JP2006208759A - Adsorbent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain a satisfactory office environment in which an organic volatile gas generated from a coated paper sheet used in an image forming apparatus such as a copier, a printer, a fax, or the like is not exhausted to the outside of the apparatus. <P>SOLUTION: The organic volatile gas is adsorbed by bringing the coated paper sheet immediately after the fixation into contact with the adsorbent like a carbon nano horn having fine holes at about the molecular size. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an adsorbent used for a copying machine, a printer, a FAX, and the like.

  2. Description of the Related Art Conventionally, as a fixing unit in an image forming apparatus such as an electrophotographic copying machine or a printer, a heat roller type having excellent thermal efficiency and safety is generally employed.

  The heat roller type fixing device includes a heat roller (fixing roller) in which an aluminum or iron core metal surface is coated with an elastic layer and a heat-resistant release layer as required, and a heat resistant elastic layer around a core metal such as stainless steel. The pressure roller on which the roller is formed is a basic configuration, and the pair of rollers are pressed and rotated to form a fixing nip portion (pressure nip portion) between the two rollers.

  A recording material (recording material sheet, electrostatic recording paper, electrofax paper, printing paper, etc.) as a heated material carrying an unfixed image (unfixed toner image) is introduced into the fixing nip portion, and the fixing nip portion Then, the recording material is nipped and conveyed to fix the unfixed image as a permanently fixed image on the surface of the recording material by the heat from the heating roller and the pressure applied to the fixing nip portion.

  A halogen heater is disposed inside the core of the heating roller as a heating element, and a temperature detection element is disposed at the paper passing portion on the surface of the heating roller. The detection result of the surface temperature of the heating roller by the temperature detection element is displayed. Originally, the halogen heater is turned ON / OFF, and the surface of the heating roller is held at a constant temperature for fixing temperature adjustment or standby temperature adjustment during printing standby.

  In a conventional image forming apparatus, for example, a toner image is formed on an image carrier, and the toner image is transferred onto a recording material P that is a sheet to obtain an image on the sheet. Then, the recording material P onto which the toner image has been transferred is applied with heat and pressure by the fixing device as described above, and after the toner image is fixed, the recording material P is discharged out of the apparatus by a discharge roller. ing.

  In such a conventional image forming apparatus, the recording material P is discharged with static electricity due to charging at the time of transfer or sliding with a member forming a conveyance path. As a result, when the recording material P is stacked, the recording material P discharged with static electricity may come into close contact with the recording material P already stacked on the sheet stacking portion due to static electricity, and the recording material P may be pushed out. When the sheets already stacked are pushed out in this way, there is a problem that the sheets cannot be stacked on the sheet stacking section in an orderly manner. In order to solve this problem, a charge removal needle is provided at the paper discharge port, and the charge removal is performed by bringing the charge removal needle into contact with the recording material P.

  However, when paper containing resin such as coated paper is passed as the recording material P in such an image forming apparatus, the resin of the coated paper is vaporized by heat of fixing, and organic volatile gas such as formaldehyde is generated. There is a problem. In such a case, the organic volatile gas may be discharged out of the apparatus and may contaminate the air in the office environment. In order to cope with this, it is proposed to provide a filter in the image forming apparatus and filter the air discharged outside the apparatus (see Patent Document 1) or to provide an adsorbent in the vicinity of the fixing device (see Patent Document 2). However, it could not cope with the gas generated from the coated paper discharged outside the machine.

JP 2002-169432 A JP-A-4-221968

  In view of the above, the present invention aims to maintain a good office environment without discharging organic volatile gas generated from coated paper used in an image forming apparatus such as a copying machine, a printer, and a fax machine. Objective.

As a result of intensive studies to solve the above problems, the present inventor has obtained an adsorbent having pores of a molecular size such as carbon nanohorn with respect to the sheet material after fixing the toner image with heat. It has been found that contact is extremely effective. The present invention is characterized by the following inventions.
(1) An adsorbent that comes into contact with the sheet material after the toner image transferred to the sheet material has been fixed by heat, and has an inside diameter of 1 to 3 nm and a length of 10 or more times the diameter. An adsorbent comprising a member having columnar pores.
(2) The adsorbent according to (1), wherein the member having pores is a carbon nanohorn.
(3) An adsorbent that comes into contact with the sheet material after the toner image transferred to the sheet material has been fixed by heat, and has a diameter of 0.7 to 500 nm and an axial length of 10 nm to 1 mm. An adsorbent characterized by comprising an assembly of
(4) The adsorbent according to (3), wherein the aggregate is an aggregate of carbon nanotubes.
(5) An adsorbent that comes into contact with the sheet material after the toner image transferred to the sheet material has been fixed by heat, and has a circle with a diameter of 1 to 3 nm and a length of 10 times or more of the diameter. An adsorbent comprising: a member having columnar pores; and an aggregate of fine wires having a diameter of 0.7 to 500 nm and an axial length of 10 nm to 1 mm.
(6) The adsorbent according to (5), wherein the member having pores is a carbon nanohorn, and the aggregate is an aggregate of carbon nanotubes.
(7) The adsorbent according to any one of (1) to (6), wherein the adsorbent has conductivity, is electrically connected to the ground, and is a static elimination needle.
(8) The adsorbent according to any one of (1) to (7), wherein the sheet material temperature when the adsorbent comes into contact is 50 ° C. or higher.

  According to the adsorbent of the present invention, an organic volatile gas such as formaldehyde can be adsorbed very effectively by contacting the sheet material (particularly coated paper) immediately after the heat is applied. A good office environment can be maintained without discharging the generated organic volatile gas to the outside of an image forming apparatus such as a copying machine, a printer, or a fax machine.

  Hereinafter, embodiments of the present invention will be described together with specific examples.

  FIG. 1 is a longitudinal sectional view showing a schematic configuration of an image forming apparatus to which a fixing device having an adsorbent according to the present invention is applied.

  In the figure, reference numeral 1 denotes a drum-type electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) as an image carrier, and a photosensitive layer is formed on the surface of a substrate in which a conductive member such as aluminum or nickel is formed in a cylindrical shape. Is provided. As the photosensitive layer, OPC (organic semiconductor), a-Si (amorphous silicon), or the like can be used.

  The photosensitive drum 1 is rotatably supported by an image forming apparatus main body (not shown), and is driven to rotate clockwise in the drawing at a predetermined peripheral speed (process speed) by a driving unit (not shown).

  Around the photosensitive drum 1, a charging roller (charging means) 2 that uniformly charges the surface of the photosensitive drum 1 to a predetermined polarity in almost the order along the rotation direction, and the surface of the photosensitive drum 1 after charging is exposed to an image. An exposure device (exposure unit) 3 that forms an electrostatic latent image according to information, a developing unit (development unit) 4 that develops a toner image by attaching toner to the electrostatic latent image, and a toner image on the photosensitive drum 1 A transfer roller (transfer means) 5 for transferring to a recording material P such as paper and a cleaner (cleaning means) 7 for removing residual toner remaining on the surface of the photosensitive drum 1 after transfer are provided. On the downstream side of the transfer roller 5 in the conveyance direction of the recording material P, a fixing device 6 for fixing the unfixed toner transferred on the recording material P by heating and pressing is disposed.

