JP6528621B2 - Image forming device - Google Patents

Description

  The present invention relates to an image forming apparatus. In particular, the present invention relates to an image forming apparatus capable of maintaining high cleaning performance for a long time.

  The electrophotographic image forming apparatus exposes the charged photosensitive member to form an electrostatic latent image, supplies a toner and develops it, and transfers the obtained image onto a sheet. After transfer, a cleaning blade is brought into contact with the surface of the photosensitive member to remove the toner remaining on the photosensitive member, but maintaining high cleaning performance of the photosensitive member for a long period of time ensures high reliability of the image forming apparatus. And lead to durability.

  Conventionally, the hardness of the photosensitive member and the cleaning blade, the surface roughness of the photosensitive member, and the like have been optimized in order to maintain high cleaning performance by suppressing abrasion of the photosensitive member and chipping of the cleaning blade. See, for example, Patent Documents 1 and 2.).

For example, in Patent Document 1 mentioned above, a combination of a photoconductor having a universal hardness of 150 to 220 N / mm ² and a cleaning blade having a rubber hardness of 78 to 99 ° is mentioned.
However, with respect to the hardness of the cleaning blade, the hardness of the photosensitive member is insufficient to prevent abrasion, and the surface of the photosensitive member is roughened to cause toner slippage, so sufficient cleaning performance can be obtained. Absent.

On the other hand, in Patent Document 2 described above, a photosensitive member roughened to have a maximum height roughness (Rz) in the range of 0.2 to 1.5 μm, and a JIS-A hardness of 75 to 95 °. A combination of cleaning blades within the range is mentioned.
Although the contact area between the photosensitive member and the cleaning blade can be reduced by roughening, abrasion of the photosensitive member and the cleaning blade can be suppressed, but since the surface irregularities are large, it is necessary to increase the hardness of the photosensitive member. However, for example, when a photosensitive member having a universal hardness of 220 N / mm ² or more is used, chipping occurs in a cleaning blade having a JIS-A hardness of 75 to 95 °.

JP 2005-164775 A JP, 2009-157103, A

  The present invention has been made in view of the above problems and circumstances, and an object thereof is to provide an image forming apparatus capable of maintaining high cleaning performance for a long time.

  In the process of examining the cause of the above problems and the like in order to solve the above problems, the inventor of the present invention can obtain high cleaning performance by suppressing the abrasion of both by increasing the hardness of the photosensitive member and the cleaning blade. The inventors have found that by reducing unevenness on the body surface, a cleaning blade with high hardness can be caught on the unevenness and chipping can be suppressed, resulting in the present invention.

That is, the subject concerning the present invention is solved by the following means.
1. A photoreceptor carrying an image developed by the supply of toner;
And a cleaning blade that abuts on the surface of the photosensitive member to remove toner on the photosensitive member.
The maximum height roughness Rz of the surface of the photosensitive member is 0.060 μm or less, and the universal hardness is in the range of 220 to 300 N / mm ² .
An image forming apparatus, wherein the JIS-A hardness of the cleaning blade is in a range of 80 to 100 °.

2. The cleaning blade is
Contains polyurethane,
The image forming apparatus according to claim 1, wherein a cured layer containing a polymer of the polyurethane and an isocyanate compound is provided in a portion in contact with the photosensitive member.

  3. The cleaning blade is inclined at an angle within a range of 5 to 20 ° with respect to the surface of the photosensitive member, and is in contact with a linear pressure within a range of 13 to 30 N / m. Item 2. The image forming apparatus according to Item 2 or 3.

4. The photoreceptor has a protective layer on the outermost surface,
The image forming apparatus according to any one of Items 1 to 3, wherein the protective layer contains a binder resin and metal oxide particles.

  5. The image forming apparatus according to any one of claims 1 to 4, further comprising a lubricant supply unit configured to supply a lubricant to the surface of the photosensitive member.

  6. 6. The image forming apparatus according to claim 5, wherein the lubricant supply unit is a developing unit that supplies the toner to which the lubricant is externally added onto the photosensitive member.

  According to the above-described means of the present invention, it is possible to provide an image forming apparatus capable of maintaining high cleaning performance for a long time.

The mechanism or mechanism of action of the effects of the present invention is not clear but is presumed as follows.
A high hardness photosensitive member having a universal hardness in the range of 220 to 300 N / mm ² has less wear and roughness on the surface of the photosensitive member due to long-term use, and toner slippage and in-plane density unevenness can be suppressed.
By using a high hardness cleaning blade having a JIS-A hardness in the range of 80 to 100 ° with respect to the high hardness photoconductor, wear of the cleaning blade during long-term use can be reduced and the toner scraping ability can be reduced. Can be enhanced.
In addition, when image formation is repeated, a discharge product generated at the time of charging may adhere to the photosensitive member to form a deteriorated layer on the surface. The deteriorated layer is low in slipperiness and has a large friction with the cleaning blade, and therefore, the image blur due to blurring or vibration of the cleaning blade is likely to occur, but if the cleaning blade has high hardness, the image flow The surface of the photosensitive member can be refreshed by scraping off the deteriorated layer which is a factor.
If the photosensitive member and the cleaning blade have high hardness, the cleaning blade is easily caught on the unevenness of the photosensitive member and chipping is likely to occur, but the photosensitive member with the maximum height roughness Rz of 0.060 μm or less has few unevenness, so chipping It is surmised that toner slippage and the like can be effectively suppressed, and high cleaning performance can be maintained for a long time.

Front view showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention Close-up view of the contact part between the photoreceptor and the cleaning blade Cross-sectional view showing the configuration of the photosensitive member

The image forming apparatus according to the present invention comprises a photosensitive member carrying an image developed by the supply of toner, and a cleaning blade coming into contact with the surface of the photosensitive member to remove the toner on the photosensitive member. The maximum height roughness Rz of the surface of the photosensitive member is 0.060 μm or less, the universal hardness is in the range of 220 to 300 N / mm ² , and the JIS-A hardness of the cleaning blade is 80 to 100 °. An image forming apparatus characterized by being within the range is provided. This feature is a technical feature common to the inventions according to claims 1 to 6.

