JP2005219455A - Method of producing blade for electrophotographic device, and the blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high quality thermosetting polyurethane blade which does not pollute a photoreceptor or toner, and to provide a production method for the blade by which the continuous production thereof is made possible with high efficiency, the production process can easily be automated and simplified, and further equipment cost can be reduced. <P>SOLUTION: This production method comprises continuously forming a sheet for the blade using a synthetic resin as a molding raw material by using a forming drum provided with a forming groove and an internal heating apparatus, and is characterized by using, as the synthetic resin, a two-pack thermosetting polyurethane resin including a reactive catalyst being an amidine compound containing a hydroxy group represented by general formula [I]. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

This invention forms a thin film while triboelectrically charging toner in a developing blade and a cleaning blade for removing residual toner on a photoreceptor (drum, belt, etc.) in an electrophotographic copying machine, printer, facsimile, etc. The present invention relates to a method for manufacturing a blade for an electrophotographic apparatus (hereinafter also referred to as a blade) such as a developing blade, a blade sheet, and a blade obtained by joining a blade sheet and a metal holder.
Further, the present invention is not limited to blades that remove toner or form a uniform thin film of toner, but can be used for blades that are used for scraping off other powders and liquid coatings existing on a certain surface. Is.

  As shown in FIGS. 1 and 2, this type of blade (101) for an electrophotographic apparatus has an elongated polyurethane sheet (102) (in the same manner as an elongated metal plate (103) (referred to as a holder) having a cross-sectional “he” shape. A sheet for blades). This blade for an electrophotographic apparatus is used as a developing blade and a cleaning blade.

In general, the blade sheet (102), which is a thermosetting polyurethane elastomer, is prepared by a centrifugal molding method, a mold molding method, or a continuous strip-shaped molding method proposed by the present inventors (Patent Document 1: Japanese Patent No. 2645980). It is manufactured by.
In the belt-like continuous molding method, referring to FIG. 3, a urethane prepolymer having a terminal isocyanate group and a small amount of catalyst for adjusting the reaction rate of the crosslinking agent and the isocyanate are continuously mixed at a predetermined ratio by a quantitative mixing and casting machine. The mixed polyurethane liquid material is continuously discharged from the discharge port to the groove formed on the outer periphery of the rotating molding drum (3), and this space is formed in the space formed by the groove and the endless belt (4). The mixture is filled, heated for a predetermined time, polymerized, and continuously formed. Since the groove portion has a width and a depth corresponding to the width and thickness of the blade sheet, the belt blade sheet continuous in a belt shape is pulled out and cooled by a cooling roll (10) and a cooling device (11), and a cutting device (14 ) To obtain a flat blade sheet. Further, this blade sheet is bonded and fixed to a metal holder as a support with an adhesive to complete an electrophotographic apparatus blade.

  The problem with thermosetting polyurethane elastomer cleaning blades that use a catalyst for the curing reaction is that the photosensitive drum is contaminated due to the bleed-out of the catalyst used, resulting in insufficient toner adhesion to the photosensitive drum. As a result, a problem that white spots appear on the copy screen has been pointed out. The isocyanate group catalyst generally has a low molecular weight, or is poor in reactivity with the isocyanate group or poor affinity with the polyurethane resin produced by heat polymerization. Have the problem of As a result, the surface of the photosensitive drum is contaminated. As a result, the toner adheres insufficiently to the photosensitive drum, white spots occur in the copied image, or the bleed-out reaction catalyst evaporates to aggregate the toner in a lump. This causes non-uniform charging failure and roller contamination and toner contamination. One proposal for solving the problem by using hydroxyamine as a catalyst has been made in Patent Document 3 (Japanese Patent Laid-Open No. 7-290603). A cleaning blade mold is prepared, and a prepolymer obtained by partially polymerizing polyisocyanate and polyol (hereinafter referred to as “prepolymer for forming urethane rubber”) and a curing agent are mainly contained in the mold. An attempt was made to solve the bleed-out by devising a catalyst used for batch processing for producing a cleaning blade sheet by injecting a liquid cleaning blade molding composition to be cured, and then curing reaction, and then demolding the cured product. It is a proposal to do.

Commonly used catalysts include various amines, organometallic compounds such as dibutyltin dilaurate and dibutyltin 2-ethylhexoate, alkali metal compounds such as alkali metal hydroxides and fatty acid salts, and peroxides. Radical generators such as benzoyl, azobisisobutyronitrile, 1,8-diazabicyclo [5,4,0] -7-undecene, 1,5-diazabicyclo [4,4,0] -5-decene, or 1 Amidine compounds such as 1,5-diazabicyclo [4,3,0] -5-nonene have been used as they are or in the form of salts with various organic or inorganic acids, and further in the form of quaternary ammonium salts.
Japanese Patent No. 2645980 Japanese Examined Patent Publication No. 7-103355 JP 7-290603 A

  The present invention solves the problem of bleeding out from a blade by selecting a catalyst, and provides a smooth molding method for continuous strip-shaped molding.

