JP2003228197A - Dry electrophotographic toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic toner which is stably charged and carried even if being used for a long period of time, obtains high image quality high in image density and little in greasing, does not cause change in the chargeability of the toner after continuous printing, and obtains images of more than several ten thousand sheets having the image quality equal to that of the initial image, and to provide an image forming method and an image forming device. <P>SOLUTION: In the dry electrophotographic toner essentially comprising at least a binder resin, a coloring material, a charge-controlling agent and an additive, the coloring material is preliminarily treated with a resin different from the binder resin. It is preferable to combine a specified polyester resin as the binder resin with a specified polyol resin as the pretreatment resin of the coloring material, with a specified resin charge-controlling agent as the charge-controlling agent and with silica and titanium oxide as the additive. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used as a developer for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, etc., and an image forming method and image using the toner. Forming apparatus More specifically, the present invention relates to a copying machine using a direct or indirect electrophotographic development system, a laser printer, an electrophotographic toner used in plain paper fax machines, and an image forming method and an image forming apparatus using the toner. Further, a full-color copying machine using a direct or indirect electrophotographic multi-color image developing system, a full-color laser printer, an electrophotographic toner used in a full-color plain paper fax machine, and an image forming method and image forming apparatus using the toner Regarding

[0002]

2. Description of the Related Art A developer used in electrophotography, electrostatic recording, electrostatic printing, etc., is once attached to an image carrier such as a photoconductor on which an electrostatic charge image is formed in the developing process, After being transferred from the photoconductor to a transfer medium such as transfer paper in the transfer step, it is fixed on the paper surface in the fixing step. At that time, as a developer for developing the electrostatic image formed on the latent image holding surface, a two-component developer composed of a carrier and a toner, and a one-component developer not requiring a carrier (magnetic toner, Non-magnetic toner) is known. In the two-component development method, toner particles adhere to the surface of the carrier to deteriorate the developer, and since only the toner is consumed, the toner concentration in the developer decreases, so the mixing ratio with the carrier should be kept constant. Since it must be held, there is a drawback that the developing device becomes large. On the other hand, the one-component developing system has the above-mentioned drawbacks and has an advantage that the apparatus can be downsized. Therefore, the developing system is becoming the mainstream.

In recent years, OA and colorization in offices have progressed further, and not only conventional copying of originals consisting of only characters but also graphs created by a personal computer,
The image taken by the digital camera, the pictorial document read by the scanner, etc. are output by the printer,
Opportunities to make many copies as presentation materials are increasing. Many of the printer output images are solid images, line images, and halftone images, and the market demands for image quality are changing accordingly, and the demand for high reliability is further increasing.

Conventionally, an electrophotographic process using a one-component type developer has a magnetic one-component developing method using a magnetic toner,
It is classified as a non-magnetic one-component developing method using non-magnetic toner. The magnetic one-component developing method is a method of holding a magnetic toner containing a magnetic substance such as magnetite by using a developer carrying member provided with a magnetic field generating means such as a magnet, and developing the toner into a thin layer by a layer thickness regulating member. In recent years, many have been put to practical use in small printers and the like. On the other hand, in the non-magnetic one-component developing method, since the toner does not have a magnetic force, a toner replenishing roller or the like is pressed against the developer carrying member to supply the toner onto the developer carrying member and electrostatically hold it to form a layer. The layer is developed by thinning it with a thickness regulating member. Since it does not contain a colored magnetic material, it has the advantage of being compatible with colorization.Because a magnet is not used for the developer carrying member, it is lighter in weight.
Cost reduction has become possible, and it has been put to practical use in small full-color printers and the like in recent years.

However, the current situation is that the one-component developing system still has many problems to be improved. In the two-component developing method, a carrier is used as a toner charging and conveying means, and the toner and the carrier are sufficiently stirred and mixed inside the developing device and then conveyed to the developer carrying member for development, so that the toner and carrier are used for a relatively long time. It is possible to maintain stable charging and conveyance, and it is also easy to support high-speed developing devices.

