JP5492761B2 - Manufacturing method and apparatus for blade member for electrophotographic apparatus - Google Patents

Description

  The present invention relates to a blade member manufacturing method and apparatus used in an electrophotographic apparatus using an electrophotographic process such as an electrophotographic copying machine, a laser beam printer, and a facsimile machine.

  Conventionally, various blade members are used in an electrophotographic apparatus using an electrophotographic process. Specifically, there is a developer regulating blade for making a constant amount of toner on the periphery of the developing roller that supplies developer (also referred to as toner) to the electrostatic latent image formed on the photoreceptor. There is also a cleaning blade for removing the toner remaining on the photoreceptor after the developed toner image is transferred to a transfer material such as recording paper.

  Since this type of blade member is in contact with the surface of a photoreceptor, a developing roller, etc., an elastic body is generally applied so as not to damage these surfaces, and if necessary, a metal support member And is connected to the electrophotographic apparatus via a support member. For these elastic bodies, polyurethane resins are usually used because of their excellent wear resistance and mechanical properties.

  In general, an electrophotographic blade including such a polyurethane resin blade member is generally manufactured by the following manufacturing method.

  One is a manufacturing method called centrifugal molding, in which raw material is put into a cylindrical mold, rotated at high speed, filled into the inner peripheral surface by centrifugal force, and heat-cured to form a thin cylindrical sheet. . The thus obtained cylindrical sheet is taken out from the cylindrical mold, and is subjected to secondary cross-linking as necessary, and cut into a predetermined size to produce a blade member for an electrophotographic apparatus. Then, one side edge portion of the electrophotographic apparatus blade member is adhered to the support member with an adhesive or the like, thereby completing a cleaning blade or a developer amount regulating blade as a final product.

  The second method is a mold forming method. This is a method in which a support member to which an adhesive or the like has been applied is set in a split mold, a raw material is injected into the split mold, heat-cured, and the support member and the electrophotographic apparatus blade member are integrally molded. Thereafter, the split mold is opened and the molded body is taken out. In order to ensure edge (ridgeline) accuracy, one side may be cut after molding.

  These methods have the following points to be improved. First, the centrifugal molding method is a batch process, and continuous automation is difficult. In the molding method, it is necessary to prepare a considerable number of molds for mass production, and a curing furnace is also required. As a result, the overall size of the apparatus becomes large, which leads to securing space and increasing apparatus cost.

  In addition, as a conventional method for continuously forming a polyurethane sheet, a liquid material of a polyurethane prepolymer which is a thermosetting polyurethane raw material component and a liquid material of a crosslinking agent are mixed and stirred, and heated in a continuous cross-section with a concave shape. There is a method of continuously forming a belt-like blade member for an electrophotographic apparatus with a constant width by heating and pressurizing after discharging into a mold. According to this technique, it is possible to continuously form a blade member for an electrophotographic apparatus, and the manufacturing process can be easily automated, simplified, and the equipment cost can be reduced.

  As such a production method, a method is described in which a polyurethane composition is poured into a groove of a heated molding drum and the polyurethane composition is thickened and covered with an endless belt. However, in this method, curing starts immediately after the polyurethane composition comes into contact with the groove of the molding drum, resulting in a difference in the degree of curing between the contact surface side of the endless belt and the contact surface side of the molding drum. Unevenness tends to occur. When the curing rate is high, the polyurethane composition may not reach the entire molding groove and may not be molded into the target shape. (For example, patent document 1).

  In addition, as another method of continuously forming a sheet using a conventional polyurethane resin, a forming drum having a forming surface formed on the entire outer periphery and an endless belt press-contacted to a part of the outer periphery of the forming drum Describes a thermosetting elastomer continuous molding apparatus that pressurizes a sheet from the back of an endless belt with a back pressure roll. Although this device can suppress the mixing of bubbles, if the polyurethane composition thickens before pressurization by the endless belt, a molded product with a uniform thickness may not be obtained. A load device or the like to be pressed is required, and the device may be complicated. (For example, patent document 2).

Japanese Patent No. 2645980 Japanese Patent Laid-Open No. 10-15967

  The present invention is a high-quality blade member for an electrophotographic apparatus that maintains the fluidity of the polyurethane composition, suppresses the mixing of bubbles and fills the molding cavity, suppresses unevenness of curing, has a uniform thickness, and has an excellent appearance. Is to provide a manufacturing method and an apparatus thereof that can be manufactured efficiently and inexpensively.