The present inventor has continuously conducted intensive research and development on the invention related to the blade by the continuous belt forming method, as shown in Patent Document 1, Japanese Patent No. 2942183, Japanese Patent Application No. 2003-172737, and the like. As shown in FIGS. 5 and 6, the continuous molding method is to continuously form a tape-like urethane sheet using a rotary molding drum having molding grooves formed around it. Includes a process of manufacturing a sheet for a belt blade by continuously feeding urethane resin to a drum, and a continuous process of a subsequent process for cutting the belt blade sheet into a fixed size, joining to a metal holder, and finishing the blade. It is also possible to have a continuous and continuous process.
In order to realize continuous processing up to the subsequent steps, a two-component polyurethane adhesive used in a joining process of a strip-shaped polyurethane sheet manufactured by continuously mixing and supplying a two-component polyurethane composition and a metal holder is used. It is also necessary to smoothly supply the agent continuously. When the two liquids are mixed, the reaction will proceed a little. If the mixture is interrupted due to lumps occurring in the continuous use, or if a non-uniform raw material is supplied to the mold, the molding will be poor. In addition to bleed out, it is necessary to satisfy this continuous molding.

  The present invention has been made in view of the above points, and establishes a method for smoothly and continuously forming a belt-like blade sheet using a two-component thermosetting polyurethane resin using a catalyst without bleeding out. It is another object of the present invention to provide a blade sheet and a blade that can be continuously manufactured up to a joining process with a metal holder using an adhesive that does not have a bleed-out, and that has less bleed-out.

The present invention has sought to find a catalyst that does not cause bleed-out, and has found that when the catalyst is used, a two-component thermosetting polyurethane, which is a highly heat-sensitive blade sheet material, can be obtained. The present invention has been completed by utilizing the advantageous function for both bleed-out and continuous molding.
(1) In a method of continuously forming a blade sheet using a synthetic resin as a raw material for molding using a molding drum having a molding groove and an internal heating device, the hydroxyl group represented by the general formula [I] is used as the synthetic resin. A method for producing a blade sheet, comprising using a two-component thermosetting polyurethane resin using the contained amidine compound as a reaction catalyst.
Formula [I]
(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ² represents a hydrogen atom, an alkyl or alkylene group having 1 to 16 carbon atoms, or a phenyl group. Also, R ¹ and R ² May combine with each other to form a ring having 5 to 8 carbon atoms, R ³ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and m represents an integer of 2 to 4). The method for producing a blade sheet according to (1), wherein heating is performed from the outside of the forming drum. (3) A molding groove is sequentially arranged along the outer periphery of the molding drum, with a synthetic resin supply means, an external heating means, and an endless belt that is driven by the rotation of the molding drum while covering the molding groove of the molding drum. A strip-shaped blade sheet having a predetermined width and thickness is formed by the heat of the molding drum, the heat from the external heating means, and the molding space formed by the endless belt and the molding groove. The blade sheet according to (1) or (2), wherein the blade sheet is formed according to the rotation of (4) A step of cutting a strip-shaped blade sheet manufactured by the manufacturing method according to any one of (1) to (3) into a predetermined length and continuously bonding the sheet using a blade holder and an adhesive is added. A method for continuously producing a blade for an electrophotographic apparatus. (5) The continuous blade for an electrophotographic apparatus according to claim 4, wherein the adhesive is a two-component curable polyurethane adhesive using a hydroxyl group-containing amidine compound represented by the general formula [I] as a catalyst. Production method.
Formula [I]
(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ² represents a hydrogen atom, an alkyl or alkylene group having 1 to 16 carbon atoms, or a phenyl group. Also, R ¹ and R ² May combine with each other to form a ring having 5 to 8 carbon atoms, R ³ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and m represents an integer of 2 to 4). A blade for an electrophotographic apparatus manufactured by the manufacturing method according to any one of (1) to (5), or an electrophotographic apparatus blade obtained by bonding the blade sheet to a blade holder. (7) A blade sheet made of a thermosetting polyurethane resin using an amidine compound having a hydroxyl group represented by the general formula [I] as a reaction catalyst, or a blade obtained by bonding the blade sheet to a holder.
Formula [I]
(Wherein R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R2 represents a hydrogen atom, an alkyl or alkylene group having 1 to 16 carbon atoms, or a phenyl group. Also, R1 and R2 are bonded to each other. And may form a ring having 5 to 8 carbon atoms, R3 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and m represents an integer of 2 to 4.)

Due to the use of a polyurethane resin with high temperature sensitivity, the flow characteristics can be easily controlled, and a high-quality belt-like electrophotographic blade sheet can be stably produced continuously.
Polyurethane resin that significantly reduces obstacles such as contamination of the photoreceptor and toner due to transpiration of the catalyst from the blade surface and bleed out by using an amidine compound having a hydroxyl group represented by the general formula [I] as the reaction catalyst for the isocyanate group It has become possible to continuously form strips made of manufactured and striped blades. Also, by using the same catalyst for the adhesive, it is possible to realize a joining process with few obstacles, and it is possible to continuously carry out a continuous blade manufacturing process from strip-shaped molding to joining with a holder. It was. As a result, a blade sheet and a blade with little bleed out could be provided.

