JP2003287951A - Toner feeding control - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner feeding roll stabilizing toner feed. <P>SOLUTION: A plurality of projected lines 3 extending in the shaft direction are formed at a specified pitch in the circumferential direction on the surface of a sponge elastic layer 2 formed along the outer circumferential surface of a shaft body 1. The surface of the sponge elastic layer 2 and the surface of a cell 4 opening on the surface of the sponge elastic layer 2 form rough surfaces. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 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.

Therefore, when the toner supply performance of the toner supply roll becomes unstable, the image quality deteriorates. Therefore, in order to stabilize the toner supply property, the surface of the toner supply roll is made uneven. In general,
The toner supply roll, as shown in FIG.
The sponge elastic layer 52 made of urethane foam is formed on the outer peripheral surface of the sponge elastic layer 52. The uneven structure includes a plurality of ridges 53 extending in the axial direction on the surface of the sponge elastic layer 52. There is one in which the cells 54 in the surface portion of the sponge elastic layer 52 are formed at a predetermined pitch in the circumferential direction and opened to the outside (JP-A-11-38749).

[0004]

However, it is becoming difficult for the above-mentioned toner supply roll to sufficiently cope with recent high image quality and high speed. Therefore, a toner supply roll having a more stable toner supply property is desired.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a toner supply roll capable of further stabilizing the toner supply property.

[0006]

To achieve the above object, the toner supply roll of the present invention comprises a shaft and a sponge elastic layer formed along the outer peripheral surface of the shaft, A toner supply roll in which a plurality of axially extending projections are formed at a predetermined pitch on the surface of the sponge elastic layer in the circumferential direction, and the surface of the sponge elastic layer and the cells opening on the surface of the sponge elastic layer are provided. The structure is such that the surface is rough.

The present inventors have conducted extensive studies on a toner supply roll in order to stabilize the toner supply property. In the course of the research, it was found that if the slidability between the toner supply roll and other members such as the developing roll is improved, the rotation of the toner supply roll will be smooth and the toner supply property will be more stable. As a result of further intensive research, in a toner supply roll in which a plurality of axially extending projections are formed in the circumferential direction at a predetermined pitch on the surface of the sponge elastic layer, the surface of the sponge elastic layer and the sponge elastic layer are formed. It was found that if the surface of the cell having an opening on the surface is formed to be a rough surface, the slidability between the toner supply roll and the other members such as the developing roll is improved, and the toner supply performance becomes more stable, and the present invention is realized. Arrived

[0008]

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

FIG. 1 shows an embodiment of the toner supply roll of the present invention. In this embodiment, in the toner supply roll, a sponge elastic layer 2 made of urethane foam is integrally formed on the outer peripheral surface of a shaft body 1, and a plurality of ridges 3 extending in the axial direction are formed on the surface of the sponge elastic layer 2. Are formed at a predetermined pitch P (see FIG. 2) in the circumferential direction. When the surface portion of the sponge elastic layer 2 is magnified and viewed with a microscope or the like, the surface of the sponge elastic layer 2 and the surface of the cell 4 opening on the surface of the sponge elastic layer 2 are formed to be uneven. It is formed on a rough surface.

More specifically, the shaft body 1 is not particularly limited, and a cored bar made of a solid metal body, a metal cylindrical body hollowed out inside, or the like is used. Examples of the material include stainless steel, aluminum, and plated iron.

The cross-sectional shape of the ridges 3 on the surface of the elastic sponge layer 2 is not particularly limited, and is not limited to that shown in FIG.
In addition to the quadrangle shown in, triangles, semi-circles, etc. may be mentioned.
Further, it is preferable that the ridge 3 has a height H in the range of 20 to 3000 μm, a width W in the range of 100 to 2000 μm, and a circumferential pitch P in the range of 300 to 3000 μm. The reason is that if the height H of the ridges 3 and the pitch P in the circumferential direction deviate from the above ranges, the toner scraping property may deteriorate.

