JP2006227308A - Toner and image forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toner resulting in favorable stability of colors (gray balance), excellent graininess even in a highlight portion (a portion with low image density), and high picture quality, and to provide an image forming method using the toner. <P>SOLUTION: The toner is characterized in that: the toner contains at least a resin and a colorant, wherein the colorant contains at least a white colorant and a black colorant; and an image density ID0.8 at 0.8 mg/cm<SP>2</SP>toner deposition amount and an image density ID1.2 at 1.2 mg/cm<SP>2</SP>toner deposition amount satisfy the relation of 0.8≤ID0.8/ID1.2≤1.1. Preferable embodiments are, for example, that: the content of the white colorant is 5 to 50 parts by mass with respect to 100 parts by mass of the resin; the white colorant is surface treated with a surface coating material; the oil absorption amount of the white colorant is 30 ml/100 g or less;, the white colorant consists of titanium oxide; and the toner which is a pulverized toner is desirable. The image forming method etc. is carried out by using the above toner. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light black toner (gray toner) suitably used in electrophotography, electrostatic recording method, electrostatic printing method and the like, an efficient production method thereof, and development using the light black toner The present invention relates to an agent, a container containing toner, a process cartridge, an image forming apparatus, and an image forming method.

In image formation by electrophotography or the like, generally, an electrostatic image is formed on a photoreceptor (electrostatic image carrier), and the electrostatic image is developed with a developer to form a visible image (toner image). The visible image is transferred to a recording medium such as paper and fixed to form a fixed image (see Patent Document 1).
In the digital image forming apparatus, in the formation of an electrostatic charge image, exposure is performed by, for example, pulse width modulated dots, and reversal development in which toner adheres to the dot portions is performed. The amount of toner adhering to the dot portion is determined by the area and potential state of the dot portion on the electrostatic charge image carrier, the developing bias with respect to this, the state of charge of the toner, and the like.

  The high density image portion recorded by the exposure means on the electrostatic charge image carrier has a large number of dots per area and a large size of one dot. On the other hand, the low density image portion has a small number of dots per area and a small size of one dot. Therefore, the toner adhesion amount is large in the high density image portion on the electrostatic image carrier after development, and the toner adhesion amount is small in the low density image portion. As described above, the difference in the density of the recorded image is expressed by the amount of toner adhered per area deposited on the electrostatic image bearing member by development.

  However, it is difficult to form an image having good gradation using one kind of toner. In particular, since dots are small in the highlight portion (low image density portion), adhesion of a very small amount of toner per area is unstable, graininess is likely to deteriorate (image density unevenness is likely to occur), and a stable level is obtained. It is difficult to obtain tonality. In addition, there is a problem that in the high density portion, the toner is in an excessively attached state, the image density is easily saturated, and it is difficult to obtain gradation in a wide area.

  Therefore, development is performed using two types of toners of light and dark colors of the same color, and the occurrence of image roughness in the highlight portion according to a photographic image or a character image is prevented, and a wide area at a high concentration. There has been proposed a light toner having an enhanced hiding power from the background, which can be suitably used in an image forming apparatus for improving the reproduction of gradation in (see Patent Document 2). However, although the light toner described in Patent Document 3 contains a colorant and a white agent in a resin, the image density is controlled by the amount of toner adhesion simply by adding a white agent. It is difficult to stabilize the graininess in the highlight portion in a good state. When forming an image in full color, normally, yellow toner, magenta toner, and cyan toner are superimposed to reproduce the gray color. The gray color obtained in this way has graininess in the highlight area. In this respect, the above-mentioned Patent Document 2 reproduces a gray color using only a black light toner containing a black pigment and a white agent, and only by using the black light toner, There is no disclosure that a gray color having excellent graininess can be obtained even in a highlight portion.

  Therefore, a toner that has good color tone (gray balance) stability, is excellent in graininess even in a highlight portion, and can reproduce a gray color with good graininess even in a single color, and a high image quality, and The related art using the toner has not been provided yet.

US Pat. No. 2,297,691 JP 2002-139867 A

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention has a stable color tone (gray balance), is excellent in graininess even in a highlight portion (low image density portion), and provides a high image quality, and a toner using the toner. An object is to provide a developer, a container containing toner, a process cartridge, an image forming apparatus, and an image forming method capable of improving image quality.

Means for solving the problems are as follows. That is,
<1> A resin and a colorant are included, and the colorant includes at least a white agent and a black agent. When the toner adhesion amount is 0.8 mg / cm ² , the image density is ID 0.8, and the toner adhesion amount is 1. The toner is characterized by satisfying the following formula, 0.8 ≦ ID0.8 / ID1.2 ≦ 1.1, where ID1.2 is the image density at ² mg / cm ² .
<2> The toner according to <1>, wherein the whitening agent content is 5 to 50 parts by mass with respect to 100 parts by mass of the resin.
<3> The toner according to any one of <1> to <2>, wherein the content of the black agent with respect to 100 parts by mass of the resin is 0.1 to 2.0 parts by mass.
<4> A toner that is used in combination with a black toner, and when the black agent content in the black toner is X parts by mass, the black agent content in the toner is 0.05X to 0.30X parts by mass. The toner according to any one of <1> to <2>.
<5> The toner according to any one of <1> to <4>, wherein the whitening agent is surface-treated with a surface coating material.
<6> The toner according to <5>, wherein the surface coating material is a hydrated aluminum oxide.
<7> The toner according to any one of <5> to <6>, wherein the white agent has an oil absorption of 30 ml / 100 g or less.
<8> The toner according to any one of <5> to <7>, wherein the white agent has an oil absorption of 10 to 25 ml / 100 g.
<9> The toner according to any one of <1> to <8>, wherein an average particle diameter of the whitening agent is 0.03 to 0.5 μm.
<10> When the toner adhesion amount is 0.6 mg / cm ² or more, the lightness (L ^* ) expressed in the Lab color system is 20 to 60, and the toner adhesion amount is 0.2 mg / cm ² or more. The toner according to any one of <1> to <9>, wherein a hue (a ^* ) represented by the Lab color system is −5 to +5 and a hue (b ^* ) is −5 to +5. is there.
<11> The toner according to any one of <1> to <10>, wherein the whitening agent is titanium oxide (TiO ₂ ).
<12> The toner according to any one of <1> to <11>, wherein the blackening agent is carbon black.
<13> The toner according to any one of <1> to <12>, which is a pulverized toner.
<14> The toner according to any one of <1> to <13>, wherein the toner has a volume average particle diameter of 3 to 8 μm.
<15> The toner according to any one of <1> to <14>, wherein the toner has a volume average particle diameter (Dv) / number average particle diameter (Dn) of 1.00 to 1.30.

<16> A developer comprising the toner according to any one of <1> to <15>.
<17> A toner-containing container filled with the toner according to any one of <1> to <15>.
<18> An electrostatic latent image carrier and an electrostatic latent image formed on the electrostatic latent image carrier are developed using the toner according to any one of <1> to <15> to be a visible image And a developing means for forming the process cartridge.
<19> An electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image according to <1> to <15> Developing means for developing a visible image by developing using any of the toners, Transfer means for transferring the visible image to a recording medium, Fixing means for fixing the transferred image transferred to the recording medium, The image forming apparatus is characterized by having at least.
<20> The toner used in the developing unit is the toner according to any one of <1> to <15> and at least one color selected from yellow toner, magenta toner, cyan toner, and black toner <19> The image forming apparatus according to <19>.
<21> An image carrier, a toner supply unit that supplies the toner according to any one of <1> to <15> on the image carrier, and the toner brought into contact with the image carrier Visible image temporary fixing means for applying a heat corresponding to the image signal to form a visible image with the toner at the site to which the heat is applied, and temporarily fixing the visible image on the image carrier; An image forming apparatus comprising at least heat welding means for transferring and heat-welding the fixed visible image to a recording medium.
<22> The toner used in the toner supply unit is the toner described in any one of <1> to <15> and at least one color selected from yellow toner, magenta toner, cyan toner, and black toner. The image forming apparatus according to <21>.
<23> An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image using the toner according to any one of <1> to <15> An image comprising at least a developing step for developing to form a visible image, a transferring step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium It is a forming method.
<24> The development in the development step is performed with the toner according to any one of <1> to <15> and at least one color selected from yellow toner, magenta toner, cyan toner, and black toner. The image forming method according to <23>.
<25> A toner supply step of supplying the toner according to any one of <1> to <15> on the image carrier, and heat corresponding to an image signal for the toner brought into contact with the image carrier A visible image temporary fixing step of forming a visible image with the toner at the site to which the heat is applied, and temporarily fixing the visible image on the image carrier, and the temporarily fixed visible An image forming method comprising at least a heat welding step of transferring an image to a recording medium and heat-welding the image.
<26> The toner supplied in the toner supply step is the toner according to any one of <1> to <15> and at least one color selected from a yellow toner, a magenta toner, a cyan toner, and a black toner. The image forming method according to <25>.

The toner of the present invention includes at least a resin and a colorant, the colorant includes at least a white agent and a black agent, and an image density when the toner adhesion amount is 0.8 mg / cm ² is ID 0.8, When the image density when the adhesion amount is 1.2 mg / cm ² is ID1.2, the following formula, 0.8 ≦ ID0.8 / ID1.2 ≦ 1.1 is satisfied. In the toner, since the colorant includes the white agent, black is a light toner having a low concentration, and the stability of the color (gray balance) is good. Further, since the image density of the toner satisfies the above formula, the toner is excellent in graininess even in a highlight portion (low image density portion). When an image is formed using the toner, high image quality can be obtained even in a highlight portion.

  The developer of the present invention contains the toner of the present invention. For this reason, when an image is formed by electrophotography using the developer, a high-quality image with high image density and high sharpness is formed even in the highlight portion.

  The toner container of the present invention is filled with the toner of the present invention. Therefore, when an image is formed by electrophotography using the toner of the present invention filled in the toner-containing container, a high-quality image with high image density and high sharpness is formed even in the highlight portion.

  The process cartridge of the present invention comprises an electrostatic latent image carrier, and developing means for developing the electrostatic latent image formed on the electrostatic latent image carrier using the toner of the present invention to form a visible image. At least. The process cartridge is attachable to and detachable from the image forming apparatus, is excellent in convenience, and uses the toner of the present invention, so that a high quality image with high image density and high sharpness can be formed even in a highlight portion.

