JPH02208687A - Image forming method - Google Patents

Abstract

PURPOSE:To accomplish excellent cleaning ability and durability and to obtain a high-quality image by specifying the hardness of a cleaning member. CONSTITUTION:A cleaning device 10 provided with a cleaning blade member 9 arranged in contact with the surface of a photosensitive body so that it can be controlled to separate from and contact with the photosensitive body is used as a cleaning means. The cleaning blade member 9 made of the material having hardness depending on a spring system hardness test A-type >=80, desirably, >=90 is used in order to make abutting power applying to the surface of the photosensitive body 1 of the cleaning blade large and enhance cleaning performance. In such a case, the quality of material of the cleaning blade member 9 is not defined particularly but it is desirable to use urethane rubber because it is easy to adjust the hardness. Thus, the cleaning ability and the durability are improved and the high-quality image is obtained.

Description

[Detailed description of the invention]

[Industrial Field of Application J The present invention relates to an image forming method applied, for example, to electrophotography, electrostatic recording, electrostatic printing, and the like. [Prior Art] Recently, with the spread of color images and digital images, there is a strong demand for fine, clear, high-quality images, and therefore a Wgim forming method that can form images with high resolution is needed. Conventionally, in order to improve resolution, the weight average particle diameter is 8 μm.
A method using a developer containing toner with a small particle size as described below is known, but this method has a problem of poor cleaning performance for residual toner and the occurrence of image stains. For this reason, a method has been used in which a highly hard blade member is used and a high pressure is applied to the surface of the photoreceptor. [Problem to be solved by the invention] However, since a hard blade member is used, organic light 1? !
! When using an organic photoreceptor consisting of a body, 10
occurs, resulting in image deterioration, and when a Se photoreceptor is used, charging characteristics deteriorate due to crystallization, and a complete solution has not been achieved. Therefore, there has been a need for an image forming method that does not cause the above-mentioned problems, has excellent cleaning properties and durability, and can provide high-quality images. Accordingly, an object of the present invention is to provide an image forming method that has excellent cleaning properties, durability, etc., and can produce high-quality images. [182 Ways to Solve the vR Problem] The above object of the present invention is to provide a latent image forming step of forming a static W1 latent image on a photoreceptor having a surface modified v4WA with a Vickers hardness of 1000 or more, and Image mjl average particle size 1-8
A developing step of developing with a developer containing a μ-view insulating toner, a transfer step of transferring the toner image on the photoreceptor obtained by the development to a transfer material, and a transfer step of transferring the toner image on the photoreceptor after the transfer step. An image forming method including each step of a cleaning step for cleaning residual toner, characterized in that the cleaning member used in the cleaning step has a hardness of 80 or more according to a type A spring type hardness test. This is achieved by an image forming method according to the present invention. Further, it is preferable that the surface modified layer is made of amorphous silicon, and it is particularly preferable that the cleaning blade member is made of urethane rubber. FIG. 1 is an explanatory diagram showing an example of an image forming apparatus most suitable for the image forming method of the present invention. In the image forming method of the present invention, first, in the latent image forming step, 1) A static latent image is formed on the surface by charging and exposure.The static Ti latent image is then developed in a developing step with a developer containing a small particle size toner.The developing means is not particularly limited, but For example, the conventionally used contact magnetic brush development method, non-contact magnetic brush development method, cascade development method, etc. are used.The developer carrier for conveying the developer to the development area is particularly limited. However, for example, a structure similar to the conventional one to which a bias voltage can be applied can be used.The toner image on the photoreceptor (1) obtained by development is transferred to a transfer material such as paper in a transfer process. In this transfer process, an electrostatic transfer method is preferable.After the transfer process, in a cleaning process, the toner remaining on the photoreceptor surface is removed by a cleaning means to leave the photoreceptor surface as clean as before. The cleaning means includes a cleaning 1 having a cleaning blade member (9) disposed in contact with the surface of the photoreceptor in a controllable manner.
