JP6888993B2 - Develop roller - Google Patents

Description

The present invention relates to a developing roller (hereinafter, also simply referred to as a "roller"), and more particularly to a developing roller used in an electrophotographic apparatus such as a copier or a printer or an image forming apparatus such as an electrostatic recording apparatus.

In electrophotographic devices such as copiers and printers and image forming devices such as electrostatic recording devices, a developer (toner) is supplied to a latent image holder carrying an electrostatic latent image to visualize the electrostatic latent image. Development operation is performed. In this case, a semi-conductive elastic roller is generally used as the developing roller used to supply the developing agent.

FIG. 3 shows an example of a configuration of the developing device. In the illustrated developing apparatus, the developing roller 10 is arranged between the toner supply roller 11 for supplying toner and the photosensitive drum 12 holding the electrostatic latent image in contact with the photosensitive drum 12. The developing roller 10, the photosensitive drum 12, and the toner supply roller 11 rotate in the directions of arrows in the drawing, so that the toner 13 is supplied to the surface of the developing roller 10 by the toner supply roller 11. The supplied toner is prepared into a uniform thin layer by the stratifying blade 14, and in this state, the developing roller 10 rotates while in contact with the photosensitive drum 12, so that the toner formed in the thin layer is prepared from the developing roller 10 to the photosensitive drum. The latent image is visualized by adhering to the 12 latent images. Reference numeral 15 in the drawing indicates a transfer unit, where the toner image is transferred to a recording medium 20 such as paper. Further, reference numeral 16 indicates a cleaning portion, and the toner remaining on the surface of the photosensitive drum 12 after transfer is removed by the cleaning blade 17.

Conventionally, as a configuration of a developing roller, there is a structure in which shaft members are provided at both ends of a cylindrical sleeve, but if the shaft member is made of resin, it may be deformed depending on temperature and humidity, while the shaft. If the member is made of metal, the cost will be high. On the other hand, a shaft member (hybrid flange) in which a metal shaft portion and a resin flange portion are combined has also been proposed (see, for example, Patent Document 1).

JP-A-9-190033 (Claims, etc.)

However, in a shaft member in which the shaft portion is made of metal and the flange portion is made of resin, the shaft portion and the flange portion are not sufficiently fixed and may be displaced during use, especially in an environment of low temperature and low humidity. Sufficient continuity was not obtained, and image defects sometimes occurred.

Therefore, an object of the present invention is to provide a developing roller provided with a shaft member in which a shaft portion and a flange portion are sufficiently fixed and conduction can be sufficiently ensured even in an environment of low temperature and low humidity.

As a result of diligent studies by the present inventors, in a shaft member in which the shaft portion is made of metal and the flange portion is made of resin, the shaft portion and the flange portion are fixed with an adhesive, and the shaft portion is fixed. We have found that the above problems can be solved by making at least a part of the peripheral surface in contact with the flange portion, and have completed the present invention.

That is, the present invention relates to a developing roller including a cylindrical sleeve and a pair of shaft members fixed to both ends of the sleeve in the longitudinal direction.
At least one of the pair of shaft members is composed of a flange portion having an insertion hole on the central shaft and a shaft portion inserted into the insertion hole, the shaft portion is made of a metal material, and the flange portion is formed. It is made of a resin material, and an adhesive is filled between the shaft portion and the flange portion, and at least a part of the peripheral surface of the shaft portion is in contact with the flange portion, and the flange is provided. The bottom surface of the insertion hole of the portion is provided with a hole portion and / or a recess.

In the present invention, the filling amount of the adhesive is preferably 0.1 to 2.0 mg / mm ² per surface area of the shaft portion. Further, in the present invention, it is preferable that the resin material constituting the flange portion has orientation in the direction from the central axis of the flange portion toward the outer peripheral portion.

According to the present invention, it has become possible to realize a developing roller provided with a shaft member in which the shaft portion and the flange portion are sufficiently fixed and the continuity can be sufficiently ensured even in an environment of low temperature and low humidity.

