JP2006030945A - Fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of a fault due to staining of toner sticking to a separation plate by equipping a paper passage surface of the separation plate in a fixing device with a sheet member. <P>SOLUTION: The sheet member 8 which is a thin film material composed of a fluororesin and the like having an excellent release property is stuck to the paper passage surface 5a of the separation plate 5 whose front end is placed in proximity to a nip section 7 of a pressure roller 2 and a fixing belt 3. Further, the sheet member 8 is stuck up to an edge 5b of the paper passage surface 5a to which the toner is liable to stick in a separation section 5, and thereby, a countermeasure for preventing the adhesion of the toner is devised. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fixing device for fixing a toner image transferred onto a recording sheet in an image processing apparatus equipped with an electrophotographic image forming process.

  Fixing by which the recording paper on which the toner image is formed is sandwiched between the fixing belt or the fixing roller and the nip portion between the pressure roller and the pressure roller, and the toner image is fixed on the recording paper by applying heat and / or pressure. In the electrophotographic image forming apparatus having the apparatus, the recording paper on which the toner image is fixed at the nip portion is wound around the fixing belt or the fixing roller by the adhesive force of the toner, and is left as it is from the nip portion. There are many cases where it is discharged to cause separation failure. On the other hand, when performing double-sided printing, conversely, it may wrap around the pressure roller and cause separation failure.

  As one of the solutions to these separation failures, the recording is discharged in a state where the separation claw is brought into contact with the surface of the fixing belt immediately after the exit of the nip portion or a fixing member such as a fixing roller and a pressure roller. There is a technology that forces paper separation. However, when the separation claw is used, scratches (claw marks) are generated by scraping the surface of the fixing member with the separation claw, which causes image defects.

  Therefore, a separation plate is generally used instead of the separation claw. The separation plate and the separation claw are a plurality of separation claws that contact the image passing portion on the surface of the fixing member, whereas the separation plate is not in contact with the fixing member at the image passing portion. It differs in that it is installed in a state.

  One of the problems with the separation plate is adhesion of toner to the sheet passing surface of the separation plate. When the separation plate is made of sheet metal or the like, the toner adheres to the sheet passing surface over time, and this is another recording sheet. There is a problem that an image defect occurs due to retransfer at the time of passing.

  In order to solve the problem caused by the toner adhesion, as described in Patent Document 1, a technique has been proposed in which a sheet-like member is attached to a separation plate and a sheet-like member soiled with toner can be peeled off. Yes.

Conventionally, various studies have been conducted mainly on binder resins in order to achieve both fixing performance and hot offset resistance. In Patent Document 2, in a chromatograph measured by gel permeation chromatography of a resin for toner, at least one is present in each of a region having a molecular weight of 10 ^{3 to} 7 × 10 ^{4 and} a region having a molecular weight of 10 ⁵ to 2 × 10 ^6. It has been proposed to use a resin having a molecular weight distribution having the above maximum value.

  In Patent Documents 3 and 4, a fixing agent and hot offset are both achieved by inserting a release agent such as polyethylene while defining the molecular weight distribution of the vinyl copolymer. In Patent Document 5, a combination of a low-viscosity resin and a high-viscosity resin is used to improve compatibility between low-temperature fixing and hot offset.

  In addition, a number of applications have been filed for broadening the molecular weight distribution of the binder resin and taking into account the optimizing balance between the conflicting fixability and hot offset (for example, Patent Documents 3, 4, 6 to 9).

  Patent Document 10 contains a vinyl polymer and two types of polyethylene waxes having different softening points and / or two types of polypropylene waxes having different softening points, one of which is added at the time of polymerization and the other at the time of kneading. A blended electrophotographic developer is disclosed.

  In Patent Document 11, linear polyester is used as a fixing resin, and a wax having a softening point comparable to that of linear polyester and a wax having a higher softening point than linear polyester are used in combination as a release agent. Toner is disclosed.

Conventionally, dry toners used for electrophotography, electrostatic recording, electrostatic printing, and the like have been obtained by melt-kneading and finely pulverizing a toner binder such as styrene resin and polyester together with a colorant. .
JP 2003-280440 A Japanese Patent Laid-Open No. 5-107803 Japanese Patent Laid-Open No. 5-289399 JP-A-5-313413 JP-A-5-297630 Japanese Patent Laid-Open No. 5-053722 JP-A-6-027733 JP-A-6-074426 JP-A-6-118702 JP-A-4-358159 JP-A-6-130714

  However, in the prior art described in Patent Document 1, since the sheet-like member is provided only on the surface on the recording paper conveyance side of the separation plate, depending on the state of the toner adhering to the separation plate, the above-mentioned is simply used. The problem due to toner contamination cannot be prevented by simply attaching a sheet-like member to the surface.

