JP2007003882A - Cleaning blade for electrophotographic apparatus and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning blade for an electrophotographic apparatus, the cleaning blade being capable of preventing residual toner from escaping from the surface of an image carrier even in the use of polymerization toner that has a spherical shape (exactly spherical, different shapes) and a small particle diameter. <P>SOLUTION: An elastic rubber member 1 has a two-layer structure composed of an edge layer 4 that is not jointed to a support member 2, and a base layer 5 joined to the support member 2 via an adhesive layer 3. The edge layer 4 is formed from a material that has a JIS A hardness of 50° to 65° at 23°C. The base layer 5 is made of a material that has a JIS A hardness of 70° to 99° at 23°C. The ratio of the thickness (a) of the edge layer 4 to the sum of the thickness (a) of the edge layer 4 and the thickness (b) of the base layer 5 (i.e., a/(a+b)) is 0.01 to 0.1. The thickness (a) of the edge layer 4 is 50 μm or less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

According to an electrostatic electrophotographic copying machine using plain paper as a recording paper, generally, an electrostatic charge is given to the surface of the image carrier by discharge, and an image is exposed thereon to form an electrostatic latent image. Then, the charged toner is attached to the electrostatic latent image and developed, and the toner image is transferred to the recording paper. Finally, the recording paper on which the toner image is transferred is heated and pressurized to fix the toner on the recording paper. Make a copy.

Therefore, in order to sequentially copy on a plurality of recording papers, it is necessary to remove the toner remaining on the surface of the image carrier after the toner image is transferred from the image carrier to the recording paper in the above-described process. Such toner removal is usually performed by a cleaning blade for an electrophotographic apparatus. The cleaning blade for an electrophotographic apparatus is usually formed of a support member made of a metal plate, an elastic rubber member, and an adhesive layer for joining the support member and the elastic rubber member.

In recent years, in such an electrophotographic apparatus, a higher quality printed matter has been demanded, and accordingly, the shape thereof is spherical (true spherical shape, irregular shape) as compared with conventional pulverized toner, and Polymerized toners having a small particle size are used. Such a spherical toner having a small particle size is easy to roll, and therefore easily sinks into a wedge shape formed by a blade edge (cut surface) and a counterpart material (image carrier or the like). For this reason, the blade cut surface → edge → cleaning surface is easily pushed up, and residual toner slips through, resulting in a defective cleaning.

Patent Document 1 discloses an electrophotographic apparatus having a cleaning blade having a total thickness of 2 to 4 mm, a two-layer structure including a portion that contacts the photoreceptor and a portion that does not contact, and the rebound resilience of these portions is different. Is disclosed. In this document, an example is shown in which the hardness of the abutting part is smaller than the non-abutting part. However, since the thickness of the contact portion of this cleaning blade is relatively large, the blade cut surface → the edge → the cleaning surface is easily pushed up, and the residual toner may slip through and cause a cleaning failure.

Patent Documents 2 to 3 disclose a cleaning blade for an electrophotographic apparatus comprising an elastic rubber member having a two-layer structure comprising an edge layer and a base layer and a supporting member. In this elastic rubber member, the base layer is smaller in hardness than the edge layer, and the relative thickness and absolute thickness of the edge layer in the elastic rubber member having a two-layer structure are large. For this reason, when the cleaning blade disclosed herein is used, the edge portion is always pressed against the image carrier, so that sag occurs, residual toner slips through, and cleaning failure may occur. .

Patent Document 4 and the like describe a blade member obtained by coating a part of the surface of the member with a resin or the like, and Patent Document 5 and the like include a blade member obtained by impregnating a part of the member with other components. Is disclosed. However, such a blade member coated with resin or a blade member impregnated with other components has a structure different from that of a two-layer blade member, and the residual toner cannot be sufficiently prevented from slipping through. There is.
JP 2003-29594 A JP 2002-214989 A JP 2002-214990 A Japanese Patent Laid-Open No. 9-127846 JP 2003-122222 A

In view of the above situation, the present invention can prevent the residual toner on the surface of the image carrier from slipping through even when a polymerization method toner having a spherical shape (spherical shape or irregular shape) and a small particle size is used. An object of the present invention is to provide a cleaning blade for an electrophotographic apparatus.

