JP4980635B2 - Image forming method - Google Patents

Description

The present invention relates to images formed how.

  As an electrophotographic image forming method, there is an electrophotographic method in which an electrostatic latent image is formed on a latent image carrier, visualized with a developer, and transferred onto transfer paper. As the developer here, a two-component developer composed of a toner and a carrier is often used. In a copying machine or the like in which such a two-component developer is set, toner is consumed every time copying is performed. To replenish the consumed toner, toner is replenished corresponding to the number of copies. To ensure a stable image. That is, the toner density is controlled in the developing unit so that the copy image density does not change significantly. At this time, there is a problem that the external additive present on the surface of the toner is buried in the toner or peeled off by stirring of the developing unit. In addition, since the surface of the carrier is contaminated with toner, there is a problem that frictional charging between the toner and the carrier is weakened, soiling occurs, and toner scattering occurs in the machine.

As a method for eliminating such scumming, a method of detecting scumming on the image carrier and detecting the scumming of the developing unit by stirring the developing unit when the amount exceeds a predetermined value. (Refer to Patent Document 1) When the machine is turned on, the stirrer eliminates the generated background contamination such as a method of controlling the stirring of the developing unit by detecting the charged state of the two-component developer (refer to Patent Document 2). How to do is known.
Japanese Patent Application Laid-Open No. 11-237772 JP 2001-265077 A

In view of the problem of the prior art described above has, a long time, and background smear, and to provide the images formed how capable of suppressing the occurrence of toner scattering.

Invention of claim 1, a method for forming an image using a developer, the developer can have a negatively chargeable toner and a carrier, the toner is a polyester resin or a styrene copolymerization A base particle comprising a coalescence, carbon black , a fluorosurfactant, a metal salt of salicylic acid or a metal salt of a salicylic acid derivative , hydrophobic silica particles, and hydrophobic titanium oxide particles, wherein the carrier is a core particle The surface of the toner is coated with a coating layer containing a silicone resin and an aminosilane coupling agent. The coverage of the toner covering the surface of the carrier is 46% as measured by the following method for measuring the charge amount of the carrier. When the toner and the carrier are mixed, the charge amount of the carrier is 20 μC / g or more and 47 μC / g or less. When the measured background stain ΔID is 0.01, the coverage of the toner covering the surface of the carrier is 40% or more and 91% or less, and the coverage [%] is expressed by the formula TC / (100− TC) · (Rc / rt) · (ρc / ρt) · 25
(Wherein, TC is the a content of the toner in the developer [wt%], Rc, said a weight average particle diameter of the carrier [[mu] m], rt is the weight average particle diameter of the toner [Μm], ρc is the true specific gravity [g / cm ³ ] of the carrier, and ρt is the true specific gravity [g / cm ³ ] of the toner.)
Where the charge amount [μC / g] of the carrier is CT and the coverage [%] is C, the formula 1.45CT-10.37 ≦ C ≦ 2.174CT + 24.45
It is characterized by satisfying.
[Measurement method of charge amount of carrier]
The toner and the carrier are weighed so that the total coverage of the toner and the carrier is 1000 g at a ratio where the coverage ratio of the toner covering the carrier is 46%, and put into a 2 L stainless steel container. Next, the toner and carrier placed in a 2 L stainless steel container are left for 2 hours in an environment of 24 ° C. and 55% RH. Furthermore, at 24 ° C., 55% RH environment, and mixed for 10 minutes at 9 6 rpm, to prepare a developer. Next, 24 ° C., at 55% RH environment, in the following conditions: to measure the charge amount of the carrier.
Blow gas: Nitrogen Blow pressure: 1 kg / cm ²
Blow time: 40 seconds Developer amount: 0.3 g
[Measurement method of background stain ΔID]
10 ° C., at a low temperature and low humidity of RH 15% environment, a static-voltage 620V, set the developing bias 500V, performs 5000-sheet continuous paper feed test on the original image area ratio of 5% A4. Thereafter, an image is output with an A3 original having an image area ratio of 0.5%, and the power of the machine is turned off during image formation. Then, taking out the latent image bearing member, affixed to the axial direction of the latent image carrier 300 mm, a tape width 10 mm. By rubbing with a finger on the tape through the gauze, the toner on the latent image carrier is transferred to the tape, and then the tape is peeled off from the latent image carrier. Then, the tape being attached to the paper of A3 (hereinafter, referred to as sheet A). As a tape for comparison, it puts a tape that is not attached to the latent image bearing member to the paper of the A3 (hereinafter referred to as paper B). For paper A, the density of three points from the top of the tape corresponding to the background portion on the latent image carrier is measured to obtain an average value. For paper B, the density at three points from the top of the tape is measured to obtain an average value . The background stain ΔID is a difference between the density of the paper A and the density of the paper B obtained in this way.

According to a second aspect of the present invention, in the image forming method according to the first aspect , when the content [wt%] of the toner in the developer when the background stain ΔID is 0.01 is X, Formula 0.227 CT + 0.77 ≦ X ≦ 0.245 CT + 2.69
It is characterized by satisfying.

A third aspect of the present invention is the image forming method according to the first or second aspect, wherein the formula 2.165CT-30.99 ≦ C ≦ 1.955CT + 19.21.
It is characterized by satisfying.

According to a fourth aspect of the present invention, in the image forming method according to any one of the first to third aspects, the coating layer further includes an acrylic resin, an amino resin, and alumina particles.

According to a fifth aspect of the present invention, in the image forming method according to any one of the first to fourth aspects, the step of charging each of the plurality of latent image carriers, and each of the charged latent image carriers. Forming an electrostatic latent image by exposing the toner, developing a latent image formed on each latent image carrier using the developer to form a toner image, and The method includes a step of transferring a toner image formed on the latent image carrier to a transfer target and a step of fixing the toner image transferred to the transfer target.

According to the present invention can provide a long time, and scumming, the images formed how capable of suppressing the occurrence of toner scattering.

  Next, the best mode for carrying out the present invention will be described.

The developer of the present invention comprises a toner and a carrier containing at least a colorant, a binder resin, a charge control agent, and an external additive, and the toner and the toner in a state where the coverage of the toner covering the surface of the carrier is 46%. The charge amount (CT) of the carrier after mixing the carrier is 20 μC / g or more and 47 μC / g or less, and the coverage ratio (C ) Is not less than 40% and not more than 91%, and the formula 1.45CT-10.37 ≦ C ≦ 2.174CT + 24.45
Meet.

  Examples of the method of changing the charge amount (CT) of the carrier include a method of adding a silane coupling agent to the carrier coating layer. Among them, it is preferable to use an aminosilane coupling agent that makes the carrier positively charged. At this time, the toner is negatively charged. Further, the charge amount (CT) can be varied by adjusting the resistance of the carrier. Specifically, when the film thickness of the coating layer is increased, the resistance increases and the charge amount (CT) increases. Further, the charge amount (CT) can be varied by using a resin having an amino group in the carrier coating layer. For example, the addition of melamine resin or the like increases the positive chargeability of the carrier. Further, the charge amount (CT) can be varied by selecting the type of the coating layer. For example, a method of blending a fluororesin and a styrene / acrylic resin can be mentioned. At this time, if the ratio of styrene / acrylic resin is increased, the positive charge amount (CT) increases. Further, when the particle size of the carrier is reduced, the specific surface area is increased and the charge amount (CT) is increased.

  Next, a method for evaluating the background stain ΔID will be described.

  Prepare carriers with different charge amounts (CT), use the same toner, set the charging voltage to 620 V and the developing bias to 500 V in a low-temperature and low-humidity environment of 10 ° C. and 15% RH, and an original with an image area ratio of 5% Execute a continuous sheet passing test of 5000 sheets. Thereafter, an image is output with an A3 original having an image area ratio of 0.5%, and the power of the machine is turned off during image formation. Then, the latent image carrier is taken out, and a printerac tape (manufactured by Nitto Co., Ltd.) having a width of 300 mm and a width of 10 mm is attached in the axial direction of the latent image carrier. By rubbing with a finger on the tape through the gauze, the toner on the latent image carrier is transferred to the tape, and then the tape is peeled off from the latent image carrier. Next, the tape is affixed to A3 paper type 6000 (manufactured by Ricoh) (hereinafter referred to as paper A). As a comparative tape, a tape that is not attached to the latent image carrier is attached to A3 paper type 6000 (manufactured by Ricoh) (hereinafter referred to as paper B). For paper A, the density of three points from the top of the tape corresponding to the background portion on the latent image carrier is measured to obtain an average value. For paper B, the density at three points from the top of the tape is measured to obtain an average value. The concentration is measured using X-Rite 938 (Amtech). The background stain ΔID is a difference between the density of the paper A and the density of the paper B obtained in this way.

The background stain ΔID can be determined with an arbitrary toner concentration (the toner content in the developer), and the toner concentration is preferably 5 to 14%. When the background stain ΔID is large, the stain on the latent image carrier becomes remarkable, leading to background stain on the copy paper and toner scattering. Note that the toner concentration (X) at which the background stain ΔID becomes 0.01 can be obtained by measuring and plotting the background stain ΔID while changing the toner concentration. At this time, the toner density (X) is expressed by the equation 0.227CT + 0.77 ≦ X ≦ 0.245CT + 2.69.
It is preferable to satisfy. Note that the relationship between the charge amount (CT) of the carrier and the toner concentration (X) is lower when CT is smaller. When CT is less than 20 μC / g, toner scattering may become significant. On the other hand, when CT is larger than 47 μC / g, the occurrence of toner scattering is small, but the image density may be lowered.

The background stain is good when the CT is 20 to 47 μC / g, the toner coverage (C) with respect to the carrier at the toner concentration (X) is 40 to 91%, and the relationship between CT and C is expressed by the formula 1.45 CT−. 10.37 ≦ C ≦ 2.174CT + 24.45
This is the case. More preferably, CT is 23 to 45 μC / g, C is 42 to 86%, and the relationship between CT and C is the formula 2.165CT-30.99 ≦ C ≦ 1.955CT + 19.21
This is the case.

