JP2018091902A - Blade for electrophotographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blade for an electrophotographic apparatus capable of improving durability by reducing friction and by lowering a residual charge on the surface.SOLUTION: There is provided a blade 10 for an electrophotographic apparatus having an impregnation part 16 formed by impregnating and curing a curable composition containing an ion conductive agent, to an abutting part 12a abutting on an opposite member of a substrate containing urethane rubber. As the ion conductive agent in the impregnation part 16, a potassium salt or an ammonium salt is preferable. The substrate may further contain the ion conductive agent.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a blade for electrophotographic equipment, and more particularly to a blade for electrophotographic equipment suitable as a cleaning blade, a layer forming blade, or the like in an electrophotographic equipment.

  In electrophotographic equipment such as copying machines, printers, and facsimiles that employ an electrophotographic system, cleaning is used to remove residual toner remaining on the surface of the mating member by sliding contact with the mating member such as a photosensitive drum or transfer belt. Blades such as a blade and a layer forming blade used for forming a uniform toner layer on the outer peripheral surface of the developing roll are provided.

  For the base material of the blade, urethane rubber having excellent mechanical properties such as wear resistance may be used. However, a blade using urethane rubber has a large friction with respect to a mating member to be abutted, and turning or chipping may occur around the abutting portion. Thereby, durability may be insufficient. For this reason, for example, Patent Document 1 proposes to impregnate an abutting portion with a counterpart member with an isocyanate compound and react with urethane rubber to form a cured layer.

JP 2004-280086 A

  In the method described in Patent Document 1, although the contact portion with the counterpart member can be reduced in friction, the surface resistance of the contact portion is increased by the impregnation treatment, and charged toner or toner external additive, Paper dust and the like easily adhere to and accumulate on the surface, and chipping and abrasion are likely to occur at the contact portion. Thereby, there exists a possibility that durability may fall.

  The problem to be solved by the present invention is to provide a blade for an electrophotographic apparatus having improved durability by reducing the residual charge on the surface while reducing friction.

  In order to solve the above problems, the blade for an electrophotographic apparatus according to the present invention is obtained by impregnating a curable composition containing an ionic conductive agent into a contact portion that comes into contact with a mating member of a base material containing urethane rubber and curing it. It has a gist of having an impregnation part.

  The ionic conductive agent in the impregnated portion is preferably a potassium salt or a quaternary ammonium salt. The ionic conductive agent in the impregnated portion preferably has at least one group selected from a hydroxyl group, a (meth) acryloyl group, and an alkenyl group in the anion component or cation component. The ionic conductive agent in the impregnated portion is preferably an ionic liquid. It is preferable that the base material further contains an ionic conductive agent. It is preferable to have an impregnation part formed by impregnating and curing the curable composition containing an ionic conductive agent on the entire surface of the base material. It is preferable to further have a layer formed by impregnating and curing a curable composition containing an ionic conductive agent on the impregnated portion of the base material. The curable composition preferably contains (meth) acrylate.

  According to the blade for electrophotographic equipment according to the present invention, the impregnated portion formed by impregnating and curing the curable composition containing the ionic conductive agent on the abutting portion contacting the mating member of the base material containing urethane rubber. Therefore, the friction of the contact portion can be reduced and the residual charge on the surface of the contact portion can be reduced. Thereby, durability can be improved.

  When the ionic conductive agent in the impregnated portion is a potassium salt or a quaternary ammonium salt, the influence of secondary curing of the urethane rubber contained in the base material can be reduced, and the physical properties of the base material can be easily secured. If the ionic conductive agent in the impregnated portion has at least one group of a hydroxyl group, a (meth) acryloyl group, and an alkenyl group in the anion component or cation component, the ionic conductive agent can be immobilized in the impregnated portion. Transition to the inside of the substrate can be suppressed. When the ionic conductive agent in the impregnation part is an ionic liquid, the dispersibility in the impregnation part is more excellent. When the base material further contains an ionic conductive agent, the residual charge on the surface of the contact portion can be further reduced, thereby improving the charge removal effect and improving the durability. If the entire surface of the substrate has an impregnated portion obtained by impregnating and curing a curable composition containing an ionic conductive agent, the residual charge on the surface of the abutting portion can be further reduced, thereby improving the static elimination effect. And durability is improved. It is more excellent in wear resistance when it further has a layer formed by impregnating a curable composition containing an ionic conductive agent on the impregnated portion of the base material and curing it. When the said curable composition contains (meth) acrylate, it will be easy to adjust to the liquid which is easy to impregnate a base material.

It is a schematic diagram of the blade for electrophotographic equipment according to an embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a state where an electrophotographic blade according to an embodiment of the present invention slides on an outer peripheral surface of a rotating photosensitive drum. It is sectional drawing which showed an example of the range which performs an impregnation process. It is sectional drawing which showed an example of the braid | blade for electrophotographic apparatuses which has a hardened layer further on an impregnation part. It is the schematic diagram which showed the measuring method of the residual potential.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing a blade for electrophotographic equipment (hereinafter sometimes referred to as this blade) according to an embodiment of the present invention, and FIG. 2 is a diagram showing the blade sliding on the outer peripheral surface of the photosensitive drum. It is the schematic diagram which showed a mode that it does. FIG. 3 is a cross-sectional view showing an example of a range in which the impregnation treatment is performed.

  As shown in FIG. 1, an electrophotographic apparatus blade (present blade) 10 according to an embodiment of the present invention includes a blade portion 12. A holding portion 14 that holds the blade portion 12 is attached to the blade portion 12. The blade part 12 has a flat plate shape. The holding part 14 is made of a metal fitting having an L-shaped cross section. The blade portion 12 is in contact (sliding contact) with the mating member at the tip portion (ridge line portion) 12a. This tip portion (ridge line portion) becomes the contact portion 12a.