The present invention includes a step of mixing and stirring raw materials using a molding cavity formed by a molding drum formed with continuous molding grooves on the outer peripheral surface and an endless belt in contact with the outer peripheral surface of the molding drum, A step of injecting the agitated material, a step of heat-curing by the sandwiched portion of the forming drum and the endless belt, a step of releasing the heat-cured formed body from the forming drum and the endless belt, and the predetermined size of the formed body In the method of manufacturing a blade member for an electrophotographic apparatus, the step of cutting into
The electrophotographic blade member is formed of a polyurethane resin obtained by heat-curing a polyurethane composition,
When the viscosity of the polyurethane composition is V1 after the mixing and stirring of the polyurethane composition and before the injection is V1, and the viscosity of the polyurethane composition when starting the heat curing at the sandwiched portion of the molding drum and the endless belt is V2. Is 500 mPa · s or more and 3000 mPa · s or less, and the V1 and V2 viscosity ratio (V2 / V1) is represented by 1 ≦ V2 / V1 ≦ 1.5,
The polyurethane composition is disposed in the molding groove on the endless belt on the upstream side of the moving direction of the endless belt from the portion where the molding drum and the endless belt first contact each other. The present invention relates to a method for manufacturing a blade member for an electrophotographic apparatus, wherein the blade member is in an opposing position.

Further, the present invention provides means for injecting a mixed and stirred material into a molding cavity formed by a molding drum having a continuous molding groove on the outer peripheral surface and an endless belt in contact with the outer peripheral surface of the molding drum. An electronic device having means for heat-curing by a sandwiching portion between the forming drum and the endless belt, means for releasing the heat-cured formed body from the forming drum and the endless belt, and means for cutting the formed body into a predetermined size In a blade member manufacturing apparatus for a photographic apparatus,
The blade member for an electrophotographic apparatus is formed of a polyurethane resin obtained by heat-curing a polyurethane composition, and the viscosity after mixing and stirring of the polyurethane composition is V1, and the molding drum and the endless belt are sandwiched. V1 is 500 mPa · s or more and 3000 mPa · s or less, and V1 and V2 viscosity ratio (V2 / V1) is 1 ≦ V2 / V. V1 ≦ 1.5,
The polyurethane composition is disposed on the endless belt within a range of 5 mm or more and within 350 mm upstream from the position where the molding drum and the endless belt first contact each other with respect to the moving direction of the endless belt. The blade member for an electrophotographic apparatus, wherein the blade member is a position facing the molding groove, and a discharge position of the polyurethane composition is 5 mm or more and 200 mm or less upward in the vertical direction from the arrangement position. It relates to a manufacturing apparatus.

  The method for producing a blade member for an electrophotographic apparatus according to the present invention comprises filling a molding composition with a polyurethane composition while maintaining its fluidity and suppressing bubble mixing, suppressing unevenness in curing, having a constant thickness, and having an external appearance. It is possible to manufacture an excellent and high-quality blade member for an electrophotographic apparatus efficiently and inexpensively.

It is a figure which shows the shaping | molding cavity used for an example of the manufacturing method of the blade member for electrophotographic apparatuses of this invention. It is explanatory drawing explaining the discharge position of the polyurethane composition in the manufacturing method of the blade member for electrophotographic apparatuses of this invention. It is a figure which shows the groove | channel for a shaping | molding used for an example of the manufacturing method of the blade member for electrophotographic apparatuses of this invention. It is a schematic block diagram which shows an example of the manufacturing apparatus of the blade member for electrophotographic apparatuses of this invention.

  The method for producing a blade member for an electrophotographic apparatus according to the present invention comprises a step of mixing and stirring raw materials, a forming drum having a continuous forming groove formed on the outer peripheral surface, and an endless belt in contact with the outer peripheral surface of the forming drum. The step of injecting the mixed and stirred material into the molding cavity to be formed, the step of heat-curing by the sandwiched portion of the molding drum and the endless belt, and releasing the molded body after the heat-curing from the molding drum and the endless belt And a step of cutting the molded body into a predetermined dimension.

[raw materials]
As said raw material, the polyisocyanate and polyol which form a urethane resin can be mentioned. Preferably,
(A) Polyisocyanate (B) Adipate polyester polyol having a number average molecular weight of 1000 to 4000 (C) Chain extender having a molecular weight of 200 or less (D) Isocyanurate catalyst 20 ppm to 500 ppm and Urethane catalyst 200 ppm to 1500 ppm The following are preferably used:

  Specific examples of (A) polyisocyanate include the following. 4,4'-diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), trimethylhexamethylene diisocyanate (TMHDI). Tolylene diisocyanate (TDI), carbodiimide modified MDI, polymethylene phenyl polyisocyanate (PAPI), orthotoluidine diisocyanate (TODI), naphthylene diisocyanate (NDI), xylene diisocyanate (XDI).

  Hexamethylene diisocyanate (HMDI), paraphenylene diisocyanate (PDI), lysine diisocyanate methyl ester (LDI), dimethyl diisocyanate (DDI) and the like. These can be used alone or in combination of two or more. Among these, it is particularly preferable to use MDI.

  Specific examples of the (B) adipate-based polyester polyol include the following. Polyethylene adipate polyester polyol, polybutylene adipate polyester polyol, polyhexylene adipate polyester polyol, polyethylene-propylene adipate polyester polyol, polyethylene-butylene adipate polyester polyol, polyethylene-neopentylene adipate polyester polyol. These preferably have a number average molecular weight of 1000 to 4000.