  As an embodiment of the present invention, the cleaning blade contains a polyurethane and contains a polymer of the polyurethane and an isocyanate compound, from the viewpoint of facilitating compatibility between the flexibility of the cleaning blade and the high hardness of the above range. It is preferable to provide a hardened layer at a portion in contact with the photosensitive member.

  Further, from the viewpoint of obtaining higher cleaning performance, the cleaning blade is inclined at an angle within the range of 5 to 20 ° with respect to the surface of the photosensitive member, and at a linear pressure within the range of 13 to 30 N / m. It is preferable to be in contact.

  Further, from the viewpoint of obtaining high hardness in the above-mentioned range, it is preferable that the photosensitive member has a protective layer on the outermost surface, and the protective layer contains a binder resin and metal oxide particles.

Further, from the viewpoint of prolonging the life by reducing the wear of the photosensitive member and the cleaning blade, it is preferable to include a lubricant supply unit for supplying a lubricant to the surface of the photosensitive member.
The lubricant supply unit may be a developing unit for supplying the toner to which the lubricant is externally added onto the photosensitive member.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention, its components, and modes for carrying out the present invention will be described in detail below.
In the present application, “to” is used in the meaning including the numerical values described before and after that as the lower limit value and the upper limit value.

[Image forming apparatus]
FIG. 1 shows a schematic configuration of an image forming apparatus 1 according to an embodiment of the present invention.
As shown in FIG. 1, the image forming apparatus 1 includes a writing unit 21, a transfer roller 23, a fixing device 24, and a sheet feeding tray 25.
The writing unit 21 includes a drum-shaped photosensitive member 2a, a charging unit 2b disposed along the rotational direction of the photosensitive member 2a, an exposure unit 2c, a developing unit 2d, and a cleaning device 2e.

At the time of image formation, in the writing unit 21, after the charging unit 2 b applies a uniform potential to the photosensitive member 2 a to charge it, the light beam emitted by the exposure unit 2 c scans the photosensitive member 2 a based on the original image data. Form an electrostatic latent image. The exposure unit 2c includes a polygon mirror that deflects a light beam emitted by a light source such as an LED, an optical system that guides the light beam to the photosensitive member 2a, and the like.
Next, the toner is supplied onto the photosensitive member 2a by the developing unit 2d. The photosensitive member 2a carries an image developed by the supply of toner.

When the sheet P is fed from the paper feed tray 25 at the timing when the image carried on the photosensitive member 2a reaches the position of the transfer roller 23 by the rotation of the photosensitive member 2a, the sheet is nipped by the transfer roller 23 and the photosensitive member 2a. The image on the photosensitive member 2a is transferred onto the paper P. After transfer, the toner remaining on the photosensitive member 2a is removed by the cleaning device 2e.
Next, the sheet P on which the image is transferred is heated and pressed by the fixing device 24 to fix the image on the sheet P. When forming an image on both sides of the sheet P, the sheet P is transported to the transport path 26 to reverse the sheet surface, and then the sheet P is fed again to the position of the transfer roller 23.

FIG. 2 is an enlarged view of the photosensitive member 2a near the cleaning device 2e.
As shown in FIG. 2, the cleaning device 2e includes a cleaning blade 51 that abuts on the surface of the photosensitive member 2a to remove residual toner on the photosensitive member 2a, and a support 53 of the cleaning blade.
The photosensitive member 2a has a maximum surface roughness Rz of 0.060 μm or less and a universal hardness (HU) of the surface in the range of 220 to 300 N / mm ² .
Further, the cleaning blade 51 has a JIS-A hardness of 80 to 100 ° in the contact portion with the photosensitive member 2a.

The photosensitive member 2a having a high hardness of 220 N / mm ² or more with a universal hardness (HU) has a small penetration of the cleaning blade 51 and is hard to be drawn in, so that the toner can be effectively prevented from slipping through. If the universal hardness is too high, the deteriorated layer formed by oxidation of the surface can not be removed, and image flow is likely to occur, but the universal hardness of the photosensitive member 2a is 300 N / mm ² or less. A high-hardness cleaning blade having a hardness of 80 ° or more can scrape away the deteriorated layer that causes image flow.

  For such a high hardness photosensitive member 2a, the wear of the cleaning blade 51 due to contact with the photosensitive member 2a is reduced by using a high hardness cleaning blade 51 having a JIS-A hardness of 80 ° or more. , Can extend the life. Since the JIS-A hardness of the cleaning blade 51 is 100 ° or less, sufficient toughness can be imparted to the cleaning blade 51, and chipping due to rubbing with an external additive on the surface of the toner can be reduced. Further, since the cleaning blade 51 with high hardness has a large pressing force and a high toner scraping force, the cleaning performance can be enhanced.

  When a high hardness cleaning blade 51 is used for the high hardness photosensitive member 2a, if the surface of the photosensitive member 2a is rough and has a large number of irregularities, the cleaning blade 51 is likely to abrade on the convex portion to cause chipping. However, the maximum height roughness Rz of the surface of the photosensitive member 2a is 0.060 μm or less, and there are few irregularities. Therefore, it is possible to reduce the chipping due to the unevenness and to effectively suppress the toner slipping through due to the chipping.

[Cleaning device]
The JIS-A hardness of the cleaning blade 51 described above refers to a value measured at a temperature of 25 ° C. using a type A durometer in accordance with the hardness test method defined in JIS K6253.

As a material of the cleaning blade 51, for example, polyurethane, silicone rubber, fluororubber, chloropyrene rubber, butadiene rubber or the like can be used. Among them, polyurethane is preferable in that appropriate strength and flexibility capable of coming into contact with the rotating photosensitive member 2a can be obtained.
The cleaning blade 51 using polyurethane is prepared, for example, by mixing a dehydrated polyol and an isocyanate compound, and reacting the mixture in a temperature range of 100 to 120 ° C. for 30 to 90 minutes to add a crosslinking agent to the prepolymer obtained. It can be manufactured by pouring into a mold and curing.

