JP2006267281A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and an image forming method by which excellent image quality is maintained for a long period when a contact charging system is used. <P>SOLUTION: In the image forming apparatus and the image forming method using the same, the image forming apparatus has at least an electrostatic latent image carrier, a charging means including a contact type charger for charging the electrostatic latent image carrier, a latent image forming means for forming a latent image on the surface of the electrostatic latent image carrier, a development means for developing a latent image formed on the surface of the electrostatic latent image carrier by developer to form a toner image, a transfer means for transferring the toner image formed on the surface of the electrostatic latent image carrier on a transferred object, a lubricant supply means for supplying powder lubricant to the surface of the electrostatic latent image carrier and a cleaning means for removing residual toner on the surface of the electrostatic latent image carrier after transfer, the powder lubricant contains 10-40 volume % of inorganic particles with volume average particle diameter of 10-80 nm and of which the volume resistance when applied voltage is 1000V cm is 10<SP>8</SP>-10<SP>11Ω</SP>cm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and an image forming method.

In electrophotography, an electrostatic latent image formed on an electrostatic latent image carrier (photoconductor) is developed with a toner containing a colorant, and the obtained toner image is transferred onto a transfer target. An image is obtained by fixing the toner with a heat roll or the like. On the other hand, the residual toner on the surface is removed / cleaned by a cleaning device equipped with a cleaning blade or the like in order to form an electrostatic latent image again on the photoreceptor. .
Until now, the lifetime of the image forming unit has been determined by the lifetime of the photosensitive member that is worn by the cleaning blade and the cleaning brush. For this reason, for the purpose of extending the life of the photoconductor, it has been attempted to increase the hardness of the surface of the photoconductor that is not easily worn, that is, the electrostatic latent image carrier.

  However, when the surface hardness of the photoconductor is increased as described above, it is possible to reduce the amount of photoconductor wear. On the other hand, so-called discharge such as ozone products and nitrogen oxides that occur when a bias is applied and adhere to the photoconductor surface. Product removal is difficult. In the conventional photoconductor, the surface layer of the photoconductor is scraped little by little when removing the discharge product. However, by increasing the hardness of the surface layer of the photoconductor, the discharge product can no longer be scraped off and removed. A problem has arisen that the discharge products that have not been accumulated accumulate. When the discharge product adhering to and accumulating on the surface of the photoconductor absorbs water in a high humidity environment, the surface resistance of the photoconductor is lowered, and an image drift (dilation) occurs in which an electrostatic latent image flows. In an actual print sample, it is observed as a phenomenon such that characters cannot be identified, or white spots in a halftone image occur.

  Also, in order to meet the recent demands for higher image quality and low environmental impact in the electrophotographic market, toner tends to be reduced in diameter and sphere, but the small diameter and spherical toner remaining on the photoreceptor should be removed. Is very difficult. For example, in a cleaning method using a cleaning blade, there is a problem that such a small particle size or spherical toner rotates between the photosensitive member and the blade and enters a gap, so that it is difficult to clean. For this reason, it is necessary to greatly increase the linear pressure of the cleaning blade. On the other hand, if contaminants such as discharge products accumulate on the photoreceptor as described above, the friction coefficient of the photoreceptor increases. When the friction coefficient is increased, the torque of the photosensitive member is increased, and the contact portion between the cleaning blade and the photosensitive member is deformed to be distorted.

  As a means for solving problems such as image drift due to accumulation of discharge products on the photoreceptor as described above, and photoreceptor torque increase, a method of applying a lubricant to the photoreceptor surface has been proposed (for example, a patent) Reference 1). This reduces the coefficient of friction of the surface of the photoconductor with a lubricant, prevents deformation of the cleaning blade, and discharge products do not adhere directly to the surface of the photoconductor. It has the effect of facilitating scraping. In addition, the effect of facilitating scraping off the toner in the cleaning unit is not limited to the cleaning method using a blade, and is an effective method even in a method using a brush.

  On the other hand, it is difficult to completely clean the lubricant itself, and the lubricant remains on the photosensitive member and proceeds to the next image forming process. When the method of charging the photosensitive member is a contact charging method, there is a problem that the remaining lubricant is transferred to the charging member. When the lubricant, which is an insulating material, adheres to the charging member, charging failure is induced in the charging process. Lubricant does not deposit uniformly on the charging member, but easily accumulates in the recesses, so the photoreceptor cannot be charged uniformly, and is observed as white spots or streaky density unevenness on the print sample. .

Furthermore, in the small-diameter or spherical toner as described above, the amount of the external additive inevitably tends to increase in order to ensure powder flowability and transferability. As the amount added increases, the amount of external additives released from the toner surface increases. However, since such external additives are even smaller than the toner, they cannot be completely removed by the cleaning process. The external additive that could not be removed adheres to and accumulates on the contact charging member, and causes charging failure as well as the lubricant.
JP 2004-53892 A

  The present invention has been made in view of the above problems, and an object thereof is to provide an image forming apparatus and an image forming method capable of maintaining good image quality over a long period of time when a contact charging method is used.

In order to solve the above-mentioned problems, a method for cleaning a charging member to which a lubricant or an external additive is attached, a method for imparting contamination accumulation characteristics depending on the surface smoothness or material of the contact charging member, or charging A method of using a material that does not easily adhere to a member as a lubricant or an external additive has been proposed.
However, for example, the method of cleaning the contact charging member with a brush or the like cannot prevent contamination of minute concave portions of the charging member, and has a problem in maintainability when used for a long period of time.
When the surface smoothness of the charging member is increased, the adhesion of minute external additives and the like can be prevented, but the adhesion and accumulation of a lubricant having excellent coating properties cannot be prevented.
Even when the material of the charging member is changed, although it plays an initial role, there is a problem that the effect is not sustained as it is used for a long time.
On the other hand, if the material of the lubricant is changed to a material that does not easily adhere, there is a problem that the applicability to the photosensitive member is also lowered. Furthermore, even when some of the above methods are combined, an effect sufficient to solve this problem cannot be expressed.

As described above, since there are various problems with the method for suppressing the adhesion to the charging member, the present invention has studied the method for controlling the resistance on the premise that the contaminant adheres to the charging member. In other words, the above-mentioned problem occurs because the lubricant or external additive, which is an insulating material, adheres to the charging member, current does not flow through the attached portion, and it becomes impossible to give a charge to the photoreceptor. If is a semiconductive material, the above problem does not occur.
When a semiconductive material is used as an external additive, there is a problem that the chargeability required for the toner cannot be maintained. Further, since the supply portion depends on the output image, it cannot be uniformly supplied to the charging member.
Externally supplied lubricant can be supplied uniformly to the charging member. However, if a semiconductive material is used as the lubricant, the resistance of the photoreceptor to which the lubricant is applied decreases, so the image is exposed during the exposure process. There is a problem of causing a flow.
As a result of intensive studies by the present researchers, it has been found that, by adopting the following configuration, the problem can be solved without causing the above-described defect due to the semiconductive material.
That is, the present invention

<1> An electrostatic latent image carrier, charging means including a contact charger for charging the electrostatic latent image carrier, and a latent image that forms a latent image on the surface of the charged electrostatic latent image carrier Forming means, developing means for developing the latent image formed on the surface of the electrostatic latent image carrier with a developer to form a toner image, and toner image formed on the surface of the electrostatic latent image carrier Transfer means for transferring the toner onto the transfer body, lubricant supply means for supplying a powder lubricant to the surface of the electrostatic latent image carrier, and residual toner on the surface of the electrostatic latent image carrier after transfer. An image forming apparatus including at least a cleaning unit for removing the powder lubricant. Image forming apparatus having a volume resistance of 10 ⁸ to 10 ¹¹ Ω · cm when It is.

  <2> The transfer means secondarily transfers an intermediate transfer body on which a toner image formed on the surface of the electrostatic latent image carrier is primarily transferred and an unfixed toner image on the intermediate transfer body to a transfer target. Secondary transfer means, and the lubricant supply means applies the powder lubricant to the surface of the intermediate transfer body, and applies the powder lubricant applied to the surface of the intermediate transfer body to the static transfer. The image forming apparatus according to <1>, wherein the image forming apparatus is supplied to the surface of the electrostatic latent image carrier.

<3> The developer includes a toner including at least a crystalline resin and a colorant, and a carrier including a core material and a resin coat layer that covers a surface of the core material, and the core material is a magnetic powder. The conductive material is dispersed in the resin coat layer, the carrier has a volume resistance of 10 ⁸ to 10 ¹³ Ω · cm, and the core material exposure rate on the carrier surface is 2% or less < The image forming apparatus according to 1> or <2>.

  <4> The image forming apparatus according to <3>, wherein the conductive material is a titanium compound, and a ratio of titanium atoms to carbon atoms on a surface of the resin coat layer is 0.8 to 7.0%.

<5> A charging step of charging the electrostatic latent image carrier with a contact charger, a latent image forming step of forming a latent image on the surface of the charged electrostatic latent image carrier, and the electrostatic latent image carrier A developing step of developing a latent image formed on the surface of the body with a developer to form a toner image, and a transferring step of transferring the toner image formed on the surface of the electrostatic latent image carrier to a transfer target. An image having at least a lubricant supplying step for supplying a powder lubricant to the surface of the electrostatic latent image carrier and a cleaning step for removing residual toner on the surface of the electrostatic latent image carrier after transfer. In the forming method, the powder lubricant contains 10 to 40% by volume of inorganic fine particles having a volume average particle diameter of 10 to 80 nm, and has a volume resistance of 10 ⁸ to 10 ¹¹ when an applied voltage is 1000 V · cm. The image forming method is Ω · cm.

  According to the present invention, it is possible to provide an image forming apparatus and an image forming method capable of maintaining good image quality over a long period of time when the contact charging method is used.

Hereinafter, the image forming apparatus and the image forming method of the present invention will be described in detail.
<First embodiment>
FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment of the present invention. The image forming apparatus of FIG. 1 includes an electrostatic latent image carrier 1, a contact charger 2 that is a charging unit that charges the electrostatic latent image carrier 1, and an electrostatic latent image charged by the contact charger 2. An exposure device 3 that is a latent image forming unit that exposes the image carrier 1 to form a latent image, and a developing unit that develops the latent image formed by the exposure device 3 with a developer to form a toner image. An inorganic transfer device 5 having a volume average particle size of 10 to 80 nm on the surface of the electrostatic latent image carrier 1 and a transfer device 5 serving as a transfer means for transferring the toner image formed by the developing device 4 to the transfer target A. A lubricant application device 6 which is a lubricant supply means for supplying a powder lubricant having a volume resistance of 10 ⁸ to 10 ¹¹ Ω · cm when the applied voltage is 1000 V · cm and containing 10 to 40% by volume of fine particles; Cleaner for removing residual toner on the surface of the electrostatic latent image carrier 1 after transfer A cleaning device 7 serving as a cleaning means, a charge eliminating device 8 for removing the residual potential on the surface of the electrostatic latent image carrier 1, and a fixing device for fixing the toner image transferred to the transfer target A by heat and / or pressure. 9.

  The volume average particle size of the inorganic fine particles contained in the powder lubricant supplied to the electrostatic latent image carrier 1 is 10 to 80 μm, preferably 20 to 70 μm, and more preferably 30 to 60 μm. If the volume average particle size of the inorganic fine particles is larger than 80 μm, most of the inorganic fine particles are scraped off by the cleaning device 7 and are not sufficiently supplied to the contact charger 2. Even if the cleaning device 7 has passed through, if the volume average particle size is large, it may not adhere to the contact charger 2 and cause problems in the exposure and development processes. When the volume average particle size of the inorganic fine particles is smaller than 10 μm, the aggregates of the inorganic fine particles increase and the dispersibility when added to the lubricant is not good, and the powder lubricant is uniformly applied to the electrostatic latent image carrier. It may not be possible to supply.

The content of the inorganic fine particles in the powder lubricant is 10 to 40% by volume, preferably 10 to 35% by volume, and more preferably 15 to 30% by volume. The inorganic fine particles contained in the powder lubricant are not all supplied to the contact charger 2, but are mostly scraped off by the cleaning device 7. For this reason, if the content of the inorganic fine particles is less than 10% by volume, the supply amount to the contact charger 2 decreases, and external additives may adhere to cause a charging failure of the contact charger. .
On the other hand, if the content of inorganic fine particles exceeds 40% by volume, the powder lubricant cannot be collected by the contact charger 2 and is carried over to the next exposure and development process, which may cause image quality defects. .

The volume resistance of the powder lubricant is 10 ⁸ to 10 ¹¹ Ω · cm at an applied electric field of 1000 V · cm, preferably 10 ^8.2 to 10 ¹¹ Ω · cm, and more preferably 10 ^8.5 to 10 ^10.5 Ω · cm. If the volume resistance of the powder lubricant is less than 10 ⁸ Ω · cm, the inorganic fine particles that could not be collected by the charging member may cause image quality defects in the exposure and development processes. On the other hand, if the volume resistance of the powder lubricant is higher than 10 ¹¹ Ω · cm, it may cause charging failure when adhering to the contact charger.

As described above, the powder lubricant is not entirely attached to the contact charger 2, but is largely scraped off by the cleaning device 7. At this time, for example, when the inorganic fine particles have a large particle size, the scraping rate is larger than that of the small particle size, so that the charged amount of the inorganic fine particles changes from the initial one in the cleaning process. However, when the volume resistance of the powder lubricant is 10 ⁸ to 10 ¹¹ Ω · cm at an applied electric field of 1000 V · cm when 25% by volume of inorganic fine particles are added, even if the composition changes due to scraping by the cleaning device 7. The necessary resistance can be maintained by the contact charger 2 and no problem is caused in the next image forming process.

  The inorganic fine particles used in the present invention are not limited as long as they satisfy the above particle diameter and volume resistance, and may be any known material such as silica, titania, zinc oxide, aluminum oxide, and the like. Absent. Further, these fine particles may be subjected to a surface treatment. Moreover, the manufacturing method of this inorganic fine particle, the surface treatment method, etc. may be any known method.

  The lubricant used in the present invention is not limited as long as it can be used as a powder. For example, lead oleate, zinc oleate, copper oleate, zinc stearate, iron stearate, stearin Fatty acid metal salts such as magnesium oxide, iron stearate, copper stearate, iron palmitate, copper palmitate, zinc myristate, and fluorine resins such as polyvinylidene fluoride, polytrifluoroethylene, and tetrafluoroethylene In particular, zinc stearate is preferable because it is excellent not only in lubricity but also in applicability.

