JP2000337356A - Urethane sponge roll and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a urethane sponge roll having a sponge layer excellent in roll size precision and surface cell numerical aperture and uniform in surface cell diameter by forming the sponge layer around a mandrel, removing a skin layer formed concurrently, and opening the cells directly below the skin layer on the outer periphery. SOLUTION: A skin layer portion constituting the surface of the sponge layer 42 of a coarse roll body is removed by the peeling action of an adhesive tape, cells 46 located directly below the skin layer are opened, and a urethane sponge roll 60 having an extremely high cell numerical aperture equal to that of a conventional polished sponge roll is formed. The size precision of this urethane sponge roll 60 is ensured by a molding die as a whole, and a product with little size irregularity can be obtained after the skin layer portion is removed. The urethane sponge roll 60 having the extremely high surface numerical aperture and good roll size precision can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a urethane sponge roll and a method for producing the same, and more particularly, to a toner supply roll, a development roll, a charging roll, a transfer roll, and a paper supply in an image forming apparatus such as a copying machine, an image recording apparatus, a printer, and a facsimile. The present invention relates to a urethane sponge roll that can be suitably used as a roll, a cleaning roll, and the like, and a method for producing the same advantageously.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying apparatus, an image recording apparatus, a printer, and a facsimile, an electrostatic latent image formed on an image carrier made of an electrophotographic photosensitive member or an electrostatic recording dielectric is used. Developing with a toner (developer) supplied from a developing roll of a developing device and visualizing the toner image as a toner image has been performed. And a toner supply roll composed of a soft elastic roll for supplying the toner to the developing roll and further to the image carrier side, and further for transferring the formed toner image to transfer paper. Transfer rolls, paper feed rolls for supplying such transfer paper, charging rolls for charging the surface of the image carrier, removal of transfer residual images and residual toner on the surface of the image carrier To the cleaning roller or the like in order of the cleaning device, a predetermined elastic roll is used.

As one type of various types of elastic rolls used in such an image forming apparatus, a sponge layer of a predetermined thickness made of polyurethane foam is provided around a long bar-shaped core bar serving as a roll axis. Urethane sponge rolls have been proposed. For example, JP-A-3-155575 and JP-A-6-30
JP-A-1281 discloses a toner supply roll composed of a urethane sponge roll in which the cell diameter of the sponge layer and the number of cells per inch are specified, and JP-A-2-287576 and JP-A-2-287576. Kaihei 4-5
No. 5873, JP-A-7-36273, etc.
It has been clarified that a urethane sponge roll is used as a developing roll in a developing device. Further, Japanese Patent Application Laid-Open No. 5-35110 discloses a roll foaming used for a conductive roll used for the purpose of controlling an object electrostatically, such as a toner transport roll, a charging roll, a transfer roll, and a cleaning roll. As a method of manufacturing a body, a method has been disclosed in which a foamed sponge layer made of a polyurethane foam is integrally formed around the core by performing foam molding integrally with the core in a roll-shaped mold. .

The urethane sponge roll is generally used as a surface porous roll in which a cell for providing a sponge structure of the sponge layer is opened on the outer peripheral surface of the sponge layer.
The urethane sponge roll proposed above, the outer layer portion of the sponge layer made of polyurethane foam provided at a predetermined thickness around the core metal, by high-speed rotary polishing using a grindstone, the roll outer diameter is obtained Meanwhile, a method of opening the cell to the outside, or cutting using a hot wire such as a nichrome wire, and further as disclosed in JP-A-8-156144 and JP-A-10-104937, etc. By a method such as cutting the sponge layer into a cylinder using a rotating cylindrical knife or band knife, etc.
The cells of the sponge layer are opened on the outer peripheral surface to form a target surface porous roll. Although there is an advantage that the cell opening ratio is increased, the size of the cells opened on the roll surface is not uniform according to the size of the cells inside the sponge layer. Various problems were inherent.

For example, in the above-described method, a polished product is obtained by high-speed rotation polishing of a surface layer of a sponge layer. In the above-described method, the softer the sponge layer (polyurethane foam), the more the grindstone is pressed. Since the sponge layer is deformed, it is difficult to obtain the accuracy of the roll dimensions, and the large amount of grinding dust is extremely troublesome to handle when the roll needs to be handled as a precision member. This necessitates the thorough removal of abrasive swarf from the roll surface, which leads to an increase in man-hours and troublesome work.

