JP2001105440A - Method for producing urethane sponge roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily produce a urethane sponge roll, which is excellent in roll dimensional accuracy and surface cell opening ratio and integrally has a sponge layer having a uniform surface cell size, in an industrially advantageous manner. SOLUTION: A urethane sponge raw material is supplied into the molding cavity of a mold in such a state that a predetermined core is arranged in the molding cavity of the mold and a thin-walled film layer 44 is provided to the inner surface on the side imparting a roll surface of the molding cavity to be subjected to foam molding to prepare a molded article 50 wherein a soft polyurethane sponge layer is integrally formed to the periphery of the core and the film layer 44 is integrally present on the surface of the sponge layer 48 and, subsequently, the film layer 44 is peeled from the surface of the molded article 50 to obtain a target urethane sponge roll 60 wherein the cells 56 of the outer peripheral surface of the molded article 50 are opened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[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 of integrally forming a sponge layer made of a polyurethane foam around the core metal by performing foam molding integrally with the core metal in a roll-shaped mold has also been clarified. I have.

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.

[0005] For example, in the above-described method of obtaining a polished product (porous surface roll) by high-speed rotational polishing of the surface layer portion of the sponge layer, the sponge layer (polyurethane foam) becomes soft. As the sponge layer is deformed by the pressing of the grindstone, it is difficult to obtain the accuracy of the roll dimensions, and the large amount of grinding dust is extremely troublesome when the roll needs to be handled as a precision member. This necessitates a thorough removal of such polishing debris from the roll surface, leading to an increase in man-hours and troublesome work.

[0006] Further, a method of obtaining a cut product (surface porous roll) 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 described above, as the sponge layer becomes softer, it is difficult to obtain roll dimensional accuracy, as described above, In order to maintain accuracy, the frequency of changing the cutting tool will inevitably increase,
A problem arises 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.
A sponge layer (soft polyurethane sponge layer) made of a soft polyurethane foam having a skin layer forming a continuous and smooth surface of 50 g or less is formed, and each cell located immediately below the skin layer has a thickness of 100 g.
Independently open to the outside at an opening diameter of ~ 800 μm,
Further, a urethane sponge roll configured so that the total area of the openings of the cells occupies 20% or more of the surface of the skin layer, and further, such a urethane sponge roll is foamed with a polyurethane foam raw material in a molding cavity having a final roll shape. The manufacturing method was clarified by the molding operation (molding operation).

However, according to the urethane sponge roll manufacturing method employing the molding method proposed by the applicant of the present invention, the above-mentioned problems of polishing dust and roll dimensional accuracy can be completely eliminated. However, in order to open each cell in the surface layer of the sponge layer independently to the outside on the surface of the skin layer, it is necessary to provide an opening penetrating the skin layer, so there is an inevitable limit. As in the case of the polished or cut products obtained by the above-described conventional method, the cell opening ratio on the surface of the sponge layer is 70%.
%, Especially 80% or more, and even as high as 90%, has not been easy.

[0009] 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, and suppression of toner powdering. Further, since it is desirable from the viewpoint of uniformly supplying the toner, there is a demand for such a urethane sponge roll to have the opening ratio of its surface cells as high 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. It is an object of the present invention to provide a method for easily and industrially producing a urethane sponge roll having a sponge layer having a uniform (opening diameter).

[0011]

[Solution] To solve such a problem,
The present invention provides a method in which a predetermined core metal is arranged in a molding cavity of a molding die, and a thin film layer is provided on an inner surface of the molding cavity on a side where a roll surface is provided so as to cover the entire surface. By supplying a urethane sponge raw material into the molding cavity and performing foam molding, a soft polyurethane sponge layer is integrally formed around the cored bar, and the film layer is integrally formed on the surface of the sponge layer. A step of preparing a molded article present in the mold, and a step of peeling the film layer from the surface of the molded article to open cells on the surface of the molded article to the outer peripheral surface. The gist is a method for producing a sponge roll.

In short, in the method for producing a urethane sponge roll according to the present invention as described above, first, in a molding cavity of a molding die, a predetermined cored metal is arranged inside, while a surface on which the roll surface is provided is provided. By providing a thin film layer so as to cover the entire inner surface, and performing the predetermined foaming operation (molding operation) in such a state, the soft polyurethane sponge layer is integrated around the cored bar. In order to prepare a molded article in which the thin film layer is integrally formed on the surface of the sponge layer, the molded article obtained in this way is prepared. In addition, a skin layer is formed on the surface of the soft polyurethane sponge layer, and in such a skin layer,
The structure is such that the film layer has a structure in which the film layer is well fixed or adhered to the sponge layer.

