JP2007108394A - Developer amount restriction blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer amount restriction blade which does not form a development stripe due to toner fusion and enables images to stably be formed for a long period by applying stable electric charges. <P>SOLUTION: The developer amount restriction blade comprises an elastic rubber member and a support member, and is characterized in that: very-small-area hardness A measured on the outermost surface of a contact surface between the elastic rubber member and a developing sleeve is 0.15 to 0.5 mN/μm<SP>2</SP>, very-small-area hardness B at its core center part is 0.05 to 0.20 mN/μm<SP>2</SP>, and the difference A-B is ≥0.01 mN/μm<SP>2</SP>; the thickness of a hardness-increased layer is 5 to 300 μm; surface roughness Rz<SB>jis</SB>of the contact surface is 3 to 25 μm; and the thickness of the elastic rubber member is 0.3 to 2 mm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a developer amount regulating blade used in an electrophotographic apparatus.

  As a developing device widely used in electrophotographic technology such as a laser beam printer and a copying machine, a one-component developer (toner) is used. This toner is stored in the developing container and has a partially opened shape. A roller-shaped member called a developing sleeve is attached to the opening, and the toner is carried on the developing sleeve. It is carried out against the body. A device called a developer amount regulating blade is brought into contact with the developing sleeve on the surface of the plate member, and the toner fed into the contact portion (nip portion) is uniformly and thinly formed on the developing sleeve. In addition, a toner layer is formed and a predetermined triboelectric charge is imparted to the toner.

  The development amount regulating blade is generally formed of a rubber plate, a metal thin plate, a resin plate, and a laminate thereof. As the development of electrophotographic technology in recent years requires more stable triboelectric charge application to toner, a rubber blade member in contact with the developing sleeve and a predetermined blade blade member are used as a developer amount regulating blade. A material made from a support member that supports a position is often used. The surface of the rubber blade member that contacts the developing sleeve (contact surface) is called a charge control surface because it has a function of controlling the frictional charge of the toner. The surface layer is also called a charge control layer.

  Nowadays, these electrophotographic processes have further increased in speed and image quality, and as a result, image streaks and image unevenness have occurred as a result of the developer amount regulating blade, and on the developing sleeve. However, the influence of the toner moving afterimage during development remains considerably, the afterimage erasing due to friction with the developer amount regulating blade is insufficient, and appears as a ghost on the image (hereinafter, this ghost is also regulated by the developer amount). Since this will be described as one of the image defects of the blade), a technique for preventing these is being studied.

  The occurrence of image streaks is considered to be a major cause of toner fusion to the contact surface due to rubber stickiness or tackiness of the rubber blade member, and various studies have been made to suppress this.

  For example, as means for controlling image streaks by suppressing stickiness on the contact surface of the blade member and suppressing toner fusion, (1) UV irradiation treatment, corona discharge treatment, ozone treatment, plasma treatment on the contact surface of the blade member For example, means for oxidizing the surface and forming an oxide thin film layer on the contact surface (Patent Document 1) and (2) means for including a silicon layer on the surface of urethane rubber (Patent Document 2) are known. These common points are to have a modified layer on the surface, and the blade member as a whole has a sufficiently elastic property, but has a chemically modified hard and thin layer on the surface.

  However, the modification means as in (1) requires a lot of additional processing equipment, and it is difficult to keep the running cost low. Further, these surface treatment methods control the amount of treatment and determine the amount of treatment. There is a drawback that it is difficult to make and stabilize, and mass production is difficult. In (2), after adding a reaction initiator to the UV curable silicon-containing compound and impregnating it with a urethane member, the contact portion is further subjected to a UV treatment. There is a difficulty in the manufacturing process. That is, these processing means are not simple and their effects are still insufficient as described below.

  In other words, the means (1) and (2) can reduce the tackiness of the rubber member and suppress the toner fusion and defects derived therefrom, but at the same time to reduce image unevenness and ghosting. It is insufficient.

  On the other hand, in order to solve image unevenness and ghost, it has been studied to control the surface roughness of the contact surface of the blade member. For example, the surface roughness Rz of the contact portion of the rubber blade member of the developer amount regulating blade is set to 1.0 to 1.5 μm, preferably stripes are formed at a pitch interval of 5 to 10 μm substantially perpendicular to the rotation direction. Means to do is proposed (Patent Document 3). However, with this method, it is difficult to form a uniform thin layer of developer on the developing sleeve, and as a result, generation of image unevenness and ghost cannot be completely suppressed.

