JP6511882B2 - Toner, toner storage unit and image forming apparatus - Google Patents

Description

  The present invention relates to a toner, a toner storage unit, and an image forming apparatus.

  In recent years, in the one-component developing type printer, there is a tendency that further miniaturization and long life are required, and in addition to these, low-temperature fixing has been promoted. Along with this, there is an urgent need to improve the stress resistance of the toner and to secure excellent fixability.

  Patent Document 1 discloses, in a toner containing at least a binder resin, a colorant and a release agent, a molecular weight by GPC (gel permeation chromatography) determined by the THF soluble content of the toner (mainly binder resin). A toner has a main peak between 1000 and 10000, a half width of the distribution has a molecular weight of 15,000 or less, and contains 5 to 40% of chloroform insoluble matter. It is disclosed. As a result, it is possible to provide a toner achieving low-temperature fixing that can be fixed at low temperatures, and to provide an image-forming toner having good hot offset resistance and good heat storage property. There is.

However, in Patent Document 1, the stress resistance of the toner is not sufficient, and when it is used in the one-component development method, the problem that the crack and chipping of the toner occur can not be solved.
As described above, even if the conventional toner is excellent in fixability (low-temperature fixability and hot offset resistance), the stress resistance is not sufficient, and particularly in the one-component development method in which the toner is easily stressed. There is a problem that toner breakage and breakage occur, and quality problems (such as blade sticking and photoreceptor filming) due to the toner breakage and breakage are likely to occur.

  Then, this invention makes it a subject to solve the said problem and to achieve the following objective. That is, according to the present invention, while having excellent fixing properties (low-temperature fixing property and hot offset resistance), it has sufficient stress resistance and cracking occurs even when used in a one-component development system. The purpose is to provide a toner.

In order to solve the above problems, the present invention is a toner containing at least a binder resin and a charge control agent, wherein the toner contains 10 to 40% of THF insoluble matter and GPC determined by THF soluble matter In the molecular weight distribution by (gel permeation chromatography), it has a main peak between 12000 and 18000, and the half width of the main peak has a molecular weight of 20000 to 50000 and a component having a molecular weight of 2000 or less is 10% by weight 20 percent by weight, and a molecular weight of 100,000 or more components is not more than 8 wt%, the charge controlling agent, see containing the azo iron compound, the binder resin is characterized in that a polyester resin .

  According to the present invention, while having excellent fixing properties (low-temperature fixing property and hot offset resistance), it has sufficient stress resistance and cracking occurs even when used in a one-component development system Not provide toner.

FIG. 2 is a schematic view showing an example of the molecular weight distribution of the toner. It is a schematic diagram which shows an example of the process cartridge which concerns on this invention. FIG. 1 is a schematic view showing an example of an image forming apparatus according to the present invention. It is a schematic diagram which shows the other example of the image forming apparatus which concerns on this invention. It is a schematic diagram which shows the other example of the image forming apparatus which concerns on this invention. It is a schematic diagram which shows the other example of the image forming apparatus which concerns on this invention.

  Hereinafter, a toner, a toner storage unit, and an image forming apparatus according to the present invention will be described with reference to the drawings. In addition, this invention is not limited to embodiment shown below, It can change in the range which those skilled in the art could concidentize, such as other embodiment, addition, correction, deletion, and any aspect Even within the scope of the present invention, as long as the functions and effects of the present invention can be achieved.

  The present invention is a toner including at least a binder resin and a charge control agent, wherein the toner contains 10 to 40% of THF insoluble matter, and is determined by GPC (gel permeation chromatography) determined by the THF soluble matter. The molecular weight distribution has a main peak between 12000 and 18000, and the half width of the main peak is a molecular weight of 20000 to 50000, and the component having a molecular weight of 2000 or less is 10% by weight to 20% by weight, And a component having a molecular weight of 100,000 or more is 8% by weight or less, and the charge control agent includes an azo iron compound.

  According to the present invention, while having excellent fixability (low-temperature fixability and hot offset resistance), it has sufficient stress resistance and is used even in a one-component development system (one-component development It is possible to provide a toner which is free from cracking even if it is a toner for use.

  In the present invention, after sharpening the main peak in the molecular weight distribution of the toner, the present inventors define the peak molecular weight and add the azo iron compound, which is very effective for improving the crack and chipping resistance of the toner. Confirmed the new technical idea of being

  As a result of repeated research, the value of the molecular weight distribution by GPC determined by the THF soluble matter of the resin constituting the toner has a main peak between 12000 and 18000, and the half value width of the main peak has a molecular weight of 20,000 to 50,000 In addition, it is important to add an azo iron compound and make it exist in the surface layer. As a result, it has been found that particularly excellent crack and chipping resistance can be realized as compared with the prior art, and the present invention has been achieved. Details will be described below.

(toner)
The toner of the present invention contains 10 to 40% of THF insoluble matter. It is important to reduce the absolute amount of the THF insoluble matter of the toner to 10 to 40%, which is smaller than the absolute amount of the THF soluble matter. By this, the low temperature fixing property and the hot offset resistance can be improved. If the amount is less than 10%, the fixability may be deteriorated or the toner may be broken, and if the amount is more than 40%, the low temperature fixability may be deteriorated.

  The method of determining the THF insoluble matter is not particularly limited, but can be determined, for example, as follows. About 50 mg of toner is weighed, 10 g of THF is added thereto, and a solution sufficiently dissolved is separated by centrifugation, and then the supernatant is dried to calculate the solid content concentration of the supernatant. The difference between the initially prepared toner solution and the supernatant is taken as the THF insoluble matter.

  A schematic diagram of an example of the molecular weight distribution obtained by GPC measurement of the THF soluble component of the toner is shown in FIG. The horizontal axis of FIG. 1 is molecular weight, and the vertical axis is peak intensity. (A) shown in FIG. 1 shows a low molecular weight range, and the components in the low molecular weight range ensure low temperature fixability. Further, FIG. 1B shows that a main peak exists between molecular weights 12000 and 18000, and by controlling the molecular weight and half width of the peak, the toughness of the toner is secured. (C) of FIG. 1 shows a high molecular weight range, and the influence on the fixing lower limit can be suppressed by reducing the components of the high molecular weight range.