Next, in the method of the present invention, an operation of peeling off the film layer present on the surface of the molded article obtained above is performed. The skin layer, which is the surface layer of the polyurethane sponge layer, can be effectively peeled and removed from the sponge layer together with the film layer in a state in which the skin layer is well fixed (adhered) to the film layer in a state in which it is adhered to the film layer. As a result, the cells on the surface of the molded article, that is, the cells immediately below the skin layer, are opened on the outer peripheral surface.

Therefore, according to the manufacturing method according to the present invention, the flexible polyurethane sponge layer having the skin layer on the surface is integrally formed around the core by the molding operation. Therefore, even if such a skin layer is removed as described above, the dimensional accuracy of the roll does not deteriorate, and the dimensional accuracy of the mold can be obtained as it is. Also, by removing the skin layer on the surface of the sponge layer, Since the cells located immediately below the skin layer can be opened, the cells can be opened at a much higher aperture ratio than when each cell is opened through the skin layer, Furthermore, by such a cell immediately under the skin layer, having a relatively uniform cell diameter, is formed neatly arranged,
On the outer surface of the sponge layer of the finally obtained roll,
The uniformity of the cell openings can be further enhanced.

Further, according to the present invention, the urethane sponge roll having such excellent characteristics can be molded by a predetermined molding operation using a molding die provided with a core metal and provided with a film layer. Is formed, simply by peeling off the film layer from the surface of the obtained molded article, it can be easily manufactured, and in the molded article, the film layer and the soft polyurethane sponge layer are formed in the foam molding step. Even if the sponge layer has a relatively strong bonding state between the skin layer constituting the surface thereof and the internal layer constituted by the cells immediately below the skin layer, the sponge layer can be firmly fixed or adhered. ,
By peeling off the film layer, the skin layer can be reliably and sufficiently removed, and in terms of industrial productivity,
This is extremely advantageous.

In the method for producing a urethane sponge roll according to the present invention as described above, the film layer is preferably formed so that the outer diameter dimension is the same as the inner diameter dimension of the inner surface of the molding cavity on the roll surface side. It is desirable to be formed with a tube having That is, a tube configured to have such an outer diameter is simply fitted and set on the inner surface of the molding cavity of the mold, and a film covering the entire inner surface on the side that provides the roll surface of the mold is set. The layers can be provided very easily, so that urethane sponge rolls can be produced more efficiently.

According to one preferred embodiment of the urethane sponge roll production method according to the present invention, the surface roughness Rz of the surface of the film layer on the side of the molded article on which the sponge layer is provided is 3%. ~ 20 μm
It will be. If a film layer having such a surface roughness is employed, it is possible to advantageously form a molded article having extremely excellent adhesion strength or adhesion strength between the soft polyurethane sponge layer (skin layer) and the film layer. From, by removing the film layer from such a molded product, the removal of the skin layer,
There is an advantage that it can be performed more effectively and easily, and various effects as described above can be more effectively exerted.

In another preferred embodiment of the production method according to the present invention, the thickness of the film layer is:
10 to 10 so that the work of peeling the film layer from the surface of the molded article can be performed well and effectively.
The thickness is desirably set to 00 μm, whereby the productivity and production efficiency of the urethane sponge roll can be effectively increased.

Further, according to one preferred embodiment of the method for producing a urethane sponge roll according to the present invention, the cell on the surface of the molded article is formed by the operation of peeling the film layer from the surface of the molded article as described above. In the total opening area, at least 70% of the outer peripheral surface of the roll
An opening is made to occupy the above. If the urethane sponge roll having a cell opening ratio of 70% or more on the outer surface of the sponge layer obtained according to the method of the present invention is used as various kinds of elastic rolls in an image forming apparatus, the toner can be transported, supplied, and carried. In addition, a dramatic improvement in characteristics such as chargeability and transferability can be more advantageously achieved.

According to another preferred embodiment of the present invention, an operation of heating the film layer before peeling the film layer from the surface of the molded article is employed. The film layer, by its heating,
Since the film layer is more easily deformed, the work of peeling off the film layer after heating the film layer can significantly improve the workability.