One aspect of the image forming apparatus of the present invention is an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image. Development means for developing a visible image by developing with the toner of the present invention, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium Have at least. In the image forming apparatus, the electrostatic latent image forming unit forms an electrostatic latent image on the electrostatic latent image carrier. The developing means develops the electrostatic latent image using the toner of the present invention to form a visible image. The transfer means transfers the visible image to a recording medium. The fixing unit fixes the transferred image transferred to the recording medium. As a result, a high-quality image with high image density and high sharpness is formed even in the highlight portion.
The toner used in the developing unit is preferably the toner of the present invention and at least one color selected from yellow toner, magenta toner, cyan toner, and black toner.

According to another aspect of the image forming apparatus of the present invention, an image carrier, a toner supply unit that supplies the toner of the present invention on the image carrier, and an image with respect to the toner brought into contact with the image carrier. Visible image temporary fixing means for applying a heat corresponding to a signal to form a visible image with toner at a portion to which the heat is applied, and temporarily fixing the visible image on the image carrier; And a thermal welding means for transferring the visible image to a recording medium and thermally welding the visible image. In the image forming apparatus, the toner supply unit supplies the toner of the present invention onto the image carrier. The visible image temporary fixing means applies heat according to an image signal to the toner brought into contact with the image carrier to form a visible image with the toner at the site to which the heat is applied, A visible image is temporarily fixed on the image carrier. The thermal welding means transfers the temporarily fixed visible image to a recording medium and thermally welds it. As a result, it is not necessary to form an electrostatic latent image by the photoconductor, and it is not affected by density unevenness due to deterioration of the photoconductor, so that a stable and high-quality image can be obtained over a long period of time.
The toner used in the toner supply means is preferably the toner of the present invention and at least one color selected from yellow toner, magenta toner, cyan toner, and black toner.

One aspect of the image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and developing the electrostatic latent image using the toner of the present invention. Development step for forming a visible image, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium. In the image forming apparatus, an electrostatic latent image is formed on the electrostatic latent image carrier in the electrostatic latent image forming step. In the developing step, the electrostatic latent image is developed using the toner of the present invention to form a visible image. In the transfer step, the visible image is transferred to a recording medium. In the fixing step, the transferred image transferred to the recording medium is fixed. As a result, a high-quality image with high image density and high sharpness is formed even in the highlight portion.
The development in the development step is preferably performed with at least one color selected from the toner of the present invention and yellow toner, magenta toner, cyan toner, and black toner.

According to another aspect of the image forming method of the present invention, a toner supply step of supplying the toner of the present invention onto an image carrier, and heat corresponding to an image signal is applied to the toner brought into contact with the image carrier. A visible image temporary fixing step in which a visible image is formed by toner applied to the portion to which the heat is applied, and the visible image is temporarily fixed on the image carrier; and the temporarily fixed visible image At least a heat welding step of transferring the material to a recording medium and heat welding. In the image forming method, the toner of the present invention is supplied onto the image carrier in the toner supply step. In the visible image temporary fixing step, heat corresponding to an image signal is applied to the toner brought into contact with the image carrier, and a visible image is formed by the toner in the portion to which the heat is applied. A visual image is temporarily fixed on the image carrier. In the thermal welding step, the temporarily fixed visible image is transferred to the recording medium and thermally welded. The formation of an electrostatic latent image by the photoconductor becomes unnecessary, and it is not affected by density unevenness due to deterioration of the photoconductor, so that a stable and high-quality image can be obtained over a long period of time.
The toner supplied in the toner supply step is preferably the toner of the present invention and at least one color selected from yellow toner, magenta toner, cyan toner, and black toner.

  According to the present invention, conventional problems can be solved, the color (gray balance) is stable, the graininess is excellent even in the highlight portion (low image density portion), and high image quality is obtained. A toner, a developer, a toner-containing container, a process cartridge, an image forming apparatus, and an image forming method that can improve the image quality by using the toner can be provided.

(toner)
The toner of the present invention includes at least a resin and a colorant, and the colorant includes at least a whitening agent and a blackening agent. When the toner adhesion amount is 0.8 mg / cm ² , the image density is ID0.8. When the image density when the adhesion amount is 1.2 mg / cm ² is ID1.2, the following formula is satisfied: 0.8 ≦ ID0.8 / ID1.2 ≦ 1.1, and if necessary, release And other components such as a charge control agent.
As the coloring of the toner of the present invention, light black is preferable. The light black has a lighter achromatic color than black and belongs to chromatic gray.

When the image density when the toner adhesion amount is 0.8 mg / cm ² is ID 0.8, and the image density when the toner adhesion amount is 1.2 mg / cm ² is ID 1.2, the following equation is given: 0.8 ≦ ID0 .8 / ID1.2 ≦ 1.1 is required, and it is preferable to satisfy the following formula: 0.8 ≦ ID0.8 / ID1.2 ≦ 1.0. If the ID0.8 / ID1.2 is less than 0.8, the graininess in the highlight portion may become unstable, and if it exceeds 1.1, the saturation ID may vary.

The image density is, for example, such that the amount of developer applied to copy paper (“TYPE 6000 <70W>”; manufactured by Ricoh Co., Ltd.) is 0. 0 using a digital full color printer (“IPSIO CX7500”; manufactured by Ricoh Co., Ltd.) Solid images of 80 ± 0.1 mg / cm ² and 1.20 ± 0.1 mg / cm ² were formed, and the image density at any five positions in the obtained solid image was measured with a spectrometer (“938 Spectrodensitite It can be measured by measuring using “Meter” (manufactured by X-Light) and calculating the average value.

Further, when the toner adhesion amount is 0.6 mg / cm ² or more, the lightness (L ^* ) expressed in the Lab color system is 20 to 60, and when the toner adhesion amount is 0.2 mg / cm ² or more. It is preferable that the hue (a ^* ) represented by the Lab color system is -5 to +5 and the hue (b ^* ) is 5 to +5.
When the lightness (L ^* ) is 20 to 60, it is possible to impart a hiding power for obtaining good graininess in the highlight portion and to suppress toner consumption.
When the hue (a ^* ) is -5 to +5 and the hue (b ^* ) is -5 to +5, the image sharpness and the color of the original are faithfully reproduced during full-color image formation. Color taste such as taste can be suppressed. On the other hand, when the hue (a ^* ) and the hue (b ^* ) are out of the numerical range, when an image having a density range from highlight to shadow is formed, the user feels uncomfortable when the color changes. May occur. When forming a color image, it is possible to cope by forming a color correction parameter in consideration of redness, but when forming a monochrome image, the image is formed with the light black toner and the black toner of the present invention. In order to form these toners from highlight to shadow without changing the color, it is important that the hue satisfies the numerical range. That is, the black toner using only the black agent has a color of red to yellow, particularly in a region where the toner adhesion amount exceeds 0.8 mg / cm ^2. It is necessary to use the light black toner of the present invention in which fine particle titanium oxide as the whitening agent is used as a complementary colorant with respect to carbon black as the blackening agent.

-Resin-
There is no restriction | limiting in particular as said resin, Although it can select suitably according to the objective, For example, a polyester resin can be used conveniently as binder resin.
The polyester resin can be obtained by condensation polymerization of alcohol and carboxylic acid.
Examples of the alcohol include diols such as polyethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, and 1,4-butanediol. , Etherified bisphenols such as 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylenated bisphenol A and the like, saturated with 3 to 22 carbon atoms Or the bivalent alcohol simple substance substituted with the unsaturated hydrocarbon group, the other divalent alcohol simple substance, etc. are mentioned.
Examples of the carboxylic acid include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, and malonic acid. , Divalent organic acid monomers in which these are substituted with a saturated or unsaturated hydrocarbon group having 3 to 22 carbon atoms, acid anhydrides thereof, dimers of lower alkyl esters and linolenic acid, other divalents And organic acid monomers.

Moreover, as said polyester resin, the polymer containing the component by a trifunctional or more polyfunctional monomer other than the polymer only by the above-mentioned bifunctional monomer can also be used.
Examples of the polyhydric alcohol monomer having a valence of 3 or more that is a polyfunctional monomer include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sarbitane, pentaerythritol, dipentaerythritol, Tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, tri And methylolpropane and 1,3,5-trihydroxymethylbenzene.
Examples of the trivalent or higher polyvalent carboxylic acid monomer include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylene Examples thereof include carboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, empole trimer acid, and acid anhydrides thereof.

Moreover, well-known binder resin can be used with the said polyester resin as binder resin.
Examples of the binder resin include homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene, and the like; and styrene-p-chlorostyrene copolymers, styrene-propylene copolymers, styrene. -Vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer Styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl Methyl ether copolymer, styrene-vinyl ether Ruether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester Examples thereof include styrenic copolymers such as copolymers.

  Furthermore, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, Aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes, and the like, and the polyester resins can also be mixed and used.

  Among the binder resins, particularly suitable binder resins for pressure fixing include, for example, polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, polyethylene oxide, polytetrafluoroethylene, etc.), epoxy resin, polyester resin, styrene. -Butadiene copolymer (monomer ratio 5-30: 95-70), olefin copolymer (ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid) Acid ester copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, ionomer resin), polyvinylpyrrolidone, methyl vinyl ether-maleic anhydride copolymer, maleic acid-modified phenol resin, phenol-modified terpene resin, Etc.

-Colorant-
The colorant includes at least a whitening agent and a blackening agent, and further includes other coloring components appropriately selected from known dyes and pigments according to the purpose.

--White agent--
As the whitening agent is not particularly limited and may be appropriately selected depending on the purpose, for example, titanium oxide _(TiO 2), zinc oxide (ZnO), white lead _{(2PbCO 3 · Pb (OH)} 2), Lithopone (ZnS · BaSO ₄ ), zinc sulfide (ZnS), antimony oxide (SbCO ₃ ), calcium carbonate (CaCO ₃ ), kaolin (Al ₂ , Si ₂ , O ₅ (OH) ₄ ), mica (H ₂ , Kal ₃ , (SiO ₄ ) ₃ ), barium sulfate (BaSO ₄ ), gloss white (Al (OH) ₃ .BaSO ₄ ), alumina ((Al (OH) ₃ ), talc (Mg ₃ , SiO ₄ O ₁₀ (OH ) _2), silica _(SiO 2), calcium silicate _{(xSiO 2 · CaO · nH 2} O), and the like. among these, hiding power is strong, electrically conductive Readily point anti adjustment, titanium oxide (TiO2) is particularly preferred.
In addition, since fine particle titanium oxide scatters blue light preferentially in visible light, it can also be used for imparting a blue tint.

