JP2016138964A - Solid lubricant and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid lubricant and an image forming apparatus that can provide a cleaning property in a low-temperature and low-humidity environment, and suppress lubricant from being mixed into a developing unit.SOLUTION: A solid lubricant of the present invention is a solid lubricant formed by a lubricant to be applied onto the surfaces of photoreceptors included in an image forming apparatus of an electrophotographic system molded into a solid shape, and contains a fatty acid metal salt and a fatty acid amide represented by the following general formula (1): CH-(CH)-CONH, where n represents an integer of from 10 to 20, and the content ratio of the fatty acid amide is from 5 to 70 mass%. In the solid lubricant, it is preferable that the fatty acid metal salt be zinc stearate, and the fatty acid amide be a compound where n in the general formula (1) is an integer of from 14 to 18.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electrophotographic image forming apparatus and a solid lubricant used therefor.

In an electrophotographic image forming apparatus, the surface of a photoconductor is charged by discharge, the charged photoconductor is exposed to form an electrostatic latent image, and toner is supplied to the electrostatic latent image. An image is formed, the toner image is transferred to a transfer material, and the toner image is fixed on the transfer material, thereby forming a visible image.
In such an image forming apparatus, deposits including untransferred toner remaining on the surface of the photoconductor after the toner image is transferred are removed by a cleaning unit so as not to adversely affect the next image process. To be done.
As the cleaning means, for example, a cleaning blade made of an elastic material such as rubber that rubs the surface of the photoreceptor is generally used.

  However, the cleaning blade wears with time as it is used, resulting in chipping and deformation, and there is a problem that the cleaning performance gradually deteriorates. Another problem is that the wear of the surface of the photoconductor progresses and the life of the photoconductor is shortened.

In order to solve such problems, a lubricant film is formed on the surface of the photoconductor by applying a lubricant to the surface of the photoconductor, thereby reducing the frictional resistance between the photoconductor and the cleaning blade. Has been done.
As a method for forming such a lubricant film, for example, a powder lubricant is scraped off by a brush roller from a solid lubricant in which the lubricant is formed into a rod shape, and this lubricant is supplied to the surface of the photoreceptor, and then the photosensitive film is coated. A method is known in which a cleaning blade is brought into sliding contact with the surface of a body (see Patent Documents 1 and 2).
Conventionally, fatty acid metal salts such as zinc stearate have been used as lubricants.

  However, the fatty acid metal salt that constitutes the lubricant, due to its characteristics, significantly reduces the effect of reducing the frictional resistance in a low-temperature and low-humidity environment, so that the frictional resistance between the photosensitive member and the cleaning blade is maintained at a desired low level. In order to achieve this, it is necessary to supply a large amount of fatty acid metal salt to the surface of the photoreceptor. However, if the supply amount of the fatty acid metal salt is increased, the amount of the lubricant mixed in the developing device also increases, and as a result, the chargeability of the toner decreases, and the toner scattering and fogging occur. There is.

JP-A-6-342236 JP-A-8-202226

  The present invention has been made in consideration of the above circumstances, and its object is to provide a solid lubricant capable of suppressing the incorporation of a lubricant into a developing device while obtaining a cleaning property in a low-temperature and low-humidity environment. An object is to provide an image forming apparatus.

The solid lubricant of the present invention is a solid lubricant formed by solidifying a lubricant applied to the surface of a photoreceptor provided in an electrophotographic image forming apparatus,
It contains a fatty acid metal salt and a fatty acid amide represented by the following general formula (1), and the content ratio of the fatty acid amide is 5 to 70% by mass.
Formula _{(1): CH 3 - (} CH 2) n -CONH 2
[In said formula, n shows the integer of 10-20. ]

In the solid lubricant of the present invention, the fatty acid metal salt is zinc stearate,
The fatty acid amide is preferably a compound in which n in the general formula (1) is an integer of 14 to 18.

  In the solid lubricant of this invention, it is preferable that the content rate of the said fatty acid amide is 30-50 mass%.

The image forming apparatus of the present invention includes a photosensitive member, a charging unit that charges the surface of the photosensitive member, an exposure unit that exposes the photosensitive member charged by the charging unit to form an electrostatic latent image, and the static unit. Developing means for supplying toner to the photoreceptor on which the electrostatic latent image is formed to form a toner image; transfer means for transferring the toner image to a transfer material; and toner remaining on the surface of the photoreceptor by a cleaning blade An image forming apparatus comprising: cleaning means for removing; and lubricant supply means for applying and supplying a lubricant to the surface of the photoreceptor,
The lubricant of the lubricant supply means is the solid lubricant described above.

In the image forming apparatus of the present invention, the photoreceptor has a protective layer on the organic photosensitive layer,
The protective layer contains a resin component composed of a cross-linked curable resin obtained by polymerizing a polymerizable compound having at least an acryloyl group or a methacryloyl group, and inorganic fine particles treated with a surface treatment agent having a polymerizable functional group It is preferable to do.

  According to the solid lubricant of the present invention, since the lubricant constituting the lubricant is composed of a fatty acid metal salt and a fatty acid amide having a specific linear structure, basically good cleaning properties can be obtained even in a low temperature and low humidity environment. Further, mixing of the lubricant into the developing device is suppressed, and good chargeability of the toner is maintained. As a result, toner scattering and fogging are suppressed.