[0006] Further, in the method for obtaining a cut product by cutting (cutting) the surface layer portion of the sponge layer using a hot wire or a cutting tool to form a sponge layer having a circular outer peripheral surface, Although there is no problem of generation of fine cutting chips as in the high-speed rotation polishing method, as the sponge layer becomes soft, it is difficult to obtain roll dimensional accuracy, as described above, and in order to maintain roll dimensional accuracy, Inevitably, the frequency of replacement of the cutting tool is inevitably increased, which causes a problem in cost.

Therefore, the applicant of the present application firstly
Japanese Patent Application Laid-Open No. 9-274373 discloses a toner supply roll and a method of manufacturing the toner supply roll.
50 g or less, having a skin layer forming a continuous smooth surface, forming a sponge layer made of a flexible polyurethane foam, and each cell located immediately below the skin layer has an opening diameter of 100 to 800 μm. A urethane sponge roll which is independently opened to the outside, and the entire area of the cells occupies 20% or more of the surface of the skin layer, and further, such a urethane sponge roll is formed into a molding cavity having a final roll shape. The method of producing polyurethane foam raw materials by foam molding operation (molding operation) in the inside was clarified.

However, according to the urethane sponge roll manufacturing method employing the molding method proposed by the applicant of the present application, the above-mentioned problems of polishing dust and roll dimensional accuracy can be completely eliminated. In order to independently open each cell on the surface layer of the sponge layer to the outside on the skin layer surface, it is necessary to provide an opening penetrating through the skin layer. The cell opening ratio on the surface of the sponge layer exceeds 70%, particularly 80%
As described above, furthermore, to achieve a high aperture ratio of as much as 90%,
It was not easy.

However, increasing the opening ratio of the surface cells of the sponge layer in the urethane sponge roll is effective, for example, in terms of toner transportability, supply stability, suppression of toner powdering, and the like. Since it is desirable in terms of uniformly supplying the toner, there is a demand for the urethane sponge roll to have as high an aperture ratio of the surface cells as possible.

[0010]

Here, the present invention has been made in view of such circumstances, and it is an object of the present invention to provide excellent roll dimensional accuracy and surface cell aperture ratio, and furthermore, surface cell diameter. To provide a urethane sponge roll integrally having a uniform sponge layer, and a method for easily and industrially producing a urethane sponge roll having such excellent properties. It is in.

[0011]

According to the present invention, a sponge layer made of a flexible polyurethane foam is integrally formed around a long bar-shaped core by a molding operation. The gist of the present invention is a urethane sponge roll characterized in that the skin layer formed simultaneously on the surface of the sponge layer is removed, and cells immediately below the skin layer are opened on the outer peripheral surface.

That is, in the urethane sponge roll according to the present invention, by the molding operation,
Since the sponge layer made of a flexible polyurethane foam is integrally formed around the cored bar, even if the skin layer, which is the surface layer of the sponge layer, is peeled off, the roll dimensional accuracy does not deteriorate, and the mold dimensional accuracy is kept as it is. It is also possible to open the cells immediately below the skin layer by removing the skin layer on the surface of the sponge layer, so that each cell is opened through the skin layer. With a much higher aperture ratio, cells in the surface layer can be opened, and the cells immediately below such a skin layer have a relatively uniform cell diameter, so that the outer surface of the sponge layer has The uniformity of the cell openings can be further improved.

In the urethane sponge roll according to the present invention, preferably, the sponge layer is removed at a thickness of 1 to 100 μm from its surface, and the skin layer is removed. ,
By removing the skin layer portion at such a thickness, the first layer inside the skin layer, in other words, the layer of relatively uniform cells immediately below the skin layer is advantageously opened. It is.

Further, the present invention relates to a method for advantageously producing a urethane sponge roll having the above-mentioned excellent characteristics by (a) forming a sponge made of a flexible polyurethane foam around a long bar-shaped core by a molding operation. A step of preparing a rough roll body in which a layer is integrally formed and a skin layer is formed on the surface of the sponge layer;
(B) removing the skin layer on the surface of the sponge layer in the rough roll body, and opening a cell immediately below the sponge layer to the outer peripheral surface. Is what you do.