The whitening agent is preferably surface-treated with a surface coating material. The surface treatment improves the dispersibility of the white agent in the toner.
There is no restriction | limiting in particular as said surface coating material, According to the objective, it can select suitably from well-known things, For example, an inorganic compound and an organic compound are mentioned.
The inorganic compound is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include oxides such as aluminum, silicon, zirconium, tin, titanium, and antimony, hydroxides, and hydrated oxides. It is done.
There is no restriction | limiting in particular as said organic compound, According to the objective, it can select suitably, For example, a polyhydric alcohol, an organosilicon compound, a higher fatty acid, its metal salt, etc. are mentioned.
Examples of the polyhydric alcohol include trimethylol ethane, trimethylol propane, pentacisitol and the like.
Examples of the organosilicon compound include siloxanes such as dimethylpolysiloxane and methylhydrogenpolysiloxane; alkylsilanes such as hexyltrimethoxysilane; and organosilanes as silane coupling agents such as aminosilane.
Examples of the higher fatty acid include stearic acid, and examples of the higher fatty acid salt include zinc stearate.
The said surface coating material may be used individually by 1 type, and may use 2 or more types together. Among these, aluminum hydrated oxide is particularly preferable in that the lipophilicity to the resin can be increased and the dispersibility can be improved.
The coating amount of the surface coating material on the white agent is, for example, preferably 0.05 to 10% by mass, and more preferably 0.5 to 5% by mass.
When the coating amount is less than 0.05% by mass, the effect of the surface coating material may not be sufficiently exhibited. When the coating amount exceeds 10% by mass, the influence of the surface coating material becomes large and adversely affects charging characteristics and the like. May affect.

The dispersibility of the whitening agent can be represented by an oil absorption amount. The oil supply amount is preferably 30 ml / 100 g or less, more preferably 10 to 25 ml / 100 g.
When the amount of oil supply exceeds 30 ml / 100 g, the mixing and dispersibility with the resin cannot be maintained, and the exposure of the white agent to the toner surface after toner formation may not be suppressed.
The amount of the white agent supplied can be measured in accordance with, for example, JIS K 5101.

There is no restriction | limiting in particular as an average particle diameter of the particle | grains of the said whitening agent, Although it can select suitably according to the objective, For example, 0.03-0.5 micrometer is preferable and 0.1-0.3 micrometer is more. preferable.
When the average particle size is less than 0.03 μm, the transparency is increased and the hiding power may be insufficient. When the average particle size is more than 0.5 μm, the surface area of the white agent is increased. Therefore, when the average particle diameter is 0.5 μm or less, the surface area of the white agent is small, and when it is 0.03 μm or more, a white effect can be exhibited.
The average particle diameter is measured, for example, by taking an electron micrograph (× 50,000), measuring the particle diameters of 350 particles shown in the electron micrograph, and calculating the average value. Can do.

As content in the toner of the said white agent, 5-50 mass parts is preferable with respect to 100 mass parts of said resin, and 10-30 mass parts is more preferable.
When the content is less than 5 parts by mass, the effect of concealment cannot be sufficiently exerted as the effect of the whitening agent, and the image density (ID) varies greatly with respect to the toner adhesion amount, and the saturation ID may vary. When the amount exceeds 50 parts by mass, the fixing property is deteriorated, and when the image is formed by superimposing multiple colors, the difference in the melting state of the toner becomes large, so that the unevenness of the toner surface on the recording medium increases. The glossiness and light transmittance may deteriorate, and the graininess at the highlight portion may also deteriorate.

--Black agent--
There is no restriction | limiting in particular as said black agent, According to the objective, it can select suitably, For example, carbon black, such as acetylene black and aniline black, black iron oxide, titanium black, nigrosine dye, etc. are mentioned. Among these, carbon black is particularly preferable in terms of conductivity, resistance adjustment is easy and inexpensive.

There is no restriction | limiting in particular as content in the toner of the said black agent, Although it can select suitably according to the objective, 0.1-2.0 mass parts is preferable with respect to 100 mass parts of said resin, and is 0.00. 5-1.5 mass parts is more preferable.
When the content is less than 0.1 parts by mass, sufficient coloring power may be lacking, and when it exceeds 2.0 parts by mass, coloring power may be too high and granularity at the highlight part may be lacking. is there.

When the toner of the present invention is used in combination with a black toner, the resulting achromatic image is excellent in graininess in a highlight portion.
The black agent content when the toner of the present invention is used in combination with a black toner is not particularly limited and may be appropriately selected depending on the intended purpose. When the content is X parts by mass, the content of the black agent in the toner of the present invention is preferably 0.05X to 0.30X parts by mass.
When used in combination with the black toner, if the content of the black agent in the toner of the present invention is less than 0.05X, the coloring power may be insufficient, and if it exceeds 0.30X, coloring may occur. The force is too high and the graininess at the highlight may be lacking.

The content of the colorant in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 to 15% by mass, and more preferably 3 to 10% by mass.
When the content is less than 1% by mass, a reduction in the coloring power of the toner is observed, and when the content exceeds 15% by mass, a poor dispersion of the pigment in the toner occurs. The characteristics may be degraded.

  The colorant may be used as a master batch combined with a resin. The resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, styrene or a substituted polymer thereof, a styrene copolymer, polymethyl methacrylate, polybutyl methacrylate , Polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic hydrocarbon resin, alicyclic ring Aromatic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the polymer of styrene or a substituted product thereof include polyester resin, polystyrene, poly p-chlorostyrene, polyvinyl toluene, and the like. Examples of the styrene copolymer include a styrene-p-chlorostyrene copolymer, a styrene-propylene copolymer, a styrene-vinyltoluene copolymer, a styrene-vinylnaphthalene copolymer, and a styrene-methyl acrylate copolymer. Polymer, 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-butadiene copolymer, styrene-isoprene copolymer, styrene An acrylonitrile-indene copolymer, Styrene - maleic acid copolymer, styrene - maleic acid ester copolymer, and the like.

The masterbatch can be produced by mixing or kneading the masterbatch resin and the colorant under high shear. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the colorant and the resin. The so-called flushing method is also preferable in that the wet cake of the colorant can be used as it is, and it does not need to be dried. This flushing method is a method in which an aqueous paste containing water as a colorant is mixed or kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture and organic solvent components. For the mixing or kneading, for example, a high shear dispersion device such as a three roll mill is preferably used.
As content of the said coloring agent in the said masterbatch, it is 80 mass% or less normally, and 30-60 mass% is preferable.

-Other ingredients-
The other components are not particularly limited and may be appropriately selected depending on the purpose. For example, a release agent, a charge control agent, inorganic fine particles, a fluidity improver, a cleaning property improver, a magnetic material, etc. Is mentioned.

There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably from well-known things, For example, waxes etc. are mentioned suitably.
Examples of the waxes include carbonyl group-containing waxes, polyolefin waxes, and long-chain hydrocarbons. These may be used individually by 1 type and may use 2 or more types together. Among these, a carbonyl group-containing wax is preferable.
Examples of the carbonyl group-containing wax include polyalkanoic acid esters, polyalkanol esters, polyalkanoic acid amides, polyalkylamides, dialkyl ketones, and the like. Examples of the polyalkanoic acid ester include carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, and 1,18-octadecane. Examples thereof include diol distearate. Examples of the polyalkanol ester include tristearyl trimellitic acid and distearyl maleate. Examples of the polyalkanoic acid amide include dibehenyl amide. Examples of the polyalkylamide include trimellitic acid tristearylamide. Examples of the dialkyl ketone include distearyl ketone. Of these carbonyl group-containing waxes, polyalkanoic acid esters are particularly preferred.
Examples of the polyolefin wax include polyethylene wax and polypropylene wax.
Examples of the long chain hydrocarbon include paraffin wax and sazol wax.

There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 40-160 degreeC is preferable, 50-120 degreeC is more preferable, 60-90 degreeC is especially preferable.
If the melting point is less than 40 ° C., the release agent may adversely affect storage stability, and if it exceeds 160 ° C., cold offset may easily occur during fixing at a low temperature.
The melt viscosity of the release agent 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 of the release agent.
If the melt viscosity is less than 5 cps, the releasability may be lowered, and if it exceeds 1000 cps, the effect of improving hot offset resistance and low-temperature fixability may not be obtained.

There is no restriction | limiting in particular as content in the said toner of the said mold release agent, Although it can select suitably according to the objective, 0-40 mass% is preferable and 3-30 mass% is more preferable.
When the content exceeds 40% by mass, the fluidity of the toner may be deteriorated.

The charge control agent is not particularly limited and may be appropriately selected from known materials according to the purpose. However, since a color tone may change when a colored material is used, a material that is colorless to nearly white is used. Preferably, for example, triphenylmethane dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus alone or compounds thereof, tungsten Examples thereof include a single substance or a compound thereof, a fluorine-based activator, a metal salt of salicylic acid, and a metal salt of a salicylic acid derivative. These may be used individually by 1 type and may use 2 or more types together.
Commercially available products may be used as the charge control agent. Examples of the commercially available products include quaternary ammonium salt Bontron P-51, oxynaphthoic acid metal complex E-82, and salicylic acid metal complex. E-84, phenolic condensate E-89 (above, manufactured by Orient Chemical Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, manufactured by Hodogaya Chemical Co., Ltd.), fourth Copy charge PSY VP2038 of quaternary ammonium salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR which is a boron complex -147 (manufactured by Nippon Carlit), quinacridone, azo pigments, other sulfonic acid groups, carbo Sill group, polymer compounds having a functional group such as quaternary ammonium salts, and the like.
The charge control agent may be melted and kneaded together with the master batch and then dissolved or dispersed, or may be added together with the toner components when directly dissolving or dispersing in the organic solvent, or The toner particles may be fixed on the toner surface after production.

  The content of the charge control agent in the toner varies depending on the type of the binder resin, the presence / absence of an additive, a dispersion method, and the like, and cannot be generally specified. On the other hand, 0.1-10 mass parts is preferable, and 0.2-5 mass parts is more preferable. When the content is less than 0.1 parts by mass, the charge controllability may not be obtained. When the content exceeds 10 parts by mass, the chargeability of the toner becomes too large, and the effect of the main charge control agent is reduced. As a result, the electrostatic attractive force with the developing roller increases, which may lead to a decrease in developer fluidity and a decrease in image density.

