JP2002166483A - Method for manufacturing foamed roller and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently manufacturing a foamed roller having no useful skin layer as a toner supply roller or the like used for an image forming apparatus, by removing the skin layer of the roller having the skin layer on a surface by a simple method. SOLUTION: The method for manufacturing the foamed roller comprises the steps of contacting a roller having a rotary shaft and a foamed elastic layer provided on an outer periphery of the shaft and having a skin layer on its surface with a heated hot plate, rotating the roller, and moving the roller or the plate to melt and remove the skin layer on the surface of the elastic layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a foam roller and an image forming apparatus. More specifically, the present invention removes the skin layer of a foamed roller having a skin layer on the surface by a simple method, and efficiently uses a foamed roller without a skin layer useful as a toner supply roller used in an image forming apparatus. The present invention relates to a method of manufacturing well and an image forming apparatus equipped with the foam roller obtained by this method.

[0002]

2. Description of the Related Art In recent years, with the progress of electrophotographic technology, image forming apparatuses such as a dry electrophotographic apparatus have been used for developing, transferring, and the like.
Polymer members have attracted attention as components for toner supply, cleaning, paper supply, and the like, and generally include developing rollers, transfer rollers, toner supply rollers, cleaning rollers, and paper supply rollers. It is used in the form of an elastic roller. For the polymer member used for these purposes, usually a polymer elastomer or foam such as rubber or polyurethane is used, and
These are required to have low hardness and not to contaminate the image forming body and the transfer material.

However, in order to reduce the hardness of rubber or polyurethane elastomers, it is necessary to incorporate a plasticizer such as dioctyl phthalate or an oil such as aroma oil, and as a result, does not contaminate the image forming body. It is difficult to meet the demand. Therefore, a foam obtained by foaming ethylene-propylene-diene rubber (EPDM) or silicone rubber with a foaming agent such as 4,4'-oxybis (benzenesulfonylhydrazide), or a polyurethane foamed with a foaming agent such as water or Freon is used. Advantageously, foams are used, in particular polyurethane foams.

Conventionally, as a method of manufacturing a foamed roller having a foamed elastic layer provided on the outer periphery of a rotating shaft, for example, a foamed roller which is foamed in a large block shape is cut and then formed into a prismatic shape close to a finished size. Next, a method is known in which a rotating shaft insertion hole is provided, a rotating shaft is inserted into the hole, and the surface is processed to produce a foamed roller having a predetermined size. However, in this method, (1) a large number of man-hours are required until the surface processing, and (2) a cutting allowance is required because the surface is cut or ground with a cutting tool or the like. (3) There is a problem that the blade used has a service life, so that regular blade sharpening or dressing is required. On the other hand, in the production of polyurethane foam rollers and the like, there is known an integral foam molding method in which a foam forming material is cast into a cylindrical mold having a rotating shaft set therein and foam-hardened. In this method,
Since no cutting or grinding is required after demolding, the productivity is superior to that of the above method. However, in this method, a thin film generally called a skin layer is formed on the surface of the foamed elastic material layer provided on the outer periphery of the rotating shaft. As a result, when the foamed roller is used as a toner supply roller, for example, However, there is a problem that its performance is hindered. Therefore, it has been desired to develop a method in which a skin layer is not formed in the above-mentioned integral foam molding method and a method in which the skin layer can be easily removed.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a toner supply roller for use in an image forming apparatus, in which a skin layer of a foamed roller having a skin layer on the surface is removed by a simple method. It is an object of the present invention to provide a method for efficiently producing a foamed roller without a skin layer, which is useful as such.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, a foamed roller having a skin layer on its surface is brought into contact with a heated hot plate. It has been found that the object can be achieved by rotating the roller or the hot plate while rotating the roller. The present invention has been completed based on such findings. That is, the present invention is to rotate a roller formed of a rotating shaft and a foamed elastic material layer having a skin layer on its surface provided on the outer periphery thereof, while being in contact with a heated hot plate and rotating the roller.
An object of the present invention is to provide a method for manufacturing a foamed roller, characterized in that a skin layer on the surface of a foamed elastic layer is melted and removed by moving the roller or the hot plate. Further, the present invention also provides an image forming apparatus equipped with the foam roller obtained by the above manufacturing method.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the method of the present invention, a roller composed of a rotating shaft and a foamed elastic layer provided on the outer periphery thereof and having a skin layer on its surface is used. The foamed elastic layer in this roller is not particularly limited, and may be a polyurethane foam layer, a silicone rubber foam layer, an EPDM
Any of a foam layer and the like may be used. For the toner supply roller, in particular, a polyurethane foam layer (a roller having a polyurethane foam layer provided on the outer periphery of a rotating shaft is hereinafter referred to as a polyurethane foam roller). ) Is preferable from the viewpoint of performance and the like. In the production of this polyurethane foam roller, as a polyurethane foam forming material,
Those containing a polyol component, a polyisocyanate component, a foaming agent, and a conductivity-imparting agent, a catalyst, a foam stabilizer and the like used as desired are used.