1 is a cross-sectional view illustrating an example of a configuration of an image forming apparatus according to the present invention. FIG. 2 is an explanatory cross-sectional view illustrating an example of a configuration of a main part of the image forming apparatus of the present invention.

  Hereinafter, the present invention will be specifically described.

[Solid lubricant]
The solid lubricant of the present invention is a solid lubricant formed on a surface of a photoconductor provided in an electrophotographic image forming apparatus and formed into a solid form. The solid lubricant includes the fatty acid metal salt and the general formula (1). (Hereinafter, also referred to as “specific fatty acid amide”).

[Fatty acid metal salt]
As the fatty acid metal salt, for example, zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, zinc oleate, zinc myristate, zinc behenate, zinc laurate, zinc arachidate and the like can be used. Among these, zinc stearate is preferably used from the viewpoint of wear resistance and hydrophobization.
These can be used alone or in combination of two or more.

[Specific fatty acid amide]
The specific fatty acid amide is a compound having a linear structure represented by the general formula (1): CH ₃ — (CH ₂ ) _n —CONH ₂ (n is an integer of 10 to 20). The fatty acid amide having a linear structure has a characteristic of being uniformly adsorbed on the surface of the photoreceptor. It should be noted that fatty acid amides having a branched structure such as oleic acid amide and isostearic acid amide are difficult to obtain homogeneous adsorption on the surface of the photoreceptor due to the presence of branching sites.

  Specific examples of the fatty acid amide include, for example, lauric acid amide (n = 10), pentadecylic acid amide (n = 13), palmitic acid amide (n = 14), stearic acid amide (n = 16), arachidic acid amide ( n = 18) behenic acid amide (n = 20) and the like. These can be used alone or in combination of two or more. When a compound having n of 9 or less is used as the fatty acid amide, it is difficult to mold as a solid lubricant. Moreover, when the compound whose n is 21 or more is used as a fatty acid amide, it is hard to mix with a fatty acid metal salt.

As the specific fatty acid amide, it is preferable to use a fatty acid having the same or close carbon number as that of the fatty acid constituting the fatty acid metal salt used together. By using such a specific fatty acid amide and a fatty acid metal salt in combination, it is possible to suppress the occurrence of cracking and chipping of the obtained solid lubricant.
For example, when zinc stearate is used as the fatty acid metal salt, it is preferable to use, for example, a compound in which n is 14 to 18 in the general formula (1) as the specific fatty acid amide.

The content rate of the specific fatty acid amide in a solid lubricant is 5-70 mass%, Preferably it is 30-50 mass%.
When the content ratio of the specific fatty acid amide is 5% by mass or more, homogeneous adsorption to the surface of the photoconductor by the specific fatty acid amide is obtained, and the adhesion force of the lubricant to the photoconductor is obtained. As a result, mixing of the lubricant into the developing device is suppressed. On the other hand, when the content ratio of the specific fatty acid amide is 70% by mass or less, the desired content ratio of the fatty acid metal salt can be ensured, and thus the abrasion resistance of the cleaning blade and the photoreceptor can be obtained. .

[Method for producing solid lubricant]
The solid lubricant of the present invention is produced by molding a mixture of a fatty acid metal salt and a specific fatty acid amide into a rod shape by a general molding method such as casting, injection molding, extrusion molding or compression molding. Can do.

According to the solid lubricant as described above, since the lubricant constituting the lubricant is a mixture of a fatty acid metal salt and a specific fatty acid amide having a linear structure, basically good cleaning properties can be obtained even in a low temperature and low humidity environment. As a result, homogeneous adsorption to the surface of the photoconductor by the specific fatty acid amide is obtained, and adhesion of the lubricant to the photoconductor is obtained, so that mixing of the lubricant into the developing device is suppressed and the toner is suppressed. As a result, toner scattering and fogging are suppressed.
The principle by which the adhesion of the lubricant to the photoconductor is unknown, but it is presumed that the SP value of a specific fatty acid amide is closer to the SP value of the surface of the photoconductor than the SP value of the fatty acid metal salt. The

[Image forming apparatus]
FIG. 1 is an explanatory sectional view showing an example of the configuration of the image forming apparatus of the present invention, and FIG. 2 is an explanatory sectional view showing an example of the configuration of the main part of the image forming apparatus of the present invention.
The image forming apparatus 100 is called a tandem type color image forming apparatus, and includes four sets of image forming units 110Y, 110M, 110C, and 110Bk, a sheet feeding / conveying unit 150, and a fixing unit 170. A document image reading device SC is arranged on the upper part of the main body of the image forming apparatus 100.

