JP2010066332A - Cleaning blade, developing blade, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning blade or a developing blade using an elastic member made of polyurethane, to which a friction lowering agent, an abrasive agent and a conductive agent are applied. <P>SOLUTION: For the cleaning blade or the developing blade, the elastic member made of polyurethane in which the composition of the polyurethane forming an edge part or a nip part and a backup layer is different is bonded to a metallic support member. The polyurethane forming the edge part or the nip part is the polyurethane in which an additive is mixed, and the polyurethane forming the backup layer is the polyurethane in which an additive is not mixed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cleaning blade and a developing blade for an electrophotographic apparatus in which a polyurethane elastic member composed of a layer having a different polyurethane composition forming an edge portion or a nip portion is bonded to a metal support member. Examples of the electrophotographic apparatus include an electrophotographic copying machine, a printer, and a facsimile. In particular, the present invention relates to a cleaning blade made of thermosetting polyurethane, a developing blade, and a manufacturing method thereof.

Conventional toner cleaning using an electrophotographic method has widely used a blade cleaning method that is small in size and cost-effective. Blades are required to have long life, power saving, countermeasures against abnormal noise at high temperatures, countermeasures for deterioration of cleaning properties at low temperatures, countermeasures for deterioration of cleaning properties due to settling in long-term pressure contact conditions at high temperatures, and the like.
In recent years, an increasing number of models using so-called spherical toner, which is a substantially spherical toner, for reasons such as improved image quality due to colorization. This spherical toner tends to enter the gap between the cleaning edge and the roll, and pushes the edge to slip through. It's getting easier. As the speed of the apparatus increases, the requirements for the cleaning blade are becoming more and more complex.

As polyurethane elastic members for cleaning blades or developing blades, polyurethane elastic members molded with additives such as low friction agents, abrasives, conductive agents, etc., or these agents can be sprayed on the surface of polyurethane elastic members. Attempted coating by dipping.
In the dipping method, since the same coating solution is used repeatedly, the pot life of the coating solution must be long. The equipment becomes large-scale in order to keep the physical properties (viscosity, solid content ratio, etc.) of the coating liquid constant. Masking is required, and the masking needs to be attached and detached before and after the coating and drying of the coating solution, which makes it difficult to automate and is not practical. There is a problem that the number of processes increases in the dipping method and the spray method.
In the spray coating method, the coating solution is used up and is superior to dipping in terms of pot life, but the coating efficiency is poor and masking is also required. In addition, the film tends to vary depending on the environment such as temperature and humidity.
It is difficult to make the width and thickness of the coating layer uniform by a coating method using a dispenser.
In particular, when used for a cleaning blade, there is a problem that the accuracy of the edge accuracy is inferior.
When an elastic member made of polyurethane mixed with additives or an elastic member made of polyurethane with additives attached to the surface is bonded to a metal support material, the adhesive force cannot be obtained sufficiently and cannot be used in practice. There is also. Causes of adhesion failure include deterioration of the surface properties of polyurethane due to the additive and a decrease in conformity with the adhesive, and deterioration of the adhesion due to bleeding of the additive on the surface.

On the other hand, the present applicant has continuously proposed inventions relating to a polyurethane cleaning blade or developing blade for an electrophotographic apparatus comprising a layer having a different polyurethane composition forming the backup layer and the edge portion or nip portion.
In Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-30385), a continuous molding method is used, and a synthetic resin is used as a molding raw material by using a molding drum having a molding groove on the outer periphery and a heating device inside. In the method of continuously forming the raw material of the blade, a method of manufacturing a blade raw material combining different materials by separately casting two or more different liquid synthetic resin raw materials was proposed.
In Patent Document 2 (Japanese Patent Laid-Open No. 2007-163676), a casting method is used, and a liquid synthetic resin that forms a partial layer is cast into a bead shape in one mold of a split mold. Later, a method of manufacturing a blade was proposed in which a mold was assembled, a liquid synthetic resin for forming a base layer was cast, and then heat cured to form a blade material.

JP 2007-30385 A JP 2007-163676 A

  An object of the present invention is to provide a cleaning blade or a developing blade using a polyurethane elastic member to which a friction reducing agent, an abrasive, and a conductive agent are applied.

  The present invention has been completed by applying the manufacturing technology of polyurethane elastic members formed with partial layers of different materials, which the applicant has continuously pursued.