[0021]

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

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 pressure 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 2
8, 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, as described above, the developing roller 28 is brought into contact with the photosensitive drum 2 at １ ／ rotation about the rotation axis of the developing unit 8, and the photosensitive layer is formed by the toner layer formed on the developing roller 28. The electrostatic latent image on the body drum 2 will be developed.

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 / pressing action of the fixing roll 18.

The present invention is directed to a toner supply roll 26 and a development roll 2 in a printer having the above-described 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 as follows.

Specifically, first, a suitable foaming mold, preferably a so-called pipe mold having a mold structure exhibiting a pipe shape as shown in FIG. 3, is used. A flexible polyurethane sponge layer made of a flexible polyurethane foam is integrally formed around a long bar-shaped core, and a thin film layer is integrally formed on the surface of the sponge layer. Be prepared.

That is, in FIG. 3, a molding die 30 includes 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. 3A, which are attached to each other to close the respective ends. Particularly, as shown in FIG. 3A, in a state where a predetermined core metal 36 is positioned in the pipe 32,
By closing both ends of the pipe 32 with caps 34 and 34 and supporting the core metal 36 with the caps 34 and 34, the final roll shape (outer shape) of the target urethane sponge roll is formed in the pipe 32. ) Is formed so as to give an outer shape substantially similar to ().

In the present invention, as shown in FIG. 3 (b), a core metal 36 is arranged at a predetermined position of such a molding die 30 to form a molding cavity 38,
A thin film material 42 is superimposed or disposed on the inner surface of the molding cavity 38 on the side where the roll surface is provided, that is, on the inner surface 40 of the pipe 32.
After forming a film layer 44 having a constant thickness covering the entirety of the mold, a polyurethane foam raw material (urethane sponge raw material) for providing a sponge layer made of a desired soft polyurethane foam is formed in the molding cavity 38 of the molding die 30. The mold is supplied and molded by a normal integral foam molding operation, whereby a sponge layer 48 made of a flexible polyurethane foam is formed around the core metal 36 as shown in FIG. On the surface of the sponge layer 48, the film layer 4
4 is fixed or adhered to form a target molded product 50 having the metal core 36, the sponge layer 48, and the film layer 44 integrally.

More specifically, in the method of the present invention, the film material 42 for providing the film layer 44 provided on the inner surface 40 of the molding cavity 38 (the pipe 32) is generally a sponge obtained by foaming a polyurethane foam material. A material having good conformability and adhesion to the layer 48 and having a degree of flexibility capable of being deformed by applying an external force, such as urethane resin, natural rubber (NR), and nitrile rubber (NBR) ), A rubber material such as styrene-butadiene rubber (SBR), which is formed in a predetermined shape by a known molding method, can be appropriately adopted. As described above, the work of peeling the film layer 44 provided by the film material 42 from the surface of the molded product 50 is performed well. In order for the film to be effectively formed, it is necessary that the film be sufficiently deformed by the action of an external force, and usually, a film having a thickness of about 10 to 1000 μm, preferably about 100 to 500 μm is used. The material 42 is advantageously used. However, if the film material 42, that is, the film layer 44 is too thin, the film layer 44 is liable to be broken at the time of the peeling operation, so that there is a problem in strength. And film layer 4
This is because there is a possibility that the peeling operation of No. 4 cannot be performed well.

In the present invention, the film material 42
As described above, the (film layer 44) is required to have appropriate flexibility.
JIS-A hardness of 50 ° or less, more preferably JIS
It is desirable to use a relatively soft material having an SA hardness of 30 ° or less. In the film material 42, at least one of the surfaces thereof is
When the sponge layer 48 is disposed or arranged on the surface, which is the surface on the side on which the sponge layer 48 is provided opposite to the inner surface 40 (the surface indicated by 52 in FIG. 3B), the sponge layer 48 and the film It is preferable that a roughening treatment is performed by a normal processing method such as a shot blasting process so that a sufficient fixing strength or an adhesive strength with the layer 44 can be secured. Generally, the roughness (Rz) is 3
To 30 μm, more preferably 5 to 20 μm. However, if the surface roughness is smaller than 3 μm, the effect of such surface roughening treatment cannot be sufficiently exerted. On the other hand, if it exceeds 30 μm, the sponge layer 48 and the film The adhesion strength (adhesion strength) with the layer 44 becomes too strong, and as will be described in detail later, the skin layer formed on the surface of the sponge layer 48 is not easily peeled off cleanly when the film layer 44 is peeled off. Therefore, problems such as difficulty in obtaining a smooth surface in the sponge layer 48 after the peeling operation are caused.

