JP3278733B2 - Method of manufacturing blade for image forming apparatus and image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade for an image forming apparatus which rubs the surface of a moving member such as a drum-shaped or belt-shaped photoreceptor or a roll in a developing unit, and a method of manufacturing the same. The present invention relates to a blade used as a cleaning blade for cleaning and removing toner adhered to the surface of a photoreceptor, a toner charging blade for charging a toner by rubbing a roll surface in a developing unit, and a method of manufacturing the same. The blade for an image forming apparatus according to the present invention is made of a sheet-like molded body of polyurethane rubber, and is used by being fixed to an appropriate fixing member (such as a blade holder). The blade for an image forming apparatus can be applied to a copying machine, a printer, and a composite OA device having both of these functions.

[0002]

2. Description of the Related Art The following techniques are known as conventional cleaning blades. (J01) (Technology described in Japanese Patent Publication No. 4-58630) An unsaturated fatty acid amide having 16 to 24 carbon atoms, which is incompatible with the polyurethane rubber, is added to a polyurethane rubber as a molding material.
Using a blade with a low-friction layer formed on the surface using fatty acid amide as a lubricant that gradually precipitates. (J02) (JP-A-57-201276, JP-A-5-201276)
7-201277) A blade having a reduced friction coefficient by adding a polysiloxane oil or a modified polysiloxane oil to polyurethane rubber as a molding material. (J03) (Technique described in JP-A-57-201275) A polyurethane rubber and a fluorine-based lubricant such as a perfluoroalkylethylene oxide adduct are kneaded and molded.
Blade with reduced coefficient of friction. (J04) (Technique described in JP-A-58-203480) A low friction composite blade in which a relatively thin lubricating blade material is adhered or sandwiched to an elastic member such as polyurethane rubber to reinforce it in strength. (J05) (Technique described in JP-A-59-15967) A silicone oil having active hydrogen at the terminal is applied to a mold surface, and then a liquid polyurethane is injected onto the surface to form a surface of the polyurethane rubber molded body. For producing a blade containing a polymer in which a silicone oil and a polyurethane have reacted. (J06) (Method of manufacturing blade using centrifugal molding machine) While rotating a mold of a centrifugal molding machine having a mold release agent applied to the inner surface at a high speed, liquid polyurethane rubber is poured into the mold surface and molded. To manufacture blades. In this method, a blade holder is adhered to a mold surface of a rubber molded body usually obtained, and a surface on the opposite side is used as a rubbing surface.

[0003]

However, the above-mentioned conventional method has the following disadvantages, and has a practical problem. Problem of (J01) In the technique of (J01), since the lubricant bleeds from the inside of the cleaning blade with time, it is significant for squeal (occurrence of abnormal noise), In this case, the friction coefficient increases, and the wear of the photoconductor is not suppressed. Problem of (J02) In the technology of (J02), since the lubricant bleeds from the inside of the cleaning blade over time,
When the photoreceptor is rubbed and cleaned, the lubricant adheres to the photoreceptor surface and becomes contaminated. Problem of (J03) In the technique of (J03), since a lubricant is mixed during the crosslinking of the thermosetting polyurethane resin to cut the crosslinking, the blade material gradually deteriorates when the blade is used for a long period of time, This leads to a decrease in cleaning performance. Problem of (J04) In the technique of (J04), when the cleaning blade rubs the photoreceptor surface for a long time, the lubricating blade material comes off from the elastic member. Therefore, the amount of friction increases as a result, and the effect of preventing the cleaning blade from turning due to low friction and the abrasion of the photoconductor surface is not exhibited. Further, in the manufacturing process, an operation of bonding or holding and fixing the lubricating blade material to the elastic member is required.

[0004] The problem of (J05) In the technique of (J05), although the low friction polymer is uniformly contained in the surface layer of the rubber molded product, the friction coefficient of the blade cannot be reduced so much. Wear of the photosensitive member itself and the surface of the photosensitive member over time is relatively large. Also,
The silicone oil component reacts with the photoreceptor and contaminates the photoreceptor. On the other hand, if a solid lubricant having a large effect of lowering the friction coefficient is mixed into the rubber molded article in order to improve the abrasion, the crosslinking of the thermosetting polyurethane rubber is cut off in the same manner as in (J03). For this reason (J0
The technology of 5) was not commercialized.

Problems of (J06) The technique of (J06) cannot obtain a low friction layer having a long life. Since the mold release agent is previously applied to the mold surface of the centrifugal molding machine, the surface layer of the obtained rubber molded body is impregnated with the release agent, and it has been difficult to directly adhere the blade holder. Therefore, in order to improve the adhesiveness with the holder, it was necessary to scrape off the release agent from the surface layer of the molded body. For this reason, conventionally, it has been necessary to perform the washing step of the surface layer of the rubber molded article impregnated with the release agent three times, which has increased the manufacturing cost of the blade.