The main solution of the present invention is as follows.
(1) A cleaning blade or a developing blade obtained by adhering an elastic member made of polyurethane having a different polyurethane composition to the edge portion or nip portion to form a backup layer to a metal support member, and the polyurethane forming the edge portion or nip portion is A cleaning blade or a developing blade, which is a polyurethane mixed with an additive, and the polyurethane forming the backup layer is a polyurethane not mixed with the additive.
(2) The cleaning blade or developing blade according to (1), wherein the polyurethane in the edge portion or nip portion is made of ester polyurethane, and the polyurethane in the backup layer is made of ether polyurethane.
(3) The cleaning blade or the developing blade according to (1) or (2), wherein the edge portion or the nip portion has a color different from that of the backup layer.
(4) The cleaning blade or developing blade according to any one of (1) to (3), wherein the additive is any one of a friction reducing agent, an abrasive, and a conductive agent.
(5) The cleaning blade or developing blade according to (4), wherein the friction reducing agent is any one of a fatty acid metal salt, silicone oil, organic fine particles, and inorganic fine particles.
(6) The cleaning blade or developing blade according to (4), wherein the abrasive is cerium oxide or silica.
(7) The cleaning blade or developing blade according to (4), wherein the conductive agent is carbon black or imidolithium.
(8) A method of manufacturing a cleaning blade or a developing blade by adhering an elastic member made of polyurethane having an edge portion or nip portion and a backup layer made of different materials to a metal support member, comprising a molding groove on the outer periphery, A molding drum provided with a heating device inside, endlessly rotating along the outer periphery of the molding drum in synchronism with the rotation of the molding drum while covering the molding groove with the synthetic resin supply means and the molding drum A method of manufacturing a belt-like blade material having a predetermined width and thickness according to the rotation of a molding drum by using a molding space formed by an endless belt and a molding groove by using a synthetic resin raw material supplied to the molding groove by sequentially arranging belts. A method for producing the polyurethane elastic member used,
The polyurethane material mixed with the additive that forms the edge layer is poured into a cylindrical mold and cured while rotating the mold. After semi-curing, the polyurethane material that forms the backup layer is poured and rotated. Take out the band-shaped blade material composed of two layers by curing, cut the width and length to a certain size, mold the polyurethane elastic member, and then adhere the polyurethane elastic member to the metal support member A method of manufacturing a cleaning blade or a developing blade.
(9) A method of manufacturing a cleaning blade or a developing blade by bonding a polyurethane elastic member having an edge portion or nip portion and a backup layer made of different materials to a metal support member, wherein two mold members are molded A method for producing an elastic member made of polyurethane using a split mold method in which a liquid polyurethane raw material is cast into a cavity formed by assembly and then demolded after polymerization and curing. Apply polyurethane mixed with a liquid additive that forms a streak-like edge to the wall of one split mold, mold it after semi-curing, inject the polyurethane raw material that forms the backup layer, and cure A method for producing a cleaning blade or a developing blade by demolding to obtain a polyurethane elastic member and bonding the polyurethane elastic member to a metal support member.
(10) The cleaning blade according to (8) or (9), wherein the polyurethane raw material forming the edge portion or nip portion is an ester polyurethane raw material, and the polyurethane raw material forming the backup layer is an ether polyurethane raw material Development method of developing blade.

By using a polyurethane elastic member using polyurethane with an additive different from the backup layer only on the edge or nip that comes into contact with the mating material such as a roll, the influence of the additive is limited only to the edge or nip. Thus, it is possible to provide a cleaning blade or a developing blade that does not require other elements such as adhesion to the metal support member to be changed. Since conventional manufacturing processes, adhesives, and the like can be used, performance can be improved while maintaining productivity.
When a conductive agent is added, the cleaning blade can neutralize the residual charge of the toner, reduce the adhesion of the toner, improve the cleaning performance for a long time, and the developing blade can keep the linear pressure constant for a long time. Printing defects such as fogging can be reduced.
When a friction reducing agent is added, the cleaning performance and rubbing can be maintained without increasing the pressure contact force, the driving force of the photosensitive drum can be suppressed, and the frictional heat can be reduced. Therefore, it is possible to reduce the cooling device such as heat dissipation, and to save power. Further, when the pressure contact force is increased, the frictional force is increased and the blade is turned up and turned over. However, such a problem can be prevented by using a low friction blade.
When an abrasive is added, it is possible to effectively remove transfer residual toner and adhered substances on the photoreceptor. Removal of deposits such as ozone and nitrogen oxide caused by bias application can be improved by adding an abrasive.
Since the area | region to which the elastic member made from a polyurethane adhere | attached with a metal support member adheres is a part which is not influenced by an additive, adhesive strength can fully be ensured.

  A cleaning blade or developing blade using polyurethane having a different composition for the edge portion or nip portion and the backup layer, and a combination of the edge portion or nip portion made of ester polyurethane and the backup layer made of ether polyurethane is suitable. . When the edge portion is colored, measurement of the edge portion and trimming are facilitated.

<Blade shape and configuration>
The cleaning blade of the present invention is configured, for example, by adhering a polyurethane elastic member comprising a partial layer 1 at an edge portion and a base layer 2 as a backup layer shown in FIG. In the present invention, it is basically preferable to use ester polyurethane for the edge portion and ether polyurethane for the base portion.
The developing blade of the present invention is constituted by adhering a polyurethane elastic member provided with a nip portion that rubs with toner as a partial layer to a support member.

<Additives>
Additives are mixed into the polyurethane forming the edge or nip. Examples of the additive include a friction reducing agent (low-μ material), an abrasive, and a conductive agent. These additives are not added to the backup layer.

