JP2016173386A - Cleaning blade, process cartridge and image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning blade capable of suppressing peeling of an abutment part of an elastic body blade while providing good trackability of the abutment part, suppressing noise and blade wearing, capable of keeping a good cleaning property for an extended period.SOLUTION: A cleaning blade includes an elastic body blade and removes a remaining object sticking from a cleaned member surface that abuts with a tip ridge line part of the elastic body blade, in which the elastic body blade has following requirements: a. the elastic body blade consists of an elastic body member and a surface layer formed on a surface containing the tip ridge line part of the elastic body member; b. the elastic body member consists of a base material and a cured object of a first ultraviolet curing composition which is contained in a region in thickness direction from a surface containing the tip ridge line part of the elastic body member; c. the surface layer is made from a cured object of a second ultraviolet curing composition, and becomes thicker as comes away from the tip ridge line part of the elastic body blade as far as a position of 100 μm, with a line angle of the tip ridge line part being 90° or lager.SELECTED DRAWING: Figure 3C

Description

  The present invention relates to a cleaning blade, a process cartridge, and an image forming apparatus.

Conventionally, in an electrophotographic image forming apparatus, an image carrier (hereinafter, also referred to as “photosensitive member”, “electrophotographic photosensitive member”, or “electrostatic latent image carrier”) as a member to be cleaned, Unnecessary transfer residual toner adhering to the surface after the toner image is transferred to the transfer paper or intermediate transfer member is removed by a cleaning means.
As the cleaning member of the cleaning means, one that uses a strip-shaped cleaning blade is well known because it can generally be simplified in configuration and has excellent cleaning performance. The cleaning blade is made of an elastic body such as polyurethane rubber. Then, the base end of the cleaning blade is supported by a support member, the contact portion is pressed against the peripheral surface of the image carrier, and the toner remaining on the image carrier is dammed and scraped off and removed.

  In addition, in order to meet the recent demand for higher image quality, an image forming apparatus using a near-spherical toner having a small particle diameter formed by a polymerization method or the like (hereinafter sometimes referred to as “polymerized toner”) is known. ing. The polymerized toner has characteristics such as higher transfer efficiency than conventional pulverized toner, and can meet the demand. However, it is difficult to remove the polymerized toner sufficiently from the surface of the image carrier using a cleaning blade, and there is a problem that cleaning failure occurs. This is because the polymerized toner having a small particle diameter and excellent sphericity passes through a slight gap formed between the cleaning blade and the image carrier.

  In order to suppress the slip-through, it is necessary to increase the contact pressure between the image carrier and the cleaning blade to enhance the cleaning ability. However, when the contact pressure of the cleaning blade is increased, as shown in FIG. 7A, the frictional force between the image carrier 123 and the cleaning blade 62 increases, and the cleaning blade 62 is pulled in the moving direction of the image carrier 123. The contact portion 62c of the cleaning blade 62 is turned up. When the turned cleaning blade 62 is restored to its original state against the turn, abnormal noise may occur. Further, when the cleaning is continued with the contact portion 62c of the cleaning blade 62 turned up, as shown in FIG. 7B, the cleaning blade 62 is locally removed at a location several μm away from the contact portion 62c of the blade tip surface 62a. Wear will occur. In this state, if the cleaning is further continued, this local wear increases. Eventually, as shown in FIG. 7C, the contact portion 62c is missing. If the contact portion 62c is missing as described above, there is a problem that the toner cannot be properly cleaned and a cleaning failure occurs. 7A to 7C, 62b is the lower surface of the cleaning blade.

  In order to solve the above problem, for example, Patent Document 1 proposes that a contact layer of an elastic member made of polyurethane elastomer is provided with a surface layer made of a resin having a pencil hardness of B to 6H. ing.

  Patent Document 2 discloses a cleaning blade in which an ultraviolet curable composition containing silicone is impregnated into a rubber elastic body member to be swollen and then irradiated with an ultraviolet ray to cure the ultraviolet curable composition. Has been proposed.

  Further, in Patent Document 3, at least one selected from an isocyanate compound, a fluorine compound, and a silicone compound is impregnated in a portion including the contact portion of the elastic member, and the surface of the elastic member including the contact portion is included in the surface. A cleaning blade having a harder surface layer than an elastic member has been proposed.

Although the conventional cleaning blade has a hardened contact portion, it has a drawback that the followability to fine vibrations of the image carrier is reduced and cleaning failure tends to occur.
In recent years, there is an increasing need for higher speed in an electrophotographic image forming apparatus. When the image forming speed is increased, the image carrier that rotates at high speed does not vibrate due to the shake of the image carrier, and the conventional cleaning blade can sufficiently cope with the increased speed of the image forming apparatus. There wasn't. Further, the followability to the minute waviness on the surface of the image bearing member cannot be sufficiently dealt with.

  Therefore, the present invention aims to solve the above-described problems and achieve the following object. That is, the present invention can suppress the turning of the contact portion of the elastic blade and improve the followability of the contact portion with respect to the member to be cleaned, and also suppresses abnormal noise and blade wear, and has good cleaning properties. An object of the present invention is to provide a cleaning blade capable of maintaining the temperature for a long time.

The cleaning blade of the present invention as means for solving the above problems is as follows.
A cleaning blade that has an elastic blade and removes residue adhering to the surface of the member to be cleaned from the surface of the member to be cleaned that is in contact with the tip ridge line portion of the elastic blade, wherein the elastic blade has the following a, A cleaning blade comprising the requirements of b and c.
a. The elastic blade is composed of an elastic member and a surface layer formed on the surface including the tip ridge line portion of the elastic member.
b. The elastic member includes a base material and a cured product of the first ultraviolet curable composition contained in a region in the thickness direction from the surface including the tip ridge line portion of the elastic member.
c. The surface layer is made of a cured product of the second ultraviolet curable composition, and becomes thicker away from the tip ridge line portion of the elastic blade to a position of 100 μm, and the ridge angle of the tip ridge line portion is 90 degrees or more. is there.

  According to the present invention, the conventional problems can be solved, the object can be achieved, curling of the contact portion of the elastic blade is suppressed, and the followability of the contact portion to the member to be cleaned is good. In addition, it is possible to provide a cleaning blade capable of suppressing abnormal noise and blade wear and maintaining good cleaning performance over a long period of time.

FIG. 1A is an enlarged sectional view showing a state where the cleaning blade is in contact with the surface of the image carrier. FIG. 1B is an enlarged view of the vicinity of the contact portion of the cleaning blade. FIG. 2 is a perspective view showing an example of the cleaning blade of the present invention. FIG. 3A is a diagram illustrating an incline angle of a tip ridge line portion of the cleaning blade base material in an untreated state. FIG. 3B is a diagram illustrating the angle of inclination of the tip ridge line portion of the elastic member in a state where the cured product of the first ultraviolet curable composition is contained in the region in the thickness direction of the contact portion. FIG. 3C is a diagram illustrating an incline angle of a tip ridge line portion of an elastic blade in which a surface layer is further formed. FIG. 4 is a schematic configuration diagram showing an example of the image forming apparatus of the present invention. FIG. 5 is a schematic configuration diagram of an image forming unit in an example of the image forming apparatus of the present invention. FIG. 6A is a diagram for explaining a method of measuring the average circularity of the toner. FIG. 6B is a diagram for explaining a method of measuring the average circularity of the toner. FIG. 7A is a diagram illustrating a state where the contact portion of the cleaning blade is rolled. FIG. 7B is a diagram illustrating local wear on the tip surface of the cleaning blade. FIG. 7C is a diagram illustrating a state where the contact portion of the cleaning blade is missing. FIG. 8 is an explanatory diagram of the elastic power. FIG. 9 is a schematic view showing a method for forming a surface layer in the example.

(Cleaning blade)
The cleaning blade of the present invention comprises an elastic blade that abuts the tip ridge line portion on the surface of the member to be cleaned and removes the residue adhering to the surface of the member to be cleaned. Accordingly, other members are included.

  The cleaning blade preferably includes a support member and a flat plate-like elastic blade having one end connected to the support member and a free end having a predetermined length at the other end. The cleaning blade is disposed such that a contact portion including a tip ridge line portion, which is one end on the free end side of the elastic blade, contacts the surface of the member to be cleaned along the longitudinal direction.

In the present invention, the elastic blade has the following requirements a, b and c.
a. The elastic blade is composed of an elastic member and a surface layer formed on the surface including the tip ridge line portion of the elastic member.
b. The elastic member includes a base material and a cured product of the first ultraviolet curable composition contained in a region in the thickness direction from the surface including the tip ridge line portion of the elastic member.
c. The surface layer is made of a cured product of the second ultraviolet curable composition, and becomes thicker away from the tip ridge line portion of the elastic blade to a position of 100 μm, and the ridge angle of the tip ridge line portion is 90 degrees or more. is there.
As a result, the contact of the elastic blade can be suppressed and the followability of the contact to the member to be cleaned can be improved, and noise and blade wear can be suppressed. Even if the wear of the surface proceeds, the high hardness inside the vicinity of the surface layer is maintained, so that good cleaning properties can be maintained for a long time.

<To be cleaned>
The member to be cleaned is not particularly limited with respect to its material, shape, structure, size, etc., and can be appropriately selected according to the purpose. Examples of the shape of the member to be cleaned include a drum shape, a belt shape, a flat plate shape, and a sheet shape. There is no restriction | limiting in particular as a magnitude | size of the said member to be cleaned, Although it can select suitably according to the objective, The magnitude | size normally used is preferable.
There is no restriction | limiting in particular as a material of the said to-be-cleaned member, According to the objective, it can select suitably, For example, a metal, a plastic, a ceramic, etc. are mentioned.
There is no restriction | limiting in particular as said member to be cleaned, According to the objective, it can select suitably, For example, when the said cleaning blade is applied to an image forming apparatus, an image carrier etc. are mentioned.

<Residue>
The residue is not particularly limited as long as it is attached to the surface of the member to be cleaned and is to be removed by the cleaning blade, and can be appropriately selected according to the purpose. For example, toner, lubricant , Inorganic fine particles, organic fine particles, dust, dust or a mixture thereof. Among these, a toner is preferable, and a low-temperature fixable toner having a glass transition temperature of 50 ° C. or lower is particularly preferable.

<Supporting member>
There is no restriction | limiting in particular about the shape, a magnitude | size, a material, etc. as said support member, According to the objective, it can select suitably. Examples of the shape of the support member include a flat plate shape, a strip shape, and a sheet shape. There is no restriction | limiting in particular as a magnitude | size of the said supporting member, According to the magnitude | size of the said member to be cleaned, it can select suitably.
Examples of the material of the support member include metals, plastics, and ceramics. Among these, a metal plate is preferable from the viewpoint of strength, and a steel plate such as stainless steel, an aluminum plate, and a phosphor bronze plate are particularly preferable.