The cells 4 on the surface of the sponge elastic layer 2 are open on the surface of the sponge elastic layer 2, and the average opening diameter is preferably set in the range of 100 to 800 μm. The reason is that the average opening diameter is 10
If it is less than 0 μm, the toner that has entered the cell 4 tends to be difficult to come out, and if it exceeds 800 μm, the toner supply amount tends to decrease, and in any case, the image quality may deteriorate. The average cell diameter of the cells 4 in the sponge elastic layer 2 is equal to or larger than the average opening diameter,
It is preferably set in the range of 100 to 1000 μm. The reason is that when the average cell diameter is less than 100 μm, the toner tends to be clogged in the cells 4, and
If it exceeds 000 μm, the amount of toner that enters the cells 4 tends to be too large, and in any case, the image quality may deteriorate. Further, in the sponge elastic layer 2, since the deterioration of the toner can be suppressed, the opening 6 having the above-mentioned average opening diameter is formed in all or part of the cell film 5 existing at the boundary between the adjacent cells 4. It is preferable that the cells 4 have a continuous cell structure in which all or some of the cells 4 are three-dimensionally connected (see FIGS. 1 and 2), but a closed cell structure that does not have such a structure may be used.

The average height difference of the unevenness formed on the surface of the sponge elastic layer 2 and the surface of the cell 4 opening on the surface of the sponge elastic layer 2 is set in the range of 5 to 20 μm. Is preferred. The reason is that if the average height difference of the irregularities is out of the above range, the toner supply property tends to be unstable.

As the material for forming the elastic sponge layer 2, 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 (MD form),
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 toner supply roll is produced by molding. For this purpose, first, the molding die shown in FIG. 3 is prepared. This mold is composed of a cylindrical mold 11 having a length substantially equal to the axial length of the sponge elastic layer 2 (see FIG. 1) of the toner supply roll, and caps 12 for closing both ends of the cylindrical mold 11. ing. Also, this mold is
When the shaft body 1 is loaded in the cylindrical mold 11 and both ends of the cylindrical mold 11 are closed by the caps 12, the shaft body 1 is supported coaxially with the cylindrical mold 11 by the caps 12,
A molding cavity 13 which gives the final roll shape of the intended toner supply roll is formed in the inside 1. Further, on the inner peripheral surface of the cylindrical mold 11, a groove 14 corresponding to the protrusion 3 on the surface of the sponge elastic layer 2 (see FIG. 2) is formed.
Are formed at a predetermined pitch P in the circumferential direction,
Concavities and convexities corresponding to the concavities and convexities on the surface of the sponge elastic layer 2 and the surface of the cells 4 opening on the surface of the sponge elastic layer 2 are formed.

The irregularities on the inner peripheral surface of the cylindrical mold 11 can be formed by, for example, the following two methods. That is, the first method is to mix a cylindrical body in which the groove 14 is formed on the inner peripheral surface with a predetermined pitch P in the circumferential direction and a spherical silicone powder into a silicone or fluorine release agent. The prepared mixed liquid is prepared, and the mixed liquid is applied to the inner peripheral surface of the cylindrical body and then baked. Thereby, the silicone-based powder remains on the inner peripheral surface of the cylindrical body, and the irregularities can be formed on the inner peripheral surface. The second method is a method in which the inner peripheral surface of the cylindrical body is shot blasted.

The toner supply roll is manufactured by
First, the shaft body 1 is loaded into the cylindrical mold 11 of the above-mentioned molding die, and both ends of the cylindrical mold 11 are closed by the caps 12. Then, the material for forming the sponge elastic layer 2 is injected into the formed molding cavity 13, foamed and cured, and then released from the mold.
By producing in this manner, the groove 14 and the irregularities on the inner peripheral surface of the cylindrical mold 11 are transferred to the surface of the sponge elastic layer 2, and the toner supply roll can be easily produced.