(1) Friction reducing agent (low μ material)
An additive having a function of reducing the coefficient of friction is administered to make a low μ blade.
Examples of additives include fatty acid metal salts, silicone oil, organic fine particles, inorganic fine particles, polysiloxane, dimethylpolysiloxane, polysiloxane oil, perfluoropolyethers such as perfluoropolyether diols and polyalkoxylated diols of perfluoropolyethers. Compounds, graphite fluoride, zinc stearate, metal oxide powders, and the like. Also, resin fine particles such as vinyl resin, fluorine resin, silicone resin, polyester resin, amide resin, urethane resin, phenol resin, epoxy resin, etc. can be used. Inorganic elements such as aluminum, silicon and calcium, waxes and oils can be contained.
By using a blade with a small coefficient of friction, it is possible to suppress blade curling and to reduce the driving torque of an image carrier such as a roll. In the conventional blade, it has been necessary to increase the driving torque of the image bearing member against the occurrence of blade curl or to increase the pressure contact force in order to maintain the cleaning performance.
When a friction reducing agent is added, the cleaning performance and rubbing can be maintained without increasing the pressure contact force, the driving force of the photosensitive drum can be suppressed, and the frictional heat can be reduced. Therefore, it is possible to reduce the cooling device such as heat dissipation, and to save power. Further, when the pressure contact force is increased, the frictional force is increased and the blade is turned up and turned over. However, such a problem can be prevented by using a low friction blade.

(2) Abrasive
A particle having a polishing function is administered to form a polishing blade. Examples of the abrasive include cerium oxide, silica, cerium, zirconium, strontium and the like.
The abrasive particles are applied to a blade used for the purpose of refreshing the surface of a mating material that comes into contact with the photosensitive member or the like. When an abrasive is added, it is possible to effectively remove transfer residual toner and adhered substances on the photoreceptor. Removal of deposits such as ozone and nitrogen oxide caused by bias application can be improved by adding an abrasive.

(3) Conductive agent A material capable of changing the charging characteristics in the vicinity of the edge is administered to form a conductive blade. Examples of imparting conductivity include magnetic materials such as carbon black, imide lithium, bis (trifluoromethanesulfonyl) imide lithium, magnetite, azine compounds, quaternary ammonium salts, metal-containing azo dyes, and the like.
When a conductive agent is added, the cleaning blade can neutralize the residual charge of the toner, reduce the adhesion of the toner, improve the cleaning performance for a long time, and the developing blade can keep the linear pressure constant for a long time. Printing defects such as fogging can be reduced.

<Types of polyurethane>
The blade used in the present invention is suitably made of a thermosetting polyurethane resin.
As the urethane forming material, a polyurethane composition containing a polyisocyanate and a polyol is used.
As the polyol component, it is suitable to use an ester-based polyurethane for the layer including the edge portion or the nip portion, and use an ether-based polyurethane for the base portion other than the layer including the edge portion or the nip portion.
The polyurethane raw material used in the present invention is preferably non-solvent type thermosetting. For example, ester polyurethane and ether polyurethane disclosed in Japanese Patent Application No. 2007-18162 filed earlier by the present applicant can be used. If a colorant is added to the edge portion or nip portion polyurethane resin to make the color different from that of the backup layer, the size of the edge portion can be clearly identified. It becomes easy to trim and form the edge size after the polyurethane is cured.

(1) Ester polyol
As the ester-based polyurethane forming the edge layer used in the present invention, conventionally used ester-based polyurethane can be used. Polyester polyols such as polyester diol and polyester triol. By setting the tan δ peak temperature to -20 to 5 ° C, ester polyurethane can be used as a backup layer.
The polyester polyol is produced from a polybasic organic acid and a polyol. Polycaprolactone polyols such as polycaprolactone diol obtained from ring-opening polymerization of ε-caprolactam can also be used.
Polybasic organic acid is not particularly limited, 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, Examples thereof include unsaturated fatty acids such as fumaric acid, and dicarboxylic acids such as aromatic acids such as phthalic acid, isophthalic acid and terephthalic acid. In addition, acid anhydrides such as maleic anhydride and phthalic anhydride, and dialkyl esters such as dimethyl terephthalate can also be used. Furthermore, dimer acid obtained by dimerization of unsaturated fatty acid can also be used. These may be used alone or in combination of two or more.

  The polyol is not particularly limited, and diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, 1,6-hexylene glycol, trimethylolethane, Examples include triols such as trimethylolpropane, hexanetriol, glycerin, hexaols such as sorbitol, polybutylene adipate (PBA), polyethylene adipate, and the like. These may be used alone or in combination of two or more.

(2) Ether type polyol In this invention, ether type urethane is used as a backup layer.
Polyether polyols such as polyoxytetramethylene glycol and polypropylene glycol.
Examples of the polyether polyol include cyclic ethers such as ethylene oxide, propylene oxide, trimethylene oxide, butylene oxide, α-methyltrimethylene oxide, 3,3′-dimethyltrimethylene oxide, tetrahydrofuran, dioxane, and dioxamine.

(3) Polyisocyanate
The polyisocyanate is not particularly limited. For example, 4,4'-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2, 6-TDI), 3,3′-vitrylene-4,4′-diisocyanate, 3,3′-dimethyldiphenylmethane-4,4′-diisocyanate, 2,4-tolylene diisocyanate uretidinedione (2,4-TDI) Dimer), 1,5-naphthylene diisocyanate, metaphenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), carbodiimide-modified MDI, orthotoluidine diisocyanate, xylene Diisocyanate, paraphenylene diisocyanate, diisocyanate such as lysine diisocyanate methyl ester, triisocyanate such as triphenylmethane-4,4 ′, 4 ″ -triisocyanate, and polymeric MDI. These may be used alone or in combination of two or more. Of these, MDI is preferred from the viewpoint of wear resistance.

(4) Other materials In addition to the above polyisocyanates and polyols, polyurethane compositions typically include chain extenders, surfactants, flame retardants, colorants, fillers, plasticizers, stabilizers, mold release agents, catalysts, etc. The agent currently used can be mix | blended.