  As described above, a plurality of means must be combined to solve the image streak / unevenness and ghost phenomenon with respect to the developer amount regulating blade.

In response to the recent demand for higher image quality, various external additives are added to the toner, which causes the toner to adhere to the contact surface of the developer amount regulating blade and cause image defects resulting therefrom. Yes. By the way, image defects are certainly alleviated by preventing toner fusion, but there are still some parts that cannot be solved by that alone, and the developer amount regulating blade not only prevents toner fusion, but also to this. Is also required.
JP 11-052717 A JP 2004-233818 A JP 2000-330376 A

  That is, the present invention not only prevents the toner and the toner external additive from being fused, but also can impart a sufficient charge to the toner, resulting in image defects such as image streaks, image unevenness, and ghosts. It is an object of the present invention to provide a developer amount regulating blade that does not cause the problem.

  The object of the present invention is achieved by the following configurations.

(1) A developer amount regulating blade in which a plate-like elastic rubber member is bonded to a rigid plate-like support member, and the ultrafine measured at the outermost surface of the plate-like elastic rubber member at the contact surface with the developing sleeve A high hardness layer having a small area hardness A of 0.15 to 0.5 mN / μm ² is formed with a thickness of 5 to 300 μm. The micro region hardness B is 0.05 to 0.2 mN / μm ² , the ultra micro region hardness difference (A−B) is 0.01 mN / μm ² or more, and more than 10 A developer amount regulating blade having a point average roughness (Rz _JIS ) of 3 to 25 μm and a plate-like elastic rubber member having a thickness of 0.3 to 2 mm.

(2) The developer amount regulating blade according to (1), wherein the plate-like elastic rubber member is made of urethane rubber, and the hardened layer is formed by impregnation of an isocyanate compound.

  According to the present invention, a uniform toner layer can be formed in a developer amount regulating blade that discharges the developer from the developer container and uniformly forms a toner layer on the sleeve, and the toner is fused on the blade. Therefore, a sufficiently charged charge can be applied, and stable image formation can be achieved over a long period of time.

  The present invention relates to a developer amount regulating blade used for regulating the amount of developer (toner) on a developing sleeve in an electrophotographic apparatus.

  A schematic sectional view of the developer amount regulating blade of the present invention is shown in FIG. 1, and a schematic sectional view (main part) of the developer amount regulating blade of the present invention in contact with the developing sleeve is shown in FIG.

  The developer amount regulating blade 14 of the present invention has a configuration in which a plate-like support member 11 is mounted on a plate-like elastic rubber member 10. The surface layer (hardened layer) 12 at least in contact with the developing sleeve of the plate-like elastic rubber member 10 has a high hardness and is softer than the surface layer 12, that is, a portion that is not a hardened layer (internal Layer) 13 is formed. The plate-like elastic rubber member 10 is not particularly limited as long as the material is a rubber raw material. However, urethane rubber is preferable from the viewpoint of good wear resistance and the like.

  A developer amount regulating blade 14 is mounted on the developing sleeve 20 in contact with the hardened layer 12 of the plate-like elastic rubber member 10 at the contact portion 22. The developer 21 is conveyed by the rotation of the developing sleeve 20 in the direction of the arrow, and the amount thereof is regulated by the abutting plate-like elastic rubber member 10. Further, the developer particles 21 are rubbed in a passing gap formed in the contact portion 22, whereby a predetermined frictional charge is imparted and the developer is uniformly conveyed to the photosensitive member. At this time, the plate-like elastic rubber member 10 is divided into a hardened layer (surface layer portion) 12 and an inner layer 13 at a contact portion 22 with the developing sleeve 20. 1 and 2, the example in which the high hardness layer is provided not only on the side in contact with the developing sleeve but also on the opposite side is shown. Can be used, and may be preferable because of its great flexibility.