<Elastic body member>
The elastic member includes a base material and a cured product of the first ultraviolet curable composition contained in a region in the thickness direction from the surface including the tip ridge line portion of the elastic member.
There is no restriction | limiting in particular about the shape, a material, a magnitude | size, a structure, etc. as said elastic body member, According to the objective, it can select suitably. Examples of the shape of the elastic member include a flat plate shape, a strip shape, and a sheet shape. There is no restriction | limiting in particular as a magnitude | size of the said elastic body member, According to the magnitude | size of the said member to be cleaned, it can select suitably.
The material for the base material is not particularly limited and may be appropriately selected depending on the intended purpose. However, polyurethane rubber, polyurethane elastomer, and the like are preferable because high elasticity is easily obtained.

  There is no restriction | limiting in particular in the said base material, According to the objective, it can select suitably. For example, a polyurethane prepolymer is prepared using a polyol compound and a polyisocyanate compound, a curing agent and, if necessary, a curing catalyst are added to the polyurethane prepolymer, crosslinked in a predetermined mold, and placed in a furnace. Then, after the cross-linked product is molded into a sheet by centrifugal molding, the product is allowed to stand at room temperature and aged and cut into a flat plate with a predetermined size.

There is no restriction | limiting in particular as said polyol compound, According to the objective, it can select suitably, For example, high molecular weight polyol, low molecular weight polyol, etc. are mentioned.
Examples of the high molecular weight polyol include a polyester polyol which is a condensate of an alkylene glycol and an aliphatic dibasic acid; ethylene adipate ester polyol, butylene adipate ester polyol, hexylene adipate ester polyol, ethylene propylene adipate ester polyol, ethylene butylene Polyester polyols such as polyester polyols of alkylene glycol and adipic acid such as adipate ester polyol and ethylene neopentylene adipate ester polyol; polycaprolactone polyols such as polycaprolactone ester polyol obtained by ring-opening polymerization of caprolactone; Polyethers such as oxytetramethylene) glycol and poly (oxypropylene) glycol Polyol, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the low molecular weight polyol include 1,4-butanediol, ethylene glycol, neopentyl glycol, hydroquinone-bis (2-hydroxyethyl) ether, 3,3′-dichloro-4,4′-diaminodiphenyllmethane. Dihydric alcohols such as 4,4′-diaminodiphenylmethane; 1,1,1-trimethylolpropane, glycerin, 1,2,6-hexanetriol, 1,2,4-butanetriol, trimethylolethane, 1, Examples thereof include trivalent or higher polyhydric alcohols such as 1,1-tris (hydroxyethoxymethyl) propane, diglycerin and pentaerythritol. These may be used individually by 1 type and may use 2 or more types together.

There is no restriction | limiting in particular as said polyisocyanate compound, According to the objective, it can select suitably, For example, a methylene diphenyl diisocyanate (MDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), naphthylene 1,5 Diisocyanate (NDI), tetramethylxylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate (H ₆ XDI), dicyclohexylmethane diisocyanate (H ₁₂ MDI), hexamethylene diisocyanate (HDI), dimer acid diisocyanate (DDI), norbornene diisocyanate (NBDI), trimethylhexamethylene diisocyanate (TMDI), and the like. These may be used individually by 1 type and may use 2 or more types together.

The curing catalyst is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include 2-methylimidazole and 1,2-dimethylimidazole.
The content of the curing catalyst is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.01% by mass or more and 0.5% by mass or less, and 0.05% by mass or more and 0.3% by mass. % Or less is more preferable.

The JIS-A hardness of the substrate is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 60 degrees or more, and more preferably 65 degrees or more and 80 degrees or less. When the JIS-A hardness is less than 60 degrees, it is difficult to obtain the blade linear pressure, and the area of the contact portion with the image carrier is likely to be enlarged, so that a cleaning failure may occur.
Here, the JIS-A hardness of the substrate can be measured using, for example, a micro rubber hardness meter MD-1 manufactured by Kobunshi Keiki Co., Ltd.

The rebound resilience based on the JIS K6255 standard of the base material is not particularly limited and can be appropriately selected according to the purpose. However, at 23 ° C., 35% or less is preferable, and 20% or more and 30% or less is more. preferable. If the rebound resilience exceeds 35%, the cleaning blade base material may be tacky, resulting in poor cleaning.
Here, the rebound elastic modulus of the base material is, for example, No. manufactured by Toyo Seiki Seisakusho Co., Ltd. at 23 ° C. in accordance with JIS K6255 standard. It can be measured using a 221 resilience tester.

  There is no restriction | limiting in particular in the average thickness of the said base material, Although it can select suitably according to the objective, 1.0 mm or more and 3.0 mm or less are preferable.

The tip ridge line portion that contacts the surface of the member to be cleaned of the elastic member contains a cured product of the first ultraviolet curable composition in a region in the thickness direction from the surface including the tip ridge line portion.
The phrase “containing a cured product of the first ultraviolet curable composition in a region in the thickness direction from the surface including the tip ridge line portion” means that the cured product of the first ultraviolet curable composition is the surface of the tip ridge line portion. It means that it is contained in the inside from the surface in contact with the layer, and is contained in the inside of the tip ridge line portion, and the first ultraviolet curable composition is cured on the surface inside the surface layer of the tip ridge line portion. The case where the layer which consists of a thing is formed is also included.
In addition, if the hardened | cured material of a 1st ultraviolet curable composition is contained in the area | region of the thickness direction from the surface containing the at least front-end ridgeline part of the said elastic body member, it will be in site | parts other than the front-end ridgeline part of the said elastic body member. Also, a cured product of the first ultraviolet curable composition may be contained in the region in the thickness direction.
The portion containing the cured product of the first ultraviolet curable composition is preferably in the range of 500 μm or more from the tip ridge line portion on the tip surface and the bottom surface of the elastic member.
Moreover, it is preferable that the depth of the thickness direction is 20-500 micrometers from the surface in which the hardened | cured material of a 1st ultraviolet curable composition is contained. If it is too deep, the flexibility of the elastic member will be low, and if it is too shallow, there will be no portion containing the ultraviolet curable composition when worn by long-term use, and the effect of suppressing twisting and deformation will be low.

<< first UV curable composition >>
The first ultraviolet curable composition preferably contains a (meth) acrylate compound, and further contains other components as necessary.

  There is no restriction | limiting in particular as said (meth) acrylate compound, Although it can select suitably according to the objective, The (meth) acrylate compound which has an alicyclic structure in a molecule | numerator is preferable.

-(Meth) acrylate compounds having an alicyclic structure in the molecule-
Since the (meth) acrylate compound having an alicyclic structure in the molecule has a special bulky alicyclic structure in the molecule, a (meth) acrylate compound having a small number of functional groups and a small molecular weight should be used. Therefore, the contact portion of the base material is easily impregnated, and the hardness of the contact portion can be improved efficiently.

6 or more are preferable and, as for carbon number of the alicyclic structure of the (meth) acrylate compound which has an alicyclic structure in the said molecule | numerator, 6 or more and 12 or less are more preferable. When the carbon number is less than 6, the hardness of the contact portion may be weakened, and when it exceeds 12, steric hindrance may occur.
The number of functional groups of the (meth) acrylate compound having an alicyclic structure having 6 or more carbon atoms in the molecule is preferably 2 or more, more preferably 2 or more and 6 or less, and still more preferably 2 or more and 4 or less. When the number of functional groups is less than 2, the hardness of the contact portion may be weakened, and when it exceeds 6, steric hindrance may occur.
The functional group equivalent molecular weight of the (meth) acrylate compound having an alicyclic structure in the molecule is preferably 200 or less. When the molecular weight exceeds 200, the molecular size increases, so that it is difficult to impregnate the base material, and it may be difficult to increase the hardness.

  The (meth) acrylate compound having an alicyclic structure in the molecule is a (meth) acrylate having a tricyclodecane structure from the point that even if there are few functional groups, the lack of crosslinking points can be compensated by a special cyclic structure. Compounds and (meth) acrylate compounds having an adamantane structure are preferred.

The (meth) acrylate compound having a tricyclodecane structure is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include tricyclodecane dimethanol diacrylate and tricyclodecane dimethanol dimethacrylate. Is mentioned.
As the (meth) acrylate compound having the tricyclodecane structure, an appropriately synthesized compound or a commercially available product may be used. As this commercial item, brand name: A-DCP (made by Shin-Nakamura Chemical Co., Ltd.) etc. are mentioned, for example.

The (meth) acrylate compound having an adamantane structure is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 1,3-adamantane dimethanol diacrylate, 1,3-adamantane dimethanol dimethacrylate 1,3,5-adamantane trimethanol triacrylate, 1,3,5-adamantane trimethanol trimethacrylate, and the like.
As the (meth) acrylate compound having an adamantane structure, an appropriately synthesized one or a commercially available product may be used. As this commercial item, a brand name: X-DA (made by Idemitsu Kosan Co., Ltd.), a brand name: X-A-201 (made by Idemitsu Kosan Co., Ltd.), a brand name: ADTM (made by Mitsubishi Gas Chemical Co., Ltd.) , Etc.

The content of the (meth) acrylate compound having an alicyclic structure in the molecule is not particularly limited and may be appropriately selected depending on the intended purpose. However, the solid content relative to the first ultraviolet curable composition is not limited. The amount is preferably 20% by mass or more and 100% by mass or less, and more preferably 50% by mass or more and 100% by mass or less. When the content is less than 20% by mass, high hardness due to a special cyclic structure may be impaired.
A (meth) acrylate compound having an alicyclic structure in the molecule (particularly, a (meth) acrylate compound having a tricyclodecane structure) is included in the tip ridge line portion that contacts the surface of the member to be cleaned of the elastic member. This can be analyzed, for example, by infrared microscopy or liquid chromatography.

In addition to the (meth) acrylate compound having an alicyclic structure in the molecule, the first ultraviolet curable composition includes a (meth) acrylate compound having a molecular weight of 100 to 1,500, and a fluorine-based (meth) acrylate. Compounds can be included.
The (meth) acrylate compound having a molecular weight of 100 to 1,500 is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include dipentaerythritol hexa (meth) acrylate and pentaerythritol tetra (meth). ) Acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, 1,6-hexanediol di (meth) acrylate , Ethoxylated bisphenol A di (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,5-pentanedioe Di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,7-heptanediol di (meth) acrylate, 1,8-octanediol di (meth) acrylate, 1,9-nonanediol di ( (Meth) acrylate, 1,10-decanediol di (meth) acrylate, 1,11-undecanediol di (meth) acrylate, 1,18-octadecanediol di (meth) acrylate, glycerin propoxytri (meth) acrylate, dipropylene Glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, PO-modified neopentyl glycol di (meth) acrylate, PEG600 di (meth) acrylate, PEG400 di (meth) acrylate, PEG200 di (meth) acrylate , Neopentyl glycol hydroxypivalate ester di (meth) acrylate, octyl / decyl (meth) acrylate, isobornyl (meth) acrylate, ethoxylated phenyl (meth) acrylate, 9,9-bis [4- (2- (meta ) Acryloyloxyethoxy) phenyl] fluorene, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, a compound having a pentaerythritol triacrylate structure having 3 to 6 functional groups is preferable.
Examples of the compound having a pentaerythritol triacrylate structure having 3 to 6 functional groups include pentaerythritol triacrylate and dipentaerythritol hexaacrylate.