The inorganic fine particles can be suitably used as an external additive for improving the fluidity, developability, chargeability and the like of the toner. The inorganic fine particles are preferably the same type as the inorganic fine particles that can be dispersed in the organic solvent.
The inorganic fine particles are not particularly limited and may be appropriately selected from known ones according to the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, titanate Strontium, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, carbonized Examples include silicon and silicon nitride. These may be used individually by 1 type and may use 2 or more types together.
The primary particle diameter of the inorganic fine particles is preferably 5 nm to 2 μm, and more preferably 5 nm to 500 nm. The specific surface area of the inorganic fine particles by BET method is preferably 20 to 500 m ² / g.
The content of the inorganic fine particles in the toner is preferably 0.01 to 5.0% by mass, and more preferably 0.01 to 5.0% by mass.

The fluidity improver means a material that can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, a silane coupling agent, a silylating agent, Examples thereof include a silane coupling agent having an alkyl fluoride group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and modified silicone oil.
The cleaning improver is added to the toner in order to remove the developer after transfer remaining on the photoreceptor or the primary transfer medium. For example, a fatty acid metal salt such as zinc stearate, calcium stearate, stearic acid, Examples thereof include polymer fine particles produced by soap-free emulsion polymerization such as methyl methacrylate fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 to 1 μm are suitable.
There is no restriction | limiting in particular as said magnetic material, According to the objective, it can select suitably from well-known things, For example, iron powder, a magnetite, a ferrite, etc. are mentioned. Among these, white is preferable in terms of color tone.

  The toner of the present invention can be produced by a known method, but is a pulverized toner produced by a known pulverization method in that the white agent becomes a pulverization interface and pulverization is improved by the addition of the white agent. Is preferred.

  The toner of the present invention has the following volume average particle diameter (Dv), volume average particle diameter (Dv) / number average particle diameter (Dn), granularity (density unevenness), low temperature fixability, and the like. It is preferable.

The volume average particle diameter (Dv) of the toner is preferably 3 to 8 μm, and more preferably 4 to 7 μm, for example.
When the volume average particle size is less than 3 μm, in the two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be reduced. In the developer, toner filming on the developing roller and toner fusion to a member such as a blade are likely to occur because the toner is thinned, and if it exceeds 8 μm, the resolution is high and the resolution is high. It becomes difficult to obtain an image having an image quality, and when the balance of the toner in the developer is performed, the variation in the particle diameter of the toner may increase.

The ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) in the toner is, for example, preferably 1.30 or less, and more preferably 1.00-1.30.
When the ratio of the volume average particle diameter to the number average particle diameter (Dv / Dn) is less than 1.00, with the two-component developer, the toner is fused to the surface of the carrier during long-term stirring in the developing device, The chargeability of the carrier may be reduced, and the cleaning property may be deteriorated. In the case of a one-component developer, the filming of the toner on the developing roller and the thinning of the toner are performed. Toner fusion may occur easily, and if it exceeds 1.30, it will be difficult to obtain a high-resolution and high-quality image, and toner particles in the developer balance will be generated. Variation in diameter may be large.
When the ratio of the volume average particle diameter to the number average particle diameter (Dv / Dn) is 1.00 to 1.30, the storage stability, low-temperature fixability, and hot offset resistance are all excellent. In particular, when used in a full-color copying machine, the glossiness of the image is excellent. With two-component developers, there is little fluctuation in the toner particle diameter in the developer even if the toner balance for a long period of time is achieved, and good and stable developability can be obtained even with long-term stirring in the developing device. Even if the balance of the toner is carried out with the agent, fluctuations in the particle diameter of the toner are reduced, and there is no filming of the toner on the developing roller and no fusion of the toner to the member to the blade for thinning the toner. Even in the long-term use (stirring) of the developing device, good and stable developability can be obtained, so that a high-quality image can be obtained.

  The volume average particle diameter and the ratio (Dv / Dn) between the volume average particle diameter and the number average particle diameter are measured using, for example, a particle size measuring device “Multisizer II” manufactured by Beckman Coulter, Inc. Can do.

The image quality may be deteriorated by changing the volume and area after the toner image is transferred or fixed. This phenomenon becomes remarkable in the case of digital development, and the reproducibility of independent dots is greatly affected.
The graininess (uneven density) indicates the uniformity of the halftone portion of the image. The better the graininess, the smoother the image. When microscopic density unevenness exists, May give a rough impression.
The granularity can be evaluated by measuring granularity, which is a physical evaluation value of roughness. The smaller the numerical value, the smoother the image becomes. For example, less than 0.2 Is preferable, and 0.15 or less is more preferable. When the granularity is 0.2 or more, a rough and poor image may be obtained, and a smooth image may not be obtained.
The granularity (GS) is a value obtained by integrating the product of noise (Wiener Spectrum (WS), which is a frequency characteristic of density fluctuation), and visual frequency characteristic (Visual Transfer Function: VTF). 1).
Granularity (GS) = exp (−1.8 <D>) ∫WS (u) 1 / 2VTF (u) du (1)
In the above formula (1), exp (−1.8 <D>) is a coefficient for correcting the density and the brightness difference perceived by humans, and <D> is the average value of the density. To express.
Further, WS can be obtained from the following equations (2) and (3), where f (x) dx is a density fluctuation component having an average value of 0.
F (u) = ∫f (x) exp (−2∫iux) dx (2)
WS (u) = F (u) 2 Formula (3)
However, u is a spatial frequency in said Formula (2) and Formula (3).

  The granularity is measured by, for example, using a digital full-color printer (“IPSIO CX7500”; manufactured by Ricoh Co., Ltd.), printing a sample image, and using a gray scale (halftone portion) formed by the dots of the sample image as a scanner ( "GenaScan 5000" (manufactured by Dainippon Screen) is read at 1,000 dpi to obtain image data. The image data can be converted into a density distribution and evaluated by the equation (1).

As the low temperature fixability, from the viewpoint of achieving both a decrease in fixing temperature and no occurrence of offset, a lower fixing lower limit temperature is preferable, and a higher offset non-reaction temperature is preferable. As a temperature range in which both can be achieved, the minimum fixing temperature is less than 170 ° C., and the non-offset temperature is 200 ° C. or more.
The fixing minimum temperature is, for example, an image forming apparatus, a transfer sheet is set, a copy test is performed, and the obtained fixed image is rubbed with a pad. The fixing roll temperature is the lower limit fixing temperature.

  The toner of the present invention has good color (gray balance) stability, and is excellent in graininess even in a highlight portion (low image density portion). Further, the toner of the present invention (light black toner) can reduce unevenness in density and obtain a smooth image, and can be used not only for a halftone image relating to black but also for a full color image. The color toner consumption can be reduced. Therefore, the toner of the present invention can be suitably used in various fields, and can be more suitably used for image formation by electrophotography. The following toner-containing container, developer, and process of the present invention are described below. It can be particularly suitably used for a cartridge, an image forming apparatus and an image forming method.

(Developer)
The developer of the present invention contains at least the toner of the present invention and other components appropriately selected such as the carrier. The developer may be a one-component developer or a two-component developer. However, when it is used for a high-speed printer or the like corresponding to the recent improvement in information processing speed, the life is improved. In view of the above, the two-component developer is preferable.
In the case of the one-component developer using the toner of the present invention, even if the balance of the toner is performed, there is little fluctuation in the particle diameter of the toner, and the filming of the toner on the developing roller or the toner is made thin. Therefore, toner is not fused to a member such as a blade, and good and stable developability and images can be obtained even when the developing device is used (stirred) for a long time. Further, in the case of the two-component developer using the toner of the present invention, even if the balance of the toner over a long period of time is performed, the fluctuation of the toner particle diameter in the developer is small, and even in the long-term stirring in the developing device, Good and stable developability can be obtained.

  There is no restriction | limiting in particular as said carrier, Although it can select suitably according to the objective, What has a core material and the resin layer which coat | covers this core material is preferable.

  There is no restriction | limiting in particular as a material of the said core material, It can select suitably from well-known things, For example, 50-90 emu / g manganese-strontium (Mn-Sr) type material, manganese-magnesium (Mn-) Mg) -based materials and the like are preferable, and high magnetization materials such as iron powder (100 emu / g or more) and magnetite (75 to 120 emu / g) are preferable in terms of securing image density. In addition, a weakly magnetized material such as a copper-zinc (Cu—Zn) -based (30 to 80 emu / g) is advantageous in that it can weaken the contact with the photoconductor in which the toner is in a spiked state and is advantageous in improving the image quality. Is preferred. These may be used alone or in combination of two or more.

The core material has a volume average particle size of preferably 10 to 150 μm, and more preferably 40 to 100 μm.
When the average particle diameter (volume average particle diameter (D ₅₀ )) is less than 10 μm, the distribution of carrier particles may increase the number of fine powders, lower the magnetization per particle, and cause carrier scattering. If the thickness exceeds 150 μm, the specific surface area may decrease and toner scattering may occur. In the case of a full color having a large solid portion, the reproduction of the solid portion may be deteriorated.

  The material of the resin layer is not particularly limited and can be appropriately selected from known resins according to the purpose. For example, amino resins, polyvinyl resins, polystyrene resins, halogenated olefin resins, Polyester resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, vinylidene fluoride And a copolymer of vinyl fluoride, a fluoroterpolymer such as a terpolymer of tetrafluoroethylene, vinylidene fluoride, and a non-fluorinated monomer, and a silicone resin. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the amino resin include urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Examples of the polyvinyl resin include acrylic resin, polymethyl methacrylate resin, poly Examples include acrylonitrile resin, polyvinyl acetate resin, polyvinyl alcohol resin, and polyvinyl butyral resin. Examples of the polystyrene resin include polystyrene resin and styrene acrylic copolymer resin. Examples of the halogenated olefin resin include polyvinyl chloride. Examples of the polyester resin include polyethylene terephthalate resin and polybutylene terephthalate resin.

  The resin layer may contain conductive powder or the like, if necessary. Examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. The average particle diameter of these conductive powders is preferably 1 μm or less. When the average particle diameter exceeds 1 μm, it may be difficult to control electric resistance.

For example, the resin layer is prepared by dissolving the silicone resin or the like in a solvent to prepare a coating solution, and then uniformly coating the coating solution on the surface of the core material by a known coating method, drying, and baking. It can be formed by doing. Examples of the coating method include a dipping method, a spray method, and a brush coating method.
There is no restriction | limiting in particular as said solvent, Although it can select suitably according to the objective, For example, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cersol butyl acetate, etc. are mentioned.
The baking is not particularly limited, and may be an external heating method or an internal heating method. For example, a stationary electric furnace, a fluid electric furnace, a rotary electric furnace, a burner furnace, etc. The method of using, the method of using a microwave, etc. are mentioned.