  If the number average molecular weight of the polyol is 1000 or more, the physical properties of the resulting urethane resin can be prevented from decreasing, and if it is 4000 or less, the viscosity of the prepolymer is increased and handling is difficult. It is possible to suppress unevenness in curing of the polyurethane. The use amount of the adipate-based polyester polyol is preferably 40 to 80% with respect to the total mass of the cured body as mass%.

  As said (C) chain extender, low molecular weight polyols, such as glycol, can be used, Specifically, the following can be illustrated. Ethylene glycol (EG), diethylene glycol (DEG), propylene glycol (PG), dipropylene glycol (DPG), 1,4-butanediol (1,4-BD), hexanediol (HD), 1,4-cyclohexanediol . 1,4-cyclohexanedimethanol, P-xylylene glycol (terephthalyl alcohol), triethylene glycol and the like.

  In addition to the glycol, other polyhydric alcohols can be used, and examples include trimethylolpropane, glycerin, pentaerythritol, sorbitol, and the like. These may be used alone or in combination of two or more. When the molecular weight of the chain extender is 200 or less, the density of the hard segments can be increased, and a blade member having excellent mechanical properties can be formed. It is preferable that the usage-amount of a chain extension agent is 2 to 15% with respect to the hardening body total mass as mass%.

  The (D) isocyanurate-forming catalyst can promote the curing reaction, can shorten the production time and reduce the size of the apparatus, improve the production efficiency, and reduce the cost of the apparatus. Further, by imparting temperature sensitivity, the reaction can be delayed at room temperature, and curing can be accelerated by heating. The amount of the isocyanurate catalyst used is preferably 20 ppm or more and 500 ppm or less in the raw material. If the amount of the isocyanurate catalyst used is 20 ppm or more, the curing reaction can be promoted, and if it is 500 ppm or less, the initiation of the curing reaction during the raw material mixing and stirring step can be suppressed.

  Examples of the isocyanurate-forming catalyst include the following. Tertiary amines such as N-ethylpiperidine, N, N'-dimethylpiperazine, N-ethylmorpholine. Tetraalkylammonium hydroxides and organic weak acid salts such as tetramethylammonium, tetraethylammonium and tetrabutylammonium. Hydroxyalkylammonium hydroxides and organic weak acid salts such as trimethylhydroxypropylammonium and triethylhydroxypropylammonium.

  Metal salts of carboxylic acids such as acetic acid, propionic acid, butyric acid, caproic acid, capric acid, valeric acid, octylic acid, myristic acid, naphthenic acid. These can be used alone or in combination of two or more. Among these, a metal salt of a carboxylic acid that has a temperature sensitivity that initiates a curing reaction by heating and that does not bloom after molding and does not affect other parts is preferable.

  By using the urethanization catalyst, it is possible to obtain a blade member having appropriate properties such as elasticity, flexibility, mechanical strength, and friction resistance necessary for the blade member. The amount of the urethanization catalyst used is preferably 200 ppm or more and 1500 ppm or less, more preferably 300 ppm or more and 1000 ppm or less in the raw material. If the amount of the urethanization catalyst used is 200 ppm or more, the urethanization reaction is promoted, and a blade member having the necessary characteristics as a blade member can be obtained. If it is 1500 ppm or less, the raw material is mixed and stirred. Initiation of the urethanization reaction can be suppressed.

Examples of the urethanization catalyst include the following. Amino alcohols such as dimethylethanolamine, trialkylamines such as triethylamine, tetraalkyldiamines such as N, N, N ′, N′-tetramethyl-1,3-butanediamine, triethylenediamine, piperazine, and triazine. Metal catalysts such as dibutyltin dilaurate. These can be used alone or in combination of two or more.
[Blade member manufacturing method and apparatus for electrophotographic apparatus]
Embodiments of a manufacturing method according to the present invention will be described below together with a manufacturing apparatus based on the drawings. FIG. 1 is a schematic view showing an example of a blade member manufacturing apparatus for an electrophotographic apparatus.

(Weighing, mixing, stirring)
First, a polyurethane composition is measured, mixed and stirred to prepare a mixture. As shown in FIG. 1, the apparatus for mixing and stirring the polyurethane composition includes at least two tanks 10 and 11. Further, each tank outlet is connected to a mixing head 16 via metering pumps 12 and 13, and the mixing head 16 and the tanks 10 and 11 are connected by discharge / circulation pipes 14 and 15. Further, the mixing head 16 has a known structure in which a stirring rotor is provided in a chamber having an introduction port and a discharge port for a liquid material, and can discharge the polyurethane composition with high accuracy. Using such a quantitative mixer, a fixed amount is supplied to the mixing head by a metering pump, and mixed and stirred uniformly.

