JP4653876B2 - Image forming apparatus member and image forming apparatus using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus member used in an image forming apparatus such as an electrophotographic apparatus, an electrostatic recording apparatus, and a toner flying recording apparatus. More specifically, the recording medium (transfer material) such as plain paper is jammed. In particular, the present invention relates to an image forming apparatus member that maintains a sufficient strength even if excessive stress is applied to the member and does not cause problems such as tearing of the member, and an image forming apparatus equipped with the member.
[0002]
[Prior art]
In recent years, along with the advancement of electrophotographic technology, image forming apparatuses such as dry electrophotographic apparatuses are used as members for charging, developing, transferring, supplying toner (developer), cleaning, etc. Molecular elastic members are attracting attention, and are used in the form of elastic rollers such as charging rollers, developing rollers, transfer rollers, toner supply rollers, and cleaning rollers, and elastic blades such as toner layer regulating blades and cleaning blades. ing.
For the image forming apparatus member used for these purposes, a polymer elastomer or polymer foam having rubber elasticity is used as a material. The image forming apparatus member has a low hardness, and an image carrier or transfer material is used. It is required that the toner is not contaminated and not fused with the toner.
Here, as materials constituting the polymer elastomer and polymer foam, solid rubber vulcanizates such as isoprene rubber, ethylene propylene rubber, silicone rubber, epichlorohydrin rubber, acrylonitrile butadiene rubber, and liquid raw materials such as polyol are isocyanate. Polyurethane and the like cured by the above are used. An image forming apparatus member made of these materials may be required to have conductivity. For example, a predetermined electric power may be obtained by mixing a conductive material such as carbon black or metal oxide or adding an electrolyte. It is adjusted to the resistance value. Here, there is little variation in the position of electrical resistance, and there is little voltage dependence of electrical resistance, so polar polymers such as epichlorohydrin rubber, acrylonitrile butadiene rubber, polyurethane, etc., alkali metals, alkaline earth metals, quaternary ammonium, etc. It is advantageous to add conductivity by blending electrolytes such as chlorides, perchloric oxides, borofluorides, alkylsulfuric oxides, and carboxylic oxides, especially ease of manufacture, raw material prices, and long-term electricity From the standpoint of resistance stability, polyurethane imparted with conductivity by a quaternary ammonium salt or the like is preferably used.
[0003]
However, as the image forming apparatus increases in speed, a recording medium (transfer material) such as plain paper exerts excessive stress on the member when jamming or the like, and the member is torn, causing an image defect or being torn. There is a problem that the broken pieces of the member are clogged in the rotating part inside the machine and the image forming apparatus cannot be operated.
[0004]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide an image forming apparatus member having sufficient strength without impairing various performances required for the image forming apparatus member and an image forming apparatus equipped with the member. To do.
[0005]
[Means for Solving the Problems]
  As a result of intensive studies to achieve the above object, the present inventor specified a specific polyol as the polyol component in an image forming apparatus member made of polyurethane obtained by reaction curing of an isocyanate component and a polyol component. It has been found that by using a material containing a sufficient amount, sufficient strength can be imparted without impairing various performances required for the image forming apparatus member. The present invention has been completed based on such findings.
  That is, the present invention relates to an image forming apparatus member comprising a polyurethane mainly obtained by reaction curing of an isocyanate component and a polyol component, wherein the polyol component is acrylonitrile.as well asstyreneOne or more selected from the group ofEthylenically unsaturated compoundThingsThe present invention provides an image forming apparatus member comprising 5 to 95% by weight of a polymer polyol graft-polymerized to a polyol, and an image forming apparatus equipped with the member.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
  In the present invention, the polyol component is acrylonitrile.as well asstyreneOne or more selected from the group ofEthylenically unsaturated compoundThingsA polymer polyol graft-polymerized to a polyol is used. By using a polyol component containing 5 to 95% by weight of such a specific polymer polyol in the total polyol component, sufficient strength can be obtained without impairing various properties as an image forming apparatus member. The content of the specific polymer polyol is preferably 10 to 85% by weight in the total polyol component. Where acrylonitrileas well asstyreneOne or more selected from the group ofEthylenically unsaturated compoundobjectThe polyol to be graft polymerized is preferably a polyether polyol from the viewpoint of moisture resistance, and more preferably a polyether polyol or polytetramethylene ether glycol obtained by addition polymerization of ethylene oxide and propylene oxide. In this case, the ratio of ethylene oxide to propylene oxide and the microstructure of the polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide is preferably 2 to 80% by weight, more preferably 5 to 25%. % By weight. And what has ethylene oxide added to the terminal is preferably used. Further, the arrangement of ethylene oxide and propylene oxide in the molecular chain is preferably random.