  The chain extender is not particularly limited as long as it is a conventionally known one. For example, 1,4-butanediol (1,4-BD), ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, Hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, xylene glycol, triethylene glycol, trimethylolpropane (TMP), glycerin, pentaerythritol, sorbitol, 1,2,6-hexanetriol, etc. Examples include polyols having a molecular weight of 300 or less. These may be used alone or in combination of two or more.

Examples of the catalyst include amine compounds such as tertiary amines and organometallic compounds such as organotin compounds. Of these, amine compounds are preferred.
Examples of the tertiary amine include trialkylamines such as triethylamine, tetraalkyldiamines such as N, N, N ′, N′-tetramethyl-1,3-butanediamine, aminoalcohols such as dimethylethanolamine, Ethoxylated amines, ethoxylated diamines, ester amines such as bis (diethylethanolamine) adipate, triethylenediamine, cyclohexylamine derivatives such as N, N-dimethylcyclohexylamine, N-methylmorpholine, N- (2 Morpholine derivatives such as -hydroxypropyl) -dimethylmorpholine and piperazine derivatives such as N, N'-diethyl-2-methylpiperazine and N, N'-bis- (2-hydroxypropyl) -2-methylpiperazine It is done.
Examples of the organic tin compound include dialkyltin compounds such as dibutyltin dilaurate and dibutyltin di (2-ethylhexoate). Moreover, 2-ethyl caproic acid stannous, oleic acid stannous, etc. are mention | raise | lifted.

(5) Resin Example The synthetic resin used in the present invention is mainly a thermosetting polyurethane resin. In particular, a non-solvent two-component thermosetting polyurethane is suitable. In the continuous molding method using the outer peripheral molding groove rotating drum, the time from casting to taking out is within one rotation of the forming drum, and it is necessary to be polymerized and solidified so that it can be taken out in about 30 to 60 seconds. Select and design isocyanates and polyols, crosslinking agents, and catalysts that satisfy these conditions. In the post-removal step, secondary cross-linking and aging steps can be performed. Even when the split mold is used, it is desirable to shorten the initial curing time of the ester polyurethane used as the edge portion or the nip portion.

For example, the polyurethane resin previously proposed in Japanese Patent No. 3004586, Japanese Patent No. 2942183, Japanese Patent No. 2645980, Japanese Patent Application Laid-Open No. 2002-214989, Japanese Patent Application Laid-Open No. 2002-214990, and the like is exemplified. The following polyurethanes can be used.
A bifunctional polyol having a number average molecular weight of 1000 to 3000, a trifunctional polyol having a number average molecular weight of 92 to 980, and a high molecular weight polyol component mixed in at least one of a liquid material of a urethane prepolymer and a liquid material of a crosslinking agent, Is mixed with a polyol having an average functional group number of 2.02 to 2.20 and a diisocyanate compound having an isocyanate group content of 5 to 20% to prepare a prepolymer, and the prepolymer is mixed with an OH group / NCO. A polyurethane liquid (uncured polyurethane composition) is prepared by mixing the cross-linking agent in an amount such that the equivalent ratio of groups becomes 0.85 to 1.00 at 40 to 70 ° C.

The number average molecular weight of the high molecular weight polyol component is preferably in the range of 1000 to 3000. By casting this composition, the reaction is carried out smoothly, and the properties of the resulting blade are also preferred. That is, the number average molecular weight of the polyol used is in the range of 1000 to 3000, and if it is less than 1000, the finished urethane rubber becomes too hard to obtain the necessary physical properties (flexibility), and exceeds 3000. And the viscosity at the time of molding is high, making it difficult to cast.
In addition, when the average number of functional groups (f) is f = 1, it becomes monool, so that it does not polymerize, and when f ≧ 5, it becomes too polyfunctional, so that the viscosity of the polymer increases and the physical properties decrease.

  The following can be used as a component for producing the polyurethane elastomer according to the present invention. Examples of polyether polyols include polyoxyalkylene glycols such as polyethylene glycol, polypropylene glycol and polyoxytetramethylene glycol, or polyether-type polyols of alkylene oxide adducts such as bisphenol A, glycerin ethylene oxide and propylene oxide. Is done. Examples of polyester polyols include dibasic acids such as adipic acid, phthalic anhydride, isophthalic acid, maleic acid, and fumaric acid, and ethylene glycol, propylene glycol, 1,4 butanediol, 1,6 hexanediol, trimethylolpropane, and the like. Mention may be made of polyester polyols and polycaprolactone diols obtained by polymerization reactions with glycols.

  Examples of the diisocyanate compound include tolylene diisocyanate, 4,4 diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 1,4 cyclohexane diisocyanate, and the like. Examples of the chain extender include low molecular weight diols such as ethylene glycol, 1,4 butanediol, diethylene glycol, 1,6 hexanediol, and neopentyl glycol, and diamines such as ethylenediamine, hexamethylenediamine, and isophoronediamine. Desirably, a low molecular weight diol is used. Furthermore, you may add a trimethylol propane, a triethanolamine, glycerol, and these ethylene oxide and a propylene oxide adduct as a polyfunctional component as needed.