According to one preferred embodiment of the production method according to the present invention, the removal of the skin layer is performed by removing the adhesive layer from the surface of the sponge layer in the rough roll obtained by molding. This is easily realized by removing the adhesive layer from the surface of the sponge layer and removing the skin layer on the surface of the sponge layer together with the adhesive member after attaching and sticking the member.

According to another preferred embodiment of the method for producing a urethane sponge roll according to the present invention, the roll surface and one or both of the adhesive members are heated in advance and then brought into close contact with each other. Alternatively, by heating them after they are brought into close contact with each other, the adhesion between the pressure-sensitive adhesive member and the skin layer is effectively increased, whereby the skin layer is held on the pressure-sensitive adhesive member side. In the above, the adhesive member can be peeled off from the surface of the sponge layer, and the cell existing immediately below the skin layer can be advantageously opened.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be more specifically described below with reference to the drawings.

First, FIG. 1 is a view showing a schematic structure of an example of a full-color laser beam printer using a urethane sponge roll according to the present invention, wherein reference numeral 2 denotes a photosensitive drum. 2
, A charging roll 4 for charging the surface of the photosensitive drum 2, an exposure mechanism section 6 for sending image information by a laser signal to form an electrostatic latent image on the photosensitive drum 2, and a photosensitive drum 2. A developing unit 8 for developing a toner image corresponding to the electrostatic latent image formed on the surface; a transfer drum 10 on which the developed toner image is transferred onto the photosensitive drum 2; A cleaning device 12 for removing transfer residual images and residual toner on the surface is provided. And
The toner image transferred from the photosensitive drum 2 onto the transfer drum 10 is further transferred to a copy paper (transfer paper) supplied from a paper supply device 14 by a paper supply roll 15 to a transfer roll 16.
After the transfer, the image is fixed on the copy paper by the fixing roll 18.

More specifically, in this laser beam printer, the developing unit 8 uses a toner of four colors of cyan, yellow, magenta, and black (here, a non-magnetic one-component developer is used for full-color printing). Are separately accommodated.
0, and the four developing units 20
Each developing unit 20 comes into contact with the photosensitive drum 2 at every 1/4 rotation around the rotation axis, and has a structure in which each hue is arranged with a phase difference of 90 degrees around the rotation axis. (Color developer) is supplied onto the photosensitive drum 2 to develop the electrostatic latent image.

As shown in FIG. 2, each developing unit 20 in the developing section 8 accommodates a toner (non-magnetic one-component developer) 24 as a color developer in a hopper 22, and The toner supply roll 26 and the developing roll 28 provided at the lower portion are rotated in the same direction while contacting each other with a predetermined press contact amount, so that the toner 24 remaining on the developing roll 28 is removed. On the side that is separated from the contact portion with the toner supply roll 26 with the rotation while being scraped off by the toner supply roll 26, the developing roll 28
At the top, the toner 24 in the hopper 22 is supplied. Note that the thickness of the toner layer formed on the developing roll 28 is regulated by a layer forming blade 29. Then, the developing roll 2
As described above, the developing roller 8 is brought into contact with the photosensitive drum 2 by １ ／ rotation about the rotation axis of the developing unit 8 and
The electrostatic latent image on the photosensitive drum 2 is developed by the toner layer formed on the photosensitive drum 8.

Next, the toner image formed by developing the electrostatic latent image on the photosensitive drum 2 in this manner is transferred onto a transfer drum 10 which is rotated in contact with the photosensitive drum 2, and The transfer is performed under the pressure between the transfer drum 10 and the transfer roll 16 on the copy paper (transfer paper) supplied from the paper supply device 14 by the paper feed roll 15 in accordance with the rotation of the transfer drum 10, and then the transfer is performed. The image is fixed on the copy paper by the heating and pressurizing action of the fixing roll 18.

By the way, the present invention relates to a toner supply roll 26 and a developing roll 2 in a printer having such a configuration.
8, charging roll 4, paper feed roll 15, transfer roll 16,
Further, the present invention is directed to a urethane sponge roll used as a cleaning roll or the like in the cleaning device 12, and such a roll is manufactured and configured as described below.

