JP2009042293A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, stably forming a lubricant layer on a photoreceptor even at the initial stage and at a low temperature, and stably obtaining a favorable image to variation with passage of time and environmental variation. <P>SOLUTION: A solid lubricant coater 107 includes a solid lubricant 3 and an application brush 2, wherein the application brush 2 is disposed to apply the lubricant to the surface to be coated of the photoreceptor 1 in rotational contact with the solid lubricant 3 and the photoreceptor 1, the solid lubricant 3 is integrally formed by a surface layer part 22 and an inner layer part 23, the surface layer part 22 contains inorganic particles 21 in the solid lubricant material similarly to the inner layer part 23, and a rubber blade used in a blade cleaning device 106 has impact resilience of 25% or more at 10°C. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a solid lubricant application device for applying a lubricant to a photoreceptor and an image forming apparatus equipped with a blade cleaning device.

Conventionally, in a transfer type image forming apparatus, as a latent image carrier uniformly charged by a charger, for example, a latent image is formed on a photosensitive member by exposing a document image, and then the latent image is formed on the latent image. A toner is attached by a developing device to form a visible image as a toner image. This toner image is transferred to transfer paper or an intermediate transfer medium by a transfer device. The toner remaining on the photoconductor after transfer is removed from the photoconductor by a cleaning device, and the photoconductor is continuously used repeatedly.
As a cleaning device, a blade cleaning method in which a plate-like urethane rubber is brought into contact with a photosensitive member as a cleaning blade is mainly used.
However, if the above-mentioned cleaning blade continues rubbing with the photosensitive member, it is worn over time and the cleaning property is deteriorated. Therefore, in order to reduce the frictional resistance acting between the photoconductor and the cleaning blade and eliminate problems such as wear of the cleaning blade and photoconductor, a technique such as applying a lubricant to the surface of the photoconductor is taken. ing. In addition, when a lubricant is applied to the surface of the photoreceptor, the friction coefficient of the surface of the photoreceptor decreases, so that a fluidizing agent or a charge control agent added to the toner is applied to the surface of the photoreceptor by the contact pressure with the cleaning blade. It is possible to prevent so-called filming that is fixed in a film form. Transferability of the toner developed on the photoreceptor is also improved by reducing the adhesive force with the surface of the photoreceptor.

Recently, in order to improve the image quality, the diameter of the toner has been reduced. When the diameter of the toner is reduced, the dot reproducibility of the latent image is improved and a high-definition image can be obtained. Since it is difficult to reduce the diameter of the toner by a conventional pulverization method, the toner is often manufactured by a polymerization method. The toner produced by the polymerization method has fewer corners than the pulverized toner and is nearly spherical.
However, a toner having a small diameter and a nearly spherical shape makes it easier for the toner to enter the gaps at the blade edge portion than the conventional pulverized toner, and it is difficult to perform cleaning. When these toners are used, a cleaning failure often occurs unless a lubricant is applied to the surface of the photoreceptor, and the lubricant is generally applied. That is, when using a small diameter, spherical toner, it is important to stably apply a lubricant to the photoreceptor.
As a means for applying the lubricant to the surface of the photoreceptor, for example, a solid lubricant obtained by molding a lubricant such as a fatty acid metal salt into a rod shape is installed, and the brush roller is in contact with both the solid lubricant and the photoreceptor There is something with. According to this application means, when the brush roller is driven to rotate, the solid lubricant is scraped by the friction of the brush roller to become powder and adheres to the brush fibers of the brush roller, and the powder adhered to the brush roller. A body-like lubricant is applied to the surface of the photoreceptor.
Further, the lubricant applied on the photoconductor is made uniform by a cleaning blade, and a uniform lubricant layer is formed on the photoconductor to reduce the coefficient of friction on the surface of the photoconductor.

The lubricant layer formed on the surface of the photoconductor is applied when the amount of lubricant supplied from the brush to the photoconductor is too small, or when the supplied lubricant is insufficient with the cleaning blade. Unevenness occurs. Such uneven coating causes the occurrence of poor cleaning and increases the wear of the cleaning blade. On the other hand, if the amount of lubricant applied is too large, the surface of the charging roller that is close to or in contact with the surface of the photoreceptor is contaminated, or the lubricant is absorbed in a high-temperature and high-humidity environment to form on the surface of the photoreceptor. The electrostatic latent image flows and causes image blur.
In particular, there is a variation in the coating amount between the initial stage when the lubricant is new and the time after running, and there are many problems due to the small amount of coating at the initial stage. Further, when spherical or small-diameter toner is used, it causes defective cleaning and contamination of the charging roller, resulting in an abnormal image.
When the solid lubricant is new, the amount of lubricant applied is less than that due to factors such as the small contact area between the brush roller and the solid lubricant and the presence of a skin layer on the surface of the solid lubricant. It is considered to be. In order to increase the initial coating amount, there is a method of increasing the pressure of the brush pressed against the solid lubricant, but there is a problem that the coating amount with time is excessive due to the increase in pressure. The following methods are known as methods for avoiding such problems and reducing fluctuations in the amount of solid lubricant applied between the initial stage and the elapsed time.
For example, the solid lubricant has a two-layer structure, and the upper layer portion on the fur brush contact side is more easily scraped than the lower layer portion (the solid lubricant layer on the brush contact side uses zinc stearate as a lubricant. , A configuration in which the lubricant layer on the opposite side is ethylene bisstearylamide is described.) A method has been proposed (see, for example, Patent Document 1). That is, the solid lubricant layer on the side in contact with the brush is made of a soft material lubricant, so that it can be easily scraped to eliminate the initial application failure and suppress the fluctuation of the application amount.
However, because it is a solid lubricant composed of two types of lubricants with different materials (substances), the physical properties of each layer are different, and the joints may crack and peel due to changes in temperature and humidity. Lack.