  In the production of the above polyurethane, the equivalent ratio of OH group / NCO group is preferably 0.8 to 1.05, preferably 0.85 to 1.00, from the physical properties of the polyurethane to be produced. Moreover, reaction accelerators, such as a general amine compound and an organic tin type compound, are used as needed. For example, the reaction accelerator disclosed in Japanese Patent No. 2942183, paragraph 0022 is an imidazole derivative or the like represented by the following general chemical formula, and specific examples thereof include a reaction temperature highly dependent on the chemical structure. Examples thereof include 2-methylimidazole and 1,2 dimethylimidazole.

式中Ｒは水素、メチル基，又はエチル基を示す。

In the formula, R represents hydrogen, a methyl group, or an ethyl group.

  Such a reaction accelerator is used in an amount of 0.01 to 0.5 parts by weight, preferably 0.05 to 0.3 parts by weight, based on 100 parts by weight of the prepolymer as an effective amount. Desirably, those having a temperature sensitivity or a slow-acting property are preferably used because the usable time of the mixed resin can be increased and the demolding time is shortened. Specific examples thereof include 1,8-diazabicyclo (5,4,0) undecene-7-organic acid salt called block amine, 1,5-diazabicyclo (4,3,0) nonene-5-organic acid. Examples thereof include a salt or a mixture thereof. In this invention, a commercially available thing can be used for the two-component mixing casting machine used for mixing and stirring the liquid material of the urethane prepolymer which is the raw material component of the thermosetting polyurethane and the liquid material of the crosslinking agent. In consideration of the quantitative accuracy, the metering pump preferably uses a triple or more plunger type, but a gear pump type can also be used. In particular, in the production apparatus of the present invention, it is necessary to use a reaction accelerator in order to obtain a predetermined hardness at the time of demolding, and therefore, a stirring and mixing chamber is disclosed in Japanese Patent Publication No. 6-11389. A small-capacity type that prevents residence in the mixing chamber and suppresses heat generation due to reaction heat is preferable.

  Although the two-component thermosetting polyurethane resin is illustrated in detail, the blade resin that can be used in the present invention is not limited to this. Either a thermoplastic resin or a thermosetting resin can be used. Since a heated rotating molding drum is used, the non-solvent type containing no solvent is preferable because the thermosetting reaction is started immediately after casting.

  By blending these synthetic resin components, a resin composition to be a partial layer and a resin composition to be a base layer are prepared and used. Synthetic resin used as a partial layer for the edge or nip is designed with high hardness and high resilience, and the resin used for the base layer (backup layer) is designed for lower hardness and low resilience than the edge layer or nip. Is done.

<Method for producing polyurethane elastic member>
A method of forming a polyurethane layer as a partial layer for forming an edge portion or a nip portion and a polyurethane layer of a base portion layer (backup layer) is as follows. (A) Using a rotary molding drum in which grooves are formed on the outer periphery. A continuous molding method and (b) an individual molding method using a split mold can be used. Additives such as a friction reducing agent, an abrasive and a conductive agent are blended in the polyurethane forming this partial layer.
(1) Method of Continuous Molding Using a Rotating Molding Drum with Grooves on the Outer Peripheral This molding means can use the means disclosed in Japanese Patent Application Laid-Open No. 2007-30385 previously proposed by the inventor of the present application. . Continuously produce a synthetic resin tape having a width that is the same as or slightly larger than the width of the synthetic resin elastic rubber used in the blade, cut the long tape to a fixed size, A technique for joining a side edge of a metal support and finishing it to a developing blade, a cleaning blade or the like is a basic manufacturing method.
The basic manufacturing means used for this manufacturing method is to continuously cast a liquid material such as polyurethane into the forming groove from the vicinity of the apex while rotating a forming drum having a forming groove on the outer periphery around the horizontal axis, and forming drum A continuous molding such as polyurethane which is polymerized during the rotation operation and becomes tape-like at a position before the casting position is peeled off, taken out from the molding groove, and supplied to the subsequent process. Since tape-shaped moldings are continuously produced, in the subsequent process, a series of operations such as cutting to a single standard, joining to a metal support, and so on can be carried out continuously. Is expensive.

This continuous molding method includes a plurality of casting machines. This is a method for producing a synthetic resin blade material having two partial synthetic resin layers by continuously supplying synthetic resins having different compositions from the respective casting machines to the molding grooves of the molding drum. When the casting port is arranged at the front and back of the molding groove of the continuously rotating molding drum, it hardens with the synthetic resin cast later on the synthetic resin cast earlier. Layer is formed. The position, width, and thickness of the resin layer can be controlled by the position, supply amount, composition and type of the synthetic resin, and the rotational speed of the molding drum. The synthetic resin to be cast later is supplied in an amount necessary for filling the whole, and forms a base layer.
When the preceding synthetic resin is cast in the corner portion of the molding groove, a blade material in which a different material is provided at the edge portion can be manufactured. In the case of casting in the intermediate portion, a different material can be provided at an intermediate position corresponding to the nip portion of the blade material.
The basic configuration is shown in FIG.
As shown in FIG. 2, the blade material manufacturing apparatus, which is an elastic rubber member, includes a molding drum 13 having molding grooves formed on the outer periphery, a first casting machine mixing head 11 that supplies a resin, and a second feeding head. It comprises a casting machine mixing head 12, an endless belt 14 having a steel mirror surface, a cooling conveyor 20, a cutting device 24, a carry-out conveyor 25, and the like.