FIG. 9 is an explanatory view of the state of sliding of a conventional cleaning blade. FIG. 9A shows a normal rubbing state. The toner 04 attached to the surface of the photoconductor 01 is cleaned and removed by the edge portion 03 of the cleaning blade 02 rubbing the surface of the photoconductor 01. However, with the blade 02 of the type in which the lubricant bleeds, the sliding frictional force cannot be reduced over time. In the blade 02 of the type in which the lubricant bleeds, the lubricant adheres to the surface of the photoconductor 01 and is contaminated. Further, if the physical properties of the material of the blade 02 deteriorate with time or the lubricating blade material peels off, the sliding friction force with the photoconductor 01 increases. If the sliding frictional force is high, as shown in FIG. 9B, the edge portion 03 of the cleaning blade 02 may be turned up or the wear amount of the photoconductor 01 may be increased, and in some cases, the surface of the photoconductor 01 may be damaged. There was something. As described above, the conventional image forming apparatus blade cannot maintain a low sliding friction force for a long period of time, bleeds the lubricant contained in the blade, deteriorates the blade material, or reduces the friction. There was a problem that the layer was easily peeled off. Further, as for the toner charging blade disposed in the developing unit, a material having excellent wear resistance has been demanded.

Accordingly, an object of the present invention is not only to reduce the amount of wear of the blade itself, but also to obtain a blade excellent in lubricity, durability, cleaning properties, and the like. The aim is to produce a low friction blade with a simple method. More specifically, a first object of the present invention is to reduce the amount of lubricant adhering to the photoreceptor to prevent contamination of the photoreceptor, to prevent the cleaning performance from deteriorating with time, and to reduce the cleaning performance. An object of the present invention is to provide a cleaning blade for an image forming apparatus, which can prevent blade turning and abrasion and damage of the surface of a photosensitive member. A second object of the present invention is to provide a low-friction toner charging blade for an image forming apparatus that can reduce the amount of toner adhering to the toner charging blade and extend the life of the developing unit. Third of the present invention
It is an object of the present invention to provide an inexpensive method for manufacturing a blade for an image forming apparatus in which a low-friction layer is integrated with a blade molding material by a simple method without changing an existing molding machine.

[0008]

The present inventors have made intensive studies to reduce the friction coefficient of the blade and found the following facts. (1) When the low friction layer in which the particles of the solid lubricant are embedded only in the surface layer of the blade molding material is used as the sliding surface, the blade is used for a long time because the low friction layer and the blade molding material are integrated. However, the performance or damage of the low friction layer does not occur. (2) When the lubricant is buried only in the surface layer of the blade molding material and does not mix into the inner deep layer, the lubricant does not affect the internal structure of the blade molding material.
The blade does not deteriorate even after long use. (3) When the lubricant is buried only on one surface of the surface layer of the blade and no lubricant is buried on the other surface, the other surface where the lubricant is not buried is compared with the one surface where the lubricant is buried.
The bonding strength with the fixing member (blade holder) for fixing the blade is high. Therefore, when the other surface is used as an adhesive surface to the fixing member, the blade assembly including the blade and the fixing member can be made robust.

The present invention has been completed based on the above-mentioned research results. Next, the present invention will be described. In order to facilitate correspondence with the elements of the present invention, the elements of the present invention are described below.
The reference numerals in parentheses indicate the elements of the embodiments.
The reason why the present invention is described in correspondence with the reference numerals of the following embodiments is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

(First Invention) A method of manufacturing a blade for an image forming apparatus according to a first invention of the present application is directed to a moving member (11, 33) having toner (19, 33) attached thereto.
34) In a method of manufacturing a blade (7 ', 35) for an image forming apparatus comprising a sheet-like polyurethane rubber molded body (6) rubbing the surface, a liquid polyurethane rubber is poured into a mold (2). Before the polyurethane rubber is cured, the solid lubricant (4a) is applied by spraying, and particles of the solid lubricant (4a) are embedded in the polyurethane rubber molded body (6) on the air contact surface side of the polyurethane rubber. is to form a low-friction layer (7a '), the sheet-like
Cut the polyurethane rubber molded body (6)
Of the cut sheet-like polyurethane rubber molded article (6)
Table on the side opposite to the side on which the low friction layer (7a ') is formed
Adhering the surface to the blade holder (8)
You.

(Second Invention) The method for manufacturing a blade for an image forming apparatus according to the second invention of the present application is the method for manufacturing a blade for an image forming apparatus according to the second or third invention, wherein the mold (2 ) Is characterized by using a rotating centrifugal mold.