! (10) is used. According to such a blade type cleaning device (10), the surface of the photoconductor is rubbed by the cleaning blade member (9) to scrape off residual toner, but the cleaning blade is pressed against the surface of the photoconductor. In order to increase the force and improve the cleaning performance, in the present invention, the hardness is 9 according to the spring type hardness test type A.
Using a cleaning blade member made of a material with a hardness of 0 or more, preferably 90 or more, while maintaining the cleaning blade member so that the antenna angle between the cleaning blade member and the photoreceptor is π/2 or more on the front side of the cleaning process. R9li? so that the pressure in contact with the photoreceptor is 10 to 40 g/cf. It is preferable to do so. In this case, the material of the cleaning blade member is not particularly limited as long as it has the above-mentioned hardness, but it is preferable to use urethane rubber because it is easy to form a hardness of M knot. The hardness of urethane rubber can be easily adjusted by appropriately changing the synthesis conditions. The hardness according to the spring type hardness test type A referred to in the present invention is described in detail in JIS K6301. In the present invention, it is preferable to add a static elimination step of removing nitrogen from the surface of the photoreceptor after this cleaning step. This static elimination step can be performed using, for example, a static eliminator that generates AC corona discharge or a static elimination lamp (11). On the other hand, the toner image transferred onto the transfer material in the transfer process is then fixed in a fixing process by a fixing device such as a heat roller fixing Fi (8) or a pressure fixing device to form a fixed image. Next, the photoreceptor used in the present invention will be specifically explained using figures. FIG. 2 is a sectional view of a specific example of the structure of a preferable photoreceptor used in the present invention. The photoreceptor has surface-modified El (27) made of amorphous silicon. However, the Vickers hardness of the surface modified layer is 1000 or more, preferably 10
00-5000. Note that the Vickers hardness (lv) is given by the formula 1-1v -1854P/d2. In the formula, P is the magnitude of the load (ko), and d is the length of the diagonal of the square of the indentation (a) when the indenter is pressed against the measurement surface.
m). Details of the measurement method are described in JIS Z2244. As such a surface modification layer, in particular, halogen atoms (X) such as hydrogen atoms (H) and/or fluorine atoms (F) are added to amorphous silicon (a-8t) to block dangling bonds. (a-8i: l-((X)
), and a modified IR atom (
Y) is preferably introduced (a-8i:Y:l-1(X))Lr. Specifically, a-3i:C:H(X)JP! , a-8i
:C:O:H(X) WJ, a-
8i :N:H<x>m, a-8i :N:
O:l-1(X)'J! i, a-8i :C:N
:H(X)W! i, a-3i :C:N:0:H(
X) It is possible to take various configurations such as I. In surface modification ff27, hydrogen atom (1'') and /
Or the content ratio of halogen atoms (X) is 10 to 3 Qat
■% is preferred. In addition, carbon atoms (C), oxygen atoms (0
) and nitrogen atoms (N), the content ratio of the modifying atoms (Y) is 100 at-%, when the total of silicon atoms (Si) and modifying atoms (Y) is (Y) is 0.5 to 9 Qatm%, preferably 10 to
The ratio is 70atl1%. Modifying atom (Y
) If the content ratio of the modifying atoms (Y) is too high, the properties as a semiconductor will be impaired, while if the content ratio of the modifying atoms (Y) is too low, the mechanical strength will be low, the dark resistance will be low, and the sensitivity will decrease. However, when containing oxygen atoms as modifying atoms (Y), the content ratio of these is 0.5-7Qat1%,
Particularly 5-30atI 11% strong. In addition, when containing multiple types of modifying atoms (Y) consisting of carbon atom (C), ta elementary atom (0) and nitrogen atom (N>), carbon atom: oxygen atom: nitrogen atom -□-90 : 0.5~70
: The ratio (ats%) is preferably 0 to 90, and the total ratio of modifying atoms (Y) is 0.5 to 9Qat-%.