  A blade material with a dissimilar material layer at the edge or nip can exert the characteristics of the edge or nip without affecting the base, so it can take advantage of the characteristics of the blade with a partial layer. Can do. By combining dissimilar materials, the physical property value of the elastic rubber can be controlled, so that it is possible to improve suitability for temperature change such as a high temperature range or a low temperature range, or wear resistance. Moreover, the continuous molding method of the synthetic resin tape using this molding drum can use each manufacturing method and component already proposed by the present applicant.

The synthetic resin cast in the molding groove receives heat from the molding drum in an area covered with a rotating metal endless belt provided in a state where the molding groove is covered on a part of the outer periphery of the molding drum. Thus, at a position where the curing polymerization proceeds and the endless belt is separated from the forming drum, it is formed in a tape shape having a cross-sectional shape of the groove. It is the same as the conventional proposal that a continuous synthetic resin tape can be obtained by pulling out this tape from the molding groove.
In this method, the resin is removed from the molding groove within several tens of seconds (for example, about 30 to 60 seconds) after resin casting, is not pressurized for molding, and polymerization curing is performed in the lower half of the rotating molding drum. Is the molding condition such that the angle at the center and the peeling angle from the molding groove can be reduced, so that peeling from the bottom of the molding groove is relatively easy, and it is not always necessary to use a release agent. . When the toner is made finer or colored, the release agent may have an adverse effect. In one embodiment of the present invention, such a problem does not occur when the release agent is not used. In addition, the fact that it is not necessary to use a mold release agent enables other surface treatment agents to act, and can be used positively for surface modification.

Further, in order to control the polymerization, an external heating means for heating toward the groove of the molding drum can be provided between the synthetic resin supply position and the endless belt. In the vicinity of the tape take-out portion, it is possible to provide a cooling means for blowing cold air or the like from the outside in order to facilitate peeling. As for the size of the resin tape obtained in the present invention, both the width and the thickness can sufficiently satisfy the range of a developing blade and a cleaning blade that are conventionally used. For example, a thickness of about 0.40 to 3.00 mm can be sufficiently manufactured.
A schematic diagram of the molding process is shown in FIG.

An example of forming a partial layer in an arc shape is schematically shown.
This example is an example based on actually measured values obtained on a trial basis, and is not limited thereto. FIG. 4 shows an elastic rubber member provided with a base layer 2 and an arc-shaped partial layer 1. The arc is schematically treated as an arc as follows. It can be assumed that the arc-shaped partial layer 1 is a partial arc having an imaginary radius R, twice the chord X is wide, and the height is the height Y of the arc.
The relationship between the width X and the height Y is graphed and shown in FIG. A cleaning blade having a desired edge size can be manufactured by trimming the polyurethane elastic rubber member obtained in this way so that the partial layer 1 has a predetermined thickness and width and cutting and molding. it can. If the edge portion and the base portion are colored in different colors, the cutting position can be easily determined.

(2) Individual molding method using split mold (split mold molding method)
The split mold method combines two mold members that mold a cavity corresponding to the size of a single polyurethane elastic blade, casts a liquid polyurethane material into the cavity, and after polymerization and curing. It is manufactured by demolding. An ether system that forms a base part by applying a liquid ester polyurethane raw material that forms an edge or nip in a streak shape to the wall surface of one split mold before assembling and semi-curing the mold. A raw material of polyurethane is injected, cured, and demolded to obtain a blade material in which two partial layers are formed.
The method disclosed in Japanese Patent Application Laid-Open No. 2007-163676 filed by the present applicant can be used for the method of forming the partial two layers by the split mold.
That is, it is as follows.
After moving the head for discharging the liquid synthetic resin, which is a thermosetting resin, to a position corresponding to the partial layer, or by casting so that the thermosetting resin is applied in a bead shape by moving the mold, A split mold is assembled, a thermosetting resin as a base is cast, and is integrally formed in a heating furnace. The integrally formed blade material is disassembled and taken out from the split mold, cut into a predetermined size, and used as a blade. When a mold is assembled, a part of the support is set inside the cavity, and the base-forming resin is cast to integrally bond the support and the blade rubber body. In this example, the polyurethane is cured and integrated with the support at the same time. However, only the polyurethane elastic member can be cured and then bonded to the support.

(A) Mold
FIG. 6 shows a schematic sectional view of the split mold structure.
The mold 110 includes left and right divided molds 110a and 110b. In the middle of the divided molds 110a and 110b, a projecting member is formed for sandwiching the core metal AA serving as a support member. The split molds 110a and 110b are disposed between a base plate 113, a side wall 114 standing on the left and right of the base plate 113, and an inclined side wall 115, and a mold clamping member 116 is pushed in a wedge shape toward the inclined side wall 115. Thus, the mold is clamped and assembled. A blade is molded by casting a synthetic resin serving as a base into a space formed between the two split molds 110a and 110b.
The example shown in FIG. 6 shows an example in which a core metal AA is arranged and resin heat molding and the core metal are joined simultaneously. It is also possible to manufacture a blade by molding a blade material obtained by curing the resin without arranging the core metal AA, and then joining the support member.
FIG. 7 shows a state in which the resin forming the divided layer is discharged from one of the divided molds (110a or 110b) from the discharge head 108 in a longitudinal direction and a bead shape. As the partial layer casting means, for example, a method of moving the ejection head and two methods of moving the split mold can be adopted.

