JP4082227B2 - Sponge roll and its manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sponge roll such as a toner supply roll used in an electrophotographic apparatus such as a copying machine, a printer, and a facsimile machine, and a manufacturing method thereof .
[0002]
[Prior art]
In general, copying in an electrophotographic apparatus forms a document image as an electrostatic latent image on the surface of a photosensitive drum, forms a toner image by attaching toner to the electrostatic latent image, and transfers the toner image onto a copy sheet. This is done by fixing. The toner image is formed in this copying by supplying toner from the toner box to the surface of the developing roll and attaching the toner on the surface of the developing roll to the electrostatic latent image. The remaining toner remaining on the surface of the developing roll without being attached to the electrostatic latent image is scraped off by the toner supply roll, returned to the toner box, and then stirred by the agitator (stirrer) in the toner box. To be reused.
[0003]
Accordingly, the toner supply roll is required to have a toner scraping performance for reliably scraping off the toner remaining on the surface of the developing roll in addition to a toner supplying performance for stably supplying the toner to the developing roll. Therefore, in order to improve the toner scraping performance, a plurality of ridges extending in the axial direction are formed on the surface of the toner supply roll at a predetermined pitch in the circumferential direction (for example, Patent Documents). 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-38749
[Problems to be solved by the invention]
By the way, the toner supply roll generally comprises a shaft body and a sponge elastic layer made of urethane foam formed on the outer peripheral surface thereof, and the rough surface of the sponge elastic layer surface exhibits toner supply performance. Yes. In order to further improve the toner scraping performance and the like, the ridges are formed on the surface of the sponge elastic layer as described above. As the method for forming the ridges, the following (1) and ( The method 2) can be considered.
(1) After forming the sponge elastic layer on the outer peripheral surface of the shaft body, a plurality of concave grooves extending in the axial direction are formed on the surface of the sponge elastic layer by cutting or the like in the circumferential direction at a predetermined pitch. The above-mentioned ridge is developed between the matching grooves.
(2) As a molding die for molding the sponge elastic layer, a special molding die in which a groove corresponding to the above-mentioned convex stripe is formed on the inner peripheral surface is used.
[0006]
However, in the above method (1) , the sponge elastic layer itself has a low hardness, and is deformed when attempting to perform cutting or the like, so that processing such as cutting is difficult. For this reason, it is difficult to maintain the processing accuracy even if processing is forcibly performed. Moreover, the processing time becomes longer and the productivity is lowered. Further, in the method (2) , it takes time and cost to produce a molding die, and because of the limitation of the processing technology of the molding die and the limitation of workability at the time of molding, a feasible ridge arrangement ( Pattern) is limited, and it is difficult to obtain desired toner scraping performance.
[0007]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a sponge roll that is highly productive and that can handle even complex surface protrusions (patterns) on the surface and a method for producing the same.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention includes a shaft body and a sponge elastic layer formed along the outer peripheral surface of the shaft body, and a plurality of axially extending surfaces on the surface of the sponge elastic layer. The ridges are sponge rolls formed at a predetermined pitch in the circumferential direction, and the ridges are made of a photocurable resin, and the ridges virtually divide the outer peripheral surface of the sponge roll in the axial direction. The first aspect is a sponge roll that is formed in a plurality of regions in a short length and that is alternately formed in adjacent regions .
[0009]
In the sponge roll, the height of the ridges or the distribution density of the ridges can be varied for each region .
[0010]
Further, in the present invention, after forming a sponge elastic layer along the outer peripheral surface of the shaft body using a mold, a plurality of protrusions extending substantially in the axial direction are formed on the surface of the sponge elastic layer in the circumferential direction. a method of on kissing Ponjiroru be formed at a pitch, the formation of the ridges, the part for forming the ridges of the surface of the sponge elastic layer, after applying the photo-curable resin solventless, its The second gist is a method for producing a sponge roll, which is performed by irradiating light to a photocurable resin portion and curing the photocurable resin portion.
[0011]
This inventor repeated earnest research about the formation method of the said protruding item | line in order to be able to respond | correspond to what has high productivity and complicated arrangement | positioning (pattern) of the protruding item | line of a surface in sponge roll. As a result of the research, if the ridges are made of a photo-curing resin, the surface of the sponge elastic layer is not cut, and the mold is used to mold the sponge elastic layer. Thus, the present inventors have reached the present invention by ascertaining that the intended purpose can be achieved without forming the groove to be processed. In the present invention, the “substantially axial direction” means not only a precise axial direction but also a direction that forms an angle of 45 ° or less with the axial direction.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings.