  The blade 10 is suitable as a cleaning blade or a layer forming blade in an electrophotographic apparatus. Examples of the mating member of the cleaning blade include a photosensitive drum and a transfer belt. Examples of the mating member of the layer forming blade include a developing roll. Both blades are in contact (sliding contact) with the mating member. The cleaning blade contacts (sliding) the mating member to remove residual toner. For example, as shown in FIG. 2, the blade portion 12 contacts the outer peripheral surface 20 a of the photosensitive drum 20 at the tip end (ridge line portion) 12 a and slides on the outer peripheral surface 20 a of the rotating photosensitive drum 20. Thereby, the toner remaining on the outer peripheral surface 20a of the photosensitive drum 20 is removed. The front end portion 12a serves as a contact portion 12a that contacts the photosensitive drum 20 that is a member to be cleaned. The layer forming blade abuts (slidably contacts) the surface of the developing roll, which is a counterpart member, and forms a uniform toner layer on the outer peripheral surface of the developing roll.

  The base material of the blade part 12 contains urethane rubber. The base material of the blade part 12 is comprised with the hardened | cured material of a urethane composition. The base material of the blade part 12 is a molded body formed by the urethane composition before the impregnation treatment. As shown in FIG. 3, in the blade part 12, the contact part 12a of the base material has an impregnated part 16 formed by impregnating and curing a curable composition containing an ionic conductive agent. FIG. 3A shows an example of a configuration in which the impregnation portion 16 is provided only on the tip surface of the base material including the contact portion 12a, and FIG. 3B shows the impregnation portion on the entire surface of the base material. An example of a configuration having 16 is shown. The entire surface of the substrate is the entire surface of the blade portion 12 except for the surface of the blade portion 12 in contact with the holding portion 14.

  The ion conductive agent of the impregnation part 16 is not specifically limited. Examples of the ionic conductive agent include imidazolium salts, pyridinium salts, ammonium salts, phosphonium salts, sulfonium salts, borates, metal salts, and surfactants. These may be used alone or in combination of two or more as the ionic conductive agent of the impregnation portion 16. Of these, ammonium salts and metal salts are particularly preferable from the viewpoint of hardly affecting the urethane curability of the substrate. Examples of the metal of the metal salt include lithium, sodium, and potassium. Of these metals, potassium is particularly preferable from the viewpoints of low hygroscopicity, high solubility in water and organic solvents, and excellent ionic conductivity.

Examples of the cation component of the ionic conductive agent include imidazolium ion, pyridinium ion, ammonium ion, phosphonium ion, sulfonium ion, and metal ion. As an anion component of the ion conductive agent, AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , NO ₃ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , CH ₃ COO ⁻ , CF ₃ COO ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ C ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , F (HF) _n ⁻ , CF ₃ (CF ₂ ) ₃ SO ₃ ⁻ , (CF ₃ CF ₂ SO ₂ ) ₂ N ⁻ , (CF ₃ CF ₂ CF ₂ CF ₂ SO ₂ ) ₂ N ⁻ , CF ₃ CF ₂ CF ₂ COO ⁻ , ClO ₄ ^{— and the} like. Among these anion components, those containing an electron-withdrawing fluorine atom cause delocalization of negative charges in the anion, which reduces electrostatic interaction with the cation and facilitates ion dissociation. It is more preferable from the viewpoint of becoming. In particular, (CF ₃ SO ₂ ) ₂ N ⁻ , (CF ₃ CF ₂ SO ₂ ) ₂ N ⁻ , and (CF ₃ CF ₂ CF ₂ CF ₂ SO ₂ ) ₂ N ⁻ are preferable.

  The ionic conductive agent of the impregnation part 16 may be either a room temperature solid or a room temperature liquid (room temperature molten salt, ionic liquid). A solid at room temperature is preferable from the viewpoint of being difficult to bleed at the impregnating part 16 and being easy to suppress the transition from the impregnating part 16 to the substrate. Examples of the solid at normal temperature include metal salts and ammonium salts. An ionic liquid is preferable from the viewpoints of dispersibility and uniformity in the impregnation portion 16. Examples of the ionic liquid include nitrogen-based cation derivatives. Examples of nitrogen-based cation derivatives include imidazolium salts, pyridinium salts, ammonium salts, and the like.

  The ionic conductive agent of the impregnation part 16 may have a reactive group capable of immobilizing the ionic conductive agent in the impregnation part 16 on the anion component or the cation component. Thereby, the ionic conductive agent which is relatively easy to bleed and migrate can be fixed in the impregnating portion 16 to suppress bleed and migration. Examples of such a reactive group include a hydroxyl group, a (meth) acryloyl group, and an alkenyl group. These may have 1 type in the anion component or the cation component as a reactive group, and may have 2 or more types. Examples of the alkenyl group include a vinyl group, an allyl group, a butenyl group, a pentenyl group, and a hexenyl group.

  As shown in FIG. 3A, the impregnation portion 16 may have only the tip surface of the base material including the contact portion 12a, or the surface of the base material as shown in FIG. 3B. You may have in the whole. What has the impregnation part 16 in the whole surface of a base material can lower the residual potential of the contact part 12a more. In particular, the effect is high when the substrate is non-conductive.

  The curable compound of the curable composition is not particularly limited as long as it is cured on a substrate containing urethane rubber. Examples of the curable compound include (meth) acrylate and isocyanate. As isocyanate, the isocyanate etc. which are illustrated in the urethane composition which comprises a base material are mentioned. These may be used individually by 1 type as a sclerosing | hardenable compound of a curable composition, and may be used together 2 or more types. Among these, (meth) acrylate is particularly preferable from the viewpoints of being photocurable, having excellent permeability to a substrate containing urethane rubber, and having a viscosity with excellent permeability without using a solvent. .