The present invention relates to an electrophotographic apparatus cleaning blade having an elastic rubber member, a support member, and an adhesive layer, wherein the elastic rubber member includes an edge layer not joined to the support member, the support member, and the adhesive. The edge layer is made of a material having a JIS A hardness of 50 ° to 65 ° at 23 ° C., and the base layer has a two-layer structure composed of base layers joined through layers. It is made of a material having a JIS A hardness of 70 ° to 99 ° at ° C., and the sum of the thickness (a) of the edge layer, the thickness (a) of the edge layer, and the thickness (b) of the base layer (a + b) ) (A / (a + b)) is 0.01 to 0.1, and the thickness (a) of the edge layer is 50 μm or less. .

In the cleaning blade for an electrophotographic apparatus, the edge layer and the base layer are preferably made of polyurethane.

The present invention also includes a step (1) of producing an elastic rubber member having a two-layer structure of an edge layer and a base layer using a centrifugal molding method, and the elastic rubber member obtained in the step (1) and a support. The edge layer is made of a material having a JIS A hardness of 50 ° to 65 ° at 23 ° C., and the base layer has a JIS A hardness at 23 ° C. Of the edge layer thickness (a) and the sum of the edge layer thickness (a) and the base layer thickness (b) (a + b) (a / b) (A + b)) is 0.01 to 0.1, and the thickness (a) of the edge layer is 50 μm or less.

In the method of manufacturing the cleaning blade for an electrophotographic apparatus, the edge layer and the base layer are preferably made of polyurethane.
Hereinafter, the present invention will be described in detail.

The cleaning blade for an electrophotographic apparatus of the present invention has an elastic rubber member having a two-layer structure comprising an edge layer not joined to a support member and a base layer joined to the support member via an adhesive layer. . The edge layer is made of a material having a JIS A hardness of 50 ° to 65 ° at 23 ° C., and the base layer is made of a material having a JIS A hardness of 70 ° to 99 ° at 23 ° C. It will be. Furthermore, the ratio (a / (a + b)) of the thickness (a) of the edge layer to the sum (a + b) of the thickness (a) of the edge layer and the thickness (b) of the base layer is 0.01 to 0.1, and the thickness (a) of the edge layer is 50 μm or less. Since the cleaning blade for an electrophotographic apparatus has such a configuration, when this is used as a cleaning blade, a spherical (true spherical, irregular shape) toner with a small particle size is used as a toner. Even in this case, it is possible to prevent the toner remaining on the surface of the image carrier from slipping through. As a result, it is possible to prevent poor cleaning due to slipping of residual toner.

When the cleaning blade for an electrophotographic apparatus of the present invention is used, the reason why it is possible to prevent the residual toner from slipping through is not clear, but it is presumed to be due to the following action.

The cleaning blade for an electrophotographic apparatus of the present invention has a configuration as schematically shown in FIG. The cleaning blade for an electrophotographic apparatus shown in FIG. 1 has an elastic rubber member 1, a support member 2, and an adhesive layer 3. The elastic rubber member has a low hardness edge layer 4 and a high hardness. The base layer 5 has a two-layer structure. FIG. 2 is a schematic diagram showing the cleaning behavior of the surface of the image carrier (counter member) 6 when the cleaning blade for an electrophotographic apparatus having such a configuration is used. The elastic rubber member 1 is the counterpart member 6. It is the figure which showed the state contact | abutted to.

