JP2003280260A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfactorily clean an image carrier and an intermediate transfer medium and also to effectively prevent a toner left after transfer from melt- sticking to the cleaning blades by suppressing the backlash of cleaning blades for the image carrier and for the intermediate transfer medium. <P>SOLUTION: In the toner 5 having urethane-based resin as main component, the toner left after transfer remains on the organic photoreceptor 2 and the intermediate transfer belt 7 after primary and secondary transfer processes. Since the additive agent isolation ratio of the toner 5 is set to be ≥1%, the amount of the free additive agent of the toner left after transfer is increased, then, the free additive agent works as lubricant between the respective cleaning blades 12a and 13a constituted of urethane-based resin and the organic photoreceptor 2 and the intermediate transfer belt 7 so as to reduce the friction between them. The backlash of each cleaning blade 12a and 13a is suppressed, and satisfactory cleaning is attained, then, the toner is prevented from melt- sticking to the cleaning blades 12a and 13a. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a toner in which a large number of particles of an external additive are attached to a large number of mother particles containing a urethane resin as a main component, and a toner is also used on an image carrier or an intermediate transfer medium. Belongs to the technical field of the image forming apparatus in which the transfer residual toner is cleaned by a cleaning blade.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic apparatus, an electrostatic latent image formed on an image carrier is developed with toner to form a toner image, and the toner image is transferred to transfer paper or the like. An image is formed on the transfer material by transferring the toner image onto the material and fixing the toner image on the transfer material. After the toner image is transferred from the image carrier to the transfer material, the untransferred toner remains on the image carrier, and the untransferred toner is cleaned by a cleaning blade and collected as waste toner.

There is also an image forming apparatus which primarily transfers a toner image on an image carrier to an intermediate transfer medium and secondarily transfers the toner image on the intermediate transfer medium to a transfer material. In this case,
The transfer residual toner remaining on the image carrier after the primary transfer is cleaned by the cleaning blade for the image carrier, and the transfer residual toner remaining on the intermediate transfer medium after the secondary transfer is cleaned by the cleaning blade for the intermediate transfer medium. It

Conventionally, the toner used in such an image forming apparatus is generally externally added according to the purpose of improving the toner characteristics in order to improve the toner characteristics such as fluidity and chargeability. The agent is attached to the mother particles.

On the other hand, recently, in electrophotography, higher speed and lower temperature fixing are required, and the low temperature melting property of the binder resin constituting the toner mother particles is essential. To meet such demands, there is an internal dispersion type toner base particle in which wax is dispersed in a binder resin, and oilless fixing toner base particles. For example, in JP-A-9-34170, a binder resin, a colorant and a lubricant are exemplified, and a urethane resin is exemplified as the binder resin, and the weight average molecular weight of the binder resin is 50,000 or more, and the melting point of the lubricant is Disclosed is a toner base particle which is excellent in low-temperature fixing property, anti-offset property and anti-blocking property by being specified.

[0006]

By the way, in the conventional image forming apparatus for cleaning the transfer residual toner by the cleaning blade, the cleaning is performed when the image bearing member rotates due to the frictional resistance between the image bearing member and the cleaning blade. Good cleaning cannot be performed because the blade vibrates and vibrates. Further, heat is generated at the cleaning point due to the above-mentioned frictional resistance. Therefore, the friction between the image carrier and the cleaning blade is reduced to reduce the amplitude of this vibration.

However, in the toner base particles containing the urethane resin as the main component as described above, since the urethane resin is relatively hard, the external additive is easily separated from the base particles,
In some cases, the mother particles may not be sufficiently covered with the external additive,
The mother particles are easy to melt. When such toner becomes transfer residual toner and moves toward the cleaning blade, the heat generated at the cleaning point melts the mother particles and fuses them to the cleaning blade. In particular, when the cleaning blade is made of urethane resin, the cleaning blade made of urethane resin has a high affinity with the toner base particles containing urethane resin as the main component.
The toner mother particles are further fused by the cleaning blade. The cleaning failure due to the chattering of the cleaning blade and the fusion of the toner to the cleaning blade also occur in the image forming apparatus that performs the secondary transfer by the above-described intermediate transfer medium.

The present invention has been made in view of the above circumstances, and an object thereof is to suppress the chattering of a cleaning blade for an image bearing member, to perform good cleaning of the image bearing member, and to perform cleaning. An object of the present invention is to provide an image forming apparatus capable of effectively preventing fusion of transfer residual toner to a blade.

Another object of the present invention is to suppress chattering of a cleaning blade for an intermediate transfer medium, to perform good cleaning of the intermediate transfer medium, and to effectively prevent fusion of transfer residual toner to the cleaning blade. It is to provide an image forming apparatus capable of performing the same.

[0010]

In order to solve this problem, the image forming apparatus according to the first aspect of the present invention provides an electrostatic latent image formed on an image carrier with a large number of mother particles and these mother particles. And a toner composed of a large number of particles of an external additive attached to each of the toner particles, and the developed toner image is transferred to a transfer material to form an image. In an image forming apparatus for cleaning with a cleaning blade for an image carrier, the mother particles are mainly composed of urethane resin,
The external additive liberation rate of the free external additive liberated from the mother particles is 1
It is characterized by being set to% or more. Also,
The invention of claim 2 is characterized in that the cleaning blade is made of urethane resin.

Further, according to the invention of claim 3, the developed toner image is primarily transferred to an intermediate transfer medium, and the toner image primarily transferred to the intermediate transfer medium is secondarily transferred to the transfer material to form an image. And the residual toner remaining on the intermediate transfer medium is cleaned by a cleaning blade for the intermediate transfer medium.
Further, the invention of claim 4 is characterized in that at least one cleaning blade of the cleaning blades for the image carrier and the intermediate transfer medium is formed of urethane resin.

[0012]

In the image forming apparatus of the present invention thus constructed, the toner containing the urethane resin as the main component is used, and the transfer blade residual toner remaining on the image carrier after the transfer is transferred by the cleaning blade. To be cleaned. At this time, since the release rate of the external additive in the toner is set to 1% or more, the amount of the free external additive in the toner increases.
As a result, the amount of the free external additive of the transfer residual toner also becomes relatively large, and the free external additive acts as a lubricant between the cleaning blade and the image carrier. as a result,
Friction resistance between the cleaning blade and the image carrier is reduced. Therefore, the occurrence of chattering of the cleaning blade on the image carrier can be effectively suppressed, and the cleaning of the image carrier by the cleaning blade can be favorably performed for a long period of time.

Further, at the cleaning point, the friction between the cleaning blade and the image bearing member is reduced, so that heat generation due to this friction is suppressed, so that the mother particles of the toner do not melt relatively easily. As a result, fusion of the transfer residual toner to the cleaning blade for the image bearing member is suppressed, and filming of the cleaning blade is prevented.

