture thereof may be used.

  Further, a surface layer in which lubricant powder having high lubricity and water repellency is dispersed in an arbitrary binder may be provided on the surface of the elastic layer.

  There are no particular limitations on the lubricant, but various fluororubbers, fluoroelastomers, fluorocarbons and polytetrafluoroethylenes, polytetrafluoroethylenes, polyvinylidene fluorides, ethylene-tetrafluoroethylene copolymers, and tetrafluoroethylene-perfluorocarbons with fluorine bonded to graphite or graphite. Fluorine compounds such as fluoroalkyl vinyl ether copolymers, silicone compounds such as silicone resins, silicone rubbers, and silicone elastomers, polyethylene, polypropylene, polystyrene, acrylic resins, polyamide resins, phenol resins, and epoxy resins are preferably used.

  In addition, a conductive agent may be added to the surface layer binder in order to control resistance. Examples of the conductive agent include various conductive inorganic particles and carbon black, an ionic conductive agent, a conductive resin, and a conductive particle-dispersed resin.

  The multiple toner images formed on the intermediate transfer drum 5 are secondarily transferred collectively onto the recording material P by the second transfer device 8, and the transfer means 8 is a non-contact electrostatic transfer such as a corona charger. Means or contact electrostatic transfer means such as transfer rollers and transfer belts can be used.

  When using a transfer roller, the voltage applied to the transfer roller can be reduced by setting the volume resistivity of the elastic layer of the transfer roller smaller than the volume resistivity of the elastic layer of the intermediate transfer drum. A good toner image can be formed and winding of the transfer material around the intermediate transfer member can be prevented. In particular, the volume specific resistance value of the elastic layer of the intermediate transfer member is particularly preferably 10 times or more than the volume specific resistance value of the elastic layer of the transfer roller.

  The hardness of the intermediate transfer drum and the transfer roller is measured according to JIS K-6301. The intermediate transfer drum used in the present invention is preferably composed of an elastic layer in the range of 10 to 40 degrees, while the hardness of the elastic layer of the transfer roller is harder than the hardness of the elastic layer of the intermediate transfer drum. Those having a value of ˜80 degrees are preferable for preventing the transfer material from being wound around the intermediate transfer drum. When the hardness of the intermediate transfer drum and that of the transfer roller are reversed, a recess is formed on the transfer roller side, and the transfer material is easily wound around the intermediate transfer drum.

  The fixing device 9 is replaced with a heat roller fixing device having a heating roller 9a and a pressure roller 9b, and the toner image on the recording material P is heated by heating a film in contact with the toner image on the recording material P. Also, a film heat fixing device that heat-fixes a multiple toner image on the recording material P can be used.

  In place of the intermediate transfer drum as the intermediate transfer member used in the image forming apparatus shown in FIG. 2, it is also possible to batch transfer the multiple toner images onto the recording material using an intermediate transfer belt. The configuration of the intermediate transfer belt is shown in FIG.

  The toner image formed and supported on the electrostatic latent image carrier (photosensitive drum) 1 is applied from the primary transfer roller 312 to the intermediate transfer belt 310 in the process of passing through the nip portion between the photosensitive drum 1 and the intermediate transfer belt 310. The primary transfer is sequentially performed on the outer peripheral surface of the intermediate transfer belt 310 by the electric field formed by the primary transfer bias. Reference numeral 311 denotes a roller around which the intermediate transfer belt 310 is stretched.

  A primary transfer bias for sequentially superimposing and transferring toner images of the first to fourth colors from the photosensitive drum 1 to the intermediate transfer belt 310 is applied from a bias power source 314 with a polarity opposite to that of the toner.

  In the primary transfer process of the first to third color toner images from the photosensitive drum 1 to the intermediate transfer belt 310, the secondary transfer roller 13 b and the cleaning charging member 309 can be separated from the intermediate transfer belt 10.

  Reference numeral 313b denotes a secondary transfer roller, which is supported in parallel with the secondary transfer counter roller 313a so as to be separated from the lower surface portion of the intermediate transfer belt 310.

  When the multi-color toner image transferred onto the intermediate transfer belt 310 is transferred to the transfer material P, the secondary transfer roller 313b is brought into contact with the intermediate transfer belt 310, and the intermediate transfer belt 310 and the secondary transfer roller 313b. The transfer material P is fed to the contact nip with a predetermined timing, and a secondary transfer bias is applied from the bias power source 316 to the secondary transfer roller 313b. The multi-color toner image is secondarily transferred from the intermediate transfer belt 310 to the transfer material P by the secondary transfer bias.

  After the image transfer to the transfer material P is completed, a cleaning charging member 309 is brought into contact with the intermediate transfer belt 310, and a bias having a polarity opposite to that of the photosensitive drum 1 is applied from the bias power source 315, thereby transferring the image to the transfer material P. Instead, a charge having a polarity opposite to that of the photosensitive drum 1 is applied to the toner (transfer residual toner) remaining on the intermediate transfer belt 310.

  The transfer residual toner is electrostatically transferred to the photosensitive drum 1 at and near the nip portion with the photosensitive drum 1 to clean the intermediate transfer member.

  The intermediate transfer belt includes a belt-shaped base layer and a surface treatment layer provided on the base layer. The surface treatment layer may be composed of a plurality of layers. Rubber, elastomer, or resin can be used for the base layer and the surface treatment layer.