In particular, in each of the methods for forming the irregularities on the inner peripheral surface of the cylindrical mold 11, a silicone powder or shot having a particle size in the range of 5 to 10 μm is used, and the inner periphery of the cylindrical body is When the surface of the sponge elastic layer 2 and the surface of the cells 4 opened on the surface of the sponge elastic layer 2 are formed, the surface of the sponge elastic layer 2 is formed by forming irregularities on the surface and molding the toner supply roll using the cylindrical mold 11 thus manufactured. It is possible to form irregularities having an average height difference of 5 to 20 μm. This average height difference can be adjusted by changing the particle size of the silicone powder or shot.

The sponge elastic layer 2 in the molding die
When the expansion ratio is set to about 5 to 20 times, the average opening diameter of the cells 4 opened on the surface of the sponge elastic layer 2 can be formed in the range of 100 to 800 μm, and the sponge elastic layer is formed. The average cell diameter of the cells 4 in 2 can be formed in the range of 100 to 1000 μm. The average opening diameter and the average cell diameter can be adjusted by changing the expansion ratio.

Further, when the toner supply roll is rotated around the shaft body 1 after the mold is released, a high-pressure gas (gas such as air or nitrogen) is sprayed onto the sponge elastic layer 2 by using a nozzle or the like. The high-pressure gas diffuses into the sponge elastic layer 2 due to the resistance of the shaft body 1, and the opening action of the cell membranes 5 is remarkably exhibited. As a result, the opening portions 6 are formed in the cell membranes 5 existing at the boundaries between the adjacent cells 4. It is formed. The degree of formation of the opening 6 can be adjusted by changing the pressure of the gas to be injected.

According to the toner supply roll of the above-described embodiment thus manufactured, the slidability with other members such as the developing roll is improved, the toner supply roll rotates smoothly, and the toner supply roll is supplied. Sex is more stable. As a result, the image quality can be further improved.

FIG. 4 shows another embodiment of the toner supply roll of the present invention. In this embodiment, a spherical silicone powder (fine particles) 7 is adhered to the surface of the sponge elastic layer 2 and the surface of the cell 4 opening on the surface of the sponge elastic layer 2 to form a rough surface. . The other parts are the same as those in the above embodiment, and the same parts are denoted by the same reference numerals.

The toner supply roll of this embodiment can be manufactured, for example, as follows. That is, first, a molding die is prepared. This molding die is different from the one shown in FIG. 3 used in the above-described embodiment in the cylindrical die 15, and the inner peripheral surface of this cylindrical die 15 has the surface of the sponge elastic layer 2 in the above-mentioned embodiment and this. The unevenness corresponding to the unevenness on the surface of the cell 4 opening on the surface of the sponge elastic layer 2 is not formed. Other than that, it is the same as the cylindrical mold 11 used in the above-described embodiment. Then, the shaft 1 is loaded into the cylindrical mold 15 and the cylindrical mold 1
Both ends of 5 are closed with caps 12. Next, the forming material of the sponge elastic layer 2 is injected into the formed molding cavity 13, foamed and cured, and then released from the mold. And prepare a binder containing spherical silicone powder 7,
After spraying on the surface of the sponge elastic layer 2, secondary vulcanization is performed. By this secondary vulcanization, the binder reacts with the urethane of the sponge elastic layer 2 and is bonded, and the silicone-based powder 7 is fixed on the surface of the sponge elastic layer 2 and the surface of the cell 4 opening on the surface of the sponge elastic layer 2. Being adhered. In this way, the toner supply roll can be easily manufactured.

In particular, the particle size of the silicone powder 7 is 5 to 5 in the binder containing the silicone powder 7.
If the average particle size is in the range of 10 μm, the surface of the sponge elastic layer 2 and the surface of the cell 4 opening on the surface of the sponge elastic layer 2 will have a silicone powder-adhered portion having an average height difference of 5 to 20 μm. Can be formed. This average height difference can be adjusted by changing the particle size of the silicone powder 7.

The toner supply roll of this embodiment manufactured in this manner also has the same operation and effect as the toner supply roll of the above embodiment.

