JP5262462B2 - Image carrier protecting agent manufacturing method, image carrier protecting agent, protective layer forming apparatus, image forming method, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an image carrier protective agent that prevents cracks during formation, without using binder, even for a shape that has a large aspect ratio in a powder pressing method, and to provide a method for manufacturing an image carrier protective agent which is free from variations depending on the area. <P>SOLUTION: After powdery or granular raw material 36 containing fatty acid metal salt is poured into a die, the raw material 36 is disposed so that the total weight of powder present in each of the areas H and H', located in 20% of the entire length of the die from its ends, becomes 95 to 30% of the total weights of powder present in an area B located in 20% of the entire length from the center of the die. Thereafter, the powder is compressed into a block form. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an image carrier protecting agent for protecting the surface of the image carrier, a method for producing the same, a protective layer forming apparatus provided with the image carrier protecting agent, an image forming method using the image carrier protecting agent, and the protection The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and a plotter having a layer forming apparatus, and a multifunction machine having at least one of them.

Conventionally, higher fatty acid metal salts have been used as lubricants, cleaning aids or development aids in office machines such as electrostatic copying machines. Higher fatty acid metal salts are ultimately used in powder form, so there is a method of storing them in powder form in the equipment to be used and supplying them to the necessary places. Since there is a problem that it is difficult to feed, a method in which a higher fatty acid metal salt is blocked in advance, scraped with a brush or the like, and supplied to a necessary portion is generally used.
As a method for molding a higher fatty acid metal salt block, a powder press method, a melt solidification method, and the like are known.

At present, the melt-solidification method is generally used, but this has a problem that the shrinkage is large in the cooling and solidification process, and particularly a molded body having a large aspect ratio cracks and breaks.
In order to solve this problem, Patent Document 1 proposes a measure for preventing cracking by using a long die in the vertical direction and cooling and solidifying sequentially from the lower part to the upper part.
However, this method requires strict temperature control of the mold, and further requires a long time for cooling, so that the cost is high and the productivity is not increased.
Furthermore, in the case of melting and solidification, the cooling conditions cannot be made completely the same at all positions of the mold, so the hardness of the solid lubricant that is produced varies depending on the location, and the lubricant cannot be supplied uniformly to the entire image carrier. There was a problem.
To deal with this problem, Patent Document 2 proposes a method in which fine powder such as pigment / polymer resin fine powder powder is added to zinc stearate as a main component to make the scraping amount uniform.

On the other hand, the powder press method does not need to be cooled and solidified in contrast to the melt-solidification method, so the above-described problem of density difference due to shrinkage can be solved. It is believed that the addition of a binder is essential to eliminate it. However, this addition reduces the original function of the higher fatty acid metal salt.
With respect to this problem, Patent Document 3 proposes a method in which the addition of a binder is not required by pressing a mold to be pressed at a temperature slightly lower than the melting point of the material.

Japanese Patent No. 2796486 JP 2007-224137 A JP 2000-319224 A

  However, even in the method disclosed in Patent Document 3, it is necessary to control the temperature of the mold, and some of the powder is temporarily heated to the melting point or higher, resulting in variation in hardness depending on the location.

  The present invention has been made in view of the above problems. In the powder pressing method, even if the shape has a large aspect ratio, it does not crack at the time of molding without using a binder, and variation due to location does not occur. The main object is to provide a method for producing an image carrier protecting agent.

In order to achieve the above object, according to the first aspect of the present invention, in the method for producing an image carrier protecting agent, a granular or granular raw material containing a fatty acid metal salt is compression-molded in a mold to form a block. The weight of the powder existing in the end region in the longitudinal direction of the mold is less than the weight of the powder in the region having the same length as the end region in the center of the mold. The raw material is placed in the mold and then compressed, and the weight of the powder existing within 20% of the entire length in the longitudinal direction from the end of the mold is It is characterized by being 95 to 30% of the weight of the powder existing within 20% .

According to a second aspect of the present invention, in the method for manufacturing the image carrier protecting agent according to the first aspect, the weight of the powder existing within 20% of the length in the longitudinal direction from the end of the mold is the center of the mold. 80 to 50 % of the weight of the powder existing within 20% of the entire length in the longitudinal direction from the part.
According to a third aspect of the present invention, in the image carrier protective agent used in the image forming method comprising the step of applying or adhering the image carrier protective agent to the surface of the image carrier, the image carrier protective agent is the first or the second aspect. It is manufactured by the method for manufacturing an image carrier protecting agent described in 2.

According to a fourth aspect of the present invention, in the protective layer forming apparatus for applying or adhering an image carrier protective agent to the surface of the image carrier, the image carrier protective agent is the image carrier protective agent according to the third aspect. It is characterized by that.
According to a fifth aspect of the present invention, in the protective layer forming apparatus according to the fourth aspect, the image carrier protecting agent is supplied to the surface of the image carrier through a supply member.
According to a sixth aspect of the present invention, the protective layer forming apparatus according to the fourth or fifth aspect further comprises a layer forming means for pressing the image carrier protective agent supplied to the surface of the image carrier to form a film. Features.

According to the seventh aspect of the present invention, the toner image on the image carrier that has undergone the step of carrying the toner image is transferred to a transfer medium by a transfer device, and the toner image is transferred to the transfer medium. In an image forming method in which an image carrier protecting agent is applied or adhered to a surface by a protective layer forming apparatus, the image carrier protecting agent is the image carrier protecting agent according to claim 3.
According to an eighth aspect of the present invention, an image carrier that undergoes a step of carrying a toner image, a transfer device that transfers the toner image on the image carrier to a transfer medium, and after the toner image is transferred to the transfer medium The image forming apparatus having a protective layer forming apparatus for applying or adhering an image carrier protecting agent to the surface of the image carrier, wherein the protective layer forming apparatus protects according to any one of claims 4 to 6. It is a layer forming apparatus.

According to the present invention, it is not necessary to adjust the temperature or the like as compared with the conventional production method, so that the fatty acid metal salt block can be supplied at low cost, and further, it is not necessary to add a binder or the like. The function of the metal salt is not impaired.
Therefore, by using the fatty acid metal salt block of the present invention as an image carrier protective agent, it is possible to provide a low-cost, high-functional image carrier protective agent / protective layer forming apparatus and an image forming apparatus using the same. Can do.

Embodiments of the present invention will be described below with reference to the drawings. First, a method for producing a carrier protecting agent according to this embodiment will be described.
FIG. 1 is an overall view of a mold used in the present invention. The raw material 36 before being compressed is put in a place (region) 35 where the lower mold 30 is sandwiched between the horizontal molds 31 and 32 and the end molds 33 and 34, and pressed by the upper mold 37.
FIG. 2 is a schematic sectional view seen from the longitudinal direction of the mold. After compression (FIG. 2B), the lower mold 30 is pushed out, and a block 38 used as an image carrier protecting agent described later is taken out (FIG. 2C).
3 to 5 are schematic cross-sectional views seen from the lateral direction after the raw material is charged. It is a general | schematic perspective view of the block 38 as an image carrier protective agent.

The image carrier protecting agent according to the present invention is required to contain a fatty acid metal salt.
Examples of fatty acid metal salts include barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, magnesium stearate, zinc stearate , Zinc oleate, magnesium oleate, iron oleate, cobalt oleate, copper oleate, lead oleate, manganese oleate, zinc palmitate, cobalt palmitate, lead palmitate, magnesium palmitate, aluminum palmitate, palmitate Calcium acid, lead caprylate, lead caprate, zinc linolenate, cobalt linolenate, calcium linolenate, zinc ricinoleate, cadmium ricinoleate and mixtures thereof However, the present invention is not limited to this. Moreover, you may mix and use these.

After putting the powdery or granular raw material 36 containing the fatty acid metal salt into the mold, as shown in FIG. 3, the region (part) H within 20% of the length in the longitudinal direction from the end of the mold. , The total weight of the powder existing in H ′ is 95 to 30% of the total weight of the powder existing in the region (part) B within 20% of the entire length in the longitudinal direction from the center of the mold. To be. That is, the raw material 36 is disposed so as to satisfy the relationship of Expression 1.
[Formula 1]
0.3 ≦ (weight of powder in portion H) / (weight of powder in portion M) ≦ 0.95
And 0.3 ≦ (weight of the powder in the H ′ portion) / (weight of the powder in the M portion) ≦ 0.95
Hereinafter, (weight of the powder in the H portion) / (weight of the powder in the M portion) and (weight of the powder in the H ′ portion) / (weight of the powder in the M portion) are expressed as “weight ratio”. ".