In this case, in the toner containing a urethane resin as a main component, since the external additive is easily peeled off because the urethane is hard, there is a possibility that the external additive adhered to the mother particles may be reduced. Since the heat generation is suppressed as described above, the melting of the mother particles can be more effectively suppressed even if the external additive is easily peeled off.

Particularly, in the second aspect of the invention, the cleaning blade is made of urethane resin. Since the cleaning blade made of urethane resin and the toner containing urethane resin as a main component have a high affinity, the transfer residual toner is easily fused to the cleaning blade, but the free external additive is increased in this way. Thus, the fusion of the toner on the cleaning blade can be effectively suppressed.

Since good cleaning is performed, more uniform charging and development are possible, uneven charging and uneven development are prevented, and image smearing is prevented. Furthermore, the chatter of the cleaning blade is suppressed,
In addition, since the friction between the cleaning blade and the image carrier is reduced, changes with time such as the curling of the cleaning blade and insufficient torque of the image carrier can be suppressed.

Further, since the fusion of the toner to the cleaning blade is effectively suppressed, the urethane resin toner can be stably used for a long period of time, and the image forming apparatus for oilless fixing can be more reliably used. Will be feasible.

On the other hand, in the third aspect of the invention, the secondary transfer is carried out by the intermediate transfer medium. In the case of the secondary transfer by the intermediate transfer medium, the secondary transfer is carried out on the intermediate transfer medium similarly to the image carrier. The amount of the free external additive of the secondary transfer residual toner remaining in the toner becomes relatively large, and the free external additive acts as a lubricant between the cleaning blade and the intermediate transfer medium. As a result, the frictional resistance between the cleaning blade and the intermediate transfer medium is likewise reduced. Therefore,
The chattering of the cleaning blade is effectively suppressed also in the intermediate transfer medium, and the cleaning of the intermediate transfer medium by the cleaning blade is favorably performed over a long period of time.

Further, at the cleaning point, heat generation due to friction between the cleaning blade and the intermediate transfer medium is suppressed, so that the mother particles are not melted relatively easily, and the transfer residual toner on the cleaning blade for the intermediate transfer medium remains. Fusing is suppressed, and filming of the cleaning blade is prevented.

Particularly, in the invention of claim 4, at least one of the cleaning blades for the image carrier and the intermediate transfer medium is formed of urethane resin. Similar to the above, since the cleaning blade made of the urethane resin and the toner containing the urethane resin as a main component have a high affinity, the transfer residual toner is easily fused to the cleaning blade. By increasing the amount of the agent, the fusion of the toner to the cleaning blade can be effectively suppressed.

Also in the case of the secondary transfer by the intermediate transfer medium, as described above, the uneven charging and the uneven development are prevented and the image is prevented from being contaminated. Further, the cleaning blade is turned up and the intermediate transfer is performed. The change with time such as insufficient torque of the medium is suppressed.

Further, since the fusion of the toner to the cleaning blade is effectively suppressed, the urethane resin toner can be stably used for a long period of time, and the oil for secondary transfer by the intermediate transfer medium can be used. It becomes possible to more reliably realize the image forming apparatus of the fixingless method.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing an example of an embodiment of an image forming apparatus according to the present invention.

As shown in FIG. 1, an image forming apparatus 1 of this example has an organic photoconductor 2 which is an image carrier for carrying an electrostatic latent image and a toner image, and a charging roller 2a for the organic photoconductor 2. Charger 3 for contact charging to a uniform potential by
And an exposure device 4 for forming an electrostatic latent image on the organic photoconductor 2 charged to a uniform potential by exposure, and an organic photoconductor by developing the electrostatic latent image on the organic photoconductor 2 with one-component toner 5. 2, a developing device 6 for forming a toner image on the photosensitive drum 2, a primary transfer device 8 for primarily transferring the toner image on the organic photoconductor 2 to an intermediate transfer belt 7 which is an intermediate transfer medium by a primary transfer roller 8a, and a secondary transfer roller 10a. A transfer device 7 for transferring the toner image on the intermediate transfer belt 7 to the transfer material 6 by means of the above, and a fixing device 11 for fixing the toner image on the transfer material 9 by means of the pressure roller 11a and the heating roller 11b.

The developing device 6 has a developing roller 6a which carries the one-component toner 5 and conveys it to the organic photoconductor 2, and a supply roller 6b which supplies the one-component toner 5 to the developing roller 6a.
And a regulation blade 6c for regulating the one-component toner 5 to form a thin layer of the toner 5 with a predetermined thickness.

Further, as shown in FIG. 2, the one-component toner 5
Is composed of a large number of toner base particles 5a and a large number of particles of the external additive 5b. In that case, in the one-component toner 5, the synchronous toner in which the external additive 5b is attached to the toner mother particle 5a, and the asynchronous mother particle 5a 'to which the external additive 5b is not attached,
Asynchronous external additive (free external additive) 5b 'particles that do not adhere to the toner mother particles 5a are mixed. The synchronous external additive 5b attached to the toner base particles 5a is indicated by reference numeral "5b""in FIG. 2, and the toner base particles 5a to which the external additive 5b is attached is referred to as synchronous toner.

In the image forming apparatus 1 of this example configured as described above, first, the charging roller 3a of the charging device 3 charges the organic photoreceptor 2 to a uniform potential. Next, the organic photoconductor 2 is exposed by a laser beam or the like from the exposure device 4 to form an electrostatic latent image. Next, the electrostatic latent image forming portion of the organic photoconductor 2 is exposed to light so that the developing roller 6a
Is developed with the one-component toner 5 conveyed by, and a toner image is formed. Then, the intermediate transfer belt 7 is pressed against the organic photoconductor 2 by the primary transfer roller 8 a of the primary transfer device 8, and the toner image on the organic photoconductor 2 is primarily transferred onto the intermediate transfer belt 7. Then, the transfer material 9 such as paper is pressed against the intermediate transfer belt 7 by the secondary transfer roller 10 a of the secondary transfer device 10, and the toner image on the intermediate transfer belt 7 is secondarily transferred onto the transfer material 9. Then, the transfer material 9 is pinched between the pressure roller 11a of the fixing device 11 and the heating roller 11b and the toner on the transfer material 9 moves while being heated, and the toner image on the transfer material 9 is fixed. An image is formed on the transfer material 9.

In such an image forming process, the untransferred toner remaining on the organic photoconductor 2 after the primary transfer is removed by the cleaning blade 12a of the cleaning device 12 for the organic photoconductor, and the surface of the organic photoconductor 2 is cleaned. It Similarly, the transfer residual toner remaining on the intermediate transfer belt 7 after the secondary transfer is removed by the cleaning blade 13a of the cleaning device 13 for the intermediate transfer belt, and the surface of the intermediate transfer belt 7 is cleaned.

By the way, the mother particles 5a of the one-component toner 5 used in the image forming apparatus 1 of this example are formed of urethane resin as a main component, and the external additive liberation rate of the toner 5 is 1% or more. Is set to.

