JP2002310136A - Manufacturing method of foaming body roller and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a foaming body roller of stabilized quality without requiring a long drying line, and to provide an image forming device provided with the foaming roller manufactured by this method. SOLUTION: When providing a solid layer formed of one or more resin layers in a surface of an elastic layer of the foaming body roller having the elastic layer formed of a foaming body layer or a foaming body layer and a skin layer, at least one layer of the resin layers is formed by coating a ultraviolet curing type resin for curing to manufacture the foaming body roller. The foaming body roller manufactured by this method is installed in the image forming device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a foam roller suitably used in an electrophotographic apparatus such as a copying machine, a facsimile, a printer and the like, and an image forming apparatus equipped with the foam roller manufactured by the method. It concerns the device.

[0002]

2. Description of the Related Art In recent years, with the progress of electrophotography technology, image forming apparatuses such as dry electrophotographic apparatuses use polymer elastic members as a charging roller, a developing roller, a transfer roller, a paper feed roller, and a toner supply roller. The rollers used, especially foamed rollers having an elastic layer made of a low-hardness polymer elastic foam, are widely used. However, since the elastic layer made of a low-hardness polymer elastic foam has a relatively large coefficient of friction, the toner tends to thermally and physically adhere to the surface.
Therefore, there is a problem that toner filming occurs and sufficient chargeability cannot be obtained, and the image quality decreases as the number of images increases. On the other hand, a solid layer is provided on the surface of the elastic layer to lower the friction coefficient. In addition, improvement of surface strength with extension of machine life,
For the purpose of improving the surface smoothness and imparting electrical characteristics to the surface, it has been practiced to provide a solid layer on the surface.

As a method of providing the solid layer, there are a method of covering the tube after forming the elastic layer and a method of setting the tube in a cylindrical mold in advance and integrally forming the elastic layer and the solid layer. These methods require a separate step for forming the tube, and the method of covering the tube after forming the elastic layer requires that technical issues such as adhesion between the tube and the elastic layer be solved, In the method of integrally molding with the above, there are problems in terms of quality and cost, such as complicated mold structure and easy wrinkling. As a method for solving these problems, there is a method of providing a solid layer by surface coating after forming the elastic layer, but is dried and cured by hot or hot air after dipping or spraying a roller in a solvent-based or water-based paint. With the conventional method of surface painting,
Since a long drying time is required, mass production requires a long drying line and the solid layer of the roller requires delicate conductivity and surface condition from the application, so the temperature distribution in the drying line, There were problems in cost and quality, such as variations in air volume greatly affecting performance.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and does not require a long drying line.
Moreover, it is an object of the present invention to provide a method of manufacturing a foam roller having stable quality and an image forming apparatus equipped with the foam roller manufactured by the method.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above object can be achieved by applying a UV-curable resin and curing it to form a resin layer. The present invention has been reached. That is, the present invention, when providing a solid layer consisting of one or more resin layers on the surface of the elastic layer of a foam roller having an elastic layer consisting of a foam layer or a foam layer and a skin layer, at least the resin layer An object of the present invention is to provide a method for manufacturing a foam roller, in which one layer is formed by applying and curing an ultraviolet curable resin, and an image forming apparatus equipped with a foam roller manufactured by the method.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, polyurethane foam, silicone rubber foam,
Ethylene propylene rubber foam, nitrile butadiene rubber foam, urethane rubber foam, and the like.
Of these, polyurethane foam is preferred. As the polyisocyanate constituting the polyurethane raw material, an aromatic isocyanate or a derivative thereof, an aliphatic isocyanate or a derivative thereof, and an alicyclic isocyanate or a derivative thereof are used. Of these, aromatic isocyanates or derivatives thereof are preferable, and tolylene diisocyanate or derivatives thereof, diphenylmethane diisocyanate or derivatives thereof are particularly preferably used. As tolylene diisocyanate or its derivative, crude tolylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-
Tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, a urea-modified product, a buret-modified product, a carbodiimide-modified product thereof, and the like are used.