  In Patent Documents 2 to 9, both good fixing performance and hot offset resistance performance are compatible, but in electrophotography, not only these two conflicting properties but also low molecular weight components are present. The heat-resistant storage stability that greatly affects must also be satisfied.

  These are the effects of molecular weight distribution and low molecular weight olefins, and although low-temperature fixing and heat-resistant storage stability are improved, they have not yet been adequately addressed in recent energy savings or low power consumption. Improvement is desired.

  In particular, in order to improve the low-temperature fixability, it is required to lower the glass transition point (Tg) and molecular weight of the binder resin, but considering the balance with hot offset and storage stability, the toner satisfying all of these needs. Development is difficult.

  In addition, the invention described in Patent Document 10 has a high softening point of wax used at 100 ° C. or higher, and the temperature difference between the softening points of the two waxes is as small as 2 ° C. to 20 ° C. Although it has excellent properties, it has poor low-temperature fixability.

  In the invention described in Patent Document 11, although the toner is at a level where there is no practical problem in both blocking resistance and offset resistance, the wax used has a high melting point and is inferior in low-temperature fixability.

  In addition, as described above, as dry toner used for electrophotography, electrostatic recording, electrostatic printing, etc., a toner binder such as styrene resin and polyester is melt-kneaded together with a colorant and finely pulverized. It has been.

  Usually, in order to obtain high-quality and high-quality images, improvements have been made by reducing the particle diameter of the toner. However, in the usual manufacturing method using kneading and pulverization, the particle shape is indefinite. Even after passing through the classification step, there is a problem that the ultrafine particles have a strong adhesion and remain attached to the toner having the target particle size and are difficult to classify.

  Further, in the inside of the machine, when used as a one-component developer, stirring with a carrier in the developing unit, contact stress caused by a developing roller and a toner supply roller, a layer thickness regulating blade, a friction charging blade, etc. There is a phenomenon that the image quality deteriorates because the fine particles adhere to and adhere to the carrier or the machine part and the fluidizing agent is embedded in the toner surface.

  Further, due to the shape of the toner, the fluidity as a powder is poor, a large amount of fluidization is required, and the filling rate into the toner bottle is low, which is an obstacle to downsizing. Therefore, the current situation is that the merit of reducing the particle size is not utilized. In addition, the pulverization method has a limit on the particle size, and it is difficult to cope with further reduction of the particle size, and even if possible, the productivity or the yield is insufficient.

  Furthermore, in order to create a full-color image, the process of transferring an image formed from multi-color toner from a photoconductor to a transfer medium or paper has become complicated, and due to the poor transferability due to the irregular shape, There have been problems such as omission of the transferred image or a large amount of toner consumption to compensate for it.

  On the other hand, at present, a sufficient causal relationship between the toner fixing property and the characteristics such as the particle size and shape of the toner is not grasped.

  An object of the present invention is to solve the above-described conventional problems, and to provide a sheet member on the sheet passing surface of the separation plate to prevent the occurrence of problems due to toner contamination adhering to the separation plate. It is an object of the present invention to provide a fixing device that takes into account releasability and recording paper separation.

  In order to achieve the above-mentioned object, the invention according to claim 1 is configured such that the recording paper is passed through the nip portion between the fixing member and the pressure member to fix the toner image on the recording paper, and the paper separating mechanism serves as the paper separating mechanism. In a fixing device including a separation plate installed in non-contact with the fixing member and the pressure member, a thin film material for preventing toner adhesion is provided on a sheet passing surface of the separation plate, and the thin film material is attached to the separation plate. In this configuration, the thin film material is extended to the edge portion of the separation plate to prevent toner adhesion at the edge portion where the toner is likely to adhere. In addition, it is possible to prevent deterioration in the image quality of the formed image, such as dirt caused by toner adhering to the sheet passing surface of the separation plate.

  According to a second aspect of the present invention, in the fixing device according to the first aspect, the thin film material is provided on the separation plate wider than the width of the recording paper that can be conveyed by the fixing device. Toner adhesion is prevented over the entire separation plate.

  According to a third aspect of the present invention, in the fixing device according to the first or second aspect, the thin film material extends from the sheet passing surface to the opposite surface through the edge portion of the separation plate. Thus, the thin film body can be easily provided so as to wind the edge portion, and the edge portion is not exposed, so that better toner adhesion prevention is achieved.

  According to a fourth aspect of the present invention, in the fixing device according to the third aspect, a thin film material is provided so that air does not enter between the thin film material and the edge portion. Is installed in a stable state, the gap between the edge portion and each portion can be stabilized, and problems such as interference with paper passing are eliminated.

  According to the fifth and sixth aspects of the invention, in the fixing device according to any one of the first to fourth aspects, a resin sheet or a coating film can be formed as the thin film material.

  According to a seventh aspect of the present invention, in the fixing device according to any one of the first to sixth aspects, at least a binder resin, a colorant, and a release agent are contained, and the components of the release agent are contained in the resin. The toner is dispersed in islands and has an average dispersed particle size of the release agent set to 0.1 μm to 1.0 μm. This configuration improves toner releasability and enables recording. Paper separability is improved and winding of the recording paper is improved.