In order to secure the crack and chipping property, the peak value of the molecular weight distribution by GPC and the half-width molecular weight of the distribution are important, and by controlling them to the desired values, it is necessary to obtain the crack and chipping resistance. The backbone part of the molecular weight distribution is defined (see FIG. 1B).
In the present invention, the value of the molecular weight distribution by GPC determined by the THF soluble component has a main peak between 12000 and 18000, and the half value width of the main peak is a molecular weight of 20,000 to 50,000. In the present invention, the main peak refers to the peak with the highest intensity among the measurement results.

  Thus, by adjusting the value of the main peak in the molecular weight distribution and the half-width molecular weight of the main peak, it is possible to suppress the breakage and breakage of the toner. When the value of the main peak is less than 12000, cracking of the toner occurs, and when it is more than 18000, the low temperature fixability is deteriorated. If the half width of the main peak is less than 20000, the surface of the photoreceptor may be soiled, and if it is more than 50000, the low temperature fixability may be deteriorated.

Further, it is considered that as the length of the main chain of the binder resin in the toner is longer, the toughness of the binder resin is improved, but as the length of the main chain of the resin is longer, the toughness of the resin is improved. By setting the value of the main peak within the desired range, the toughness of the resin can be improved, and cracking and chipping of the toner can be suppressed. Further, the variation in molecular weight distribution is to indicate the presence of a low molecular weight component, and by setting the half width to the desired range, it is possible to suppress the low molecular weight component leading to a decrease in the toughness of the resin.
Further, in the present invention, the value of the main peak in the molecular weight distribution is preferably 15,000 to 18,000, and the half value width of the main peak is preferably 3,500 to 50,000.

  Furthermore, in the present invention, it is important to control the proportion of the low molecular weight region and the proportion of the high molecular weight region of the molecular weight distribution by GPC for securing low temperature fixability (see (A) and (C) in FIG. 1). . That is, in the present invention, in the molecular weight distribution by GPC determined by the THF soluble content of the toner, the component having a molecular weight of 2000 or less is 10% by weight to 20% by weight, and the component with a molecular weight of 100,000 or more is 8% by weight or less It is important to be. By satisfying this, excellent low temperature fixability can be realized.

  This is mainly because the low molecular weight component of the resin contributes to the lower limit of fixation, and by securing the fixability by the content of the gel component (THF insoluble component) for securing the hot offset resistance, It becomes possible to secure fixability without losing stress.

  Further, in the present invention, it is important that the charge control agent contains an azo iron compound. The stress resistance can be improved by adding a relatively hard azo iron compound among the charge control agents (hereinafter sometimes referred to as CCA) and causing the compound to be present in the surface layer portion.

GPC measurement can be performed as follows.
-Device: GPC-150C (manufactured by Waters)
Column: KF 801 to 807 (manufactured by Shawdex)
Temperature: 40 ° C
Solvent: THF (tetrahydrofuran)
Flow rate: 1.0 mL / min Sample: inject 0.1 mL of a sample with a concentration of 0.05 to 0.6%.
From the molecular weight distribution measured under the above conditions, the number average molecular weight and the weight average molecular weight of the resin are calculated using the molecular weight calibration curve prepared from the monodispersed polystyrene standard sample.

  No. S-7300, S-210, S-390, S- 875, S-1980, S-10.9, S-629, Std. S-3.0, S-0.580, toluene is used. As a detector, an RI (refractive index) detector is used.

<Toner component>
The toner of the present invention comprises, as required, other components as needed, and an external additive, if necessary, added to a toner matrix containing at least a binder resin and a charge control agent.

<< Binder resin >>
As a binder resin used by this invention, a polyester resin is mentioned, for example, A polyester resin is normally obtained by condensation polymerization of alcohol and carboxylic acid.
Examples of the alcohol include glycols such as ethylene glycol, diethylene glycol, triethylene glycol and propylene glycol, etherified bisphenols such as 1.4-bis (hydroxymethyl) cyclohexane and bisphenol A, and other dihydric alcohols alone. It is possible to cite monomers and trivalent or higher polyhydric alcohol monomers.
Further, as the carboxylic acid, for example, divalent organic acid monomers such as maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, malonic acid, 1,2,4-benzenetricarboxylic acid, 1 1,2,5-benzene tricarboxylic acid, 1,2,4-cyclohexane tricarboxylic acid, 1,2,4-naphthalene tricarboxylic acid, 1,2,5-hexane tricarboxylic acid, 1,3-dicarboxyl-2-methylene carboxy Examples thereof include trivalent or higher polyvalent carboxylic acid monomers such as propane and 1,2,7,8-octane tetracarboxylic acid.

  Here, as the polyester resin, those having a glass transition temperature Tg of 55 ° C. or more, more preferably 60 ° C. or more are preferable from the viewpoint of heat storage stability.

As described above, it is most suitable to use a polyester resin as a resin component in the toner, but other resins may be used in combination as long as the performance of the toner is not impaired. Examples of usable resins other than polyester resins include the following.
Polystyrene, chloropolystyrene, poly α-methylstyrene, styrene / chlorostyrene copolymer, styrene / propylene copolymer, styrene / butadiene copolymer, styrene / vinyl chloride copolymer, styrene / vinyl acetate copolymer, styrene / Maleic acid copolymer, styrene / acrylic acid ester copolymer (styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer Combination, styrene / phenyl acrylate copolymer etc., styrene / methacrylic acid ester copolymer (styrene / methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene) / Phenyl methacrylate copolymer etc.), Styrene-based resins (styrene or homopolymers or copolymers containing a styrene-substituted compound) such as styrene / acrylonitrile / acrylic acid ester copolymer, etc., vinyl chloride resin, styrene / (α-chloromethyl acrylate copolymer, etc.) Vinyl acetate copolymer, rosin modified maleic resin, phenol resin, epoxy resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene / ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin Etc., petroleum based resins, hydrogenated petroleum based resins.