(Third Invention) An image forming apparatus according to a third invention of the present application has an image forming apparatus blade manufactured by the method for manufacturing an image forming apparatus blade according to the first invention or the second invention. The image forming apparatus further includes a cleaning unit that cleans the surface of the photoconductor with the blade for the image forming apparatus. (Fourth Invention) An image forming apparatus according to a fourth invention of the present application includes the image forming apparatus blade manufactured by the method for manufacturing an image forming apparatus blade according to the first invention or the second invention, and includes the image forming apparatus. The image forming apparatus further includes a developing unit that rubs the surface of the developing roll with the apparatus blade.

(Detailed Description of Means for Solving the Problems) (Description of Constituent Requirements Common to Each Invention of the Present Application) In each invention of the present application, the liquid polyurethane rubber used as a blade molding material is It is synthesized from an isocyanate and a polyol having an average molecular weight of 1,000 to 4,000, and is molded using a low molecular polyol or a polyamine as a curing agent. As the polyisocyanate, 2,4-
Tolylene diisocyanate, 1,5-naphthylene diisocyanate, o-tolidine diisocyanate (3,3 '
-Dimethyldiphenyl-4,4'-diisocyanate), aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, aliphatic diisocyanates such as 1,6-hexane diisocyanate, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate. And aralkyl diisocyanates such as alicyclic diisocyanate and xylylene diisocyanate.

The polyol having an average molecular weight of 1,000 to 4,000 includes ethylene glycol, propylene glycol, 1,4-butylene glycol, 1,5-pentylene glycol, 1,6-hexylene glycol, and 3-methyl-1,5- There are polyester polyols obtained by condensation of one or more polyols such as pentanediol and two or more polyols such as aliphatic or aromatic dicarboxylic acids such as adipic acid and phthalic acid. In addition, for example, hydroxypolycarbonate having a hydroxyl group at one end or both ends obtained by condensation of polyol and phosgene, hydroxypolyester obtained by ring-opening addition polymerization of ε-caprolactone, polyalkylene oxide added to various active hydrogen compounds Oxyalkylene glycol, polyoxytetramethylene glycol obtained by ring-opening addition polymerization of tetrahydrofuran, and the like.

Examples of the low molecular polyol include, in addition to the diols described above, aliphatic polyhydric alcohols such as glycerin, trimethylolpropane, and pentaerythritol;
Alicyclic dihydric alcohols such as 1,4-cyclohexanediol and 1,4-cyclohexane dimethanol, aromatic dihydric alcohols such as p-xylylene glycol and 1,4-bis (β-hydroxyethoxy) benzene, etc. No. Examples of the low-molecular polyamine include ethylene diamine, propylene diamine, and diethylene triamine. These polymerization components and curing agents can be used alone or in combination of two or more.

The solid lubricant (4a) used in the present invention includes silicone-based low friction agents, fluorine-based low friction agents, molybdenum disulfide, graphite, fluorinated graphite, boron nitride, tungsten disulfide, talc and the like. And inorganic substances. These solid lubricants (4a) have a particle size of 20 μm or less, preferably 10 μm or less.

The blade (7, 3) for the image forming apparatus of the present invention
In the manufacturing method of 5), the mold-shaped polyurethane rubber molded article (6) to be molded is easily released from the surface of the mold surface, and the solid lubricant (4a) in the upper layer is coated with the polyurethane molded article (4a). It is preferable to form the release layer (3) as a lower layer in order to facilitate migration to the 6) side.
The release layer (3) as a lower layer can be formed by the following method. (1) RTV (room temperature vulcanizing), LT
A method in which a silicone rubber such as V (low temperature vulcanizing) or a silicone resin diluted with a solvent is coated in a mold (2) to form a silicone release layer. (2) A method in which a fluorine resin such as polytetrafluoroethylene (PTFE) or polyperfluoroalkyl acrylate (PFA) is coated in a mold (2) to form a fluorine-based release layer. (3) An inorganic substance such as molybdenum disulfide, graphite, fluorinated graphite, boron nitride, tungsten disulfide, or talc, and a binder (eg, polyurethane rubber, epoxy resin, phenol resin, alkyd resin, etc.) are mixed with a solvent (eg, , Toluene, butyl acetate, ethyl acetate, MEK, methyl isobutyl ketone, etc.) and coat in a mold (2) to form an inorganic material-based release layer.