More specifically, first, as a foaming mold, for example, a mold having a pipe-shaped mold structure as shown in FIG. 3, that is, a so-called pipe mold is suitably used. A sponge layer made of a flexible polyurethane foam is integrally formed around a long bar-shaped core bar, and a rough roll body having a skin layer formed on the surface of the sponge layer is foamed and prepared. Becomes

That is, in FIG. 3, a molding die 30 has a pipe 32 having a length substantially equal to the axial length of the sponge layer in the final shape of the target urethane sponge roll, and two ends of the pipe 32. Caps 34, 34 attached to each other to close the respective ends. When a predetermined metal core 36 is positioned in the pipe 32, both ends of the pipe 32 are
4 and 34 and the caps 34 and 3
By supporting the metal core 36 at 4, a molding cavity 38 is formed in the pipe 32 to give an outer shape substantially similar to the final roll shape (outer shape) of the target urethane sponge roll.

Then, a polyurethane foam raw material for providing a sponge layer made of a desired flexible polyurethane foam is guided into the molding cavity 38 of such a molding die 30, and molding is performed by a usual integral foam molding operation. Thus, as shown in FIG. 4, a sponge layer 42 made of a flexible polyurethane foam is integrally formed around the cored bar 36, and a skin layer 44 is simultaneously formed on the surface of such a sponge layer 42. Thus, the desired coarse roll body 40 is obtained. In the formed sponge layer 42,
The first layer and the second layer composed of the cells 46 immediately below the skin layer 44 have a structure with a relatively uniform cell diameter.

The polyurethane foam raw material guided into the molding cavity 38 and reacted and foamed is a liquid material similar to the conventional one, and is a conventionally known reactive raw material which foams and hardens in a mold. Any of (a blend of a polyol component and a polyisocyanate component) is appropriately selected and used without any particular limitation. For example, as the polyol component constituting such a liquid polyurethane foam raw material, generally, any of known polyols such as polyether polyol, polyester polyol, and polymer polyol used in the production of flexible polyurethane foam is used. Can be
As the polyisocyanate component, all known polyisocyanates having at least bifunctionality or more can be used. For example, 2,4- and 2,6-tolylene diisocyanate (TDI), ortho toluidine diisocyanate (TODI), naphthylene diisocyanate Isocyanate (ND
I), xylylene diisocyanate (XDI), 4,
4'-diphenylmethane diisocyanate (MDI) and carbodiimide-modified MDI, polymethylene polyphenyl isocyanate, polymeric polyisocyanate and the like can be used alone or in combination.

Further, the polyurethane foam raw material in which the polyol component and the polyisocyanate component are blended may further contain a crosslinking agent, a foaming agent (water,
Low-boiling substances, gaseous substances, etc.), foam stabilizers, surfactants, catalysts, etc. are appropriately added so as to have a well-known composition which is easy to produce a sponge structure of a sponge layer after foaming. It is a reactive foaming raw material, and such a raw material may contain, if necessary, a flame retardant or a filler, and further a conductivity imparting agent or an antistatic agent for imparting a desired conductivity. Etc. can be added in the same manner as in the prior art.

In particular, in the foam structure of the sponge layer 42 of the rough roll body 40 formed by such a foam molding operation, the size of the cell 46 is appropriately determined according to the intended use of the urethane sponge roll. The cell size is controlled by various known methods, for example, by controlling the injection amount of the polyurethane foam raw material into the molding cavity 38 of the mold 30. In addition, it is controlled by the blending amount of the foaming agent and the foam stabilizer. Specifically, for example, in the case where water is used as a foaming agent, if the amount of the compound is small, the generated cells are fine, and therefore, the compound is generally compounded in a range of 0.5 to 5 phr, In the case of a foam stabilizer, it is 0.1 to
It is blended at a rate of 3 phr, and the raw material injection amount is generally about 0.05 to 0.5 g / cm ³ .