In addition, an image forming apparatus having a solid release agent having a softer hardness distribution on the opposite surface side to the toner carrier and a harder hardness distribution on the opposite surface side has been proposed (for example, see Patent Document 2). That is, the two-layer type in which solid lubricants with different hardnesses are bonded together and the type in which the hardness of the solid lubricant continuously changes from the surface layer toward the inside are described. A solid lubricant made of a soft and hard material is disclosed.
However, as described above, the type in which two layers having different hardnesses are bonded together also has two layers having different physical properties, so that cracks are likely to occur at the boundary between the two layers due to environmental changes and the like, and peeling easily occurs. Moreover, it is extremely difficult to reproducibly produce a solid lubricant whose hardness changes continuously, and such a configuration is not realistic.
In addition, there is known a method of performing surface polishing of a new solid lubricant surface with a brush. According to such a coating apparatus, even a new photoconductor unit can apply a predetermined amount of lubricant immediately after mounting, and filming can be prevented. (For example, refer to Patent Document 3) When surface polishing is performed with a brush, since the solid lubricant is brittle, depending on the type of the solid lubricant, there is a concern that cracks or chipping may occur, resulting in defective products.
In addition, the uneven application of the lubricant varies not only due to initial and temporal variations, but also due to environmental variations. In particular, when the temperature is low, the lubricant layer formed on the photoconductor is not uniformly formed, and the low μ of the photoconductor cannot be maintained, and cleaning failure tends to occur.
Like the above invention, the technology to eliminate the fluctuation in the amount of solid lubricant applied between the initial and time courses has been reported, both of which are prone to problems such as cracks and cracks in the solid lubricant due to environmental fluctuations, Furthermore, the application stability of the lubricant at low temperatures is not taken into consideration, and it cannot be said that the lubricant can be applied stably.

JP 2000-338819 A JP 2004-177811 A JP 2006-113420 A

Therefore, the present invention has been made in view of the above problems, and a first object of the present invention is to stably form a lubricant layer on a photoconductor even at an initial stage and at a low temperature, to prevent aging fluctuations and environmental fluctuations. An object of the present invention is to provide an image forming apparatus capable of stably obtaining a good image.
Furthermore, the second object is to obtain a very high-definition image by using spherical and small-diameter toner, and a lubricating layer can be stably formed on the photoreceptor even with various fluctuations, resulting in poor cleaning. An object of the present invention is to provide an image forming apparatus that does not generate any problems.

The features of the present invention, which is a means for solving the above problems, are listed below.
A photoconductor, a developing device that forms a toner image on the photoconductor, a transfer device that transfers the toner image to a transfer target, and a blade cleaning that presses a blade against the photoconductor to remove toner remaining on the photoconductor An image forming apparatus including at least a solid lubricant application device for applying a lubricant to a photoconductor, wherein the solid lubricant application device includes a solid lubricant and an application brush, and the application brush is a solid lubricant The lubricant is applied to the surface to be coated of the photosensitive member while being in rotational contact with the photosensitive member, and the solid lubricant is integrally formed by the surface layer portion and the inner layer portion, and the surface layer portion is the inner layer portion. The rubber blade used in the blade cleaning device has a rebound resilience at 10 ° C. of 25% or more. An image forming apparatus. Hereinafter, the “surface layer portion” may be expressed as “tip layer” and the “inner layer portion” may be expressed as “base layer”.

As described above, the image forming apparatus according to the present invention includes a surface layer portion (tip layer) and an inner layer portion (base layer: the same solid lubricant material as that of the tip layer) each containing inorganic fine particles in the solid lubricant material in the solid lubricant coating device. ), The solid lubricant and the application brush are integrated, so that when the lubricant is new, the solid lubricant and the application brush are more easily caught, and uneven application and poor application of the lubricant are suppressed in the initial stage. Therefore, it becomes possible to apply the lubricant to the coated surface of the photoreceptor stably from the initial stage to the time. Further, since the tip layer and the base layer are integrally formed of the same solid lubricant, the solid lubricant is hardly cracked or cracked against environmental fluctuations, and is highly reliable. In the image forming apparatus of the present invention, in the cleaning blade, the rubber property of the cleaning blade is set to 25% or more of the impact resilience at 10 ° C., so that the lubricant by the cleaning blade is sufficient even at a low temperature. This makes it possible to form a uniform lubricant layer even at a low temperature, and an image can be obtained that is good against environmental fluctuations.
The image forming apparatus provided with the solid lubricant coating device and the cleaning blade can form a lubricant layer on the photosensitive member stably against initial fluctuations and low temperature environments, and a good image can be obtained.
In the above image forming apparatus, when a small-diameter and spherical toner is used, a lubricant layer is formed on a stable photoconductor, and cleaning failure hardly occurs, and an extremely high-definition image can be obtained. .

