JP2009009065A - Toner conveying roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner conveying roller having higher toner conveying performance and scraping performance than before by improving an irregular structure of the surface of the roller. <P>SOLUTION: The toner conveying roller abuts on a developing roller which forms a visible image by conveying toner carried on its surface to an image forming body, and supplies the toner to the developing roller. It is constituted by carrying urethane foam on the outer periphery of a shaft. A wall-like projecting part is formed on the surface of the urethane foam, and the maximum width w of the wall-like projecting part is within 200 to 1,000 μm and the height thereof is within 10 to 500 μm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is used in an image forming apparatus such as a copying machine or a printer to supply toner to a developing roller that conveys toner to an image forming body such as a photoreceptor or paper and forms a visible image on the surface. The present invention relates to a toner conveying roller (hereinafter also simply referred to as “roller”).

  In general, an image forming body that holds an electrostatic latent image and a toner that is in contact with the image forming body and adheres to the surface are attached to a developing unit in an electrophotographic image forming apparatus such as a copying machine or a printer. Thus, a developing roller that visualizes the electrostatic latent image and a toner conveying roller that supplies toner to the developing roller (including a toner supplying roller and a cleaning roller for removing unnecessary toner) are provided. Thus, image formation is performed by a series of processes in which the toner is conveyed from the toner container to the image forming body via the toner conveying roller and the developing roller.

  In order to perform good image formation in this developing mechanism, it is necessary that a thin layer of toner is uniformly formed and supported on the surface of the developing roller without unevenness. Therefore, in such a developing mechanism, in addition to the toner holding performance of the developing roller itself, the performance of the toner transport roller, particularly the surface performance is important. That is, the toner conveying roller is required to form a uniform toner layer on the surface of the developing roller by contacting the developing roller and performing frictional charging, toner supply, and scraping.

  Various studies have been made in the past to obtain a toner conveying roller having satisfactory surface performance that satisfies the above requirements. As such a toner conveying roller, generally, a urethane roller obtained by integrally forming a urethane foam formed by stirring and mixing polyol, isocyanate, water as a foaming agent, a catalyst, and the like with a shaft in a mold. In such a urethane roller, the toner can be held in the roller by communicating the foam cell inside the roller, and the toner held through the opening on the roller surface is conveyed to the developing roller. Can do.

  On the other hand, for example, in Patent Document 1, the outer peripheral surface of the polyurethane foam layer has a height in the roll circumferential direction of 20 to 3000 μm and a pitch in the roll circumferential direction of 300 to 3000 μm provided so as to extend linearly in the roll axis direction. A toner supply roll having a concavo-convex surface structure is disclosed by a plurality of ridges, and in Patent Document 2, an outer peripheral surface of a polyurethane foam layer is provided so as to extend spirally in the roll axis direction. A toner supply roll having a concavo-convex surface structure by a plurality of ridges extending with a gear-shaped cross section in the roll circumferential direction is disclosed.

Further, in Patent Document 3, the sponge elastic layer is formed with coarse opening recesses having an average opening diameter of 1000 to 3000 μm on the outer peripheral surface, and the average opening is formed between the scattered coarse opening recesses. A toner supply roll in which a large number of fine opening recesses having a diameter of 150 to 300 μm are distributed is disclosed.
Japanese Patent No. 3536598 (claims, etc.) JP 2000-56556 A (Claims etc.) JP 2007-121698 A (Claims etc.)

  However, in a roller having a concavo-convex surface shape with groove-like ridges as disclosed in Patent Documents 1 and 2, when toner with high fluidity is used, the movement in the groove direction is not restricted, so the toner Constantly flows along the groove direction, and the amount of toner (toner density) held in the groove and conveyed to the developing roller is reduced, resulting in insufficient image density. Further, in the roller having a coarse opening recess of Patent Document 3, since the opening shape is circular, the opening area cannot be gained, toner transportability becomes insufficient, and the recess is spherical. Also, it was difficult to secure the volume of the recess.

  Therefore, none of the conventional toner transport rollers are sufficient, and there has been a demand for the realization of a toner transport roller having better toner transport performance and scraping performance.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a toner transport roller that is superior in conventional toner transport performance and scraping performance by solving the above-described problems and improving the uneven structure of the roller surface.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by forming wall-shaped convex portions having a predetermined size on the roller surface, and have completed the present invention.