[0007] As diphenylmethane diisocyanate or its derivative, for example, diphenylmethane diisocyanate or its derivative obtained by phosgenating diaminodiphenylmethane or its derivative is used. Examples of the derivative of diaminodiphenylmethane include polynuclear substances, and pure diphenylmethane diisocyanate obtained from diaminodiphenylmethane, and polymeric diphenylmethane diisocyanate obtained from a polynuclear substance of diaminodiphenylmethane can be used. As for the number of functional groups of polymeric diphenylmethane diisocyanate, a mixture of pure diphenylmethane diisocyanate and polymeric diphenylmethane diisocyanate having various functional groups is used, and the average number of functional groups is preferably 2.05 to 4.00, more preferably 2. 50-3.5
0 is used. Derivatives obtained by modifying these diphenylmethane diisocyanates or derivatives thereof, for example, urethane modified products modified with polyols and the like,
A dimer, isocyanurate-modified product, carbodiimide / uretonimine-modified product, allohanate-modified product, urea-modified product, and buret-modified product can also be used. In addition, several kinds of diphenylmethane diisocyanates and derivatives thereof can be used by blending.

[0008] Polyol components constituting polyurethane raw materials include polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide, polytetramethylene ether glycol, polyester polyol obtained by condensing an acid component and a glycol component, and caprolactone by ring-opening polymerization. Polyester polyol, polycarbonate diol and the like can be used. Polyether polyols obtained by addition polymerization of ethylene oxide and propylene oxide include, for example, water, propylene glycol, ethylene glycol, glycerin, trimethylolpropane, hexanetriol, triethanolamine, diglycerin, pentaerythritol, ethylenediamine, methylglucode, Starting materials are aromatic diamines, sorbitol, sucrose, phosphoric acid, and the like, and examples of addition polymerization of ethylene oxide and propylene oxide include water, propylene glycol, ethylene glycol, glycerin, trimethylolpropane, and the like. Those using hexanetriol as a starting material are preferred. Regarding the ratio of ethylene oxide to propylene oxide and the microstructure to be added, the ratio of ethylene oxide is preferably from 2 to 95% by weight, more preferably from 5 to 90% by weight. Those having ethylene oxide added to the terminal are preferably used. Also, the arrangement of ethylene oxide and propylene oxide in the molecular chain is preferably random.

The molecular weight of this polyether polyol is
When water, propylene glycol or ethylene glycol is used as a starting material, it becomes bifunctional and has a weight average molecular weight of 30.
It is preferably in the range of 0 to 6000, particularly 400 to 3
000 is preferred. When glycerin, trimethylolpropane, or hexanetriol is used as a starting material, the compound becomes trifunctional and has a weight average molecular weight of 900 to 900.
It is preferably in the range of 9000, particularly 1500 to 60
A range of 00 is preferred. In addition, a bifunctional polyol and a trifunctional polyol can be appropriately blended and used.

The polytetramethylene ether glycol is obtained, for example, by cationic polymerization of tetrahydrofuran, and those having a weight average molecular weight of 400 to 4000, particularly preferably 650 to 3000 are preferably used. It is also preferable to blend polytetramethylene ether glycols having different molecular weights. further,
Polytetramethylene ether glycol obtained by copolymerizing an alkylene oxide such as ethylene oxide or propylene oxide can also be used. It is also preferable to use a polytetramethylene ether glycol and a polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide,
In this case, polytetramethylene ether glycol,
The ratio of polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide is 9 by weight.
It is preferably used so as to be in the range of 5: 5 to 20:80, particularly preferably in the range of 90:10 to 50:50. Further, together with the polyol component, a polymer polyol obtained by modifying the polyol with acrylonitrile, a polyol obtained by adding melamine to the polyol, a diol such as butanediol, a polyol such as trimethylolpropane, or a derivative thereof can be used in combination.