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

The solid lubricant application device used in the image forming apparatus of the present invention will be described in more detail.
<Solid lubricant application device>
The solid lubricant application device used in the image forming apparatus of the present invention comprises a solid lubricant (3) and an application brush (2) that contacts the solid lubricant (3), and the application brush (2) rotates. Thus, the solid lubricant (3) is applied to the surface to be coated of the photoreceptor. FIG. 1 is a schematic configuration diagram illustrating an example of a solid lubricant application device according to the present invention. In the case of the solid lubricant application apparatus shown in FIG. 1, the lubricant is applied to the surface to be coated of the photoreceptor (1).
As shown in FIG. 1, the application brush (2) has a solid lubricant (3) and a photoreceptor (1) formed by sticking a lubricant such as a fatty acid metal salt into a rod shape (comprising a tip layer containing inorganic fine particles and a base layer). ) To be in contact with both. The application brush (2) is a so-called brush roller, and when it is driven to rotate, the solid lubricant (3) is scraped by the friction of the application brush (2) to become powder and adheres to the brush fibers of the brush roller. The powdery lubricant adhering to the brush roller is applied to the surface of the photoreceptor (1).
Further, when the solid lubricant (3) is worn, the spring (5) is attached to the support metal plate (4) of the solid lubricant (3) so that the contact pressure with the application brush (2) does not change greatly compared to the initial stage. It may be attached to a spring pressurization method.

<Solid lubricant>
The solid lubricant (3) of the solid lubricant application device used in the image forming apparatus of the present invention is integrally formed of a tip layer and a base layer in order from the side where the application brush (2) contacts when the lubricant is new. The tip layer includes inorganic fine particles in the same solid lubricant as the base layer (inorganic particles are dispersed in the solid lubricant). That is, the solid lubricating material of the base layer is the same as the solid lubricating material of the tip layer, but does not contain inorganic fine particles. The schematic diagram of FIG. 2 shows a schematic configuration of the solid lubricant used in the present invention.
In the solid lubricant (3) of FIG. 2, the lower side in the drawing is a surface that comes into contact with the application brush (2), and has a two-layer structure of a tip layer (22) and a base layer (23). That is, the tip layer (22) and the application brush (2) are disposed so as to contact each other in the initial stage when the solid lubricant (3) is new. That is, the inorganic fine particles (21) are dispersed only in the solid lubricant layer on the side in contact with the application brush (2) when the lubricant is new.
By including the inorganic fine particles (21) in the tip layer (22), especially in the initial stage when the solid lubricant (3) is new, the solid lubricant (3) and the application brush (2) are improved in catching. There is an effect of increasing the scraping of the solid lubricant (3). That is, by adding the inorganic fine particles (21), the scraping amount of the solid lubricant (3) can be increased, the initial application failure of the solid lubricant (3) can be eliminated, and the base layer (23) With this integrated structure, it becomes possible to apply the lubricant stably over time.

The thickness of the tip layer (22) is preferably 1 mm to 3 mm. If it is thinner than 1 mm, scraping of the solid lubricant (3) in the initial stage becomes insufficient, which causes uneven coating and poor coating, and easily causes poor cleaning. On the other hand, if it is thicker than 3 mm, the solid lubricant (3 ) Is excessively scraped, and the surface of the charging roller, the flow of the electrostatic latent image, and the image blur are likely to occur.
As described above, the difference between the tip layer (22) and the base layer (23) is only the presence or absence of inorganic fine particles (21), and the same lubricant is used. For this reason, even if the inorganic fine particles (21) are added to the tip layer, the tip layer (22) and the base layer (23) are not significantly different in physical properties such as hardness. Therefore, the solid lubricant (3) used in the present invention is different from the solid lubricant (3) produced by bonding two kinds of solid lubricants having different hardness and physical properties, and has a two-layer structure even with respect to temperature and humidity changes. The environmental stability of the solid lubricant (3) is good without cracks or cracks occurring at the boundary.

The volume average particle size of the inorganic fine particles (21) added to the tip layer (22) is preferably about 2 μm or less, and particularly preferably 0.01 μm or more and 1 μm or less. When the solid lubricant (3) is applied, since the inorganic fine particles (21) contained together with the solid lubricant (3) are supplied onto the photoreceptor (1), the volume of the inorganic fine particles (21) is increased. When the average particle size is larger than about 2 μm, the inorganic fine particles (21) may damage the photoreceptor (1) and the blade, and may cause an abnormal image. A quality image can be formed. When it is smaller than 0.01 μm, the sticking of the coating brush (2) tends to be reduced when the solid lubricant (3) is new.
The volume average particle size of the inorganic fine particles (21) can be measured with a nanotrack particle size distribution measuring device (UPA-EX150 manufactured by Nikkiso Co., Ltd.) which is a powder particle size distribution measuring device by a dynamic light scattering method. Is possible. The inorganic fine particles (21) can be measured by dispersing them in a suitable solvent such as N-methyl-2-pyrrolidone (NMP).
As the inorganic material for the inorganic fine particles (21) contained in the solid lubricant (solid lubricant) of the tip layer (22), a conventionally known material can be used. Examples thereof include fine powders made of inorganic materials such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide, and potassium titanate. Among these, at least one selected from alumina, silica, and titanium oxide is preferable. In particular, silica and titanium oxide are preferable.

In particular, silica or titanium oxide is generally used as an external additive for toner used in an image forming apparatus, and an external additive released from the toner during development or the like is also present on the photoreceptor. Since the image forming system is constructed based on this, even if silica or titanium oxide is detached from the front end layer of the solid lubricant (3) and supplied to the photoconductor (1), problems are unlikely to occur.
The content of the inorganic fine particles (21) contained in the tip layer is preferably 1 to 20 parts by weight with respect to 100 parts of the lubricant. If the addition amount is less than 1 part, the amount of scraping of the solid lubricant (3) is not sufficient, and application failure may occur. In addition, when the amount is more than 20 parts, the ratio of the inorganic fine particles (21) is large with respect to the solid lubricant (3). Therefore, when the molding of the solid lubricant (3) is not successful, or the temperature and humidity change, Cracks are likely to occur at the interface of the base layer. Further, the amount of the inorganic fine particles (21) of the solid lubricant (3) that is detached and supplied to the photoreceptor (1) increases, which may cause fimming or the like.
As the substance used as the solid lubricant (3), for example, higher fatty acid metal salts such as zinc stearate can be used. These higher fatty acid metal salts include zinc stearate, barium stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, magnesium stearate, oleic acid Zinc, manganese oleate, iron oleate, cobalt oleate, lead oleate, magnesium oleate, zinc palmitate, copper oleate, cobalt palmitate, copper palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate, Examples include fatty acid metal salts such as lead caprylate, copper caproate, zinc linolenate, cobalt linolenate, calcium linolenate, zinc ricolinolenate and cadmium ricolinolenate. That.