In general, the sponge layer 42 formed by the foam molding operation desirably has a Asker C hardness of 70 degrees or less. There is a problem that removal is difficult, for example, there is a problem that the skin layer 44 is difficult to peel off, and a material having a small tensile strength has a feature that the skin layer 44 is easy to peel off, and the density of the sponge layer 42 has a particular effect. However, in general, the density is 0.05
If it is less than g / cm ³ , the surface of the sponge layer 42 after peeling is difficult to be flat, and if it exceeds 0.7 g / cm ³ , the skin layer 44 becomes too thick and difficult to peel off. The type of raw material components and foaming conditions are appropriately selected so as to provide the sponge layer 42 having such characteristics.

The material of the molding die 30 used in the molding operation by foam molding using the polyurethane foam raw material as described above is such that at least the inner surface of the molding die 30 is made of such polyurethane foam raw material, The polyurethane mold (sponge layer 42) generated by the foam molding operation described above is made of a material (for example, a polyolefin material such as a fluororesin material, a silicone resin material, polypropylene, and polyethylene) to which the molding die 30 is difficult to adhere. It is desirable to apply a suitable release agent, for example, a silicone-based or fluorine-based release agent, to the inner surface of the cavity (the inner surface of the pipe 32), and to perform a foam molding operation. The removal from the inner surface of the mold 30, especially the pipe 32, is effectively performed. By We get to it. The inner surface of the mold 30 (pipe 32) is provided with a skin layer 4 described later.
In the removing operation of 4, for example, when an adhesive tape is used, it is preferable that the surface is slightly rough so that the adhesiveness can be stably exhibited, but a mirror surface can be used at all. . However, if the degree of the surface roughening is large and the surface roughness (Rz) exceeds 50 μm, on the contrary, the tackiness of the pressure-sensitive adhesive tape becomes unstable. Normal surface roughening such as shot blasting is performed as described below.

Then, a sponge layer made of a flexible polyurethane foam is formed around a rough roll body 40, that is, a long bar-shaped core metal 36 as shown in FIG. 4 by a molding operation by foam molding using such a molding die 30. 42 is integrally formed, and on the surface of the sponge layer 42, a molded product is formed by simultaneously forming the skin layer 44 at a predetermined thickness of usually about 1 to 100 μm. In the rough rough roll body 40, since the skin layer 44 on the surface of the sponge layer 42 is to be removed as described later, the skin layer 44 has no hole for opening the cell 46 located immediately below to the outside. It is not necessary to be formed as a film, and even if pinholes or cell openings are present, it does not matter at all,
If a large number of such cell openings exist, it becomes difficult to remove the skin layer 44, which will be described later.
In general, it is desirable that the total ratio of cell openings on the surface of the skin layer, in other words, the cell opening ratio, is generally 70% or less, and preferably 50% or less, since it becomes difficult to peel off.

According to the present invention, the sponge layer 42 is further added to the rough roll body 40 thus obtained.
The operation of removing the skin layer 44 on the surface is performed, so that the cell 46 located immediately below the skin layer 44 is opened on the outer peripheral surface. Is cell 4 located immediately below
6, in other words, the cells 46 of the first layer inside the sponge layer 42
If it is to be opened, any method can be adopted, in particular, an adhesive member such as a tape, a plate or a roll, for example, using an adhesive tape, and applying it to the surface of the sponge layer 42. After the adhesive tape is adhered and adhered, the skin layer 44 on the surface of the sponge layer 42 is removed together with the adhesive tape by peeling off the adhesive tape from the surface of the sponge layer 42. Therefore, a method of removing the skin layer using such an adhesive member is advantageously employed.

In the operation of removing the skin layer 44 using, for example, an adhesive tape as such an adhesive member, as shown in FIG.
An adhesive tape 50 having an adhesive layer 50b formed thereon.
Are superimposed on the skin layer 44 on the surface of the sponge layer 42 and adhered to each other. In this case, the sticking direction of the adhesive tape 50 is as follows.
Any direction such as the roll axis direction and the roll circumferential direction is appropriately adopted. In addition, in order to increase the adhesion of the adhesive tape 50 to the surface of the sponge layer 42, it is preferable to perform a heat treatment after attaching such an adhesive tape 50, whereby the adhesive tape 50 is strongly adhered. It can be done. In addition, such a heat treatment is generally performed by holding at a temperature of about 60 to 150 ° C. for about 1 to 10 minutes. The same effect as above can be achieved by heating one or both of the roll surface of the rough roll body 40 and the adhesive tape 50 prior to the close contact.