The outline of the manufacturing procedure of the block of the present invention will be described below.
(A) The raw material 36 is put into a place 35 where the lower mold 30 is sandwiched between the horizontal molds 31 and 32 and the end molds 33 and 34.
(B) The introduced raw material 36 is made uniform with a spatula or the like as shown in FIG.
(C) With a spatula or the like again, bring the raw materials 36 in the H and H ′ portions inside, and arrange the powder so as to satisfy the formula 1.
(D) The upper mold | type 37 is installed and it compresses with the movable body 40 of the press apparatus which is not shown in figure. At this time, by installing the stopper 41, a block having the same height can be molded.
(E) The press is released, the upper die 37 is removed, the lower die 30 is pushed up, and the compressed block 38 is taken out.
In this way, by sequentially performing the steps (A) to (E), a block containing a higher fatty acid metal salt can be used in a powder press method without using a binder even in a shape having a large aspect ratio. However, it can be manufactured so that it does not break during molding and does not vary depending on the location. However, the processes (A) to (E) are merely examples, and the process is not limited thereto.

Next, a protective layer forming apparatus using the fatty acid metal salt block produced by the above method as an image carrier protecting agent and an image forming apparatus having the protective layer forming apparatus will be described.
FIG. 7 is a schematic configuration diagram of the protective layer forming apparatus 2 according to the present embodiment. A protective layer forming apparatus 2 disposed opposite to the photosensitive drum 1 as an image carrier is an image carrier protective agent (hereinafter also simply referred to as “protective agent”) 21 formed in a block shape (columnar shape). The protective agent supplying member 22 as a supply member, the pressing force applying mechanism 23, the protective layer forming mechanism 24 as a layer forming means, and the like are mainly configured.
The protective layer forming mechanism 24 includes a blade 24a that contacts the photosensitive drum 1 in a non-counter direction, a blade support 24b that supports the blade 24a, and the blade 24a together with the blade support 24b toward the photosensitive drum 1 side. It has a biasing means 24c for biasing.
Here, a coil spring is illustrated as an urging means of the pressing force applying mechanism 23 and the protective layer forming mechanism 24. However, the present invention is not limited thereto. But you can.
The image carrier protecting agent 21 contacts the rotating brush-like protecting agent supply member 22 by the pressing force from the pressing force applying mechanism 23. The protective agent supply member 22 rotates and rubs with the image carrier 1 with a linear velocity difference. At this time, the image carrier protective agent held on the surface of the protective agent supply member 22 is applied to the surface of the image carrier. Supply.
The protective agent for the image carrier supplied to the surface of the image carrier is thinned (formed into a film) by the protective layer forming mechanism 24.

The deteriorated image carrier protective agent is removed by a cleaning mechanism together with other components such as toner remaining on the image carrier by a normal cleaning mechanism. Although the cleaning mechanism may be used also as the protective layer forming apparatus 2, the function of removing the image carrier surface residue and the function of forming the protective layer may differ in the rubbing state of an appropriate member. Therefore, in this embodiment, the functions are separated, and as shown in FIG. 7, the cleaning device 4 is disposed downstream of the transfer device described later in the rotation direction of the photosensitive drum 1 and upstream of the protective layer forming device 2. Is provided.
The cleaning device 4 includes a cleaning blade 41 as a cleaning member, a cleaning pressing mechanism 42, and the like. Here, although the coil spring is illustrated as the cleaning pressing mechanism 42, it is not limited to this, and for example, a member having rubber elasticity, a leaf spring, and other elastic members may be used.

The material of the blade 24a used in the protective layer forming mechanism 24 is not particularly limited. For example, elastic materials such as urethane rubber, hydrin rubber, silicone rubber, and fluorine rubber, which are generally known as cleaning blade materials, may be used alone or in a blend. Can be used. Further, these rubber blades may be coated or impregnated with a low friction coefficient material at the contact portion with the image carrier. Further, in order to adjust the hardness of the elastic body, fillers represented by other organic fillers and inorganic fillers may be dispersed.
These blades are fixed to the blade support 24b by an arbitrary method such as adhesion or fusion so that the tip can be pressed against the surface of the image carrier.
The thickness of the blade 24a is not uniquely defined in consideration of the force applied by pressing, but is preferably about 0.5 to 5 mm, more preferably about 1 to 3 mm. .
Also, the length of the blade that protrudes from the support and can bend, that is, the so-called free length, is applied by pressing in the same manner, but it cannot be uniquely defined in terms of force, but is approximately 1 to 15 mm. If it is about 2-10 mm, it can be used more preferably.

As another configuration of the protective layer forming blade member, a layer of resin, rubber, elastomer or the like is coated on the surface of an elastic metal blade such as a spring plate, if necessary, via a coupling agent, a primer component, etc. It may be formed by a method, and if necessary, heat curing or the like, and if necessary, surface polishing or the like may be applied.
The thickness of the elastic metal blade is preferably about 0.05 to 3 mm, and more preferably about 0.1 to 1 mm.
Moreover, in an elastic metal blade, in order to suppress the twist of a blade, you may perform processes, such as a bending process, in the direction substantially parallel to a spindle after attachment.
As a material for forming the surface layer, fluorine resin such as PFA, PTFE, FEP, PVdF, silicone elastomer such as fluorine rubber, methylphenyl silicone elastomer, and the like can be used together with a filler, if necessary. It is not limited to this.
Further, the force that presses the image carrier with the protective layer forming mechanism 24 is sufficient as the force that the image carrier protective agent 21 spreads to form a protective layer or a protective film, and the linear pressure is 5 gf / cm or more and 80 gf / It is preferably cm or less, and more preferably 10 gf / cm or more and 60 gf / cm or less.

The brush-like member 22 is preferably used as a protective agent supply member. In this case, the brush fiber is preferably flexible in order to suppress mechanical stress on the surface of the image carrier.
As a specific material of the flexible brush fiber, one or more kinds can be selected and used from generally known materials. Specifically, polyolefin resins (eg, polyethylene, polypropylene); polyvinyl and polyvinylidene resins (eg, polystyrene, acrylic resin, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether, and Polyvinyl chloride); vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer; styrene-butadiene resin; fluorine resin (for example, polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene); Polyester; Nylon; Acrylic; Rayon; Polyurethane; Polycarbonate; Phenol resin; Amino resin (eg urea-formaldehyde resin, melamine) Fat, benzoguanamine resins, urea resins, polyamide resins); Among such, may be a resin having flexibility.
Also, in order to adjust the degree of bending, diene rubber, styrene-butadiene rubber (SBR), ethylene propylene rubber, isoprene rubber, nitrile rubber, urethane rubber, silicone rubber, hydrin rubber, norbornene rubber, etc. are used in combination. Also good.

The support body of the protective agent supply member 22 includes a fixed mold and a rotatable roll. As the roll-shaped supply member, for example, there is a roll brush in which a tape having brush fibers piled is wound around a metal core in a spiral shape. The brush fiber has a fiber diameter of about 10 to 500 μm, the length of the brush fiber is 1 to 15 mm, and the brush density is 10,000 to 300,000 per square inch (1.5 × 10 ^{7 to} 4.5 × 10 per square meter). ^Eight ) are preferably used.
For the protective agent supply member, it is preferable to use a material having a very high brush density from the viewpoint of supply uniformity and stability, and it is also possible to make one fiber from several to several hundred fine fibers. preferable. For example, bundling 50 fine fibers of 6.7 decitex (6 denier), such as 333 decitex = 6.7 decitex × 50 filament (300 denier = 6 denier × 50 filament), and implanting as one fiber Is also possible.
Moreover, you may provide a coating layer in the brush surface for the purpose of stabilizing the surface shape of a brush, environmental stability, etc. as needed. As a component constituting the coating layer, it is preferable to use a coating layer component that can be deformed according to the bending of the brush fiber, and these are not limited as long as the material can maintain flexibility. Polyolefin resins such as polyethylene, polypropylene, chlorinated polyethylene, chlorosulfonated polyethylene, etc .; polystyrene, acrylic (for example, polymethyl methacrylate), polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, Polyvinyl and polyvinylidene resins such as polyvinyl carbazole, polyvinyl ether, and polybiliketones; vinyl chloride-vinyl acetate copolymers; silicone resins composed of organosiloxane bonds or modified products thereof (for example, alkyd resins, Modified products by reester resin, epoxy resin, polyurethane, etc.); Fluororesin such as perfluoroalkyl ether, polyfluorovinyl, polyfluorovinylidene, polychlorotrifluoroethylene; polyamide; polyester; polyurethane; polycarbonate; urea-formaldehyde resin, etc. Amino resins; epoxy resins, composite resins of these, and the like.