  Further, on the upstream side of the transfer roller 5 with respect to the conveyance direction of the recording material P, a manual feed tray 21 on which a recording material P other than the manually inserted standard paper is set, and the recording material P on the manual tray 21 are fed. A paper roller 22 and a registration roller 23 that synchronizes the conveyed recording material P and the toner image on the photosensitive drum 1 are disposed. Further, below the transfer roller 5, a paper feed cassette 24 that stores the regular recording material P, and a paper feed roller 25 that feeds the recording material P toward the registration roller 23 are disposed.

  Next, the operation of the image forming apparatus configured as described above will be briefly described.

  The surface of the photosensitive drum 1 driven to rotate clockwise in FIG. 1 is uniformly charged to a predetermined potential by the charging roller 2. The charged surface of the photosensitive drum 1 is subjected to scanning exposure (image exposure) of a laser beam from an exposure device 3 that is ON / OFF controlled in accordance with image information to form an electrostatic latent image.

  The electrostatic latent image is developed as a toner image (visible image) by the toner attached by the developing device 4. As a development method, a jumping development method, a two-component development method, a FEED development method, or the like is used, and reversal development is often used in combination with the above-described image exposure.

  The recording material P is taken out from the manual feed tray 21 or the paper feed cassette 24 by the paper feed roller 22 or the paper feed roller 25. Regardless of whether the paper is fed from the manual feed tray 21 or the paper feed cassette 24, the recording material P is synchronized with the toner image formed on the surface of the photosensitive drum 1 by the registration roller 23, and the photosensitive drum 1 and the transfer roller 5. To a transfer nip formed by

  In the transfer nip portion, the toner image on the photosensitive drum 1 is transferred onto the surface of the recording material P by the action of a transfer bias by a power source (not shown). The recording material P carrying the unfixed toner image on the surface is conveyed to the fixing device 6, and the unfixed toner image on the surface is heated and pressurized at the fixing nip portion of the fixing device 6 and then discharged outside the apparatus main body. Is done.

  On the other hand, the transfer residual toner remaining on the surface of the photosensitive drum 1 after the transfer of the toner image is removed by the cleaner 7 and used for the next image formation.

  Next, the fixing operation in the above-described fixing device 6 will be described in detail.

  FIG. 2 is a schematic sectional view of a roller heating type fixing device as an example of the fixing device according to the present invention. The configuration and operation will be described below with reference to FIG.

  The fixing roller 61 is covered with a silicon rubber 611 having a thickness of 2 mm on an aluminum core having an outer diameter of 40 mm and a wall thickness of 1 mm, and a PFA tube layer 612 having a thickness of 50 μm is provided as a release layer on the outermost layer. The temperature was controlled to rotate at 150 mm / s so that the surface temperature was 190 ° C. The hardness of the fixing roller 61 is 60 ° (measured with Asker-C at 1 kg load). The pressure roller 62 is covered with a silicon rubber 622 as an elastic layer having a thickness of 8 mm on an iron core bar 621 having a diameter of 20 mm, and a PFA tube layer 623 having a thickness of 50 μm as a release layer on the outermost layer. The pressure roller 62 was pressed against the fixing roller 61 with a pressure of 21.5 N to obtain a fixing nip N of about 6 mm.

Next, the brush member 64 according to the present invention will be described with reference to FIG.
The brush member 64 has a core plate 110 made of a rigid body such as a metal or a hard resin, and a brush made of a large number of conductive fibers 120 whose base ends are fixed to the core plate 110, and the tips of the fibers. The part side is in contact with the paper transport path. The length of the conductive fiber 120 was 10 mm, and the pitch was 3 mm. The distance from the fixing nip is 50 mm.

  A carbon nanohorn 131 is bonded to the conductive fiber 120. Although three methods will be described below as the coupling method, the present invention is not limited to this.

(A) Adhesive carbon nanohorn with conductive adhesive Apply conductive adhesive at a thickness of 2 to 10 μm only at the tip of the conductive fiber, and then use the electrostatic force to suck the carbon nanohorn into the conductive fiber and make contact Further, the conductive adhesive is thermally cured, the carbon nanohorn is fixed, and the brush member 64 is completed.

(B) Conductive fiber and fusion The conductive nanofiber and the conductive fiber are fused by heating the conductive fiber to melt the tip, then contacting with the carbon nanohorn, and further cooling and re-curing the conductive fiber. The brush member 64 is completed.

(C) Electrophoresis Method Polymethylphenylsilane is applied only to the tip of the conductive fiber, and then light with a wavelength of about 400 nm is irradiated with an ultrahigh pressure mercury lamp to cut the Si-Si bond of polymethylphenylsilane. Thereafter, the conductive fibers are immersed in a solution in which carbon nanohorns are dispersed in isopropyl alcohol, a negative voltage is applied to the conductive fibers using the Al electrode as a counter electrode, and the carbon nanohorns are brought into contact with the conductive fibers by electrophoresis.

  Since the carbon nanohorn moves in a direction parallel to the applied electric field, the carbon nanohorn comes into contact with the conductive fiber and is stabbed into the polymethylphenylsilane having a broken Si—Si bond to be immobilized.

  When the above method is used, a conductive adhesive or polymethylphenylsilane is applied to the surface of the conductive fiber, or a softened layer is formed on the surface of the conductive fiber, and the carbon nanohorn is fixed by these layers. The

  In the brush member 64 as described above, the carbon nanohorn 131 is brought into contact with the recording material P mainly. The carbon nanohorn 131 includes a single-layer carbon nanohorn and a multi-layer carbon nanohorn, both of which have an extremely fine fiber shape with a very large aspect ratio.

  Since the carbon nanohorn 131 has a seamless structure, it has a very high elastic modulus and a large tensile strength in the axial direction of the tube. As will be described later, since the carbon nanohorn 131 has an extremely fine diameter, it can be densely arranged on the surface of the conductive fiber via the resin layer.

  Further, since the carbon nanohorn 131 has great elasticity, it can be bent when it comes into contact with the recording material P, and can contact the recording material P not only at the tip but also at the side surface.

  Here, since the carbon nanohorn 131 has semiconducting or metallic (that is, ohmic contact) conductive characteristics, it is possible to inject charges directly from the carbon nanohorn 131 into the recording material P.

  Furthermore, since the carbon nanohorn 131 has a large tensile strength in the axial direction, even if it is extremely thin, it is very unlikely to break in contact with the recording material P, and there is very little variation in static elimination in the long term, thus extending the service life. realizable.

Further, in the brush member 64 according to the present invention, the carbon nanohorn 131 is fixed to the conductive fiber 120 only by the resin layers 130 arranged discretely. Therefore, the resin layer 130 only needs to have a size capable of holding the carbon nanohorn 131. Depending on the length of the carbon nanohorn 131, the resin layer 130 has a capacity (capacity per piece) of 10 to 8000 μm ³ . For example, 10 to 2000 μm ² is sufficient.

  Therefore, the probability of adhering adjacent conductive fibers 120 by the resin layer 130 is reduced. Further, even if the adjacent conductive fibers 120 are bonded, since the point bonding is different from the conventional brush member, the adhesive force is small, and the conductive fibers 120 are bonded to each other by contact with the recording material P. The flexibility of the conductive fiber 120 of the member 64 is not lowered.

  However, since the resin layer 130 has a sufficient capacity for fixing the carbon nanohorn 131, the carbon nanohorn 131 does not come out by contact with the recording material P, and the long-term reliability of the brush member 64 is not lowered.