As a production method of the solid lubricant (3) (solid release agent), a conventionally known powder pressurizing method or a melting method in which it is heated and melted and cooled and solidified can be used. As a multilayering method in which the tip layer and the base layer are integrally formed, for example, there are the following methods.
For the tip layer and the base layer, the solid lubricant (3) is prepared separately, and then the layers are combined by heat compression by secondary processing. The tip layer containing the inorganic fine particles (21) is prepared by mixing a lubricant powder such as zinc stearate and the inorganic fine particles (21), heating and melting the mixed powder while stirring, pouring into a mold and cooling. Can be produced.
The above-mentioned solid lubricant applicator prevents cracks in the solid lubricant (3) against environmental fluctuations, suppresses insufficient scraping of the initial lubricant, and enables stable supply of lubricant from the beginning to time It became.
However, even when the above-described solid lubricant coating device is used, uneven coating may occur at low temperatures, resulting in poor cleaning. This was not a problem of insufficient supply of lubricant in the solid lubricant application device, and the leveling of lubricant with the cleaning blade was insufficient. Therefore, physical properties of the cleaning blade were examined. Details of the cleaning blade used in the image forming apparatus of the present invention will be described below.

<Cleaning blade>
The cleaning blade used in the image forming apparatus of the present invention has a rebound resilience at 10 ° C. of 25% or more.
If the impact resilience at 10 ° C. is less than 25%, cleaning failure occurs. This is not due to the problem of insufficient supply of lubricant in the solid lubricant application apparatus, but due to insufficient lubrication of the lubricant by the cleaning blade. At low temperatures, the impact resilience of the rubber is low, and it is difficult to form a uniform lubricant layer. In order to form a uniform lubricant layer even at a low temperature and suppress poor cleaning, the rubber properties of the blade must have a rebound resilience of 25% or more at 10 ° C. The impact resilience was measured according to JISK6255.
Regarding the contact condition, the contact pressure of the cleaning blade to the photosensitive member (1) is preferably 0.20 N / cm or more. By setting the contact pressure to 0.20 N / cm or more, a uniform lubricant layer is formed at a lower temperature, and cleaning failure is unlikely to occur. The contact pressure shown here is a linear pressure obtained by dividing the load applied to the photosensitive member (1) by the length of the blade in the longitudinal direction of the photosensitive member (1). The load applied to the photoreceptor (1) was measured by a pressure distribution measurement system I-SCAN (manufactured by Nitta Corporation).

A conventionally known material can be used as the rubber elastic body of the cleaning blade, but polyurethane rubber is preferred. Polyurethane rubber usually uses a polyethylene adipate ester or polycaprolactone ester as a polyol component, and a prepolymer is prepared using 4,4′-diphenylmethane diisocyanate as a polyisocyanate component. It is manufactured by adding a catalyst, crosslinking in a predetermined mold, post-crosslinking in a furnace, and then aging at room temperature.
As the high molecular weight polyol, for example, a polyester polyol which is a condensate of an alkylene glycol and an aliphatic dibasic acid, for example, ethylene adipate ester polyol, butylene adipate ester polyol, hexylene adipate ester polyol, ethylene propylene adipate ester polyol, ethylene Polyester polyols such as butylene adipate ester polyol, polyester polyols of alkylene glycol and adipic acid such as ethylene neopentylene adipate polyol, polycaprolactone polyols such as polycaprolactone ester polyol obtained by ring-opening polymerization of caprolactone, poly Polyesters such as (oxytetramethylene) glycol and poly (oxypropylene) glycol Ether-based polyols, or the like is used.
Other low molecular weight polyols include, for example, 1,4-butanediol, ethylene glycol, neopentyl glycol, hydroquinone-bis (2-hydroxyethyl) ether, 3,3′-dichloro-4,4′-diaminodiphenyl. Dihydric alcohols such as methane, 4,4'-diaminodiphenylmethane, 1,1,1-trimethylolpropane, glycerin, 1,2,6-hexanetriol, 1,2,4-butanetriol, trimethylol Mention may be made of trihydric and higher polyhydric alcohols such as ethane, 1,1,1-tris (hydroxyethoxymethyl) propane, diglycerin, pentaerythritol.
Specific examples of the curing catalyst include 2-methylimidazole and 1,2-dimethylimidazole, and 1,2-dimethylimidazole is particularly preferably used. Such a catalyst is usually used in an amount of 0.01 to 0.5 parts by weight, preferably 0.05 to 0.3 parts by weight, based on 100 parts by weight of the main agent.