  For example, as rubber and elastomer, natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, butyl rubber, ethylene-propylene rubber, ethylene-propylene terpolymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, acrylonitrile butadiene rubber, Urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, acrylic rubber, silicone rubber, fluorine rubber, polysulfurized rubber, polynorbornene rubber, hydrogenated nitrile rubber and thermoplastic elastomer (for example, polystyrene, polyolefin, 1 type or 2 types or more selected from the group consisting of polyvinyl chloride, polyurethane, polyamide, polyester, fluororesin, etc. can be used.However, it is not limited to the said material.

  As the resin, a resin such as a polyolefin resin, a silicone resin, a fluorine resin, or a polycarbonate can be used. A copolymer or a mixture of these resins may be used.

  As the base layer, one obtained by coating, dipping, or spraying the above-described rubber, elastomer, or resin on one side or both sides of a core layer having a woven fabric shape, a nonwoven fabric shape, a thread shape, or a film shape may be used.

  The material constituting the core layer is not particularly limited. For example, natural fibers such as cotton, silk, hemp and wool; regenerated fibers such as chitin fiber, alginic acid fiber and regenerated cellulose fiber; and half fibers such as acetate fiber Synthetic fiber: polyester fiber, nylon fiber, acrylic fiber, polyolefin fiber, polyvinyl alcohol fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber, polyurethane fiber, polyalkyl paraoxybenzoate fiber, polyacetal fiber, aramid fiber, polyfluoroethylene fiber and phenol Synthetic fibers such as fibers; inorganic fibers such as carbon fibers, glass fibers, and boron fibers; one or more selected from the group consisting of metal fibers such as iron fibers and copper fibers can be used.

  Further, a conductive agent may be added to the base layer and the surface treatment layer in order to adjust the resistance value of the intermediate transfer belt. Although it does not specifically limit as a electrically conductive agent, For example, metal powder, such as carbon, aluminum, and nickel, metal oxides, such as a titanium oxide, and quaternary ammonium salt containing polymethyl methacrylate, polyvinyl aniline, polyvinyl pyrrole, One kind or two or more kinds selected from the group consisting of polydiacetylene, polyethyleneimine, boron-containing polymer compounds, conductive polymer compounds such as polypyrrole, and the like can be used.

  Further, a lubricant may be added as necessary in order to increase the slipperiness of the intermediate transfer belt surface and improve the transferability. As the lubricant, the same lubricant as that used for the elastic layer of the intermediate transfer drum can be used.

  Next, an image forming method will be described with reference to FIG. 4 in which toner images of respective colors are formed in a plurality of image forming portions, and these are sequentially transferred onto the same transfer material.

  In the image forming apparatus shown in FIG. 4, first, second, third, and fourth image forming units 29a, 29b, 29c, and 29d are arranged in parallel, and each image forming unit has its own electrostatic capacity. A latent image carrier, so-called photosensitive drums 19a, 19b, 19c and 19d are provided.

  On the outer peripheral side of the photosensitive drums 19a to 19d, charging means 30a, 30b, 30c and 30d, latent image forming means 23a, 23b, 23c and 23d, developing means 17a, 17b, 17c and 17d, transfer means (transfer discharge means) ) 24a, 24b, 24c and 24d and cleaning means 18a, 18b, 18c and 18d are arranged.

  With such a configuration, first, the photosensitive drum 19a of the first image forming unit 29a is charged by the charging unit 30a, and a latent image of, for example, a yellow component color in the original image is formed by the latent image forming unit 23a. The latent image is converted into a visible image by the developer having yellow toner of the developing unit 17a, and transferred to the recording material S as a transfer material by the transfer unit 24a.

  As described above, while the yellow image is transferred to the transfer material S, the second image forming unit 29b forms a magenta component color latent image on the photosensitive drum 19b, and subsequently has the magenta toner of the developing unit 17b. A visible image is formed with the developer. This visible image (magenta toner image) is transferred to a predetermined position of the transfer material S when the transfer material S, which has been transferred by the first image forming unit 29a, is transferred to the transfer unit 24b. The

  Thereafter, cyan and black images are formed by the third and fourth image forming portions 29c and 29d in the same manner as described above, and the cyan and black colors are transferred onto the same transfer material S. To do. After such an image forming process is completed, the transfer material S is conveyed to the fixing unit 22 and the image on the transfer material S is fixed. As a result, a multicolor image is obtained on the transfer material S. The photosensitive drums 19a, 19b, 19c, and 19d that have completed the transfer have the residual toner removed by the cleaning units 18a, 18b, 18c, and 18d, and then a series of image forming processes are repeated.

  In the image forming apparatus, a conveyance belt 25 is used for conveying the recording material S as a transfer material.

  In this image forming apparatus, a transport belt using a mesh of Tetron (registered trademark) fiber as a transport means for transporting a transfer material and a polyethylene terephthalate resin, a polyimide resin, and a urethane resin from the viewpoint of durability. A conveyance belt using such a thin dielectric sheet is preferably used.