  There is no restriction | limiting in particular in content in the said 1st ultraviolet curable composition of the said (meth) acrylate compound, Although it can select suitably according to the objective, 5 mass% or more and 80 mass% or less are solid content. Is preferred.

As the fluorine-based (meth) acrylate compound, those having a perfluoropolyether skeleton are preferable, those having a perfluoropolyether skeleton and having two or more functional groups are more preferable.
The fluorine-based (meth) acrylate compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 2,2,2-trifluoroethyl acrylate, 2,2,2-trifluoroethyl methacrylate 2,2,3,3-tetrafluoropropyl acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 2,2,3,3,4,4,4-heptafluorobutyl acrylate, 2,2, 3,3,4,4,4-heptafluorobutyl methacrylate, 2,2,3,4,4,4-hexafluorobutyl acrylate, 2,2,3,4,4,4-hexafluorobutyl methacrylate, 1 , 1,1,3,3,3-hexafluoroisopropyl acrylate, 1,1,1,3,3,3-hexafluoroisopropylmeta Relate, 1H, 1H, 5H-octafluoropentyl acrylate, 1H, 1H, 5H-octafluoropentyl methacrylate, 2,2,3,3,3-pentafluoropropyl acrylate, 2,2,3,3,3- Pentafluoropropyl methacrylate, 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl acrylate, 3,3,4,4,5,5,6,6 7,7,8,8,8-tridecafluorooctyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl methacrylate, 2- [(1 ′, 1 ′, 1′-trifluoro-2 ′-(trifluoromethyl) -2′-hydroxy) propyl] -3-norbornyl methacrylate, 1,1,1-trifluoro-2- ( Trifluoro Til) -2-hydroxy-4-methyl-5-pentyl methacrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10 -Heptadecafluorodecyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl methacrylate, 3,3 , 4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-henicosafluorododecyl acrylate, 3,3,4 , 4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-henicosafluorododecyl methacrylate, 3,3,4,4 5,5,6,6,7,7,8,8,9,9,10,10,11,12,12,12-henicother 1- (trifluoromethyl) dodecyl methacrylate, and the like. These may be used individually by 1 type and may use 2 or more types together.

  As the fluorine-based (meth) acrylate compound, a commercially available product can be used. Examples of the commercially available product include OPTOOL DAC-HP (manufactured by Daikin Industries, Ltd.) and MegaFac RS-75 (manufactured by DIC Corporation). ), Biscoat V-3F (Osaka Organic Chemical Industry Co., Ltd.), and the like.

  There is no restriction | limiting in particular in content in the said 1st ultraviolet curable composition of the said fluorine-type (meth) acrylate compound, Although it can select suitably according to the objective, 0.1 mass% or more in solid content 50 mass% or less is preferable.

<< Other ingredients >>
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a photoinitiator, a polymerization inhibitor, a diluent, etc. are mentioned.

-Photopolymerization initiator-
The photopolymerization initiator is not particularly limited as long as it generates active species such as radicals and cations by light energy and initiates polymerization, and can be appropriately selected according to the purpose. A radical polymerization initiator, a photocationic polymerization initiator, etc. are mentioned. Among these, a photo radical polymerization initiator is particularly preferable.

  Examples of the radical photopolymerization initiator include aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazoles, and the like. Examples thereof include compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds.

  The radical photopolymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone , Xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoin propyl ether , Benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1 Phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, bis (2 , 4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4-diethylthioxanthone, bis- (2,6-dimethoxybenzoyl) -2,4 , 4-trimethylpentylphosphine oxide, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Commercially available products can be used as the photoradical polymerization initiator. Examples of the commercially available products include Irgacure 651, Irgacure 184, DAROCUR 1173, Irgacure 2959, Irgacure 127, Irgacure 907, Irgacure 369, Irgacure 379, and DAROCUR. TPO, IRGACURE 819, IRGACURE 784, IRGACURE OXE 01, IRGACURE OXE 02, IRGACURE 754 (above, manufactured by Ciba Specialty Chemicals); Speedcure TPO (manufactured by Lambson); Lucirin TPO, LR 8893, LR 8970 (above, manufactured by BASF); Ubekrill P36 (manufactured by UCB), etc. It is below. These may be used individually by 1 type and may use 2 or more types together.

  The content of the photopolymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. It is preferably 1% by mass or more and 20% by mass or less with respect to the first ultraviolet curable composition. .

-Polymerization inhibitor-
The polymerization inhibitor is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include p-methoxyphenol, cresol, t-butylcatechol, di-t-butylparacresol, hydroquinone monomethyl ether, α Naphthol, 3,5-di-tert-butyl-4-hydroxytoluene, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-butylphenol) ), 4,4′-thiobis (3-methyl-6-t-butylphenol); p-benzoquinone, anthraquinone, naphthoquinone, phenanthraquinone, p-xyloquinone, p-toluquinone, 2,6-dichloro Quinone, 2,5-diphenyl-p-benzoquinone, 2,5-diacetoxy-p-benzox 2,5-dicaproxy-p-benzoquinone, 2,5-diacyloxy-p-benzoquinone, hydroquinone, 2,5-di-butylhydroquinone, mono-t-butylhydroquinone, monomethylhydroquinone, 2,5-di-t A quinone compound such as amylhydroquinone; an amine compound such as phenyl-β-naphthylamine, p-benzylaminophenol, di-β-naphthylparaphenylenediamine, dibenzylhydroxylamine, phenylhydroxylamine, diethylhydroxylamine; Nitro compounds such as nitrotoluene and picric acid; oxime compounds such as quinone dioxime and cyclohexanone oxime; and sulfur compounds such as phenothiazine. These may be used individually by 1 type and may use 2 or more types together.

-Diluent-
The diluent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include hydrocarbon solvents such as toluene and xylene; ethyl acetate, n-butyl acetate, methyl cellosolve acetate, propylene glycol monomethyl ether Ester solvents such as acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, cyclopentanone; ether solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether; ethanol, Examples thereof include alcohol solvents such as propanol, 1-butanol, isopropyl alcohol, and isobutyl alcohol. These may be used individually by 1 type and may use 2 or more types together.

The method for allowing the impregnated portion of the base material to contain (impregnate) the cured product of the first ultraviolet curable composition is not particularly limited and may be appropriately selected depending on the purpose. Examples include a method in which the contact portion of the base material is impregnated with the first ultraviolet curable composition by brushing, dip coating or the like and then cured by irradiation with ultraviolet rays.
The irradiation condition of the ultraviolet rays is not particularly limited and may be appropriately selected depending on the purpose, but the integrated light amount is preferably 500 mJ / cm ² or more. In order to suppress a decrease in the curing rate due to oxygen inhibition, irradiation in an inert gas (Ar, N ₂ , CO _2, etc.) atmosphere is more preferable.

In this invention, the front-end | tip ridgeline part of the said elastic body member contains the hardened | cured material of the 1st ultraviolet curable composition in the area | region of the thickness direction from the surface containing the said front-end | tip ridgeline part.
By including the cured product of the first ultraviolet curable composition in the tip ridge line portion of the elastic member, a mixed layer containing the material of the base material and the cured product of the first ultraviolet curable composition is formed. The Then, it is thought that the crosslink density of the base material itself is increased in a pseudo manner by forming a resin network chain inside the base material, and the wear resistance is improved. As a result, the contact portion of the elastic member is increased in hardness, and the contact portion can be prevented from being bent or deformed. Furthermore, even when the inside is exposed due to wear of the contact portion over time, the dripping and deformation can be similarly suppressed by the impregnation action.

As shown in FIG. 3A and FIG. 3B, the contact portion swells by the impregnation operation containing the first ultraviolet curable composition, and becomes smaller than the incline angle of the tip ridge line portion of the original substrate. Less than degrees. When the angle of the leading edge portion is smaller than 90 degrees, even if the contact portion is hardened, the contact portion is likely to bend or deform in the image forming apparatus that is increased in speed. When the contact part is rolled, the contact part is torn and worn, and defective cleaning tends to occur.
Therefore, the ridge angle of the tip ridge line portion that has become smaller due to swelling is formed such that the surface layer described later becomes thicker as it moves away from the tip ridge line portion to a position of 100 μm, and as shown in FIG. By setting the ridge angle of the tip ridge line portion to 90 degrees or more, the contact portion can be prevented from being bent or deformed.
The inclination angle of the tip ridge line portion of the elastic blade is preferably 90 degrees or more and 95 degrees or less.
In addition, by forming the surface layer so as to increase away from the tip ridge line portion to a position of 100 μm, the vicinity of the tip ridge line portion where the surface layer is thin can maintain the followability derived from the elastic member, and the tip ridge line At a position away from the portion, the posture of the contact portion can be maintained by the surface layer and high cleaning performance can be exhibited.
The ridge angle of the tip ridge line is measured by cutting the elastic blade into a ring and observing with a digital microscope VHX-2000 (manufactured by Keyence Co., Ltd.). The angle was measured using three points on the tip surface.

<Surface layer>
The elastic blade has a surface layer formed on the surface including the tip ridge line portion of the elastic member. The surface layer is made of a cured product of the second ultraviolet curable composition, and becomes thicker away from the tip ridge line portion of the elastic blade to a position of 100 μm, and the ridge angle of the tip ridge line portion is 90 degrees or more. .
The surface layer is preferably formed to be equal to or more than the portion containing the cured product of the first ultraviolet curable composition, and in the distal end surface and the lower surface of the elastic member, in the range of 500 μm or more from the distal end ridge line portion. It is preferably formed, and more preferably 500 μm or more and 5 mm or less from the viewpoint of flexibility of the elastic blade.

<< second ultraviolet curable composition >>
The second ultraviolet curable composition preferably contains a (meth) acrylate compound, and further contains other components as necessary.

  There is no restriction | limiting in particular as said (meth) acrylate compound, Although it can select suitably according to the objective, The (meth) acrylate compound which has a pentaerythritol structure in a molecule | numerator is preferable.

-(Meth) acrylate compound having pentaerythritol structure in the molecule-
The (meth) acrylate compound having a pentaerythritol structure in the molecule preferably has a functional group equivalent molecular weight of 350 or less and a number of functional groups of 3 to 6, for example, pentaerythritol tetra (meth) acrylate, pentaerythritol tris. (Meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like. Among these, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate are preferable.
If the functional group equivalent molecular weight exceeds 350 or a material other than the pentaerythritol triacrylate skeleton is used, the surface layer may become too brittle. When the surface layer becomes brittle, the tip edge line portion of the cleaning blade is turned over, and the tip surface wear as shown in FIG. 7B occurs, so that the cleaning property cannot be maintained for a long time.

