JP2006198887A - Manufacturing method of blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a blade having good dimensional precision in a cutting direction in a case that two blades are manufactured at the same time. <P>SOLUTION: Two holders are arranged in opposed relationship, a blade member 3 is formed from a thermosetting resin and the blade member 3 is cut and divided to obtain two blades. In this blade manufacturing method, a monolithic molded product having two holders and the blade member 3 is characterized in that the leading end part 6 of the other holder opposed to one holder is shifted from the perpendicular line 8 with the cutting line 7 turned toward the opposed other holder from the leading end part 6 in the cutting line direction at the thermosetting resin joined part of one holder. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a blade used in an electrophotographic apparatus.

  In general, in an electrophotographic apparatus, after transferring to a recording sheet, in order to remove the toner remaining on the photosensitive member and perform copying repeatedly, a cleaning blade in which a blade member is bonded to a support, A blade having an elastic member bonded to a support, such as a developing blade that forms a thin film while frictionally charging toner is provided.

  The cleaning blade is formed by integrating a metal holder that attaches the blade to the apparatus and the like, and a blade member made of an elastic body at one end of the holder, and the blade member has a degree of wear resistance and permanent distortion. For example, polyurethane elastomer is usually used.

  By the way, a cleaning blade having such a polyurethane blade member is conventionally manufactured by performing a cast molding operation using a polyurethane-forming material. In other words, a cleaning blade mold composed of an upper mold and a lower mold was prepared, and a holder with an adhesive applied to one end was placed in a mold cavity with the adhesive applied portion of the holder protruding. A cleaning blade is manufactured by injecting a liquid composition containing a prepolymer obtained by partially polymerizing polyisocyanate and polyol and a curing agent into a mold, curing it, and then demolding the cured product. can do.

  Moreover, in order to raise production efficiency, it manufactures also with the following methods. Two holders with adhesive applied to one end are placed facing each other in the mold cavity with the adhesive application part of the holder protruding, and the polyisocyanate and polyol are partially placed in this mold. A liquid composition containing a polymerized prepolymer and a curing agent is poured, and a curing reaction is performed to obtain a molded product in which two holders are integrated with a polyurethane elastomer. Then, by cutting the urethane part of the molded product into two parts, and further removing the urethane part along both longitudinal ends of the holder, two cleaning blades can be manufactured. . However, since the curing reaction is performed at 120 to 150 ° C., distortion due to heat shrinkage remains. At this time, the amount of heat shrinkage is larger in polyurethane elastomer than the holder made of metal, so the part bonded to the holder is fixed to the metal holder with small heat shrinkage even if trying to shrink Although it is suppressed, the portion not fixed to the holder contracts greatly.

  For this reason, the blade after cutting has a shape in which the vicinity of both ends is raised by contracting from the end in the longitudinal direction of the blade toward the center. Therefore, the length A (5 in FIG. 1) from the reference line in the short direction of the holder shown in FIG. 1 to the edge of the blade member 3 is not uniform in the longitudinal direction and both ends are long. Become.

For this reason, when the cleaning blade is pressed against the photosensitive drum, the blade nip width varies in the longitudinal direction of the cleaning blade, resulting in a problem that uniform cleaning properties cannot be obtained. In particular, recently, since the toner particle size has been reduced with the full color of the laser beam printer, a cleaning blade having a highly accurate edge position in the longitudinal direction of the blade member 3 is required. Further, since the dimension A (5 in FIG. 1) at both ends in the longitudinal direction of the blade is long, both ends in the longitudinal direction are more strongly pressed against the drum. In order to solve such a problem, a method of notching at both ends in the longitudinal direction of the urethane joint of the holder and a method of tapering from the center to the end have been proposed (for example, Patent Document 1). However, this method has a problem that the shape of the holder becomes complicated, so that it is difficult to obtain the accuracy of the holder and the cost is increased. Further, when the accuracy of the holder itself is lowered, there is a problem that the dimensional accuracy of the blade itself is also lowered.
Japanese Patent Laid-Open No. 11-194689

  An object of the present invention is to provide a method for manufacturing a blade, which is a case where two blades are manufactured at the same time and has good dimensional accuracy in the cutting direction.

  The present invention achieves the object by the following means.

  The first embodiment of the present invention is a blade manufacturing method obtained by dividing two holders by arranging two holders facing each other, forming a blade member 3 with a thermosetting resin, and cutting the blade member 3. An integrally molded product having the two holders and the blade member 3 has a cutting line 7 from the front end portion 6 in the cutting line direction at the thermosetting resin joint portion of one holder to the other holder facing the other. The blade manufacturing method is characterized in that the tip 6 of the opposite holder is displaced from the vertical line 8.

  The 2nd form of this invention is a manufacturing method of the braid | blade whose deviation | shift amount of the cutting direction front-end | tip part of the thermosetting resin joining part in an opposing holder is 3-100 mm.

  The third aspect of the present invention is a method for manufacturing a blade in which the thermosetting resin is a polyurethane elastomer.

  According to the present invention, it is possible to manufacture a blade with good dimensional accuracy in the cutting direction with high production efficiency.