(Injection)
Next, as shown in FIG. 2, the molding apparatus includes a molding drum 18 having a continuous molding groove 18 g of the original body of the blade member in the rotational direction on the outer peripheral surface, and a part of the outer peripheral surface of the molding drum 18. An endless belt 19 disposed so as to cover the molding groove 18g is disposed. Further, a heating means is provided which is disposed in close proximity to or close to a position in or close to the forming drum 18, or the endless belt 19 side of a portion where the forming drum 18 and the endless belt 19 are in pressure contact. The polyurethane composition injected into the molding groove 18g is heat-cured in the molding cavity 23 surrounded by the molding groove 18g on the molding drum 18 and the endless belt 19 shown in FIG. be able to.

  The forming drum 18 is made of, for example, hard aluminum, iron, stainless steel, and the like. The center portion of the forming drum is rotatably supported by a horizontal rotating shaft 17 and is rotated at a predetermined speed by a driving device.

  The shape of the molding groove 18g formed continuously on the outer peripheral surface of the molding drum 18 is appropriately selected according to the shape of the electrophotographic blade member to be manufactured. For example, the cross section may have a rectangular shape as shown in FIG. 3 (a), or the cross section may have a trapezoidal shape as shown in FIG. 3 (b).

  Moreover, the endless belt 19 consists of metal strips, such as stainless steel, for example. The mechanism is also possible with resin belts other than stainless steel, but at that time, it is preferable to use means that can be heated from the outside of the resin belt.

  The endless belt 19 is stretched over a driving roll 20 having a driving mechanism different from that of the forming drum 18, a guide roll 21 for adjusting endless belt travel, and a tension roll 22 for applying tension to the endless belt 19. The forming drum 18 and the endless belt 19 rotate at the same peripheral speed.

  Further, it is preferable to separate the driving means for the forming drum 18 and the endless belt 19 because the tension of the endless belt 19 can be reduced. As the driving means, for example, a combination of a motor, a clutch, a brake and the like can be considered. However, in order to make the tension between the molding drum 18 and the endless belt 19 constant in accordance with the peripheral speed of the molding drum 18, the molding drum 18 is preferably driven by a motor, and the endless belt 19 is preferably driven by a powder brake and a motor. It is preferable to set the peripheral speed of the forming drum 18 and the peripheral speed of the endless belt 19 in consideration of scratches on the endless belt 19 and the pattern of the molded product.

The tension of the tension roll 22 that applies tension to the endless belt 19 is equal to the tension that the endless belt 19 presses against the forming drum 18 while considering the influence on the tension during driving of the endless belt 19 and the bending of the endless belt 19. The following is preferable.
(Heating method)
As the heating method of the heating means, there is a heating method from the outside or from the inside of the molding drum 18. However, from the outside, since it is affected by disturbance (such as room temperature), internal heating for directly heating the molding drum 18 is performed. Is preferred. As means for performing the internal heating, there are means such as a heater, oil, and water, but the heater is optimal from the viewpoint of space saving and temperature management. It is desirable that the temperature is within a predetermined temperature ± 5 degrees in consideration of abnormal appearance on the molded product.

  In the apparatus shown in FIG. 1, the mixing head 16 serving as a raw material arranging means is provided with a discharge port 28 through which a polyurethane composition can be discharged at a predetermined speed. The polyurethane composition in the mixing head 16 is discharged from the discharge port 28 and disposed on the endless belt 19. At this time, the forming drum 18 and the endless belt 19 are rotating at a predetermined speed, and a necessary amount corresponding to a space (groove) formed by the forming drum 18 and the endless belt 19 is continuously injected. In the present invention, the position of the discharge port 28 is defined as a discharge position.

[Viscosity]
In the method according to the present invention, when the blade member for an electrophotographic apparatus is molded, it is necessary that the polyurethane composition efficiently flows into the molding groove 18g formed continuously on the outer peripheral surface of the molding drum 18. . In the polyurethane composition of at least two kinds of raw materials shown in the present invention, the reaction is started by mixing and stirring, and the thickening proceeds. Therefore, in order to obtain good fluidity, after mixing and stirring, before the injection, From the viscosity, the viscosity of the polyurethane composition at the start of heat curing is an important item in the sandwiched portion of the molding drum 18 and the endless belt 19. The raw material quantified by the metering pumps 12 and 13 is mixed by the mixing head 16 and the viscosity before injection is V1, and the raw material injected from the discharge port of the mixing head 16 is sandwiched between the forming drum 18 and the endless belt 19. In V, the viscosity ratio V2 / V1 of V1 and V2 is expressed by 1 ≦ V2 / V1 ≦ 1.5, where V2 is the viscosity of the polyurethane composition at the start of heat curing. In order to make the viscosity of the polyurethane composition within this range, the type and blending ratio of the polyurethane composition and the temperature at the time of mixing and stirring can be adjusted.