  The cleaning blade 51 having a JIS-A hardness in the above range can be obtained by selection of materials, adjustment of the degree of crosslinking, and the like. For example, when using a polyurethane, JIS-A hardness can be adjusted in the said range by changing the density | concentration of a polyol and an isocyanate compound, reaction time, etc. and adjusting to a large crosslinking degree.

  For example, polyester polyols such as polyethylene adipate and polycaprolactone can be used as the polyol, and diphenylmethane diisocyanate can be used as the isocyanate compound. Moreover, as a crosslinking agent, 1, 4- butanediol, trimethylol propane, ethylene glycol, these mixtures etc. can be used.

The cleaning blade 51 may have the entire JIS-A hardness in the above range, but as shown in FIG. 2, the hardened layer 52 having the JIS-A hardness in the above range is in contact with the photosensitive member 2a. The configuration may be provided in the part.
The hardness of the main body of the cleaning blade 51 is obtained such that the softness of the cleaning blade 51 appropriately bends when the cleaning blade 51 abuts on the photosensitive member 2 a by making only the contact portion a hardened layer 52 of high hardness It will be easier to adjust the.

The hardened layer 52 may be a layer provided on the surface of the cleaning blade 51, but from the viewpoint of enhancing the durability, it is preferable that the layer be a part of the main body of the cleaning blade 51 processed.
When polyurethane is used as the base of the cleaning blade 51, the contact portion of the cleaning blade 51 with the photosensitive member 2a is impregnated with an isocyanate compound for a certain period of time, and the polyurethane contained in the cleaning blade 51 is reacted with the isocyanate compound. The reaction portion can be formed as the hardened layer 52.

  The cured layer 52 formed as described above contains a polymer of polyurethane and an isocyanate compound. The polyurethane constituting the cleaning blade 51 has a urethane bond having active hydrogen, and the polyurethane contained in the cleaning blade 51 and the hardened layer 52 are produced by reacting the urethane bond with the impregnated isocyanate compound. An allophanate bond that enhances the hardness of the cured layer 52 can be formed between the polymer contained. In addition, since the multimerization reaction of the impregnated isocyanate compound also proceeds simultaneously, a thick cured layer 52 can be formed, and even if the cured layer 52 is worn, the cured layer 52 is thick, so that the cleaning blade 51 is good. JIS-A hardness can be maintained for a long time.

  The cleaning blade 51 has an inclination angle θ of 5 to 20 ° with respect to the surface of the photosensitive member 2a, as shown in FIG. 2, from the viewpoint of enhancing the scraping power of the residual toner and obtaining higher cleaning performance. It is preferable to contact | abut by the linear pressure within the range of 13-30 N / m.

  The size of the cleaning blade 51 can be appropriately selected, but in general, the width can be 5 to 30 mm, the thickness 2 to 3 mm, and the length 200 to 500 mm.

From the viewpoint of reducing the friction between the photosensitive member 2a and the cleaning blade 51 and prolonging the life of the both, as shown in FIG. 2, the cleaning device 2e is a lubricant supplying portion disposed along the rotational direction of the photosensitive member 2a. It is preferable to provide 2f.
The lubricant supplying portion 2 f scrapes out the solid lubricant 41 urged by the pressing member 43 by the brush roller 42 to supply lubricant particles to the surface of the photosensitive member 2 a.

  The developing unit 2d can be used as the lubricant supply unit 2f, and the toner to which the lubricant is externally added can be supplied onto the photosensitive member 2a by the developing unit 2d.

  As lubricants, fatty acid metal salts such as calcium undecylate, calcium laurate, calcium stearate, zinc stearate, zinc laurate, strontium stearate, strontium laurate and barium stearate can be used. A divalent metal salt is preferable to a monovalent metal salt because it is less deteriorated by discharge at the time of charging and the like and image flow can be suppressed.

[Photoreceptor]
As described above, the photosensitive member 2a has the maximum surface roughness Rz of 0.060 μm or less and the universal hardness (HU) of the surface in the range of 220 to 300 N / mm ² .
The maximum height roughness Rz can be calculated from the surface roughness curve measured according to JIS B0601: 2013. The roughness curve can be measured by a stylus type surface roughness measuring device according to JIS B 0601: 2013, a non-contact type surface analysis device using a laser or the like, or the like.
The following conditions are mentioned as a measurement condition at the time of using a stylus type surface roughness measuring device.
(Measurement condition)
Measuring device: Surfcom 1400D (made by Tokyo Seimitsu Co., Ltd.)
Measurement mode: Roughness measurement Measurement length: 20.0 mm
Cutoff: 0.08 mm (Gaussian)
Measuring speed: 0.15 mm / sec

The photoreceptor 2a having the maximum height roughness Rz in the above range can be manufactured, for example, by polishing or processing the surface of the photoreceptor 2a.
The lower limit of the maximum height roughness Rz is preferably 0.020 μm or more. If it is 0.020 μm or more, the contact area between the photosensitive member 2 a and the cleaning blade 51 can be reduced, and the occurrence of the curling of the cleaning blade 51 can be suppressed.

Further, the universal hardness (HU) of the surface of the photosensitive member 2a can be measured by Fischer Scope H100 (a hardness test system manufactured by Fisher Instruments Inc. in accordance with ISO / FDIS 14577).
Specifically, in Fisher scope H100, load F (N) is applied stepwise to a square pyramidal diamond indenter whose facing angle is specified as 136 ° (maximum load 2 mN), and the indenter is pressed into the sample The universal hardness (HU) is calculated from the indentation depth h (mm) and the load F at that time according to the following equation.
HU (N / mm ² ) = F / (26.43 × h ² )

  When the photosensitive member 2a is provided with a protective layer on the outermost surface, and the protective layer contains a binder resin and metal oxide particles, it is possible to obtain the photosensitive member 2a having a universal hardness (HU) within the above range.