On the other hand, in the one-component developing system, since there is no stable charging and conveying means like a carrier, charging and conveyance defects are likely to occur due to long-term use and speeding up. That is, in the one-component developing method, after the toner is conveyed onto the developer carrier,
Although the toner is made thin by the layer thickness regulating member to develop, the carrier was used because the contact / friction charging time between the toner and the friction carrying member such as the developer carrying member and the layer thickness regulating member is very short. Compared to the two-component development method, the amount of low-charged and reverse-charged toner tends to increase. Particularly, in the non-magnetic one-component developing method, there is usually a means for carrying toner (developer) by at least one toner carrying member and developing the electrostatic latent image formed on the latent image carrier by the carried toner. However, in this case, it is said that the layer thickness of the toner on the surface of the toner conveying member must be made as thin as possible. This also applies when using a two-component developer having a very small carrier diameter, and especially when a one-component developer is used and its toner has a high electric resistance. Since it is necessary to charge this toner by the developing device, the layer thickness of the toner must be remarkably thin. This is because if the toner layer is thick, only the vicinity of the surface of the toner layer is charged, and it becomes difficult to uniformly charge the entire toner layer. For this reason, the toner is required to maintain a faster charging speed and an appropriate amount of charge.

Conventionally, it has been practiced to add a charge control agent in order to stabilize the charge of the toner. The charge control agent controls the triboelectric charge amount of the toner and maintains the triboelectric charge amount. Typical negative charge control agents include monoazo dyes, salicylic acid, naphthoic acid, metal salts / complexes of dicarboxylic acids, diazo compounds, complex compounds with boron, and the like. Examples of the charge control agent include quaternary ammonium salt compounds, imidazole compounds, nigrosine and azine dyes.
However, some of these charge control agents have a color, and many cannot be used for color toners. In addition, since some of these charge control agents have poor compatibility with the binder resin, those existing on the toner surface, which are greatly involved in charging, are easily desorbed, resulting in uneven charging of the toner, development sleeve, and photosensitivity. It has a drawback that it is easily polluted such as body filming. Therefore, in the past, a good image was obtained in the initial stage, but a phenomenon in which the image quality gradually changed and scumming and scumming occurred, especially when applied to color copying and continuously used while supplying toner, The toner charge amount has decreased and the color tone of the copied image is significantly different from that of the initial copy image.The image cannot be used for a long period of time, and after several thousand sheets, the image forming unit called process cartridge must be replaced early. It had the drawback that it should not. Therefore, the load on the environment is large and the user's time and effort are required. Further, since many of these contain heavy metals such as chromium, they are becoming a problem in terms of safety in recent years.

In order to solve the above problems, Japanese Patent Laid-Open Nos. 63-88564, 63-184762 and 3-56974, 6-230609 disclose compatibility with a binder resin and transparency of a toner-fixed image. A resin charge control agent having improved properties and safety is disclosed. Since these resin charge control agents have good compatibility with the binder resin, they are excellent in stable chargeability and transparency. However, these resin charge control agents have the drawback of being inferior in charge amount and charge rate as compared with toners using a metal salt / metal complex salt of a monoazo dye, salicylic acid, naphthoic acid, or dicarboxylic acid. Further, although the chargeability is improved by increasing the addition amount of the resin charge control agent, it adversely affects the toner fixability (low temperature fixability, offset resistance). Further, these compounds have poor environmental stability (moisture resistance) in charge amount. Therefore, there is also a problem that scumming (fog) is likely to occur.
Then, again, JP-A-8-30017, 9-17127
1, 9-212896, 11-218965 discloses a copolymer of a monomer containing an organic acid salt such as a sulfonate group and an aromatic monomer having an electron-withdrawing group. However, due to hygroscopicity and adhesiveness that are thought to be due to monomers containing organic acid salts such as sulfonate groups, a sufficient amount of charge is secured, but the dispersion in the binder resin is not sufficient, and the toner is charged for a long time. The effect of suppressing the dispersion of the toner and preventing the developing sleeve and the photoconductor filming is not sufficient. Further, in order to further improve the compatibility with the binder resin such as styrene resin or polyester resin, a monomer containing an organic acid salt such as a sulfonate group, an aromatic monomer having an electron-withdrawing group, a styrene monomer or a polyester, respectively. Although a copolymer with a system monomer has been proposed, the effects of maintaining the charge amount for a long period of time and preventing the filming of the developing sleeve and the photoreceptor are not sufficient. In particular, as a binder resin for a full-color toner, it is insufficient for a polyester resin and a polyol resin which are suitable in terms of color developability and image strength.