The amount of the resin layer in the carrier is preferably 0.01 to 5.0% by mass.
When the amount is less than 0.01% by mass, the uniform resin layer may not be formed on the surface of the core material. When the amount exceeds 5.0% by mass, the resin layer becomes thick. In some cases, granulation of carriers occurs, and uniform carrier particles may not be obtained.

  When the developer is the two-component developer, the content of the carrier in the two-component developer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 90 to 98% by mass Is preferable, and 93-97 mass% is more preferable.

Since the developer of the present invention contains the toner, the color tone (gray balance) stability is good, and even in the highlight portion (low image density portion), the graininess is excellent, and a high-quality image is stable. Can be formed.
The developer of the present invention can be suitably used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, and a two-component development method. It can be particularly suitably used for containers, process cartridges, image forming apparatuses and image forming methods.

(Toner container)
The toner-containing container of the present invention is formed by filling the container of the toner of the present invention or the developer.
There is no restriction | limiting in particular as said container, It can select suitably from well-known things, For example, what has a container main body and a cap containing a toner etc. are mentioned suitably.
The size, shape, structure, material, etc. of the container body containing toner is not particularly limited and can be appropriately selected according to the purpose. For example, the shape is preferably cylindrical. The spiral surface irregularities are formed on the peripheral surface, and the toner as the contents can be transferred to the discharge port side by rotating, and part or all of the spiral part has a bellows function, etc. Is particularly preferred.
The material of the toner-containing container body is not particularly limited, and those having good dimensional accuracy are preferable. For example, a resin is preferably used. Among them, for example, polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, Preferable examples include vinyl chloride resin, polyacrylic acid, polycarbonate resin, ABS resin, polyacetal resin, and the like.
The toner-containing container of the present invention is easy to store and transport, has excellent handleability, and is preferably used for replenishing toner by being detachably attached to the process cartridge and image forming apparatus of the present invention described later. Can do.

(Process cartridge)
The process cartridge of the present invention develops an electrostatic latent image carrier carrying an electrostatic latent image and the electrostatic latent image carried on the electrostatic latent image carrier using a developer to form a visible image. At least a developing means for forming the film, and other means appropriately selected as necessary.
The developing means includes a developer container that contains the toner or developer of the present invention, and a developer carrier that carries and transports the toner or developer contained in the developer container. And a layer thickness regulating member for regulating the thickness of the toner layer to be carried.
The process cartridge of the present invention can be detachably provided in various electrophotographic apparatuses, and is preferably provided detachably in the image forming apparatus of the present invention described later.

(Image forming method and image forming apparatus)
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transferring step, and a fixing step, preferably including a cleaning step, and other steps appropriately selected as necessary. For example, a static elimination process, a recycling process, a control process, etc. are included.
The image forming apparatus of the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit, and preferably includes a cleaning unit. In addition, other means appropriately selected as necessary, for example, static elimination means, recycling means, control means and the like are provided.

  The image forming method of the present invention can be preferably carried out by the image forming apparatus of the present invention, the electrostatic latent image forming step can be performed by the electrostatic latent image forming means, and the developing step is the developing The transfer step can be performed by the transfer unit, the fixing step can be performed by the fixing unit, and the other steps can be performed by the other unit.

<Electrostatic latent image forming step and electrostatic latent image forming means>
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
There are no particular restrictions on the material, shape, structure, size, etc. of the electrostatic latent image bearing member (sometimes referred to as “photoconductive insulator” or “photosensitive member”), and among the known ones The shape is preferably a drum shape, and examples of the material include inorganic photoconductors such as amorphous silicon and selenium, and organic photoconductors such as polysilane and phthalopolymethine. It is done. Among these, amorphous silicon or the like is preferable in terms of long life.

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 performing imagewise exposure, and is performed by the electrostatic latent image forming unit. be able to.
The electrostatic latent image forming means includes, for example, at least a charger that uniformly charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise. Prepare.

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. And a non-contact charger using corona discharge such as a corotron and a scorotron.

The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device.
The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger so as to form an image to be formed, and is 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, and a liquid crystal shutter optical system can be used.
In the present invention, a back light system in which imagewise exposure is performed from the back surface side of the electrostatic latent image carrier may be adopted.

<Development process and development means>
The developing step is a step of developing the electrostatic latent image using the toner or the developer of the present invention to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer of the present invention, and can be performed by the developing unit.
The developing unit is not particularly limited as long as it can be developed using, for example, the toner or the developer of the present invention, and can be appropriately selected from known ones. For example, the toner of the present invention Preferred examples include a developer containing at least a developer, and at least a developing device capable of contacting or non-contacting the toner or the developer with the electrostatic latent image. More preferred is a developing device.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photoconductor), 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 (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

  The developer accommodated in the developing device is a developer containing the toner of the present invention, but the developer may be a one-component developer or a two-component developer. The toner contained in the developer is the toner of the present invention.

  The development in the development step is preferably performed with the toner of the present invention and at least one color selected from a yellow toner, a magenta toner, a cyan toner, and a black toner. The toner of the invention is preferably at least one color selected from yellow toner, magenta toner, cyan toner, and black toner. By using the light black toner of the present invention in combination with any of these four color toners, an image having excellent graininess can be formed. For example, the yellow toner and the light black toner A smooth dark yellow image can be obtained.

<Transfer process and transfer means>
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the latent electrostatic image bearing member (photoconductor) of the visible image using a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer means (the primary transfer means, the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. There may be one transfer means or two or more transfer means.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
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 the fixing unit, and may be performed each time the toner of each color is transferred to the recording medium, or may be applied to the toner of each color. On the other hand, it may be carried out simultaneously at the same time in a state of being laminated.
The fixing unit is not particularly limited and may be appropriately selected depending on the intended purpose, but a known heating and pressing unit is preferable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The heating in the heating and pressurizing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.
The neutralizing means is not particularly limited and may be appropriately selected from known neutralizers as long as it can apply a neutralizing bias to the latent electrostatic image bearing member. Preferably mentioned.

The cleaning step is a step of removing the electrophotographic toner remaining on the electrostatic latent image carrier, and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited as long as it can remove the electrophotographic toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Suitable examples include brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

The recycling step is a step of recycling the electrophotographic color 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 means is a process for controlling the respective steps, and 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 devices such as a sequencer and a computer.

  One mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. An image forming apparatus 100 shown in FIG. 1 includes a photosensitive drum 10 (hereinafter referred to as “photosensitive member 10”) as the electrostatic latent image carrier, a charging roller 20 as the charging unit, and exposure as the exposure unit. The apparatus 30 includes a developing device 40 as the developing means, an intermediate transfer member 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a static elimination lamp 70 as the static elimination means.

  The intermediate transfer member 50 is an endless belt, and is designed to be movable in the direction of an arrow by three rollers 51 that are arranged inside and stretched. Part of the three rollers 51 also functions as a transfer bias roller that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer member 50. The intermediate transfer body 50 is provided with a cleaning device 90 having a cleaning blade in the vicinity thereof, and for transferring (secondary transfer) a developed image (toner image) to a transfer sheet 95 as a final transfer material. A transfer roller 80 serving as a transfer unit to which a transfer bias can be applied is disposed to face the transfer roller 80. Around the intermediate transfer member 50, a corona charger 52 for applying a charge to the toner image on the intermediate transfer member 50 is arranged between the photosensitive member 10 and the intermediate transfer member 50 in the rotation direction of the intermediate transfer member 50. It is disposed between the contact portion and the contact portion between the intermediate transfer member 50 and the transfer paper 95.

  The developing device 40 includes a developing belt 41 as the developer carrying member, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C provided around the developing belt 41. . The black developing unit 45K includes a developer accommodating portion 42K, a developer supplying roller 43K, and a developing roller 44K. The yellow developing unit 45Y includes a developer accommodating portion 42Y, a developer supplying roller 43Y, and a developing roller 44Y. The magenta developing unit 45M includes a developer accommodating portion 42M, a developer supplying roller 43M, and a developing roller 44M, and the cyan developing unit 45C includes a developer accommodating portion 42C and a developer supplying roller 43C. And a developing roller 44C. The developing belt 41 is an endless belt, is rotatably stretched around a plurality of belt rollers, and a part thereof is in contact with the photoconductor 10.

  In the image forming apparatus 100 shown in FIG. 1, for example, the charging roller 20 charges the photosensitive drum 10 uniformly. The exposure device 30 performs imagewise exposure on the photosensitive drum 10 to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 10 is developed by supplying toner from the developing device 40 to form a visible image (toner image). The visible image (toner image) is transferred (primary transfer) onto the intermediate transfer member 50 by the voltage applied from the roller 51, and further transferred (secondary transfer) onto the transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. The residual toner on the photoconductor 10 is removed by the cleaning device 60, and the charge on the photoconductor 10 is temporarily removed by the charge eliminating lamp 70.

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. The image forming apparatus 100 shown in FIG. 2 does not include the developing belt 41 in the image forming apparatus 100 shown in FIG. 1, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and Except for the fact that the cyan developing unit 45C is disposed directly opposite, it has the same configuration as the image forming apparatus 100 shown in FIG. In FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals.

Another mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. A tandem image forming apparatus 100 shown in FIG. 3 is a tandem color image forming apparatus. The tandem image forming apparatus 100 includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.
The copying apparatus main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center. The intermediate transfer member 50 is stretched around the support rollers 14, 15, and 16 and can be rotated clockwise in FIG. 3. An intermediate transfer body cleaning device 17 for removing residual toner on the intermediate transfer body 50 is disposed in the vicinity of the support roller 15. The intermediate transfer body 50 stretched by the support roller 14 and the support roller 15 is a tandem type in which four image forming means 18 of yellow, cyan, magenta, and black are arranged in parallel and facing each other along the conveyance direction. A developing device 120 is disposed. An exposure device 21 is disposed in the vicinity of the tandem developing device 120. A secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the transfer paper conveyed on the secondary transfer belt 24 and the intermediate transfer body 50 are in contact with each other. Is possible. A fixing device 25 is disposed in the vicinity of the secondary transfer device 22. The fixing device 25 includes a fixing belt 26 that is an endless belt, and a pressure roller 27 that is pressed against the fixing belt 26.
In the tandem image forming apparatus 100, a sheet reversing device 28 for reversing the transfer paper for image formation on both sides of the transfer paper is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25. Yes.

  Next, formation of a full-color image (color copy) using the tandem developing device 120 will be described. That is, first, a document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and the document is set on the contact glass 32 of the scanner 300. 400 is closed.