  (Meth) acrylate is a compound selected from acrylate (acrylic ester) and methacrylate (methacrylic ester). The (meth) acrylate may be a monofunctional (meth) acrylate having one (meth) acryloyl group or a polyfunctional (meth) acrylate having two or more (meth) acryloyl groups. Of these, polyfunctional (meth) acrylates are preferable from the viewpoint of curability and the like. In addition, polyfunctional acrylates and monofunctional (meth) acrylates are preferable from the viewpoint of having a viscosity excellent in permeability without using a solvent.

  The (meth) acrylate may have any one of an aromatic ring, an alicyclic ring, an aliphatic hydrocarbon chain (non-cyclic), or a heterocyclic ring in the molecule, or may have two or more types. May be.

  Examples of the monofunctional (meth) acrylate compound having an aromatic ring in the molecule include benzyl (meth) acrylate. Monofunctional (meth) acrylate compounds having an alicyclic ring in the molecule include tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and dicyclopentanyl. (Meth) acrylate, dicyclopentenyl (meth) acrylate, cyclohexyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate and the like can be mentioned. Monofunctional (meth) acrylate compounds having an aliphatic hydrocarbon chain (acyclic) in the molecule include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, octyl ( (Meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) Examples include acrylate and isostearyl (meth) acrylate.

  Examples of the monofunctional (meth) acrylate compound having a hydroxyl group in the molecule include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the like. Examples of the monofunctional (meth) acrylate compound having an ether bond in the molecule include methoxyethylene glycol (meth) acrylate and ethoxyethyl (meth) acrylate. Monofunctional (meth) acrylate compounds having a polyether structure in the molecule include polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, Examples include polyoxyethylene nonylphenyl ether acrylate.

  Examples of the bifunctional (meth) acrylate compound include butanediol di (meth) acrylate, hexanediol di (meth) acrylate, nonanediol di (meth) acrylate, decanediol di (meth) acrylate, 2-butyl-2-ethyl- 1,3-propanediol di (meth) acrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate , Tetraethylene glycol di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, 1,4-butanepolyol di (meth) acrylate, 1,6-hexanepolyol di (meth) acrylate Neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 9,9-bis [4- (2-acryloyloxy ethoxy) phenyl] fluorene can be cited.

  The trifunctional or higher polyfunctional (meth) acrylate compounds include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane EO adduct tri (meth) acrylate, pentaerythritol tetra (meth) acrylate. , Tetrafurfuryl alcohol oligo (meth) acrylate, ethyl carbitol oligo (meth) acrylate, 1,4-butanediol oligo (meth) acrylate, 1,6-hexanediol oligo (meth) acrylate, trimethylolpropane oligo (meta ) Acrylate, pentaerythritol oligo (meth) acrylate, and the like.

  (Meth) acrylate can be cured using a radical generator (radical initiator). The radical generator is not particularly limited as long as it generates radicals. Any of those that generate radicals by light (photo radical generator) and those that generate radicals by heat (thermal radical generator) may be used. As the radical generator, only one of a photo radical generator and a thermal radical generator may be used, or a combination of both a photo radical generator and a thermal radical generator may be used. Among these, a photo radical generator is more preferable from the viewpoint of high curing speed.

  Examples of the photo radical generator include azo compounds, benzoins, benzophenones, alkylphenones, acylphosphine oxides, oxime esters, anthraquinones, thioxanthones, and the like. Examples of the alkylphenone series include benzyldimethyl ketal, α-hydroxyalkylphenone, α-aminoalkylphenone and the like.

  More specifically, examples of the photo radical generator include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, benzaldehyde, fluorene, anthraquinone, ethyl anthraquinone, triphenylamine, carbazole, 3- Methyl acetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy 2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxyl , 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, azobisisobutyronitrile (AIBN), and the like.

  Examples of the thermal radical generator include azo compounds and organic peroxides. Examples of the azo compound include azobisisobutyronitrile (AIBN). Examples of organic peroxides include benzoyl peroxide (BPO), lauroyl peroxide, acetyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, di-tert-butyl peroxide, tert-butyl perbenzoate, and cyclohexanone peroxide. Can be mentioned.

  Content of a radical generator is not specifically limited, What is necessary is just in the range of 0.1-10 mass parts with respect to 100 mass parts of (meth) acrylate.

  The curable composition may contain a solvent from the viewpoint of liquefaction and viscosity adjustment. Examples of the solvent include methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), toluene, methanol and the like. By using a solvent, solid content concentration can be adjusted and the impregnation depth (impregnation amount) can be adjusted. Thereby, a friction coefficient can be set to a desired value. The solid content concentration is the concentration (mass%) of the total components other than the solvent. The solid content concentration of the curable composition is preferably in the range of 0.1 to 60% by mass from the viewpoint of the coefficient of friction depending on the amount of impregnation. More preferably, it exists in the range of 1.0-50 mass%, More preferably, it exists in the range of 3.0-30 mass%.

  Further, the curable composition may contain an additive as long as it does not inhibit the present invention. In the curable composition, an electronic conductive agent such as carbon may be included as long as it does not significantly affect the permeability of the curable composition to the substrate, but does not include an electronic conductive agent such as carbon. It is more preferable.

  The content of the ionic conductive agent in the curable composition is not particularly limited, but from the standpoint that the residual potential of the contact portion 12a can be kept lower, the total amount excluding the solvent is 100% by mass. It is preferable that it is 0.01 mass% or more. More preferably, it is 0.1 mass% or more. Further, from the viewpoint of being difficult to bleed at the impregnated part 16 and being easy to suppress the transition from the impregnated part 16 to the base material, it is preferably 20% by mass or less with respect to 100% by mass of the total amount excluding the solvent. More preferably, it is 10 mass% or less.