  In this example, the resin layer is formed on the surface of the conductive fiber, but the surface of the conductive fiber is etched with a chemical solution to form a recess in the surface of the conductive fiber, and the resin layer is partially embedded in the conductive fiber. The adhesive strength between the conductive fiber and the resin layer can be improved. As described above, the case where the surface of the conductive fiber is smooth or recessed and the resin layer is partially embedded is also included in the present invention.

  Next, constituent members of the brush member 64 of the present invention will be described.

  The core plate 110 is made of a metal or alloy such as Fe, Al, Cu, or stainless steel, and is connected to an external ground, and charges for discharging the recording material P through the conductive fibers 120 and the carbon nanohorn 131 are carbon nanohorns. It works to supply to 131.

  Examples of the conductive fiber 120 include SUS fiber, carbon black, and metal fine particles dispersed in rayon resin, nylon resin, acrylic resin, polyester resin, etc., and then spun into a fiber shape, or tetracyanoquinoji. A material obtained by spinning a polymer resin in which a charge transfer complex composed of an electron accepting compound such as methane (TCNQ) and an electron donating compound such as tetrathiafulvalene (TTF) is substituted with a polymer network is used. These conductive fibers 120 are used by being attached to the core plate 110.

  The resin layer 130 requires a function of satisfying both the adhesive strength with the conductive fibers 120 and the holding strength of the carbon nanohorn 131 and not adhering the adjacent conductive fibers 120. An example of the structure that holds the carbon nanohorn 131 is a structure as shown in FIG.

  The resin layer 130 is made of a resin composed of at least one of a thermoplastic polymer resin or a hot melt type adhesive, and the carbon nanohorn 131 is partially embedded in the resin (the dotted line in the figure is embedded). The carbon nanohorn protrudes from the surface of the resin layer 130. Note that the end of the carbon nanohorn 131 embedded in the resin layer 130 may protrude from the resin and be in direct contact with the conductive fiber 120.

  Moreover, the resistance of the resin layer 130 is reduced by mixing the carbon nanohorns 131 in the resin. When the resistance of the resin layer 130 is reduced to the same level as the resistance of the conductive fiber 120, the charge is transported from the resin layer to the carbon nanohorn even if the carbon nanohorn 131 on the embedded side is in the resin. Does not become a large resistance component.

Therefore, in general, when the resistance of the resin layer 130 is reduced to 10 ³ to 10 ⁸ Ω · cm, the carbon nanohorn 131 on the embedded side may be terminated in the resin.

  Furthermore, if the resin layer 130 contains conductive particles (arranged in a resin in a dispersed state) to further reduce the resistance of the resin layer 130, the transport of charges from the conductive fiber 120 to the resin layer 130, It is desirable because charge transport from the resin layer 130 to the carbon nanohorn 131 becomes easier.

  For example, as conductive particles, fine particles of metals and alloys such as Fe, Ni, Co, Al, Au, Ag, and Pt, conductive inorganic materials such as graphite and fullerene, or metal thin films such as Ni, Co, and Al on the surface It is possible to use fine particles of a polymer resin that has been conductively processed by forming a conductive layer. The size of the conductive particles is preferably 10 μm or less, although it depends on the size of the resin layer and the material of the conductive particles.

  In addition to holding the carbon nanohorn, the resin constituting the resin layer 130 is fixed on the surface of the conductive fiber, so that adhesiveness is required. Since general polymer resins and adhesives have a certain degree of adhesiveness, it is not difficult to fix the resin layer 130 to the conductive fibers 120.

  However, in the process of forming the resin layer 130 on the surface of the conductive fiber 120, when the resin is liquid, it is very difficult to dispose the resin layers in a discrete manner. Therefore, inevitably in the process of fixing the resin layer to the conductive fiber, the resin must be in the form of a finely divided solid, and it is important to exhibit adhesion only in the bonding process with the conductive fiber. .

  As a material that exhibits these functions, there is a thermoplastic polymer resin that exhibits adhesiveness by heating. A hot-melt adhesive is more suitable because it has a higher adhesiveness than a thermoplastic polymer resin. When thermoplastic polymer resins or hot melt adhesives are used, their melting points must be lower than the softening point of the conductive fibers, the melting point.

  Other materials that can exhibit adhesiveness only in the bonding process include an ultraviolet curable adhesive, but in the case of an ultraviolet curable adhesive, when the resin layer 130 is formed at the base portion of the conductive fiber 120, the conductive layer It is necessary to make the ultraviolet rays reach the base portion of the conductive fiber 120, and it is necessary to devise a method for irradiating the ultraviolet rays. As a result, it is difficult to produce the brush member 64 holding the carbon nanohorn at a low cost.

  Further, when the resin layer 130 is fixed on the surface of the conductive fiber 120, it is necessary to avoid adhesion with the adjacent conductive fiber 120 in order to maintain the flexibility of the conductive fiber, and the size of the resin layer 130 is reduced. There is a need.

In general, the resin layer 130 has a capacity of 10 to 8000 μm ³ as a capacity (capacity per piece) in consideration of retention of carbon nanohorns, adhesion with conductive fibers, and avoidance of adhesion with adjacent conductive fibers. For example, 10 to 2000 μm ² is sufficient.

By avoiding adhesion with adjacent conductive fibers, good contact with the recording material P can be maintained, and the efficiency of adsorption of formaldehyde and charge removal is not lowered. In addition, as a means for reducing the size of the resin layer 130, in addition to reducing the capacity of the thermoplastic polymer resin or hot-melt adhesive fixed to the surface of the conductive fiber 120, the resin layer is formed on the surface of the conductive fiber 120. After forming 130, the resin layer 130 may be partially etched by plasma using a gas such as CF ₄ , O ₂ , and CO ₂ .

Since the polymer resin and the adhesive are mainly composed of C—H bonds, the etching rate is significantly higher than that of the carbon nanohorn composed only of carbon sp ² hybrid orbitals. Therefore, when exposed to the above plasma, the resin layer can be preferentially etched, and only the resin layer can be reduced.

  In addition, by reducing only the resin layer 130, the tip of the carbon nanohorn 131 that was initially completely buried in the resin layer 130 can be protruded from the surface of the resin layer 130, and the protrusion density of the carbon nanohorn can be reduced. The efficiency of formaldehyde adsorption and static elimination can be further improved.

Next, a method for producing a carbon nanohorn will be described.
As the single-walled carbon nanohorn aggregate, those produced by various conventionally known methods can be used. For example, it can be produced by a synthesis method such as a CO ₂ laser ablation method using graphite without a catalyst as a target in an Ar atmosphere at room temperature and 1.013 × 10 ⁵ Pa (760 Torr).

Specifically, a CO ₂ laser with a wavelength of 10.6 μm is applied at a beam diameter of 10 mm to a graphite target of φ30 × 50 mm rotating in a reaction chamber of room temperature, 1.013 × 10 ⁵ Pa (760 Torr), Ar atmosphere. Irradiation was performed, and carbon nanohorn as a product was recovered from the collection filter. The obtained carbon nanohorn is a spherical single-walled carbon nanohorn aggregate having a diameter of about 70 nm, in which a plurality of carbon nanohorns are gathered in a configuration in which the tubular portion is the center side and the conical portion protrudes to the surface portion like a corner. It was. Each carbon nanohorn had a tubular portion with a diameter of about 2 to 3 nm and a tubular portion with a length of about 30 nm.

