JP2000075748A - Cleaning blade for electrophotographic device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning blade capable of maintaining excellent cleaning performance over a long period without causing the peeling of adhesion. SOLUTION: A cleaning blade 10 comprises a plate-shaped elastic member 4 having an edge portion 7 for removing a toner remaining on a photoreceptor after transfer and a support member 5 to which the plate-shaped elastic member 4 is bonded via an adhesive 6 on the side opposite to the edge portion 7. In this case, the outside corner part 8 of the part of the plate-shaped elastic member 4 bonded to the support member 5 is chamfered in the form of a curved or flat face; when it is chamfered in the form of a curved face, the radius of the curved face is set at 0.3 to 2.0 mm, and wen it is chamfered in the form of a flat face, the length of each of two sides forming the right angle of a triangle which the cross section of the chamfered part forms is set at 0.3 to 2.0 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cleaning blade and a method for manufacturing the same.

[0002]

2. Description of the Related Art According to an electrostatic electrophotographic copying machine using plain paper as recording paper, an electrostatic charge is generally applied to the surface of a photoreceptor by discharging, and an image is exposed thereon to form an electrostatic latent image. Forming, then applying toner of opposite polarity to the electrostatic latent image and developing, transferring the toner image to recording paper, and finally,
Copying is performed by heating and pressing the recording paper on which the toner image has been transferred and fixing the toner on the recording paper.

Therefore, in order to sequentially perform copying on a plurality of recording papers, it is necessary to remove the toner remaining on the surface of the photoreceptor after transferring the toner image from the photoreceptor to the recording paper in the above process. , The removal of such toner is usually
This is performed by a cleaning blade. The cleaning blade is usually formed of a support member made of a metal plate, a plate-like elastic member made of an elastomer, and an adhesive layer for joining the support member and the plate-like elastic member.

In the conventional blade member, since the outer corner of the bonding portion between the plate-like elastic member and the support member is at a right angle, a bending moment due to pressure contact with the photoreceptor is applied to the bonding portion. Since chatter due to rubbing vibration is added, there has been a problem that the adhesive peels off when used for a long time.

[0005]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a cleaning blade capable of maintaining excellent cleaning performance without causing peeling of the adhesive for a long period of time and a method of manufacturing the same. It is assumed that.

[0006]

According to the present invention, there is provided a plate-like elastic member having an edge for removing toner remaining on a photoreceptor after transfer, and the plate-like elastic member is bonded on the opposite side of the edge. A cleaning member comprising a support member adhered via an agent, wherein an outer corner of an adhesion portion of the plate-like elastic member with the support member is chamfered to a curved surface or a plane, and the chamfer is formed. In the case of a curved surface, the radius of the curved surface is set to 0.3 to 2.0 mm, and when the chamfer is a plane, the length of two sides sandwiching a right angle of a triangle formed by the cross section of the chamfered portion Is 0.3 to 2.0 respectively
mm. Hereinafter, the present invention will be described in detail.

The cleaning blade according to the present invention comprises a plate-like elastic member having an edge portion for removing toner, and a supporting member to which the plate-like elastic member is bonded via an adhesive on the side opposite to the edge portion. And the outer corner of the bonding portion is chamfered to a curved surface or a flat surface.

When the chamfer is a curved surface, as shown in FIG. 2A, the cleaning blade 10 has the plate-like elastic member 4 on the opposite side of the edge portion 7 via the support member 5 and the adhesive 6. The outer corner 8 is chamfered to a curved surface.

[0009] The radius of the curved surface is 0.3 to 2.0 mm. If the radius of the curved surface is less than 0.3 mm, the relaxation of bending stress due to pressure contact with the photoreceptor is insufficient, and the adhesive tends to peel off. When the thickness is 1.5 to 2.5 mm, the stiffness at the bonding portion is weakened, and the edge portion is less likely to be pressed against the photoreceptor. Therefore, the thickness is limited to the above range.

The angle θ between two surfaces connected to the curved surface
Is preferably 90 to 110 °. The hardness of the plate-like elastic member is preferably 60 to 80 ° in Walles hardness in that the pressure contact force of the photoreceptor and the frictional heat can be balanced and good cleaning properties can be maintained.