FIG. 3 is a cross-sectional view showing a schematic configuration of the photosensitive member 2a.
As shown in FIG. 3, the photosensitive member 2a includes an intermediate layer 32, a photosensitive layer 33, and a protective layer 34 in this order on a drum-shaped conductive support 31.

[Protective layer]
The protective layer 34 is provided on the outermost surface of the photosensitive member 2 a from the viewpoint of protecting the photosensitive member 2 a from external force. The protective layer 34 located on the outermost surface is subjected to surface processing so that the maximum height roughness Rz of the surface is 0.060 μm or less as described above.

The protective layer 34 preferably contains a binder resin and metal oxide particles, because it is easy to obtain the photosensitive member 2 a having the above-mentioned universal hardness (HU).
Examples of the binder resin include polyester resin, polycarbonate resin, polyurethane, and silicone resin. Among them, from the viewpoint of enhancing the wear resistance and durability of the photosensitive member 2a, a cured resin obtained by polymerizing and curing a polymerizable compound by irradiation of active rays such as ultraviolet rays and electron beams is preferable. A cured resin and a non-cured resin can also be used in combination.

(Curing resin)
As a polymerizable compound which can be used for the cured resin, a monomer (polyfunctional polymerizable compound) having two or more polymerizable functional groups can be used, and a monomer having one polymerizable functional group (monofunctional polymerizable compound) ) Can also be used together.
As the polymerizable compound, a monomer having three or more polymerizable functional groups can be used. Moreover, when using together 2 or more types of polymeric compounds, it is preferable to use the monomer which has 3 or more of polymerizable functional groups in the ratio of 50 mass% or more.

Specific examples of the polymerizable compound include styrene monomers, acrylic monomers, methacrylic monomers, vinyl toluene monomers, vinyl acetate monomers, N-vinylpyrrolidone monomers, and the like. One of these may be used alone, or two or more of these may be used in combination.
Among them, acrylic monomers having two or more of an acryloyl group (CH ₂ = CHCO-) or a methacryloyl group (CH ₂ = CCH ₃ CO-), or these, because they can be cured in a small amount of light or in a short time It is preferable that it is an oligomer of

Examples of the polymerizable compound include the following exemplified compounds (M1) to (M15), but the polymerizable substance that can be used in the present invention is not limited thereto.
In the following exemplified compounds (M1) to (M15), R represents an acryloyl group (CH ₂ CHCHCO—), and R ′ represents a methacryloyl group (CH ₂ CCCH ₃ CO—).

(Polymerization initiator)
Examples of a method of causing a polymerization reaction of a polymerizable compound that can be used for the protective layer 34 include a method of utilizing an electron beam cleavage reaction, a method of utilizing light or heat in the presence of a radical polymerization initiator, and the like.
As a radical polymerization initiator, any of a photoinitiator and a thermal polymerization initiator can be used, and multiple types of combined use is also possible.

  As a photoinitiator, an alkyl phenone type compound, a phosphine oxide type compound, etc. can be used, and the compound which has an alpha-hydroxy acetophenone structure or an acyl phosphine oxide structure is preferable. Examples of commercial products of the photopolymerization initiator include bis (2,4,6-trimethyl benzoyl) phenyl phosphine oxide (IRGACURE 819: manufactured by BASF Japan Ltd.).

  As a thermal polymerization initiator, ketone peroxide compounds, peroxy ketal compounds, hydroperoxide compounds, dialkyl peroxide compounds, diacyl peroxide compounds, peroxy dicarbonate compounds, peroxy ester compounds, etc. Can be used.

The content of the polymerization initiator can be 0.1 to 40 parts by mass, preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable compound. Within this range, the polymerization of the polymerizable compound proceeds sufficiently, and the universal hardness of the surface of the photosensitive member 2a can be adjusted within the range of 220 to 300 N / mm ² .

(Radical scavenger)
A radical scavenger can also be used during the polymerization reaction to adjust the degree of polymerization.
As a commercial item of a radical scavenger, Sumilyzer GS (made by Sumitomo Chemical Co., Ltd.) etc. are mentioned, for example.

(Metal oxide particles)
Examples of metal oxide particles that can be used for the protective layer 34 include silica (silicon oxide), magnesium oxide, zinc oxide, lead oxide, alumina (aluminum oxide), zirconium oxide, tin oxide, titania (titanium oxide), niobium oxide And metal oxide particles such as molybdenum oxide and vanadium oxide. Among them, tin oxide, titanium oxide or zinc oxide is preferred, and tin oxide is more preferred because of its excellent electrical properties.
The method for producing the metal oxide particles is not particularly limited. For example, the indirect method (French method), the direct method (US method), the plasma method, etc. described in JIS K 1410 can be used.

The number average primary particle size of the metal oxide particles is preferably in the range of 1 to 300 nm, and more preferably in the range of 3 to 100 nm.
The number average primary particle size of the above metal oxide particles is a photographic image obtained by photographing a 10000 × magnification photograph with a scanning electron microscope (manufactured by Nippon Denshi) and randomly acquiring 300 particles by a scanner (excluding aggregated particles) Can be calculated using an automatic image processing and analysis apparatus LUZEX AP (manufactured by Nireco, software version Ver.1.32).

As the metal oxide particles, those in which reactive organic groups are introduced to the particle surfaces can be used by surface-treating the metal oxide particles with a surface treatment agent having reactive organic groups.
As a surface treatment agent, what reacts with the hydroxyl group etc. which exist on the surface of metal oxide particle is preferable, and a silane coupling agent, a titanium coupling agent, etc. are mentioned.
Moreover, as a surface treatment agent, it is also preferable to use a surface treatment agent having a radically polymerizable reactive group such as a vinyl group, an acryloyl group or a methacryloyl group. Such a radically polymerizable reactive group can also react with the polymerizable compound constituting the binder resin to form a strong protective layer 34. As a surface treatment agent which has a radically polymerizable reactive group, the silane coupling agent which has a radically polymerizable reactive group, a silane compound, etc. are preferable.