The production method of these resins is not particularly limited, and any of bulk polymerization, solution polymerization, emulsion polymerization and suspension polymerization can be used.
Further, the glass transition temperature Tg of the above-mentioned resin is preferably 55 ° C. or more, more preferably 60 ° C. or more, in the same manner as the polyester resin, from the viewpoint of heat storage property.

<< mold release agent >>
In the present invention, all known releasing agents can be used as toners for toners, and in particular, free fatty acid type carnauba wax, montan wax and oxidized rice wax can be used alone or in combination.

As the carnauba wax, a microcrystalline one is preferable, one having an acid value of 5 or less, and a particle diameter of 1 μm or less when dispersed in a toner binder is preferable.
The montan wax generally refers to a montan wax refined from a mineral, and like the carnauba wax, it is preferably microcrystalline and has an acid value of 5 to 14.
The oxidized rice wax is obtained by air-oxidizing rice bran wax, and the acid value thereof is preferably 10 to 30.
As other mold release agents, any conventionally known mold release agents such as solid silicone varnish, higher fatty acid / higher alcohol, montan ester wax, low molecular weight polypropylene wax and the like can be mixed and used.
The amount of the release agent used is 1 to 20 parts by weight, preferably 2 to 10 parts by weight, with respect to the binder resin in the toner.

<< Charge control agent >>
As the charge control agent used in the toner of the present invention, any conventionally known charge control agent such as nigrosine dye, metal complex salt type dye, quaternary ammonium salt, salicylic acid metal complex and the like can be used alone or in combination. It is essential to use the compound. By using the azo iron compound, the stress resistance of the toner can be improved.

In the present invention, the metal complex is preferably a trivalent or higher metal capable of having a six-coordinate configuration, and among them, it is preferable to use Fe which is not toxic as a central metal.
As an azo iron compound in this invention, the compound represented, for example by following Structural formula (1) and following Structural formula (2) is mentioned.

In the structural formula (1), A ⁺ represents an ammonium ion.

前記構造式（２）中、Ｊ^＋は、Ｈ、アルカリ金属、アンモニウム又はアルキルアンモニウムを表す。

In the structural formula (2), J ⁺ represents H, an alkali metal, ammonium or an alkylammonium.

Two or more of those described above may be mixed.
Among these, it is preferable to use a compound represented by the above-mentioned structural formula (1) which has appropriate chargeability and is highly effective in the improvement of background dirt.

Although it does not restrict | limit especially as a commercial item of the compound represented by said Structural formula (1), For example, T-77 by Hodogaya chemical company is mentioned.
Although it does not restrict | limit especially as a commercial item of the compound represented by said Structural formula (2), For example, T-159 by Hodogaya chemical company is mentioned.

  The content of the azo iron compound is preferably 0.5 to 3.0 parts by weight with respect to 100 parts by weight of the binder resin in the toner.

Other charge control agents include, for example, zirconium salicylate. The commercially available product of zirconium salicylate is not particularly limited, but can be obtained from Hodogaya Chemical Co., Ltd.
The other charge control agent is 0.1 to 5 parts by weight, preferably 1 to 3 parts by weight, with respect to the binder resin in the toner.

<< Colorant >>
Examples of colorants used in the toner of the present invention include carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine 6 C lake, chalco oil blue, chromium yellow, quinacridone, benzidine yellow, Any conventionally known dye or pigment such as a dye such as rose bengal or triallylmethane dye can be used alone or in combination, and it can be used as a black toner or a full color toner.
The amount of these colorants used is usually 1 to 30% by weight, preferably 3 to 20% by weight, based on the toner resin component.

<< Others >>
The toner of the present invention can also be blended with a flowability improver and the like as required.
As the flowability improver, any flowability improver known so far such as silicon oxide, titanium oxide, silicon carbide, aluminum oxide, barium titanate and the like can be used alone or in combination. The amount of the flowability improver used is 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, with respect to 100 parts by weight of the toner.

(Toner accommodation unit)
The toner storage unit in the present invention is a unit in which toner is stored in a unit having a function of storing toner. Here, examples of the toner storage unit include a toner storage container, a developing device, and a process cartridge.
The toner container refers to a container containing toner.
The developing device is one having a means for containing and developing the toner.
The process cartridge is a cartridge in which at least an image carrier and a developing unit are integrated, a toner is accommodated, and the image forming apparatus is detachably attachable. The process cartridge may further include at least one selected from a charging unit, an exposure unit, and a cleaning unit.

  Next, one embodiment of the process cartridge is shown in FIG. As shown in FIG. 2, the process cartridge of the present embodiment incorporates a latent image carrier 101, includes a charging device 102, a developing device 104, and a cleaning unit 107, and further has other means as necessary. In FIG. 2, reference numeral 103 denotes exposure from the exposure device, and reference numeral 105 denotes a recording sheet.

As the latent image carrier 101, the same one as an image forming apparatus described later can be used. For the charging device 102, any charging member is used.
In the image forming process by the process cartridge shown in FIG. 2, the latent image carrier 101 is exposed on the surface thereof by the charging by the charging device 102 and the exposure 103 by the exposure unit (not shown) while rotating in the arrow direction. An electrostatic latent image corresponding to is formed.
The electrostatic latent image is toner-developed by the developing device 104, and the toner development is transferred to the recording paper 105 by the transfer roller 108 and printed out. Next, the surface of the latent image carrier after image transfer is cleaned by the cleaning unit 107, and is further neutralized by the static elimination unit (not shown), and the above operation is repeated again.

(Image forming method and image forming apparatus)
The image forming method used in the present invention includes an electrostatic latent image forming step (charging step and exposure step), a developing step, a transfer step, and a fixing step, and further, other appropriately selected as necessary. The process includes, for example, a charge removal process, a cleaning process, a recycling process, a control process and the like.
An image forming apparatus according to the present invention comprises an electrostatic latent image carrier, electrostatic latent image forming means (charging means and exposure means) for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic Developing means for developing a latent image with a developer to form a visible image, transfer means for transferring the visible image onto a recording medium, and fixing for fixing the transferred image transferred onto the recording medium And means. Furthermore, it has other means suitably selected as needed, for example, a static elimination means, a cleaning means, a recycling means, a control means and the like.