In the case where the chamfer is flat, as shown in FIG. 2B, the cleaning blade 10 has the plate-like elastic member 4 on the opposite side of the edge portion 7 via the support member 5 and the adhesive 6. And the outer corner 8 is chamfered in a plane.

In the chamfered portion 108 when the plane is chamfered, the lengths x and y of two sides of a right angle of the triangle formed by the cross section of the chamfered portion 108 are 0.3 to 2 respectively. 0.0 mm. X and / or y above
However, when the thickness is less than 0.3 mm, the bending stress due to pressure contact with the photoreceptor is insufficiently relaxed and adhesive peeling tends to occur. When the thickness exceeds 2.0 mm, the thickness of the elastic plate member is reduced. In the case of 1.5 to 2.5 mm, the stiffness at the bonding portion is weakened, and the edge portion is less likely to be pressed against the photoreceptor.

The material of the plate-like elastic member is not particularly limited, and examples thereof include polyurethane, silicone rubber, and ethylene-propylene-diene copolymer (EPDM). Of these, polyurethane is
It is preferable because the contamination of the mating member is small, the permanent set is small, and the wear resistance is excellent. As the polyurethane, those obtained by a reaction between a polymer polyol and a diisocyanate are preferable.

As the above-mentioned high molecular polyol, for example,
Polyethylene glycol, polypropylene glycol,
Polyoxyalkylene glycols such as polyoxytetramethylene glycol; polyether-type polyols of bisphenol A and glycerin ethylene oxide adduct; dibasic acids such as adipic acid, phthalic anhydride, isophthalic acid, maleic acid, fumaric acid and ethylene glycol ,
Propylene glycol, 1,4-butanediol, 1,
Polyester-type polyols obtained by a polymerization reaction with glycols such as 6-hexanediol and trimethylolpropane; polycaprolactone diol, polycarbonate diol and the like. The number average molecular weight of the high molecular polyol is preferably from 500 to 5,000, more preferably from 1,000 to 3,000. The above polymer polyols may be used alone or in combination of two or more.

Examples of the diisocyanate compound include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and 1,4-cyclohexane diisocyanate. The diisocyanate compounds may be used alone or in combination of two or more.

Examples of the chain extender include low molecular weight diols such as ethylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexanediol and neopentyl glycol; diamines such as ethylenediamine, hexamethylenediamine and isophoronediamine And the like. Of these, low molecular weight diols are preferred. Further, if necessary, as a polyfunctional component,
Trimethylolpropane, triethanolamine, glycerin, and ethylene oxide and propylene oxide adducts thereof may be added. A method for manufacturing a cleaning blade using these materials will be described later.

The support member used in the present invention is not particularly limited. For example, a rigid metal, an elastic metal,
Those manufactured from plastics, ceramics and the like can be mentioned. Among these support members, a rigid metal is preferably used. As a method of bonding the plate-like elastic member and the support member, for example, polyamide-based,
Polyurethane-based hot melt adhesives, epoxy-based, and phenol-based adhesives can be used.
Among these, a bonding method using a hot melt adhesive is preferable.

According to the method of manufacturing a cleaning blade of the present invention, there is provided a drum having a groove formed over the entire outer periphery thereof, wherein the cross section of the groove is part of a cross section perpendicular to the longitudinal direction of the plate-like elastic member. While rotating a continuous molding die having a drum formed in the same shape as above and a belt body running along a part of the outer periphery of the drum and covering the groove, the plate-shaped member is formed in the groove. Injecting a liquid composition for forming an elastic member, performing molding, forming a continuous belt-like body, and cutting the continuous belt-like body into a predetermined length to produce a plate-like elastic member. .

FIG. 3 is a perspective view schematically showing a plate-like elastic member manufacturing apparatus used in the cleaning blade manufacturing method of the present invention. As shown in FIG. 3, the manufacturing apparatus 20 for a plate-like elastic member includes a mixing head 2
Liquid composition injection device (not shown) containing 1 and drum 4
1. Continuous rotary forming mold 40 including endless belt (belt body) 22 and the like, cooling belt conveyor 3
0, a cutting device 38 and the like.