FIG. 8 is a cross-sectional view illustrating an outline of a configuration example of a process cartridge using the protective layer forming apparatus 2.
In the process cartridge 12, the photosensitive drum 1, the protective layer forming device 2, the charging roller 3, the developing device 5, the cleaning device 4 and the like are integrally accommodated. The developing device 5 includes a developing roller 51, conveying screws 52 and 53 that circulate the developer while stirring and conveying, a preset case 54 that stores toner, and the like.
The photosensitive drum 1 has a surface on which the image carrier protecting agent and toner components partially deteriorated after the transfer process remain, but the surface residue is cleaned and cleaned by the cleaning blade 41.
The cleaning blade 41 is abutted at an angle similar to a so-called counter type (leading type).

An image carrier protective agent 21 is supplied from a protective agent supply member 22 to the surface of the photosensitive drum 1 from which the residual toner and the deteriorated image carrier protective agent on the surface have been removed by the cleaning device 4 to form a protective layer. A film-like protective layer is formed by the mechanism 24.
The photosensitive drum 1 having a protective layer formed on the surface thereof by the protective layer forming device 2 is charged with an electrostatic latent image by exposure light L such as a laser. The latent image is visualized as a toner image by the developing device 5 and transferred to an intermediate transfer belt 105 as a transfer medium by a transfer roller 6 as a transfer device outside the process cartridge 12. In the case of the direct transfer method, the transfer medium is a sheet-like recording medium.

FIG. 9 is a cross-sectional view showing an example of a tandem type intermediate transfer type color copying machine 100 as an image forming apparatus having the protective layer forming apparatus 2.
The color copying machine 100 includes an apparatus main body 101, a scanner 102 provided on the upper surface of the apparatus main body 101, and an automatic document feeder (ADF) 103 provided on the scanner 102.
A paper feed unit 104 including a plurality of paper feed cassettes 104 a, 104 b, 104 c, and 104 d is provided at the lower part of the apparatus main body 101.
An endless intermediate transfer belt 105 as an intermediate transfer member is disposed at a substantially central portion of the apparatus main body 101. The intermediate transfer belt 105 is supported by being wound around a plurality of support rollers 106, 107, 108 and the like, and is rotated in the clockwise direction in the drawing by a drive source (not shown).
In the vicinity of the support roller 108, an intermediate transfer member cleaning device 109 is provided for removing residual toner remaining on the intermediate transfer belt 105 after the secondary transfer.
On the intermediate transfer belt 105 stretched between the support roller 106 and the support roller 107, four colors of yellow (Y), magenta (M), cyan (C), and black (K) are arranged along the conveyance direction. Process cartridges 12Y, 12M, 12C, and 12K as image forming means are arranged side by side to constitute a tandem image forming unit 10. However, these four color orders are examples, and are not limited to this.

An exposure device 8 is disposed above the tandem image forming unit 10. A secondary transfer roller 110 as a transfer device is disposed on the opposite side of the intermediate transfer belt 105 from the support roller 108. The image on the intermediate transfer belt 105 is transferred to a sheet (paper) fed from the paper feeding unit 104 by the secondary transfer roller 110.
On the left side of the secondary transfer roller 110, a fixing device 111 for fixing the transferred image on the sheet is provided. The fixing device 111 has a configuration in which a pressure roller 111b is pressed against an endless belt-like fixing belt 111a.
Below the fixing device 111, a sheet reversing device 112 that reverses the sheet when recording images on both sides of the sheet is provided substantially parallel to the tandem image forming unit 10 described above.

A series of processes for image formation will be described using a negative-positive process.
The photosensitive drum 1 typified by a photosensitive member (OPC) having an organic photoconductive layer is neutralized by a neutralizing lamp (not shown) or the like, and uniformly negative by a charging roller 3 (see FIG. 8) as a charging device. Charged.
When the photosensitive drum 1 is charged by the charging roller 3, an appropriate voltage or voltage suitable for charging the photosensitive drum 1 to a desired potential is applied to the charging roller 3 from a voltage application device (not shown). A charging voltage in which an AC voltage is superimposed on this is applied.
The charged photosensitive drum 1 is formed with a latent image by laser light irradiated by an exposure device 8 such as a laser optical system (the absolute value of the exposed portion potential is lower than the absolute value of the non-exposed portion potential). Done.
Laser light is emitted from a semiconductor laser, and the surface of the photosensitive drum 1 is scanned in the direction of the rotational axis of the photosensitive drum 1 by a polygonal polygonal mirror (polygon) that rotates at high speed.

The latent image formed in this way is developed with a developer made of toner particles or a mixture of toner particles and carrier particles supplied onto the developing roller 51 of the developing device 5 to form a toner visible image. .
At the time of developing the latent image, a voltage of an appropriate magnitude between the exposed portion and the non-exposed portion of the photosensitive drum 1 or a development in which an AC voltage is superimposed on the developing sleeve from a voltage application mechanism (not shown). A bias is applied.
The toner image formed on the photosensitive drum 1 corresponding to each color is transferred onto the intermediate transfer belt 105 by the transfer roller 6 and transferred from the paper supply unit 104 or from the manual feed tray 113. The superimposed toner images (color images) are collectively transferred onto a transfer medium (sheet) such as a sheet of paper by the secondary transfer roller 110.
The transfer roller 6 is preferably applied with a potential having a polarity opposite to that of toner charging as a transfer bias.

The toner particles remaining on the photosensitive drum 1 are cleaned by the cleaning blade 41 and recovered into the toner recovery chamber in the cleaning device 4.
The sheet after the image transfer is sent to the fixing device 111 where heat and pressure are applied to fix the transferred image, and the sheet is stacked on the paper discharge tray 116 by the paper discharge roller pair 115.
Alternatively, the conveying path is switched by a switching claw (not shown), and the sheet is put into the sheet reversing device 112 where it is reversed and guided to the transfer position again. The paper is discharged onto the paper tray 116.
After the image transfer, the intermediate transfer belt 105 has the residual toner removed by the intermediate transfer member cleaning device 109, and prepares for another image formation by the tandem image forming unit 10.

  As described above, as the image forming apparatus, a plurality of developing devices are used, and a plurality of toner images with different colors sequentially produced by the plurality of developing devices are sequentially and sequentially transferred onto an intermediate transfer medium. It is not limited to the “tandem type intermediate transfer method” in which the toner images are transferred to a transfer medium such as paper and then fixed, and a plurality of toner images similarly manufactured are sequentially placed on the transfer medium. A “tandem direct transfer method” or the like in which the image is fixed after being transferred in an overlapping manner may be used.

Further, the charging device described above is preferably a charging device disposed in contact with or close to the surface of the image bearing member, and thereby, a corona discharge device called a corotron or a scorotron using a discharge wire. In comparison, it is possible to greatly suppress the amount of ozone generated during charging.
However, in the charging device that charges the charging member in contact with or close to the surface of the image carrier, as described above, since the discharge is performed in the region near the surface of the image carrier, the electrical stress on the image carrier is large. It tends to be. By using the protective layer forming apparatus using the image carrier protecting agent of the present invention, the image carrier can be maintained for a long time without deteriorating. It can be greatly suppressed and stable image quality can be ensured.

[Example]
Table 1 shows examples of the present invention together with comparative examples.
In all of the examples and comparative examples shown here, zinc stearate (Nippon Yushi GF-200) was used as a raw material, and a press brake (AMADA RG-25) was used for the press in the step (D).
In addition, the dimensions of the blocks molded here were molded in a longitudinal direction of 327 mm, a lateral direction of 8 mm, and a longitudinal direction of 6.5 mm.
Moreover, the filling rate shown below is represented by Formula 2.
[Formula 2]
Filling rate (%) = (weight of block) / (specific gravity of raw material × volume of block) × 100

  The filling rate is preferably 80% to 99%, particularly preferably 90% to 97%. If the filling rate is 60% or less, it is impossible to mold the block unless a binder is added. If it is 60% to 80%, the molding is possible, but it is very easy to break. On the other hand, when the filling rate is 99% or more, the sample melts during compression and cracks due to shrinkage occur.