-Electrostatic latent image forming process and electrostatic latent image forming means-
The electrostatic latent image forming step is a step of forming an electrostatic latent image on an electrostatic latent image carrier.
The electrostatic latent image carrier (sometimes referred to as "electrophotographic photosensitive member" or "photosensitive member") is not particularly limited as to its material, shape, structure, size, etc. It can be selected appropriately. The shape thereof is preferably a drum shape, and examples of the material thereof include inorganic photoreceptors such as amorphous silicon and selenium, organic photoreceptors (OPC) such as polysilane and phthalopolymethine, and the like. Among these, organic photoreceptors (OPCs) are preferred in that higher-definition images can be obtained.

The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then imagewise exposing the surface, and the electrostatic latent image forming means performs the formation. Can.
The electrostatic latent image forming unit is, for example, a charging unit (charging unit) for uniformly charging the surface of the electrostatic latent image carrier, and exposure for exposing the surface of the electrostatic latent image carrier in an image manner Means (exposure device) at least.

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
There is no restriction | limiting in particular as said charging device, Although it can select suitably according to the objective, For example, the contact charge known per se provided with the electroconductive or semiconductive roll, a brush, a film, a rubber blade etc. Non-contact chargers using corona discharge, such as a container, corotron, scorotron, etc., and the like.
It is preferable that the charging device be disposed in a contact or non-contact state with the electrostatic latent image carrier, and charge the surface of the electrostatic latent image carrier by applying a direct current voltage and an AC voltage in a superimposed manner.
Further, the charging device is a charging roller disposed in non-contact proximity to the electrostatic latent image carrier via a gap tape, and an electrostatic latent image is held by applying a direct current voltage and an alternating voltage to the charging roller in a superimposed manner. Those which charge the body surface are preferred.

The exposure can be performed, for example, by imagewise exposing the surface of the electrostatic latent image carrier using the exposure device.
The exposure unit is not particularly limited as long as the exposure can be performed like the image to be formed on the surface of the electrostatic latent image bearing member charged by the charging unit, and may be appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, a liquid crystal shutter optical system and the like can be mentioned.
In the present invention, a back light method may be employed in which exposure is performed imagewisely from the back side of the electrostatic latent image carrier.

-Development step and developing means-
The developing step is a step of developing the electrostatic latent image with the toner to form a visible image.
The formation of the visible image can be performed, for example, by developing the electrostatic latent image using the toner, and can be performed by the developing unit.
The developing unit preferably contains, for example, the toner, and at least includes a developing unit capable of applying the toner to the electrostatic latent image in contact or non-contact with the electrostatic latent image. Etc. is more preferable.

The developing device may be a developing device for single color or a developing device for multiple colors, and for example, has a stirrer that frictionally stirs and charges the toner, and a rotatable magnet roller The thing etc. are mentioned suitably.
In the developing unit, for example, the toner and the carrier are mixed and stirred, and the friction at that time causes the toner to be charged and held in a brushed state on the surface of the rotating magnet roller to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photosensitive member), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted It moves to the surface of the electrostatic latent image carrier (photosensitive member) by force. As a result, the electrostatic latent image is developed by the toner to form a visible image of the toner on the surface of the electrostatic latent image carrier (photosensitive member).

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image to a recording medium, wherein after the primary transfer of the visible image onto the intermediate transfer body using an intermediate transfer member, the visible image is transferred onto the recording medium In the first transfer process, a visible image is transferred onto an intermediate transfer member to form a composite transfer image by using a secondary transfer mode, and using two or more colors, preferably full color toner, as the toner. It is more preferable to include a second transfer step of transferring the transfer image onto the recording medium.
The transfer can be performed, for example, by charging the electrostatic latent image carrier (photosensitive member) using the transfer charger with the visible image, and can be performed by the transfer unit. The transfer means includes a first transfer means for transferring a visible image onto an intermediate transfer body to form a composite transfer image, and a second transfer means for transferring the composite transfer image onto a recording medium. Aspects are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose, and suitable examples include a transfer belt and the like.

The transfer unit (the first transfer unit, the second transfer unit) transfers and charges the visible image formed on the electrostatic latent image carrier (photosensitive member) to the recording medium side It is preferred to have at least a container. The number of the transfer means may be one, or two or more.
Examples of the transfer unit include a corona transfer unit by corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer unit.
The recording medium is not particularly limited, and can be appropriately selected from known recording media (recording paper).

-Fixing process and fixing means-
The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the developer of each color is transferred to the recording medium, or the developer of each color On the other hand, it may be simultaneously carried out at the same time in the state of laminating them.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heat-and-pressing means is suitable. Examples of the heating and pressurizing unit include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller and an endless belt, and the like.
The fixing device includes a heating body having a heating element, a film in contact with the heating body, and a pressing member in pressure contact with the heating body via the film, the film and the pressing member It is preferable that the recording medium having the unfixed image formed thereon be passed through for heat fixation. As for the heating in the said heating-pressing means, 80 to 200 degreeC is preferable normally.
In the present invention, depending on the purpose, for example, a known light fixing device may be used together with or instead of the fixing step and the fixing means.

-Other processes and other means-
The charge removal step is a step for charge removal by applying a charge removal bias to the latent electrostatic image bearing member, and can be suitably performed by a charge removal unit.
The charge removing unit is not particularly limited as long as a charge removing bias can be applied to the latent electrostatic image bearing member, and can be appropriately selected from known charge removing devices, for example, a charge removing lamp and the like. Preferably it is mentioned.

The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier, and can be suitably performed by a cleaning unit.
The cleaning unit is not particularly limited as long as it can remove the toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners, for example, a magnetic brush cleaner Preferred are an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, a web cleaner and the like.