It is an axial sectional view which shows an example of the developing roller of this invention. It is an enlarged sectional view which shows the shaft member which concerns on this invention. It is a schematic explanatory drawing which shows one configuration example of a developing apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows an axial sectional view showing an example of the developing roller of the present invention. Further, FIG. 2 is an enlarged cross-sectional view showing a shaft member according to the present invention.

As shown in the figure, the developing roller 10 of the present invention includes a cylindrical sleeve 1 and a pair of shaft members 2 fixed to both ends in the longitudinal direction thereof. Further, on the outer periphery of the sleeve 1, one or more layers, for example, 2 to 4 layers, or 1 layer in the illustrated example, a resin layer 8 is provided.

In the developing roller 10 of the present invention, at least one of the shaft members 2 and, in the illustrated example, both, a flange portion 4 having an insertion hole 4A on the central shaft and a shaft portion 3 inserted into the insertion hole 4A. The shaft portion 3 is made of a metal material, and the flange portion 4 is made of a resin material. Further, in the present invention, the adhesive 5 is filled between the shaft portion 3 and the flange portion 4 constituting the shaft member 2, and at least a part of the peripheral surface of the shaft portion 3 is in contact with the flange portion 4. It is important to be. According to the present invention, by filling the adhesive 5 between the shaft portion 3 and the flange portion 4, even when the shaft portion 3 is made of metal and the flange portion 4 is made of resin, the shaft portion 3 and the flange portion 4 are formed. It is possible to securely fix the flange portion 4 and suppress the occurrence of misalignment during use. Further, in the roller 10 of the present invention, since at least a part of the peripheral surface of the shaft portion 3 is in contact with the flange portion 4, sufficient continuity is ensured in this portion even in a low temperature and low humidity environment. be able to. Here, the fact that the peripheral surface of the shaft portion 3 is in contact with the flange portion 4 means that the peripheral surface of the shaft portion 3 and the surface of the flange portion 4 are in direct contact with each other without an adhesive 5 or the like. To do.

In the present invention, the adhesive 5 to be filled between the shaft portion 3 and the flange portion 4 has adhesiveness to both the metal material constituting the shaft portion 3 and the resin material constituting the flange portion 4. If there is, there is no particular limitation, and a general-purpose adhesive can be used. Specifically, for example, as the anaerobic adhesive, Loctite series manufactured by Henkel can be used. In particular, in the present invention, the conduction between the shaft portion 3 and the flange portion 4 can be ensured at at least a part of the contact portion of the peripheral surface of the shaft portion 3, so that the adhesive 5 is conductive. There is a merit that it is possible to use a material having no property.

Further, in the present invention, the filling amount of the adhesive 5 to be filled between the shaft portion 3 and the flange portion 4 is preferably ^{0.1 to 2.0 mg / mm 2 per surface area of the shaft portion 3.} It is more preferably 0.2 to 1.9 mg / mm ² , and even more preferably 0.3 to 1.0 mg / mm ² . If the filling amount of the adhesive 5 is too small, the fixing between the shaft portion 3 and the flange portion 4 may be insufficient, and if it is too large, the adhesive 5 is applied to the peripheral surface of the shaft portion 3 and the flange portion 4. There is a possibility that the continuity between them may be hindered, and the fixed position of the shaft portion 3 may be displaced, which is not preferable.

In the present invention, by adjusting the filling amount of the adhesive 5, the adhesive 5 is filled only between the end surface 3a of the shaft portion 3 and the bottom surface 4a of the insertion hole 4A of the flange portion 4. It is preferable to do so. That is, it is preferable that the adhesive 5 is not filled between the peripheral surface of the shaft portion 3 and the flange portion 4. As a result, it is possible to more reliably secure the continuity without adversely affecting the runout accuracy and the roundness, and without hindering the continuity between the peripheral surface of the shaft portion 3 and the flange portion 4. It is preferable.

In the present invention, it is necessary that at least a part of the peripheral surface of the shaft portion 3 is in contact with the flange portion 4, preferably 80% or more of the surface area of the peripheral surface of the shaft portion 3, more preferably the shaft portion 3. It is assumed that the entire peripheral surface of the above surface is substantially in contact with the flange portion 4. The larger the area in which the peripheral surface of the shaft portion 3 and the flange portion 4 are in contact with each other, the more reliably the conduction can be ensured, which is preferable.