  Hereinafter, embodiments of the present invention will be described in detail.

  The electrophotographic apparatus blade manufactured in the present invention is made of a metal holder and a polyurethane elastomer as a blade member. In these, a cleaning blade mold composed of an upper mold and a lower mold is prepared, an adhesive is applied to one end of the holder, and this portion protrudes into the cavity for forming the blade of the mold. The liquid composition containing the prepolymer and the curing agent is injected into the mold, and the curing reaction is performed at 120 ° C. to 150 ° C., and the two holders are made of polyurethane elastomer. An integrated molded product is obtained. Then, by cutting the central portion of the urethane part of the molded product in the short direction and separating it into two parts, and further cutting and removing the urethane part along both longitudinal ends of the holder, two cleaning blades Can be manufactured.

  When this holder is placed, the cutting direction tip 6 at the joining portion of the opposing holder is perpendicular to the cutting line toward the opposing holder from the cutting direction tip 6 at the urethane joining portion of the holder. By shifting, the length A from the reference line in the short direction of the holder to the edge of the blade member 3 can be made accurate in the longitudinal direction. When there is a cutting direction tip 6 at the joining portion of the holder facing the perpendicular to the cutting line from the cutting direction tip 6 at the joining portion of the holder toward the opposing holder, two holders are The urethane part of the molded product integrated with the polyurethane elastomer shrinks from both ends toward the center in the blade longitudinal direction. However, by shifting the tip 6 in the cutting direction at the joining portion of the holder, the environment of the ends in the longitudinal direction of the holders facing each other changes, and the direction of contraction of the ends in the blade longitudinal direction is dispersed. It is thought that the jumping up near the both ends of the is reduced.

  The shift distance is preferably 3 to 100 mm. If it is less than 3 mm, there is almost no effect of improving the distance from the holder reference to the edge, and if it exceeds 100 mm, there is an effect, but the amount of urethane at both ends in the longitudinal direction that cannot be used as a product Is unfavorable because of an increase in the size and the mold becomes too large. In addition, the shape of the holder may be the same shape for the two facing each other or not. For example, the holders of different lengths in the longitudinal direction of the holder may be placed facing each other in a mold and cast.

  The polyurethane forming the blade part is a mixture of a polyisocyanate, a prepolymer comprising a polyol and a curing agent comprising a polyol, a chain extender, and a catalyst.

  Examples of the polyisocyanate include 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), and xylene diisocyanate. (XDI), 1,5-naphthylene diisocyanate (1,5-NDI), p-phenylene diisocyanate (PPDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (water) And MDI), tetramethylxylene diisocyanate (TMXDI), carbodiimide-modified MDI, polymethylenephenyl polyisocyanate (PAPI), and the like. Among these, it is preferable to use MDI.

  Examples of the polyol include polyester polyols, polyether polyols, caprolactone ester polyols, polycarbonate ester polyols, silicone polyols, and the like, and the number average molecular weight is preferably 1500 to 5000. This is because if it is less than 1500, the physical properties of the resulting urethane rubber tend to be reduced, and if it exceeds 5000, the viscosity of the prepolymer tends to increase and handling tends to be difficult.

  As the chain extender, for example, glycol is used. Examples of such glycol include ethylene glycol (EG), diethylene glycol (DEG), propylene glycol (PG), dipropylene glycol (DPG), and 1,4-butanediol. (1,4-BD), 1,6-hexanediol (1,6-HD), 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, xylylene glycol (terephthalyl alcohol), triethylene glycol, and the like Is mentioned. In addition to the above glycols, polyhydric alcohols are used, and examples of such polyhydric alcohols include trimethylolpropane, glycerin, pentaerythritol, and sorbitol.

  As the catalyst, those generally used for curing polyurethane can be used, and examples thereof include a tertiary amine catalyst. Trialkylamines such as triethylamine, tetraalkyldiamines such as N, N, N ′, N′-tetramethyl-1,3-butanediamine, aminoalcohols such as dimethylethanolamine, triethylenediamine, piperazine, triazine, 4 Examples thereof include organic acid salts and phenol salts of secondary amines. Alternatively, an organic acid salt of a metal such as potassium acetate or potassium octylate alkali may be used. Moreover, the metal catalyst normally used for urethane may be sufficient and a dibutyl tin dilaurate etc. can be illustrated. These may be used alone or in combination.

  If necessary, additives such as catalysts, pigments, plasticizers, waterproofing agents, antioxidants, ultraviolet absorbers, and light stabilizers can be added to the curing agent.

  The polyurethane elastomer of the blade member according to the present invention can be produced according to a conventional method using the above materials. Specifically, it can be produced according to a prepolymer method, a semi one-shot method, or a one-shot method.

  The holder used in the present invention is not particularly limited as long as it is generally used for a blade for an electrophotographic apparatus, and examples thereof include a highly rigid steel plate, stainless steel plate, galvanized chromate coated steel plate, and chromium-free steel plate.