In recent years, the demand for printers has expanded, and the downsizing, speeding up and cost reduction of devices have progressed, and higher reliability and longer life have begun to be demanded for the devices, and toners have various characteristics over a long period of time. However, these resin charge control agents are unable to maintain their charge control effect, which contaminates the developing sleeve and layer thickness control members (blades and rollers) and reduces the toner charging performance, and reduces the photosensitivity. There was a problem of filming the body.

Further, due to the downsizing and speeding up, a process for developing in a short time with a small amount of developer is required, and a developer having a better charge rising property is required.

Regarding development, various development methods have been proposed for both two-component and one-component developers, but downsizing,
Non-magnetic one-component development, which is excellent in weight saving and does not require the use of a carrier, is often proposed for printer applications. In this developing method, since the replenishment property of the toner to the developing roller and the toner holding property of the developing roller are poor, the toner is forcibly rubbed against the developing roller or the amount of toner on the developing roller is regulated by a blade. As a result, the toner is likely to be filmed on the developing roller, resulting in a problem that the life of the developing roller is shortened and the amount of charge of the toner becomes unstable. Also, this prevents good development.

Further, in the color toner for non-magnetic one-component development, in addition to the properties required for general color toner, the heat resistance of the binder resin used for the toner is often inferior, so that the development roller is not affected. The toner filming is likely to occur.

Japanese Unexamined Patent Publication No. 5-53369 discloses an inorganic material having a BET specific surface area of 1 to 150 m ² / g and treated with a coupling agent having a saturated or unsaturated cyclic or acyclic organic group having 5 or more carbon atoms. Fine powder with a BET specific surface area of 16
Although a toner having an inorganic fine powder having a hydrophobicity of 30 or more at 0 to 400 m ² / g is disclosed, the charging property of the toner on the developing roller becomes unstable, and the toner spills or scatters from the developing roller. There are cases.

Further, Japanese Patent Laid-Open No. 6-202374 discloses a non-magnetic one-component toner in which inorganic fine particles having an average particle size of 30 nm or more and less than 100 nm are adhered, but the fluidity of the toner is not sufficient. In some cases, the toner replenishment property becomes insufficient.

Further, JP-A-8-15890 discloses that toner particles having an average particle diameter of 4 to 9 μm and a small particle diameter (7 to 20 nm).
And a large particle size (20 to 80 nm) external additive, and a 1-component developer containing 1 to 2% by weight of a small particle size external additive, the charging property of the toner on the developing roller is unstable. The toner may spill or scatter from the developing roller.

In Japanese Patent Laid-Open No. 9-288369, B
A toner containing silica fine particles having an ET specific surface area of 20 to 50 m ² / g, a pH of 6 to 8 and a hydrophobicity of 85% or more is disclosed, but the fluidity of the toner is insufficient and the replenishment property of the toner is insufficient. May be.

Further, in Japanese Patent Laid-Open No. 2000-172003, silica fine particles having an average particle diameter of 7 to 20 nm are 0.3 to
Although a toner containing 1.2 parts by weight and 0.8 to 1.6 parts by weight of titanium oxide having an average particle diameter of 30 to 100 nm is disclosed, the toner fluidity is not sufficient and the toner is not formed on the developing sleeve in one-component development. A uniform thin layer cannot be formed, and toner replenishability is poor.