  According to an eighth aspect of the present invention, in the fixing device according to any one of the first to seventh aspects, at least a binder resin, a colorant, and a release agent are contained, and the weight average particle diameter (D4) is 2. The toner is characterized in that the toner having an average circularity of 0.95 to 0.99 is used, and this structure improves the releasability of the toner and the separation of the recording paper. Will be better.

  According to the present invention, an edge on which a toner is easily attached is provided on a separation plate for paper separation installed on a fixing member and a pressure member by extending a thin film material to the edge portion of the separation plate. Therefore, it is possible to prevent the toner from adhering to the portion, and it is possible to prevent deterioration in image quality such as contamination of the formed image caused by the toner adhering to each part of the separation plate. In addition, toner releasability at the fixing portion is improved, recording paper separation is improved, and recording paper wrapping is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of an image forming apparatus for explaining an embodiment of the present invention, where 100 is an image forming apparatus body, 200 is a paper feed table on which the image forming apparatus body 100 is placed, and 300 is an image forming apparatus body 100. A scanner 400 provided above is an automatic document feeder (ADF) provided on the scanner 300.

  The copying machine main body 100 is provided with an endless belt-like intermediate transfer member 10 at the center. The intermediate transfer member 10 is wound around three support rollers 11, 12, and 13 so as to be able to rotate and convey clockwise in the figure.

  In this example, an intermediate transfer body cleaning device 14 that removes residual toner remaining on the intermediate transfer body 10 after image transfer is disposed on the left side of the support roller 12 on the left in the drawing among the three support rollers 11, 12, and 13. Further, four images of yellow, cyan, magenta, and black are formed on the intermediate transfer body 10 stretched between the support rollers 11 and the support rollers 12 on both sides in the drawing along the conveyance direction. Forming means 15 are arranged side by side to constitute a tandem type image forming apparatus 20. An exposure device 21 is provided on the image forming apparatus 20. Each image forming unit 15 includes a charging device, a developing device 16, a primary transfer device 17, a photoconductor cleaning device, a static eliminator, and the like around a drum-shaped photoconductor 18.

  On the other hand, a secondary transfer device 22 is provided on the side opposite to the image forming apparatus 20 with the intermediate transfer body 10 interposed therebetween. The secondary transfer device 22 is disposed so as to be pressed against the support roller 13 at the center in the drawing via the intermediate transfer member 10 and transfers the image on the intermediate transfer member 10 to a recording sheet.

  On the paper discharge side of the secondary transfer device 22, there is installed a recording paper transport device configured by passing an endless belt 24 between two rollers 23, and the recording paper after toner image transfer is fixed to the fixing device 25. It is designed to be transported to. The fixing device 25 performs a fixing process for heating and pressurizing the transfer toner image on the recording paper.

  In this example, a recording paper reversing device 26 for reversing the recording paper to record images on both sides of the recording paper is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the image forming device 20. ing.

  Next, the fixing device 25 in the present embodiment will be described.

  FIG. 2 is a schematic configuration diagram of the fixing device according to the present embodiment, where 1 is a fixing roller having a built-in heater and the like, 2 is a pressure roller in pressure contact with the fixing roller 1, and 3 is between the driving roller 4 and the fixing roller 1. The fixing belt 5, which is mounted on the belt and driven by the rotational driving force, is provided on the support member 6, and the tip portion is disposed in the vicinity of the nip portion 7 between the pressure roller 2 and the fixing belt 3. It is a board.

  Untransferred toner by heating and pressurizing a recording paper on which a toner image has been transferred at a transfer portion constituting an electrophotographic forming process (not shown) at a nip portion 7 between the pressure roller 2 and the fixing belt 3. Fix the image. The recording paper that has passed through the nip portion 7 is wound around the fixing belt 3 by the adhesive force of the toner, and is discharged as if it is a sheet. At this time, the separating plate 5 fulfills the function of forcibly separating the recording paper.

  The separation plate 5 performs a function of forcibly separating and guiding the recording paper discharged in a wound manner, and the recording paper always passes on the separation plate 5 while being rubbed against the separation plate 5 on the sheet passing surface 5a. Yes. Further, since the separation plate 5 is close to the heated fixing belt 3 when the paper is passed, the temperature is normally high near 150 ° C.

  For this reason, when the separation plate 5 is used in a state in which it is made of sheet metal or the like, the toner on the image surface of the recording paper adheres to the paper passing surface 5a of the separation plate 5 over time. Further, according to the verification test, it was confirmed that the toner easily adheres to the edge portion 5b of the separation plate 5 among the sheet passing surface 5a of the separation plate 5. The toner adhering in this way is re-transferred to another recording sheet that is subsequently transported, causing image defects.