  In general, such a conveyance belt has a high volume resistance, and the charge amount of the conveyance belt increases in the process of repeating several times of transfer in color image formation. Therefore, in order to maintain uniform transfer, each transfer is required. However, since the toner of the present invention has excellent transferability, even if the charge of the conveying means increases each time the transfer is repeated, the transfer property of the toner in each transfer can be increased with the same transfer current. It can be made uniform and a high-quality image with good quality can be obtained.

  When the transfer material S passes through the fourth image forming portion 29d, an AC voltage is applied to the static eliminator 20, the transfer material S is neutralized and separated from the belt 25, and then enters the fixing device 22 where the image is fixed and discharged. It is discharged from the outlet 26.

  FIG. 5 shows an image formation using a transfer belt as a secondary transfer unit when a color toner image of four colors transferred onto the intermediate transfer drum using the intermediate transfer drum is secondarily transferred to a recording material. It is explanatory drawing of an apparatus.

In the apparatus system shown in FIG. 5, each of the developing devices 244-1, 244-2, 244-3, and 244-4 includes a developer having cyan toner, a developer having magenta toner, a developer having yellow toner, and A developer having black toner has been introduced. The photosensitive member 241 is charged by charging means, and further exposed to light 243 to form an electrostatic latent image. The electrostatic image is developed using the developing devices 244-1 to 244-4, and each color toner image is electrostatically charged. They are sequentially formed on a latent image carrier (photoconductor) 241. The photosensitive member 241 is a photosensitive drum or a photosensitive belt having a photoconductive insulating material layer such as a-Se, Cds, ZnO ₂ , OPC, or a-Si. The photoreceptor 241 is rotated in the direction of the arrow by a driving device (not shown).

  In the charging step, a charging roller 242 having a basic configuration of a central cored bar 242b and a conductive elastic layer 242a that forms the outer periphery thereof is used. The charging roller 242 is pressed against the surface of the photoconductor 241 with a pressing force, and is driven to rotate as the photoconductor 241 rotates.

  The toner image on the photoreceptor is transferred to an intermediate transfer drum 245 to which a voltage (for example, ± 0.1 to ± 5 kV) is applied. The surface of the photoreceptor after the transfer is cleaned by a cleaning unit 249 having a cleaning blade 248.

  As the intermediate transfer drum 245, the same intermediate transfer drum as described above can be used. 245b is a rigid conductive support, and 245a is an elastic layer covering the surface.

  The intermediate transfer drum 245 is disposed in parallel with the photoconductor 241 and is in contact with the lower surface of the photoconductor 241, and rotates in the counterclockwise direction indicated by an arrow at the same peripheral speed as the photoconductor 241.

  The first color toner image formed and supported on the surface of the photosensitive member 241 passes through the transfer nip where the photosensitive member 241 and the intermediate transfer drum 245 are in contact with each other, and is applied to the transfer nip region by the transfer bias applied to the intermediate transfer drum 245. The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer drum 245 by the formed electric field.

  If necessary, the surface of the intermediate transfer drum 245 is cleaned by a removable cleaning unit 280 after the toner image is transferred onto the transfer material. When there is a toner image on the intermediate transfer drum, the cleaning means 280 is separated from the surface of the intermediate transfer member so as not to disturb the toner image.

  In FIG. 5, a transfer belt 247 is disposed below the intermediate transfer drum 245. The transfer belt 247 is stretched between two rollers arranged in parallel to the axis of the intermediate transfer drum 245, that is, a bias roller 247a and a tension roller 247c, and is driven by a driving unit (not shown). Since the transfer belt 247 is configured such that the bias roller 247a side can move in the arrow direction around the tension roller 247c side, the transfer belt 247 can contact and separate from the intermediate transfer drum 245 in the arrow direction from below. A desired secondary transfer bias is applied to the bias roller 247a by a secondary transfer bias source 247d, while the tension roller 247c is grounded.

Next, as for the transfer belt 247, in this embodiment, a thermosetting urethane elastomer layer in which carbon is dispersed (thickness: about 300 μm, volume resistivity: 10 ⁸ to 10 ¹² Ω · cm (when 1 kV is applied)) A rubber belt was used in which a fluororubber layer (thickness 20 μm, volume resistivity 10 ¹⁵ Ω · cm (when 1 kV was applied)) was stacked thereon. The outer diameter is a tube shape with a circumference of 80 × width of 300 mm.

  The transfer belt 247 described above may be applied with a tension that extends about 5% by the bias roller 247a and the tension roller 247c.

  The transfer belt 247 is rotated at a constant speed or a peripheral speed with respect to the intermediate transfer drum 245. The transfer material 246 is conveyed between the intermediate transfer drum 245 and the transfer belt 247, and at the same time, a bias having a polarity opposite to the frictional charge of the toner is applied to the transfer belt 247 from the secondary transfer bias source 247d. The toner image on the transfer drum 245 is transferred to the surface side of the transfer material 246.

  As the material of the bias roller, the same material as that of the charging roller can be used. As preferable transfer process conditions, the contact pressure of the roller is 4.9 to 490 N / m (5 to 500 gf / cm), and the direct current is DC. The voltage is ± 0.2 to ± 10 kV.

For example, the conductive elastic layer 247a1 of the bias roller 247a has a volume resistance of about 10 ⁶ to 10 ¹⁰ Ωcm such as polyurethane, ethylene-propylene-diene terpolymer (EPDM) in which a conductive material such as carbon is dispersed. Made with body. A bias is applied to the cored bar 247a2 by a constant voltage power source. The bias condition is preferably ± 0.2 to ± 10 kV.