  The coverage (C) can be obtained from the following equation.

C [%] = TC / (100-TC). (Rc / rt). (Ρc / ρt) .25
TC: toner concentration [% by weight]
Rc: Weight average particle diameter of carrier [μm]
rt: weight average particle diameter of toner [μm]
ρc: True specific gravity of carrier [g / cm ³ ]
ρt: True specific gravity of toner [g / cm ³ ]
Hereinafter, the toner used in the present invention will be described.

  In the present invention, known dyes and pigments can be used as the colorant. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow Iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, p- Rollo-o-nitroaniline red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carnmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, alizarin lake, thioindigo red B, thioindigo maroon, oil red, quinacridone red, Lazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indance Ren Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green , Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Gree Lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  In the present invention, the colorant can also be used as a master batch combined with a resin. Examples of the resin to be kneaded with the production of the master batch or the master batch include polymers of styrene such as polystyrene, poly (p-chlorostyrene), polyvinyltoluene and the like; styrene-p-chlorostyrene copolymers, styrene- Propylene copolymer, 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 Polymer, styrene-vinylmethyl Styrene copolymers such as ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers Polymerized methyl 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, Examples include terpene resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, and paraffin waxes, which can be used alone or in combination.

  The master batch can be obtained by mixing and kneading a resin and a colorant under a high shear force. At this time, an organic solvent can be used in order to enhance the interaction between the colorant and the resin. Also, a so-called flushing method called an aqueous paste of a colorant is mixed and kneaded with a resin and an organic solvent, the colorant is transferred to the resin side, and moisture and organic solvent components are removed. It can be used and is preferably used because it does not need to be dried. When mixing and kneading, a high shear dispersion device such as a three-roll mill can be used.

  In the present invention, known charge control agents for imparting charging characteristics to the toner can be used, for example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, Rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorosurfactants, salicylic acid metal salts, salicylic acid derivatives And metal salts thereof. Specifically, Bontron 03 of nigrosine dye, Bontron P-51 of quaternary ammonium salt, Bontron S-34 of metal-containing azo dye, E-82 of oxynaphthoic acid metal complex, E- of salicylic acid metal complex 84, E-89 of phenol-based condensate (above, manufactured by Orient Chemical Industries), TP-302, TP-415 of quaternary ammonium salt molybdenum complex, TN-105 of zirconium compound (above, manufactured by Hodogaya Chemical Co., Ltd.) ) Quaternary ammonium salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, boron complex LR-147 (manufactured by Nippon Carlit), copper phthalosis Examples include anine, perylene, quinacridone, azo pigments, and other polymer compounds having a sulfonic acid group, a carboxyl group, a quaternary ammonium salt, and the like. Among them, a crystalline compound that is easy to be crushed into fine particles of 1 μm by stress or the like is preferable. These charge control agents may be added in advance to the toner base particles containing a colorant for chargeability reinforcement. The addition amount of the charge control agent that is agitated with the toner base particles containing the colorant is preferably 0.01 to 2 parts by weight, and more preferably 0.000 parts by weight with respect to 100 parts by weight of the toner base particles. 05 to 1 part by weight, particularly preferably 0.1 to 0.5 part by weight.

In the present invention, inorganic fine particles are preferably used as an external additive for assisting fluidity, developability and chargeability of the toner. In particular, hydrophobic silica and / or hydrophobic titanium oxide are preferred. The average primary particle diameter of the inorganic fine particles is preferably 5 nm to 2 μm, more preferably 5 to 500 nm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5% by weight of the toner, and more preferably 0.01 to 2.0% by weight.

  Specific examples of other inorganic fine particles include, for example, alumina, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, Examples thereof include chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

  In addition, polymer fine particles, for example, polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, dispersion polymerization, methacrylate ester, acrylate copolymer, polycondensation resin such as silicone, benzoguanamine, nylon, heat Examples thereof include polymer particles made of a curable resin.

  Such an external additive can be surface-treated to increase hydrophobicity, thereby preventing flow characteristics and charging characteristics from being deteriorated even under high humidity. Examples of the surface treatment agent include a silane coupling agent, a silylating agent, a silane coupling agent having a fluorinated alkyl group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and modified silicone oil. Is mentioned.

  In order to facilitate removal of the developer after transfer remaining on the latent image carrier or the intermediate transfer member, a cleaning property improving agent can be used as an external additive. Examples of the cleaning improver include fatty acid metal salts such as zinc stearate, calcium stearate and stearic acid; polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles. The fine polymer particles preferably have a narrow particle size distribution and an average particle size of 0.01 to 1 μm.

  In the present invention, a polyester resin is preferably used as the binder resin for the toner. As the polyester resin, as the diol component, the general formula (1)

（式中、Ｒ^１は、炭素数２〜４のアルキレン基であり、ｘ及びｙは、正の整数であり、その和の平均値は、２〜１６である。）
で示される化合物と、２価以上の多価カルボン酸、その無水物及びその低級アルキルエステルからなる群から選択される酸成分として、一般式（２）又は（３）

(In the formula, R ¹ is an alkylene group having 2 to 4 carbon atoms, x and y are positive integers, and the average value of the sum is 2 to 16).
As an acid component selected from the group consisting of a compound represented by the formula: a divalent or higher polyvalent carboxylic acid, an anhydride thereof and a lower alkyl ester thereof, the compound represented by the general formula (2) or (3)

（式中、Ｒ^２及びＲ^３は、それぞれ独立に、炭素数４〜２０の飽和又は不飽和の炭化水素基である。）
で示される化合物若しくはその無水物を含有する酸成分又はトリメリット酸若しくはその無水物を含有する酸成分を縮合重合して得られるものが好ましい。また、この他に、酸成分としては、フタル酸、イソフタル酸、テレフタル酸、マレイン酸、フマル酸、それらの無水物、それらの低級アルキルエステル等が使用できる。また、一般式（２）又は（３）で示される化合物としては、ｎ−ドデセニルコハク酸、ｎ−ドデシルコハク酸、ｎ−ブチルコハク酸、イソドデセニルコハク酸、イソオクチルコハク酸等のコハク酸の誘導体が挙げられる。これにより、低温時の画像定着性が十分で、発色性及び光沢も良好なトナーが得られる。また、一般式（１）で示されるジオールとしては、ポリオキシプロピレン（２，２）−２，２−ビス（４−ヒドロキシフェニル）プロパン、ポリオキシエステル（２）−２，２−ビス（４−ヒドロキシルフェニル）プロパン、ポリオキシプロピレン（６）−２，２−ビス（４−ヒドロキシフェニル）プロパン、ポリオキシプロピレン（６）−２，２−ビス（４−ヒドロキシフェニル）プロパン等が挙げられる。

(In the formula, R ² and R ³ are each independently a saturated or unsaturated hydrocarbon group having 4 to 20 carbon atoms.)
Those obtained by condensation polymerization of an acid component containing a compound represented by the formula (1) or an anhydride thereof or trimellitic acid or an acid component containing an anhydride thereof are preferred. In addition, as the acid component, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, anhydrides thereof, lower alkyl esters thereof and the like can be used. Examples of the compound represented by the general formula (2) or (3) include succinic acids such as n-dodecenyl succinic acid, n-dodecyl succinic acid, n-butyl succinic acid, isododecenyl succinic acid, isooctyl succinic acid, and the like. Derivatives. As a result, a toner having sufficient image fixability at low temperatures and good color developability and gloss can be obtained. Examples of the diol represented by the general formula (1) include polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyester (2) -2,2-bis (4 -Hydroxylphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane and the like.

  Further, a polyol resin can be used as the toner binder resin. Various types of polyol resins can be used, and compounds having an epoxy group, a dihydric phenol alkylene oxide adduct or its glycidyl ether, and one active hydrogen that reacts with the epoxy group in the molecule. And a polyol formed by reacting a compound having two or more active hydrogens in the molecule that react with an epoxy group. Furthermore, the compound having an epoxy group is preferably at least two bisphenol A type epoxy resins having different number average molecular weights. Such a polyol resin provides good image gloss and transparency, and has an effect of improving offset resistance if it is roller-fixed.

  The epoxy resin is preferably obtained by reacting bisphenol such as bisphenol A and bisphenol F with epichlorohydrin. The epoxy resin is at least two or more types of bisphenol A type epoxy resins having different number average molecular weights in order to obtain stable fixing characteristics, the number average molecular weight of the low molecular weight component is 360 to 2000, and the number of high molecular weight components. The average molecular weight is preferably 3000 to 10,000. Further, the low molecular weight component is preferably 20 to 50% by weight and the high molecular weight component is preferably 5 to 40% by weight. When the amount of the low molecular weight component is more than 50% by weight and when the number average molecular weight of the low molecular weight component is smaller than 360, the gloss may be excessively increased or the storage stability may be deteriorated. Further, when the high molecular weight component is more than 40% by weight and when the number average molecular weight of the high molecular weight component is larger than 10,000, the image gloss may be insufficient or the fixability may be deteriorated.

  Examples of the divalent phenol alkylene oxide adduct include reaction products of ethylene oxide, propylene oxide, butylene oxide and mixtures thereof, and bisphenols such as bisphenol A and bisphenol F. The obtained adduct may be used after glycidylation with epichlorohydrin or β-methylepichlorohydrin. Among them, general formula (4)

（式中、Ｒ^４は、炭素数２〜４のアルキレン基であり、ｎ及びｍは、１以上であり、その和は、２〜６である。）
で表わされる化合物が好ましい。

(In the formula, R ⁴ is an alkylene group having 2 to 4 carbon atoms, n and m are 1 or more, and the sum is 2 to 6).
The compound represented by these is preferable.

  Further, the content of the dihydric phenol alkylene oxide adduct or its glycidyl ether in the polyol resin is preferably 10 to 40% by weight. When this content is less than 10% by weight, problems such as an increase in curl occur, and when this content exceeds 40% by weight and when the sum of n and m exceeds 6, gloss may be excessively high. , Storage stability may decrease.