[0013]
FIG. 1 shows an embodiment of the sponge roll of the present invention. In this sponge roll, a sponge elastic layer 2 made of urethane foam is formed on the outer peripheral surface of the 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 in the circumferential direction. It is formed with a pitch P (see FIG. 2). And the said protruding item | line 3 consists of photocurable resin. In this embodiment, separated into imaginary into four regions an outer peripheral surface of the sponge roll axially in the respective regions, that form a plurality of ridges 3 of the short so that the alternating. In addition, in FIG. 1, in order to help an understanding, while showing the said protruding item | line 3 large, the number of the protruding item | line 3 is illustrated few.
[0014]
When a sponge roll in which the ridges 3 are made of a photocurable resin is used as a toner supply roll, the ridges 3 are harder than the sponge elastic layer 2 and the toner remaining on the surface of the developing roll is removed. It can be scraped more reliably. Furthermore, the slidability with other members such as a developing roll is improved, the rotation of the toner supply roll becomes smooth, and the toner supply becomes more stable. As a result, the image quality can be further improved.
[0015]
Further, when the sponge roll is used as a cleaning roll, the scraping property and the sliding property are improved, so that the cleaning effect is exhibited even if the pressure contact force to the member to be cleaned is lowered, and the stress to the member to be cleaned is reduced. In addition, the load on the driving device of the cleaning mechanism can be reduced. Further, when the sponge roll is used as a paper feeding (feeding / conveying) roll, the nip width is increased and the slidability is stabilized, so that it is possible to achieve stable paper feeding.
[0016]
In the sponge roll, it is possible to easily optimize the frictional force acting between the sponge roll and the contacted body in contact with the sponge roll by adjusting the shape, pitch, and the like of the ridges 3. it can. Further, the arrangement (pattern) of the ridges 3 makes it possible to easily set the toner scraping performance to a desired performance. Further, the toner scraping performance can be set to a desired performance by changing the height, distribution density, and the like of the ridges 3 for each region.
[0017]
More specifically, the shaft body 1 is not particularly limited, and a metal core made of a metal solid body, a metal cylinder body hollowed out inside, or the like is used. Examples of the material include stainless steel, aluminum, and iron plated.
[0018]
When the sponge roll is used as a toner supply roll, the protrusion 3 on the surface of the sponge elastic layer 2 is preferably set to have a height H in the range of 20 to 3000 μm as shown in FIG. . This is because if the height H of the ridges 3 is out of the above range, the toner scraping performance tends to be inferior. Further, the ridges 3 are preferably set such that the width W is in the range of 100 to 2000 μm and the circumferential pitch P is in the range of 300 to 3000 μm from the viewpoint of further improving the toner scraping performance. In addition, in FIG. 2, in order to help an understanding, the partially expanded cross section of the surface part of a sponge roll is shown in figure.
[0019]
Most of the cells 4 in the surface portion of the sponge elastic layer 2 are open to the surface of the sponge elastic layer 2, and the average opening diameter is preferably set in the range of 100 to 800 μm. That is, when the average opening diameter is less than 100 μm, the toner that has entered the cell 4 tends to be difficult to come out, and when it exceeds 800 μm, the toner supply amount tends to decrease, and in any case, the image quality may deteriorate. Because there is. And the average cell diameter of the cell 4 in the sponge elastic layer 2 is more than the said average opening diameter, and it is preferable to be set to the range of 100-1000 micrometers. That is, when the average cell diameter is less than 100 μm, the toner tends to be easily clogged in the cell 4, and when it exceeds 1000 μm, the amount of toner entering the cell 4 tends to be too much. This is because there is a risk of deterioration. Further, in the sponge elastic layer 2, the opening 6 having the average opening diameter is formed in all or a part of the cell film 5 existing at the boundary between the adjacent cells 4 in that the deterioration of the toner can be suppressed. The cell 4 preferably has a continuous bubble structure (see FIG. 2) in which all or part of the cells 4 are connected three-dimensionally, but may have a closed cell structure that is not so.