<Continuous manufacturing process>
The continuous production to which the present invention is applied is based on the following general steps.
Continuous forming of polyurethane tape, which is a blade sheet (mixing process-> casting to a heated rotating drum for molding-> primary cross-linking-> taking out and cooling the tape-like polyurethane blade sheet)-> fixed size cut-> secondary cross-linking-> metal holder Bonding (adhesive mixing->application-> heat curing)-> inspection.
The pot life of urethane resin at low temperature and the fast curing at high temperature function advantageously in the process of molding into a tape shape with a molding drum and the process of joining a metal holder.
As the belt-like continuous forming method, the previously proposed one can be used, and for example, it can be manufactured by the apparatus shown in FIG. As an example of the developing blade, the molding size is 1.2 mm thick, 14 mm wide,
As an example of the cleaning blade, one having a thickness of 2.0 mm and a width of 11.5 mm is manufactured.

<Polyurethane resin for blade sheet>
The composition of the blade sheet forming polyurethane resin is basically known, and the non-solvent two-component thermosetting polyurethane composition previously proposed by the present applicant can be adopted. An example disclosed in Japanese Patent No. 2942183 will be described. As the catalyst, a catalyst that does not bleed out and can withstand continuous processing is used.

High molecular weight polyols for blade sheets include polyoxyalkylene glycols such as polyethylene glycol, polypropylene glycol, polyoxytetramethylene glycol, and polyoxyalkylene glycols such as bisphenol A, glycerin ethylene oxide, and propylene oxide. Ether-type polyols and dibasic acids such as adipic acid, phthalic anhydride, isophthalic acid, maleic acid and fumaric acid, and glycols such as ethylene glycol, propylene glycol, 1,4 butanediol, 1,6 hexanediol and trimethylolpropane And polyester-type polyols obtained by polymerization reaction with polycaprolactone diol, polycarbonate diol, and the like.
The number average molecular weight of these high molecular weight polyols is in the range of 500 to 5000, particularly preferably 1000 to 3000.

  Examples of the diisocyanate compound include tolylene diisocyanate, 4,4 diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and 1,4 cyclohexane diisocyanate. 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. These polyols and diisocyanate compounds may be reacted by any one of the one-shot method, pseudo-prepolymer method, and prepolymer method employed in the conventional polyurethane production method, but the pseudo-prepolymer method or prepolymer method. The physical properties of the product obtained by using the are stable and the properties are good.

  In the production of the above polyurethane, the equivalent ratio of OH group / NCO group is preferably 0.8 to 1.05, more preferably 0.85 to 1.00, from the physical properties of the polyurethane to be produced. If necessary, an amidine compound catalyst having a hydroxyl group represented by the general formula [I] may be used as a reaction accelerator. The polyurethane of the present invention can be applied to a casting blade, a developing roller, a photosensitive drum, a belt-type photosensitive member, and the like.

<Catalyst>
As described above, the amidine compound having a hydroxyl group is represented by the general formula [I], in which R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, and an n-propyl group. R ² represents a hydrogen atom, an alkyl or alkylene group having 1 to 16 carbon atoms, or a phenyl group. Examples of the alkyl group or alkylene group having 1 to 16 carbon atoms include saturated alkyl groups such as methyl group, ethyl group, hexyl group and stearyl group; alkylene groups such as 3-butylene group and 7-octylene group; butoxymethyl group And substituted alkyl groups such as a phenoxymethyl group, a methacryloyloxymethyl group, a benzoyloxymethyl group, a fluoromethyl group, and a chloromethyl group. Further, when R ² is a phenyl group, the phenyl group may be substituted with a halogen group, an alkyl group, a substituted alkyl group, and the like, and examples thereof include a fluoro group methyl group and a 4-chloromethylphenyl group. It is done.

R ¹ and R ² may be combined with each other to form a ring having 5 to 8 carbon atoms. Examples of the ring having 5 to 8 carbon atoms formed by combining R ¹ and R ² with each other include a cyclopentane ring, a cyclohexane ring, a norbornane ring, a cyclooctane ring, and the like. These rings may have various substituents, and examples of the substituent include a methyl group, a vinyl group, and a 1-methylvinyl group.

R ³ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and examples of the alkyl group having 1 to ³ carbon atoms in R ³ include a methyl group, an ethyl group, and an n-propyl group.

Among R ¹ , R ² , and R ³ described above, R ¹ , R ² , and R ³ are both hydrogen atoms, or R ¹ , from the viewpoint of ease of distillation purification in the production of the amidine compound of the present invention. R ³ is preferably a hydrogen atom and R ² is preferably a methyl group. In the above formula, m is an integer of 2 to 4, but 2 or 4 is preferable for the same reason. That is, preferred specific examples of the novel amidine compound of the present invention include 6- (2-hydroxyethyl) -1,8-diazacyclo [5,4,0] -7-undecene, 6- (2-hydroxypropyl)- 1,8-diazabicyclo [5,4,0] -7-undecene, 7- (2-hydroxyethyl) -1,5-diazabicyclo [4,3,0] -5-nonene, 7- (2-hydroxypropyl) ) -1,5-diazabicyclo [4,3,0] -5-nonene.
As an example of the catalyst used in the present invention, there is an example disclosed in JP-A-2003-81975.