  The molecular weight of this polyether polyol is preferably in the range of 300 to 6,000, particularly in the range of 400 to 3,000 in terms of weight average molecular weight when it is bifunctional. In the case of trifunctional, those having a weight average molecular weight in the range of 900 to 9,000 are preferable, and those in the range of 1,500 to 6,000 are particularly preferable. Acrylonitrile in polytetramethylene ether glycolas well asstyreneOne or more selected from the group ofEthylenically unsaturated compoundobjectIs graft-polymerized, the weight average molecular weight of polytetramethylene ether glycol is preferably in the range of 400 to 4,000, particularly preferably 650 to 3,000.
[0007]
As the remaining polyol component constituting the polyurethane, polyether polyol or polyester polyol is used, and polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide is particularly preferable. Polyether polyols obtained by addition polymerization of ethylene oxide and propylene oxide are water, propylene glycol, ethylene glycol, glycerin, trimethylolpropane, hexanetriol, triethanolamine, diglycerin, pentaerythritol, ethylenediamine, methylglucotite, aromatic diamine. , Sorbitol, sucrose, phosphoric acid and the like as starting materials, and those obtained by addition polymerization of ethylene oxide and propylene oxide. In particular, water, propylene glycol, ethylene glycol, glycerin, trimethylolpropane, and hexanetriol are preferred as starting materials. Regarding the ratio of ethylene oxide and propylene oxide to be added and the microstructure, the ratio of ethylene oxide is preferably 2 to 80% by weight, more preferably 5 to 25% by weight. And what has ethylene oxide added to the terminal is preferably used. Further, the arrangement of ethylene oxide and propylene oxide in the molecular chain is preferably random.
[0008]
The molecular weight of the polyether polyol is bifunctional when water, propylene glycol, or ethylene glycol is used as a starting material, and preferably has a weight average molecular weight in the range of 300 to 6,000, particularly in the range of 400 to 3,000. Are preferred. When glycerin, trimethylolpropane and hexane santriol are used as starting materials, they are trifunctional and preferably have a weight average molecular weight of 900 to 9,000, particularly 1,500 to 6,000. Is preferred. Further, a bifunctional polyol and a trifunctional polyol can be appropriately blended and used.
[0009]
Polytetramethylene ether glycol can also be included as a polyol component constituting the polyurethane. Polytetramethylene ether glycol is obtained, for example, by cationic polymerization of tetrahydrofuran, and preferably has a weight average molecular weight in the range of 400 to 4,000, particularly preferably in the range of 650 to 3,000. It is also preferable to blend polytetramethylene ether glycols having different molecular weights. Furthermore, polytetramethylene ether glycol obtained by copolymerizing alkylene oxide such as ethylene oxide or propylene oxide can also be used.
[0010]
It is also preferable to use a blend of polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide and polytetramethylene ether glycol. In this case, a polyether polyol obtained by addition polymerization of ethylene oxide and propylene oxide, and polytetramethylene ether glycol The ratio is preferably 90:10 to 10:90, and more preferably 70:30 to 40:60.
[0011]
In addition to the above polyol component, a polyol obtained by condensing an acid component such as adipic acid and a glycol component such as ethylene glycol and ε Polyester polyols obtained by ring-opening polymerization of caprolactam, diols such as polycarbonate diol and butanediol, polyols such as trimethylolpropane, and derivatives thereof can be used in combination.