  The image forming units 110Y, 110M, 110C, and 110Bk are arranged side by side in the vertical direction. The image forming units 110Y, 110M, 110C, and 110Bk include drum-shaped photoreceptors 111Y, 111M, 111C, and 111Bk that are rotated, and a charging unit 113Y that is sequentially arranged along the rotation direction of the photoreceptor in the outer peripheral surface area. 113M, 113C, 113Bk, exposure means 115Y, 115M, 115C, 115Bk, development means 117Y, 117M, 117C, 117Bk, primary transfer rollers (primary transfer means) 133Y, 133M, 133C, 133Bk, and cleaning means 119Y. 119M, 119C, and 119Bk. Then, toner images of yellow (Y), magenta (M), cyan (C), and black (Bk) are formed on the photoreceptors 111Y, 111M, 111C, and 111Bk, respectively. Since the image forming units 110Y, 110M, 110C, and 110Bk are configured similarly except that the colors of the toner images formed on the photoconductors 111Y, 111M, 111C, and 111Bk are different, the following description will be made with an example of the image forming unit 110Y. .

  In the present invention, a lubricant supply means 116Y for applying and supplying a lubricant to the surface of the photoreceptor 111Y is provided, for example, on the downstream side of the cleaning means 119Y and the upstream side of the charging means 113Y.

[Lubricant supply means]
Lubricant supply means 116Y is a belt-like rotating body 24 that includes a rod-like solid lubricant 22 extending along the axial direction of the photoconductor 111Y and a finely powdered lubricant scraped by rubbing the surface of the solid lubricant 22. The solid lubricant 22 is composed of the solid lubricant of the present invention comprising the above-mentioned fatty acid metal salt and a specific fatty acid amide.

The belt-like rotating body 24 of the coating mechanism is inserted into the endless coating belt 24b and the coating belt 24b, and presses the surface of the photoreceptor 111Y via the coating belt 24b to form the nip portion N. It consists of a pressing roller 24a. In this nip portion N, the fine powder lubricant supplied from the lubricant supply roller 21 is applied to the surface of the photoreceptor 111Y.
The pressing roller 24a is rotationally driven by a driving mechanism (not shown) in the same rotation direction as the photosensitive member 111Y.
The application belt 24b is rotated in the same direction as the photoconductor 111Y following the rotation of the pressing roller 24a.

The coating belt 24b is configured by electrostatically flocking nylon fibers or polyphenylene sulfide (PPS) fibers on a base material. The coating belt 24b may have a felt on the substrate, may be formed by applying whisker particles on the substrate, and has a microfiber on the substrate. It may also have chamois leather on the substrate.
The surface of the coating belt 24b is subjected to a process of imparting roughness such as a blast process. By imparting roughness to the surface of the coating belt 24b, high retention and transportability of the lubricant on the surface of the coating belt 24b can be stably obtained.

  The pressing roller 24a is a sponge roller in which a conductive urethane foam layer is formed on the outer peripheral surface of a metal cored bar. The pressing roller 24a may be an elastic roller made of conductive urethane rubber, silicone rubber, EPDM rubber, or the like.

The lubricant supply roller 21 of the coating mechanism is installed in contact with the coating belt 24b of the belt-like rotating body 24, and the fine powdery lubricant scraped off by rubbing the surface of the solid lubricant 22 is rotated in the belt-like manner. It is supplied to the surface of the application belt 24b of the body 24.
The surface of the lubricant supply roller 21 is subjected to a process of imparting roughness such as a blast process. By providing the surface of the lubricant supply roller 21 with roughness, it becomes easy to smoothly scrape the lubricant from the solid lubricant 22, and the high retention and transportability of the lubricant on the surface of the lubricant supply roller 21 are stable. Is obtained.
The lubricant supply roller 21 is rotationally driven by a drive mechanism (not shown) in the direction opposite to the rotation direction of the coating belt 24b of the belt-like rotating body 24.

  The solid lubricant 22 is installed in a state where it is pressed in a direction close to the lubricant supply roller 21 of the coating mechanism by a pressing spring 23 provided in contact with the back surface thereof.

  In FIG. 2, reference numeral 25 denotes a scraping brush roller that scrapes and removes the lubricant adhering to the surface of the application belt 24 b of the belt-like rotating body 24. The scraping brush roller 25 is rotationally driven by a driving mechanism (not shown) in the same rotation direction as the rotation direction of the belt-like rotating body 24.

In the lubricant supply means 116Y, for example, the lubricant of the solid lubricant 22 is applied so that the coating amount per 1 cm ² of the surface of the photoreceptor 111Y is 0.5 × 10 ^{−7 to} 1.5 × 10 ⁻⁷ g / cm ^2. The pressing force on the supply roller 21 and the rotational speed of the lubricant supply roller 21 are adjusted.

  In the configuration shown in FIG. 2, the leveling blade 118Y that uniformly applies the lubricant supplied to the surface of the photoreceptor 111Y by the lubricant supply unit 116Y is provided downstream of the lubricant supply unit 116Y and upstream of the charging unit 113Y. Is provided.

[Photoreceptor]
Photoreceptor 111Y is an organic photoreceptor having a protective layer on an organic photosensitive layer, and the protective layer is formed from a cross-linked curable resin obtained by polymerizing a polymerizable compound having at least an acryloyl group or a methacryloyl group. It is preferable to contain the resin component which becomes, and the inorganic fine particle processed with the surface treating agent which has a polymerizable functional group.

  The layer structure of the organic photoreceptor is not particularly limited as long as the organic photosensitive layer and the protective layer are laminated in this order on the conductive support. Specifically, the following (1) and (2) The thing which has the following layer structure is mentioned.