Description of Examples (Example 1)
The weight ratio was set to 95% in the arrangement shown in FIG. 4 and the filling rate was 97%.
(Example 2)
The weight ratio was set to 90% in the arrangement shown in FIG. 4 and the filling rate was 97%.
(Example 3)
The weight ratio was set to 80% in the arrangement shown in FIG. 4 and the filling rate was molded at 97%.
Example 4
The weight ratio was set to 70% in the arrangement shown in FIG. 4 and the filling rate was 97%.
(Example 5)
The weight ratio was set to 60% in the arrangement shown in FIG. 4 and the filling rate was 97%.
(Example 6)
The weight ratio was set to 50% in the arrangement shown in FIG. 4, and the filling rate was 97%.
(Example 7)
The weight ratio was set to 30% in the arrangement shown in FIG. 4 and the filling rate was molded at 97%.
(Example 8)
The weight ratio was set to 95% in the arrangement shown in FIG. 4, and the filling rate was 90%.
Example 9
The weight ratio was set to 90% in the arrangement shown in FIG. 4 and the filling rate was 90%.
(Example 10)
The weight ratio was set to 80% in the arrangement form shown in FIG. 4, and the filling rate was 90%.
(Example 11)
The weight ratio was set to 70% in the arrangement form shown in FIG. 4, and the filling rate was 90%.
(Example 12)
The weight ratio was set to 60% in the arrangement shown in FIG. 4, and the filling rate was 90%.
(Example 13)
The weight ratio was set to 50% in the arrangement form shown in FIG. 4, and the filling rate was 90%.
(Example 14)
The weight ratio was set to 30% in the arrangement shown in FIG. 4, and the filling rate was 90%.

Description of Comparative Example (Comparative Example 1)
The weight ratio was set to 100% in the arrangement shown in FIG. 3, and the filling rate was 97%.
(Comparative Example 2)
The weight ratio was set to 97% in the arrangement shown in FIG. 3, and the filling rate was set to 97%.
(Comparative Example 3)
The weight ratio was set to 25% in the arrangement shown in FIG. 5 and the filling rate was 97%.
(Comparative Example 4)
The weight ratio was set to 100% in the arrangement shown in FIG. 3, and the filling rate was 90%.
(Comparative Example 5)
The weight ratio was set to 97% in the arrangement shown in FIG. 3, and the filling rate was 90%.
(Comparative Example 6)
The weight ratio was set to 25% in the arrangement form shown in FIG. 5, and the filling rate was 90%.

In addition, for the ones that could be produced without cracking, the image carrier protecting agent of the present invention was supplied from the portion where zinc stearate was supplied in the image forming unit of IMAGIO MP C4500 manufactured by Ricoh.
A continuous paper passing test of A4 size, image area ratio of 5%, and 1000 originals was conducted to check whether there was any deviation in the way the blocks were cut.

In the method for producing a block containing a fatty acid metal salt of the present invention, it is considered that cracking does not occur at the time of molding even if there is no binder for the following reasons.
Usually, when a granular or granular raw material is compression-molded, the powder before compression is introduced uniformly in the longitudinal direction of the mold as shown in FIG. However, in the case of a thing with high fluidity like the powder of a fatty acid metal salt, the powder in the central part tends to escape toward the end part during compression. For this reason, when the powder is uniformly charged, the center portion can be molded without cracks or the like, but the powder density at the end portion becomes too high and cracks are generated.
Therefore, the powder at the end portion is brought close to the central portion in advance, and the powder at the central portion flows to the end portion in the process of compression, so that the entire density becomes uniform.

Comparing Comparative Examples 1, 2, 4, and 5 with Examples 1 and 8, in Examples 1 and 8, it was possible to prevent cracks at the ends by bringing the powder at the ends to the center. Yes.
On the other hand, comparing Comparative Examples 3 and 6 with Examples 7 and 14, Comparative Examples 3 and 6 cause the powder to be brought too close to the central part, the density of the central part becomes too high, and the central part is cracked. .
Therefore, at the time before compression, the weight of the powder existing within 20% of the entire length in the longitudinal direction from the end of the mold is present within 20% of the total length in the longitudinal direction from the center of the mold. By setting the weight to 95-30% of the weight of the powder, a block containing a fatty acid metal salt without cracks can be produced.
Furthermore, in Examples 1, 2, 7, 8, and 14, although there is no cracking at the time of molding, deviation occurs when scraping with a brush. Therefore, at the time before compression, the weight of the powder existing within 20% of the entire length in the longitudinal direction from the end of the mold is present within 20% of the total length in the longitudinal direction from the center of the mold. More preferably, it is 80 to 50% of the weight of the powder.

Since the fatty acid metal salt block according to the present invention does not require temperature control or the like as compared with the conventional production method, it can be supplied at low cost, and further, it is not necessary to add a binder or the like. There is no loss of salt function.
Therefore, by using the fatty acid metal salt block of the present invention as a protective agent, it is possible to provide a low-cost, high-functional image carrier protective agent / protective layer forming apparatus and an image forming apparatus using the same.

Next, a photoconductor preferably used in the present invention will be described.
In the photoreceptor used in the image forming apparatus of the present invention, a photosensitive layer is provided on a conductive support. The photosensitive layer is composed of a single layer type in which a charge generation material and a charge transport material are mixed, a forward layer type in which a charge transport layer is provided on the charge generation layer, or a charge generation layer provided on the charge transport layer. There is a reverse layer type. In addition, a protective layer can be provided on the photosensitive layer in order to improve the mechanical strength, abrasion resistance, gas resistance, cleaning property, and the like of the photoreceptor. An undercoat layer may be provided between the photosensitive layer and the conductive support. In addition, an appropriate amount of a plasticizer, an antioxidant, a leveling agent and the like can be added to each layer as necessary.
As the conductive support of the photoreceptor, a material having a volume resistance of 10 ¹⁰ Ω · cm or less, for example, a metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, oxidation A metal oxide such as indium is deposited or sputtered on a film or cylindrical plastic or paper, or a plate of aluminum, aluminum alloy, nickel, stainless steel, etc. After forming the tube into a drum shape, it is possible to use a tube that has been surface-treated by cutting, superfinishing, polishing, or the like.
A drum-shaped support having a diameter of 20 to 150 mm, preferably 24 to 100 mm, and more preferably 28 to 70 mm can be used. If the diameter of the drum-shaped support is 20 mm or less, it is physically difficult to arrange the charging, exposure, development, transfer, and cleaning steps around the drum. If the diameter of the drum-shaped support is 150 mm or more, image formation is performed. The apparatus becomes undesirably large. In particular, when the image forming apparatus is a tandem type, it is necessary to mount a plurality of photoconductors, and thus the diameter is preferably 70 mm or less, and preferably 60 mm or less.
Further, endless nickel belts and endless stainless steel belts disclosed in JP-A-52-36016 can also be used as the conductive support.

As the undercoat layer of the photosensitive member used in the image forming apparatus of the present invention, a resin or a material mainly composed of a white pigment and a resin, a metal oxide film obtained by chemically or electrochemically oxidizing the surface of a conductive substrate, etc. However, those containing a white pigment and a resin as main components are preferable.
Examples of the white pigment include metal oxides such as titanium oxide, aluminum oxide, zirconium oxide, and zinc oxide. Among them, it is most preferable to contain titanium oxide that is excellent in preventing charge injection from the conductive substrate. As the resin used for the undercoat layer, thermoplastic resins such as polyamide, polyvinyl alcohol, casein, and methylcellulose, thermosetting resins such as acrylic, phenol, melamine, alkyd, unsaturated polyester, and epoxy, one or various kinds of these Mixtures can be exemplified.

  Examples of the charge generating material for the photoreceptor used in the image forming apparatus of the present invention include azo pigments such as monoazo pigments, bisazo pigments, trisazo pigments, and tetrakisazo pigments, triarylmethane dyes, thiazine dyes, and oxazines. Dyes, xanthene dyes, cyanine dyes, styryl dyes, pyrylium dyes, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments, indanthrone pigments, squarylium pigments Inorganic materials such as pigments, organic pigments and dyes such as phthalocyanine pigments, selenium, selenium-arsenic, selenium-tellurium, cadmium sulfide, zinc oxide, titanium oxide, and amorphous silicon can be used. It can be used alone or in combination. The undercoat layer may be a single layer or a plurality of layers.