Further, in the present invention, as shown in the drawing, it is preferable that the hole portion 6 and / or the recess 7 is provided on the bottom surface 4a of the insertion hole 4A of the flange portion 4. By providing the hole 6 and the recess 7 in the bottom surface 4a of the insertion hole 4A of the flange 4 into which the shaft 3 is inserted, excess adhesive 5 can be released from the hole 6 and the recess 7 and filled. The amount can be adjusted appropriately. Further, a hole 6 or a recess 7 is provided in the bottom surface 4a of the insertion hole 4A of the flange portion 4, and the adhesive 5 is filled in the hole 6 or the recess 7, so that the shaft portion 3 is provided by the anchor effect. It is also preferable in that a stronger adhesion can be obtained between the flange portion 4 and the flange portion 4. Here, as shown in the figure, the hole portion 6 is usually provided at a position deviated from the central axis of the flange portion 4 on the bottom surface 4a of the insertion hole 4A of the flange portion 4. Further, as shown in the drawing, the recess 7 is usually provided on the central axis of the flange portion 4 at the bottom surface 4a of the insertion hole 4A of the flange portion 4.

In the present invention, the flange portion 4 has a cylindrical shape that can be inserted into the longitudinal end of the cylindrical sleeve 1, and has an insertion hole 4A into which the shaft portion 3 can be inserted on the central axis thereof. is there. In the illustrated example, the flange portion 4 has a uniform wall thickness as a whole and is formed as a hollow body having a hollow portion 4B inside, but may be formed as a medium entity having no hollow portion 4B. , There are no particular restrictions. A hollow body is preferable from the viewpoints of light weight, cost, heat dissipation, and the like. The flange portion 4 can be manufactured by injection molding using a resin material. In this case, the flange portion 4 is provided by providing an injection hole for the resin material in the portion of the molding die that corresponds to the center of the bottom surface 4a of the insertion hole 4A. The resin material constituting the portion 4 can be oriented in the direction from the central axis of the flange portion 4 toward the outer peripheral portion. By making the flange portion 4 have such orientation, the strength of the flange portion 4 can be improved, which is preferable.

In the present invention, as the metal material constituting the shaft portion 3, for example, sulfur free-cutting steel (SUM), aluminum, stainless steel, or the like coated with nickel, zinc, or the like can be used.

Examples of the resin material constituting the flange portion 4 include polyacetal (polyoxymethylene, POM), polyamide resin (for example, polyamide 6, polyamide 6.6, polyamide 12, polyamide 4.6, polyamide 6/10, etc.). Polyamide 6/12, Polyamide 11, Polyamide MXD6 (polyamide obtained from metaxylene diamine and adipic acid), polybutylene terephthalate, polyphenylene oxide, polyphenylene ether, polyphenylene sulfide, polyether sulfone, polycarbonate (PC), polyimide, Examples thereof include polyamideimide, polyetherimide, polysulfone, polyether ether ketone, polyethylene terephthalate, polyarylate, liquid crystal polymer, polytetrafluoroethylene, polypropylene, acrylonitrile-butadiene-styrene (ABS) resin, polystyrene, polyethylene and the like. In addition, melamine resin, phenol resin, silicone resin and the like can also be used. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Among the above, engineering plastics are preferable, and polyacetal, polyamide resin, polybutylene terephthalate, polyphenylene ether, polyphenylene sulfide, polycarbonate and the like are more preferable because they are thermoplastic, have excellent moldability, and have excellent mechanical strength. ..

Further, examples of the conductive agent used for imparting conductivity to the flange portion 4 include carbon black powder, graphite powder, metal powder such as carbon fiber, aluminum, copper and nickel, tin oxide, titanium oxide and zinc oxide. A powdery conductive agent such as a metal oxide powder such as, or a conductive glass powder is preferably used. These may be used individually by 1 type, and may be used in combination of 2 or more type.

In the present invention, the shaft member 2 can obtain the desired effect by applying it to at least the side of the developing roller 10 that takes conduction in the longitudinal direction, but it is applied to both. You may.