The hardness of the outermost surface and the hardness of the inner layer at the abutting portion of the plate-like elastic rubber member are very small, such as Shimadzu Dynamic Micro Hardness Tester DUH-W201S (trade name) manufactured by Shimadzu Corporation. Ultra-fine area hardness A measured at the outermost surface of the contact portion when defined by the hardness measured by a device for measuring the hardness of the area (referred to as “ultra-fine area hardness” in the present invention). there was 0.15~0.5mN / μm ^2, it is essential that the ultra-micro region hardness B measured at the inner layer is in the range of 0.05~0.2mN / μm ^2, and its The difference (A−B) is 0.01 mN / μm ² or more. The ultra-small region hardness B measured on the inner layer is usually measured when the plate-like elastic rubber member is cut almost perpendicular to the contact surface and the cut surface is sufficiently separated from the hardened layer. The For the sake of simplicity, measurement may be performed with a full length elastic rubber member before forming a hardened layer on the surface, or it is cut almost vertically at a location where the hardened layer of the plate-like elastic rubber member is not formed. Then, the measurement may be performed at the center.

When the ultra-fine area hardness A measured on the outermost surface is less than 0.15 mN / μm ² , the friction increases and stickiness further occurs, resulting in fusion during durable use. This causes image defects. On the other hand, if it becomes too hard and exceeds 0.5 mN / μm ² , toner deterioration will occur during durability and image streaks will occur. In addition, the nip width between the sleeve and the sleeve is not high enough and the toner is poorly charged.

Next, when the ultra-small area hardness B measured in the inner surface of the contact surface is less than 0.05 mN / μm ² , the contact pressure on the sleeve becomes insufficient because the toner becomes too soft and the toner is insufficient. Cannot be sufficiently charged. On the other hand, if it exceeds 0.2 mN / μm ² , the blade body itself becomes too hard, which also deteriorates the durability of the toner and causes image streaks.

In the present invention, the surface needs to be sufficiently harder than the inside at least at the contact surface, but the difference in hardness between the surface at the contact surface with the developing sleeve and the internal hardness (A−B) is small. When it is as small as less than 0.01 mN / μm ² , the effect that the outermost surface has high hardness cannot be sufficiently exhibited.

  The plate-like elastic rubber member has a thickness of 0.3 to 2 mm. When the thickness is less than 0.3 mm, the contact with the developing sleeve becomes insufficient, and the toner cannot be sufficiently charged. On the other hand, if it exceeds 2 mm, the contact pressure becomes too large and the frictional charge of the toner becomes too large.

  The plate-like elastic rubber member has at least a surface abutting against the developing sleeve having a higher hardness than the inside thereof. For this purpose, surface treatment or curing treatment is usually performed. In this case, the hardened layer formed by curing is sufficiently hard even when rubbed and worn, and is also required to be resistant to wear. If it is too thin, the hardened layer (modified layer) is worn away and the inner layer of the contact portion comes out. On the other hand, if the layer is too thick, this layer is hard, so that the hardened layer property appears predominantly in the plate-like elastic rubber member, and the rubber elasticity necessary for the member is lost. Accordingly, the thickness of the hardened layer is suitably in the range of 5 to 300 μm.

Further, the 10-point average roughness Rz _{JIS of 3} to 25 μm at the outermost surface of the contact surface is preferable from the viewpoint of the effect of imparting charge to the developer because ghost generation is reduced.

  In the developer amount regulating blade of the present invention, it is desirable that the plate-like elastic rubber member is made of a material having good wear resistance in order to keep in contact with the rotating body and keep rubbing in the usage environment. The material is not particularly limited as long as it satisfies this condition, but urethane rubber is mainly used because of its good performance and ease of processing.

  Urethane rubber is produced by thermosetting in the presence or absence of a catalyst using polyisocyanate and high molecular weight polyol, if necessary, low molecular weight dihydric alcohol or trihydric or higher polyhydric alcohol as a curing agent. The

  In the present invention, as the polyisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (H-MDI), trimethylhexamethylene diisocyanate (TMHDI), Tolylene diisocyanate (TDI), carbodiimide-modified MDI, polymethylene phenyl polyisocyanate, orthotoluidine isocyanate (TODI), naphthylene diisocyanate (NDI), xylene diisocyanate (XDI), hexamethylene diisocyanate (HDI), paraphenylene diisocyanate (PDI) Lysine diisocyanate methyl ester (LDI) or the like is used alone or in combination of two or more.