  The adhesive that can be used in the present invention may be a general polyurethane-metal adhesive, and examples thereof include phenol-based and urethane-based adhesives.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1
<Preparation of thermosetting polyurethane raw material>
4,4'-diphenylmethane diisocyanate as the isocyanate, a prepolymer having an NCO% of 7.0% using an adipate-based polyester polyol having a number average molecular weight of 2000 as the polyol, 1,4-butanediol and trimethylolpropane A curing agent was prepared by adding 1000 ppm of P15 (manufactured by Air Products Japan) and 3000 ppm of triethylenediamine (TEDA) to a mixture having a mass ratio of 65:35.

<Molding of cleaning blade>
Prepare a cleaning blade mold consisting of an upper mold and a lower mold, apply phenolic adhesive to one end of the holder, and project this part into the cavity for forming the blade of the mold. They were placed facing each other. At this time, assuming that the left side holder is (1) and the right side holder is (2) with the inlet side facing up and the edge side facing forward, the cutting direction in which the urethane in the holder (1) is joined The tip (inlet side) was placed on the 10 mm inlet side with respect to the holder (2). A liquid composition containing a prepolymer and a curing agent was injected into the mold, and this was subjected to a curing reaction at 120 ° C. to 150 ° C. to obtain a molded product in which two holders were integrated with a polyurethane elastomer. Then, the urethane part of the molded product is cut at the center portion to be separated into two pieces, and further, the blade member is cut and removed along both longitudinal end portions of the holder, whereby two cleaning blades (1 ) And (2) were obtained.

<Measurement of edge position>
In the cleaning blades (1) and (2) obtained, the reference in the short direction of the holder at both longitudinal ends (10 and 11 in FIG. 4) and the center position (12 in FIG. 4) of the blade member 3 The length A from the line to the edge of the blade member 3 was measured, and the difference in the distance A between the longitudinal end portions and the central portion was calculated. If the difference is 30 μm or less at both ends of the blade, ◎, ◯ when 31 to 50 μm at one end, and × when 51 μm or more at one end. The results are shown in Table 1.

(Example 2)
Example 1 is the same as Example 1 except that the end (inlet side) in the longitudinal direction where the urethane of the holder (1) is joined is arranged on the opposite side of Example 1 on the 10 mm inlet side with respect to the holder (2). I went there. The results are shown in Table 1.

(Example 3)
The same procedure as in Example 1 was performed except that the end (injection port side) in the longitudinal direction where the urethane of the holder (1) was joined was arranged on the 3 mm injection port side with respect to the holder (2). The results are shown in Table 1.

Example 4
The same procedure as in Example 1 was performed, except that the end (injection port side) in the longitudinal direction where the urethane of the holder (1) was bonded was arranged on the 100 mm injection port side with respect to the holder (2). The results are shown in Table 1.

(Comparative Example 1)
The same procedure as in Example 1 was performed except that the end (injection port side) in the longitudinal direction where the urethane of the holder (1) was joined was disposed at the same position as the holder (2). The results are shown in Table 1.

  As can be seen from Table 1, the difference between the end and the center is small in Examples 1 to 4, and the length A from the reference line in the short direction of the holder to the edge of the blade member 3 is accurate in the longitudinal direction. I understand that is good. In contrast, in Comparative Example 1, the difference between the end and the center is large, the length A from the reference line in the short direction of the holder to the edge of the blade member 3 is long at both ends in the longitudinal direction, and the accuracy is high. It turns out that it is low.

It is the schematic of the cleaning blade obtained by the manufacturing method of the braid | blade for electrophotographic apparatuses of this invention. It is explanatory drawing which shows embodiment of the manufacturing method of the braid | blade for electrophotographic apparatuses of this invention. It is explanatory drawing which shows the form of the manufacturing method of the braid | blade for the conventional electrophotographic apparatus. It is explanatory drawing which shows the edge position measurement in the Example of a braid | blade.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrophotographic device blade 2 Holder 3 Blade member 4 Reference line in the short direction of the holder 5 Length A from the reference line in the short direction of the holder to the edge of the blade member 3
6 Cutting line direction front end portion 7 at the thermosetting resin joint portion of the holder 7 Cutting line 8 Perpendicular line 9 to the cutting line 10 Inlet side 10 The left end 11 of the blade member that is the measurement point of the dimension A The blade that is the measurement point of the dimension A The right end 12 of the member The center of the blade member that is the measurement point of the dimension A

Claims (3)

  A blade manufacturing method in which two holders are placed face to face, a blade member 3 is formed of a thermosetting resin, and the blade member 3 is cut into two parts by cutting, the two holders and the holder The integrally molded product having the blade member 3 is formed on the perpendicular 8 with the cutting line 7 toward the other holder facing the other holder from the cutting line direction front end 6 at the thermosetting resin bonding portion of one holder, and the other facing the other. The blade manufacturing method is characterized in that the tip portion 6 of the holder is displaced.   The blade manufacturing method according to claim 1, wherein a deviation amount of a tip portion in a cutting direction of the thermosetting resin joint portion at the opposing holder is 3 to 100 mm. The blade manufacturing method according to claim 1, wherein the thermosetting resin is a polyurethane elastomer.

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