In the present invention, the material of the sleeve 1 is not particularly limited as long as it is made of a metal material having good conductivity, but for example, iron, stainless steel, aluminum, an alloy containing these, or the like is used. be able to. Further, the wall thickness of the sleeve 1 is preferably thin in terms of weight reduction as long as the strength is sufficient, and can be, for example, 0.3 to 2 mm.

The resin layer 8 provided on the outer periphery of the sleeve 1 is not particularly limited, but is preferably formed by using an ultraviolet curable resin. Specifically, for example, it is formed by using an ultraviolet curable resin composition containing a urethane (meth) acrylate oligomer, a (meth) acrylate monomer, a photopolymerization initiator and a conductive agent, and optionally various additives. Can be done.

The urethane (meth) acrylate oligomer has _{one or more acryloyloxy groups (CH 2} = CHCOO-) or methacryloyloxy groups (CH ₂ = C (CH ₃ ) COO-) and has a plurality of urethane bonds (-NHCOO-). It is a compound that has. The urethane (meth) acrylate oligomer preferably has a functional group number of 3.0 or less, and more preferably 1.5 to 2.5. Here, the functional group means an acryloyloxy group and a methacryloyloxy group, and the number of functional groups means the average number of functional groups. When the number of functional groups of the urethane (meth) acrylate oligomer is 3.0 or less, the crosslink density is appropriately increased, so that the amount of acetone extracted can be reduced without increasing the hardness of the resin layer.

The urethane (meth) acrylate oligomer preferably has a polystyrene-equivalent number average molecular weight of 5,000 to 100,000. If the molecular weight of the urethane (meth) acrylate oligomer is less than 5,000, the hardness of the resin layer may become too high, while if it exceeds 100,000, the compressive residual strain of the resin layer may become too large.

The urethane (meth) acrylate oligomer is not particularly limited, but can be produced, for example, by synthesizing a urethane prepolymer from a polyol and a polyisocyanate and adding a (meth) acrylate having a hydroxyl group to the urethane prepolymer. ..

The polyol used in the synthesis of the urethane prepolymer is a compound having a plurality of hydroxyl groups (OH groups). Specific examples of such polyols include polyether polyols, polyester polyols, polytetramethylene glycol, polybutadiene polyols, alkylene oxide-modified polybutadiene polyols and polyisoprene polyols, and among these, polyether polyols are particularly preferable. Specific preferred examples of the polyether polyol include polyoxypropylene glycol, polyoxyethylene glycol, polyoxymethylene glycol, polyoxytetramethylene glycol, and polyoxybutylene glycol. The above-mentioned polyether polyol is obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to a polyhydric alcohol such as ethylene glycol, propylene glycol or glycerin. These polyols may be used alone or in a blend of two or more.

The polyisocyanate is a compound having a plurality of isocyanate groups (NCO groups). Specific examples of such polyisocyanates include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate (crude MDI), isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, and hexamethylene. Examples thereof include diisocyanate (HDI), these isocyanurate-modified products, carbodiimide-modified products, and glycol-modified products. These polyisocyanates may be used alone or in a blend of two or more.

In the synthesis of the urethane prepolymer, the ratio of the polyol to the polyisocyanate can be appropriately selected depending on the intended purpose. Here, the urethane prepolymer preferably has an isocyanate index in the range of 110 to 200, and more preferably in the range of 115 to 200.