  Examples of the high molecular weight polyol include polyethylene adipate, polybutylene adipate, polyhexylene adipate, a copolymer of ethylene adipate and butylene adipate, polyester polyol such as polycaprolactone, polyoxytetramethylene glycol, polyoxytetramethylene glycol Polyether polyols such as polyoxypropylene glycol can be used. Among these, those having a molecular weight of about 1500 to 3000 are preferably used. If the molecular weight is less than 1500, the physical properties of the resulting urethane rubber tend to be reduced, and if the molecular weight is 3000 or more, the prepolymer viscosity increases, and the workability of the elastic rubber member molding tends to be remarkably deteriorated.

  Further, as the curing agent, a low molecular weight dihydric alcohol having a molecular weight of 300 or less or a polyhydric alcohol having a valence of 3 or more is used. Low molecular weight dihydric alcohols include, for example, ethylene glycol (EG), diethylene glycol (DEG), propylene glycol (PG), 1,4-butanediol (BD), hexanediol, 1,4-hexanediol (HD), etc. In addition, examples of trihydric or higher alcohols include trifunctional aliphatics such as glycerin, 1,2,4-butanetriol, trimethylolethane, trimethylolpropane (TMP), 1,2,6-hexanetriol, and the like. Examples include polyols, polyether triols obtained by adding ethylene oxide, butylene oxide and the like to these trifunctional aliphatic polyols, and polyester triols obtained by adding lactone and the like to these trifunctional aliphatic polyols. These curing agents can be used alone or in admixture of two or more.

  The developer amount regulating blade of the present invention is manufactured as follows.

  First, an elastic rubber member raw material is formed into a sheet shape having a predetermined thickness, vulcanized and cured to obtain an elastic rubber sheet, and then the elastic rubber sheet is cut into a predetermined shape to obtain a plate-shaped elastic rubber having an uncured surface. Get a member. Then, after trimming as necessary, it is adhered to the rigid plate-like support member with an adhesive, and thereafter, at least the surface in contact with the developing sleeve is hardened so that the plate-like elastic rubber member is integrated. Get a dose control blade. After that, the surface roughness is adjusted by polishing or the like if necessary.

  An uncured plate-like elastic rubber member can also be produced by injecting, vulcanizing and curing an elastic rubber member raw material into a mold having a predetermined shape. In this case, the surface layer portion is made of a material having a higher hardness than the elastic rubber member obtained by vulcanization of the elastic rubber member raw material, or a material having a high hardness, so that the surface-cured elastic rubber member is obtained. can get. In such a case, it is not necessary to perform a surface hardening treatment after being attached to the rigid plate-like support member. In addition, when the elastic rubber member raw material is vulcanized and cured by sheet-like molding or mold molding, if the difference in hardness of the predetermined ultra-fine region of the present invention is achieved between the surface and the inside, it is re- Although surface treatment is unnecessary, surface hardening treatment is desirable from the viewpoint of wear resistance and the like.

  In the present invention, as described above, as the developer amount regulating blade, it is desirable that the plate-like elastic rubber member is made of urethane rubber. Such a developer amount regulating blade is not limited to this, but is as follows. Can be manufactured.

  A urethane rubber raw material mixed with polyol, polyisocyanate and catalyst is put into a centrifugal molding machine. Thereafter, it is cured at 110 to 150 ° C. and demolded to obtain a sheet-like member. Further, this is cut into a strip shape and adhered to a rigid plate-like support member to produce a developer amount regulating blade whose surface is uncured.

  The method for forming the hardened layer on the surface is not particularly limited, but it is appropriate to impregnate the surface of urethane rubber with polyisocyanate and heat-harden it to impart wear resistance to the hardened layer. . The impregnation method includes application of liquid polyisocyanate, immersion in liquid polyisocyanate, etc. Also, when forming the hardened surface on one side, what is the side on which the hardened surface is formed? Mask the reverse side and remove the masking after the high hardness treatment.

  For example, a method of forming a hardened layer from both sides using MDI (4,4 ',-diphenylmethane diisocyanate) as a polyisocyanate will be shown.