Hereinafter, exemplified compounds (S-1) to (S-30) of the surface treatment agent are shown.
_{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 CC (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

The surface treatment agent may be used alone or in combination of two or more.
The amount of the surface treatment agent used is preferably in the range of 0.1 to 200 parts by mass, more preferably 7 to 70 parts by mass with respect to 100 parts by mass of the metal oxide particles.

As a method of surface treatment, for example, there is a method of wet pulverizing a slurry (suspension of solid particles) containing metal oxide particles, a surface treatment agent and a solvent, and removing the solvent to form a powder. According to this method, surface treatment of the metal oxide particles can be advanced while preventing reaggregation of the metal oxide particles.
As a surface treatment apparatus, a sand mill, an ultravisco mill, a pearl mill, a grain mill, a dyno mill, an agitator mill, a dynamic mill etc. can be used, for example.

The protective layer 34 can further contain an antioxidant, lubricant particles, a charge transport agent, and the like.
As an antioxidant, the thing of Unexamined-Japanese-Patent No. 2000-305291 can be used, for example.
As the lubricant particles, fluorine atom-containing resin particles and the like can be used. As the fluorine atom-containing resin particles, for example, tetrafluoroethylene resin, trifluorochlorinated ethylene resin, hexafluorochlorinated ethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluoride dichloride ethylene resin, etc. are used it can.
In addition, as the charge transport agent, a charge transport substance contained in charge transport layer 33b described later can be used.

  The layer thickness of the protective layer 34 is preferably in the range of 0.2 to 10 μm, and more preferably in the range of 0.5 to 6 μm, from the viewpoint of obtaining sufficient impact resistance.

  The protective layer 34 can be formed by preparing a coating solution containing the above-described binder resin, metal oxide particles, and the like, applying the coating solution on the photosensitive layer 33, and then drying. When a cured resin is used as the binder resin, the protective layer 34 can be formed by forming a coating film containing a polymerizable compound, a polymerization initiator and the like on the photosensitive layer 33, and then drying and curing.

As the coating method, known methods such as immersion method, spray method, spinner method, bead method, blade method, beam method and slide hopper method can be used.
Drying may be natural drying or heat drying.

  When a cured resin is used as a binder resin, a coating film containing a polymerizable compound, a polymerization initiator, etc. may be irradiated with actinic radiation to form a cross-linking bond by cross-linking reaction between molecules and in a molecule to be cured. preferable. As the actinic radiation, ultraviolet light and electron beam are preferable.

As the ultraviolet light source, any light source that generates ultraviolet light can be used without limitation. For example, a mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp or the like can be used.
The irradiation conditions vary depending on individual lamps, irradiation of actinic rays is in the range of usually 5~500mJ / cm ^2, preferably in the range of 5 to 100 mJ / cm ^2.
The power of the lamp is preferably 0.1 kW to 5 kW, particularly preferably 0.5 kW to 3 kW.

  There is no particular limitation on the electron beam irradiation apparatus as an electron beam source, and in general, a curtain beam system capable of obtaining a large output at relatively low cost as an electron beam accelerator for such electron beam irradiation is effective. Used. The acceleration voltage at the time of electron beam irradiation is preferably 100 to 300 kV. The absorbed dose is preferably 0.5 to 10 Mrad.

  The irradiation time for obtaining the necessary actinic radiation dose is preferably 0.1 seconds to 10 minutes, and more preferably 0.1 seconds to 5 minutes from the viewpoint of working efficiency.

Hereinafter, each layer of the photoreceptor 2 a other than the protective layer 34 will be described.
[Conductive Support]
As the conductive support 31, if it has conductivity, for example, a drum formed of a metal such as aluminum, copper, chromium, nickel, zinc or stainless steel can be used.
When the photosensitive member 2a is not in the form of a drum but in the form of a belt, a plate, etc., a conductive polymer, a conductive material such as indium oxide or tin oxide, or a resin film on which a metal film such as aluminum or copper is formed A belt, a plate or the like using paper or the like can also be used as the conductive support 31.

[Intermediate layer]
The intermediate layer 32 can be provided as needed between the conductive support 31 and the photosensitive layer 33 from the viewpoint of enhancing the gas barrier properties and adhesion.

The intermediate layer 32 can be formed by dissolving a binder resin in a known solvent, dip coating or the like to form a coating film, and then drying.
As the binder resin, for example, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide, polyurethane, gelatin and the like can be used, and among them, alcohol-soluble polyamide resin is preferable.
The concentration of the binder resin can be appropriately selected in accordance with the layer thickness of the intermediate layer 32 and the production rate.

  The intermediate layer 32 is an inorganic particle such as alumina, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, metal oxide particles such as bismuth oxide, tin-doped indium oxide, antimony from the viewpoint of adjusting the resistance. And conductive fine particles such as tin oxide and zirconium oxide. These inorganic particles may be used alone or in combination of two or more, and when two or more are mixed, they may be in a solid solution or fused state.

The content of the inorganic particles is preferably in the range of 20 to 400 parts by mass of the inorganic particles with respect to 100 parts by mass of the binder resin, and more preferably in the range of 50 to 200 parts by mass.
The number primary average particle diameter of the inorganic particles is preferably 0.3 μm or less, more preferably 0.1 μm or less.

  0.1-15 micrometers is preferable and, as for the layer thickness of the intermediate | middle layer 32, 0.3-10 micrometers is more preferable.