[0020]
As the material for forming the sponge elastic layer 2, a polyol component and an isocyanate component that are used in the production of a normal flexible polyurethane foam are used. Examples of the polyol component include polyether polyol, polyester polyol, polymer polyol and the like, and these are used alone or in combination of two or more. The isocyanate component is not particularly limited as long as it is a bifunctional or higher polyisocyanate. For example, 2,4- (or 2,6-) tolylene diisocyanate (TDI), orthotoluidine diisocyanate (TODI), naphthylene diisocyanate. (NDI), xylylene diisocyanate (XDI), 4,4'-diphenylmethane diisocyanate (MDI), carbodiimide-modified MDI, polymethylene polyphenyl isocyanate, polymeric polyisocyanate, etc., which may be used alone or in combination of two or more. Used.
[0021]
In addition to the polyol component and the isocyanate component, the raw materials include a crosslinking agent, a foaming agent (water, low-boiling substances, gas bodies, etc.), a surfactant, a catalyst, a flame retardant, a filler, as necessary. You may mix | blend an electroconductivity imparting agent, an antistatic agent, etc. suitably.
[0022]
Examples of the photo-curing resin as the material for forming the ridges 3 include those obtained by adding a photopolymerization initiator and a photosensitizer to unsaturated polyester resin, polybutadiene, or the like, or acrylic, urethane, epoxy, or the like. Examples include those obtained by adding a photosensitizer to an unsaturated resin having an unsaturated group introduced into a polymer. Specifically, Aronix (manufactured by Toagosei Co., Ltd.), APR (manufactured by Asahi Kasei Co., Ltd.), Hitaroid (Hitachi Chemical) Etc.). Any photo-curable resin is cured in a short time in the range of 1 second to 1 minute by irradiation with light such as ultraviolet rays. The light curable resin, Ru der those solventless. This is because the sponge elastic layer 2 swells when a solvent is used.
[0023]
Moreover, you may mix | blend an electroconductivity imparting agent, an antistatic agent, etc. with the said photocurable resin suitably as needed.
[0024]
Next, a method for producing the toner supply roll will be described. This toner supply roll can be manufactured as follows, for example. That is, first, a mold shown in FIG. 3 is prepared. The mold includes 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 that close both ends of the cylindrical mold 11. ing. Further, in this mold, when the shaft body 1 is loaded into the cylindrical mold 11 and both ends of the cylindrical mold 11 are closed with the caps 12, the shaft body 1 is supported coaxially with the cylindrical mold 11 by the caps 12, A molding cavity 13 is formed in the cylindrical mold 11 to give the final roll shape of the target toner supply roll. Next, the shaft body 1 is loaded into the cylindrical mold 11 of the above-described mold, and both ends of the cylindrical mold 11 are closed with caps 12, and then a material for forming the sponge elastic layer 2 is injected into the molding cavity 13 to be formed. , Foam cure. Next, after demolding, a photocurable resin is applied to the portion of the surface of the sponge elastic layer 2 where the ridges 3 are formed by printing or the like. Then, the photocurable resin portion is irradiated with light such as ultraviolet rays using a lamp such as an ultraviolet lamp. Thereby, a photocurable resin part hardens | cures and the said protruding item | line 3 is formed.
[0025]
In the formation of the sponge elastic layer 2 in the mold, when the expansion ratio is set to about 5 to 20, the average opening diameter of the cells 4 opened on the surface of the sponge elastic layer 2 is in the range of 100 to 800 μm. While being able to form, the average cell diameter of the cell 4 in the sponge elastic layer 2 can be formed in the range of 100-1000 micrometers. These average opening diameter and average cell diameter can be adjusted by changing the expansion ratio.
[0026]
Further, when the toner supply roll is rotated about the shaft 1 after the demolding and a high-pressure gas (gas such as air or nitrogen) is sprayed onto the sponge elastic layer 2 using a nozzle or the like, the high-pressure gas Is diffused into the sponge elastic layer 2 by the resistance of the shaft 1 and the opening action of the cell film 5 is remarkably exhibited. As a result, the opening 6 is formed in the cell film 5 existing at the boundary between the adjacent cells 4. . The degree of formation of the opening 6 can be adjusted by changing the pressure of the gas to be injected.