Although not shown, the liquid composition injecting apparatus has two tanks for storing a prepolymer and a cross-linking agent, respectively, which are raw materials for producing polyurethane. A pipe provided via a pump is connected to the mixing head 21. In the mixing head 21, the raw materials flowing from each tank are mixed therein, and the mixed liquid composition can be discharged to the molding grooves (grooves) 42.

The drum 41 has a forming groove 42 formed over the entire outer periphery thereof. The cross section of the forming groove 42 shown in FIG. 4 is perpendicular to the outer corner 8 of the plate-like elastic member 4. Is formed in the same shape as the portion excluding the upper main surface 9 (see FIG. 2). Further, the molding groove 42 is formed extremely precisely, and the surface thereof is formed extremely smooth. Further, on both sides of the molding groove 42, overflow grooves 43 and 44 are provided.

A heating facility is disposed inside the drum 41, and its outer peripheral surface is heated to a predetermined temperature in order to promote a polymerization reaction of the discharged liquid composition. A heater 23 is also provided in the upper left half of the outer peripheral portion of the drum 41 so that heating can be performed from the outside.
The center of the drum 41 is supported by a rotating shaft 45 and rotates counterclockwise at a predetermined slow rotation speed.

Further, an endless belt 22 running at the same speed as the drum 41 is provided so as to cover the forming groove 42 so as to be in close contact with the lower half of the outer periphery of the drum 41.
The endless belt 22 is hung around a driving roll 24 and driven rolls 25 and 26. The endless belt 22 also includes a plurality of heaters 23 for heating the formed body. Disposed at the upper right of the drum 41 is a release agent spraying device for preventing the compact from adhering to the drum 42.

A cooling belt conveyor 3 is provided adjacent to the driving roll 24 to cool the formed continuous belt-shaped body 120.
0 is installed, and the belt 31 is rolled 32, 33,
34, 35, 36, and 37. The rolls 36 and 37 are disposed inside a cooling device (not shown), and the belt 31 is cooled by passing through the cooling device.

A support table 39 is provided in the vicinity of the roll 33, and a cutting device 38 is provided on the support table 39. The continuous belt 120 transported by the cooling belt conveyor 30 is subjected to the cutting. The cutter 38a of the device 38
Is cut into a predetermined length.

Next, a method of manufacturing the plate-like elastic member 4 using the plate-like elastic member manufacturing apparatus will be described. First,
The two liquids are sent from the tank storing the prepolymer and the crosslinking agent to the mixing head 21 via a pipe,
After mixing with a mixing head to prepare a liquid composition 27 for molding, the liquid composition 27 is poured into a molding groove 42 formed on the drum 41 by the mixing head 21.
To be discharged. The discharge amount is adjusted by the rotation speed of the drum 41 and the capacity of the forming groove 42.

The liquid composition 27 is mixed with the mixing head 21.
Is discharged in the vicinity of the point a directly below the point a, moves in the direction of the point b with the rotation of the drum 41, is heated from the point a to the point b, and the reaction proceeds. From point c to point c, heating and pressure are applied by the endless belt 22 to substantially end the polyurethane polymerization reaction, and a continuous belt-like body 120 having the same cross-sectional shape as the plate-like elastic member 4 is produced.

The continuous strip 120 is then transported while being cooled by the cooling belt conveyor 30, cut into a predetermined length by a cutter 38a, and has a very smooth and precisely shaped outer corner. The plate-like elastic member 4 having 8 is manufactured. The obtained plate-like elastic member 4
Thereafter, at the upper end 9 of the upper main surface, the support member 5 and the adhesive 6 are adhered to each other, and the cleaning blade 10 is completed by forming an edge by cutting the width.

According to the manufacturing method of the cleaning blade, the plate-shaped elastic member is manufactured continuously and efficiently by using the plate-shaped elastic member manufacturing apparatus. A cleaning blade can be manufactured.

When this cleaning blade is mounted on a cleaning section of an electrophotographic developing apparatus having a developing section, a charging section, a photosensitive drum, and the like, chatter vibration caused by contact with the photosensitive member causes a curved surface provided outside the bonding section. , The adhesive peeling does not occur for a long period of time, so that excellent cleaning properties can be maintained.