(1) A layer structure in which a charge generation layer, a charge transport layer, and a protective layer are laminated in this order as an intermediate layer and an organic photosensitive layer on a conductive support.
(2) A layer structure in which an intermediate layer, a layer containing a charge generation material and a charge transport material as an organic photosensitive layer, and a protective layer are laminated in this order on a conductive support.

  In the present invention, the organic photoreceptor means a structure constituted by an organic compound that exhibits at least one of a charge generation function and a charge transport function essential for the construction of an electrophotographic organic photoreceptor. Known organic photosensitive materials such as organic photoreceptors having an organic photosensitive layer composed of a charge generating material or an organic charge transporting material, and organic photoreceptors having an organic photosensitive layer in which a charge generating function and a charge transporting function are composed of a polymer complex It includes the whole body.

  The organic photosensitive layer can be prepared by various conventionally known production methods using conventionally known raw materials.

(Protective layer)
The protective layer in the organic photoreceptor has inorganic fine particles treated with a resin component comprising a cross-linked curable resin obtained by polymerizing a polymerizable compound having at least an acryloyl group or a methacryloyl group, and a surface treatment agent having a polymerizable functional group It is preferable that it contains.
Such a protective layer is composed of a polymerizable compound, a polymerization initiator, inorganic fine particles, and, if necessary, other than a lubricant particle, an antioxidant, or a crosslinked cured resin. A protective layer-forming coating solution is prepared by dissolving or dispersing the resin in a known solvent, and this protective layer-forming coating solution is applied to the outer peripheral surface of the organic photosensitive layer to form a coating film. It can be formed by drying and irradiating active rays such as ultraviolet rays and electron beams to polymerize a polymerizable compound in the coating film to synthesize and cure a cross-linked curable resin.

  The thickness of the protective layer is preferably 0.2 to 10 μm, more preferably 0.5 to 5 μm.

The protective layer can also be constituted by using other known resins in combination with the cross-linked curable resin.
Examples of other known resins include polyester resins, polycarbonate resins, polyurethane resins, acrylic resins, epoxy resins, silicone resins, and alkyd resins.

(Polymerizable compound)
The polymerizable compound for forming the cross-linked curable resin is not particularly limited, and examples thereof include styrene monomers, acrylic monomers, methacrylic monomers, vinyl toluene monomers, vinyl acetate monomers, and N-vinyl pyrrolidone. System monomers and the like. These polymerizable compounds can be used alone or in combination of two or more.

As the polymerizable compound, a compound having an acryloyl group (CH ₂ ═CHCO—) or a methacryloyl group (CH ₂ ═CCH ₃ CO—) as a polymerizable functional group can be cured with a small amount of light or in a short time. In particular, it is preferable to use a polymerizable compound having 2 to 6 polymerizable functional groups from the viewpoint that the crosslinkable density of the resulting crosslinkable curable resin can be increased and wear resistance can be improved. . These polymerizable compounds are described in Japanese Patent Application Laid-Open No. 2011-175140, and some of the representative compounds are exemplified below.

Here, R represents an acryloyl group (CH ₂ ═CHCO—), and R ′ represents a methacryloyl group (CH ₂ ═CCH ₃ CO—).

(Inorganic fine particles)
The protective layer preferably contains inorganic fine particles treated with a surface treatment agent having a polymerizable functional group. As the inorganic fine particles, aluminum oxide (alumina: Al ₂ O ₃ ), titanium oxide (titania: TiO ₂ ), silicon oxide (silica: SiO ₂ ), zirconium oxide (zirconia: ZrO ₂ ), tin oxide (SnO ₂ ), Alternatively, fine particles of metal oxide such as zinc oxide (ZnO) can be used. Among these, it is preferable to use aluminum oxide fine particles and tin oxide fine particles.

  The number average primary particle size of the inorganic fine particles contained in the protective layer is preferably 1 to 300 nm, particularly 3 to 100 nm. If the particle size is too small, the wear resistance improvement performance is not sufficient. Conversely, if the particle size is too large, light is scattered during image writing, and the photocuring reaction is inhibited during surface layer formation, so that the wear resistance is also reduced. May adversely affect sex.

  The number average primary particle size of the above-mentioned inorganic fine particles is a photographic image (excluding agglomerated particles) taken with a scanning electron microscope (manufactured by JEOL Ltd.) and a magnified image of a magnification of 100,000 times, and randomly capturing 300 particles with a scanner. The automatic image processing analyzer “LUZEX (registered trademark) AP” (manufactured by Nireco Corporation) software version Ver. Calculate the number average primary particle size using 1.32.

  The inorganic fine particles contained in the protective layer are preferably treated with a surface treating agent having a polymerizable functional group from the viewpoint of improving the durability of the photoreceptor.