  Examples of the compound having one active hydrogen that reacts with an epoxy group in the molecule include phenols, secondary amines, and carboxylic acids. Examples of phenols include phenol, cresol, isopropylphenol, aminophenol, nonylphenol, dodecylphenol, xylene, p-cumylphenol, and the like. Secondary amines include diethylamine, dipropylamine, dibutylamine, N-methyl (ethyl) piperazine and the like. Moreover, propionic acid etc. are mentioned as carboxylic acid.

  In the present invention, various raw materials can be combined to obtain a polyol resin having an epoxy resin portion and an alkylene oxide portion in the main chain. For example, it can be obtained by reacting an epoxy resin having a glycidyl group at both ends and an alkylene oxide adduct of a dihydric phenol having both glycidyl groups with dihydride, diisocyanate, diamine, dithiol, polyhydric phenol, or dicarboxylic acid. Of these, the reaction with dihydric phenol is most preferable from the viewpoint of reaction stability. Moreover, it is also preferable to use polyhydric phenols and polyhydric carboxylic acids in combination with dihydric phenols as long as they do not gel. Here, the addition amount of polyhydric phenols and polyhydric carboxylic acids is usually 15% by weight or less, preferably 10% by weight or less, based on the total amount of the reaction product. Examples of polyhydric phenols include tris (4-hydroxyphenyl) methane and 1- [α-methyl-α- (4-hydroxyphenyl) ethyl] benzene. Examples of the polyvalent carboxylic acids include malonic acid, succinic acid, glutaric acid, adipic acid, terephthalic acid, trimellitic acid, and trimellitic anhydride.

  These polyester resins and polyol resins are preferably non-crosslinked or weakly crosslinked (THF insoluble content of 5% by weight or less) because it is difficult to obtain transparency and gloss when the crosslinking density is increased.

  In the present invention, other resins may be used in combination as the binder resin in order to improve fluidity, filming on the latent image carrier, pulverization property, storage stability, chargeability and the like. For example, styrene such as polystyrene, poly (p-chlorostyrene), polyvinyltoluene, and the like, and its substituted polymer; styrene / p-chlorostyrene copolymer, styrene / propylene copolymer, styrene / vinyltoluene copolymer Styrene / vinyl naphthalene copolymer, styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer, styrene / methyl methacrylate Copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene / α-chloromethyl methacrylate copolymer, styrene / acrylonitrile copolymer, styrene / vinyl methyl ketone copolymer, Styrene / butadiene copolymer, styrene / Styrene copolymers such as soprene copolymers and styrene / maleic acid copolymers; acrylate homopolymers such as polymethyl acrylate, polybutyl acrylate, polymethyl methacrylate, polybutyl methacrylate, and the like Copolymers; Polyvinyl derivatives such as polyvinyl chloride and polyvinyl acetate; polyurethane polymers, polyamide polymers, polyimide polymers, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, etc. These can be used alone or in combination, but are not particularly limited thereto.

  As a method for producing the toner of the present invention, a constituent material of the toner is melt-kneaded, pulverized and classified, and spheroidized, and a radical polymerizable monomer containing a colorant and a chain transfer agent in an aqueous medium. A method for suspension polymerization of the composition, a radically polymerizable monomer composition containing a chain transfer agent is emulsion-polymerized or emulsion-polymerized in a water-based medium using a water-soluble polymerization initiator, and the resulting resin particles are water-based. Examples include a method of fusing in a medium, in particular, an organic solvent from a dispersion in which fine droplet particles containing at least an organic solvent, a binder resin, and a colorant are dispersed in an aqueous medium containing resin fine particles. A toner obtained by removing the toner is preferable. Further, a prepolymer comprising an isocyanate group-containing polyester resin in an organic solvent, a compound that elongates or crosslinks with the prepolymer, and a toner component are dissolved or dispersed, and the resulting solution or dispersion is subjected to a crosslinking reaction in an aqueous medium. In addition, there is a method of obtaining a toner by performing an elongation reaction and removing a solvent from the obtained dispersion. A polyester-based prepolymer containing an isocyanate group can be obtained by further reacting a polyester having an active hydrogen group with a polycondensate of a polyol (PO) and a polycarboxylic acid (PC) with a polyisocyanate (PIC). . In this case, examples of the active hydrogen group of the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

  The particle size distribution and average particle size of the toner can be measured as follows.

Measuring machine: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 100 μm
Electrolyte: Isoton II (Beckman Coulter, Inc.)
Dispersion: 5% electrolyte solution of HLB 13.6 polyoxyethylene lauryl ether Emulgen 109P (manufactured by Kao Corporation) Dispersion condition: Place 5 ml of the dispersion in a 100 ml beaker, and add 10 mg of the measurement sample to it. And after making it disperse | distribute for 1 minute with an ultrasonic disperser, 25 ml of electrolyte solution is added and it is made to disperse | distribute for another 1 minute with an ultrasonic disperser.

  Measurement conditions: 70 ml of electrolyte solution is put into a 100 ml beaker. Then, a liquid in which the sample is dispersed is added. As a concentration condition for adding the dispersion liquid, an amount of the dispersion liquid that can measure 30,000 particles in 20 seconds is added. The particle size of the particles is measured for 20 seconds to determine the particle size distribution. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter of the toner can be obtained.

  As a channel, it is 2.00 micrometers or more and less than 2.52 micrometers; 2.52 micrometers or more and less than 3.17 micrometers; 3.17 micrometers or more and less than 4.00 micrometers; 4.00 micrometers or more and less than 5.04 micrometers; 5.04 micrometers or more and less than 6.35 micrometers; .35 μm or more and less than 8.00 μm; 8.00 μm or more and less than 10.08 μm; 10.08 μm or more and less than 12.70 μm; 12.70 μm or more and less than 16.00 μm; 16.00 μm or more and less than 20.20 μm; Less than 40 μm; 25.40 μm or more and less than 32.00 μm; 3 channels of 32.00 μm or more and less than 40.30 μm are used, and particles having a particle size of 2.00 μm or more and less than 40.30 μm are targeted.

  In the present invention, the charge amount (Q / M) can be measured using a blow-off method. The outline is that a two-component developer consisting of a toner and a carrier is put in a cage made of a metal cylinder with a metal mesh on both sides of the cylinder, and the metal cylinder cage is set horizontally in the Faraday cage. A compressed gas is blown from the other end or both ends of the metal cylindrical cage to separate the toner and the carrier. For the mesh opening of the metal mesh, the size of the opening through which the toner passes but the carrier cannot pass is selected. The charged toner passes through the mesh of the metal mesh and is blown out of the cage, but the carrier remains in the cage. The carrier in the cage retains a charge Q of the opposite polarity in the same amount as the charged toner is carried away, and charges a capacitor of capacitance C connected to the cage. The voltage V across the capacitor is measured, and the charge (Q) is obtained from the following equation.

Charge (Q) = Capacitance (C) × Voltage (V)
Further, the charge amount (Q / M) is obtained using the developer amount (M). The cage made of a metal cylinder containing the two-component developer is completely insulated by another grounded metal cylinder. A TB-200 model (manufactured by Toshiba Chemical Co., Ltd.) can be used as a measuring device.

  A method for measuring the charge amount (CT) of the carrier will be described. The measurement environment is 24 ° C. and 55% RH. First, the toner is coated so that the coverage of the carrier is 46% and the total amount of the toner and the carrier is 1000 g and is put in a 2 L stainless steel container. Next, the toner and the carrier are left for 2 hours in order to adapt to the environment of 24 ° C. and 55% RH. After leaving for 2 hours, mixing is performed at 96 rpm for 10 minutes using a tumbler shaker mixer T2F type (manufactured by Shinmaru Enterprises). The charge amount (CT) of the mixed developer is measured by a blow-off method. As a measuring device, a TB-200 model (manufactured by Toshiba Chemical Co., Ltd.) is used, and a 500 mesh wire mesh (which can be appropriately changed to a size that does not allow carrier particles to pass through) is used. Detailed measurement conditions are shown below.

Blow gas: Nitrogen Blow pressure: 1 kg / cm ²
Blow time: 40 seconds Measured developer amount: 0.3 g
Next, the carrier used in the present invention will be described. The functions of the carrier are the following two, and one is a function of conveying the toner to the developing region by agitation in the developing device and a function of charging the toner by agitation.

  In the present invention, the carrier is reduced iron powder, Ni—Zn ferrite, Cu—Zn ferrite, Ba ferrite, Sr ferrite, Zn—Fe ferrite, Mn—Zn—Fe ferrite, Mn—Mg—Fe ferrite, Ca—Mn—. It is preferable to have approximately spherical core material particles having an average particle diameter of 20 to 65 μm made of Fe ferrite, Ca—Mg—Fe ferrite, Li—Fe ferrite, magnetite or the like. When the average particle size is smaller than 20 μm, the carrier may aggregate or scatter. When the average particle size is larger than 65 μm, the toner transportability becomes non-uniform or the carrier spikes during development become rough. Therefore, the uniformity of solid and halftone may be inferior.

  Moreover, it is preferable that the surface of core material particle is coat | covered with resin. Although it does not specifically limit as coating resin, An acrylic resin, a silicone resin, and / or a fluororesin are preferable. When these core material particles are used, these resins can strongly convey the toner and exert a strong effect of uniformly charging the toner. Acrylic resin has excellent adhesion properties and low brittleness, so it has very good wear resistance, but on the other hand, because of its high surface energy, the spent (the toner melts on the surface of the carrier, In the case of a combination with a toner that tends to be fused), problems such as a decrease in charge amount due to accumulation of toner spent may occur. In that case, since the surface energy is low, the spent of the toner is less likely to occur, and the silicone resin and / or the fluororesin, which can effectively prevent the accumulation of spent components due to film abrasion, can be used in combination. Can be resolved. However, since the silicone resin and the fluororesin are weak in adhesiveness and high in brittleness, it also has a weak point that the abrasion resistance is bad. Therefore, it is important to obtain the properties of these two resins in a balanced manner. Thus, it is possible to obtain a coating film that is difficult to spend and that also has wear resistance. Specifically, when the content of the acrylic resin in the coating film made of an acrylic resin, a silicone resin and / or a fluororesin is 10 to 90% by weight, the effect is remarkably obtained. When the content of the acrylic resin is less than 10% by weight, most of the coating layer is occupied by the silicone resin and / or the fluororesin, so that the wear resistance deteriorates due to the high brittleness of the silicone resin and / or the fluororesin. Sometimes. On the other hand, when the ratio of the acrylic resin exceeds 90% by weight, since most of the coating layer is occupied by the acrylic resin component, the toner component spent accumulates due to the high surface energy of the acrylic resin and the difficulty of film scraping. May occur.

