JP2014106443A - Image forming apparatus, image forming method, and replacement toner container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus configured to reduce pressure to be applied to an image carrier protective agent, and to reduce torque of a drive unit and consumption of protective agent, while preventing stains on an image carrier.SOLUTION: An image forming apparatus includes: protective layer forming means 2 having a protective agent supply member 22 in contact with a surface of an image carrier 1 in a rotatable manner and an image carrier protective agent, the image carrier protective agent containing fatty acid metal salt and inorganic lubricant, the protective agent supply member having a core material and a foam layer formed on an outer periphery of the core material and having a plurality of air bubbles; a toner storage part which stores toner T1; and a replacement toner storage member for storing toner T2 to be supplied to the toner storage part and replenishment toner T3. The toner T1, toner T2, and toner T3 satisfy F1>30 percent by number≥F3, and F2>30 percent by number≥F3. (F1 is the content of fine particles having a particle diameter of 3 μm or less in the toner T1, F2 is the content of fine particles having a particle diameter of 3 μm or less in the toner T2, and F3 is the content of fine particles having a particle diameter of 3 μm or less in the replenishment toner T3).

Description

  The present invention relates to an image forming apparatus, an image forming method, and a replacement toner containing member.

  Conventionally, in electrophotography, image formation is performed by the following method, for example. A drum-shaped or belt-shaped image carrier (hereinafter, also referred to as “photosensitive member”, “electrophotographic photosensitive member”, or “electrostatic latent image carrier”) is uniformly charged while rotating. Subsequently, an electrostatic latent image by an electrostatic charge is formed on the image carrier by laser light or the like. Subsequently, using a developing device, charged toner is attached to the electrostatic latent image to form a visible image on the image carrier. Subsequently, the visible image is transferred to a recording medium such as paper and fixed on the recording medium with heat, pressure, solvent, or the like.

  Untransferred toner remains on the image carrier after the visible image is transferred to the recording medium. When the charging step is performed with the toner remaining on the image carrier, even charging of the image carrier is often hindered. Therefore, in general, the image carrier after the transfer step is performed. The toner remaining on the top is removed by a cleaning process. Then, the surface of the image carrier is sufficiently cleaned and a charging process is performed.

In each step such as charging, development, transfer, and cleaning, the surface of the image carrier is subjected to various physical stresses and electrical stresses, and the surface state changes with use time.
Of these stresses, stress due to friction in the cleaning process not only wears the image bearing member but also reduces the life of the cleaning means.

  The longevity of the image forming apparatus and the members used therefor is of great interest in the market from the viewpoint of reducing the running cost and protecting the global environment by reducing waste. From such a flow, in recent years, not only the image carrier but also the life of peripheral members has been demanded, and the reduction of stress in the cleaning process has become a major issue.

  In recent years, the contact charging method and the proximity charging method have been used more and more for the purpose of reducing the size and cost of the image forming apparatus. In the proximity charging method, the surface of the image carrier is made uniform by minute contact unevenness between the charging means and the surface of the image carrier, and by fluctuation in the gap between the charging means and the surface of the image carrier when not in contact. Since it is difficult to charge, in recent years, an AC superposition charging method in which an alternating current (AC) component is superimposed on a direct current (DC) component has been widely used.

The proximity charging method in which the AC component is superimposed can reduce the size of the image forming apparatus and improve the image quality, and at the same time, can maintain the charging uniformity and make the charging unit and the image carrier non-contact. Therefore, it can be said that this is a very advantageous technique for downsizing, high image quality, and high durability of the image forming apparatus.
However, in the case where the image carrier is an organic photoreceptor (OPC), the energy of AC superimposed charging cuts the resin chain on the surface of the image carrier and reduces the mechanical strength. It has been shown that wear is significantly accelerated.
In addition, the AC superposition charging activates the surface of the image carrier, so that the adhesion between the surface of the image carrier and the toner is increased, which is also disadvantageous for the cleaning property.
Further, in recent years, the diameter of the toner and the spheroidization have been promoted from the viewpoint of high image quality, and the margin for the cleaning property is decreasing.

In order to solve these problems, an image is formed for the purpose of reducing the frictional force between the image carrier and the cleaning unit, protecting both the image carrier and the cleaning unit, and improving the cleaning property. Many methods using a carrier protective agent (hereinafter sometimes referred to as “protective agent”) have been proposed.
For example, in order to extend the life of the image carrier and the cleaning blade, it has been proposed to supply a solid protective agent mainly composed of zinc stearate to the surface of the image carrier to form a protective film on the surface of the image carrier. (For example, refer to Patent Document 1).
It has also been proposed to supply a protective agent containing a fatty acid metal salt and an inorganic lubricant to the surface of the image carrier (see, for example, Patent Document 2).
Examples of the protective agent coating apparatus used in these proposed techniques include a brush-like rotating member (for example, a brush roller) that is in sliding contact with an image carrier, a solid protective agent that is in contact with the brush-like rotating member, and the solid protection. A protective agent supply device (applying member) having a pressurizing mechanism (for example, a spring) that urges the agent toward the brush-like rotating member has been proposed (see, for example, Patent Document 3).
However, in the configuration in which the spring contacts and is pressed against the brush roller, the spring expands as the solid protective agent is scraped off, so that the pressing force is inevitably weakened. As a result, the shaving amount of the solid protective agent decreases, and the amount of the solid protective agent supplied to the image carrier and the intermediate transfer belt also decreases. Therefore, the image carrier and the intermediate transfer belt are There is a problem that it cannot be sufficiently protected.
In addition, when the brush roller rotates, there is a problem that a large amount of powder of the protective agent rubbed from the solid protective agent flies and a large amount of the protective agent is wasted. There is also a problem that the brush fibers are liable to fall down and deteriorate.

In relation to these problems, in order to keep the pressure applied to the solid protective agent constant, the protective agent supply device is provided with a movable pressing member on the member holding the solid protective agent and pressurizes it with a spring member. Has been proposed (see, for example, Patent Document 4).
However, even if this proposed technique is used, the problem is that a large amount of protective agent powder rubbed from the solid protective agent flies by rotating the brush roller, and a large amount of protective agent is wasted. The problem that the brush fibers tend to fall and deteriorate cannot be solved.
Furthermore, there is a problem that the consumption of the protective agent is not stable over time, and the protective agent cannot be supplied in a constant amount over a long period of time. In particular, this problem becomes significant in a protective agent produced by compression molding.

In order to solve this problem, a technique using a protective agent supply member (roller) having a foam layer has been proposed (see, for example, Patent Documents 5 and 6). In these proposed techniques, the protective agent powder hardly flies by rubbing. In addition, since no brush is used, there is no effect of brush falling or deterioration, the protective agent can be supplied in a constant amount over a long period of time, and a protective agent film can be applied to the surface of the image carrier with a relatively small consumption. It can be formed uniformly. Moreover, since it can be manufactured at a relatively low cost compared to the brush, it contributes to the cost reduction of the unit.
However, this proposed technique has a smaller grinding action on the solid protective agent than the brush, and in order to obtain the desired protective agent consumption, the pressure of the solid protective agent against the roller having the foam layer (pressurizing force) ) Must be set very high. This is because the brush comes in contact with the solid protective agent at the tip of the hair, and when viewed microscopically, it has an action of scraping off the solid protective agent with a very strong pressure, whereas the foam is This is because, when a roller having a body layer is used, the foam layer is in contact with the solid protective agent on the surface, so that it is close to the action of rubbing with a weak pressure and the grinding force is not strong in principle. .
Therefore, when the applied pressure of the solid protective agent for obtaining the desired protective agent consumption becomes excessively high, the torque of the entire device is increased, and the shaft of the protective agent supply member is bent due to the torque increase. There is a problem that a defect occurs. On the other hand, when the applied pressure of the solid protective agent is low, there is a problem that the image carrier is soiled.

  Therefore, the pressure applied to the image carrier protective agent is low, the torque of the drive device can be reduced, the target protective agent consumption can be stably obtained over a long period of time, and contamination of the image carrier and the like can be further prevented. At present, it is required to provide an image forming apparatus.

  An object of the present invention is to solve the above-described problems and achieve the following objects. In other words, the pressure applied to the image carrier protective agent is low, the torque of the drive device can be reduced, the desired amount of protective agent consumption can be obtained stably over a long period of time, and contamination of the image carrier can be prevented. An object is to provide an image forming apparatus.

The image forming apparatus of the present invention as means for solving the above-described problems includes an image carrier,
A protective layer forming means having a protective agent supplying member and an image carrier protective agent that rotatably contact the surface of the image carrier;
A developing unit that has a toner storage unit that stores toner T1, and that develops an electrostatic latent image formed on the image carrier using the toner T1 to form a visible image;
A toner containing member for containing toner T2 for replenishing the toner containing portion;
A replacement toner storage member that stores the replenishment toner T3, and
An image forming apparatus in which the replenishment toner T3 is replenished by exchanging the replacement toner accommodation member with the toner accommodation member,
The image carrier protective agent contains a fatty acid metal salt and an inorganic lubricant,
The protective agent supply member has a core material and a foam layer formed on the outer periphery of the core material and having a plurality of bubbles,
The toner T1, the toner T2, and the replenishing toner T3 satisfy a relationship represented by the following formulas 1 and 2.
F1> 30 number% ≧ F3 Formula 1
F2> 30 number% ≧ F3 Formula 2
In Formula 1 and Formula 2, F1 is a fine powder content of 3 μm or less in the toner T1, F2 is a fine powder content of 3 μm or less in the toner T2, and F3 is the replenishing toner. The content of fine powder having a particle size of 3 μm or less at T3 is represented, and the units of F1 to F3 are number%.

  According to the present invention, the above-mentioned problems can be solved, the applied pressure to the image carrier protecting agent is low, the torque of the driving device can be reduced, and the desired protective agent consumption can be obtained stably over a long period of time. In addition, it is possible to provide an image forming apparatus that can prevent contamination of the image carrier and the like.

FIG. 1A is a schematic cross section showing an example of an open-cell foam layer. FIG. 1B is a schematic cross-sectional view showing an example of a closed cell foam layer. FIG. 2A is a side view showing an example of the protective agent supply member. FIG. 2B is an enlarged schematic view showing an example of an exposed surface of the continuous foam type foam layer. FIG. 3A is a perspective view showing an example of a process for forming a protective agent block by compression molding using an image carrier protective agent manufacturing apparatus. FIG. 3B is a schematic cross-sectional view of the image carrier protecting agent production apparatus of FIG. 3A. FIG. 3C is a perspective view showing an example of a protective agent block formed by compression molding. FIG. 3D is a schematic cross-sectional view illustrating an example of a protective agent block fixed to a holder. FIG. 4 is a schematic sectional view showing an example of the protective layer forming means. FIG. 5 is a schematic sectional view showing an example of the developing means. FIG. 6 is a schematic perspective view showing another example of the developing means. FIG. 7 is a schematic perspective view showing another example of the developing means. FIG. 8 is a schematic diagram illustrating an example of a toner storage member. FIG. 9 is a schematic sectional view showing an example of the image forming apparatus of the present invention.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention includes at least an image carrier, a protective layer forming unit, a developing unit, and a toner containing member, and further includes other units as necessary.
The image forming method of the present invention includes at least a protective layer forming step and a developing step, and further includes other steps as necessary.
In the image forming apparatus and the image forming method, the replenishment toner is replenished by exchanging the replacement toner accommodating member with the toner accommodating member.
The image forming method can be preferably carried out by the image forming apparatus, the protective layer forming step can be suitably carried out by the protective layer forming means, the developing step can be suitably carried out by the developing means, and the others This step can be preferably carried out by the other means.