[0012]
Tolylene diisocyanate, diphenylmethane diisocyanate or a derivative thereof is used as an isocyanate component constituting the polyurethane material. Tolylene diisocyanate or derivatives thereof include crude tolylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate. A mixture of natto, a urea-modified product thereof, a burette-modified product, a carbosiimide-modified product, a urethane-modified product modified with a polyol or the like is used.
As diphenylmethane diisocyanate or a derivative thereof, diphenylmethane diindianate obtained by phosgenating diaminodiphenylmethane or a derivative thereof is used. The derivatives of diaminodiphenylmethane include polynuclear bodies, and pure diphenylmethane diisocyanate obtained from diaminodiphenylmethane and polymeric diphenylmethane diisocyanate obtained from the polynuclear body of diaminodiphenylmethane can be used in the present invention. The number of functional groups of polymeric diphenylmethane diisocyanate is usually pure diphenylmethane diisocyanate and a mixture of polymeric diphenylmethane diisocyanate having various functional groups, and the average number of functional groups is preferably from 2.05 to 4.00, more preferably. Is 2.50-3.50. Derivatives obtained by modifying these diphenylmethane diisocyanates or their derivatives, such as urethane modified products modified with polyols, dimers formed by uretidione formation, isocyanurate modified products, carbociimide / uretonimine modified products, allophanate modified products , Urea-modified products, burette-modified products, and the like can also be used. Of these, urethane-modified products and carbosiimide / uretonimine-modified products are particularly preferable.
[0013]
In the present invention, tolylene diisocyanate or a derivative thereof, diphenylmethane diisocyanate or a derivative thereof may be used alone, or two or more kinds may be used in combination. Further, various aliphatic isocyanates such as hexamethylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, or derivatives thereof may be used in combination.
The amount of the isocyanate component is such that the ratio NCO group / OH group of the isocyanate group in the isocyanate component to the hydroxyl group in the polyol component is 0.9 to 1.5 in molar ratio. The amount is preferably set, and more preferably in the range of 1.0 to 1.2.
[0014]
When imparting conductivity to the image forming apparatus member, the conductivity imparting material is mixed or dissolved in the polyurethane material constituting the image forming apparatus member. Conductivity imparting materials include conductive materials and electrolytes. Conductive materials such as gas black, oil furnace black including ink black, carbon black such as thermal black, channel black, and lamp black, and conductivity such as conductive zinc white A metal oxide etc. are mentioned. The blending amount of the conductive material is preferably 0.5 to 20 parts by weight, particularly preferably 1 to 10 parts by weight with respect to 100 parts by weight of the polyurethane material.
Electrolytes include tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium (eg, lauryltrimethylammonium), hexadecyltrimethylammonium, octadecyltrimethylammonium (eg, stearyltrimethylammonium), benzyltrimethylammonium, modified fatty acid dimethylethylammonium, lauroylaminopropyl. Quaternary ammonium salts such as dimethylethylammonium, perchlorates, chlorates, hydrochlorides, bromates, iodic acids such as alkali metals and alkaline earth metals such as lithium, sodium, potassium, calcium and magnesium Salts, borofluoride, sulfate, alkyl sulfate, carboxylate, sulfonate, trifluoromethyl sulfate, and the like. Among these, quaternary ammonium salts of alkyl sulfates and quaternary ammonium salts of polybasic carboxylic acids are preferable, and quaternary ammonium alkyl sulfates having an amide bond are particularly preferable. The blending amount of the electrolyte is preferably 0.01 to 10 parts by weight, particularly preferably 0.1 to 3 parts by weight with respect to 100 parts by weight of the polyurethane material.
In addition to the conductivity imparting material, a filler, an antioxidant, a friction reducing agent, a charge adjusting agent, and the like can be added to the polyurethane material.