Next, the adhesive tape 50 adhered to the surface of the sponge layer 42 in this manner is
As shown in (b), by turning up from the end and slowly peeling off, the skin layer 44 of the sponge layer 42 is removed.
By breaking the portion of the cell 46 directly below the skin layer 44 in a state where the portion is adhered to the adhesive tape 50, each cell 46 immediately below the skin layer can be effectively opened on the outer peripheral surface. Note that the peeling operation of the adhesive tape 50 is performed by peeling the adhesive tape 50 from the entire surface of the sponge layer 42 at a time.
In addition to this, the adhesive tape 50 is peeled off in a range of a predetermined width, and the cells 4 immediately below the skin layer in the range of the width are peeled off.
6 is repeated to open the cells 46 on the entire surface of the sponge layer 42 as appropriate, and even if the adhesive tape 50 is peeled off, An appropriate direction such as the roll axis direction or the roll circumferential direction of the roll body 40 is selected, but advantageously, the adhesive tape 5 having a predetermined width in the roll axis direction is used.
A method of repeating the operation of peeling 0 a plurality of times in the roll circumferential direction is advantageously employed.

As described above, the adhesive tape 50 for removing the skin layer 44 from the surface of the sponge layer 42 needs to be strongly adhered to the surface of the sponge layer 42. In general, those having an adhesive strength to polyurethane of 24 N / cm or more are preferably used, and the tape base material 5 is subjected to heat treatment or the like in order to improve adhesion.
0a and the pressure-sensitive adhesive layer 50b are preferably those having good heat resistance. Particularly, in the case of the tape substrate 50a, those made of polypropylene are preferable from the viewpoint of heat resistance and strength.
It will be suitably used. Further, the adhesive tape 50
For the peeling operation, it is desirable that the material is thin and soft as a whole. Generally, a material having the above-mentioned characteristics as much as possible at a thickness of 0.5 mm or less is selected.

Then, the skin layer 44 constituting the surface of the sponge layer 42 of the rough roll body 40 is removed by the peeling operation of the adhesive tape 50 as described above. Cell 4 located
6, the entire outer peripheral surface of the sponge layer 42 has an extremely high cell opening ratio on the entire outer peripheral surface of the sponge layer 42, which is equivalent to a conventional polished product or the like. The urethane sponge roll 60 is formed. In addition, in such a urethane sponge roll 60, dimensional accuracy can be secured as a whole by the molding die 30, and even if the skin layer 44 is removed, a product with small dimensional variations can be obtained. The removal of only the skin layer 44 (generally a thickness of about 1 to 100 μm) allows the skin layer 44 to be removed.
In the cell 46 of the inner first layer composed of the relatively uniform cells 46 located immediately below, since the cells are to be opened, the cell opening state on the roll surface becomes more uniform than a conventional polished product or the like, Thus, a urethane sponge roll 60 having improved characteristics of the sponge layer 42 can be obtained.

The opening diameter of the surface cells in the urethane sponge roll 60 obtained as described above is appropriately determined according to the intended use. The thickness is adjusted to 200 μm or less for a roll or a charging roll, and to 300 μm or less for a transfer roll. Also, the degree of softness of the sponge layer 42 is appropriately determined according to the application. For example, in the case of the toner supply roll in the hardness display, according to the measurement method shown in FIG. 5 of JP-A-9-274373. Surface length direction 50mm
Under a load of 1 mm, the hardness is set to be 350 g or less. In the case of a developing roll or a charging roll, the Asker C hardness is preferably 20 to 70 degrees. , At Asker C hardness,
An angle of 40 to 70 degrees is preferably used.