The urethane composition constituting the base of the blade part 12 contains a polyol and a polyisocyanate. The urethane composition may contain a conductive agent (ionic conductive agent or electronic conductive agent) from the viewpoint of conductivity, or may not contain a conductive agent. When a conductive agent is included, the urethane composition may include only an ionic conductive agent as a conductive agent, or may include both an ionic conductive agent and an electronic conductive agent. When the conductive agent is included, it is preferable that only the ionic conductive agent is included as the conductive agent from the viewpoint of suppressing the increase in the hardness of the urethane rubber and easily suppressing the wear and chipping of the contact portion 12a of the base material. And the base material of the blade part 12 may be electrically conductive or non-conductive. When the base material of the blade portion 12 is conductive, the residual potential of the contact portion 12a can be further reduced as compared with a non-conductive material. Moreover, it is excellent in the effect which suppresses abrasion and a chip | tip of the contact part 12a. Conductivity means that the volume resistivity is 1.0 × 10 ¹² Ω · cm or less. The volume resistivity is a value measured under an LL environment (10 ° C. × 10% RH). The conductivity is obtained when the urethane composition constituting the base material of the blade portion 12 contains a conductive agent. As the electron conductive agent, carbon black, _{graphite, c-TiO 2, c-} ZnO, c-SnO 2 (c- means conductive.) And the like. Examples of the ionic conductive agent include those exemplified as the ionic conductive agent of the impregnated portion 16.

  The polyol is not particularly limited, and examples thereof include polyester polyol, polyether polyol, polycarbonate polyol, and acrylic polyol. Of these, polyester polyol is more preferable.

  The polyester polyol is preferably obtained from a polybasic organic acid and a polyol and having a hydroxyl group as a terminal group. By using a polyester polyol as a polyol for forming polyurethane, it is possible to ensure wear resistance necessary for durability. Polybasic organic acids are not particularly limited, but are saturated fatty acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, isosebacic acid, maleic acid, Unsaturated fatty acids such as fumaric acid, dicarboxylic acids such as aromatic acids such as phthalic acid, isophthalic acid and terephthalic acid, acid anhydrides such as maleic anhydride and phthalic anhydride, dialkyl esters such as dimethyl terephthalate, unsaturated fatty acids And dimer acid obtained by dimerization. The polyol used together with the polybasic organic acid is not particularly limited. For example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, 1,6-hexylene. Examples include diols such as glycol, triols such as trimethylolethane, trimethylolpropane, hexanetriol, and glycerin, and hexaols such as sorbitol.

  Specific examples of the polyester polyol include polyethylene adipate (PEA), polybutylene adipate (PBA), polyhexylene adipate (PHA), and a copolymer of ethylene adipate and butylene adipate (PEA / BA). Can be cited as These may be used alone or in combination of two or more. Among these, polybutylene adipate (PBA) is particularly preferable from the viewpoint of improving wear resistance and durability.

  The polyester polyol preferably has a number average molecular weight of 1,000 to 3,000. By adjusting the tan δ peak temperature and the tan δ peak value, which are indices of the viscoelasticity of polyurethane, it is easy to obtain physical properties and improve moldability. From this viewpoint, the number average molecular weight is more preferably in the range of 1500 to 2500.

  Examples of the polyether polyol include polypropylene glycol (PPG), polytetramethylene glycol (PTMG), these ethylene oxide-modified type polyols, and polyethylene glycol (PEG). The average molecular weight (Mn) of the polyether polyol is preferably in the range of 1000 to 10,000.

  Examples of polyisocyanates include 4,4′-diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), trimethylhexamethylene diisocyanate (TMHDI), and tolylene diisocyanate (TDI). , Carbodiimide-modified MDI, polymethylene phenyl isocyanate (PAPI), orthotoluidine diisocyanate (TODI), naphthylene diisocyanate (NDI), xylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), paraphenylene diisocyanate (PDI), lysine diisocyanate methyl Examples include ester (LDI), dimethyl diisocyanate (DDI), and the like. These may be used alone or in combination of two or more. Among these, 4,4'-diphenylmethane diisocyanate (MDI) is particularly preferable from the viewpoints of improvement in wear resistance, ease of handling, availability, and cost.

As the polyisocyanate, an NCO-terminated urethane prepolymer obtained by reacting a polyisocyanate such as MDI described above and a polyol may be used. Since the urethane prepolymer used as the polyisocyanate has an NCO terminal, the NCO% is preferably in the range of 5 to 30% by mass. NCO% is calculated by the following equation.

  The blending amount of the polyisocyanate is preferably set so that the NCO index (isocyanate index) is 110 or more from the viewpoints of easily improving the wear resistance, easily securing the strength, and hardly sticking. The NCO index is more preferably 115 or more, still more preferably 120 or more, 125 or more, or 130 or more. On the other hand, it is preferable to set the NCO index to be 250 or less from the viewpoints of not being too hard, satisfying cleaning properties at low temperatures, and easy to mold. The NCO index is more preferably 200 or less, and still more preferably 180 or less. The NCO index is calculated as the equivalent of the isocyanate group with respect to the total equivalent 100 of active hydrogen groups (hydroxyl group, amino group, etc.) that react with the isocyanate group.

  In addition to polyols and polyisocyanates, urethane compositions contain chain extenders, crosslinking agents, catalysts, foaming agents, surfactants, flame retardants, colorants, fillers, plasticizers, stabilizers, release agents, etc. You may make it contain.