In the polyurethane foam-forming material, the polyol component and the polyisocyanate component may be contained in the form of a prepolymer obtained by reacting them. The polyol component used for producing the polyol or the prepolymer is not particularly limited, and examples thereof include a polyether polyol, a polyester polyol, and a hydrophobic polyol. Here, as the polyether polyol, a polyol obtained by addition-polymerizing ethylene oxide or propylene oxide to glycerin or the like, or a polyol such as polytetramethylene glycol, ethylene glycol, propanediol, or butanediol is preferably used. As the polyester polyol, a condensation-based polyester polyol obtained by condensation of a dicarboxylic acid and a diol or a triol, a lactone-based polyester polyol obtained by ring-opening polymerization of a lactone based on a diol or a triol, and a polyether polyol having a lactone terminal. A polyol such as an ester-modified ester-modified polyol is preferably used. Further, as the hydrophobic polyol, polyisoprene polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, or the like is used. These polyol components may be used alone or in combination of two or more.

On the other hand, the polyisocyanate component used for producing a polyisocyanate or a prepolymer includes tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate (crude MDI), isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate; Examples include hydrogenated tolylene diisocyanate; polyisocyanates having no unsaturated bond such as hexamethylene diisocyanate, and modified products thereof with isocyanurate, carbodiimide, glycol, and the like. These polyisocyanate components may be used alone or in combination of two or more.

Next, as the foaming agent, taking into account the ease of handling in the manufacturing process, the ease of vaporization and foaming, etc.,
Generally, a physical foaming agent having a boiling point in the range of 20 to 60 ° C is preferably used. When this foaming agent is used as a raw material of a polyurethane foam, it is difficult to obtain a stable flow rate by using a foaming agent alone and to obtain a stable flow rate with a foaming machine. It is advantageous. Examples of such a foaming agent include n-pentane, isopentane, cyclopentane, methylene chloride, Freon 134a (1,1,1,2-tetrafluoroethane), and Freon 245fa (1,1,1,1).
3,3-pentafluoropropane), CFC 365mf
c (1,1,1,3,3-pentafluorobutane), Freon 356, Freon 141b (1,1-dichloro-1-
Fluoroethane), Freon 142b (1-chloro-1,
1-difluoroethane), Freon 22 (chlorodifluoromethane), and water. These may be used alone or in combination of two or more.

Next, in the polyurethane foam forming material of the present invention, carbon black, an ionic conductive agent, and the like can be used as the conductivity imparting agent if desired. Examples of carbon black include gas black such as electrified black, Ketjen black, and acetylene black, oil furnace black including ink black, thermal black, channel black, and lamp black. As the ion conductive agent,
For example, tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium such as lauryltrimethylammonium, octadecyltrimethylammonium such as stearyltrimethylammonium,
Perchlorates, chlorates, hydrochlorides, bromates, such as hexadecyltrimethylammonium, benzyltrimethylammonium, modified aliphatic dimethylethylammonium,
Ammonium salts such as iodate, borofluoride, sulfate, alkyl sulfate, carboxylate and sulfonate; perchlorates of alkali metals or alkaline earth metals such as lithium, sodium, calcium and magnesium Chlorate, hydrochloride, bromate, iodate, borofluoride, trifluoromethyl sulfate, sulfonate and the like.

These conductivity-imparting agents may be used alone or in combination of two or more. The amount is not particularly limited and is appropriately selected according to various situations. Usually, the amount is 0.1 to 100 parts by weight of the polymer material.
４０40 parts by weight, preferably 0.3-20 parts by weight. In addition, a filler-based conductive agent such as a metal powder and a metal oxide powder can be added together with the carbon black and the ionic conductive agent. Further, in the polyurethane foam forming material, as a catalyst optionally used, for example, organometallic catalysts such as dibutyltin dilaurate, dibutyltin diacetate, stannas octoate, dibutyltin marker butide, dibutyltin thiocarboxylate, and dibutyltin dimaleate Neat, dioctyltin marker butide, dioctyltin thiocarboxylate, phenylmercury, silver propionate, tin octenoate, amine-catalyzed triethylamine, N, N, N'N'-tetramethylethylenediamine, triethylenediamine, N
-Methylmorpholine, dimethylaminoethanol, bis (2-dimethylaminoethyl) ether, 1,8-diazabicyclo (5,4,0) -undecene-7 and the like are preferably used. These catalysts may be used alone,
Two or more kinds may be used in combination.