[0038]

EXAMPLES Examples of the present invention will be described below to clarify the present invention more specifically. However, the present invention is not limited by the description of such examples. Not that, of course. Also,
In the present invention, various changes, modifications, improvements, etc., based on the knowledge of those skilled in the art, in addition to the following embodiments, in addition to the above-described specific description, without departing from the spirit of the present invention. It should be understood that

First, a pipe die (30) as shown in FIG. 3 is used as a molding die, and the inner surface of a metal pipe (32) corresponding to the inner surface of the die is subjected to shot blasting, and the surface thereof is cleaned. Surface Roughness: After roughening the surface so that Rz is 10 μm, a silicone release agent (a solution containing a modified silicone resin as a main component and a resin solid content of 3 to 5%)
And then cured by heating to form a cured layer (thickness: 5) of the silicone release agent.
μm) was formed on the inner surface of the mold. The inner diameter of the metal pipe (32) of the pipe type (30) is 16 mmφ.
The pipe mold (30) was heated to 50 ° C., and a core metal (36) having an outer diameter of 5 mmφ was set therein as shown in the figure.

On the other hand, 90 parts by weight of EP-828 (polyether polyol manufactured by Mitsui Chemicals, Inc., OH value = 28)
10 parts by weight of POP-31-28 (a polymer polyol manufactured by Mitsui Chemicals, Inc., OH value = 28), and Kaolinizer No.
31 (tertiary amine catalyst manufactured by Kao Corporation) 0.5 part by weight,
0.1 parts by weight of Toyocat HX-35 (tertiary amine catalyst manufactured by Tosoh Corporation), 2 parts by weight of water (blowing agent), SZ-1
142 (Silicone foam stabilizer manufactured by Nippon Unicar Co., Ltd.)
0.1 parts by weight and Sumidur VT-80 (isocyanate manufactured by Sumitomo Bayer Urethane Co., Ltd., NCO% = 4
5) The desired polyurethane foam raw material was prepared by mixing 26.9 parts by weight.

Next, using a polyurethane foam raw material having the above composition, 5 g of the raw material was charged into the pipe mold (30) and kept in an oven at 50 ° C. for 30 minutes to foam and harden. After the pipe type (3
From (0), the foamed rough roll body (40) was taken out.

Next, the obtained rough roll body (4
An adhesive tape (No. 375, manufactured by Nitto Denko Corporation; adhesive strength to polyurethane = 27.4 N / cm) (50) was attached in the roll axis direction to the surface of the sponge layer (42) as the roll surface of 0), After being pressed from above to completely adhere, it was stored in an oven at 110 ° C. for 10 minutes as it was, thereby improving the adhesiveness of the pressure-sensitive adhesive tape (50) to the coarse roll body (40). In addition, as for the method of applying the adhesive tape (50), the operation of applying the adhesive tape in the roll axis direction was repeated in the roll circumferential direction so as to cover the entire outer peripheral surface of the rough roll body (40).

Thereafter, the heat-treated rough roll body (40) is taken out of the oven and allowed to cool naturally. After the surface temperature reaches 30 to 40 ° C., the adhesive tape (50) is moved to the end in the roll axis direction. By winding up from the part and slowly peeling it off in the roll axis direction, in the state where the skin layer (44) having a thickness of 10 to 20 μm on the surface layer of the sponge layer (42) is brought into close contact with the adhesive tape (50), By breaking from the sponge layer (42), a target urethane sponge roll (60) having cells (46) immediately below the skin layer (44) opened in the outer peripheral surface as shown in FIG. 6 was obtained. . The operation of peeling off the adhesive tape (50) was repeated in the roll circumferential direction, so that the adhesive tape (50) on the entire circumferential surface of the roll was finally peeled off.

The urethane sponge roll (60) obtained as described above has a cell (46) immediately below the skin layer (44) opened on the entire surface of the outer peripheral surface of the roll, thereby opening the surface cell. The rate is about 9
It was recognized that the opening ratio of the surface cell (46) was high, as well as 0%, which is approximately equal to that of the polished or cut product. The sponge layer (42) of the urethane sponge roll (60) thus obtained.
Has a hardness of 50 g and a load of 300 g when compressed by 1 mm.
Met.

[0045]

As is apparent from the above description, according to the present invention, a urethane sponge roll having an extremely high surface cell opening ratio and excellent roll dimensional accuracy can be advantageously provided. It is possible to provide a urethane sponge roll having a porous surface having a uniform surface cell diameter, which was difficult to realize with a polished or cut product of the above, and furthermore, a urethane sponge roll having such characteristics can be provided in a simple process. Therefore, it can also exhibit the feature that it can be manufactured at low cost.