FIG. 2 (i) is a schematic view showing a state in which the counterpart material 6 is stationary, and FIG. FIG. 6 is a schematic diagram showing a state where residual toner (not shown) on the material 6 is being scraped off. When the cleaning blade for an electrophotographic apparatus of the present invention is used, as shown in FIG. 2 (ii), the toner and the outer layer are formed on the base layer 5 (with a small nip width) with a high hardness in a state where the edge of the blade is wound. It is presumed that it is possible to dam up the additives and the like, and to dampen the toner, external additives and the like that have entered the high hardness base layer 5 with the low hardness edge layer 4 (large nip width). That is, in the present invention, by using the elastic rubber member 1 having a two-layer structure in which the edge layer 4 is provided with a thin layer having a low hardness and the base layer 5 is provided with a high hardness layer, a high hardness edge effect and a low hardness are achieved. It is presumed that the two-edge effect can be obtained, and as a result, the toner, the external additive and the like can be appropriately dammed by the blade. As a result, it is presumed that slipping of residual toner on the surface of the image carrier can be suitably prevented even when a spherical toner having a small particle diameter is used.

Since the cleaning blade for an electrophotographic apparatus of the present invention has an elastic rubber member having a specific configuration as described above, even when a polymerization toner having a spherical shape and a small particle size is used, an image bearing member is used. Although it is possible to suitably prevent the residual toner from slipping through the body surface, when the elastic rubber member is composed of only one layer formed of a material having high hardness, the edge portion is always on the image carrier. Due to the pressure contact, sag occurs, residual toner slips through, and image defects are likely to occur. Further, when a polymerization toner having a spherical shape and a small particle diameter is used, it is not possible to sufficiently prevent the residual toner from slipping through.

The cleaning blade for an electrophotographic apparatus has an elastic rubber member, a support member, and an adhesive layer.
The elastic rubber member scrapes off toner, external additives, and the like on the surface of the image carrier when using the cleaning blade for an electrophotographic apparatus, and includes an edge layer not bonded to the support member and the support member. It has a two-layer structure consisting of a base layer bonded through the adhesive layer. Here, joining means being in contact with each other. In the present invention, as shown in FIG. 1, the edge layer is not in contact with the support member (not joined), and the base layer is in contact with the support member through the adhesive layer. (Joined).

In the elastic rubber member, the edge layer is made of a material having a JIS A hardness of 50 ° to 65 ° at 23 ° C., and the base layer has a JIS A hardness of 70 ° to 99 ° at 23 ° C. It consists of the material which is. By using an elastic rubber member composed of an edge layer and a base layer having a hardness in the above range, it is possible to suitably prevent slipping of residual toner and external additives on the surface of the image carrier.

In the present invention, it is important to use an elastic rubber member comprising an edge layer and a base layer having a hardness in the above range. For example, even when an elastic rubber member having a two-layer structure consisting of an edge layer and a base layer is used, when an edge layer having a hardness value larger than that of the base layer is used. As the electrophotographic apparatus cleaning blade of the present invention is used, it may be difficult to prevent the residual toner and external additives from slipping through the surface of the image carrier.

As shown in FIG. 1, the edge layer is a thin layer that constitutes an elastic rubber member, and is a thin layer that is not joined to the support member. Then, when the cleaning blade for an electrophotographic apparatus of the present invention is used, the edge layer is formed of a toner that cannot be blocked by the base layer due to the low hardness edge effect, as shown in (ii) of FIG. It is presumed to have a function of blocking additives and the like.

Further, as shown in FIG. 1, the base layer is a layer constituting an elastic rubber member, and is a layer bonded to the support member via an adhesive layer. When the cleaning blade for an electrophotographic apparatus of the present invention is used, the base layer is formed on the image carrier (the counterpart material) by the edge effect of high hardness, as shown in (ii) of FIG. It is inferred that it has a function of blocking toner, external additives and the like remaining on the toner.

If the edge layer has a hardness of less than 50 °, the tackiness of the surface increases and the frictional resistance becomes too high. If the angle exceeds 65 °, the deformation is small, and the edge effect due to the base layer is hardly exhibited. The edge layer preferably has a hardness of 60 ° to 65 °.

When the hardness of the base layer is less than 70 °, the edge effect with high hardness is hardly exhibited, and when it exceeds 99 °, it is difficult to form an edge by cutting. The base layer preferably has a hardness of 75 ° to 99 °. In the present specification, the JIS A hardness is a value measured by a spring type A hardness tester according to JIS K 7312. In the present invention, the edge layer and the base layer having the above-described hardness can be obtained by appropriately selecting materials constituting the edge layer and the base layer.