  When V1 is less than 500 mPa · s, the fluidity of the polyurethane composition is too high when it is placed on the endless belt. For this reason, the flow spreads on the endless belt, and even if it comes into contact with the molding drum later, the molding groove of the molding drum cannot be filled, and the size and thickness required as a blade member for an electrophotographic apparatus cannot be obtained. On the other hand, when V1 is greater than 3000 mPa · s, the fluidity of the polyurethane composition is too low, so that it does not spread into the forming groove, and this also fails to provide the size and thickness necessary for a blade member for an electrophotographic apparatus. From the viewpoint of the flowability on the endless belt and the filling property to the forming drum, the viscosity V1 is more preferably 800 mPa · s or more and 2000 mPa · s or less.

  The viscosity V1 immediately before discharge was sampled immediately after mixing and stirring, and the measured value was V1. The measurement was carried out using a Brookfield digital viscometer with a measuring spindle rotating at 10 rpm.

  If the viscosity ratio V2 / V1 between V1 and V2 is less than 1, the viscosity at the time of being sandwiched between the forming drum 18 and the endless belt 19 will decrease, and the groove width will not spread, but will flow out in the direction that follows gravity. The blade width may not be obtained.

  Further, if the viscosity ratio V2 / V1 of V1 and V2 is larger than 1.5, the viscosity is increased more than necessary when sandwiched between the molding drum 18 and the endless belt 19, and flows sufficiently into the molding groove of the molding drum 18. In some cases, the required blade width cannot be obtained. In addition, the thickened material is forcibly crushed by the forming drum 18 and the endless belt 19, resulting in generation of surface patterns and uneven physical properties.

  Adjustment of the viscosity V2 of the polyurethane composition at the starting point of the molding cavity to the above range can also be achieved by adjusting the temperature of the endless belt. The temperature of the endless belt is preferably adjusted to a range of 15 ° C to 60 ° C. Here, the viscosity V2 of the polyurethane composition at the time of starting the heat curing at the sandwiching portion between the molding drum 18 and the endless belt 19 is the time required from the position where the polyurethane composition is placed to the sandwiching start position between the molding drum and the endless belt. After the measurement and calculation, the polyurethane composition was mixed and stirred, and then set on a Brookfield digital viscometer, and the viscosity when the time calculated above was passed was measured.

[Positions]
In the method according to the present invention, the polyurethane composition is disposed in the pouring step in the molding groove on the endless belt on the upstream side with respect to the moving direction of the endless belt from the portion where the molding drum and the endless belt first contact each other. It is in the position opposite to. In the present invention, this position is the arrangement position.

  Further, the polyurethane composition is disposed on the endless belt 19 at a position not less than 5 mm and not more than 350 mm on the upstream side with respect to the moving direction of the endless belt 19 from a portion where the molding drum 18 and the endless belt 19 first contact each other. The position is preferably opposite to the molding groove. In the case where the position is less than 5 mm (shown by a in FIG. 4), the discharged polyurethane composition may cause bubbles to be mixed during injection or uneven injection, so that a desired blade member may not be obtained. . On the other hand, if it is larger than 350 mm, the discharged polyurethane composition flows and spreads beyond the width of the space (groove), and the desired blade member size (thickness) may not be obtained. The arrangement position of the present invention is adjusted to a position facing the molding groove on the endless belt 19, and the adjustment method may be selected from known techniques such as cylinder, NC, mechanical stopper and the like.

[Discharge position]
Here, the discharge port position (discharge position) 28 of the mixing head 16 of the quantitative mixer is preferably disposed above the endless belt 19 within a range of 5 mm or more and 200 mm or less vertically above the polyurethane composition arrangement position. If it is less than 5 mm (shown as b in FIG. 4), the discharge port is likely to come into contact with the discharged polyurethane composition, and the discharge port may become dirty. As a result, foreign matter is introduced into the injected polyurethane composition. There is a possibility that a high-quality blade member for an electrophotographic apparatus may not be obtained. When discharged from a position higher than 200 mm, it is easily affected by the surrounding environment such as the air flow around the discharge port, and the discharge liquid fluctuates. For this reason, the polyurethane composition may be displaced at an appropriate position on the endless belt 19 corresponding to the molding groove, or bubbles may be mixed into the polyurethane composition.

  In the polyurethane composition shown in the present invention, the curing reaction is accelerated by heating. However, the polyurethane composition is injected onto the endless belt 19 having no heating mechanism, so that the urethane polymerization reaction accelerated by heat proceeds. First, thickening can be suppressed. After the endless belt 19 comes into contact with the heated molding drum, the contact surface immediately rises in temperature, and when the polyurethane composition injected onto the endless belt 19 is moved and filled into the molding groove on the molding drum 18, it is heated. And it pressurizes and a urethane polymerization reaction is started. Thereby, a polyurethane composition can be hardened uniformly. When the polyurethane composition is injected into the groove portion on the molding drum 18, the curing proceeds from the first contacted surface. Therefore, the curing proceeds only on the contact surface of the heated molding drum 18, and the contact surface of the endless belt 19. Unevenness of surface pattern and physical properties due to uneven curing occurs. A cooling mechanism for cooling the endless belt 19 may be provided in a portion that is not in contact with the forming drum 18.