<Urethane adhesive component>
As components of the non-solvent type two-component thermosetting polyurethane resin adhesive in which these catalysts are used, polyisocyanate prepolymer (component A) and polyol (component B) conventionally known components can be used. For example, it is illustrated in Japanese Patent Publication No. 7-103355.

  Examples of the component A polyisocyanate include xylylene diisocyanate, polyphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate. Diisocyanate such as dicyclohexylmethane diisocyanate, or a polymer thereof. Furthermore, a compound having a plurality of isocyanate groups such as allophanate bond, isocyanurate bond, carbodiimide bond, etc. It can also be used as a compound.

  Examples of the B component polyol include ethylene glycol, propylene glycol, polypropylene glycol, trimethylolpropane, diethylene glycol, triethylene glycol, hexamethylene glycol, glycerin, 1,3-butylene glycol, 1,4-butanediol, hexanetriol, and penta. Polyhydric alcohols such as erythritol, sorbitol, neopentyl glycol; polyether polyols obtained by addition polymerization of the polyhydric alcohols and alkylene oxides such as ethylene oxide and propylene oxide; the polyhydric alcohols and maleic acid Polyester polyol obtained by condensation reaction with polybasic acids such as succinic acid, adipic acid, sebacic acid, tartaric acid, terephthalic acid, isophthalic acid; Polyester polyols obtained by ring-opening polymerization of lactones such as caprolactone and γ-valerolactone; polymerizing alone polymerizable monomers containing hydroxyl groups such as hydroxyethyl acrylate, hydroxybutyl acrylate, trimethylolpropane acrylate monoester Or an acrylic polyol obtained by copolymerizing a monomer copolymerizable therewith, such as acrylic acid, methacrylic acid, styrene, acrylonitrile, α-methylstyrene; castor oil or a derivative thereof; epoxy groups at both ends And an epoxy polyol obtained by reacting an epoxy resin having a monoethanolamine, diethanolamine and the like;

  The catalyst mentioned above is added in the 2nd component which contains the urethane B component as an adhesive agent as a main component.

<Reaction catalyst properties of amidine compounds having a hydroxyl group>
(1) Bleed-out prevention performance 1,8-diazabicyclo [5,4,0] -7-undecene and those into which a hydroxyl group is introduced, that is, 6- (2-hydroxypropyl) -1,8-diazabicyclo [ Using 5,4,0] -7-undecene as a reaction catalyst, 44.1 parts by weight of polypropylene glycol (PP-1000, molecular weight 1,000), 1,4-butylene glycol (1,4-BG) 11.9 A polyurethane resin composed of 3 parts by weight, 39.1 parts by weight of isophorone diisocyanate (IPDI), and 0.5 parts by weight of a reaction catalyst was synthesized, and these resins were separately dissolved in dimethylformamide and remained in each resin solution 1 , 8-Diazabicyclo [5,4,0] -7-undecene and 6- (2-hydroxypropyl) -1,8-diazabicyclo [5,4,0] -7-Undecene was quantified by gas chromatography.
As a result, 1,8-diazabicyclo [5,4,0] -7-undecene added as a reaction catalyst remained in 60% by weight, whereas 6- (2-hydroxypropyl) -1, 8-Diazabicyclo [5,4,0] -7-undecene is almost completely incorporated into the urethane resin and is a reactive catalyst that can prevent bleed out and transpiration.

(2) Unreactive at low temperatures In a continuous manufacturing process, the liquid blade molding sheet of polyurethane and the liquid adhesive must always be supplied in a stable state. The two liquids are always supplied while mixing. At the same time as the mixing, the reaction starts not a little, and may remain in the mixing apparatus or the like to cause supply failure or failure after molding or adhesion. For this reason, cooling is performed from the mixing device to the supply device by taking measures such as air cooling so that the reaction does not proceed in a low temperature state.
The urethane resin using 6- (2-hydroxypropyl) -1,8-diazabicyclo [5,4,0] -7-undecene is a test result combined with the following reaction acceleration at a high temperature (3) As can be seen from this, it is a resin that does not easily react at low temperatures.

(3) Rapid reactivity at high temperature The blade size is, for example, 1.2 mm or 2.0 mm thick and 15 mm wide.
It is formed into a strip-like tape in about 0 to 60 seconds. Thereafter, the length is cut to 305 mm and bonded to the metal holder with a paste margin width of 4 mm. In order to be molded into an accurate width and thickness continuously during a heating time of 40 to 60 seconds at a heating temperature of 100 to 150 ° C., it is necessary to satisfy rapid curing reactivity. Also in the bonding, it is necessary to apply the adhesive accurately and uniformly to the elongated area as described above, and complete the bonding with high accuracy. If it is not finished precisely, fine toner cannot be scraped and a beautiful image cannot be formed. A urethane resin using 6- (2-hydroxypropyl) -1,8-diazabicyclo [5,4,0] -7-undecene is a resin that can obtain rapid reaction acceleration at high temperatures.