  The polyurethane elastic rubber member was manufactured by using a continuous molding method using a rotary molding drum having grooves formed on the outer periphery, and the cleaning blade shown in FIG. 1 was created. See Figure 2 for manufacturing equipment.

<Cleaning blade>
Elastic rubber member made of polyurethane: thickness 2.0mm, width 12.3mm, length 326mm
Metal support: Steel plate with a thickness of 1.2 mm Adhesion treatment: Use of a dimer acid-based hot melt adhesive The polyurethane elastic member used in each example has a different composition of polyurethane constituting the edge portion and the base layer It is.
The polyurethane elastic member used in each comparative example has the same polyurethane composition as a whole.

<Thermosetting polyurethane>
The blends of ester urethane and ether urethane used for the edge layer or base layer are as shown in Tables 1-6.

<Print test>
Evaluation machine: Use a commercially available printer Evaluation pattern-Endurance evaluation (23 ° C x 53%)
Implement up to 100,000 sheets with 5% area cover output. A halftone image was output every 10,000 sheets to check for cleaning defects.
・ Evaluation with cleaning performance evaluation (10 ℃ × 15%) Up to 2000 sheets with 1% area cover output. Half-tone images were output every 200 sheets to check for poor cleaning.

<Evaluation of adhesive strength>
A polyurethane elastic member was cut into a predetermined length to obtain a test piece, which was bonded to a steel material used for the blade. At that time, the free length of the polyurethane elastic member was set to 7 mm, and the width of the bonding portion was set to 5 mm so as to have a generally used shape. As the adhesive, the hot melt adhesive used in the specification of this example was used. For the adhesive strength test, cut the adhesive part and polyurethane elastic member using a guillotine cutter so that the adhesive width is 10 mm, remove the rest, and obtain a rubber test piece. did.
In the form as shown in FIG. 8, the tip of the rubber test piece was chucked over 10 mm and peeled perpendicular to the direction of 90 degrees with respect to the steel plate surface.
The peeling speed was 20 mm / min. Pull until the polyurethane elastic member is peeled from the metal fitting or cut.
The evaluation standard was 1 kN / m or more, which is an adhesive strength that can generally withstand use.

<Example of conductive blade>
Examples of cleaning blades using the polyurethane elastic members of Examples 1 and 2 and Comparative Examples 1 and 2 shown in Table 2 using polyurethane having the composition shown in Table 1 are shown. The evaluation test results are shown in Table 2. Bis (trifluoromethanesulfonyl) imide lithium was used as the conductive additive.

[Discussion]
In Comparative Example 2 using a single-layer polyurethane elastic member to which a conductive agent is added, the adhesiveness with the metal support member is not sufficient, and the number of printed sheets is small. In Comparative Example 1 using a single-layer polyurethane elastic member to which no conductive agent is added, the adhesiveness is sufficient for the adhesiveness, but the number of printed sheets is insufficient.
In Examples 1 and 2 in which cerium oxide was added only to the edge portion, the adhesive force was sufficient, and the printing test for 100,000 sheets could be passed without passing through the toner. By improving the conductivity, the cleaning performance and printing durability could be improved. Example 2 in which an ester polyurethane was used for the edge portion and an ether polyurethane was used for the backup layer showed good printing evaluation.
When used as a cleaning blade, the residual charge of the toner was neutralized, the adhesion of the toner was reduced, and the cleaning performance could be improved over the long term.

<Example of low friction (low μ) blade>
Examples of cleaning blades using polyurethane having the composition shown in Table 3 and polyurethane elastic members of Examples 3 and 4 and Comparative Examples 3 and 4 shown in Table 4 are shown. The evaluation test results are shown in Table 4. Fluorinated graphite was used as a low μ additive.

[Discussion]
In Comparative Example 4 using the single-layer polyurethane elastic member to which fluorinated graphite was added, the adhesion to the metal support member was not sufficient, and the number of printed sheets was small. In Comparative Example 3 using a single-layer polyurethane elastic member to which fluorinated graphite is not added, the adhesiveness is sufficient, but the number of printed sheets is insufficient.
In Examples 3 and 4 in which fluorinated graphite was added only to the edge portion, the adhesive force was sufficient, and the printing test for 100,000 sheets could be passed without passing through the toner. By realizing a low μ, frictional resistance is reduced even with the same pressure contact force, and problems such as blade turning and reversal can be solved without causing defective cleaning. Moreover, it is effective in reducing power consumption. Example 4 in which the ester polyurethane was used for the edge portion and the ether polyurethane was used for the backup layer showed good printing evaluation.

<Example of polishing blade>
Examples of cleaning blades using the polyurethane elastic members of Examples 5 and 6 and Comparative Examples 5 and 6 shown in Table 6 using polyurethane having the composition shown in Table 5 are shown. The evaluation test results are shown in Table 6. Cerium oxide was used as an additive abrasive.