  As a result of various studies, the present inventors have made it possible for the protective agent supply member to carry the image on the surface of the foam layer of the protective agent supply member by enclosing particles such as toner and protective agent powder. It was found that the power to grind body protectors was greatly improved. Then, by increasing the content of fine powder having a particle size of 3 μm or less in the toner at the beginning of image formation, the amount of toner slipping from the cleaning means is temporarily increased, and the toner is held in the cells on the surface of the foam layer. It became possible to put it in. Therefore, the content of fine powder having a particle size of 3 μm or less was increased only for the toner contained in the toner accommodating portion of the developing means and the toner accommodating member, which is bundled at the time of shipment. By doing so, it was discovered that the protective agent supply member can greatly improve the grinding force of the image carrier protective agent with a very simple configuration, and the present invention has been achieved.

The foam layer alone has a small ability to grind the image carrier protective agent, but if the harder particles can be held in the cells of the foam layer, the grinding ability is improved as described above. Can be made. Although it is possible to make such particles adhere to the surface of the foam layer from the beginning, in that case, the number of steps during the production of the protective agent supply member increases, which increases the cost.
Therefore, in the present invention, the increase in toner slipping from the cleaning means is used only at the initial stage of image formation. This will be described with reference to FIG. The greater the proportion of fine powder contained in the toner, the greater the amount of toner that passes through the cleaning means 4 and reaches the foam layer of the protective agent supply member 22. According to the study by the present inventors, when the toner particle size is 3 μm or less, the cleaning means using the cleaning blade has insufficient cleaning properties. In the present invention, for example, at the initial stage of use of the image forming apparatus, a large amount of fine powder toner having a particle size of 3 μm or less is contained, so that a large amount of toner passes through the cleaning unit 4. By holding the slipping toner in the cell of the foam layer of the protective agent supply member 22, the force with which the protective agent supply member 22 grinds the protective agent block 21 can be improved.
For example, the toner slipping continues to increase until the toner in the toner containing member that is bundled with the image forming apparatus at the time of shipment is used up. After the toner is used up and the toner storage member is replaced with a replacement toner storage member, the content of fine powder having a particle size of 3 μm or less decreases, so that the slip-through toner decreases. Therefore, the cleaning property is not deteriorated for a long time, and the contamination of the charging means is not accelerated. On the other hand, the foam layer has the ability to hold the toner for a relatively long period of time, and the powder formed by grinding the protective agent block 21 is gradually held in the cells of the foam layer, resulting in grinding. There is no loss of power.

<Image carrier>
The material, shape, structure, and size of the image carrier are not particularly limited and may be appropriately selected depending on the purpose. As the shape of the image carrier, for example, a drum shape is preferable. Examples of the material of the image carrier include inorganic image carriers such as amorphous silicon and selenium; organic image carriers such as polysilane and phthalopolymethine. These may be used alone or in combination of two or more.

The image carrier preferably comprises a conductive support and at least a photosensitive layer on the conductive support, and further comprises other layers such as an undercoat layer and an outermost surface layer as necessary. Have.
An appropriate amount of a plasticizer, an antioxidant, a leveling agent or the like can be added to each layer as necessary.

<< Conductive support >>
There is no restriction | limiting in particular as said electroconductive support body, Although it can select suitably according to the objective, What shows electroconductivity whose volume resistance value is 1.0 * 10 < ¹⁰ > (omega | ohm) * cm or less is preferable.
As the conductive support, for example, a metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, or a metal oxide such as tin oxide or indium oxide is deposited or sputtered to form a film or Cylindrical plastic, paper-coated, or aluminum, aluminum alloy, nickel, stainless steel, etc., and after extruding and drawing them into drums, cutting, superfinishing, polishing, etc. A surface-treated tube or the like can be used.

There is no restriction | limiting in particular as said drum-shaped support body, Although it can select suitably according to the objective, A diameter is preferable 20 mm-150 mm, 24 mm-100 mm are more preferable, 28 mm-70 mm are especially preferable. When the diameter of the drum-shaped support is less than 20 mm, it is physically difficult to arrange each means such as a charging means, an exposure means, a developing means, a transfer means, and a cleaning means around the drum. If it exceeds 150 mm, the image forming apparatus may become large. In particular, when the image forming apparatus is a tandem type, since it is necessary to mount a plurality of image carriers, the diameter is preferably 70 mm or less, and more preferably 60 mm or less.
Further, an endless nickel belt or an endless stainless steel belt as disclosed in JP-A-52-36016 can also be used as the conductive support.

<< Photosensitive layer >>
The photosensitive layer is not particularly limited and may be appropriately selected depending on the intended purpose. However, the photosensitive layer preferably contains a charge generation material, a charge transport material, and a binder resin. Contains ingredients.
The photosensitive layer may be a single layer type in which the charge generation material and the charge transport material are mixed, a forward layer type in which a charge transport layer is provided on the charge generation layer, or a charge generation layer on the charge transport layer. There is a reverse layer type provided.

-Charge generation material-
The charge generating material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include azo pigments such as monoazo pigments, bisazo pigments, trisazo pigments, tetrakisazo pigments, and triarylmethane dyes. , Thiazine dyes, oxazine dyes, xanthene dyes, cyanine dyes, styryl dyes, pyrylium dyes, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments, indus Organic pigments or dyes such as Ron pigments, squarylium pigments, and phthalocyanine pigments; inorganic materials such as selenium, selenium-arsenic, selenium-tellurium, cadmium sulfide, zinc oxide, titanium oxide, and amorphous silicon. These may be used individually by 1 type and may use 2 or more types together.

-Charge transport material-
The charge transport material is not particularly limited and may be appropriately selected depending on the intended purpose. Compounds, styrylhydrazone compounds, enamine compounds, butadiene compounds, distyryl compounds, oxazole compounds, oxadiazole compounds, thiazole compounds, imidazole compounds, triphenylamine derivatives, phenylenediamine derivatives, aminostilbene derivatives, triphenylmethane derivatives, etc. It is done. These may be used individually by 1 type and may use 2 or more types together.

-Binder resin-
The binder resin is electrically insulating, and known thermoplastic resins, thermosetting resins, photocurable resins, photoconductive resins, and the like can be used. The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-anhydrous maleic acid. Heat of acid copolymer, ethylene-vinyl acetate copolymer, polyvinyl butyral, polyvinyl acetal, polyester, phenoxy resin, (meth) acrylic resin, polystyrene, polycarbonate, polyarylate, polysulfone, polyethersulfone, ABS resin, etc. Examples include thermoplastic resins, phenol resins, epoxy resins, urethane resins, melamine resins, isocyanate resins, alkyd resins, silicone resins, thermosetting resins such as thermosetting acrylic resins, polyvinyl carbazole, polyvinyl anthracene, and polyvinyl pyrene. These may be used individually by 1 type and may use 2 or more types together.

<< undercoat layer >>
An undercoat layer may be provided between the photosensitive layer and the conductive support.
The undercoat layer may be a single layer or a plurality of layers. For example, (1) a resin-based component, (2) a white pigment and a resin-based component, and (3) a metal oxide film obtained by chemically or electrochemically oxidizing the surface of a conductive substrate. Is mentioned. Among these, those containing a white pigment and a resin as main components are preferable.

  There is no restriction | limiting in particular as said white pigment, According to the objective, it can select suitably, For example, metal oxides, such as a titanium oxide, aluminum oxide, a zirconium oxide, a zinc oxide, etc. are mentioned. These may be used alone or in combination of two or more. Among these, titanium oxide is particularly preferable in terms of excellent charge injection preventing properties from the conductive support.

  There is no restriction | limiting in particular as said resin, According to the objective, it can select suitably, For example, thermoplastic resins, such as polyamide, polyvinyl alcohol, casein, and methylcellulose, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as average thickness of the said undercoat layer, Although it can select suitably according to the objective, 0.1 micrometer-10 micrometers are preferable, and 1 micrometer-5 micrometers are more preferable.

<< outermost layer >>
The image carrier may be provided with an outermost surface layer on the photosensitive layer in order to improve mechanical strength, abrasion resistance, gas resistance, cleaning properties, and the like.
The outermost surface layer is not particularly limited and may be appropriately selected depending on the intended purpose. However, the outermost layer preferably contains an inorganic filler, and is a polymer compound having higher mechanical strength than the material of the photosensitive layer, A polymer compound in which an inorganic filler is dispersed is more preferable.

  The polymer compound is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably a thermoplastic resin, a thermosetting resin or the like, has high mechanical strength, and wear due to friction with the cleaning means. A thermosetting resin is more preferable in that it can be greatly reduced, and a thermosetting resin cross-linked by a cross-linking agent having a polyfunctional acryloyl group, carboxyl group, hydroxyl group, amino group or the like is particularly preferable.

  There is no restriction | limiting in particular as resin used for the said outermost surface layer, According to the objective, it can select suitably, For example, ABS resin, ACS resin, an olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, Phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, Examples thereof include polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin. These may be used alone or in combination of two or more.

  If the outermost surface layer has a small thickness, there is no problem even if it does not have the charge transport capability, but if the outermost surface layer without the charge transport capability is formed thick, the sensitivity of the image carrier decreases. Since it tends to cause a potential increase after exposure and a residual potential increase, the above-mentioned charge transport material may be contained in the outermost surface layer, or a polymer resin having charge transporting ability may be used as the outermost surface layer. preferable.

Since the mechanical strength of the photosensitive layer and the outermost surface layer generally differs greatly, when the outermost surface layer is worn away due to friction with the cleaning means, the photosensitive layer is worn away immediately. When providing a layer, it is important to have a sufficient thickness.
There is no restriction | limiting in particular in the average thickness of the said outermost surface layer, Although it can select suitably according to the objective, 0.1 micrometer-12 micrometers are preferable, 1 micrometer-10 micrometers are more preferable, and 2 micrometers-8 micrometers are especially preferable. When the average thickness is less than 0.1 μm, it is too thin and easily disappears due to friction with the cleaning blade, and wear of the photosensitive layer may proceed from the disappeared portion, and when it exceeds 12 μm. In addition, a decrease in sensitivity, an increase in potential after exposure, and an increase in residual potential are likely to occur. In particular, when a polymer having a charge transport capability is used, the cost of the polymer having a charge transport capability may increase.

  The outermost surface layer preferably has a charge transport capability. In order to give the outermost surface layer a charge transporting capability, there are a method in which a polymer used for the outermost surface layer and the aforementioned charge transporting material are mixed and a method in which a polymer having a charge transporting capability is used in the outermost surface layer. It is conceivable that the latter method is preferable because it can obtain an image carrier having high sensitivity and little increase in potential after exposure and little increase in residual potential.