Further, in Japanese Patent Application Laid-Open No. 9-297424, the softening point (Sp) is 90 to 115 ° C., and the Sp and glass transition point are
The relationship with (Tg) is Sp + 110 ≦ 4 Tg ≦ Sp + 170
Although a non-magnetic one-component toner having fine particles having a BET specific surface area of 70 m ² is disclosed on the surface of a toner having a polyester resin, the toner has insufficient fluidity and may have insufficient toner replenishment. is there.

It is a known technique to form an image by subtractive color mixing in a full color printer using electrophotography, and two or more toner particles of each color of yellow, magenta, cyan and black having a volume average particle size of 6 to 10 μm are used. By overlapping and heating and pressing, secondary colors and tertiary colors are developed to form a full-color image. Therefore, the coloring power of each color toner, that is, the dispersibility of the pigment affects the color developability in a full-color image. The dispersibility of the pigment affects not only the color developability of the full-color image but also the image transparency of the OHP sheet.

Japanese Unexamined Patent Publication No. 6-230607 and Patent No. 3
Although Japanese Patent No. 039191 discloses the use of a specific yellow pigment, the dispersibility with a binder resin is insufficient although the characteristics of the pigment are clear.

Further, Japanese Patent Application Laid-Open No. 62-280755 and Japanese Patent Application Laid-Open No. 4-242752 disclose a masterbatch method and a flushing method, but they are effective as a construction method but are insufficient in the characteristics of the pigment and the resin. is there.

[0022]

SUMMARY OF THE INVENTION In view of the above situation, the present invention does not impair the advantages of the resin charge control agent that are excellent in compatibility with a binder resin, transparency of a toner-fixed image, and safety, and the problem thereof is solved. It was made for the purpose of solving the problems. That is, an object of the present invention is to provide an electrophotographic toner, an image forming method, and an image-forming toner, in which the charge amount and the conveyance amount of the toner are stable even when used for a long period of time, and a high image quality with high image density and less background stain is obtained. A forming device is provided. In particular, a two-component developing method in which a two-component developer consisting of a carrier and a toner is formed on a developer carrier (developing sleeve) by a developer layer thickness regulating member to perform development, and a developer carrier. In the one-component development method in which a thin layer of developer is formed on the (developing roller) by a developer layer thickness regulating member and the development is performed, the chargeability of the toner does not change after continuous printing, and the image quality equivalent to the initial image is several. It is an object of the present invention to provide an electrophotographic toner, an image forming method, and an image forming apparatus capable of obtaining 10,000 or more sheets.

Another object of the present invention is for electrophotography, which prevents contamination of the developer carrier or developer layer thickness controlling member (blade or roller) and filming of the photoconductor for tens of thousands or more during long-term use. A toner, an image forming method, and an image forming apparatus are provided. Another object of the present invention is to provide an electrophotographic toner, an image forming method, and an image forming apparatus in which toner scattering in the developing machine is small even after long-term use. Another object of the present invention is that the developing unit and the photoconductor unit can be used for a long period of time,
The present invention provides an electrophotographic toner, an image forming method, and an image forming apparatus that reduce the burden on the environment and reduce the user's labor for replacement.

Another object of the present invention is to provide an electrophotographic toner having good color reproducibility by using a colorless or light colored resin charge control agent. Another object of the present invention is a method obtained from a production process of kneading, pulverizing and classifying toner, which does not have sticking in the pulverizing process, is not over-pulverized, and has a large amount of pulverization processing per unit time, thus having high productivity. It is to provide a toner for electrophotography. Another object of the present invention is to provide a developer excellent in charge rising property. Another object of the present invention is to provide an electrophotographic toner which has excellent colorability, charge stability and transparency in a yellow toner and is excellent in color reproducibility of a full color image.

[0025]

In order to solve the above problems, the inventors of the present invention have made intensive studies by paying attention to the constituent components and the constituent ratio of the resin charge control agent, and as a result, as a binder resin for a full-color toner, the coloring property and the image strength are obtained. In view of the above, when a resin charge control agent and an additive having specific constituent components and constituent ratios with respect to a suitable polyester resin are used, a high charge amount and a sharp charge amount distribution can be obtained, and the charge rise is good. It is excellent in stain resistance and can prevent contamination of the developer bearing member (developing roller, sleeve) and development layer thickness control member (blade or roller) and photoconductor filming for a long time over tens of thousands of sheets, and has good crushability. The inventors have found that a highly productive electrophotographic toner and an image forming method can be obtained. Furthermore, it has been found that a specific binder resin and pigment have excellent colorability, transparency, and charge stability, and a vivid toner having a full-color image can be obtained.