Next, the toner used in the present invention will be described.
<Toner>
As an example of the toner used in the present invention, a toner produced by a conventionally known method can be used, and a toner of either a pulverization method or a polymerization method can be used as a production method. To achieve high image quality, a small-diameter and spherical toner is preferable, and a volume average particle diameter of 5.8 μm or less, a circularity of 0.96 or more are preferable, and a volume average particle diameter of 5.5 μm or less is further preferable. Particularly preferred are those having a circularity of 0.97 or more.
By using a toner of 5.5 μm or less, it is possible to develop faithfully with respect to the latent image, and an extremely high-definition image can be obtained. By setting the circularity to 0.97 or more, developability and transferability are improved, and an extremely high quality image without halftone unevenness can be obtained. In addition, the volume average particle diameter and the circularity were measured using Sysmex FPIA-2100.
Such a small-diameter and spherical toner can be produced by a polymerization method. For example, after dispersing an organic solvent liquid of a toner material containing at least a resin material for a binder and / or a prepolymer thereof, a colorant, and a release agent in an organic solvent in an aqueous medium, The organic solvent and aqueous medium are prepared by removing the solvent and aqueous medium, or / and after the prepolymer in the droplets has been cross-linked and / or extended during or after the dispersion. It can manufacture by removing.

Preferably, at least in an organic solvent, a compound having active hydrogen and a polymer having a site capable of reacting with the compound, or a self-polymerizable material having active hydrogen and a site capable of reacting with it in the molecule at the same time The organic solvent and the aqueous system are dissolved or dispersed, preferably in the form of a composition containing them, after reacting with or reacting with the active hydrogen reactive site. The medium can be removed, washed and dried. The circularity of the toner may be adjusted by adjusting the stirring strength during the reaction or by forced stirring after drying.
As the resin material or / and its prepolymer, various materials can be used, and in particular, a polyester resin or / and a polyester prepolymer can be preferably used. These are merely examples, and the spherical toner may of course be manufactured by a method other than such a manufacturing method.

Next, the image forming apparatus of the present invention will be described.
That is, the image forming apparatus of the present invention includes a photoconductor (1), a developing device that forms a toner image on the photoconductor (1), a transfer device that transfers the toner image to a transfer target, and a photoconductor ( 1) An image including at least a blade cleaning device that presses a blade to remove toner remaining on the photoreceptor (1) and a solid lubricant application device (107) that applies a lubricant to the photoreceptor (1). In the forming apparatus (100), the solid lubricant application device (107) includes a solid lubricant (3) and an application brush (2), and the application brush (2) includes a solid lubricant (3) and a photoreceptor ( 1) The lubricant is disposed on the surface to be coated of the photosensitive member (1) while being in rotational contact with the surface of the photosensitive member (1), and the solid lubricant (3) includes a surface layer portion (tip layer) (22) and an inner layer portion. (Substrate layer) (23) is integrally formed and the surface layer portion (tip) ) (22) is characterized in that it contains inorganic fine particles (21) in the same solid lubricant as the inner layer (base layer) (23), and the rubber physical properties of the blade (106) of the blade cleaning device are 10 The impact resilience at 25 ° C. is 25% or more.
The image forming apparatus of the present invention will be described below with reference to the drawings.

<Image forming apparatus>
An example of the configuration of the image forming apparatus according to the present invention is shown in the schematic diagram of FIG.
In FIG. 3, the photoconductor (101) shows a drum shape, but it may be a sheet or endless belt. A charging member (102) is disposed on the photoreceptor (101). Although a charging roller is shown in FIG. 3, known means such as a corotron, a scorotron, and a solid state charger (solid state charger) are arranged.
The charging roller which is the charging member (102) may be in contact with the photosensitive member (101). However, by arranging a suitable gap, for example, about 10 to 200 μm between them, The amount of wear can be reduced and toner filming on the charging member (102) can be suppressed, which can be preferably used. The voltage applied to the charging member (102) may superimpose an AC component on a DC component in order to stabilize charging and suppress charging unevenness.

As the transfer means, the above charger can be generally used, but FIG. 3 shows the transfer roller (105). Further, light sources such as an image exposure unit (103) and a static elimination lamp (109) include a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL). ) And other luminescent materials can be used.
Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range. In addition to the steps shown in FIG. 3, these light sources can also be used for a transfer step, a static elimination step, a cleaning step, a pre-exposure step and the like using light irradiation. Irradiated.

The toner developed on the photoreceptor (101) by the developing unit (104) as the developing means is transferred to the transfer paper conveyed from the paper feed tray (110), but not all is transferred. Some toner remains on the photoreceptor (101), and such toner is removed from the photoreceptor (101) by a cleaning blade of a cleaning unit (106) as a cleaning unit. As the cleaning blade, polyurethane rubber is generally used.
A solid lubricant application device (107) is provided upstream of the cleaning unit (106). The solid lubricant (3) supplied from the solid lubricant applicator (107) by the application brush (2) and applied to and adhered to the photoconductor (101) is leveled with the cleaning blade of the cleaning unit (106) and uniform. A layer of lubricant is formed. The toner image transferred onto the transfer paper by the transfer roller (105) is conveyed to a fixing device (108) which is a fixing unit, and the toner image is fixed on the paper and discharged to a discharge tray (111).
As described above, as the toner used in the image forming apparatus (100), an extremely high-definition and high-quality image can be obtained. Therefore, the volume average particle size is 5.5 μm or less and the circularity is 0.97 or more. Some are particularly preferably used.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not restrict | limited by these Examples.
Example 1
A two-layer type solid lubricant comprising a tip layer containing inorganic fine particles in a solid lubricant as shown in FIG. 2 and a base layer containing no inorganic fine particles in the solid lubricant was prepared under the following conditions. .
<Solid lubricant>
The tip layer is a solid lubricant layer in which the solid lubricant substance is zinc stearate, and alumina (inorganic fine particles) having a volume average particle diameter of 2 μm is dispersed in the zinc stearate. On the other hand, the base layer is a single-layer solid lubricant layer containing only zinc stearate and no inorganic fine particles.
As for the production method, first, the tip layer and the base layer were each molded by a melting method.
For the preparation of the tip layer, zinc stearate in which inorganic fine particles are dispersed by mixing with 100 parts by weight of zinc stearate powder and 2 parts of alumina having a volume average particle diameter of 2 μm by heating and stirring. A molten solution of was obtained. The molten solution is poured into a mold and cooled to obtain a rod-like solid lubricant having a longitudinal width of 310 mm, a width of 8 mm, and a height (thickness) of 2 mm, in which inorganic fine particles are dispersed. used.
In addition, the volume average particle diameter of the inorganic fine particles is measured by dispersing the inorganic fine particles in a solvent of N-methyl-2-pyrrolidone (NMP) and using a nanotrack particle size distribution measuring device (UPA-EX150 manufactured by Nikkiso Co., Ltd.). Went.
For the production of the base layer, inorganic fine particles were not added, and only the zinc stearate powder was melted and heated, and cast into a mold. A solid lubricant having a longitudinal width of 310 mm, a width of 8 mm, and a height (thickness) of 5 mm was obtained and used for the base layer.
Next, by the secondary processing, the tip layer and the base layer formed as described above are combined and heat-compressed to be integrated, and a two-layer structure in which the longitudinal width is 310 mm, the width is 8 mm, and the height is 7 mm. The solid lubricant A was obtained. The specifications of the constituent layers of the obtained solid lubricant A are shown in Table 1 below.