  Next, the transfer material 246 is conveyed to a fixing device 281 which basically includes a heating roller incorporating a heating element such as a halogen heater and an elastic pressure roller pressed against it with a pressing force. By passing between the pressure rollers, the toner image is fixed to the transfer material by heating and pressing. A method of fixing with a heater through a film may be used.

  Hereinafter, the present invention will be specifically described with reference to production examples and examples, but this does not limit the present invention in any way. In addition, all the parts in the following mixing | blending are a mass part.

(Production Example of Polar Polymer 1 (Resin A))
In a pressurizable reaction vessel equipped with a reflux tube, a stirrer, a thermometer, a nitrogen introduction tube, a dropping device and a decompression device, 250 parts of methanol as a solvent, 150 parts of 2-butanone and 100 parts of 2-propanol, styrene as a monomer 88 parts, 7 parts of 2-ethylhexyl acrylate and 5 parts of 2-acrylamido-2-methylpropanesulfonic acid were added and heated to reflux temperature with stirring. A solution prepared by diluting 1 part of 2,2′-azobisisobutyronitrile as a polymerization initiator with 20 parts of 2-butanone was added dropwise over 30 minutes, and stirring was continued for 5 hours. Further, 2,2′-azo A solution obtained by diluting 1 part of bisisobutyronitrile with 20 parts of 2-butanone was added dropwise over 30 minutes, and the mixture was further stirred for 5 hours to complete the polymerization.

  Next, the polymer obtained after the polymerization solvent was distilled off under reduced pressure was coarsely pulverized to 100 μm or less by a cutter mill equipped with a 150 mesh screen, and further finely pulverized by a jet mill. The fine powder was classified with a 250 mesh sieve to obtain particles of 60 μm or less. Next, the particles were dissolved by adding MEK to a concentration of 10%, and the above solution was gradually poured into 20 times the amount of MEK in methanol for reprecipitation. The resulting precipitate was washed with one-half the amount of methanol used for reprecipitation, and the filtered particles were vacuum dried at 35 ° C. for 48 hours.

  Further, MEK was added and redissolved so that the particles after the vacuum drying had a concentration of 10%, and the above solution was gradually poured into n-hexane 20 times the amount of MEK for reprecipitation. The obtained precipitate was washed with half the amount of n-hexane used for reprecipitation, and the filtered particles were vacuum dried at 35 ° C. for 48 hours. The polar polymer thus obtained had a Tg of about 83 ° C., main peak molecular weights (Mp) of 22000, Mn 12000 and Mw 32000, AV (r) of 14.5 and AV (s) of 13.6. . Further, the composition measured by 1H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is designated as polar polymer 1.

(Production example of polar polymer 2)
Except for drying at 110 ° C. for 3 hours, the same procedure as in Production Example of Polar Polymer 1 was performed. The polar polymer thus obtained had a Tg of about 84 ° C., a main peak molecular weight (Mp) of 23000, Mn 11000 and Mw 36000, AV (r) of 16.2 and AV (s) of 13.6. . Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is designated as polar polymer 2.

(Production example of polar polymer 3)
The same procedure as in Production Example of Polar Polymer 1 was conducted except that the drying temperature was 30 ° C. and drying was performed over 1 week. The polar polymer thus obtained had a Tg of about 82 ° C., main peak molecular weights (Mp) of 22000, Mn 12000 and Mw 31000, AV (r) of 13.9 and AV (s) of 13.6. . Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is designated as polar polymer 3.

(Production example of polar polymer 4)
The same procedure as in Production Example of Polar Polymer 1 was conducted except that 95 parts of styrene and 5 parts of 2-acrylamido-2-methylpropanesulfonic acid were used as monomers. The polar polymer thus obtained had a Tg of about 100 ° C., main peak molecular weights (Mp) of 22000, Mn 12000 and Mw 31000, AV (r) of 14.0 and AV (s) of 13.5. . Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is designated as polar polymer 4.

(Production example of polar polymer 5)
The same procedure as in Production Example of Polar Polymer 1 was conducted except that the monomer was changed to 95 parts of styrene, 2 parts of 2-ethylhexyl acrylate, 5 parts of methyl methacrylate, and 5 parts of 2-acrylamido-2-methylpropanesulfonic acid. The polar polymer thus obtained had a Tg of about 95 ° C., a main peak molecular weight (Mp) of 24000, Mn 13000 and Mw 33000, AV (r) of 14.2 and AV (s) of 13.5. . Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. Let the obtained resin be the polar polymer 5.

(Production example of polar polymer 6)
Except for changing the polymerization temperature to 60 ° C., it was the same as the production example of polar polymer 1. The polar polymer thus obtained had a Tg of about 84 ° C., main peak molecular weights (Mp) of 30000, Mn 20000 and Mw 48000, AV (r) of 15.8 and AV (s) of 13.4. . Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is designated as polar polymer 6.

(Production example of polar polymer 7)
It was made to be the same as that of the production example of the polar polymer 1 except that the amount of the polymerization initiator added first and the amount of the polymerization initiator added additionally were increased from 1 part to 1.5 parts. The polar polymer thus obtained had a Tg of about 81 ° C., main peak molecular weights (Mp) of 18000, Mn5000 and Mw25000, AV (r) of 14.5 and AV (s) of 13.6. . Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is designated as polar polymer 7.