[0027]
The method for forming the ridge 3 is not particularly limited, and examples thereof include a printing method, a method using an ink jet, and a coating method such as a normal spraying method using a spray nozzle. For example, the printing method uses a printing roll 21 as shown in FIG. That is, on the surface of the printing roll 21, a groove 22 corresponding to the protruding stripe 3 is formed, and the printing roll 21 and the toner supply roll are arranged in parallel and are in contact with each other. The printing roll 21 is rotated, and the toner supply roll rotates with the printing roll 21 by the rotation. A part of the printing roll 21 is immersed in the liquid photocurable resin 3a, and the photocurable resin 3a filled in the groove 22 on the surface of the printing roll 21 is printed on the surface of the toner supply roll. It is like that.
[0028]
As described above, according to the sponge roll of the above embodiment, the protrusion 3 made of a photocurable resin is formed on the surface of the sponge elastic layer 2, so that the toner supply performance and the toner scraping performance are excellent. It can function as a toner supply roll. Further, it can also function as a cleaning roll excellent in cleaning property and a paper feeding / conveying roll excellent in paper conveyance property. In the production of the sponge roll, since the ridges 3 are formed of a photocurable resin, difficult processing such as forming the ridges by cutting the sponge elastic layer or the like becomes unnecessary. In addition, the ridge 3 can be cured and formed with a photo-curable resin in a short time. As a result, the sponge roll of the above embodiment can improve productivity. Further, when the ridge 3 is formed of a photocurable resin, it is not necessary to use a special molding die in which a groove corresponding to the ridge is formed, thereby reducing the time and cost for producing the molding die. be able to. Furthermore, in the case of applying a photocurable resin to form the ridges 3, since a printing method, an ink jet method, or the like is used, the degree of freedom in designing the arrangement (pattern) of the ridges 3 is used. And the arrangement (pattern) of the ridges 3 can be complicated as in this embodiment .
[0029]
FIG. 5 shows a reference form of the sponge roll of the present invention. In this reference embodiment, ridges 3 are formed in a spiral shape, direction Yuku extending the ridges 3 has no axial and predetermined angle θ indicated by a chain line A. The angle θ is preferably 45 ° or less. This is because if it exceeds 45 °, the toner scraping performance tends to be inferior. Other parts are the same as those in the above embodiment, and the same reference numerals are given to the same parts. And in this reference form, there exists an effect | action and effect similar to the above .
[0030]
Next, reference examples will be described together with comparative examples.
[0031]
[Reference Example 1]
The sponge roll shown in FIG. 6 was produced as described above. That is, in this sponge roll, a SUM22 round bar having a diameter of 5 mm was used as the shaft body 1, the sponge elastic layer 2 was made to have a continuous foam structure, and the outer diameter was set to 16 mm. The average opening diameter of the cells 4 in 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. Further, the ridges 3 on the surface of the sponge elastic layer 2 were parallel to the axial direction, the height H was 200 μm, the width W was 200 μm, and the circumferential pitch P was 800 μm.
[0032]
In the production of this sponge roll, the material for forming the sponge elastic layer 2 was prepared as follows. That is, 90 parts by weight of polyether polyol (Mitsui Chemicals, EP-828, OH number = 28), 10 parts by weight of polymer polyol (Mitsui Chemicals, POP-31-28, OH number = 28), diethanolamine 2 parts by weight, 3 parts by weight of a silicone foam stabilizer (manufactured by Nippon Unicar Co., Ltd., L-5309), 2 parts by weight of water, 0.5 parts by weight of a tertiary amine catalyst (manufactured by Kao Corporation, Kaorizer No. 31) Parts, tertiary amine catalyst (Tosoh Corporation, Toyocat HX-35) 0.1 parts by weight, DBTDL 0.1 parts by weight, and isocyanate (Sumitomo Bayer Urethane Co., Ltd., Sumidur VT-80, NCO% = 45) was mixed with 30.5 parts by weight to prepare a material for forming the sponge elastic layer 2.
[0033]
In addition, the above-described protrusion 3 is formed by using Aronix (M-113, manufactured by Toagosei Co., Ltd.) as a photocurable resin, printing using a printing roll 21, and then using an ultraviolet lamp UB013-2A / BM type (eye graphic). Was cured by irradiation with ultraviolet rays for 30 seconds.
[0034]
[Comparative Example 1]
In Reference Example 1 described above, the example in which the ridge 3 was not formed was referred to as Comparative Example 1.