<Cleaning blade>
A flat polyurethane rubber was used.
Table 2 shows a list of rubber properties, and rubber A in Table 2 was used as a cleaning blade. The impact resilience was measured according to JISK6255.
A strip having a length of 325 mm in the longitudinal direction, a width of 12 mm, and a thickness of 2 mm was cut out and attached to a support sheet metal to obtain a cleaning blade A having a rubber blade protruding from the support sheet metal of 7.3 mm.

<Evaluation test of actual machine>
The solid lubricant A obtained as described above was mounted on a Ricoh copier Imagio NEO-C455. By default, Imagio NEO-C455 is equipped with a solid lubricant application device (equipped with a solid lubricant and an application brush, and the application brush is disposed so that the lubricant can be applied to the application surface of the photoconductor while rotatingly contacting the solid lubricant and the photoconductor. Therefore, only the solid lubricant of the present invention was replaced and the test was performed.
The cleaning blade was replaced with the cleaning blade A described above. The contact pressure between the cleaning blade and the photosensitive member was adjusted to 0.22 N / cm in an environment with a temperature and humidity of 23 ° C. and 50%.
The contact pressure was calculated as a linear pressure by measuring the load applied to the photosensitive member with a pressure distribution measurement system: I-SCAN (made by Nitta Corporation), dividing the measured load by the length in the longitudinal direction of the cleaning blade. .
The toner used was subjected to a paper passing test using a toner produced by a polymerization method and having a volume average particle diameter of 5.8 μm and a circularity of 0.96.

The paper-passing test was conducted in two environments: high temperature and high humidity (30 ° C., 80%) and low temperature and low humidity (10 ° C., 15%). A chart with a printing rate of 5% was printed. When the number of sheets passed was 50 and 3000, image evaluation, measurement of the coefficient of friction (μ) of the photoreceptor, and a cleaning test were performed.
For each environmental test, the solid lubricant, cleaning blade, and photoconductor were replaced with new ones.
The conditions of the actual machine test are summarized in Table 3.
In the image evaluation, the printed images were visually evaluated for “halftone uniformity of gray scale image” and “fine line image resolution”. The evaluation method is a ranking evaluation, where rank 5 is the best and rank 1 is the lowest.
Regarding the measurement of the coefficient of friction (μ) of the photoconductor, the coefficient of friction of the photoconductor was measured by the Euler belt method.
For the cleaning test, when the number of sheets passed was 50, 3000, 30 solid images were printed continuously, and the surface of the photoreceptor after the test and the contamination of the charging roller were visually observed to evaluate the rank. went. Rank 5 is the best and rank 1 is the lowest. Rank 3 or higher is necessary to withstand actual use.

<Crack resistance due to environmental fluctuation of solid lubricant>
A heat cycle [(temperature, relative humidity, time) × cycle] was given to the solid lubricant separately from the paper passing test by mounting the actual machine, and it was visually confirmed whether the solid lubricant was cracked or cracked.
As specific conditions of the heat cycle, observation was performed after leaving in the following environment.
[Heat cycle conditions]: 30 ° C., 80%, 6 hours → 5 ° C., 10%, 6 hours → 30 ° C., 80%, 6 hours → 5 ° C., 10%, 6 hours Actual machine evaluation test conducted under the above conditions Tables 4 to 6 below show the evaluation results of the crack resistance test of the solid lubricant and the solid lubricant.

(Example 2)
A solid lubricant B having a two-layer structure was obtained in the same manner as in Example 1 except that the volume average particle size of the inorganic fine particles added to and mixed with the tip layer in Example 1 was changed to 0.3 μm alumina particles. The specifications of the constituent layers of the obtained solid lubricant B are shown in Table 1 below. The cleaning blade uses the same rubber A as in Example 1, but the contact pressure between the cleaning blade and the photosensitive member is 0.22 N / cm in an environment of 23 ° C. and 50% temperature and humidity. changed.
The conditions of the actual machine test are summarized in Table 3.
Using the solid lubricant B, an actual machine evaluation test and a crack resistance test of the solid lubricant were performed in the same manner as in Example 1 except that the blade contact pressure was changed. The evaluation results are shown in Tables 4 to 6 below.