(4) Temperature Sensitivity The characteristics of unreacted at low temperature (2) and rapid reactivity at high temperature (3) were confirmed as follows. The following aliphatic and aromatic isocyanates were used.
Polycaprolactone ester diol 200 (PCL200); 88.1 parts by weight, 1,4-butylene glycol; 11.9 parts by weight, isophorone diisocyanate; 39.1 parts by weight, catalyst; 0.5 parts by weight of polyurethane resin gel The time until curing from the hot plate of the chemical tester was allowed to cure, the times were compared, and the results are shown in Table 1. Similarly, until the aromatic polyurethane resin comprising GP-3700M; 20.0 parts by weight, Millionate MR-200; 2.2 parts by weight, catalyst; 0.03 parts by weight can be removed from the hot plate of the gelation tester The results are shown in Table 2.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this.

<Adjustment of polyurethane for blade sheet and molding of belt-like blade sheet>
66.1 parts by weight of polycaprolactone ester diol (average molecular weight 2000) was dehydrated by heating and stirring under reduced pressure (5 mmHg) at 70 ° C. for 3 hours, and then charged in a reaction vessel, followed by 27.8 parts by weight. 4,4 diphenylmethane diisocyanate was added to the reaction vessel and stirred at 70 ° C. for 1 to 4 hours under a nitrogen gas atmosphere to obtain a liquid urethane prepolymer having a residual isocyanate group content of 7.0%. Isocyanate group / hydroxyl group equivalence ratio is 3.4

  On the other hand, 4.3 parts by weight of 1,4 butanediol, 1.8 parts by weight of trimethylolpropane and catalyst 6- (2-hydroxypropyl) -1,8-diazabicyclo [5,4,0] -7 were used as the crosslinking agent component. -0.07 part by weight of undecene was heated and stirred under reduced pressure (5 mmHg) at 70 ° C. for 3 hours to dehydrate to obtain a crosslinking agent having a hydroxyl group equivalent of 45.

  The prepolymer and the crosslinking agent obtained as described above are put into the tanks (201) and (202) of the mixer (200) shown in FIG. 7, and heated and stirred so that the liquid temperature becomes 70 ° C. Feeding to the mixing head (207) by the metering pumps (203) and (204) of the two-component quantitative mixing and casting machine, while stirring and mixing uniformly so that the equivalent ratio of OH group / NCO group is 0.95 It discharged from the discharge port in the groove | channel for shaping | molding of the shaping | molding drum temperature-controlled at 145 degreeC.

<Manufacturing equipment>
Embodiments of a blade sheet and a manufacturing apparatus thereof according to the present invention will be described based on FIGS. 3, 4, 5, and 6 together with a manufacturing method.
FIG. 3 is an overall front view schematically showing an embodiment of a blade sheet manufacturing apparatus used in an electrophotographic apparatus. The blade sheet manufacturing apparatus includes a forming drum (3), a supply port (1) for supplying resin, an external heating device (2), an endless belt (4), a cooling conveyor (10), a cutting device (14), Consists of a carry-out conveyor (15) and the like.
The discharge port (1) for the liquid material of the polyurethane resin is disposed at a clockwise position at about 10 o'clock from the apex of the molding drum (3), followed by the external heating device (2), followed by molding. An endless belt (4) that is in contact with the outer peripheral surface of the drum and covers approximately half of the drum is disposed. Subsequently, the strip-shaped blade sheet S that has been peeled off is cooled and conveyed, and the cutting device and the conveying device follow the steps in this order. Arranged.
The forming drum (3) is made of, for example, hard aluminum or stainless steel, and includes a rotational drive, a forming groove, and a built-in heating structure.
The forming groove is formed around the outer periphery of a forming groove having a concave cross section that is engraved with a predetermined dimension corresponding to the width and thickness of the blade sheet. This forming groove corresponds to a mold. The heating means supplies heat for curing a resin such as polyurethane. The heating temperature is appropriately determined depending on the resin used, the rotation speed, and the like. For example, it is set to 110 ° C to 150 ° C. The rotation direction is set clockwise in the drawing.
The resin supply port (1) supplies the resin component to be used to the molding groove of the molding drum (3) continuously through a two-component mixing controller shown in FIG.
The external heating device (2) fulfills the function of irradiating and heating the resin cast into the molding groove from the supply port (1). This heat promotes curing of the resin surface side. Curing of the cast resin is accelerated by the heat of the molding drum and heat from the outside, the viscosity is increased, and the flow of the endless belt into the contact start end can be controlled. The installation position of the external heating device can be adjusted between the discharge port (1) and the preheating roll (6). This position can also be determined by the type of resin and the thickness of the blade. In this example, it is installed near the top of the forming drum. The external heating device can be omitted.
The endless belt (4) has a structure in which a space is formed to cover the molding groove and the polyurethane liquid material is filled. A cavity for molding is formed by the endless belt (4) and the molding groove, the outer shape of the blade sheet is adjusted, and the resin curing reaction proceeds. The section where the endless belt (4) covers the molding groove of the molding drum (3) needs to be designed to such an extent that the resin can be hardened and peeled off from the molding groove as a strip-like tape. For example, 180 ° corresponding to a section from 2 o'clock to 8 o'clock on the watch is an easy-to-operate area.
The cooling conveyor (10) conveys the blade sheet formed in a strip shape peeled from the (3) forming groove of the forming drum to the subsequent process while cooling. Note that this cooling conveyor may not require cooling depending on the blade sheet. If cooling is not required, this conveyor can be a transfer device to a subsequent process or can be omitted.
The cutting device (14) is a device that cuts a continuous belt-like sheet into the length of a blade. By this cutting, the blade sheet is formed into a final shape. After this, it is carried out to the adhering process to the metal blade holder. In order to synchronize with the action of this cutting device, a feed roll (13) for controlling the feed is arranged immediately before the cutting device (14), and in order to cope with the speed of feed by the feed roll (13), the feed roll Provide a space for the tape to sag before (13), and measure the timing of the cooling conveyor (10) and the cutting device (14).
In addition, a heating process can be added as needed as a post process for the secondary bridge | crosslinking which performs a secondary bridge | crosslinking and finally implement | achieves hardening reaction.