Next, as the lubricant layer (upper layer) (4), the above-mentioned lubricant (4a) powder of silicone, fluorine or inorganic substance is diluted with a solvent (eg, toluene, methylene chloride, etc.). , On the mold surface or on the release layer (3). Then, when a liquid polyurethane rubber containing a curing agent is injected and cured on the lubricant layer (4), the lubricant (4a) is deposited inside the surface layer on the mold surface side of the polyurethane rubber molded body (6). A permeated binderless low friction layer (7a) is formed. As described above, by forming the release layer (3) as a lower layer on the mold surface, the solid lubricant (4a) of the lubricant layer formed thereon is transferred to the rubber molded body (6) side. Becomes easier. Note that the release layer (3) can be omitted. And even if the upper layer and the lower layer are the lubricant layer (4) of the same component, there is no problem. In that case, in the same lubricant layer (4), the lubricant (4a) acts as a release layer attached to the mold surface side and a lubricant layer attached to the polyurethane rubber side. The polyurethane rubber sheet molded as described above, that is, the polyurethane molded body (6) is dispersed in the surface layer and a low friction layer containing the lubricant (4a) in a state where it is partially exposed on the surface. (7a) is formed integrally with the polyurethane rubber of the blade material.

As the method for molding the polyurethane rubber sheet, a molding method such as a centrifugal molding method or an injection molding method can be employed. In the case of producing a polyurethane rubber sheet having a thickness of about 3 mm or less, it is preferable to employ a centrifugal molding method because mass production can be efficiently performed. The cylindrical polyurethane rubber sheet formed by the centrifugal molding method becomes a flat sheet when it is cut along the axial direction after forming and spreads out, and this sheet is cut into an appropriate size and shape for image forming equipment. The material of the blade (7, 35) can be obtained.

The method for producing a blade (7 ', 35) for an image forming apparatus according to the present invention, in which the surface formed on the air contact surface side of the molded polyurethane rubber molded body (6) is used as a rubbing surface. In step (2), a liquid polyurethane rubber containing a curing agent is injected into the mold (2), and the lubricant (4a) is sprayed and applied onto the polyurethane rubber on the side that comes into contact with air before curing proceeds. afterwards,
In the early stage of curing of low viscosity polyurethane rubber,
Many solid lubricants (4a) are embedded in the surface of the polyurethane rubber. When the curing of the polyurethane rubber is completed,
A binderless low friction layer (7 ') in which a lubricant (4a) is embedded in the surface layer of the polyurethane rubber molded body (6) is formed on the air contact surface side. The polyurethane rubber sheet molded as described above is dispersed in the surface layer and partially contains the lubricant (4a) and contains a lubricant (4a) in the same manner as in the second invention. (8a
') Is formed integrally with the polyurethane rubber of the blade material.

An image forming apparatus blade (7 ', 3) in which the surface formed on the air contact surface side of the molded polyurethane rubber molded body (6) is used as a rubbing surface.
In the manufacturing method 5), as a method for molding the polyurethane rubber sheet, a molding method such as a centrifugal molding method or an injection molding method can be employed, but it is preferable to employ a centrifugal molding method. When the polyurethane rubber is molded by the centrifugal molding method, the liquid polyurethane rubber is poured onto the mold surface while rotating the centrifugal molding machine (1). Subsequently, the lubricant (4a) is sprayed and applied onto the polyurethane rubber to be the air contact surface. Thereafter, when the curing of the polyurethane rubber progresses and the rotation of the molding machine (1) is stopped, the low friction layer (7) is formed on the air contact surface side of the polyurethane rubber molded product (6) opposite to the mold surface.
a ′) is formed. The molded cylindrical polyurethane rubber sheet is taken out of the centrifugal molding machine (1), cut in the axial direction, developed into a flat sheet, and then cut into a predetermined shape, so that a low friction layer (7a ') is formed on one surface. Is formed, and a blade (7 ', 35) having a thickness of 1.5 to 3 mm is obtained.
The molding method is not particularly limited to the centrifugal molding method as long as the polyurethane rubber can be molded into a sheet.

[0022]

When the blade (7, 7 ', 35) of the present invention is used as a cleaning blade (7, 7'), the distance between the electrostatic latent image transfer unit in the image forming apparatus and the charger of the photosensitive member is reduced. Of the cleaning unit.
In that case, not only the amount of wear of the cleaning blade (7, 7 ') itself is reduced, but also the contamination of the photoconductor is prevented,
It is possible to prevent the cleaning performance from deteriorating with time and prevent the cleaning blades (7, 7 ') from being turned up and the photoreceptor surface from being worn. Further, the blade (7, 7 ', 35) of the present invention can also be used as a toner charging blade (35) of a developing unit in an image forming apparatus. In this case, the toner (19, 33) adheres to the charging blade (35) and the charging blade (3)
5) Wear of itself can be reduced. For this reason,
The life of the developing unit can be extended.