  The content of the (meth) acrylate compound having a pentaerythritol structure in the molecule is not particularly limited and may be appropriately selected depending on the intended purpose. However, the solid content relative to the second ultraviolet curable composition is solid. The amount is preferably 20% by mass or more and 90% by mass or less, and more preferably 50% by mass or more and 80% by mass or less.

In addition to the (meth) acrylate compound having a pentaerythritol structure in the molecule, the second ultraviolet curable composition includes a (meth) acrylate compound having a molecular weight of 100 to 1,500, and a fluorine-based (meth) acrylate. The compound and the (meth) acrylate compound which has an alicyclic structure in a molecule | numerator can be contained.
Other (meth) acrylate compounds having a molecular weight of 100 or more and 1,500 or less, the fluorine-based (meth) acrylate compounds, and the (meth) acrylate compounds having an alicyclic structure in the molecule include the first ultraviolet ray. It can select suitably from the thing similar to a curable composition.
As said other component, the thing similar to a said 1st ultraviolet curable composition can be used.

The method for forming the surface layer containing the cured product of the second ultraviolet curable composition at the contact portion of the elastic member is not particularly limited and can be appropriately selected depending on the purpose. And a method of spraying the second ultraviolet curable composition on the contact portion to form a surface layer and irradiating with ultraviolet rays to cure.
As a method for forming the surface layer so as to become thicker away from the tip ridge line portion to a position of 100 μm, for example, the following method can be used.
In the case of coating with a spray gun, the film thickness distribution is the thickest at the coating center position (spray discharge center position) and becomes thinner as the distance from the center increases. Therefore, by shifting the coating center position by 100 μm or more from the tip ridge line portion to the blade side, the film thickness of the tip ridge line portion is thin, and a thicker film can be formed as the distance increases to the position of 100 μm. In addition, in this method, the coating center becomes thicker and becomes thinner as it approaches the holder side, so that it can be coated so as to become thicker as the distance from the tip ridge line portion increases by applying a masking tape or the like to the coating center. .
As another method, the thickness can be increased by increasing the number of ejections at a position away from the tip ridge line portion by ink-jet coating. Further, the surface layer can be formed so as to become thicker as the distance increases from the contact portion to the position of 100 μm by adjusting the pulling speed by dip coating.
The ultraviolet irradiation condition is not particularly limited and may be appropriately selected depending on the intended purpose. However, the integrated light amount is preferably 500 mJ / cm ² or more. In order to suppress a decrease in the curing rate due to oxygen inhibition, irradiation in an inert gas (Ar, N ₂ , CO _2, etc.) atmosphere is more preferable.

The elastic power of the cleaning blade is preferably 60% or more and 90% or less. The elastic power is a characteristic value obtained as follows from the accumulated stress at the time of measuring Martens hardness. The Martens hardness is measured using a microhardness meter while performing an operation of pushing the Vickers indenter with a constant force, for example, pressing it for 30 seconds, holding it for 5 seconds, and pulling it for 30 seconds with a constant force. In the present invention, like the Martens hardness, the elastic yield is a value measured at a distance of 20 μm from the tip ridge line portion on the blade tip surface of the elastic blade, as will be described later.
Here, if the cumulative stress when pushing in the Vickers indenter is Wplast, and the cumulative stress when unloading the test load is Welast, the elastic power is
Welast / Wplast × 100 (%)
(See FIG. 8). The higher the elastic power, the smaller the plastic deformation, that is, the higher the rubber property. If the elastic power is too low, it is in a state closer to glass than rubber, and the movement of the abutting portion is suppressed too much, and conversely, wear resistance is deteriorated. Usually, the (meth) acrylic resin has a relatively high elastic power in the range of the Martens hardness, and a rubbery state is obtained. However, depending on the structure of the (meth) acrylic resin, the elastic power may be too high, and the posture as a cleaning blade may not be maintained appropriately.

Here, FIG. 2 is a perspective view of the cleaning blade 62, and FIGS. 1A and 1B are enlarged sectional views of the cleaning blade 62. FIG. 1A is an explanatory diagram of a state in which the cleaning blade 62 is in contact with the surface of the photosensitive member 3, and FIG. 1B is an enlarged view of the vicinity of the contact portion including the tip ridge line portion 62 c of the elastic blade 622 of the cleaning blade 62. It is explanatory drawing.
As shown in FIG. 2, the cleaning blade 62 includes a flat support member 621 made of a rigid material such as metal or hard plastic, and a flat elastic blade 622. The elastic blade 622 is fixed to one end side of the support member 621 with an adhesive or the like, and the other end side of the support member 621 is cantilevered by the case of the cleaning device.
As shown in FIG. 1A, the cleaning blade 62 includes a support member 621 and a flat plate-like elastic blade 622 having one end connected to the support member and a free end having a predetermined length at the other end. The leading edge ridge line portion 62c, which is one end of the elastic blade 622 on the free end side, is disposed so as to contact the surface of the image carrier 3 along the longitudinal direction.

  The tip ridge line portion 62c that contacts the surface of the image carrier of the elastic member 622 contains a cured product of the first ultraviolet curable composition in a region in the thickness direction from the surface including the tip ridge line portion. The thickness direction from the surface including the tip ridge line portion is represented by an arrow in FIG. 1B. The contact portion containing the cured product of the first ultraviolet curable composition has a surface layer 623 containing a cured product of the second ultraviolet curable composition.

In the cleaning blade 62, for example, a base material made of urethane rubber is impregnated with the first ultraviolet curable composition by dip coating, and further, the second ultraviolet curable composition for forming the surface layer 623 is sprayed. After coating, the resin may be cured by ultraviolet irradiation.
The timing of irradiating the ultraviolet rays to cure the impregnated first ultraviolet curable composition is as follows. After the substrate is impregnated with the first ultraviolet curable composition, before the surface layer 623 is coated. Further, ultraviolet rays may be irradiated. After impregnating the first ultraviolet curable composition into the urethane rubber as the base material, the surface layer 623 is cured after the first ultraviolet curable composition impregnated by irradiation with ultraviolet rays is once cured. If the composition is coated with the second ultraviolet curable composition to form the surface, the impregnation state of the first ultraviolet curable composition is fixed to the urethane rubber before the surface layer 623 is formed, and the surface is later Even when the second ultraviolet curable composition for forming the layer 623 is applied, the impregnation state does not change, and thus the elastic blade 622 in a desired impregnation state can be produced.

The impregnation treatment to the tip ridge line portion 62c of the elastic blade 622 can be performed by impregnating the ultraviolet curable composition by brush coating, spray coating, dip coating, or the like.
In the case of impregnation, the type of monomer of the UV curable composition, the type of polymerization initiator, the curing method, the solid content concentration of the formulation liquid, the polymerization initiator concentration of the formulation liquid, the impregnation time, the resin on the blade surface after impregnation The depth of the portion to be hardened varies depending on the residue cleaning process, the formation of the surface layer, and the like.

  The surface layer 623 is formed by impregnating the substrate with the first ultraviolet curable composition and air-drying for a predetermined time, or after impregnating the first ultraviolet curable composition and curing, followed by spray coating or dip coating. It can be formed by coating the surface of the elastic blade including the tip ridge line portion 62c of the elastic blade with the second ultraviolet curable composition by a process or screen printing.

The surface layer 623 is preferably a second ultraviolet curable composition that is harder than the Martens hardness of the base material, and the thickness of the surface layer is 0.1 μm or more and 3 μm or less at a distance of 20 μm from the tip ridge line portion. It is preferable that the thickness of the surface layer at a position where the distance from the tip ridge line portion is 100 μm is 1.1 to 6 times the thickness at the position of 20 μm.
If the thickness of the surface layer at a distance of 20 μm from the tip ridge is less than 0.1 μm, the movement of the tip ridge is not able to be suppressed, and turning is likely to occur. If it exceeds 3 μm, it may be too thick and too rigid, and wear during long-term use may easily progress. Further, if the thickness of the surface layer at the distance of 100 μm from the tip ridge is less than 1.1 times the thickness at the position of 20 μm, it is difficult to make the angle of the tip ridge 90 or more. It tends to occur. On the other hand, if it exceeds 6 times, the difference in film thickness at the position away from the vicinity of the tip ridge line portion becomes too large, and the surface layer is easily peeled off.

Further, since the surface layer 623 is made of a member having a hardness higher than that of the base material, the surface layer 623 is rigid and thus is difficult to be deformed, and the turn-up of the contact portion including the tip ridge line portion 62c of the elastic blade can be further suppressed. .
After impregnating the ultraviolet curable composition or coating with the surface layer 623, the impregnated portion 62d shown in FIGS. 1A and 1B is formed by irradiating with ultraviolet rays, and the hardness of the tip ridge line portion 62c It is possible to produce a reforming effect that increases.
By impregnating the first ultraviolet curable composition and setting the surface layer made of the second ultraviolet curable composition to a thickness of 0.1 μm or more and 3 μm or less at a position where the distance from the tip ridge line portion is 20 μm The surface Martens hardness at a distance of 20 μm from the contact portion can be realized to be 1 to 15 N / m ² .
When the Martens hardness is less than 1 N / m ² , the contact portion is too soft, so that the wear tends to progress due to long-term use. On the other hand, if it exceeds 15 N / m ² , the contact portion becomes too hard, and the followability to the photosensitive member is lost, and cleaning failure is likely to occur.

  As described above, according to the present invention, the contact portion of the elastic blade can be prevented from being turned over, and the followability of the contact portion to the member to be cleaned can be improved, and noise and blade wear can be suppressed. A cleaning blade capable of obtaining good cleaning properties can be provided.

  The cleaning blade of the present invention can prevent the contact portion of the elastic blade contacting the surface of the member to be cleaned from being curled, has little wear on the elastic blade contact portion during use, and provides good cleaning performance for a long period of time. However, it can be used widely in various fields, but is particularly preferably used in the image forming apparatus and process cartridge of the present invention described below.

(Image forming device)
The image forming apparatus of the present invention includes an image carrier, a charging unit that charges the surface of the image carrier, an exposure unit that exposes the charged image carrier to form an electrostatic latent image, and the electrostatic Developing means for developing a latent image with toner to form a visible image; transfer means for transferring the visible image to a recording medium; and fixing means for fixing the transferred image transferred to the recording medium; An image forming apparatus having a cleaning unit that removes toner remaining on the image carrier, wherein the cleaning unit includes the cleaning blade of the present invention.
Furthermore, other means appropriately selected as necessary are provided. The charging unit and the exposure unit may be collectively referred to as an electrostatic latent image forming unit.

  The image forming method used in the present invention can be preferably carried out by the image forming apparatus of the present invention.

<Image carrier>
The image carrier (hereinafter sometimes referred to as “electrophotographic photoreceptor” or “photoreceptor”) is not particularly limited in terms of material, shape, structure, size, etc., and is appropriately selected from known ones. can do. Examples of the shape of the image carrier include a drum shape and a belt shape. Examples of the material of the image carrier include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors (OPC) such as polysilane and phthalopolymethine.