[0031]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Polycaprolactone ester diol (average molecular weight: 2000) was used as a high molecular polyol at 70 ° C. for 3 hours.
After heating and stirring under reduced pressure (5 mmHg) and dehydrating,
This was charged into a reactor, and subsequently, 4,4-diphenylmethane diisocyanate was added as a diisocyanate, and the mixture was stirred at 70 ° C. for 1 to 4 hours under a nitrogen gas atmosphere to obtain a liquid urethane prepolymer. The amount of the polymer polyol and diisocyanate added, the content of residual isocyanate groups, and the equivalent ratio (isocyanate group /
(Hydroxyl group) is shown in Table 1 below.

Further, 1,4-butanediol, trimethylolpropane, and 1,2-dimethylimidazole as a reaction accelerator were reduced at 70 ° C. for 3 hours under reduced pressure (5 mm
Hg), followed by dehydration after heating and stirring to obtain a crosslinking agent having a hydroxyl equivalent of 45. The amounts of 1,4-butanediol, trimethylolpropane, and 1,2-dimethylimidazole are shown in Table 1 below.

The prepolymer and the cross-linking agent obtained as described above were respectively charged into a raw material tank, temperature-adjusted to the temperature shown in Table 1, and mixed by a mixing head to obtain a liquid. After preparing the composition and discharging the liquid composition from the mixing head 21 into the molding groove 42 of the apparatus for manufacturing a plate-like elastic member shown in FIG. 3, the apparatus for manufacturing a plate-like elastic member shown in FIG. The plate-like elastic member 4 was manufactured by the method described in the above description. The manufacturing conditions are shown in Table 1 below.

Example 2 Polyethylene adipate diol (average molecular weight: 2000) was used in place of polycaprolactone ester diol as a polymer polyol, and the curved surface radius of the outer corner of the plate-like elastic member to be produced was changed. In the same manner as in Example 1, the plate-like elastic member 4 was manufactured. Table 1 below shows the amount of each raw material added and the conditions for producing the plate-like elastic member.

Example 3 In preparing the prepolymer, the amount of the polymer polyol used was reduced, and in preparing the cross-linking agent, the above-mentioned polymer polyol was used, and the outer corners of the plate-like elastic member to be produced were manufactured. A plate-like elastic member 4 was manufactured in the same manner as in Example 1 except that the radius of the curved surface was changed. Table 1 below shows the amount of each raw material added and the conditions for producing the plate-like elastic member.

Example 4 In the preparation of the prepolymer, the amount of the polymer polyol used was reduced, and in the preparation of the cross-linking agent, the polymer polyol was used, and the outer corners of the plate-like elastic member produced were used. The plate-shaped elastic member 4 was manufactured in the same manner as in Example 2 except that Table 1 below shows the amount of each raw material added and the conditions for producing the plate-like elastic member.

Comparative Example 1 A plate-like elastic member 4 was produced in the same manner as in Example 1 except that the radius of the curved surface of the outer corner portion of the plate-like elastic member to be produced was changed. Table 2 below shows the amount of each raw material added and the conditions for producing the plate-like elastic member.

Comparative Example 2 A plate-like elastic member 4 was manufactured in the same manner as in Example 1 except that the radius of the curved surface of the outer corner portion of the plate-like elastic member to be manufactured was changed. Table 2 below shows the amount of each raw material added and the conditions for producing the plate-like elastic member.

Comparative Example 3 A plate-like elastic member 4 was produced in the same manner as in Example 1 except that the shape of the plate-like elastic member to be produced and the amount of each raw material added were changed. Table 2 below shows the amount of each raw material added and the conditions for producing the plate-like elastic member.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]Evaluation method  (1) Dimensions of plate-like elastic member, etc. Dimensions of plate-like elastic member obtained by the above Examples and Comparative Examples
Method and the like were measured. The results are shown in Tables 3 and 4 below.
Was.

(2) Physical properties of the plate-like elastic member The plate-like elastic member obtained according to the above-described embodiment is described in JIS.
Tables 3 and 4 according to the physical test method of the thermosetting polyurethane elastomer molded product of K 7312 (1996)
Were measured. The results are shown in Tables 3 and 4 below.