A representative example of the polymerizable functional group is a radical polymerizable functional group. Therefore, the surface treatment agent may be a compound having a radical polymerizable functional group and a compound capable of covering the surface of the inorganic fine particles. Can be used. A particularly preferred radical polymerizable functional group is a reactive acryloyl group or a methacryloyl group, and a portion bonded to the surface of the inorganic fine particle so as to cover the surface of the inorganic fine particle has a structure as a silane coupling agent.
The surface treatment agent having a polymerizable functional group that can be preferably used in the present invention is a silane coupling agent having a reactive vinyl group, an acryloyl group, or a methacryloyl group. For example, it is a silane compound represented by the following general formula (2).

In the formula, R ¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aralkyl group having 1 to 10 carbon atoms, R ² is an organic group having a reactive double bond such as a vinyl group, an acryloyl group, or a methacryloyl group. X represents a halogen atom, an alkoxy group, an acyloxy group, an aminoxy group, or a phenoxy group. n is an integer of 1 to 3.

Examples of the compound represented by the general formula (2) will be given below.
_{S-1: CH 2 = CHSi} (CH 3) (OCH 3) 2
_{S-2: CH 2 = CHSi} (OCH 3) 3
S-3: CH ₂ = CHSiCl _{3
S-4: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) (OCH 3) 2
_{S-5: CH 2 = CHCOO} (CH 2) 2 Si (OCH 3) 3
_{S-6: CH 2 = CHCOO} (CH 2) 2 Si (OC 2 H 5) (OCH 3) 2
_{S-7: CH 2 = CHCOO} (CH 2) 3 Si (OCH 3) 3
_{S-8: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) Cl 2
_{S-9: CH 2 = CHCOO} (CH 2) 2 SiCl 3
_{S-10: CH 2 = CHCOO} (CH 2) 3 Si (CH 3) Cl 2
S-11: CH ₂ = CHCOO (CH ₂ ) ₃ SiCl _{3
S-12: CH 2 = C} (CH 3) COO (CH 2) 2 Si (CH 3) (OCH 3) 2
_{S-13: CH 2 = C} (CH 3) COO (CH 2) 2 Si (OCH 3) 3
_{S-14: CH 2 = C} (CH 3) COO (CH 2) 3 Si (CH 3) (OCH 3) 2
_{S-15: CH 2 = C} (CH 3) COO (CH 2) 3 Si (OCH 3) 3
_{S-16: CH 2 = C} (CH 3) COO (CH 2) 2 Si (CH 3) Cl 2
_{S-17: CH 2 = C} (CH 3) COO (CH 2) 2 SiCl 3
_{S-18: CH 2 = C} (CH 3) COO (CH 2) 3 Si (CH 3) Cl 2
_{S-19: CH 2 = C} (CH 3) COO (CH 2) 3 SiCl 3
_{S-20: CH 2 = CHSi} (C 2 H 5) (OCH 3) 2
_{S-21: CH 2 = C} (CH 3) Si (OCH 3) 3
_{S-22: CH 2 = C} (CH 3) Si (OC 2 H 5) 3
_{S-23: CH 2 = CHSi} (OCH 3) 3
_{S-24: CH 2 = C} (CH 3) Si (CH 3) (OCH 3) 2
_{S-25: CH 2 = CHSi} (CH 3) Cl 2
_{S-26: CH 2 = CHCOOSi} (OCH 3) 3
_{S-27: CH 2 = CHCOOSi} (OC 2 H 5) 3
_{S-28: CH 2 = C} (CH 3) COOSi (OCH 3) 3
_{S-29: CH 2 = C} (CH 3) COOSi (OC 2 H 5) 3
_{S-30: CH 2 = C} (CH 3) COO (CH 2) 3 Si (OC 2 H 5) 3
These silane compounds can be used alone or in admixture of two or more.

  Surface treatment of inorganic fine particles with a surface treatment agent having a polymerizable functional group is wet using 0.1 to 200 parts by weight of a silane compound as a surface treatment agent and 50 to 5000 parts by weight of a solvent with respect to 100 parts by weight of inorganic fine particles. This is preferably done by processing using a media distributed device.

  In the present invention, the surface of the inorganic fine particles is covered with a surface treatment agent having a polymerizable functional group. Photoelectron spectroscopy (ESCA), Auger electron spectroscopy (Auger), secondary ion mass spectrometry (SIMS) And surface analysis techniques such as diffuse reflection FT-IR can be combined.

(Polymerization initiator)
When the polymerizable compound used in the protective layer is subjected to a polymerization reaction, a method of reacting by electron beam cleavage, a method of adding a radical polymerization initiator and reacting with light or heat are used. As the polymerization initiator, either a photopolymerization initiator or a thermal polymerization initiator can be used. Further, both light and heat initiators can be used in combination.

As the radical polymerization initiator, a photopolymerization initiator is preferable, and among them, an alkylphenone compound or a phosphine oxide compound is preferable. In particular, a compound having an α-hydroxyacetophenone structure or an acylphosphine oxide structure is preferable. The compound that initiates cationic polymerization, e.g., diazonium, ammonium, iodonium, sulfonium, and _B of an aromatic onium compound such as phosphonium ^{_{(C 6 F 5) 4 -}} , PF 6 -, AsF 6 -, SbF 6 ^-, and CF 3 _SO 3 ^_- ionic polymerization initiator or sulfonated compound generating a sulfonic acid such as salts or halides or generates hydrogen halide, be mentioned nonionic polymerization initiators such as iron arene complex, Can do. In particular, a sulfonate that generates a sulfonic acid that is a nonionic polymerization initiator or a halide that generates a hydrogen halide is preferable.

