JP2003177600A - Method of making toner supply roll - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of making a toner supply roll capable of easily forming an elastic sponge layer to a crown shape of good accuracy. <P>SOLUTION: A roll substrate 1 integrally formed with the elastic sponge layer 3 consisting of a urethane foam on the outer peripheral surface of a shaft body 2 is inserted by pressure coaxially into a crown cylindrical mold 4 which has an inner diameter smaller than the external diameter of the substrate 1 and is formed with the inner peripheral surface to the crown shape and in this state the layer 3 is shaped to the crown shape of the mold 4 by secondary vulcanizing (heating) and thereafter the molding is parted from the mold. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a toner supply roll used in an electrophotographic apparatus such as a copying machine, a printer and a facsimile.

[0002]

2. Description of the Related Art Generally, copying in an electrophotographic apparatus is
This is performed by forming an original image as an electrostatic latent image on the surface of a photosensitive drum, adhering toner to the electrostatic latent image to form a toner image, and transferring and fixing the toner image onto a copy sheet. The formation of the toner image in this copying is performed by the toner supply roll supplying the toner from the toner box to the developing roll and adhering the toner to the electrostatic latent image. The toner remaining on the surface of the developing roll is scraped off by the toner supply roll, returned to the toner box, and then agitated by an agitator (agitator) in the toner box.

On the other hand, the toner supply roll comprises a shaft body and a sponge elastic layer made of urethane foam formed on the outer peripheral surface of the shaft body. In the electrophotographic apparatus, the toner supply roll is pressed in parallel with the developing roll. Abutting.
Since the bending rigidity of the toner supply roll is usually lower, the shaft of the toner supply roll is warped. Due to the warp of the shaft body, the contact pressure between the both rolls is larger at both end portions than at the center portion of the contact portion. Therefore, the toner is likely to deteriorate and the image quality deteriorates.

Therefore, in order to prevent the deterioration of the toner and the deterioration of the image quality, the applicant of the present application has proposed to make the sponge elastic layer of the toner supply roll into a crown shape (Japanese Patent Laid-Open No. 2000-275953). . That is, in the toner supply roll, the sponge elastic layer has a shape (crown shape) in which the thickness gradually increases from both axial end portions toward the central portion (see FIG. 4). And
To form the crown shape of the sponge elastic layer, the sponge elastic layer is polished or the cavity of the molding die is crowned (the inner diameter of the molding die is gradually expanded from both ends in the axial direction toward the center). Shape).

[0005]

However, in the method of making the sponge elastic layer into a crown shape by polishing, the accuracy of the crown shape is poor and the polishing process is troublesome. Moreover, dimensional variations occur in the crown shape. Further, in the method of forming the cavity portion of the molding die in a crown shape, it is necessary to make the cavity portion of the molding die precise in order to form the sponge elastic layer with high precision only by molding. Is difficult to manufacture stably, and it takes too much time and cost to manufacture it.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a method of manufacturing a toner supply roll capable of easily forming a sponge elastic layer in an accurate crown shape.

[0007]

In order to achieve the above object, a method of manufacturing a toner supply roll of the present invention comprises a step of preparing a roll base having a sponge elastic layer formed along an outer peripheral surface of a shaft body, The inner diameter is a diameter smaller than the outer diameter of the roll base, and a step of coaxially inserting the roll base into a cylindrical shape whose diameter gradually increases from both ends in the axial direction toward the center, And the step of heating the sponge elastic layer in the coaxial press-fitting state and shaping the sponge elastic layer into the cylindrical die shape, and then removing the die.