Further, in such an arrangement or arrangement of the film material 42, in other words, in the formation of the film layer 44, the entire surface of the inner surface 40 of the molding cavity 38 should be covered with a constant thickness. There is no particular limitation as long as it can be formed, and one or more of the film materials 42 having an appropriate shape may be extended in the axial direction or the circumferential direction of the inner surface 40 according to the shape, The film layer 44 can be advantageously formed by arranging or disposing in a spiral form or the like on the inner surface 40. In the present invention, in particular, in the present invention, the film material 42 It is desirable to use a cylindrical tube having an outer diameter dimension that is the same as the inner diameter dimension of the inner surface 40, thereby forming the film layer 44. That is, in the case of the film material 42 made of a tube having such an outer diameter, the film material 42 is formed into the molding cavity 3.
8 (pipe 32) with the respective central axes aligned with each other, the inner surface 40 is merely fitted.
The film layer 44 can be easily and advantageously provided on the surface. And, such an effect is obtained by using a tube having a length corresponding to the axial length of the molding cavity 38 (here, the length of the pipe 32) together with the outer diameter, in other words, only one tube. By constituting the film material 42, it can be more effectively exhibited,
When such a film material 42 is used,
There is also an advantage that the dimensional accuracy of the sponge layer 48 formed by molding can be further increased. Further, when the film material 42 is arranged and arranged, there is no problem even if the film material 42 and the inner surface 40 are temporarily fixed and bonded as long as the removal operation after forming the molded product 50 is not hindered. .

On the other hand, in the above, the molding cavity 38
The polyurethane foam raw material introduced and reacted and foamed is the same as the conventional one, and is a conventionally known reactive raw material (formulation of a polyol component and a polyisocyanate component) which foams and cures in a mold. ),
There is no particular limitation, and they can be appropriately selected and used. For example, as a polyol component constituting such a polyurethane foam raw material, any of known polyols such as polyether polyol, polyester polyol, and polymer polyol which have been conventionally generally used for production of a flexible polyurethane foam can be used. As the polyisocyanate component, any known polyisocyanate having at least two or more functionalities can be used. For example, 2,4- and 2,6-tolylene diisocyanate (TDI), orthotoluidine diisocyanate (TODI) ), Naphthylene diisocyanate (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.

The polyurethane foam raw material obtained by mixing the polyol component and the polyisocyanate component may further contain a crosslinking agent, a foaming agent (water,
Low-boiling substances, gas bodies, etc.), foam stabilizers, surfactants, catalysts, etc. are appropriately added so as to have a well-known composition that is easy to produce a sponge structure of the sponge layer 48 after foaming. The raw material is a reactive foaming raw material, and such a raw material may include a flame retardant and a filler, as needed, a conductivity-imparting agent for imparting a desired conductivity, and an antistatic material. Agents and the like can be added as in the conventional case.

In the present invention, the core metal 36 is set at a predetermined position, and the film material 42 as described above is superimposed on the entire inner surface 40 of the molding cavity 38 to form a thin film layer. By performing the above-mentioned foaming operation of the polyurethane foam raw material using the molding die 30 provided with the mold 44, a molded product 50 is formed.
Where the molding cavity 3 is formed based on the foaming of the polyurethane foam raw material.
8, the film layer 44 having a constant thickness is sufficiently pressed against the inner surface 40, so that the sponge layer 48 has a constant thickness around the cored bar 36. Such sponge layers 48 can be advantageously formed with high dimensional accuracy and
On the other hand, the film layer 44 can be fixed or adhered with sufficient strength, so that the demolding operation of the molded product 50 from the molding die 30 can be performed well and simply. Can be done.

Further, in the present invention, since the sponge layer 48 is formed by molding, as shown in FIG.
Since the skin layer 54 having a predetermined thickness of about 0 μm is formed, the film layer 44 is firmly fixed to the sponge layer 48 in the skin layer 54, and the sponge layer 48 In the above, the first layer and the second layer composed of the cells 56 immediately below the skin layer 54 are formed with a structure having a relatively uniform cell diameter.