The edge layer preferably has a resilience of 10 to 35%. If it is less than 10%, the restoring speed of the edge portion elastically deformed following the surface of the image bearing member is slow, and residual toner slips through the rotating image bearing member, resulting in image defects such as streaks. May occur. If it exceeds 35%, there is a risk that abnormal noise (squeaking) is likely to occur at high temperatures when the electrophotographic apparatus is started and stopped, and continuously during operation.

The base layer preferably has a resilience of 5 to 50%. If it is less than 5%, the rubber elasticity (elastomer property) becomes poor, the force for pressing the image bearing member becomes too weak, and the residual toner may slip through. If it exceeds 50%, abnormal noise (squeaking) may easily occur at high temperatures when the electrophotographic apparatus is started and stopped, and continuously during operation. In addition, in this specification, the said impact resilience is a value measured according to the impact resilience test of JISK7312. In the present invention, the edge layer and the base layer having the above-described impact resilience can be obtained by appropriately selecting the materials constituting the edge layer and the base layer.

In the elastic rubber member, the ratio (a / (a + b)) of the thickness (a) of the edge layer and the sum (a + b) of the thickness (a) of the edge layer and the thickness (b) of the base layer is: 0.01 to 0.1. In the elastic rubber member, the edge layer has a thickness (a) of 50 μm or less. That is, the elastic rubber member according to the present invention has a relatively small edge layer thickness (a) with respect to the entire elastic rubber member and a small absolute edge layer thickness (a). Since the elastic rubber member having such a configuration is provided, it is possible to suitably prevent slipping of residual toner, external additives, and the like on the surface of the image carrier. Such an effect is presumed to result from a two-edge effect of a high-hardness edge effect and a low-hardness edge effect due to the action shown in FIG. 2 (ii).

In the present invention, it is extremely important to use an elastic rubber member having the specific a / (a + b) and a. For example, even when an elastic rubber member having a two-layer structure consisting of an edge layer and a base layer is used, when the edge layer having a large absolute thickness (a) is used, the residual toner on the surface of the image carrier And slipping of external additives cannot be sufficiently prevented. This is because when the blade having such a two-layer structure is used, both the edge layer and the base layer as shown in (ii) of FIG. It is assumed that this is because slip-through cannot be prevented to the same extent as in the present invention. Further, even when an edge layer having a thin absolute thickness (a) is used, if the value of a / (a + b) is out of the above range, it is possible to sufficiently prevent slipping through. Can not. Therefore, it is important from the viewpoint of obtaining the effect of the present invention to use the elastic rubber member having the specific a / (a + b) and a.

When the ratio (a / (a + b)) is less than 0.01 or exceeds 0.1, there is a possibility that residual toner, external additives, and the like on the surface of the image carrier may slip through. This is presumably because the above-described two-edge effect cannot be obtained suitably. It is preferable that it is 0.01-0.05, and it is more preferable that it is 0.015-0.045.

When the thickness (a) of the edge layer exceeds 50 μm, there is a possibility that residual toner, external additives, and the like on the surface of the image carrier may slip through. This is presumably because the above-described two-edge effect cannot be obtained suitably. It is preferable that it is 25-50 micrometers, and it is more preferable that it is 30-50 micrometers.

Both the edge layer and the base layer are preferably made of polyurethane. As a result, it is possible to more effectively prevent slipping of residual toner, external additives, and the like on the surface of the image carrier. Examples of the polyurethane forming the elastic rubber member include those obtained by reacting polyol, polyisocyanate and, if necessary, a crosslinking agent.

It does not specifically limit as said polyol, For example, a polyester polyol, polyether polyol, polycaprolactone polyol etc. can be mentioned. Of these, polyester polyols and polycaprolactone polyols are preferred from the viewpoint that slipping of residual toner, external additives and the like on the surface of the image carrier can be prevented. These may be used alone or in combination of two or more.