It is preferably within the range of . The thickness of the surface modified WJ27 is preferably 4008 to 1 μm. Further, a surface modification layer 27 as described in, for example, Japanese Unexamined Patent Publication No. 59-204048 may be provided. A photoreceptor having such a surface-modified layer is non-polluting and exhibits excellent light resistance, corona ion resistance, fA humidity resistance, and abrasion resistance. Since the surface-modified layer described above has excellent abrasion resistance, the cleaning performance can be improved by increasing the pressing force of the cleaning blade against the surface of the photoreceptor in the cleaning process. In addition, since the above-mentioned surface modification layer has high hardness, the physical adhesion of the I/toner to the photoreceptor surface is reduced, and the toner can easily move from the photoreceptor to the transfer material in the transfer process. , the transfer rate increases. And as a result of the higher transfer rate, some residue remains on the photoreceptor without being transferred! - Since m of toner is reduced and embedding of toner into the surface number jlFJ is also prevented, cleaning becomes easier. In addition, the above surface modified layer itself has excellent light! ! In addition to being electrically conductive, the modified atom (Y) has a dark resistance of 1012 to 1013 Ω・CI (normal a-
In the 8ixH layer, the resistance increases to about 10 6 to 10 9 Ω·cm), and as a result, the charge retention ability of the photoreceptor becomes significantly higher. Further, the repeatability of charging and exposure is stable, and good potential characteristics are exhibited even if the photoreceptor is left for a long period of time, for example, 1 ton month or more. The surface modification layer may be laminated directly on the photoconductive layer, or may be laminated on the photoconductive layer provided with an intermediate layer. The light smi is an optical IJm layer made of amorphous silicon, an inorganic light guide 1! The material can be selected from a photoconductive T1 layer formed by dispersing materials in a binder resin, a selenium-based photoconductive layer, a photoconductive layer containing a charge transport substance, and the like. The layers of the organic light 8I may have a functionally separated layer structure in which charge generation and transport are shared by separate layers. When using such a light guide ffi layer having a multilayer structure, the surface modification layer may be laminated on the layer on the outermost surface side of the light guide N layer. In the present invention, a photoconductive layer made of amorphous silicon can be particularly preferably used. The photoreceptor 21 shown in FIG. 2 is an example preferably used in the present invention, and a P-type charge blocking i! ! 23
, a charge transport M24, an intermediate layer 25, a charge generation layer 26, and a surface modification layer 27 are sequentially W4HJed to form a positively chargeable photoreceptor. The base body 22 may be formed of either conductive or insulating material. The shape of the base body 22 can be selected from various shapes such as a cylindrical shape, a belt shape, and a plate shape. The thickness of the base body 22 is not particularly limited, and is appropriately selected from the viewpoints of manufacturing, handling, mechanical strength, and the like. The P-type charge blocking layer 23 is heavily doped with elements of Group 3A of the periodic table (boron, aluminum, gallium, etc.), and is doped with at least carbon atoms (C), oxygen atoms (0), and nitrogen atoms (N). Modifying atoms consisting of one type (Y
) containing a-8t :C:H(X)Jf! I,
a-8i :C:O:H(X)li! l, a-
8i: N: l-1(X) layer, a-8i:N:
O:H(X) layer, a-8i: O:I''(X)
It is preferable to configure it with a layer such as m, a-3i :C:0:N:H(X). The charge transport layer 1m24 is a modified layer lightly doped with a Group 3A element of the periodic table and, like the charge blocking layer 23, made of at least one of carbon atoms (C), oxygen atoms (0), and nitrogen atoms (N). a- containing a positive atom (Y)
8i : Y: H ( 1! It is preferable that it is thicker than the load generation layer 26. The intermediate layer 25 contains modified atoms (Y
) is preferably constituted by an a-8i:Y:H(X) layer. The thickness of the intermediate layer 25 is 0.01
~2μ- is preferred. The intermediate layer 25 may be a laminate of two or more layers. The charge generation WJ26 can be set according to periodic table 3A F as necessary.