In general, the sponge layer 48 formed by the above-mentioned foam molding operation desirably has a Asker C hardness of 70 degrees or less. It becomes difficult to remove the skin layer 54 by the peeling operation of the skin layer 54.
The sponge layer 48 has a characteristic that the skin layer 54 is more easily peeled off, and the density of the sponge layer 48 is not particularly affected. is less than .05g / cm ^3, the surface of the sponge layer 48 after removal hardly becomes flat and comes to exceed 0.7 g / cm ^3, too thick a skin layer 54, from where it becomes difficult peeled To provide a sponge layer 48 of such properties,
The type of raw material components and foaming conditions are appropriately selected.

In such a foamed structure of the sponge layer 48, an appropriate size is selected as the size of the cell 56 constituting the foam according to the intended use of the urethane sponge roll. , The cell size can be controlled by various known methods, for example,
In addition to being controlled by the supply amount of the polyurethane foam raw material into the molding cavity 38 of the molding die 30, it is controlled by the blending amount of the foaming agent and the foam stabilizer. Specifically, for example, in the case of using water as a foaming agent, if the amount of the water is reduced, the generated cells 56 become finer, and therefore, generally, in a range of 0.5 to 5 phr. In the case of a foam stabilizer, it is blended in a ratio of 0.1 to 3 phr, and the raw material supply amount is usually 0.05 to 0.
The ratio will be about 5 g / cm ³ .

After the mold 50 thus obtained is released from the mold 30, the film layer 44 is further peeled off from the surface in accordance with the present invention. However, as described above, in the molded product 50, the film layer 44
Is firmly fixed (adhered) to the skin layer 54 as the surface layer of the sponge layer 48, and as shown in FIG. 5, the peeling operation of the film layer 44 causes the skin layer 54 of the sponge layer 48 to be peeled off. 54 is a film layer 4
In the state of being kept in close contact with the skin layer 54, the cell 56 is broken at the portion of the cell 56 immediately below the skin layer 54, and is peeled off and removed from the sponge layer 48 together with the film layer 44. Molded product 5
The cell 56 immediately below the skin layer 54 on the surface of the zero is opened in the outer peripheral surface.

As a specific method of peeling the film layer 44, as shown in FIG.
As long as the skin layer 54 can be effectively peeled off together with the film layer 4, an appropriate method can be used in accordance with the form of formation of the film layer 44.
Is composed of a single tubular film material 42, the film layer 44 (film material 42)
However, if the film layer 44 is formed of a material having excellent extensibility, the film layer 44 is wound from the end thereof, stretched by being pulled in the roll axis direction, and peeled off, so that the skin layer 54 is formed together with the film layer 44. For example, if the film layer 44 is made of a film material 42 with low extensibility, the film layer 44 on the surface of the molded product 50 is After a cut notch extending in the axial direction and having a depth smaller than the thickness is provided at one or more positions in the circumferential direction, each of the film layers 44 separated in the circumferential direction by such cuts is provided. It is possible to adopt a method of peeling off the film layer 44 and the skin layer 54 on the entire peripheral surface of the roll by rolling up from the end and peeling off in the roll axis direction. Possible it is. Incidentally, in the above description, when the cut is provided in the film layer 44, a cut depth that is 20 to 80% of the thickness of the film layer 44 is suitably adopted.

According to the present invention, the molded article 5
When the film layer 44 is peeled off from the surface 0, it is desirable to perform a heat treatment on the film layer 44 prior to the operation, since this causes the film layer 44 to be softened and significantly deformed. Thus, the stripping workability can be effectively improved. It is needless to say that such a heat treatment is performed to such an extent that the film layer 44 cannot be melted, but generally, at a temperature of about 60 to 150 ° C.
It is carried out by holding for about 1 to 10 minutes.

Then, in this manner, the film layer 44
By removing the skin layer 54 constituting the surface of the sponge layer 48 of the molded article 50 by the peeling operation of the molded article 50, the cell 56 located immediately below the skin layer 54 is opened. As shown in the figure, a urethane sponge roll 60 according to the present invention is formed on the entire outer peripheral surface of the sponge layer 48, which has a structure in which the cells 56 are opened and has an extremely high cell opening ratio equivalent to a conventional polished product or the like. It is done.

The urethane sponge roll 60
In the above, in the foam molding process in forming the molded article 50 as a precursor, the film layer 44 is sufficiently pressed against the inner surface 40 of the molding cavity 38, so that high dimensional accuracy can be secured. Since the sponge layer 48 is formed by removing the skin layer 54 portion, a product with small dimensional variation can be advantageously produced. Further, the skin layer 54 portion (generally, about 1 to 100 μm) is obtained. By removing only the thickness)
In the cell 56 of the inner first layer composed of the relatively uniform cells 56 located directly under such a skin layer 54, the cell opening state on the roll surface is changed from the conventional cell opening state. This makes it possible to obtain a urethane sponge roll 60 in which the properties of the sponge layer 48 are enhanced, which is more uniform than a polished product or the like.