  The outermost surface layer preferably contains a filler in order to increase the mechanical strength of the outermost surface layer. Examples of the filler include inorganic fillers and organic fillers. Among these, an inorganic filler is preferable. Examples of the inorganic filler include aluminum oxide (alumina), titanium oxide, tin oxide, potassium titanate, titanium nitride, zinc oxide, indium oxide, and antimony oxide. Examples of the organic filler include fluorine resins such as polytetrafluoroethylene, silicone resins, and the like.

<Protective layer forming means and protective layer forming step>
The protective layer forming means includes at least a protective agent supply member and an image carrier protective agent that are rotatably abutted on the surface of the image carrier, and further includes other members as necessary.
The protective layer forming step is not particularly limited as long as it is a step for forming a protective layer by applying an image carrier protective agent to the surface of the image carrier using a protective agent supply member, and is appropriately selected depending on the purpose. For example, it can be performed by the protective layer forming means.

<< Protective agent supply member >>
The protective agent supply member includes at least a core material and a foam layer formed on the outer periphery of the core material and having a plurality of bubbles, and further includes other portions as necessary.
The protective agent supply member is means for scraping off the protective agent and supplying the protective agent to the surface of the image carrier.
There is no restriction | limiting in particular as a shape of the said protective agent supply member, Although it can select suitably according to the objective, It is preferable that it is a roller form.

−Core material−
There is no restriction | limiting in particular as a material of the said core material, a shape, a magnitude | size, and a structure, According to the objective, it can select suitably.
Examples of the material of the core material include resins such as epoxy resins and phenol resins; metals such as iron, aluminum, and stainless steel.
Examples of the shape of the core material include a columnar shape and a cylindrical shape.

-Foam layer-
The foam layer is a layer formed on the outer periphery of the core material, and has a plurality of bubbles (sometimes referred to as “cell”, “hole”, “void”, etc.).
There is no restriction | limiting in particular as a shape of the said foam layer, According to the objective, it can select suitably, For example, cylindrical shape etc. are mentioned.

-Foam polyurethane-
There is no restriction | limiting in particular as a material of the said foam layer, According to the objective, it can select suitably, For example, foaming polyurethane etc. are mentioned.
There is no restriction | limiting in particular as said foaming polyurethane, According to the objective, it can select suitably, For example, a polyol, polyisocyanate, a catalyst, and a foaming agent are mixed at least, and also if necessary, foam control Examples thereof include foamed polyurethane obtained by mixing and reacting other components such as an agent.

--- Polyol ---
There is no restriction | limiting in particular as said polyol, According to the objective, it can select suitably from conventionally well-known various polyols, For example, polyether polyol, polyester polyol, etc. are mentioned. Among these, polyether polyol is particularly preferable from the viewpoint of easy adjustment of processability and foam layer hardness.

As the polyether polyol, for example, at least one of a low molecular polyol and a low molecular polyamine having 2 to 8 active hydrogen groups is used as an initiator, and at least one of ethylene oxide and propylene oxide is opened. Examples include polyether polyols obtained by addition polymerization.
Examples of the polyether polyol include polyether polyether polyols, polyester polyether polyols, and polymer polyether polyols that are generally used in the production of flexible polyurethane foams.
The polyether polyol is preferably a polyether polyether polyol in which ethylene oxide is bonded to the terminal at 5 mol% or more from the viewpoint of moldability.

Examples of the polyester polyol include dibasic acids such as adipic acid, phthalic anhydride, isophthalic acid, terephthalic acid, and maleic anhydride, and anhydrides thereof, such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, Examples thereof include polyester polyols obtained by polymerizing glycols and triols such as propylene glycol, 1,4-butanediol, glycerin, and trimethylolpropane.
Further, as the polyester polyol, those obtained by depolymerizing a waste material of polyethylene terephthalate resin with the above-mentioned glycol can also be used.
The said polyol may be used individually by 1 type, and may use 2 or more types together.

--- Polyisocyanate ---
There is no restriction | limiting in particular as said polyisocyanate, According to the objective, it can select suitably from conventionally well-known various polyisocyanate, For example, 2, 4- tolylene diisocyanate (2, 4-TDI), 2 , 6-tolylene diisocyanate (2,6-TDI), tolidine diisocyanate (TODI), naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI), 4,4'-diphenylmethane diisocyanate (MDI), carbodiimide-modified MDI, poly Examples include methylene polyphenyl polyisocyanate and polymeric polyisocyanate. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as content of the said polyisocyanate, Although it can select suitably according to the objective, As an equivalent ratio (NCO / OH) of the isocyanate group of the said polyisocyanate with respect to the hydroxyl group of the said polyol, it is 1.0. A range of ˜3.0 is preferred.

---- Catalyst ---
The catalyst is not particularly limited and can be appropriately selected according to the purpose from catalysts used for conventionally known urethanization reactions. Examples include amine-based catalysts and organometallic catalysts. It is done.
Examples of the amine catalyst include triethylenediamine, dimethylethanolamine, bis (dimethylamino) ethyl ether, and the like.
Examples of the organometallic catalyst include dioctyltin, distearyltin dibutyrate, and the like.
The catalyst may be a reactive catalyst such as dimethylaminoethanol having active hydrogen. These may be used individually by 1 type and may use 2 or more types together.

There is no restriction | limiting in particular in content of the said catalyst, Although it can select suitably according to the objective, 0.01 mass part-20 mass parts are preferable with respect to 100 mass parts of said polyols.
By appropriately selecting the type of the catalyst and controlling its content, the cell wall width, open cell diameter, hardness, air flow rate, etc. of the foam layer can be adjusted.

---- Foaming agent ---
There is no restriction | limiting in particular as said foaming agent, According to the objective, it can select suitably, For example, water, a fluorocarbon compound, a low boiling point hydrocarbon type compound, etc. are mentioned. These may be used alone or in combination of two or more.
Examples of the fluorocarbon compounds include HCFC-141b, HFC-134a, HFC-245fa, HFC-365mfc, and the like.
Examples of the low-boiling hydrocarbon compound include cyclopentane, n-pentane, iso-pentane, and n-butane.
The content of the foaming agent is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 parts by mass to 50 parts by mass with respect to 100 parts by mass of the polyol.
By appropriately selecting the type of the foaming agent and controlling the amount of the foaming agent used, the cell wall width, open cell diameter, hardness, air flow rate, etc. of the foam layer can be adjusted.

--- Other ingredients ---
The other components are not particularly limited and may be appropriately selected depending on the purpose. For example, foam stabilizers, crosslinking agents, foam breakers, conductive agents, antistatic agents, flame retardants, viscosity reducers, Examples include pigments, stabilizers, colorants, anti-aging agents, ultraviolet absorbers, and antioxidants. These may be used alone or in combination of two or more.

There is no restriction | limiting in particular as said foam stabilizer, According to the objective, it can select suitably, For example, silicone type surfactant etc. are mentioned.
Commercially available products can be used as the silicone surfactant, and specific examples of the commercially available products include dimethylsiloxane foam stabilizers (for example, “SRX-253” manufactured by Toledo Corning Silicone, Shin-Etsu Chemical Co., Ltd.). "F-122" manufactured by Kogyo Co., Ltd.), polyether-modified dimethylsiloxane-based foam stabilizer (for example, "L-5309", "SZ-1311" manufactured by Nippon Unicar Co., Ltd.), and the like. These may be used alone or in combination of two or more.
The content of the foam stabilizer is not particularly limited and may be appropriately selected depending on the intended purpose. It is preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the polyol.

The said crosslinking agent and the said foam breaker are mix | blended in order to control the closed-cell property of the bubble of the said foam layer, and open-cell property.
There is no restriction | limiting in particular as said crosslinking agent, According to the objective, it can select suitably, For example, a triethanolamine, a diethanolamine, etc. are mentioned.
There is no restriction | limiting in particular as said foam breaker, According to the objective, it can select suitably, For example, the thing with high foam breakability is mentioned in the said foam stabilizer.
There is no restriction | limiting in particular as content of the said crosslinking agent and a foam breaker, According to the objective, it can select suitably.

  Usually, components other than the polyisocyanate are mixed in advance and mixed with the polyisocyanate component immediately before molding.

  A commercially available product can be used as the polyurethane foam. Examples of the commercial products include QM60 (manufactured by Bridgestone Chemicals), QZK70 (manufactured by Bridgestone Chemicals), SPG (manufactured by Bridgestone Chemicals), EP70 (manufactured by Inoac Corporation), and the like. It is done.

  There is no restriction | limiting in particular as a structure of the said foam layer, According to the objective, it can select suitably, For example, a closed cell type, an open cell type, or these mixed types etc. are mentioned.

Here, FIG. 1A is a schematic cross-sectional view showing an example of the open cell foam layer. The open-cell foam layer is a foam layer having a structure in which air and water are allowed to pass through since adjacent bubbles are connected to each other. FIG. 1B is a schematic cross-sectional view showing an example of the closed cell foam layer. The closed cell foam layer is a foam layer having a structure in which bubbles are independent and air and water are not allowed to pass through.
Among these, the open-cell type is preferable in that it has a small compressive residual strain and is easy to return to its original shape even when compressed, and therefore hardly deforms even in long-term use. Further, the open cell type is less costly than the closed cell type, and it is advantageous in terms of cost, and the amount of protective agent supplied (protective agent block shaving amount) is small. Since the image carrier can be sufficiently protected without unevenness, filming of the image carrier can be prevented, a smaller protective agent block can be obtained, and the apparatus can be downsized.

There is no restriction | limiting in particular as an average bubble diameter of the said foam layer, Although it can select suitably according to the objective, 100 micrometers-1,200 micrometers are preferable.
The average cell diameter of the foam layer can be measured, for example, with a laser microscope (VK9500, manufactured by Keyence Corporation).

  The number of bubbles per inch (25.4 mm) of the foam layer is not particularly limited and may be appropriately selected depending on the intended purpose, but may be 20 / inch (25.4 mm) to 300 / Inch (25.4 mm) is preferable, and 40 / inch (25.4 mm) to 100 / inch (25.4 mm) is more preferable. If the number of bubbles is less than 20 / inch (25.4 mm), the image carrier protective agent cannot be applied efficiently even if the linear velocity difference between the image carrier and the protective agent supply member is increased. When the number exceeds 300 / inch (25.4 mm), the hardness of the foam layer may increase. When the linear velocity difference between the image carrier and the protective agent supply member is provided, the drive torque may increase if the hardness is large.

  Here, a method for measuring the number of bubbles per inch (25.4 mm) of the foam layer will be described with reference to FIGS. 2A and 2B. FIG. 2A is a side view showing an example of the protective agent supply member 32 having the foam layer 10 on the outer periphery of the core material 9. FIG. 2B is an enlarged schematic diagram illustrating an example of an exposed surface of the continuous foam type foam layer 10 in which a plurality of adjacent bubbles 11 are connected to each other. In the present specification, 1 inch means 25.4 mm.

  As shown in FIG. 2A, on the surface of the foam layer 10, three measurement points are arbitrarily selected at the axial end portions and the central portion of the protective agent supply member 32. Here, in FIG. 2A, reference numeral 30 indicates an end measurement part, and reference numeral 31 indicates a central measurement part. Next, at each measurement point 30, 31, two more points are selected in the circumferential direction of the protective agent supply member 32 (not shown), and a total of nine measurement points are determined. Next, using a microscope (for example, digital microscope VHX-100, manufactured by Keyence Corporation), a photographic screen of each measurement location is observed.