  The acrylic resin refers to all resins having an acrylic component and is not particularly limited. In addition, it is possible to use the acrylic resin alone, but it is also possible to use at least one component that undergoes a crosslinking reaction at the same time. Examples of other components that undergo a crosslinking reaction include amino resins and acidic catalysts, but are not limited thereto. Examples of amino resins include, but are not limited to, guanamine and melamine resins. Moreover, as an acidic catalyst, all having a catalytic action can be used. Examples include, but are not limited to, those having reactive groups such as a fully alkylated type, a methylol group type, an imino group type, and a methylol / imino group type.

  Silicone resin refers to all commonly known silicone resins, including straight silicone consisting only of organosiloxane bonds, and silicone resins modified with alkyd resins, polyesters, epoxy resins, acrylic resins, urethanes, etc. However, it is not limited to this. Examples of commercially available straight silicone resins include KR271, KR255, KR152 (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2400, SR2406, SR2410 (manufactured by Toray Dow Corning). In this case, it is possible to use the silicone resin alone, but it is also possible to simultaneously use a component that undergoes a crosslinking reaction, a component that adjusts the charge amount, and the like. Further, as modified silicone resins, KR206 (alkyd modified), KR5208 (acryl modified), ES1001N (epoxy modified), KR305 (urethane modified) (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2115 (epoxy modified), SR2110 (alkyd) Modification) (above, manufactured by Toray Dow Corning).

  Examples of fluororesins include vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene copolymer, perfluoroalkyl vinyl ether-vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride polymer, Tetrafluoroethylene copolymer, polymer containing vinyl ether substituted with fluorine atom, polymer containing vinyl ketone substituted with fluorine atom, fluorinated alkyl acrylate polymer or fluorinated alkyl methacrylate polymer, etc. Is mentioned.

  In the present invention, the coating resin may have fine particles dispersed therein. The fine particles are preferably alumina or surface-treated alumina in terms of charging of the negatively chargeable toner.

  The reason why the fine particles are dispersed in the coating resin of the carrier includes an effect of protecting the coating layer from an external force applied to the carrier surface. If the particles are easily crushed or worn by this external force, the effect of protecting the coating layer can be initially obtained, but cannot be maintained over a long period of time, and stable quality can be obtained. This is not preferable. Since the fine particles listed here have tough properties, they are strong against external forces, are not easily cracked, and can maintain the effect of protecting the coating layer over a long period of time. The average particle size of the fine particles is preferably 5 μm or less, and the fine particles in the coating layer are preferably present in the acrylic resin. The reason is that fine particles can be held for a long time due to the strong adhesiveness of the acrylic resin, but it is not necessarily required to be present in the acrylic resin.

  It is also effective to contain carbon black in the coating resin as necessary. The effect is remarkable, and in the case of a coating layer composed of only the coating resin or the coating resin and fine particles, when the resistance is high, it can be used as a regulator for reducing the resistance. In general, when a carrier having high resistance is used as a component of a developer, an edge effect (so-called image density in the central portion is very thin and only the edge portion is expressed deeply on the image surface of a copy image having a large area). The effect). Further, when the image is a character or a thin line, the image is clear due to the edge effect. However, when the image is halftone, there is a disadvantage that the image is very poorly reproducible. Therefore, an excellent image can be obtained by appropriately using carbon black. Furthermore, it can also be used for a color carrier.

  In the case of a carrier for a color developer, a shaved coating layer is mixed in the image, and if the coating layer has a dark color because it contains carbon black, it becomes a defective image because it clearly stands out in the image, In the present invention, the coating resin has an acrylic resin, and as described above, the acrylic resin has a property of being highly adhesive and difficult to scrape. Since it is difficult to scrape itself, the carbon black is hardly detached from the carrier. In particular, the effect of avoiding a defect image becomes significant by dispersing carbon black in an acrylic resin. And in a coating layer, the effect of avoiding a defect image becomes remarkable by forming the acrylic resin layer which disperse | distributed carbon black in the lower layer, and forming the silicone resin layer which does not contain carbon black in the upper layer.

  As carbon black, those generally used for carriers or toners can be used. In the case of a highly brittle and easily scraped resin such as a silicone resin, if carbon black is included in the coating resin, a scraped black coating layer will appear in the image, which may result in a defective image. It is not preferable.

  In the present invention, a coupling agent may be added to the coating layer. Addition of the coupling agent improves the adhesion between the core material particles and the coating layer, and the coating layer is less likely to be peeled off even when the developing part is stirred. In addition, the charge amount can be adjusted. For example, under high temperature and high humidity conditions, it is difficult to charge due to the influence of moisture, but a good charge amount can be secured by adding a coupling agent.

  As the coupling agent, SH6020 (γ- (2-aminoethyl) aminopropyltrimethoxysilane), SZ6023 (γ- (2-aminoethyl) aminopropylmethyldimethoxysilane), SH6026 (aminosilane), SZ6030 (γ-methacrylic acid) were used. Roxypropyltrimethoxysilane), SZ6032 (hydrochloride of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane), SZ6050 (aminosilane), SZ6040 (γ-glycidoxypropyltrimethoxysilane) ), SH6062 (γ-mercaptopropyltrimethoxysilane), SZ6070 (methyltrimethoxysilane), SZ6072 (methyltriethoxysilane), SZ6075 (vinyltriacetoxysilane), SZ6076 (γ-chloro) Ropropyltrimethoxysilane), SZ6079 (hexamethyldisilazane), SZ6083 (γ-anilinopropyltrimethoxysilane) (above, manufactured by Toray Dow Corning), KA1003 (vinylchlorosilane), KBC1003 (vinyltris (β-methoxy) Ethoxy) silane), KBM1003 (vinyltrimethoxysilane), KBE1003 (vinyltriethoxysilane), KBM503 (γ-methacryloyloxypropyltrimethoxysilane), KBM303 (β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane) , KBM403 (γ-glycidoxypropyltrimethoxysilane), KBM402 (γ-glycidoxypropylmethylethoxysilane), KBM603 (N-β-aminoethyl-γ-aminopropyl) Trimethoxysilane), KBM602 (N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane), KBM903 (γ-aminopropyltriethoxysilane), KBM803 (γ-mercaptopropyltrimethoxysilane), KBM573 (N-phenyl) Silane coupling agents such as -γ-aminopropyltrimethoxysilane) and KBM703 (γ-chloropropyltrimethoxysilane) (manufactured by Shin-Etsu Chemical Co., Ltd.), aluminum coupling agents, titanium coupling agents and the like are used. be able to.

A method for measuring the particle size of the carrier will be described. The weight average particle diameter (Dw) based on the particle size distribution of the relationship between the particle number frequency and the particle diameter measured on the basis of the number is calculated. The weight average particle diameter (Dw) is expressed by the formula: weight average particle diameter (Dw) = (ΣnD ⁴ / ΣnD ³ )
D is the representative particle size (μm) of particles present in each channel
n is obtained from the total number of particles present in each channel. The channel represents a length for equally dividing the particle size range in the particle size distribution diagram. As a particle size analyzer for measuring the particle size distribution, a Microtrac particle size analyzer model HRA 9320-X100 (manufactured by Honeywell) can be used. Specifically, the particle size is measured in the range of 8 to 100 μm, the channel length (width) is 2 μm, and the refractive index is 2.42.

A method for measuring the volume resistivity of the carrier will be described. From an insulating container provided with two electrode plates having an area of 10 cm ² (length: 4.0 cm, width: 2.5 cm) in an environment of 20 ° C. and 60% RH, with the electrode plates facing each other at an interval of 2 mm Prepare a cell. The sample to be measured is put into the cell so as to overflow within the interval of 2 mm. The cell in this state is dropped 30 times from the position of 15 mm onto the flat plate, and the operation of tapping the sample on the cell is repeated 30 times, and the sample to be measured is filled in the cell. The excess sample on the cell is then removed with a brush. A voltage corresponding to a DC electric field of 500 V / cm is applied between the two electrodes, and the DC resistance is measured with a high resistance meter 4329A (manufactured by Yokogawa Hewlett-Packard Company). The volume resistivity is obtained from the following equation.

Volume resistivity [Ω · cm] = DC resistance [Ω] × 10 [cm ² ] /0.2 [cm]
The image forming method of the present invention forms an image using the developer of the present invention. At this time, a step of charging each of the plurality of latent image carriers, a step of exposing each of the charged latent image carriers to form an electrostatic latent image, and a step of forming each of the electrostatic latent images. Developing the latent image carrier with the developer to form a toner image, transferring the toner image formed on each latent image carrier to the transfer target, and the toner image transferred to the transfer target It is preferable to have the process of fixing.

  The image forming apparatus of the present invention forms an image using the image forming method of the present invention. FIG. 1 shows a schematic configuration of a tandem color laser printer that directly transfers a toner image onto paper as an example of the image forming apparatus of the present invention.

  In this laser printer, a paper feeding unit (paper feeding cassettes 3 and 4) is provided at the bottom of the apparatus main body, an image forming unit is arranged above the paper feeding unit, and a paper discharge unit (paper discharge tray 8) is arranged on the upper surface of the apparatus. It has a configuration. As indicated by the broken line in the drawing, the recording paper is transported from the paper feeding unit, the image formed by the image forming unit is transferred onto the paper, fixed by the fixing unit 7, and discharged from the paper discharge tray 8. Paper is discharged.

