JP2022016656A - Toner supply roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner supply roller that has satisfactory toner supply properties and toner scraping properties and is suitable for an image forming apparatus of an electrophotographic system, such as a copying device, an image recording device, a printer, and a facsimile.

SOLUTION: A toner supply roller 10 is provided with a cylindrical polyurethane foam 21 on an outer periphery of a shaft 11. The cylindrical polyurethane foam 21 has, on its outer peripheral surface, a coating 23 in which cells are further compressed than the inside 22 of the polyurethane foam 21, and pin hole-like pores are scattered in a surface of the coating 23 to have satisfactory toner supply properties and toner scraping properties.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a toner supply roller used in an electrophotographic image forming apparatus such as a copying apparatus, an image recording apparatus, a printer, and a facsimile, and a manufacturing method thereof.

The toner supply roller is a roller for supplying toner to a developing roller that adheres toner to an electrostatic latent image formed on an image carrier made of an electrophotographic photosensitive member and visualizes it as a toner image on the surface thereof. Those with a foam on the outer circumference of the shaft are often used. The toner supply roller is required to have a toner supply function and a toner scraping function for the developing roller.

Examples of the foam on the outer periphery of the shaft in the toner supply roller include polyurethane foam and EPDM foam. In particular, polyurethane foam is a material having many advantages such as low density but moderate hardness and low compression set, so that it is the mainstream as a foam on the outer periphery of the shaft.

As a method for manufacturing a toner supply roller in which the polyurethane foam is provided on the outer periphery of the shaft, (1) a shaft insertion hole is formed in the slab polyurethane foam, then the polyurethane foam is cut out to the size of one roller, and then the polyurethane foam is inserted into the shaft. A manufacturing method in which a shaft is inserted into a hole and then the surface of the polyurethane foam is cut and polished to form a circumferential surface. Manufacturing method to make a cylindrical shape by melt cutting with a wire, (3) Manufacturing method to make a polyurethane foam formed on the outer circumference of a shaft into a cylindrical shape by peeling, (4) Inside a roller-shaped split foam molding mold in which a shaft is arranged. There is a manufacturing method in which polyurethane foam is foamed (mold foamed) to form the polyurethane foam integrally with the shaft. The slab polyurethane foam is continuously manufactured by discharging the mixed and agitated polyurethane foam raw material onto a belt conveyor, naturally foaming the raw material at room temperature and atmospheric pressure while the conveyor belt moves, and curing it. After that, it is cured (cured) in a drying furnace and then cut into blocks of a predetermined size (usually a rectangular shape).

However, in the method of cutting and polishing by inserting a shaft into a cut-out product of slab polyurethane foam, the uncut cell remains on the surface after polishing in a fluffy manner, and the fluffy uncut surface is in contact with the developing roller. Is not uniform, which causes poor scraping and cleaning properties.
Further, since the slab polyurethane foam has anisotropy in which the cell shape differs between the foaming direction and the direction orthogonal to the foaming direction, a portion having a relatively large elliptical recess on the surface after cutting and polishing and a portion having a relatively large elliptical recess. There is a problem that a portion having a small concave portion close to a perfect circle is formed, the toner supply performance and the toner scraping performance are deteriorated, and the image is adversely affected.

Further, in the manufacturing method of melt cutting with nichrome wire and the manufacturing method of peeling, a cell having a large opening is formed on the surface of the polyurethane foam by melt cutting or peeling, so that the toner supply performance and the toner scraping performance are inferior. There is.

In addition, the method of foaming (mold foaming) polyurethane foam in a roller-shaped split foam molding mold in which a shaft is placed to form the polyurethane foam integrally with the shaft is a parting line using a split foam molding mold on the surface of the polyurethane foam. Is formed parallel to the axis of the shaft, which has a problem of adversely affecting the image.
Further, in order to prevent the parting line from being formed, an expensive vertical mold must be used for the split foam molding mold, which causes a problem that the product cost is high and a problem that demolding after foaming is difficult.

Japanese Unexamined Patent Publication No. 8-334971 Japanese Unexamined Patent Publication No. 8-332679 Japanese Unexamined Patent Publication No. 10-10437 Japanese Unexamined Patent Publication No. 2006-337657

The present invention has been made in view of the above points, and an object of the present invention is to provide a toner supply roller having good toner supply property and toner scraping property, and a method for manufacturing the same.