(Example 3)
A solid lubricant C having a two-layer structure was obtained in the same manner as in Example 1, except that the volume average particle size of the inorganic fine particles added and mixed in the tip layer in Example 1 was changed to silica particles of 0.1 μm. The specifications of the constituent layers of the obtained solid lubricant C are shown in Table 1 below.
The cleaning blade uses the same rubber A as in Example 1, but the contact pressure between the cleaning blade and the photosensitive member is 0.22 N / cm in an environment of 23 ° C. and 50% temperature and humidity. changed.
The conditions of the actual machine test are summarized in Table 3. Using this solid lubricant C, an actual machine evaluation test and a crack resistance test of the solid lubricant were performed in the same manner as in Example 1 except that the contact pressure of the blade was changed. The evaluation results are shown in Tables 4 to 6 below.

Example 4
A solid lubricant D having a two-layer structure was obtained in the same manner as in Example 1, except that the volume average particle size of the inorganic fine particles added and mixed in the tip layer in Example 1 was changed to silica particles of 0.03 μm. The specifications of the constituent layers of the obtained solid lubricant D are shown in Table 1 below. The cleaning blade uses the same rubber A as in Example 1, but the contact pressure between the cleaning blade and the photosensitive member is 0.22 N / cm in an environment of 23 ° C. and 50% temperature and humidity. changed.
The conditions of the actual machine test are summarized in Table 3. Using this solid lubricant D, an actual machine evaluation test and a crack resistance test of the solid lubricant were performed in the same manner as in Example 1 except that the contact pressure of the blade was changed. The evaluation results are shown in Tables 4 to 6 below.

(Example 5)
A solid lubricant E having a two-layer structure was obtained in the same manner as in Example 1, except that the volume average particle size of the inorganic fine particles added and mixed in the tip layer in Example 1 was changed to 0.04 μm titanium oxide particles. Table 1 shows the specifications of the constituent layers of the obtained solid lubricant E.
The cleaning blade uses the same rubber A as in Example 1, but the contact pressure between the cleaning blade and the photosensitive member is 0.22 N / cm in an environment of 23 ° C. and 50% temperature and humidity. changed. The conditions of the actual machine test are summarized in Table 3. Using this solid lubricant E, an actual machine evaluation test and a crack resistance test of the solid lubricant were performed in the same manner as in Example 1 except that the contact pressure of the blade was changed. The evaluation results are shown in Tables 4 to 6 below.

(Example 6)
A solid lubricant D produced under the same conditions as the solid lubricant produced in Example 4 was obtained. The specifications of the constituent layers of the obtained solid lubricant D are as shown in Table 1 below. The same cleaning blade as in Example 1 was obtained except that rubber B in Table 2 was used as the rubber for the cleaning blade. The contact pressure of this cleaning blade was changed to 0.23 N / cm in an environment of a temperature and humidity of 23 ° C. and 50%. The conditions of the actual machine test are summarized in Table 3. Using this solid lubricant D, a cleaning blade using rubber B was used, the contact pressure of the blade was changed to 0.23 N / m, and the volume average particle diameter of the toner used in Example 1 was 5. The actual machine evaluation test and the crack resistance test of the solid lubricant were performed in the same manner as in Example 1 except that the diameter was changed to 2 μm and the circularity was 0.98. The evaluation results are shown in Tables 4 to 6 below.

(Comparative Example 1)
Melting rod solid lubricant of zinc stearate with longitudinal width 310mm, width 8mm, height (thickness) 2mm, ethylene bisstearylamide rod solid lubricant with longitudinal width 310mm, width 8mm, height (thickness) 5mm Each was manufactured by the method, and these were overlapped by secondary processing and integrated by heating and compression. As a result, a solid lubricant F having a two-layer structure in which the tip layer was zinc stearate and the base layer was ethylenebisstearylamide was obtained. Table 1 shows the specifications of the constituent layers of the obtained solid lubricant F. The cleaning blade uses the same rubber A as in Example 1, but the contact pressure between the cleaning blade and the photosensitive member is 0.22 N / cm in an environment of 23 ° C. and 50% temperature and humidity. changed. The conditions of the actual machine test are summarized in Table 3.
Using this solid lubricant F, an actual machine evaluation test and a crack resistance test of the solid lubricant were performed in the same manner as in Example 1 except that the contact pressure of the blade was changed. The evaluation results are shown in Table 3 below. In the test under low temperature and low humidity, the defective cleaning was severe from the beginning, and it was judged that the test could not be continued when 50 sheets were completed, and the subsequent tests were stopped.

(Comparative Example 2)
A rod-like solid lubricant of stearic acid sulfite having a longitudinal width of 310 mm, a width of 8 mm, and a height (thickness) of 7 mm was produced by a melting method, and a solid lubricant G having a single layer structure was obtained. The composition of the obtained solid lubricant G is shown in Table 1 below. The cleaning blade uses the same rubber A as in Example 1, but the contact pressure between the cleaning blade and the photosensitive member is 0.22 N / cm in an environment of 23 ° C. and 50% temperature and humidity. changed. The conditions of the actual machine test are summarized in Table 3. Using this solid lubricant G, an actual machine evaluation test and a crack resistance test of the solid lubricant were performed in the same manner as in Example 1 except that the contact pressure of the blade was changed. The evaluation results are shown in Tables 4 to 6 below. In the test under low temperature and low humidity, the cleaning failure was severe from the beginning, and it was judged that the test could not be continued at the end of 50 sheets, and the subsequent tests were stopped.