[0023]

Next, embodiments of the present invention will be described, but the present invention is not limited to the embodiments. (Embodiment 1) Embodiment 1 of the method of manufacturing a blade according to the present invention will be described below. In addition, the following "parts" means "parts by weight". (Blade) FIG. 1 is an explanatory view of a centrifugal molding machine for producing a blade molded body. FIG. 1A is a perspective view of a main part thereof, and FIG.
FIG. 2 is a sectional view taken along the line IB-IB of FIG. 1A. The centrifugal molding machine 1 has a drum-shaped mold 2 that is rotationally driven by a rotational drive unit (not shown). The drum-shaped mold 2 is made of steel and has an inner diameter of 120 cm and a depth of 80 cm. The inner surface of the mold 2 is coated with a release layer 3 formed using a liquid LTV silicone rubber in order to facilitate release of the formed sheet (molded body). A commercially available silicone-based curable release agent (Monocoat E91A: Chem. USA) is used as a solid lubricant 4a on the release layer 3.
(Made by Trend Co., Ltd.) to form a lubricant layer 4. The lubricant layer 4 is a layer in which a powdery lubricant 4a diluted with a suitable solvent such as methylene chloride is attached to the surface of the release layer 3.

On the other hand, as a liquid polyurethane rubber, a condensed polyester having a molecular weight of 2,000 (having a hydroxyl value of 54, Nipporan 4040: manufactured by Nippon Polyurethane Co., Ltd.) containing ethylene glycol and adipic acid as polymerization components is dehydrated, and 100 parts of the polyester is dehydrated. , 5-naphthylene diisocyanate at 18 DEG C. for 20 minutes to form a prepolymer. To this prepolymer, 2 parts of 1,4-butanediol as a curing agent is added, and a liquid polyurethane rubber of a reaction mixture produced by stirring is poured onto the lubricant layer 4 in the mold 2 of the centrifugal molding machine 1. , 1
The molding was performed at 20 ° C. while rotating the molding machine 1 at a high speed for 90 minutes.

Thereafter, the cylindrical urethane rubber molded body 6 was taken out of the mold 2. In this rubber molded body 6,
The low friction layer 7a in which the lubricant 4a was embedded was formed on the urethane rubber surface layer on the mold 2 side. The cylindrical rubber molded body 6 was cut and developed in the axial direction, placed on a surface plate, and further heated and cured at 110 ° C. for 10 hours to obtain a polyurethane sheet. The hardness (JIS-A scale) of this polyurethane sheet was 80 °. (Cleaning blade assembly) The obtained polyurethane sheet (2 mm thick) was cut into 20 x 218 mm,
A cleaning blade 7 (see FIG. 2) was manufactured. Next, as shown in FIG. 2, a cleaning blade 7 is attached to a blade holder (cold-rolled zinc-treated steel plate) 8 having a thickness of 1.2 mm and a length of 320 mm with an adhesive, and the low friction layer is formed on the surface layer. A cleaning blade assembly 9 having 7a was fabricated.

FIG. 3 shows a photograph of the surface of the low friction layer 7a formed on the surface of the cleaning blade 7 taken with a light microscope at a magnification of 400. FIG.
FIG. 4 is a diagram showing a photograph of the edge of the surface layer of the cleaning blade 7 shown in FIG. 3 taken by a scanning electron microscope (SEM) at a magnification of 2000. FIG. 5 shows a photograph of the edge edge of the surface layer of the cleaning blade 7 shown in FIG. 4 taken by a SEM with a magnification of 5000. As is clear from the figures of these photographs, a part of the lubricant 4a is embedded in a state of being exposed on the surface of the low friction layer 7a.

Table 1 shows the cleaning blade assembly 9 in which the mirror side of the cleaning blade 7 is adhered to the blade holder 8 and the cleaning in which the mold side of the cleaning blade 7 is adhered to the blade holder. The results obtained by performing a 90 ° peel strength test at a peel speed of 20 mm / min on the adhesive strength of the blade assembly (comparative example) are shown.

[Table 1] As is clear from the results shown in Table 1, the cleaning blade 7 of the present embodiment has the surface on the side where the used edge in contact with the photoconductor is formed (the surface on the mold side where the low friction layer is formed).
And the opposite surface (mirror surface) have different adhesive strength. The cleaning blade 7 and the blade holder 8
Since the mirror surface of the cleaning blade 7 having a large bonding strength can be used for bonding with the cleaning blade 7, the bonding strength between the cleaning blade 7 and the blade holder 8 can be increased. As in the first embodiment, the cleaning blade 7
If a low friction agent layer is formed on the mold surface side and the air contact surface side (mirror surface side) is used as an adhesive surface with the blade holder 8, the blade holder can be cleaned only once by cleaning the air contact surface side. 8 can be strongly adhered. If the mold surface is used as an adhesive surface with the blade holder 8, a cleaning agent needs to be performed three times because a release agent or the like is attached. Can be.