The recycling step is a step of recycling the toner removed in the cleaning step to the developing unit, and can be suitably performed by the recycling unit. There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.
The control step is a step of controlling each of the steps, and each step can be suitably performed by the control means.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include equipment such as sequencers and computers.

  FIG. 3 shows a first example of the image forming apparatus of the present invention. The image forming apparatus 100A includes a photosensitive drum 10, a charging roller 20, an exposure device, a developing device 40, an intermediate transfer belt 50, a cleaning device 60 having a cleaning blade, and a charge removing lamp 70.

  The intermediate transfer belt 50 is an endless belt stretched by three rollers 51 disposed inside, and can move in the arrow direction in the drawing. Some of the three rollers 51 also function as a transfer bias roller capable of applying a transfer bias (primary transfer bias) to the intermediate transfer belt 50. Further, in the vicinity of the intermediate transfer belt 50, a cleaning device 90 having a cleaning blade is disposed. Further, a transfer roller 80 capable of applying a transfer bias (secondary transfer bias) for transferring a toner image to the transfer paper 95 is disposed to face the intermediate transfer belt 50. Further, a corona charging device 58 for applying an electric charge to the toner image transferred to the intermediate transfer belt 50 is provided around the intermediate transfer belt 50 with the photosensitive drum 10 in the rotational direction of the intermediate transfer belt 50. The contact portion between the intermediate transfer belt 50 and the contact portion between the intermediate transfer belt 50 and the transfer paper 95 is disposed.

  The developing device 40 includes a developing belt 41, a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C arranged around the developing belt 41. The developing unit 45 for each color includes a developer storage portion 42, a developer supply roller 43, and a developing roller (developer carrier) 44. Further, the developing belt 41 is an endless belt stretched by a plurality of belt rollers, and can move in the arrow direction in the drawing. Further, a part of the developing belt 41 is in contact with the photosensitive drum 10.

  Next, a method of forming an image using the image forming apparatus 100A will be described. First, after uniformly charging the surface of the photosensitive drum 10 using the charging roller 20, the photosensitive drum 10 is exposed to the exposure light L using an exposure device (not shown) to form an electrostatic latent image. Form. Next, the electrostatic latent image formed on the photosensitive drum 10 is developed with the toner supplied from the developing device 40 to form a toner image. Furthermore, after the toner image formed on the photosensitive drum 10 is transferred (primary transfer) onto the intermediate transfer belt 50 by the transfer bias applied from the roller 51, the transfer bias applied from the transfer roller 80 , Onto the transfer paper 95 (secondary transfer). On the other hand, after the toner remaining on the surface of the photosensitive drum 10 on which the toner image has been transferred to the intermediate transfer belt 50 is removed by the cleaning device 60, the photosensitive drum 10 is discharged by the discharge lamp 70.

  FIG. 4 shows a second example of the image forming apparatus used in the present invention. In the image forming apparatus 100B, the black developing unit 45K, the yellow developing unit 45Y, the magenta developing unit 45M, and the cyan developing unit 45C are directly opposed to each other around the photosensitive drum 10 without providing the developing belt 41. The configuration is the same as that of the image forming apparatus 100A except for the above.

  FIG. 5 shows a third example of the image forming apparatus used in the present invention. The image forming apparatus 100C is a tandem-type color image forming apparatus, and includes a copying apparatus main body 150, a sheet feeding table 200, a scanner 300, and an automatic document feeder (ADF) 400.

  An intermediate transfer belt 50 provided at the central portion of the copying machine main body 150 is an endless belt stretched around three rollers 14, 15 and 16, and can move in the direction of the arrow in the figure. In the vicinity of the roller 15, a cleaning device 17 having a cleaning blade for removing the toner remaining on the intermediate transfer belt 50 on which the toner image has been transferred to the recording paper is disposed. The yellow, cyan, magenta, and black image forming units 120Y, 120C, 120M, and 120K are juxtaposed along the conveyance direction while facing the intermediate transfer belt 50 stretched by the rollers 14 and 15.

  Further, in the vicinity of the image forming unit 120, the exposure device 21 is disposed. Further, the secondary transfer belt 24 is disposed on the side opposite to the side on which the image forming unit 120 of the intermediate transfer belt 50 is disposed. The secondary transfer belt 24 is an endless belt stretched around a pair of rollers 23, and the recording paper conveyed on the secondary transfer belt 24 and the intermediate transfer belt 50 are between the rollers 16 and 23. It can touch.

  Further, in the vicinity of the secondary transfer belt 24, a fixing belt 26, which is an endless belt stretched around a pair of rollers, and a pressure roller 27 disposed so as to be pressed by the fixing belt 26. Is arranged. A sheet reversing device 28 is disposed in the vicinity of the secondary transfer belt 24 and the fixing device 25 to reverse the recording sheet when forming an image on both sides of the recording sheet.

Next, a method for forming a full color image using the image forming apparatus 100C will be described. First, a color document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and a color document is set on the contact glass 32 of the scanner 300 to automatically feed the document. Close the device 400.
When the original is set in the automatic document feeder 400 when the start switch is pressed, the original is conveyed and moved onto the contact glass 32, and when the original is set on the contact glass 32, Immediately, the scanner 300 is driven, and the first traveling body 33 including the light source and the second traveling body 34 including the mirror travel. At this time, the reflected light from the document surface of the light emitted from the first traveling body 33 is reflected by the second traveling body 34, and then the document is received by the reading sensor 36 through the imaging lens 35. Reading is performed to obtain black, yellow, magenta and cyan image information.

The image information of each color is transmitted to the image forming unit 120 of each color to form a toner image of each color. As shown in FIG. 6, the image forming unit 120 of each color includes the photosensitive drum 10, the charging roller 160 for uniformly charging the photosensitive drum 10, and the photosensitive drum 10 based on the image information of each color. Exposure device for exposing the exposure light L to form an electrostatic latent image of each color, a developing device 61 for developing the electrostatic latent image with a developer of each color to form a toner image of each color, and a toner image A transfer roller 62 for transferring onto the transfer belt 50, a cleaning device 63 having a cleaning blade, and a charge removing lamp 64 are provided.
The toner images of the respective colors formed by the image forming units 120 of the respective colors are sequentially transferred (primary transfer) onto the intermediate transfer member 50 moved by being tensioned by the rollers 14, 15 and 16, and superimposed to form a composite toner image. It is formed.