  On the other hand, as the thermal polymerization initiator, ketone peroxide compounds, peroxyketal compounds, hydroperoxide compounds, dialkyl peroxide compounds, diacyl peroxide compounds, peroxydicarbonate compounds, or peroxy esters These thermal polymerization initiators are published in company product catalogs and the like.

  These polymerization initiators can be used alone or in combination of two or more.

It is preferable that the addition amount of a polymerization initiator is 0.1-20 mass parts with respect to 100 mass parts of polymeric compounds, More preferably, it is 0.5-10 mass parts. When the addition amount of the polymerization initiator is within this range, the crosslinking of the resin in the protective layer proceeds sufficiently, and the universal hardness HU of the photoreceptor surface can be set within the range of 200 to 500 N / mm ² .

The universal hardness HU of the surface of the photoreceptor is a hardness value obtained from a surface film physical property test using a Fisherscope H100V (trade name) manufactured by Fisher Instruments in accordance with ISO / FDIS14577. For the measurement, a square pyramid diamond indenter having a facing angle of 136 ° is used. The hardness value is obtained by stepping the measurement load F (unit: N) on the indenter and pushing it into the sample to be measured, and the indentation depth h (unit: mm) when the load is applied. It is a value calculated by the following formula (A). In the following formula (A), K = 1 / 26.43.
Formula (A): HU = K × F / h ² [N / mm ² ]

  In the photoreceptor, various known layers can be adopted as layers other than the protective layer.

(Charging means)
The charging unit 113Y is a unit that uniformly charges the surface of the photoreceptor 111Y to a negative polarity. As the charging unit 113Y, for example, a corona discharge type charger is used.

[Exposure means]
The exposure unit 115Y exposes the surface of the photoreceptor 111Y to which the uniform potential is applied by the charging unit 113Y based on an image signal (yellow image signal), and forms an electrostatic latent image corresponding to the yellow image. It is means to do. As the exposure means 115Y, a device composed of an LED in which light emitting elements are arranged in an array in the axial direction of the photoconductor 111Y and an imaging element, or a laser optical system is used.

[Development means]
The developing unit 117Y is a unit that supplies toner to the surface of the photoreceptor 111Y, develops the electrostatic latent image formed on the surface of the photoreceptor 111Y, and forms a toner image. Specifically, the developing means 117Y in this example includes a housing in which the developer is accommodated, a developing sleeve that is provided in the housing and rotates while holding the developer, a photoconductor, and the photoconductor. It comprises a developing device constituted by a voltage applying device for applying a direct current and / or alternating current bias voltage between the developing sleeves.

[Transfer means]
The primary transfer roller 133Y constituting the transfer means is a means for transferring the toner image formed on the photoreceptor 111Y to the endless belt-like intermediate transfer body 131. The primary transfer roller 133Y is disposed in contact with the intermediate transfer member 131.

  In this image forming apparatus 100, the toner images formed on the photoconductors 111Y, 111M, 111C, and 111Bk are transferred to the intermediate transfer body 131 by primary transfer rollers (primary transfer means) 133Y, 133M, 133C, and 133Bk. An intermediate transfer method is employed in which each toner image transferred onto the transfer member 131 is transferred to a transfer material P by a secondary transfer roller (secondary transfer means) 217. However, the toner image formed on the photosensitive member is not transferred. A direct transfer method in which the image is directly transferred onto a transfer material by a transfer unit may be employed.

[Cleaning means]
The cleaning unit 119Y is a unit that removes toner remaining on the surface of the photoreceptor 111Y. The cleaning means 119Y in this example is constituted by a cleaning blade. The cleaning blade is disposed in a state where the tip of the cleaning blade faces in a direction (counter direction) opposite to the rotation direction of the photoconductor 111Y at a contact portion with the surface of the photoconductor 111Y.

The intermediate transfer member 131 is wound around a plurality of rollers 137, 137, 137, and 137 and is rotatably supported.
On the intermediate transfer member 131, a cleaning unit 135 for removing the toner remaining on the intermediate transfer member is disposed.

  The sheet feeding / conveying means 150 is provided so that the transfer material P in the sheet feeding cassette 211 can be conveyed to the secondary transfer roller 217 via a plurality of intermediate rollers 213A, 213B, 213C, 213D and a registration roller 215.

  The fixing unit 170 fixes the color image transferred by the secondary transfer roller 217. The paper discharge roller 219 is provided so as to be placed on the paper discharge tray 221 with the transfer material P that has been subjected to the fixing process interposed therebetween.

  In the image forming apparatus 100 configured as described above, a toner image is formed by the image forming units 110Y, 110M, 110C, and 110Bk. Specifically, first, the charging means 113Y, 113M, 113C, and 113Bk are discharged to the surface of the photoreceptors 111Y, 111M, 111C, and 111Bk to be negatively charged. Next, the surface of the photoconductors 111Y, 111M, 111C, and 111Bk is exposed based on the image signal by the exposure means 115Y, 115M, 115C, and 115Bk, and an electrostatic latent image is formed. Thereafter, with the developing means 117Y, 117M, 117C, and 117Bk, toner is applied to the surface of the photoreceptors 111Y, 111M, 111C, and 111Bk and developed to form a toner image.