The polyol may be pre-polymerized with a polyisocyanate in advance. The method is as follows. The polyol and the polyisocyanate are placed in an appropriate container and sufficiently stirred at 30 to 90 ° C., more preferably 40 to 90 ° C.
~ 70 ° C for 6-240 hours, more preferably 24-7
There is a method of keeping the temperature for 2 hours.

Examples of the catalyst used for the curing reaction of the polyurethane raw material include monoamines such as triethylamine and dimethylcyclohexylamine, diamines such as tetramethylethylenediamine, tetramethylpropanediamine and tetramethylhexanediamine, pentamethyldiethylenetriamine and pentamethyldipropylene. Triamines such as triamine and tetramethylguanidine; cyclic amines such as triethylenediamine, dimethylpiperazine, methylethylpiperazine, methylmorpholine, dimethylaminoethylmorpholine and dimethylimidazole; dimethylaminoethanol, dimethylaminoethoxyethanol and trimethylaminoethylethanolamine , Methylhydroxyethylpiperazine, hydroxyethylmorpholine and other alcohols Min, bis (dimethylaminoethyl) ether, ethylene glycol bis (dimethyl)
Ether amines such as aminopropyl ether, stannas octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin marker, dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin marker, dioctyltin thiocarboxylate, phenylmercurypropion And organometallic compounds such as lead octenoate. These catalysts may be used alone or in combination of two or more.

When the foam roller of the present invention is a conductive roller, a conductive material is added to the foam material. The conductive material includes an ionic conductive material and an electronic conductive material. The conductive material added to the foam raw material is not limited, but it is preferable to use an ionic conductive material. Examples of the ion conductive material include dodecyltrimethylammonium such as tetraethylammonium, tetrabutylammonium, and lauryltrimethylammonium, hexadecyltrimethylammonium,
Ammonium perchlorate, chlorate, hydrochloride, bromate, iodate, borofluoride, octadecyltrimethylammonium such as stearyltrimethylammonium, benzyltrimethylammonium, modified aliphatic dimethylethylammonium, Organic ion conductive materials such as sulfates, alkyl sulfates, carboxylates, sulfonates; alkali metal or alkaline earth metal perchlorates such as lithium, sodium, calcium, and magnesium;
Inorganic ion conductive materials such as chlorate, hydrochloride, bromate, iodate, borofluoride, trifluoromethyl sulfate and sulfonate can be used. Examples of the electronic conductive material include conductive carbon black such as Ketjen black and acetylene black; SAF, ISAF, HAF, FE
Carbon black for rubber such as F, GPF, SRF, FT, MT; carbon black for ink such as carbon oxide black, pyrolytic carbon black, graphite; conductive metal oxide such as tin oxide, titanium oxide, zinc oxide; nickel Whisker such as carbon whisker, graphite whisker, titanium carbide whisker, conductive potassium titanate whisker, conductive barium titanate whisker, conductive titanium oxide whisker, conductive zinc whisker, etc. . By adding the conductive material, the volume resistivity of the foam roller of the present invention can be adjusted.

[0014] In addition to the above-mentioned conductive materials, fillers such as inorganic carbonates, foam stabilizers such as silicone foam stabilizers and various surfactants, and antioxidants such as phenol and phenylamine are used in the foam materials such as polyurethane materials. Agents, low friction agents, charge control agents and the like can be added. As the silicone foam stabilizer, a dimethylpolysiloxane-polyoxyalkylene copolymer or the like is suitably used, and those comprising a dimethylpolysiloxane portion having a molecular weight of 350 to 15,000 and a polyoxyalkylene portion having a molecular weight of 200 to 4000 are particularly preferable.
The molecular structure of the polyoxyalkylene moiety is preferably an ethylene oxide addition polymer or a co-addition polymer of ethylene oxide and propylene oxide, and it is also preferable that the molecular terminal is ethylene oxide. Examples of the surfactant include cationic surfactants, anionic surfactants, ionic surfactants such as amphoteric surfactants, and nonionic surfactants such as various polyethers and various polyesters. The amount of the silicone foam stabilizer and various surfactants is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the foam raw material.