  An endless belt (4) for forming a molding space (mold) made of a metal strip such as stainless steel is brought into contact with the outer peripheral surface of almost half of the forming drum (3). The endless belt (4) A preheating roll (6) for preheating the endless belt (4), a guide roll (7) for adjusting belt running, a tension roll (8) for applying tension to the endless belt, and a cooling roll for cooling the endless belt (4) ( 9) and is rotated following the rotation of the forming drum (3). The endless belt (4) is heated to a predetermined temperature (for example, around 145 ° C., which is about the same as that of the molding drum) by a heater, and this temperature prevents a temperature drop of the polyurethane liquid material.

As a means for supplying the molding resin to the molding drum, a two-component quantitative mixing and casting machine (200) shown in FIG. 7 is used.
Pipes (205) and (206) provided with two tanks (201) and (202) and provided with metering pumps (203) and (204) from the outlets of the respective tanks (201) and (202) are mixed heads (two liquids). (Quantitative mixing casting machine) (207). The mixing head (207) and the tanks (201) (202) are connected to each other by circulation pipes (205a) (206a). In addition, the mixing head (207) has a liquid material inlet at the upper end and a liquid discharge port at the lower end center, and a stirring rotor is supported rotatably at the upper end center. In addition, it has a known structure that is rotationally driven by an upper motor (207c).
The prepolymer and the crosslinking agent were respectively added to the tanks (201) and (202) of the two-component quantitative mixing and casting machine, and degassed by heating, decompression and stirring. The prepolymer and the crosslinking agent thus obtained are supplied to the mixing head (207) by the metering pumps (203) and (204), and the temperature is adjusted to 145 ° C. from the discharge port while stirring and mixing uniformly. Discharge into the molding groove (3). At this time, the forming drum (3) is rotating at a predetermined speed (1 rotation / 80 seconds), and the necessary amount corresponding to the peripheral speed of the forming drum (3) and the engraving depth and width of the forming groove is continuous. Injected into. The mixing head is cooled to about 20 ° C. so that the reaction does not proceed after mixing the two liquids.

  A polyurethane liquid material is measured in a molding groove of a molding drum (3) whose temperature is adjusted to a predetermined temperature, for example, 145 ° C., from a discharge port (1) while measuring a prepolymer and a crosslinking agent and stirring and mixing uniformly. Is discharged and cast. At this time, the forming drum (3) is rotating clockwise at a predetermined speed (for example, 80 seconds / revolution), and there is a necessary amount corresponding to the peripheral speed of the drum (3) and the groove engraving depth and width. Infused continuously.

The liquid polyurethane is from point A directly below the discharge port (1) disposed at about 10 o'clock from the top of the molding drum (3) to point C directly above the molding drum (heating position by an external heating device). After the reaction was started, it was heated by an external heating device at point C, and then heated by a preheating roll from the contact start position E of the endless belt, for example, to 145 ° C. only by heating with the forming drum. The endless belt for molding is heated and held between point E and point G of the forming drum (3). As a result, the urethane polymerization reaction of the liquid material is almost completed, and the blade sheet having the necessary width and thickness and a smooth mirror surface is continuously formed into a strip shape.
The position of the discharge port (1) is adjusted by the type of resin, the thickness of the blade, the manufacturing speed, and the like. In this example, it is installed at a clock position from 9 o'clock to 12 o'clock in the counter-rotating direction of the forming drum. Preferably, it is installed around 10:00. The synthetic resin liquid discharged toward the counter-rotation direction tends to fall according to gravity, and is lifted toward the top of the molding drum as the molding drum rotates.
In this example, the time for the polyurethane liquid to move by rotating from point A to point E is set to 13 seconds, and the time for moving from point E to point G is set to about 40 seconds. By changing the position of point E by the approach / separation operation of the preheating roll (6) with respect to the forming drum (3), the angle between point A and point E and the angle between point C and point G are changed. The reaction and molding time can be fine-tuned.

  It is desirable that the reaction does not proceed until the mixed urethane composition is ejected, and the reaction proceeds in a time of about 40 to 60 seconds from the point G after ejection until it is pulled out in the form of a tape. Needs to be molded.