  In the image forming unit, a transfer unit 6 is disposed so as to be inclined so that the paper feed side is on the bottom and the paper discharge side is on the top. Four image forming units 1M, 1C, and 1Y for magenta (M), cyan (C), yellow (Y), and black (K) in order from the bottom along the upper traveling side of the transfer conveyance belt 50 of the transfer unit. , 1K are arranged side by side. Each of the image forming units 1M, 1C, 1Y, and 1K includes photosensitive drums 11M, 11C, 11Y, and 11K as image carriers and a developing unit. Further, the arrangement of the image forming units is set so that the rotation axes of the photosensitive drums are parallel to each other and arranged at a predetermined pitch in the transfer paper moving direction.

  In addition, the laser printer includes an optical writing unit 2, a registration roller pair 5, a manual feed tray MF, a toner supply container TC, and the like. The optical writing unit 2 includes a light source, a polygon mirror, an f-θ lens, a reflection mirror, and the like, and irradiates the surface of each of the photosensitive drums 11M, 11C, 11Y, and 11K while scanning the laser beam based on the image data. To do.

  The transfer conveyance belt 50 used in the transfer unit 6 is a high-resistance endless single-layer belt having a volume resistivity of 109 to 1011 Ωcm, and the material thereof is PVDF (polyvinylidene fluoride). As the material of the belt, other materials such as PI (polyimide) that is resistant to elongation can be used. The transfer conveyance belt 50 is wound around support rollers 61 to 68 so as to pass through the transfer positions that are in contact with and face the photosensitive drums 11M, 11C, 11Y, and 11K of each image forming unit.

  Among these support rollers, the entrance roller 61 on the upstream side in the transfer paper moving direction is disposed on the outer peripheral surface of the transfer conveyance belt 50 so that the electrostatic adsorption roller 80 to which a predetermined voltage is applied from the power source 80a is opposed. Yes. The transfer paper that has passed between the two rollers 61 and 80 is electrostatically attracted onto the transfer conveyance belt 50. The roller 63 is a driving roller that frictionally drives the transfer conveyance belt 50, and is connected to a driving source (not shown) and rotates in the direction of the arrow.

  Transfer bias applying members 67M, 67C, 67Y, and 67K are provided as transfer electric field forming means for forming a transfer electric field at each transfer position so as to be in contact with the back surface of the transfer conveyance belt 50 at a position facing the photosensitive drum. ing. These are bias rollers provided with a sponge or the like on the outer periphery, and a transfer bias is applied to the roller mandrel from each transfer bias power source 9M, 9C, 9Y, 9K. Due to the action of the applied transfer bias, a transfer charge is applied to the transfer conveyance belt 50, and a transfer electric field having a predetermined strength is formed between the transfer conveyance belt 50 and the surface of the photosensitive drum at each transfer position. In addition, a backup roller 68 is provided to keep the contact between the transfer paper and the photoconductor in the area where the transfer is performed, and to obtain the best transfer nip.

  The transfer bias applying members 67M, 67C, 67Y and the backup roller 68 disposed in the vicinity thereof rotate in the counterclockwise direction by rotating in the direction of the arrow in a rotatable manner.

  The entrance roller 61 and the suction roller 80 rotate together in an integrated manner.

  The bias applying members 67M, 67C, and 67Y and the backup roller 68 disposed in the vicinity thereof are separated from the photoreceptors 11M, 11C, and 11Y, and the entrance roller 61 and the suction roller 80 also move downward. It is possible to avoid contact between the photoconductors 11M, 11C, and 11Y and the transfer conveyance belt 50 when forming a black-only image. That is, in this example, in the case of color printing, the transfer conveyance belt 50 is held in contact with the four color image forming units 1M, 1C, 1Y, and 1K (photosensitive drums thereof), and in the case of black monochrome printing, the printing is performed. The state in which the transfer conveyance belt 50 is in contact with only the image unit 1K (the photosensitive drum) is maintained.

  A cleaning device 85 composed of a brush roller and a cleaning blade is disposed on the outer peripheral surface of the transfer / conveying belt 50 wound around the driving roller 63. The cleaning device 85 removes foreign matters such as toner adhering to the transfer / conveying belt 50.

  A roller 64 is provided downstream of the drive roller 63 in the traveling direction of the transfer / conveyance belt 50 in a direction to push the outer peripheral surface of the transfer / conveyance belt, and a winding angle around the drive roller 63 is secured. A tension roller 65 that applies tension to the belt by a spring 69 that is a pressing member is provided in the loop of the transfer conveyance belt 60 further downstream from the roller 64.

  In FIG. 1, the conveyance path of the transfer paper 100 is indicated by a one-dot chain line. The transfer paper 100 fed from the paper feed cassettes 3 and 4 or the manual feed tray MF is transported by transport rollers while being guided by a transport guide (not shown), and is transported to a temporary stop position where the registration roller pair 5 is provided. The transfer paper 100 delivered at a predetermined timing by the registration roller pair 5 is carried on the transfer conveyance belt 50, conveyed toward the image forming units 1M, 1C, 1Y, and 1K, and passes through the transfer nips.

  The toner images developed on the photosensitive drums 11M, 11C, 11Y, and 11K of the image forming units 1M, 1C, 1Y, and 1K are superimposed on the transfer paper 100 at the respective transfer nips, and the transfer electric field and the nip pressure described above. Is transferred onto the transfer paper 100 in response to the above action. By this superposition transfer, a full-color toner image is formed on the transfer paper 100. The surfaces of the photoconductive drums 11M, 11C, 11Y, and 11K after the toner image transfer are cleaned by a cleaning device, and further discharged to prepare for the formation of the next electrostatic latent image.

  On the other hand, the transfer paper 100 on which the full-color toner image is formed is fixed in the first paper discharge direction B in accordance with the rotation posture of the switching guide G after the full-color toner image is fixed on the paper by the fixing unit 7. Or, it goes in the second paper discharge direction C. When the paper is discharged from the first paper discharge direction B onto the paper discharge tray 8, it is stacked in a so-called face-down state with the image surface down. On the other hand, when the paper is discharged in the second paper discharge direction C, it is transported to a post-processing device such as another sorter and binding device (not shown), or again for double-sided printing via a switchback portion (not shown). It is conveyed to the registration roller pair 5.

  The process cartridge of the present invention at least integrally supports the developing means for developing with the developer of the present invention and the latent image carrier, and is detachable from the image forming apparatus main body. The process cartridge may further support means such as charging means and cleaning means.

Hereinafter, the present invention will be described in more detail with reference to production examples and examples, but the present invention is not limited to these examples. In addition, the part in an Example means a weight part unless there is particular notice.
(1) Manufacture of masterbatch pigment 1, manufacture of yellow toner masterbatch Binder resin 50 parts Polyester resin (Propylene oxide adduct of bisphenol A terephthalic acid, polyester synthesized from succinic acid derivative)
Colorant 50 parts Imidazolone yellow pigment (CI Pigment yellow 180)
30 parts of water The above raw materials were mixed in a Henschel mixer and then kneaded for 45 minutes with two rolls set at a roll surface temperature of 130 ° C. to obtain a yellow masterbatch pigment.
2. Manufacture of magenta toner masterbatch Binder resin 50 parts Polyester resin (Propylene oxide adduct of bisphenol A, polyester synthesized from terephthalic acid and succinic acid derivative)
Colorant 50 parts Quinacridone magenta pigment (CI Pigment Red122)
30 parts of water The above raw materials were mixed in a Henschel mixer and then kneaded for 45 minutes with two rolls set at a roll surface temperature of 130 ° C. to obtain a magenta master batch pigment.
3. Manufacture of cyan toner masterbatch Binder resin 50 parts Polyester resin (Propylene oxide adduct of bisphenol A, polyester synthesized from terephthalic acid and succinic acid derivative)
Colorant 50 parts Copper phthalocyanine cyan pigment (CI Pigment Blue 15: 3)
30 parts of water The above raw materials were mixed in a Henschel mixer and then kneaded for 45 minutes with two rolls set at a roll surface temperature of 130 ° C. to obtain a cyan master batch pigment.
4. Production of black toner masterbatch Binder 50 parts Polyester resin (Propylene oxide adduct of bisphenol A, polyester synthesized from terephthalic acid and succinic acid derivative)
Colorant 50 parts Carbon black pigment # 44 (Mitsubishi Chemical Corporation)
30 parts of water The above raw materials were mixed in a Henschel mixer and then kneaded for 45 minutes with two rolls set at a roll surface temperature of 130 ° C. to obtain a black masterbatch pigment.
(2) Production of Toner Yellow, magenta, cyan and black toners were prepared for each master batch pigment (yellow, magenta, cyan and black) according to the following formulation.

Binder resin 100 parts Polyester resin (Propylene oxide adduct of bisphenol A, polyester synthesized from terephthalic acid, succinic acid derivative)
Master batch pigment 12 parts Mold release agent (carnauba wax) 5 parts Charge control agent (salicylic acid derivative zinc salt) 2.5 parts The above raw materials are mixed in a Henschel mixer and then melted in a twin-screw kneader set at 110 ° C. Kneaded. The kneaded product was cooled with water, coarsely pulverized with a cutter mill, and pulverized with a fine pulverizer using a jet stream. Next, by using a wind classifier, mother particles of yellow, magenta, cyan, and black toner having a weight average particle diameter (D4) of 6.0 μm were prepared.

With respect to 100 parts by weight of the base particles of the toner of each color, 1.3 parts of silica fine powder having an average particle diameter of 12 nm treated with hexamethyldisilazane and an average particle diameter treated with isobutyltrimethoxysilane on the surface A ratio of 0.7 parts of 15 nm fine titanium powder and 0.6 parts of silica fine powder having an average particle size of 120 nm whose surface was treated with hexamethyldisilazane was mixed at a peripheral speed of 20 m / sec using a Henschel mixer. Thereafter, a negatively charged yellow, magenta, cyan and black toner was prepared by sieving.
(3) Manufacture of carrier The carrier prepared the coating liquid of the carriers 1-5 by changing the amount of silane coupling agents in the following prescription.