  Therefore, as a countermeasure for this problem, in the present embodiment, a sheet member 8 that is a thin film material made of a fluororesin or the like excellent in releasability is attached to the sheet passing surface 5a of the separation plate 5 as shown in FIG. Since the toner easily adheres to the edge portion 5b of the separation plate 5 as described above, the sheet member 8 is stuck to the edge portion 5b of the sheet passing surface 5a of the separation plate 5 to take measures for preventing toner adhesion.

  Further, in the portion where the sheet metal that is the base material of the separation plate 5 is exposed on the sheet passing surface 5a, the toner of the recording paper conveyed over time adheres. This can be said to be the same in the entire region in the paper width direction perpendicular to the conveying direction in the separation plate 5. Therefore, in the present embodiment, as shown in FIG. 3, the sheet member extends over a range wider than the maximum sheet passing width in the paper width direction. 8 is extended to the edge portion 5a to prevent toner adhesion more reliably.

  Further, as described above, it is possible to prevent adhesion of toner by sticking the sheet member 8 to the sheet passing surface 5a of the separation plate 5. However, when the sheet member 8 is stuck, an edge of the sheet metal as a base material is used. It can be said that it is very difficult to apply a clean application to a state where no exposed part of the part 5b remains at all in consideration of processing steps (variation of sheet metal due to dimensional tolerance or accuracy of equipment for attaching a sheet member). Such).

  Further, as shown in FIG. 4, if the sheet member 8 is not affixed to the leading end portion 5c in the thickness direction of the edge portion 5b of the separation plate 5, toner is also applied to the leading end portion 5c due to jamming of recording paper or the like. It is thought that it adheres.

  For this reason, in this embodiment, the sheet member 8 to be attached to the separation plate 5 is extended to the back surface 5d of the separation plate 5 so as to involve not only the edge portion 5b of the paper passing surface 5a but also the tip portion 5c including the edge portion 5b. (See the enlarged perspective view of the rear surface of the separation plate in FIG. 5).

  In this way, the edge portion 5b is wound and the back surface 5d of the separation plate 5 is covered with the sheet member 8, thereby completely covering the sheet passing portion 5a on the surface of the separation plate 5, particularly the exposure of the edge portion 5b. Thus, it is possible to prevent toner from adhering to the tip 5c.

  Moreover, in this embodiment, by sticking the edge portion 5b of the separation plate 5 so as to be wound by the sheet member 8, the exposed portion of the sheet metal that is the base material of the separation plate 5 can be completely covered. The problem is that the sheet member 8 is stuck so that an air layer does not enter between the edge portion 5b and the front end portion 5d and the sheet member 8.

  The separation plate 5 is not in contact with the fixing roller 1, the pressure roller 2, and the fixing belt 3, which are fixing members, and is installed with a certain gap, but between the edge portion 5 b and the sheet member 8. When the air layer is formed on the edge portion 5b, the edge portion 5b of the separation plate 5 becomes a high temperature of about 150 ° C. due to the fixing temperature when the paper is passed. There is a possibility that the gap is narrowed, and further, the portion becomes convex, and it is conceivable that the recording paper is caught and a jam occurs.

  As a countermeasure, in this embodiment, it is necessary to stick the sheet member 8 to the sheet passing surface 5a, the edge portion 5b, and the tip portion 5c of the separation plate 5 so that an air layer is not formed. Specifically, it is preferable to use a sticking process in which sticking is performed so that air is expelled from the center to the end in the width direction of the separation plate 5 during the sticking process.

  In the above-described embodiment, a method of sticking the sheet member 8 is proposed as a measure for preventing toner adhesion to the separation plate 5. However, as an alternative, the separation plate 5 is coated with a fluororesin (for example, Teflon (registered trademark)). It is also possible to take measures for preventing toner adhesion by forming a thin film material.

  As an advantage of adopting this coating treatment, it is possible to make the manufacturing process easier by coating rather than attaching the sheet member 8. Further, the problem due to the formation of the air layer described above is eliminated.

  However, a problem with the coating process is a surface property problem. That is, when the paper passing surface becomes rough, in the worst case, the recording paper to be passed through is caught and a jam occurs. This problem can be solved by setting the surface roughness Ra after the coating treatment to 5 μm or less.

  Next, the toner used in this embodiment will be described.

  The toner used in this example is a toner containing at least a binder resin, a colorant, and a release agent, and the release agent component is dispersed in an island shape in the binder resin. The dispersed particle diameter is 0.1 to 1.0 μm.

  The fixing device according to the present embodiment has an advantage that the release property can be improved by applying a coating or the like to the sheet passing surface of the separation plate, but the separation of the recording paper is insufficient at the time of fixing, and the recording paper is wound. The problem that it is easy to occur remains.