The present inventor has conducted earnest studies on a method of manufacturing a toner supply roll so that the sponge elastic layer can be easily formed into an accurate crown shape. In the process of the research, when the roll base on which the sponge elastic layer was formed along the outer peripheral surface of the shaft body was pressed into a cylindrical shape with an inner diameter smaller than the outer diameter of the roll base and heated, the shape of the sponge elastic layer was changed. I found that I could correct As a result of further earnest research, the inner diameter is smaller than the outer diameter of the roll base, and the roll is formed into a cylindrical shape in which the diameter gradually increases from both axial end portions toward the central portion. When the base body is press-fitted coaxially and heated in the coaxial press-fitting state, the sponge elastic layer can be shaped into the cylindrical mold shape, and the sponge elastic layer can be easily formed into an accurate crown shape. And has reached the present invention.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 3 show an embodiment of a method of manufacturing a toner supply roll of the present invention. In the method for manufacturing the toner supply roll in this embodiment, the roll base 1 in which the sponge elastic layer 3 made of urethane foam is integrally formed on the outer peripheral surface of the shaft body 2 has an inner diameter smaller than the outer diameter of the roll base 1. In addition, it is coaxially press-fitted into a crown cylindrical mold 4 having an inner peripheral surface formed in a crown shape, and secondary vulcanization (heating) is performed in this state to make the sponge elastic layer 3 into a crown shape of the crown cylindrical mold 4. After shaping, it is a method of demolding.

More specifically, the roll base 1 is described above.
Has a uniform thickness of the sponge elastic layer 3 along the axial direction and the circumferential direction, and is manufactured by molding. For this molding, a straight cylindrical mold whose inner diameter is constant along the axial direction is used. The shaft body 2 is loaded in this straight cylindrical mold, and both ends of the straight cylindrical mold are covered with the caps 5 (see FIG. 3). When closed, the shaft body 2 is supported coaxially with the straight cylindrical mold by the caps 5, and a molding cavity that gives the final roll shape of the roll base 1 that is the target is formed in the straight cylindrical mold.

The shaft body 2 is not particularly limited, and a cored bar made of a solid metal body, a metal cylindrical body hollowed out from the inside, or the like is used. Examples of the material include stainless steel, aluminum, and plated iron.

As a material for forming the sponge elastic layer 3, a polyol component and an isocyanate component used in the usual production of flexible polyurethane foam are used. Examples of the above-mentioned polyol component include polyether polyol, polyester polyol, polymer polyol and the like, and these may be used alone or in combination of two or more kinds. The isocyanate component is not particularly limited as long as it is a polyisocyanate having two or more functional groups, and examples thereof include 2,4- (or 2,6-) tolylene diisocyanate (TDI), orthotoluidine diisocyanate (TODI), and naphthylene diisocyanate. (ND
I), xylylene diisocyanate (XDI), 4,
4'-diphenylmethane diisocyanate (MDI),
Carbodiimide-modified MDI, polymethylene polyphenyl isocyanate, polymeric polyisocyanate and the like can be mentioned, and these can be used alone or in combination of two or more kinds.

In addition to the polyol component and the isocyanate component, a cross-linking agent, a foaming agent (water, low-boiling substance, gas, etc.), a surfactant,
You may mix | blend a catalyst, a flame retardant, a filler, an electroconductivity imparting agent, an antistatic agent, etc. suitably.

The crown cylindrical mold 4 into which the roll base 1 is pressed at the time of the secondary vulcanization (heating) has an inner peripheral surface formed in a crown shape. What is the crown shape of the crown cylindrical mold 4? The crown cylinder 4 has a shape in which the inner diameter gradually increases from both axial end portions toward the central portion, and there is a portion where the inner diameter is constant along the axial direction in the central portion. It is meant to include things. Moreover, even in the central portion where the inner diameter is maximum, the roll base 1
It is smaller than the outer diameter of. Further, the crown cylindrical mold 4 is provided with caps 5 for closing both ends, and the roll base 1 is press-fitted into the crown cylindrical mold 4,
When both ends of the crown cylindrical mold 4 are closed by the caps 5, the shaft 2 is supported by the caps 5 coaxially with the crown cylindrical mold 4.