(Production example of polar polymer 8)
Manufacture of polar polymer 1 except that 88 parts of styrene, 4.5 parts of 2-ethylhexyl acrylate, and 7.5 parts of 2-acrylamido-2-methylpropanesulfonic acid are used as monomers and dried at 110 ° C. for 3 hours. Same as example. The polar polymer thus obtained had a Tg of about 89 ° C., main peak molecular weights (Mp) of 22000, Mn10000 and Mw35000, AV (r) of 24 and AV (s) of 20.2. Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is designated as polar polymer 8.

(Production example of polar polymer 9)
Similar to the production example of the polar polymer 1 except that 93 parts of styrene, 5 parts of 2-ethylhexyl acrylate, and 2 parts of 2-acrylamido-2-methylpropanesulfonic acid are used as monomers and the mixture is dried at 110 ° C. for 3 hours. did. The polar polymer thus obtained had a Tg of about 88 ° C., a main peak molecular weight (Mp) of 25000, Mn 13000 and Mw 38000, AV (r) of 5.8 and AV (s) of 5.4. . Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is designated as polar polymer 9.

(Production example of polar polymer 10)
The same procedure as in Production Example of Polar Polymer 1 was conducted except that the monomer was changed to 75 parts of styrene, 20 parts of methyl methacrylate, and 5 parts of 2-acrylamido-2-methylpropanesulfonic acid. The polar polymer thus obtained had a Tg of about 102 ° C., a main peak molecular weight (Mp) of 21,000, Mn 11000 and Mw 30000, AV (r) of 15.5 and AV (s) of 13.5. . Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is designated as polar polymer 10.

(Production example of polar polymer 11)
Except for drying at 130 ° C. for 3 hours, the same procedure as in Production Example of Polar Polymer 1 was performed. The polar polymer thus obtained had a Tg of about 85 ° C., a main peak molecular weight (Mp) of 23000, Mn 11000 and Mw 36000, AV (r) of 17.6 and AV (s) of 13.5. . Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is designated as polar polymer 11.

(Production example of polar polymer 12)
Similar to the production example of the polar polymer 1 except that 83 parts of styrene, 12 parts of 2-ethylhexyl acrylate, and 5 parts of 2-acrylamido-2-methylpropanesulfonic acid are used as monomers, and drying is performed at 110 ° C. for 3 hours. did. The polar polymer thus obtained had a Tg of about 73 ° C., main peak molecular weights (Mp) of 22000, Mn10000, Mw35000, AV (r) of 15.5, and AV (s) of 13.6. . Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is designated as polar polymer 12.

(Production example of polymer 1)
The same procedure as in Production Example of Polar Polymer 1 was conducted except that 93 parts of styrene and 7 parts of 2-ethylhexyl acrylate were used as monomers. The polymer thus obtained had a Tg of about 83 ° C., main peak molecular weights (Mp) of 24000, Mn 14000 and Mw 35000, AV (r) of 0.5 and AV (s) of 0. Further, the composition measured by ¹ H-NMR (EX-400: 400 MHz manufactured by JEOL Ltd.) was as charged. The obtained resin is referred to as Polymer 1.

  Table 1 shows the physical property values of the obtained polar polymers 1 to 12 and polymer 1.

<Example 1>
First, a polymerized toner was prepared according to the following procedure. 3 parts of tricalcium phosphate is added to 900 parts of ion-exchanged water heated to 60 ° C., and stirred at 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo) to produce an aqueous medium. did.

Further, the following polymerizable monomer composition was put into a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), heated to 60 ° C., stirred at 9,000 rpm, dissolved and dispersed.
-Styrene 160 parts-n-butyl acrylate 40 parts-C.I. I. Pigment Blue 15: 3 14 parts, polar polymer 1 2 parts, polyester resin 7 parts (polycondensation product of propylene oxide-modified bisphenol A and isophthalic acid, Tg = 65 ° C., Mw = 10000, Mn = 6000)
-Stearyl stearate wax (DSC main peak 60 ° C) 30 parts-Divinylbenzene 0.5 part In this, 5 parts of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) is dissolved and polymerized. A monomer composition was prepared.

  The polymerizable monomer composition was put into the aqueous medium, and the mixture was granulated by stirring at 9,000 rpm using a TK homomixer at 60 ° C. in a nitrogen atmosphere.

  Then, the temperature was raised to 70 ° C. over 2 hours while stirring by transferring to a propeller type stirring device. After another 4 hours, the temperature was raised to 80 ° C. at a rate of temperature rise of 40 ° C./hr and reacted at 80 ° C. for 5 hours. To produce polymer particles. After the completion of the polymerization reaction, the slurry containing the particles was cooled, washed with an amount of water 10 times that of the slurry, filtered and dried, and then the particle diameter was adjusted by classification to obtain cyan toner particles.

Hydrophobic silica fine powder (primary particle size: 10 nm, BET specific surface area) treated with silicone oil as a fluidity improver and charged to the same polarity (negative polarity) as the toner particles with respect to 100 parts of the cyan toner particles. : 170 m ^{2 /} g) 1.5 parts was mixed with a Henschel mixer (manufactured by Mitsui Miike) for 5 minutes to obtain a toner (1) of the present invention.