Then, as shown in FIG. 2B, a line X having a length corresponding to an actual size of 1 inch (25.4 mm) is drawn at the center of the photographic screen, and the number of bubbles 11 existing on the line X is counted and measured. The average value of 9 points is obtained, and this is defined as the number of bubbles (number / inch (25.4 mm)).
Here, the bubble 11 existing on the line X is not only when the line X penetrates the inside of the bubble 11 but also when the line X and a part of the outer periphery of the bubble 11 are slight. It includes everything in contact and counts this as one bubble.
For example, the number of bubbles in the case of FIG. 2B is 12 / inch (25.4 mm).

  Note that 1 inch (25.4 mm) when measuring the number of bubbles is a relationship calculated from a plane photograph in the measurement method, and as shown in measurement points 30 and 31 in FIG. Although it is 1 inch, as shown in the manufacturing method of the protective agent supply member described later, the protective agent supply member is usually a part of a foam produced in advance and wound around the core material. The number of bubbles per inch (25.4 mm) in the axial direction of the protective agent supply member and the number of bubbles per inch (25.4 mm) in the circumferential direction of the protective agent supply member are substantially equal to each other. Is the same.

There is no restriction | limiting in particular as average thickness of the said foam layer, Although it can select suitably according to the objective, 1 mm-4 mm are preferable. When the average thickness is less than 1 mm, the influence of the shaft (core material) is easily picked up, and when it exceeds 4 mm, the amount of the protective agent scraped may be reduced.
When the foam layer is cylindrical, the thickness is defined as the distance between the cylindrical inner peripheral surface and the outer peripheral surface. Here, the average thickness is an average value when the thickness of the foam layer is arbitrarily measured at three points.

There is no restriction | limiting in particular as hardness of the said foam layer, Although it can select suitably according to the objective, 40N-430N are preferable and 40N-300N are more preferable. If the hardness is less than 40N, it may be difficult to suppress contamination of the image carrier, and if it exceeds 430N, it may be difficult to suppress contamination of the image carrier. When the hardness is in the more preferable range, it is advantageous in that the suppression of contamination of the image carrier is more excellent.
The hardness is an average value of values measured based on JIS K 6400 at arbitrary three points on the surface of the foam layer.

  In the foam layer, the form of the bubbles (open-cell type or closed-cell type), the number of the bubbles, the hardness of the foam layer, and the like are the types of the polyurethane foam raw material when producing the foam layer, It can be controlled by appropriately adjusting the amount of the foaming agent, reaction conditions, and the like.

-Manufacturing method of protective agent supply member-
There is no restriction | limiting in particular as a manufacturing method of the said protective agent supply member, According to the objective, it can select suitably.
As an example of the method for producing the protective agent supply member, a production example in which the foamed polyurethane is used as the material of the foam layer will be described.
First, a foamed polyurethane raw material is foam-cured by a known method to form a block-shaped foamed polyurethane. Then, after cutting into a required shape, polishing the surface, processing into a cylindrical shape having bubbles opened on the surface, the core material is inserted into the cylindrical shape. Thereafter, a polishing blade or the like is applied while rotating the polyurethane foam using a polishing machine and a cutting machine, and the blade is moved parallel to the axial direction of the protective agent supply member to cut to a predetermined thickness (traverse grinding). Thereby, the cylindrical protective agent supply member which has the bubble opened on the surface is obtained. Furthermore, irregular unevenness | corrugation can also be formed in the foam layer surface by changing the rotational speed of the protective agent supply member, or the moving speed.
An adhesive may be applied to the core material in order to improve the adhesiveness with the foam layer. By these steps, the protective agent supply member is manufactured.

Moreover, another example of the manufacturing method of the said protective agent supply member is also demonstrated.
A foamed polyurethane raw material is injected into a mold for molding the protective agent supply member containing the core material, and foamed and cured. Thus, the protective agent supply member is manufactured.

Among these production methods, the method using a mold is preferable because the formation of the foam layer and the opening of the foam layer can be simultaneously performed and the processing accuracy is good.
The manufacturing method using the mold does not require complicated processing, and the foam layer having a suitable opening property can be formed. Therefore, the inner surface of the mold is separated by a fluororesin coating agent, a release agent, or the like. It is preferable to provide a mold layer.

<< Image carrier protecting agent >>
The image carrier protecting agent contains at least a fatty acid metal salt and an inorganic lubricant, and further contains other components as necessary.

-Fatty acid metal salt-
The fatty acid metal salt is not particularly limited and may be appropriately selected depending on the intended purpose.For example, lauric acid metal salt, stearic acid metal salt, oleic acid metal salt, palmitic acid metal salt, caprylic acid metal salt, Examples include linolenic acid metal salts and ricinoleic acid metal salts. These may be used alone or in combination of two or more.

  Examples of the lauric acid metal salt include barium laurate, lead laurate, iron laurate, nickel laurate, cobalt laurate, copper laurate, strontium laurate, calcium laurate, cadmium laurate, magnesium laurate, and laurin. And zinc acid.

  Examples of the metal stearate include, for example, barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, magnesium stearate, stearin And zinc acid.

  Examples of the metal oleate include zinc oleate, magnesium oleate, iron oleate, cobalt oleate, copper oleate, lead oleate, manganese oleate, and the like.

  Examples of the metal palmitate include zinc palmitate, cobalt palmitate, lead palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate, and the like.

  Examples of the caprylic acid metal salt include lead caprylate.

  Examples of the linolenic acid metal salt include zinc linolenate, cobalt linolenate, and calcium linolenate.

  Examples of the ricinoleic acid metal salt include zinc ricinoleate and cadmium ricinoleate.

  Among these, as the fatty acid metal salt, the substance having a lamellar crystal has a layered structure in which amphiphilic molecules are self-organized, and when shearing force is applied, the crystal breaks along the interlayer and is slippery. A metal stearate salt is preferable in that it is excellent in lubricity, covers the surface of the image carrier relatively evenly, protects well from electrical stress in the charging process, and is excellent in suppressing contamination of the image carrier, and stearic acid metal salt. Zinc acid is more preferred.

  There is no restriction | limiting in particular as content of the said fatty-acid metal salt in the said image carrier protective agent, Although it can select suitably according to the objective, 50 mass%-95 mass% are preferable, 70 mass%-90 mass. % Is more preferable.

-Inorganic lubricant-
The inorganic lubricant is not particularly limited and may be appropriately selected depending on the intended purpose.For example, mica, boron nitride, molybdenum disulfide, tungsten disulfide, talc, kaolin, montmorillonite, calcium fluoride, graphite, Etc. These may be used alone or in combination of two or more. Among these, as the inorganic lubricant, boron nitride, mica, and talc are preferable, and boron nitride is more preferable because it is excellent in suppressing contamination of the charging means.

  There is no restriction | limiting in particular as content of the said inorganic lubricant in the said image carrier protection agent, According to the objective, it can select suitably.

  The mass ratio of the fatty acid metal salt to the inorganic lubricant (fatty acid metal salt: inorganic lubricant) in the image carrier protecting agent is not particularly limited and may be appropriately selected depending on the intended purpose. : 0-50: 50 is preferable, and 90: 10-60: 40 is more preferable. If the fatty acid metal salt is less than 50:50 in the mass ratio, it may be difficult to form a protective layer on the image carrier. When the mass ratio is in the more preferable range, it is advantageous in that it is excellent in suppressing the contamination of the image carrier and the contamination of the charging means.

  There is no restriction | limiting in particular as a magnitude | size and a shape of the said image carrier protection agent, According to the objective, it can select suitably. Examples of the shape include a square columnar shape and a bar shape such as a cylindrical shape. Among these, the shape of the image carrier protecting agent is preferably a quadrangular prism.

-Molding method-
There is no restriction | limiting in particular as a shaping | molding method of the said image carrier protective agent, According to the objective, it can select suitably, For example, a melt molding method, a compression molding method, etc. are mentioned. In general, the image carrier protective agent formed by the melt molding method is translucent, and the image carrier protective agent formed by the compression molding method is white. Is possible.
Among these, the compression molding method is preferable as the molding method of the image carrier protecting agent.

  An example of the compression molding method will be described with reference to the drawings. FIG. 3A is a perspective view showing an example of a process for forming a protective agent block by compression molding using an image carrier protective agent manufacturing apparatus. 3B is a schematic cross-sectional view of the manufacturing apparatus shown in FIG. 3A. FIG. 3D is a schematic cross-sectional view illustrating an example of a protective agent block fixed to a holder.

  As shown in FIGS. 3A and 3B, the image carrier protecting agent manufacturing apparatus 60 forms a lower mold 61 and a side surface that is arranged so as to sandwich the lower mold 61 and extends in the longitudinal direction of the protecting agent block. It has a pair of horizontal molds 62, a pair of end molds 63 which are arranged so as to sandwich the lower mold 61 and the horizontal mold 62 and form an end surface in the longitudinal direction of the protective agent block, and an upper mold 64.

  In FIG. 3A, one end mold 63 is shown in a disassembled state, but actually, it occupies a position facing the other end mold 63, and at the time of compression molding of the image carrier protecting agent described below. The end mold 63, the lower mold 61, and the horizontal mold 62 form a sealed space except for the space into which the upper mold 64 enters. 3A and 3B, when the upper mold 64 moves and enters the sealed space, a completely sealed space is formed by the lower mold 61, the horizontal mold 62, the end mold 63, and the upper mold 64. Is done.

  With the upper mold 64 removed, the formed space is filled with powder G that is a raw material of the image carrier protecting agent. The powder G may be granular, granular, or a mixture thereof.

When the introduction of the powder G is completed, the upper die 64 is made to enter the sealed space in the direction of arrow Y, and pressing is performed while forming a complete sealed space, thereby forming a block of protective agent.
Through the above steps, a quadrangular columnar protective agent block as shown in FIG. 3C is manufactured by compression molding. The protective agent block manufactured in this way is fixed to the holder as shown in FIG. 3D, and is attached to the image forming apparatus.

  The size of the square columnar protective agent block is not particularly limited and can be appropriately selected according to the width of the recording medium output from the image forming apparatus.

<< Other parts >>
There is no restriction | limiting in particular as said other member in the said protective layer formation means, According to the objective, it can select suitably, For example, a pressing force provision member, a protective layer formation member, etc. are mentioned.

-Pressure applying member-
The pressing force applying member is not particularly limited as long as it is a member that presses the protective agent and causes the protective agent to contact the protective agent supply member, and can be appropriately selected according to the purpose. , Pressure springs, and the like.

  The pressing force applying member is preferably a member that can uniformly press the protective agent. Examples of the pressing force applying member include a pressing mechanism described in Japanese Patent Application Laid-Open No. 2007-293240.

-Protective layer forming member-
The protective layer forming member is not particularly limited as long as it can form a protective layer by thinning the protective agent supplied to the surface of the image carrier, and is appropriately selected depending on the purpose. For example, a blade can be used.

There is no restriction | limiting in particular as a material of the said blade, According to the objective, it can select suitably, For example, urethane rubber, hydrin rubber, silicone rubber, fluororubber, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
The blade may be coated or impregnated with a low friction coefficient material at the contact point with the image carrier. Further, in order to adjust the hardness of the blade, a filler such as an organic filler or an inorganic filler may be dispersed.