  On the other hand, in the sheet feeding table 200, one of the sheet feeding rollers 142 is selectively rotated, and the recording sheet is fed out from one of the sheet feeding cassettes 144 provided in multiple stages in the paper bank 143. The sheet is separated and sent to the sheet feeding path 146, conveyed by the conveyance roller 147, guided to the sheet feeding path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the paper feed roller is rotated to feed the recording paper on the manual feed tray 54, separated one by one by the separation roller 52, guided to the manual paper feed path 53, and abutted against the registration roller 49 and stopped. Although the registration roller 49 is generally used while being grounded, it may be used in a state where a bias is applied to remove paper dust of the recording paper.

  Next, by rotating the registration roller 49 in time with the composite toner image formed on the intermediate transfer belt 50, the recording paper is sent out between the intermediate transfer belt 50 and the secondary transfer belt 24, and the composite is formed. The toner image is transferred (secondary transfer) onto recording paper. The toner remaining on the intermediate transfer belt 50 to which the composite toner image has been transferred is removed by the cleaning device 17.

  The recording paper on which the composite toner image has been transferred is conveyed by the secondary transfer belt 24, and then the composite toner image is fixed by the fixing device 25. Next, the transport path of the recording paper is switched by the switching claw 55, and the recording paper is discharged onto the paper discharge tray 57 by the discharge roller 56. Alternatively, the conveyance path is switched by the switching claw 55, the recording paper is reversed by the sheet reversing device 28, and an image is similarly formed on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56. .

  Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to the following examples. In the description in the examples, “%” indicates weight%, and unless otherwise noted, “parts” means “parts by weight” unless otherwise stated.

(Production of polyester)
The compositions shown in Table 1 and Table 2 are placed in a 1 L 4-neck round bottom flask equipped with a thermometer, a stirrer, a condenser and a nitrogen gas inlet tube, this flask is set to a mantle heater, and Nitrogen gas was introduced from the gas introduction pipe to raise the temperature while maintaining the inside of the flask under an inert atmosphere. Next, 0.05 g of dibutyltin oxide was added, and the mixture was reacted while maintaining the temperature at 200 ° C. to obtain each polyester shown in Tables 1 and 2.

<Physical property measurement>
The following measurement was performed about each obtained polyester.

-Molecular weight measurement (GPC)-
GPC (gel permeation chromatography) measurement was performed under the following conditions.
-Device: GPC-150C (manufactured by Waters)
Column: KF 801 to 807 (manufactured by Shawdex)
Temperature: 40 ° C
Solvent: THF (tetrahydrofuran)
Flow rate: 1.0 mL / min Sample: 0.1 mL of a sample with a concentration of 0.05 to 0.6% was injected.
From the molecular weight distribution of the resin measured under the above conditions, the number average molecular weight and the weight average molecular weight of the resin were calculated using a molecular weight calibration curve prepared from monodispersed polystyrene standard samples.
No. S-7300, S-210, S-390, S- 875, S-1980, S-10.9, S-629, Std. S-3.0, S-0.580, and toluene were used. As a detector, an RI (refractive index) detector was used.

-THF insoluble matter-
About 50 mg of the binder resin was weighed, 10 g of THF (tetrahydrofuran) was added thereto, and a solution sufficiently dissolved was separated by centrifugation, and then the supernatant was dried to calculate the solid content concentration of the supernatant. The difference between the initially prepared toner solution and the supernatant was regarded as THF insoluble matter.

  The formulation and physical properties of each polyester are shown in Tables 1 and 2. In addition, in a table | surface, an acid component and an alcohol component represent a "weight part", "Mw" represents a weight average molecular weight, and THF insoluble content represents "%".

Example 1
A mixture of the following composition is sufficiently stirred and mixed in a Henschel mixer, then melt-kneaded by a twin-screw extrusion kneader (TEM-18 SS, manufactured by Toshiba Machine Co., Ltd.) and cooled to room temperature, and the obtained kneaded product is jet mill (IDS) The resultant was pulverized and classified by an N--2 (manufactured by Nippon New Matchuc Co., Ltd.) and a rotor classifier (50 ATP, manufactured by Hosokawa Micron Corporation) to obtain a toner matrix having an average particle diameter of 8 μm.

-Composition-
Polyester resin A-1 50 parts Polyester resin B-1 50 parts Refined rice wax (manufactured by TOA KASEI CO., LTD. Endothermic onset temperature 66.3 ° C.) 3 parts Carbon black (# 44, manufactured by Mitsubishi Chemical Corporation) 10 parts azo iron compound (T -77, Hodogaya Chemical Co., Ltd., [CCA1], 1.8 parts

  To the obtained toner base, 2 parts by weight of HMDS-treated hydrophobic silica (RX 200: manufactured by Nippon Aerosil Co., Ltd.) was added and mixed to obtain [Toner 1]. The toner physical properties are shown in Table 3.

(Example 2)
[Toner 2] was obtained in the same manner as in Example 1 except that [Polyester resin B-1] was changed to [Polyester resin B-2].

(Example 3)
Example 1 is the same as Example 1 except that [polyester resin A-1] is changed to [polyester resin A-2] and [polyester resin B-1] is changed to [polyester resin B-3]. Obtained [Toner 3].

(Example 4)
[Toner 4] was obtained in the same manner as in Example 1 except that [Polyester resin B-1] was changed to [Polyester resin B-4].

(Example 5)
In the same manner as in Example 1 except that the type and the addition amount of the binder resin are changed to 60 parts by weight of [polyester resin A-2] and 40 parts by weight of [polyester resin B-3] in Example 1. 5] got.

(Example 6)
In the same manner as in Example 1 except that the type and the addition amount of the binder resin are changed to 50 parts by weight of [Polyester resin A-3] and 50 parts by weight of [Polyester resin B-4] in Example 1. 6] got.