<Charging means>
The charging means is not particularly limited and may be appropriately selected depending on the purpose. For example, the charging means known per se provided with a conductive or semiconductive roller, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons and corotrons.
The shape of the charging means may take any form, such as a roller, a magnetic brush, or a fur brush, and can be selected according to the specifications and form of the electrophotographic image forming apparatus. In the case of using a magnetic brush, the magnetic brush is composed of, for example, various ferrite particles such as Zn-Cu ferrite as a charging means, a non-magnetic conductive sleeve for supporting it, and a magnet roll included therein. The Or when using a brush, for example, as the material of the fur brush, a fur treated with carbon, copper sulfide, metal or metal oxide is used, and this is wound around a metal or other conductive core. Make it a charger by sticking.
The charger is not limited to the contact charger as described above, but has an advantage that an image forming apparatus in which ozone generated from the charger is reduced can be obtained.
It is preferable that the charger is arranged in contact or non-contact with the image carrier and charges the surface of the image carrier by applying a direct current and an alternating voltage.
In addition, there is a charging roller in which a charging roller having a gap tape on an image carrier and arranged in a non-contact manner, and charging the surface of the image carrier by applying a direct current and an alternating voltage to the charging roller. preferable.

<Exposure means>
The exposure means is not particularly limited as long as it can be exposed like an image to be formed on the surface of the image carrier charged by the charging means, and can be appropriately selected according to the purpose. Examples thereof include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, a liquid crystal shutter optical system, and an LED optical system.
In the present invention, an optical back side system in which imagewise exposure is performed from the back side of the image carrier may be adopted.

<Developing means>
The developing unit is not particularly limited as long as it can be developed using the toner, for example, and can be appropriately selected from known ones. For example, the toner is accommodated and the electrostatic latent image is formed on the electrostatic latent image. Preferable examples include those having at least a developing unit capable of applying the toner in a contact or non-contact manner.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner by frictional stirring and a rotatable magnet roller is preferable.

  In the developing unit, for example, the toner and, if necessary, a carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state. Is formed. Since the magnet roller is disposed in the vicinity of the image carrier, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted to the image carrier. Move to the surface. As a result, the electrostatic latent image is developed with the toner to form a visible image with the toner on the surface of the image carrier.

  The toner stored in the developing device may be a developer containing the toner, and the developer may be a one-component developer or a two-component developer.

-Toner-
The toner contains toner base particles and an external additive, and further contains other components as necessary.
The toner may be a monochrome toner or a color toner.
The toner base particles include at least a binder resin and a colorant and, if necessary, other components such as a release agent and a charge control agent.

  As the toner, it is preferable to use a polymerized toner produced by a suspension polymerization method, an emulsion polymerization method, or a dispersion polymerization method, which can easily increase the circularity and reduce the particle size in order to improve the image quality. In particular, it is preferable to use a polymerized toner having a circularity of 0.97 or more and a volume average particle size of 5.5 [μm] or less. By using a material having an average circularity of 0.97 or more and a volume average particle size of 5.5 [μm], a higher resolution image can be formed.

  The “circularity” here is an average circularity measured by a flow type particle image analyzer FPIA-2000 (trade name, manufactured by Toa Medical Electronics Co., Ltd.). Specifically, a surfactant, preferably an alkylbenzene sulfonate, is added in an amount of 0.1 to 0.5 [ml] as a dispersant in 100 to 150 [ml] of water from which impure solids have been removed in advance. Further, about 0.1 to 0.5 [g] of a measurement sample (toner) is added. Thereafter, the suspension in which the toner is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes so that the dispersion concentration becomes 3000 to 10,000 [pieces / μl]. Set and measure toner shape and distribution. Based on this measurement result, when the outer peripheral length of the actual toner projection shape shown in FIG. 6A is C1, the projection area is S, and the outer circumference of the perfect circle shown in FIG. C2 / C1 was determined, and the average value was defined as the circularity.

  The volume average particle diameter can be determined by a Coulter counter method. Specifically, the toner number distribution and volume distribution data measured by the Coulter Multisizer 2e type (manufactured by Coulter) are sent to a personal computer via an interface (manufactured by Nikkaki Co., Ltd.) for analysis. More specifically, a 1% NaCl aqueous solution using first grade sodium chloride is prepared as an electrolytic solution. Then, 0.1 to 5 [ml] of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 [ml] of the electrolytic aqueous solution. Further, 2 to 20 [mg] of toner as a test sample is added thereto, and dispersion treatment is performed for about 1 to 3 [minutes] with an ultrasonic disperser. Then, 100 to 200 [ml] of the electrolytic aqueous solution is put into another beaker, and the solution after the dispersion treatment is added to the beaker so as to have a predetermined concentration, and then applied to the Coulter Multisizer 2e type. The aperture is 100 [μm], and the particle size of 50,000 toner particles is measured. As a channel, it is less than 2.00-2.52 [micrometer]; 2.52-less than 3.17 [micrometer]; 3.17-less than 4.00 [micrometer]; 4.00-5.04 [micrometer] Less than 5.04 to 6.35 [μm]; 6.35 to less than 8.00 [μm]; 8.00 to less than 10.08 [μm]; 10.08 to less than 12.70 [μm]; 12.70 to less than 16.00 [μm]; 16.00 to less than 20.20 [μm]; 20.20 to less than 25.40 [μm]; 25.40 to less than 32.00 [μm]; Using 13 channels of 00 to less than 40.30 [μm], toner particles with a particle size of 2.00 [μm] or more and 32.0 [μm] or less are targeted. Then, the volume average particle diameter is calculated based on the relational expression “volume average particle diameter = ΣXfV / ΣfV”. However, “X” is the representative diameter in each channel, “V” is the equivalent volume in the representative diameter of each channel, and “f” is the number of particles in each channel.

In such a polymerized toner, even if an attempt is made to remove the pulverized toner with the cleaning blade 62 in the same manner as when the conventional pulverized toner is removed from the surface of the photoreceptor 3, the polymerized toner cannot be sufficiently removed from the surface of the photoreceptor 3. A cleaning failure occurs. Further, low-temperature fixing toner using a crystalline resin in recent years is greatly deformed when passing through the blade, and is fixed to the edge of the blade or fused to the surface of the photoreceptor. Therefore, when the contact pressure of the cleaning blade 62 to the photosensitive member 3 is increased to improve the cleaning performance, there is a problem that the cleaning blade 62 wears out early. In addition, the frictional force between the cleaning blade 62 and the photosensitive member 3 is increased, and the leading edge portion of the cleaning blade 62 in contact with the photosensitive member 3 is pulled in the moving direction of the photosensitive member 3 so that the leading edge portion is turned. End up. When the tip ridge line portion of the cleaning blade 62 is turned, various problems such as abnormal noise, vibration, and lack of the tip ridge line portion occur.
The cleaning blade of the present invention does not cause poor cleaning even with the above-described polymerized toner, and does not cause abnormal noise, vibration, or lack of a tip ridge line portion.

  The ratio (Dv / Dn) between the volume average particle diameter (Dv) and the number average particle diameter (Dn) of the toner is not particularly limited and may be appropriately selected depending on the intended purpose. 1.40 or less is preferable. The closer the ratio (Dv / Dn) is to 1.00, the sharper the particle size distribution. With such a toner having a small particle size and a narrow particle size distribution, the toner charge amount distribution is uniform, a high-quality image with little background fogging can be obtained, and the electrostatic transfer method has a high transfer rate. can do.

  The volume average particle size and particle size distribution of the toner are measured by, for example, Coulter Counter TA-II, Coulter Multisizer II (both manufactured by Coulter Co., Ltd.), etc. can do.

  The toner preferably has a glass transition temperature of 50 ° C. or lower. Even with such low-temperature fixing toner, it is possible to prevent the toner from being crushed and greatly deformed, and to prevent the toner from adhering to the contact portion of the cleaning blade and the image carrier.

The toner can be mixed with a magnetic carrier and used as a two-component developer. In this case, the mass ratio of the carrier and the toner in the two-component developer is not particularly limited and can be appropriately selected according to the purpose. However, the toner is 1 part by mass or more and 10 parts by mass with respect to 100 parts by mass of the carrier. Part or less is preferred.
Examples of the magnetic carrier include iron powder, ferrite powder, magnetite powder, and magnetic resin carrier having a particle diameter of about 20 μm to 200 μm.
The coating resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, epoxy resin, polyvinyl and polyvinylidene resin , Halogenated olefin resins such as acrylic resin, polymethyl methacrylate resin, polyacrylonitrile resin, polyvinyl acetate resin, polyvinyl alcohol resin, polyvinyl butyral resin, polystyrene resin, styrene-acrylic copolymer resin, polyvinyl chloride; polyethylene terephthalate resin, Polyester resins such as polybutylene terephthalate resin; polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyester resins Hexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, terpolymer of tetrafluoroethylene, vinylidene fluoride and non-fluorinated monomer And fluoroterpolymers such as silicone resins.

Furthermore, you may make conductive powder etc. contain in coating resin as needed. Examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter exceeds 1 μm, it may be difficult to control electric resistance.
The toner can also be used as a one-component magnetic toner or a non-magnetic toner that does not use a carrier.

<Transfer means>
The transfer unit includes a primary transfer unit that transfers a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer unit that transfers the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. Examples thereof include a transfer belt.

The transfer unit (the primary transfer unit and the secondary transfer unit) preferably includes at least a transfer unit that peels and charges the visible image formed on the image carrier to the recording medium side. . There may be one transfer means or two or more transfer means. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. A PET base or the like can also be used.

<Fixing means>
The fixing unit is not particularly limited, and a heat fixing method using a known heating and pressing unit can be employed. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, and a combination of a heating roller, a pressure roller, and an endless belt. At this time, the heating temperature is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 80 ° C to 200 ° C. If necessary, for example, a known optical fixing device may be used together with the fixing unit.

<Cleaning means>
As the cleaning means, the cleaning blade of the present invention is used.
The elastic blade of the cleaning blade is preferably in contact with the surface of the image carrier at a linear pressure of 10 N / m to 100 N / m. When the linear pressure is less than 10 N / m, a cleaning failure is likely to occur due to toner passing through a contact portion where the elastic blade of the cleaning blade contacts the surface of the image carrier. The cleaning blade may roll up due to an increase in the frictional force at the contact part. The linear pressure is more preferably 10 N / m or more and 50 N / m or less.
The linear pressure can be measured, for example, using a measuring apparatus incorporating a small compression type load cell manufactured by Kyowa Denki Co., Ltd.

The angle formed between the tangent line at the portion where the elastic blade of the cleaning blade comes into contact with the surface of the image carrier and the end face of the cleaning blade is not particularly limited and can be appropriately selected according to the purpose. It is preferably 85 ° or less.
If the angle θ formed is less than 65 °, the cleaning blade may be swung up, and if it exceeds 85 °, a cleaning failure may occur.

<Other means>
Examples of the other means include a lubricant application means, a static elimination means, a recycling means, and a control means.