Examples of the charge transport material for the photoreceptor used in the image forming apparatus of the present invention include anthracene derivatives, pyrene derivatives, carbazole derivatives, tetrazole derivatives, metallocene derivatives, phenothiazine derivatives, pyrazoline compounds, hydrazone compounds, styryl compounds, styryl hydrazone compounds, Enamine compounds, butadiene compounds, distyryl compounds, oxazole compounds, oxadiazole compounds, thiazole compounds, imidazole compounds, triphenylamine derivatives, phenylenediamine derivatives, aminostilbene derivatives, triphenylmethane derivatives, etc. can do.
The binder resin used to form the photosensitive layer of the charge generation layer and the charge transport layer is electrically insulating and is a known thermoplastic resin, thermosetting resin, photocurable resin, and photoconductive material. Suitable binder resins include, for example, polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, Ethylene-vinyl acetate copolymer, polyvinyl butyral, polyvinyl acetal, polyester, phenoxy resin, (meth) acrylic resin, polystyrene, polycarbonate, polyarylate, thermoplastic resin such as polysulfone, polyethersulfone, ABS resin, phenol resin , Epoxy resin, urethane resin, melamine resin, isocyanate resin, alkyd resin, Examples thereof include a thermosetting resin such as a ricone resin, a thermosetting acrylic resin, a type of binder resin such as a photoconductive resin such as polyvinyl carbazole, polyvinyl anthracene, and polyvinyl pyrene, or a mixture of various types of binder resins. In particular, it is not limited to these.

As antioxidant, the following are used, for example.
(Monophenol compound)
2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5-di-t-butyl-4 -Hydroxyphenyl) propionate, 3-t-butyl-4-hydroxynisol and the like.
(Bisphenol compounds)
2,2′-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2′-methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4′-thiobis- ( 3-methyl-6-t-butylphenol), 4,4′-butylidenebis- (3-methyl-6-t-butylphenol) and the like.
(High molecular phenolic compounds)
1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t- Butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4 ′) -Hydroxy-3'-t-butylphenyl) butyric acid] glycol ester, tocophenols and the like.
(Paraphenylenediamines)
N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N, N'- Di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.
(Hydroquinones)
2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2- (2-octadecenyl) ) -5-methylhydroquinone and the like.
(Organic sulfur compounds)
Dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like.
(Organic phosphorus compounds)
Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine, and the like.

As the plasticizer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is about 0 to 30 parts by weight with respect to 100 parts by weight of the binder resin. Is appropriate.
A leveling agent may be added to the charge transport layer. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the chain are used, and the amount used is 100 parts by weight of binder resin. 0 to 1 part by weight is suitable.
As described above, the surface layer is provided to improve the mechanical strength, abrasion resistance, gas resistance, cleaning property, etc. of the photoreceptor. Examples of the surface layer include a polymer having a mechanical strength higher than that of the photosensitive layer and a polymer in which an inorganic filler is dispersed. The polymer used for the surface layer may be either a thermoplastic polymer or a thermosetting polymer, but the thermosetting polymer has a high mechanical strength and does not wear due to friction with the cleaning blade. It is very preferable because of its extremely high ability to suppress. If the surface layer has a thin film thickness, there is no problem even if it does not have the charge transport capability. However, if the surface layer without the charge transport capability is formed thick, the sensitivity of the photoreceptor decreases, the potential increases after exposure, and the residual layer remains. Since the potential rise is likely to occur, it is preferable to use the above-mentioned charge transporting substance in the surface layer or to use a polymer having a charge transporting capability for the protective layer. When the surface layer is provided, the mechanical strength of the photosensitive layer and the surface layer is generally greatly different, and therefore the protective layer is worn away due to friction with the cleaning blade. It is important that the surface layer has a sufficient film thickness, and is 0.01 to 12 μm, preferably 1 to 10 μm, more preferably 2 to 8 μm. If the film thickness of the surface layer is 0.1 μm or less, it is not preferable because it is too thin and easily disappears due to friction with the cleaning blade, and wear of the photosensitive layer proceeds from the disappeared portion. When the film thickness of the surface layer is 12 μm or more, the sensitivity is lowered, the potential after exposure is increased, and the residual potential is easily increased. In particular, when a polymer having charge transport capability is used, the cost of the polymer having charge transport capability is high. This is not preferable.

  The polymer used for the surface layer is preferably a material that is transparent to the writing light during image formation and has excellent insulation, mechanical strength, and adhesiveness. ABS resin, ACS resin, olefin-vinyl monomer copolymer , Chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethyl Examples include resins such as bentene, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin. . These polymers may be thermoplastic polymers, but in order to increase the mechanical strength of the polymers, they are crosslinked with a crosslinking agent having a polyfunctional acryloyl group, carboxyl group, hydroxyl group, amino group, etc. By using a curable polymer, the mechanical strength of the surface layer is increased, and wear due to friction with the cleaning blade can be greatly reduced.

As described above, it is preferable that the surface layer has a charge transport capability. In order to provide the surface layer with a charge transport capability, a polymer used for the surface layer and the above-described charge transport material are mixed. A method of using a polymer having a charge transporting capability for the surface layer is conceivable, and the latter method is preferable because it can obtain a photoconductor with high sensitivity and little increase in potential after exposure and little increase in residual potential.
The image carrier of the present invention is an intermediate used for image formation by a so-called intermediate transfer method in which a toner image formed on a photoreceptor is primarily transferred to perform color superposition and further transferred to a transfer medium. It may be a transfer medium.
As the intermediate transfer medium, a medium having a volume resistance of 10 ⁵ to 10 ¹¹ Ω · cm is preferable. If the surface resistance is below 10 ⁵ Omega / □, when the transfer of the toner image is performed from the photosensitive member onto the intermediate transfer medium, there is so-called transfer dust which the toner image with the discharge is disturbed occurs, 10 ¹¹ If it exceeds Ω / □, after the toner image is transferred from the intermediate transfer medium to a transfer medium such as paper, the counter charge of the toner image remains on the intermediate transfer medium and appears as an afterimage on the next image. is there.

As an intermediate transfer medium, for example, a metal oxide such as tin oxide or indium oxide, or conductive particles such as carbon black or a conductive polymer, alone or in combination, kneaded with a thermoplastic resin, and then extruded into a belt shape Alternatively, a cylindrical plastic can be used. In addition to this, the above-mentioned conductive particles and conductive polymer are added to a resin solution containing a thermal crosslinking reactive monomer or oligomer, if necessary, and subjected to centrifugal molding while heating to obtain an intermediate transfer medium on an endless belt. You can also.
When providing a surface layer on the intermediate transfer medium, among the surface layer materials used for the above-mentioned photoreceptor surface layer, the composition excluding the charge transport material is appropriately adjusted in combination with a conductive substance, Can be used.

Next, the toner suitably used in the present invention will be described.
First, the toner of the present invention preferably has an average circularity of 0.93 to 1.00. In the present invention, the value obtained from the following formula (3) is defined as circularity. This circularity is an index of the degree of unevenness of the toner particles, and indicates 1.00 when the toner is a perfect sphere, and the circularity becomes smaller as the surface shape becomes more complicated.
Circularity SR = perimeter of a circle having the same area as the particle projection area / perimeter of the particle projection image
When the average circularity is in the range of 0.93 to 1.00, the surface of the toner particles is smooth, and the contact area between the toner particles and between the toner particles and the photosensitive member is small, so that the transferability is excellent.
Since the toner particles have no corners, the developer agitation torque in the developing device is small, and the agitation drive is stabilized, so that no abnormal image is generated.
Since there are no angular toner particles in the toner that forms the dots, when the pressure is brought into contact with the transfer medium during the transfer, the pressure is uniformly applied to the entire toner that forms the dots, and the transfer is not easily lost.
Since the toner particles are not angular, the abrasive power of the toner particles themselves is small, and the surface of the image carrier is not damaged or worn.