Next, examples will be described together with comparative examples.

[0028]

Example 1 Similar to the last-described embodiment,
A toner supply roll having an outer diameter of 16 mm was produced. Prior to this preparation, a SUM22 round bar having a diameter of 5 mm was prepared as the shaft body 1. A material for forming the sponge elastic layer 2 was prepared. That is, 90 parts by weight of polyether polyol (manufactured by Mitsui Chemicals, Inc., EP-828, OH value = 28),
Polymer polyol (Mitsui Chemicals, POP-31-2
8, OH value = 28) 10 parts by weight, diethanolamine 2 parts by weight, a silicon foam stabilizer (manufactured by Nippon Unicar, L-).
5309), 3 parts by weight, 2 parts by weight of water, 0.5 part by weight of a tertiary amine catalyst (Kaolyzer No. 31 manufactured by Kao Corporation), tertiary amine catalyst (Toyocat HX manufactured by Tosoh Corporation).
-35) 0.1 part by weight, DBTDL 0.1 part by weight,
And 30.5 parts by weight of isocyanate (Sumitomo Bayer Urethane Co., Ltd., Sumidule VT-80, NCO% = 45) were mixed to prepare a material for forming the sponge elastic layer 2.

In the manufactured toner supply roll, the ridges 3 on the surface of the sponge elastic layer 2 have a rectangular cross section, a height H of 200 μm, a width W of 400 μm, and a circumferential pitch P of 600 μm. The inside of the sponge elastic layer 2 was formed into an open cell structure. In the manufactured toner supply roll, the average opening diameter of the cells 4 on the surface portion of the sponge elastic layer 2 was 400 μm, and the average cell diameter of the cells 4 in the sponge elastic layer 2 was 600 μm. The silicone powder 7 having a particle size of 5 μm is used, and the average height of the silicone powder-attached portion formed on the surface of the sponge elastic layer 2 and the surface of the cell 4 opening on the surface of the sponge elastic layer 2 is low. The difference was 5 μm. When the surface of the sponge elastic layer 2 of this toner supply roll is observed with a microscope, it is as shown in FIG.

[0030]

[Example 2] Silicone powder 7 having a particle size of 7
The average height difference of the silicone-based powder adhered portion was set to 10 μm. Other than that was the same as that of the above-mentioned Example 1.

[0031]

[Embodiment 3] Silicone powder 7 has a particle size of 1
The average height difference of the silicone-based powder adhered portion was set to 20 μm. Other than that was the same as that of the above-mentioned Example 1.

[0032]

Comparative Example 1 In Example 1 above, the silicone powder 7 was not attached. Other than that, Example 1 above
Same as. When the surface of the sponge elastic layer 2 of this toner supply roll is observed with a microscope, it is as shown in FIG.

The toner supply rolls of Examples 1 to 3 and Comparative Example 1 thus obtained were incorporated into a color laser printer to perform image formation. This image was printed using a toner having an average particle size of 7 to 10 μm, and 5% printing was performed under conditions of low temperature and low humidity (15 ° C. × 10%).
It was set to 000 sheets. Then, the slidability with other members, the toner supply property, and the image quality were evaluated. The results are shown in Table 1 below.

[Sliding Property] An adhesive tape (SPV-A-303S, manufactured by Nitto Co., Ltd.) was attached on a flat plate with the adhesive surface facing upward, and each toner supply roll was placed on the adhesive surface. A horizontal force of 1N was applied to each toner supply roll to roll it. As a result, 100m of each toner supply roll
When the time required to roll m was 5 seconds or less, it was evaluated as ◯, and when it took more than 5 seconds was evaluated as x.

[Toner Supplyability] Each toner supply roll was incorporated into a toner cartridge of a color laser printer, the developing roll was idled at a rotation speed of 60 rpm, and the toner supply state to the surface of the developing roll was visually determined. As a result, it was evaluated as ◯ when the toner was uniformly supplied to the surface of the developing roll and as Δ when the toner was slightly uneven.