-Lubricant application means-
The image forming apparatus of the present invention may have a lubricant application unit, and the lubricant application unit can be appropriately selected from known lubricant application units.

-Static elimination means-
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the image carrier. For example, a neutralization lamp or the like is preferable. It is done.

-Recycling means-
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

-Control means-
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

Here, an example of the image forming apparatus of the present invention will be described with reference to the drawings.
FIG. 4 is a schematic configuration diagram showing an example of the image forming apparatus 500 of the present invention. The image forming apparatus 500 includes four image forming units 1Y, 1C, 1M, and 1K for yellow, magenta, cyan, and black (hereinafter sometimes referred to as Y, C, M, and K). . These use Y, C, M, and K toners of different colors as image forming substances for forming an image, but the other configurations are the same.

Above the four image forming units 1, a transfer unit 60 including an intermediate transfer belt 14 as an intermediate transfer member is disposed. The toner images of the respective colors formed on the surfaces of the photoreceptors 3Y, 3C, 3M, and 3K included in the image forming units 1Y, 1C, 1M, and 1K, which will be described in detail later, are superimposed on the surface of the intermediate transfer belt. It is a configuration to be transferred.
Further, an optical writing unit 40 is disposed below the four image forming units 1. The optical writing unit 40 serving as a latent image forming unit irradiates the photoconductors 3Y, 3C, 3M, and 3K of the image forming units 1Y, 1C, 1M, and 1K with the laser light L emitted based on the image information. Thereby, electrostatic latent images for Y, C, M, and K are formed on the photoreceptors 3Y, 3C, 3M, and 3K. The optical writing unit 40 polarizes the laser light L emitted from the light source by the polygon mirror 41 that is rotationally driven by a motor, and passes the photosensitive members 3Y, 3C, 3M, and 3K through a plurality of optical lenses and mirrors. Is irradiated. Instead of the configuration described above, it is also possible to employ one that performs light scanning with an LED array.

  Below the optical writing unit 40, a first paper feed cassette 151 and a second paper feed cassette 152 are arranged so as to overlap in the vertical direction. Each of these paper feed cassettes stores a plurality of recording media P in a stacked state, and the uppermost recording medium P has a first paper feed roller 151a and a second paper feed. The rollers 152a are in contact with each other. When the first paper feed roller 151a is driven to rotate counterclockwise in FIG. 4 by the driving means, the uppermost recording medium P in the first paper feed cassette 151 extends in the vertical direction on the right side of the cassette in FIG. The paper is discharged toward the paper feed path 153 arranged to exist. Further, when the second paper feeding roller 152a is driven to rotate counterclockwise in FIG. 4 by the driving means, the uppermost recording medium P in the second paper feeding cassette 152 is discharged toward the paper feeding path 153. .

  A plurality of conveying roller pairs 154 are arranged in the paper feed path 153. The recording medium P sent to the paper feed path 153 is conveyed from the lower side to the upper side in FIG. 4 while being sandwiched between the rollers of the conveyance roller pair 154.

  A registration roller pair 55 is disposed at the downstream end of the paper feed path 153 in the transport direction. The registration roller pair 55 temporarily stops the rotation of both rollers as soon as the recording medium P sent from the conveying roller pair 154 is sandwiched between the rollers. Then, the recording medium P is sent out toward a secondary transfer nip described later at an appropriate timing.

FIG. 5 is a schematic diagram showing the configuration of one of the four image forming units 1.
As shown in FIG. 5, the image forming unit 1 includes a drum-shaped photoconductor 3 as an image carrier. The photoconductor 3 has a drum shape, but may have a sheet shape or an endless belt shape.
Around the photoreceptor 3, a charging roller 4, a developing device 5, a primary transfer roller 7, a cleaning device 6, a lubricant application device 10, a charge removal lamp, and the like are disposed. The charging roller 4 is a charging member provided in a charging device as a charging unit, and the developing device 5 is a developing unit that converts a latent image formed on the surface of the photoreceptor 3 into a toner image. The primary transfer roller 7 is a primary transfer member provided in a primary transfer device as a primary transfer unit that transfers a toner image on the surface of the photoreceptor 3 to the intermediate transfer belt 14. The cleaning device 6 is a cleaning unit that cleans the toner remaining on the photoreceptor 3 after the toner image is transferred to the intermediate transfer belt 14. The lubricant application device 10 is a lubricant application unit that applies a lubricant onto the surface of the photoreceptor 3 after the cleaning device 6 performs cleaning. The neutralization lamp is a neutralization unit that neutralizes the surface potential of the photoreceptor 3 after cleaning.

The charging roller 4 is arranged in a non-contact manner with a predetermined distance from the photoconductor 3, and charges the photoconductor 3 to a predetermined polarity and a predetermined potential. The surface of the photoreceptor 3 uniformly charged by the charging roller 4 is irradiated with laser light L from an optical writing unit 40 serving as a latent image forming unit based on image information, thereby forming an electrostatic latent image.
The developing device 5 has a developing roller 51 as a developer carrier. A developing bias is applied to the developing roller 51 from a power source. In the casing of the developing device 5, a supply screw 52 and a stirring screw 53 are provided for stirring the developer contained in the casing while conveying the developer in opposite directions. A doctor 54 for regulating the developer carried on the developing roller 51 is also provided. The toner in the developer stirred and conveyed by the two screws of the supply screw 52 and the stirring screw 53 is charged to a predetermined polarity. The developer is pumped up on the surface of the developing roller 51, and the developer pumped up is regulated by the doctor 54, and the toner adheres to the latent image on the photoconductor 3 in the development area facing the photoconductor 3. .

The cleaning device 6 includes a fur brush 101, a cleaning blade 62, and the like. The cleaning blade 62 is in contact with the photoconductor 3 in the counter direction with respect to the surface movement direction of the photoconductor 3. The cleaning blade 62 is the cleaning blade of the present invention.
The lubricant application device 10 includes a solid lubricant 103, a lubricant pressure spring 103 a, and the like, and uses a fur brush 101 as an application brush for applying the solid lubricant 103 onto the photoreceptor 3. The solid lubricant 103 is held by the bracket 103b and is pressed toward the fur brush 101 by a lubricant pressurizing spring 103a. Then, the solid lubricant 103 is scraped by the fur brush 101 that rotates in the rotational direction with respect to the rotation direction of the photoconductor 3, and the lubricant is applied onto the photoconductor 3. It is preferable that the coefficient of friction of the surface of the photoconductor 3 is maintained at 0.2 or less during non-image formation by applying a lubricant to the photoconductor.

  The charging device is a non-contact proximity arrangement system in which the charging roller 4 is brought close to the photosensitive member 3, and as the charging device, known devices such as a corotron, a scorotron, and a solid state charger (solid state charger) are known. A configuration can be used. Among these charging methods, the contact charging method or the non-contact proximity arrangement method is more desirable, and has advantages such as high charging efficiency, a small amount of ozone generation, and miniaturization of the apparatus.

The light source of the laser light L of the optical writing unit 40 and the light source such as a static elimination lamp include a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL). ) And other luminescent materials can be used.
In addition, various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
Among these light sources, light emitting diodes and semiconductor lasers are used favorably because they have high irradiation energy and have long wavelength light of 600 nm to 800 nm.

  4 includes a belt cleaning unit 162, a first bracket 63, a second bracket 64, and the like in addition to the intermediate transfer belt 14. In addition, four primary transfer rollers 7Y, 7C, 7M, and 7K, a secondary transfer backup roller 66, a driving roller 67, an auxiliary roller 68, a tension roller 69, and the like are also provided. The intermediate transfer belt 14 is endlessly moved counterclockwise in FIG. 4 by the rotational drive of the drive roller 67 while being stretched around these eight roller members. The four primary transfer rollers 7Y, 7C, 7M, and 7K sandwich the intermediate transfer belt 14 that is moved endlessly between the photoreceptors 3Y, 3C, 3M, and 3K to form primary transfer nips. . Then, a transfer bias having a polarity opposite to that of the toner (for example, plus) is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 14. The intermediate transfer belt 14 sequentially passes through the primary transfer nips for Y, C, M, and K along with the endless movement thereof, and on the front surface thereof, the intermediate transfer belt 14 is on the photoreceptors 3Y, 3C, 3M, and 3K. Y, C, M, and K toner images are superimposed and primarily transferred. As a result, a four-color superimposed toner image (hereinafter sometimes referred to as a four-color toner image) is formed on the intermediate transfer belt 14.

  The secondary transfer backup roller 66 sandwiches the intermediate transfer belt 14 with the secondary transfer roller 70 disposed outside the loop of the intermediate transfer belt 14 to form a secondary transfer nip. The registration roller pair 55 described above feeds the recording medium P sandwiched between the rollers toward the secondary transfer nip at a timing at which the recording medium P can be synchronized with the four-color toner image on the intermediate transfer belt 14. The four-color toner image on the intermediate transfer belt 14 is affected by the secondary transfer electric field formed between the secondary transfer roller 70 to which the secondary transfer bias is applied and the secondary transfer backup roller 66, and the influence of the nip pressure. Then, the secondary transfer is batch-transferred onto the recording medium P in the secondary transfer nip. Then, combined with the white color of the recording medium P, a full color toner image is obtained.

  Untransferred toner that has not been transferred to the recording medium P adheres to the intermediate transfer belt 14 after passing through the secondary transfer nip. This is cleaned by the belt cleaning unit 162. The belt cleaning unit 162 has a belt cleaning blade 162a in contact with the front surface of the intermediate transfer belt 14, thereby scraping off and removing the transfer residual toner on the intermediate transfer belt 14.

  The first bracket 63 of the transfer unit 60 swings at a predetermined rotation angle about the rotation axis of the auxiliary roller 68 as the solenoid is turned on / off. When forming a monochrome image, the image forming apparatus 500 slightly rotates the first bracket 63 counterclockwise in FIG. 4 by driving the solenoid described above. By this rotation, the primary transfer rollers 7Y, 7C, and 7M for Y, C, and M are revolved counterclockwise in FIG. 4 around the rotation axis of the auxiliary roller 68, so that the intermediate transfer belt 14 is rotated in the Y, C direction. , M is separated from the photoconductors 3Y, 3C, 3M. Of the four image forming units 1Y, 1C, 1M, and 1K, only the K image forming unit 1K is driven to form a monochrome image. Accordingly, it is possible to avoid wear of each member constituting the image forming unit 1 due to wasteful driving of the Y, C, M image forming unit 1 during monochrome image formation.

  A fixing unit 80 is disposed above the secondary transfer nip in FIG. The fixing unit 80 includes a pressure heating roller 81 that contains a heat source such as a halogen lamp, and a fixing belt unit 82. The fixing belt unit 82 includes a fixing belt 84 as a fixing member, a heating roller 83 containing a heat source such as a halogen lamp, a tension roller 85, a driving roller 86, a temperature sensor, and the like. Then, the endless fixing belt 84 is endlessly moved in the counterclockwise direction in FIG. 4 while being stretched by the heating roller 83, the tension roller 85, and the driving roller 86. In the process of endless movement, the fixing belt 84 is heated from the back side by the heating roller 83. A pressure heating roller 81 that is driven to rotate in the clockwise direction in FIG. 4 is in contact with the surface of the fixing belt 84 that is heated in this manner. Thus, a fixing nip where the pressure heating roller 81 and the fixing belt 84 abut is formed.