  When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. Immediately after that, the scanner 300 is driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, light from the light source is irradiated by the first traveling body 33 and reflected light from the document surface is reflected by the mirror in the second traveling body 34 and is received by the reading sensor 36 through the imaging lens 35 to be color. An original (color image) is read and used as black, yellow, magenta, and cyan image information.

  Each image information of black, yellow, magenta and cyan is stored in each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means and cyan image forming means in the tandem developing device 120. ) And black, yellow, magenta and cyan toner images are formed in the respective image forming means. That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem developing device 120 is photosensitive as shown in FIG. On the basis of the body 10 (the black photoreceptor 10K, the yellow photoreceptor 10Y, the magenta photoreceptor 10M, and the cyan photoreceptor 10C), the charger 60 that uniformly charges the photoreceptor, and each color image information. The photosensitive member is exposed to each color image corresponding image (L in FIG. 4), and an electrostatic latent image corresponding to each color image is formed on the photosensitive member. A developing device 61 that develops using color toner (black toner, yellow toner, magenta toner, and cyan toner) to form a toner image of each color toner, and the toner image is transferred to the intermediate transfer member 5. The image forming apparatus includes a transfer charger 62 for transferring the image on the upper surface, a photoconductor cleaning device 63, and a static eliminator 64. And cyan image) can be formed. The black image, the yellow image, the magenta image, and the cyan image formed in this way are formed on the black photoconductor 10K on the intermediate transfer member 50 that is rotationally moved by the support rollers 14, 15, and 16, respectively. The black image, the yellow image formed on the yellow photoconductor 10Y, the magenta image formed on the magenta photoconductor 10M, and the cyan image formed on the cyan photoconductor 10C are sequentially transferred (primary transfer). Is done. Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member 50 to form a composite color image (color transfer image).

On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Each sheet is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the sheet feeding roller 150 is rotated to feed out the sheets (recording paper) on the manual feed tray 51, separated one by one by the separation roller 58, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. . The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet.
Then, the registration roller 49 is rotated in synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member 50, and a sheet (recording paper) is interposed between the intermediate transfer member 50 and the secondary transfer device 22. The secondary color transfer device 22 transfers the composite color image (color transfer image) onto the sheet (recording paper), thereby transferring the color image onto the sheet (recording paper). Is formed. The residual toner on the intermediate transfer member 50 after image transfer is cleaned by the intermediate transfer member cleaning device 17.

  The sheet (recording paper) on which the color image has been transferred is conveyed by the secondary transfer device 22 and sent to the fixing device 25, where the combined color image (color) is generated by heat and pressure. (Transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw 55 and discharged by the discharge roller 56 and stacked on the paper discharge tray 57, or switched by the switching claw 55 and reversed by the sheet reversing device 28 and transferred again. After being guided to the position and recording an image on the back surface, the image is discharged by the discharge roller 56 and stacked on the discharge tray 57.

As the image forming method and the image forming apparatus of the present invention, those adopting the adhesive transfer method shown below can also be suitably used.
When the adhesive transfer method is employed, the toner of the present invention needs to contain at least a heat-sensitive adhesive. The heat-sensitive adhesive contains a solid plasticizer and a thermoplastic resin as essential components, and includes a tackifier as necessary.
The heat-sensitive adhesive does not exhibit any adhesiveness at room temperature, but develops adhesiveness by heating and external load, and maintains adhesiveness for a while after removing the heat source. First, the solid plasticizer is melted, and the thermoplastic resin and the tackifier are melted to develop tackiness. That is, the adhesiveness is caused by causing the solid plasticizer to be melted by heat and compatible with the thermoplastic resin, thereby plasticizing the thermoplastic resin.

The image forming method of the present invention using the adhesive transfer method includes at least a toner supplying step, a visible image temporary fixing step, and a heat welding step, and further other steps appropriately selected as necessary, for example, toner removal Including processes.
The adhesive transfer type image forming apparatus of the present invention comprises at least an image carrier, a toner supply unit, a visible image temporary fixing unit, and a heat welding unit, and further appropriately selected as necessary. It has other means, for example, toner removing means.

  The image forming method of the present invention using the adhesive transfer method can be preferably implemented by the image forming apparatus of the present invention using the adhesive transfer method, and the toner supplying step can be performed by the toner supplying means. The visual image temporary fixing step can be performed by the visible image temporary fixing unit, the thermal welding step can be performed by the thermal welding unit, and the other steps can be performed by the other unit.

<Toner supply step and toner supply means>
The toner supply step is a step of supplying the toner of the present invention onto the image carrier.
The image carrier is not particularly limited with respect to the material, shape, structure, size, etc., and can be appropriately selected from known ones. The shape is preferably an endless film. Examples of the material include a light-transmitting resin, and polycarbonate is preferable.

The toner supply means is not particularly limited and may be appropriately selected from known ones. For example, the toner supply unit and a container for storing the toner and the toner carrying unit are transported to the opposing portion of the image carrier. A toner supply device having at least a toner carrier, a replenishing member for replenishing the toner carrier with the toner in the container, and a layer thickness regulating member for equalizing the layer thickness of the toner on the toner carrier. Preferably mentioned.
The toner may be supplied by applying an electrostatic adhesive force to the toner of the present invention to replenish the toner carrier, or by applying a non-electrostatic adhesive force such as a magnetic force. The carrier may be replenished.
The toner supplied in the toner supply step and the toner used in the toner supply means are the toner of the present invention and at least one color selected from yellow toner, magenta toner, cyan toner, and black toner. preferable. By using the light black toner of the present invention in combination with any of these four color toners, an image having excellent graininess can be formed. For example, the yellow toner and the light black toner A smooth dark yellow image can be obtained.

<Visible image temporary fixing step and visible image temporary fixing means>
In the visible image temporary fixing step, a heat corresponding to an image signal is applied to the toner brought into contact with the image carrier to form a visible image with the toner at a portion to which the heat is applied, In this step, the visible image is temporarily fixed on the image carrier.
The visible image temporary fixing means preferably has at least viscosity imparting means for imparting viscosity to the toner.
As the viscosity applying means, for example, a laser beam scanning device having at least a laser light source, a collimator lens, a polygon mirror, an fθ lens, and a reflecting mirror is preferably exemplified. The laser beam scanning device can apply heat according to an image signal to the toner imagewise with a laser beam. A thermal head can be used instead of the laser beam.
Viscosity can be selectively imparted to the toner present at a position corresponding to the image portion on the toner carrier by the heat from the laser beam in the viscosity imparting means. A viscous visible image is formed, and the visible image is temporarily fixed on the image carrier.
Here, the application of the viscosity includes not only the case where the material that originally has no viscosity is made viscous, but also the case where the viscosity of the material that was originally viscous is further increased.
The adhesion force of the temporarily fixed visible image to the image carrier is weaker than the adhesion force due to electrostatic force between the toner and the toner carrier, and the residual toner on the image carrier in the toner removal step described later. Is of a size that can be easily removed.

<Thermal welding process and thermal welding means>
The thermal welding process is a process in which the temporarily fixed visible image is transferred to a recording medium and thermally welded, and can be suitably performed by a thermal welding means.
The heat welding means is not particularly limited and may be appropriately selected according to the purpose. However, it is preferable to simultaneously transfer and fix the visible image onto the recording medium, for example, a heating roller is preferable. Listed.

The toner removing step is a step of removing toner existing in a part other than the visible image on the image carrier, and can be suitably performed by a toner removing unit.
The toner removing means is not particularly limited and may be selected as appropriate from known cleaners as long as the toner remaining on the image carrier can be removed. For example, a magnetic roller cleaner, A blade cleaner or the like is preferably used.

  One mode of carrying out the image forming method of the present invention by the image forming apparatus of the present invention adopting the adhesive transfer method will be described with reference to FIG. An image forming apparatus 500 shown in FIG. 5 includes an image carrier 510, a toner supply device 520 as the toner supply unit, a laser beam scanning device 530 as the viscosity applying unit in the visible image temporary fixing unit, and the A toner removing roller 540 as a toner removing unit and a heating roller 550 as the heat welding unit are provided.

  The image carrier 510 has an endless film shape, and is formed of polycarbonate as a light-transmitting resin film that transmits light in a predetermined wavelength range, and has a thickness of 0.02 to 0.2 mm. The image carrier 510 is designed to be movable in the direction of the arrow a when one of a roller 511 and a roller 512 that are arranged inside and stretches the image carrier 510 is rotated by driving means such as a motor. A cleaning device 514 having a cleaning roller 513 that is in contact with the roller 512 via the image carrier 510 is disposed in the vicinity of the roller 512. A blade 515 is disposed in contact with the cleaning roller 513.

The toner supply device 520 includes a case 521 that accommodates the toner T, a toner carrying roller 522 that carries the toner T to a portion facing the image carrier 510, and the toner T in the case 521 to the toner carrying roller 522. A replenishing roller 523 for replenishing and a blade 524 for uniformizing the layer thickness of the toner T carried on the toner carrying roller 522 are provided in the vicinity of the image carrier 510. The toner carrying roller 522 and the replenishing roller 523 are each designed to be rotatable in the arrow direction.
Further, a toner removing roller 540 with a leading edge of the cleaning blade 541 in contact with the toner supply device 520 is disposed.

The laser beam scanning device 530 includes a laser light source and a collimator lens (not shown), a polygon mirror 531, an fθ lens 532, and a strip-shaped reflecting mirror 534 having substantially the same length as the width of the image carrier 510. On the back side of the image carrier 510, the toner carrier roller 522 is disposed at a position where the toner T is supplied. Further, the laser beam scanning device 530 applies heat corresponding to the image signal to the toner T on the toner carrying roller 522 via the image carrier 510 in an image-like manner. In this example, the laser beam is irradiated from the back side of the image carrier 510. However, a laser beam scanning device 530 is disposed outside the image carrier 510, and the toner is directly passed through the image carrier 510. Thermal energy may be applied by irradiating T with laser light.
The heating roller 550 is disposed so as to face and separate from the roller 511 via the image carrier 510, and when the recording medium S is sent between the heating roller 550 and the roller 511 by the registration roller pair 551, The roller 511 is in pressure contact with the image carrier 510.