In the synthesis of the urethane prepolymer, it is preferable to use a catalyst for the urethanization reaction. Examples of the catalyst for the urethanization reaction include organic tin compounds such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltinthiocarboxylate, dibutyltin dimalate, dioctyltinthiocarboxylate, tin octate, monobutyltin oxide and the like; stannous chloride and the like. Inorganic tin compounds; organic lead compounds such as lead octenoate; monoamines such as triethylamine and dimethylcyclohexylamine; diamines such as tetramethylethylenediamine, tetramethylpropanediamine and tetramethylhexanediamine; pentamethyldiethylenetriamine and pentamethyldipropylene Triamines such as triamines and tetramethylguanidines; cyclic amines such as triethylenediamine, dimethylpiperazin, methylethylpiperazin, methylmorpholin, dimethylaminoethylmorpholin, dimethylimidazole, pyridine; dimethylaminoethanol, dimethylaminoethoxyethanol, trimethylaminoethyl Alcohol amines such as ethanolamine, methylhydroxyethylpiperazine, hydroxyethylmorpholin; etheramines such as bis (dimethylaminoethyl) ether, ethylene glycol bis (dimethyl) aminopropyl ether; p-toluenesulfonic acid, methanesulfonic acid, Organic sulfonic acids such as fluorosulfate; Inorganic acids such as sulfuric acid, phosphoric acid, perchloric acid; Bases such as sodium alcoholate, lithium hydroxide, aluminum alcoholate, sodium hydroxide; tetrabutyl titanate, tetraethyl titanate, tetraisopropyl titanate, etc. Titanium compounds; bismuth compounds; quaternary ammonium salts and the like. Among these catalysts, organotin compounds are preferable. These catalysts may be used alone or in combination of two or more. The amount of the catalyst used is preferably in the range of 0.001 to 2.0 parts by mass with respect to 100 parts by mass of the polyol.

The (meth) acrylate having a hydroxyl group to be added to the urethane prepolymer has one or more hydroxyl groups and has an acryloyloxy group (CH ₂ = CHCOO−) or a methacryloyloxy group (CH ₂ = C (CH ₃ ) COO. -) Is a compound having one or more. The (meth) acrylate having such a hydroxyl group can be added to the isocyanate group of the urethane prepolymer. Examples of the (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. The acrylate having these hydroxyl groups may be used alone or in combination of two or more.

Next, the (meth) acrylate monomer is _{a monomer having one or more acryloyloxy group (CH 2} = CHCOO−) or methacryloyloxy group (CH ₂ = C (CH ₃ ) COO−), and is used as a reactive diluent. In addition to acting, i.e. curing with ultraviolet light, it is possible to reduce the viscosity of the ultraviolet curable resin composition.

The (meth) acrylate monomer preferably has a functional group number of 3.0 or less, and more preferably 1-2. Here, the functional group means an acryloyloxy group and a methacryloyloxy group, and the number of functional groups means the average number of functional groups. When the number of functional groups of the (meth) acrylate monomer is 3.0 or less, the crosslink density is appropriately increased, so that the amount of acetone extracted can be reduced without increasing the hardness of the resin layer. When the (meth) acrylate monomer contains a bifunctional (meth) acrylate monomer, the content of the bifunctional (meth) acrylate monomer in the total of the urethane (meth) acrylate oligomer and the (meth) acrylate monomer. Is preferably 1 to 15% by mass. If the content of the bifunctional (meth) acrylate monomer is less than 1% by mass, the crosslink density cannot be sufficiently increased, while if it exceeds 15% by mass, the crosslink density becomes too high and the hardness of the resin layer becomes too high. May increase. Further, the (meth) acrylate monomer preferably has a glass transition point (Tg) of 50 ° C. or lower.

Specific examples of the (meth) acrylate monomer include lauryl (meth) acrylate, isomiristyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, triethylene glycol di (meth) acrylate, and β- (meth). Acryloyloxyethyl hydrogen succinate, isobornyl (meth) acrylate, ethyl (meth) acrylate, isobutyl (meth) acrylate, n-butyl (meth) acrylate, isoamyl (meth) acrylate, glycidyl (meth) acrylate, butoxyethyl (meth) ) Acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and the like. These (meth) acrylate monomers may be used alone or in combination of two or more.

In the above ultraviolet curable resin composition, the ratio of the urethane (meth) acrylate oligomer to the total of the urethane (meth) acrylate oligomer and the (meth) acrylate monomer is preferably 50% by mass or more, preferably 60 to 90% by mass. Is more preferable. If the content of the urethane (meth) acrylate oligomer is less than 50% by mass, the proportion of the monomer increases, so that the amount of low-molecular-weight polymer increases, and as a result, the amount of acetone extracted may increase.