Next, an example of a method for producing the brush member 64 of the present invention will be described with reference to FIG.
[Step (a)]
The carbon nanohorn 131 is mixed with a resin 151 composed of at least a thermoplastic polymer resin or a hot-melt adhesive to form fine particles 150. Further, if the carbon nanohorn 131 protrudes from the surface of the fine particle 150, the proportion of the carbon nanohorn 131 protruding from the resin layer 130 increases after the step (d) described later. 150 is heat-melted in the step (d) and bonded to the conductive fiber 120 to form one resin layer 130 holding the carbon nanohorn 131. Therefore, the size of the fine particles 150 is as good as the resin layer. 10 to 8000 μm ³ (the size is 10 to 2000 μm ² ).

  Since the resin 151 is a material that melts by heat, the resin 151 needs to have a melting point at a temperature lower than the melting point and softening point of the conductive fiber 120, and a hot-melt adhesive is more preferable than a thermoplastic polymer resin. Easy to select.

  As the thermoplastic polymer resin, polyethylene, polypropylene, polycarbonate, or the like can be used, and a hot-melt adhesive that is suitable for the following process may be selected from those that are widely available on the market. For example, PES100 series manufactured by Toa Gosei Co., Ltd. can be mentioned.

  Further, when the resin layer containing conductive particles is fixed to the conductive fiber 120, carbon nanohorn 131 and fine particles of metal or alloy such as Fe, Ni, Co, Al, Au, Ag, Pt or the like on the resin 151, or A conductive inorganic material such as graphite or fullerene, or fine particles obtained by mixing a polymer resin obtained by forming a metal thin film such as Ni, Co, or Al on the surface and conducting a conductive treatment may be used.

[Step (b)]
Thereafter, the fine particles 150 are dispersed in a solvent 152 that does not dissolve the resin 151. For example, when polyethylene, which is a thermoplastic polymer resin, is used, it is preferably dispersed in methanol, ethanol, water, or the like. When using Toa Gosei PES100 series as a hot melt adhesive, it is preferable to disperse the fine particles 150 in water.

  The addition amount of the fine particles 150 with respect to the solvent 152 is influenced by the density of the resin layer 130 attached to the conductive fibers 120 and the flocking density of the conductive fibers 120, but considering the uniform dispersion of the fine particles 150, 0.01 to 10 volumes. % Is good. Further, a surfactant may be added to the solvent 152 in order to prevent aggregation of the fine particles 150.

  It is necessary to select a solvent 152 that does not dissolve the conductive fiber 120 itself, but SUS, rayon, nylon, polyester, etc. constituting the conductive fiber are not damaged by water or a considerable number of general-purpose organic solvents. It is not difficult to select the solvent 152.

[Step (c)]
Thereafter, the conductive fibers 120 (the core plate 110 that holds the conductive fibers 120) is immersed in the dispersion in which the fine particles 150 are dispersed, and the fine particles 150 are attached to the surface of the conductive fibers 120. Note that the amount of the fine particles 150 attached to the conductive fiber 120 is preferably controlled by the amount of the fine particles 150 dispersed, the immersion time, the number of immersions, and the like.

[Step (d)]
Thereafter, the conductive fiber 120 is taken out from the dispersion liquid in which the fine particles 150 are dispersed, and heated to a temperature equal to or higher than the melting point of the thermoplastic polymer resin or the hot melt adhesive to melt the resin. Thereafter, the resin is cooled and cured again, thereby fixing the resin on the surface of the conductive fiber 120 and forming the discrete resin layers 130 holding the carbon nanohorns 131.

  Since the fine particles are small, the amount of resin that melts is small, and the flow of resin is small. Furthermore, by controlling the melting temperature, the flow of the resin can be further suppressed by optimizing the viscosity of the resin at the time of melting, so that while maintaining the carbon nanohorn without adhering adjacent conductive fibers, Sufficient adhesive strength can be secured.

  For example, when polyethylene is used as the thermoplastic polymer resin, the hot melt adhesive PES100 series is heated in the oven by 10 ° C. to 10 ° C. for 10 minutes and then naturally cooled. By heating for 15 minutes and then naturally cooling, the discrete resin layers 130 holding the carbon nanohorns 131 on the conductive fibers 120 can be formed.

Finally, when the carbon nanohorn 131 does not protrude from the resin layer 130, the resin layer 130 is partially etched by plasma using a gas such as CF ₄ , O ₂ , CO ₂ , and the protrusion of the carbon nanohorn is realized. good.

In the step (a), it is desirable that the carbon nanohorn 131 protrudes from the surface of the fine particles 150. However, even if the carbon nanohorn 131 does not protrude, the resin layer 130 is partially formed by plasma using a gas such as CF ₄ , O ₂ , CO _2. Therefore, the carbon nanohorn need not necessarily protrude from the surface in the form of fine particles.

Next, another method for producing the brush member 64 will be described with reference to FIG.
[Step (a)]
Similar to the above-described method, fine particles 150 in which a resin 151 made of at least a thermoplastic polymer resin or a hot melt adhesive and a carbon nanohorn 131 are mixed are dispersed in a solvent 152 that does not dissolve the resin 151.

[Step (b)]
Thereafter, conductive fibers 120 knitted in a pile fabric (110 for the core plate holding the conductive fibers 120) are immersed in the dispersion liquid in which the fine particles 150 are dispersed, and the fine particles adhere to the surface of the conductive fibers 120. Note that the amount of the fine particles 150 attached to the conductive fiber 120 is preferably controlled by the amount of the fine particles 150 dispersed, the immersion time, the number of immersions, and the like.

[Step (c)]
Thereafter, the conductive fiber 120 is taken out of the dispersion in which the fine particles 150 are dispersed, and heated to a temperature not higher than the melting point of the thermoplastic polymer resin or the hot melt adhesive to evaporate the solvent 152. For example, when polyethylene is used as the thermoplastic polymer resin and methanol is used as the solvent, the methanol can be evaporated without melting the polyethylene by heating to 80 ° C.

[Step (d)]
Thereafter, the fine particles 150 are heated to a temperature equal to or higher than the melting point of the thermoplastic polymer resin or hot melt adhesive to melt the resin. Thereafter, the resin is cooled and cured again, thereby fixing the resin on the surface of the conductive fiber 120 and forming the discrete resin layers 130 holding the carbon nanohorns 131.

  According to this method, since the solvent 152 at the interface between the fine particles 150 and the conductive fibers 120 can be completely removed before the fine particles 150 are heated and melted, the adhesive force between the resin layer 130 and the conductive fibers 120 is improved. As a result, the carbon nanohorn 131 is not easily detached even by contact with the recording material P, and the long-term reliability of the brush member 64 is improved.

  When a solvent having a high boiling point such as water is used as the solvent 152, the evaporation of the solvent 152 can be accelerated by heating under reduced pressure, and the solvent can be completely removed at a low temperature, that is, without melting the resin.

Finally, if necessary, the resin layer 130 may be partially etched by plasma using a gas such as CF ₄ , O ₂ , and CO _{2 in} the same manner as described above.

The brush member 64 can also be produced by the method shown in FIG.
[Step (a)]
Similar to the above-described method, fine particles 150 in which a resin 151 made of at least a thermoplastic polymer resin or a hot melt adhesive and a carbon nanohorn 131 are mixed are dispersed in a solvent 152 that does not dissolve the resin 151.

[Step (b)]
After that, the dispersion liquid in which the fine particles 150 are dispersed is atomized using the spraying device 153 and applied to the conductive fibers 120 (the conductive fibers 120 are held by the core plate 110), and the fine particles are applied to the surface of the conductive fibers 120. 150 is deposited.