Next, as shown in FIG. 6, the low friction layer 7a of the cleaning blade assembly 9 is brought into contact with the flat glass G at an inclination angle of 22 °, and the flat glass G surface The cleaning blade 7 was pressed against the flat glass G by applying a force of 469 g in the direction. At this time, the flat glass G was pulled in the direction B at a speed of 500 mm / min, and the sliding friction force was measured. For comparison, the sliding friction force of a cleaning blade assembly (conventional product) not subjected to a lubricant treatment was also measured. As a result, the low friction layer 7a
The sliding frictional force of the cleaning blade assembly 9 of the present invention having the above was 476 g, whereas the sliding frictional force of the conventional product (cleaning blade assembly not subjected to the lubricant treatment) was 616 g. As described above, the cleaning blade assembly 9 of the present invention has a sliding friction force significantly reduced to -23% as compared with the conventional product.

Next, an image forming apparatus in which the cleaning blade assembly 9 shown in FIG. 2 is incorporated in a cleaning unit will be described with reference to FIG. (Image Forming Apparatus) In the main body of the image forming apparatus A, a photoconductor (moving member) 11 that rotates in the direction of the arrow (clockwise in FIG. 7).
Is provided. The charging corotron 12, the developing unit 13, the transfer corotron 14, and the peeling corotron 1 are provided on the outer peripheral portion of the photoconductor 11 along the rotation direction of the photoconductor 11.
5. Cleaning corotron 16 and cleaning unit 1
7 and the like are provided. In the developing unit 13, a developing magnet roll 18 facing the surface of the photoconductor 11 is provided.
And a toner 19 is stored in the bottom of the developing unit 13. Further, the cleaning unit 1
7, a cleaning blade assembly 9 and the like according to the present invention, which include a deter bar brush 20, the cleaning blade 7, and a blade holder 8 formed of a cold-rolled zinc-treated steel plate or the like, are incorporated. In FIG. 7,
Although only one unit is shown, two to four units containing a plurality of magenta, yellow, cyan, and black toners, respectively, are arranged adjacent to the outer peripheral portion of the photoconductor 11. You may.

Next, the cleaning blade assembly 9
The operation of the image forming apparatus A in which is incorporated will be described.
First, the surface of the photoconductor 11 is charged by the charging corotron 12. Next, a laser beam L is irradiated from an exposure optical system (not shown) to expose the surface of the photoreceptor 11 to write out image information. Then, while rotating a developing magnet roll 18 in the developing unit 13, To photoconductor 11
A toner image is formed on the photoreceptor 11 by being attached to the surface. Next, a sheet supplied from a paper feeding mechanism (not shown) is supplied between the photoconductor 11 and the transfer corotron 14, and the transfer corotron 14 generates an electrostatic charge opposite to the charging polarity on the surface of the photoconductor 11. The sheet is charged, and the toner image is transferred to the sheet. Thereafter, the sheet on which the toner image has been transferred is peeled from the photoconductor 11 by the peeling corotron 15. The sheet peeled from the photoconductor 11 is then fixed by a fixing device (not shown).
And the toner image on the paper is fixed. The toner 19 remaining on the surface of the photoconductor 11 is cleaned by the cleaning corotron 1
Then, the charge is removed by the cleaning unit 6 and the cleaning unit 17 scrapes off the dust. The photoconductor 1
The toner 19 slightly remaining and adhering to one surface is completely removed by the cleaning blade assembly 9 rubbing the surface of the photoconductor 11.

When a plurality of developing units 13 are provided, in the developing step, development is performed for each color using two to four types of magenta, yellow, cyan toner and black toner, and a color toner image is formed. When transferred to paper, an image colored to a desired hue is obtained. When three color toners of magenta, yellow and cyan are used, a full-color copy is obtained.

Here, the cleaning blade assembly 9 is connected to the above-described image forming apparatus (Vivache-
500: Fuji Xerox Co., Ltd.) Attached to the cleaning unit 17 in the A main body. At this time, the low friction layer 7a side was pressed against the photosensitive member 11 with a pressing force of 469 g. Under these parameter conditions, the image forming apparatus A was operated to repeat the copying operation, and the amount of wear on the surface of the photoconductor 11 after the photoconductor 11 was rotated 160,000 times was measured. For comparison, the wear amount of the conventional product was also measured. As a result, the wear amount when the cleaning blade assembly 9 of the present invention was used was 1.1 μm, whereas the wear amount when the conventional product was used was 2.3 μm. Thus, the cleaning blade assembly 9 of the present invention is
The amount of wear was greatly reduced to -52%.