Next, the photopolymerization initiator has an action of initiating the polymerization of the above-mentioned urethane (meth) acrylate oligomer and (meth) acrylate monomer by being irradiated with ultraviolet rays. Examples of such photopolymerization initiators include 4-dimethylaminobenzoic acid, 4-dimethylaminobenzoic acid ester, 2,2-dimethoxy-2-phenylacetophenone, acetophenone diethyl ketal, alkoxyacetophenone, benzyl dimethyl ketal, benzophenone and 3,3. -Benzophenone derivatives such as dimethyl-4-methoxybenzophenone, 4,4-dimethoxybenzophenone, 4,4-diaminobenzophenone, alkyl benzoyl benzoate, bis (4-dialkylaminophenyl) ketone, benzyl and benzyl derivatives such as benzyl methyl ketal , Benzoyl derivatives such as benzoin and benzoin isobutyl ether, benzoin isopropyl ether, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexylphenyl ketone, xanthone, thioxanthone and thioxanthone derivatives, fluorene, 2,4,6-trimethylbenzoyl Diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-methyl-1- [4- (Methylthio) phenyl] -2-morpholinopropane-1,2-benzyl-2-dimethylamino-1- (morpholinophenyl) -butanone-1 and the like can be mentioned. These photopolymerization initiators may be used alone or in combination of two or more.

The amount of the photopolymerization initiator compounded in the ultraviolet curable resin composition is 0.2 to 5.0 parts by mass with respect to 100 parts by mass in total of the urethane (meth) acrylate oligomer and the (meth) acrylate monomer. The range is preferred.

Next, the conductive agent has an action of imparting conductivity to the elastic layer. As such a conductive agent, one capable of transmitting ultraviolet rays is preferable, and for example, an ionic conductive agent or a transparent electronic conductive agent can be used, and among them, an ionic conductive agent is preferably used. By using the ionic conductive agent, even if the resin layer is applied thickly, the ultraviolet rays sufficiently reach the inside of the coating film and can be sufficiently cured. Examples of the ionic conductive agent include perchlorates such as tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium and modified fatty acid dimethylethylammonate, chlorates, hydrochlorides, bromates, and iodine. Ammonites such as acid salts, borohydrofluoride salts, sulfates, ethyl sulfates, carboxylates, sulfonates; alkali metals such as lithium, sodium, potassium, calcium and magnesium, and perchlorates of alkaline earth metals Examples thereof include salts, chlorates, hydrochlorides, bromines, iodates, borohydrochlorides, sulfates, trifluoromethylsulfates, sulfonates and the like. Further, as the transparent electronic conductive agent, fine particles of metal oxides such as ITO, tin oxide, titanium oxide and zinc oxide; fine particles of metals such as nickel, copper, silver and germanium: conductive titanium oxide whiskers and conductive titanium. Examples thereof include conductive whiskers such as barium acid whiskers. These conductive agents may be used alone or in combination of two or more.

The blending amount of the conductive agent in the ultraviolet curable resin composition is in the range of 0.1 to 5.0 parts by mass with respect to 100 parts by mass in total of the urethane (meth) acrylate oligomer and the (meth) acrylate monomer. preferable.

The resin layer 8 is not particularly limited, but can be formed, for example, with a thickness of 0.5 to 4 mm.

In the shaft member 2 according to the present invention, after filling the inside of the insertion hole 4A of the flange portion 4 with the adhesive 5, the shaft portion 3 is inserted, and the end surface 3a of the shaft portion 3 and the bottom surface of the insertion hole 4A of the flange portion are inserted. It can be manufactured by adhering and fixing 4a to and from the adhesive 5. After that, the shaft member 2 and, if desired, another shaft member, for example, a shaft member whose shaft portion and flange portion are both made of a resin material, are attached to both ends of the sleeve 1 in the longitudinal direction, if necessary. Fix with. Further, the developing roller 10 of the present invention can be obtained by coating one or more resin layers 8 on the outer periphery of the sleeve 1 according to a conventional method and curing the resin layer 8 by irradiation with ultraviolet rays.