The external additive release rate of the one-component toner 5 is most appropriately determined for the toner 5 transferred to the intermediate transfer belt 7 or the transfer material 9 during the primary transfer or the secondary transfer, but these toners are most suitable. Since it is relatively difficult to obtain the external additive release rate of No. 5, the external additive release rate of the one-component toner 5 supplied to the developing device 6 (as well as the one-component toner 5 in the developing device 6) is obtained. By doing
This external additive release rate can be calculated more easily.

The amount of free external additive 5b 'of the one-component toner 5,
The external additive release rate and the slope of the synchronization straight line (synchronization distribution graph) are, for example, the particle analyzer (PT1
000) to determine the toner mother particles 5
It can be determined easily and more accurately by analyzing the state of adhesion between a and the external additive 5b. Particle Analyzer (PT
In toner analysis using 1000), the quantity is expressed in number.

The toner analysis method using this particle analyzer is disclosed in detail in Japanese Patent Application Laid-Open No. 2000-047425, and since it can be understood by referring to this publication, a detailed description thereof will be omitted here, but for the time being. ,
Briefly explained.

The toner base particles 5a and the external additive 5 obtained by this toner analysis method are shown on a diagram in which the horizontal axis represents the equivalent particle diameter of the toner base particles 5a and the vertical axis represents the external additive 5b.
When the equivalent particle diameter of each equivalent particle of b is plotted for each particle of the one-component toner 5, an equivalent particle diameter distribution chart of the toner particles is obtained. From this equivalent particle size distribution diagram, the adhesion state of the external additive 5b to the toner base particles 5a of the one-component toner 5 is analyzed. In that case, in this equivalent particle size distribution chart, a minimum of 2
One approximate straight line passing through the origin obtained by using the multiplication method is obtained (for details, refer to the above-mentioned publication), and the toner mother particles 5a
The adhesion state between the external additive 5b and the external additive 5b is analyzed by the slope of this approximate straight line (that is, the synchronous distribution graph) (equivalent particle diameter of the external additive 5b / equivalent particle diameter of the toner base particles 5a). The external additive liberation rate is given as a percentage of the amount of the free external additive 5b 'with respect to the total amount of the external additive 5b of the one-component toner 5 obtained by the toner analysis method using this particle analyzer.

In the synchronous toner in which the external additive 5b is attached to the toner base particles 5a, some of the external additives 5b are solidified as shown in FIG.
Some of them are sparsely attached to the entire surface a, and some of the external additives 5b are almost uniformly attached to the toner mother particles 5a as shown in FIG. 3B. Now, assuming that the toner base particles 5a and the external additive 5b have the same amount in these synchronized toners, the external additive 5b shown in FIG.
The slope of the synchronization straight line (the slope of the above-mentioned approximate straight line) of the synchronization toner that is sparsely attached to the toner is relatively small, and
In the synchronous toner in which the external additive 5b shown in (b) adheres to the toner base particles 5a almost uniformly, the inclination of the synchronous straight line becomes relatively large. Therefore, the state of the synchronous toner can be known from the inclination of this straight line. Further, toners having the same inclination of the synchronization straight line have uniform charging characteristics, and have the same developing condition.

As a binder for the toner mother particles 5a containing urethane resin as a main component in the one-component toner 5 used in the image forming apparatus 1 of this example, a urethane bond formed as a result of a reaction between polyisocyanate and a polyactive hydrogen compound. (-A-NHCOO-B-, where A is a polyisocyanate residue, B is a polyactive hydrogen compound residue), or a urea bond (-NHCONH-) resulting from the reaction of an amino group and a polyisocyanate is a binding element. Contained as.

As the polyisocyanate in the present invention, aliphatic diisocyanates such as ethane diisocyanate, propane diisocyanate, butene diisocyanate, butane diisocyanate, thiodiethyl diisocyanate, pentane diisocyanate, β-methylbutane diisocyanate, hexane diisocyanate,
ω, ω′-dipropyl ether diisocyanate, thiodipropyl diisocyanate, heptane diisocyanate, 2,2-dimethylpentane diisocyanate, 3-
Methoxyhexane diisocyanate, octane diisocyanate, 2,2,4-trimethylpentane diisocyanate, nonane diisocyanate, decane diisocyanate, 3-butoxyhexane diisocyanate, 1,4
-Butylene glycol-dipropyl ether-ω, ω '
-Diisocyanate, undecane diisocyanate, dodecane diisocyanate, thiodihexyl diisocyanate and the like.

As the aliphatic diisocyanate having a cyclic group, ω, ω'-1,3-dimethylbenzene diisocyanate, ω, ω'-1,2-dimethylbenzene diisocyanate, ω, ω'-1,2-dimethyl Cyclohexane diisocyanate, ω, ω′-1,4-dimethylcyclohexane diisocyanate, ω, ω′-1,4-
Diethylbenzene diisocyanate, ω, ω′-1,4
-Dimethylnaphthalene diisocyanate, ω, ω'-
1,5-dimethylnaphthalene diisocyanate, 3,5
-Dimer cyclohexane-1-methyl isocyanate-
2-propyl isocyanate, ω, ω′-n-propyl-biphenyl diisocyanate and the like can be mentioned.

1,3 as the aromatic diisocyanates
-Phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methylbenzene-2,4-diisocyanate, 1-methylbenzene-2,5-diisocyanate, 1-methylbenzene-3,5-diisocyanate, 1,3-dimethylbenzene -2,4-diisocyanate, 1,3-dimethylbenzene-4,6-diisocyanate, 1,4-dimethylbenzene-2,5-diisocyanate, 1-ethylbenzene-2,4-diisocyanate, 1-isopropylbenzene-2, 4-diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate and the like can be mentioned.

Examples of naphthalene diisocyanates include naphthalene-1,4-diisocyanate and naphthalene-
1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1′-dinaphthyl-2,2′-diisocyanate and the like can be mentioned.

The biphenyl diisocyanates include biphenyl-2,4'-diisocyanate and biphenyl-
4,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, 2-
Examples thereof include nitrobiphenyl-4,4'-diisocyanate.

Examples of di- or triphenylmethane diisocyanate and di- or triphenylethane diisocyanate include diphenylmethane-4,4'-
Diisocyanate, 2,2'-dimethyldiphenylmethane-4,4'-diisocyanate, diphenyldimethylmethane-4,4'-diisocyanate, 2,5,2 ',
5'-tetramethyldiphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxydiphenylmethane-4,4'-diisocyanate, 4,4'-dimethoxyphenyl-3,3'-diisocyanate, 4,4'-diisocyanate Ethoxyphenylmethane-3,3'-diisocyanate, 2,2'-dimethyl-5,5'-dimethoxydiphenylmethane-4,4'-diisocyanate, 3,3-dichlorodiphenyldimethylmethane-4,4'-diisocyanate, benzophenone -3,3'-diisocyanate, α, β-diphenylethane-2,4-diisocyanate, 3-nitrotriphenylmethane-4,4'-diisocyanate, 4-nitrotriphenylmethane-4,
4'-diisocyanate and the like can be mentioned.