  The MDI is heated to 80 ° C. in a thermostat to make it liquid, and the portion corresponding to the contact surface of the urethane rubber blade produced as described above with the developing sleeve is impregnated for about 0.5 to 5 minutes. . Thereafter, solvent cleaning is performed to obtain a blade member having only a hard surface. The surface hardness and the thickness of the surface layer can be changed by the temperature of the MDI tank, the impregnation time, and the like. In the case of forming the hardened layer only on one side, it is preferable to immerse the urethane rubber blade in MDI after protecting the surface which does not become the contact surface with a masking tape.

  Since the contact surface of the plate-like elastic rubber member is at least two layers by increasing the surface hardness, the degree of toner fusion of the developer amount regulating blade is reduced. The reason for this is considered that the rubber surface is in a state close to that of a hard resin, the tackiness is extremely lowered, and this performance can be exhibited.

The surface roughness (ten-point average roughness Rz _jis ) of the contact surface at this time is preferably 3 to _{25 μm} as described above, and after the surface is hardened, the contact surface is made of sandpaper. Etc. to obtain the desired surface roughness. Note that the surface roughness of the corresponding contact surface is greatly reflected in the ghost at the time of image output. In particular, this surface roughness range is an optimum region for reducing the occurrence of ghost. In order to make this range, it is appropriate to use 500 to 2000 sandpaper and rub for about 5 to 30 seconds. In addition to the rubbing method using sand paper, a sand blasting method and a shot blasting method can be used, and in some cases, they can be used in combination.

  Examples of the present invention are shown below, but this is an example, and the present invention is not limited to these.

Reference Example 1 (Preparation of an uncured developer amount regulating blade)
100 parts by weight of adipate-based urethane elastomer (Mn2000 NCO 6.25% by mass) preheated for 12 hours at 80 ° C., 3.7 parts by weight of 1,4-butanediol and 1.9 parts by weight of trimethylolpropane A mixture of 1000 ppm of TEDA was mixed, put into a centrifugal molding machine heated to 150 ° C., and cured for 40 minutes to obtain a 1.2 mm-thick urethane rubber sheet. This sheet was cut into a width of 12 mm and a length of 220 mm, and cut into an appropriate size for mounting on a test laser beam printer (LBP) described later, and the formed electrogalvanized steel sheet “JINCOAT 21” (trade name) , Manufactured by Shin Nippon Steel Co., Ltd.) and a film-like hot melt adhesive “ELFAN-UH” (trade name: manufactured by Nippon Matai Co., Ltd.) A raw material blade).

Reference Examples 2-4
The thickness is 0.31 mm (Reference Example 2), 0.28 mm (Reference Example 3) or 2.1 mm (Reference Example 4) in the same manner as in Reference Example 1 except that the amount of polyurethane raw material input to the centrifugal molding machine is adjusted. ) Surface uncured raw material blade.

(Measurement of ultra-small area hardness)
The ultra-small region hardness of the plate-like elastic rubber member of the developer amount regulating blade was measured with a Shimadzu dynamic micro-hardness meter DUH-W201S (trade name, manufactured by Shimadzu Corporation). It should be noted that the ultra-fine area hardness A of the surface is directly, and the ultra-fine area hardness B of the portion where the hardened layer is not formed is obtained by cutting the plate-like elastic rubber member, so It was measured at the part that was hardened. At this time, Triangular 115 (trade name, manufactured by Shimadzu Corporation) was used as a measurement indenter, and each measurement was performed five times in an environment of 23 ° C. and 60% RH, and the average value was defined as the ultrafine hardness.

(Measurement of surface roughness Rz _jis of contact surface)
The contact surface roughness Rz _jis was measured based on JIS B0601-1994 using an ultra-deep laser microscope VK-8510 (trade name, manufactured by Keyence Corporation).

(Measurement of the thickness of the hardened layer)
After the end of the mounting test (below), the developer amount regulating blade is cut and observed with a digital microscope VH-6200 (trade name) manufactured by Keyence Corporation. The thickness of the layer was measured.

(Image evaluation)
The developer amount regulating blade produced below is incorporated as a developer amount regulating blade in a cartridge for LASER SHOT-LBP (trade name, manufactured by Canon Inc.), set in this device, and a standard chart is output. The chart image was visually observed, and ghosts and image streaks were evaluated according to the following criteria, and further comprehensive evaluation was performed from these results.
・ Ghost ○: Almost unknown, Δ: Within practical range, ×: Occurrence is obvious and impractical.
Image streak A: Not generated, O: Almost unknown, Δ: Within practical range, X: Generation is obvious and impractical.
-Comprehensive judgment ◎: Excellent, ○: Good with no practical problem, Δ: Ghost and image streak are within practical range, ×: Ghost or image streak is “x” or “evaluation not possible”.