  As a method for preparing a powder lubricant, (1) a method of mixing inorganic fine particles and a lubricant in a powder state using a sample mill or a Henschel mixer, and (2) a melt mixing of the lubricant and inorganic fine particles. And (3) a method in which both the lubricant and the inorganic fine particles are heat-dispersed in an insoluble solution to produce associated particles having a desired particle size range, and (4) (1) to (3) Examples thereof include a method in which a powder lubricant prepared by the above method is melted and / or compression-molded and formed into a solid plate shape to be pulverized by brush rubbing.

  In the present invention, the volume resistance of the powder lubricant means a value measured by a method similar to the method used for measuring the volume resistance of the carrier described later.

In the image forming apparatus of the present invention, the electrostatic latent image carrier 1 is charged by using the contact type charger 2 as the charging means. The charging means is not particularly limited as long as it is a contact-type charger that charges the electrostatic latent image carrier 1 by applying a voltage to the conductive member brought into contact with the surface of the electrostatic latent image carrier 1. It is not something. By using a contact-type charger, the amount of ozone generated is small, environmentally friendly, and excellent printing durability.
In the contact charging type charger, the shape of the conductive member may be any of a brush shape, a blade shape, a pin electrode shape, a roller shape, and the like, and is not limited.

  A latent image is formed on the surface of the charged electrostatic latent image carrier 1 using the exposure device 3. As the exposure apparatus 3, for example, a laser optical system, an LED array, or the like is used.

The latent image formed on the surface of the electrostatic latent image carrier 1 is developed with a developer to form a toner image. For example, a developer carrier having a developer layer formed on the surface thereof is brought into contact with or close to the electrostatic latent image carrier 1, and toner is attached to the latent image on the surface of the electrostatic latent image carrier 1 to form a toner image. Is formed.
The developing device 4 is not particularly limited, and examples of the developing device using a two-component developer include a cascade type and magnetic brush type developing device.

The toner image formed on the surface of the electrostatic latent image carrier 1 is transferred to the transfer target A to form a transfer image.
A corotron can be used as a transfer device for transferring the toner image from the electrostatic latent image carrier 1 onto paper or the like. The corotron is effective as a means for uniformly charging the paper, but a high voltage of several kV must be applied and a high voltage power source is required in order to give a predetermined charge to the paper as a transfer target. Also, since ozone is generated by corona discharge, it may cause deterioration of rubber parts and the electrostatic latent image carrier, so a conductive transfer roll made of an elastic material is pressed against the electrostatic latent image carrier, A contact transfer system that transfers a toner image onto a sheet is preferable, but the transfer device is not particularly limited.

The powder lubricant according to the present invention is supplied to the surface of the electrostatic latent image carrier 1 after the transfer by the lubricant application device 6. The lubricant application device 6 is not particularly limited, and powder fine particles supported on the surface thereof may be supplied to the surface of the electrostatic latent image carrier 1 using a brush roll or a sponge roll. Alternatively, two blades may be stacked and a powder lubricant may be applied between them.
The supply amount of the powder lubricant to the surface of the electrostatic latent image carrier 1 may be a constant amount, but the supply amount may be changed according to the output image. The supply amount may be changed according to the deterioration of the vessel 2. By changing the supply amount of the powder lubricant according to the output image and the deterioration of the electrostatic latent image carrier 1 or the contact charger 2, the resistance of the contact charger can be reduced with a minimum amount of the powder lubricant. Change can be prevented.

  After the powder lubricant is supplied, the residual toner on the surface of the electrostatic latent image carrier 1 is removed by the cleaning device 7. As the cleaning device 7, for example, a cleaning blade, a cleaning brush, a cleaning roll, or the like can be used.

  The most commonly employed method in the cleaning process is a blade cleaning method in which a rubber blade such as polyurethane is pressed against the electrostatic latent image carrier 1. On the other hand, a magnet is fixedly arranged inside, a rotatable cylindrical non-magnetic sleeve is provided on the outer periphery thereof, and a magnetic carrier system that collects toner by carrying a magnetic carrier on the sleeve surface, or a semiconductive It is also possible to remove the toner by making the resin fiber or animal hair rotatable in the form of a roll and applying a bias having a polarity opposite to that of the toner to the roll. In the former magnetic brush system, a cleaning pretreatment corotron may be provided. In the present invention, the cleaning method is not particularly limited.

  The static eliminator 8 is not particularly limited, but is appropriately selected depending on the type of the electrostatic latent image carrier 1 because the spectral sensitivity and the light fatigue characteristics differ depending on the type of the electrostatic latent image carrier 1.

  The toner image transferred to the transfer target A is fixed by the fixing device 9. As the fixing device 9, a heat fixing device using a heat roll is preferably used. The heat fixing device includes a fixing roller having a heater lamp for heating inside a cylindrical metal core, a so-called release layer formed on the outer peripheral surface by a heat resistant resin film layer or a heat resistant rubber film layer, and the fixing roller. The pressure roller or pressure belt is disposed in pressure contact with the roller and has a heat-resistant elastic body layer formed on the outer peripheral surface of the cylindrical metal core or the surface of the belt-like base material. The fixing process of an unfixed toner image is performed by inserting a transfer body on which an unfixed toner image is formed between a fixing roller and a pressure roller or a pressure belt, and using a binder resin, an additive, etc. in the toner. Fixing is performed by heat melting.

  The electrostatic latent image carrier 1 used in the image forming apparatus of the present invention may be any known photoreceptor such as a selenium photoreceptor, an organic photoreceptor, a zinc oxide photoreceptor, an amorphous silicon photoreceptor, It is appropriately selected as necessary.

The developer used in the present invention is not particularly limited, but a carrier including a toner containing at least a crystalline resin and a colorant, a core material and a resin coat layer covering the surface of the core material, The core material is magnetic powder, a conductive material is dispersed in the resin coating layer, the volume resistance of the carrier is 10 ⁸ to 10 ¹³ Ω · cm, and the core on the surface of the carrier It is preferable to use a developer having a material exposure rate of 2% or less. The developer has appropriate developability and chargeability, has no image quality problems such as fog, and has excellent charge stability.

The toner includes at least a crystalline resin as a binder resin and a colorant, and other components as necessary.
(Binder resin)
The main component of the binder resin of the toner is preferably a crystalline resin. The polymerizable monomer and resin constituting the binder resin in the present invention are not particularly limited as long as they can constitute a resin having crystallinity.
When the main component of the binder resin of the toner used in the present invention is not crystalline, that is, when it is amorphous, the toner blocking resistance and image storage stability are maintained while ensuring good low-temperature fixability. I can't. In the present invention, “crystalline resin” refers to a resin having a clear endothermic peak rather than a stepwise endothermic amount change in differential scanning calorimetry (DSC). In the case of a polymer obtained by copolymerizing another component with the main chain of the crystalline resin, if the other component is 50% by mass or less, this copolymer is also called a crystalline resin.

  As described above, the binder resin of the toner used in the present invention contains a crystalline resin as a main component. Here, the “main component” is a main component among the components constituting the binder resin. Specifically, the component which comprises 50 mass% or more of the said binder resin is pointed out. However, in the present invention, among the binder resins, the crystalline resin is preferably 70% by mass or more, more preferably 90% by mass or more, and particularly preferably all are crystalline resins.

  Specific examples of the crystalline resin include long-chain alkyl dicarboxylic acids such as adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tridecanedioic acid, and butanediol, pentanediol, hexanediol. , Polyester resins using long-chain alkyl and alkenyl diols such as heptanediol, octanediol, nonanediol, decanediol, batyl alcohol; amyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylic acid Heptyl, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, tridecyl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) acrylate , (Meth) acrylic acid steer , Vinyl resins using long-chain alkyls such as (meth) acrylic acid oleyl and (meth) acrylic acid behenyl, alkenyl (meth) acrylic acid esters; From the viewpoint of chargeability and adjustment of the melting point within a preferable range, a polyester resin-based crystalline resin is preferable. An aliphatic crystalline polyester resin having an appropriate melting point is preferred.

  The crystalline polyester resin is synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. In the following description, in the polyester resin, the component that was an acid component before the synthesis of the polyester resin is referred to as “acid-derived component”, and the component that was the alcohol component before the synthesis of the polyester resin is referred to as “alcohol. "Derived component".

-Acid-derived components-
Examples of the acid for forming the acid-derived constituent component include various dicarboxylic acids, and aromatic dicarboxylic acids and aliphatic dicarboxylic acids are preferable, among which aliphatic dicarboxylic acids are desirable, and linear dicarboxylic acids are particularly preferable. desirable.
Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decanedicarboxylic acid. 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, Or lower alkyl esters and acid anhydrides thereof, but are not limited thereto.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, etc. Among them, terephthalic acid is an easily available, low melting point polymer. It is preferable in terms of easy formation.
As the acid-derived constituent component, in addition to the aforementioned aliphatic dicarboxylic acid-derived constituent component and aromatic dicarboxylic acid-derived constituent component, a dicarboxylic acid-derived constituent component having a double bond, a dicarboxylic acid-derived constituent component having a sulfonic acid group, etc. Are preferably included.

  The component derived from a dicarboxylic acid having a double bond is derived from a lower alkyl ester or acid anhydride of a dicarboxylic acid having a double bond, in addition to a component derived from a dicarboxylic acid having a double bond. Components are also included. The dicarboxylic acid-derived component having a sulfonic acid group is derived from a lower alkyl ester or acid anhydride of a dicarboxylic acid having a sulfonic acid group, in addition to a component derived from a dicarboxylic acid having a sulfonic acid group. Components are also included.

  The dicarboxylic acid having a double bond can be suitably used to prevent hot offset at the time of fixing since the entire resin can be crosslinked using the double bond. Examples of such dicarboxylic acids include, but are not limited to, fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, fumaric acid, maleic acid and the like are preferable in terms of cost.

  The dicarboxylic acid having a sulfonic acid group is effective in that it can favorably disperse a coloring material such as a pigment. Further, when a fine particle is produced by emulsifying or suspending the entire resin in water, if the sulfonic acid group is present, the resin can be emulsified or suspended without using a surfactant. Examples of the dicarboxylic acid having a sulfonic acid group include, but are not limited to, 2-sulfoterephthalic acid sodium salt, 5-sulfoisophthalic acid sodium salt, and sulfosuccinic acid sodium salt. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, 5-sulfoisophthalic acid sodium salt is preferable in terms of cost.

All of these acid-derived components other than aliphatic dicarboxylic acid-derived components and aromatic dicarboxylic acid-derived components (dicarboxylic acid-derived components having double bonds and dicarboxylic acid-derived components having sulfonic acid groups) As content in an acid origin structural component, 1-20 structural mol% is preferable and 2-10 structural mol% is more preferable.
When the content is less than 1 component mol%, pigment dispersion is not good, the emulsion particle size becomes large, and adjustment of the toner diameter by aggregation may be difficult, whereas it exceeds 20 component mol%. In some cases, the crystallinity of the polyester resin is lowered, the melting point is lowered, the storability of the image is deteriorated, or the emulsified particle diameter is too small to be dissolved in water, thereby causing no latex. In the present specification, “constituent mol%” refers to a percentage when each constituent component (acid-derived constituent component or alcohol-derived constituent component) in the polyester resin is defined as one unit (mol).

-Alcohol-derived components-
As the alcohol to be an alcohol-derived constituent component, an aliphatic diol is preferable. Specifically, for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1, 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13 -Tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol, and the like, but are not limited thereto.

  The alcohol-derived constituent component has an aliphatic diol-derived constituent component content of 80 constituent mol% or more, and includes other components as necessary. As the alcohol-derived constituent component, the content of the aliphatic diol-derived constituent component is preferably 90 constituent mol% or more.

  When the content of the aliphatic diol-derived constituent component is less than 80 mol%, the crystallinity of the polyester resin is lowered and the melting point is lowered, so that toner blocking resistance, image storage stability, and low-temperature fixability deteriorate. May end up. Other components included as necessary include diol-derived components having double bonds and diol-derived components having sulfonic acid groups.

  Examples of the diol having a double bond include 2-butene-1,4-diol, 3-butene-1,6-diol, 4-butene-1,8-diol, and the like. Examples of the diol having a sulfonic acid group include 1,4-dihydroxy-2-sulfonic acid benzene sodium salt, 1,3-dihydroxymethyl-5-sulfonic acid benzene sodium salt, and 2-sulfo-1,4-butanediol sodium. Examples include salts.

When adding these alcohol-derived components other than aliphatic diol-derived components (diol-derived component having a double bond and diol-derived component having a sulfonic acid group), the content in these alcohol-derived components Is preferably 1 to 20 mol%, more preferably 2 to 10 mol%.
When the content of the alcohol-derived constituent component other than the aliphatic diol-derived constituent component is less than 1 constituent mol%, the pigment dispersion is not good, the emulsified particle size is large, and it is difficult to adjust the toner diameter by aggregation. On the other hand, if it exceeds 20 component mol%, the crystallinity of the polyester resin is lowered and no clear melting point is exhibited. Or the solubility of the resin in water increases and latex may not be produced.

The melting point of the binder resin in the toner used in the present invention is preferably 60 to 120 ° C, more preferably 60 to 100 ° C. When the melting point is lower than 60 ° C., toner storage stability and image storage stability after fixing become a problem. On the other hand, when the temperature is higher than 120 ° C., sufficient low-temperature fixing cannot be obtained as compared with the conventional toner.
In the present invention, the melting point of the crystalline resin is measured using a differential scanning calorimeter (DSC) using JIS K- when the temperature is measured from room temperature to 150 ° C. at a rate of temperature increase of 10 ° C. per minute. The melting peak temperature of the input compensation differential scanning calorimetry shown in 7121 can be obtained. The crystalline resin may show a plurality of melting peaks, but in the present invention, the maximum peak is regarded as the melting point.

The method for producing the polyester resin is not particularly limited, and can be produced by a general polyester polymerization method in which an acid component and an alcohol component are reacted. For example, direct polycondensation, transesterification method, etc. Produced separately for different types. The molar ratio (acid component / alcohol component) when the acid component reacts with the alcohol component varies depending on the reaction conditions and the like, and cannot be generally stated, but is usually about 1/1.
The production of the polyester resin can be carried out at a polymerization temperature of 180 to 230 ° C., and the reaction system is reacted under reduced pressure as necessary to remove water and alcohol generated during condensation. When the monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution aid is distilled off. If there is a monomer with poor compatibility in the copolymerization reaction, it is advisable to condense the monomer with poor compatibility with the monomer and the acid or alcohol to be polycondensed in advance before polycondensing with the main component. .