[Photosensitive layer]
The photosensitive layer 33, as shown in FIG. 3, includes a charge generation layer 33a and a charge transport layer 33b.
When the light irradiated by the exposure portion 2c reaches the photosensitive layer 33, charges corresponding to the amount of light emitted are generated in the charge generation layer 33a, and the charges move in the charge transport layer 33b and the surface of the photoreceptor 2a The electrostatic latent image is formed.
The photosensitive layer 33 shown in FIG. 3 has a multilayer structure, but may have a single layer structure containing both a charge generating substance and a charge transporting substance.

[Charge generation layer]
The charge generation layer 33a contains a binder resin and a charge generation material that generates an electric charge when it absorbs light energy.
The charge generation layer 33a can be formed by drying a coated film formed by dispersing and applying a charge generation substance in a binder resin solution.

Examples of charge generating materials include azo raw materials such as sudan red and diane blue, quinone pigments such as pyrene quinone and anthanthrone, quinocyanine pigments, perylene pigments, indigo pigments such as indigo and thioindigo, and polycycles such as pyranthrone and diphthaloyl pyrene A quinone pigment, a phthalocyanine pigment, etc. are mentioned. These charge generation materials can be used alone or in the state of being dispersed in a known resin.
As a means for dispersing the charge generation material, for example, an ultrasonic disperser, a ball mill, a sand grinder, a homomixer or the like can be used.

  As the binder resin, known resins can be used. For example, polystyrene resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane, phenol resin, Polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, copolymer resin containing two or more of these resins (for example, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride) An acid copolymer resin etc., poly-vinyl carbazole resin etc. are mentioned.

The content of the charge generation substance in the charge generation layer 33a is preferably in the range of 1 to 600 parts by mass, more preferably 50 to 500 parts by mass with respect to 100 parts by mass of the binder resin. is there.
The layer thickness of the charge generation layer varies depending on the characteristics of the charge generation substance, the characteristics of the binder resin, the content, etc., but is preferably in the range of 0.01 to 5 μm, more preferably in the range of 0.05 to 3 μm. is there.

[Charge transport layer]
The charge transport layer 33 b contains a binder resin and a charge transport material (CTM: also referred to as Charge Transport Material).
The charge transport layer 33 b can be formed by dissolving a charge transport substance in a binder resin solution and applying it to form a coating film, and then drying.

Examples of the charge transport material include triphenylamine derivatives, hydrazone compounds, styryl compounds, benzidine derivatives, butadiene compounds and the like, and the following compound A and the like. You may use these individually or in mixture of 2 or more types.

  Examples of the binder resin include polycarbonate resin, polyacrylate resin, polyester resin, polystyrene resin, styrene-acrylonitrile copolymer resin, polymethacrylic acid ester resin, and styrene-methacrylic acid ester copolymer resin. Among them, polycarbonate resins are preferred, and from the viewpoint of enhancing the crack resistance, the abrasion resistance and the charging characteristics, bisphenol A (BPA) type, bisphenol Z (BPZ) type, dimethyl BPA type, BPA-dimethyl BPA copolymer type Polycarbonate resin and the like are preferable.

  The content of the charge transport substance in the charge transport layer 33b is preferably in the range of 10 to 500 parts by mass, and more preferably in the range of 20 to 250 parts by mass with respect to 100 parts by mass of the binder resin.

  The layer thickness of the charge transport layer 33b varies depending on the properties of the charge transport substance, the properties of the binder resin, the content and the like, but is preferably in the range of 5 to 40 μm, and more preferably in the range of 10 to 30 μm preferable.

The charge transport layer 33 b can further contain an antioxidant, an electron conductive agent, a stabilizer, a silicone oil, and the like.
Materials described in JP-A-2000-305291 as an antioxidant and JP-A-50-137543 and JP-A-58-76483 can be used as an electron conductive agent.

  Although the example of the monochrome image forming apparatus 1 is shown, the present invention can be applied to a color image forming apparatus.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in the Example, unless otherwise indicated, it represents "mass part" or "mass%."

[Photoreceptor 1]
(Conductive support)
The surface of an aluminum drum having a diameter of 100 mm and a height of 360 mm was cut to prepare a conductive support having a maximum height roughness Rz of 1.5 μm.

(Intermediate layer)
The following raw materials were dispersed using a sand mill as a dispersing machine to prepare a coating solution for an intermediate layer. Dispersion was performed for 10 hours by a batch system.
Polyamide resin X1010 (binder resin manufactured by Daicel-Evonik): 1 part by mass Ethanol (solvent): 20 parts by mass Titanium oxide fine particles SMT500SAS (number average primary particle diameter 0.035 μm metal oxide fine particles manufactured by Tayca Corporation): 1 .1 Part by Mass The prepared coating solution for an intermediate layer is applied by dip coating onto the above-mentioned conductive support to form a coated film, and this coated film is dried at 110 ° C for 20 minutes, and the layer thickness is 2 μm. Formed an intermediate layer.

(Charge generation layer)
The following raw materials were dispersed using a sand mill as a disperser to prepare a coating solution for charge generation layer. Dispersion was performed for 10 hours.
Titanyl phthalocyanine pigment (a charge generating material having a maximum diffraction peak at a position of at least 5 at 27.3 ° according to Cu-Kα characteristic X-ray diffraction spectrum measurement): 20 parts by mass Polyvinyl butyral resin # 6000-C (manufactured by Denki Kagaku Kogyo Co., Ltd.) Binder resin): 10 parts by mass t-butyl acetate (solvent): 700 parts by mass 4-methoxy-4-methyl-2-pentanone (solvent): 300 parts by mass Coating for the charge generating layer prepared on the above-mentioned intermediate layer The solution was applied by a dip coating method to form a coating film, and a charge generation layer having a layer thickness of 0.3 μm was formed.