Example 1
The portion where the plate-like elastic rubber member with a thickness of 1.2 mm of the raw material blade produced in Reference Example 1 is in contact with the developing sleeve is immersed in MDI at 80 ° C. for 2 minutes, pulled up, and then wiped with gauze impregnated with toluene, Further, the surface is cured by treating at 80 ° C. for 30 minutes, and further, the cured surface is rubbed with sandpaper, the surface hardened layer thickness is 100 μm, the surface roughness Rz _jis is 10 μm, and the surface is a very small region A developer amount regulating blade having a hardness A of 0.15 mN / μm ² was obtained. The ultra-fine region hardness B at the non-hardened portion of the plate-like elastic rubber member was 0.10 mN / μm ² , and the difference (A−B) was 0.05 mN / μm ² .

Example 2
Except for setting the MDI impregnation time to 5 minutes, in the same manner as in Example 1, the ultrafine region hardness A was 0.50 mN / μm ² , the ultrafine region hardness B was 0.10 mN / μm ² , A developer amount regulating blade having a difference (A−B) of 0.40 mN / μm ² , a surface hardened layer thickness of 200 μm, and a surface roughness Rz _jis of 10 μm was prepared.

Example 3
Except for setting the MDI impregnation time to 3 minutes, in the same manner as in Example 1, the ultrafine region hardness A was 0.30 mN / μm ² , the ultrafine region hardness B was 0.10 mN / μm ² , A developer amount regulating blade having a difference (A−B) of _{0.20 mN} / μm ² , a surface hardened layer thickness of 150 μm, and a surface roughness Rz _jis of 10 μm was prepared.

Example 4
Except for adjusting the degree of polishing with sandpaper, in the same manner as in Example 3, the ultrafine region hardness A was 0.30 mN / μm ² , the ultrafine region hardness B was 0.10 mN / μm ² , A developer amount regulating blade having a difference (A−B) of _{0.20 mN} / μm ² , a surface hardened layer thickness of 150 μm, and a surface roughness Rz _jis of 3 μm was prepared.

Example 5
Except for adjusting the degree of polishing with sandpaper, in the same manner as in Example 3, the ultrafine region hardness A was 0.30 mN / μm ² , the ultrafine region hardness B was 0.10 mN / μm ² , A developer amount regulating blade having a difference (A−B) of _{0.20 mN} / μm ² , a surface hardened layer thickness of 150 μm, and a surface roughness Rz _jis of 15 μm was prepared.

Example 6
As the raw material blade, the surface of the raw material blade produced in Reference Example 2 that was not contacted with the developing sleeve was masked with a celluloid adhesive tape, and after forming a hardened layer in the same manner as in Example 3, masking was performed. , The ultra-fine area hardness A of the surface of the hardened layer is 0.30 mN / μm ² , the ultra-fine area hardness B of the elastic rubber part is 0.10 mN / μm ² , the difference (A− A developer amount regulating blade having B) of _{0.20 mN} / μm ² , a surface hardened layer thickness of 150 μm, and a surface roughness Rz _jis of 10 μm was prepared.

Comparative Example 1
Except for setting the MDI impregnation time to 1 minute, in the same manner as in Example 1, the ultrafine region hardness A was 0.12 mN / μm ² , the ultrafine region hardness B was 0.10 mN / μm ² , A developer amount regulating blade having a difference (A−B) of 0.02 mN / μm ² , a surface hardened layer thickness of 5 μm, and a surface roughness Rz _jis of 10 μm was prepared.

Comparative Example 2
Except for setting the MDI impregnation time to 10 minutes, in the same manner as in Example 1, the ultrafine region hardness A was 0.60 mN / μm ² , the ultrafine region hardness B was 0.10 mN / μm ² , A developer amount regulating blade having a difference (A−B) of 0.50 mN / μm ² , a surface hardened layer thickness of 400 μm, and a surface roughness Rz _jis of 10 μm was prepared.