[0015]
Examples of a reaction catalyst for curing a polyurethane composition containing a polyurethane material and a conductivity-imparting material include monoamines such as triethylamine and dimethylcyclohexylamine, and diamines such as tetramethylethylenediamine, tetramethylpropanediamine, and tetramethylhexanediamine. , Triamines such as pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, tetramethylguanidine, cyclic amines such as triethylenediamine, dimethylpiperazine, methylethylpiperazine, methylmorpholine, dimethylaminoethylmorpholine, dimethylimidazole, dimethylaminoethanol, Dimethylaminoethoxyethanol, trimethylaminoethylethanolamine, methylhydroxyethylpiperazine, Alcohol amines such as droxyethylmorpholine, ether amines such as bis (dimethylaminoethyl) ether, ethylene glycol bis (dimethyl) aminopropyl ether, stannous octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin marker peptide , Organic metal compounds such as dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin marker peptide, dioctyltin thiocarboxylate, phenylmercury propionate, lead octenoate and the like. Among these, an organic tin catalyst is particularly preferable. These catalysts may be used alone or in combination of two or more.
[0016]
When the polyurethane member is in the form of a foam, it is preferable to add various surfactants and silicone foam stabilizers to the polyurethane composition in order to stabilize the cells of the foam material. As the silicone foam stabilizer, a dimethylpolysiloxane-polyoxyalkylene copolymer or the like is preferably used, and comprises a dimethylpolysiloxane moiety having a molecular weight of 350 to 15,000 and a polyoxyalkylene moiety having a molecular weight of 200 to 4,000. Is particularly preferred. As the molecular structure of the polyoxyalkylene moiety, an addition polymer of ethylene oxide or a co-addition polymer of ethylene oxide and propylene oxide is preferably used, and the molecular terminal is preferably ethylene oxide. Examples of the surfactant include ionic surfactants such as cationic surfactants, anionic surfactants and amphoteric surfactants, and nonionic surfactants such as various polyethers and various polyesters.
The blending amount of the silicone foam stabilizer and various surfactants is preferably 0.1 to 10 parts by weight, and more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the polyurethane material.
[0017]
As a foaming method for producing a polyurethane foam, for example, a method using a foaming agent such as water, an organic solvent or various alternative chlorofluorocarbons, a method of mixing bubbles by mechanical stirring, and the like are preferably used. A method in which bubbles are mixed by a typical stirring frame is particularly preferable. The foaming ratio of the polyurethane foam is preferably such that the maximum cell diameter is less than 500 μm, particularly less than 200 μm, and the bulk density is in the range of 0.2 to 0.7 g / ml, particularly 0.3 to 0.6 g / ml. It is preferable to set it as the range.
[0018]
The blending and heat-curing in producing the polyurethane member are performed by mixing and stirring the above polyol component, isocyanate component, conductivity-imparting material, reaction catalyst and various additive components used as required, and by the above method if necessary. It is preferable to use a method of heat curing after performing an operation such as mixing in a predetermined mold or performing free foaming in a block shape.
[0019]
In addition, a polyol component and an isocyanate component are reacted in advance to prepare a prepolymer having an isocyanate group, and this is prepared from ethylene glycol, 1,4 monobutanediol, trimethylolpropane, or a polyol having a molecular weight of 400 to 5,000. A prepolymer method for curing using a chain extender such as ethylene oxide, propylene oxide addition polymerization type diol, triol or polytetramethylene ether glycol having a primary terminal hydroxyl group is preferably used.
[0020]
The image forming apparatus member of the present invention includes an image forming apparatus member comprising a metal member and the above polyurethane. The structure is a metal member such as sulfur free cutting steel plated with zinc or the like, or a metal member such as aluminum, stainless steel, phosphor bronze, etc., part or all of which is covered with a polyurethane member, Used in the form of rollers, drums, blades, etc., depending on the application. Specifically, the case where the image forming apparatus member is a conductive roller will be specifically described as an example. A cored bar obtained by plating zinc free plating steel or the like on a sulfur free-cutting steel or the like is covered with a polyurethane member in a cylindrical shape, and further required. Correspondingly, an example in which a conductive, semiconductive or insulating paint is applied to the outside can be exemplified.