In addition, in such a urethane sponge roll 60, the core metal 36 is arranged in the molding die 30, and the film layer 44 is provided in the molding cavity 38. After the formation of the molded product 50, the obtained molded product 5 is simply obtained.
It can be formed very easily only by performing an operation of peeling the film layer 44 from the surface of the film layer 44 and the film layer 44 and the sponge layer 48 (skin layer 54) by foam molding.
Are bonded or adhered to each other with high strength, so that in the sponge layer 48 of the molded article 50, the skin layer 54 and the internal layer immediately below the skin layer 54 are relatively strongly bonded to each other. In this case, the peeling operation of the film layer 44 allows the skin layer 54 to be effectively peeled and removed. In short, according to the method of the present invention, the urethane sponge roll 60 having the above-mentioned excellent characteristics can be easily and advantageously produced in industrial production.

The surface cells 56 of the urethane sponge roll 60 obtained according to the present invention as described above.
In other words, the opening ratio of the roll 56, that is, the total area of the openings of the cells 56, is preferably at least 70% or more, preferably 80% or more, more preferably 90% or more. Accordingly, various characteristics required according to the use of the urethane sponge roll 60, such as toner transportability, supply property, carrying property, charging property, transfer property, etc., can be further improved. It can be demonstrated to a high degree. The opening diameter of the surface cell 56 is determined in consideration of the use of the urethane sponge roll 60.
It is appropriately determined. For example, it is adjusted to be 500 μm or less for a toner supply roll, 200 μm or less for a developing roll or a charging roll, and 300 μm or less for a transfer roll. .

Further, the urethane sponge roll 60
The degree of softness of the sponge layer 48 is appropriately determined according to the intended use. For example, in terms of hardness, in the case of a toner supply roll, the surface length is determined according to the measurement method shown in FIG. 5 of JP-A-9-274373. 50mm in direction 1
mm, the hardness is 350 g or less under a compressed load, and in the case of a developing roll or a charging roll,
A Asker C hardness of 20 to 70 degrees is desirable,
Further, in the transfer roll, the Asker C hardness is 40
An angle of 70 to 70 degrees is preferably used.

[0047]

EXAMPLES Hereinafter, some examples of the present invention will be described to clarify the present invention more specifically. However, the present invention imposes some restrictions by the description of such examples. It goes without saying that you don't receive anything. In addition, the present invention, in addition to the following examples, in addition to the above specific description, various modifications based on the knowledge of those skilled in the art, unless departing from the spirit of the present invention,
It should be understood that modifications, improvements and the like can be made.

First, 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 (a polyisocyanate manufactured by Sumitomo Bayer Urethane Co., Ltd., NCO%
= 45) By mixing 26.9 parts by weight, the intended polyurethane foam raw material was prepared.

On the other hand, using nitrile rubber (NBR),
By extrusion molding, four tube-shaped rubber molded articles having a thickness of 400 μm, an outer diameter of 16 mm, and an inner surface roughness of 2 μm were produced, and one of them was used as a No. 1 tube (42) as a film material. While preparing, the inner surfaces of the remaining three rubber molded bodies were further subjected to shot blasting, so that the inner surface roughness was 5 μm and 10 μm, respectively.
No. 2 as a film material, with a thickness of 20 μm.
Three or four tubes (42) were prepared.

Next, a pipe die (30) as shown in FIG. 3 is used as a molding die, and according to the present invention, a core metal (36) having an outer diameter of 5 mmφ is formed in the molding cavity (38).
And the inner surface (4) of the metal pipe (32) corresponding to the inner surface of the inner surface of the die on which the roll surface is provided.
0), the tubes (42) of Nos. 1 to 4 obtained above were fitted together, and a film layer (44) was formed with the tubes (42). Then, 6 g thereof is put into a molding cavity (38) of a pipe mold (30) heated to 50 ° C.
By holding in an oven at 50 ° C. for 30 minutes, foaming and curing were performed to obtain foam molded articles No. 1 to No. 4 (50), respectively. The inner diameter of the metal pipe (32) of the pipe type (30) used was 16
mm, and its axial length was 250 mm.