The first invention is a toner supply roller provided with a tubular polyurethane foam on the outer periphery of the shaft, in which the tubular polyurethane foam has cells compressed and solidified on the outer peripheral surface from the inside of the polyurethane foam. The film is characterized by having pinhole-shaped holes scattered on the surface of the film.

The second invention is a method for manufacturing a toner supply roller in which a tubular polyurethane foam is provided on the outer periphery of the shaft. In the method of manufacturing the polyurethane foam, the outer diameter of the shaft is formed into a tubular polyurethane foam having a diameter larger than the outer diameter of the toner supply roller. The polyurethane foam intermediate molded body is formed by heating a mouthpiece having a through hole whose hole diameter is smaller from the inlet side to the outlet side, which has a hole diameter larger than the outer diameter of the toner supply roller. The polyurethane is supplied to the through hole of the mouthpiece from the entrance side, and the outer peripheral surface of the polyurethane foam intermediate molded body is heated and compressed on the inner surface of the through hole of the mouthpiece and rubbed through the through hole of the mouthpiece. It is characterized in that a film having pinhole-shaped holes scattered on the outer peripheral surface of the foam intermediate molded body is formed in a state where the cells are compressed and melted and solidified rather than the inside of the polyurethane foam intermediate molded body.

According to the first invention, on the outer peripheral surface of the tubular polyurethane foam, there is no uncut cell residue due to cutting and polishing, and the cell is compressed and melted and solidified more than the inside of the polyurethane foam. Therefore, the scraping property of the toner is improved. Therefore, the old toner remaining on the developing roller can be cleaned, the print quality can be improved, and the life of the cartridge can be extended. Further, good toner supply is obtained by the pinhole-shaped small holes scattered on the surface of the coating film on the outer peripheral surface of the tubular polyurethane foam.
According to the second invention, a toner supply roller having excellent toner scraping property is manufactured, in which a film is formed on the outer peripheral surface of a tubular polyurethane foam in a state where cells are compressed and melted and solidified rather than inside the polyurethane foam. be able to. Further, it is possible to manufacture a toner supply roller having excellent toner supply property in which pinhole-shaped small holes are scattered on the surface of the coating film. That is, it is possible to manufacture a toner supply roller that satisfies both the toner scraping property and the toner supply property.

It is a side view of the toner supply roller of one Embodiment of this invention. It is a 2-2 sectional view of FIG. It is an enlarged view of the surface of the tubular polyurethane foam in FIG. 1. It is a perspective view which shows the initial molded body and the intermediate molded body of a toner supply roller. It is a top view and a side view of a film forming apparatus. It is a perspective view of a base. It is a cross-sectional enlarged photograph of the state of the coating film. It is a table which shows the structure and performance evaluation of an Example and a comparative example. It is a figure which shows the measuring method of a compression load. It is a figure which shows the measuring method of the air permeability. It is a figure which shows the sampling position at the time of measuring the toner scraping property.

Hereinafter, embodiments of the toner supply roller of the present invention will be described. The toner supply roller 10 of the embodiment of the present invention shown in FIGS. 1 and 2 is composed of a shaft 11 and a tubular polyurethane foam 21 provided on the outer periphery thereof, and is used for a copying device, an image recording device, a printer, a facsimile, or the like. It is used as a toner supply roller in an image forming apparatus or the like. Note that d is the outer diameter of the toner supply roller 10 and coincides with the outer diameter of the tubular polyurethane foam 21. Further, a is the total length of the tubular polyurethane foam 21, which is shorter than the total length of the shaft 11. The outer diameter d and the total length a are set according to the device to which the toner supply roller 10 is attached.

The shaft 11 serves as a central axis of the toner supply roller 10, is made of a material having a required rigidity such as metal, and may be hollow or solid, and is a material corresponding to the toner supply roller 10. It is said to be the size.

The tubular polyurethane foam 21 has a cylindrical outer shape, and the shaft 11 penetrates the center of the cross section. The tubular polyurethane foam 21 has a coating film 23 on the outer peripheral surface as shown in FIG. 2, although the thickness and boundaries of the coating layer may be unclear depending on the heating and melting state or the compressed state. The coating film 23 is in a state where cells (air bubbles) are compressed and melted and solidified from the inside 22 of the tubular polyurethane foam 21, and the surface of the coating film 23 is as shown in FIG. 3 showing an enlarged surface of the coating film 23. Pinhole-shaped holes 24 are scattered.
The thickness of the coating film 23 is preferably 30 to 300 μm, more preferably 50 to 150 μm.