Next, a method for measuring the circularity will be described.
The circularity can be measured using a flow type particle image analyzer FPIA-1000 manufactured by Toa Medical Electronics.
As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance, and further measurement is performed. Add about 0.1-0.5g of sample. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the shape and particle size of the toner are measured by the above apparatus with the dispersion concentration being 3000 to 10000 / μl.
In the present invention, the weight average diameter D4 of the toner is preferably 3 to 10 μm.
In this range, since the toner particles have a sufficiently small particle size with respect to the minute latent image dots, the dot reproducibility is excellent.
When the weight average diameter D4 is less than 3 μm, phenomena such as a decrease in transfer efficiency and a decrease in blade cleaning properties tend to occur.
When the weight average diameter D4 exceeds 10 μm, it is difficult to suppress scattering of characters and lines.
In the toner of the present invention, the ratio of the weight average diameter D4 to the number average diameter D1 (D4 / D1) is preferably 1.00 to 1.40. The closer the value of (D4 / D1) is to 1, the sharper the particle size distribution of the toner.

Therefore, when (D4 / D1) is in the range of 1.00 to 1.40, the selective development due to the toner particle size does not occur, and the stability of the image quality is excellent.
Since the toner particle size distribution is sharp, the triboelectric charge amount distribution is also sharp, and fogging is suppressed.
When the toner particle size is uniform, the latent image dots are developed so as to be arranged in a precise and orderly manner, so that the dot reproducibility is excellent.

Next, a method for measuring the particle size distribution of toner particles will be described.
Examples of the measuring device for the particle size distribution of toner particles by the Coulter counter method include Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkyl benzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. Volume distribution and number distribution are calculated. From the obtained distribution, the weight average diameter D4 and the number average diameter D1 of the toner can be obtained.

As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.
In addition, as such a substantially spherical toner, a toner composition containing a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent in an aqueous medium in the presence of fine resin particles. A toner that undergoes crosslinking and / or elongation reaction is preferred. The toner produced by this reaction can reduce the hot offset by curing the toner surface, and can prevent the fixing device from becoming dirty and appearing on the image.

Examples of the prepolymer comprising a modified polyester resin that can be used for toner preparation include a polyester prepolymer (A) having an isocyanate group, and examples of a compound that extends or crosslinks with the prepolymer include amines (B). Can be mentioned.
Examples of the polyester prepolymer (A) having an isocyanate group include a product obtained by further reacting a polyester having an active hydrogen group with a polyisocyanate (3), which is a polycondensate of polyol (1) and polycarboxylic acid (2). Can be mentioned. Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred.

  Examples of the polyol (1) include a diol (1-1) and a tri- or higher valent polyol (1-2). (1-1) alone or (1-1) and a small amount of (1-2) Mixtures are preferred. Diol (1-1) includes alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide phenol compound (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyol (1-2) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2). (2-1) alone and (2-1) with a small amount of ( The mixture of 2-2) is preferred. Dicarboxylic acid (2-1) includes alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, and the like). In addition, as polycarboxylic acid (2), you may make it react with polyol (1) using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.
The ratio of the polyol (1) to the polycarboxylic acid (2) is usually 2/1 to 1/1, preferably 1. 5/1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

Examples of the polyisocyanate (3) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); aromatic aliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; the polyisocyanates as phenol derivatives, oximes, caprolactam And a combination of two or more of these.
The ratio of the polyisocyanate (3) is usually 5/1 to 1/1, preferably 4 /, as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester will be low, and the hot offset resistance will deteriorate. The content of the polyisocyanate (3) component in the prepolymer (A) having an isocyanate group at the terminal is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, more preferably 2 to 20% by weight. It is. If it is less than 0.5% by weight, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40% by weight, the low-temperature fixability deteriorates.

The number of isocyanate groups contained per molecule in the prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.
As amines (B), diamine (B1), trivalent or higher polyamine (B2), aminoalcohol (B3), aminomercaptan (B4), amino acid (B5), and amino acids B1-B5 blocked (B6) etc. are mentioned. Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine etc.) and the like. Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the B1 to B5 amino group blocked (B6) include ketimine compounds and oxazoline compounds obtained from the B1 to B5 amines and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

Furthermore, if necessary, the molecular weight of the urea-modified polyester can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
The ratio of amines (B) is the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). The ratio is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] exceeds 2 or less than 1/2, the molecular weight of the urea-modified polyester (i) becomes low, and the hot offset resistance deteriorates. In the present invention, the polyester (i) modified with a urea bond may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

By these reactions, the modified polyester used in the toner of the present invention, especially the urea-modified polyester (i) can be prepared. These urea-modified polyesters (i) are produced by a one-shot method or a prepolymer method. The weight average molecular weight of the urea-modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.
Moreover, in this invention, not only polyester (i) modified | denatured with the said urea bond but polyester (ii) which is not modified | denatured with this (i) can also be contained as a binder resin component. By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to the single use. Examples of (ii) include the same polycondensates of polyol (1) and polycarboxylic acid (2) as in the polyester component (i) above, and preferred ones are also the same as (i). Further, (ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, for example, may be modified with a urethane bond. It is preferable that (i) and (ii) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, the polyester component (i) and (ii) preferably have similar compositions. In the case of containing (ii), the weight ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. If the weight ratio of (i) is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

The peak molecular weight of (ii) is usually 1000-30000, preferably 1500-10000, more preferably 2000-8000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is usually 1-30, preferably 5-20. By having an acid value, it tends to be negatively charged.
In the present invention, the glass transition point (Tg) of the binder resin is usually 50 to 70 ° C., preferably 55 to 65 ° C. If it is less than 50 ° C., the blocking of the toner during high temperature storage deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of the urea-modified polyester resin, the dry toner of the present invention tends to have good heat-resistant storage stability even when the glass transition point is low, as compared with known polyester-based toners. As the storage elastic modulus of the binder resin, the temperature (TG ′) at which 10000 dyne / cm 2 is obtained at a measurement frequency of 20 Hz is usually 100 ° C. or higher, preferably 110 to 200 ° C. If it is less than 100 ° C., the resistance to hot offset deteriorates. As the viscosity of the binder resin, the temperature (Tη) at 1000 poise at a measurement frequency of 20 Hz is usually 180 ° C. or less, preferably 90 to 160 ° C. If it exceeds 180 ° C., the low-temperature fixability deteriorates. That is, TG ′ is preferably higher than Tη from the viewpoint of achieving both low temperature fixability and hot offset resistance. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or higher. More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more. The upper limit of the difference is not particularly limited. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 to 100 ° C. More preferably, it is 10-90 degreeC, Most preferably, it is 20-80 degreeC.

The binder resin can be produced by the following method. The polyol (1) and the polycarboxylic acid (2) are heated to 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and the generated water is distilled off as necessary. Thus, a polyester having a hydroxyl group is obtained. Next, this is reacted with polyisocyanate (3) at 40 to 140 ° C. to obtain a prepolymer (A) having an isocyanate group. Further, (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a polyester modified with a urea bond. When (3) is reacted and (A) and (B) are reacted, a solvent can be used as necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to the isocyanate (3), such as tetrahydrofuran (such as tetrahydrofuran). When polyester (ii) not modified with urea bond is used in combination, (ii) is produced in the same manner as polyester having a hydroxyl group, and this is dissolved in the solution after completion of the reaction of (i) and mixed. To do.
In addition, the toner used in the present invention can be produced generally by the following method, but is not limited thereto.

The aqueous medium used in the present invention may be water alone, or a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methylcellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like.
The toner particles may be formed by reacting a dispersion composed of a prepolymer (A) having an isocyanate group in an aqueous medium with (B), or using a urea-modified polyester (i) produced in advance. good. As a method for stably forming a dispersion comprising urea-modified polyester (i) or prepolymer (A) in an aqueous medium, a toner raw material comprising urea-modified polyester (i) or prepolymer (A) in an aqueous medium is used. And a method of dispersing by shearing force. The prepolymer (A) and other toner compositions (hereinafter referred to as toner raw materials), a colorant masterbatch, a release agent, a charge control agent, an unmodified polyester resin, etc. are dispersed in an aqueous medium. It may be mixed at the time of formation, but it is more preferable to mix the toner raw materials in advance and then add and disperse the mixture in the aqueous medium. In the present invention, other toner materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium, but after the particles are formed. , May be added. For example, after forming particles containing no colorant, the colorant can be added by a known dyeing method.

The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferable. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C. Higher temperatures are preferred in that the dispersion made of urea-modified polyester (i) or prepolymer (A) has a low viscosity and is easy to disperse.
The amount of the aqueous medium used is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight, based on 100 parts of the toner composition containing urea-modified polyester (i) and prepolymer (A). If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.
In the step of synthesizing the urea-modified polyester (i) from the prepolymer (A), the amine (B) may be added and reacted before the toner composition is dispersed in the aqueous medium, or may be dispersed in the aqueous medium. An amine (B) may be added later to cause a reaction from the particle interface. In this case, urea-modified polyester is preferentially produced on the surface of the manufactured toner, and a concentration gradient can be provided inside the particles.

Anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphates, etc., alkylamines as dispersants for emulsifying and dispersing the oily phase in which the toner composition is dispersed in a liquid containing water Amine salts such as salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, etc. Nonionic surfactants such as quaternary ammonium salt type cationic surfactants, fatty acid amide derivatives, polyhydric alcohol derivatives, such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl N, amphoteric surfactants such as N-dimethyl ammonium betaine and the like.
Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 31- [omega-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) mono-N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carboxylic acid and metal Salts, perfluoroalkylcarboxylic acids (C7 to C13) and their metal salts, perfluoroalkyl (C4 to C12) sulfonic acids and their metal salts, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2 hydroxyethyl) -Fluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Is mentioned.

Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS 1-101 , DS-102 (Made by Taikin Kogyo Co., Ltd.), Mega-Fac F-l0, F-l20, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.) 102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fagento F-100, F150 (manufactured by Neos).
Further, as the cationic surfactant, aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6 1 C10) sulfonamidopropyltrimethylammonium salt which right the fluoroalkyl group, Benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, trade names include Surflon S-21 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Daikin Industries Co., Ltd.) ), Megafuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-32 (Tochem Products Co., Ltd.), Footgent F 1300 (Neos Co., Ltd.), and the like.

Further, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite and the like can be used as an inorganic compound dispersant which is hardly soluble in water.
Further, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups, For example, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-chloro-2-acrylate -Hydroxypropyl, 3-chloro-2-methacrylic acid methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N -Methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or esters of compounds containing vinyl alcohol and carboxyl groups For example, pinyl acetate, pinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, pinylviridine, vinylpyrrolidone, vinylimidazole, ethyleneimine Homopolymers or copolymers such as those having a nitrogen atom or its heterocyclic ring, polyoxyethylene, polyoxypropylene, Oxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl Polyoxyethylenes such as esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

In addition, when an acid such as calcium phosphate salt or an alkali-soluble substance is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. To do. It can also be removed by operations such as enzymatic degradation.
When a dispersant is used, the dispersant may remain on the surface of the toner particles, but it is preferable from the charged surface of the toner that the dispersant is washed and removed after the elongation and / or crosslinking reaction.
Furthermore, in order to lower the viscosity of the toner composition, a solvent in which the urea-modified polyester (i) or the prepolymer (A) is soluble can be used. The use of a solvent is preferable in that the particle size distribution becomes sharp. The solvent is preferably volatile from the viewpoint of easy removal. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable, and aromatic solvents such as toluene and xylene are more preferable. The usage-amount of the solvent with respect to 100 parts of prepolymers (A) is 0-300 parts normally, Preferably it is 0-100 parts, More preferably, it is 25-70 parts. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after elongation and / or crosslinking reaction.

The elongation and / or cross-linking reaction time is selected depending on the reactivity of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. is there. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.
In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the entire system is gradually raised to completely evaporate and remove the organic solvent in the droplets can be employed. Alternatively, the emulsified dispersion can be sprayed into a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and the aqueous dispersant can be removed by evaporation together. . As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air streams heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used are generally used. Sufficient quality can be obtained with a short treatment such as spray dryer, belt dryer or rotary kiln.
When the particle size distribution at the time of emulsification dispersion is wide and washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classifying into a desired particle size distribution.

In the classification operation, the fine particle portion can be removed in the liquid by a cyclone, a decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder as a powder after drying, but it is preferable in the liquid to perform the classification operation. The unnecessary fine particles or coarse particles obtained can be returned to the kneading step and used for the formation of particles. At that time, fine particles or coarse particles may be wet.
The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.
By mixing the resulting dried toner powder with dissimilar particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, or by giving mechanical impact force to the mixed powder By immobilizing and fusing on the surface, it is possible to prevent the detachment of the foreign particles from the surface of the resulting composite particle.

Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture in a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) has been modified to reduce the pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar, etc.
As the colorant used in the toner, pigments and dyes conventionally used as toner colorants can be used. Specifically, carbon black, lamp black, iron black, ultramarine, nigrosine dye, Aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine 6C lake, calco oil blue, chrome yellow, quinacridone red, benzidine yellow, rose bengal and the like can be used alone or in combination.
Further, if necessary, in order to give the toner particles magnetic properties, magnetic components such as iron oxides such as ferrite, magnetite and maghemite, metals such as iron, cobalt and nickel, or alloys of these with other metals. May be contained alone or in combination in the toner particles. Moreover, these components can also be used / used together as a colorant component.
The number average diameter of the colorant in the toner used in the present invention is desirably 0.5 μm or less, preferably 0.4 μm or less, more preferably 0.3 μm or less.

When the number average diameter of the colorant in the toner is larger than 0.5 μm, the dispersibility of the pigment does not reach a sufficient level, and preferable transparency may not be obtained.
A colorant having a fine particle diameter of less than 0.1 μm is sufficiently smaller than a half wavelength of visible light, and thus is considered not to adversely affect light reflection and absorption characteristics. Therefore, the colorant particles of less than 0.1 μm contribute to good color reproducibility and transparency of the OHP sheet having a fixed image. On the other hand, if there are many colorants having a particle size larger than 0.5 μm, the transmission of incident light is hindered or scattered, and the brightness and color of the projected image of the OHP sheet tend to decrease. There is.
Further, if there are many colorants having a particle size larger than 0.5 μm, the colorant is detached from the surface of the toner particles, and various problems such as fogging, drum contamination, and poor cleaning are liable to occur. In particular, the colorant having a particle size larger than 0.7 μm is preferably 10% by number or less, more preferably 5% by number or less of the total colorant.
In addition, by adding a wetting liquid in advance with a part or all of the binder resin and kneading the colorant, the binder resin and the colorant are initially sufficiently adhered, In the toner production process, the colorant is dispersed more effectively in the toner particles, the dispersed particle diameter of the colorant is reduced, and better transparency can be obtained.

As the binder resin used for kneading in advance, the resins exemplified as the binder resin for toner can be used as they are, but are not limited thereto.
As a specific method for kneading the mixture of the binder resin and the colorant with the wetting liquid in advance, for example, the binder resin, the colorant and the wetting liquid are obtained after mixing with a blender such as a Henschel mixer. The obtained mixture is kneaded at a temperature lower than the melting temperature of the binder resin by a kneader such as a two-roll or three-roll to obtain a sample.
In addition, as the wetting liquid, a general one can be used in consideration of the solubility of the binder resin and the paintability with the colorant, but in particular, an organic solvent such as acetone, toluene, butanone, or water, It is preferable from the viewpoint of dispersibility of the colorant.
Among these, the use of water is more preferable from the viewpoint of environmental considerations and maintaining the dispersion stability of the colorant in the subsequent toner production process.
According to this manufacturing method, not only the particle diameter of the colorant particles contained in the obtained toner is reduced, but also the uniformity of the dispersion state of the particles is increased, so that the color reproducibility of the projected image by OHP is further improved. Get better.
In addition, as long as the configuration of the present invention is adopted, a release agent represented by wax can be contained in the toner together with the binder resin and the colorant.
Known release agents 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. .

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 (ethylene diamine 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 these release agents 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. 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 have poor effects for 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.

In addition, a charge control agent may be contained in the toner as necessary in order to accelerate the toner charge amount and its rise. Here, since a color change occurs when a colored material is used as the charge control agent, a material that is colorless and close to white is preferable.
All known charge control agents can be used, such as triphenylmethane dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkyls. Amide, phosphorus simple substance or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. Specifically, Bontron P-51 of a quaternary ammonium salt, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex, E-89 of a phenol condensate (above, Orient Chemical Co., Ltd.) Manufactured), TP-302 of quaternary ammonium salt molybdenum complex, TP-1415 (above, manufactured by Hodogaya Chemical Co., Ltd.), copy charge PSY VP2038 of quaternary ammonium salt, copy blue PR of triphenylmethane derivative, Quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, boron complex LR-147 (manufactured by Nippon Kalit Ltd), quinacridone, azo pigment, other sulfone Polymerization with functional groups such as acid groups, carboxyl groups, and quaternary ammonium salts Thing, and the like.
In the present invention, the amount of 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 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 attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline. These charge control agents can be dissolved and dispersed after being melt-kneaded with a masterbatch and resin, or may be added when directly dissolving and dispersing in an organic solvent, or may be fixed on the toner surface after preparation of toner particles. Also good.