That is, the present invention provides the following (1) to (7).
Consists of. (1) A dry electrophotographic toner mainly containing at least a binder resin, a coloring material, a charge control agent and an additive, wherein the coloring material is pretreated with a resin different from the binder resin. Toner for electrophotography.

(2) The binder resin is made of one or more kinds of polyester resins and has the following characteristics, and the colorant pretreatment resin different from the binder resin is a polyol resin having the following components. The dry electrophotographic toner according to (1), wherein the charge control agent is a resin charge control agent having the following characteristics, and the additive has the following configuration: . Binder resin; polyester resin, containing no THF insoluble component, and having a weight average molecular weight of 5 × 10 ² or less in the molecular weight distribution in gel permeation chromatography (GPC), 4% by weight or less, It has a main peak in the region where the weight average molecular weight is 3 × 10 ³ or more and 9 × 10 ³ or less. Polyol resin: A polyol having an epoxy resin part and an alkylene oxide part in the main chain and having an inactive resin terminal. A polyol obtained by reacting an epoxy resin, an alkylene oxide adduct of a dihydric phenol or a glycidyl ether thereof with a compound having two or more active hydrogens that react with an epoxy group in the molecule. Alternatively, the epoxy resin forming the polyol is at least two kinds of bisphenol A type epoxy resins having different number average molecular weights. At least 2 having different number average molecular weights
The low molecular weight component of the one or more bisphenol A type epoxy resins has a number average molecular weight of 360 to 2000, and the high molecular weight component has a number average molecular weight of 3000 to 10,000. In the above, the low molecular weight component and the high molecular weight component of at least two kinds of bisphenol A type epoxy resins having different number average molecular weights are 20 to 50% by weight and 5 to 40% by weight with respect to the polyol. In the above, the glycidyl ether of the alkylene oxide adduct of the dihydric phenol constituting the polyol is a diglycidyl ether of the alkylene oxide adduct of bisphenol A and is represented by the following general formula (1).

[0028]

[Chemical 3] (Where R is

[0029]

[Chemical 4] And n and m are the numbers of repeating units, each being 1 or more and n + m = 2 to 6. ) Or, the alkylene oxide adduct of dihydric phenol or its glycidyl ether constituting the polyol is 10 to 40 with respect to the polyol.
Contains% by weight. Charge control agent: a resin charge control agent, and at least (a) a sulfonate group-containing monomer as a monomer, (b) an aromatic monomer having an electron-withdrawing group, (c) an acrylic acid ester monomer, and / or methacrylic acid. An ester monomer and (d) an aromatic vinyl monomer, or (a), (b), and (c) as a constituent unit, and the resin charge control agent has a volume resistance of 9.5 to 11.5 Log Ω · cm.
Is. Additives; hydrophobized silica having a primary particle diameter of 0.01 to 0.03 μm and primary particle diameter of 0.01 to 0.03 μm
And titanium oxide having a specific surface area of 60 to 140 m ² / g that has been hydrophobized.

(3) The colorant has one or more kinds of yellow colorants, and at least one of them is a benzimidazolone yellow pigment, wherein (1) or (2) is a feature. Dry electrophotographic toner.