  Accordingly, the present inventors have conducted intensive research on the above problems, and as a result of using the toner having the above-described configuration, the toner releasability is improved, the separation of the recording paper is improved, and the winding of the recording paper is improved. I found out that

  That is, in the present toner, the release agent component is dispersed in an island shape in the binder resin, and the average dispersion particle size of the release agent is 0.1 to 1.0 μm. The mold oozes out on the toner surface and has excellent offset resistance.

  As a method to disperse the release agent to the required size, it is possible to use a selection agent considering the compatibility of the resin and the wax and a dispersion aid for the release agent, and control by the amount of the release agent and the dispersant. can do.

  In this example, the amount of the release agent in all the components in the toner depends on the average dispersion diameter of the finely divided release agent, but usually 2 wt% to 10 wt% is appropriate. If it is less than 2% by weight, the desired hot offset property cannot be obtained, and if it exceeds 10% by weight, developability and transferability are deteriorated, and filming on the photosensitive member and the charge imparting member becomes remarkable. Therefore, neither is preferable.

(Measurement of particle size of release agent dispersed by TEM)
In this example, the particle size in the maximum direction of the release agent was defined as the release agent dispersion diameter. Specifically, the toner is embedded in an epoxy resin, sliced to about 100 nm, dyed with ruthenium tetroxide, and then observed with a transmission electron microscope (TEM) at a magnification of 10,000 to 50,000 times. Images were taken and image evaluation of this photograph was conducted to observe the dispersion state of the release agent at 50 locations, and the dispersion diameter was measured and averaged.

  As the release agent used in the present toner, a low melting point release agent having a melting point of 110 ° C. or lower works more effectively between the fixing roller or belt and the toner interface. It was found that high temperature offset can be prevented without applying such a release material.

  When the melting point is 110 ° C. or more, the effect of releasability is not sufficient. Further, if the melting point is 30 ° C. or lower, the toner may not have sufficient blocking resistance and storage stability, which is not preferable. The melting point of the release agent in this example was the maximum endothermic peak measured by a differential scanning calorimeter (DSC).

  As a release agent component that functions as a release agent that can be used in this example, the following wax materials are used.

  Known waxes can be used, such as polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbons (paraffin wax, sasol wax, etc.); carbonyl group-containing wax, etc. It is done. Among these, a carbonyl group-containing wax is preferable. Examples of the carbonyl group-containing wax include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18. -Octadecanediol distearate, etc.); polyalkanol esters (tristearyl trimellitic acid, distearyl maleate, etc.); polyalkanoic acid amides (ethylenediamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearylamide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred.

  The melting point of the wax used in this example is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset during fixing at a low temperature.

  Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps are poor in improving hot offset resistance and low temperature fixability.

  The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight.

  Further, as the binder resin used in the toner, those having the following composition can be used as long as the properties of the toner are satisfied.

  For example, a homopolymer of styrene such as polyester, polystyrene, poly p-chlorostyrene, polyvinyltoluene, or a substituted product thereof; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer , Styrene-vinyl naphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate Copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, Styrene-vinyl ethyl acetate Copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester Examples thereof include styrene copolymers such as copolymers.

  The fixing to the recording paper by the roller fixing or the belt fixing is estimated to start at around 70 ° C. to 100 ° C. in the copying machine, printer, FAX, etc. in which the fixing temperature of the toner is energy-saving these days. In order to allow the toner to melt, the toner must start to flow near this temperature. Therefore, the toner must be softened at least in the vicinity of 90 to 110 ° C. and fixing must be started.

  However, in order to soften at 90 ° C., the glass transition must be 50 ° C. or lower, and the Tg (glass transition point) of such a polymer is also related to the molecular weight. Usually, when the glass transition point is 50 ° C. or less, the fixability is good, but the storage stability is not satisfied.

  In addition, as the colorant of the toner, known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium Mu yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG) ), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthracene Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu , Permanent Red 4R, Para Red, Faisere , Parachlor ortho nitroaniline red, risor fast scarlet G, brilliant fast scarlet, brilliant carmine BS, permanent red (F2R, F4R, FRL, FRLL, F4RH), fast scarlet VD, velkan fast rubin B, brilliant scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, alizarin lake, thioindigo red B, thioindigo maroon, oil red, quinacrid Red, pyrazolone red, polyazo red, chrome vermillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue , Indanthrene Blue (RS, BC), Indigo, Ultraviolet, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian , Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Mara Kite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, lithopone and mixtures thereof can be used. The content of the colorant is usually 1 to 15 wt%, preferably 3 to 10 wt%, based on the toner.

  The colorant can also be used as a master batch combined with a resin. In addition to the above-mentioned modified and unmodified polyester resins, the binder resin kneaded with the masterbatch production or the masterbatch is not limited to the weight of styrene such as polystyrene, poly p-chlorostyrene, and polyvinyltoluene, and substitutes thereof. Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer Polymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene- α-Chloromethyl methacrylate copolymer , Styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene- Styrene copolymers such as maleate ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, Polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. Can be used.