As a method for producing the foam roller, there are a mechanical floss method, a water foaming method, a foaming agent floss method and the like. To manufacture a foam roller by mecarcal floss, a metal shaft or the like is placed in advance, and a foam material that has been foamed by mechanical stirring is injected into a preheated inner cylindrical mold, and reaction hardening is performed. Alternatively, the raw material of the foam may be injected into a mold, and may be reactively hardened while mixing an inert gas and adding mechanical stirring. here,
The inert gas used in the mechanical floss method may be, for example, in the case of a polyurethane reaction, an inert gas in the polyurethane reaction. In addition to inert gases in a narrow sense such as helium, argon, xenon, radon, and krypton,
Gases that do not react with the polyisocyanate, such as nitrogen, carbon dioxide, and dry air, may be used. The foam roller obtained by such a method is a foam roller in which a skin layer is formed in a portion in contact with a mold, and the method of the present invention employs an elastic layer comprising the foam layer and the skin layer. This method is applied when a solid layer composed of one or more resin layers is provided on the surface of the elastic layer composed of only the foam layer obtained by polishing the skin layer.

According to the method of manufacturing a foam roller of the present invention, there is provided a foam roller having an elastic layer comprising a foam layer or a foam layer and a skin layer. When a solid layer is formed, at least one of the resin layers is formed by applying and curing an ultraviolet curable resin. The thickness of the solid layer is suitably from 10 to 500 μm, preferably from 50 to 300 μm, for the purpose of improving the strength of the surface, and the electrical properties of the surface (interface) or prevention of toner adhesion. When the purpose is to improve physical properties, it is 1 to 50 μm, preferably 5 to 50 μm.
It is appropriate to set it to 30 μm. The UV-curable resin is not particularly limited, but a (meth) acrylate-based UV-curable resin composition containing a (meth) acrylate oligomer and a UV polymerization initiator is suitable. Such (meth) acrylate oligomers include:
For example, epoxy (meth) acrylate oligomer, urethane (meth) acrylate oligomer, ether (meth) acrylate oligomer, ester (meth)
Acrylate oligomer, polycarbonate (meta)
Acrylate oligomers and the like can be mentioned.

The above (meth) acrylate oligomer is
Reaction of compounds such as polyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, bisphenol A type epoxy resin, phenol novolak type epoxy resin, adduct of polyhydric alcohol and ε-caprolactone with (meth) acrylic acid Alternatively, it can be synthesized by urethane-forming a polyisocyanate compound and a (meth) acrylate compound having a hydroxyl group. As an example of the epoxy (meth) acrylate oligomer, any reaction product of a compound having a glycidyl group and (meth) acrylic acid may be used. Among them, a benzene ring, a naphthalene ring,
A reaction product of a compound having a cyclic structure such as a spiro ring, dicyclopentadiene, and tricyclodecane and having a glycidyl group and (meth) acrylic acid is preferred. The urethane (meth) acrylate oligomer is obtained by urethane-forming a polyol, an isocyanate compound and a (meth) acrylate compound having a hydroxyl group. As the polyol and isocyanate compound,
The same materials as those exemplified as constituting the polyurethane foam raw material as the foam raw material can be used.

Further, the ether (meth) acrylate oligomer, the ester (meth) acrylate oligomer and the polycarbonate (meth) acrylate oligomer include a corresponding polyol (polyether polyol, polyester polyol and polycarbonate polyol) and (meth) It can be obtained by reaction with acrylic acid. As the polyol, those similar to those exemplified as constituting the polyurethane foam raw material as the foam raw material can be used. A reactive diluent having a polymerizable double bond is added to the ultraviolet-curable resin composition for viscosity adjustment, if necessary. Examples of such a reactive diluent include monofunctional, bifunctional or polyfunctional polymerizable compounds having a structure in which (meth) acrylic acid is bonded to a compound containing an amino group or a hydroxyl group by an esterification reaction and an amidation reaction. Can be used. These diluents
It is usually preferred to use 10 to 200 parts by weight per 100 parts by weight of the (meth) acrylate oligomer (A).
When the foam roller of the present invention is a conductive roller, it is preferable to add a conductive material to the ultraviolet curable resin, and as the conductive material, those exemplified as the conductive material to be added to the foam raw material can be used.