The blade is fixed to the blade support by any method such as adhesion or fusion so that the tip can be pressed against the surface of the image carrier. There is no restriction | limiting in particular in the average thickness of the said braid | blade, Although it cannot define uniquely by balance with the force added by press, 0.5 mm-5 mm are preferable and 1 mm-3 mm are more preferable.
Also, the length of the blade that protrudes from the blade support and can be deflected, that is, the so-called free length is not uniquely defined in consideration of the force applied by pressing in the same manner. Preferably, 2 mm to 10 mm is more preferable.

  As another configuration of the protective layer forming member, a coating layer of resin, rubber, elastomer or the like is coated or dipped on the surface of an elastic metal blade such as a spring plate via a coupling agent or a primer component as necessary. For example, the film may be formed by a method such as heat curing if necessary, and surface polishing if necessary.

The coating layer contains at least a binder resin and a filler, and further contains other components as necessary.
The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, perfluoroalkoxyalkane (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), fluororesin such as polyvinylidene chloride (PVdF); fluoroelastomer, silicone elastomer such as methylphenyl silicone elastomer, and the like.

  There is no restriction | limiting in particular as average thickness of the said elastic metal braid | blade, Although it can select suitably according to the objective, 0.05 mm-3 mm are preferable and 0.1 mm-1 mm are more preferable. The elastic metal blade may be subjected to a process such as a bending process in a direction substantially parallel to the support shaft after installation in order to suppress twisting of the blade.

  The force that presses the image carrier with the protective layer forming member is sufficient as the force that the protective agent for the image carrier spreads to form a protective layer, and is not particularly limited, and can be appropriately selected according to the purpose. However, the linear pressure is preferably 5 gf / cm to 80 gf / cm, and more preferably 10 gf / cm to 60 gf / cm.

  The protective layer forming member may also serve as a cleaning unit. However, in order to more reliably form the protective layer, the residual material mainly composed of the toner on the image carrier is previously removed by the cleaning unit, and the residual material is formed. It is preferable not to mix in the protective layer.

The protective layer forming means will be described with reference to the drawings. FIG. 4 is a schematic sectional view showing an example of the protective layer forming means.
The protective layer forming means 2 disposed facing the image carrier 1 includes a protective agent block 21, a protective agent supply member 22 having a foamed elastic layer, a pressing force applying member 20, and a protective layer fixed to the support 42. A forming member 41 is provided.

The protective agent block 21 contacts the roller-shaped protective agent supply member 22 by the pressing force of the pressing force applying member 20. The protective agent supply member 22 is preferably rotated and rubbed with the image carrier 1 with a linear velocity difference, whereby the protective agent held on the surface of the protective agent supply member 22 is supplied to the surface of the image carrier 1.
Since the protective agent supplied to the surface of the image carrier 1 may not be a sufficient protective layer at the time of supply depending on the selection of the material type, for example, a blade-like member is used to form a more uniform protective layer. The protective layer forming member 41 is thinned to form a protective layer.

  The image carrier 1 on which the protective layer is formed has, for example, a charging roller (charging means) 3 to which a DC voltage or a voltage obtained by superimposing an AC voltage is applied by a high-voltage power source (not shown) in contact with or close to the image carrier 1. The image carrier is charged by discharge in a minute gap. At this time, a part of the protective layer is decomposed or oxidized due to electrical stress, and air discharge products adhere to the surface of the protective layer.

  The deteriorated image carrier protective agent is removed together with components such as toner remaining on the image carrier by a normal cleaning means. The cleaning means may be used also as the protective layer forming member 41, but the function of removing the residue on the surface of the image carrier and the function of forming the protective layer differ in the rubbing state of an appropriate member. Therefore, it is preferable to separate the functions in order to form the protective layer more reliably. As such an embodiment, as shown in FIG. 4, the cleaning means 4 including the cleaning member 43, the cleaning pressing member 44, and the like is provided upstream of the protective agent supply member 22 with respect to the rotation direction of the image carrier 1. It is preferable to remove the residue such as toner on the surface of the image carrier 1 with the cleaning member 43 in advance so that the residue does not enter the protective layer.

<Developing means and development process>
The developing means is a means having a toner containing portion for containing the toner T1 and developing the electrostatic latent image formed on the image carrier using the toner T1 to form a visible image. .
The developing unit is not particularly limited as long as it can be developed using the toner, and can be appropriately selected according to the purpose. For example, the developing unit includes the toner container, and the electrostatic latent image includes the toner. Examples include those having at least a developing device capable of applying toner in a contact or non-contact manner.
The development step is not particularly limited as long as the electrostatic latent image formed on the image carrier is developed using the toner T1 accommodated in the toner accommodating portion to form a visible image. Depending on the purpose, it can be selected as appropriate. For example, the developing means can be used.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner or a developer having a stirrer for charging the toner or developer by frictional stirring and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the image carrier, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted to the image carrier. Move to the surface. As a result, the electrostatic latent image is developed with the toner to form a visible image with the toner on the surface of the image carrier.

  The toner and the replenishing toner that can be used in the present invention are not particularly limited and may be appropriately selected depending on the purpose.

<< Toner container >>
The toner storage unit stores the toner T1.

  The amount of the toner T1 contained in the toner container in the initial use of the image forming apparatus and the initial stage of image formation by the image forming method is not particularly limited and can be appropriately selected according to the purpose. 10 g to 200 g is preferable. In the case of a developing method using a one-component developer, the amount of the toner is preferably 50 g to 200 g, and in the case of a developing method using a two-component developer, 10 g to 200 g is preferable. Here, the initial use and the initial represent a state in which each member (for example, an image carrier) used in the image forming apparatus and the image forming method is unused or hardly used.

<Toner storage member>
The toner storage member is not particularly limited as long as it is a member that stores the toner T2 to be replenished in the toner storage portion, and can be appropriately selected according to the purpose. Examples thereof include a toner bottle. It is done.

  In the image forming method, the toner T2 is supplied from the toner containing member to the toner containing portion.

  The toner storage member stores the toner T2.

  The amount of the toner T2 contained in the toner containing member in the initial use of the image forming apparatus and in the initial stage of image formation by the image forming method is not particularly limited and may be appropriately selected depending on the purpose. 100g to 2,000g is preferable, 100g to 1,000g is more preferable, and 300g to 800g is particularly preferable. If the amount is less than 100 g, a sufficient amount of toner may not be retained in the foam layer of the protective agent supply member, and if it exceeds 2,000 g, the charging means may be soiled. There is. When the amount is within the particularly preferable range, it is advantageous in that all the effects of the present invention can be sufficiently obtained without side effects.

Here, the developing unit and the toner containing member will be described with reference to the drawings.
FIG. 5 is a schematic sectional view of an example of the developing means 5 used in the present invention.
6 and 7 are schematic perspective views of an example of the developing unit 5, and are schematic perspective views of the developing unit 5 viewed from obliquely above in different directions.
The developing casing 51 that forms the outer shape of the developing means 5 is formed by combining an upper case 511, an intermediate case 512, and a lower case 513. The middle case 512 forms a toner container 53, and the upper case 511 has a toner supply port 155 that communicates the toner container 53 with the outside. The upper case 511 is provided with an inlet seal 57 that seals the gap between the developing roller 52 and the upper case 511.

The middle case 512 is provided with a developing roller 52, a supply roller 54, a doctor blade 55, a paddle 56, a supply screw 58, and the like.
The developing means 5 is provided with an opening that communicates the inside and the outside along the longitudinal direction (Y-axis direction in the figure). A cylindrical developing roller 52 that carries and transports toner from the inside to the outside (development area α facing the image carrier) is provided in the opening.

In the developing means 5, the supply roller 54 rotates in the direction of arrow C in FIG. 5 (clockwise direction in FIG. 5) and moves on the surface, so that the toner T in the toner storage portion 53 faces the developing roller 52. Then, the toner is supplied to the surface of the developing roller 52. The developing roller 52 carries the supplied toner on the surface, rotates in the direction of arrow B in FIG. 5 (clockwise direction in FIG. 5), and moves on the surface, thereby removing the toner on the developing roller 52. The toner is conveyed to a portion facing the doctor blade 55 that is regulated to a predetermined amount. The doctor blade 55 is opposed to the developing roller 52 and is in a counter direction with respect to the surface movement direction of the developing roller 52 (the distal end of the doctor blade 55 is upstream of the rotation direction of the developing roller 52 from the base of the doctor blade 55). The toner that is in contact with the doctor blade 55 and restricted to a predetermined amount at the portion facing the doctor blade 55 reaches the developing area α that is the portion facing the image carrier 1 by the rotation of the developing roller 52.
At this time, the fatty acid metal salt stored together with the toner in the toner storage portion 53 also reaches the development region α.

  FIG. 8 shows an example of the toner containing member. A toner storage member 500 shown in FIG. 8 is made of plastic and has a helical groove 501 on the outer peripheral portion and a cylindrical toner container body 503 having a toner supply port 502 at one end thereof, and is fitted to the toner supply port 502. And an inner cap 504. During transport or storage before the toner container 500 is mounted on the developing means of the image forming apparatus, the outer cap 505 is screwed around the outer periphery of the toner supply port 502 with the inner cap 504 fitted into the toner supply port 502. The inner cap 504 is removed and the toner stored in the toner container main body 503 is prevented from spilling outside. When the toner containing member 500 is attached to the developing means of the image forming apparatus, the outer cap 505 is removed from the toner container main body 503, and the toner container main body 503 is fixed to a predetermined state with the inner cap 504 fitted into the toner supply port 502. Attach to the mounting position. When the toner container main body 503 is mounted, the inner cap 504 is automatically removed from the toner supply port 502 by the inner cap removing mechanism of the image forming apparatus. By rotating the toner container main body 503 in this state, the toner stored in the toner container main body 503 is supplied from the toner supply port 502 to the developing means. By doing so, the toner container main body 503 is not provided with an agitator for stirring and conveying, and the toner in the toner container main body 503 is stirred and prevented from aggregating and supplied to the developing means.

  The toner containing member 500 is connected to the toner supply port 155. Then, the toner and the fatty acid metal salt stored in the toner storage member 500 are supplied to the toner storage unit 53 via the toner supply port 155.

<Other means and other processes>
The other means in the image forming apparatus is not particularly limited and may be appropriately selected according to the purpose. For example, the electrostatic latent image forming means, the transfer means, the fixing means, the charge eliminating means, the cleaning means, and the recycling Means, control means, and the like.
The other steps in the image forming method are not particularly limited and may be appropriately selected depending on the purpose. For example, the electrostatic latent image forming step, the transfer step, the fixing step, the static elimination step, the cleaning step, and the recycling Process, control process, and the like.

<< Electrostatic latent image forming means and electrostatic latent image forming process >>
The electrostatic latent image forming means is not particularly limited as long as it is a means for forming an electrostatic latent image on the image carrier, and can be appropriately selected according to the purpose. For example, the image carrier A means for charging the surface of the image bearing member and an exposure device for exposing the surface of the image carrier imagewise.
The electrostatic latent image forming step is not particularly limited as long as it is a step of forming an electrostatic latent image on the image carrier, and can be appropriately selected according to the purpose. This can be done using image forming means.