400 parts of a silicone resin SR2411 having a solid content of 20% by weight (manufactured by Dow Corning Toray) γ- (2-aminoethyl) aminopropyltrimethoxysilane (addition amount is listed in Table 1)
1200 parts of toluene Each of the above coating solutions was coated on 5 kg of ferrite core material particles having an average particle diameter of 35 μm using a rotating disk type fluidized bed coating apparatus. Thereafter, the coating was taken out from the apparatus and heated at 250 ° C. for 2 hours to age the coating layer.

  The carrier charge amount (CT) was measured for each of the carriers 1 to 5 in the environmental chamber at 24 ° C. and 55% RH using the black toner produced in the above (2) toner as the reference toner. The toner was weighed so that the total amount of toner and carrier was 1000 g at a toner concentration (7% by weight) with a covering ratio of 46% covering the carrier, and placed in a 2 L stainless steel container. The toner and carrier were left for 2 hours in order to adapt to the environment of 24 ° C. and 55% RH. After being left for 2 hours, it was mixed for 10 minutes with a tumbler shaker mixer. The charge amount (CT) of the mixed developer was measured by a blow-off method. The results are shown in Table 1.

次に、上記（２）トナーの製造のイエロー、マゼンタ、シアン及びブラックのトナーと、キャリア１（表１参照）を用いて、トナー濃度が５重量％になるようにトナーとキャリアの合計量が１０００ｇに計量して２Ｌのステンレス容器に入れて、ターブラーシェイカー・ミキサーで１０分間混合して現像剤を作製した。そして、１０℃、１５％ＲＨの環境でカラー複写機Ｉｍａｇｉｏ Ｎｅｏ Ｃ４５５（リコー社製）に、所定量の現像剤を各色の現像部にセットした。地汚れΔＩＤの測定は、ブラック現像部にセットした現像剤のみで行った。イエロー、マゼンタ及びシアンの現像剤は、セットして複写はするが、地汚れΔＩＤの評価は実施しない。帯電電圧を６２０Ｖ、現像バイアスを５００Ｖに設定して、画像面積率が５％のＡ４原稿で５０００枚の連続通紙テストを行った。そして、画像面積率が０．５％のＡ３原稿で画像出しを実施して、その際、画像形成途中でマシンの電源をＯＦＦにした。そして、潜像担持体を取り出して、潜像担持体の軸方向に３００ｍｍ、幅１０ｍｍのプリンタックテープ（日東社製）を貼った。次に、テープの上からガーゼを介して指で擦って、潜像担持体上のトナーをテープに移行させた。テープを潜像担持体上から剥がし、そのテープをＡ３用紙タイプ６０００（リコー社製）に貼った。この地肌部に相当する濃度は０．１１０であった。比較用のテープとして、潜像担持体に貼りつけていないテープをＡ３用紙タイプ６０００（リコー社製）に貼った。この濃度は０．１０４である。したがって、地汚れΔＩＤは、０．００６である。

Next, using (2) toner production yellow, magenta, cyan and black toner and carrier 1 (see Table 1), the total amount of toner and carrier is adjusted so that the toner concentration becomes 5% by weight. The developer was prepared by weighing 1000 g and putting it in a 2 L stainless steel container, and mixing for 10 minutes with a tumbler shaker mixer. Then, a predetermined amount of developer was set in the developing section of each color in a color copier Imagio Neo C455 (manufactured by Ricoh) in an environment of 10 ° C. and 15% RH. The background stain ΔID was measured only with the developer set in the black developing portion. The yellow, magenta and cyan developers are set and copied, but the background stain ΔID is not evaluated. A continuous sheet feeding test of 5000 sheets was performed with an A4 original having an image area ratio of 5% with a charging voltage set to 620 V and a developing bias set to 500 V. Then, an image was output with an A3 original having an image area ratio of 0.5%. At that time, the machine was turned off during image formation. Then, the latent image carrier was taken out, and a printerac tape (manufactured by Nitto Co., Ltd.) having a width of 300 mm and a width of 10 mm was attached in the axial direction of the latent image carrier. Next, the toner on the latent image carrier was transferred to the tape by rubbing with a finger through the gauze from above the tape. The tape was peeled off from the latent image carrier, and the tape was attached to A3 paper type 6000 (manufactured by Ricoh Company). The density corresponding to the background portion was 0.110. As a comparative tape, a tape not attached to the latent image carrier was attached to A3 paper type 6000 (manufactured by Ricoh). This concentration is 0.104. Therefore, the background stain ΔID is 0.006.

  Next, only the developer set in the black developing portion for which the background stain ΔID was evaluated was replenished with toner to make the developer having a toner concentration of 6.1% by weight. In the same manner as described above, the background stain ΔID was determined to be 0.016. Further, only the developer set in the black developing portion was replenished with toner, so that the developer had a toner concentration of 7.4% by weight. Similarly, the background stain ΔID was 0.026. The results are summarized as shown in FIG. From FIG. 2, the toner concentration (X) at which the background stain ΔID becomes 0.01 is determined to be 5.4% by weight. The coverage (C) at a toner concentration of 5.4% by weight was 35% from a weight average particle diameter of 35 μm of the carrier and a weight average particle diameter of 6.0 μm of the toner.

Similarly to the carrier 1, the toner concentration (X) and the coverage (C) of the carriers 2 to 5 were obtained. 3 and 4 show the relationship between the charge amount (CT) and the toner density (X) and the relationship between the charge amount (CT) and the coverage (C), respectively.
(Examples 1 to 3, Comparative Example 1)
The toner and carrier shown in Table 2 were produced in the same manner as in Examples (1) to (3), and a developer was produced using the toner and carrier. In Table 2, the carrier charge amount (CT) of the carriers 6 to 16 is measured at 24 ° C. using the black toner produced in the above (2) toner as a reference toner for each of the carriers 6 to 16. , And measured in an environmental room at 55% RH. The toner was weighed so that the total amount of toner and carrier was 1000 g at a toner concentration of 46% covering the carrier, and placed in a 2 L stainless steel container. The toner and carrier were left for 2 hours in order to adapt to the environment of 24 ° C. and 55% RH. After being left for 2 hours, it was mixed for 10 minutes with a tumbler shaker mixer. The mixed developer was measured for carrier charge (CT) by a blow-off method. The results are shown in Table 2. Next, the total amount of toner and carrier is weighed to 1000 g so that the toner concentration is 5% by weight for the yellow, magenta, cyan, and black toners and the carrier corresponding to each example and comparative example, and a 2 L stainless steel container And mixed with a tumbler shaker mixer for 10 minutes to produce a developer. Then, a predetermined amount of developer was set in the developing section of each color in a color copier Imagio Neo C455 (manufactured by Ricoh) in an environment of 10 ° C. and 15% RH. Next, as for the background stain ΔID, for each developer of yellow developer, magenta developer, cyan developer and black developer, the toner concentration of each color developer is gradually increased, as shown in FIG. And a toner density (X) in a state where the background stain ΔID is 0.01 was determined. Table 2 shows the obtained toner density (X) [wt%] and coverage (C) [%] results.

  In order to evaluate the developers of the examples and comparative examples, developers of respective colors corresponding to the toner density (X) were prepared. In the yellow developer of Example 1, since the toner concentration (X) is 6.2% by weight, the total amount of 1000 g of 62 g of yellow toner and 938 g of the carrier is weighed and placed in a 2 L stainless steel container. A developer was prepared by mixing for 10 minutes with a mixer. Thereafter, magenta, cyan and black developers were prepared in the same manner. A predetermined amount of each color developer was set in a color copier Imagio Neo C455 (manufactured by Ricoh). A continuous paper feeding test of 50,000 sheets was performed with an A4 original having an image area ratio of 5% with a charging voltage set to 620 V and a developing bias set to 500 V. As a result, in Comparative Example 1, the yellow developer had a low image density from the beginning. Further, the magenta developer, cyan developer and black developer had a lot of background stains and toner scattering, and the test was stopped after 1000 sheets. However, in Examples 1 to 3, the image density was high, and no scumming or toner scattering was observed.

（実施例４）
〜微粒子分散液の合成〜
撹拌棒および温度計をセットした反応容器に、水６８３部、メタクリル酸エチレンオキサイド付加物硫酸エステルのナトリウム塩エレミノールＲＳ−３０（三洋化成工業社製）１１部、スチレン８３部、メタクリル酸８３部、アクリル酸ブチル１１０部、過硫酸アンモニウム１部を仕込み、４００回転／分で１５分間撹拌したところ、白色の乳濁液が得られた。加熱して、系内温度７５℃まで昇温し、５時間反応させた。さらに、１％過硫酸アンモニウム水溶液３０部加え、７５℃で５時間熟成してビニル系樹脂（スチレン−メタクリル酸−アクリル酸ブチル−メタクリル酸エチレンオキサイド付加物硫酸エステルのナトリウム塩の共重合体）の水性分散液［微粒子分散液１］を得た。［微粒子分散液１］をＬＡ−９２０で測定した平均粒径は、１０５ｎｍであった。［微粒子分散液１］の一部を乾燥して樹脂分を単離した。該樹脂分のＴｇは５９℃であり、重量平均分子量は１５万であった。
〜水相の調製〜
水９９０部、［微粒子分散液１］９９部、ドデシルジフェニルェーテルジスルホン酸ナトリウムの４８．５重量％水溶液エレミノールＭＯＮ−７（三洋化成工業社製）３５部、酢酸エチル７０部を混合撹拌し、乳白色の液体を得た。これを［水相１］とする。
〜フッ素系活性剤水溶液の調整〜
Ｎ，Ｎ，Ｎ，−トリメチル−［３−（４−ペルフルオロノネニルオキシベンズアミド）プロピル］アンモニウムヨージド（製品名：フタージェント３１０；ネオス社製）１０部、メタノール２９７部を容器に入れ、５０℃に加熱し透明になるまで攪拌する。得られたフッ素系活性剤メタノール溶液を、攪拌しているイオン交換水６９３部に滴下し、滴下終了後５０℃で３０分攪拌して、［フッ素系活性剤水溶液１］を得た。
〜低分子ポリエステルの合成〜
冷却管、撹拌機および窒素導入管の付いた反応容器中に、ビスフェノールＡエチレンオキサイド２モル付加物２２９部、ビスフェノールＡプロピレンオキサイド３モル付加物５２９部、テレフタル酸２０８部、アジピン酸４６部およびジブチルスズオキサイド２部を入れ、常圧、２３０℃で８時間反応し、さらに１０〜１５ｍｍＨｇの減圧で５時聞反応した後、反応容器に無水トリメリット酸４４部を入れ、１８０℃、常圧で１．８時間反応し、［低分子ポリエステル１］を得た。［低分子ポリエステル１］は、数平均分子量２５００、重量平均分子量６７００、ピーク分子量５０００、Ｔｇ４３℃、酸価２５ｍｇＫＯＨ／ｇであった。
〜中間体ポリエステルの合成〜
冷却管、撹拌機および窒索導入管の付いた反応容器中に、ビスフェノールＡエチレンオキサイド２モル付加物６８２部、ビスフェノールＡプロピレンオキサイド２モル付加物８１部、テレフタル酸２８３部、無水トリメリット酸２２部およびジブチルスズオキサイド２部を入れ、常圧、２３０℃で８時間反応し、さらに１０〜１５ｍｍＨｇの減圧で５時間反応した［中間体ポリエステル１］を得た。［中間体ポリエステル１］は、数平均分子量２１００、重量平均分子量９５００、Ｔｇ５５℃、酸価０．５ｍｇＫＯＨ／ｇ、水酸基価５１ｍｇＫＯＨ／ｇであった。