  Next, primary transfer rollers (primary transfer means) 133Y, 133M, 133C, and 133Bk are brought into contact with the rotating intermediate transfer member 131. As a result, the toner images of the respective colors formed on the photoreceptors 111Y, 111M, 111C, and 111Bk are sequentially transferred onto the rotating intermediate transfer member 131 to transfer the color image (primary transfer). During the image forming process, the primary transfer roller 133Bk is always in contact with the photoreceptor 111Bk. On the other hand, the other primary transfer rollers 133Y, 133M, and 133C are in contact with the corresponding photoreceptors 111Y, 111M, and 111C, respectively, only during color image formation.

  Then, after separating the primary transfer rollers 133Y, 133M, 133C, and 133Bk from the intermediate transfer member 131, the toner remaining on the surfaces of the photosensitive members 111Y, 111M, 111C, and 111Bk is cleaned with the cleaning units 119Y, 119M, 119C, and 119Bk. Remove with. Thereafter, in preparation for the next image forming process, the lubricant is supplied to the surfaces of the photoreceptors 111Y, 111M, 111C, and 111Bk by the lubricant supply means 116Y, 116M, 116C, and 116Bk, and if necessary, the photoreceptors 111Y, 111M, and 111C. , 111Bk is neutralized by a neutralizing means (not shown) and then negatively charged by charging means 113Y, 113M, 113C, 113Bk.

  On the other hand, a transfer material P (for example, a support for carrying a final image such as plain paper or a transparent sheet) accommodated in a paper feed cassette 211 is fed by a paper feed / conveying means 150 and a plurality of intermediate rollers 213A and 213B. 213C, 213D, and registration rollers 215, and then conveyed to a secondary transfer roller (secondary transfer means) 217. Then, the secondary transfer roller 217 is brought into contact with the rotating intermediate transfer member 131 to transfer the color image onto the transfer material P in a lump (secondary transfer). The secondary transfer roller 217 contacts the intermediate transfer member 131 only when performing secondary transfer on the transfer material P. Thereafter, the transfer material P on which the color images are collectively transferred is separated at a portion where the curvature of the intermediate transfer member 131 is high.

  The transfer material P onto which the color images have been transferred in this way is fixed by the fixing unit 170 and then sandwiched by the paper discharge roller 219 and placed on the paper discharge tray 221 outside the apparatus. Further, after separating the transfer material P onto which the color image has been collectively transferred from the intermediate transfer member 131, the residual toner on the intermediate transfer member 131 is removed by the cleaning unit 135.

  As described above, according to the image forming apparatus of the present invention, since the above-described solid lubricant is used, the surface of the photoreceptor by the specific fatty acid amide can be obtained while basically obtaining good cleaning properties even in a low temperature and low humidity environment. As a result, the toner adhering to the photosensitive member and the adhesion of the lubricant to the photosensitive member can be suppressed, so that the lubricant can be prevented from being mixed into the developing device and the toner can be kept in good chargeability. The occurrence of fog is suppressed.

〔toner〕
The toner used in the image forming apparatus of the present invention is not particularly limited, and includes toner particles containing a binder resin and a colorant. The toner particles may include other components such as a release agent as desired. May be contained.
The toner particles constituting the toner preferably have a volume average particle diameter of 2 to 8 μm from the viewpoint of achieving high image quality.

  The method for producing the toner is not particularly limited. For example, a known pulverization method, a wet melt spheronization method prepared in a dispersion medium, suspension polymerization, dispersion polymerization, emulsion polymerization aggregation method and the like are known. And the like.

  In addition, an appropriate amount of inorganic fine particles such as silica and titania having an average particle diameter of about 10 to 300 nm and an abrasive of about 0.2 to 3 μm can be externally added to the toner particles as external additives.

The toner can be used as a magnetic or nonmagnetic one-component developer, but may be mixed with a carrier and used as a two-component developer.
In the case where the toner is used as a two-component developer, the carrier may be a conventionally known material such as a ferromagnetic metal such as iron, an alloy such as ferromagnetic metal and aluminum and lead, and a compound of ferromagnetic metal such as ferrite and magnetite. In particular, ferrite is preferable.

  As mentioned above, although embodiment of this invention was described concretely, embodiment of this invention is not limited to said example, A various change can be added.

  Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto.

[Production Example 1 of Solid Lubricant]
3 kg of zinc stearate and 3 kg of stearamide were powder mixed to obtain a powder mixture. This powder mixture was filled into an injection molding machine to produce a rod-shaped solid lubricant [1] of 0.8 mm × 1.0 mm × 330 mm.

[Production Examples 2 to 16 of solid lubricant]
In Preparation Example 1 of the solid lubricant, the solid lubricants [2] to [16] were changed in the same manner except that the type and content ratio of the fatty acid amide and the content ratio of the fatty acid metal salt were changed according to Table 1. Produced.