The charging can be performed, for example, by applying a voltage to the surface of the image carrier using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charger including a conductive or semiconductive roll, brush, film, rubber blade, or the like. And non-contact chargers utilizing corona discharge such as corotron and scorotron.
The charger preferably has voltage applying means for applying a voltage having an AC component.

The exposure can be performed, for example, by exposing the surface of the image carrier imagewise using the exposure device.
The exposure device is not particularly limited as long as it can be exposed like an image to be formed on the surface of the image carrier charged by the charger, and can be appropriately selected according to the purpose. Examples thereof include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.
In the present invention, an optical back side system in which imagewise exposure is performed from the back side of the image carrier may be adopted.

<< Transfer means and transfer process >>
The transfer means is means for transferring the visible image to a recording medium. The transfer means includes a primary transfer means for transferring the visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. The aspect which has is preferable.
The transfer step is not particularly limited as long as it is a step of transferring the visible image to a recording medium, and can be appropriately selected according to the purpose. For example, the transfer step can be performed using the transfer unit.

The transfer unit (the primary transfer unit and the secondary transfer unit) includes at least a transfer unit that peels and charges the visible image formed on the image carrier to the recording medium side. preferable. There may be one transfer means or two or more transfer means. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

  The image carrier is used to perform image transfer by a so-called intermediate transfer method in which a toner image formed on the image carrier is primarily transferred to perform color superposition and then transferred to a recording medium. It may be a body.

  There is no restriction | limiting in particular as said intermediate transfer body, According to the objective, it can select suitably from well-known transfer bodies, For example, a transfer belt etc. are mentioned suitably.

The intermediate transfer member is not particularly limited and may be appropriately selected depending on the intended purpose. However, it has a volume resistance value of 1.0 × 10 ⁵ Ω · cm to 1.0 × 10 ¹¹ Ω · cm. Is preferable. When the volume resistance value is less than 1.0 × 10 ⁵ Ω · cm, there is so-called transfer dust in which the toner image is disturbed due to discharge when the toner image is transferred from the image carrier onto the intermediate transfer member. If it exceeds 1.0 × 10 ¹¹ Ω · cm, the counter charge of the toner image remains on the intermediate transfer member after the toner image is transferred from the intermediate transfer member to a recording medium such as paper. May appear as an afterimage on other images.

As the intermediate transfer member, for example, metal oxides such as tin oxide and indium oxide, conductive particles such as carbon black, and conductive polymers may be used alone or in combination with a thermoplastic resin, and then extruded. A belt-like or cylindrical plastic can be used. In addition, it is also possible to add conductive particles or conductive polymer to a resin solution containing a thermal crosslinking reactive monomer or oligomer, if necessary, and perform centrifugal molding while heating to obtain an intermediate transfer member on an endless belt. it can.
When providing a surface layer on the intermediate transfer member, the resistance is adjusted by appropriately using a conductive material in combination with the composition excluding the charge transport material among the surface layer materials used for the outermost surface layer. be able to.

<< Fixing means and fixing process >>
The fixing means is means for fixing the visible image transferred to the recording medium. It may be performed each time the toner of each color is transferred to the recording medium, or may be performed at the same time in a state where the toner of each color is laminated.
The fixing unit is not particularly limited and may be appropriately selected depending on the intended purpose, but a known heating and pressing unit is preferable. Examples of the heating and pressing unit include a combination of a heating roller and a pressure roller, and a combination of a heating roller, a pressure roller, and an endless belt.
There is no restriction | limiting in particular in the heating in the said heating-pressing means, Although it can select suitably according to the objective, 80 to 200 degreeC is preferable.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing unit depending on the purpose.
The fixing step is a step of fixing the visible image transferred to the recording medium using the fixing unit, and may be performed each time the toner of each color is transferred to the recording medium, or may be applied to the toner of each color. On the other hand, it may be carried out simultaneously at the same time in a state of being laminated.

<< Static elimination means and static elimination process >>
The neutralization unit is not particularly limited, and may be any appropriate neutralization unit as long as it can apply a neutralization bias to the image carrier. Examples thereof include a neutralization lamp.
The neutralization step is a step of performing neutralization by applying a neutralization bias to the image carrier, and can be suitably performed by the neutralization unit.

<< Cleaning means and cleaning process >>
The cleaning means is not particularly limited as long as it is a means for removing toner remaining on the image carrier, and can be appropriately selected according to the purpose. For example, a magnetic brush cleaner, an electrostatic brush cleaner, Examples thereof include a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.
It is preferable that the cleaning unit is provided downstream of the transfer unit and upstream of the protective layer forming unit.
The cleaning step is a step of removing toner remaining on the image carrier, and can be suitably performed by the cleaning unit.

<< Recycling means and recycling process >>
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.
The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.

<< Control means and control process >>
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.
The control step is a step of controlling each step, and can be suitably performed by the control means.

<Replacement toner storage member>
The replacement toner storage member is not particularly limited as long as it is a member that stores the replenishment toner T3, and can be appropriately selected according to the purpose. Examples thereof include replacement toner bottles.
It is preferable that the toner containing member and the replacement toner containing member have the same shape.

  The amount of the replenishing toner T3 contained in the replacement toner containing member is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 100 g to 2,000 g.

<Toner fine powder content>
The fine powder content (number%) F1, F2, and F3 having a particle diameter of 3 μm or less contained in each of the toners T1, T2, and T3 will be described.
A Coulter Counter TA-II (manufactured by Beckman Coulter, Inc.) can be used for measuring the fine powder content in the toner in the present invention.
The electrolytic solution is adjusted to a 1% by mass NaCl aqueous solution using primary sodium chloride.
As a measuring method, 0.1 mL to 5 mL of a surfactant, preferably alkyl benzene sulfonate, is added as a dispersant to 50 to 100 mL of the electrolytic solution, and 1 mg to 10 mg of a sample is added. This is subjected to a dispersion treatment for 1 minute with an ultrasonic disperser, and 100 mL to 200 mL of an electrolytic aqueous solution is put into another beaker, and the sample dispersion is added to a predetermined concentration therein, and the Coulter Counter TA- Measure the particle size distribution of 30,000 particles from 2 μm to 40 μm on the basis of the number using 100 μm aperture as type II aperture, calculate the volume distribution and number distribution of particles from 2 μm to 40 μm, particle size of 3 μm or less The fine powder content can be determined.

In the present invention, the fine powder contents (number%) F1, F2, and F3 having a particle diameter of 3 μm or less contained in each of the toners T1, T2, and T3 satisfy the following relationship.
F1> 30 number% ≧ F3 Formula 1
F2> 30 number% ≧ F3 Formula 2

Satisfying the above relationship means that, for example, in the toner in the toner containing member that is bundled with the image forming apparatus at the time of shipment, the content of fine powder having a particle size of 3 μm or less in the toner is temporarily increased, For the toner in the replacement toner storage member after it is used up and then replaced, the content of fine powder having a particle size of 3 μm or less is lowered. With such a configuration, the amount of toner passing from the cleaning unit is increased in the initial stage, and a sufficient amount of toner can be held in the foam layer of the protective agent supply member.
On the other hand, after replenishing the toner from the replacement toner containing member, the amount of toner slipping from the cleaning unit can be suppressed, and the cleaning failure and the contamination of the charging unit during long-term use can be prevented. From this point of view, the fine powder content F3 having a particle diameter of 3 μm or less contained in the replenishing toner T3 accommodated in the replacement toner accommodating member needs to be 30% by number or less, and 15% by number or less. It is preferable. If the F3 exceeds 30% by number, the amount of toner passing through increases, and the contamination of the charging means proceeds with time. When the ratio is 15% by number or less, contamination of the charging means can be kept extremely low over a long period of time.

  Further, the same kind of toner can be used for the fine powder content F1 having a particle diameter of 3 μm or less contained in the toner T1 and the fine powder content F2 having a particle diameter of 3 μm or less contained in the toner T2. It is preferable to satisfy the following formula, F1 = F2, in that the manufacturing load can be reduced.

  The fine particle content F1 and F2 having a particle diameter of 3 μm or less in the toners T1 and T2 may be a value larger than 30% by number, but is preferably 40% by number to 75% by number, more preferably 40% by number 60% by number is particularly preferred. If it is less than 40% by number, the amount of slip-through toner in the initial state is not sufficient, and the effect of improving the grinding force of the protective agent by holding the toner in the foam layer of the protective agent supplying member is slightly reduced. On the other hand, if it exceeds 75% by number, the charging means may be contaminated, or problems such as toner scattering may occur.

  As a method for producing the toner particles in the present invention, known means such as a pulverization method and a polymerization method can be used. Further, the method for adjusting the content of fine powder having a particle diameter of 3 μm or less in the toner is not particularly limited. For example, the amount of fine powder toner may be adjusted by changing the production conditions or the classification method.

Hereinafter, an example of the image forming apparatus of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to this. FIG. 9 is a schematic sectional view showing an example of the image forming apparatus 100 of the present invention.
Around the drum-shaped image carrier (1Y, 1M, 1C, 1K), a protective layer forming unit 2, a charging unit 3, an exposure unit 8, a developing unit 5, a transfer unit 6, and a cleaning unit 4 are arranged, respectively. Yes.

Next, a series of processes for image formation will be described using a negative-positive process.
An image carrier represented by an organic photoconductor (OPC) having an organic photoconductive layer is neutralized by a neutralizing lamp (not shown) or the like, and is uniformly negatively charged by the charging means 3.
When the image carrier is charged by the charging unit 3, the image carrier (1Y, 1M, 1C, 1K) is charged to a desired potential from the voltage application mechanism (not shown) to the charging unit 3. A suitable and appropriate voltage or a charging voltage obtained by superimposing an AC voltage thereon is applied.

The charged image carrier (1Y, 1M, 1C, 1K) forms a latent image with the laser beam irradiated by the exposure means 8 such as a laser optical system (the absolute value of the exposed portion potential is the absolute value of the non-exposed portion potential). Is lower than the value).
Laser light is emitted from a semiconductor laser, and the surface of the image carrier (1Y, 1M, 1C, 1K) is scanned in the direction of the rotation axis of the image carrier by a polygonal polygonal mirror (polygon) that rotates at high speed. .

The latent image formed in this manner is developed with a developer made of toner particles or a mixture of toner particles and carrier particles supplied on a developing sleeve which is a developer carrying member in the developing means 5, and toner can be transferred. A visual image is formed.
At the time of developing the latent image, a voltage of an appropriate magnitude between the exposed portion and the non-exposed portion of the image carrier (1Y, 1M, 1C, 1K) is applied from the voltage applying mechanism (not shown) to the developing sleeve. A developing bias with an alternating voltage superimposed thereon is applied thereto.

The toner image formed on the image carrier (1Y, 1M, 1C, 1K) corresponding to each color is transferred onto the intermediate transfer body 60 by the transfer means 6 and fed from the paper feed mechanism 200. The toner image is transferred onto a recording medium such as
At this time, it is preferable that a potential having a polarity opposite to the polarity of toner charging is applied to the transfer unit 6 as a transfer bias. Thereafter, the intermediate transfer member 60 is separated from the image carrier to obtain a transfer image.