  Toner (1) had a weight average particle diameter of 6.8 μm, an average circularity of 0.970, and a mode circularity of 1.00.

  The toner (1) was a non-magnetic one-component developer (1), and image evaluation was performed using an image forming apparatus as shown in FIG. The image forming apparatus will be described below.

  FIG. 6 is a schematic view of a modified 1200 dpi laser beam printer (manufactured by Canon: LBP-840) using a nonmagnetic one-component contact development type electrophotographic process. In this example, an apparatus in which the following parts (a) to (h) were modified was used.

  (A) The charging method of the apparatus was direct charging performed by contacting a rubber roller, and the applied voltage was a direct current component (-1200 V).

(B) The toner carrier was changed to a medium resistance rubber roller (diameter 16 mm, hardness ASKER-C 45 degrees, resistance 10 ⁵ Ω · cm) made of silicone rubber dispersed with carbon black, and contacted with the photoreceptor.

  (C) The rotational speed of the toner carrier was the same in the contact portion with the photoconductor, and was driven to be 145% with respect to the rotational speed of the photoconductor.

  (D) The photoconductor was changed to the following.

The photoreceptor used here was an Al cylinder as a substrate, and layers having the following constitution were sequentially laminated by dip coating to produce a photoreceptor.
-Conductive coating layer: Mainly composed of tin oxide and titanium oxide powder dispersed in phenolic resin. Film thickness 15 μm.
-Undercoat layer: Mainly composed of modified nylon and copolymer nylon. Film thickness 0.6 μm.
-Charge generation layer: Mainly composed of a titanyl phthalocyanine pigment having absorption in a long wavelength region dispersed in butyral resin. Film thickness 0.6 μm.
Charge transport layer: Mainly composed of a hole-transporting triphenylamine compound dissolved in a polycarbonate resin (molecular weight 20,000 by the Ostwald viscosity method) at a mass ratio of 8:10. Film thickness 20 μm.

  (E) As a means for applying the toner to the toner carrier, an application roller made of foamed urethane rubber was provided in the developing unit and brought into contact with the toner carrier. A voltage of about −550 V was applied to the coating roller.

  (F) A resin-coated stainless steel blade was used to control the coat layer of the toner on the toner carrier.

  (G) Only the DC component (-450 V) was applied during development.

  A commercially available paint is applied very thinly on the surface of a rubber roller having the same diameter, the same hardness, and the same resistance as the toner carrier used in the image forming apparatus, and after temporarily assembling the image forming apparatus, the rubber roller is removed, The surface of the stainless steel blade was observed and the NE length was measured. The NE length was 1.05 mm.

  The electrophotographic apparatus was remodeled and process conditions were set as follows in order to conform to the remodeling of these process cartridges.

  The modified device uses a roller charger (applying only DC) to charge the image carrier. Subsequent to charging, an image portion is exposed with a laser beam to form an electrostatic latent image, and a visible image is formed with toner, and then the toner image is transferred to a transfer material by a roller to which a voltage of +700 V is applied.

  As for the photosensitive member charging potential, the dark portion potential was set to -600V and the bright portion potential was set to -150V.

  Under the above conditions, 2% in a high temperature and high humidity environment (30 ° C., 80% RH), a normal temperature and normal humidity environment (23 ° C., 50% RH), and a low temperature low humidity environment (15 ° C., 10% RH). After printing out an image with a printing ratio up to 5000 sheets in the intermittent 2-sheet mode (that is, a mode in which the developer is paused for 10 seconds every time two sheets are printed out and toner deterioration is promoted by a preliminary operation upon restarting). Further, the fog amount on the drum was evaluated by the method described later.

  Further, as an evaluation of image quality, image density and fog were also evaluated as follows. The evaluation results are shown in Table 2.

(1) Image density Evaluation is performed by outputting a solid image at the initial stage and at the end of durability evaluation in an image output test using a normal copying machine plain paper (75 g / m ² ) transfer material, and measuring the density. did. The image density was measured by using a “Macbeth reflection densitometer RD918” (manufactured by Macbeth Co., Ltd.) to measure the relative density with respect to an image of a white background portion having a document density of 0.00.
A: Very good 1.40 or more B: Good 1.35 or more, less than 1.40 C: No problem in practical use 1.00 or more, less than 1.35 D: Somewhat difficult Less than 1.00

(2) Image fog The fog density (%) is calculated from the difference between the whiteness of the white portion of the printout image and the whiteness of the transfer paper measured by “REFLECTMETER MODEL TC-6DS” (manufactured by Tokyo Denshoku). Image fog at the end of durability evaluation was evaluated. The filter used was amber light for cyan, blue for yellow, and green for magenta and black.
A: Very good Less than 0.5% B: Good 0.5% or more and less than 1.0% C: No practical problem 1.0% or more and less than 1.5% D: Somewhat difficult 1.5% or more

(3) Roughness of halftone image In order to evaluate the balance between the fluidity and chargeability of the toner, it was judged by the uniformity of the halftone image output after printing three solid images.
A: Very good Image uniformity is very excellent and extremely clear image B: Good Image uniformity is excellent and good image C: No problem in practical use Image quality D: no problem in practical use Image uniformity is poor and is not practically desirable

(4) Contamination of main body and cartridge due to scattering of toner In order to evaluate the balance between chargeability and fluidity of toner, the degree of contamination by toner around the cartridge after printing 5000 sheets and the cartridge in the main body was observed.
A: Very good No contamination due to toner around the cartridge and cartridge inside the main unit is observed B: Good Contamination due to a small amount of toner is observed on the cartridge C: No problem in practical use No contamination due to toner around the cartridge inside the cartridge inside the main unit Observed, but does not affect the attachment / detachment of the image / cartridge D: Somewhat difficult The area around the cartridge and the cartridge in the main body is extremely dirty with toner, and the attachment / detachment of the image / cartridge is also adversely affected

  Table 2 shows the physical properties of Toner (1) and Table 3 shows the evaluation results.