[Discussion]
In Comparative Example 6 using the single-layer polyurethane elastic member added with cerium oxide, the adhesiveness with the metal support member is not sufficient, and the number of printed sheets is small. In Comparative Example 5 using a single-layer polyurethane elastic member to which cerium oxide is not added, the adhesiveness is sufficient, but the number of printed sheets is insufficient.
In Examples 5 and 6 in which cerium oxide was added only to the edge portion, the adhesive force was sufficient, and the printing test for 100,000 sheets could be passed without passing through the toner. By improving the polishing performance, cleaning performance and printing durability could be improved. Example 6 in which the ester polyurethane was used for the edge portion and the ether polyurethane was used for the backup layer showed good printing evaluation.
Without damaging the surface of the photoconductor, the toner that adheres to the surface of the photoconductor, the ozone when the toner additive bias is applied, and the deposits of nitrogen oxides can be cleaned more effectively than conventional cleaning blades, and good images can be obtained for a long time. Can be provided over a long period of time. In the past, excessive pressure contact was used to remove the deposits, which damaged the photoconductor and reduced the image quality, or turned the blade tip and rolled it up. Such harmful effects can be suppressed.

The figure which shows the example of a cleaning blade apparatus. The figure which shows the example of the apparatus which manufactures a cleaning blade continuously. The figure which shows the hardening process of the polyurethane in a cleaning blade continuous molding method. The figure which shows the example of the partial layer formed in arc shape. The graph which shows the magnitude | size of the arc-shaped partial layer formed. Sectional drawing which shows the outline of a split mold structure. The figure which shows the outline which forms the polyurethane resin for partial layers in one side of a split mold in bead shape. The figure which shows the outline of an adhesive force test apparatus.

Explanation of symbols

1 Partial layer (edge, nip)
2 Base layer 3 Elastic rubber member (cleaning blade)
4 Support Member 10 External Heating Device 11 First Casting Machine Mixing Belt 12 Second Casting Machine Mixing Belt 13 Forming Drum 14 Endless Belt 15 Rotating Shaft 16 Preheating Roll 17 Guide Roll 18 Tension Roll 19 Cooling Roll 20 Cooling Conveyor 21 Cooling Device 22 Loosening detector 23 Feed roll 24 Cutting device 25 Conveyor 26 Upper sensor 27 Lower sensor 101 Strip blade material 103 Standard size blade member 108 Discharge head 110 Mold 110a, 110b Split mold 111 Apparatus for casting into split mold 112 Slide plate 113 Base plate 114 Side wall 115 Inclined side wall 116 Clamping member

Claims (10)

A cleaning blade or a developing blade in which an elastic member made of polyurethane having a different composition of polyurethane forming the backup layer and the edge portion or nip portion is bonded to a metal support member,
The polyurethane forming the edge part or nip part is a polyurethane mixed with an additive,
A cleaning blade or a developing blade, wherein the polyurethane forming the backup layer is a polyurethane not mixed with the additive. The polyurethane in the edge part or nip part is made of ester polyurethane,
The cleaning blade or developing blade according to claim 1, wherein the polyurethane of the backup layer is made of ether-based polyurethane.   3. A cleaning blade or a developing blade according to claim 1, wherein the edge portion or the nip portion has a color different from that of the backup layer.   The cleaning blade or the developing blade according to claim 1, wherein the additive is any one of a friction reducing agent, an abrasive, and a conductive agent.   5. The cleaning blade or the developing blade according to claim 4, wherein the friction reducing agent is any one of a fatty acid metal salt, silicone oil, organic fine particles, and inorganic fine particles.   5. A cleaning blade or a developing blade according to claim 4, wherein the abrasive is cerium oxide or silica.   The cleaning blade or developing blade according to claim 4, wherein the conductive agent is carbon black or imidolithium. A method of manufacturing a cleaning blade or a developing blade by bonding a polyurethane elastic member having an edge portion or nip portion and a backup layer made of different materials to a metal support member,
A molding drum having a molding groove on its outer periphery and a heating device inside. The synthetic drum feeding means and the molding drum rotate while covering the molding groove of the molding drum along the outer periphery of the molding drum. Endless belts that rotate in synchronization are arranged in sequence, and a belt-shaped blade material having a predetermined width and thickness is formed by a molding space formed by the endless belt and the molding grooves from the synthetic resin material supplied to the molding grooves. A method for producing an elastic member made of polyurethane using a method of producing according to the rotation of
The polyurethane material mixed with the additive that forms the edge layer is poured into a cylindrical mold and cured while rotating the mold. After semi-curing, the polyurethane material that forms the backup layer is poured and rotated. Take out the band-shaped blade material composed of two layers by curing, cut the width and length to a certain size and mold the polyurethane elastic member,
A method of manufacturing a cleaning blade or a developing blade by bonding the polyurethane elastic member to a metal support member. A method of manufacturing a cleaning blade or a developing blade by bonding a polyurethane elastic member having an edge portion or nip portion and a backup layer made of different materials to a metal support member,
A polyurethane elastic member manufacturing method using a split mold method in which a liquid polyurethane raw material is poured into a cavity formed by assembling two mold members, and then demolded after polymerization and curing. There,
Before assembling the mold, apply polyurethane mixed with a liquid additive that forms a streak-like edge on the wall of one split mold,
Molded after semi-curing,
Injecting polyurethane raw material to form a backup layer,
Curing and demolding to obtain polyurethane elastic member,
A method of manufacturing a cleaning blade or a developing blade by bonding the polyurethane elastic member to a metal support member.   10. The method for producing a cleaning blade or a developing blade according to claim 8, wherein the polyurethane raw material forming the edge portion or nip portion is an ester-based polyurethane raw material, and the polyurethane raw material forming the backup layer is an ether-based polyurethane raw material. .

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