Further, the toner particles remaining on the image carrier are collected by the cleaning member into the toner collecting chamber in the cleaning unit 4.
The transferred recording medium is heated by the fixing means 7 and the toner is fixed to the recording medium.
As the image forming apparatus, an apparatus in which a plurality of developing means 5 are arranged is used, and a plurality of toner images having different colors sequentially produced by the plurality of developing means 5 are sequentially transferred onto a recording medium and then sent to a fixing means, The toner fixing device may be used, or a plurality of similarly produced toner images may be sequentially transferred onto the intermediate transfer member 60 and then transferred to a recording medium such as paper. An apparatus for fixing in the same manner may be used later.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

(Production Examples 1-4)
<Production of protective agents 1-4>
According to the mixing ratio (mass basis) in Table 1, the fatty acid metal salt and the inorganic lubricant were mixed. For mixing, a wonder blender (WB-1, manufactured by Osaka Chemical Co., Ltd.) was used. Mixing was performed twice at a rotational speed of 25,000 rpm for 10 seconds to obtain a mixed powder.
Next, the obtained mixed powder is put into an aluminum mold having an inner depth of 20 mm, a width of 8 mm, and a length of 350 mm, and the surface of the mixed powder is leveled with a spatula. As described above, the powder compacted body was molded by pressing with a pressing die. At this time, the weight of the powder put into the mold was adjusted so that the filling ratio of the powder compacted body was 90%. That is, the weight of the powder to be charged = the volume inside the mold (8 mm × 8 mm × 350 mm) × the true specific gravity of the powder × 0.9.
After molding, the obtained solid was removed from the mold to obtain protective agents 1 to 4 of 8 mm × 8 mm × 320 mm. The obtained protective agents 1 to 4 were used by being attached to a metal support with a double-sided tape.

(Production Example 5)
<Production of protective agent 5>
The mixed powder mixed at the mixing ratio shown in Table 1 is heated to about 150 ° C. in a stainless steel cup to melt the fatty acid metal salt, and then sufficiently agitated to perform inorganic lubrication on the molten fatty acid metal salt. A melt dispersion in which the agent was uniformly dispersed was prepared.
The molten dispersion was slowly poured into an aluminum mold having an internal depth of 8 mm, a width of 8 mm, and a length of 320 mm, and naturally cooled and solidified at room temperature to be molded.
After molding, the obtained solid was removed from the mold to obtain protective agent 5. The obtained protective agent 5 was used by being attached to a metal support with a double-sided tape.

Each material shown in Table 1 is as follows. Moreover, the zinc stearate and zinc laurate used in the following examples are the same.
-Zinc stearate: GF-200, manufactured by NOF Corporation-Zinc laurate: Reagent, manufactured by Wako Pure Chemical Industries, Ltd.-Boron nitride: NX5, manufactured by Momentive Performance Materials, Inc.-Mica: SA Mica, Miyoshi Kasei Made by Kogyo Co., Ltd.

Example 1
<Preparation of image carrier unit>
The image carrier unit was taken out from the black station of the color MFP imagio MP C5000 (manufactured by Ricoh Co., Ltd.), which is an image forming apparatus provided with a protective agent coating means downstream of the cleaning means with respect to the rotation direction of the image carrier. . Protective agent 1 was used as a protective agent. Furthermore, instead of the brush roller as the protective agent supply member, a foam having 70 cells (cells / inch (25.4 mm)), a hardness of 150 N, and an open cell polyurethane layer (manufactured by Bridgestone Chemicals) A roller was attached. Note that the core metal of the foam roller was the same as the core metal of the brush roller, and the thickness of the polyurethane layer was adjusted so that the outer diameter of the foam roller was the same as the outer diameter of the brush roller.
Further, the pressure applied to the foam roller of the protective agent was set to 6N (calculated value). In the system of imgio MP C5000, the target consumption of the protective agent is required to be around 0.20 g / km (0.16 g / km to 0.23 g / km).
The pressure applied to the foam roller of the protective agent can be calculated from the spring constant and the amount of contraction of the spring in the pressurizing method using a spring. When the spring constant is k and the contraction amount is x, the following formula, F = kx, that is, the spring constant × the contraction amount is the applied pressure. When a plurality of springs are used, the total applied pressure is indicated.

<Production of toner>
-Toner prescription-
Polyester resin 1 (Kao Corporation, weight average molecular weight Mw: 5,500, melting point 110 ° C., glass transition temperature Tg: 58 ° C.) 65 parts by mass Polyester resin 2 (Kao Corporation, weight average molecular weight Mw: 190,000, melting point 166 ° C., glass transition temperature Tg: 65 ° C.) 30 parts by mass Carbon black (Cabot, Regal 400R) 10 parts by mass Paraffin wax (Nippon Seiwa Co., Ltd.) Manufactured, HNP-9PD, melting point 76.1 ° C.) 7 parts by mass Charge control agent (Orient Chemical Co., Ltd. Bontron E-84) 0.5 parts by mass

The mixture having the above composition was premixed with a Henschel mixer (Mitsui Mining Co., Ltd.), melt-kneaded with a two-roll mill, and then at a temperature of 100 ° C. to 130 ° C. with a twin-screw kneader (Ikegai Co., Ltd., PCM-30). Kneading while melting.
The obtained kneaded product was cooled to room temperature and then coarsely pulverized to a particle size of 200 μm to 300 μm with a hammer mill.
Next, the mixture was finely pulverized while appropriately adjusting the pulverization air pressure with a supersonic jet pulverizer lab jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), and then the air classifier (manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I). Then, each toner base particle having a fine powder content of 3 μm or less was obtained as shown in Table 2 while appropriately adjusting the louver opening. At this time, the particle size distribution was adjusted so that the volume average particle size of all the toner base particles was about 5.5 μm. The volume average particle size was also measured by the aforementioned Coulter Counter TA-II (manufactured by Beckman Coulter).
Next, with respect to 100 parts by mass of each toner base particle, 1.0 part by mass of hydrophobic silica fine particles (HDK-2000, manufactured by Clariant Co., Ltd.) and 0.3% of hydrophobic titanium oxide fine particles (MT-150IB, manufactured by Teika Co., Ltd.) 0.3 Part by mass was stirred and mixed with a Henschel mixer to prepare toners A to G shown in Table 2.

<Creation of carrier>
・ Silicone resin (solid content 23% by mass, SR2410, manufactured by Toray Dow Corning Silicone Co., Ltd.) 167 mass parts Aminosilane (solid content 100% by mass, SH6020, manufactured by Toray Dow Corning Silicone Co., Ltd.) 0.66 parts by mass Toluene: 300 parts by mass The above materials were dispersed with a homomixer for 10 minutes to obtain a silicone resin coating film forming solution. A calcined Mn ferrite powder having an average particle size of 50 μm is used as the core material, and the temperature inside the coater is 40 by a Spira coater (Okada Seiko Co., Ltd.) so that the coating film forming solution has a film thickness of 0.5 μm on the core material surface. It was applied at 0 ° C. and dried.
The obtained carrier was fired in an electric furnace at 300 ° C. for 1 hour.
After cooling, the ferrite powder bulk was crushed using a sieve having an aperture of 63 μm to obtain a magnetic carrier.

<Preparation of developer and development unit>
As the initial developing toner T1, 6 parts by mass of the toner A in Table 2 was mixed with 94 parts by mass of the magnetic carrier with a ball mill to prepare a two-component developer. 240 g of each developer was sealed in a black developing unit of imagio MP C5000 (manufactured by Ricoh Co., Ltd.).

The image carrier unit and the developing unit thus produced were mounted on the black station of the image forming apparatus (image MP C5000, manufactured by Ricoh Co., Ltd.).
Furthermore, assuming the bundled toner T2 at the time of shipment, take out the entire amount of toner from the black toner bottle for imagio MP C5000, and instead fill the bottle with toner B (510 g) in Table 2 and set it in the image forming apparatus did.
Further, as the replenishing toner T3, a plurality of replacement toner bottles obtained by taking out the entire amount of toner from another black toner bottle for imgio MP C5000 and filling the bottle with toner D (510 g) in Table 2 were prepared instead. .
Under the above conditions, various characteristics were evaluated as follows. The results are shown in Table 4.

<Relative value of load current applied to drive motor of image carrier>
Using the image forming apparatus (image MP MP5000, manufactured by Ricoh Co., Ltd.) modified as described above, 10 sheets are continuously passed using an A4 size plate and a 5% image area ratio chart, and the image carrier at this time The average value of the load current applied to the drive motor was measured. A relative comparison was made as to how many times this value was relative to the load current of imgio MP C5000 in a standard state (a state where a brush roller was used as a protective agent supply member).

<Consumer consumption per 1,000 sheets>
A total of 80,000 sheets were passed using an A4 size plate and a 5% image area ratio chart, and the initial to 1,000 sheets and 1,000 sheets before the end of the run (79,000 to 80,000) The consumption of the protective agent between each travel distance was measured. The consumption of the protective agent was calculated by measuring the difference (g) in the mass of the protective agent before and after the run and dividing it by the photosensitive member driving distance (km).

<Contamination after run>
The state of contamination of the charging means and the image carrier at the end of the run was visually observed and evaluated according to the following evaluation criteria. In addition, when there was an abnormality, it was confirmed whether or not an abnormal image occurred at the corresponding location. We also checked whether there was any other abnormality in the image at the end of the run.
〔Evaluation criteria〕
◎: No stain ○: Dirty but does not appear in image △: Dirty and appears in image but acceptable level ×: Dirty image NG (unacceptable level)

  When the toner runs out during the run, the replacement toner bottle produced as described above was set in the machine and the evaluation was continued. Further, in the image forming apparatus (image MPC5000, manufactured by Ricoh Co., Ltd.), the protective agent supply member is driven by the drive motor of the image carrier, so that the force required to drive the protective agent supply member is larger. The load applied to the drive motor of the image carrier increases, and more current is detected. Further, in the image forming apparatus (imagio MP C5000, manufactured by Ricoh Co., Ltd.), the technique described in Japanese Patent Application Laid-Open No. 2007-293240 is adopted as a mechanism for pressurizing the protective agent, and the pressure is almost constant over time. . Therefore, the change in the consumption of the protective agent accompanying the run is not affected by the pressurizing mechanism of the protective agent.

(Examples 2-9)
In Example 1, the type of the protective agent, the initial developer, the type of the initial developing toner T1 accommodated in the toner accommodating portion of the developing unit, the type of the bundled toner T2 accommodated in the toner bottle, and the replacement Evaluation was performed in the same manner as in Example 1 except that the type of replenishing toner T3 contained in the toner bottle was changed as shown in Table 3. The results are shown in Table 4.

(Example 10)
In Example 9, the evaluation was performed in the same manner as in Example 9 except that the pressure applied to the foam roller of the protective agent was set to 7 N (calculated value). The results are shown in Table 4.

(Example 11)
In Example 4, the polyurethane layer of the foam roller was replaced with a cell number of 50 (pieces / inch (25.4 mm)), a hardness of 250 N, and an open-cell type polyurethane layer (manufactured by Bridgestone Chemicals Co., Ltd.). Evaluation was performed in the same manner as in Example 4. The results are shown in Table 4.