The polyol preferably has a number average molecular weight of 1000 to 3000. By using a polyol within the above range, it is possible to effectively prevent slipping of residual toner, external additives, and the like on the surface of the image carrier.

As said polyester polyol, what can be obtained by making dicarboxylic acid and glycol react according to a conventional method can be mentioned, for example.
Examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid, and oxycarboxylic acids such as oxybenzoic acid. Examples thereof include acids and ester-forming derivatives thereof. Examples of the glycol include aliphatic glycols such as ethylene glycol, 1,4-butanediol, diethylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, and triethylene glycol. Examples include alicyclic glycols such as 1,4-cyclohexanedimethanol, aromatic diols such as p-xylene diol, polyoxyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Polyester polyols based on these have a linear structure, but may be branched polyesters using a trivalent or higher valent ester-forming component. Of these, aliphatic dicarboxylic acids are preferred, and adipic acid is more preferred from the standpoint that slipping of residual toner, external additives and the like on the surface of the carrier can be prevented. As the glycol, aliphatic glycol is preferable, and ethylene glycol and 1,4-butanediol are more preferable.

Examples of the polyether polyol include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and copolymers thereof. Of these, polytetramethylene glycol is preferred because it can prevent the residual toner and external additives from slipping on the surface of the carrier.

Examples of the polycaprolactone polyol include those that can be obtained by ring-opening addition of ε-caprolactone using a low molecular weight glycol as an initiator in the presence of a catalyst. As the low molecular weight glycol, divalent alcohols such as ethylene glycol, propylene glycol, 1,3-butylene glycol and neopentyl glycol and trivalent alcohols such as trimethylene glycol and glycerin are preferably used. Examples of the catalyst include organic titanium compounds such as tetrabutyl titanate, tetrapropyl titanate, and tetraethyl titanate, tin compounds such as tin octylate, dibutyltin oxide, dibutyltin laurate, stannous chloride, and stannous bromide. Preferably used. In addition to the above ε-caprolactone, other cyclic lactones such as trimethylcaprolactone and valerolactone may be partially mixed.

It does not specifically limit as said polyisocyanate, A conventionally well-known thing can be used, For example, aliphatic isocyanate, alicyclic isocyanate, aromatic isocyanate etc. can be mentioned. Of these, aromatic isocyanates are preferred because they can prevent the residual toner and external additives from slipping on the surface of the carrier.

Examples of the aliphatic isocyanate include 1,6-hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. Moreover, the isocyanurate body of hexamethylene diisocyanate and isophorone diisocyanate, the biuret body, the modified body of an adduct body, etc. can be mentioned. Examples of the alicyclic isocyanate include alicyclic diisocyanates such as isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, and norbornane diisocyanate (NBDI). Examples of the aromatic isocyanate include tolylene diisocyanate (TDI), phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate, xylylene diisocyanate (XDI), carbodiimide-modified MDI, and urethane. Examples include modified MDI. Among the above polyisocyanates, MDI and urethane-modified MDI are preferred, and MDI is particularly preferred from the viewpoint that slipping of residual toner and external additives on the surface of the carrier can be prevented.

Examples of the crosslinking agent used as necessary in the polyurethane include ethylene glycol, propylene glycol, butanediol, hexanediol, diethylene glycol, trimethylolpropane, glycerin, hydrazine, ethylenediamine, diethylenetriamine, 4,4′-diaminodiphenylmethane. 4,4′-diaminodicyclohexylmethane, N, N-bis (2-hydroxypropyl) aniline, water and the like. Among these, ethylene glycol, 1,4-butanediol, trimethylolpropane, N, N-bis (2-hydroxypropyl) is preferred because it can prevent slipping of residual toner and external additives on the surface of the carrier. Aniline is preferable, and ethylene glycol, 1,4-butanediol, and trimethylolpropane are particularly preferable.

The polyurethane can be produced by a known method using the above raw materials. For example, a catalyst is used in an appropriate organic solvent as necessary, and the equivalent ratio of each raw material is NCO / OH = 0.9 to It can be produced by adjusting to 1.1 and reacting, or by melting reaction without solvent. Moreover, it can manufacture by the method of making all the raw materials react simultaneously, the prepolymer method, etc.