(Curing)
Next, the space portion 23 formed by the molding groove of the molding drum 18 and the endless belt 19 is heated and cured for a predetermined time while being filled with the polyurethane composition. As a result, the urethane polymerization reaction of the polyurethane composition is completed to the extent that it can be released from the molding drum 18 and the endless belt 19, and the blade member prototype for the electrophotographic apparatus having the necessary width, thickness, and surface properties is continuous. Formed. In the present embodiment using the manufacturing apparatus shown in FIG. 1, the heating temperature is preferably about 80 to 200 ° C., and the polyurethane composition can be released from the molding drum 18 and the endless belt 19 as the urethane polymerization reaction proceeds. The time required for this is 20 to 90 seconds. However, since the mold can be released if curing is completed to the extent that it can be released from the molding drum 18 and the endless belt 19, the heating temperature and the heating time are the composition of the polyurethane composition and the manufacturing apparatus. It can be appropriately selected according to the configuration.

(Release / cutting)
The polyurethane resin thus heat-cured is released from the forming drum 18 and the endless belt 19 by the releasing means 24.
It is desirable that the molding drum 18 is subjected to a mold release treatment at least at a portion where the polyurethane composition comes into contact, for example, a molding groove 18g. The mold release treatment uses a mold release agent processing apparatus or the like, a method of applying a mold release agent to the surface of the mold, a method of performing plating treatment such as PTFE or fluorine-containing plating on the surface of the molding drum 18, or a mold release property such as silicon. For example, a method of coating a certain resin. However, if the urethane resin can be released, a suitable one may be selected.

  Further, for the endless belt 19 as well, it is desirable that at least the polyurethane composition is subjected to a mold release treatment. As a method for the mold release treatment, the same method as the mold release treatment for the molding drum 18 can be performed.

  The strip-shaped molded body 29 of polyurethane resin that has been released from the mold is conveyed 25 and cut 26 to a predetermined size to obtain a blade member 30. For the cutting, a suitable one may be selected from known methods such as NC cutting with a blade or a punching die.

The blade member manufacturing apparatus for an electrophotographic apparatus of the present invention has the following means.
Means for injecting the mixed and agitated material into a molding cavity formed by a molding drum having a continuous molding groove on the outer peripheral surface and an endless belt in contact with the outer peripheral surface of the molding drum. Means for heat-curing by a sandwiching portion between the forming drum and the endless belt;
A means for releasing the molded body after heat curing from the molding drum and the endless belt.
Means for cutting the molded body into a predetermined dimension.

  The blade member for an electrophotographic apparatus is formed of a polyurethane resin obtained by heat-curing a polyurethane composition. V1 is 500 mPa · s, where V1 is the viscosity after mixing and stirring of the polyurethane composition, and V2 is the viscosity of the polyurethane composition when heat curing is started by the sandwiched portion of the molding drum and the endless belt. The V1 and V2 viscosity ratio (V2 / V1) is expressed as 1 ≦ V2 / V1 ≦ 1.5.

  The polyurethane composition is disposed on the endless belt that is 5 mm or more and 350 mm or less upstream from the position where the molding drum and the endless belt first contact each other in the moving direction of the endless belt. Thus, the position is opposite to the molding groove. Furthermore, the discharge position of the polyurethane composition is 5 mm or more and 200 mm or less above the endless belt in the vertical direction from the arrangement position.

Hereinafter, the present invention will be described in detail with reference to examples.
[Example 1]
[Preparation of raw materials]
[Prepolymer]
A reaction of 32.0 parts by mass of 4,4′-diphenylmethane diisocyanate (MDI) and 61.0 parts by mass of a polybutylene adipate polyester polyol (PBA) having a molecular weight of 2000 was carried out in a nitrogen atmosphere at 80 ° C. for 3 hours. A polymer was obtained. MDI used was Millionate MT (manufactured by Nippon Polyurethane Industry Co., Ltd.), and PBA was Nippon Run 4010 (manufactured by Nippon Polyurethane Industry Co., Ltd.).

  The molecular weight of PBA was calculated by the following formula. The hydroxyl value in the formula was calculated according to JIS-K1557-1.

[Curing agent]
3.9 parts by mass of 1,4-butanediol (14BD) (manufactured by Mitsubishi Chemical Co., Ltd.), 3.2 parts by mass of trimethylolpropane (TMP) (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and a curing catalyst are mixed, and a curing agent is added. Obtained.
[Curing catalyst]
As an isocyanurate-forming catalyst, an ethylene glycol (EG) solution of potassium acetate (P15: manufactured by Air Products Japan Co., Ltd.) was prepared so that the blending amount was 80 ppm with respect to the polyurethane composition. Further, as a urethanization catalyst, triethylenediamine (DABCO crystal: manufactured by Air Products Japan Co., Ltd.) was prepared so that the blending amount was 340 ppm with respect to the polyurethane composition.