<Example 2>
The same procedure as in Example 1 was performed except that the polar polymer 1 was changed to the polar polymer 2. The physical properties of Toner (2) are shown in Table 2 and the same as in Example 1. The evaluation results are shown in Table 3.

<Example 3>
The same procedure as in Example 1 was performed except that the polar polymer 1 was changed to the polar polymer 3. The physical properties of Toner (3) are shown in Table 2 and the same as in Example 1. The evaluation results are shown in Table 3.

<Example 4>
The same procedure as in Example 1 was performed except that the polar polymer 1 was changed to the polar polymer 4. The physical properties of Toner (4) are shown in Table 2 and the same as in Example 1. The evaluation results are shown in Table 3.

<Example 5>
The same procedure as in Example 1 was performed except that the polar polymer 1 was changed to the polar polymer 5. The physical properties of Toner (5) are shown in Table 2 and the same as in Example 1. The evaluation results are shown in Table 3.

<Example 6>
The same procedure as in Example 1 was performed except that the polar polymer 1 was changed to the polar polymer 6. The physical properties of Toner (6) are shown in Table 2 in the same manner as in Example 1. The evaluation results are shown in Table 3.

<Example 7>
The same procedure as in Example 1 was performed except that the polar polymer 1 was changed to the polar polymer 7. The physical properties of Toner (7) are shown in Table 2 in the same manner as in Example 1. The evaluation results are shown in Table 3.

<Example 8>
The same procedure as in Example 1 was performed except that the polar polymer 1 was changed to the polar polymer 8. The physical properties of Toner (8) are shown in Table 2 in the same manner as in Example 1. The evaluation results are shown in Table 3.

<Example 9>
The same procedure as in Example 1 was performed except that the polar polymer 1 was changed to the polar polymer 9. The physical properties of Toner (9) are shown in Table 2 and the same as in Example 1. The evaluation results are shown in Table 3.

<Example 10>
The same procedure as in Example 1 was performed except that the addition amount of the polar polymer 1 was changed from 2 parts to 1 part. The physical properties of Toner (10) are shown in Table 2 in the same manner as in Example 1. The evaluation results are shown in Table 3.

<Example 11>
The same procedure as in Example 1 was conducted except that the addition amount of the polar polymer 1 was changed from 2 parts to 4 parts. The physical properties of Toner (11) are shown in Table 2 and the same as in Example 1. The evaluation results are shown in Table 3.

<Example 12>
The same procedure as in Example 1 was performed except that the time until the temperature was raised to 70 ° C. was changed to 30 minutes. The physical properties of Toner (12) are shown in Table 2 in the same manner as in Example 1. Table 3 shows the evaluation results.

<Example 13>
The same procedure as in Example 1 was performed except that the polar polymer 1 was changed to the polar polymer 10. The physical properties of Toner (13) are shown in Table 2 in the same manner as in Example 1. The evaluation results are shown in Table 3.

<Example 14>
As a colorant, C.I. I. Instead of using 14 parts of Pigment Blue 15: 3, C.I. I. This was carried out in the same manner as in Example 1 except that 10 parts of Pigment Yellow 17 was used. The physical properties of Toner (14) are shown in Table 2, and the evaluation results obtained in the same manner as in Example 1 are shown in Table 3.

<Example 15>
As a colorant, C.I. I. Instead of using 14 parts of Pigment Blue 15: 3, C.I. I. This was performed in the same manner as in Example 1 except that 16 parts of Pigment Red 122 were used. Table 2 shows the physical properties of Toner (15), and Table 3 shows the evaluation results obtained in the same manner as in Example 1.

<Example 16>
As a colorant, C.I. I. It carried out like Example 1 except using carbon black (DBP oil absorption 42cm < ³ > / 100g, specific surface area 60m < ² > / g) instead of using 14 parts of pigment blue 15: 3. The physical properties of Toner (16) are shown in Table 2, and the evaluation results obtained in the same manner as in Example 1 are shown in Table 3.

<Comparative Example 1>
The same procedure as in Example 1 was carried out except that the polar polymer 1 was changed to the polymer 1 and 1 part of benzyl acid boron complex (Nippon Carlit: LR-147) was added. Table 2 shows the physical properties of Toner (17), and Table 3 shows the evaluation results obtained in the same manner as in Example 1.

<Comparative example 2>
The same procedure as in Example 1 was performed except that the polar polymer 1 was changed to the polar polymer 11. Table 2 shows the physical properties of Toner (18), and Table 3 shows the evaluation results obtained in the same manner as in Example 1.