The method for molding the elastic rubber member made of polyurethane is not particularly limited. For example, normal pressure casting, reduced pressure casting, centrifugal molding, rotational molding, extrusion molding, injection molding, reaction injection molding (RIM), spin coating Etc. Among these, it is preferable to manufacture by molding by centrifugal molding from the viewpoint that a blade in which residual toner, external additives and the like on the surface of the carrier are prevented from slipping through can be suitably obtained.

The support member has a function of supporting the elastic rubber member. The support member is not particularly limited, and a conventionally known member can be used, and examples thereof include a rigid metal, an elastic metal, a plastic, a ceramic, and the like. Among these, a rigid metal is preferable.

The adhesive layer is a layer having a function of bonding the support member and the elastic rubber member. The adhesive layer can be formed by, for example, an EVA-based, polyamide-based, polyurethane-based hot melt adhesive, a curable adhesive, a bonding method using a double-sided tape, or sandwiching with a sheet metal. Among these, the adhesive layer is preferably formed using a hot melt adhesive from the viewpoint that a blade in which residual toner, external additives, and the like on the surface of the carrier are prevented from slipping through can be suitably obtained. .

The present invention is also a method of manufacturing a cleaning blade for an electrophotographic apparatus described below.
The method for producing a cleaning blade for an electrophotographic apparatus according to the present invention comprises a step (1) of producing an elastic rubber member having a two-layer structure of an edge layer and a base layer using a centrifugal molding method, and the above step (1). The edge layer is made of a material having a JIS A hardness of 50 ° to 65 ° at 23 ° C., wherein the base layer is The thickness of the edge layer (a) is the sum of the edge layer thickness (a) and the base layer thickness (b) at 23 ° C. The ratio (a / (a + b)) to (a + b) is 0.01 to 0.1, and the thickness (a) of the edge layer is 50 μm or less. In the step (1), by manufacturing the elastic rubber member by centrifugal molding, it is possible to manufacture a blade that can effectively prevent the residual toner and external additives from slipping through the surface of the carrier.

In the manufacturing method, the edge layer and the base layer are the same as those described above. The material of the edge layer and the base layer is preferably made of polyurethane from the viewpoint that it is possible to suitably obtain a blade that prevents the residual toner and external additives on the surface of the carrier from slipping through.

The centrifugal molding method for producing the elastic rubber member in the step (1) can be performed by a conventionally known method. In the step (1), both the edge layer and the base layer are made of polyurethane, for example, using the method shown below.

First, the edge layer material is poured into a mold of a centrifugal molding machine preheated to 130 to 150 ° C. and cured for 5 to 10 minutes. After the curing reaction, the base layer material is poured onto the cured edge layer and cured for 25 to 50 minutes. After the curing reaction, a cylindrical two-layer structure sheet having a thickness of 1 to 3 mm can be obtained by taking out from the mold. An elastic rubber member can be obtained by cutting this into a strip shape having a width of 8 to 20 mm and a length of 220 to 500 mm.

In the manufacturing method, the edge layer and the base layer can be obtained by a prepolymer method, a one-shot method, or the like.
In the case of using the prepolymer method, a polyol and isocyanate subjected to dehydration treatment are mixed and reacted at a temperature of 50 to 80 ° C. for 10 to 600 minutes. A cured edge layer and base layer can be obtained by a method of injecting and curing.
When using the one-shot method, weigh the polyol and cross-linking agent that have been dehydrated, add polyisocyanate to them, weigh and mix them, inject them into the mold, and cure them, etc. A cured edge layer and base layer can be obtained.

In the said manufacturing method, after performing the said process (1), the process (2) which adhere | attaches the elastic rubber member obtained by the said process (1) and a support member is performed. The step (2) can be performed by a conventionally known method, for example, by bonding using the above-described adhesive. In the step (2), the support member is the same as described above.