[0021]
As a method for joining the metal member and the polyurethane member, a method in which the metal member is disposed in the mold in advance and the polyurethane raw material is cast and cured, or a method in which the polyurethane member is molded into a predetermined shape and then bonded is used. it can. In either method, an adhesive layer can be provided between the metal member and the polyurethane member as required, and an adhesive made of a conductive paint, a hot melt sheet, or the like can be used.
The molding method of the polyurethane member of the present invention includes the method of casting into a mold having a predetermined shape as described above, the method of cutting from a block to a predetermined dimension by cutting, the method of making a predetermined dimension by polishing, or these A method of appropriately combining these methods can be used.
The image forming apparatus member of the present invention can be exemplified by a charging member, a developing member, a transfer member, a cleaning member, etc. as an image forming apparatus member used in contact with an image carrier such as a photosensitive member. Examples of the image forming apparatus member used include a developing member, a developer supplying member, a cleaning member, and a developer layer regulating member. These members can be used in the form of a roller or a blade.
[0022]
FIG. 1 is an explanatory view showing an example of an electrophotographic image forming apparatus in which the image forming apparatus member of the present invention is mounted as a transfer roller, and is an image carrier holding a toner supply roller 3 and an electrostatic latent image. 1, the developing roller 2 has a structure in which the outer peripheral surface of the developing roller 2 is in contact with the image carrier 1 via a recording medium (transfer material) 8 such as paper. When the transfer material 8 is not passing, the transfer roller 5 is in contact with the image carrier 1. By rotating the toner supply roller 3, the developing roller 2, and the image carrier 1 in the direction of the arrow, the toner is supplied to the surface of the developing roller 2 by the toner supply roller 3, and a uniform thin layer is formed by the layer regulating blade 4. Then, the image is attached to the latent image on the image carrier 1 and the latent image is visualized. Then, by generating an electric field between the image carrier 1 and the transfer roller 5, the toner image on the image carrier 1 is transferred to the transfer material 8. A cleaning roller 6 removes the toner remaining on the surface of the image carrier 1 after the transfer. Reference numeral 7 denotes a charging roller.
[0023]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
Example 1
Roller production
Polyether polyol with random addition of propylene oxide and ethylene oxide to glycerin, ethylene oxide unit content of 16% by weight, substantial number of functional groups, weight average molecular weight of 5,000 and OH number of 34mgKOH / g 80 parts by weight, propylene oxide and ethylene oxide are randomly added to glycerin, acrylonitrile is graft-polymerized to a polyether polyol having a functional group number of 3 and a weight average molecular weight of 5,000, and the weight ratio of the polyether component to the acrylonitrile component is 80:20 polymer polyol 20 parts by weight, a mixture of diphenylmethane diisocyanate, urethane-modified diphenylmethane diisocyanate and carbosiimide-modified diphenylmethane diisocyanate 26.3% by weight isocyanate content 11.2 parts by weight of isocyanate, 4 parts by weight of a silicone foam stabilizer with a dimethylpolysiloxane-polyoxyalkylene copolymer and an OH number of 32 mg KOH / g, 0.4 parts by weight of ethyl sulfate-modified aliphatic diethyl as an electrolyte, dibutyltin 0.04 parts by weight of dilaurate and 2.5 parts by weight of a black colorant having an OH number of 45 mgKOH / g obtained by dispersing a black pigment in a polyol are mixed while being foamed by mechanical stirring, and the mixture is 6 mm in diameter. After casting into a mold having a metal shaft at the center, it was cured at 100 ° C. for 10 hours to produce a urethane foam roller having a diameter of 16.5 mm and a length of 215 mm.