The triisocyanates include 1-methylbenzene-2,4,6-triisocyanate, 1,3,3.
5-trimethylbenzene-2,4,6-triisocyanate, naphthalene-1,3,7-triisocyanate,
Biphenyl-1,3,7-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, 3-
Examples include methyldiphenylmethane-4,6,4'-triisocyanate, triphenylmethane-4,4 ', 4 "-triisocyanate, diphenyl-4,4'-diisocyanatecarbamic acid chloride and the like.

In the present invention, in particular, diphenylmethane-4,4'-diisocyanate (MDI), isophorone diisocyanate (IPDI), norbornane diisocyanate (NBDI), dicyclohexylmethane-
4,4'-diisocyanate (hydrogenated MDI), p-xylylene diisocyanate, m-xylylene diisocyanate (XDI), p-phenylene diisocyanate,
p-tetramethylxylylene diisocyanate, m-tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane (hydrogenated XDI), 2,4- Diisocyanates having alicyclic hydrocarbons and aromatic hydrocarbons such as tolylene diisocyanate (TDI) are preferable, and it is preferable to use a mixture of these polyisocyanates.

Examples of the polyactive hydrogen compound include polyols, polyamines and the like. Examples of polyols include hydrogenated bisphenol A, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, polyethylene glycol,
Examples include polypropylene glycol, polytetramethylene glycol, poly (caprolactone polyol), poly (hexamethylene carbonate), and the like. Examples of polyols include bisphenol A ethylene oxide 2
To 6 mol adduct and propylene oxide 2 to 4 mol adduct of bisphenol A are particularly preferable, and the hydroxyl value in these polyols is 100 to 350 KOHmg /
g, preferably 200 to 290 KOHmg / g.

Examples of polyamines include hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, o-phenylenediamine and m-phenylenediamine. It

The binder polymer of the present invention has a medium number average molecular weight (Mn) of 1,500 to 20,000, and its properties depend on the chemical structures of polyisocyanates and polyactive hydrogen compounds as constituent components. There is a large dependence, and even in the above polyisocyanates, it is preferable to use a mixture of several kinds of polyisocyanates, or to use a mixture of several kinds of multiactive hydrogen compounds even as a multiactive hydrogen compound, for example, a fat Preferable examples include a mixture of cyclic polyisocyanate and aromatic polyisocyanate, and a mixture of ethylene oxide adduct of bisphenol A and propylene oxide adduct of bisphenol A.

The mixing ratio of the polyisocyanate and the polyactive hydrogen compound is such that the ratio of the number of active hydrogen groups in the polyactive hydrogen compound to the number of isocyanate groups in the polyisocyanate (NCO / active hydrogen) is 0.5 to 1.0, preferably 0. It is advisable to react in the range of 0.7 to 1.0.

In producing the binder polymer,
Polyisocyanates in a multi-active hydrogen compound at a temperature of 3
At 0 ° C. to 180 ° C., preferably 30 ° C. to 140 ° C., it is advisable to carry out batchwise or divided addition under atmospheric pressure and without solvent, and carry out bulk polymerization for several minutes to several hours. Examples of the catalyst include dibutyltin dichloride, dimethyltin dichloride, tin octylate, triphenylammonium dichloride and the like.

The binder polymer manufacturing method in the present invention may be manufactured by bulk polymerization in a container.
Since it does not require steps such as removal of solvent in solution polymerization or polycondensation reaction, or removal of by-product water, it is possible to efficiently perform continuous production by removing the solvent during the reaction. Can be performed by using a kneading means having a built-in screw. At that time, polyisocyanates may be continuously added to the multi-active hydrogen compound and kneaded to react, and an extruder is preferable as a kneading means, and a twin-screw extruder is particularly preferable.

The binder polymer in the present invention has a number average molecular weight (Mn) of 1,500 to 20,000, preferably 2,000 to 1 based on polystyrene.
50,000, more preferably 3,000 to 8,000.

The weight average molecular weight (Mw) is 3,000.
0 to 300,000, preferably 5,000 to 50,000
00, more preferably 8,000 to 20,000, Mw / Mn of 1.5 to 20, preferably 1.5 to 1
It is 0, more preferably 1.5 to 5. Mw / Mn is 2
When it exceeds 0, the sharp melt property is deteriorated and the color goodness upon color mixing and the transparency of the OHP image are deteriorated.

To control the number average molecular weight (Mn) of the binder polymer of the present invention within the range of 1,500 to 20,000, the ratio of the number of active hydrogen groups in the polyactive hydrogen compound to the number of isocyanate groups in the polyisocyanate (NCO / Since the molecular weight can be lowered by decreasing the active hydrogen) and the molecular weight can be increased by approaching the equimolar amount, it can be easily controlled by appropriately controlling the reaction mole number of polyisocyanate.

Further, a chain extender may be appropriately used within a range that does not affect the physical properties of the binder polymer of the present invention. As the chain extender, ethylene glycol, propylene glycol, 1,4-butanediol, bis- (β-
(Hydroxy) benzene, trimethylolpropane and the like can be mentioned.

If the number average molecular weight (Mn) is less than 1,500, the low-temperature fixability is excellent, but the colorant retention, filming resistance, offset resistance, fixed image strength, and storage stability are poor. On the other hand, if it is more than 20,000, the low-temperature fixability becomes poor, and it cannot be used alone as a binder resin.

The binder polymer of the present invention has a flow softening point (Tm) of 90 ° C to 140 ° C, preferably 90 ° C.
C. to 120.degree. C., more preferably 100.degree. C. to 110.degree. C., and the glass transition temperature (Tg) is 55.degree.
90 ° C, preferably 55 ° C to 80 ° C, more preferably 60 ° C to 70 ° C.

That is, since the binder polymer in the present invention has a high intermolecular bonding force and is a highly crystalline polymer, it is possible to reduce the decrease width of Tg when the molecular design is performed to lower the molecular weight and lower Tm. So low T
m and high Tg can be compatible.

The binder polymer in the present invention is excellent in cohesiveness at the time of heat melting and excellent in high temperature offset property due to its urethane bond or urea bond,
Further, the melt viscosity at the 50% outflow point is 3 × 10 ³ to
It can be 1.5 × 10 ⁴ Pa · s, which is suitable as an oilless fixing toner.

The binder polymer in the present invention may be produced by bulk polymerization in a container, but it does not require steps such as solvent removal in solution polymerization and polycondensation reaction or removal of by-product water. It is possible to carry out bulk polymerization while pouring polyisocyanates into a polyactive hydrogen compound in a twin-screw extruder or the like, and use the obtained polymer as it is as a binder resin in a toner.