[0035]
The sponge rolls of Reference Example 1 and Comparative Example 1 obtained in this way were incorporated into a toner cartridge as a toner supply roll, and the toner cartridge was left for 7 days in an environment of low temperature and low humidity (15 ° C. × 10%). Later, it was set in a color laser printer and imaged. For this image formation, a toner having an average particle diameter of 7 to 10 μm was used. Then, the toner scraping performance was evaluated.
[0036]
[Toner scraping performance]
The above imaged images were visually confirmed for the presence of streaks and uneven density. As a result, it can be evaluated that the image by the color laser printer incorporating the sponge roll of Reference Example 1 has no streak and density unevenness and excellent toner scraping performance. On the other hand, it can be evaluated that the image by the color laser printer incorporating the sponge roll of Comparative Example 1 has slight streaks and uneven density, and the toner scraping performance is slightly inferior.
[0037]
【The invention's effect】
As described above, according to the scan Ponjiroru of the present invention, since a plurality of ridges extending generally axially to the surface of the sponge elastic layer is formed of a photocurable resin, sponge to form the ridges Difficult processing such as cutting the elastic layer is not required, and the ridges can be cured and formed with a photocurable resin in a short time. As a result, according to the sponge roll of the present invention, productivity can be significantly improved. In addition, by forming the ridges with a photo-curable resin, there is no need to use a special molding die with grooves corresponding to the ridges, thus reducing the time and cost for producing the molding dies. can do. Furthermore, in the case of applying a photocurable resin to form the ridges, a printing method or a method using an ink jet is used. Therefore, the arrangement (pattern) of the ridges can be simplified as necessary. Since it can be changed and it is possible to cope with a complicated arrangement (pattern), the degree of freedom of design is greatly increased.
[0038]
In particular , when the height of the ridges is different for each region or when the distribution density of the ridges is different, the sponge rolls having different performances can be set.
[0039]
Further, when the height of the strip upper Kitotsu is in the range of 20~3000μm it can function as a toner supply roll having excellent by toner scraping performance.
[0040]
Furthermore, in the present invention, when the circumferential pitch of the ridge is in the range of 300 to 3000 μm, it can function as a toner supply roll with improved toner scraping performance.
[0041]
In the method for producing a sponge roll as the second gist of the present invention, the sponge elastic layer is formed because the sponge elastic layer is formed with a ridge by applying a solvent-free photocurable resin to the sponge elastic layer. It does not swell.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a sponge roll of the present invention.
FIG. 2 is a partially enlarged sectional view of a surface portion of the sponge roll.
FIG. 3 is a cross-sectional view showing a mold used for forming a sponge elastic layer of the sponge roll.
FIG. 4 is an explanatory view showing a printing method of a photocurable resin for forming the ridges.
FIG. 5 is a perspective view showing a reference form of the sponge roll of the present invention.
FIG. 6 is a perspective view showing a reference example of the sponge roll of the present invention.
[Explanation of symbols]
1 shaft body 2 sponge elastic layer 3 ridge

Claims (6)

  A shaft body and a sponge elastic layer formed along the outer peripheral surface of the shaft body, and a plurality of ridges extending substantially in the axial direction are formed at a predetermined pitch in the circumferential direction on the surface of the sponge elastic layer. The above-mentioned ridge is made of a photo-curable resin, and the ridge is formed in a short length in a plurality of regions virtually dividing the outer peripheral surface of the sponge roll in the axial direction. A sponge roll characterized by being formed so as to be staggered in adjacent regions. Sponge roll according to claim 1, wherein the height of the ridges in each said respective areas are different. The sponge roll according to claim 1 or 2, wherein the distribution density of the ridges is different for each region. The sponge roll according to any one of claims 1 to 3 , wherein a height of the ridge is in a range of 20 to 3000 µm. The sponge roll according to claim 4 , wherein a pitch in the circumferential direction of the ridges is in a range of 300 to 3000 μm. A sponge elastic layer is formed along the outer peripheral surface of the shaft body using a mold, and then a plurality of ridges extending substantially in the axial direction are formed on the surface of the sponge elastic layer at a predetermined pitch in the circumferential direction. a process for preparing 1 Symbol placement sponge roll, after formation of the ridges, the part for forming the ridges of the surface of the sponge elastic layer was applied solventless photocurable resin, the light curing A process for producing a sponge roll, which is carried out by irradiating a light-sensitive resin part with light and curing the light-curable resin part.

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