Since the cleaning blade for an electrophotographic apparatus of the present invention has the elastic rubber member, the supporting member and the adhesive layer having the above-mentioned specific configuration, the residual toner and external additives on the surface of the image bearing member are prevented from slipping through. It can prevent suitably. Therefore, even when a polymerization method toner having a spherical shape (spherical shape or irregular shape) and a small particle diameter is used, such slipping of residual toner or the like can be suitably prevented. As a result, it is possible to prevent a cleaning failure caused by slipping of residual toner or the like.

Since the cleaning blade for an electrophotographic apparatus of the present invention has the above-described configuration, even when a polymerization method toner having a spherical shape (spherical shape or irregular shape) and a small particle size is used, It is possible to prevent the residual toner from slipping through, and it is possible to prevent a cleaning failure caused by the slippage.

EXAMPLES Hereinafter, although an Example is hung up and demonstrated in more detail, this invention is not limited only to these Examples. In the examples, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.

Examples 1-5 and Comparative Examples 1-6 Manufacture of a cleaning blade for an electrophotographic apparatus First, an edge layer material is injected into a mold of a centrifugal molding machine preheated to 140C and cured for 10 minutes. It was. After the curing reaction, the base layer material was poured onto the cured edge layer and cured for 30 minutes. After the curing reaction, a cylindrical two-layer structure sheet having a thickness of 2.00 mm could be obtained by taking out from the mold. An elastic rubber member could be obtained by cutting this into a strip shape having a width of 12 mm and a length of 330 mm.
The obtained elastic rubber member was bonded to a support member made of plated steel using a polyurethane-based hot melt adhesive to obtain a cleaning blade for an electrophotographic apparatus.
Since Comparative Example 1 has one elastic rubber member, the step of injecting and curing the base layer material into the centrifugal molding machine was not performed.

Table 1 shows the edge layer material, base layer material, edge layer, base layer thickness (a), (b), a / (a + b), hardness (23 ° C.), and resilience used. It is. The hardness and impact resilience of the edge layer and the base layer are values measured by the method described above.

The polyurethanes in Table 1 have the following composition, respectively.
<Polyurethane A>
Prepolymer [Polyol: Polyethylene adipate ester diol (number average molecular weight 2000), isocyanate: 4,4′-diphenylmethane diisocyanate (pure-MDI) (NCO content 6.20%)] 100 parts by mass crosslinking agent (1,4- Butanediol: trimethylolpropane = 60: 40) 6.04 parts by mass <Polyurethane B>
Polyol: Polyethylene butylene adipate ester diol (number average molecular weight 2000) 363.64 parts by mass Polyisocyanate: Urethane-modified MDI (crude-MDI) (NCO content 31%) 100 parts by mass Cross-linking agent (N, N-bis (2 -Hydroxypropyl) aniline) 36.36 parts by mass <Polyurethane C>
Prepolymer [polyol: polyethylene adipate ester diol (number average molecular weight 2000), isocyanate: pure-MDI (NCO content 9.95%)] 100 parts by mass crosslinking agent (1,4-butanediol: trimethylolpropane = 80: 20) 9.79 parts by mass <Polyurethane D>
Prepolymer [polyol: polyethylene adipate ester diol (number average molecular weight 2000), isocyanate: pure-MDI (NCO content 8.54%)] 100 parts by mass crosslinking agent (1,4-butanediol: trimethylolpropane = 70: 30) 8.39 parts by mass <Polyurethane E>
Polyol: Polyethylene butylene adipate ester diol (number average molecular weight 2000) 136.61 parts by mass Polyisocyanate: crude-MDI (NCO content 31%) 100 parts by mass Crosslinking agent (trimethylolpropane: N, N-bis (2-hydroxy) Propyl) aniline = 20: 80) 34.15 parts by mass <Polyurethane F>
Prepolymer [polyol: polycaprolactone polyol (number average molecular weight 2000), isocyanate: pure-MDI (NCO content 6.70%)] 100 parts by mass cross-linking agent (1,4-butanediol: trimethylolpropane = 65: 35 6.46 parts by mass

In the production of the cleaning blade for an electrophotographic apparatus, each polyurethane material (polyurethane A to F) is injected into the mold as an edge layer material and a base layer material as follows.
[Polyurethane A, C, D, F Material Injection Method]
The polyol and isocyanate subjected to the dehydration treatment were mixed and reacted at a temperature of 70 ° C. for 240 minutes, and then a crosslinking agent was added to the prepolymer, which was then injected (prepolymer method).
[Method of injecting polyurethane B and E materials]
The dehydrated polyol and the cross-linking agent were weighed, and polyisocyanate was further added thereto, weighed, mixed, and injected (one-shot method).