  The master batch can be obtained by mixing and kneading the resin for the master batch and the colorant while applying a high shearing force. At this time, an organic solvent can be used in order to enhance the interaction between the colorant and the resin. In addition, a so-called flushing method, which is a method of removing water and organic solvent components by mixing and kneading an aqueous paste containing water of a colorant together with a resin and an organic solvent to transfer the colorant to the resin side Since the wet cake can be used as it is, it is preferable because it does not need to be dried. For mixing and kneading, a high shearing dispersion device such as a three-roll mill can be used.

  The toner may contain a charge control substance as necessary. In particular, a high charge amount can be imparted by fixing the charge control substance to the surface of the toner. That is, by fixing the toner on the surface of the toner, the amount and state of existence on the toner surface are stabilized, and the charge amount can be stabilized. In particular, in the toner having the configuration of this example, the charge amount stability is increased.

  As the charge control substance, all known substances can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (Including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and salicylic acid derivative metal salts.

  Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of a phenol-based condensate (above, manufactured by Orient Chemical Industries), TP-302, TP-415 of a quaternary ammonium salt molybdenum complex (above, manufactured by Hodogaya Chemical Co., Ltd.), quaternary ammonium Copy charge PSY VP2038 of salt, copy blue PR of triphenylmethane derivative, copy charge NEG VP2036 of quaternary ammonium salt, copy charge NX VP434 (above, manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit), copper phthalocyanine, perylene, quinacridone, Zone-based pigment, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts.

  The amount of the charge control agent used is determined by the toner production method including the type of binder resin, the presence or absence of additives used as necessary, and the dispersion method, and is not uniquely limited. However, it is preferably used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attraction force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline.

  It is also conceivable to use a fluidity improver used for the purpose of improving the fluidity of the toner. Specifically, silica, titanium oxide, alumina and the like are preferable, and silica subjected to hydrophobic treatment is particularly preferable.

  Such a fluidizing agent increases the hydrophobicity by performing a surface treatment, and can prevent the deterioration of the flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having a fluoroalkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .

  Further, in order to remove the developer after transfer remaining on the photosensitive member or the primary transfer medium, a cleaning property improver may be included. Examples of the cleaning property improver include zinc stearate, calcium stearate, stearic acid. Examples thereof include fatty acid metal salts such as polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles.

  The polymer fine particles preferably have a relatively narrow particle size distribution and an average particle size of 0.01 to 1 μm.

(Developer)
When this toner is used in a two-component developer, it may be used by mixing with a magnetic carrier. The carrier to toner content ratio in the developer is 1 to 10 parts by weight of toner with respect to 100 parts by weight of carrier. preferable.

  As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 100 μm can be used.

  The carrier may be coated with a resin, and examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene-acrylic copolymer resins, Halogenated olefin resin such as vinyl chloride, polyester resin such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexa Fluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinyl fluoride Den and non-fluoride monomers including a fluoro terpolymers such as terpolymers, and silicone resins and the like can be used.

  Moreover, you may contain conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide, or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.

  The toner can also be used as a one-component magnetic toner that does not use a carrier or a non-magnetic toner.

  Further, the fixing device of this embodiment contains at least a binder resin, a colorant, and a release agent, has a weight average particle diameter (D4) of 2.5 to 5.0 μm, and an average circularity of 0.95 to 0. .99 should be used.

  When the weight average particle diameter of the toner is smaller than the above range, in the case of a two-component developer, the toner is fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier is reduced. When used as a developer, toner filming on the developing roller or toner fusion to a member such as a blade for thinning the toner is likely to occur.

  Conversely, if the toner particle diameter is larger than the above range, the toner layer on the recording paper becomes non-uniform, the toner releasability deteriorates, and the recording paper separation may become insufficient. However, it became clear as a result of the demonstration test.

  Further, as a result of studying the toner shape and releasability at the time of fixing, in addition to the factor of the toner particle size, the average circularity of the toner is preferably 0.95 to 0.99, and 0.95. If it is smaller than 1, the toner layer on the recording paper becomes non-uniform, the toner releasability deteriorates, and it becomes clear that the releasability of the recording paper may be insufficient. If it is greater than 0.99, the toner is likely to be scattered during transfer, which may cause a problem on the image.

  Further, as the binder resin used in the toner, those having the following composition can be used as long as the properties of the toner are satisfied.

  For example, homopolymers of styrene such as polyester, polystyrene, poly p-chlorostyrene, polyvinyltoluene and the like; and styrene-p-chlorostyrene copolymers, styrene-propylene copolymers, styrene-vinyltoluene copolymers , Styrene-vinyl naphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate Copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, Styrene-vinylethyl ester Ter copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester Examples thereof include styrene copolymers such as copolymers.