That is, the toner transport roller of the present invention is a toner transport roller that contacts the developing roller that forms a visible image by transporting the toner carried on the surface to the image forming body and supplies the toner to the developing roller. In the toner transport roller formed by supporting urethane foam on the outer periphery of the shaft,
A wall-like convex part is formed on the urethane foam surface, and the maximum width of the wall-like convex part is in the range of 200 to 1000 μm and the height is in the range of 10 to 500 μm. It is a feature.

  In the roller of this invention, it is preferable that the cross-sectional shape of the said wall-shaped convex part is a substantially triangular shape. Moreover, it is also preferable that the formation direction of the said wall-shaped convex part inclines with respect to a roller axial direction. Furthermore, the wall-like convex portion is preferably formed by forming a lattice-like, twill-like or staggered pattern as a whole on the roller surface.

  According to the present invention, with the above-described configuration, it is possible to realize a toner transport roller that is more excellent in toner transport performance and scraping performance than in the past.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1A is a perspective view of an example of the toner conveying roller of the present invention. The toner conveying roller 10 of the present invention is in contact with a developing roller that forms a visible image by conveying toner carried on the surface to an image forming body, and supplies the toner to this developing roller. As described above, the urethane foam 2 is supported on the outer periphery of the shaft 1.

  FIG. 2 shows an uneven surface structure of an example of the toner conveying roller of the present invention. As shown in the drawing, wall-shaped convex portions are formed on the urethane foam surface of the roller of the present invention. By providing the wall-like convex portion on the surface, it is possible to increase the opening area while maintaining the scraping performance, and thereby it is possible to improve the transport amount. Further, according to the surface uneven structure according to the present invention, the phenomenon that the toner contained in the concave portion flows down through the concave groove as in the conventional case can be prevented, and the amount of toner that is stored and conveyed in the concave portion increases. In this respect, the image density can be improved. That is, since the fluidity of the toner is suppressed by providing the wall-shaped convex portions in an appropriate arrangement, the toner density contained in the opening (concave portion) formed by the wall-shaped convex portions is increased, and the amount of toner conveyed. Will increase. Further, since the toner flow when pressed against the developing roller can be reduced, the toner transport efficiency can be improved also in this respect.

  The maximum width w of the wall-like convex portion according to the present invention needs to be in the range of 200 to 1000 μm. By reducing the maximum width w of the wall-shaped convex portion, the amount of conveyance can be further improved. On the other hand, if the maximum width w is too thin, tearing or the like tends to occur during demolding or use.

  Moreover, the height of the wall-shaped convex part which concerns on this invention needs to be in the range of 10-500 micrometers. By setting the height of the wall-shaped convex portion within the above range, both the toner transportability and the scraping performance can be improved satisfactorily. On the other hand, if the height exceeds 500 μm, the scraping performance may be lowered. Moreover, there exists a possibility that a conveyance property may fall that it is less than 10 micrometers.

  Further, from the viewpoint of ensuring a large volume of the opening, for example, the wall-shaped convex portion preferably has a substantially triangular cross section as illustrated.

  In the present invention, as shown in the drawing, it is preferable that the wall-like convex portions form a lattice-like pattern as a whole on the roller surface. By combining the wall-shaped convex portions to form convex portions having a regular lattice pattern, the volumetric efficiency can be improved and the transportability can be improved. In this case, the shape of each lattice may be not only a rectangle but also a rhombus, a parallelogram, etc., and the dimensions thereof are, for example, 0.5 to 3 mm with respect to the intervals X and Y between the convex portions forming each lattice. Can do.

  In each figure, the arrow indicates the axial direction of the roller and is not particularly limited. However, in the present invention, the wall-like convex portion is preferably provided so as to be inclined with respect to the axial direction of the roller as shown. Thereby, toner scraping unevenness can be reduced. Specifically, for example, it can be provided so as to form 20 to 70 ° with respect to the roller axial direction. In particular, in the case of the lattice pattern shown in the figure, it is preferable that the diagonal direction of the lattice is substantially coincident with the roller axial direction and the direction orthogonal thereto.