The uniformity of the opening of the surface cells makes it possible to use the urethane sponge roll according to the present invention as a toner supply roll, so that unevenness in toner supply and scraping hardly occurs. When used as a toner, the toner has good and uniform toner carrying properties and is less likely to cause image unevenness. Further, the charging roll exhibits uniform charging characteristics, and the transfer roll hardly causes transfer unevenness. Etc. will be exhibited.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view clarifying a mechanism of a full-color laser printer using a urethane sponge roll according to the present invention.

FIG. 2 is an explanatory sectional view showing one of the developing units in FIG. 1 in an enlarged manner.

FIG. 3 is an explanatory longitudinal sectional view showing an example of a molding die used in the method for producing a urethane sponge roll according to the present invention.

FIG. 4 is an explanatory view showing a rough roll obtained by using the forming die shown in FIG. 3;

FIG. 5 is a partially enlarged cross-sectional explanatory view showing an example of a technique for removing a skin layer from a coarse roll according to the present invention, wherein (a) is an adhesive tape for a sponge layer of such a coarse roll. (B) is a sectional explanatory view showing a state in which a skin layer portion on the surface of a sponge layer is brought into close contact with an adhesive tape and peeled off.

FIG. 6 is an explanatory view showing an example of a urethane sponge roll obtained according to the present invention.

[Explanation of symbols]

2 Photoreceptor drum 4 Charging roll 6 Exposure mechanism 8 Developing unit 10 Transfer drum 12 Cleaning device 14 Feeder 15 Feeder roll 16 Transfer roll 18 Fixing roll 20 Developing unit 22 Hopper 24 Toner 26 Toner supply roll 28 Developing roll 29 Layer Forming blade 30 Mold 32 Pipe 34 Cap 36 Core metal 38 Mold cavity 40 Coarse roll body 42 Sponge layer 44 Skin layer 46 Cell 50 Adhesive tape 50a Tape base 50b Adhesive layer 60 Urethane sponge roll

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/02 101 G03G 15/02 101 3F343 15/08 501 15/08 501A 3J103 501D 4F212 15/16 15 / 16 21/10 21/00 312 // B29K 75:00 105: 04 105: 20 B29L 31:32 F term (reference) 2H003 BB11 BB13 BB16 CC05 2H032 AA05 2H034 BC03 2H077 AA15 AC04 AD06 FA00 FA13 FA22 3F049 AA03 CA11 DA12 DA19 LA02 LA05 LA07 LB03 3F343 FA02 FB02 FB03 FB04 JA11 KB04 KB05 KB06 KB16 3J103 AA02 AA13 AA23 EA02 FA15 GA02 GA33 GA52 GA57 GA58 GA60 GA64 GA74 HA03 HA12 HA18 4F212 AA31 AD18 AG14 AG20 AH04 UA10 UB01 UB11 UB01 UB10

Claims (4)

[Claims] 1. A sponge layer made of a flexible polyurethane foam is integrally formed around a long bar-shaped core metal by a molding operation, and a skin layer formed simultaneously on a surface of the sponge layer is removed. A urethane sponge roll, wherein cells immediately below the skin layer are opened on the outer peripheral surface. 2. The method according to claim 1, wherein the sponge layer is 1 to 1 from its surface.
The urethane sponge roll according to claim 1, wherein the urethane sponge roll is removed at a thickness of 00 µm to remove the skin layer. 3. A rough roll body in which a sponge layer made of a flexible polyurethane foam is integrally formed around a long rod-shaped core by a molding operation, and a skin layer is formed on the surface of the sponge layer is prepared. And removing the skin layer on the surface of the sponge layer in the rough roll body, and opening the cell immediately below the outer peripheral surface,
A method for producing a urethane sponge roll, comprising: 4. The method according to claim 1, wherein the skin layer is removed by attaching and sticking an adhesive member to the surface of the sponge layer in the rough roll obtained by molding. The method for producing a urethane sponge roll according to claim 3, which is realized by removing the skin layer on the surface of the sponge layer together with the adhesive member by peeling off the surface from the surface.