Example 2 (Blade) A liquid polyurethane rubber having a molecular weight of 2 containing ethylene glycol and adipic acid as polymerization components
000 condensed polyester (Nipporan 4040)
After dehydration, 100 parts of the polyester was combined with 18 parts of 1,5-naphthylene diisocyanate at 130 ° C for 20 parts.
After reacting for 1 minute, a prepolymer was synthesized. To this prepolymer, 2 parts of 1,4-butanediol as a curing agent was added, and a liquid polyurethane rubber of a reaction mixture produced by stirring was added to a mold 2 of a centrifugal molding machine 1 rotating at high speed as shown in FIG.
Poured into. Next, at the beginning of the curing of the liquid polyurethane rubber, a commercially available silicone-based curable mold release agent (the monocoat E91A) was used as the solid lubricant 4a, and the air of the liquid polyurethane rubber was mixed with the air in the mold 2 of the centrifugal molding machine 1. Spraying and application were performed on the contacting surface side, and molding was performed at 120 ° C. for 90 minutes while rotating the mold 2. Thereafter, the rubber molded body 6 having the same low friction layer 7a 'as in Example 1 formed on the air contact surface side was taken out of the mold 2. The obtained cylindrical rubber molded body 6 is cut in the axial direction and developed, and is placed on a surface plate.
It was cured by heating for 0 hours. The hardness (JIS-A scale) of this polyurethane sheet was 80 °.

(Cleaning blade assembly) The cleaning blade 7 'obtained in the same manner as in Example 1
(2 mm thick) is adhered to the blade holder 8 'with an adhesive to produce a cleaning blade assembly 9' having a low friction layer 7a 'on its surface (see FIG. 2).
a ′ was brought into contact with the flat glass G at an inclination angle of 22 °, and the flat glass G was pulled in the direction B to measure the sliding frictional force (see FIG. 6). As a result, the low friction layer 7a
Cleaning blade assembly 9 'of the present invention having a
Had a sliding friction force of 493 g, whereas the sliding friction force of the conventional product not subjected to the lubricant treatment was 616 g. As described above, the cleaning blade assembly 9 of the present invention has a sliding friction force significantly reduced to -20% as compared with the conventional product.

Further, in the same manner as in the first embodiment, the cleaning blade assembly 9 'was mounted on a cleaning unit 17 in the main body of the image forming apparatus A shown in FIG.
At this time, the low friction layer 7a was pressed against the photoconductor 11 with a pressing force of 469 g, and the abrasion amount on the surface of the photoconductor 11 was measured.
As a result, the abrasion loss of the photoconductor 11 when the cleaning blade assembly 9 'of the present invention was used was 1.3 [mu] m, whereas the abrasion loss when the conventional product was used was 2.3.
μm. Thus, the cleaning blade assembly 9 'of the present invention has a wear amount of -43 compared to the conventional product.
% Fell significantly.

The blades 7, 7 'produced in the first and second embodiments of the present invention were incorporated as a toner charging blade into a one-component developing unit developing unit shown in FIG. 8 in the image forming apparatus, and the copying operation was repeated. . (Developing Unit) In FIG. 8, reference numeral 31 denotes a photoconductor provided in the image forming apparatus. A developing unit main body 32 is arranged close to the photoreceptor 31, and a toner 33 is stored at the bottom thereof. A rotatable magnet roll (moving member) 34 is pivotally mounted below the developing unit main body 32, and the magnet roll 34 is partially exposed from the opening of the developing unit main body 32 so as to substantially contact the surface of the photoconductor 31. ing. The blade assembly 3 of the present invention in which a blade holder 36 formed of a zinc-treated steel sheet is adhered to an upper end of a toner charging blade 35 rubbing a magnet roll 34 is provided in an upper portion inside the developing unit main body 32.
7 is mounted.

In the developing unit shown in FIG. 8, after being charged by a charging corotron (not shown), the photosensitive member 31 exposed to image information is rubbed against the magnet roll 34 while rotating. The magnet roll 34 transfers the toner 33 to the surface of the photoreceptor 31 while charging the electrostatic charge of the opposite polarity to the photoreceptor 31 and attaching the toner 33 by the blade assembly 37. Blade assembly 37 of the present invention
Since the rubbing surface is formed of a low friction material, any of the blades 7 and 7 obtained in the first and second embodiments can be used.
Even when 7 'is used, the wear of the toner charging blade 35 itself and the wear on the blade 35 are reduced as compared with conventional blade materials such as a thermoplastic urethane sheet, a thermosetting urethane sheet, and a silicone sheet which are not subjected to a lubricant treatment. Was significantly reduced.