4 (a), 4 (b) and 5 (a), 5 (b) each show another example of a wall-like convex portion formed on the roller surface. Shows a case where they are arranged in a twill pattern, and the latter shows a case where they are arranged in a staggered pattern. As described above, when the wall-shaped convex portions are arranged without being in contact with each other, the opening concave portions formed on the roller surface communicate with each other, so that the toner density in the concave portions is secured to some extent. Even when the toner stays in the vicinity of the bottom of the concave portion, the toner can flow between the concave portions, and the circulation property can be improved. In this case, the preferred dimensions of each part are the distances A, A ₁ and A ₂ between the wall-shaped convex parts of 0.5 to 3 mm, and the angle β formed with respect to the roller-axis direction of the wall-shaped convex part (the arrow direction in the figure) Is 20 to 70 °. In addition, in this invention, it cannot be overemphasized that the arrangement pattern of a wall-shaped convex part is not restrict | limited to these.

  The toner conveying roller of the present invention can be applied to, for example, a non-magnetic one-component developing device schematically shown in FIG. 6. In this case, the toner conveying roller 10 is disposed in contact with the developing roller 12. The toner 14 in the toner container is once carried on the surface of the developing roller 12 and conveyed to the image forming body 13 through this, thereby constituting a part of the developing process for visualizing the electrostatic latent image.

  The roller of the present invention can be easily manufactured by using a cylindrical roller manufacturing mold 20 having irregularities on the inner peripheral surface A as shown in FIG. That is, a mold having a groove-like recess corresponding to the wall-like protrusion on the roller surface is used on the inner peripheral surface A.

  As an example of the unevenness provided on the inner peripheral surface of the mold, FIG. 3 shows an uneven structure on the inner peripheral surface of the mold corresponding to the uneven structure on the roller surface of FIG. By using a mold having a lattice-shaped concave portion as shown in the figure on the inner peripheral surface A, a toner conveying roller having a lattice-shaped convex portion as shown in FIG. It can be formed.

  In addition, there is no restriction | limiting in particular also about the specific method at the time of manufacturing the roller of this invention using the above molds, For example, it can carry out in accordance with a conventional method, For example, the inner peripheral surface of the metal mold | die 20 is carried out. After applying a silicone-based release agent as desired, the shaft 1 is set as shown in FIG. 1 (b), and a mixed liquid obtained by appropriately adding an additive to the urethane foam raw material is injected and foamed. Thus, it is possible to obtain the roller 10 having the urethane foam 2 supported on the outer periphery of the shaft 1 and having irregularities formed on the surface thereof ((a) in the figure).

  The unevenness of the inner peripheral surface of the mold used for manufacturing the roller of the present invention can be formed by rolling, for example. By using the rolling process, the surface shape of the unevenness can be seamless, and the deep uneven shape required for the roller can be given, and a molding die that can withstand repeated use can be produced at low cost and in a short time. Can be produced. Moreover, since the corner | angular part of uneven | corrugated shape can be formed sharply, the scraping performance of a roller can be improved more. In particular, since the rolling process is suitable for forming regular continuous irregularities, a toner conveying roller having a desired regular surface irregularity shape by using a die having irregularities formed by the rolling process. Can be easily obtained. In addition, if rolling is used, there is a great merit in that even if the unevenness is in the range of 10 to 500 μm, it can be formed without causing corner sagging. Further, the irregularities of the regular lattice pattern as shown in FIG. 3 can be easily formed by rolling by adjusting the pitch of the irregularities to the circumference of the inner peripheral surface A.

  The toner conveying roller of the present invention is important only in that the surface has the wall-shaped convex portion having the specific dimension on the surface, and thereby the desired effect of the present invention can be obtained. The roller shape, material, etc. are not particularly limited.

  Here, since the toner conveying roller of the present invention has a relatively high unevenness on the surface, when the roller is manufactured using the mold, the roller surface becomes uneven on the inner peripheral surface of the mold at the time of demolding. It is important that the mold can be removed smoothly without being caught, broken or fluffed. From such a viewpoint, it is preferable to use a flexible urethane foam having excellent extensibility and high strength as the roller material. Preferably, a urethane foam having an elongation rate of 100% or more is used.

  The material of the urethane foam is not particularly limited as long as it contains a urethane bond in the resin. For example, the following materials can be used.

  Examples of the polyol component include polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide, polytetramethylene ether glycol, polyester polyol obtained by condensing an acid component and a glycol component, polyester polyol obtained by ring-opening polymerization of caprolactone, polycarbonate diol, and the like. Can be used.