The preferable air permeability of the tubular polyurethane foam 21 is 0.01 to 0.70 kPa, more preferably 0.01 to 0.40 kPa, as measured by the measuring method described later. The higher the number, the lower the breathability, and the smaller the number, the higher the breathability. If the above value is smaller than 0.01 kPa and the air permeability is too high, the toner adhering to the surface of the tubular polyurethane foam 21 when the toner is supplied enters the inside of the tubular polyurethane foam 21 and sticks to the inside. It may cause a problem of hardening. On the other hand, if it is larger than 0.70 kPa, the air permeability becomes too low and the toner supply becomes low.

An embodiment of the method for manufacturing the toner supply roller will be described. The method for manufacturing the toner supply roller includes an initial molded body forming step, an intermediate molded body forming step, and a film forming step.
In the initial molded body forming step, the slab polyurethane foam is cut out to the size of one toner supply roller, then a shaft insertion hole is formed, and then the shaft is inserted into the shaft insertion hole of the slab polyurethane foam. The toner supply roller initial molded body 10A shown in (4-A) of No. 1 is manufactured. Reference numeral 11 is a shaft, 14 is a shaft insertion hole, and 21A is a slab polyurethane foam cut-out product. The shaft insertion hole 14 is formed to be smaller than the outer diameter of the shaft 11 by a predetermined size so that the shaft 11 is fixed to the slab polyurethane foam cut-out product 21A by inserting the shaft 11. An adhesive may be applied to the outer periphery of the shaft 11. The slab polyurethane foam preferably has a density (JIS K7222: 2005) of 10 to 350 kg / m ³ and a cell number (JIS K 6400) of 20 to 80/25 mm. More preferably, the slab polyurethane foam has a density (JIS K7222: 2005) of 10 to 100 kg / m ³ and a cell number (JIS K 6400) of 40 to 80/25 mm, and is formed on the outer peripheral surface of the toner supply roller. It is preferable in that the state of the film is suitable for toner scraping property.
Further, the slab polyurethane foam cut-out product 21A is formed of a prism having a cross-sectional shape larger than the outer diameter d of the toner supply roller, for example, a quadrangular cross-sectional shape having one side larger than the outer diameter d of the toner supply roller. ..

In the intermediate molded body forming step, the outer periphery of the slab polyurethane foam cut-out product 21A in the toner supply roller initial molded body 10A is polished to form the slab polyurethane foam cut-out product 21A into a cylindrical shape. As a result, the polyurethane foam intermediate molded body 21B shown in FIG. 4 (4-B) having a cylindrical shape having a diameter larger than the outer diameter d of the toner supply roller is formed, and the polyurethane foam intermediate molded body 21B and the shaft are formed. A toner supply roller intermediate molded body 10B made of 11 is obtained. The outer diameter of the polyurethane foam intermediate molded body 21B depends on the number of cells of the polyurethane foam used, but is preferably about 0.2 to 5 mm larger than the set outer diameter of the target toner supply roller. When the number of cells (JIS K 6400) is 20 to 80/25 mm, it is important to make it about 1 to 5 mm larger than the set outer diameter of the target toner supply roller in terms of film formation and toner scraping. It is preferable. More preferably, when the number of cells (JIS K 6400) is 20 to 40/25 mm, the number of cells (JIS K 6400) is preferably 2.5 to 4 mm larger than the set outer diameter of the target toner supply roller. When JIS K 6400) is 40 to 80/25 mm, making it about 1 to 3 mm larger than the set outer diameter of the target toner supply roller is to scratch the toner on the formability of the film and the state of the film to be formed. It is preferable in that it is suitable for takeability.
The set outer diameter of the toner supply roller is the target outer diameter at the time of manufacturing the toner supply roller, and the actual product outer diameter is the value obtained by adding the variation at the time of manufacturing to the set outer diameter (target outer diameter). Become.

In the film forming step, a film is formed on the outer peripheral surface of the polyurethane foam intermediate molded body 21B by using a film forming apparatus.
FIG. 5 shows an example of the film forming apparatus 71. The film forming device 71 is a set of a plurality of conveyor rollers 72 rotated by a drive device such as a motor, a conveyor 73 mounted on the conveyor rollers 72, and a set erected on the conveyor 73. The molded body holding portions 75 and 79, a base support portion 85 erected so as to straddle the conveyor 73, and a base 87 fixed on the base support portion 85 are provided.