Example 4
~ Synthesis of fine particle dispersion ~
In a reaction vessel in which a stir bar and a thermometer were set, 683 parts of water, 11 parts of sodium salt Eleminol RS-30 (manufactured by Sanyo Chemical Industries), ethylene oxide methacrylate adduct sulfate, 83 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate and 1 part of ammonium persulfate were added and stirred at 400 rpm for 15 minutes, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion [fine particle dispersion 1] was obtained. The average particle diameter of [fine particle dispersion 1] measured with LA-920 was 105 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The resin content had a Tg of 59 ° C. and a weight average molecular weight of 150,000.
~ Preparation of aqueous phase ~
990 parts of water, 99 parts of [fine particle dispersion 1], 35 parts of 48.5% by weight aqueous solution of sodium dodecyl diphenyl ether disulfonate, Eleminol MON-7 (manufactured by Sanyo Chemical Industries), and 70 parts of ethyl acetate are mixed and stirred. A milky white liquid was obtained. This is designated [Aqueous Phase 1].
-Preparation of aqueous solution of fluorinated activator-
10 parts of N, N, N, -trimethyl- [3- (4-perfluorononenyloxybenzamido) propyl] ammonium iodide (product name: Footage 310; manufactured by Neos) and 297 parts of methanol are placed in a container. Heat to ℃ and stir until clear. The obtained fluorine-based activator methanol solution was added dropwise to 693 parts of stirred ion-exchanged water, and stirred at 50 ° C. for 30 minutes after completion of the addition to obtain [Fluorine-based activator aqueous solution 1].
~ Synthesis of low molecular weight polyester ~
229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts of terephthalic acid, 46 parts of adipic acid and dibutyltin in a reaction vessel equipped with a condenser, stirrer and nitrogen inlet tube After putting 2 parts of oxide and reacting at normal pressure and 230 ° C. for 8 hours, and further reacting at 10 to 15 mmHg under reduced pressure for 5 hours, 44 parts of trimellitic anhydride was put into the reaction vessel, and 1 part at 180 ° C. and normal pressure. After reacting for 8 hours, [low molecular weight polyester 1] was obtained. [Low molecular polyester 1] had a number average molecular weight of 2500, a weight average molecular weight of 6700, a peak molecular weight of 5000, a Tg of 43 ° C., and an acid value of 25 mgKOH / g.
~ Synthesis of intermediate polyester ~
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 Part and 2 parts of dibutyltin oxide were added, reacted at 230 ° C. under normal pressure for 8 hours, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 51 mgKOH / g.

Next, 410 parts of [Intermediate Polyester 1], 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Polymer 1] was obtained. [Prepolymer 1] had a free isocyanate weight% of 1.53%.
~ Synthesis of ketimine ~
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 418 mgKOH / g.
~ Synthesis of MB ~
Add 1200 parts of water, 540 parts of carbon black Printex 35 (made by Dexa) (DBP oil absorption = 42 ml / 100 mg, pH = 9.5) and 1200 parts of [low molecular weight polyester 1], and use a Henschel mixer (made by Mitsui Mining). After mixing, the mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch 1 (BK)].
~ Preparation of oil phase ~
378 parts of [Low molecular weight polyester 1], 110 parts of carnauba wax, and 947 parts of ethyl acetate were charged into a container equipped with a stirring bar and a thermometer, heated to 80 ° C. with stirring, and maintained at 80 ° C. for 5 hours. It was cooled to 30 ° C at 1 hour. Next, 500 parts of [Masterbatch 1 (BK)] and 500 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution 1].

[Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), zirconia beads having a liquid feeding speed of 1 kg / hour, a disk peripheral speed of 6 m / second, and a particle diameter of 0.5 mm. The carbon black and the wax were dispersed under the condition of 3 passes. Next, 1324 parts of a 65% by weight ethyl acetate solution of [low molecular weight polyester 1] was added, and one pass was performed with a bead mill under the above conditions to obtain [Pigment / Wax Dispersion 1]. The solid content concentration of [Pigment / Wax Dispersion 1] (measurement conditions: 130 ° C., 30 minutes) was 50% by weight.
~ Emulsification⇒Desolvation ~
[Pigment / Wax Dispersion 1] 749 parts, [Prepolymer 1] 115 parts, [Ketimine Compound 1] 2.9 parts in a container, and TK homomixer (manufactured by Koki Co., Ltd.) at 5000 rpm for 1 minute After mixing, 1200 parts of [Aqueous Phase 1] was added to the container, and mixed with TK homomixer at 12500 rpm for 30 minutes to obtain [Emulsified Slurry 1].

[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 35 ° C. for 7 hours, aging was carried out at 45 ° C. for 4 hours to obtain [Dispersion slurry 1]. In the middle of solvent removal, the sample was transferred to a TK homomixer and stirred at 12,500 rpm for 40 minutes to deform the toner.
~ Washing⇒Drying ~
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1) 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (12000 rpm for 10 minutes), and then filtered.
(2) 100 parts of a 10% sodium hydroxide aqueous solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12000 rpm), and then filtered under reduced pressure.
(3) 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (12000 rpm for 10 minutes), and then filtered.
(4) 300 parts of ion-exchanged water was added to the filter cake of (3), mixed with a TK homomixer (10 minutes at 12000 rpm), and then filtered twice to obtain [filter cake 1].
~ Fluoroactive agent treatment ~
[Filter cake 1] 630 parts and 2928 parts of ion-exchanged water were placed in a container, stirred with a three-one motor (manufactured by Shinto Kagaku Co., Ltd.) (heated to 400 rpm for 5 minutes) and heated to 30 ° C. While maintaining the rotational speed and temperature, 11 parts of [Fluoroactive aqueous solution 1] was added dropwise. After completion of the dropwise addition, the mixture was stirred for 60 minutes and filtered to obtain [filter cake 1 after treatment with a fluoro-active agent].
(Dry / Wind Sieve)
[Filtered cake 1 after treatment with fluorine-based activator] was dried at 45 ° C. for 48 hours with a circulating dryer, and sieved with a mesh of 75 μm to obtain [Base toner 1]. [Mother toner 1] had a weight average particle diameter of 6.0 μm.
~ Adding external additives ~
[Base toner 1] 100 parts, 0.7 parts of 15 mμ hydrophobic titanium oxide surface-treated with methyltrimethoxysilane, 1.3 parts of 12 mμ hydrophobic silica surface-treated with dimethylsiloxane, and surface with dimethylsiloxane A black toner was prepared by mixing 0.6 parts of the treated 120 mμ hydrophobic silica with a Henschel mixer.

  Similarly, the following colorant was used in place of the carbon black used for the black toner, and yellow toner, magenta toner, and cyan toner were similarly obtained. That is, instead of 540 parts of carbon black Printex 35 (made by Dexa), 540 parts of yellow pigment (disazo yellow pigment CI Pigment Yellow 180), magenta pigment (naphthol pigment CI Pigment Red 184) , 400 parts of a cyan pigment (copper phthalocyanine pigment CI Pigment BLUE 15: 3) were used.

On the other hand, the carrier was produced as follows. 21.0 parts of acrylic resin solution having a solid content of 50% by weight, 6.4 parts of guanamine resin solution having a solid content of 70% by weight, 7.6 parts of alumina particles having an average particle size of 0.3 μm and a specific resistance of 10 ¹⁴ Ω · cm, solids A 23 wt% silicone resin solution SR2410 (Toray Dow Corning) 65.0 parts, aminosilane SH6020 (Toray Dow Corning) 0.3 parts, toluene 60 parts and butyl cellosolve 60 parts with a homomixer for 10 minutes Dispersed to obtain a blend coating film forming solution of acrylic resin and silicone resin containing alumina particles. As the core material particles, a sintered ferrite powder having an average particle size of 35 μm is used, and a coating film forming solution is used on a surface of the core material particles using a Spira coater (manufactured by Okada Seiko Co., Ltd.) so that the film thickness becomes 0.15 μm. Applied and dried. The obtained carrier was baked in an electric furnace at 150 ° C. for 1 hour. After cooling, the ferrite powder bulk was crushed using a sieve having an opening of 106 μm, and carrier 17 was obtained. The film thickness of the coating layer was measured by observing the cross section of the carrier 17 with a transmission electron microscope, and the average value was taken as the film thickness.