(4) The temperature at which the apparent viscosity of the binder resin by the flow tester becomes 10 ³ Pa · s is T
1. When T2 is the temperature at which the apparent viscosity of the resin charge control agent by the flow tester becomes 10 ⁴ Pa · s, T
1. The dry electrophotographic toner according to any one of (1) to (3), wherein T1 and T2 are 0.9 <T1 / T2 <1.4. (5) A latent image forming step of forming a latent image on a latent image holding body, a developing step of developing the latent image using a developer on a developer carrying body, and a developed toner image is transferred onto a transfer body. In the image forming method having a transfer step of performing a heat treatment and a fixing step of heating and fixing the toner image on the transfer body, the developer (1) to
An image forming method comprising using the developer containing the dry electrophotographic toner according to any one of (4). (6) A container holding a developer containing the dry electrophotographic toner according to any one of (1) to (4), an apparatus having the developing step, an apparatus having the transfer step, and the fixing step. An image forming apparatus having a device.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The present invention is a dry electrophotographic toner mainly containing at least a binder resin, a coloring material, a charge control agent, and an additive, wherein the coloring material is pretreated with a resin different from the binder resin. It is a dry electrophotographic toner.

The binder resin used in the present invention is a color developing agent as a binder resin for full-color toner,
A polyester resin suitable from the viewpoint of image strength is used. In a color image, several types of toner layers are layered in layers, so that the toner layer becomes thick and cracks or defects occur in the image due to insufficient strength of the toner layer, and proper gloss is lost. For this reason, a polyester resin is used in order to maintain appropriate gloss and excellent strength.

The polyester resin can be generally obtained by an esterification reaction of a polyhydric alcohol and a polycarboxylic acid. Among the monomers constituting the polyester resin in the present invention, examples of the alcohol monomer include polyfunctional monomers having a valence of 3 or more, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3- Propylene glycol, 1,4-butadieneol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol and other diols, bisphenol A, hydrogenated bisphenol A, polyoxypropylene Bisphenol A alkylene oxide adduct such as bisphenol A, other dihydric alcohol, or sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol Le, tripentaerythritol, 1,2,4-butanetriol, 1, 2, 5
-Pentanetriol, glycerol, diglycerol, 2-methylpropanetriol, 2-methyl-1,
Examples thereof include 2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, and other polyhydric alcohols having 3 or more valences.

Among these monomers, those using a bisphenol A alkylene oxide adduct as a main component monomer are preferably used. Bisphenol A
When an alkylene oxide adduct is used as a constituent monomer, a polyester having a relatively high glass transition point is obtained due to the properties of the bisphenol A skeleton, and the copy blocking resistance and heat resistant storage stability are good. Further, the presence of the alkyl groups on both sides of the bisphenol A skeleton functions as a soft segment in the polymer, and the color developability and the image strength at the time of fixing the toner are improved. Of the bisphenol A alkylene oxide adducts, those having an ethylene group or a propylene group are particularly preferably used.

Among the monomers constituting the polyester resin in the present invention, examples of the acid monomer include polyfunctional monomers having a valence of 3 or more, such as maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid and phthalic acid. , Isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, or n-dodecenylsuccinic acid, n
Alkenylsuccinic acids or alkylsuccinic acids such as dodecylsuccinic acid, anhydrides of these acids, alkyl esters, other divalent carboxylic acids, and 1,2,
4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,
4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid Examples thereof include enpol trimer acid, anhydrides thereof, alkyl esters, alkenyl esters, aryl esters, and other trivalent or higher carboxylic acids.

Specific examples of the alkyl group, alkenyl group or aryl ester described here include 1,2,
4-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid trimethyl, 1,2,4-benzenetricarboxylic acid triethyl, 1,2,4-benzenetricarboxylic acid tri-n-butyl, 1,2,4-benzenetricarboxylic acid Acid isobutyl, 1,2,4-benzenetricarboxylic acid tri-n-octyl, 1,2,4-benzenetricarboxylic acid tri-2-ethylhexyl, 1,2,4-benzenetricarboxylic acid tribenzyl, 1,2,4-benzenetricarboxylic acid Acid tris (4-isopropylbenzyl) and the like.

The production method for obtaining the polyester used in the present invention is not particularly limited, and the esterification reaction can be carried out by a known method. The transesterification reaction can be carried out by a known method, and at this time, a known transesterification catalyst can be used. For example, magnesium acetate, zinc acetate, manganese acetate, calcium acetate, tin acetate, lead acetate, titanium tetrabutoxide and the like can be mentioned. The polycondensation reaction can be carried out by a known method, in which case a known polymerization catalyst can be used. Specific examples include antimony trioxide, germanium dioxide and the like.