Catalysts that can be used in the production of the polyester resin include alkali metal compounds such as sodium and lithium, alkaline earth metal compounds such as magnesium and calcium, and metal compounds such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium. , Phosphorous acid compounds, phosphoric acid compounds, and amine compounds. Specific examples include the following compounds.
For example, sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, zinc stearate, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium tetraethoxide, titanium Tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, antimony trioxide, triphenylantimony, tributylantimony, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, zirconium tetrabutoxide, naphthene Zirconate, zirconyl carbonate, zirconyl acetate, zirconyl stearate, zirconyl octylate, germanium oxide, triphenyl Phosphite, tris (2,4-di -t- butyl-phenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, compounds such as triphenyl amine.

(Coloring agent)
The colorant in the toner used in the present invention is not particularly limited and may be a dye or a pigment, but a pigment is preferable from the viewpoint of light resistance and water resistance. Preferred pigments include carbon black, aniline black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, Quinacridone, benzidine yellow, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 185, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 74, C.I. I. Pigment blue 15: 1, C.I. I. A known pigment such as CI Pigment Blue 15: 3 can be used.

Magnetic powder can also be used as a colorant. As the magnetic powder, known magnetic materials such as ferromagnetic metals such as cobalt, iron and nickel, alloys and oxides of metals such as cobalt, iron, nickel, aluminum, lead, magnesium, zinc and manganese can be used.
The above colorants can be used alone or in combination of two or more. The content of the colorant in the toner used in the present invention is preferably 0.1 to 40 parts by mass, more preferably 1 to 30 parts by mass with respect to 100 parts by mass of the total toner raw materials. In addition, by appropriately selecting the type of the colorant, each color toner such as yellow toner, magenta toner, cyan toner, and black toner can be obtained.

(Other ingredients)
The other components that can be used in the toner used in the present invention are not particularly limited and may be appropriately selected depending on the purpose. For example, various known components such as inorganic fine particles, organic fine particles, charge control agents, release agents, etc. An additive etc. are mentioned.
As the inorganic fine particles, known fine inorganic particles such as silica fine particles, titanium oxide fine particles, alumina fine particles, cerium oxide fine particles, or those obtained by hydrophobizing the surface thereof can be used alone or in combination of two or more. However, silica fine particles having a refractive index smaller than that of the binder resin are preferable from the viewpoint of not impairing transparency such as color developability and OHP permeability. Further, the silica fine particles may be subjected to various surface treatments, and for example, those subjected to surface treatment with a silane coupling agent, a titanium coupling agent, silicone oil or the like are preferable.

  By adding these inorganic fine particles, the viscoelasticity of the toner can be adjusted, and offset resistance and releasability can be improved. The inorganic fine particles are preferably contained in an amount of 0.2 to 40% by mass, more preferably 0.5 to 20% by mass, based on the total amount of toner.

  The organic fine particles are generally used for the purpose of improving cleaning properties and transferability. Examples of the organic fine particles include fine particles such as polystyrene, polymethyl methacrylate, and polyvinylidene fluoride.

  The charge control agent is generally used for the purpose of improving chargeability. Examples of the charge control agent include metal-containing azo compounds such as chromium azo dyes, iron azo dyes, and aluminum azo dyes; salicylic acid metal complexes, nigrosine and quaternary ammonium salts.

  The release agent is generally used for the purpose of improving release properties. Specific examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene; silicones having a softening point by heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc. Mineral / petroleum waxes; ester waxes such as fatty acid esters, montanic acid esters, and carboxylic acid esters. In this invention, these mold release agents may be used individually by 1 type, and may use 2 or more types together.

  The content of the release agent is preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass with respect to 100 parts by mass of the total toner raw materials. If the amount is less than 1 part by mass, the effect of adding a release agent is not obtained. If the amount exceeds 20 parts by mass, adverse effects on the chargeability tend to appear, and the toner is easily destroyed inside the developing machine. In addition to the effect that the resin is spent on the carrier and the charge is likely to be lowered, for example, when color toner is used, the image surface tends to be insufficiently oozed out at the time of fixing. Since the release agent tends to stay in the film, the transparency is deteriorated, which is not preferable. The melting point of the release agent is preferably 50 to 120 ° C, more preferably 60 to 100 ° C. If the melting point of the release agent is less than 60 ° C., the change temperature of the release agent is too low, and the blocking resistance is inferior, or the developability deteriorates when the temperature in the copying machine increases. When it exceeds 120 ° C., the change temperature of the release agent is too high, and the low-temperature fixability of the crystalline resin is impaired.

The volume average particle size of the toner used in the present invention is preferably 1 to 12 μm, more preferably 2 to 8 μm, and further preferably 3 to 6 μm. Moreover, as a number average particle diameter, 1-20 micrometers is preferable and 2-8 micrometers is more preferable. In addition, the value of (volume average particle diameter ÷ number average particle diameter), which is an index of particle size distribution, is preferably 1.6 or less, and more preferably 1.5 or less. If this value is larger than 1.6, the spread of the particle size distribution becomes large, so that the distribution of charge amount becomes wide, and reverse polarity toner and low charge toner are likely to be generated.
The volume average particle diameter and the number average particle diameter can be determined, for example, by measuring with a 50 μm aperture diameter using a Coulter counter [TA-II] type (manufactured by Coulter). At this time, the measurement is performed after the toner is dispersed in an electrolyte aqueous solution (Isoton aqueous solution) and dispersed by ultrasonic waves for 30 seconds or more.

(Preferred physical properties of toner used in the present invention)
It is desirable that the toner used in the present invention has sufficient hardness at normal temperature. Specifically, the dynamic viscoelasticity is that the storage elastic modulus G _L (30) is 1 × 10 ⁶ Pa or more and the loss elastic modulus G _N (30) is 1 at an angular frequency of 1 rad / sec and 30 ° C. It is desirable that it is 10 ⁶ Pa or more. Incidentally, the storage elastic modulus G _L and the loss modulus G _N has its details are specified in JIS K-6900.

When the storage elastic modulus G _L (30) is less than 1 × 10 ⁶ Pa or the loss elastic modulus G _N (30) is less than 1 × 10 ⁶ Pa at an angular frequency of 1 rad / sec and 30 ° C. When the toner is mixed with the carrier, the toner particles may be deformed by the pressure or shearing force received from the carrier, and stable charge development characteristics may not be maintained. Further, when the toner on the electrostatic latent image carrier (photoconductor) is cleaned, it may be deformed by a shearing force received from the cleaning blade, resulting in poor cleaning. When the storage elastic modulus G _L (30) and the loss elastic modulus G _N (30) are within the above ranges at the angular frequency of 1 rad / sec and 30 ° C., the characteristics at the time of fixing even when used in a high-speed image forming apparatus. Is stable and preferred.
Further, the toner used in the present invention, the variation of the value of the storage modulus G _L and the loss modulus G _N due to a temperature change, the temperature at which the 2 digits or more in a temperature range of 10 ° C. interval (10 ° C. Temperature when raised, the value of G _L and G _N are preferably has a temperature interval), such as changes from 1 or less than that of the 100 minutes. The storage modulus G _L and the loss modulus G _N is a no section of the temperature, the fixing temperature is increased, as a result, insufficient fixed at low temperatures, reducing the energy consumption of the fixing step It may become.

FIG. 2 is a graph showing preferable characteristics of the toner used in the present invention. In FIG. 2, the vertical axis common logarithm log G _L storage modulus or represents a common logarithm log G _N of the loss elastic modulus and the horizontal axis represents temperature. The toner having such characteristics shows a sudden drop in elastic modulus at the melting point in the temperature range of 60 to 120 ° C., and the elastic modulus is stabilized within a predetermined range. Even if it becomes, the viscosity does not decrease more than necessary, and it is possible to prevent excessive permeation and offset of the transfer medium such as paper.

  The method for producing the toner used in the present invention described above is not particularly limited, but the method for producing the toner used in the present invention described later is particularly preferable. Further, since the toner used in the present invention has the above-described configuration, it is excellent in toner blocking resistance, image storage stability, and low-temperature fixability. Further, when the polyester resin has a cross-linked structure due to an unsaturated bond, in particular, the polyester resin has a wide fixing latitude with good offset resistance and excessive toner in the transfer medium such as paper. Thus, it is possible to obtain a toner which prevents the penetration of the toner. Furthermore, by making the toner particle shape spherical, it is possible to improve transfer performance such as transfer efficiency.

(Toner production method)
The method for producing the toner used in the present invention is not particularly limited, but wet granulation is preferred. Suitable examples of the wet granulation method include known melt suspension methods, emulsion aggregation methods, and dissolution suspension methods. Hereinafter, the emulsion aggregation method will be described as an example.
The emulsification aggregation method is an emulsification step of emulsifying a crystalline resin such as the crystalline polyester resin already described in the “Binder resin” section of the “toner” used in the present invention to form emulsified particles (droplets). And an aggregating step for forming an aggregate of the emulsified particles (droplets), and a fusing step for fusing the aggregate to cause heat fusion. In the following description, a case where a crystalline polyester resin is used as the crystalline resin will be described as an example.

<Emulsification process>
In the emulsification step, the emulsified particles (droplets) of the polyester resin are mixed into a solution obtained by mixing an aqueous medium and a sulfonated polyester resin and a mixed liquid (polymer liquid) containing a colorant as necessary. It is formed by applying a shearing force.
At that time, the viscosity of the polymer liquid can be lowered to form emulsified particles by heating or dissolving the polyester resin in an organic solvent. Moreover, a dispersing agent can also be used for stabilization of emulsified particles and thickening of the aqueous medium. Hereinafter, such a dispersion of emulsified particles may be referred to as a “resin particle dispersion”.

  Examples of the dispersant include water-soluble polymers such as polyvinyl alcohol, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, sodium polyacrylate, and sodium polymethacrylate, sodium dodecylbenzenesulfonate, sodium octadecylsulfate, and sodium oleate. Anionic surfactants such as sodium laurate and potassium stearate, cationic surfactants such as laurylamine acetate, stearylamine acetate and lauryltrimethylammonium chloride, zwitterionic surfactants such as lauryldimethylamine oxide, poly Oxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, etc. Surfactants such as on-surfactant, tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate, and inorganic compounds such as barium carbonate.

When an inorganic compound is used as the dispersant, a commercially available product may be used as it is. However, for the purpose of obtaining fine particles, a method of producing fine particles of an inorganic compound in the dispersant may be employed. As the usage-amount of the said dispersing agent, 0.01-20 mass parts is preferable with respect to 100 mass parts of said polyester resins (binder resin).
In the emulsification step, the polyester resin is copolymerized with a dicarboxylic acid having a sulfonic acid group (that is, a suitable amount of a dicarboxylic acid-derived component having a sulfonic acid group is included in the acid-derived component). ) And dispersion stabilizers such as surfactants can be reduced, or emulsified particles can be formed without using them. Examples of the organic solvent include ethyl acetate and toluene, which are appropriately selected according to the polyester resin.

As the usage-amount of the said organic solvent, it is 50-5000 mass with respect to 100 mass parts of total amounts of the said polyester resin and the other monomer (henceforth abbreviated as "polymer") used as needed. Part is preferable, and 120 to 1000 parts by mass are more preferable. In addition, a colorant can be mixed before forming the emulsified particles. As a method of mixing the colorant into the resin, melt dispersion using a disperser or the like can be mentioned. The colorant used is the same as already described in the section “Colorant” of the toner used in the present invention.
Examples of the emulsifier used for forming the emulsified particles include a homogenizer, a homomixer, a pressure kneader coater, an extruder, and a media disperser. The size of the emulsified particles (droplets) of the polyester resin is preferably 0.01 to 1 μm, more preferably 0.03 to 0.4 μm, more preferably 0.03 to 0.03 in terms of an average particle size (volume average particle size). 0.3 μm is more preferable.

As a method for dispersing the colorant, any method such as a general dispersion method such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, or a dyno mill can be used, and is not limited at all. If necessary, an aqueous dispersion of these colorants can be prepared using a surfactant, or an organic solvent dispersion of these colorants can be prepared using a dispersant. As the surfactant and the dispersing agent used for dispersion, the same dispersing agents that can be used when dispersing the polyester resin can be used.
The addition amount of the colorant is preferably 1 to 20% by mass, more preferably 1 to 12% by mass, and still more preferably 2 to 10% by mass with respect to the total amount of the polymer. . When a colorant is mixed in the emulsification step, the polymer and the colorant can be mixed by mixing the colorant or the organic solvent dispersion of the colorant with the organic solvent solution of the polymer.

<Aggregation process>
In the aggregation step, the resulting emulsified particles are aggregated by heating at a temperature in the vicinity of the melting point of the polyester resin and a temperature below the melting point to form an aggregate. Formation of the aggregate of the emulsified particles is performed by acidifying the pH of the emulsion under stirring. As said pH, 1-6 are preferable and 1.5-5 are more preferable. At this time, it is also effective to use a flocculant.
As the flocculant to be used, a surfactant having a reverse polarity to the surfactant used for the dispersant, an inorganic metal salt, and a metal complex having a valence of 2 or more can be preferably used. In particular, the use of a metal complex is preferable because the amount of the surfactant used can be reduced and the charging characteristics are improved.

  Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include inorganic metal salt polymers. Of these, aluminum salts and polymers thereof are particularly preferred. In order to obtain a sharper particle size distribution, the valence of the inorganic metal salt is bivalent than monovalent, trivalent than bivalent, trivalent than trivalent, and tetravalent than trivalent. The inorganic metal salt polymer is more suitable.

<Fusion process>
In the fusion step, under the same stirring as in the aggregation step, the aggregation suspension is stopped by setting the pH of the suspension of the aggregate to a range of 3 to 7, and heated at a temperature equal to or higher than the melting point of the polyester resin. To fuse the aggregates. There is no problem if the heating temperature is equal to or higher than the melting point of the polyester resin. The heating time may be performed so that the fusion is sufficiently performed, and may be performed for about 0.5 to 10 hours.
The fused particles obtained by fusing can be made into toner particles through a solid-liquid separation process such as filtration and, if necessary, a washing process and a drying process. In this case, in order to ensure sufficient charging characteristics and reliability as a toner, it is preferable to sufficiently wash in the washing step.
In the drying process, an arbitrary method such as a normal vibration type fluidized drying method, a spray drying method, a freeze drying method, or a flash jet method can be adopted. It is desirable that the toner particles have a moisture content after drying of 1.0% or less, preferably 0.5% or less.