  Examples of polyether polyols obtained by addition polymerization of ethylene oxide and propylene oxide include water, propylene glycol, ethylene glycol, glycerin, trimethylolpropane, hexanetriol, triethanolamine, diglycerin, pentaerythritol, ethylenediamine, and methylglucotite. , Aromatic diamine, sorbitol, sucrose, phosphoric acid, etc. as starting materials, and those obtained by addition polymerization of ethylene oxide and propylene oxide. Particularly, water, propylene glycol, ethylene glycol, glycerin, trimethylolpropane. Those starting from hexanetriol are preferred. Regarding the ratio of ethylene oxide and propylene oxide to be added and the microstructure, the ratio of ethylene oxide is preferably 2 to 95% by weight, more preferably 5 to 90% by weight, and ethylene oxide is added to the terminal. preferable. In addition, the arrangement of ethylene oxide and propylene oxide in the molecular chain is preferably random.

  The molecular weight of the polyether polyol is bifunctional when water, propylene glycol or ethylene glycol is used as a starting material, and preferably has a weight average molecular weight in the range of 300 to 6000, preferably in the range of 3000 to 5000. Is more preferable. Further, when glycerin, trimethylolpropane, and hexanetriol are used as starting materials, they are trifunctional, and those having a weight average molecular weight in the range of 900 to 9000 are preferable, and those in the range of 4000 to 8000 are more preferable. Furthermore, a bifunctional polyol and a trifunctional polyol can be appropriately blended and used. As will be described later, when the number of functional groups is small and the number of functional groups is the same, a higher molecular weight is preferable because a higher elongation can be realized.

  Polytetramethylene ether glycol can be obtained, for example, by cationic polymerization of tetrahydrofuran, and those having a weight average molecular weight in the range of 400 to 4000, particularly in the range of 650 to 3000 are preferably used. It is also preferable to blend polytetramethylene ether glycols having different molecular weights. Furthermore, polytetramethylene ether glycol obtained by copolymerizing an alkylene oxide such as ethylene oxide or propylene oxide can also be used.

  Further, it is also preferable to use a blend of polytetramethylene ether glycol and a polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide. In this case, it is preferable to use such a blend ratio so that the weight ratio is in the range of 95: 5 to 20:80, particularly 90:10 to 50:50.

  In addition to the polyol component, a polymer polyol obtained by modifying the polyol with acrylonitrile, a polyol obtained by adding melamine to the polyol, a diol such as butanediol, a polyol such as trimethylolpropane, or a derivative thereof may be used in combination.

  As the isocyanate constituting the urethane foam, aromatic isocyanate or a derivative thereof, aliphatic isocyanate or a derivative thereof, alicyclic isocyanate or a derivative thereof is used. Among these, aromatic isocyanate or a derivative thereof is preferable, and tolylene diisocyanate (TDI) or a derivative thereof, diphenylmethane diisocyanate (MDI) or a derivative thereof is particularly preferably used.

  Tolylene diisocyanate or derivatives thereof include crude tolylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, these These are urea-modified products, burette-modified products, carbodiimide-modified products, urethane-modified products modified with polyols, and the like. As diphenylmethane diisocyanate or a derivative thereof, for example, diphenylmethane diisocyanate or a derivative thereof obtained by phosgenating diaminodiphenylmethane or a derivative thereof is used. Examples of the derivatives of diaminodiphenylmethane include polynuclear bodies, and pure diphenylmethane diisocyanate obtained from diaminodiphenylmethane, polymeric diphenylmethane diisocyanate obtained from a polynuclear body of diaminodiphenylmethane, and the like can be used. Regarding the number of functional groups of polymeric diphenylmethane diisocyanate, a mixture of pure diphenylmethane diisocyanate and polymeric diphenylmethane diisocyanate having various functional groups is usually used, and the average number of functional groups is preferably 2.05 to 4.00, more preferably 2. .50 to 3.50 are used. Derivatives obtained by modifying these diphenylmethane diisocyanates or derivatives thereof, such as urethane modified products modified with polyols, dimers formed by uretidione formation, isocyanurate modified products, carbodiimide / uretonimine modified products, allophanate modified products , Urea-modified products, burette-modified products, and the like can also be used. Also, several types of diphenylmethane diisocyanate and its derivatives can be blended and used.