  The chain extender is a bifunctional compound such as diol or diamine that can react with polyurethane. Those having a number average molecular weight of 300 or less are preferred. As chain extenders, 1,4-butanediol (1,4-BD), ethylene glycol (EG), 1,6-hexanediol (1,6-HD), diethylene glycol (DEG), propylene glycol (PG) Diols such as dipropylene glycol (DPG), 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, xylene glycol, triethylene glycol, and 2,2 ′, 3,3′-tetrachloro-4,4 '-Diaminodiphenylmethane, 3,3'-dichloro-4,4'-diphenylmethane, trimethylene-bis (4-aminobenzoate), 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane Aromatic diamines and the like. These may be used alone or in combination of two or more. Among these, from the viewpoints of adjusting the hardness of the polyurethane, the tan δ peak temperature and the tan δ peak value, which are indicators of the viscoelasticity of the polyurethane, it is easy to obtain physical properties and improve moldability. Butanediol (1,4-BD), ethylene glycol (EG), 1,6-hexanediol (1,6-HD) and the like are suitable.

  The crosslinking agent is a trifunctional or higher functional compound such as triol or triamine that can react with polyurethane. Those having a number average molecular weight of 300 or less are preferred. Examples of the crosslinking agent include trimethylolpropane (TMP), glycerin, pentaerythritol, sorbitol, 1,2,6-hexanetriol, and the like. These may be used alone or in combination of two or more. Among these, from the viewpoints of adjusting the hardness of the polyurethane, the tan δ peak temperature, which is an index of the viscoelasticity of the polyurethane, and the tan δ peak value, it is easy to obtain physical properties and improve moldability. TMP) is preferred.

  The catalyst is not particularly limited, and examples thereof include amine compounds such as tertiary amines and organometallic compounds such as organotin compounds. This catalyst is a catalyst that promotes urethanization and isocyanuration. Tertiary amines include, for example, trialkylamines such as triethylamine, tetraalkyldiamines such as N, N, N ′, N′-tetramethyl-1,3-butanediamine, aminoalcohols such as dimethylethanolamine, and ethoxyl. Amines, ethoxylated diamines, ester amines such as bis (diethylethanolamine) adipate, cyclohexylamine derivatives such as triethylenediamine (TEDA), N, N-dimethylcyclohexylamine, N-methylmorpholine, N- (2-hydroxypropyl) ) -Dimethylmorpholine, morpholine derivatives, N, N'-diethyl-2-methylpiperazine, piperazine derivatives such as N, N'-bis- (2-hydroxypropyl) -2-methylpiperazine, and the like. Examples of the organic tin compound include dialkyltin compounds such as dibutyltin dilaurate and dibutyltin di (2-ethylhexoate), stannous 2-ethylcaproate, stannous oleate, and the like. . These may be used alone or in combination of two or more. Among these, triethylenediamine (TEDA) is preferably used from the viewpoint of being difficult to hydrolyze and less contaminated by bleed.

  The hardness of the base material of the blade part 12 can be set to a predetermined range by adjusting the urethane composition. The hardness is preferably 60 or more from the viewpoint of suppressing the peeling of the contact portion 12a of the substrate. More preferably, it is 65 or more. Further, the hardness is preferably 85 or less from the viewpoint of suppressing the abrasion of the abutting photosensitive drum 20 and suppressing wear and chipping of the abutting portion 12a of the base material. More preferably, it is 80 or less. The hardness of the base material of the blade part 12 can be measured by JIS-A hardness.

The base material of the blade part 12 can be set to a predetermined volume resistivity by adjusting the urethane composition. In the case of having conductivity, the volume resistivity of the base material of the blade portion 12 is set to a range of 10 ² to 10 ¹² Ω · cm, 10 ³ to 10 ¹⁰ Ω · cm, 10 ⁴ to 10 ⁹ Ω · cm, and the like. do it. In the case of a non-conductive material, the volume resistivity of the base material of the blade portion 12 may be set to more than 10 ¹² Ω · cm. The volume resistivity of the base material of the blade portion 12 is determined by cutting a base material or a separately prepared sheet into 30 mm × 30 mm, and then applying a silver paste thereon to produce a 10 mm × 10 mm electrode, and the LL environment (10 The volume resistivity (Ω · cm) after 30 seconds is measured using a model 237 (manufactured by KEITHLEY) under a voltage of 100 V under a temperature of 10 ° C.).

The surface resistivity of the impregnation part 16 can be set within a predetermined range depending on the type and content of the ionic conductive agent in the curable composition, the amount of impregnation of the curable composition (impregnation depth), and the like. From the viewpoint of suppressing chipping of the contact portion 12a due to adhesion of paper dust or the like, the surface resistivity of the impregnated portion 16 is preferably 1.0 × 10 ¹² Ω / □ or less. More preferably, it is 1.0 × 10 ¹⁰ Ω / □ or less. The surface resistivity of the impregnated part 16 was measured using a Hiresta UP (URS probe) manufactured by Mitsubishi Chemical under the conditions of an applied voltage of 500 V and an applied time of 10 seconds under an LL environment (10 ° C. × 10% RH). Measurement can be performed by bringing a probe into contact with the surface.

  The residual potential of the impregnated portion 16 can be set within a predetermined range by using the type and content of the ionic conductive agent in the curable composition, using a conductive base material, and the like. From the standpoint of suppressing chipping of the contact portion 12a due to adhesion of paper dust or the like, the residual potential of the impregnation portion 16 is preferably 200 V or less. More preferably, they are 180V or less, 140V or less, and 100V or less. The residual potential of the impregnation part 16 can be measured using a surface potential meter.

  Further, the friction coefficient (μ) of the impregnated portion 16 can be set within a predetermined range depending on the composition of the curable composition, the solid content concentration, the amount of impregnation (impregnation depth), and the like. From the viewpoint of suppressing the contact of the contact portion 12a, the impregnation portion 16 preferably has a friction coefficient of 0.9 or less. More preferably, it is 0.8 or less, 0.7 or less, or 0.6 or less. The friction coefficient (μ) of the impregnated portion 16 can be measured using a static friction coefficient meter.