  In the fusion step, a crosslinking reaction may be performed when the polyester resin is heated to a melting point or higher, or after the fusion is completed. Moreover, a crosslinking reaction can also be performed simultaneously with aggregation. When the crosslinking reaction is performed, for example, an unsaturated sulfonated crystalline polyester resin obtained by copolymerizing a double bond component as a binder resin is used, and a radical reaction is caused to the resin to introduce a crosslinked structure. . At this time, the following polymerization initiator is used.

  Examples of the polymerization initiator include t-butyl peroxy-2-ethylhexanoate, cumyl perpivalate, t-butyl peroxylaurate, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, di-t. -Butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane 1,1-bis (t-butylperoxy) cyclohexane, 1,4-bis (t-butylperoxyca) Bonyl) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, , 3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylper) Oxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, di-t-butyldiperoxyisophthalate, 2,2-bis (4,4-di-t-butylperoxy) (Cyclohexyl) propane, di-t-butylperoxy α-methylsuccinate, di-t-butylperoxydimethylglutarate, di-t-butylperoxyhexahydrotereph Tartrate, di-t-butylperoxyazelate, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, diethylene glycol-bis (t-butylperoxycarbonate), di-t-butylper Oxytrimethyl adipate, tris (t-butylperoxy) triazine, vinyltris (t-butylperoxy) silane, 2,2'-azobis (2-methylpropionamidine dihydrochloride), 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine], 4,4′-azobis (4-cyanovaleric acid) and the like.

  These polymerization initiators can be used alone or in combination of two or more. The amount and type of the polymerization initiator are selected depending on the amount of unsaturated sites in the polymer and the type and amount of the coexisting colorant. The polymerization initiator may be mixed with the polymer in advance before the emulsification step, or may be incorporated into the aggregate in the aggregation step. Further, it may be introduced after the fusion step or after the fusion step. In the case of introduction after the aggregation step, the fusion step, or the fusion step, a solution obtained by dissolving or emulsifying a polymerization initiator in an organic solvent is added to a particle dispersion (resin particle dispersion or the like). These polymerization initiators may be added with known crosslinking agents, chain transfer agents, polymerization inhibitors and the like for the purpose of controlling the degree of polymerization.

  According to the toner manufacturing method described above, the particle shape of the toner can be controlled. The toner particle shape is preferably spherical. By making it spherical, it becomes possible to improve the transfer efficiency by reducing the non-electrostatic adhesion force, and also improve the powder fluidity.

  To the toner used in the present invention, an external additive such as a fluidizing agent or an auxiliary agent may be added to the surface of the toner particles. Examples of the external additive include silica fine particles whose surfaces have been hydrophobized, titanium fine particles, alumina fine particles, cerium oxide fine particles, inorganic fine particles such as carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Fine particles can be used, but at least two of these external additives are used, and at least one of the external additives has a volume average particle size of 30 nm to 200 nm, more preferably 30 nm to 150 nm. preferable.

  By reducing the particle size of the toner, non-electrostatic adhesion to the electrostatic latent image carrier increases, which causes transfer defects and image loss called hollow characters, and causes transfer unevenness such as superimposed images. In order to cause this, it is effective to add a large-sized external additive having a volume average particle size of 30 nm to 200 nm to improve transferability. If the volume average particle size is less than 30 nm, the initial toner fluidity is good, but the non-electrostatic adhesion between the toner and the photoreceptor cannot be sufficiently reduced, resulting in a decrease in transfer efficiency and image omission. In addition, the uniformity of the image is deteriorated, and the external additive is embedded in the toner surface due to the stress in the developing machine over time, and the charging property is changed to cause problems such as a decrease in copy density and fogging in the background portion. . On the other hand, if the volume average particle size is larger than 200 nm, it is easily detached from the toner surface and the fluidity is deteriorated.

<Career>
The carrier that can be used in the developer of the present invention includes a core material and a resin coat layer that covers the surface of the core material, the core material is magnetic powder, and a conductive material is dispersed in the resin coat layer. It is preferable that the volume resistance of the carrier is 10 ⁸ to 10 ¹³ Ω · cm, and the core material exposure rate on the surface of the carrier is 2% or less. However, even in a toner using a crystalline resin having a low electrical resistance as a binder resin, the charging property is allowed to be stable, and a high image quality can be achieved.

  The coating resin / matrix resin used for the resin coating layer is polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether, polyvinyl ketone, vinyl chloride-acetic acid. Vinyl copolymer, styrene-acrylic acid copolymer, straight silicone resin composed of organosiloxane bond or modified product thereof, fluorine resin, polyester, polyurethane, polycarbonate, phenol resin, amino resin, melamine resin, benzoguanamine resin, urea resin, Examples include amide resins and epoxy resins, but are not limited thereto. Particularly preferred are polystyrene resin, acrylic resin, and styrene acrylic copolymer. When these resins are used, the coating film strength is high and the conductive material can be dispersed.

Examples of the conductive material include metals such as gold, silver and copper, and zinc oxide, barium sulfate, aluminum borate, tin oxide, carbon black, etc. This is preferable in terms of uniform dispersion and resistance control. However, it is not limited to these. The content of the conductive material is preferably 1 to 50 parts by mass and more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the resin in order to make the volume resistance of the carrier have desired characteristics.
Magnetic powder is used as a carrier core material to convey the developer on the developing roll.

Examples of the core material include those in which magnetic powder is used alone for the core material, and those in which magnetic powder is finely divided and dispersed in a resin. Examples of the material of the magnetic powder include magnetic metals such as iron, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite.
The magnetic powder is made into fine particles and dispersed in the resin. The resin and magnetic powder are kneaded and pulverized, the resin and magnetic powder are melted and spray dried, and the polymerization method is used to contain the magnetic powder in the solution. Examples thereof include a method of polymerizing a resin. The carrier preferably contains 80 parts by mass or more of fine magnetic powder with respect to the total mass of the carrier from the viewpoint of making it difficult for carrier scattering to occur.

The core material has a volume average particle size of generally 10 to 500 μm, preferably 25 to 80 μm.
As a method of forming a resin coat layer on the surface of the core material, a coating layer forming solution containing the resin, conductive material and solvent is prepared, and a dipping method in which the carrier core material is immersed therein, and a coating layer forming solution Spraying on the surface of the carrier core material, fluidized bed method of spraying the coating layer forming solution in a state where the carrier core material is suspended by flowing air, and the carrier core material and the coating layer forming solution in a kneader coater. A kneader coater method of mixing and removing the solvent may be used.

The solvent used for the preparation of the coating layer forming solution is not particularly limited as long as it dissolves the resin. For example, aromatic hydrocarbons such as toluene and xylene, ketones such as acetone and methyl ethyl ketone, and the like. , Ethers such as tetrahydrofuran and dioxane can be used.
The average film thickness of the resin coat layer is usually 0.1 to 10 μm, but in the present invention, it is preferably 0.5 to 3 μm in order to develop a stable volume resistance of the carrier over time.

The volume resistivity of the carrier used in the present invention, in order to achieve high image quality, in 1000V time corresponding to the upper and lower limits of normal development contrast potential is preferably from ^{10 8 ~10 13 Ω · cm,} 10 10 and more preferably ~10 ¹² Ω · cm. If the volume resistance of the carrier is less than 10 ⁸ Ω · cm, the amount of carrier transferred to the electrostatic latent image carrier increases, which causes image blanking and photoconductor damage, while the carrier volume resistance is 10 ^13. When it is larger than Ω · cm, the image reproducibility of the edge portion is deteriorated.

The volume resistance was measured using the apparatus shown in FIG. As shown in FIG. 3, the measurement sample 53 is sandwiched between the lower electrode 54 and the upper electrode 52, and the thickness H of the measurement sample 53 is measured with a dial gauge while applying pressure from above, and the volume resistance of the measurement sample 53 is increased. The voltage resistance meter 55 was used for measurement.
Specifically, when titanium oxide as an external additive is used as the measurement sample 53, a measurement disk of 100 mmφ and a thickness of about 2 mm is prepared by applying a pressure of 500 kg / cm ^{2 with} a molding machine, The surface of the disk was cleaned with a brush, sandwiched between the upper electrode 52 and the lower electrode 54 (both electrodes 100 mmφ) in the cell, and the thickness H was measured with a dial gauge. After that, the volume resistance was obtained by applying a voltage and reading the current value with the high voltage resistance meter 55.

On the other hand, when the carrier is the measurement sample 53, the lower electrode 54 of 100 mmφ is filled, the upper electrode 52 having the same diameter is set, a load of 3.43 kg is applied from above, and the thickness H is measured with a dial gauge. did. Next, the volume resistance was calculated | required by applying a voltage with the high voltage resistance meter 55, and reading an electric current value.

The core material exposure rate on the carrier surface used in the present invention prevents the leakage of toner charging core material using a crystalline resin having a low electrical resistance as a binder resin, and stabilizes the neglected chargeability as a developer. For the purpose of illustration, it is preferably 2% or less.
In the present invention, the core material exposure rate of the carrier surface is
[Atomic% of Fe of carrier] / [atomic% of Fe of carrier core]]
For example, it can be measured and calculated by the following measuring machine and conditions.
Measuring instrument: JPS-9000MX manufactured by JEOL Ltd.
Condition: Measurement intensity; 10.0 kV 20 mV
Source; MgKa
Fe atomic%: The percentage of iron atoms among all elements having an atomic number of 3 or more is determined. In the examples described later, the core material exposure rate on the carrier surface was also measured using the same measuring machine and conditions as described above.
The developer used in the present invention is prepared by mixing the above carrier and toner at an appropriate blending ratio. The carrier content ((carrier) / (carrier + toner) × 100) in the developer is preferably in the range of 85 to 99% by mass, more preferably in the range of 87 to 98% by mass, and still more preferably 89 to 97%. It is the range of mass%.

In the carrier used in the present invention, the conductive material is preferably a titanium compound, and the ratio of titanium atoms to carbon atoms on the surface of the resin coat layer is preferably 0.8 to 7.0%.
The presence of titanium atoms in the range of 0.8% to 7.0% with respect to the carbon atoms on the surface of the resin coating layer makes the surface of the carrier appear to have a low resistance, and the surface of the carrier comes into contact with the toner. The charge generated in the toner quickly moves to the contactless carrier surface. As a result, excessive charging of the toner is suppressed, and at the same time, the charge exchange property and the charge rising speed are improved, and a high-quality image can be obtained from the beginning. it can.

When the abundance of titanium on the carrier surface is less than 0.8% in terms of carbon ratio, sufficient charge transfer is not performed and the function is not manifested. On the other hand, in the region exceeding 7.0%, improvement in charge exchange property and charge rising speed is recognized, but charge leakage is likely to occur and fogging due to low charge is caused. The ratio of titanium atoms to carbon atoms is more preferably 1.0% to 6.0%, particularly preferably 1.0% to 4.5%.
In the present invention, since most of the resin coat layer is carbon atoms, the ratio of titanium atoms is defined with respect to carbon atoms.

In the present invention, the ratio of titanium atoms to carbon atoms was measured by X-ray photoelectron spectroscopy. Details of the measurement of the ratio of titanium atoms to carbon atoms by X-ray photoelectron spectroscopy are as follows.
Measuring instrument: JPS-9000MX manufactured by JEOL Ltd.
Condition: Measurement intensity; 10.0 kV 20 mV
Source; MgKa
The ratio of titanium atoms to carbon atoms is calculated by comparing the peak intensities of the carbon-derived component and the titanium-derived component among the peaks derived from the respective elements obtained by the measuring instrument and measurement conditions.

In the present invention, as means for supplying titanium atoms to the surface of the resin coat layer, a method in which a compound having titanium atoms (titanium compound) is dispersed and contained in the resin coat layer, and a titanium compound is added to the surface of the resin coat layer. And the method of doing.
As the titanium compound, titanium oxide is particularly preferable. Hereinafter, the present invention will be described by taking as an example the case where the titanium compound is titanium oxide.

The carrier used in the present invention is preferably a carrier obtained by adding titanium oxide to the surface of the resin coat layer. In the present invention, the ratio of titanium atoms to carbon atoms on the surface of the resin coat layer is preferably 0.8% to 7.0%.
The titanium oxide can be selected from known ones that can be used as an external additive for the toner. The surface of the titanium oxide to be used may be subjected to a known surface treatment (for example, a hydrophobic treatment with silicone oil) for the purpose of hydrophobization, charge amount adjustment, resistance adjustment and the like.
Further, when the volume average particle diameter of the titanium oxide exceeds 200 nm, desorption from the surface may occur due to stress in the developing machine, and it may be difficult to maintain the function. On the other hand, if the volume average particle size of the titanium oxide is less than 10 nm, the cohesive force of the secondary aggregates may become strong, and when uniform dispersion is difficult, when the adhesion state becomes uneven, In some cases, charge leakage is likely to occur from the collection portion, the charge amount distribution of the toner is widened, and fogging or in-machine contamination may be caused.

The volume resistance of titanium oxide is preferably 10 ¹⁰ to 10 ¹⁶ Ω · cm, more preferably 10 ¹² to 10 ¹⁶ Ω · cm. If the volume resistance of the titanium oxide is less than 10 ¹⁰ Ω · cm, the charge exchange property is improved, but charge leakage may occur and cause fogging. On the other hand, if the volume resistance of the titanium oxide exceeds 10 ¹⁶ Ω · cm, sufficient charge exchange property may not be obtained, and rapid charge rise may not be obtained.
The method for adhering and adding titanium oxide to the carrier surface is not particularly limited as long as it is a commonly used mixing apparatus. Specific examples include a V-type blender, a cement mixer, a paint shaker, a Henschel mixer, and a kneader coater.