Further, when the toner composition is dispersed in the aqueous medium during the toner production process, resin fine particles mainly for stabilizing the dispersion may be added.
The resin fine particles used may be any resin that can form an aqueous dispersion, and may be a thermoplastic resin or a thermosetting resin. For example, vinyl resins, polyurethane resins, epoxy resins, polyester resins, Examples thereof include polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, and polycarbonate resin. As the resin fine particles, two or more of the above resins may be used in combination. Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles is easily obtained.
The vinyl resin is a polymer obtained by homopolymerization or copolymerization of a vinyl monomer, such as a styrene- (meth) acrylate resin, a styrene-butadiene copolymer, a (meth) acrylic acid-acrylate polymer, Examples include, but are not limited to, styrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, styrene- (meth) acrylic acid copolymers, and the like.
Further, inorganic fine particles can be preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles.
The primary particle diameter of the inorganic fine particles is preferably 5 mμ to 2 μm, and particularly preferably 5 mμ to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight. Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

In addition, polymer fine particles such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization and dispersion polymerization, methacrylic acid ester and acrylic acid ester copolymer, polycondensation system such as silicone, benzoguanamine and nylon, thermosetting resin And polymer particles.
Such a fluidizing agent can be surface-treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .
Examples of the cleaning property improver for removing the developer after transfer remaining on the photosensitive member or the primary transfer medium include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, such as polymethyl methacrylate fine particles, polystyrene. Examples thereof include fine polymer particles produced by soap-free emulsion polymerization of fine particles and the like. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.
By using these toners, a high-quality toner image having excellent development stability can be formed as described above. However, the toner that is not transferred to the transfer medium or intermediate transfer medium by the transfer device and remains on the image carrier is difficult to remove by the cleaning device due to its fineness and good rolling properties. May end up. In order to completely remove the toner from the image carrier, it is necessary to strongly press a toner removing member such as a cleaning blade against the image carrier. Such a load not only shortens the life of the image carrier and the cleaning device, but also uses extra energy.

When the load on the image carrier is reduced, the toner and the small-diameter carrier on the image carrier are not sufficiently removed, and these damage the surface of the image carrier when passing through the cleaning device. It becomes a factor which fluctuates performance.
As described above, the image forming apparatus of the present invention has an excellent tolerance for fluctuations in the surface state of the image carrier, particularly the presence of a low-resistance portion, and highly suppresses fluctuations in charging performance to the image carrier. Because of the configuration, when used in combination with the toner having the above configuration, an extremely high quality image can be stably obtained over a long period of time.
In addition, the image forming apparatus of the present invention can be applied not only to the use of the toner having a configuration suitable for obtaining a high quality image as described above, but also to an irregular shaped toner by a pulverization method, and the life of the apparatus. Needless to say, it will be greatly extended.
As a material constituting such a pulverized toner, those usually used as an electrophotographic toner can be applied without particular limitation.
Examples of general binder resins used in the toner include homopolymers of styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and the like; styrene / p-chlorostyrene copolymers; Styrene / propylene copolymer, styrene / vinyl toluene 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 ketone copolymer, Styrene copolymers such as tylene / butadiene copolymers, styrene / isoprene copolymers, styrene / maleic acid copolymers; polymethyl acrylate, polybutyl acrylate, polymethyl methacrylate, polybutyl methacrylate, etc. Acrylic ester-based homopolymers and copolymers thereof; polyvinyl derivatives such as polyvinyl chloride and polyvinyl acetate; polyester-based polymers, polyurethane-based polymers, polyamide-based polymers, polyimide-based polymers, polyol-based polymers, Examples thereof include an epoxy polymer, a terpene polymer, an aliphatic or alicyclic hydrocarbon resin, an aromatic petroleum resin, and the like. These can be used alone or in combination, but are not particularly limited thereto. Among these, at least one selected from styrene-acrylic copolymer resins, polyester resins, and polyol resins is more preferable from the viewpoint of electrical characteristics, cost, and the like. Furthermore, it is more preferable to use a polyester-based resin and / or a polyol-based resin as having good fixing characteristics.

For the reasons described above, the same resin component as the binder resin of the toner contained in the coating layer of the charging member includes a linear polyester resin composition, a linear polyol resin composition, and a linear styrene acrylic resin. At least one of the compositions or these cross-linked products can be preferably used.
In the pulverized toner, together with these resin components, the colorant component, wax component, charge control component, and the like as described above are premixed as necessary, and then kneaded at a temperature close to the melting temperature of the resin component, and then cooled. Thereafter, a toner may be prepared through a pulverization and classification step, and the above-mentioned external additive components may be appropriately added and mixed as necessary.

It is a perspective view of the type | mold used for the manufacturing method which concerns on embodiment of this invention. It is sectional drawing which shows the manufacturing process of an image carrier protective agent. It is sectional drawing which shows the state which injected | threw-in raw material to the type | mold, and was equalized uniformly in the longitudinal direction. It is sectional drawing which shows the state which has arrange | positioned less the weight of the powder of the edge part in the longitudinal direction of a type | mold before compression compared with a center part. It is sectional drawing which shows the state which has arrange | positioned the weight of the center part roughly. It is a perspective view of a block-shaped molded product. It is a schematic block diagram of the protective layer forming apparatus which concerns on embodiment of this invention. It is a schematic sectional drawing of the process cartridge which has the protective layer forming apparatus of FIG. 1 is a schematic sectional view of a color copying machine as an image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum as an image carrier 2 Protection layer formation apparatus 6 Transfer roller as a transfer apparatus 21 Image carrier protection agent 22 Protection agent supply member as supply member 24 Layer formation mechanism as layer formation means

Claims (8)

In the method for producing an image carrier protecting agent, wherein a granular or granular raw material containing a fatty acid metal salt is compression-molded in a mold and formed into a block shape,
The weight of the powder existing in the end region in the longitudinal direction of the mold is less than the weight of the powder in the region having the same length as the end region in the center of the mold. The raw material is placed in a mold and then compressed ,
The weight of the powder existing within 20% of the entire length in the longitudinal direction from the end of the mold is 95 to 30% of the weight of the powder present within 20% of the total length in the longitudinal direction from the center of the mold. % . A method for producing an image carrier protecting agent, wherein In the manufacturing method of the image carrier protective agent of Claim 1,
The weight of the powder existing within 20% of the entire length in the longitudinal direction from the end of the mold is 80 to 50 of the weight of the powder present within 20% of the total length in the longitudinal direction from the center of the mold. %. A method for producing an image carrier protecting agent, wherein In the image carrier protecting agent used in the image forming method including the step of applying or adhering the image carrier protecting agent to the surface of the image carrier,
An image carrier protective agent, wherein the image carrier protective agent is produced by the method for producing an image carrier protective agent according to claim 1 or 2. In a protective layer forming apparatus for applying or attaching an image carrier protecting agent to the surface of the image carrier,
4. The protective layer forming apparatus, wherein the image carrier protective agent is the image carrier protective agent according to claim 3. In the protective layer formation apparatus of Claim 4,
The protective layer forming apparatus, wherein the image carrier protecting agent is supplied to a surface of the image carrier through a supply member. In the protective layer formation apparatus of Claim 4 or 5,
An apparatus for forming a protective layer, comprising layer forming means for pressing the image carrier protective agent supplied to the surface of the image carrier to form a film. The toner image on the image carrier that has undergone the process of carrying the toner image is transferred to a transfer medium by a transfer device, and the surface of the image carrier after the toner image is transferred to the transfer medium is formed by a protective layer forming device. In an image forming method of applying or adhering an image carrier protecting agent,
The image forming method according to claim 3, wherein the image carrier protecting agent is the image carrier protecting agent according to claim 3. An image carrier that undergoes a step of carrying a toner image, a transfer device that transfers the toner image on the image carrier to a transfer medium, and a surface of the image carrier after the toner image is transferred to the transfer medium, In an image forming apparatus having a protective layer forming apparatus for applying or adhering an image carrier protecting agent,
An image forming apparatus, wherein the protective layer forming apparatus is the protective layer forming apparatus according to any one of claims 4 to 6.

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