The method of manufacturing the toner supply roll is as follows.
For example, the following can be performed using the roll base 1 and the crown cylinder type 4. That is, first,
The roll base 1 is pressed into the crown cylinder 4 (see FIG. 2), and both ends of the crown cylinder 4 are closed with the caps 5 (see FIG. 3). As a result, the shaft body 2 of the roll base 1 and the crown cylindrical mold 4 are made coaxial with each other.
Then, secondary vulcanization (heating) is performed in this state. The temperature of the secondary vulcanization (heating) is usually in the range of 70 to 300 ° C, and the time thereof is in the range of 1 to 120 minutes. And this 2
The sponge elastic layer 3 is shaped into the crown shape of the crown cylindrical mold 4 by subsequent vulcanization (heating). Then, the mold is removed. With such a manufacturing method, as shown in FIG. 4, the toner supply roll A in which the sponge elastic layer 3 has a crown shape can be manufactured.

According to the manufacturing method of the toner supply roll of the above embodiment, the shaft body 2 of the roll base 1 is subjected to the secondary vulcanization (heating).
Since the crown cylindrical mold 4 and the crown cylindrical mold 4 are coaxial with each other, the secondary vulcanization (heating) thereof allows the sponge elastic layer 3 to be easily and accurately formed into a crown shape. Therefore, in the manufactured toner supply roll A, the shake of the surface of the sponge elastic layer 3 can be reduced. As a result, when the toner supply roll A is incorporated in an actual machine, the image quality can be stabilized.

Further, in the method of manufacturing the toner supply roll,
Since the roll base 1 is secondly vulcanized (heated) while being pressed into the crown cylindrical mold 4, the sponge elastic layer 3 of the toner supply roll A produced is compressed, and the cells are crushed and small. Has become. For this reason, when the toner supply roll A is incorporated in an actual machine, it becomes difficult for the toner to enter the sponge elastic layer 3, and it is possible to prevent the toner from deteriorating and also to prevent the sponge elastic layer 3 from hardening. . As a result, image fogging can be prevented. In particular, at both ends of the sponge elastic layer 3, the degree of compression increases due to the crown shape of the inner peripheral surface of the crown cylindrical mold 4, so that deterioration of toner and prevention of hardening of the sponge elastic layer 3 become remarkable, Image fogging can be further prevented.

FIG. 5 shows another embodiment of the method for producing the toner supply roll of the present invention. In this embodiment,
As the roll substrate 6, a roll substrate having a plurality of axially extending projections 7 formed at a predetermined pitch on the outer peripheral surface of the sponge elastic layer 3 is used. The other parts are the same as those in the above embodiment, and the same parts are denoted by the same reference numerals. With this manufacturing method, as shown in FIG. 6, the sponge elastic layer 3 has a crown shape, and
It is possible to manufacture the toner supply roll B in which the ridges 7 are formed on the outer peripheral surface of the sponge elastic layer 3 at a predetermined pitch in the circumferential direction.

The cross-sectional shape of the ridge 7 on the outer peripheral surface of the roll base 6 is not particularly limited, and may be a quadrangle, a triangle, a semicircle diameter, or the like. In addition, the ridge 7
Has a height in the range of 20 to 3000 μm and a width of 50 to 50
Range of 00 μm, pitch in the circumferential direction is 300 to 3000 μm
It is preferably set in the range of m. The reason is that if the height and the pitch in the circumferential direction of the ridges 7 deviate from the above ranges, the toner scraping property of the manufactured toner supply roll B may deteriorate. Also,
If the width of the ridges 7 is less than 50 μm, the frictional force of the toner supply roll B to be produced on the developing roll tends to be too low, and if it exceeds 5000 μm, the frictional force tends to be too high. This is because the image quality may deteriorate.