Further, in the polyurethane foam-forming material, as the foam stabilizer optionally used, for example, polyether silicone oil, nonionic surfactant, ionic surfactant and the like can be mentioned. Or two or more of them may be used in combination.
In the production of the polyurethane foam roller, for example, the polyurethane foam forming material is foamed and cured in a cylindrical mold in which a rotation shaft is set, and has a rotation shaft and a polyurethane foam layer provided on the outer periphery thereof. Manufacture rollers. As the foam hardening conditions, foaming is started usually at a temperature in the range of 15 to 80 ° C., preferably 20 to 65 ° C., and after the voids in the mold are filled with the polyurethane foam, the temperature is reduced to about 70 to 120 ° C. Do the cure. Next, the polyurethane foam roller is obtained by removing the mold and cutting it to a desired size.

The material of the cylindrical mold used in the above-mentioned method is not particularly limited, and a metal or resin material conventionally used in the production of a polyurethane foam roller can be used. (SUS)
Is preferred. If desired, a coating layer made of a fluororesin or the like may be provided on the inner surface of the cylindrical mold, or a known silicone-based or fluorine-based release agent may be applied. Examples of the rotating shaft constituting the foam roller in the method of the present invention include a metal member obtained by plating a steel material such as sulfur free-cutting steel with zinc or the like, and a metal member such as aluminum, stainless steel, and a magnesium alloy. Can be

In the foam roller manufactured in this way, a skin layer is formed on the surface of the polyurethane foam layer in which the polyurethane is in a dense state having substantially no voids. Removes the skin layer by the following method. In the method of the present invention, a rotating shaft and a roller formed of a foamed elastic material layer provided on the outer periphery thereof and having a skin layer on its surface are rotated by bringing the roller into contact with a heated hot plate and rotating the roller. By moving the roller or the hot plate in accordance with the above, the skin layer on the surface of the foamed elastic material layer is melted and attached to the hot plate and removed. The material of the hot plate used in this method is not particularly limited as long as it has thermal conductivity and has a certain degree of mechanical strength at the operating temperature, and various materials can be used. , For example, iron,
Examples thereof include metals such as stainless steel, copper, brass, aluminum and alloys thereof, and glass, ceramics, and heat-resistant cloths. The shape of the hot plate is not particularly limited, and any of a flat plate, a drum, and the like can be used.

As a specific method for removing the skin layer, for example, a heated flat plate-like hot plate is fixed, and a foam roller having a skin layer on its surface is brought into contact with the hot plate, and the rotation speed is reduced. By moving the rollers together,
The skin layer on the surface of the foamed elastic material layer can be melted and attached to a hot plate and removed. The flat hot plate can be used repeatedly by scraping and removing the fused skin layer with a scraping knife. FIG. 1 is an explanatory view showing an example of a method for removing a surface skin layer of a foamed roller using a fixed flat hot plate. FIG.
(A), a foamed roller 1 having a skin layer on the surface thereof is brought into contact with a heated flat plate-shaped hot plate 2 and is moved on the flat plate-shaped hot plate 2 while rotating; A method is described in which the surface skin layer of No. 1 is melted and adhered to a flat hot plate and removed.

FIG. 1B shows that the skin layer 4 fused on the flat hot plate 2 is scraped off with a scraping knife 3 and removed from the flat hot plate 2. How to play is shown. Reference numeral 1 'denotes a foam roller from which the surface skin layer has been removed. Further, a heating drum is used as a hot plate, and a foam roller having a surface skin layer is brought into contact with the drum and rotated, and the heating drum is also rotated to melt the skin layer and adhere to the heating drum. A removing method can be used. In this method, by bringing the scraping knife into contact with the rotating heating drum, it is possible to continuously scrape and remove the skin layer fused and adhered on the drum. This method is more excellent in mass productivity than the above method.

FIG. 2 is an explanatory view showing an example of a method for removing a skin layer from the surface of a foam roller by using a heating drum. The heating roller 5 includes a foam roller 1 having a surface skin layer. A method is shown in which the heating drum 5 and the foam roller 1 are brought into contact with each other, and the surface skin layer of the foam roller 1 is melted and removed. The skin layer 4 melt-adhered to the surface of the heating drum 5 is continuously scraped off by the scraping knife 3 and removed. Further, in the present invention, a band-shaped heat-resistant member such as a metal foil such as aluminum foil or a heat-resistant cloth is heated by a method such as contacting with a heating drum, and a foam roller having a skin layer on the surface thereof is contacted. While rotating, the foam roller or the belt-shaped heat-resistant member may be moved to melt the skin layer and adhere to the belt-shaped heat-resistant member.