The plurality of conveyor rollers 72 rotate the conveyor 73 in one direction to hold the conveyor 73 between the molded body holding portions 75, 79 and the molded body holding portions 75, 79 on the conveyor 73. It is conveyed in one direction together with the supply roller intermediate molded body 10B, and is conveyed in the opposite direction by rotating in the opposite direction. The transporting means is not limited to the conveyor rollers, and may be a conveyor belt or other method.

The transport table 73 is made of a plate-shaped body longer than the total length of the toner supply roller intermediate molded body 10B, and the molded body holding portions 75 and 79 are separated and fixed to the upper surface so as to face each other.

The molded body holding portions 75, 79 are composed of vertical strut portions 76, 80 and arm portions 77, 81 provided on the upper portions of the strut portions 76, 80 so as to face each other in the horizontal direction. The distance between the opposing tips of the arms 77 and 81 is smaller than the total length of the shaft 11 and larger than the total length of the polyurethane foam intermediate molded body 21B. Further, on the upper surface of the tip portions of the arm portions 77 and 81, grooves 78 and 82 for fitting both ends of the shaft 11 protruding from both ends of the polyurethane foam intermediate molded body 21B in the toner supply roller intermediate molded body 10B are formed. Has been done.

The base support portion 85 is erected so as to straddle the transport table 73 at a position near one of the molded body holding portions 75 side between the molded body holding portions 75 and 79. The height of the base support portion 85 is lower than the position of the arm portion 77 of the molded body holding portion 75, and the base 87 is fixed to the upper surface of the base support portion 85.

As shown in FIG. 6, the base 87 has a thickness b in the transport direction of the transport table 73, and a through hole 88 penetrates both sides of the base 87 in parallel with the transport direction of the transport table 73. It is formed. A toner supply roller in which the center of the through hole 88 of the base 87 is held between the arms 77, 81 of the molded body holding portions 75, 79 and the arms 77, 78 by the transport (movement) of the transport table 73. The intermediate molded body 10B is configured to pass through. The through hole 88 is located on an extension of the arm portions 77 and 81 of the molded body holding portions 75 and 79, one side facing the molded body holding portion 75 is the outlet side 90, and the other molded body. The side facing the holding portion 79 is the entrance side 89.

The through hole 88 of the base 87 has a hole diameter d1 of the inlet side 89 larger than the outer diameter d (more accurately, the set outer diameter) of the toner supply roller 10. On the other hand, the hole diameter d2 of the outlet side 90 of the through hole 88 is substantially the same as the outer diameter d of the toner supply roller 10 (to be exact, the set outer diameter, which is actually the outer diameter immediately after manufacturing because it expands and contracts due to heating and cooling or the like). Equal diameter (small diameter). Therefore, the through hole 88 of the mouthpiece 87 has a smaller hole diameter from the entrance side 89 of the large diameter toward the exit side 90 of the small diameter. It is more preferable that the diameter d1 of the entrance side 89 of the large diameter is larger than the outer diameter of the polyurethane foam intermediate molded body 21B. As a result, the polyurethane foam intermediate molded body 21B can be smoothly inserted into the through hole 88 from the entrance side 89, and the polyurethane foam intermediate molded body 21B can be reliably compressed and melted.
The difference (d1-d2) between the diameter d1 on the inlet side and the diameter d2 on the outlet side of the through hole 88 is preferably about 1 to 40 mm. The thickness b of the base 87 (the length of the through hole 88) is appropriately set, and 20 to 100 mm is given as an example.

The base 87 is provided with heating devices 91 and 92 for heating the inner surface of the through hole 88. The illustrated heating devices 91 and 92 consist of heaters connected to a power source and are attached to both sides of the base 87. The heating devices 91 and 92 may have a heater or the like embedded inside the base 87. The heating temperature of the through hole 88 of the base 87 is a temperature at which the outer peripheral surface of the polyurethane foam intermediate molded body 21B can be melted or compression-plastically deformed, preferably 300 to 400 ° C, and even more preferably 340 to 380 ° C. Is.