Other binder resins may be added to the binder polymer of the present invention within a range that does not impair the properties of the binder polymer. Other binder resins include
The binder polymer may be allowed to coexist when it is produced, or may be kneaded after the production. When the binder polymer of the present invention is made to coexist when produced, a resin which does not contain active hydrogen having reactivity with polyisocyanates is preferable.

Examples of other binder resins include polystyrene, poly-α-methylstyrene, chloropolystyrene, styrene-chlorostyrene copolymer, styrene-
Propylene copolymer, styrene-butadiene copolymer,
Styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-
Acrylic ester copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylic acid ester-methacrylic acid ester copolymer, styrene-α-chloromethyl acrylate copolymer, styrene-acrylonitrile-acrylic acid ester copolymer A homopolymer or a copolymer containing styrene or a styrene substitute in a styrene resin such as a polymer,
Polyester resin, epoxy resin, urethane modified epoxy resin, silicone modified epoxy resin, vinyl chloride resin, rosin modified maleic acid resin, phenyl resin, polyethylene, polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-
Ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin and the like can be used alone or in combination.

The toner particles of the present invention comprise a binder resin (collectively referred to as a binder resin) comprising the binder polymer produced above and another resin added as necessary, a colorant and a charge control agent. .

As the colorant, various organic or inorganic pigments and dyes of various colors as described below can be used. That is, as the black pigment, carbon black,
Examples include copper oxide, ferrosoferric oxide, manganese dioxide, aniline black, and activated carbon. Examples of yellow pigments include yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, bunzer yellow G, bunzer yellow 10G, benzidine yellow G, benzidine yellow GR, Quinoline yellow rake, permanent yellow NC
G, Tartrazine rake, etc. Examples of orange pigments include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, induslen brilliant orange RK, benzidine orange G and induslen brilliant orange GKM. Red pigments include red iron oxide, cadmium red, red lead, mercury sulfide, cadmium, permanent red
4R, Resole Red, Pyrozolone Red, Watching Red, Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B.
Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake. Blue pigments include navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue,
Metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated, fast sky blue, and indanthrene blue BC are available. Examples of green pigments include chrome green, chrome oxide, pigment green B, malachite green lake, and final yellow green G. White pigments include zinc white, titanium oxide, antimony white, and zinc sulfide. Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white. Various dyes such as basic dyes, acid dyes, dispersion dyes, and direct dyes include nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.

These colorants may be used alone or in combination of two or more, but it is desirable to use 1 to 20 parts by weight, more preferably 2 to 10 parts by weight, based on 100 parts by weight of the binder resin. . If it is more than 20 parts by weight, the fixing property of the toner will be deteriorated, while if it is less than 1 part by weight, a desired image density cannot be obtained.

When used as a translucent color toner, various kinds of pigments and dyes of the following colors can be used as the colorant. As a yellow pigment, C.I.
I.10316 (Naphthol Yellow S), CI11710 (Hansa Yellow 10G), CI11660 (Hansa Yellow 5G), CI1
1670 (Hansa Yellow 3G), CI11680 (Hansa Yellow G), CI11730 (Hansa Yellow GR), CI11735 (Hansa Yellow A), CI11740 (Hansa Yellow NR), CI
12710 (Hansa Yellow R), CI12720 (Pigment Yellow L), CI21090 (Benzidine Yellow), CI21
095 (Benzidine Yellow G), CI21100 (Benzidine Yellow GR), CI20040 (Permanent Yellow NCG),
CI21220 (Vulcan Fast Yellow 5), CI21135
(Vulcan Fast Yellow R) etc. Red pigments include CI12055 (Stalin I), CI12075 (Permanent Orange), CI12175 (Resor Fast Orange 3GL), CI12305 (Permanent Orange GT)
R), CI11725 (Hansa Yellow 3R), CI21165 (Vulcan Fast Orange GG), CI21110 (Benzidine Orange G), CI12120 (Permanent Red 4R),
CI1270 (Para Red), CI12085 (Fire Red), CI12315 (Brilliant Fast Scarlet), CI12310 (Permanent Red F2R), CI12
335 (Permanent Red F4R), CI12440 (Permanent Red FRL), CI12460 (Permanent Red)
FRLL), CI12420 (Permanent Red F4RH), CI
12450 (Light Fast Red Toner B), CI1249
0 (permanent carmine FB), CI15850 (brilliant carmine 6B) and others. Also, as blue pigments, CI74100 (metal-free phthalocyanine blue), CI74100
74160 (phthalocyanine blue), CI74180 (first sky blue), etc.

These colorants may be used alone or in combination of two or more, but it is desirable to use 5 to 15 parts by weight, preferably 6 to 12 parts by weight, based on 100 parts by weight of the binder resin. If it is more than 15 parts by weight, the fixability and transparency of the toner will be deteriorated, while if it is less than 5 parts by weight, the desired image density may not be obtained.

Further, in the toner of the present invention, the binder polymer is excellent in heat melting property, so that the release agent is unnecessary, but when added, it is 0 to 100 parts by weight of the binder resin. It is about 2 parts by weight and enables oilless fixing.

Specific examples of the releasing agent include paraffin wax, polyolefin wax, modified wax having an aromatic group, hydrocarbon compound having an alicyclic group, natural wax, and a long-chain hydrocarbon chain having 12 or more carbon atoms. CH ₃ (CH ₂ ) ₁₁
Alternatively, a long-chain carboxylic acid having CH ₃ (CH ₂ ) ₁₂ or more aliphatic carbon chain], its ester fatty acid metal salt, fatty acid acid, fatty acid bisacid, etc. can be exemplified. Different low softening point compounds may be mixed and used. Specifically, paraffin wax (manufactured by Nippon Oil Co., Ltd.), paraffin wax (manufactured by Nippon Seiro Co., Ltd.), microwax (manufactured by Nippon Oil Co., Ltd.), microcrystalline wax (manufactured by Nippon Seiro Wax Co., Ltd.), hard paraffin wax (manufactured by Nippon Seiro Wax Co., Ltd.), PE-130 (Hoechst), Mitsui High Wax 110P (Mitsui Petrochemical), Mitsui High Wax 220P (Mitsui Petrochemical), Mitsui High Wax 660P
(Mitsui Petrochemical), Mitsui High Wax 210P (Mitsui Petrochemical), Mitsui High Wax 320P (Mitsui Petrochemical),
Mitsui High Wax 410P (Mitsui Petrochemical), Mitsui High Wax 420P (Mitsui Petrochemical), Modified Wax JC-1141
(Mitsui Petrochemical), modified wax JC-2130 (Mitsui Petrochemical), modified wax JC-4020 (Mitsui Petrochemical),
Modified wax JC-1142 (manufactured by Mitsui Petrochemical), modified wax JC-5020 (manufactured by Mitsui Petrochemical), beeswax, carnauba wax, montan wax and the like can be mentioned. As fatty acid metal salts, zinc stearate, calcium stearate, magnesium stearate, zinc oleate,
Examples include zinc palmitate and magnesium palmitate.