  The impregnation depth (impregnation amount) of the impregnation part 16 is preferably 0.05 μm or more from the viewpoint of easily reducing the friction coefficient to a desired range. More preferably, it is 0.1 μm or more. Moreover, it is preferable that it is 5.0 micrometers or less from a viewpoint of suppressing the raise of hardness and being easy to suppress the abrasion and notch | chip of the contact part 12a. More preferably, it is 3.0 μm or less. The impregnation depth of the impregnation portion 16 can be measured by cross-sectional observation or cross-section hardness measurement. The impregnation depth of the impregnation part 16 can be adjusted by adjusting the solid content concentration of the curable composition.

  The base material of the blade part 12 can be produced by injecting and molding the urethane composition into a predetermined molding die. Cast molding can be performed according to a prepolymer method, a semi one-shot method, and a one-shot method. The semi-one shot method is preferable because of excellent processability. In the semi-one shot method, a urethane prepolymer (main agent liquid) is prepared from polyisocyanate and polyol, and a curing agent is blended with polyol, if necessary, conductive agent, chain extender, crosslinking agent, catalyst, additive, etc. The liquid is prepared, and the main agent liquid and the curing agent liquid are mixed at a predetermined ratio to obtain a urethane composition. The urethane composition is injected into a molding die to be reacted and cured, whereby a blade portion 12 having a predetermined shape is obtained. The base material can be produced. The holding part 14 is formed by burying a part in the base material of the blade part 12 at the time of molding, or by adhering to a predetermined position using an adhesive after the base material of the blade part 12 is molded. Can be integrated with the substrate.

  The impregnation treatment to the base material of the blade part 12 is performed by immersing a part or all of the base material of the blade part 12 for a predetermined time in the liquid of the curable composition. It can be carried out by spraying with a liquid of the curable composition or by applying with a brush. At this time, excess curable composition liquid remaining on the surface of the substrate can be removed by wiping or washing with a solvent. Thereafter, the impregnated curable composition is cured by a curing treatment such as light irradiation or heating. Thus, the impregnated portion 16 can be formed.

  According to the blade 10 having the above-described configuration, the impregnation portion 16 formed by impregnating and curing the curable composition containing the ionic conductive agent in the contact portion 12a that contacts the mating member of the base material containing urethane rubber. Therefore, the friction of the contact portion 12a can be reduced and the residual charge on the surface of the contact portion 12a can be reduced. Thereby, durability can be improved.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment at all, A various change is possible in the range which does not deviate from the summary of this invention.

  For example, in the said embodiment, as shown to Fig.3 (a) (b), the structure which does not have the layer (surface layer) which appears on the surface on the impregnation part 16 of the base material of the blade part 12 is shown. However, as shown in FIGS. 4A and 4B, a layer (surface layer) 18 formed by impregnating and curing a curable composition containing an ionic conductive agent on the base impregnated portion 16 is further provided. The blade 30 may be used. The curable composition at this time may be the same as the curable composition forming the impregnated portion 16. If the substrate further has a layer (surface layer) 18 formed by impregnating and curing a curable composition containing an ionic conductive agent on the impregnated portion 16 of the base material, it is more excellent in wear resistance. The blade 30 in FIG. 4A has a layer (surface layer) 18 only on the tip surface of the substrate including the contact portion 12a, as in FIG. 3A. The blade 30 in FIG. 4B has a layer (surface layer) 18 on the entire surface of the substrate, as in FIG. 3B.

  The surface layer 18 is formed by further applying and curing the curable composition on the impregnated portion 16 that is cured without removing the excess curable composition liquid remaining on the substrate surface in the impregnation treatment. be able to.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to this structure.

Details of the materials used are shown below.
PBA (polybutylene adipate): “Nipporan 4010” manufactured by Nippon Polyurethane Industry
MDI (4,4′-diphenylmethane diisocyanate): “Millionate MT” manufactured by Nippon Polyurethane Industry
・ TMP (trimethylolpropane): manufactured by Mitsubishi Gas Chemical Co., Ltd. ・ 1,4BD (1,4-butanediol): manufactured by Mitsubishi Chemical Corporation ・ TEDA (triethylenediamine): manufactured by Tosoh Corporation ・ Acrylate: pentaerythritol triacrylate (“Aronix manufactured by Toagosei Co., Ltd.”) M305 ")
Photopolymerization initiator: “Darocur 1173” manufactured by Ciba Specialty Chemicals
・ Ionic conductive agent (1): potassium salt (solid, melting point 200 ° C.), potassium bis (trifluoromethanesulfonyl) imide, Morita Chemical Co., Ltd. ・ Ionic conductive agent (2): quaternary ammonium salt (solid at room temperature) , Trimethyloctylammonium chloride (reagent), Tokyo Chemical Industry Co., Ltd., ionic conductive agent (3): quaternary ammonium salt (liquid at room temperature), hydroxyl group-containing, bis (2-hydroxyethyl) dimethylammonium chloride (reagent), Tokyo Chemical Industry Co., Ltd./Ionic Conductive Agent (4): Quaternary ammonium salt (liquid at room temperature), methacryloyl group-containing, 2- (methacryloyloxy) ethyltrimethylammonium chloride, MRC Unitech Co., Ltd. “QDM”
-Ionic conductive agent (5): quaternary ammonium salt (liquid at room temperature), allyl group-containing, diallyldimethylammonium chloride (reagent), Tokyo Chemical Industry Co., Ltd. CB: carbon black, "Denka Black" manufactured by Electrochemical Industry