  A temperature sensor is disposed outside the loop of the fixing belt 84 so as to face the front surface of the fixing belt 84 with a predetermined gap, and the surface temperature of the fixing belt 84 immediately before entering the fixing nip. Is detected. This detection result is sent to the fixing power supply circuit. The fixing power supply circuit performs on / off control of power supply to the heat generation source included in the heating roller 83 and the heat generation source included in the pressure heating roller 81 based on the detection result of the temperature sensor.

  The recording medium P that has passed through the secondary transfer nip described above is separated from the intermediate transfer belt 14 and then sent into the fixing unit 80. Then, in the process of being conveyed from the lower side to the upper side in FIG. 4 while being sandwiched by the fixing nip in the fixing unit 80, the full-color toner image is fixed on the recording medium P by being heated and pressed by the fixing belt 84. Is done.

  The recording medium P on which the fixing process has been performed in this manner is discharged to the outside of the image forming apparatus after passing between the rollers of the paper discharge roller pair 87. A stack unit 88 is formed on the upper surface of the casing of the image forming apparatus 500 main body, and the recording media P discharged to the outside of the image forming apparatus by the discharge roller pair 87 are sequentially stacked on the stack unit 88.

  Above the transfer unit 60, four toner cartridges 100Y, 100C, 100M, and 100K that store Y, C, M, and K toners are disposed. The Y, C, M, and K toners in the toner cartridges 100Y, 100C, 100M, and 100K are appropriately supplied to the developing devices 5Y, 5C, 5M, and 5K of the image forming units 1Y, 1C, 1M, and 1K. These toner cartridges 100Y, 100C, 100M, and 100K are detachable from the image forming apparatus main body independently of the image forming units 1Y, 1C, 1M, and 1K.

Next, an image forming operation in the image forming apparatus 500 will be described.
First, when a print execution signal is received from the operation unit or the like, a predetermined voltage or current is sequentially applied to the charging roller 4 and the developing roller 51 respectively at a predetermined timing. Similarly, a predetermined voltage or current is sequentially applied to the optical writing unit 40 and a light source such as a static elimination lamp at a predetermined timing. In synchronism with this, the photosensitive member 3 is rotationally driven in the direction of the arrow in FIG. 4 by a photosensitive member driving motor as driving means.

When the photoreceptor 3 rotates in the direction of the arrow in FIG. 4, first, the surface of the photoreceptor 3 is uniformly charged to a predetermined potential by the charging roller 4. Then, the laser beam L corresponding to the image information is irradiated onto the photoconductor 3 from the optical writing unit 40, and the portion irradiated with the laser light L on the surface of the photoconductor 3 is neutralized to form an electrostatic latent image. .
The surface of the photoreceptor 3 on which the electrostatic latent image is formed is rubbed by a developer magnetic brush formed on the developing roller 51 at a portion facing the developing device 5. At this time, the negatively charged toner on the developing roller 51 is moved to the electrostatic latent image side by a predetermined developing bias applied to the developing roller 51 to be converted into a toner image (development). In each image forming unit 1, the same image forming process is executed, and a toner image of each color is formed on the surface of each photoconductor 3Y, 3C, 3M, 3K of each image forming unit 1Y, 1C, 1M, 1K. .
As described above, in the image forming apparatus 500, the electrostatic latent image formed on the photoreceptor 3 is reversely developed by the developing device 5 with the negatively charged toner. In this embodiment, an example using a non-contact charging roller system of N / P (negative positive: toner adheres to a place where the potential is low) has been described, but the present invention is not limited to this.

The toner images of the respective colors formed on the surfaces of the photoreceptors 3Y, 3C, 3M, and 3K are sequentially primary-transferred so as to overlap on the surface of the intermediate transfer belt 14. As a result, a four-color toner image is formed on the intermediate transfer belt 14.
The four-color toner image formed on the intermediate transfer belt 14 is fed from the first paper feed cassette 151 or the second paper feed cassette 152, passed between the rollers of the registration roller pair 55, and fed to the secondary transfer nip. To the recording medium P to be transferred. At this time, the recording medium P is temporarily stopped while being sandwiched between the registration roller pair 55, and is supplied to the secondary transfer nip in synchronization with the leading edge of the image on the intermediate transfer belt 14. The recording medium P onto which the toner image has been transferred is separated from the intermediate transfer belt 14 and conveyed to the fixing unit 80. Then, the recording medium P to which the toner image is transferred passes through the fixing unit 80, whereby the toner image is fixed on the recording medium P by the action of heat and pressure, and the recording medium P on which the toner image is fixed is an image. It is discharged out of the forming apparatus 500 and stacked on the stack unit 88.

On the other hand, the transfer residual toner on the surface of the intermediate transfer belt 14 that has transferred the toner image onto the recording medium P at the secondary transfer nip is removed by the belt cleaning unit 162.
Further, the surface of the photoreceptor 3 on which the toner images of the respective colors are transferred to the intermediate transfer belt 14 at the primary transfer nip, the residual toner after the transfer is removed by the cleaning device 6, and the lubricant is applied by the lubricant applying device 10. Thereafter, the charge is removed by a charge removal lamp.

  As shown in FIG. 5, the image forming unit 1 of the image forming apparatus 500 includes a photoconductor 3 and a charging roller 4, a developing device 5, a cleaning device 6, a lubricant applying device 10, and the like as process means. It has been. The image forming unit 1 can be integrally attached to and detached from the main body of the image forming apparatus 500 as a process cartridge. In the image forming apparatus 500, the image forming unit 1 integrally replaces the photosensitive member 3 as a process cartridge and the process means, but the photosensitive member 3, the charging roller 4, the developing device 5, and the cleaning device 6. Alternatively, the lubricant application device 10 may be replaced with a new one in units.

(Process cartridge)
The process cartridge of the present invention comprises at least an image carrier and cleaning means for removing toner remaining on the image carrier, and further comprises other means as necessary.
As the cleaning means, the cleaning blade of the present invention is used.
The process cartridge includes an image carrier and the cleaning blade of the present invention, and further includes at least one of a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit. An apparatus (part) that is detachable from the image forming apparatus.

  Examples of the present invention will be described below, but the present invention is not limited to these examples. In addition, "part" used in an Example represents a "mass part".

<JIS-A hardness of substrate>
The JIS-A hardness of the substrate was measured according to JIS K6253 using a micro rubber hardness meter MD-1 manufactured by Kobunshi Keiki Co., Ltd. (23 ° C.).

<Rebound resilience of substrate>
The base material has a rebound resilience of 23 ° C., No. The measurement was performed according to JIS K6255 using a 221 regilynester. The sample used was a stack of 2 mm thick sheets so that the thickness was 4 mm or more.

<Average circularity of toner>
The average circularity of the toner was measured by a flow type particle image analyzer (FPIA-2000, manufactured by Sysmex Corporation). Specifically, 0.1 mL to 0.5 mL of a surfactant (alkylbenzene sulfonate) is added as a dispersant to 100 mL to 150 mL of water from which impure solids have been removed in advance, and a measurement sample (toner) About 0.1 to 0.5 g was added. Thereafter, the suspension in which the toner is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for 1 to 3 minutes so that the concentration of the dispersion becomes 3,000 / μL to 10,000 / μL. Was set in the analyzer, and the shape and distribution of the toner were measured. Based on this measurement result, when the outer peripheral length of the actual toner projection shape shown in FIG. 6A is C1, the projection area is S, and the outer circumference of the perfect circle shown in FIG. C2 / C1 was determined, and the average value was defined as the average circularity.

<Volume average particle diameter of toner>
The volume average particle diameter of the toner was determined by a Coulter counter method. Specifically, the toner number distribution and volume distribution data measured by a Coulter Multisizer 2e type (manufactured by Beckman Coulter) were sent to a personal computer for analysis via an interface (manufactured by Nikkaki Co., Ltd.). . More specifically, a 1% by mass NaCl aqueous solution using primary sodium chloride was prepared as an electrolytic solution. Then, 0.1 mL to 5 mL of a surfactant (alkyl benzene sulfonate) was added as a dispersant to 100 mL to 150 mL of the electrolytic aqueous solution. Further, 2 mg to 20 mg of toner as a test sample was added thereto, and dispersed with an ultrasonic disperser for 1 minute to 3 minutes. Then, 100 mL to 200 mL of the electrolytic aqueous solution was put into another beaker, and the solution after the dispersion treatment was added therein to a predetermined concentration, and applied to the Coulter Multisizer 2e type.
The aperture is 100 μm, and the particle size of 50,000 toner particles is measured. As a channel, it is 2.00 micrometers or more and less than 2.52 micrometers; 2.52 micrometers or more and less than 3.17 micrometers; 3.17 micrometers or more and less than 4.00 micrometers; 4.00 micrometers or more and less than 5.04 micrometers; 5.04 micrometers or more and less than 6.35 micrometers; .35 μm or more and less than 8.00 μm; 8.00 μm or more and less than 10.08 μm; 10.08 μm or more and less than 12.70 μm; 12.70 μm or more and less than 16.00 μm; 16.00 μm or more and less than 20.20 μm; Less than 40 μm; 25.40 μm or more and less than 32.00 μm; 13 channels of 32.00 μm or more and less than 40.30 μm were used, and toner having a particle diameter of 2.00 μm or more and 32.0 μm or less was used.
The volume average particle diameter was calculated based on the relational expression “volume average particle diameter = ΣXfV / ΣfV”. However, “X” is the representative diameter in each channel, “V” is the equivalent volume in the representative diameter of each channel, and “f” is the number of particles in each channel.

<Measurement of glass transition temperature of toner>
The glass transition temperature of the toner was measured by DSC (Differential Scanning Calorimeter, manufactured by Seiko Instruments Inc.) at a heating rate of 10 ° C./min.

(Production Example 1)
-Substrate No. Production of 1-3
A urethane rubber having the average thickness of 1.8 mm and the physical properties described in Table 1 was prepared. 1-3.
These substrate Nos. The physical properties 1 to 3 are shown in Table 1 below.

(Production Example 2)
-Preparation of UV curable composition-
The ultraviolet curable composition material prescription No. having the composition shown in Table 2 below. 1-6 were prepared by a conventional method.

  The ultraviolet curable composition material formulation No. Details of the materials used in 1 to 6 are as shown in Table 3 and Table 4 below.