In the film forming step, first, the transport table 73 is positioned so that the space between the molded body holding portions 75 and 79 is in front of the inlet side 89 of the through hole 88 of the base 87. In that state, both ends of the shaft 11 of the toner supply roller intermediate molded body 10B are fitted into the grooves 78 and 82 formed in the arm portions 77 and 81 of the molded body holding portions 75 and 79 to supply the toner. The roller intermediate molded body 10B is held between the molded body holding portions 75 and 79.

Next, the transfer table 73 is conveyed from the molded body holding portion 79 side toward the molded body holding portion 75 side, and the polyurethane is held by the arm portions 77, 81 of the molded body holding portions 75, 79. The foam intermediate molded body 21B is supplied from the inlet side 89 to the through hole 88 of the heated base 87 and passed through the through hole 88. At that time, the outer peripheral surface of the polyurethane foam intermediate molded body 21B is heated and compressed by the inner surface of the through hole 88 of the mouthpiece 87 and rubbed to move the inside of the through hole 88. As a result, a film that is compressed and melted and solidified from the inside of the polyurethane foam intermediate molded body 21B is formed on the outer peripheral surface of the polyurethane foam intermediate molded body 21B, and the cylinder shown in FIG. 1 is formed on the outer peripheral surface of the shaft 11. A toner supply roller 10 having the shape of the polyurethane foam 21 is manufactured. The film formed on the outer peripheral surface of the polyurethane foam intermediate molded body 21B is a state in which the cells are compressed and crushed smaller than the inside of the polyurethane foam intermediate molded body 21B (that is, the inside of the tubular polyurethane foam 21). A state in which all or part of the polyurethane foam is melted and solidified is in a mixed state, and pinhole-shaped holes are scattered on the surface. An enlarged cross-sectional photograph of this film state is shown in FIG. The pinhole-shaped holes are crushed when the pores existing on the surface of the polyurethane foam intermediate molded body 21B before being passed through the through hole 88 of the base 87 are crushed when passing through the through hole 88 of the base 87. It was formed.

In the toner supply roller of the present invention manufactured in this manner, since the fluff-like uncut portion of the cell due to cutting and polishing does not exist on the surface of the tubular polyurethane foam, the toner scraping property is improved, and the printer and the facsimile can be used. Image quality is improved. Further, good toner supply is obtained by the pinhole-shaped holes scattered on the surface of the coating film on the outer peripheral surface of the tubular polyurethane foam.

After forming a shaft insertion hole having a diameter of 5 mm in the polyurethane foams of Examples 1 to 6 and Comparative Examples 1 to 3 shown in the table of FIG. A metal shaft having a diameter of 4 mm and a length of 235 mm was inserted into the shaft insertion hole of the polyurethane foam to prepare the toner supply roller initial molded body 10A shown in FIG. 4 (4-A).

The polyurethane foams used in Examples 1 and 2 and Comparative Example 1 were polyurethane foams having a density (JIS K7222: 2005) of 57 kg / m ³ and a number of cells (JIS K 6400) of 52/25 mm (part number: SM-55, (Part No .: SM-55). (Made by Inoac Corporation).
The polyurethane foam used in Examples 3 and 4 and Comparative Example 2 was a polyurethane foam having a density (JIS K7222: 2005) of 31 kg / m ³ and a number of cells (JIS K 6400) of 28/25 mm (product number: SC, Co., Ltd.). (Made by Inoac Corporation).
The polyurethane foams used in Examples 5 and 6 and Comparative Example 3 were polyurethane foams having a density (JIS K7222: 2005) of 22 kg / m ³ and a number of cells (JIS K 6400) of 32/25 mm (product number: UEH, Co., Ltd.). (Made by Inoac Corporation).

After that, in Examples 1 to 6, the polyurethane foam of the toner supply roller initial molded body was cut and polished to form the polyurethane foam intermediate molded body 21B, and the toner supply roller intermediate shown in FIG. 4 (4-B) was formed. A molded body 10B was produced. Cutting and polishing was performed by a grinding machine.
With respect to the obtained toner supply roller intermediate molded body 10B of Examples 1 to 6, the outer diameter of the polyurethane foam intermediate molded body 21B was measured by a laser micro measuring machine (LSM-6200 manufactured by Mitutoyo).

Next, the toner supply roller intermediate molded body 10B of Examples 1 to 6 was processed as described later using the film forming apparatus 71 shown in FIG. In the mouthpiece 87, the hole diameter d1 of the inlet side 89 of the through hole 88 is 40 mm, the hole diameter d2 of the outlet side 90 is 13 mm, the thickness b shown in FIG. 6 is 50 mm, and the heating temperature of the mouthpiece 87 is 360 ° C. Yes, it was common to each example.