Roller properties, image evaluation
The bulk density of the foam part was 0.40 g / ml and the Asker C hardness was 33 °. The roller was placed on an aluminum plate having a thickness of 5 mm, and the electrical resistance between the shaft and the copper plate was measured while pressing both ends of the roller with a force of 500 g each. The measurement temperature and humidity are 23 ° C and 50%, respectively, and the electrical resistance is 10 when the applied voltage is 1,000V.^7.78[Ω]. This roller is incorporated as a transfer roller in the image forming apparatus shown in FIG. 1 and printed with grayscale, black solid, and white solid images in an environment where the temperature and humidity are 23 ° C. and 50%, respectively. Good images were obtained for both solid and white solids.
Long-term durability evaluation
Next, 50,000 grayscale images were printed on this roller in the image forming apparatus shown in FIG. 1 in an environment where the temperature and humidity were 23 ° C. and 50%, respectively. Paper jamming occurred ten times or more during printing, but a good image was obtained until the end of printing 50,000 sheets.
[0024]
Comparative Example 1
Roller production
Polyether polyol with random addition of propylene oxide and ethylene oxide to glycerin, ethylene oxide unit content of 16% by weight, substantial number of functional groups, weight average molecular weight of 5,000 and OH number of 34mgKOH / g 100 parts by weight, a mixture of diphenylmethane diisocyanate, urethane-modified diphenylmethane diisocyanate, and carbosiimide-modified diphenylmethane diisocyanate, 11.8 parts by weight of isocyanate having a content of 26.3% by weight, dimethylpolysiloxane-polyoxyalkylene 4 parts by weight of a silicone foam stabilizer having an OH value of 32 mg KOH / g as a copolymer, 0.4 parts by weight of ethyl sulfate-modified aliphatic diethyl as an electrolyte, 0.04 parts by weight of dibutyltin dilaurate, and a black pigment dispersed in a polyol. OH number A urethane foam roller was produced in the same manner as in Example 1 by mixing 2.5 parts by weight of black colorant of 45 mg KOH / g while foaming by mechanical stirring.
Roller properties, image evaluation
When the roller physical properties were evaluated in the same manner as in Example 1, the bulk density of the foam part was 0.40 g / ml, the Asker C hardness was 31 °, and the electrical resistance was 10^7.75Ω, and good images were obtained for all of the gray scale, black solid, and white solid.
Long-term durability evaluation
When durability was evaluated in the same manner as in Example 1, when about 13,000 sheets were printed, there was a fourth paper jam, and the end of the roller was missing. When the durability evaluation was further continued, the roller debris narrowed in the drive portion of the image forming apparatus, which hindered the operation of the image forming apparatus.
[0025]
Example 2
Roller production
Polyether polyol with random addition of propylene oxide and ethylene oxide to glycerin, ethylene oxide unit content of 16% by weight, substantial number of functional groups, weight average molecular weight of 5,000 and OH number of 34mgKOH / g 80 parts by weight, propylene oxide and ethylene oxide are randomly added to glycerin, acrylonitrile is graft-polymerized to a polyether polyol having a functional group number of 3 and a weight average molecular weight of 5,000, and the weight ratio of the polyether component to the acrylonitrile component is 80:20 polymer polyol 20 parts by weight, a mixture of diphenylmethane diisocyanate, urethane-modified diphenylmethane diisocyanate, and carbosiimide-modified diphenylmethane diisocyanate 26.3% by weight isocyanate content 10.6 parts by weight of isocyanate, 4 parts by weight of a silicone foam stabilizer having a dimethylpolysiloxane-polyoxyalkylene copolymer and an OH value of 32 mg KOH / g, 0.4 parts by weight of ethyl sulfate-modified aliphatic diethyl as an electrolyte, dibutyltin In the same manner as in Example 1, 0.04 parts by weight of dilaurate and 2.5 parts by weight of a black colorant having an OH value of 45 mgKOH / g obtained by dispersing a black pigment in a polyol were mixed while being foamed by mechanical stirring. A urethane foam roller was prepared.