(Charge transport layer)
The following raw materials were mixed and dissolved to prepare a coating solution for charge transport layer.
Compound (charge transport material) having a structure represented by the above formula (A): 150 parts by mass Polycarbonate resin Z300 (binder resin manufactured by Mitsubishi Gas Chemical Company): 300 parts by mass Mixed solvent of toluene and tetrahydrofuran (toluene / tetrahydrofuran Volume ratio is 1/9): 2000 parts by mass Irganox 1010 (antioxidant manufactured by Nippon Ciba Geigy): 6 parts by mass Silicone oil KF-54 (leveling agent manufactured by Shin-Etsu Chemical Co., Ltd.): 1 part by mass

  The prepared coating for a charge transport layer is applied onto the charge generation layer by dip coating to form a coated film, and the coated film is dried at 120 ° C. for 70 minutes to form a charge transport layer having a layer thickness of 20 μm. Formed.

(Protective layer)
Using a sand mill as a disperser, the following polymerizable compound, solvent and metal oxide fine particles were dispersed for 10 hours under light shielding. Further, the following photopolymerization initiator and radical scavenger were added, mixed, stirred and dissolved under light shielding to prepare a coating solution for a protective layer.
Trimethylolpropane trimethacrylate (polymerizable compound): 100 parts by mass sec-butanol (solvent): 315 parts by mass Tetrahydrofuran (solvent): 15 parts by mass Tin oxide particles having a number average primary particle diameter of 20 nm ((CH ₂ CC (CH) ₃ ) Metal oxide fine particles surface-treated with a surface treatment agent having a structure represented by the formula COO (CH ₂ ) ₂ Si (OCH ₃ ) ₃ ): 150 parts by mass Irgacure 819 (BASF Japan Ltd. light) Polymerization initiator): 12 parts by mass Sumilyzer GS (a radical scavenger manufactured by Sumitomo Chemical Co., Ltd.): 7 parts by mass

The coating solution prepared above was applied onto the charge transport layer using a circular slide hopper coating apparatus to form a coating film. The coated film is dried at room temperature for 20 minutes, and then irradiated with light of 365 nm at a lamp output of 4 kW for 18 seconds using a xenon lamp as a light source under a nitrogen flow of 13.5 L / min under a nitrogen flow rate of 13.5 L / min. A photosensitive layer 1 was obtained by forming a 3.5 μm thick protective layer. The intensity of the light source is 4000 mW / cm ^2, the irradiation intensity of the light in the coating film, the distance between 1,800 mW / cm ^2, light source and the surface of the coating film was 5 mm.

The maximum height roughness Rz of the surface of the photosensitive member 1 was measured using Surfcom 1400D (manufactured by Tokyo Seimitsu Co., Ltd.) under the following measurement conditions, and was 0.050 μm.
(Measurement condition)
Measuring device: Surfcom 1400D (made by Tokyo Seimitsu Co., Ltd.)
Measurement mode: Roughness measurement Measurement length: 20.0 mm
Cutoff: 0.08 mm (Gaussian)
Measuring speed: 0.15 mm / sec

In addition, the universal hardness (HU) of the surface of the photosensitive member 1 was 240 (N / mm ² ) as measured using a Fisherscope H100 (manufactured by Fisher Instruments).

[Photosensitive members 2 to 9]
The types of metal oxide fine particles and the number average primary particle size (nm) are changed as shown in Table 1 below so that the universal hardness (HU) of the photosensitive members 2 to 9 becomes the hardness in Table 1 below, The photosensitive members 2 to 9 were manufactured in the same manner as the photosensitive member 1 except that the addition amount of the capturing agent (Sumilyzer GS) was also changed to form a protective layer.
The maximum height roughness Rz and the universal hardness HU of the surfaces of the photosensitive members 2 to 9 were measured in the same manner as the photosensitive member 1 respectively. The measurement results are shown in Table 1 below.

[Cleaning blade 1]
The cleaning blade 1 was manufactured by the method described in Example 1 of JP-A-2007-52062.
Each raw material was mixed and placed in a mold so that the molar ratio of hydroxy group to NCO group (hydroxy group / NCO group) of the following raw materials was 0.8. It was cured for 30 minutes and molded to obtain a main body of the cleaning blade 1.
Isocyanate compound: MDI (4,4'-diphenylmethane diisocyanate manufactured by Nippon Polyurethane Industry Co., Ltd.)
Polyol: butylene-xylene adipate-based polyester polyol Cross-linking agent: mixed liquid of 1,4-butanediol and trimethylolpropane (mass ratio 65: 35)

The contact portion of the obtained main unit with the photosensitive member is immersed for 3 minutes in a tank containing a mixture of MDI at 80 ° C. (4,4′-diphenylmethane diisocyanate manufactured by Nippon Polyurethane Industry Co., Ltd.) and butyl acetate. A hardened layer was formed. The MDI concentration in the mixed solution was adjusted to obtain a hardened layer having a JIS-A hardness of 80 °. Thereafter, excess MDI adhering to the body surface withdrawn from the tank was wiped off and aged for 2 days in an NN environment to produce a cleaning blade 1 having a hardened layer.
When the cross section of the hardened layer of the cleaning blade 1 was observed with an optical microscope, the thickness of the hardened layer was 0.2 mm.

  The JIS-A hardness (°) of the contact portion of the cleaning blade 1 with the photosensitive member, that is, the cured layer was 80 °. JIS-A hardness (°) was measured at a temperature of 25 ° C. using a type A durometer in accordance with the hardness test method defined in JIS K6253.

[Cleaning blade 2-5]
In the same manner as the cleaning blade 1 described above, except that the concentration of MDI in the bath for immersing the main body was changed to form the hardened layer so that the JIS-A hardness of the hardened layer becomes the hardness shown in Table 1 below. Each cleaning blade 2 to 5 was manufactured.
The JIS-A hardness of the contact portion of each of the cleaning blades 2 to 5 with the photosensitive member, that is, the cured layer was measured in the same manner as the cleaning blade 1. The measurement results are shown in Table 1 below.