(Examples 1-8 and Comparative Examples 1-6)
<Production of cleaning blades 1 to 14>
In the combinations shown in Table 5, a strip-shaped substrate No. 1 having a thickness of 1.8 mm. 1-3 mm from the front end surface of No. 1 to 3 as an impregnated ultraviolet curable composition. After immersion for 1 to 3 in Table 5, the residue of the ultraviolet curable composition adhering to the surface of the elastic member was washed with cyclohexane and air-dried for 2 minutes.
Next, with respect to the contact portion of the obtained impregnated elastic body member, the ultraviolet curable composition material prescription No. 5 shown in Table 5 as a surface layer forming ultraviolet curable composition was used. Any one of 4 to 6 was spray coated to form a surface layer. Specifically, as shown in FIG. 9, each impregnated elastic body member is fixed, the height of the spray gun is fixed at a position 2 mm from the tip ridge line portion, and, for example, 6 mm / s in the spray operation direction. The surface including the tip ridge line portion of the elastic body member was applied at a spray gun moving speed, and overcoated. The blade lower surface of the elastic member was coated so that the surface layer having the average thickness shown in Table 5 was formed at a width of about 5 mm from the tip edge line portion by changing the overcoating conditions and the moving speed of the spray gun. At this time, the coating center position of the spray gun was set at a position 2 mm from the tip ridge line portion, so that a film was formed so as to become thicker away from the tip ridge line portion to a position 2 mm away. After forming the surface layer on the lower surface, the surface layer was also formed on the tip surface of the elastic member under the same conditions as the lower surface. Thereafter, finger touch drying was performed for 3 minutes, and ultraviolet exposure was performed using a high-pressure mercury lamp so that the integrated light amount was 6000 mJ / cm ² . In this way, each elastic blade having a surface layer formed on the contact portion was produced.

Next, each elastic blade having a surface layer formed on the contact portion was fixed to a sheet metal holder with an adhesive so that it could be mounted on a color composite machine (image MPC4500, manufactured by Ricoh Co., Ltd.). The cleaning blades 1 to 14 were produced as described above.
About the produced said elastic body blade and the cleaning blades 1-14, various characteristics were measured as follows. The results are shown in Table 6.

<Ling angle of tip ridge>
The elastic blade was cut into a ring, the cross-section faced upward, and observed with a digital microscope VHX-2000 (manufactured by Keyence Corporation), and the ridge angle of the tip ridge line portion was measured.
As a method of cutting the elastic blade, the razor was used to cut perpendicularly to the contact portion so that the thickness was 3 mm. At that time, if a vertical slicer is used, the cross section can be cut more neatly.
The position in the longitudinal direction for cutting the elastic blade was a position excluding the 2 cm portions at both ends.
The angle was measured using three points at a distance of about 100 μm (blade lower surface, tip surface) from the tip ridge line part and the tip ridge line part.

<Martens hardness>
The Martens hardness (HM) of the surface at a distance of 20 μm from the tip ridge line portion is obtained by pushing a Vickers indenter with a force of 1.0 mN for 10 seconds and holding for 5 seconds using a micro hardness tester HM-2000 manufactured by Fischer Instruments. Then, the measurement was performed with a force of 1.0 mN for 10 seconds.

<Average thickness of surface layer>
The elastic blade was cut into a ring and the cross section was faced up, and observed with a digital microscope VHX-2000 (manufactured by Keyence Corporation). The measurement location measured the thickness of the surface layer in the 20 micrometer position and 100 micrometer position in the thickness direction from the contact part (front-end ridgeline part) of the contact side long-axis surface.
As a method of cutting the elastic blade, the razor was used to cut perpendicularly to the contact portion so that the thickness was 3 mm. At that time, if a vertical slicer is used, the cross section can be cut more neatly.
The position in the longitudinal direction for cutting the elastic blade was a position excluding the 2 cm portions at both ends.

(Production Example 4)
<Production of toner>
A toner prepared by the following polymerization method (Japanese Patent Application Laid-Open No. 2014-92633) was used. The physical properties of the produced toner are as follows.
Toner base particles: average circularity 0.98, volume average particle size 4.9 μm
External additive: 1.5 parts by mass of small particle size silica (manufactured by Clariant, H2000)
0.5 parts by mass of small particle size titanium oxide (manufactured by Teika, MT-150AI)
1.0 part by mass of large particle silica (manufactured by Denki Kagaku Kogyo Co., UFP-30H)
-Glass transition temperature of toner: 50 ° C

<Assembly of image forming apparatus>
The prepared cleaning blades are attached to a color multifunction machine (image MPC4500, manufactured by Ricoh Co., Ltd.) (the printer unit has the same configuration as the printer 500 shown in FIG. 4), and the images of Examples 1 to 8 and Comparative Examples 1 to 6 The forming device was assembled.
The cleaning blade was attached to the image forming apparatus so that the linear pressure was 19.8 N / m and the cleaning angle was 79 °.
The image forming apparatus includes a lubricant application device on the surface of the photoconductor, and the coefficient of static friction on the surface of the photoconductor is maintained at 0.2 or less during non-image formation by applying the lubricant.
The static friction coefficient on the surface of the photoreceptor was measured by the Euler belt method described in paragraph No. [0046] of JP-A-9-166919.

<Image forming conditions>
Using each of the image forming apparatuses described above, a laboratory environment: 65% RH at 21 ° C., a sheet passing condition: an image area ratio of 5%, 20,000 sheets (A4 size landscape) are output at 3 prints / job, and the following Various characteristics were evaluated as described above. The results are shown in Table 6.

<Cleanability>
As an evaluation image, a vertical band pattern (with respect to the paper traveling direction) 43 mm width, 3 charts, 20 A4 size sides, output 20 images, visually observe the obtained image, depending on the presence or absence of image abnormality due to poor cleaning, The cleaning property was evaluated.
[Evaluation criteria]
○: Toner missing due to poor cleaning cannot be visually confirmed on both the printing paper and the photoreceptor. Δ: Toner missing due to poor cleaning does not exist on the printing paper, but can be visually confirmed on the photoreceptor. ×: Cleaning Defectively removed toner can be visually confirmed on both the printing paper and the photoreceptor.

<Noise>
○: No abnormal noise occurs ×: An abnormal noise occurs

In Examples 1 to 8, the contact portion is impregnated with an ultraviolet curable composition, contains the cured product, and the surface layer is formed so as to be separated from the tip ridge line portion to a position of 100 μm, and the tip ridge line portion is formed. Since the dip angle was 90 degrees or more, turning-up of the abutting portion was suppressed, followability was good, good cleaning properties could be maintained, and no abnormal noise was generated.
In Comparative Example 1, since the ultraviolet curable composition was not impregnated and the surface layer was not formed, the contact portion was turned up and the amount of wear increased, resulting in poor cleaning and abnormal noise.
In Comparative Examples 2, 4, 5, and 6, since the angle of the edge of the leading edge is small, the leading edge is turned and the amount of wear increases due to long-term use, resulting in poor cleaning.
In Comparative Example 3, since the ultraviolet curable composition was not impregnated, the friction coefficient at the tip ridge line portion was increased and abnormal noise was generated.

DESCRIPTION OF SYMBOLS 1 Image forming unit 3 Photoconductor 4 Charging roller 5 Developing device 6 Cleaning device 7 Primary transfer roller 10 Lubricant coating device 14 Intermediate transfer belt 40 Optical writing unit 41 Polygon mirror 51 Developing roller 52 Supply screw 53 Stirring screw 54 Doctor 55 Resist Roller pair 60 Transfer unit 62 Cleaning blade 62a Blade tip surface 62b Cleaning blade bottom surface 62c Tip edge line 63 First bracket 64 Second bracket 66 Secondary transfer backup roller 67 Drive roller 68 Auxiliary roller 69 Tension roller 70 Secondary transfer roller 80 Fixing Unit 81 Pressurizing and heating roller 82 Fixing belt unit 84 Fixing belt 83 Heating roller 85 Tension roller 86 Driving roller 87 Discharge roller pair 88 Stack unit 100 Toner cartridge 101 Fur brush 103 Solid lubricant 103a Lubricant pressure spring 103b Bracket 123 Image carrier 151 First paper feed cassette 151a First paper feed roller 152 Second paper feed cassette 152a Second paper feed roller 153 Paper feed path 154 Conveying roller pair 162 Belt cleaning unit 500 Image forming apparatus 621 Support member 622 Elastic body blade 623 Surface layer

Japanese Patent No. 3602898 JP 2004-233818 A JP 2010-152295 A

Claims (10)

A cleaning blade that has an elastic blade and removes residue adhering to the surface of the member to be cleaned from the surface of the member to be cleaned that is in contact with the tip ridge line portion of the elastic blade, wherein the elastic blade has the following a, A cleaning blade comprising the requirements of b and c.
a. The elastic blade is composed of an elastic member and a surface layer formed on the surface including the tip ridge line portion of the elastic member.
b. The elastic member includes a base material and a cured product of the first ultraviolet curable composition contained in a region in the thickness direction from the surface including the tip ridge line portion of the elastic member.
c. The surface layer is made of a cured product of the second ultraviolet curable composition, and becomes thicker away from the tip ridge line portion of the elastic blade to a position of 100 μm, and the ridge angle of the tip ridge line portion is 90 degrees or more. is there.   The thickness of the surface layer of the surface layer made of the cured product of the second ultraviolet curable composition is 0.1 μm or more and 3 μm or less at a position of 20 μm from the tip ridge line portion, 2. The cleaning blade according to claim 1, wherein a thickness at a distance of 100 μm is 1.1 to 6 times a thickness at a position of 20 μm. 3. The cleaning blade according to claim 1, wherein the elastic blade has a Martens hardness of 1 to 15 N / m ² on a surface at a distance of 20 μm from a tip ridge line portion on a blade tip surface.   The cleaning blade according to any one of claims 1 to 3, wherein the first ultraviolet curable composition and the second ultraviolet curable composition contain a (meth) acrylate compound.   5. The cleaning blade according to claim 1, wherein the first ultraviolet curable composition contains a (meth) acrylate compound having an alicyclic structure having 6 or more carbon atoms in the molecule. .   6. The cleaning blade according to claim 1, wherein the second ultraviolet curable composition contains a (meth) acrylate compound having a pentaerythritol structure in the molecule.   The (meth) acrylate compound having a pentaerythritol structure in the molecule is a (meth) acrylate compound having a pentaerythritol structure having a functional group equivalent molecular weight of 350 or less and a functional group number of 3 to 6. The cleaning blade described.   The cleaning blade according to any one of claims 1 to 7, wherein the base material is a urethane rubber having a rebound elastic modulus at 23 ° C of 35% or less and a JIS-A hardness of 60 degrees or more. . An image carrier, a charging unit for charging the surface of the image carrier, an exposure unit for exposing the charged image carrier to form an electrostatic latent image, and developing the electrostatic latent image using toner Developing means for forming a visible image, transfer means for transferring the visible image to a recording medium, fixing means for fixing the transferred image transferred to the recording medium, and remaining on the image carrier. An image forming apparatus having cleaning means for removing toner,
An image forming apparatus, wherein the cleaning unit includes the cleaning blade according to claim 1. A process cartridge having at least an image carrier and cleaning means for removing toner remaining on the image carrier;
9. A process cartridge, wherein the cleaning means has the cleaning blade according to claim 1.