(Examples 1 to 10)
<Preparation of urethane composition>
PBA (44 parts by mass) degassed in vacuum and MDI (56 parts by mass) were mixed and reacted at 80 ° C. for 180 minutes under a nitrogen atmosphere, whereby the main agent (NCO-terminated urethane prepolymer, NCO% = 17.0%) Was prepared. Next, PBA (87 parts by mass), low molecular weight polyol (13 parts by mass) in which 1,4BD and TMP were mixed at a molar ratio of 5: 5, and TEDA (0.01 parts by mass) as a curing catalyst were added to nitrogen. A curing agent (hydroxyl value 210 (KOHmg / g)) was prepared by mixing for 60 minutes at 80 ° C. in an atmosphere. Subsequently, the main agent (100 parts by mass) and the curing agent (94 parts by mass) were mixed at 60 ° C. for 3 minutes in a vacuum atmosphere and sufficiently degassed. Thereby, the urethane composition which does not contain a conductive agent (ionic conductive agent and electronic conductive agent) was prepared.

<Preparation of curable composition>
A curable composition is prepared by mixing pentaerythritol triacrylate, a photopolymerization initiator, an ionic conductive agent, and MEK so as to have a predetermined blending ratio (parts by mass) and a solid content concentration (% by mass). Prepared. The solid content concentration is a concentration of total components other than MEK.

<Production of blade>
A plate-like holder is placed in a blade mold, and the prepared urethane composition is poured into the mold, and then heated to 130 ° C. to cure the urethane composition, and then demold and cut. A non-conductive molded article containing no conductive agent, in which the part and the holding part were integrated, was produced. Next, a predetermined range (tip or whole) of the blade portion was immersed in the prepared curable composition containing the ionic conductive agent for 30 minutes, and the substrate of the blade portion was impregnated with the curable composition. Next, the curable composition remaining on the surface of the blade portion (not soaked) was washed and removed with MEK. Next, the curable composition impregnated in the blade portion was cured by irradiating with ultraviolet rays. Thus, a blade was produced. The tip of the processing range is the tip portion (FIG. 3A) including the contact portion (ridge line), and the whole is the entire surface of the blade portion excluding the surface with which the holding portion is in contact (FIG. b)).

(Comparative Example 1)
The same as in Examples 1 to 10, the blade part and the holding part were integrated, and the non-conductive molded body containing no conductive agent was not impregnated with the curable composition. The blade of Comparative Example 1 was obtained.

(Comparative Example 2)
In preparation of a curable composition, the curable composition which does not contain an ionic conductive agent was prepared like Example 1-10 except not having mix | blended the ionic conductive agent. Next, impregnated with a curable composition not containing an ionic conductive agent for a non-conductive molded article containing no conductive agent, in which the blade part and the holding part are integrated, as in Examples 1 to 10. A blade was produced in the same manner as in Examples 1 to 10 except that the treatment was performed.

(Examples 11 to 20)
In the preparation of the urethane composition, a urethane composition containing an ionic conductive agent was prepared in the same manner as in Examples 1 to 10, except that the ionic conductive agent (1) was further added. Subsequently, the electroconductivity containing the ionic conductive agent (1) in which the blade part and the holding part are integrated in the same manner as in Examples 1 to 10 except that the urethane composition containing the ionic conductive agent (1) was used. A molded body was prepared. Subsequently, the impregnation process by the curable composition containing the same ionic conductive agent as Examples 1-10 was performed, and the braid | blade was produced.

(Comparative Example 3)
As in Examples 11 to 20, the conductive molded body containing the ionic conductive agent (1) in which the blade portion and the holding portion are integrated is not subjected to the impregnation treatment with the curable composition, and the conductive property is obtained. Was used as a blade of Comparative Example 3.

(Comparative Example 4)
Example 11 except that the curable composition containing no ionic conductive agent as in Comparative Example 2 was used, and the conductive molded body containing the same ionic conductive agent (1) as in Examples 11 to 20 was impregnated. A blade was produced in the same manner as in -20.

(Examples 21 to 25)
In the preparation of the urethane composition, a urethane composition containing no ionic conductive agent was prepared in the same manner as in Examples 1 to 10, except that the ionic conductive agent (2) was further added. Subsequently, the electroconductivity containing the ionic conductive agent (2) in which the blade part and the holding part are integrated in the same manner as in Examples 1 to 10 except that the urethane composition containing the ionic conductive agent (2) was used. A molded body was prepared. Subsequently, the impregnation process by the curable composition containing the same ionic conductive agent as Examples 1-10 was performed, and the braid | blade was produced.

(Comparative Example 5)
As in Examples 21 to 25, the conductive molded body containing the ionic conductive agent (2) in which the blade part and the holding part are integrated is not subjected to the impregnation treatment with the curable composition. Was used as a blade of Comparative Example 5.

(Comparative Example 6)
Example 21 except that the same ionic conductive agent-free curable composition as in Comparative Example 2 was used and the conductive molded body containing the same ionic conductive agent (2) as in Examples 21 to 25 was impregnated. A blade was prepared in the same manner as in ˜25.

(Comparative Example 7)
In the preparation of the curable composition, a curable composition not containing an ionic conductive agent but containing an electronic conductive agent was prepared in the same manner as in Example 1 except that an electronic conductive agent (CB) was added instead of the ionic conductive agent. Prepared. Next, the same curable composition containing an electronic conductive agent as that of Examples 11 to 20 was used for a conductive molded article containing an ionic conductive agent (1) in which a blade part and a holding part were integrated. A blade was produced in the same manner as in Examples 11 to 20 except that the impregnation treatment was performed.

  The residual potential and the coefficient of friction were measured for each manufactured blade. Moreover, image evaluation was performed about each produced braid | blade and the meklet | creckle and the chip of the contact part were investigated. An evaluation result is shown in the following table | surfaces with a mixing | blending (mass part) of a urethane composition and a curable composition.