The manufacturing method of the toner supply roll of this embodiment also provides the same operation and effect as those of the above embodiment. Further, in the method of manufacturing the toner supply roll, the ridges 7 are formed on the surface of the sponge elastic layer 3 of the manufactured toner supply roll B. Therefore, when the toner supply roll B is incorporated into an actual machine, the toner supply roll B is manufactured. The toner supplying property of B can be stabilized. As a result, the image quality can be stabilized.

The ridges 7 on the outer peripheral surface of the roll base 6 are
May be formed by processing the outer peripheral surface of the roll base 1 shown in FIG. 1 (the one on which the ridges 7 are not formed on the outer peripheral surface), or a straight cylinder used when the roll base 6 is formed. The mold may be formed by using a mold having a groove formed on the inner peripheral surface corresponding to the convex stripe 7.

Next, examples will be described together with comparative examples.

[0024]

Example 1 Similar to the first embodiment,
A toner supply roll A was prepared. Prior to this production,
As the shaft body 2, a SUM22 round bar having a diameter of 5 mm was prepared. A material for forming the sponge elastic layer 3 was prepared. That is, polyether polyol (EP, manufactured by Mitsui Chemicals, Inc.
-828, OH value = 28), 90 parts by weight, polymer polyol (Mitsui Chemicals, Inc., POP-31-28, OH value =
28) 10 parts by weight, diethanolamine 2 parts by weight,
3 parts by weight of a silicone foam stabilizer (L-5309 manufactured by Nippon Unicar Co., Ltd.), 2 parts by weight of water, 0.5 parts by weight of a tertiary amine catalyst (Kaolyzer No. 31, manufactured by Kao Corporation), a tertiary grade 0.1 parts by weight of amine catalyst (Toyocat HX-35, manufactured by Tosoh Corporation), 0.1 parts by weight of DBTDL, and 31 parts of isocyanate (Sumitomo Bayer Urethane Co., Sumidule VT-80, NCO% = 45) 0.5 part by weight was blended to prepare a material for forming the sponge elastic layer 3.

Then, first, the roll substrate 1 was molded.
For this molding, a straight cylindrical mold having an inner diameter of 17 mm along the axial direction and constant is prepared, the shaft body 2 is loaded into the straight cylindrical mold, and the forming material of the sponge elastic layer 3 is injected into the molding. did. The outer diameter of the molded roll substrate 1 was 16.7 mm. Next, a cylindrical cylinder 4 having an inner diameter of 15.5 mm at both ends in the axial direction and an inner diameter of 16.5 mm at the central portion and gradually expanding in diameter from both end portions toward the central portion is prepared. Cylindrical type 4
The roll base 1 is press-fitted in the
Both ends of the roll base 1 were closed by caps 5 so that the shaft body 2 of the roll base 1 and the crown cylindrical mold 4 were coaxial with each other. Then, in this state, secondary vulcanization (heating) was performed at 150 ° C. for 60 minutes. Then, after demolding, it was cooled. In this way, the toner supply roll A having the sponge elastic layer 3 in the shape of a crown was obtained.

[0026]

Second Embodiment Similar to the last-described embodiment,
A toner supply roll B was prepared. That is, as the roll base 6, a roll base having a plurality of axially extending projections 7 formed on the outer peripheral surface of the sponge elastic layer 3 at a predetermined pitch was used. The ridge 7 has a rectangular cross section,
The height is 300 μm, the width is 500 μm, and the pitch is 80.
It was set to 0 μm. Other than that was the same as that of the above-mentioned Example 1. Thus, the toner supply roll B in which the sponge elastic layer 3 has a crown shape and the ridges 7 are formed on the surface of the sponge elastic layer 3 is obtained.

In Examples 1 and 2, the outer diameters and the maximum values of the runouts of the roll bases 1 and 6 and the toner supply rolls A and B were measured at the left and right ends and the center thereof, respectively. The deflection of the toner supply roll B of Example 2 was measured on the top surface of the ridge 7 on the surface of the sponge elastic layer 3. The results are shown in Table 1 below.