  An electrophotographic blade member was prepared from the raw material by using the electrophotographic blade member manufacturing apparatus shown in FIG. The forming drum 18 was made of stainless steel, and the outer peripheral portion was subjected to a fluorine-containing plating process, had a continuous forming groove having a width of 20 mm and a depth of 1 mm, and was driven to rotate at 1.5 rpm. The endless belt 19 is made of metal, and the portion where the molding cavity is molded is subjected to a fluorine-containing plating treatment and is run at the same speed as the peripheral speed of the molding drum. The endless belt was adjusted to 40 ° C., and the molding cavity was adjusted to 135 ° C. A cutting die with a Thomson blade was set in the cutting device for the molded body.

  The obtained prepolymer and curing agent are put into tanks 10 and 11, respectively, and the discharge position of the polyurethane composition is 5 mm upstream from the starting point of the molding cavity, 5 mm above the endless belt, and the heat curing time is 40 seconds. It was adjusted. Viscosity V1 and V2 were measured as follows, and V2 / V1 was calculated. The results are shown in Table 1.

  The obtained blade member having a thickness of 1 mm was heat-bonded to the support member using a film-like hot melt adhesive Elfhan-UH (manufactured by Nippon Matai Co., Ltd.) as an adhesive to obtain a developer amount regulating blade. . The obtained developer amount regulating blade was measured for rubber hardness / rubber hardness difference, and surface patterns due to uneven curing, bubbles / foreign matter contamination, and images were evaluated according to the following criteria. The results are shown in Table 1.

[viscosity]
The viscosity was measured using a digital viscometer rheometer DV-III manufactured by Brookfield. The measurement was performed using a disk-shaped spindle and the rotation speed of the spindle was 10 rpm.

[thickness]
A digital thickness gauge was used to measure up to two decimal places. The measurement was carried out by measuring 10 parts of the molded blade member for an electrophotographic apparatus every 100 mm, and showed the difference between the maximum value and the minimum value.

[Rubber hardness, rubber hardness difference]
The measurement of international rubber hardness (IRHD) was performed based on JIS K 6253 using a Wallace microhardness meter manufactured by Wallace (HW, WALLACE). The measurement was carried out by measuring the molded body of the molded blade member for an electrophotographic apparatus at 500 locations every 500 mm, the average value thereof was taken as the rubber hardness, and the difference between the maximum value and the minimum value was shown as the hardness difference.

[Unevenness of hardness]
The surface unevenness of the surface was evaluated by visually confirming the surface of the blade member for an electrophotographic apparatus and by the following criteria.
○: There is no surface pattern.
Δ: There is a surface pattern that can be distinguished in appearance.
X: There is a surface pattern at a level where image defects occur.

[Bubble and foreign matter mixed in]
The mixture of bubbles and foreign substances were evaluated by visually checking the surface of the blade member for an electrophotographic apparatus, and evaluated according to the following criteria.
○: No bubbles or foreign matters are mixed.
X: Bubbles / foreign substances are mixed.

[Image evaluation]
The produced developer amount regulating blade was incorporated into a cartridge for LASER SHOT-LBP (manufactured by Canon Inc.), and ghosts and image streaks were evaluated according to the following criteria.
[ghost]
○: No ghost occurs.
Δ: Slight ghost is confirmed.
X: A ghost is clearly confirmed.
[Image stripe]
○: No image streak is generated.
Δ: Image streak is confirmed as a slight change on the image.
X: Image streak is confirmed as a large change on the image.

[Examples 2-11, Comparative Examples 1-8]
Tables 1 and 2 show the amounts of 4,4'-MDI and PBA used for the prepolymer, 1,4-BD, TMP, polyol used for the curing agent, P15 used for the curing catalyst, and DABCO. changed. Further, the discharge position of the polyurethane composition (distance upstream from the start point of the molding cavity) and the temperature of the endless belt were changed as shown in Tables 1 and 2.

  In Comparative Example 7, the temperature of the endless belt was changed to 40 ° C. at the polyurethane composition discharge position and 100 ° C. at the start point of the molding cavity. In Comparative Example 8, the polyurethane composition discharge position was changed to the molding position. The top of the drum (position indicated by 27 in FIG. 4) was used, and the heat curing time was 90 seconds.

  Except for these, a developer amount regulating blade was prepared and evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

  In the table, PBA having a molecular weight of 4000 (Example 6) was a prototype, and NIPPOLAN 4009 (manufactured by Nippon Polyurethane Industry Co., Ltd.) was used as the PBA having a molecular weight of 1000.

  From these results, in Examples, the accuracy of thickness was good, the unevenness of physical properties such as hardness was reduced, the appearance pattern and the occurrence of bubbles were reduced, and the image evaluation was also good. On the other hand, in the comparative example, the hardness difference of the polyurethane composition after curing was large, an uneven curing pattern was generated on the surface, bubbles and foreign matters were mixed, and an image defect occurred.