  It is estimated that the fixing to the recording paper by the roller fixing or the belt fixing starts at around 70 ° C. to 100 ° C. in a copying machine, printer, FAX, etc. in which the toner fixing effective temperature is energy-saving. In order to allow the toner to melt, the toner must start to flow near this temperature. Therefore, the toner must be softened at least in the vicinity of 90 to 110 ° C. and fixing must be started.

  However, in order to soften at 90 ° C., the glass transition must be 50 ° C. or lower, and the Tg (glass transition point) of such a polymer is also related to the molecular weight. Usually, when the glass transition point is 50 ° C. or lower, the fixability is good, but the storage stability is not satisfied.

  Further, the following materials can be used as a release agent that can be used in the present toner.

  Known waxes can be used as the release agent, such as polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax, sazol wax, etc.); carbonyl group-containing Wax etc. are mentioned. Of these, carbonyl group-containing waxes are preferred. Examples of the carbonyl group-containing wax include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18. -Octadecanediol distearate, etc.); polyalkanol esters (tristearyl trimellitic acid, distearyl maleate, etc.); polyalkanoic acid amides (ethylenediamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred.

  The melting point of the wax used in this example is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat-resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature.

  The melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps are poor in improving hot offset resistance and low temperature fixability.

  The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight.

  As the colorant of the toner, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow , Yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Tan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sa Red Parachlor ortho nitroaniline red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX , Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y , Alizarin lake, thioindigo red B, thioindigo maroon, oil red, quinacridone , Pyrazolone red, polyazo red, chrome vermilion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal free phthalocyanine blue, phthalocyanine blue, fast sky blue , Indanthrene Blue (RS, BC), Indigo, Ultraviolet, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian , Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malaca DOO green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc oxide, can be used lithopone and mixtures thereof.

  The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant used in this example can also be used as a master batch combined with a resin.

  As a binder resin to be kneaded together with the production of the master batch or the master batch, in addition to the above-mentioned modified or unmodified polyester resin, styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and its substitutes Polymer of: styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-acrylic acid Ethyl copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, Styrene-α-Chlormetac Methyl formate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid Styrene copolymers such as copolymers, styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane , Polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. These can be used alone or in combination.

  The master batch can be obtained by mixing and kneading the resin for the master batch and the colorant while applying a high shearing force. At this time, an organic solvent can be used in order to enhance the interaction between the colorant and the resin. In addition, a so-called flushing method, which is a method of mixing and kneading an aqueous paste containing water of a colorant together with a resin and an organic solvent, transferring the colorant to the resin side, and removing moisture and organic solvent components, is a wet colorant. Since the cake can be used as it is, it is preferable because it does not need to be dried. For mixing and kneading, a high shearing dispersion device such as a three-roll mill can be used.

  The toner may contain a charge control substance as necessary. In particular, a high charge amount can be imparted by fixing the charge control substance to the surface of the toner. That is, by fixing the toner on the surface of the toner, the amount and state of existence on the toner surface are stabilized, and the charge amount can be stabilized. In particular, in the toner having the configuration of this example, the charge amount stability is increased.

  As the charge control substance, all known substances can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (Including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and salicylic acid derivative metal salts.

  Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of a phenol-based condensate (above, manufactured by Orient Chemical Industries), TP-302, TP-415 of a quaternary ammonium salt molybdenum complex (above, manufactured by Hodogaya Chemical Co., Ltd.), quaternary ammonium Copy charge PSYVP 2038 of salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex ( (Made by Nippon Carlit), copper phthalocyanine, perylene, quinacridone, Zone-based pigment, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts.

  In this example, the amount of charge control agent used is determined uniquely by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is uniquely limited. Although it is not a thing, Preferably it is used in 0.1-10 weight part with respect to 100 weight part of binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the flowability of the developer is lowered, or the image density is reduced. Incurs a decline.

  Further, a fluidity improver used for the purpose of improving the fluidity of the toner may be used. Specifically, silica, titanium oxide, alumina and the like are preferable, and silica subjected to hydrophobic treatment is particularly preferable.

  Such a fluidizing agent increases the hydrophobicity by performing a surface treatment, and can prevent the deterioration of the flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having a fluoroalkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .

  Further, in order to remove the developer after transfer remaining on the photosensitive member or the primary transfer medium, a cleaning property improver may be included. Examples of the cleaning property improver include zinc stearate, calcium stearate, stearic acid. Examples thereof include fatty acid metal salts such as polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles.

  The polymer fine particles preferably have a relatively narrow particle size distribution and an average particle size of 0.01 to 1 μm.

(Developer)
When this toner is used in a two-component developer, it may be used by mixing with a magnetic carrier. The carrier to toner content ratio in the developer is 1 to 10 parts by weight of toner with respect to 100 parts by weight of carrier. preferable.

  As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 100 μm can be used.