In particular, examples of the polyolefin wax include low molecular weight polypropylene, low molecular weight polyethylene, or oxidative polypropylene, oxidative polyethylene. Specific examples of the polyolefin wax include, for example, Hoechst Wax PE520 and Hoechs.
t Wax PE130, Hoechst Wax PE190 (made by Hoechst),
Mitsui High Wax 200, Mitsui High Wax 210, Mitsui High Wax 210M, Mitsui High Wax 220, Mitsui High Wax 220M (Mitsui Petrochemical Industry Co., Ltd.), Sun Wax 131
-P, Sun Wax 151 -P, Sun Wax 161 -P
Non-oxidized polyethylene wax such as (manufactured by Sanyo Chemical Industries), Hoechst Wax PED121, Hoechst Wax PED15
3, Hoechst Wax PED521, Hoechst Wax PED522, and Cerid
ust 3620, Ceridust VP130, Ceridust VP5905,
Ceridust VP9615A, Ceridust TM9610F, Ceridu
Hoechist Wachs, oxidized polyethylene waxes such as st 3715 (made by Hoechst), Mitsui High Wax 420M (made by Mitsui Petrochemical Co., Ltd.), Sun Wax E-300, Sun Wax E-250P (made by Sanyo Kasei Co., Ltd.) PP230 (Hoechst), Viscole 330-P, Viscole 550-
P, Viscole 660P (manufactured by Sanyo Chemical Industry Co., Ltd.), non-oxidizing polypropylene wax, Piscor TS-200
(Sanyo Kasei Kogyo Co., Ltd.) and other oxidized polypropylene waxes are exemplified. These release agents can be used alone or in combination of two or more kinds. As a releasing agent added as necessary, DSC measured by "DSC120" manufactured by Seiko Instruments Inc.
The softening point (melting point) which is the endothermic main peak value in the endothermic curve is 40 to 130 ° C, preferably 50 to 120 ° C.

The charge control agent is not particularly limited as long as it can give positive or negative charge by triboelectric charging, and various organic or inorganic charge control agents can be used. Examples of the positive charge control agent include nigrosine base EX (manufactured by Orient Chemical Industry Co., Ltd.), quaternary ammonium salt P-51.
(Orient Chemical Co., Ltd.), Nigrosine Bontron N-01 (Orient Chemical Co., Ltd.), Sudan Chief Schwarz BB (Solvent Black 3: Colr Index)
26150), Fett Schwarz HBN (CINO.26150),
Brilliant spirits Schwarz TN (manufactured by Farben-Fabricken Bayer), Savong Schwarz X (manufactured by Farberke Hoechst), alkoxylated amines, alkylamides, molybdic acid chelate pigments and the like can be mentioned. Among them, the quaternary ammonium salt P-51 is preferable.

Further, as the negative charge control agent, for example, oil black (Color Index 26150), oil black B
Y (Orient Chemical Co., Ltd.), Bontron S-22
(Produced by Orient Chemical Industry Co., Ltd.), salicylic acid metal complex E-81 (produced by Orient Chemical Industry Co., Ltd.), thioindigo pigment, sulfonylamine derivative of copper phthalocyanine,
Spiron Black TRH (Hodogaya Chemical Co., Ltd.), Bontron S-34 (Orient Chemical Co., Ltd.), Nigrosine SO (Orient Chemical Co., Ltd.), Celes Schwarz (R) G (Farben Fabricen Bayer), Chromogen Schwarz ETOO (CINO.14645),
Examples thereof include Azo Oil Black (R) (manufactured by National Aniline Co.). Among them, salicylic acid metal complex E
-81 is preferable.

These charge control agents can be used alone or in combination of two or more kinds. The addition amount of the charge control agent added to the binder resin is 0.001 with respect to 100 parts by weight of the binder resin. To 5 parts by weight, preferably 0.00
It is 1 to 3 parts by weight. In addition, additives such as magnetic particles and a dispersant may be appropriately added to the toner particles.

The toner particles in the present invention include a binder resin,
Internal additives such as colorants, charge control agents, and release agents that are added as necessary are kneaded and melted in a twin-screw extruder, and then pulverized and classified by a fine pulverizing means. The toner particles are obtained by erasing the surface of the toner particles under flow.

As the external additive 15 of the toner 13,
Silica, titanium dioxide, alumina, magnesium fluoride, silicon carbide, boron carbide, titanium carbide, zirconium carbide, boron nitride, titanium nitride, zirconium nitride,
Fine particles of magnetite, molybdenum disulfide, aluminum stearate, magnesium stearate, zinc stearate, calcium stearate, metal titanate, and silicon metal salt, each having an average primary particle size of 1 to 500.
nm, preferably 5-200 nm can be used.
However, it is desirable that the composition contains an element that is rarely contained in the composition of the mother particles so that it can be detected by PT-1000.

The external additives 5b are surface-treated for hydrophobization and fluidization. In the case of negative charging treatment, the surface treatment of this external additive is carried out by chemically treating with a surface treating agent such as a silane coupling agent, a higher fatty acid, or a silicone oil, which reacts or physically adsorbs with the external additive. Done. As the surface treatment agent, for example, hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, Brommethyldimethylchlorosilane, α-chloroethyltrichlorosilane, ρ-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxy. Silane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,
For example, 3-diphenyltetramethyldisiloxane and dimethylpolysiloxane having 2 to 12 siloxane units per molecule and having a hydroxyl group bonded to Si in each terminal unit are used. Moreover, these can also be used in 1 type (s) or 2 or more types of mixture. Further, in the case of the positive charging treatment, the surface treatment of the external additive is performed by chemically treating it with a coupling agent having an amino group or a surface treatment agent such as silicone oil. Furthermore, this external additive 5b is also manufactured by a general manufacturing method that has been conventionally performed.

Then, the toner mother particles 5a and the external additive 5b are added in appropriate amounts to a known mixer such as a Henschel mixer, a V-type blender, a reversing mixer, a high speed mixer, a cyclomix, an axial mixer. Then, the toner particles are prepared by adding the external additive 5b particles to the toner mother particles 5a.

Further, the cleaning blade 12a for the organic photoconductor and the cleaning blade 13a for the intermediate transfer belt in the image forming apparatus 1 of this example are made of urethane resin. As a specific material for both of the cleaning blades 12a and 13a, for example, polyurethane, polyurethane in which fluororesin powder is dispersed, polyurethane in which conductive fine particles are dispersed, or the like can be used.