(Comparative Example 3)
A solid lubricant H having a single layer structure in which silica particles having a volume average particle size of 0.03 μm were dispersed in a zinc stearate having a longitudinal width of 310 mm, a width of 8 mm, and a height of 7 mm was produced.
The solid lubricant H is prepared by mixing zinc stearate powder 100 parts (parts by weight) and silica parts 2 parts (parts by weight), heating with stirring, and stirring the zinc stearate in which the silica particles are dispersed. A molten solution was obtained, and the molten solution was poured into a mold, cooled, and the rod-shaped solid lubricant H was molded. The structure of the obtained solid lubricant H is shown in Table 1 below.
The cleaning blade uses the same rubber A as in Example 1, but the contact pressure between the cleaning blade and the photosensitive member is 0.22 N / cm in an environment of 23 ° C. and 50% temperature and humidity. changed. The conditions of the actual machine test are summarized in Table 3.
Using this solid lubricant H, an actual machine evaluation test and a crack resistance test of the solid lubricant were performed in the same manner as in Example 1 except that the contact pressure was changed. In the test under high temperature and high humidity, an abnormal image with blurred image occurred after the end of 3000 sheets. The evaluation results are shown in Tables 4 to 6 below.

(Comparative Example 4)
Example 1 A solid lubricant A produced under the same conditions as the produced solid lubricant was obtained. The specifications of the constituent layers of the obtained solid lubricant A are as shown in the following Table 1 as described above. The rubber C in Table 2 was used as the rubber used for the cleaning blade. The contact pressure between the cleaning blade and the photosensitive member was set to 0.19 N / cm in an environment with a temperature and humidity of 23 ° C. and 50%. The conditions of the actual machine test are summarized in Table 3. An actual machine evaluation test and a solid lubricant crack resistance test were conducted in the same manner as in Example 1 except that a rubber C cleaning blade was used. The evaluation results are shown in Tables 4 to 6 below.

Below, the front end layer of the produced solid lubricant, the structure of the base layer, and the layer thickness are shown in a list.

The rubber properties of the cleaning blade used are listed below.

Listed below are various setting conditions such as process conditions in actual machine evaluation.

The actual machine test results under high temperature and high humidity are listed below.

The actual machine test results under high temperature and high humidity are listed below.

The test results of the environmental change crack resistance test of the solid lubricant are listed below.

Examples 1 to 6 of the present invention shown in Tables 1 to 6 show good friction coefficient (μ), cleaning property and image evaluation of the photoreceptor in the actual machine test under any environment of low temperature and low humidity and high temperature and high humidity. Moreover, the crack resistance by the environmental change of a solid lubricant is also favorable. Examples 1 to 6 in which the contact pressure of the blade was 0.20 N / cm or more show better friction coefficient (μ), cleaning property and image evaluation of the photosensitive member at low temperature. In Examples 3 to 6, in which the inorganic fine particles are silica or titanium oxide, the cleaning property after 3000 sheets is excellent. Further, Example 6 having a volume average particle size of 5.5 μm or less and a circularity of 0.97 or more is excellent in image evaluation, and an extremely high quality image is obtained.
On the other hand, all of Comparative Examples 1 to 4 are unpractical in terms of the coefficient of friction (μ), cleaning properties, and image evaluation of the photoreceptor.

It is a schematic structure figure showing an example of a solid lubricant application device in the present invention. It is a schematic diagram which shows schematic structure of the solid lubricant used for this invention. 1 is a schematic diagram illustrating an example of a configuration of an image forming apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Application brush 3 Solid lubricant 4 Support metal plate 5 Spring 21 Inorganic fine particle 22 Tip layer 23 Base layer 100 Image forming apparatus 101 Photoconductor 102 Charging member 103 Image exposure part 104 Development unit 105 Transfer roller 106 Cleaning unit 107 Solid lubrication Agent coating device 108 fixing device 109 static elimination lamp 110 paper feed tray

Claims (7)

A photoreceptor,
A developing device for forming a toner image on the photoreceptor;
A transfer device for transferring the toner image to a transfer target;
A blade cleaning device that presses a blade against the photoconductor to remove toner remaining on the photoconductor;
In an image forming apparatus comprising at least a solid lubricant application device for applying a lubricant to the photoreceptor,
The solid lubricant application device includes a solid lubricant and an application brush,
The application brush is disposed so that the lubricant can be applied to the surface to be coated of the photoconductor while being in rotational contact with the solid lubricant and the photoconductor,
The solid lubricant is integrally composed of a surface layer portion and an inner layer portion, and the surface layer portion contains inorganic fine particles in the same solid lubricant as the inner layer portion,
The rubber blade used in the blade cleaning device has an impact resilience at 10 ° C. of 25% or more. The image forming apparatus according to claim 1,
The image forming apparatus, wherein the blade cleaning device has a contact pressure with respect to the photosensitive member of 0.20 N / cm or more. The image forming apparatus according to claim 1, wherein
An image forming apparatus, wherein a particle size of inorganic fine particles contained in a surface layer portion of the solid lubricant is 0.01 μm or more and 1 μm or less. The image forming apparatus according to any one of claims 1 to 3,
The image forming apparatus, wherein the inorganic fine particles contained in the surface layer portion of the solid lubricant are at least one kind of fine particles selected from alumina, silica, and titanium oxide. The image forming apparatus according to claim 4.
The image forming apparatus, wherein the inorganic fine particles contained in the surface layer portion of the solid lubricant are silica and / or titanium oxide. The image forming apparatus according to claim 5.
An image forming apparatus, wherein the toner has a volume average particle size of 5.8 μm or less and a circularity of 0.96 or more. The image forming apparatus according to claim 6.
The volume average particle diameter of the toner is 5.5 μm or less, and the circularity is 0.97 or more.

Images