FIG. 3 is an explanatory view showing an example of a method of removing the skin layer on the surface of the foamed roller by using the belt-shaped heat-resistant member. The foamed roller 1 having the surface skin layer is brought into contact with the belt-shaped heat-resistant member 6, the heating drum 5 and the foamed roller 1 are rotated together, and the belt-shaped heat-resistant member 6 is moved together with the rotation of the heating drum 5. Discloses a method of melting the surface skin layer of the foamed roller 1 and attaching it to the belt-shaped heat-resistant member 6 to remove the same. In this case, the belt-shaped heating member used as the hot plate is disposable,
The step of removing the melted deposit 4 is not required. The hot plate can be subjected to a coating process using a fluorine-based resin such as polytetrafluoroethylene, a silicone-based resin, or the like in order to easily scrape off the skin layer that has been melt-adhered.

The temperature of the hot plate may be any temperature at which the skin layer can be melted and removed, and is determined according to the type of the foamed elastic layer, and is usually selected in the range of 200 to 400 ° C. If the temperature is lower than 200 ° C., the skin layer may be insufficiently melted and removed. If the temperature is higher than 400 ° C., the skin layer is fused to the hot plate, and the skin layer peeled off from the surface of the foamed elastic layer is decomposed. As a result, there may be a case where gasification and smoking occur. For this reason, when the foamed elastic layer is a polyurethane foam layer, the preferable temperature of the hot plate is 230 to 30.
0 ° C, more preferred temperature is in the range of 240-270 ° C. In the method of the present invention, the pressing force when the foam roller having the skin layer on the surface is brought into contact with the heated hot plate is usually 0.02 to 0.2 mN, preferably 0.1 to 0.2 mN.
The range is from 03 to 0.1 mN. The moving speed of the foam roller or the hot plate substantially corresponds to the rotation speed of the foam roller, and is usually 10 to 100 mm / sec, preferably 30 to 60 mm / sec.
mm / sec.

The foamed roller having no skin layer on the surface produced by the method of the present invention can be used for various members for an image forming apparatus such as an electrophotographic apparatus and an electrostatic recording apparatus, for example, a developing roller, a transfer roller and a toner supply roller. It can be used as a cleaning roller, a paper feed roller, and the like. Particularly, when it is used for a toner supply roller, it can supply a stable toner, which is preferable. Further, the image forming apparatus of the present invention includes:
A foam roller having no skin layer on the surface obtained by the method of the present invention described above is mounted as the various members described above. Next, an example in which the foam roller is mounted on an image forming apparatus as a toner supply roller will be described.

FIG. 4 is an explanatory view showing an example of an electrophotographic image forming apparatus in which a foam roller having no skin layer on the surface obtained by the method of the present invention is mounted as a toner supply roller. Developing roller 12 between toner supply roller 13 according to the present invention and image forming body 11 holding an electrostatic latent image;
Is disposed with its outer peripheral surface close to the surface of the image forming body 11, and the recording medium 1 such as paper is attached to the image forming body 11.
8 shows a structure in which the transfer roller 15 is brought into contact with the transfer roller 8. The toner is supplied to the surface of the developing roller 12 by the toner supply roller 13 by rotating the toner supply roller 13, the developing roller 12, and the image forming body 11 in the direction of the arrow, and is adjusted to a uniform thin layer by the layer regulating blade 14. Thereafter, the latent image adheres to the latent image on the image forming body 11, and the latent image is visualized. Then, by generating an electric field between the image forming body 11 and the transfer roller 15, the toner image on the image forming body 11 is transferred to the recording medium 18. Reference numeral 16 denotes a cleaning roller which removes toner remaining on the surface of the image forming body 11 after transfer. Reference numeral 17 denotes a charging roller.

[0023]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Preparation Example 1 70 parts by weight of a polyether polyol having an average molecular weight of 5,000 and a number of functional groups of 3; 30 parts by weight of a styrene graft type polymer polyol;
3 parts by weight, 0.2 part by weight of N-methylmorpholine,
1.5 parts by weight of water, 1.5 parts by weight of silicone foam stabilizer and 50 parts by weight of TDI-80 / polymeric MDI
A polyurethane foam-forming material was prepared by blending an isocyanate of / 50 at an index of 105. In a free foaming experiment in a cup, which was separately performed, the polyurethane foam-forming material started foaming at 25 ° C. for 10 seconds after stirring and pouring, and completed foaming in 90 seconds. The density at that time was 0.10 g / milliliter.