[Evaluation]
The photosensitive members 1 to 9 and the cleaning blades 1 to 5 manufactured in the monochrome image forming device bizhub PRO 1250 (manufactured by Konica Minolta) are mounted in a combination shown in Table 1 below, and the image forming devices 1 to 11 and 31 to 31 are mounted. It was 36.
The image formation for evaluating the in-plane density unevenness, the image flow, and the cleaning performance was performed as follows by the image forming apparatuses 1 to 11 and 31 to 36. At the time of image formation, zinc stearate was used as a lubricant, and the toner was externally added to the toner and supplied from the developing unit. The cleaning blades 1 to 5 were brought into contact with the surfaces of the photosensitive members 1 to 9 at an inclination angle θ of 12 ° and a contact pressure of 20 N / m.

[In-plane concentration unevenness]
Under the environment of temperature 20 ° C. and relative humidity 50% RH, images with a printing rate of 5% were continuously formed on 1,000,000 sheets of A4 size neutral paper.
After that, a monochrome halftone image (average relative reflection density measured with a Macbeth densitometer is 0 on the entire surface of A3 size (297 mm long × 420 mm wide) neutral paper under an environment of a temperature of 10 ° C. and a relative humidity of 20% RH. Image was formed. A total of eight points 33 mm apart from the end of the A3 size sheet at the position of 180 mm in the horizontal direction from the corner of the sheet surface are a1, a2, ... a8 respectively, and the end in the longitudinal direction at the position of 195 mm in the lateral direction from the corner The total of eight points 33 mm apart were similarly designated b1, b2, ... b8, and the reflection density of each point was measured with a Macbeth densitometer.

The tolerance (difference between the maximum value and the minimum value) of these 16 measured values was calculated and ranked according to the following evaluation criteria. The smaller the tolerance of the measurement value, the smaller the unevenness in density in the sheet surface.
A: Tolerance of measured value is less than 0.01 and hardly uneven density B: Tolerance of measured value is not less than 0.01 and less than 0.02, uneven density occurs, but there is little problem in practical use C: Tolerance of measured value is 0.02 or more and less than 0.04 and uneven density occurs, but practicable D: Tolerance of measured value is equal to or more than 0.04, clear uneven density occurs , Not practical

[Image flow]
Under the environment of temperature 20 ° C. and relative humidity 50% RH, images with a printing rate of 5% were continuously formed on 1,000,000 sheets of A4 size neutral paper.
Thereafter, an image having a Bk (black) printing ratio of 5.0% is formed on 1000 sheets of A4 size paper in an environment of a temperature of 30 ° C. and a relative humidity of 80% RH, and then an image is formed immediately. The main power of the device was turned off. After 12 hours, the main power was turned on again, and immediately after printing was possible, a halftone image (relative reflection density measured with a Macbeth densitometer was 0.4 (maximum value is 2) on the entire surface of A3 size neutral paper immediately Image) and a grid image with a line width of 6 dots.

The state of the image on the sheet was visually observed and ranked according to the following evaluation criteria.
A: No blurring of the image occurred in both the halftone image and the lattice image, and no image flow occurred B: A long band-like density loss was recognized in the width direction (rotational axis direction of the photosensitive member) only in the halftone image Image flow is generated, but there is no problem in practical use. C: image flow such as loss of lattice image due to image blurring, narrowing of line width, etc., and there is a problem in practical use)

[Bypass]
Under the environment of temperature 20 ° C. and relative humidity 50% RH, images with a printing rate of 5% were continuously formed on 1,000,000 sheets of A4 size neutral paper.
Thereafter, a band-shaped solid image (the relative reflection density of the Macbeth densitometer is 2.0 (maximum value) on the center portion of 1000 A4 sized neutral papers under an environment of a temperature of 10 ° C. and a relative humidity of 20% RH). Were formed respectively.
The presence or absence of the toner in the margin of the sheet was visually evaluated according to the following evaluation criteria.
A: There is the same amount of toner as the surrounding white background, and no slip-through has occurred. B: There is toner above the surrounding white background, and slip-through has occurred.

Table 1 below shows the evaluation results.

As shown in Table 1, a photoconductor having a maximum height roughness Rz of 0.060 μm or less and a universal hardness of 220 to 300 N / mm ² , and a JIS-A hardness of 80 to 100. By combining with a cleaning blade in the range of °°, even after 1,000,000 sheets of image formation are continuously performed, in-plane density unevenness, image flow and slip-through are effectively suppressed, and high cleaning performance can be achieved. It turns out that it can be maintained for a long time.

Reference Signs List 1 image forming apparatus 21 writing unit 2a photoconductor 34 protective layer 2c developing unit 2e cleaning device 51 cleaning blade 52 hardened layer 2f lubricant supplying unit

Claims (6)

A photoreceptor carrying an image developed by the supply of toner;
And a cleaning blade that abuts on the surface of the photosensitive member to remove toner on the photosensitive member.
The maximum height roughness Rz of the surface of the photosensitive member is 0.060 μm or less, and the universal hardness is in the range of 220 to 300 N / mm ² .
An image forming apparatus, wherein the JIS-A hardness of the cleaning blade is in a range of 80 to 100 °. The cleaning blade is
Contains polyurethane,
The image forming apparatus according to claim 1, wherein a cured layer containing a polymer of the polyurethane and an isocyanate compound is provided at a contact portion with the photosensitive member.   The cleaning blade is inclined at an angle within the range of 5 to 20 ° with respect to the surface of the photosensitive member, and is in contact with a linear pressure within the range of 13 to 30 N / m. An image forming apparatus according to claim 1 or 2. The photoreceptor has a protective layer on the outermost surface,
The image forming apparatus according to any one of claims 1 to 3, wherein the protective layer contains a binder resin and metal oxide particles.   The image forming apparatus according to any one of claims 1 to 4, further comprising a lubricant supply unit configured to supply a lubricant to the surface of the photosensitive member.   6. The image forming apparatus according to claim 5, wherein the lubricant supply unit is a developing unit that supplies the toner to which the lubricant is externally added onto the photosensitive member.

Images