The film forming apparatus 71 is in a state where the space between the molded body holding portions 75 and 79 is positioned in front of the base 89, and the toner is supplied to the tip end side of the arm portions 77 and 81 of the molded body holding portions 75 and 79. Both ends of the shaft 11 of the roller initial molded body 10B were set, and the toner supply roller intermediate molded body 10B was held between the molded body holding portions 75 and 79. Subsequently, by the rotation of the conveyor roller 72, the transport table 73 is moved from the molded body holding portion 79 side to the molded body holding portion 75 side at a speed of 1 m / min, and the molded body holding portions 75, 79. The polyurethane foam intermediate molded body 21B of the toner supply roller intermediate molded body 10B held between them was passed through the through hole 88 of the mouthpiece 87 from the inlet side 89 and taken out of the through hole 89 from the outlet side 90. As a result, the coating film 23 was formed on the outer peripheral surface of the polyurethane foam intermediate molded body 21B, and the toner supply roller 10 of the embodiment, which was the final molded body, was manufactured.

The compressive load of the toner supply roller 10 of the embodiment, which is the final molded product, was measured as follows. As shown in FIG. 9, the surface of the tubular polyurethane foam 21 in the toner supply roller 10 is formed at three positions in the shaft direction and four positions every 90 degrees in the circumferential direction (12 positions in total). A metal disk-shaped pressing plate having a diameter of 50 mm and a thickness of 7 mm was pressed at a pressing speed of 10 mm / min, the load (g) at 1 mm compression was measured, and the average value was adopted as the compression load. The compressive load of the toner supply roller 10 is preferably 0.020 to 0.500N, more preferably 0.050 to 0.200N.

The compressive load of Examples 1 and 2 was 0.097 N, the compressive load of Examples 3 and 4 was 0.055 N, and the compressive load of Examples 5 and 6 was 0.049 N.

On the other hand, with respect to Comparative Examples 1 to 3, the toner supply roller of Comparative Example, which is the final molded body, was manufactured by polishing the toner supply roller initial molded body 10A after producing the toner supply roller initial molded body 10A. In Comparative Examples 1 to 3, the compressive load was measured for each toner supply roller as the final molded body in the same manner as in the above-mentioned embodiment. The compressive load of Comparative Example 1 was 0.097 N, the compressive load of Comparative Example 2 was 0.055 N, and the compressive load of Comparative Example 3 was 0.049 N.

For the toner supply rollers (final molded bodies) of Examples 1 to 6 and Comparative Examples 1 to 3, the outer diameter was measured, the presence or absence of a coating film was confirmed, the air permeability was measured, and the toner residual ratio was measured. The results are shown in FIG.
The outer diameter was measured by measuring the outer diameter of the tubular polyurethane foam with a laser micro.
The presence or absence of the coating was confirmed with a microscope, and if there was a coating, it was also confirmed whether or not pinhole-shaped holes were scattered on the surface of the coating.

The air permeability of the tubular polyurethane foam was measured using the tubular measuring jig 51 shown in FIG. 10 (10-A). The tubular measuring jig 51 has a cylindrical shape having an inner diameter of 12 mm and a length of 43 mm, which is smaller than the outer diameter of the tubular urethane foam, and the through holes 53 and 54 having a diameter of 7.8 mm face each other in opposite directions. It is formed in the position.

As shown in FIG. 10 (10-B), the measuring toner supply roller 100 is press-fitted into the cylindrical measuring jig 51. Reference numeral 110 is a shaft, and reference numeral 210 is a tubular urethane foam.
Next, as shown in FIG. 10 (10-C), one end of the measuring tube 63 is connected to the through hole 54 of the cylindrical measuring jig 51, and the blower pump 67 is connected to the other end of the measuring tube 63. do. A differential pressure gauge 64 and a flow meter 65 are connected in the middle of the measuring tube 63. In addition, airtight containers 61 and 62 are attached to both ends of the tubular measuring jig 51, and airtightened except for the through hole 53.