<Second embodiment>
FIG. 4 is a schematic configuration diagram showing an image forming apparatus according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same part as the image forming apparatus (FIG. 1) which concerns on 1st embodiment, and description is abbreviate | omitted. In the image forming apparatus according to the second embodiment of the present invention, the contact charger 2, the exposure device 3, and the developing device 4 are sequentially arranged around the electrostatic latent image carrier 1 along the rotation direction indicated by the arrow A. The primary transfer device 5a, the cleaning device 7 and the like are arranged, and the developing devices 4a to 4d of the developing device 4 store toners of black, yellow, magenta, and cyan, respectively.
A transfer belt 10, which is an intermediate transfer member that is in contact with the electrostatic latent image carrier 1 and runs between the electrostatic latent image carrier 1 and the primary transfer device 5a in the direction of arrow B, includes tension rolls 11a, 11b, 11c and the backup roll 12. A bias roll 13 and a belt cleaner 14 are disposed at positions facing the backup roll 12 and the tension roll 11a, respectively.

In FIG. 4, a portion where the primary transfer device 5a presses the electrostatic latent image carrier 1 via the transfer belt 10 is a primary transfer portion, and a portion where the bias roll 13 presses the backup roll 12 is a secondary transfer portion. . A toner image is transferred from the transfer belt 10 to the transfer target A supplied from the paper feed tray 15 to the secondary transfer unit in the direction of arrow C, and is sent to the fixing device 9 to fix the toner image. .
Further, 10-40 vol% inorganic fine particles having a volume average particle size of 10 to 80 nm are included on the surface of the transfer belt 10 on the downstream side in the rotation direction of the transfer belt 10 from the secondary transfer portion, and the applied voltage is set to 1000 V · cm. A lubricant application device 6 for applying a powder lubricant having a volume resistance of 10 ⁸ to 10 ¹¹ Ω · cm is disposed.

The toner image formed on the surface of the electrostatic latent image carrier 1 is transferred to the transfer belt 10 by the primary transfer device 5a. Cyan, magenta, yellow, and black toners are transferred onto the transfer belt 10 to form a full-color image. As the primary transfer device 5a, for example, a corotron can be used, but is not limited thereto.
In this embodiment, a transfer belt is used as the intermediate transfer member, but a drum-shaped intermediate transfer member can also be used.
As the intermediate transfer member, for example, a semiconductive belt in which an appropriate amount of an antistatic agent such as carbon black is contained in a resin such as acrylic, vinyl chloride, polyester, polycarbonate, polyimide, or various rubbers can be used. .

  Examples of the bias roll 13 include those whose roll portion is made of a rubber material such as urethane, EPDM (polyisopyrene / blend elastomer), CR (chloroprene rubber), silicone rubber, or a foamed sponge of these materials. The hardness of this roll part is about 40 degrees with an ASKER C 500 gram load (hereinafter abbreviated as g) as a JIS standard. This hardness is effective not only for stabilizing the conveyance performance of the transfer target A but also for preventing the character blanking phenomenon during transfer of the toner image.

The powder lubricant applied to the transfer belt 10 is subjected to charge injection from the primary transfer unit 5a in the primary transfer portion, and exhibits a charge opposite to that of the toner. As a result, the powder lubricant is supplied from the transfer belt 10 to the electrostatic latent image carrier 1. By reducing the bias of the primary transfer unit 5a to easily cause fogging, the powder lubricant is transferred from the transfer belt 10 to a portion (interimage portion) where the toner image of the electrostatic latent image carrier 1 is not formed. You may make it supply to the electrostatic latent image carrier 1. FIG. In this case, the powder lubricant can be moved to the electrostatic latent image carrier 1 regardless of the polarity of the toner.
As in the image forming apparatus according to the second embodiment, the powder lubricant is supplied to the electrostatic latent image carrier 1 via the transfer belt 10, whereby the powder lubricant is applied to the electrostatic latent image carrier having a small diameter. Can be supplied.

A charging step of charging the electrostatic latent image carrier with a contact charger, a latent image forming step of forming a latent image on the surface of the charged electrostatic latent image carrier, and a surface of the electrostatic latent image carrier The latent image formed on the surface is developed with a developer to form a toner image, the transfer step for transferring the toner image formed on the surface of the electrostatic latent image carrier to the transfer target, and the static image The surface of the electrostatic latent image bearing member contains 10 to 40% by volume of inorganic fine particles having a volume average particle diameter of 10 to 80 nm, and the volume resistance is 10 ⁸ to 10 ¹¹ Ω · cm when the applied voltage is 1000 V · cm. The image forming method of the present invention includes at least a lubricant supply step for supplying a powder lubricant and a cleaning step for removing residual toner on the surface of the electrostatic latent image carrier after transfer. And the image forming apparatus according to the second embodiment. It is.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.
(Preparation of resin fine particle dispersion A)
380 parts by mass of styrene, 25 parts by mass of n-butyl acrylate, 5 parts by mass of acrylic acid, and 25 parts by mass of dodecanethiol were mixed and dissolved in a nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) 8 parts by weight and 9 parts by weight of an anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were emulsion-polymerized in a flask in which 550 parts by weight of ion-exchanged water was dissolved. Was charged with 50 parts by mass of ion-exchanged water in which 5 parts by mass of ammonium persulfate was dissolved. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the content reached 75 ° C., and emulsion polymerization was continued for 4 hours. As a result, a resin fine particle dispersion A in which resin fine particles having a volume average particle diameter of 129 nm and a weight average molecular weight Mw = 11000 were dispersed was obtained. The solid content concentration of this dispersion was 42%.

(Adjustment of colorant dispersion A)
Cyan pigment B15: 3 60 parts by mass, nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) 5 parts by mass, and ion-exchanged water 240 parts by mass were mixed to produce a homogenizer (Ultra Turrax T50: manufactured by IKA). ) Was then used for 30 minutes, and then a colorant dispersant A in which colorant (Cyan pigment) particles having a volume average particle size of 230 nm were dispersed was prepared by dispersing with an optimizer.

(Preparation of release agent dispersion A)
100 parts by weight of paraffin wax (HNP0190: Nippon Seiwa Co., Ltd., melting point 85 ° C.), 5 parts by weight of a cationic surfactant (Sanisol B50: manufactured by Kao Corporation), 240 parts by weight of ion-exchanged water, round shape After dispersing for 30 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA) in a stainless steel flask, the pressure release type homogenizer is used to disperse the release agent particles having a volume average particle size of 523 nm. A release agent dispersion A was prepared.

<Preparation of toner mother particle A>
Resin fine particle dispersion A 240 parts by weight Colorant dispersion A 25 parts by weight Release agent dispersion A 45 parts by weight Polyaluminum hydroxide (Pho2S manufactured by Asada Chemical Co., Ltd.) 0.8 parts by weight Ion-exchanged water 800 parts by weight The components were mixed and dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50: manufactured by IKA). In order to agglomerate the fine particles, the inside of the flask was heated to 42 ° C. with stirring in a heating oil bath and held for 30 minutes, and then the temperature of the heating oil bath was further raised and held at 58 ° C. for 60 minutes. When the size of the particles in the slurry was measured, the weight average particle diameter D50 was 5.5 μm. Thereafter, in order to control the shape of the aggregate particles, 1N sodium hydroxide is added to the slurry containing the aggregate particles, and the pH of the system is adjusted to 7.2. Using a seal, the mixture was heated to 83 ° C. while stirring and was maintained for 4 hours. After cooling, the toner base particles A were separated by filtration, washed four times with ion exchange water, and then freeze-dried to obtain toner base particles A. Toner base particle A had a volume average particle size of 6.0 μm, a shape factor (ML ² / A) of 130, and a specific gravity of 1.1 g / cm ³ . The shape factor is a value defined by the following formula.

Shape factor = 100 × π × ML ² / 4A

  In the above formula, ML represents the absolute maximum length of the toner base particles, and A represents the projected area of the toner base particles. ML and A can be measured using, for example, a Luzex image analyzer (FT manufactured by Nireco Corporation).

<Creation of Toner 1A>
100 parts by mass of toner base particle A 100 parts by mass of rutile titanium oxide (volume average particle size 20 nm, n-decyltrimethoxysilane treatment), silica (volume average particle size 40 nm, silicone oil treatment, gas phase oxidation method) 1 .2 parts by mass and 1.5 parts by mass of silica (volume average particle size 120 nm, HMDS treatment, sol-gel method) were added and blended with a 5 L Henschel mixer at a peripheral speed of 30 m / s × 15 minutes. Coarse particles were removed using a sieve to obtain toner 1A. The surface coverage of the external additive with respect to toner 1A was 66%.
The surface coverage of the external additive is determined by measuring the carbon amount of the toner not previously added externally by XPS, measuring the carbon amount of the toner surface, and then performing the same operation on the surface of the toner having the external additive. To compare the amount of carbon loss. The surface coverage of the external additive is obtained by dividing the carbon amount of the toner having the external additive by the carbon amount of the toner having no external additive. Ordinary resins are mostly composed of carbon, hydrogen, and oxygen, of which carbon is overwhelmingly large, so the amount of external additive can be measured from the ratio of the amount of carbon.

<Creation of developer 1A>
Create carrier 1A:
Ferrite particles (volume average particle size 40 μm) 100 parts by mass Toluene 14 parts by mass Perfluorooctylethyl methacrylate-methyl methacrylate copolymer
3 parts by mass carbon black (R330: manufactured by Cabot Corporation) 0.3 part by mass First, all the components except the ferrite particles were stirred for 10 minutes with a stirrer and dispersed to prepare a coating layer forming solution. Next, the coating layer forming solution and the ferrite particles are put into a vacuum degassing kneader, stirred at 60 ° C. for 30 minutes, further depressurized while being heated, degassed, and dried to dry the carrier 1A. Manufactured.
Preparation of developer 1A:
Developer 1A was obtained by stirring 8 parts by weight of toner 1A and 100 parts by weight of carrier 1A at 40 rpm for 20 minutes using a V-blender and sieving with a sieve having a 177 μm mesh.

<Creation of Toner 2A>
100 parts by mass of toner base particle A 100 parts by mass of rutile type titanium oxide (volume average particle diameter 20 nm, n-decyltrimethoxysilane treatment), silica (volume average particle diameter 40 nm, silicone oil treatment, gas phase oxidation method) 1 0.0 parts by mass and 2.0 parts by mass of silica (volume average particle size 120 nm, HMDS treatment, sol-gel method) were added and blended with a 5 L Henschel mixer at a peripheral speed of 30 m / s × 15 minutes. Coarse particles were removed using a sieve to obtain toner 2A. The surface coverage of the external additive with respect to the toner 2A was 64%.

<Creation of developer 2A>
Developer 2A was obtained by stirring 8 parts by weight of toner 2A and 100 parts by weight of carrier 1A with a V-blender at 40 rpm for 20 minutes and sieving with a sieve having a 177 μm mesh.

<Preparation of powder lubricant 1A>
30% by volume of zinc oxide having a volume average particle size of 80 nm and a specific gravity of 5.6 g / cm ³ is added to zinc stearate having a specific gravity of 1.09 g / cm ³ , blending is performed at 13000 rpm × 30 s in a sample mill, and powder lubricant 1A is obtained. Obtained. The volume resistivity of the powder lubricant 1A containing 30% by volume of zinc oxide at an applied electric field of 1000 V · cm was 7 × 10 ¹⁰ Ω · cm.

<Preparation of powder lubricant 2A>
Titanium oxide surface-treated with aluminum stearate having a volume average particle size of 15 nm and a specific gravity of 4.17 g / cm ³ is added to 40% by volume of zinc stearate having a specific gravity of 1.09 g / cm ³ and blended at 13000 rpm × 30 s in a sample mill. The powder lubricant 2A was obtained. The volume resistivity of the powder lubricant 2A containing 40% by volume of titanium oxide at an applied electric field of 1000 V · cm was 9 × 10 ¹⁰ Ω · cm.

<Preparation of powder lubricant 3A>
10% by volume of non-surface-treated titanium oxide having a volume average particle size of 35 nm and a specific gravity of 4.17 g / cm ³ is added to boron nitride having a specific gravity of 2.26 g / cm ³ and blended in a sample mill at 13000 rpm × 30 s. A body lubricant 3A was obtained. The volume resistivity of the powder lubricant 3A containing 10% by volume of titanium oxide at an applied electric field of 1000 V · cm was 2 × 10 ⁸ Ω · cm.

<Preparation of powder lubricant 4A>
Aluminum oxide that has not been surface-treated with a volume average particle size of 70 nm and a specific gravity of 3.9 g / cm ³ is added to 30% by volume of zinc stearate with a specific gravity of 1.09 g / cm ³ . A powder lubricant 4A was obtained. The volume resistance of the powder lubricant 4A containing 30% by volume of aluminum oxide at an applied electric field of 1000 V · cm was 3 × 10 ¹⁰ Ω · cm.

<Preparation of powder lubricant 5A>
Silicon oxide surface-treated with hexamethyldisilazane (HMDS) having a volume average particle size of 40 nm and a specific gravity of 2.2 g / cm ³ is added to 40% by volume of zinc stearate having a specific gravity of 1.09 g / cm ³ and 13,000 rpm in a sample mill. X30 s blending was performed to obtain a powder lubricant 5A. The volume resistance of the powder lubricant 5A containing 40% by volume of silicon oxide at an applied electric field of 1000 V · cm was 1 × 10 ¹⁵ Ω · cm.

<Preparation of powder lubricant 6A>
Titanium oxide surface-treated with aluminum stearate having a volume average particle size of 35 nm is added to 50% by volume of zinc stearate having a specific gravity of 1.09 g / cm ³ , blended at 13000 rpm × 30 s with a sample mill, and powder lubricant 6A Got. The volume resistivity of the powder lubricant 6A containing 50% by volume of titanium oxide at an applied electric field of 1000 V · cm was 8 × 10 ¹¹ Ω · cm.

<Preparation of powder lubricant 7A>
Titanium oxide that has not been surface-treated with a volume average particle size of 15 nm and a specific gravity of 4.17 g / cm ³ is added to zinc stearate with a specific gravity of 1.09 g / cm ³ at 20 vol% and blended at 13000 rpm × 30 s in a sample mill. A powder lubricant 7A was obtained. The volume resistivity of the powder lubricant 7A containing 20% by volume of titanium oxide at an applied electric field of 1000 V · cm was 5 × 10 ⁷ Ω · cm.

(Examples 1A-5A, Comparative Examples 1A-5A)
Modified DocuCentre Color 500 equipped with a rotating brush that contacts and moves the electrostatic latent image carrier so that the powder lubricant can be applied to the cleaning blade upstream of the electrostatic latent image carrier in the rotational direction. The experiment was conducted using a machine. The modified DocuCentre Color 500 was placed in an environmental chamber adjusted to a temperature of 30 ° C. and a humidity of 85%, and the toner, developer and powder lubricant to be evaluated were attached in combinations shown in Table 1. After leaving it for a whole day and night, 20000 images of a full halftone 30% were output, and the quality of output images of the 500, 5000 and 20000th images was evaluated based on the following criteria. A full color paper J (A4 size) manufactured by Fuji Xerox Co., Ltd. was used as the transfer target. The obtained results are shown in Table 1.