  In addition, the isocyanate may be prepolymerized with a polyol in advance. As a method for this, the polyol and the isocyanate are put in a suitable container and sufficiently stirred, and 30 to 90 ° C, more preferably 40 to 70 ° C, A method of keeping the temperature for 240 hours, more preferably 24 to 72 hours can be mentioned. In this case, the ratio of the amount of polyol and isocyanate is preferably adjusted so that the isocyanate content of the resulting prepolymer is 4 to 30% by weight, more preferably 6 to 15% by weight. If the isocyanate content is less than 4% by weight, the stability of the prepolymer is impaired, and the prepolymer may be cured during storage, making it impossible to use. If the isocyanate content exceeds 30% by weight, the content of isocyanate that has not been prepolymerized increases, and this polyisocyanate undergoes a prepolymerization reaction with the polyol component used in the subsequent polyurethane curing reaction. The effect of using the prepolymer method is diminished because it cures by a reaction mechanism similar to the one-shot process. In the case of using an isocyanate component in which isocyanate is prepolymerized with a polyol in advance, in addition to the above polyol component, diols such as ethylene glycol and butanediol, polyols such as trimethylolpropane and sorbitol, and derivatives thereof Can also be used.

  In addition to the polyol component and isocyanate component described above, a conductive agent, a foaming agent (water, low-boiling substances, gas bodies, etc.), a crosslinking agent, a surfactant, a catalyst, a foam stabilizer, etc. are added to the urethane foam as required. Thus, a layer structure as desired can be obtained. In addition, flame retardants and fillers, conductive agents such as ionic conductive agents and electronic conductive agents, and known fillers and cross-linking agents can be used as appropriate.

  Examples of ionic conductive agents include tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium (eg, lauryltrimethylammonium), hexadecyltrimethylammonium, octadecyltrimethylammonium (eg, stearyltrimethylammonium), benzyltrimethylammonium, modified fatty acid dimethylethyl. Perchlorates such as ammonium, chlorates, hydrochlorides, bromates, iodates, borofluorides, sulfates, alkyl sulfates, carboxylates, sulfonates, ammonium salts such as lithium, Perchlorate, chlorate, hydrochloride, bromate, iodate, borofluoride, trifluoromedium of alkali metals and alkaline earth metals such as sodium, potassium, calcium and magnesium Le sulfate, and sulfonic acid salts.

  Examples of the electronic conductive agent include conductive carbon such as ketjen black and acetylene black; carbon for rubber such as SAF, ISAF, HAF, FEF, GPF, SRF, FT, and MT; for ink subjected to oxidation treatment Examples thereof include carbon, pyrolytic carbon, natural graphite, and artificial graphite; conductive metal oxides such as tin oxide, titanium oxide, and zinc oxide; metals such as nickel, copper, silver, and germanium. These conductive agents may be used alone or in combination of two or more. There is no restriction | limiting in particular in the compounding quantity, Although it can select suitably as desired, Usually, it is 0.1-40 weight part with respect to 100 weight part of total amounts of a polyol and isocyanate, Preferably it is 0.3-20. It is the ratio of parts by weight.

  Catalysts used for urethane foam curing reactions include monoamines such as triethylamine and dimethylcyclohexylamine, diamines such as tetramethylethylenediamine, tetramethylpropanediamine, and tetramethylhexanediamine, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, tetra Triamines such as methylguanidine, triethylenediamine, dimethylpiperazine, methylethylpiperazine, cyclic amines such as methylmorpholine, dimethylaminoethylmorpholine, dimethylimidazole, dimethylaminoethanol, dimethylaminoethoxyethanol, trimethylaminoethylethanolamine, methylhydroxy Alcohol amines such as ethyl piperazine and hydroxyethyl morpholine; (Dimethylaminoethyl) ether, ether amines such as ethylene glycol bis (dimethyl) aminopropyl ether, stannous octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin marker peptide, dibutyltin thiocarboxylate, dibutyltin dimaleate, And organic metal compounds such as dioctyltin marker peptide, dioctyltin thiocarboxylate, phenylmercury propionate and lead octenoate. These catalysts may be used alone or in combination of two or more.