Air is blown from the blower pump 67 toward the tubular measuring jig 51 so that the value (flow rate) of the flow meter 65 is stable at a value of 0.3 liter / min, and the blower pump 67 and the toner supply roller are blown. The differential pressure was measured with a differential pressure gauge 64 located between 100, and the measured value was taken as the value of air permeability.
The larger the measured value, the larger the differential pressure and the worse the air permeability to the cross section of the toner supply roller, so that the toner supply property also deteriorates. On the other hand, as the differential pressure of this measured value becomes smaller, the air permeability of the roller becomes better, so that the toner supply becomes better. Specifically, when the measured value was 0.70 kPa or less, the toner supply was good “◯”, and when it exceeded 0.70 kPa, the toner supply was poor “×”. The differential pressure is preferably 0.01 to 0.70 kPa or less.

The toner scraping property was measured as follows.
1. 1. Forming a thin layer of toner on the developing roller Set the black cartridge in the laser printer and turn on the power of the laser printer. The roller of the cartridge spins automatically. Then remove the cartridge from the laser printer.
2. 2. Taking out the developing roller Disassemble the cartridge and take out the developing roller.
3. 3. Sampling when blank (toner thin layer state) Sampling the cellophane tape against the thin layer toner on the disassembled developing roller and rotating it to collect the toner.
4. Sampling of the developing roller when the toner supply roll is set Set and connect the toner supply roll to the developing roller.
Rotate the developing roller by one rotation while the toner supply roll is in contact with the developing roller.
Remove the toner supply roller from the developing roller, press the cellophane tape against the toner on the surface of the developing roller, and rotate it to collect the toner.
5. Sampling position As shown in FIG. 11, two positions in the longitudinal direction of the shaft of one developing roller are the cellophane tape positions (sampling positions) at the time of blanking, and the other five positions are the cellophane tape at the time of setting the toner supply roller. The position (sampling position).
6. Measuring the density of the sampled toner Measure the density of the cellophane tape with a Macbeth densitometer, and the toner remains at [mean value of density measurement value when toner supply roller is set / average value of density measurement value when blank x 100 (%)]. Calculate the rate. When the toner residual ratio was less than 20%, it was evaluated as excellent "◎", when it was 20% or more and less than 27.5%, it was evaluated as good "○", and when it was 27.5% or more, it was evaluated as defective "x".

In Examples 1 to 6, each has a film having pinhole-shaped holes scattered on the surface, and the evaluation of toner supply property is "○" and the evaluation of toner scraping property is "○" or more. Both the toner supply property and the toner scraping property were good.
On the other hand, in Comparative Examples 1 to 3, there was no film on the surface, the evaluation of the toner scraping property was "x", and the toner scraping property was inferior.

As described above, in the toner supply roller of the present invention, since there is no uncut portion due to cutting and polishing on the outer peripheral surface of the tubular polyurethane foam, white streaks are not generated in the image of a printer, facsimile or the like. Further, since the toner supply roller of the present invention has a film having pinhole-shaped holes scattered on the outer peripheral surface of the tubular polyurethane foam, the toner supply property and the toner scraping property are good.

10 Toner Supply Roller 11 Shaft 21 Cylindrical Polyurethane Foam 22 Inside Polyurethane Foam 23 Coating 24 Pinhole Shaped Hole 10A Toner Supply Roller Initial Molded Body 10B Toner Supply Roller Intermediate Molded Body 21A Slab Polyurethane Foam Cutout 21B Polyurethane Foam Intermediate Molding Body 87 Toner 88 Through hole 89 Entrance side 90 Exit side

Claims (1)

In a toner supply roller provided with a tubular polyurethane foam on the outer circumference of the shaft,
The tubular polyurethane foam has a coating film on the outer peripheral surface in which cells are compressed more than the inside of the polyurethane foam, and pinhole-shaped holes are scattered on the surface of the coating film, according to the following measurement method. A toner supply roller characterized in that the measured air permeability value is 0.103 to 0.40 kPa.
For the measurement of air permeability, the measuring toner supply roller is press-fitted into a cylindrical tubular measuring tool having an inner diameter smaller than the outer diameter of the tubular polyurethane foam in the measuring toner supply roller, and the tubular measurement is performed. One end of the measuring tube is connected to one of a set of through holes formed at opposite positions in the tool, a differential pressure gauge and a flow meter are connected in the middle of the measuring tube, and both ends of the tubular measuring tool are connected. With both ends of the measuring toner supply roller sealed, air is blown from the other end of the measuring tube so that the value of the flow meter becomes 0.3 liter / min, and the differential pressure measured by the differential pressure gauge is used. Is the value of the air permeability of the tubular polyurethane foam.

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