  In the wet spraying, the fine particles 150 are transferred to the conductive fibers 120 by controlling the liquid temperature of the dispersion and the liquid diameter of the dispersion, the distance between the outlet of the spray device 153 and the conductive fibers 120, the environmental temperature of the conductive fibers 120, and the like. During arrival, the solvent 152 can be completely evaporated, and the dry fine particles 150 can be attached to the conductive fibers 120. In order to prevent aggregation of the fine particles 150 after spraying, it is preferable to control the spraying conditions so that only one fine particle 150 enters each droplet. Note that as the spraying device 153, a low-pressure sprayer, a high-pressure sprayer, an ultrasonic sprayer, or the like can be used.

[Step (c)]
Thereafter, the fine particles 150 are heated to a temperature equal to or higher than the melting point of the thermoplastic polymer resin or hot melt adhesive to melt the resin. Thereafter, the resin is cooled and cured again, thereby fixing the resin on the surface of the conductive fiber 120 and forming the discrete resin layers 130 holding the carbon nanohorns 131.

  Also by this method, since the solvent 152 is not left between the fine particles 150 and the conductive fibers 120, the adhesive force between the resin layer 130 and the conductive fibers 120 is improved, and the carbon nanohorn 131 can be detached even by contact with the recording material P. Separation hardly occurs, and the long-term reliability of the brush member 64 is improved.

Finally, if necessary, the resin layer 130 may be partially etched by plasma using a gas such as CF ₄ , O ₂ , and CO _{2 in} the same manner as described above.

The brush member 64 of the present invention can also be produced by a method that does not use a dispersion as shown in FIG.
[Step (a)]
Similar to the above-described method, fine particles 150 are prepared by mixing a resin 151 made of at least a thermoplastic polymer resin or a hot-melt adhesive and a carbon nanohorn 131.

[Step (b)]
Thereafter, the fine particles 150 are filled in a dry spray device 154 (for example, a high-pressure sprayer), and the fine particles 150 are sprayed without agglomeration by placing the fine particles 150 on a high-pressure gas flow such as N ₂ gas. Directly below and in the vicinity of the spray flow, the flow rate of the fine particles 150 is large and the fine particles 150 do not easily adhere to the conductive fibers 120. Therefore, the conductive fibers 120 (the conductive fibers 120 are held by the core plate 110) are separated from the spray flow. The fine particles 150 placed and diffused are attached to the conductive fibers 120. Since the diffused fine particles have a low flow rate, they easily adhere to the conductive fibers 120.

  In order to prevent aggregation of the fine particles 150, it is preferable to cause electrostatic repulsion by increasing the number of collisions between the fine particles 150 and the inner wall of the device in the spraying device and charging the fine particles to the same polarity by frictional charging with the wall. . Further, by applying a voltage having a polarity opposite to that of charging charged with fine particles to the conductive fiber 120, the adhesion of the fine particles 150 to the conductive fiber 120 may be promoted by electrostatic force.

[Step (c)]
Thereafter, the fine particles 150 are heated to a temperature equal to or higher than the melting point of the thermoplastic polymer resin or hot melt adhesive to melt the resin. Thereafter, the resin is cooled and cured again, thereby fixing the resin on the surface of the conductive fiber 120 and forming the discrete resin layers 130 holding the carbon nanohorns 131.

  According to this method, since it is not necessary to disperse the fine particles 150 in a solvent, the process can be simplified and the brush member 64 can be produced at a lower cost.

  Note that the method for producing the brush member 64 according to the present invention is not limited to the method described above, and the conductive fibers 120 in a wet or dry state with the fine particles 150 in which the resin 151 and the carbon nanohorn 131 are mixed by an arbitrary method. Then, the resin is fixed to the surface of the conductive fiber 120 by holding the carbon nanohorn 131 by heating the resin 151 at a temperature equal to or higher than the melting point of the resin 151 to melt the resin, and then cooling and curing the resin again. It does not matter if the discrete resin layers 130 are formed.

Next, an example of a method for producing the fine particles 150 obtained by mixing the resin 151 and the carbon nanohorn 131 will be described with reference to FIG.
[Step (a)]
At least a pellet 161, granule or powder resin 161 made of a thermoplastic polymer resin or hot melt adhesive and carbon nanohorn 131 are premixed.

  A larger ratio of the carbon nanohorn 131 to the resin 161 is preferable because the density of the carbon nanohorn 131 protruding from the surface of the fine particle 150 is increased. However, if the carbon nanohorn 131 is too much, the formed fine particle 150 becomes brittle and becomes unsuitable for the process.

  The amount of carbon nanohorn 131 that can be added is determined by the thermoplastic polymer resin to be used and the hot melt adhesive, but is preferably about 10 to 50% volume.

When the proportion of the carbon nanohorn 131 cannot be increased, the formed fine particles 150 are exposed to plasma using a gas such as CF ₄ , O ₂ , CO ₂ , and the resin layer 130 is partially etched to protrude the carbon nanohorn 131. When the density is increased, after fixing the fine particles to the conductive fiber, the density of the carbon nanohorn protruding from the resin layer 130 tends to increase, and improvement in the efficiency of formaldehyde adsorption and charge removal can be expected.

  Further, when a resin layer containing conductive particles is prepared, fine particles of metal or alloy such as Fe, Ni, Co, Al, Au, Ag, Pt or the like, or graphite, fullerene, etc. are simultaneously formed on the resin 161 on the carbon nanohorn 131. A conductive inorganic material or fine particles of a polymer resin formed by conducting a conductive treatment by forming a metal thin film such as Ni, Co, or Al on the surface may be mixed.

[Step (b)]
Thereafter, the carbon nanohorn 131 and the resin are stirred using a homogenizer or the like in a state where the resin 161 is heated to a melting point or higher and sufficiently melted, and the carbon nanohorn 131 is uniformly dispersed in the melted resin 161.

[Step (c)]
Thereafter, the resin is cooled and re-cured to form a mixture 170 in which the carbon nanohorns 131 are uniformly dispersed in the resin.

[Step (d)]
Thereafter, the mixture 170 is preliminarily pulverized in a mortar and then pulverized using a ball mill, a jet mill or the like to form fine particles 150 made of a resin holding the carbon nanohorn 131.

  Since the carbon nanohorn is much harder than the resin, only the resin is pulverized at the time of pulverization, the carbon nanohorn is not broken, and finally, fine particles with the carbon nanohorn protruding from the surface are obtained.

  It is most preferable to finely pulverize the fine particles 150 to a size that can be used in the above-described method (this is influenced by the size of the carbon nanohorn used, but 20 μm or less is a guideline). In the case where a large amount of fine particles having a particle size of less than 1 mm cannot be obtained, the pulverized fine particles 150 may be classified by sieving, and only the fine particles 150 having a predetermined size or less may be used.

Further, when the pulverized fine particles 150 are partially etched by plasma using a gas such as CF ₄ , O ₂ , CO ₂ , and the protrusion density of the carbon nanohorn 131 is improved, the fine particles are fixed to the conductive fibers. Then, the density of the carbon nanohorn protruding from the resin layer 130 is increased, which is more desirable.

  Further, in the main pulverization, a small amount of a solvent that does not dissolve the resin may be added, and the main pulverization may be performed by a ball mill in a wet state. In this case, the fine particles together with the solvent are collected and dispersed in the solvent. What is necessary is just to produce the brush member 64 by the method of FIG.