(Residual potential)
As shown in FIG. 5, the corotron 3 and the blade 1 were installed so that the contact portion 2a of the blade portion 2 of the blade 1 was disposed at a position of 10 mm from the corotron discharge line 3a. Next, a probe 4 of a surface electrometer was installed at a position 1 mm from the front end surface 2b of the blade portion 2 of the blade 1. Next, a surface of the blade portion 2 of the blade 1 was charged by applying a corona current of 100 μA in an environment of 23 ° C. × 53% RH. The potential 5 seconds after application was measured with a surface potentiometer, and this was taken as the residual potential.

(Coefficient of friction)
Using a static friction coefficient meter (manufactured by Kyowa Interface Science Co., Ltd.), the friction coefficient of the surface of the impregnated portion of the blade was measured under the conditions of a steel ball (diameter 3 mm) indenter, a moving speed of 1 cm / second, and a load of 100 g.

(Mekure)
The blade was incorporated into a commercially available laser printer (LBP) as a cleaning blade, and the durability test was performed by printing 100,000 sheets in A4 size in an HH environment (32 ° C. × 85% RH). When initial or after endurance, the case where the creaking occurred at the contact portion of the blade part was judged as “NG”, and the case where no creaking occurred was judged as “PASS”.

(Missing, image evaluation)
The blade was incorporated into a commercially available laser printer (LBP) as a cleaning blade, and a durability test was conducted by printing 100,000 sheets in A4 size in an LL environment (10 ° C. × 10% RH). When the stain due to the chipping was confirmed in the printed image at the endurance, the image evaluation and the chipping were judged as “failed”. When the printed image shows no stain due to chipping, the image evaluation is “good”, and in this case, there are ten or more chippings in the contact portion of the blade portion after durability. “Δ”, “◯” when the number of chips was less than 10 and “◎” when no chip was generated.

  From Examples 1 to 10 and Comparative Examples 1 and 2, if the impregnation treatment with the curable composition is not performed on the contact portion of the base material of the blade portion (Comparative Example 1), the friction coefficient of the contact portion is high, From the beginning, it can be seen that the contact portion is inferior in durability due to the occurrence of peeling. Further, when the curable composition does not contain an ionic conductive agent even after the impregnation treatment with the curable composition (Comparative Example 2), the residual potential is high, and the charged toner, the toner external additive, paper dust It can be seen that adheres to and accumulates on the surface of the abutting portion of the blade portion and the abutting portion is chipped, resulting in poor durability. And by performing the impregnation process with the curable composition containing an ionic conductive agent on the contact portion of the blade portion (Examples 1 to 10), the residual potential and the friction coefficient are lowered, and the contact portion is not damaged or chipped. It is suppressed and it is understood that it is excellent in durability.

  The results of Examples 11 to 20 and Comparative Examples 3 to 4 are similar to the above results. Moreover, it is a result similar to the said result also about Examples 21-25 and Comparative Examples 5-6. From Comparative Example 7, in the impregnation treatment with the curable composition containing the electronic conductive agent, since the curable composition does not penetrate into the contact portion of the base material of the blade portion, the friction coefficient of the contact portion is high. From the beginning, it can be seen that the contact portion is indented and is inferior in durability.

  And in the comparison between Examples, when it is a conductive base material compared with a nonelectroconductive base material, a residual charge can be reduced more (Examples 1-10 and Examples 11-20, implementation). Examples 2, 6-10 and Examples 21-25). Moreover, it is excellent in the effect which suppresses abrasion and a chip | tip of a contact part, and can improve durability. These effects are particularly excellent when the ionic conductive agent (1) (potassium salt) is used. And as an ionic conductive agent mix | blended with a curable composition, when an ionic conductive agent (1) (potassium salt) is used, it is especially excellent in the effect which reduces a residual charge (Example 2 and Examples 7-10). Example 12 and Examples 16-20, Example 21 and Examples 22-25). When the processing range is the whole, the effect of reducing the residual charge is improved (Example 2 and Example 6, Example 12 and Example 16).

  If the amount of the ionic conductive agent impregnated in a predetermined range is increased, the residual charge can be further reduced. Further, if the solid content concentration of the curable composition to be impregnated is adjusted to increase the impregnation depth, the friction coefficient can be further reduced.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said Example at all, A various change is possible in the range which does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 10 Blade 12 Blade part 12a Contact part 14 Holding part 16 Impregnation part 18 Surface layer 20 Photosensitive drum

Claims (8)

  A blade for an electrophotographic apparatus, comprising an impregnated portion formed by impregnating a curable composition containing an ionic conductive agent into an abutting portion that abuts a mating member of a base material containing urethane rubber.   The blade for an electrophotographic apparatus according to claim 1, wherein the ionic conductive agent in the impregnated portion is a potassium salt or an ammonium salt.   3. The electrophotographic apparatus according to claim 1, wherein the ionic conductive agent in the impregnated portion has at least one group selected from a hydroxyl group, a (meth) acryloyl group, and an alkenyl group in an anion component or a cation component. blade.   4. The blade for an electrophotographic apparatus according to claim 3, wherein the ionic conductive agent in the impregnated portion is an ionic liquid.   The blade for electrophotographic equipment according to any one of claims 1 to 4, wherein the base material further contains an ionic conductive agent.   6. The electrophotographic apparatus according to claim 1, further comprising an impregnated portion obtained by impregnating and curing a curable composition containing an ionic conductive agent on the entire surface of the base material. blade.   7. The electron according to claim 1, further comprising a layer formed by impregnating a curable composition containing an ionic conductive agent on the impregnation portion of the base material and curing the curable composition. 7. Blade for photographic equipment.   The blade for electrophotographic equipment according to any one of claims 1 to 7, wherein the curable composition contains (meth) acrylate.

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