As the UV polymerization initiator, known ones can be used, for example, 4-dimethylaminobenzoic acid, 4-dimethylaminobenzoic acid ester, 2,2-
Dimethoxy-2-phenylacetophenone, acetophenone diethyl ketal, alkoxyacetophenone, benzyldimethyl ketal, benzophenone and 3,3-
Benzophenone derivatives such as dimethyl-4-methoxybenzophenone, 4,4-dimethoxybenzophenone, 4,4-diaminobenzophenone, alkyl benzoylbenzoate, bis (4-dialkylaminophenyl) ketone,
Benzyl derivatives such as benzyl and benzyl methyl ketal, benzoin derivatives such as benzoin and benzoin isobutyl ether, benzoin isopropyl ether,
2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, xanthone,
Thioxanthone and thioxanthone derivatives, fluorene, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) ) -Phenylphosphine oxide, 2-methyl-1- [4-
(Methylthio) phenyl] -2-morpholinopropane-
1,2-benzyl-2-dimethylamino-1- (morpholinophenyl) -butanone-1 and the like. These may be used alone or in combination of two or more. The compounding amount of the ultraviolet polymerization initiator is preferably 0.1 to 10 parts by weight per 100 parts by weight of the (meth) acrylate oligomer.

In the present invention, in addition to the above essential components, tertiary amines such as triethylamine and triethanolamine and triphenylphosphine and the like may be used, if necessary, in order to promote the photopolymerization reaction by the above photopolymerization initiator. An alkylphosphine-based photopolymerization accelerator, a thioether-based photopolymerization accelerator such as p-thiodiglycol, or the like may be added. The addition amount of these compounds is usually preferably in the range of 0.01 to 10 parts by weight per 100 parts by weight of the (meth) acrylate oligomer. There is no particular limitation on the method of applying the ultraviolet curable resin to the surface of the elastic layer of the foam roller, and depending on the situation, a method of dipping the foam roller in the resin liquid, a spray coating method, a roll coating method, etc. Can be appropriately selected and used.

As a light source for irradiating ultraviolet rays, any of a commonly used mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, metal halide lamp, xenon lamp and the like can be used. The condition of the ultraviolet irradiation may be appropriately selected according to the type and application amount of the ultraviolet curable resin.
00 to 700 mW / cm ² , integrated light amount 200 to 3000
About mJ / cm ² is appropriate.

The foam roller manufactured by the manufacturing method of the present invention can be used in an image forming apparatus such as a plain paper copier, a plain paper facsimile machine, a laser beam printer, a color laser beam printer, and a toner jet printer. It is preferably used as a transfer roller, paper feed roller, toner supply roller, or the like.

[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. In the description of the embodiments, "part"
Represents "parts by weight".

Example 1 90.0 parts of Sannics FA703 (polyether polyol manufactured by Sanyo Chemical Industries, Ltd., OH value = 33), PO
P31-28 (Mitsui Chemicals Co., Ltd. polymer polyol, OH value = 28) 10.0 parts, diethanolamine 2.0 parts, H20 (ion exchange water) 1.5 parts SRX27
4C (Foam stabilizer made by Toray Dow Corning Silicon Co., Ltd.)
2.0 parts, Kao Riser No. 31 (3 manufactured by Kao Corporation)
0.5 parts of kaolin riser No. 1 (aliphatic tertiary amine catalyst manufactured by Kao Corporation) 1.0 part and T80
(Tolylene diisocyanate manufactured by Mitsui Chemicals, Inc., NC
(O% = 48) 25.0 parts were mechanically stirred and foamed. An outer diameter of 6.0 m from one side opening of a metal cylindrical type having an inner diameter of 16 mm and a length of 250 mm and whose surface is subjected to fluorine processing.
m, a metal shaft having a length of 240 mm was arranged, and 8.0 g of the foamed polyurethane raw material was injected from a foaming machine.