Further, after each molded product (50) thus obtained is taken out of the molding die (30),
It is stored in an oven at 80 ° C. for 10 minutes and heated, and then the film layer (44) on the surface of the molded product is rolled up from the end in the roll axis direction and slowly peeled off in the roll axis direction while being pulled. Depending on the sponge layer (4
8) A skin layer (5) having a thickness of 10 to 20 μm on the surface layer
4) In a state where the portion is brought into close contact with the film layer (44), the cell (56) immediately below the skin layer (54) as shown in FIG. Urethane sponge rolls (60) of Nos. 1-4 according to the present invention having openings in the surface were obtained.

Then, No. 1 to No. 1 thus obtained are obtained.
In each of the urethane sponge rolls (4) and (4), a cell (56) immediately below the skin layer (54) is opened on the entire surface on the outer peripheral surface of the roll, so that the surface cell aperture ratio is: As shown in Table 1 below,
It was recognized that the opening ratio of the surface cells (56) was high and the opening ratio of the surface cells (56) was high as well as that of a polished or cut product. Further, the hardness of the sponge layer (48) of each urethane sponge roll (60) is as shown in Table 1 below at a load value of 50 mm width and 1 mm compression.
As shown in FIG.

[0053]

[0054]

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. Urethane sponge rolls having a porous surface with a uniform surface cell diameter, which were difficult to realize with polished or cut products of the above, can be provided.Furthermore, urethane sponge rolls having such features can be provided in a simple operation. Therefore, it is possible to exhibit characteristics such as easy and inexpensive production.

The uniform opening of the surface cells makes it possible to use the urethane sponge roll obtained according to the present invention as a toner supply roll, so that unevenness in toner supply and scraping hardly occurs.
In addition, by using the developing roll, the toner carrying property is good and uniform, and there is a characteristic that image unevenness hardly occurs. Further, the charging roll exhibits uniform charging characteristics. Characteristics, such as the difficulty of appearing.

[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 (a) is a longitudinal sectional view showing an example of a mold used in the method for producing a urethane sponge roll according to the present invention, and FIG. 3 (b) is a view of the mold shown in FIG. 3 (a). FIG. 3 is an explanatory longitudinal sectional view showing a state in which a film layer is provided on an inner surface of a pipe constituting a molding cavity.

FIG. 4 is an explanatory view showing a molded article formed according to the present invention.

FIG. 5 is a partially enlarged cross-sectional explanatory view showing a state in which a film layer is peeled off from the surface of a molded article according to the present invention.

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 bar 38 Mold cavity 42 Film material 44 Film layer 48 Sponge layer 50 Molded product 54 Skin layer 56 Cell 60 Urethane sponge roll

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 31:32 B29L 31:32 F term (Reference) 4F202 AA42 AG20 AH04 CA01 CB01 CB11 CK09 CK15 4F204 AA42 AG20 AH04 EA01 EB01 EB11 EF05 EF27 EK24 EL22 EL25

Claims (6)

[Claims] 1. A state in which a predetermined cored metal is placed in a molding cavity of a molding die, and a thin film layer is provided on an inner surface of the molding cavity on a side where a roll surface is provided so as to cover the entire surface. Below, a urethane sponge raw material is supplied into the molding cavity and foamed, whereby a soft polyurethane sponge layer is integrally formed around the core metal and the film layer is integrally formed on the surface of the sponge layer. A step of preparing an existing molded article; and a step of peeling off the film layer from the surface of the molded article to open cells on the surface of the molded article to the outer peripheral surface. A method for producing a urethane sponge roll. 2. The urethane sponge roll according to claim 1, wherein the film layer is formed of a tube having the same outer diameter as the inner diameter of the inner surface of the molding cavity on which the roll surface is provided. Production method. 3. The surface roughness of the surface of the film layer on the side where the sponge layer is provided of the molded article: Rz.
3. The method for producing a urethane sponge roll according to claim 1, wherein the particle size is 3 to 20 μm. 4. The film layer has a thickness of 10 to 1000.
The method for producing a urethane sponge roll according to any one of claims 1 to 3, wherein the thickness is μm. 5. The method for producing a urethane sponge roll according to claim 1, wherein the total opening area of the cells occupies at least 70% or more of the outer peripheral surface of the roll. 6. The method for producing a urethane sponge roll according to claim 1, wherein the film layer is heated before peeling the film layer from the surface of the molded article.