JP2002172633A - Manufacturing method for foam roller and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an efficient manufacturing method for a foam roller without a skin layer on the surface, which is useful as a toner feeding roller or the like used for an image forming device, by an integral foam-molding method. SOLUTION: This foam roller has a rotating shaft, and a foam elastic body layer which is provided on the outer periphery of the rotating shaft. When such a foam roller is manufactured, a foam forming material is injected in a porous molding die in which the rotating shaft is set, and the foam forming material is expanded and hardened. Thus, the foam roller without the skin layer on the surface is manufactured.

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 provides a foam roller having no skin layer on a surface useful as a toner supply roller used in an image forming apparatus,
The present invention relates to a method for efficiently manufacturing an integrated foam molding method using a porous mold, 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 rotation shaft insertion hole is provided,
There is known a method of manufacturing a foamed roller having a predetermined size by inserting a rotary shaft into the adhesive and then performing surface processing. However, in this method, (1) a large number of man-hours are required until the surface processing, and (2) a cutting allowance is required to cut or grind the surface with a cutting tool or the like. (3) There is a problem that the blade used has a limited life, so that regular blade sharpening and dressing are 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. Since this method does not require cutting or grinding after demolding, it is superior in productivity to the above method. However,
In this method, a thin film generally called a skin layer is formed on the surface of the foamed elastic 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, Since the performance is hindered, it was necessary to remove the skin layer by polishing or the like. Therefore, development of a method in which a skin layer is not formed in the above integral foam molding method has been desired.

[0005]

SUMMARY OF THE INVENTION Under such circumstances, the present invention is to form a foam roller having no skin layer on the surface useful as a toner supply roller used in an image forming apparatus by an integral foam molding method. It is an object of the present invention to provide a method for efficiently manufacturing.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to achieve the above object, and as a result, used a porous mold as a mold, set a rotating shaft on the mold, and formed a foam. It has been found that the purpose can be achieved by casting and foam hardening the material. The present invention has been completed based on such findings. That is, the present invention
Rotary shaft, in manufacturing a foam roller having a foam elastic layer provided on the outer periphery thereof, in casting a foam-forming material into a porous mold in which the rotary shaft is set, and foam-curing. An object of the present invention is to provide a method for producing a foamed roller having no characteristic skin layer on its surface. The present invention also provides an image forming apparatus characterized in that a foam roller without a skin layer is mounted on the surface obtained by the above-mentioned production method.

[0007]

DETAILED DESCRIPTION OF THE INVENTION In the method of the present invention, a foam roller having a rotating shaft and a foamed elastic layer provided on the outer periphery thereof and having no skin layer on its surface is manufactured by an integral foam molding method. The foamed elastic layer in the foamed roller is not particularly limited, and may be any of a polyurethane foamed layer, a silicone rubber foamed layer, an EPDM foamed layer, and the like. A 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 in terms of performance and the like. In the production of this polyurethane foam roller, a polyurethane foam-forming material 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 is 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 prepolymer is not particularly limited, and examples thereof include polyether polyol, polyester polyol, and 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 method of the present invention, a porous mold is used as the mold. As the porous mold, a cylindrical mold made of a porous resin, ceramics or metal is preferable. When using a porous resin mold,
What has resistance to the foam forming material cast into it is used. When the foam-forming material is the above-mentioned polyurethane foam-forming material, as the porous resin mold, for example, a mold made of porous polypropylene, polyethylene, or the like is preferable. The method for producing the porous mold is not particularly limited. For example, in the case of manufacturing a porous resin mold, a resin fine powder such as polypropylene is put into a mold and raised to a temperature close to its melting point.
After the surfaces of the fine powders are melted and the powders are adhered to each other, the temperature is lowered, whereby the powders are solidified while the surfaces are adhered to each other, and a porous mold is obtained.

The pore size of the porous mold used in the present invention is selected in the range of preferably 50 to 400 μm, more preferably 100 to 250 μm. Further, the average pore diameter is preferably in the range of 2 to 600 μm, more preferably 50 to 300 μm. In the method for producing a foam roller according to the present invention, after setting a rotating shaft in the porous mold, a foam-forming material is cast and foam-cured to form a foam having no skin layer on the surface. Manufacture rollers. At this time, it is desirable to apply a fluorine-based or silicone-based release agent to the inner surface of the porous mold. Examples of the rotating shaft 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 magnesium alloy. Next, the method for manufacturing the foam roller of the present invention will be described with reference to an example in which the foam roller is a polyurethane foam roller.