(Example 7)
In the same manner as in Example 1 except that the type and the addition amount of the binder resin are changed to 40 parts by weight of [Polyester resin A-3] and 60 parts by weight of [Polyester resin B-4] in Example 1. 7] got.

(Example 8)
In the same manner as in Example 1 except that the type and the addition amount of the binder resin are changed to 70 parts by weight of [Polyester resin A-2] and 30 parts by weight of [Polyester resin B-3] in Example 1. 8] got.

(Example 9)
[Toner 9] was obtained in the same manner as in Example 1 except that 1.8 parts by weight of [CCA1] was changed to 0.5 parts by weight of [CCA1].

(Example 10)
[Toner 10] was obtained in the same manner as in Example 1 except that 1.8 parts by weight of [CCA1] was changed to 3.0 parts by weight of [CCA1].

(Example 11)
[Toner 11] was obtained in the same manner as in Example 1 except that [CCA1] was changed to T-159 (referred to as [CCA2]) manufactured by HODOYA CHEMICAL CO., LTD.

(Example 12)
[Toner 12] was obtained in the same manner as in Example 1 except that 1.8 parts by weight of [CCA1] was changed to 0.3 parts by weight of [CCA1].

(Example 13)
[Toner 13] was obtained in the same manner as in Example 1 except that 1.8 parts by weight of [CCA1] was changed to 4.0 parts by weight of [CCA1].

(Comparative example 1)
[Comparative toner 1] was obtained in the same manner as in Example 1 except that [Polyester resin B-1] was changed to [Polyester resin B-5].

(Comparative example 2)
Comparative Example 1 is the same as Example 1 except that the type and addition amount of the binder resin are changed to 35 parts by weight of [Polyester resin A-1] and 65 parts by weight of [Polyester resin B-2]. Toner 2] was obtained.

(Comparative example 3)
Comparative Example 1 is the same as Example 1 except that the type and addition amount of the binder resin are changed to 65 parts by weight of [Polyester resin A-2] and 35 parts by weight of [Polyester resin B-3]. Toner 3] was obtained.

(Comparative example 4)
Comparative Example 1 is the same as Example 1 except that the type and the addition amount of the binder resin are changed to 35 parts by weight of [Polyester resin A-1] and 65 parts by weight of [Polyester resin B-4]. Toner 4] was obtained.

(Comparative example 5)
Comparative Example 1 is the same as Example 1 except that the type and the addition amount of the binder resin are changed to 50 parts by weight of [Polyester resin A-2] and 50 parts by weight of [Polyester resin B-6]. Toner 5] was obtained.

(Comparative example 6)
[Comparative toner 6] was obtained in the same manner as in Example 1 except that the type of the binder resin was changed to [Polyester resin A-3] and [Polyester resin B-4].

(Comparative example 7)
The same procedure as in Example 1 was repeated, except that the type and the addition amount of the binder resin were changed to 45 parts by weight of [Polyester resin A-4] and 55 parts by weight of [Polyester resin B-4]. Toner 7] was obtained.

(Comparative example 8)
Comparative Example 1 is the same as Example 1 except that the type and addition amount of the binder resin are changed to 70 parts by weight of [Polyester resin A-2] and 30 parts by weight of [Polyester resin B-6]. Toner 8] was obtained.

(Comparative example 9)
[Comparative toner 9] was obtained in the same manner as in Example 1 except that [CCA1] was changed to zirconium salicylate (referred to as [CCA3]) manufactured by HODOYA CHEMICAL CO., LTD.

  Physical properties of the obtained toner are shown in Table 3. In the table, the numerical values of the resins A and B represent "parts by weight", the THF insolubles represent "%", and those having 2000 or less and 100,000 or more represent "% by weight". The term “added amount of CCA (parts)” refers to the content (parts by weight) relative to 100 parts by weight of the binder resin.

(Measurement)
The following measurement was performed on the obtained toner.

<GPC measurement>
GPC (gel permeation chromatography) measurement was performed on the obtained toner under the following conditions.
-Device: GPC-150C (manufactured by Waters)
Column: KF 801 to 807 (manufactured by Shawdex)
Temperature: 40 ° C
Solvent: THF (tetrahydrofuran)
Flow rate: 1.0 mL / min Sample: 0.1 mL of a sample with a concentration of 0.05 to 0.6% was injected.
From the molecular weight distribution measured under the above conditions, the number average molecular weight and the weight average molecular weight of the resin were calculated using a molecular weight calibration curve prepared from monodispersed polystyrene standard samples.
No. S-7300, S-210, S-390, S- 875, S-1980, S-10.9, S-629, Std. S-3.0, S-0.580, and toluene were used. As a detector, an RI (refractive index) detector was used.

<THF insoluble matter>
About 50 mg of toner was weighed, 10 g of THF (tetrahydrofuran) was added thereto, and a solution sufficiently dissolved was separated by centrifugation, and then the supernatant was dried to calculate the solid content concentration of the supernatant. The difference between the initially prepared toner solution and the supernatant was regarded as THF insoluble matter.

(Evaluation)
The following evaluation was performed on the obtained toner.