(3) Performance Test of Cleaning Blade The plate-like elastic member obtained in the above example was adhered to a supporting member with an adhesive to produce a cleaning blade 50 having the shape shown in FIG. The bonding was performed by applying a hot-melt adhesive to the support member 51 side, bonding the bonded portions of the plate-shaped elastic members 52 together, and then fusing them by high frequency. Thereafter, the cleaning blade 50 was mounted on the cleaning section of a commercially available electrophotographic apparatus, and 10,000 images were printed, and the performance of the cleaning blade was evaluated by the following method.

[0046]Cleaning ability  Visually evaluate the image according to the following evaluation criteria
Was. ○ No toner slippage △ Partial toner slippage (streak-like) × Toner slippageWith or without adhesive  Visually evaluate the bonded part according to the following evaluation criteria
Was. ○ No peeling △ Local peeling × Peeling

[0047]Adhesive strength  Contact with the plate-like elastic member before mounting and after outputting 100,000 sheets of images
The adhesive strength with the attachment member was measured by a 90 ° peeling method.Photoreceptor scratches, deterioration  Visually observe the surface of the photoreceptor and perform it according to the following evaluation criteria.
Was. ○ No scratches, appropriate amount of photoreceptor film loss or no deterioration × Excessive scratches, large amount of photoreceptor film loss or deterioration

[0048]

[Table 3]

[0049]

[Table 4]

As described above, the cleaning blade of the present invention has sufficient physical properties required as a cleaning blade, and can be sufficiently used as a cleaning blade even when actually mounted on a copying machine to perform copying. It had the required performance.

[0051]

Since the cleaning blade of the present invention has the above-described structure, it is possible to provide a cleaning blade which can maintain excellent cleaning performance without causing adhesive separation for a long period of time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which toner remaining on a photoconductor is removed by a cleaning blade of the present invention.

2A is a cross-sectional view of a cooling blade with a chamfered curved surface, and FIG. 2B is a cross-sectional view of the cooling blade with a chamfered flat surface.

FIG. 3 is a perspective view schematically showing an apparatus for manufacturing a plate-like elastic member constituting the cleaning blade of the present invention.

FIG. 4 is a cross-sectional view schematically showing a forming groove formed on a drum constituting the apparatus for manufacturing a plate-like elastic member shown in FIG.

FIG. 5A is a plan view schematically showing the cleaning blade manufactured in the example, and FIG. 5B is a cross-sectional view thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Cleaning blade 4 Plate-like elastic member 5 Support member 6 Adhesive 7 Edge part 8 Outer corner 10 Cleaning blade 20 Plate-like elastic member manufacturing apparatus 22 Endless belt 27 Liquid composition 40 Mold for continuous rotation molding 42 Molding Groove 108 chamfered part 120 continuous strip

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Gogan Masuyama 3-2-15 Meiwadori, Hyogo-ku, Kobe Bando Chemical Co., Ltd. F-term (reference) 2H034 BF00 BF01 BF03 BF06

Claims (3)

[Claims] 1. A plate-like elastic member having an edge portion for removing toner remaining on a photoreceptor after transfer, and a support having the plate-like elastic member bonded to the opposite side of the edge portion via an adhesive. A cleaning blade comprising a member, wherein an outer corner portion of the bonding portion of the plate-like elastic member with the support member is chamfered to a curved surface or a flat surface, and when the chamfer is a curved surface, Radius 0.3-2.0
mm, and when the chamfer is a plane, the length of each of two sides of a right angle of a triangle formed by the cross section of the chamfer is set to 0.3 to 2.0 mm. Characteristic cleaning blade. 2. The cleaning blade according to claim 1, wherein the plate-like elastic member is made of polyurethane. 3. A method for manufacturing a cleaning blade according to claim 1, wherein a groove is formed over the entire outer periphery of the drum, wherein the cross section of the groove is a length of the plate-like elastic member. A continuous forming die having a drum formed in the same shape as a part of a cross section perpendicular to the vertical direction and a belt body running along a part of the outer periphery of the drum and covering the groove. Then, the liquid composition for forming the plate-like elastic member is injected into the groove portion, molded, and formed into a continuous band-like body. A method for producing a cleaning blade, comprising producing a member.