(Print test)
The cleaning blade for an electrophotographic apparatus obtained in Examples and Comparative Examples was mounted on a commercially available plain paper copying machine (using an organic photoreceptor, speed 10 sheets / minute), and a printing test was performed (the test was performed at 23 ° C. and Performed in an atmosphere of 10 ° C.). The print test was completed after every 100 sheets, and it was checked whether or not the toner slipped out, and when the streaks due to the toner slipping were found in the printed matter, the number of printed sheets was recorded. If no streak occurred even after printing 30000 sheets, the test was terminated. The results are shown in Table 1. Table 1 also shows the weight average particle diameter and shape of the toner used. In the comparative example, the toner slipped out when the number was less than 100 sheets, but the toner slipped out at the time of the number of sheets shown in Table 1.

From Table 1, the cleaning blade for an electrophotographic apparatus obtained in the examples has a spherical shape (true spherical shape, irregular shape), and when a polymerization toner having a small particle size is used, the toner can be satisfactorily prevented from slipping through. It was something that could be done. Also, good results were obtained at both 23 ° C. and 10 ° C. temperatures. On the other hand, it was revealed that the toner obtained in the comparative example slips through the toner.

The cleaning blade for an electrophotographic apparatus of the present invention can be suitably used for an electrostatic electrophotographic copying machine using plain paper as recording paper.

It is a schematic diagram of a cleaning blade for an electrophotographic apparatus of the present invention. FIG. 4 is a schematic view showing the cleaning behavior of the cleaning blade for an electrophotographic apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elastic rubber member 2 Support member 3 Adhesive layer 4 Edge layer 5 Base layer 6 Image carrier (partner material)

Claims (4)

An electrophotographic apparatus cleaning blade having an elastic rubber member, a support member, and an adhesive layer,
The elastic rubber member has a two-layer structure including an edge layer that is not bonded to the support member and a base layer that is bonded to the support member via the adhesive layer,
The edge layer is made of a material having a JIS A hardness of 50 ° to 65 ° at 23 ° C.,
The base layer is made of a material having a JIS A hardness of 70 ° to 99 ° at 23 ° C.,
The ratio (a / (a + b)) of the thickness (a) of the edge layer to the sum (a + b) of the thickness (a) of the edge layer and the thickness (b) of the base layer is 0.01-0. 1 and
The cleaning blade for an electrophotographic apparatus, wherein the edge layer has a thickness (a) of 50 μm or less. 2. The cleaning blade for an electrophotographic apparatus according to claim 1, wherein the edge layer and the base layer are made of polyurethane. A step (1) of manufacturing an elastic rubber member having a two-layer structure of an edge layer and a base layer by using a centrifugal molding method, and the elastic rubber member obtained in the step (1) and a support member are bonded. Including step (2),
The edge layer is made of a material having a JIS A hardness of 50 ° to 65 ° at 23 ° C.,
The base layer is made of a material having a JIS A hardness of 70 ° to 99 ° at 23 ° C.,
The ratio (a / (a + b)) of the thickness (a) of the edge layer to the sum (a + b) of the thickness (a) of the edge layer and the thickness (b) of the base layer is 0.01-0. 1 and
The method for manufacturing a cleaning blade for an electrophotographic apparatus, wherein the thickness (a) of the edge layer is 50 μm or less. 4. The method for manufacturing a cleaning blade for an electrophotographic apparatus according to claim 3, wherein the edge layer and the base layer are made of polyurethane.

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