  The belt-shaped blade sheet continuously formed in this way is peeled from the groove of the forming drum (3) at point G and guided onto the endless conveyor belt of the cooling conveyor (10). Thereafter, the sheet is cooled, conveyed, and cut into a blade sheet having a predetermined length.

The blade sheet manufactured in this way has one side edge bonded to a metal holder (103) with an adhesive (104) as shown in FIG. Complete.
It is also possible to further adjust and cut the edge of the side edge, which is the free end of the blade sheet (102), with a ceramic cutter or the like to form a ridgeline.
In the case of the present invention, unlike the conventional centrifugal molding method, the blade sheets (102) are continuously manufactured one by one. Therefore, in the step of bonding to the holder or the ridge line forming step, the blade ( 102) need only be processed one by one, so that these steps can be automated. On the other hand, in the method using a mold, the occurrence of burrs is unavoidable, and it is necessary to form the ridge line on the tip side of the blade by cutting. Waste due to cutting of burrs or the like is generated, and many resin materials are wasted.

<Adhesive adjustment>
As a non-solvent type two-component thermosetting polyurethane resin adhesive, a main agent “MLT2300A” and a curing agent “MLT2363” manufactured by ETEC Co., Ltd. were used, and 6- (2-hydroxypropyl) -1 was used as a catalyst for this curing agent. , 8-diazabicyclo [5,4,0] -7-undecene (HP-DBU) 0.3 parts by weight are added, each is put into a two-component quantitative mixer, and this is stirred and mixed uniformly. This was used for joining a blade sheet made of a polyurethane resin produced from the above production process and a metal blade holder.

<Joint process>
Using a mixing device similar to the supply of the two-component polyurethane composition of the blade sheet, each of the curing agent with the main agent and catalyst added is weighed and transferred with a gear pump so that the NCO group / OH group is 1.05. Then, by mixing mechanically with a mixing head, the band blade sheet was cut to a fixed length of 233 mm, the thickness of 2.0 mm, and the width of 11.5 mm polyurethane blade sheet, A metal holder made of a lubricated resin-treated steel plate pre-heated to 100 ° C. with a width of 4 mm was superposed, kept heated for 30 seconds, and then cooled to obtain a cleaning blade. Similarly, a developing blade having a fixed length of 226 mm, a thickness of 1.20 mm, and a width of 14.0 mm was obtained. The mixing head portion is air-cooled to 20 ° C. in order to suppress an increase in temperature due to mixing.

[Comparative example]
Comparative Examples 1-4 used the polyurethane resin of the same composition except having changed the catalyst.
The developing blade and the cleaning blade were incorporated into a cartridge for LBP IPSIO NX610 manufactured by Ricoh Co., Ltd.
Evaluation was made into the following 1-4, and the result is shown in Table 3.

Evaluation 1: Molding was continuously performed with a heating rotary molding drum apparatus, and it was confirmed whether or not an abnormality occurred in the product.
Depending on the type of catalyst, the urethane reaction is accelerated even at low temperatures, and the urethane hardened in the mixing head is discharged as a foreign substance, or the groove in the mixing part of the mixing head is filled with hardened deposits, and exhibits the original mixing performance This is not possible, and mixing defects are likely to occur. Therefore, the mixing head portion is usually cooled, but it is not sufficient.
Specifically, the items are as follows.
(1) Contamination of foreign matter: In the case of a cleaning blade, if there is a foreign matter on the ridgeline, a problem occurs in scraping off the toner. Further, in the case of the developing blade, if there is a foreign substance in a portion that contacts the surface of the developing roller, problems such as inability to form the toner layer uniformly and non-uniform toner charge amount occur.
(2) Poor mixing: The reaction of the two-component urethane does not occur and an unreacted part is formed, so that the physical properties as the original blade sheet are not exhibited. That is, defective hardness and the like occur, and the cleaning blade has a problem in scraping performance, and the developing blade has problems such as the formation of an optimal toner thin layer and the inability to optimally charge the toner.

Evaluation 2: Contamination of developing sleeve A cartridge equipped with a developing blade and a cleaning blade is left in an environment of 40 ° C. × 95% RH for 7 days, then incorporated into the printer body, 10 images of 50% gray are taken out, and there is no abnormality It was confirmed.

Evaluation 3: Toner contamination A cartridge equipped with a developing blade and a cleaning blade is installed in the printer body, 200 images of 5% character charts are printed, the cartridge is removed from the printer body, and the environment is 40 ° C. × 95% RH for 7 days. After leaving it alone, it was again incorporated into the printer body and 10 50% gray images were taken out to check for any abnormalities.

Evaluation 4: Photoconductor contamination The cartridge equipped with the developing blade and the cleaning blade is left in an environment of 40 ° C. × 95% RH for 7 days, then incorporated into the printer body, and 10 images of 50% gray are taken out. It was confirmed.