  Also, a blade member for an electrophotographic apparatus having a thickness of 2 mm was prepared in the same manner as in Examples 1 to 11 and Comparative Examples 1 to 8, except that a molding drum having a continuous molding groove having a depth of 2 mm was used. Thus, a cleaning blade was obtained. The obtained cleaning blade was incorporated into a cartridge for LASER SHOT-LBP (manufactured by Canon Inc.) to perform image formation. As a result, a good cleaning function was obtained in the example, and a good image was obtained. A streak occurred.

  The present invention is suitable for high-quality electrophotographic apparatus that has appropriate fluidity until it is filled in a molding cavity, has good thickness accuracy, has little unevenness in physical properties such as hardness, and has a reduced surface pattern and bubbles. The blade member can be continuously formed. For this reason, the blade for an electrophotographic apparatus can be produced at low cost by automated production with high production efficiency.

10, 11 Tanks 12, 13 Metering pumps 14, 15 Discharge / circulation piping 16 Mixing head 17 Molding drum drive rotary shaft 18 Molding drum 18g Molding groove 19 Endless belt 20 Belt drive roll 21 Guide roll 22 Tension roll 23 Molding Space 23s formed by drum and endless belt 23s Mold cavity start point 23e Mold cavity end point 24 Mold release mechanism 25 Mold transport mechanism 26 Cutting device 28 Discharge port (discharge position)
29 Band-shaped molded body 30 Blade member

Claims (4)

A step of mixing and stirring the raw materials using a molding cavity formed by a molding drum formed with a continuous molding groove on the outer peripheral surface and an endless belt in contact with the outer peripheral surface of the molding drum. A step of injecting, a step of heat-curing by a sandwiching portion of the forming drum and the endless belt, a step of releasing the heat-cured formed body from the forming drum and the endless belt, and a step of cutting the formed body into a predetermined dimension. In the manufacturing method of the blade member for an electrophotographic apparatus having,
The electrophotographic blade member is formed of a polyurethane resin obtained by heat-curing a polyurethane composition,
When the viscosity of the polyurethane composition is V1 after the mixing and stirring of the polyurethane composition and before the injection is V1, and the viscosity of the polyurethane composition when starting the heat curing at the sandwiched portion of the molding drum and the endless belt is V2. Is 500 mPa · s or more and 3000 mPa · s or less, and the V1 and V2 viscosity ratio (V2 / V1) is represented by 1 ≦ V2 / V1 ≦ 1.5,
The polyurethane composition is disposed in the molding groove on the endless belt on the upstream side of the moving direction of the endless belt from the portion where the molding drum and the endless belt first contact each other. A method of manufacturing a blade member for an electrophotographic apparatus, wherein the blade member is in an opposing position. The blade member for an electrophotographic apparatus according to claim 1, wherein the blade member for an electrophotographic apparatus is formed of a polyurethane resin obtained by heat-curing a polyurethane composition containing at least the following (A) to (D): Production method.
(A) Polyisocyanate (B) Adipate polyester polyol having a number average molecular weight of 1000 to 4000 (C) Chain extender having a molecular weight of 200 or less (D) Isocyanurate-forming catalyst as a curing catalyst is 20 ppm or more and 500 ppm or less, And urethanization catalyst is 200ppm or more and 1500ppm or less   The polyurethane composition is disposed on the endless belt within a range of 5 mm or more and 350 mm or less upstream from the position where the molding drum and the endless belt first contact each other with respect to the moving direction of the endless belt, The electrophotographic apparatus according to any one of claims 1 to 3, wherein the electrophotographic film is located at a position facing the groove for molding and a discharge position of the polyurethane composition is discharged in a range of 5 mm or more and 200 mm or less above the endless belt. Manufacturing method of blade member for apparatus. Means for injecting the mixed and stirred material into a molding cavity formed by a molding drum having a continuous molding groove formed on the outer peripheral surface and an endless belt in contact with the outer peripheral surface of the molding drum; Production of a blade member for an electrophotographic apparatus, comprising: means for heat-curing by an endless belt sandwiching portion; means for releasing the heat-cured molded body from the molding drum and the endless belt; and means for cutting the molded body into a predetermined size. In the device
The blade member for an electrophotographic apparatus is formed of a polyurethane resin obtained by heat-curing a polyurethane composition, and the viscosity after mixing and stirring of the polyurethane composition is V1, and the molding drum and the endless belt are sandwiched. V1 is 500 mPa · s or more and 3000 mPa · s or less, and V1 and V2 viscosity ratio (V2 / V1) is 1 ≦ V2 / V. V1 ≦ 1.5,
The polyurethane composition is disposed on the endless belt within a range of 5 mm or more and within 350 mm upstream from the position where the molding drum and the endless belt first contact each other with respect to the moving direction of the endless belt. The blade member for an electrophotographic apparatus, wherein the blade member is a position facing the molding groove, and a discharge position of the polyurethane composition is 5 mm or more and 200 mm or less upward in the vertical direction from the arrangement position. manufacturing device.

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