Evaluation of the quality of the output image is based on the following criteria.
◎: Very good image quality ○: Image quality at a level that does not cause problems in actual use ×: Low quality image quality that cannot be tolerated

  From Table 1, it is possible to print up to the 20000th sheet without deterioration in image quality in the example. However, in the comparative example, even if the initial image quality is good, it can withstand actual use up to the 20000th sheet. I understand that there is no.

(Examples 1B-5B, Comparative Examples 1B-5B)
A device for applying a powder lubricant to the transfer belt (intermediate transfer member) is provided, and a developing portion (primary transfer portion) for transferring toner from the electrostatic latent image carrier to the transfer belt is provided upstream of the cleaning blade. Experiments were performed using a DocuCentre Color500 retrofit machine. The powder lubricant is supplied from the transfer belt to the electrostatic latent image carrier in the primary transfer portion. The modified DocuCentre Color 500 was placed in an environmental chamber adjusted to a temperature of 30 ° C. and a humidity of 85%, and the toner, developer and powder lubricant to be evaluated were attached in combinations shown in Table 2. After leaving it for a whole day and night, 20000 images of a full halftone of 30% were output, and the quality of the output images of the 500, 5000 and 20000th images was evaluated based on the same criteria as in Example 1A. A full color paper J (A4 size) manufactured by Fuji Xerox Co., Ltd. was used as the transfer target. The obtained results are shown in Table 2.

  From Table 2, it is possible to print up to the 20000th sheet without deterioration in image quality in the example, but in the comparative example, even if the initial image quality is good, there are those that can withstand actual use up to the 20000th sheet. I understand that there is no.

-Synthesis of crystalline polyester resin (1C)-
In a heat-dried three-necked flask, 17.4 parts by mass of 1,10-decanediol, 2.2 parts by mass of sodium dimethyl 5-sulfoisophthalate, 10 parts by mass of dimethyl sulfoxide, and 0.03 of dibutyltin oxide as a catalyst were used. Then, the air in the container was replaced with nitrogen gas by depressurization to create an inert atmosphere, and stirring was performed at 180 ° C. for 3 hours by mechanical stirring. Dimethyl sulfoxide was distilled off under reduced pressure, 26.5 parts by mass of dimethyl dodecanedioic acid was added under a nitrogen stream, and the mixture was stirred at 180 ° C. for 1 hour.
Thereafter, the temperature was gradually raised to 220 ° C. under reduced pressure, and the mixture was stirred for 30 minutes. When it became viscous, it was air-cooled, the reaction was stopped, and 36 parts by mass of a crystalline polyester resin (1C) was synthesized. . The molecular weight measurement (polystyrene conversion) by gel permeation chromatography revealed that the obtained crystalline polyester resin (1C) had a weight average molecular weight (M _W ) of 9,200 and a number average molecular weight (M _n ) of 6,000.
Further, when the melting point (Tm) of the crystalline polyester resin (1C) was measured by a differential scanning calorimeter (DSC) by the above-described measuring method, it had a clear peak and the peak top temperature was 79 ° C. Met. The content ratio of the copolymerization component (5-sulfoisophthalic acid component) and the dodecanedioic acid component, measured and calculated from the NMR spectrum of the resin, was 7.5: 92.5.

-Production of toner (1C)-
<Preparation of resin particle dispersion (1C)>
150 parts by mass of the obtained crystalline polyester resin (1C) was put in 850 parts by mass of distilled water, and mixed and stirred with a homogenizer (IKA Japan Co., Ltd .: Ultra Tarax) while heating to 85 ° C. to disperse the resin particles. A liquid (1C) was obtained.
<Preparation of Colorant Dispersion (1C)>
250 parts by mass of a phthalocyanine pigment (manufactured by Dainichi Seika Co., Ltd .: PV FAST BLUE), 20 parts by mass of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK), 730 parts by mass of ion-exchanged water, Were mixed using a homogenizer (IKA: Ultra Tarax) to prepare a colorant dispersion (1C) in which a colorant (phthalocyanine pigment) was dispersed.
<Preparation of aggregated particles>
2400 parts by mass of resin particle dispersion (1C), 100 parts by mass of colorant dispersion (1C), 63 parts by mass of release agent dispersion A, 10 parts by mass of lauroyl peroxide, and aluminum sulfate (Wako Pure Chemical Industries, Ltd.) ) After 5 parts by mass and 100 parts by mass of ion-exchanged water are contained in a round stainless steel flask, adjusted to pH 2.0, and dispersed using a homogenizer (manufactured by IKA: Ultra Turrax T50) The mixture was heated in an oil bath for heating to 72 ° C. with stirring. After maintaining at 72 ° C. for 3 hours and observing with an optical microscope, it was confirmed that aggregated particles having an average particle diameter of about 5.0 μm were formed. After further heating and stirring at 72 ° C. for 1 hour, observation with an optical microscope confirmed that aggregated particles having an average particle diameter of about 5.5 μm were formed.
<Fusion process>
The pH of the dispersion of aggregated particles was 2.4. Therefore, an aqueous solution obtained by diluting sodium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.) to 0.5% by mass was gently added to adjust the pH to 5.0, then heated to 83 ° C. while continuing stirring, and maintained for 3 hours. did.
Thereafter, the reaction product was filtered, sufficiently washed with ion-exchanged water, and then dried using a vacuum dryer to obtain colored particles (1C). The obtained colored particles (1C) were measured for average particle size using a Coulter counter [TA-II] type (aperture diameter: 50 μm, manufactured by Coulter, Inc.). The volume average particle size was 5.5 μm and the number average The particle size was 4.7 μm.
The obtained colored particles (1C) were subjected to surface hydrophobization treatment, silica fine particles having a volume average particle size of 40 nm (hydrophobic silica manufactured by Nippon Aerosil Co., Ltd .: RX50) 0.8% by mass, and isobutyltrimethoxy to 100 parts by mass of metatitanic acid. A reaction product treated with 40 parts by mass of silane and 10 parts by mass of trifluoropropyltrimethoxysilane and 1.0 mass% of metatitanic acid compound fine particles having a volume average particle size of 20 nm are added and mixed for 5 minutes with a Henschel mixer. (1C) was produced.

-Physical property evaluation of toner (1C)-
(Measurement of viscoelasticity)
The viscoelasticity of the obtained toner (1C) was measured using a rotating plate type rheometer (RDA 2RHIOS system Ver. 4.3.2, manufactured by Rheometrics Scientific F.E.).
The sample was set in a sample holder, and the measurement was performed with a temperature rise rate of 1 ° C./min, a frequency of 1 rad / s, a strain of 20% or less, and a detected torque within the guaranteed range of measurement. If necessary, the sample holder was used separately for 8 mm and 20 mm. Changes in storage elastic modulus G ′ (Pa) and loss elastic modulus G ″ (Pa) with respect to temperature change were obtained. The glass transition or polymer melt, viscoelasticity 2 or more digits rapidly changing temperature (T1), and Table 3 the temperature (T2) when the viscoelasticity of values (G _L, G _N) becomes 10000 Pa · S Shown in In addition, Table 3 shows the viscoelasticity values ( _GL , _GN ) at 30 ° C.
(Measurement and evaluation of powder cohesion (toner blocking resistance))
Using a powder tester (manufactured by Hosokawa Micron Corporation), sieves with openings of 53 μm, 45 μm, and 38 μm are arranged in series from the top, and 2 g of toner (1C) accurately weighed is placed on the 53 μm sieve, and the amplitude A vibration was applied at 1 mm for 90 seconds, the toner mass on each sieve after vibration was measured, and the weights of 0.5, 0.3, and 0.1 were added and added, and the value calculated as a percentage was calculated. The degree of powder aggregation was taken. The sample (toner (1C)) was left for about 24 hours in an environment of 45 ° C./50% RH, and the measurement was performed in an environment of 25 ° C./50% RH. The results are shown in Table 3. In the present invention, the powder agglomeration property can be used without any practical problem as long as the toner mass after vibration is 40 or less, but is preferably 30 or less.

-Synthesis of crystalline polyester resin (2C)-
To a heat-dried three-necked flask, 124 parts by mass of ethylene glycol, 22.2 parts by mass of sodium dimethyl 5-sulfoisophthalate, 213 parts by mass of dimethyl sebacate, and 0.3 parts by mass of dibutyltin oxide as a catalyst were obtained. After putting, the air in the container was replaced with nitrogen gas by a depressurization operation to make it an inert atmosphere, and stirring was performed at 180 ° C. for 5 hours by mechanical stirring.
Thereafter, the temperature was gradually raised to 220 ° C. under reduced pressure, and the mixture was stirred for 2 hours. When it became viscous, it was cooled with air, the reaction was stopped, and 220 parts by mass of crystalline polyester resin (2C) was synthesized. The crystalline polyester resin (2C) obtained had a weight average molecular weight (M _w ) of 11000 and a number average molecular weight (M _n ) of 4700, as determined by gel permeation chromatography.
Further, when the melting point (Tm) of the crystalline polyester resin (2C) was measured by a differential scanning calorimeter (DSC) by the above-described measuring method, it had a clear peak and the peak top temperature was 69 ° C. Met. The content ratio of the copolymerization component (5-sulfoisophthalic acid component) and the sebacic acid component, measured and calculated from the NMR spectrum of the resin, was 7.5: 92.5.

-Manufacture of toner (2C)-
<Preparation of resin particle dispersion (2C)>
150 parts by mass of the obtained crystalline polyester resin (2C) was put in 850 parts by mass of distilled water, mixed and stirred with a homogenizer (manufactured by IKA Japan: Ultra Tarax) while heating to 80 ° C., and dispersed resin particles A liquid (2C) was obtained.
<Preparation of aggregated particles>
Resin particle dispersion (2C) 2400 parts, Colorant dispersion (1C) 100 parts, Release agent dispersion A 63 parts, Lauroyl peroxide 10 parts, Aluminum sulfate (Wako Pure Chemical Industries, Ltd. ) After 5 parts by mass and 100 parts by mass of ion-exchanged water are contained in a round stainless steel flask, adjusted to pH 2.0, and dispersed using a homogenizer (manufactured by IKA: Ultra Turrax T50) The mixture was heated in an oil bath for heating to 63 ° C. with stirring. After maintaining at 63 ° C. for 3 hours, observation with an optical microscope confirmed that aggregated particles having an average particle diameter of about 4.8 μm were formed. After further heating and stirring at 63 ° C. for 1 hour, observation with an optical microscope confirmed that aggregated particles having an average particle diameter of about 5.3 μm were formed.
<Fusion process>
The pH of the dispersion of aggregated particles was 2.4. Therefore, an aqueous solution obtained by diluting sodium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.) to 0.5% by mass was gently added to adjust the pH to 5.0, and then heated to 75 ° C. while stirring and maintained for 3 hours. did.
Thereafter, the reaction product was filtered, sufficiently washed with ion-exchanged water, and then dried using a vacuum dryer to obtain colored particles (2C). The obtained colored particles (2C) were measured for an average particle size using a Coulter counter [TA-II] type (aperture diameter: 50 μm, manufactured by Coulter, Inc.). As a result, the volume average particle size was 5.5 μm and the number average The particle size was 4.7 μm.
The resulting colored particles (2C) were subjected to the same external additive formulation as toner (1C) to obtain toner (2C).

-Physical property evaluation of toner (2C)-
In the same manner as “Evaluation of physical properties of toner (1C)”, physical properties of toner (2C) were evaluated. The results are shown in Table 3.

-Synthesis of crystalline polyester resin (3C)-
To a heat-dried three-necked flask, 18.9 parts by mass of 1,20-eicosanediol, 1.3 parts by mass of sodium dimethyl 5-sulfoisophthalate, 10 parts by mass of dimethyl sulfoxide, and 0. After adding 03 parts by mass, the air in the container was replaced with nitrogen gas by a depressurization operation to create an inert atmosphere, and stirring was performed at 180 ° C. for 3 hours by mechanical stirring. Dimethyl sulfoxide was distilled off under reduced pressure, 15.9 parts by weight of dimethyl dodecanedioic acid was added under a nitrogen stream, and the mixture was stirred at 180 ° C. for 1 hour.
Thereafter, the temperature was gradually raised to 220 ° C. under reduced pressure, and the mixture was stirred for 30 minutes. When it became viscous, it was air-cooled, the reaction was stopped, and 33 parts by mass of a crystalline polyester resin (3C) was synthesized. . In the molecular weight measurement (polystyrene conversion) by gel permeation chromatography, the obtained crystalline polyester resin (3C) had a weight average molecular weight (M _W ) of 10200 and a number average molecular weight (M _n ) of 6100.
Further, when the melting point (Tm) of the crystalline polyester resin (3C) was measured using a differential scanning calorimeter (DSC) by the above-described measurement method, it had a clear peak and the peak top temperature was 93 ° C. Met. The content ratio of the copolymerization component (5-sulfoisophthalic acid component) and the dodecanedioic acid component measured and calculated from the NMR spectrum of the resin was 7.7: 92.3.

-Manufacture of toner (3C)-
<Preparation of resin particle dispersion (3C)>
150 parts by mass of the obtained crystalline polyester resin (3C) was put into 850 parts by mass of distilled water, and mixed and stirred with a homogenizer (IKA Japan: Ultra Tarax) while heating to 99 ° C. to disperse the resin particles. A liquid (3C) was obtained.
<Preparation of aggregated particles>
Resin particle dispersion (3C) 2400 parts, Colorant dispersion (1C) 100 parts, Release agent dispersion A 63 parts, Lauroyl peroxide 10 parts, Aluminum sulfate (Wako Pure Chemical Industries, Ltd. ) After 5 parts by mass and 100 parts by mass of ion-exchanged water are contained in a round stainless steel flask, adjusted to pH 2.0, and dispersed using a homogenizer (manufactured by IKA: Ultra Turrax T50) The mixture was heated to 88 ° C. with stirring in an oil bath for heating. After maintaining at 88 ° C. for 3 hours and observing with an optical microscope, it was confirmed that aggregated particles having an average particle diameter of about 4.2 μm were formed. After further heating and stirring at 88 ° C. for 1 hour, observation with an optical microscope confirmed that agglomerated particles having an average particle diameter of about 5.2 μm were formed.
<Fusion process>
The pH of the dispersion of aggregated particles was 2.4. Therefore, an aqueous solution obtained by diluting sodium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.) to 0.5% by mass was gently added, and the pH was adjusted to 5.0. did.
Thereafter, the reaction product was filtered, sufficiently washed with ion exchange water, and then dried using a vacuum dryer to obtain colored particles (3C). The average particle size of the obtained colored particles (3C) was measured using a Coulter counter [TA-II] type (aperture diameter: 50 μm, manufactured by Coulter, Inc.). The volume average particle size was 5.5 μm and the number average The particle size was 4.7 μm.
The resulting colored particles (3C) were subjected to the same external additive formulation as toner (1C) to obtain toner (3C).