  In the present invention, it is preferable to blend a silicone foam stabilizer and various surfactants during the blending of the urethane foam in order to stabilize the cells of the foam material. As the silicone foam stabilizer, dimethylpolysiloxane-polyoxyalkylene copolymer and the like are preferably used, and those composed of a dimethylpolysiloxane moiety having a molecular weight of 350 to 15000 and a polyoxyalkylene moiety having a molecular weight of 200 to 4000 are particularly preferable. . The molecular structure of the polyoxyalkylene moiety is preferably an addition polymer of ethylene oxide or a co-addition polymer of ethylene oxide and propylene oxide, and its molecular terminal is preferably ethylene oxide. Examples of the surfactant include cationic surfactants, anionic surfactants, ionic surfactants such as amphoteric, nonionic surfactants such as various polyethers and various polyesters. These may be used alone or in combination of two or more. The blending amount of the silicone foam stabilizer and various surfactants is preferably 0.1 to 10 parts by weight, and 0.5 to 5 parts by weight with respect to 100 parts by weight of the total amount of the polyol component and the isocyanate component. More preferably.

  As a foaming method of the urethane foam raw material in the present invention, a conventionally used method such as a mechanical froth method (a method of foaming by mechanical stirring while mixing an inert gas), a water foaming method, a foaming agent froth method, and the like. Can be used. Here, the inert gas used in the mechanical froth method may be an inert gas in the polyurethane reaction, and in addition to inert gases in a narrow sense such as helium, argon, xenon, radon, krypton, nitrogen, carbon dioxide, drying The gas which does not react with urethane foam raw materials, such as air, is mentioned.

Further, in the present invention, it is preferable that the urethane foam 2 has a cell opening communicating with the inside thereof on the surface, so that the toner is satisfactorily supplied from the inside of the foam and the problem of destabilization of the toner conveyance amount is solved. Will be. Preferably, the diameter of the cell opening is 50 to 400 μm, and the number of the opening per 1 cm ² of the urethane foam surface is preferably 100 to 2000. Formation of a urethane foam for obtaining a structure having such a cell opening can be performed based on the prior art by a combination of a polyurethane blend and a release agent.

  Further, the shaft 1 used in the roller of the present invention is not particularly limited, and any one can be used. For example, a steel material such as sulfur free-cutting steel plated with nickel or zinc, or iron Furthermore, a metal shaft such as a metal core made of a solid metal such as stainless steel or aluminum, or a metal cylinder hollowed out inside can be used.

Hereinafter, the present invention will be described specifically by way of examples.
An iron shaft (diameter 6 mm, length 250 mm) as shaft 1 is placed on a cylindrical mold (made of SUS, inner diameter φ12 mm × length 290 mm (elastic layer forming part length: 220 mm)) as shown in FIG. The shaft 1 was fixed with the upper mold and the lower mold. A urethane foam raw material prepared with the composition shown in Table 1 below is injected into this mold, foamed, and cured at 60 ° C. for 0.5 hours, thereby supporting the urethane foam on the outer periphery of the shaft. A toner conveying roller was manufactured.

<Each Example and Comparative Example>
The concave and convex shapes corresponding to the convex shapes of the roller surfaces shown in the following Table 2 were respectively formed on the inner peripheral surface of the mold used by rolling, thereby forming the concave and convex shapes on the surface of each test roller. In each figure, the direction of the roller axis is indicated by an arrow. In Example 5 only, the lattice-like wall-shaped convex portions were formed in the direction along the roller axis direction. That is, the direction in which the wall-shaped convex portion is formed is 45 ° different from the first and second embodiments.

＊１：三洋化成（株）製、３官能ポリエーテルポリオール（Ｍｗ：５，０００）
＊２：旭硝子（株）製、３官能ポリエーテルポリオール（Ｍｗ：７，０００）
＊３：三洋化成（株）製、２官能ポリエーテルポリオール（Ｍｗ：４，０００）
＊４：東レ・ダウコーニングシリコーン（株）製、シリコーン整泡剤
＊５：花王（株）製、３級アミン触媒
＊６：花王（株）製、脂肪族３級アミン触媒

* 1: Trifunctional polyether polyol (Mw: 5,000) manufactured by Sanyo Chemical Co., Ltd.
* 2: Trifunctional polyether polyol (Mw: 7,000) manufactured by Asahi Glass Co., Ltd.
* 3: Sanyo Chemical Co., Ltd. bifunctional polyether polyol (Mw: 4,000)
* 4: Silicone foam stabilizer manufactured by Toray Dow Corning Silicone Co., Ltd. * 5: Tertiary amine catalyst manufactured by Kao Corporation * 6: Aliphatic tertiary amine catalyst manufactured by Kao Corporation

<Toner discharge amount measurement>
The obtained urethane foam of each test roller was filled with toner, rolled in a state where it was pushed in by 1 mm, and the weight of toner discharged per width of 220 mm and rolling distance of 50 mm was measured.