(Example 12)
In Example 4, except that the polyurethane layer of the foam roller was replaced with a cell number of 60 (pieces / inch (25.4 mm)), a hardness of 310 N, and an open cell type polyurethane layer (manufactured by Bridgestone Chemicals). Evaluation was performed in the same manner as in Example 4. The results are shown in Table 4.

(Comparative Examples 1-4)
In Example 1, the type of protective agent, the initial developer and the type of toner T1 accommodated in the toner accommodating portion of the development unit, the type of bundled toner T2 accommodated in the toner bottle, and the replacement toner bottle Evaluation was performed in the same manner as in Example 1 except that the type of replenishment toner T3 contained was changed as shown in Table 3. The results are shown in Table 4.

(Comparative Example 5)
In Comparative Example 2, evaluation was performed in the same manner as Comparative Example 2 except that the pressure applied to the foam roller of the protective agent was set to 12 N (calculated value). The results are shown in Table 4.

(Comparative Example 6)
In Example 4, evaluation was performed in the same manner as in Example 4 except that the protective agent 4 was used instead of the protective agent 1. The results are shown in Table 4.

(Comparative Example 7)
In Example 4, the evaluation was performed in the same manner as in Example 4 except that the brush roller mounted on the image forming apparatus (image MPC5000, manufactured by Ricoh Co., Ltd.) was used as it was as the protective agent supply member. The results are shown in Table 4.

  In all of Examples 1 to 12 and Comparative Examples 1 to 7, replacement toner bottles were used. In addition, the toner in the replacement toner bottle consumed almost the entire amount after printing about 10,000 sheets. Therefore, the replacement toner bottle was replaced after printing about 10,000 sheets.

* “Banding” in “Presence / absence of abnormal image” in Comparative Example 5 means that band-like shading unevenness occurs in the halftone image, and the torque is high and the rotation of the photoconductor is not performed constantly. It is a phenomenon that occurs.
From the results of Table 4, in Examples 1 to 12, the pressure applied to the foam roller of the protective agent, which is necessary for obtaining the target protective agent consumption, can be set low. And the consumption of the protective agent was stable over time. Further, it was found that the image bearing member contamination after the evaluation and the charging roller contamination were both small, and good quality could be maintained over a long period of time.
Further, from comparison between Example 3 and Example 4, it was found that the result of less contamination of the charging roller can be obtained by setting the content of fine powder having a particle size of 3 μm or less of the replenishment toner to 15% by number or less. .
Further, from the comparison between Example 4 and Examples 7 to 8, by using zinc stearate as the fatty acid metal salt and boron nitride as the inorganic lubricant, particularly good results with respect to contamination of the charging roller and the image carrier are obtained. Was found to be obtained.
Moreover, from the comparison between Example 4 and Examples 9 to 10, by using a compression molded body as the protective agent block, the target protective agent consumption can be reduced under the condition that the pressure applied to the foam roller of the protective agent is weaker. It turned out that it can secure.

On the other hand, in Comparative Examples 1, 2, and 4, since the toner fine powder content in the toner container and the toner bottle in the initial stage of use of the image forming apparatus is low, the amount of initial protective agent consumption is small and the image carrier Dirt has occurred.
In Comparative Example 3, the content of the toner fine powder in the toner container and the toner bottle in the initial stage of use of the image forming apparatus is high, but the content of the toner fine powder contained in the replacement toner bottle is also high. There has occurred. In addition, a fogged image that seems to be an influence of toner scattering by fine powder was generated.
In Comparative Example 5, since the toner fine powder content in the toner container in the initial stage of use of the image forming apparatus and the toner bottle is low, the target protective agent consumption is secured by increasing the pressure of the protective agent on the foam roller. However, the mechanical load (torque) was high and the consumption increased with time. Banding images were generated due to high mechanical load.
In Comparative Example 6, since the protective agent did not contain an inorganic lubricant, the charging roller became dirty over time.
In Comparative Example 7, since the brush was used as the protective agent supply member, the mechanical load was small, but the initial protective agent consumption was very large, and the consumption after the run was also reduced, so it was stable over a long period of time. It was difficult to provide images.

The aspect of the present invention is as follows.
<1> an image carrier;
A protective layer forming means having a protective agent supplying member and an image carrier protective agent that rotatably contact the surface of the image carrier;
A developing unit that has a toner storage unit that stores toner T1, and that develops an electrostatic latent image formed on the image carrier using the toner T1 to form a visible image;
A toner containing member for containing toner T2 for replenishing the toner containing portion;
A replacement toner storage member that stores the replenishment toner T3, and
An image forming apparatus in which the replenishment toner T3 is replenished by exchanging the replacement toner accommodation member with the toner accommodation member,
The image carrier protective agent contains a fatty acid metal salt and an inorganic lubricant,
The protective agent supply member has a core material and a foam layer formed on the outer periphery of the core material and having a plurality of bubbles,
The image forming apparatus is characterized in that the toner T1, the toner T2, and the replenishing toner T3 satisfy a relationship represented by the following formulas 1 and 2.
F1> 30 number% ≧ F3 Formula 1
F2> 30 number% ≧ F3 Formula 2
In Formula 1 and Formula 2, F1 is a fine powder content of 3 μm or less in the toner T1, F2 is a fine powder content of 3 μm or less in the toner T2, and F3 is the replenishing toner. The content of fine powder having a particle size of 3 μm or less at T3 is represented, and the units of F1 to F3 are number%.
<2> The image forming apparatus according to <1>, wherein a fine powder content F3 having a particle diameter of 3 μm or less in the replenishing toner T3 in the replacement toner containing member is 15% by number or less.
<3> The image forming apparatus according to any one of <1> to <2>, wherein the image carrier protecting agent is formed by compression molding.
<4> The image forming apparatus according to any one of <1> to <3>, wherein the fine powder contents F1 and F2 having a particle diameter of 3 μm or less in the toner T1 and the toner T2 satisfy the following formula: F1 = F2. is there.
<5> The image forming apparatus according to any one of <1> to <4>, wherein the fatty acid metal salt contains zinc stearate.
<6> The image forming apparatus according to any one of <1> to <5>, wherein the inorganic lubricant contains boron nitride.
<7> A replacement toner storage member that stores the replenishment toner T3 and is replaced with the toner storage member of the image forming apparatus according to any one of <1> to <6>.
<8> A protective layer forming step of forming a protective layer by applying an image carrier protective agent to the surface of the image carrier using a protective agent supply member;
A developing step of developing the electrostatic latent image formed on the image carrier using a toner T1 accommodated in a toner accommodating portion to form a visible image,
The toner T2 is replenished from the toner containing member that contains the toner T2 to the toner containing portion,
An image forming method in which the replenishment toner T3 is replenished by replacing a replacement toner accommodation member that accommodates the replenishment toner T3 with the toner accommodation member,
The image carrier protective agent contains a fatty acid metal salt and an inorganic lubricant,
The protective agent supply member has a core material and a foam layer formed on the outer periphery of the core material and having a plurality of bubbles,
In the image forming method, the toner T1, the toner T2, and the replenishing toner T3 satisfy a relationship expressed by the following formulas 1 and 2.
F1> 30 number% ≧ F3 Formula 1
F2> 30 number% ≧ F3 Formula 2
In Formula 1 and Formula 2, F1 is a fine powder content of 3 μm or less in the toner T1, F2 is a fine powder content of 3 μm or less in the toner T2, and F3 is the replenishing toner. The content of fine powder having a particle size of 3 μm or less at T3 is represented, and the units of F1 to F3 are number%.

DESCRIPTION OF SYMBOLS 1 Image carrier 2 Protective layer formation means 5 Developing means 9 Core material 10 Foam layer 21 Protective agent block 22 Protective agent supply member 32 Protective agent supply member 53 Toner storage part 100 Image forming apparatus 500 Toner storage member

Japanese Patent Publication No.51-22380 JP 2009-282160 A JP 2007-65100 A JP 2007-293240 A JP 2009-150986 A JP 2012-58539 A

Claims (8)

An image carrier;
A protective layer forming means having a protective agent supplying member and an image carrier protective agent that rotatably contact the surface of the image carrier;
A developing unit that has a toner storage unit that stores toner T1, and that develops an electrostatic latent image formed on the image carrier using the toner T1 to form a visible image;
A toner containing member for containing toner T2 for replenishing the toner containing portion;
A replacement toner storage member that stores the replenishment toner T3, and
An image forming apparatus in which the replenishment toner T3 is replenished by exchanging the replacement toner accommodation member with the toner accommodation member,
The image carrier protective agent contains a fatty acid metal salt and an inorganic lubricant,
The protective agent supply member has a core material and a foam layer formed on the outer periphery of the core material and having a plurality of bubbles,
The image forming apparatus, wherein the toner T1, the toner T2, and the replenishing toner T3 satisfy a relationship represented by the following formulas 1 and 2.
F1> 30 number% ≧ F3 Formula 1
F2> 30 number% ≧ F3 Formula 2
In Formula 1 and Formula 2, F1 is a fine powder content of 3 μm or less in the toner T1, F2 is a fine powder content of 3 μm or less in the toner T2, and F3 is the replenishing toner. The content of fine powder having a particle size of 3 μm or less at T3 is represented, and the units of F1 to F3 are number%.   2. The image forming apparatus according to claim 1, wherein a fine powder content F <b> 3 having a particle diameter of 3 μm or less in the replenishing toner T <b> 3 in the replacement toner containing member is 15% by number or less.   The image forming apparatus according to claim 1, wherein the image carrier protecting agent is formed by compression molding.   The image forming apparatus according to claim 1, wherein the fine powder contents F1 and F2 having a particle diameter of 3 μm or less in the toner T1 and the toner T2 satisfy the following formula: F1 = F2.   The image forming apparatus according to claim 1, wherein the fatty acid metal salt contains zinc stearate.   The image forming apparatus according to claim 1, wherein the inorganic lubricant contains boron nitride.   A replacement toner storage member that stores the replenishment toner T3 and is replaced with the toner storage member of the image forming apparatus according to any one of claims 1 to 6. A protective layer forming step of forming a protective layer by applying an image carrier protective agent to the surface of the image carrier using a protective agent supply member;
A developing step of developing the electrostatic latent image formed on the image carrier using a toner T1 accommodated in a toner accommodating portion to form a visible image,
The toner T2 is replenished from the toner containing member that contains the toner T2 to the toner containing portion,
An image forming method in which the replenishment toner T3 is replenished by replacing a replacement toner accommodation member that accommodates the replenishment toner T3 with the toner accommodation member,
The image carrier protective agent contains a fatty acid metal salt and an inorganic lubricant,
The protective agent supply member has a core material and a foam layer formed on the outer periphery of the core material and having a plurality of bubbles,
The image forming method, wherein the toner T1, the toner T2, and the replenishing toner T3 satisfy a relationship represented by the following formulas 1 and 2.
F1> 30 number% ≧ F3 Formula 1
F2> 30 number% ≧ F3 Formula 2
In Formula 1 and Formula 2, F1 is a fine powder content of 3 μm or less in the toner T1, F2 is a fine powder content of 3 μm or less in the toner T2, and F3 is the replenishing toner. The content of fine powder having a particle size of 3 μm or less at T3 is represented, and the units of F1 to F3 are number%.