Next, the mold into which the foamed polyurethane raw material has been injected is cured in an oven at 80 ° C. for 20 minutes, and then demolded. The outer diameter is 12 mm, and the total length of the foam portion is 21 mm.
A foam roller having an elastic layer composed of a 0 mm urethane foam foam layer and a skin layer was obtained. The density of the foam layer was 0.12 g / cm ³ , and had a uniform density and hardness throughout. Aronix M-
1310 (Toa Gosei Co., Ltd. polyester urethane acrylate) 80.0 parts, Aronix M-110
Ultraviolet light consisting of 20.0 parts (paracumylphenol ethylene oxide 1 mol modified acrylate manufactured by Toa Gosei Co., Ltd.) and 1.0 of Irgacure 184 (photopolymerization initiator, 1-hydroxycyclohexyl phenyl ketone manufactured by Ciba Specialty Chemicals) After applying the curable resin composition to a thickness of 100 μm using a roll coater, the illuminance was adjusted to 4 using a Unicur UVH-0252C (manufactured by Ushio Inc.) while rotating the roller.
When the film was irradiated with ultraviolet light at 00 mW and an integrated light amount of 1000 mJ / cm ² , the coating film was instantaneously cured to form an elastic solid layer. The obtained foam roller was suitable for a paper feed roller, a transfer roller and the like.

Example 2 An ultraviolet-curable resin composition was prepared by adding 2.5 parts of Ketjen Black EC (conductive carbon black manufactured by Lion Corporation) to the polyurethane raw material used in Example 1 as a polyurethane raw material. When the same procedure was performed as in Example 1 except that the UV-curable resin composition used in Example 1 was further added with 0.1 part of sodium perchlorate, the coating film was instantaneously cured. A resilient solid layer was formed. . The resulting foam roller is
With a load of 0.1 N applied to both ends and a pressure of 200 V between the shaft and the aluminum plate when pressed against the aluminum plate, it has a conductivity of 2 × 10 ⁷ Ω, and is suitable for various rollers that require conductivity. It was.

[0027]

The method for manufacturing a foam roller according to the present invention has many advantages as follows. This eliminates the need for a long drying line, eliminates the need for a process space and expensive equipment, and is advantageous in terms of cost. In the conventional method, when the line is stopped due to a failure of the coating (coating) line, the drying conditions (history) of many intermediate products in the drying line differ, and the individual quality varies. In this method, there is almost no influence of such a line stop, coating material and size can be easily changed, and curing under constant conditions can be performed with good reproducibility, so that there is little quality variation between rollers.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takayuki Mochizuki 1 Kashio-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) in Bridgestone Yokohama Factory 2H077 AC04 AD06 FA13 FA22 2H200 FA13 HA02 HA28 HB12 HB43 HB45 JA23 JA25 LC04 MA04 MA08 MA11 MA12 MA14 MA17 MA20 3J103 AA02 AA13 AA51 BA41 FA15 GA02 GA57 GA58 GA60 HA03 HA04 HA20 HA41 HA48

Claims (6)

[Claims] When providing a solid layer composed of one or more resin layers on the surface of an elastic layer of a foam roller having a foam layer or an elastic layer composed of a foam layer and a skin layer, at least one of the resin layers is provided. A method for manufacturing a foamed roller, wherein one layer is formed by applying and curing an ultraviolet curable resin. 2. The method according to claim 1, wherein the thickness of the solid layer is 1 to 500 μm. 3. The method for producing a foamed roller according to claim 1, wherein the ultraviolet-curable resin is a (meth) acrylate-based ultraviolet-curable resin composition. 4. The method for producing a foam roller according to claim 1, wherein the foam layer is made of polyurethane foam. 5. The method for producing a foamed roller according to claim 1, wherein the elastic layer or the elastic layer and the solid layer include a conductive material. 6. An image forming apparatus equipped with a foam roller manufactured by the method according to claim 1.