<Comparative Example 3>
The same procedure as in Example 1 was performed except that the polar polymer 1 was changed to the polar polymer 12. The physical properties of Toner (19) are shown in Table 2, and the evaluation results obtained in the same manner as in Example 1 are shown in Table 3.

  The physical properties of the toners (1) to (19) are shown in Table 2, and the evaluation results obtained in the same manner as in Example 1 are shown in Table 3.

<Example 17>
Next, using a full color printer LBP2510 (manufactured by Canon Inc.), toner (1) is used for the cyan cartridge, toner (14) is used for the yellow cartridge, toner (15) is used for the magenta cartridge, and toner (16) is used for the black cartridge. Each was filled with 150 g, and 5000 full-color images were formed. Evaluation was conducted according to Example 1, and the results are shown in Table 4.

1 is a schematic diagram illustrating an example of an image forming apparatus to which the toner of the present invention can be applied. 1 is a schematic diagram illustrating an example of an image forming apparatus using an intermediate transfer drum. FIG. 6 is an explanatory diagram illustrating an example of a configuration of an intermediate transfer belt. FIG. 5 is a schematic diagram illustrating an example of an image forming method in which toner images of respective colors are formed in a plurality of image forming units, and the toner images are sequentially superimposed and transferred onto the same transfer material. FIG. 2 is a schematic diagram illustrating an example of an image forming apparatus in which toner images of respective colors are formed in a plurality of image forming units and are sequentially transferred onto the same transfer material. 1 is a schematic diagram illustrating an example of an image forming apparatus used in an embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging roller 4Y Yellow developing device 4M Magenta developing device 4C Cyan developing device 4Bk Black developing device 5 Intermediate transfer drum 5a Conductive support 5b Elastic layer 6 Cleaner 8 Transfer device 9 Fixing device 9a Heating roller 9b Pressure roller 24 Rotary unit 17a, 17b, 17c, 17d Developing means 18a, 18b, 18c, 18d Cleaning means 19a, 19b, 19c, 19d Photosensitive drum 20 Charger 22 Fixing devices 23a, 23b, 23c, 23d Latent image forming means 24a, 24b 24c, 24d transfer means 25 belt 26 discharge port 29a, 29b, 29c, 29d image forming unit 30a, 30b, 30c, 30d charging means 100 developing device 101 developing blade 102 toner carrier 103 coating roller 104 toner -105 Transfer object 106 Transfer member 107 Fixing pressure roller 108 Fixing heating roller 109 Photoconductor 110 Primary charging member 123 Exposure 138 Cleaner 241 Photoconductor 242 Charging roller 242a Conductive elastic layer 242b Core metal 243 Exposure 244-1 244-2, 244-3, 244-4 Developer 245 Intermediate transfer drum 245a Elastic layer 245b Conductive support 246 Transfer material 247 Transfer belt 247a Bias roller 247a1 Conductive elastic layer 247a2 Core metal 247c Tension roller 247d Secondary power supply bias Source 248 Cleaning blade 249 Cleaning means 280 Cleaning means 281 Fixing device 309 Cleaning charging member 310 Intermediate transfer belt 311 Tension roller 312 Transfer roller 313a Secondary transfer counter roller 313b Secondary transfer roller 314, 315, 316 Bias power supply

Claims (9)

In a toner having toner particles and inorganic fine powder mixed in the toner particles,
A resin (resin A) in which the toner particles comprise a binder resin, a colorant, a wax, and a vinyl monomer containing styrene or a styrene derivative, (meth) acrylic acid ester, and a sulfonic acid group that satisfy the following conditions: A toner characterized by containing.
(1) The relationship between the acid value [AV (s)] obtained from the content of a vinyl monomer containing a sulfonic acid group and the total acid value of [AV (r)] in the resin (A) is
AV (s) ≦ AV (r) ≦ AV (s) × 1.2
(2) Glass transition temperature is 80 ° C or higher The toner according to claim 1, wherein the resin A satisfies the following conditions.
(A) The peak molecular weight in GPC is 18,000 or more and 30,000 or less (i) The number average molecular weight in GPC is 5,000 or more and 20,000 or less (U) The weight average molecular weight in GPC is 25,000 or more and 50,000 or less.   The toner according to claim 1, wherein the total acid value [AV (r)] of the resin A is 5 or more and 24 or less.   4. The toner according to claim 1, wherein the content of the vinyl monomer containing a sulfonic acid group in the resin A is 2 to 8% by mass.   The toner according to claim 1, wherein the glass transition temperature of the resin A is 100 ° C. or less.   The ratio (E / A) of the atomic number% (E) of the sulfur element to the atomic number% (A) of the carbon element present on the toner surface measured by X-ray photoelectron spectroscopy is 0.0010 to 0.0050. The toner according to claim 1, wherein the toner is a toner.   The toner according to claim 1, wherein the toner has an average circularity of 0.960 to 0.995 and a weight average particle diameter (D4) of 4 to 8 μm.   The toner according to any one of claims 1 to 7, wherein the toner has a mode circularity of 0.99 or more.   The toner according to any one of claims 1 to 8, wherein the inorganic fine powder having an average primary particle size of 4 to 80 nm is contained in an amount of 0.1 to 4% by mass based on the whole toner.

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