[0038]

According to the blade for an image forming apparatus of the present invention, the low friction layer in which the lubricant and the polyurethane rubber are mixed is formed integrally with the surface layer of the polyurethane rubber molded article. Surface wear can be drastically reduced, and the low friction layer does not peel off. In addition, by bonding the fixing member to the surface opposite to the used edge of the blade, the mirror surface of the blade can be used as the bonding surface, so that the bonding strength between the blade and the fixing member can be greatly increased. Further, when the blade for an image forming apparatus of the present invention is used as a cleaning blade, even if it is used for a long period of time, the friction coefficient does not increase with time, so that the blade bending phenomenon due to the high friction between the blade and the photoconductor is caused. It does not occur, and a stable cleaning effect can always be obtained. Further, it is possible to prevent generation of abnormal noise due to friction between the blade and the photoconductor, and it is not necessary to apply a friction agent between the blade and the photoconductor during maintenance. On the other hand, when the blade for an image forming apparatus of the present invention is used as a toner charging blade, the amount of toner adhering to the blade can be reduced, and the life of the developing unit can be greatly extended. Furthermore, the method of manufacturing a blade for an image forming apparatus of the present invention may be performed by coating a lubricant on a mold surface of a molding machine or spraying and applying the liquid polyurethane rubber to an air contact surface of a liquid polyurethane rubber at the beginning of curing. There is an advantage that an existing molding machine can be used as it is.

[Brief description of the drawings]

FIG. 1 is an enlarged view of a main part showing an example of a molding machine for producing a blade of the present invention.

FIG. 2 is a side view of the cleaning blade of the present invention in which the blade is fixed to a blade holder.

FIG. 3 is a photograph of a low friction layer surface of a blade of the present invention photographed at 400 times magnification with an optical microscope.

FIG. 4 is a photograph of a cross-section of an edge of the blade of the present invention and an edge thereof taken by a scanning electron microscope at a magnification of 2000 times.

FIG. 5 is a photograph of a cross section of the edge of the blade of the present invention and a photograph of the edge portion thereof taken at a magnification of 5000 times with a scanning electron microscope.

FIG. 6 is a schematic diagram illustrating measurement of a sliding friction force of the cleaning blade of the present invention.

FIG. 7 is a schematic diagram illustrating an example of an image forming apparatus incorporating the cleaning blade of the present invention.

FIG. 8 is a schematic diagram illustrating an example of a developing unit in another image forming apparatus equipped with the toner charging blade of the present invention.

FIG. 9 is an explanatory diagram of a sliding state of a conventional cleaning blade.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Centrifugal molding machine, 2 ... Die, 4 ... Lubricant layer, 4a ... Lubricant, 6 ... Polyurethane rubber molded article, 7, 7 ', 35 ... Blade for image forming apparatus, 7a, 7a' ... Low friction layer , 11 ...
Moving member (photoreceptor), 19, 33 ... toner, 34 ... moving member (magnet roll).

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Negishi 2-3-6 Shirite, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Hokushin Kogyo Co., Ltd. (56) References JP-A-4-51075 (JP, A) JP-A-4-212190 (JP, A) JP-A-6-342245 (JP, A) JP-A-3-2177872 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 21 / 10-21/12 G03G 15/08-15/08 507

Claims (4)

(57) [Claims] 1. A method of manufacturing a blade for an image forming apparatus comprising a sheet-like polyurethane rubber molded body which rubs the surface of a moving member to which toner has adhered, wherein a liquid polyurethane rubber is poured into a mold, Before curing, the solid lubricant is applied by spraying to form a low friction layer in which particles of the solid lubricant are embedded in the polyurethane rubber molded body on the air contact surface side of the polyurethane rubber, An image forming apparatus, comprising cutting a polyurethane rubber molded article into a rectangle, and bonding a surface of the cut sheet-shaped polyurethane rubber molded article opposite to a side surface on which the low friction layer is formed to a blade holder. Method of manufacturing blades. 2. The method according to claim 1, wherein a rotating centrifugal mold is used as the mold. 3. A cleaning unit, comprising: a blade for an image forming apparatus manufactured by the method for manufacturing a blade for an image forming apparatus according to claim 1; and a cleaning unit for cleaning a surface of the photoreceptor by the blade for the image forming apparatus. Image forming device. 4. A developing unit, comprising: a blade for an image forming apparatus manufactured by the method for manufacturing a blade for an image forming apparatus according to claim 1; and a developing unit for rubbing a developing roll surface with the blade for the image forming apparatus. Image forming apparatus.