Example 1 A SUS cylinder having an inner diameter of 18 mm and a length of 250 mm, a diameter of 6 m
m, an iron shaft having a length of 260 mm, an upper lid and a lower lid provided with a shaft holding hole at the center. First, SU
A lower lid was attached to one opening of the S-made cylinder, and a cylindrical mold was set up with a shaft inserted into a shaft holding hole of the lower lid. Next, 6.5 g of the polyurethane foam-forming material obtained in Preparation Example 1 was poured into the cylindrical mold from a foaming machine.
The upper lid was immediately attached to the cylindrical opening so that the end of the shaft could enter the shaft holding hole. After foaming at 25 ° C. for 90 seconds, it was cured at 90 ° C. for 20 minutes. Next, after the mold was released, it was cut to produce a polyurethane foam roller with a shaft having a diameter of 18 mm and a length of 220 mm. This roller had a thin skin layer formed on the entire surface. Next, the polyurethane foam roller was brought into contact with an iron plate coated with polytetrafluoroethylene heated to 250 ° C. with a pressing force of 0.06 mN, and moved at a speed of 40 mm / sec while rotating. As a result, the surface skin layer of the foam roller could be easily removed. Further, the skin layer fused to the iron plate could be easily scraped off with a scraping knife and removed.

[0025]

According to the present invention, a foamed roller having a skin layer on the surface is removed by a simple method, and the foamed roller without a skin layer is useful as a toner supply roller used in an image forming apparatus. The body roller can be manufactured efficiently.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of a method of removing a surface skin layer of a foam roller using a fixed flat hot plate.

FIG. 2 is an explanatory view showing an example of a method for removing a surface skin layer of a foamed roller using a heating drum.

FIG. 3 is an explanatory view showing an example of a method for removing a skin layer on the surface of a foamed roller using a belt-shaped heat-resistant member.

FIG. 4 is an explanatory diagram illustrating an example of the image forming apparatus of the present invention.

[Explanation of symbols]

 1. Foam roller having a skin layer on its surface 1 'Foam roller from which surface skin layer has been removed 2 Flat hot plate 3 Scrape knife 4 Fused skin layer 5 Heating drum 6 Strip heat resistant member 11 Image forming body 12 Developing roller 13 Toner supply roller 14 Layer regulating blade 15 Transfer roller 16 Cleaning roller 17 Charging roller 18 Recording medium

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/16 103 G03G 15/16 103 4F213 21/10 B29K 75:00 // B29K 75:00 B29L 31: 32 B29L 31:32 G03G 21/00 312 F term (reference) 2H032 AA05 BA23 2H034 BC01 BC03 2H077 AC04 AD06 AD13 EA16 FA13 FA22 3J103 BA41 EA11 EA20 FA15 GA02 GA57 GA58 HA03 HA12 HA18 4F212 AA31 AA02A03 A03 AG03 UA15 UB01 UW10 4F213 AA31 AA42 AD03 AD18 AD20 AG03 AH04 AJ02 AJ11 AR06 WA12 WA38 WA67 WA83 WB01 WK05

Claims (10)

[Claims] 1. A roller comprising a rotating shaft and a foamed elastic material layer provided on the outer periphery thereof and having a skin layer on its surface is rotated while being brought into contact with a heated hot plate.
A method for producing a foamed roller, wherein a skin layer on the surface of the foamed elastic layer is melted and removed by moving a roller or a hot plate. 2. The method according to claim 1, wherein the elastic foam layer having a skin layer on the surface is a polyurethane foam layer. 3. The method for producing a foam roller according to claim 1, wherein the temperature of the hot plate is 200 to 400 ° C. 4. The method for producing a foam roller according to claim 1, wherein the hot plate has a flat plate shape. 5. The method for producing a foamed roller according to claim 1, wherein the hot plate has a drum shape. 6. The heat plate is a belt-shaped heat-resistant member.
5. The method for producing a foamed roller according to any one of the above items 5. 7. The method for manufacturing a foamed roller according to claim 6, wherein the belt-shaped heat-resistant member is a metal foil. 8. The method of manufacturing a foam roller according to claim 1, wherein the hot plate has a surface coated with a fluorine-based resin or a silicone-based resin. 9. The method for producing a foam roller according to claim 1, wherein the foam roller is a toner supply roller. 10. An image forming apparatus equipped with a foam roller obtained by the production method according to claim 1.