-Physical property evaluation of toner (3C)-
In the same manner as “Evaluation of physical properties of toner (1C)”, physical properties of toner (3C) were evaluated. The results are shown in Table 3.

-Synthesis of crystalline polyester resin (4C)-
In a heat-dried three-necked flask, 90.1 parts by mass of 1,4-butanediol, 22.2 parts by mass of sodium dimethyl 5-sulfoisophthalate, 161.1 parts by mass of dimethyl adipate, and dibutyltin oxide as a catalyst After adding 0.3 part by mass, the air in the container was replaced with nitrogen gas by a depressurization operation to create an inert atmosphere, and the mixture was stirred at 180 ° C. for 5 hours with mechanical stirring.
Thereafter, the temperature was gradually raised to 220 ° C. under reduced pressure, and the mixture was stirred for 2 hours. When it became viscous, it was air-cooled, the reaction was stopped, and 220 parts by mass of crystalline polyester resin (4C) was synthesized. As a result of molecular weight measurement (polystyrene conversion) by gel permeation chromatography, the obtained crystalline polyester resin (4C) had a weight average molecular weight (M _W ) of 11000 and a number average molecular weight (M _n ) of 4700.
Further, the melting point (Tm) of the crystalline polyester resin (4C) was measured using a differential scanning calorimeter (DSC) by the above-described measurement method. As a result, the crystalline polyester resin (4C) had a clear peak and the peak top temperature was 55 ° C. Met. The content ratio of the copolymerization component (5-sulfoisophthalic acid component) and the adipic acid component measured and calculated from the NMR spectrum of the resin was 7.5: 92.5.

-Manufacture of toner (4C)-
<Preparation of resin particle dispersion (4C)>
150 parts by mass of the obtained crystalline polyester resin (4C) was placed in 850 parts by mass of distilled water, and mixed and stirred with a homogenizer (IKA Japan, Ultra Tarax) while heating to 70 ° C. to disperse the resin particles. A liquid (4C) was obtained.
<Preparation of aggregated particles>
2400 parts by weight of resin particle dispersion (4C), 100 parts by weight of colorant dispersion (1C), 63 parts by weight of release agent dispersion A, 10 parts by weight of lauroyl peroxide, and aluminum sulfate (Wako Pure Chemical Industries, Ltd.) ) After 5 parts by mass and 100 parts by mass of ion-exchanged water are contained in a round stainless steel flask, adjusted to pH 2.0, and dispersed using a homogenizer (manufactured by IKA: Ultra Turrax T50) The mixture was heated to 50 ° C. with stirring in an oil bath for heating. After maintaining at 50 ° C. for 3 hours, observation with an optical microscope confirmed that aggregated particles having an average particle diameter of about 4.8 μm were formed. After maintaining heating and stirring at 50 ° C. for another hour, observation with an optical microscope confirmed that aggregated particles having an average particle diameter of about 5.4 μm were formed.
<Fusion process>
The pH of the dispersion of aggregated particles was 2.4. Therefore, an aqueous solution obtained by diluting sodium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.) to 0.5% by mass was gently added to adjust the pH to 5.0, and then heated to 65 ° C. while continuing stirring, and maintained for 3 hours. did.
Thereafter, the reaction product was filtered, sufficiently washed with ion-exchanged water, and then dried using a vacuum dryer to obtain colored particles (4C). The average particle size of the obtained colored particles (4C) was measured using a Coulter counter [TA-II] type (aperture diameter: 50 μm, manufactured by Coulter). The volume average particle size was 5.5 μm and the number average The particle size was 4.7 μm.
The resulting colored particles (4C) were subjected to the same external additive formulation as toner (1C) to obtain toner (4C).

-Physical property evaluation of toner (4C)-
In the same manner as “Evaluation of physical properties of toner (1C)”, physical properties of toner (4C) were evaluated. The results are shown in Table 3.

-Synthesis of non-crystalline polyester resin (5C)-
To a heat-dried two-necked flask, 35 mol parts of polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (2,2) -2,2-bis (4 -Hydroxyphenyl) propane 65 mol part, terephthalic acid 80 mol part, n-dodecenyl succinic acid 10 mol part, trimellitic acid 10 mol part, and these acid components (terephthalic acid, n-dodecenyl succinic acid, trimellitic acid ) 0.05 mol part of dibutyltin oxide with respect to), introducing nitrogen gas into the container, keeping the temperature in an inert atmosphere and raising the temperature, and causing a copolycondensation reaction at 150 to 230 ° C. for about 12 hours, Thereafter, the pressure was gradually reduced at 210 to 250 ° C. to synthesize an amorphous polyester resin (5C).
The weight average molecular weight (M _W ) of the obtained amorphous polyester resin (5C) was 15400, and the number average molecular weight (M _n ) was 6800, as measured by gel permeation chromatography (polystyrene conversion). . Further, when the DSC spectrum of the amorphous polyester resin (5C) was measured using a differential scanning calorimeter (DSC) in the same manner as the measurement of the melting point (Tm) described above, no clear peak was shown, A change in the endothermic amount was observed. The glass transition point at the midpoint of the stepwise endothermic change was 65 ° C.

-Production of toner (5C) (dissolution suspension)-
86 parts by mass of the obtained amorphous polyester resin (5C) and 16 parts by mass of a copper phthalocyanine pigment (CI Pigment Blue 15: 3) were melt-kneaded using a Banbury type kneader to obtain a high concentration A colored resin composition was obtained. 25 parts by mass of the colored resin composition and 75 parts by mass of the amorphous polyester resin (5C) were dispersed and dissolved in 100 parts by mass of ethyl acetate to prepare a dispersion solution.
The obtained dispersion solution was added to a mixed solution of 1 part by mass of carboxymethyl cellulose, 20 parts by mass of calcium carbonate, and 100 parts by mass of water, and dispersed by stirring at high speed using a mixer. . The emulsion was transferred to a beaker, about 5 times the amount of water was added, and the mixture was kept in a warm bath at 43 ° C. for 10 hours with stirring to evaporate the ethyl acetate. 10% hydrochloric acid was added, calcium carbonate was dissolved in hydrochloric acid, washed repeatedly with water, and a mixture of water and toner was obtained. Finally, water was evaporated with a freeze dryer to produce colored particles (5C).
The obtained colored particles (5C) were measured for average particle size using a Coulter counter [TA-II] type (aperture diameter: 50 μm; manufactured by Coulter, Inc.). The volume average particle size was 5.5 μm, and the number average The particle size was 4.7 μm.
The resulting colored particles (5C) were subjected to the same external additive formulation as toner (1C) to obtain toner (5C).

-Physical property evaluation of toner (5C)-
In the same manner as “Evaluation of physical properties of toner (1C)”, physical properties of toner (5C) were evaluated. The results are shown in Table 3.

-Manufacture of carrier A-
Ferrite particles (volume average particle size: 40 μm) 100 parts by mass Toluene 14 parts by mass Styrene-methyl methacrylate copolymer (component ratio 30:70) 3 parts by mass Carbon black (R330: manufactured by Cabot Corporation) 3 parts by mass First, all the components except the ferrite particles among the above components were stirred with a stirrer for 10 minutes to prepare a dispersed coating layer forming solution. Next, this coating layer forming solution and ferrite particles are put in a vacuum degassing type kneader, stirred at 60 ° C. for 30 minutes, further depressurized while being heated, degassed, and dried to dry carrier A. Manufactured.
The obtained carrier A had a volume resistance of 10 ¹¹ Ω · cm at an applied electric field of 1000 V / cm, and a core material exposure rate of 1.50%.

-Manufacture of carrier B-
The carrier A was prepared except that the styrene-methyl methacrylate copolymer (component ratio 30:70) was 2.7 parts by mass and the carbon black (R330: manufactured by Cabot Corporation) was 0.27 parts by mass in the production of the carrier A. Carrier B was produced in the same manner as A. The obtained carrier B had a volume resistance of 10 ^11.5 Ω · cm at an applied electric field of 1000 V / cm and a core material exposure rate of 1.94%.

-Manufacture of carrier C-
The carrier A was prepared except that the styrene-methyl methacrylate copolymer (component ratio 30:70) was 2.7 parts by mass and the carbon black (R330: manufactured by Cabot) was 0.40 parts by mass in the production of the carrier A. Carrier C was produced in the same manner as A. The obtained carrier C had a volume resistance of 10 ^8.3 Ω · cm at an applied electric field of 1000 V / cm and a core material exposure rate of 1.90%.

-Production of carrier D-
In the production of carrier A, carrier D was produced in the same manner as in the production of carrier A, except that carbon black (R330: manufactured by Cabot) was changed to 0.22 parts by mass. The obtained carrier D had a volume resistance of 10 ¹³ Ω · cm at an applied electric field of 1000 V / cm and a core material exposure rate of 1.50%.

-Manufacture of carrier E-
The carrier A was prepared except that 2.4 parts by mass of styrene-methyl methacrylate copolymer (component ratio 30:70) and 0.23 parts by mass of carbon black (R330: manufactured by Cabot) were used in the production of carrier A. Carrier E was produced in the same manner as A. The obtained carrier E had a volume resistance of 10 ¹⁰ Ω · cm at an applied electric field of 1000 V / cm and a core material exposure rate of 2.20%.

-Manufacture of carrier F-
In the production of carrier A, carrier F was produced in the same manner as in the production of carrier A, except that carbon black (R330: manufactured by Cabot) was changed to 0.40 parts by mass. The obtained carrier F had a volume resistance of 10 ^7.8 Ω · cm at an applied electric field of 1000 V / cm and a core material exposure rate of 1.82%.

-Manufacture of carrier G-
In the production of carrier A, carrier G was produced in the same manner as in the production of carrier A, except that carbon black (R330: manufactured by Cabot) was changed to 0.22 parts by mass. The obtained carrier G had a volume resistance of ^10.14 Ω · cm at an applied electric field of 1000 V / cm and a core material exposure rate of 2.43%.

-Manufacture of carrier H-
Ferrite particles (volume average particle size: 40 μm) 100 parts by mass Toluene 14 parts by mass Styrene-methyl methacrylate copolymer (component ratio 30:70) 3 parts by mass Carbon black (R330: manufactured by Cabot Corporation) 3 parts by mass First, all the components except the ferrite particles among the above components were stirred with a stirrer for 10 minutes to prepare a dispersed coating layer forming solution. Next, this coating layer forming solution and ferrite particles are put into a vacuum degassing type kneader, and stirred at 60 ° C. for 30 minutes. Manufactured.
-Carrier 1C 100 parts by mass-Decyltrimethoxysilane-treated titanium oxide-(Volume average particle size: 20 nm, volume resistance: 10 ¹⁵ Ω-cm) 0.05 parts by mass The carrier 1C and decyl are added to a V-type blender (volume 5 L). After adding trimethoxysilane-treated titanium oxide and stirring at 40 rpm for 20 minutes, carrier H was produced by passing through a sieve having an opening of 75 μm. The obtained carrier H had a volume resistance of 10 ^10.5 Ω · cm at an applied electric field of 1000 V / cm, a core material exposure rate of 1.50%, and a surface titanium content of 4.3%.
-Manufacture of carrier I-
In the production of carrier H, carrier I was produced in the same manner as in the production of carrier H except that 0.01 part by mass of titanium oxide treated with decyltrimethoxysilane was used. The obtained carrier I had a volume resistance of 10 ¹¹ Ω · cm at an applied electric field of 1000 V / cm, a core material exposure rate of 1.50%, and a surface titanium content of 0.8%.

-Manufacture of carrier J-
In the production of carrier H, carrier J was produced in the same manner as in the production of carrier H, except that 0.07 part by mass of decyltrimethoxysilane-treated titanium oxide was used. The obtained carrier J had a volume resistance of 10 ^9.8 Ω · cm at an applied electric field of 1000 V / cm, a core material exposure rate of 1.50%, and a surface titanium content of 6.8%.

-Manufacture of carrier K-
The carrier H was manufactured except that the styrene-methyl methacrylate copolymer (component ratio 30:70) was 2.7 parts by mass and the carbon black (R330: manufactured by Cabot) was 0.27 parts by mass in the production of the carrier H. Carrier K was manufactured in the same manner as H. The obtained carrier K had a volume resistance of 10 ¹¹ Ω · cm at an applied electric field of 1000 V / cm, a core material exposure rate of 1.94%, and a surface titanium content of 4.0%.

-Manufacture of carrier L-
The carrier H was produced except that the styrene-methyl methacrylate copolymer (component ratio 30:70) was 2.7 parts by mass and the carbon black (R330: manufactured by Cabot) was 0.40 parts by mass in the production of the carrier H. The carrier L was manufactured in the same manner as the manufacture of H. The obtained carrier L had a volume resistance of 10 ⁸ Ω · cm at an applied electric field of 1000 V / cm, a core material exposure rate of 1.90%, and a surface titanium content of 4.4%.

-Manufacture of carrier M-
In the production of carrier H, carrier M was produced in the same manner as in the production of carrier H, except that carbon black (R330: manufactured by Cabot) was changed to 0.22 parts by mass. The obtained carrier M had a volume resistance of 10 ¹³ Ω · cm at an applied electric field of 1000 V / cm, a core material exposure rate of 1.50%, and a surface titanium content of 4.2%.

-Manufacture of carrier N-
In the production of carrier H, carrier N was produced in the same manner as in the production of carrier H except that the amount was 0.008 parts by mass of decyltrimethoxysilane-treated titanium oxide. The obtained carrier N had a volume resistance of 10 ^11.3 Ω · cm at an applied electric field of 1000 V / cm, a core material exposure rate of 1.50%, and a surface titanium content of 0.7%.