  By combining the method for producing the fine particles 150 and the method for producing the brush member 64 described above, a discrete resin layer in which carbon nanohorns are held on conductive fibers can be formed, and the brush member has excellent formaldehyde adsorption and charge removal efficiency. 64 can be realized.

  In this example, the fixed brush member 64 has been described. However, the effect of the present invention can be similarly realized even with a brush that performs driven rotation or counter rotation.

  As described above, the core plate of the brush member 64 is made of an aluminum plate, and is connected to the ground. The recording material P on which the image has been fixed by the fixing device 6 removes the charges on the front and back surfaces and the organic volatile gas such as formaldehyde present on the paper by the contact of the brush member. The brush member 64 is mainly a carbon nanohorn and contacts the surface of the recording material P.

  The amount of organic volatile gas generated increases as the temperature immediately after fixing increases. Therefore, the contact of the brush member is more efficient as the temperature of the recording material P is higher. Since the amount of generation is large at a temperature higher than room temperature, particularly 50 degrees or more, it is necessary to bring the brush member into contact before the recording material P reaches room temperature. This is considered to be due to the fact that gas tends to be generated when the glass transition temperature of the resin contained in the coated paper is exceeded.

  In the present invention, the surface layer of the brush member 64 is formed of a member having pores of about the molecular size such as the carbon nanohorn described above, and traps formaldehyde molecules. The molecular size of organic volatile gas such as formaldehyde is approximately 1 nm or less, and an adsorbent having pores of 1 nm or more is required. On the other hand, when it has an average pore diameter of 10 nm or more, the specific surface area becomes small and the adsorption efficiency is poor. Accordingly, it is desirable that the pore diameter is at least larger than that of formaldehyde molecules and 10 nm or less. In that respect, carbon nanohorns are preferred. Furthermore, the diameter of the carbon nanohorn can be changed by oxidation treatment, and the diameter can correspond to the formaldehyde molecule. They are also stable at relatively high temperatures. Since it has electrical conductivity, it can also serve as a conventional static elimination needle, saving space and reducing costs.

The carbon nanohorn will be described in more detail.
As the carbon nanohorn used in the present invention, a single-layer carbon nanohorn is suitable.

  According to the April 2003 issue of industrial materials, carbon nanohorns are one of the carbon nanotube-like substances. Single-walled carbon nanohorn (SWNH) is characterized by having a tube portion and a triangular cone-shaped cone portion. Overall, it has the shape of a horn. Single-walled carbon nanohorn particles gather to form secondary particles. This is shown in FIG. The gas is mainly adsorbed and stored in the gaps between the single-walled carbon nanohorn particles constituting the secondary particles and in the single-walled carbon nanohorn particles. The characteristics of the single-walled carbon nanohorn are that the pore structure in the nano-order is uniform compared to the conventional carbon material-based adsorbent, and that the pores are as shown in FIGS. 10 (c) and 10 (d). It has a unique shape. The pores of the single-walled carbon nanohorn consist of cylindrical pores having a diameter of about 1 to 3 nm and a length of about 30 to 50 nm inside the single-walled carbon nanohorn, and three single-walled carbon nanohorns or four single-walled carbon nanohorns. It can be classified as either a triangular prism with a slight dent in the gap or a quadrangular columnar pore.

  Since the size of the pores inside the single-walled carbon nanohorn is relatively large, large molecules can be adsorbed. In an ordinary carbon material-based adsorbent, the amount of adsorption decreases as the pore diameter increases. When compared with the same pore size, the single-walled carbon nanohorn has excellent adsorption performance. The pores inside the carbon nanohorn are assumed to have a larger adsorption area than the diameter because of the cylindrical shape having a length of 10 times or more compared to the diameter. This is shown in FIG.

  FIG. 11 shows a performance comparison between a single-walled carbon nanohorn (SWNH) and a conventional carbon material-based adsorbent. Measurement was carried out by measuring the density of adsorbed methane at 303 K and 35 atm by a gravimetric method. A-5, A-10, and A-20 are activated carbon fibers, and AX21 and a-MCMB are high surface area activated carbons. The activated carbon fiber is a fibrous carbon material and is characterized by having a more uniform pore structure than ordinary activated carbon. AX21 and a-MCMB are one type of granular activated carbon, but are one of the activated carbons having the largest pore volume. These substances have slit-shaped pores, and the average pore diameters of A-5, A-10, and A-20 are 0.7 nm, 0.8 nm, and 1.2 nm, respectively, and AX21 and a- In MCMB, they are 1.3 nm and 1.6 nm.

  Carbon nanohorns and carbon nanotubes have π electrons like benzene. Thanks to this π electron, it has the property of conducting electricity well. Therefore, it is a very suitable material for a static elimination needle.

  The amount of formaldehyde discharged out of the apparatus was measured from an image forming apparatus using a conventional product made of only SUS fibers as the brush member 64 and a product of the present invention in which carbon nanohorns were bonded to the surface. Specifically, a digital full-color copying machine (CLC5000 manufactured by Canon, copy speed A4, 50 sheets / min) was used, and measurement was performed according to the OSHA regulations measurement method. The result is shown in FIG.

  Compared with a conventional image forming apparatus, when the carbon nanohorn is brought into contact with the recording material P immediately after fixing as in the present invention, the amount of formaldehyde generated is reduced to about 1/7.

  In the above description, the surface layer of the adsorbent is composed of carbon nanohorns, but the same effect can be obtained with carbon nanotubes. Hereinafter, the carbon nanotube will be described.

  Carbon nanotubes include single-walled carbon nanotubes and multi-walled carbon nanotubes. Single-walled carbon nanotubes have a diameter of 0.7 to 50 nm and an axial length (hereinafter abbreviated as length) of 10 nm to 1 mm, which is easier to synthesize. The size is 0.7 to 5 nm in diameter and 30 nm to 100 μm in length.

  On the other hand, the multi-walled carbon nanotube has a diameter of 1 to 500 nm and a length of 10 nm to 1 mm. As a size that is easier to synthesize, the diameter is 2 to 50 nm and the length is 1 μm or more. Both have an extremely fine fiber shape with a very large aspect ratio. Therefore, these aggregates of carbon nanotubes have a pore structure similar to a cylindrical shape, and can have a large adsorption amount compared to the pore diameter.

Carbon nanotubes are produced by the following method. Single-walled carbon nanotubes use a composite rod in which a metal catalyst such as Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, La, Y is mixed with graphite as an anode, and a graphite rod as a cathode. It is synthesized by arc discharge in a He or H ₂ atmosphere of 1.33 × 10 ^{4 to} 9.31 × 10 ⁴ Pa (100 to 700 Torr).

Single-walled carbon nanotubes are present in the wall of the inner wall of the discharge chamber (chamber wall) or in the wall of the cathode surface (cathode wall) depending on the type of metal catalyst. The composite rod was heated to 1000 to 1400 ° C. in an electric furnace, and a single-walled carbon nanotube was synthesized by irradiating with an Nd: YAG pulse laser in an Ar atmosphere of 6.65 × 10 ⁴ Pa (500 Torr). Also good. Since the synthesized single-walled carbon nanotube contains various impurities, it may be purified by a hydrothermal method, a centrifugal separation method, an ultrafiltration method, or the like.

On the other hand, multi-walled carbon nanotubes are synthesized by using arc discharge in a He atmosphere of 1.33 × 10 ^{4 to} 9.31 × 10 ⁴ Pa (100 to 700 Torr) using graphite rods for both the anode and the cathode. The multi-walled carbon nanotube exists in the center of the cylindrical deposit on the cathode.