In the image forming apparatus 500 employing the adhesive transfer method shown in FIG. 5, in the toner supply device 520, the toner T in the case 521 is replenished to the toner carrying roller 522 by the replenishing roller 523 and the toner carried on the toner carrying roller 522. The layer thickness of T is made uniform by the blade 524, and an appropriate amount of toner is guided to the opposing portion between the image carrier 510 and the toner carrier roller 522. At this time, the toner carrying roller 522 and the replenishing roller 523 are brought into contact with each other with a speed difference at the opposing portion so that the toner is frictionally charged (for example, negatively charged), and the toner carrying roller 522 is supplied to the replenishing roller 523. By applying a voltage having a positive potential to the toner, an electrostatic adhesion force is applied to the toner T, and the toner T having the electrostatic adhesion force is supplied to the toner carrying roller 522.
Next, in the laser beam scanning device 530, heat corresponding to the image signal is irradiated imagewise to the toner T on the toner carrying roller 522 via the image carrier 510 by the laser beam. The toner T becomes viscous due to the thermal energy of the laser light applied to the toner T, and is temporarily fixed as a visible image on the surface of the image carrier 510. Further, after the visible image G is temporarily fixed on the image carrier 510, the toner (residual toner) existing in the portion (non-image portion) other than the visible image G on the image carrier 510 has a positive voltage. The toner is removed by the electrostatic attraction force of the applied toner removing roller 540. The toner removal roller 540 is provided for the purpose of removing toner when toner other than the toner that is originally temporarily fixed adheres to the non-image portion on the image carrier 510 and so-called scumming occurs. The suction force of the toner removing roller 540 is weaker than the temporary fixing force of the toner T to the image carrier 510. Further, when the amount of toner adhering to the non-image portion is small, the toner removing roller 540 may not be provided.

  On the downstream side of the facing portion between the image carrier 510 and the toner removing roller 540, the visible image G is transferred and fixed to the recording medium S by heat welding by the heating roller 550. Here, the recording medium S is fed from a sheet feeding device (not shown), sent to the heating roller 550 in accordance with the visible image forming area on the image carrier 510 by the registration roller pair 551, and heated from the back side. As a result, the visible image G is transferred and fixed. Note that the image carrier 510 after the transfer and fixing of the visible image is cleaned by the cleaning roller 513, and dust containing toner on the cleaning roller 513 is scraped off by the blade 515.

  In the image forming apparatus and the image forming method of the present invention, the toner of the present invention having good color (gray balance) stability is used. Therefore, the highlight portion (low image density portion) is excellent in graininess and has high image quality. Can be obtained efficiently.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

(Synthesis Example 1)
-Synthesis of polyester resin-
In a four-necked separable flask equipped with a stirrer, thermometer, nitrogen inlet, down-flow condenser, and condenser, 740 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, poly Establish 300 g of oxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 466 g of dimethyl terephthalate, 80 g of isododecenyl succinic anhydride, and 114 g of tri-n-butyl 1,2,4-benzenetricarboxylate Was added along with the catalyst. Under a nitrogen atmosphere, the temperature was raised to 210 ° C. under normal pressure, and then reacted with stirring at 210 ° C. under reduced pressure to synthesize a polyester resin. The obtained polyester resin had an acid value of 2.3 KOH mg / g, a hydroxyl value of 28.0 KOH mg / g, a softening point of 106 ° C., and a Tg of 62 ° C.

Example 1
-Preparation of toner base particles-
Based on the following composition, toner base particles were prepared.
100 parts by mass of the polyester resin
3-5 parts by weight of 3-5 ditertbutylsalicylate Zn (II) complex
Whitening agent: Titanium oxide (“Taipeke R680”; manufactured by Ishihara Sangyo) 5 parts by mass
Blacking agent: Carbon black (“# 44”; manufactured by Mitsubishi Kasei) 0.8 parts by mass
Here, the surface of the whitening agent (“Typaque R680”; manufactured by Ishihara Sangyo Co., Ltd.) is coated with aluminum hydroxide, and the oil absorption is 19 ml / 100 g. The average particle diameter is 0.21 μm.

The mixture having the above composition was sufficiently stirred and mixed in a Henschel mixer, heated and melted at a temperature of 130 ° C. for about 30 minutes with a roll mill, and cooled to room temperature. The obtained kneaded material was coarsely pulverized to 200 to 400 μm with a hammer mill. Next, a fine pulverization device that directly pulverizes the coarsely pulverized product against the impingement plate using a jet stream and a finely pulverized powder obtained by the fine pulverizer form a swirl flow in the classification chamber, and the pulverized product is centrifuged. Crushing and classification were carried out with an IDS-2 type pulverizing and classifying apparatus (manufactured by Nippon Pneumatic Industry Co., Ltd.) integrally having an air classifier that separates and classifies to obtain a toner after classification.
The desired particle size distribution includes the supply amount of the object to be crushed, the pressure and flow rate of the pulverizing high-pressure air, the shape of the pulverizing collision member, and the air inflow position and inflow direction when air is sucked in the classification device. It can be obtained by changing the exhaust blower pressure, etc.

-External additive treatment-
1. Hydrophobic silica treated with dichlorodimethylsilane as an external additive (“R972”; manufactured by Nippon Aerosil Co., Ltd., average primary particle size: 0.016 μm) with respect to 100 parts by mass of the obtained toner base particles of Example 1. 0 parts by mass and 0.5 parts by mass of octyltrimethoxysilane-treated hydrophobic titanium oxide (“T805”; manufactured by Nippon Aerosil Co., Ltd., average primary particle size: 0.02 μm) were used using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). The light black toner of Example 1 was manufactured by mixing and sieving with a mesh of 35 μm.

  With respect to the obtained toner, the volume average particle size (Dv), number average particle size (Dn), and particle size distribution (volume average particle size (Dv) / number average particle size (Dn)) were measured by the following methods. The results are shown in Table 1.

<Toner particle size>
The volume average particle diameter (Dv) of the toner and the number average particle diameter (Dn) of the toner were measured using a particle size measuring device (“Multisizer II”; manufactured by Beckman Coulter, Inc.) with an aperture diameter of 100 μm. From these results, the particle size distribution (volume average particle size (Dv) / number average particle size (Dn)) was calculated.

(Example 2)
In Example 1, the light black toner of Example 2 was produced in the same manner as in Example 1 except that the addition amount of the whitening agent was changed from 5 parts by mass to 20 parts by mass. Further, various physical properties were measured in the same manner as in Example 1. The results are shown in Table 1.

(Example 3)
A light black toner of Example 3 was produced in the same manner as in Example 1 except that the amount of whitening agent was changed from 5 parts by mass to 50 parts by mass in Example 1. Further, various physical properties were measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
In Example 1, the white agent was not added, the addition amount of the black agent (carbon black) was changed from 0.8 parts by mass to 7 parts by mass, and 0.5 parts by mass of the blue complementary colorant was further added. A black toner of Comparative Example 1 was produced in the same manner as Example 1. Further, various physical properties were measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2)
A light black toner of Comparative Example 2 was produced in the same manner as in Example 1 except that no whitening agent was added. Further, various physical properties were measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 3)
A light black toner of Comparative Example 3 was produced in the same manner as in Example 1 except that the amount of whitening agent was changed from 5 parts by mass to 60 parts by mass in Example 1. Further, various physical properties were measured in the same manner as in Example 1. The results are shown in Table 1.

  Using the obtained one-component developers of Examples 1 to 3 and Comparative Examples 1 to 3 that have been subjected to external additive treatment, (a) granularity, (b) fixability (fixing lower limit) Temperature), and (c) color reproducibility was evaluated. The results are shown in Tables 2 and 3.

(A) Graininess Using a digital full color printer (“IPSIO CX7500”; manufactured by Ricoh Co., Ltd.), sample images were printed for each one-component developer. Next, the gray scale (halftone part) formed by the dots of the obtained print image was read at 1,000 dpi with a scanner (“GenaScan 5000”; manufactured by Dainippon Screen) to obtain image data. The image data was converted into a density distribution, and the granularity was evaluated by the following formulas (1) to (3).
Granularity (GS) = exp (−1.8 <D>) ∫WS (u) 1 / 2VTF (u) du (1)
In the above formula (1), exp (−1.8 <D>) is a coefficient for correcting the density and the brightness difference perceived by humans, and <D> is the average value of the density. To express.
Further, WS can be obtained from the following equations (2) and (3), where f (x) dx is a density fluctuation component having an average value of 0.
F (u) = ∫f (x) exp (−2∫iux) dx (2)
WS (u) = F (u) 2 Formula (3)
However, u is a spatial frequency in said Formula (2) and Formula (3).

(B) Fixability (fixing lower limit temperature)
Using a digital full-color printer (“IPSIO CX7500”; manufactured by Ricoh Co., Ltd.), transfer paper (“TYPE 6200”; manufactured by Ricoh Co., Ltd.) is set, and the adhesion amount of each one-component developer is 1.00 ± 0.05 mg. A solid image of / cm ² was formed and a copy test was performed. The fixing roll temperature at which the residual ratio of the image density after rubbing the obtained fixed image with a pad becomes 70% or more was set as the minimum fixing temperature, and the low-temperature fixing property was evaluated based on the following criteria.
〔Evaluation criteria〕
A: Fixing lower limit temperature is less than 150 ° C. ○: Fixing lower limit temperature is 150 ° C. or more and less than 170 ° C.

(C) Color reproducibility Using only a single color of each toner, a transfer paper (“TYPE 6000 <70W>”; manufactured by Ricoh Co., Ltd.) was set using a digital full-color printer (“IPSIO CX7500”; manufactured by Ricoh Co., Ltd.) Solid images with the amount of each single-component developer adhering to 0.20 ± 0.03 mg / cm ² , 0.80 ± 0.03 mg / cm ² , and 1.20 ± 0.03 mg / cm ² are formed and copied. Tested. The image density of arbitrary five places in the obtained solid image was measured using a spectrometer (“938 Spectrodensitometer”; manufactured by X-Light), and the average value was calculated. Then, the image density when the toner adhesion amount 0.80 mg / cm ² and ID0.8, when the image density when the toner adhesion amount 1.20 mg / cm ² and ID1.2 ID0.8 / ID1. 2. Lightness (L ^* ), hue (a ^* ), and hue (b ^* ) were measured.

From the results of Tables 2-3, the following is clear. That is, it was found that the toners obtained in Examples 1 to 3 were excellent in graininess even in the highlight area, good in low-temperature fixability, and stable in color (gray balance).
On the other hand, the toners obtained in Comparative Examples 1 and 2 were inferior in granularity, and the toner obtained in Comparative Example 3 was found to deteriorate in low-temperature fixability because of the excessive white agent content.