[0028]

[Table 1]

From the results shown in Table 1 above, the toner supply rolls A and B, which are secondly vulcanized (heated) in a state where they are coaxially inserted into the crown cylinder type 4, rather than the roll bases 1 and 6, are
It can be seen that the shake is small.

Although the roll bases 1 and 6 are formed by molding in the above-mentioned respective embodiments, other methods may be used. For example, the base material of the sponge elastic layer 3 is cut out from a slab urethane made of urethane foam to form a shaft. After adhering to the body 2, the roll bases 1 and 6 may be manufactured by cutting or polishing the base material.

[0031]

As described above, according to the method of manufacturing the toner supply roll of the present invention, the roll base on which the sponge elastic layer is formed along the outer peripheral surface of the shaft has the inner diameter larger than the outer diameter of the roll base. Also has a small diameter and gradually expands in diameter from both ends in the axial direction toward the center, and is coaxially press-fitted, and the sponge elastic layer is heated in this coaxially-pressed state to form the cylindrical mold. Because it is shaped and then demolded,
In the manufactured toner supply roll, the sponge elastic layer can be easily formed into an accurate crown shape.
Therefore, it is possible to reduce the vibration of the surface of the sponge elastic layer of the toner supply roll. As a result, when the toner supply roll is incorporated in an actual machine, the image quality can be stabilized. Further, since the roll base is heated while being pressed into the cylindrical shape, the sponge elastic layer of the manufactured toner supply roll is compressed, and the cells are crushed to be small. For this reason, when the toner supply roll is incorporated in an actual machine, it becomes difficult for the toner to enter the sponge elastic layer, so that the deterioration of the toner can be prevented and the sponge elastic layer can be prevented from hardening. As a result, image fogging can be prevented. In particular, at both ends of the sponge elastic layer, the degree of compression becomes large, so that the above effect becomes remarkable.

Further, in the present invention, when a plurality of axially extending ridges are formed at a predetermined pitch in the circumferential direction on the outer peripheral surface of the sponge elastic layer of the roll base,
The ridges are also formed on the outer peripheral surface of the sponge elastic layer of the manufactured toner supply roll. When the toner supply roll is incorporated into an actual machine, the ridges stabilize the toner supplyability of the toner supply roll. be able to. As a result, the image quality can be made more stable.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a method for producing a toner supply roll of the present invention.

FIG. 2 is an explanatory view showing the above manufacturing method.

FIG. 3 is an explanatory diagram showing the above manufacturing method.

FIG. 4 is an explanatory diagram showing a toner supply roll manufactured by the above manufacturing method.

FIG. 5 is an explanatory view showing another embodiment of the method for producing the toner supply roll of the present invention.

FIG. 6 is an explanatory diagram showing a toner supply roll manufactured by the above manufacturing method.

[Explanation of symbols]

1 roll base Biaxial body 3 Sponge elastic layer 4 Crown cylindrical type

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H077 AC04 FA12 FA22                 3J103 AA02 BA41 EA01 EA11 FA15                       GA02 GA52 GA58 GA60 HA48                 4F204 AA31 AA45 AG08 AG20 AG28                       AH04 AH33 FA01 FB01 FG01                       FG04 FJ14 FN01 FN17

Claims (2)

[Claims] 1. A step of preparing a roll base on which a sponge elastic layer is formed along an outer peripheral surface of a shaft body, an inner diameter being smaller than an outer diameter of the roll base, and both end portions in an axial direction. The step of coaxially inserting the roll base into a cylindrical shape whose diameter gradually increases toward the central part, and heating the sponge elastic layer in the coaxial press state to shape the sponge elastic layer into the cylindrical shape. And a step of demolding the toner supply roll. 2. The method for producing a toner supply roll according to claim 1, wherein a plurality of projections extending in the axial direction are circumferentially formed at a predetermined pitch on the outer peripheral surface of the sponge elastic layer of the roll base.