-Manufacture of carrier O-
In the production of carrier H, carrier O was produced in the same manner as in the production of carrier H, except that 0.08 part by mass of decyltrimethoxysilane-treated titanium oxide was used. The obtained carrier O had a volume resistance of 10 ^10.2 Ω · cm at an applied electric field of 1000 V / cm, a core material exposure rate of 1.50%, and a surface titanium content of 7.2%.

-Manufacture of carrier P-
In the production of Carrier H, the carrier was used except that 2.4 parts by mass of styrene-methyl methacrylate copolymer (component ratio 30:70) and 0.23 parts by mass of carbon black (R330: manufactured by Cabot) were used. The carrier P was produced in the same manner as the production of P. The obtained carrier P had a volume resistance of 10 ¹⁰ Ω · cm at an applied electric field of 1000 V / cm, a core material exposure rate of 2.20%, and a surface titanium content of 5.0%.

-Manufacture of carrier Q-
In the production of carrier H, carrier Q was produced in the same manner as in the production of carrier H, except that carbon black (R330: manufactured by Cabot) was changed to 0.40 parts by mass. The obtained carrier Q had a volume resistance of 10 ^7.8 Ω · cm at an applied electric field of 1000 V / cm, a core material exposure rate of 1.80%, and a surface titanium content of 4.0%.

-Manufacture of carrier R-
In the production of carrier H, carrier R was produced in the same manner as in the production of carrier H, except that carbon black (R330: manufactured by Cabot) was changed to 0.22 parts by mass. The obtained carrier R had a volume resistance of 10 ¹⁴ Ω · cm at an applied electric field of 1000 V / cm, a core material exposure rate of 1.60%, and a surface titanium content of 4.1%.

<Creation of developer (1C)>
8 parts by mass of toner (1C) and 100 parts by mass of carrier A were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (1C). It was.

<Creation of developer (2C)>
8 parts by mass of toner (2C) and 100 parts by mass of carrier B were each stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (2C). It was.

<Creation of developer (3C)>
8 parts by mass of toner (3C) and 100 parts by mass of carrier A were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (3C). It was.

<Creation of developer (4C)>
A developer (4C) is obtained by stirring 8 parts by weight of toner (1C) and 100 parts by weight of carrier C using a V-blender at 40 rpm for 20 minutes and sieving with a sieve having a 177 μm mesh. It was.

<Creation of developer (5C)>
The developer (5C) is obtained by stirring 8 parts by weight of toner (2C) and 100 parts by weight of carrier D with a V-blender at 40 rpm for 20 minutes and sieving with a sieve having a 177 μm mesh. It was.

<Creation of developer (6C)>
8 parts by weight of toner (4C) and 100 parts by weight of carrier A were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (6C). It was.

<Creation of developer (7C)>
8 parts by weight of toner (5C) and 100 parts by weight of carrier A were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (7C). It was.

<Creation of developer (8C)>
8 parts by mass of toner (1C) and 100 parts by mass of carrier E were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (8C). It was.

<Creation of developer (9C)>
8 parts by mass of toner (1C) and 100 parts by mass of carrier F were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (9C). It was.

<Creation of developer (10C)>
8 parts by mass of toner (1C) and 100 parts by mass of carrier G were respectively stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (10C). It was.

<Creation of developer (11C)>
8 parts by mass of toner (1C) and 100 parts by mass of carrier H were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (11C). It was.

<Creation of developer (12C)>
8 parts by mass of toner (2C) and 100 parts by mass of carrier I were each stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (12C). It was.

<Creation of developer (13C)>
8 parts by mass of toner (3C) and 100 parts by mass of carrier H were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved through a sieve having a 177 μm mesh to obtain developer (13C). It was.

<Creation of developer (14C)>
The developer (14C) is obtained by stirring 8 parts by weight of toner (1C) and 100 parts by weight of carrier J with a V-blender at 40 rpm for 20 minutes and sieving with a sieve having a 177 μm mesh. It was.

<Creation of developer (15C)>
8 parts by weight of toner (2C) and 100 parts by weight of carrier K were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved through a sieve having a 177 μm mesh to obtain developer (15C). It was.

<Creation of developer (16C)>
The developer (16C) is obtained by stirring 8 parts by weight of toner (1C) and 100 parts by weight of carrier L with a V-blender at 40 rpm for 20 minutes and sieving with a sieve having a 177 μm mesh. It was.

<Creation of developer (17C)>
8 parts by mass of toner (1C) and 100 parts by mass of carrier M were respectively stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (17C). It was.

<Creation of developer (18C)>
The developer (18C) is obtained by stirring 8 parts by weight of toner (4C) and 100 parts by weight of carrier H with a V-blender at 40 rpm for 20 minutes and sieving with a sieve having a 177 μm mesh. It was.

<Creation of developer (19C)>
The developer (19C) is obtained by stirring 8 parts by weight of toner (5C) and 100 parts by weight of carrier H with a V-blender at 40 rpm for 20 minutes and sieving with a sieve having a 177 μm mesh. It was.

<Creation of developer (20C)>
8 parts by mass of toner (1C) and 100 parts by mass of carrier N were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (20C). It was.

<Creation of developer (21C)>
8 parts by weight of toner (1C) and 100 parts by weight of carrier O were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (21C). It was.

<Creation of developer (22C)>
8 parts by mass of toner (1C) and 100 parts by mass of carrier P were respectively stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (22C). It was.

<Creation of developer (23C)>
8 parts by weight of toner (1C) and 100 parts by weight of carrier Q were each stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain developer (23C). It was.

<Creation of developer (24C)>
The developer (24C) is obtained by stirring 8 parts by weight of toner (1C) and 100 parts by weight of carrier R with a V-blender at 40 rpm for 20 minutes and sieving with a sieve having a 177 μm mesh. It was.

(Low-temperature fixability evaluation)
The fixer of the modified DocuCenter Color 500 was modified so that the fixing temperature was variable, and the low temperature fixability of the toner was evaluated using an unfixed image. The unfixed image formation conditions were as follows. The obtained results are shown in Tables 3 to 5.
[Image formation conditions]
Toner image: Solid image (40 mm x 50 mm)
Toner amount (on recording paper): 0.40 mg / cm ²
Recording paper: Color paper for Fuji Xerox (J paper)
After preparing the fixed image of the obtained unfixed image at the set fixing device temperature, the image surface of each of the fixed images obtained was valley-folded, the degree of peeling of the image at the fold portion was observed, and the image was almost The lowest fixing temperature that could not be peeled off was measured as MFT (° C.) to evaluate low-temperature fixability.

(Evaluation of image preservation)
Two sheets of recording paper on which a fixed image is formed at the lowest fixing temperature (MFT (° C.)) are superimposed on the image surface, and a load of 100 g / cm ² is applied in an environment of temperature 60 ° C. and humidity 85%. Left for 7 days. The superimposed images were peeled off, the images were fused between the recording papers, and the presence or absence of transfer in the non-image area was visually observed and evaluated according to the following evaluation criteria. The obtained results are shown in Tables 3 to 5.
○: No problem in image storability △: Some change was observed but there was no practical problem ×: A large change was observed and it could not be used practically

(Examples 1C to 24C)
Developers (1C) to (24C) were evaluated using the same image forming apparatus (DocuCenter Color500 modified machine) and powder lubricant as in Example 1A. The obtained results are shown in Tables 3 to 5.
Developability (development amount), chargeability (charge amount), fog, and carrier adhesion on the 10th (initial) electrostatic latent image carrier in each environment of normal temperature and normal humidity (22 ° C, 55% RH) And the overall image quality was evaluated. Furthermore, it was left to stand at normal temperature and normal humidity (22 ° C., 55% RH) for 24 hours, and the charging property and fogging on the electrostatic latent image carrier after the standing were evaluated. The evaluation criteria are as follows.

(Developability evaluation)
Each developer was allowed to stand overnight under a predetermined temperature and humidity, an image having two 2 cm × 5 cm patches was copied, and the development amount was measured with a hard stop. Transfer the two development parts on the electrostatic latent image carrier onto the tape using adhesiveness, measure the mass of the toner-attached tape, subtract the mass of the tape, and then average the development amount. Asked. A preferred value is 4.0 to 5.0 g / m ² .

(Chargeability evaluation)
The developer was taken out from the developing machine, and the charge amount was measured with a blow-off charge amount measuring machine (manufactured by Toshiba Corporation).

(Fog and carrier adhesion evaluation)
Similarly, the background is transferred onto the tape, and the number of toners and carriers per 1 cm ² is counted using a magnifying glass or a microscope. The number of toner fog is less than 100, and from 100 to 500 is △, or more. Was evaluated as x. In addition, the carrier adhesion was evaluated as “◯” for less than 5 and “Δ” for 5 to 10, and “×” for 11 or more. The distinction between toner and carrier is mainly determined by the difference in particle size and shape.

(Comprehensive image quality evaluation)
<Solid edge portion reproducibility> The copy was visually judged, and the edge of the boundary portion where the gray image was adjacent was visually judged. ○ No problem at all, △ Slightly problem, × Fair problem, XXVery problem.
<Density unevenness / conveyance failure> The density of the solid image was determined by measuring three points (A4 upper part to lower part) with an X-rite 04A density measuring device manufactured by X-rite. ○ No problem at all, △ Slightly problematic, × Fairly problematic, × Very problematic.
<Density maintenance> The image density at the initial stage and 10,000 sheets was measured and judged by a density measuring device, X-rite 404A, manufactured by X-rite. ○ No problem at all, △ Slightly problem, × Fair problem, XXVery problem.
<Image quality defect> The image quality defect was visually observed, and white spots were determined. ○ No problem at all, △ Slightly problem, × Fair problem, XXVery problem.
<In-machine dirt> The toner scattering state due to toner scattering and sleeve streaks was visually determined. ○ No problem at all, △ Slightly problem, × Fair problem, XXVery problem.
Each item was evaluated, and if there was at least one x, the overall image quality evaluation was x.

Tables 3 to 5 show the following.
In the measurement of viscoelasticity, in toners (1C) to (4C), there is almost no difference between T1 and T2 of 5 ° C. or less, which is derived from the crystallinity of the crystalline polyester resin and has a sharp viscosity with respect to temperature. Elastic change was shown. On the other hand, in the toner (5C), the difference between T1 and T2 was about 50 ° C., and the behavior of the viscoelasticity slowly decreasing with increasing temperature from the vicinity of the glass transition point was exhibited.
In the measurement and evaluation of the powder cohesion (toner blocking resistance), all of the toners (1C) to (5C) showed good powder cohesion. In the evaluation of the low-temperature fixability, all of the toners (1C) to (4C) were fixed at a sufficiently lower temperature than the conventional amorphous electrophotographic toner (5) at 160 ° C. However, it showed good fixation that hardly peeled off.
In the image storability evaluation, in the toners (1C) to (3C), the images were hardly fused or transferred to the other non-image part. However, since toner (4C) has a low melting point, fusion between images and transfer to the non-image part on the other side were remarkable. Since the toner (5C) has a glass transition point of 65 ° C., the images were fused to each other and transferred to the non-image part on the other side.
In the initial developability, chargeability, and image quality evaluation, Examples 1C to 8C and 11C to 22C showed good development amount, charge amount, and high image quality. In Examples 9C and 23C, the volume resistance value of the carrier Is low, carrier adhesion to the electrostatic latent image bearing member occurs, and image whiteout becomes remarkable. In Examples 10C and 24C, on the contrary, the volume resistivity of the carrier was high, so that the image reproducibility of the solid edge portion was significantly deteriorated.
In the evaluation of the chargeability and fog after being left for 24 hours, Examples 1C to 7C, 11C to 19C, 23C and 24C showed sufficient charge amount, and fog was not confirmed, but in Examples 8C to 10C and 20C to 22C Deterioration of fog due to a decrease in neglected chargeability was remarkable.

1 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment of the present invention. 3 is a graph showing preferred characteristics of the toner used in the present invention, wherein the vertical axis represents the common logarithm log G _L of the storage elastic modulus or the common log log G _N of the loss elastic modulus, and the horizontal axis represents the temperature. It is the schematic for demonstrating the method to measure the volume resistance of a carrier. It is a schematic block diagram which shows the image forming apparatus which concerns on 2nd embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrostatic latent image carrier 2 Contact-type charger 3 Exposure apparatus 4 Developing apparatus 5 Transfer apparatus 6 Lubricant coating apparatus 7 Cleaning apparatus 8 Static elimination apparatus 9 Fixing apparatus 10 Transfer belt 11a, b, c Tension roll 12 Backup roll 13 Bias Roll 14 Belt cleaner 15 Paper feed tray 52 Upper electrode 53 Measurement sample 54 Lower electrode 55 High voltage resistance meter

Claims (2)

An electrostatic latent image carrier, a charging unit including a contact charger for charging the electrostatic latent image carrier, and a latent image forming unit for forming a latent image on the surface of the charged electrostatic latent image carrier. A developing means for developing a latent image formed on the surface of the electrostatic latent image carrier with a developer to form a toner image; and a toner image formed on the surface of the electrostatic latent image carrier. Transfer means for transferring to a body, lubricant supply means for supplying a powder lubricant to the surface of the electrostatic latent image carrier, and cleaning for removing residual toner on the surface of the electrostatic latent image carrier after transfer An image forming apparatus comprising at least means,
The powder lubricant contains 10 to 40% by volume of inorganic fine particles having a volume average particle size of 10 to 80 nm, and has a volume resistance of 10 ⁸ to 10 ¹¹ Ω · cm when an applied voltage is 1000 V · cm. Image forming apparatus. A charging step of charging the electrostatic latent image carrier with a contact charger, a latent image forming step of forming a latent image on the surface of the charged electrostatic latent image carrier, and a surface of the electrostatic latent image carrier The latent image formed on the surface is developed with a developer to form a toner image, the transfer step for transferring the toner image formed on the surface of the electrostatic latent image carrier to the transfer target, and the static image An image forming method comprising at least a lubricant supply step for supplying a powder lubricant to the surface of the electrostatic latent image carrier and a cleaning step for removing residual toner on the surface of the electrostatic latent image carrier after transfer. There,
The powder lubricant contains 10 to 40% by volume of inorganic fine particles having a volume average particle size of 10 to 80 nm, and has a volume resistance of 10 ⁸ to 10 ¹¹ Ω · cm when an applied voltage is 1000 V · cm. Image forming method.

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