<Examples 1-9, Comparative Examples 1-7>
As the solid lubricant of the lubricant supply means of the image forming apparatus “bizhub PRESS C8000” (manufactured by Konica Minolta Co., Ltd.), an evaluation machine was prepared in which each of the solid lubricants [1] to [16] was attached. The following evaluation was performed using this evaluation machine. The results are shown in Table 2.

(1) Evaluation of fogging For A3 fine paper, first, measure the average image density at 20 locations using a Macbeth reflection densitometer “RD-918” (manufactured by Macbeth Co., Ltd.) and average the blank paper density. It was. Next, an endurance test was performed in which 50,000 sheets of solid images with a printing rate of 100% were output to A3 fine paper (64 g / m ² ) in a low temperature and low humidity environment (temperature 10 ° C., humidity 10% RH). Thereafter, a blank paper image on which nothing was printed was output, and the absolute image density at 20 locations was similarly measured and averaged, and the value obtained by subtracting the blank paper density from this average density was evaluated as the fog density. In Table 2, “A” is a fog density of less than 0.003, “B” is a fog density of 0.003 or more and less than 0.006, “C” is a fog density of 0.006 or more and less than 0.010, “D” The fog density is 0.010 or more. In the present invention, the case where the fog density is less than 0.006, that is, “A” or “B” is regarded as acceptable.

(2) Evaluation of cleaning performance The evaluation machine was modified so that the contact pressure of the cleaning blade to the photosensitive member could be changed to 4.0 gf / mm ² or 7.0 gf / mm ² , and the printing rate was 100% after the above durability test. A solid image (A3 fine paper) was output, and the obtained test image was visually observed and evaluated according to the following evaluation criteria. The angle formed between the cleaning blade and the photosensitive member was 7.5 °. In the present invention, the case of “A” or “B” is regarded as acceptable.
-Evaluation criteria-
A: When the contact pressure is 4.0 gf / mm ² , toner slip-through is not visually recognized on the test image.
B: When the contact pressure is 7.0 gf / mm ² , no toner slips out on the test image.
C: The toner slip is visually recognized on the test image when the contact pressure is 7.0 gf / mm ² .

(3) Evaluation of formability The solid lubricants [1] to [16] were visually observed and evaluated according to the following evaluation criteria. In the present invention, the case of “A” or “B” is regarded as acceptable.
-Evaluation criteria-
A: The solid lubricant is not cracked or chipped at all.
B: Cracking or chipping in the solid lubricant is confirmed at one place or two places.
C: Three or more cracks and chips are confirmed in the solid lubricant.

21 Lubricant supply roller 22 Solid lubricant 23 Press spring 24 Belt-like rotating body 24a Press roller 24b Application belt 25 Scraping brush roller 100 Image forming apparatus 110Y, 110M, 110C, 110Bk Image forming unit 111Y, 111M, 111C, 111Bk Photoconductor 113Y, 113M, 113C, 113Bk Charging means 115Y, 115M, 115C, 115Bk Exposure means 116Y Lubricant supply means 117Y, 117M, 117C, 117Bk Developing means 118Y Leveling blades 119Y, 119M, 119C, 119Bk Cleaning means 131 Intermediate transfer body 133Y, 133M, 133C, 133Bk Primary transfer roller 135 Cleaning means 137 Roller 150 Feeding and conveying means 170 Fixing means 211 Feeding cassettes 213A and 213B 213C, 213D intermediate roller 215 registration rollers 217 secondary transfer roller 219 discharge rollers 221 discharge tray P transfer material SC document image reading apparatus

Claims (5)

The lubricant applied to the surface of the photoreceptor provided in the electrophotographic image forming apparatus is a solid lubricant formed into a solid state,
A solid lubricant comprising a fatty acid metal salt and a fatty acid amide represented by the following general formula (1), wherein a content ratio of the fatty acid amide is 5 to 70% by mass.
Formula _{(1): CH 3 - (} CH 2) n -CONH 2
[In said formula, n shows the integer of 10-20. ] The fatty acid metal salt is zinc stearate;
2. The solid lubricant according to claim 1, wherein the fatty acid amide is a compound in which n in the general formula (1) is an integer of 14 to 18. 3.   The solid lubricant according to claim 1 or 2, wherein a content ratio of the fatty acid amide is 30 to 50% by mass. A photosensitive member; a charging unit that charges the surface of the photosensitive member; an exposure unit that exposes the photosensitive member charged by the charging unit to form an electrostatic latent image; and a photosensitive member on which the electrostatic latent image is formed. A developing unit that supplies toner to the body to form a toner image; a transfer unit that transfers the toner image onto a transfer material; a cleaning unit that removes toner remaining on the surface of the photoconductor with a cleaning blade; An image forming apparatus comprising a lubricant supply means for applying and supplying a lubricant to the surface of a body,
The image forming apparatus according to claim 1, wherein the lubricant in the lubricant supply unit is the solid lubricant according to claim 1. The photoreceptor has a protective layer on the organic photosensitive layer,
The protective layer contains a resin component composed of a cross-linked curable resin obtained by polymerizing a polymerizable compound having at least an acryloyl group or a methacryloyl group, and inorganic fine particles treated with a surface treatment agent having a polymerizable functional group The image forming apparatus according to claim 4.

Images