The charge amount (CT) of the carrier was measured in an environmental chamber at 24 ° C. and 55% RH using the black toner produced in the above (2) toner as a reference toner with respect to the carrier. The toner was weighed so that the total amount of toner and carrier was 1000 g with a toner concentration of 46% covering the carrier and placed in a 2 L stainless steel container. The toner and carrier were left for 2 hours in order to adapt to the environment of 24 ° C. and 55% RH. After being left for 2 hours, it was mixed for 10 minutes with a tumbler shaker mixer. For the mixed developer, the charge amount (CT) of the carrier was measured by a blow-off method. The result was 35 μC / g. Next, using yellow, magenta, cyan, and black toners and a carrier, the total amount of the toner and the carrier is weighed to 1000 g so that the toner concentration becomes 5% by weight, and put in a 2 L stainless steel container. A developer was prepared by mixing for 10 minutes with a shaker mixer. Then, a predetermined amount of developer was set in the developing section of each color in a color copier Imagio Neo C455 (manufactured by Ricoh) in an environment of 10 ° C. and 15% RH. Next, as for the background stain ΔID, for each developer of yellow developer, magenta developer, cyan developer and black developer, the toner concentration of each color developer is gradually increased, and the background stain ΔID is increased. The toner density (X) in a state of 0.01 was obtained. Table 2 shows the results of carrier charge amount (CT) [μC / g], toner concentration (X) [wt%], and coverage (C) [%].
(Example 5)
A polymerized toner was prepared as follows.
[Black Toner]
90 parts of styrene 55 parts of n-butyl methacrylate Charge control agent (zinc salicylate) Bontron E84 (manufactured by Orient Chemical Co., Ltd.) 3.5 parts Colorant (carbon black) # 44 (manufactured by Mitsubishi Chemical Co., Ltd.) 7.5 parts Blended and put together with a polymerization initiator (2,2-azobisisobutyronitrile) in a reaction vessel, polymerization was stopped at an average particle size of 6.8 μm, and the granulated particles were washed with water. And dried to obtain polymerized toner particles. When the toner particles were observed with an electron microscope, they were spherical.
[Yellow Toner]
90 parts of styrene 55 parts of n-butyl methacrylate Charge control agent (salicylic acid zinc salt) Bontron E84 (manufactured by Orient Chemical Co., Ltd.) 3, 5 parts Colorant PV Fast Yellow HG (manufactured by Clariant) 5 parts Polymerization is carried out in a reaction vessel together with an agent (2,2-azobisisobutyronitrile), the polymerization is stopped at an average particle size of 6.8 μm, and the granulated particles are washed with water and dried. Polymerized toner particles were obtained. When the toner particles were observed with an electron microscope, they were spherical.
[Magenta toner]
Styrene 90 parts N-butyl methacrylate 55 parts Charge control agent (zinc salicylate) Bontron E84 (manufactured by Orient Chemical Co., Ltd.) 3, 5 parts Colorant Hostaperm Pink E (manufactured by Hoechst) 4 parts (2,2-azobisisobutyronitrile) is put into a reaction vessel and polymerized, the polymerization is stopped at an average particle size of 6.8 μm, and the granulated particles are washed with water, dried and polymerized. Toner particles were obtained. When the toner particles were observed with an electron microscope, they were spherical.
[Cyan toner]
90 parts of styrene 55 parts of n-butyl methacrylate Charge control agent (zinc salicylate) Bontron E84 (manufactured by Orient Chemical Co., Ltd.) 3, 5 parts Colorant Lionol Blue FG-7351 (manufactured by Toyo Ink Co., Ltd.) 2.5 parts Then, polymerization is carried out in a reaction vessel together with a polymerization initiator (2,2-azobisisobutyronitrile), the polymerization is stopped at an average particle size of 6.8 μm, and the granulated particles are washed with water. And dried to obtain polymerized toner particles. When the toner particles were observed with an electron microscope, they were spherical. On the other hand, the carrier was measured using a carrier 9 so that the toner concentration was 5% by weight to prepare 1000 g of a developer. For 100 parts of toner base particles of each color, 1.3 parts of silica fine powder having an average particle diameter of 12 nm treated with hexamethyldisilazane and an average particle diameter of 15 nm treated with isobutyltrimethoxysilane are used. After mixing with 0.7 parts of titanium fine powder and 0.5 parts of silica fine powder having an average particle diameter of 120 nm treated with hexamethyldisilazane at a peripheral speed of 20 m / sec using a Henschel mixer Then, a negatively charged yellow, magenta, cyan and black toner was prepared by sieving. Next, the total amount of toner and carrier is weighed to 1000 g and placed in a 2 L stainless steel container so that the toner density is 5% by weight with the yellow, magenta, cyan and black toners and the carrier. For 10 minutes to produce a developer. Then, a predetermined amount of developer was set in the developing section of each color in a color copier Imagio Neo C455 (manufactured by Ricoh) in an environment of 10 ° C. and 15% RH. Next, as for the background stain ΔID, for each developer of yellow developer, magenta developer, cyan developer and black developer, the toner concentration of each color developer is gradually increased, and the background stain ΔID is increased. The toner density (X) in a state of 0.01 was obtained. The results of toner concentration (X) [wt%] and coverage (C) [%] are shown in Table 2.

  In order to evaluate the developer, each color developer corresponding to the toner density (X) was prepared. In the yellow developer, since the toner density (X) is 7.8% by weight, 78 g of the yellow toner and 922 g of the carrier are weighed, and 1000 g in total is weighed and placed in a 2 L stainless steel container. A developer was prepared by mixing for 10 minutes with a mixer. Thereafter, magenta, cyan and black developers were produced in the same manner. A predetermined amount of each color developer was set in a color copier Imagio Neo C455 (manufactured by Ricoh). A continuous paper feeding test of 50,000 sheets was performed with an A4 original having an image area ratio of 5% with a charging voltage set to 620 V and a developing bias set to 500 V. As a result, the same result as in Example 1 was obtained.

It is a figure which shows an example of the image forming apparatus of this invention. FIG. 6 is a diagram illustrating a relationship between toner density and background stain ΔID. It is a figure which shows the relationship between charge amount (CT) and toner density (X). It is a figure which shows the relationship between charge amount (CT) and coverage (C).

Claims (5)

A method of forming an image using a developer,
The developer has a negatively charged toner and a carrier,
The toner includes a base particle, a hydrophobic silica particle, and a hydrophobic titanium oxide particle containing a polyester resin or a styrene copolymer, carbon black, a fluorosurfactant, a metal salt of salicylic acid or a metal salt of a salicylic acid derivative. Have
In the carrier, the surface of the core particle is coated with a coating layer containing a silicone resin and an aminosilane coupling agent,
The charge amount of the carrier when the toner and the carrier are mixed so that the coverage of the toner covering the surface of the carrier is 46% as measured by the following method for measuring the charge amount of the carrier is 20 μC. / G to 47 μC / g,
The coverage with which the toner covers the surface of the carrier when the soil stain ΔID measured by the following method for measuring soil stain ΔID is 0.01 is 40% or more and 91% or less,
The coverage [%] is expressed by the formula TC / (100-TC) · (Rc / rt) · (ρc / ρt) · 25
(Where TC is the content [wt%] of the toner in the developer, Rc is the weight average particle size [μm] of the carrier, and rt is the weight average particle size of the toner. [Μm], ρc is the true specific gravity [g / cm ³ ] of the carrier, and ρt is the true specific gravity [g / cm ³ ] of the toner.)
Calculated from
When the charge amount [μC / g] of the carrier is CT and the coverage [%] is C, the formula 1.45CT-10.37 ≦ C ≦ 2.174CT + 24.45
An image forming method characterized by satisfying the above.
[Measurement method of charge amount of carrier]
The toner and the carrier are weighed so that the total coverage of the toner and the carrier is 1000 g at a ratio where the coverage ratio of the toner covering the carrier is 46%, and put into a 2 L stainless steel container. Next, the toner and carrier placed in a 2 L stainless steel container are left for 2 hours in an environment of 24 ° C. and 55% RH. Further, a developer is prepared by mixing for 10 minutes at 96 rpm in an environment of 24 ° C. and 55% RH. Next, the charge amount of the carrier is measured under the following conditions in an environment of 24 ° C. and 55% RH.
Blow gas: Nitrogen Blow pressure: 1 kg / cm ²
Blow time: 40 seconds Developer amount: 0.3 g
[Measurement method of background stain ΔID]
In a low-temperature and low-humidity environment of 10 ° C. and 15% RH, a charging voltage of 620 V and a developing bias of 500 V are set, and a 5000 sheet continuous paper passing test is performed with an A4 original having an image area ratio of 5%. Thereafter, an image is output with an A3 original having an image area ratio of 0.5%, and the power of the machine is turned off during image formation. Then, the latent image carrier is taken out, and a tape having a width of 300 mm and a width of 10 mm is applied in the axial direction of the latent image carrier. By rubbing with a finger on the tape through the gauze, the toner on the latent image carrier is transferred to the tape, and then the tape is peeled off from the latent image carrier. Next, the tape is affixed to A3 paper (hereinafter referred to as paper A). As a comparative tape, a tape that is not attached to the latent image carrier is attached to A3 paper (hereinafter referred to as paper B). For paper A, the density of three points from the top of the tape corresponding to the background portion on the latent image carrier is measured to obtain an average value. For paper B, the density at three points from the top of the tape is measured to obtain an average value. The background stain ΔID is a difference between the density of the paper A and the density of the paper B obtained in this way. When the content [wt%] of the toner in the developer when the background stain ΔID is 0.01 is X, the formula 0.227CT + 0.77 ≦ X ≦ 0.245CT + 2.69
The image forming method according to claim 1, wherein: Formula 2.165CT-30.99 ≦ C ≦ 1.955CT + 19.21
The image forming method according to claim 1, wherein:   The image forming method according to claim 1, wherein the coating layer further includes an acrylic resin, an amino resin, and alumina particles. Charging each of the plurality of latent image carriers,
Exposing each of the charged latent image carriers to form an electrostatic latent image;
Developing electrostatic latent images formed on the respective latent image carriers using the developer to form toner images;
Transferring the toner image formed on each latent image carrier to a transfer target;
The image forming method according to any one of claims 1 to 4, characterized in that a step of fixing the toner image transferred to said transfer member.

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