  Since multi-walled carbon nanotubes also contain various impurities after synthesis, they are preferably purified to high purity by a centrifugal separation method or ultrafiltration method after being dispersed in an aqueous solution to which an organic solvent or a surfactant is added.

  Even when the unpurified carbon nanotubes are held in the resin layer 130, the carbon nanotubes protruding on the surface of the resin layer 130 contribute to an increase in the conductive contacts. Therefore, the present invention is applicable to both the purified and unpurified carbon nanotubes. References are made to carbon nanotubes.

  Further, the tip of the carbon nanotube may have a closed tube shape or an open tube shape. In addition, carbon nanotubes produced by chemical vapor deposition can produce carbon nanotubes with a higher purity than arc discharge methods or laser ablation methods.

  Since long carbon nanotubes can have more contacts with the recording material P, the efficiency of static elimination and formaldehyde removal is further improved by holding the carbon nanotubes produced by chemical vapor deposition in the resin layer 130. it can.

  Furthermore, in the chemical vapor deposition method, since the carbon nanotubes are produced with high purity, the carbon nanotube purification step is not required, and the brush member 64 can be produced at a lower cost.

  An example of chemical vapor deposition will be described. First, a catalyst layer made of one of Fe, Ni, Co, Fe alloy, Ni alloy, Co alloy, Fe oxide, Ni oxide or Co oxide is formed on the support, and the catalyst layer is made fine by annealing. To do.

Thereafter, when hydrocarbon gas such as CH ₄ , C ₂ H ₂ , C ₂ H _4, etc. is introduced and the hydrocarbon gas is pyrolyzed at around 700 to 1200 ° C., a catalyst layer is formed and carbon nanotubes are formed on the support. grow up. In particular, carbon nanotubes grown vertically from the support can also be obtained by optimizing the gas flow rate, thermal decomposition temperature, and catalyst configuration.

  The vertically aligned carbon nanotubes can be easily handled in subsequent processes. In addition, carbon nanotubes produced by this production method continue to grow during the synthesis time, so the length can be easily controlled by the synthesis time, and the length that was difficult to synthesize in large quantities by the arc discharge method. Carbon nanotubes that are long (generally, carbon nanotubes with a length of 20 μm or more can be obtained at almost 100%) can be obtained stably and in large quantities.

  Further, the surface layer of the adsorbent may be a composite of carbon nanotubes and carbon nanohorns. Higher adsorptivity can be expected.

  The carbon nanotube / carbon nanohorn composite is characterized in that carbon nanotubes and carbon nanohorn aggregates are dispersed and aggregated. This dispersion state is such that the carbon nanotubes do not form a bundle at all, or are entangled as a bundle consisting of a very small number, and the carbon nanohorn aggregates enter the carbon nanotubes in a substantially uniform distribution state. In this state, the carbon nanotubes and the carbon nanohorn aggregates are dispersed with each other to prevent aggregation of each other.

  Therefore, in the carbon nanotube / carbon nanohorn composite, for example, when attention is paid to the carbon nanohorn aggregate, it is possible to extremely effectively utilize the space formed between the tips of the carbon nanohorn, which is a surface structure unique to the carbon nanohorn aggregate. become able to. Moreover, since the bundle is not formed also in the carbon nanotube, the effective specific surface area increases.

  The carbon nanotube / carbon nanohorn complex as described above is composed of a step 1 in which carbon nanotubes are placed in a liquid solvent and irradiated with ultrasonic waves to disperse the carbon nanotubes in the liquid solvent, and a liquid solvent in which the carbon nanotubes are dispersed. It can be manufactured by a manufacturing method including step 2 of adding a carbon nanohorn aggregate and removing the liquid solvent.

  Carbon nanotubes are not limited in diameter and length, and may be either single-walled carbon nanotubes with a single cylinder or multi-walled carbon nanotubes with a single cylinder. Any one can be used accordingly.

  Similarly, the diameter of the carbon nanohorn aggregate is not limited, and either a dahlia-shaped carbon nanohorn aggregate in which carbon nanohorns are aggregated in the shape of a dahlia or a bud-shaped carbon nanohorn aggregate in which the carbon nanohorn is aggregated in a flower bud shape. Any one can be used depending on the purpose of use.

  Various liquid solvents can also be used, for example, inorganic solvents such as water, carbon disulfide, and acids, organic solvents such as hydrocarbons such as benzene, toluene, and xylene, alcohols, ethers, and derivatives thereof, Polymers such as polymethyl methacrylate (PMMA), polyethylene (PE), polyvinyl chloride (PVC), and mixtures thereof can be appropriately selected and used. In the present invention, it is an organic solvent that is easy to handle as a liquid solvent.

  In the step 1, carbon nanotubes are put into the liquid solvent, and stirred with a stirrer or the like as necessary to blend the carbon nanotubes with the liquid solvent, and then irradiated with ultrasonic waves. Here, the carbon nanotubes dispersed in the liquid solvent are unwound into bundles by being irradiated with ultrasonic waves, and some of them are cut or form defects and pores, and react with the liquid solvent molecules at the defect. To do. In other words, normal carbon nanotubes rapidly re-form the bundle due to the strong van der Waals cohesive force, but the six-membered ring network of the graphite sheet constituting the carbon nanotubes becomes discontinuous, and the carbon nanotubes The cohesive force due to the van der Waals force acting is weakened, and the dispersed state can be maintained.

It is preferable that the ultrasonic wave irradiated to the liquid solvent has a relatively strong energy. The energy of this ultrasonic wave is unclear because it is related to the state of the carbon nanotubes used, the type of liquid solvent, their amount, and the irradiation time of the ultrasonic wave. It will supply the energy needed to cut. Specifically, only an estimate to be irradiated about 3-6 hours 250~350W / cm ² of about ultrasound, more specifically, for example, 300 W / cm ² of about ultrasound for 5 hours Illumination and the like are exemplified. At this time, it is more effective to irradiate the ultrasonic wave by directly bringing the tip of the ultrasonic supply means into contact with the liquid solvent.

  Next, in the step 2, the carbon nanohorn aggregate is added to the liquid solvent in which the carbon nanotubes are dispersed in this way, and the liquid solvent is removed by stirring, filtering, or the like as necessary. There is no restriction | limiting in particular about the mixing ratio of a carbon nanotube and a carbon nanohorn aggregate | assembly, It can be set as arbitrary. However, when either of the carbon nanotubes and the carbon nanohorn aggregates is extremely large, the yield as a composite is lowered, which is not preferable. Then, the nanohorn aggregate placed in the liquid solvent uniformly enters between the dispersed nanotubes, and remains in this state even after the solvent is removed. In this process, the carbon nanohorn aggregates are physically adsorbed on the surface of the carbon nanotubes, and are chemically adsorbed on the active cutting sites or defects and pores formed on the carbon nanotubes, and are entangled simultaneously with the aggregation. . Thereby, the carbon nanotube / carbon nanohorn complex as described above can be obtained.

  In addition, for example, when carbon nanotubes are mass-produced, fullerene, amorphous carbon, catalytic metal particles, and the like may be mixed as impurities in the manufacturing process. Many of these impurities adhere to the gaps between the carbon nanotubes. Thus, as Step 1A, it is possible to consider removing the impurities that are dispersed and the carbon nanotubes are dispersed by filtering the liquid solvent obtained in Step 1 above. After the filtered carbon nanotubes are put in a new liquid solvent, the same procedure as described above can be used.