  The carrier may be coated with a resin, and examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene-acrylic copolymer resins, poly Halogenated olefin resin such as vinyl chloride, polyester resin such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexa Fluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and fluoride Fluoro terpolymers such as terpolymer of vinylidene and non-fluoride monomers including, and silicone resins and the like can be used.

  Moreover, you may contain conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide, or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.

  The toner can also be used as a one-component magnetic toner that does not use a carrier, or a non-magnetic toner.

(Characteristic measurement method)
<Toner particle size (weight average particle size (D4)>
The weight average particle diameter of the toner was measured with a Coulter Counter Model TA-II manufactured by Coulter Electronics.

  Using the measurement device, an interface (manufactured by Nikka) that outputs number distribution and weight distribution and a PC9801 personal computer (manufactured by NEC) are connected, and 1% NaCl aqueous solution is prepared using first-grade sodium chloride as the electrolyte. .

  As a measurement method, 0.1 to 5 ml of a surfactant, preferably alkylbenzenesulfonate is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. Dispersion processing is performed for about 1 to 3 minutes. In another beaker, 100 to 200 ml of an electrolytic aqueous solution is placed, and the sample dispersion is added to a predetermined concentration therein to form a suspension.

  Using this suspension, the particle size distribution of particles of 2 to 40 μm on the basis of the number was measured using the Coulter counter TAII type with an aperture of 50 μm, and the weight of particles of 1.58 to 49.18 μm was measured. The distribution and the number distribution were calculated, and the weight-based weight average particle diameter (D4: the median value of each channel is the representative value of the channel) determined from the weight distribution.

<Method of measuring roundness>
A suspension containing particles (the same one as used in the measurement of the particle size of the toner) is passed through an imaging unit detection zone on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. The method of optical detection band was used. This value can be measured as an average circularity by a flow type particle image analyzer FPIA-1000 (manufactured by Toa Medical Electronics Co., Ltd.).

  As a specific measurement method, 0.1 to 0.5 ml of a surfactant alkylbenzene sulfonate as a dispersant is added to 100 to 150 ml of water from which impure solids have been removed in advance, and a measurement sample is further added. About 0.1 to 0.5 g. The suspension in which the sample was dispersed was subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, the dispersion concentration was set to 3000 to 10,000 / μl, and the shape of the toner was measured with the apparatus.

  The present invention is applied to a fixing device for fixing an unfixed toner image in an image forming apparatus equipped with an electrophotographic image forming process, and in particular, a toner attached to a separation plate for separating a recording sheet after fixing from a fixing member. This is effective as a technique for more reliably preventing deterioration in image quality such as contamination of a formed image due to printing, or poor recording paper separation.

1 is a schematic configuration diagram of an image forming apparatus for describing an embodiment of the present invention. 1 is a schematic configuration diagram of a fixing device for describing an embodiment of the present invention. The perspective view which shows the sheet member affixing state with respect to the paper passing surface of the separation plate in this embodiment The enlarged view which shows the sheet member affixing state with respect to the edge part of a separation plate in this embodiment, and a front-end | tip part The perspective view which shows the sheet member affixing state with respect to the back surface of the separation plate in this embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixing roller 2 Pressure roller 3 Fixing belt 5 Separation plate 5a Paper passing surface 5b of separation plate Edge portion 5c of paper passing plate 5d of front end of paper passing plate 7 Nip portion 8 Sheet member

Claims (8)

The recording paper is passed through the nip portion between the fixing member and the pressure member to fix the toner image on the recording paper, and is installed in a non-contact manner with respect to the fixing member and the pressure member as a paper separation mechanism. In a fixing device provided with a separating plate,
A fixing device, wherein a thin film material for preventing toner adhesion is provided on a sheet passing surface of the separating plate, and the thin film material is extended to an edge portion on the sheet passing surface of the separating plate.   The fixing device according to claim 1, wherein the thin film material is provided on the separation plate wider than a width of a recording sheet that can be conveyed by the fixing device.   The fixing device according to claim 1, wherein the thin film material extends from the sheet passing surface to the opposite surface through the edge portion of the separation plate.   The fixing device according to claim 3, wherein the thin film material is provided so that air does not enter between the thin film material and the edge portion.   The fixing device according to claim 1, wherein a resin sheet is used as the thin film material.   The fixing device according to claim 1, wherein a coating film is formed as the thin film material.   Contains at least a binder resin, a colorant, and a release agent, the release agent components are dispersed in the form of islands in the resin, and the average dispersion particle size of the release agent is set to 0.1 μm to 1.0 μm. The fixing device according to claim 1, wherein the toner is used.   A toner containing at least a binder resin, a colorant and a release agent, having a weight average particle diameter (D4) of 2.5 μm to 5.0 μm and an average circularity of 0.95 to 0.99 is used. The fixing device according to claim 1, wherein the fixing device is a fixing device.

Images