Comparative Example 3
Except for adjusting the degree of polishing with sandpaper, in the same manner as in Example 3, the ultrafine region hardness A was 0.30 mN / μm ² , the ultrafine region hardness B was 0.10 mN / μm ² , A developer amount regulating blade having a difference (A−B) of _{0.20 mN} / μm ² , a surface hardened layer thickness of 150 μm, and a surface roughness Rz _jis of 1 μm was prepared.

Comparative Example 4
Except for adjusting the degree of polishing with sandpaper, in the same manner as in Example 3, the ultrafine region hardness A was 0.30 mN / μm ² , the ultrafine region hardness B was 0.10 mN / μm ² , A developer amount regulating blade having a difference (A−B) of _{0.20 mN} / μm ² , a surface hardened layer thickness of 150 μm, and a surface roughness Rz _jis of 30 μm was prepared.

Comparative Example 5
As the raw material blade, except that the raw material blade produced in Reference Example 3 is used, the surface in which the ultrafine region hardness A is 0.30 mN / μm ² and the high hardness layer is not formed is the same as in Example 6. in measured ultrafine region hardness B is 0.10mN / μm ^2, the difference (a-B) is 0.20mN / μm ^2, the surface high-hardness layer thickness is the 150 [mu] m, and the surface roughness A developer amount regulating blade having an Rz _jis of 10 μm was prepared.

Comparative Example 6
As the raw material blade, except that the raw material blade produced in Reference Example 4 is used, the ultrafine region hardness A is 0.30 mN / μm ² and the ultrafine region hardness B is 0.00. 10 mN / [mu] m ^2, the difference (a-B) is 0.20mN / μm ^2, the surface high-hardness layer thickness is the 150 [mu] m, and creates a toner layer thickness regulation member surface roughness Rz _jis is 10μm did.

  The developer amount regulating blades obtained in the above examples and comparative examples were incorporated into LBP, and the above evaluation was performed. The results are shown in Table 1.

The developer (toner) is contacted with the surface of the contact surface that has been increased in hardness (Examples 1 to 3) with an extremely small area hardness A of 0.15 to 0.50 mN / μm ^2. It is apparent that image defects such as development streaks derived therefrom are unlikely to occur. In particular, it is most preferable that the hardness A in the ultrafine region is in the vicinity of 0.3 mN / μm ² . On the other hand, this effect does not appear if the region is outside the range as in Comparative Examples 1 and 2.

The surface roughness Rz _jis of the contact surface is suitably 3 to _{25 μm} as seen in Examples 4 and 5 and Comparative Examples 3 and 4. Further, when the thickness of the elastic plate-like rubber member is 0.3 mm or more, sufficient performance is exhibited (Example 6). However, when the thickness is smaller than 0.3 mm, the contact pressure becomes too low, and the developer Density cannot be regulated and density unevenness occurs (Comparative Example 5), and if it is larger than 2.0 mm, the pressure becomes too high and the developer is deteriorated during the evaluation and cannot be durable (Comparative Example 6). The result was not possible.

FIG. 3 is a schematic cross-sectional view of a development amount regulating blade of the present invention. It is a schematic sectional drawing which shows the use condition of the developing amount regulation blade of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Plate-like elastic rubber member 11 Support member 12 Hardening layer 13 Inner layer 14 Development amount regulation blade 20 Developing sleeve 21 Developer (toner)
22 Contact surface

Claims (2)

A developer amount regulating blade in which a plate-like elastic rubber member is bonded to a rigid plate-like support member, and the surface of the plate-like elastic rubber member in contact with the developing sleeve is measured in the ultra-small region hardness. An ultra-fine region of a plate-like elastic rubber member having a thickness A of 0.15 to 0.5 mN / [mu] m < ² > and having a thickness of 5 to 300 [mu] m and measured at a portion that is not a hardened layer in hardness B is 0.05~0.2mN / μm ^2, the difference between the ultrafine region hardness (a-B) is at 0.01 mN / [mu] m ² or more, further, ten-point of the abutting surface average roughness (Rz _JIS ) is 3 to 25 μm, and the thickness of the plate-like elastic rubber member is 0.3 to 2 mm.   2. The developer amount regulating blade according to claim 1, wherein the plate-like elastic rubber member is made of urethane rubber and the hardened layer is formed by impregnation of an isocyanate compound.

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