It is preferable to construct the a-3i:H(X) layer lightly doped with L element. In addition, the charge generation layer 26
The thickness is preferably 2 to 15 μm; if this thickness is too small, sensitivity decreases and light easily penetrates into the lower layer. On the other hand, if the thickness is too large, the residual potential will increase, making it impractical. Each layer constituting the photoreceptor 21 can be formed using, for example, a glow discharge decomposition method, a sputtering method, an ion blating method, or a method of evaporating silicon while introducing activated or ionized hydrogen in a hydrogen discharge tube (Japanese Patent Application Laid-Open No. 78413/1983). (see Japanese Patent Publication No. 2003-120000), etc. The above description is based on the case where the charged polarity of the photoreceptor 21 is positive. When the polarity is negative, charge blocking WIi23, charge transport W! J24
, the intermediate layer 25, the charge generation layer 26, and the surface-modified WJ 27, the dopants may be changed to elements of group 5A of the periodic table (a<phosphorus, arsenic, antimony, bismuth, etc.). Note that the charge blocking layer 23 and the intermediate layer 25 are provided as necessary and may be omitted. Further, the charge transport layer 24 and the charge generation layer 26 may have a single layer structure instead of separate layer structures. The developer used in the developing step of the present invention contains toner having a weight average particle diameter of 1 to 8 μm, and optionally contains a fluidizing agent. The insulating toner herein refers to one that exhibits insulating properties with a specific resistance ρ of 10 13 ΩC1 or more given by the following equation. (In the formula, S is the area where the insulator is in contact with the electrode (cm2
), d is the thickness of the insulator (cm), V is the applied voltage (volts), Iji! indicates the so-called leakage current. ) However, electrode area 3-1cm2, applied voltage V-100V, test $11Wd-4+em, load g 1000g/cm2,
Leakage current is measured under conditions of a temperature of 25° C. and a relative humidity of 60%, and specific resistance is calculated. What is the leakage ffi style here?
The current that flows when a voltage is applied to an insulator is not constant over time; a large current flows at the moment of voltage application, but it decreases over time and settles to a constant value after a long period of time. This refers to the current in the state of The toner is basically a particulate powder in which additives such as a colorant, a charge control agent, and a fixability improver are contained in a binder resin as necessary. Also, 1if
When obtaining a l-type toner, fine particles of magnetic material are dispersed and contained in a binder resin. The average particle size in mm of the toner is 1 to 8 μm, preferably 3 to 6 μm. When the mm average particle diameter of the toner is too large, the resolution is low and it is difficult to form a high-quality image. Therefore, it is not possible to cope with the recent demands for colorization or digitalization of images. Furthermore, when the average particle diameter in mm of the toner is too small, the toner tends to scatter, resulting in a decrease in image density and the occurrence of fog. The binder resin for the toner is not particularly limited, and conventionally known resins can be used. Examples of colorants include carbon black, nigrosine dye (C, 1, No, 504153), aniline blue (C, 1, No, 50405), carfoil blue (C, 1, No, azoic Blue 3)
, Chromie []-(C, 1, No, 14090)
, Ultramarine Blue (C, 1, No. 77103
), DuPont Oil Red (C, 1, No. 2610
5>, quinoline yellow (C, [. No, 47005), methylene blue chloride (
C.I. No. 52015), Phthalocyanine Blue (C,
1,N. 741 (io), Green Off Sale to Malachi 1 (C, Summer, No. 42000 >, Lamp Black (C, 1, No. 77266), Rose Bengal (C, f, No.