Hereinafter, the present invention will be described in more detail with reference to examples.
Under the conditions shown in the table below, the shaft is inserted after filling the inside of the insertion hole provided on the central shaft of the flange with an adhesive (manufactured by Henkel, product name Loctite 410). A shaft member as shown in FIG. 2 was manufactured by adhesively fixing the portion and the flange portion with an adhesive. Each of the obtained shaft members was fixed to both ends of a cylindrical sleeve having a wall thickness of 1 mm in the longitudinal direction with an adhesive (manufactured by Henkel, product name Loctite 410), and then a resin having a thickness of 1 mm was applied to the outer periphery of the sleeve. The layer was coated with an ultraviolet curable resin composition according to a conventional method and cured by ultraviolet irradiation to form a developing roller of Example 1 as shown in FIG. 1. The flange portion was manufactured by injection molding, and the resin material constituting the flange portion had orientation in the direction from the central axis to the outer peripheral portion.

The developing roller of Comparative Example 1 was produced by changing the conditions of the shaft member as shown in the table below.

(Continuity)
Each developing roller was incorporated into a commercially available printer, and the conduction stability was confirmed when 10,000 sheets were printed in an environment of 10 ° C. and 15% RH. The case where the horizontal stripe-like shading unevenness did not occur in the image was marked with ◯, and the case where the horizontal streak-shaped shading unevenness occurred in the image was marked with x.

(Adhesiveness)
For each developing roller, the tensile strength of the shaft was measured and evaluated according to the following.
◯: 0.4 kgf / mm or more Δ: 0.2 kgf / mm or more and less than 0.4 kgf / mm ×: 0.2 kgf / mm or less

(Strength)
Each developing roller was incorporated into a commercially available printer, and the presence or absence of deformation of the shaft portion when the shaft portion was idled for 30 minutes with the sliding grease removed from the shaft portion was evaluated. The case where no deformation was observed was evaluated as ◯, and the case where deformation was observed was evaluated as x.

(Shaft runout)
For each developing roller, the runout of the shaft portion was evaluated. When the runout was less than 40 μm, it was evaluated as ◯, when it exceeded 40 μm and less than 70 μm, it was evaluated as Δ, and when it exceeded 70 μm, it was evaluated as ×.

These results are also shown in the table below.

As shown in the above table, in Comparative Example 1 in which an integral resin material is used as the shaft member, that is, the shaft portion and the flange portion are made of resin, the strength deteriorates due to insufficient mechanical and thermal strength. At the same time, the continuity is deteriorated due to the deformation of the shaft portion. On the other hand, the shaft member includes a shaft portion made of a metal material and a flange portion made of a resin material, and an adhesive is filled between the shaft portion and the flange portion, and at least a part of the peripheral surface of the shaft portion is a flange. It can be seen that in the developing roller of Example 1 in contact with the portion, sufficient continuity is ensured, and the adhesiveness, strength, and runout are also good.

1 Sleeve 2 Shaft member 3 Shaft 3a End face 4 Flange 4A Insert hole 4a Bottom 5 Adhesive 6 Hole 7 Recess 8 Resin layer 10 Development roller 11 Toner supply roller 12 Photosensitive drum 13 Toner 14 Layered blade 15 Transfer part 16 Cleaning part 17 Cleaning blade 20 Recording medium

Claims (3)

In a developing roller comprising a cylindrical sleeve and a pair of shaft members fixed to both ends of the sleeve in the longitudinal direction.
At least one of the pair of shaft members is composed of a flange portion having an insertion hole on the central shaft and a shaft portion inserted into the insertion hole, the shaft portion is made of a metal material, and the flange portion is formed. together are composed of a resin material, Ri Contact is adhesive filled between the shaft portion and said flange portion, at least a portion of the peripheral surface of the shaft portion is in contact with the flange portion, and the A developing roller characterized in that a hole and / or a recess is provided on the bottom surface of the insertion hole of the flange portion. The filling amount of the adhesive, the developing roller according to claim 1, wherein the surface area per 0.1 to 2.0 mg / mm ² of the shaft portion. The developing roller according to claim 1 or 2 , wherein the resin material constituting the flange portion is oriented in a direction from the central axis of the flange portion toward the outer peripheral portion.

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