The following can be said from the test results.
<About Evaluation Item 1>
Examples that can withstand 12 hours of continuous operation are Example 1 and Comparative Example 1.
<About Evaluation Item 2>
The developing blade catalyst (1,8-diazabicyclo (5,4,0) undecene-7) bleeds out in a high temperature and high humidity environment and adheres to the developing sleeve, and only that portion inhibits the function of the developing sleeve by some action. However, it is presumed that the developability of the toner is lower than that of other portions, that is, the image density is reduced.
<About Evaluation Item 3>
The catalyst (N, N ', N "-tris (dimethylaminopropyl) hexahydro-S-triazine) in the developing blade bleeds out in a high-temperature and high-humidity environment and adheres to the toner on the developing sleeve, and the toner is secondarily aggregated. It is expected that the fluidity of the original toner has been impaired, and the lump of toner with impaired fluidity is fixed on the sleeve, so that only that portion of the developing sleeve and the photoreceptor It is presumed that the image becomes darker than the other parts due to the gap being narrowed and the amount of toner developed on the photoreceptor increased.
<About Evaluation Item 4>
The catalyst (1,2-dimethylimidazole) in the cleaning blade bleeds out in a high-temperature and high-humidity environment and adheres to the photoconductive drum. However, it is estimated that the toner developability is low, that is, the image density is low.

<Comprehensive evaluation>
It was confirmed that the result of using “6- (2-hydroxypropyl) -1,8-diazabicyclo (5,4,0) -7-undecene” as a catalyst was excellent in continuous moldability and product performance. . As a result, the two-component polyurethane adhesive using 6- (2-hydroxypropyl) -1,8-diazabicyclo (5,4,0) -7-undecene is suitable for continuous production of blades, and It can be seen that the manufactured blade is a high performance product without the influence of bleed out. This two-component polyurethane using an amidine compound catalyst having a hydroxyl group of the chemical formula [I] such as 6- (2-hydroxypropyl) -1,8-diazabicyclo (5,4,0) -7-undecene is called continuous production. Needless to say, it exhibits excellent capabilities not only in severe conditions but also in batch processing.

Blade perspective view Blade cross section Continuous production equipment Drum molding part Molding drum Schematic diagram of sheet forming for strip blades Two-component quantitative mixing and casting machine

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polyurethane liquid discharge port 2 External heating device 3 Molding drum 4 Endless belt 5 Molding roll rotating shaft 6 Preheating roll 7 Guide roll 8 Tension roll 9 Cooling roll 10 Cooling conveyor 11 Cooling device 12 Sag detector 13 Feeding roll 14 Cutting Device 15 Conveyor 16 Upper sensor 17 Lower sensor 101 Blade 102 Blade sheet 103 Metal holder 104 Adhesive 200 Two-component quantitative mixing and casting machine 201, 202 Tank 203, 204 Metering pump 207 Mixing head 207c Motor

Claims (7)

An amidine containing a hydroxyl group represented by the general formula [I] as a synthetic resin in a method for continuously forming a blade sheet using a synthetic resin as a raw material for molding using a molding drum having a molding groove and an internal heating device A method for producing a blade sheet, comprising using a two-component thermosetting polyurethane resin using a compound as a reaction catalyst.
Formula [I]
(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ² represents a hydrogen atom, an alkyl or alkylene group having 1 to 16 carbon atoms, or a phenyl group. Also, R ¹ and R ² May combine with each other to form a ring having 5 to 8 carbon atoms, R ³ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and m represents an integer of 2 to 4.)   2. The method for producing a blade sheet according to claim 1, wherein heating is performed from the outside of the forming drum.   Along the outer periphery of the molding drum, a synthetic resin supply means, an external heating means, and an endless belt that is driven by the rotation of the molding drum while covering the molding groove of the molding drum are sequentially arranged and supplied to the molding groove. Synthetic resin raw material with the heat of the molding drum and the heat from the external heating means, and the molding space formed by the endless belt and the molding groove, the belt-like blade sheet having a predetermined width and thickness, according to the rotation of the molding drum The method for producing a blade sheet according to claim 1, wherein the blade sheet is formed.   An electrophotographic apparatus comprising a step of cutting a belt-shaped blade sheath produced by the manufacturing method according to any one of claims 1 to 3 to a predetermined length and continuously joining the blade blade and an adhesive. For continuous production of blades. 5. The method for continuously producing a blade for an electrophotographic apparatus according to claim 4, wherein the adhesive is a two-component curable polyurethane adhesive using as a catalyst an amidine compound having a hydroxyl group represented by the general formula [I].
Formula [I]
(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ² represents a hydrogen atom, an alkyl or alkylene group having 1 to 16 carbon atoms, or a phenyl group. Also, R ¹ and R ² May combine with each other to form a ring having 5 to 8 carbon atoms, R ³ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and m represents an integer of 2 to 4.)   An electrophotographic apparatus blade produced by the production method according to claim 1, or an electrophotographic apparatus blade obtained by joining the blade sheet to a blade holder. A blade sheet made of a thermosetting polyurethane resin using an amidine compound having a hydroxyl group represented by the general formula [I] as a reaction catalyst, or a blade obtained by bonding the blade sheet to a holder.
Formula [I]
(Wherein R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R2 represents a hydrogen atom, an alkyl or alkylene group having 1 to 16 carbon atoms, or a phenyl group. Also, R1 and R2 are bonded to each other. And may form a ring having 5 to 8 carbon atoms, R3 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and m represents an integer of 2 to 4.)