First, after setting the rotating shaft in a porous cylindrical mold to which a fluorine-based or silicone-based release agent has been applied, a predetermined amount of the polyurethane foam-forming material is cast. 15-80 ° C, preferably 20-65 ° C
Start foaming at a temperature in the range Next, after the cavity in the mold is filled with the polyurethane foam, 70 to 12
The polyurethane foam roller having no skin layer on the surface is obtained by curing at a temperature of about 0 ° C., then removing the mold, and cutting to a desired size. The foam 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, a toner supply roller, and a cleaning roller. Although it can be used as a paper feed roller, it is particularly suitable as a toner supply roller. Further, the image forming apparatus of the present invention comprises a foam roller having no skin layer on the surface obtained by the above-described method of the present invention as the above-mentioned various members.

Next, an example in which the foam roller is mounted on an image forming apparatus as a toner supply roller will be described.
FIG. 1 is an explanatory diagram illustrating 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.
The developing roller 2 is disposed between the toner supply roller 3 according to the present invention and the image forming body 1 holding the electrostatic latent image with its outer peripheral surface being close to the surface of the image forming body 1, and The transfer roller 5 is formed on the formed body 1 via a recording medium 8 such as paper.
2 shows a structure in which abutment is performed. Toner supply roller 3,
By rotating the developing roller 2 and the image forming body 1 in the direction of the arrow, toner is supplied to the surface of the developing roller 2 by the toner supply roller 3, and is adjusted to a uniform thin layer by the layer regulating blade 4. The latent image adheres to the latent image on the formed body 1, and the latent image is visualized. Then, by generating an electric field between the image forming body 1 and the transfer roller 5, the toner image on the image forming body 1 is transferred to the recording medium 8.
A cleaning roller 6 removes toner remaining on the surface of the image forming body 1 after transfer. Reference numeral 7 denotes a charging roller.

[0017]

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. Production Example of Porous Molding Mold A fine powder of polypropylene is put into a molding mold, and the temperature is raised to 200 ° C. close to its melting point, and after the surface of the fine powder is melted, the temperature is lowered and solidified to obtain an inner diameter of 18 mm.
A 250 mm long porous polypropylene cylinder (pore diameter 30 to 200 μm, average pore diameter 100 μm) was obtained.

Example 1 The porous polypropylene cylinder obtained above, an iron shaft (diameter 6 mm, length 260 mm), and an upper lid and a lower lid provided with a shaft holding hole in the center were prepared. First,
Attach the lower lid to one opening of the polypropylene cylinder,
A cylindrical mold was set up with the shaft inserted into the shaft holding hole of the lower lid. Then, Preparation Example 1 was added to this cylindrical mold.
6.5 g of the polyurethane foam-forming material obtained in the above was injected from a foaming machine, and the upper lid was immediately attached to the cylindrical opening so that the end of the shaft could enter the hole for holding the shaft. 25
After foaming at 90 ° C for 90 seconds, it was cured at 90 ° C for 20 minutes. Then, after demolding, it was cut to a diameter of 18 mm and a length of 22 mm.
A polyurethane foam roller with a 0 mm shaft was made. This roller had no skin layer on the surface.

Comparative Example 1 The procedure of Example 1 was repeated, except that a SUS cylinder was used instead of the porous polypropylene cylinder. A polyurethane foam with a shaft having a diameter of 18 mm and a length of 220 mm was obtained. A body roller was produced. This roller had a thin skin layer formed on the entire surface.

[0020]

According to the present invention, a foam roller having no skin layer on its surface useful as a toner supply roller or the like used in an image forming apparatus can be efficiently manufactured by an integral foam molding method using a porous mold. can do.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an example of an image forming apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming body 2 Developing roller 3 Toner supply roller 4 Layer regulating blade 5 Transfer roller 6 Cleaning roller 7 Charging roller 8 Recording medium

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16C 13/00 F16C 13/00 Z 4F204 G03G 15/08 501 G03G 15/08 501A 15/16 103 15/16 103 21/10 B29K 75:00 // B29K 75:00 105: 04 105: 04 B29L 31:32 B29L 31:32 G03G 21/00 312 F term (reference) 2H032 AA05 BA23 2H034 BC01 BC03 2H077 AC04 AD06 AD13 FA13 FA22 3J103 AA02 AA13 AA32. AJ10 EA01 EB01 EB12

Claims (6)

[Claims] In producing a foam roller having a rotating shaft and a foamed elastic layer provided on the outer periphery thereof, a foam forming material is poured into a porous mold in which the rotating shaft is set, A method for producing a foamed roller having no skin layer on its surface, characterized by foaming and curing. 2. The method according to claim 1, wherein the foamed elastic layer is a polyurethane foam layer. 3. The method according to claim 1, wherein the porous molding die is a cylindrical member made of a porous resin, ceramics or metal. 4. The porous mold has a pore diameter of 50 to 400 μm.
The method for producing a foamed roller having no skin layer on its surface according to claim 1, 2 or 3. 5. The method according to claim 1, wherein the foam roller is a toner supply roller. 6. An image forming apparatus comprising a foam roller having no skin layer mounted on a surface obtained by the method according to claim 1.