<Image density measurement and image unevenness determination>
Each test roller was mounted on a corresponding printer, an image output test was performed, and a Macbeth densitometer was used to determine whether the image density reached a specified value. Those that reached the specified value were marked with ○, and those that did not reach were marked with ×. In addition, regarding the presence or absence of image unevenness, according to the evaluation criteria: ○: image unevenness is not observed, Δ: image unevenness is observed but does not cause a problem, ×: clear image unevenness is observed, Judged.
These results are also shown in Table 2 below.

  As shown in Table 2 above, in the sample roller of Comparative Example 1, since the uneven structure was not formed on the surface, the toner discharge amount did not increase and the image density was not improved. Further, in the test roller of Comparative Example 2 provided with the dimple-like recesses, the volume of the recesses was small, so the toner discharge amount did not increase, and the image density was not improved. Furthermore, in the test roller of Comparative Example 3, the convex portion was too high, so that tearing occurred at the time of demolding, resulting in image unevenness.

  On the other hand, in the test rollers of Examples 1 and 2, it was confirmed that a sufficient image density could be obtained by ensuring a high toner discharge amount, and no image unevenness occurred. Further, in the test rollers provided with the parallel wall-shaped convex portions of Examples 3 and 4, since there is no rib for partitioning the opening groove, the toner flows along the groove direction when the developing roller is pressed, The result was slightly inferior to the image density. Further, in the test roller of Example 5 in which the wall-shaped convex portions are formed without being inclined with respect to the roller axial direction, the toner scraping is performed in parallel with the rotation direction. Appeared in. Furthermore, in the test roller of Example 6, although it did not appear in the image evaluation, the convex part was partially cut off due to the difference in the urethane foam composition. Although not shown in the table, if the wall-like convex portions are arranged in a cross pattern as shown in FIG. 4, toner clogging is reduced. It was confirmed that it was obtained.

(A) is a schematic perspective view which shows an example of the toner conveyance roller of this invention, (b) is a schematic perspective view which shows an example of the metal mold | die for roller manufacture used for the manufacture. FIG. 6 is a schematic perspective view illustrating an example of a lattice-like wall-shaped convex portion formed on the surface of the toner conveying roller of the present invention. It is a schematic perspective view which shows the grid | lattice-like recessed part formed in the internal peripheral surface of the metal mold | die for roller manufacture. It is explanatory drawing which shows an example of the wall-shaped convex part formed in the twill shape on the roller surface. It is explanatory drawing which shows an example of the wall-shaped convex part formed in the zigzag form on the roller surface. FIG. 2 is a schematic diagram illustrating an example of a non-magnetic one-component developing device. It is a schematic perspective view which shows the uneven | corrugated shape formed in the roller surface of Example 3, 4 and the comparative example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 axis | shaft 2 urethane foam 10 toner conveyance roller 12 developing roller 13 image forming body 14 toner 20 die for roller manufacture

Claims (4)

A toner conveying roller that contacts the developing roller that forms a visible image by conveying the toner carried on the surface to the image forming body and supplies the toner to the developing roller, and carries urethane foam on the outer periphery of the shaft. In the toner transport roller
A wall-like convex part is formed on the urethane foam surface, and the maximum width of the wall-like convex part is in the range of 200 to 1000 μm and the height is in the range of 10 to 500 μm. A toner transport roller.   The toner conveying roller according to claim 1, wherein a cross-sectional shape of the wall-like convex portion is a substantially triangular shape.   The toner conveying roller according to claim 1, wherein a forming direction of the wall-shaped convex portion is inclined with respect to a roller axial direction. The toner conveying roller according to any one of claims 1 to 3, wherein the wall-like convex portion forms a lattice-like, twill-like or staggered pattern as a whole on the roller surface.

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