Next, yellow toner, magenta toner, and cyan toner were produced by the following method.
-Composition of yellow colorant-
200 parts by mass of the polyester resin
CI Pigment Yellow 180 100 parts by mass
-Composition of red colorant-
200 parts by mass of the polyester resin
CI Pigment Red 122 100 parts by mass
-Composition of blue colorant-
200 parts by mass of the polyester resin
CI Pigment Blue 15.3 100 parts by mass
After mixing the materials having the above composition for each color in a Henschel mixer, the obtained mixture was put into a two-roll mill heated to 100 ° C., and melt-kneaded for 30 minutes after charging. The obtained kneaded product was cooled and coarsely pulverized with a hammer mill to obtain a polyester resin colorant of each color.

Each color toner was prepared by the following method using the obtained polyester resin colorant of each color.
-Composition of yellow toner-
88 parts by mass of the polyester resin 3 parts by mass of 3-5 ditertbutylsalicylic acid Zn (II) complex
18 parts by mass of polyester resin-yellow colorant
-Magenta toner composition-
90 parts by mass of the polyester resin 3 parts by mass of 3-5 di-tertbutylsalicylate Zn (II) complex
15 parts by mass of polyester resin-red colorant
-Composition of cyan toner-
96 parts by mass of the polyester resin 3-5 parts by mass of 3-5 ditertbutylsalicylic acid Zn (II) complex
8 parts by weight of polyester resin-blue colorant
The material having the above composition for each color was sufficiently stirred and mixed in a Henschel mixer, then heated and melted at a temperature of 130 ° C. for about 30 minutes with a roll mill, and cooled to room temperature. The obtained kneaded material was coarsely pulverized to 200 to 400 μm with a hammer mill. Next, a fine pulverization device that directly pulverizes the coarsely pulverized product against the impingement plate using a jet stream and a finely pulverized powder obtained by the fine pulverizer form a swirl flow in the classification chamber, and the pulverized product is centrifuged. Crushing and classification were carried out with an IDS-2 type pulverizing and classifying apparatus (manufactured by Nippon Pneumatic Industry Co., Ltd.) integrally having an air classifier that separates and classifies to obtain a toner after classification. The obtained toner base particles of each color were subjected to an external additive mixed sieving treatment in the same manner as in Example 1, and the volume average particle diameter (Dv) = 7 μm, the number average particle diameter (Dn) = 5.8 μm, and Dv / A yellow toner, a magenta toner, and a cyan toner having Dn = 1.21 were prepared.

Example 4
-Evaluation of graininess of dark yellow-
Using two colors of light black toner of Example 2 and yellow toner obtained by the above method, a sample image of dark yellow was printed using a digital full color printer (“IPSIO CX7500”; manufactured by Ricoh Co., Ltd.). The graininess was evaluated in the same manner as in Example 1. The results are shown in Table 4.

(Comparative Example 4)
-Evaluation of graininess of dark yellow-
Using two colors of the black toner of Comparative Example 1 and the yellow toner obtained by the above method, a sample image of dark yellow was printed using a digital full color printer (“IPSIO CX7500”; manufactured by Ricoh Co., Ltd.) Granularity was evaluated in the same manner as in Example 1. The results are shown in Table 4.

(Comparative Example 5)
-Evaluation of graininess of dark yellow-
Using a yellow toner, a cyan toner, and a magenta toner obtained by the above method, a sample image of dark yellow was printed using a digital full color printer (“IPSIO CX7500”; manufactured by Ricoh Co., Ltd.). The graininess was evaluated in the same manner as in 1. The results are shown in Table 4. The dark yellow image is a mixed color image composed of a gray color of three colors of yellow toner, cyan toner and magenta toner obtained by the above method and a yellow color of the yellow toner.

表２及び表４の結果より、実施例４では、本発明の実施例１のライトブラックトナーと、イエロートナーとを使用してダークイエロー画像を形成したので、得られる画像は粒状性に優れ、滑らかであることが判った。一方、比較例４では、ブラックトナーとイエロートナーとを使用してダークイエロー画像を形成し、比較例５では、イエロートナー、マゼンタトナー、及びシアントナーの３色により形成した従来のグレー色と、イエロートナーによるイエロー色との混色によりダークイエロー画像を形成したので、得られる画像は粒状性に極めて劣っていることが判った。

From the results of Table 2 and Table 4, in Example 4, since the dark yellow image was formed using the light black toner of Example 1 of the present invention and the yellow toner, the obtained image was excellent in graininess, It turned out to be smooth. On the other hand, in Comparative Example 4, a dark yellow image is formed using black toner and yellow toner, and in Comparative Example 5, a conventional gray color formed with three colors of yellow toner, magenta toner, and cyan toner; Since a dark yellow image was formed by mixing the yellow color with yellow toner, it was found that the obtained image was extremely inferior in graininess.

(Comparative Example 6)
-Graininess evaluation of gray in full color-
EXAMPLE 3 Using a digital full-color printer (“IPSIO CX7500”; manufactured by Ricoh Co., Ltd.) using three colors of yellow toner, cyan toner, and magenta toner obtained by the above method, a gray sample image was printed. In the same manner, the graininess was evaluated. As a result, the granularity of the gray toner of Comparative Example 6 was 0.36, which was inferior to the granularity as compared with the light black toners of Examples 1 to 3 (granularity was 0.15). In other words, it was found that the light black toners of Examples 1 to 3 of the present invention can obtain a gray image having a single color of the light black toner and excellent in graininess. On the other hand, it was found that Comparative Example 6 using a conventional gray image forming method using three colors of yellow toner, magenta toner, and cyan toner is inferior in graininess and causes density unevenness. It was.

  The toner of the present invention has good color (gray balance) stability and is excellent in graininess even in a highlight portion (low image density portion), and therefore is preferably used for high quality image formation. The developer, toner-containing container, process cartridge, image forming apparatus and image forming method of the present invention using the toner of the present invention are suitably used for high-quality image formation.

FIG. 1 is a schematic explanatory view showing an example in which the image forming method of the present invention is carried out by the image forming apparatus of the present invention. FIG. 2 is a schematic explanatory view showing another example in which the image forming method of the present invention is carried out by the image forming apparatus of the present invention. FIG. 3 is a schematic explanatory view showing an example in which the image forming method of the present invention is implemented by the image forming apparatus (tandem color image forming apparatus) of the present invention. 4 is a partially enlarged schematic explanatory diagram of the image forming apparatus shown in FIG. FIG. 5 is a schematic explanatory view showing an example in which the image forming method of the present invention is carried out by the image forming apparatus (adhesive transfer method) of the present invention.

Explanation of symbols

10 Photoconductor (Photoconductor drum)
10K black photoconductor 10Y yellow photoconductor 10M magenta photoconductor 10C cyan photoconductor 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 Pressure roller 28 Sheet reversing device 30 Exposure device 32 Contact glass 33 First traveling member 34 Second traveling member 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing belt 42K Developer container 42Y Developer container 42M Developer container 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K Developer roller 44Y Developer roller 44M Developer Roller 44C Development roller 45K Black development unit 45Y Yellow development unit 45M Magenta development unit 45C Cyan development unit 49 Registration roller 50 Intermediate transfer member 51 Roller 52 Corona charger 53 Constant current source 55 Switching claw 56 Discharge roller 57 Discharge tray 58 Separating roller 60 Cleaning device 61 Developing device 62 Transfer charger 63 Photoconductor cleaning device 64 Static eliminator 70 Static elimination lamp 80 Transfer roller 90 Cleaning device 95 Transfer paper 100 Image forming device 120 Tandem type developer 130 Document base 142 Feed roller 143 Paper bank 144 Paper feed cassette 145 Separation roller 146 Paper feed path 147 Carriage roller 148 Paper feed path 150 Copier main body 200 Paper feed table 300 Scanner 400 Automatic document feeder (ADF)
500 Image forming device (adhesive transfer method)
510 Image carrier 520 Toner supply device 530 Laser beam scanning device 540 Toner removal roller 550 Heating roller

Claims (17)

Resin and colorant are included, and the colorant includes at least a white agent and a black agent. When the toner adhesion amount is 0.8 mg / cm ² , the image density is ID 0.8, and the toner adhesion amount is 1.2 mg / cm ^2. A toner satisfying the following formula: 0.8 ≦ ID0.8 / ID1.2 ≦ 1.1 when the image density at cm ² is ID1.2.   The toner according to claim 1, wherein the content of the whitening agent is 5 to 50 parts by mass with respect to 100 parts by mass of the resin.   The toner according to claim 1, wherein the content of the black agent is 0.1 to 2.0 parts by mass with respect to 100 parts by mass of the resin.   A toner used in combination with a black toner, wherein the black agent content in the toner is 0.05X to 0.30X part by mass when the black agent content in the black toner is X parts by mass. Item 3. The toner according to any one of Items 1 to 2.   The toner according to claim 1, wherein the whitening agent is surface-treated with a surface coating material.   The toner according to claim 5, wherein the surface coating material is a hydrated aluminum oxide.   The toner according to claim 5, wherein the white agent has an oil absorption of 30 ml / 100 g or less.   The toner according to claim 1, wherein the average particle diameter of the whitening agent is 0.03 to 0.5 μm. When the toner adhesion amount is 0.6 mg / cm ² or more, the lightness (L ^* ) expressed in the Lab color system is 20 to 60, and when the toner adhesion amount is 0.2 mg / cm ² or more, the Lab The toner according to any one of claims 1 to 8, wherein a hue (a ^* ) represented by a color system is -5 to +5 and a hue (b ^* ) is -5 to +5. The toner according to claim 1, wherein the whitening agent is titanium oxide (TiO ₂ ).   The toner according to claim 1, wherein the blackening agent is carbon black.   The toner according to claim 1, which is a pulverized toner.   The toner according to claim 1, wherein the toner has a volume average particle diameter of 3 to 8 μm.   The toner according to claim 1, wherein the toner has a volume average particle diameter (Dv) / number average particle diameter (Dn) of 1.00 to 1.30.   An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with the toner according to any one of claims 1 to 14 to form a visible image An image forming method comprising: a developing step for forming the image; a transfer step for transferring the visible image to a recording medium; and a fixing step for fixing the transferred image transferred to the recording medium.   The development in the development step is performed using the toner according to any one of claims 1 to 14 and at least one color selected from yellow toner, magenta toner, cyan toner, and black toner. Image forming method. A toner supply step for supplying the toner according to any one of claims 1 to 14 onto an image carrier, and applying heat according to an image signal to the toner in contact with the image carrier, the heat A visible image is temporarily formed on the image carrier by forming a visible image with the toner at the site to which the toner is applied, and the temporarily fixed visible image is transferred to a recording medium. And an image forming method characterized by comprising at least a heat welding step of heat welding.

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