<Stain evaluation>
A modified scotch tape was made by modifying the IPSiO SP C220 manufactured by Ricoh Co., Ltd. and adding 13.5 g of the deteriorated toner prepared in the above blade adhesion durability evaluation and sticking scotch tape over the entire exposed surface of the exposed photosensitive member stopped during white paper printing. The product was attached to a Ricoh Co., Ltd. type 6000T sheet and stored. L * was measured on the tape by X-rite (manufactured by Videojet X-Rite). Evaluation criteria are as follows.
[Evaluation criteria]
:: L * is 91 or more L: L * is 89 or more and less than 91 L: L * is 85 or more and less than 89 ×: L * is less than 85

<Fixability evaluation>
-Low temperature fixability-
The IPSiO SP C220 made by Ricoh Co., Ltd. was modified and toner was added, and the adhesion amount was set to be 10 g / m ² on a type sheet made of Ricoh Co., Ltd. and an unfixed solid image of 40 mm square was printed. .
Next, using a modified fixing unit manufactured by Ricoh Co., Ltd. IPSiO SP 4510 SF, the system speed was set to 240 mm / sec, and the prepared unfixed solid image was fed to fix the image. The fixing temperature was tested from 120.degree. C. to 2.degree. C. up to 160.degree. C., visually observed, and the temperature at which no toner reflection occurred on the white paper portion was taken as the lower limit fixing temperature. Evaluation criteria are as follows.
[Evaluation criteria]
A: Fixing lower limit temperature is less than 130 ° C. ○: Fixing lower limit temperature is 130 ° C. or more but less than 140 ° C. Δ: Fixing lower limit temperature is 140 ° C. or more but less than 150 ° C. ×: Fixing lower limit temperature is 150 ° C. or more

-High temperature releasability-
The IPSiO SP C220 made by Ricoh Co., Ltd. was modified and toner was added, and the adhesion amount was set to be 10 g / m ² on a type sheet made of Ricoh Co., Ltd. and an unfixed solid image of 40 mm square was printed. .
Next, using a modified fixing unit manufactured by Ricoh Co., Ltd. IPSiO SP 4510 SF, the system speed was set to 240 mm / sec, and the prepared unfixed solid image was fed to fix the image. The fixing temperature was tested from 160 ° C. to 200 ° C. in 2 ° C. increments, visually observed, and a temperature at which no toner reflection occurred on the white paper portion was taken as the upper limit fixing temperature. Evaluation criteria are as follows.
[Evaluation criteria]
:: upper limit fixing temperature is 190 ° C. or higher ○: upper limit fixing temperature is 180 ° C. to lower than 190 ° C. Δ: upper limit fixing temperature is 170 ° C. to lower than 180 ° C. ×: upper limit fixing temperature is less than 170 ° C.

<Evaluation of cracking>
After putting 50 g of toner in a 250 ml poly container, 120 g of φ10 mm alumina beads were charged, and stirred at 150 rpm for 44 hours in a ball mill, to prepare a deteriorated toner for evaluation. The particle diameter of the toner before deterioration and the toner after deterioration was measured using COULTER COUNTER Multisizer III, and the increase in small diameter component smaller than 3 μm was measured. Evaluation criteria are as follows.
[Evaluation criteria]
:: The increase amount is less than 4% ○: The increase amount is 4% or more and less than 7% Δ: The increase amount is 7% or more and less than 10% ×: The increase amount is 10% or more

  The evaluation results of Examples and Comparative Examples are shown in Table 4.

10 electrostatic latent image carrier (photosensitive drum)
10K black electrostatic latent image carrier 10Y yellow electrostatic latent image carrier 10M magenta electrostatic latent image carrier 10C cyan electrostatic latent image carrier 14 support roller 15 support roller 16 support roller 17 intermediate transfer cleaning device 18 image forming means 20 charging roller 21 exposure device 22 secondary transfer device 23 roller 24 secondary transfer belt 25 fixing device 26 fixing belt 27 fixing belt 27 pressure roller 28 sheet reversing device 32 contact glass 33 first traveling member 34 second traveling member 35 Image forming lens 36 Reading sensor 40 Development device 41 Development belt 42K Developer storage unit 42Y Developer storage unit 42M Developer storage unit 42C Developer storage unit 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer Supply roller 44K Developer roller 44Y Developer roller 44M Developer low 44C developing roller 45K black developing unit 45Y yellow developing unit 45M magenta developing unit 45C cyan developing unit 49 registration roller 50 intermediate transfer belt 51 roller 52 separation roller 53 manual feed path 54 manual feed tray 55 switching claw 56 discharge roller 57 discharge tray 58 corona Charging device 60 cleaning device 61 developing device 62 transfer roller 63 photoconductor cleaning device 64 discharge lamp 70 discharge lamp 80 transfer roller 90 cleaning device 95 transfer paper 100A, 100B, 100C image forming device 120 image forming unit 130 document table 142 sheet feeding roller 143 paper bank 144 paper feed cassette 145 separation roller 146 paper feed path 147 transport roller 148 paper feed path 150 copier main body 160 charging device 200 paper feed Le 300 Scanner 400 automatic document feeder (ADF)

Patent No. 4118498 gazette

Claims (7)

A toner comprising at least a binder resin and a charge control agent,
The toner contains 10 to 40% of THF insoluble matter, and has a main peak between 12000 and 18000 in the molecular weight distribution by GPC (gel permeation chromatography) determined by the THF soluble matter, and The half width of the main peak has a molecular weight of 20,000 to 50,000, and the component having a molecular weight of 2,000 or less is 10% by weight to 20% by weight, and the component having a molecular weight of 100,000 or more is 8% by weight or less,
The charge controlling agent, see containing the azo iron compound,
The toner is characterized in that the binder resin is a polyester resin . The toner according to claim 1, wherein the azo iron compound is represented by the following structural formula (1).

(In the above structural formula (1), A ⁺ represents an ammonium ion.)   The toner according to claim 1, wherein the azo iron compound is contained in an amount of 0.5 parts by weight or more and 3.0 parts by weight or less with respect to 100 parts by weight of the binder resin.   The toner according to any one of claims 1 to 3, wherein the toner is a one-component developing toner. The polyester resin is obtained by polymerizing an alcohol component and a carboxylic acid component,
The alcohol component includes at least one selected from bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct,
The toner according to any one of claims 1 to 4, wherein the acid component contains at least one selected from terephthalic acid, fumaric acid, succinic acid, and trimellitic acid. A toner storage unit containing the toner according to any one of claims 1 to 5 . An electrostatic latent image carrier,
Electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier;
Developing means for developing the electrostatic latent image with a developer to form a visible image;
Transfer means for transferring the visible image onto a recording medium;
And at least fixing means for fixing the transferred image transferred onto the recording medium,
An image forming apparatus, wherein the developer is the toner according to any one of claims 1 to 5 .

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