Roller properties, image evaluation
When the roller physical properties were evaluated in the same manner as in Example 1, the bulk density of the foam part was 0.45 g / ml, the Asker C hardness was 42 °, and the electrical resistance was 10^7.95Ω, and good images were obtained for all of gray scale, black solid, and white solid.
Long-term durability evaluation
When durability was evaluated in the same manner as in Example 1, paper jamming occurred ten or more times during printing, but a good image was obtained until the end of printing 50,000 sheets.
[0026]
Comparative Example 2
Roller production
Propylene oxide and ethylene oxide are randomly added to glycerin, and acrylonitrile is graft-polymerized to a polyether polyol having a functional group number of 3 and a weight average molecular weight of 5,000. The weight ratio of the polyether component to the acrylonitrile component is 80:20. 100 parts by weight of a certain polymer polyol, a mixture of diphenylmethane diisocyanate, urethane-modified diphenylmethane diisocyanate, and carbosiimide-modified diphenylmethane diisocyanate having an isocyanate content of 26.3% by weight, 10.3 parts by weight of dimethylpolysiloxane 4 parts by weight of a silicone foam stabilizer having an OH number of 32 mgKOH / g, a polyoxyalkylene copolymer, 0.4 parts by weight of ethyl sulfate-modified aliphatic diethyl as an electrolyte, 0.04 parts by weight of dibutyltin dilaurate, black A urethane foam roller is produced in the same manner as in Example 1 by mixing 2.5 parts by weight of a black colorant having an OH value of 45 mgKOH / g obtained by dispersing a color pigment in a polyol while foaming by mechanical stirring. did.
Roller properties, image evaluation
When the roller physical properties were evaluated in the same manner as in Example 1, the bulk density of the foam part was 0.48 g / ml, the Asker C hardness was 48 °, and the electrical resistance was 10^8.15Ω and image unevenness was observed in the black solid image. Since this roller has a high bulk density and a high roller hardness, it is presumed that an image defect was caused.
[0027]
【The invention's effect】
The image forming apparatus member of the present invention is suitable as an image forming apparatus member without contaminating the image carrier after being used for a long time and without fusing with a developer or the like. The image forming apparatus can be used in the form of an elastic roller such as a transfer roller, a toner supply roller, and a cleaning roller, an elastic blade such as a toner layer regulating blade, and a cleaning blade.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an example of an electrophotographic image forming apparatus in which an image forming apparatus member of the present invention is mounted as a transfer roller.
[Explanation of symbols]
1: Image carrier
2: Developing roller
3: Roller for toner supply
4: Toner layer regulating blade
5: Transfer roller
6: Cleaning roller
7: Charging roller
8: Recording medium (transfer material)

Claims (7)

Polyurethane obtained mainly by reaction curing of isocyanate component and polyol component (however, the hardness obtained by mechanical floss method and measured by Asker C hardness meter is 20 ° or less, and the tensile strength is 0.1 MPa or more. And the polyol component contains a polymer polyol obtained by graft polymerization of acrylonitrile onto the polyol in an amount of 5 to 95% by weight of the polyol component , and the isocyanate. The image forming apparatus member, wherein the nart component is an isocyanate component including urethane-modified diphenylmethane diisocyanate and carbodiimide-modified diphenylmethane diisocyanate . 2. The image forming apparatus member according to claim 1 , wherein the polyol for graft polymerization of acrylonitrile is a polyether polyol or polytetramethylene ether glycol obtained by addition polymerization of ethylene oxide and propylene oxide. The image forming apparatus member according to claim 1 or 2 , wherein a blending ratio of the isocyanate component and the polyol component is 0.9 to 1.5 in terms of molar ratio. The image forming apparatus member according to any one of claims 1 to 3 functional groups of the polyol component is 2 or 3. Polyurethane, an image forming apparatus member according to any one of claims 1 to 4, which is a foam. Image forming apparatus member, the transfer member, a charging member, a developing member, the image forming apparatus member according to any one of claims 1 to 5 developer is a supply member or a cleaning member. An image forming apparatus comprising the image forming apparatus member according to claim 6 .

Images