According to the image forming apparatus 1 of this example, in the image forming apparatus 1 using the one-component toner 5 containing urethane resin as the main component, the external additive release rate of the one-component toner 5 is set to 1% or more. Since it is set, the amount of free external additive 5b 'of the one-component toner 5 increases. As a result, the transfer residual toner 5
Since the amount of the free external additive 5b 'can be relatively increased, the cleaning blade 12a of the organic photoconductor 2 cleans the transfer residual toner and the intermediate transfer belt 7.
Transfer residual toner 5 by the cleaning blade 13a of
In the cleaning, the free external additive 5b 'acts as a lubricant between the cleaning blades 12a and 13a and the corresponding organic photoconductor 2 and intermediate transfer belt 7. As a result, the frictional resistance between the cleaning blades 12a and 13a and the organic photoconductor 2 and the intermediate transfer belt 7 can be reduced.

Therefore, the cleaning blade 12
It is possible to effectively suppress the chattering of a and 13a, and it is possible to perform good cleaning by the cleaning blades 12a and 13a.

Further, at the cleaning point, heat generation due to friction between the cleaning blades 12a, 13a and the organic photoconductor 2 and the intermediate transfer belt 7 is suppressed, so that the toner base particles 5a cannot be melted relatively easily. In particular,
In the toner containing a urethane resin as a main component, since the urethane additive is hard, the external additive 5b is easily peeled off.
Although there is a possibility that the external additive may adhere to the toner, since the heat generation is suppressed as described above, the melting of the toner base particles 5a can be suppressed more effectively even if the external additive 5b is easily peeled off. Thereby, the cleaning blades 12a, 13a
It is possible to suppress fusion of the transfer residual toner 5 to the cleaning blades 12a and 13a and prevent filming of the cleaning blades 12a and 13a.

Further, since the urethane-based resin cleaning blades 12a, 13a and the one-component toner 5 containing the urethane-based resin as a main component have a high affinity, the transfer residual toner 5 is fused to the cleaning blades 12a, 13a. Although it is easy, by increasing the amount of the free external additive 5b ′, it is possible to effectively suppress the fusion of the toner 5 to the cleaning blades 12a and 13a.

Since good cleaning can be performed, more uniform charging and development can be performed, and uneven charging and uneven development can be prevented, and image stains can be prevented. Further, the chattering of the cleaning blades 12a, 13a can be suppressed, and the cleaning blades 12a, 1a
Since the friction between 3a and the organic photoconductor 2 and the intermediate transfer belt 7 can be reduced, the cleaning blades 12a, 13a
It is possible to suppress a change with time such as a turning up of the sheet and a torque shortage of the organic photoreceptor 2.

Further, the cleaning blades 12a, 13
Since the fusion of the toner 5 to the toner a can be effectively suppressed, the toner 5 containing a urethane resin as a main component can be stably used for a long period of time, and the image forming apparatus 1 for oilless fixing can be realized more reliably. It will be possible.

In the above example, the cleaning blades 12a, 13a are both made of urethane resin, but the cleaning blades 12a, 13a are
Either one of them may be formed of a urethane resin, or both may be formed of a material other than the urethane resin.

Further, in the above-mentioned example, the image forming apparatus of the present invention is applied to the image forming apparatus which performs the secondary transfer by using the intermediate transfer medium such as the intermediate transfer belt 7, but as shown in FIG. It can also be applied to an image forming apparatus that directly transfers a toner image of the organic photoconductor 2 onto a transfer material 9 such as paper without using an intermediate transfer medium.

Next, an embodiment of the image forming apparatus of the present invention will be described. Experiments were carried out on the cleaning of the organic photoconductor 2 and the cleaning of the intermediate transfer belt 7 for three examples belonging to the present invention and two comparative examples not belonging to the present invention.

The materials for the one-component toner 5 used in this experiment are the same in all of the examples and the comparative examples, and are as follows. (Preparation of toner mother particles 5a) Diphenylmermethane-4,
An isocyanate component is prepared by mixing and dissolving 17.6 parts by weight of 4'-diisocyanate and 14.5 parts by weight of norbornane diisocyanate. Separately, polyoxyethylene bisphenol A ether (manufactured by NOF CORPORATION, Uniol DA-400: OH group number 283 KOHmg / g) 2
A polyol component was prepared by mixing 3.4 parts by weight. Then, the isocyanate component and the polyol component are mixed and dissolved, poured into a tray of 200 mm × 300 mm, placed in an atmospheric furnace, and held at 30 ° C. for 5 hours, and then 1
The temperature was raised to 30 ° C. over time, and then the temperature was maintained at 130 ° C. for 5 hours to complete the reaction.

100 parts by weight of the resin thus obtained, 5 parts by weight of phthalocyanine blue as a cyan pigment, and salicylic acid metal complex E-81 as a charge control agent
2 parts by weight of {Orient Chemical Co., Ltd.} were uniformly mixed using a Henschel mixer, and then mixed by a twin-screw extruder and cooled. The cooled product was crushed by a jet mill and classified by an airflow classifier to obtain a toner having an average particle size of 8 μm.

(External Additive 5b and Toner External Addition Method) The above-mentioned mother particles 1 were added to a Henschel mixer (20 liters).
Hexamethyldisilazane surface-treated silica (BET 100 m ² / g, primary particle average particle size 13
(nm) was added and mixed at 2000 rpm to obtain Toner 5. The release rate of the external additive was controlled by adjusting the mixing time.

(Conditions of Cleaning Blades 12a, 13a) Material: Polyurethane, Thickness: 2 mm, Free Length: 8 mm, Contact Angle: 15 °, Contact Pressure: 20 g / cm Here, the contact angle is the organic photoreceptor. 2 and intermediate transfer belt 7
Is an angle (angle θ shown in FIG. 1) of the cleaning blades 12 a and 13 a with respect to the cleaning blade 1 with respect to the organic photoreceptor 2 and the intermediate transfer belt 7.
It is the pressing force of 2a and 13a.

(Conditions of Experiment and Evaluation Method) The chattering noise of the cleaning blades 12a, 13a in the endurance printing of 6000 sheets was measured by using the image forming apparatus 1 for performing the secondary transfer by the intermediate transfer belt 7 as shown in FIG. The quality of the cleaning blades 12a and 13a after endurance printing, the fusion of the toner to the cleaning blades 12a and 13a, and the cleaning state were observed to judge the quality.

Table 1 shows the measurement results and the observation evaluation results of the synchronization rate and the external additive release rate of the one-component toner 5 in Examples and Comparative Examples.

[0092]

[Table 1]

As shown in Table 1, as a result of the measurement, in the embodiment, the toner 5 has a synchronization rate of 0.516 and an external additive release rate of 4.5.
5%, the example has a synchronization rate of 0.498 and an external additive release rate of 2.61%, and the examples have a synchronization rate of 0.511 and an external additive release rate of 1. 31%. In the comparative example, the synchronization rate is 0.499 and the external additive release rate is 0.4.
87%, and in the comparative example, the synchronization rate is 0.496,
The external additive release rate is 0.43%.

As shown in Table 1, as a result of the experiment, with respect to the cleaning on the photosensitive member, chattering noise and fusion of the toner to the cleaning blade 12a did not occur in any of the examples and the good cleaning was performed. There was no problem. On the other hand, in the comparative example, the chattering noise was generated and the cleaning was defective, and the toner was fused to the cleaning blade 12a. Also,
In all the comparative examples, the cleaning blade 12a was curled.