, 45435), mixtures thereof, and others can be used. The blending ratio of the colorant is usually about 1 to 20 parts by weight and 6 parts by weight based on 100 parts by weight of the binder resin. Examples of fixability improvers include polyolefins, fatty acid metal salts, fatty acid esters, partially saponified fatty acid esters,
Higher fatty acids, higher alcohols, liquid or solid paraffin waxes, amide waxes, polyhydric alcohol esters, silicone varnishes, aliphatic fluorocarbons, mixtures thereof, and the like can be used. The blending ratio of such a fixability improver is usually about 1 to 20 parts by weight based on 100 parts by weight of the binder resin. Examples of charge control agents include metal complex dyes,

[''
Synthetic dyes, ammonium salt compounds,!・Rephenylmethane compounds etc. can be used. As the cleaning property improver, for example, fatty acid metal salts such as zinc stearate, calcium stearate, and aluminum stearate, and polymer fine particles such as methyl methacrylate-1 fine particles and styrene fine particles can be used. In addition, the magnetic materials used to form the magnetic toner include ferromagnetic metals or alloys such as iron, ferrite, and magnetite, nickel, and cobalt, or compounds containing these elements, and manganese. - A type of alloy called Heusler alloy containing manganese and copper such as copper-aluminum, manganese-copper-tin, chromium dioxide, and others can be mentioned. The content of the magnetic material is usually about 20 to 80% by weight, preferably about 30 to 70% by weight, based on the entire I-ner. In the invention, a fluidizing agent can be added to and mixed with the above-mentioned toner having a small particle size. The proportion of the fluidizing agent added to the toner is 0.5 to 10% by weight, preferably 1 to 5% by weight. By adding a fluidizing agent within this range, sufficient fluidity of the small particle diameter toner can be ensured. In addition, the fiffi average particle size of the fluidizing agent is 0.001 to
0°1μ- is preferable, and the specific surface area by BET method is 20
-500f/Q is preferable, especially 50-300t'/Q
is preferred. Various inorganic fine particles can be used as the fluidizing agent. For example, silica, alumina, titanium oxide, barium ditanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, silica, diatomaceous earth, chromium oxide,
Cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, and the like can be used. The above fluidizing agents are added and mixed into the toner from the outside,
In other words, the toner particles are attached to the surface of the toner particles so as not to come off, and then used. As the mixing device, a type blender or the like can be used. The developer used in the present invention may be a one-component developer in which Kyrelia is not mixed, or a two-component developer in which a carrier is mixed. Average particle size of carrier (
The weight ff1) is not particularly limited, but is, for example, 20 to 15
It is about 0μ. Magnetic materials for Kyrelia include, for example, ferrite, magnetite, iron, nickel, cobal, etc., which are ferromagnetic metals, or alloys or compounds containing these metals, manganese-copper-aluminum or manganese-copper- Examples include a type of alloy called Heusler alloy such as tin, chromium dioxide, and the like. [Examples] Specific examples of the present invention will be described below, but the present invention is not limited thereto. (Example 1) Polyester resin 100 parts by weight Carbon black "Mogulshi" (manufactured by Cabot Corporation) io parts by weight Polypropylene [Viscol 660PJ (manufactured by Sanyo Chemical Industries, Ltd.) 3 parts by weight or more of the substances were mixed together. The mixture was melt-kneaded, cooled, coarsely pulverized using a hammer mill, finely pulverized using a jet mill, and classified by air to produce a toner having an average particle size in mm as shown in Table 1. Manufacture of carrier Styrene/methyl methacrylate copolymer resin (polymerization ratio =
A carrier having a vI layer consisting of 1:1) was produced. JB Needle 11 To the toner, a fluidizing agent was added and mixed in a predetermined ratio, and a carrier was mixed in a predetermined ratio to prepare a developer with a toner concentration [4 t%]. Photoreceptor (1) Substrate Drum-shaped aluminum substrate (2) P÷ type charge blocking layer thickness 1μ1 (7) r' 10 type a-3i :C:HII
([C] = 10 atm%) (3) Charge transport layer thickness is 20 μm a-3i:C: 8 layers ([C] = 10 atm%) (4) Intermediate layer thickness is O, S μs (D a- 8i:C:HF
f! t ([C] = 5 atm%) (5) A-3i with a charge generation layer thickness of 7 urs:) 15 (6) A-3i1 with a surface modification layer thickness of 0.3 μa+ Vickers hardness 1100 (actual photo test 1) Under normal temperature and humidity environmental conditions (temperature 20°C, relative humidity 60%)
J3, an electrophotographic copying machine rU-Bix2500J (Konica
A photocopying test was carried out using a modified machine manufactured by the Company, Ltd., in which copy images were continuously formed 200,000 times using each developer, and the following items were evaluated. However, the cleaning blade was made of urethane rubber whose hardness was varied as shown in Table 1. In addition, when the copy image became significantly defective, the live-action shooting was stopped at that point. (1) Resolution In accordance with JIS 24916, copy the resolution test chart and visually judge the copied image.