  Furthermore, as the step 1B, it is possible to consider heating the carbon nanotubes filtered in the above step 1A in an oxygen atmosphere before putting them in the liquid solvent. Thereby, liquid solvent molecules reacted with the carbon nanotubes, further residual impurities, and the like can be removed.

  The carbon nanotube / carbon nanohorn composite thus obtained can maintain the structure in which the nanohorn aggregates enter between the nanotubes dispersed by the ultrasonic treatment, and each prevents aggregation of each other. Therefore, the space between the horn tips, which is peculiar to the structure of the carbon nanohorn aggregate, can be utilized very effectively. In addition, the bundle of nanotubes can be dispersed, and the surface and the inside of the nanotube can be effectively used.

  According to this carbon nanotube / carbon nanohorn complex, the specific surface area can be increased in the gas adsorption than when the nanohorn aggregate is used alone, so that the amount of adsorption can be expected to increase.

  Below, the detailed preparation method of a carbon nanotube carbon nanohorn composite_body | complex is demonstrated.

  Single-walled carbon nanotubes were produced by a laser ablation method using graphite pellets to which Co and Ni were added as metal catalysts as targets and ablating with a second harmonic of an Nd: YAG laser at 1200 ° C. in an Ar stream. About 50 single-walled carbon nanotubes having irregular lengths were aggregated to form a bundle.

A monochlorobenzene (MCB) solution of 2% polymethyl methacrylate (PMMA) was used as a liquid solvent, and 15 ml of this MBC solution and about 5 mg of single-walled carbon nanotubes were mixed with a magnetic stirrer for 2 hours. The MCB solution was irradiated with ultrasonic waves by bringing a tip (ultrasonic wave generating vibration rod) having a diameter of 3 mm of an ultrasonic wave generator into contact therewith. The ultrasonic treatment conditions were an energy of 300 W / cm ² and an irradiation time of 5 hours.

The single-walled carbon nanotube, the MCB solution, and the impurities were separated by filtering the MCB solution after ultrasonic irradiation through a filter having a pore diameter of 20 μm and 5 μm. Furthermore, in order to remove carbonaceous impurities such as remaining MCB, amorphous carbon, fullerene, and carbon nanocapsules from the single-walled carbon nanotube, 400 ° C., 3.99 × 10 ⁴ Pa (300 Torr), 100 ml. A baking treatment was performed for 30 minutes in an oxygen atmosphere of / min.

  This single-walled carbon nanotube was again put into the MCB solution and stirred with a magnetic stirrer. At this time, it was confirmed that the single-walled carbon nanotubes were easily dispersed in the MCB solution and maintained in a dispersed state without agglomeration even after stirring.

The carbon nanohorn aggregate was placed in the MCB solution in which the single-walled carbon nanotubes were dispersed. The carbon nanohorn aggregate used was a φ30 × 50 mm in which a CO ₂ laser having a wavelength of 10.6 μm and a beam diameter of 10 mm was provided in a reaction chamber (room temperature, 1.013 × 10 ⁵ Pa (760 Torr), Ar atmosphere). It was generated by irradiating a graphite target of the sample and collected on a collection filter.

  Again, this solution was stirred with a magnetic stirrer and filtered to obtain a solid. According to the results obtained by observing the obtained substance with a scanning electron microscope (SEM) or a transmission electron microscope (TEM), it was confirmed that the carbon nanotubes and the carbon nanohorn aggregates were uniformly mixed with each other. . It was also confirmed that a highly dispersed carbon nanotube / carbon nanohorn composite was obtained. Furthermore, it was observed that the carbon nanohorn aggregates were entangled with the carbon nanotubes and the graphite layers of both were complicated. From these, it can be seen that the carbon nanohorn aggregates are physically adsorbed on the surface of the porous carbon nanotubes, chemisorbed to active pores or defect sites on the surface of the porous carbon nanotubes, and entangled simultaneously with the aggregation.

1 is a schematic diagram illustrating a configuration example of an image forming apparatus to which a fixing device having an adsorbent according to the present invention is applied. It is the schematic which shows one structural example of the fixing device which has the adsorbent which concerns on this invention. It is the schematic which shows one structural example of the brush member which has the adsorption material which concerns on this invention on the surface. It is a figure for demonstrating the holding | maintenance state of the adsorbent which concerns on this invention. It is a figure for demonstrating an example of the production method of the brush member which has the adsorption material which concerns on this invention on the surface. It is a figure for demonstrating another example of the preparation methods of the brush member which has the adsorption material which concerns on this invention on the surface. It is a figure for demonstrating another example of the preparation methods of the brush member which has the adsorption material which concerns on this invention on the surface. It is a figure for demonstrating another example of the preparation methods of the brush member which has the adsorption material which concerns on this invention on the surface. It is a figure for demonstrating another example of the preparation methods of the brush member which has the adsorption material which concerns on this invention on the surface. It is a figure for demonstrating a single layer carbon nanohorn and its secondary particle. It is a figure for demonstrating the performance of a single layer carbon nanohorn and the adsorption material of the conventional carbon material type | system | group. It is a figure which shows the measurement result of the amount of formaldehyde discharged | emitted from the image forming apparatus using the conventional product made only from SUS fiber as a brush member, and the product of this invention which couple | bonded the carbon nanohorn with the surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging roller 3 Exposure apparatus 4 Developer 5 Transfer roller 6 Fixing apparatus 7 Cleaner 21 Manual feed tray 22, 25 Paper feed roller 23 Registration roller 24 Paper feed cassette 61 Fixing roller 62 Pressure roller 64 Brush member (adsorbing material)
110 Core plate 120 Conductive fiber 130 Resin layer 131 Carbon nanohorn 150 Fine particles 151 obtained by mixing carbon nanohorn with resin Resin 152 Solvent 153 Spraying device 154 Dry spraying device P Recording material (sheet material)

Claims (8)

  An adsorbent that comes into contact with the sheet material after the toner image transferred to the sheet material has been fixed by heat, and has a cylindrical shape with a diameter of 1 to 3 nm and a length that is at least 10 times the diameter. An adsorbent comprising a member having a hole.   The adsorbent according to claim 1, wherein the member having pores is a carbon nanohorn.   An aggregate of thin wires having a diameter of 0.7 to 500 nm and an axial length of 10 nm to 1 mm, which is an adsorbent that comes into contact with the sheet material after the toner image transferred to the sheet material is fixed by heat An adsorbent characterized by comprising:   The adsorbent according to claim 3, wherein the aggregate is an aggregate of carbon nanotubes.   An adsorbent that comes into contact with the sheet material after the toner image transferred to the sheet material has been fixed by heat, and has a cylindrical shape with a diameter of 1 to 3 nm and a length that is at least 10 times the diameter. An adsorbent comprising a member having a hole and an aggregate of fine wires having a diameter of 0.7 to 500 nm and an axial length of 10 nm to 1 mm.   The adsorbent according to claim 5, wherein the member having the pores is a carbon nanohorn, and the aggregate is an aggregate of carbon nanotubes.   The adsorbent according to any one of claims 1 to 6, wherein the adsorbent has conductivity, is electrically connected to ground, and is a static elimination needle.   The adsorbent according to any one of claims 1 to 7, wherein the temperature of the sheet material when the adsorbent comes into contact is 50 ° C or higher.

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