Further, as shown in Table 1, with respect to the cleaning on the intermediate transfer belt, the chattering noise and the toner fusion to the cleaning blade 12a did not occur in any of the examples and the examples, and the good cleaning was performed. , There was no problem. In contrast, the comparative example produced chatter noise. Further, in the comparative example, the cleaning blade 12a has a curl, and moreover, the cleaning blade 1 has
There was fusion of the toner to 2a.

Therefore, according to the present invention, in the image forming apparatus using the toner containing urethane resin as the main component and the cleaning blades 12a and 13a, the cleaning of the organic photoconductor 2 and the intermediate transfer belt 7 is performed for a long period of time. It turns out that it can be done well.

Incidentally, each example of the above-mentioned embodiment of the present invention,
Although each example and each comparative example of the present invention are described using a single color toner, it is needless to say that the present invention can be applied to a color image forming apparatus and a full color image forming apparatus using toners of two or more colors. Yes.

[0098]

As is apparent from the above description, according to the image forming apparatus of the present invention, the frictional resistance between the cleaning blade and the image bearing member is reduced by the free external additive of the transfer residual toner. Therefore, the occurrence of chattering of the cleaning blade in the image carrier can be effectively suppressed, and the cleaning of the image carrier by the cleaning blade can be favorably performed for a long period of time.

Further, at the cleaning point, heat generation due to friction between the cleaning blade and the image bearing member can be suppressed so that the mother particles of the toner are not melted relatively easily. Of the transfer residual toner can be suppressed, and filming of the cleaning blade can be prevented. In that case, the toner containing the urethane resin as the main component can more effectively suppress the melting of the mother particles.

In particular, according to the second aspect of the present invention, since the cleaning blade is made of urethane resin, the affinity between the cleaning blade of urethane resin and the toner containing urethane resin as a main component is high. Even if it is high, it becomes possible to effectively suppress the fusion of the toner to the cleaning blade for the image carrier.

Since good cleaning can be performed, more uniform charging and more uniform development can be performed, and uneven charging and uneven development can be prevented, and image stains can be prevented. Further, the chattering of the cleaning blade can be suppressed, and the friction between the cleaning blade and the image carrier can be reduced, so that it is possible to suppress the time-dependent changes such as the curling up of the cleaning blade and the torque shortage of the image carrier.

Further, since the fusion of the toner to the cleaning blade can be effectively suppressed, the urethane resin toner can be stably used for a long period of time, and the image forming apparatus of oilless fixing can be realized more reliably. Like

On the other hand, according to the third aspect of the invention, even in the case of the secondary transfer by the intermediate transfer medium, the frictional resistance between the cleaning blade and the intermediate transfer medium can be reduced as described above. Therefore, the chattering of the cleaning blade can be effectively suppressed even in the intermediate transfer medium, and the cleaning of the intermediate transfer medium by the cleaning blade can be favorably performed for a long period of time.

Further, at the cleaning point, heat generation due to friction between the cleaning blade and the intermediate transfer medium can be suppressed, so that the fusion of the transfer residual toner to the cleaning blade for the intermediate transfer medium can be suppressed in the same manner as described above, and this cleaning is performed. It can prevent blade filming.

In particular, according to the invention of claim 4, at least one of the cleaning blades for the image carrier and the intermediate transfer medium is made of urethane resin. It becomes possible to effectively suppress the fusion of the toner to the cleaning blade.

Also in the case of the secondary transfer by the intermediate transfer medium, it is possible to prevent the uneven charging and the uneven development as well as the stain of the image in the same manner as described above, and further, the turning up of the cleaning blade and the intermediate transfer medium. It becomes possible to suppress a change with time such as insufficient torque.

Further, since the fusion of the toner to the cleaning blade can be effectively suppressed, the urethane resin toner can be stably used for a long period of time, and the oilless fixing for the secondary transfer by the intermediate transfer medium can be performed. The image forming apparatus can be realized more reliably.

[Brief description of drawings]

FIG. 1 is a diagram schematically illustrating an example of an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a diagram showing a state of attachment of an external additive to mother particles of toner.

3A and 3B show a state in which an external additive is attached to a mother particle of a toner analyzed by a particle analyzer, FIG. 3A is a diagram showing a case where an external additive is attached to the mother particle, and a slope of a synchronization straight line is small; FIG. 4 is a diagram showing a case where a slope of a synchronization straight line in which an external additive is attached to a mother particle is large.

FIG. 4 is a diagram schematically showing another example of the embodiment of the present invention.

[Explanation of symbols]

1 ... Image forming device, 2 ... Organic photoconductor, 3 ... Charging device, 3
a ... Charging roller, 4 ... Exposure device, 5 ... One-component toner, 5
a ... Mother particles, 5b ... External additive, 5a '... Asynchronous mother particles, 5
b '... free external additive, 5b "... synchronous external additive, 6 ... developing device, 6a ... developing roller, 6b ... supply roller, 6c ... regulating blade, 7 ... intermediate transfer belt, 8 ... primary transfer device, 9
... transfer material, 10 ... secondary transfer device, 11 ... fixing device

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 21/00 310 (72) Inventor Rie Miyazaki 3-3-5 Yamato, Suwa-shi, Nagano Seiko-Epson stock In-house F-term (reference) 2H005 AA01 AA08 CA07 CA15 CB13 EA10 FA05 2H134 GA01 GA06 GB02 HD01 HD11 HD16 HD17 HD19 KD08 KD13 KG07 KH05 KH15 2H200 FA08 FA10 FA16 GA16 GA23 GA34 GA46 GB12 GB22 GB25 GB27 HA02 HA13 HA02 H02 H02 JB09 H02 LB35 MA03 MA20

Claims (4)

[Claims] 1. An electrostatic latent image formed on an image bearing member is developed with a toner composed of a large number of mother particles and a large number of particles of an external additive attached to the respective mother particles, and the developed toner is developed. In the image forming apparatus, the toner image is formed by transferring the toner image to a transfer material, and the toner remaining after the transfer on the image carrier is cleaned by a cleaning blade for the image carrier. An image forming apparatus characterized in that the external additive liberation rate of the free external additive liberated from the mother particles is set to 1% or more. 2. The image forming apparatus according to claim 1, wherein the cleaning blade is made of urethane resin. 3. The image is formed by primarily transferring the developed toner image to an intermediate transfer medium, and secondarily transferring the toner image primarily transferred to the intermediate transfer medium to the transfer material. 2. The image forming apparatus according to claim 1, wherein the transfer residual toner on the transfer medium is cleaned by a cleaning blade for the intermediate transfer medium. 4. The image forming apparatus according to claim 3, wherein at least one cleaning blade of the cleaning blades for the image carrier and the intermediate transfer medium is formed of urethane resin.