The number of resolution lines per liter was determined. (2) Cleaning property The presence or absence of image stains due to poor cleaning was investigated. The evaluation is based on a good image with almost no visible stains.
``○'', a case where some image staining was observed but within a practically acceptable range was rated as ``Δ'', and a case where image staining was significant and caused a practical problem was rated rXJ. (3) Photoreceptor surface condition The presence or absence of scratches on the photoreceptor surface was examined. The evaluation is "○" if the product is in good condition with almost no scratches, and [Δ] if it is within the acceptable range.
, Cases where the occurrence of scratches was significant and caused a practical problem were rated "X". The above results are shown in Table 1 below. (Live action test 2) High i high humidity environmental conditions (temperature 40℃, relative humidity 80%)
A live-action test was conducted in the same manner as the above-mentioned live-action tests 1 to 1, and the same items were evaluated. The above results are not shown in Table 2 below. As is clear from Tables 1 and 2, the toner particle size is 1 to 8μ.
When a cleaning blade having a hardness of 80 or higher according to type A spring type hardness test was used, excellent results were obtained in both resolution and cleaning performance. (Example 2) A photosensitive material was produced in the same manner as in Example 1, except that the l1liffi average particle size of the insulating toner in the 3A imager was set to 5 μm, and the type and Vickers hardness of the surface modification layer constituting the photoreceptor were changed. created a body. In the same manner as Live Photography Tests 1 and 2, a live photography test was conducted in which a copy image was formed. However, the hardness of the cleaning blade was changed as shown in Tables 3 and 4. The results are shown in Tables 3 and 4. As is clear from Tables 3 and 4, for each photoreceptor whose surface modified layer had a Vickers hardness of 1100.3800, good results were obtained in both mJU and cleaning performance, which were better than practical. [Effects of the Invention] As explained in detail above, the image forming method of the present invention was able to obtain an iii image with high image quality and excellent durability.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of an image forming apparatus used in the present invention, and FIG. 2 is a sectional view of a specific example of the configuration of a photoreceptor used in the present invention. 1... Photoreceptor 2... Charger 3... Exposure optical system 4... Axis device 5.11... Static elimination lamp 6... Transfer electrode 7... Separation electrode 8... - Heat roller fixing device 9...Cleaning blade member 10...Cleaning device 21...Photoconductor 22...Base 23...Charge blocking layer

Claims (3)

[Claims] (1) A latent image forming step of forming an electrostatic latent image on a photoreceptor having a surface-modified layer with a Vickers hardness of 1000 or more, and applying an insulating toner having a weight average particle size of 1 to 8 μm to A developing step of developing with a developer contained therein, a transfer step of transferring the toner image on the photoreceptor obtained by the development to a transfer material, and cleaning the toner remaining on the photoreceptor after the transfer step. 1. An image forming method comprising at least each step of a cleaning step, wherein the cleaning member used in the cleaning step has a hardness of 80 or more according to a type A spring type hardness test. (2) The image forming method according to claim 1, wherein the surface modification layer is made of amorphous silicon. (3) The image forming method according to claim 1 or 2, wherein the cleaning blade member used in the cleaning step is made of urethane rubber.