[Image Quality] The image quality of the image after outputting 5000 sheets was visually judged. As a result, an image having no streaks was evaluated as ◯, and a streak was slight but was evaluated as Δ.

[0037]

[Table 1]

From the results shown in Table 1 above, it can be seen that the toner supply roll of the example is superior in slidability with other members, toner supply property, and image quality as compared with the comparative example.

In each of the above embodiments, the silicone-based powder 7 is used to form the surface of the sponge elastic layer 2 and the surface of the cell 4 opening on the surface of the sponge elastic layer 2 into a rough surface. Similarly, if it can be formed on a rough surface,
The present invention is not limited to this, and other fine particles may be used.

[0040]

As described above, according to the toner supply roll of the present invention, in the toner supply roll in which a plurality of ridges extending in the axial direction are circumferentially formed at a predetermined pitch on the surface of the sponge elastic layer, Since the surface of the sponge elastic layer and the surface of the cells opening on the surface of the sponge elastic layer are formed to be rough, the slidability with other members such as the developing roll is improved and the rotation of the toner supply roll is prevented. Becomes smooth,
Toner supply is more stable. As a result, the image quality can be further improved.

In the present invention, when the above-mentioned rough surface is formed by forming irregularities on the surface of the sponge elastic layer and the surface of the cell, or by attaching fine particles to the surface of the sponge elastic layer and the surface of the cell. In such a case, the toner supply roll of the present invention can be easily manufactured.

Particularly, in the present invention, the average height difference of the irregularities or the average height difference of the fine particle adhering portion is 5 to 20.
When it is in the range of μm, the toner supply property is further stabilized, and the image quality can be further improved.

[Brief description of drawings]

FIG. 1 is an explanatory view (partially enlarged cross-sectional view) showing an embodiment of a toner supply roll of the present invention.

FIG. 2 is a cross-sectional view showing a surface portion of the toner supply roll.

FIG. 3 is a cross-sectional view showing a molding die used for producing the toner supply roll.

FIG. 4 is an explanatory view (partially enlarged cross-sectional view) showing another embodiment of the toner supply roll of the present invention.

FIG. 5 is a micrograph showing a surface of a sponge elastic layer of an example of the toner supply roll.

FIG. 6 is an explanatory view (partially enlarged cross-sectional view) showing a conventional toner supply roll.

FIG. 7 is a micrograph showing a surface of a sponge elastic layer of a conventional example of the toner supply roll.

[Explanation of symbols]

1 axis 2 Sponge elastic layer 3 convex stripes 4 cells

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenichi Owaki             Tokai Rubber Works, Higashi 3-chome, Komaki City, Aichi Prefecture             Business (72) Inventor Takeyama Takeda             Tokai Rubber Works, Higashi 3-chome, Komaki City, Aichi Prefecture             Business F term (reference) 2H077 AA15 AC04 FA01 FA12 FA16                       FA22                 3J103 AA02 AA13 AA61 BA41 EA02                       FA18 GA02 GA57 GA58 GA60                       HA03 HA48

Claims (5)

[Claims] 1. A shaft body and a sponge elastic layer formed along an outer peripheral surface of the shaft body, wherein a plurality of axially extending projections are circumferentially formed at a predetermined pitch on the surface of the sponge elastic layer. The toner supply roll formed on the surface of the sponge elastic layer and the surface of the cells opening on the surface of the sponge elastic layer are roughened. 2. The rough surface is formed by forming unevenness on the surface of the sponge elastic layer and the surface of the cell.
The toner supply roll described. 3. The toner supply roll according to claim 2, wherein the average height difference of the irregularities is in the range of 5 to 20 μm. 4. The toner supply roll according to claim 1, wherein the rough surface is formed by adhering fine particles to the surface of the sponge elastic layer and the surface of the cell. 5. The average height difference of the fine particle adhered portion is 5 to 5.
The toner supply roll according to claim 4, wherein the toner supply roll has a range of 20 μm.