The binder resin used in the present invention is particularly free of THF insoluble matter and has a molecular weight distribution in gel permeation chromatography (GPC)
The content ratio of the component having a weight average molecular weight of 5 × 10 ² or less is 4% by weight or less, and the weight average molecular weight of 3 × 10 ^{3 to} 9 × 10 ³
It is characterized by having a main peak in the region of. TH
When the F insoluble content is contained, the gloss is lowered and the transparency is lowered, so that a high quality image cannot be obtained when an OHP sheet is used. On the other hand, when the content of the component having a weight average molecular weight of 5 × 10 ² or less exceeds 4% by weight, the blade or sleeve is contaminated by long-term use and filming easily occurs.

Further, when the main peak is in the region where the weight average molecular weight is smaller than 3 × 10 ³ , the image gloss becomes excessive and hot offset occurs at a low temperature, so that a sufficient fixing temperature range cannot be obtained. . In addition, sticking occurs in the crusher during manufacturing, which makes stable manufacturing impossible. On the other hand, when the main peak is in the region where the weight average molecular weight is larger than 9 × 10 ³ , appropriate gloss cannot be obtained and the transparency of the OHP sheet cannot be obtained. In addition, the pulverizability is lowered during the production of the toner.

In the present invention, the molecular weight distribution is measured by GPC as follows. The column was stabilized in a heat chamber at 40 ° C., and THF as a solvent was flowed through the column at this temperature at a flow rate of 1 ml per minute to adjust the sample concentration to 0.05 to 0.6% by weight.
Inject 200 μl of HF sample solution for measurement. Before injecting the THF sample solution, a THF insoluble component is removed with a 0.45 μm liquid chromatography filter. In measuring the molecular weight of the toner sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value and the count number of a calibration curve prepared using several kinds of monodisperse polystyrene standard samples. As a standard polystyrene sample for creating a calibration curve, for example, Press
ure Chemical Co. Alternatively, the molecular weight manufactured by Toyo Soda Kogyo Co., Ltd. is 6 × 10 ² , 2.1 × 10 ³ , 4 ×.
10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 1
0 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.
It is suitable to use a standard polystyrene sample of at least 10 points by using a sample of 48 × 10 ⁶ . An RI (refractive index) detector is used as the detector.

Whether or not the binder resin is insoluble in THF is determined at the time of preparing the THF sample solution for measuring the molecular weight distribution. That is, when a 0.45 μm filter unit is attached to the tip of a syringe and a liquid is pushed out from the inside of the syringe, it is determined that there is no THF insoluble content unless the filter is clogged.

The binder resin used in the present invention preferably has an endothermic peak in DSC in the range of 60 to 70 ° C. If the temperature is lower than 60 ° C., there is a problem in toner storage stability. On the other hand, when the temperature exceeds 70 ° C., the hardness of the resin increases and the toner productivity decreases. In the present invention, DSC
Endothermic peak in Rigaku manufactured by Rigaku Denki Co., Ltd.
With THRMOFLEX TG8110, heating rate 1
It is measured at 0 ° C./min, and the main maximum peak of the endothermic curve is read.

The binder resin used in the present invention has a weight average molecular weight (Mw) and a number average molecular weight (Mw).
The ratio Mw / Mn of n) is preferably 2 to 10.
When Mw / Mn exceeds 10, gloss is not obtained when the toner is fixed as a toner, and a glossy high-quality image cannot be obtained. Further, when Mw / Mn is less than 2, the productivity is lowered in the pulverizing step at the time of toner production, the blade or sleeve is contaminated by long-term use, and filming easily occurs.

The binder resin used in the present invention preferably has an acid value of 20 KOHmg / g or less. It is known that the chargeability of a polyester resin and the acid value are almost proportional to each other, and it is known that the higher the acid value is, the greater the negative chargeability of the resin is, and at the same time, the environmental stability of charging is also affected. That is, when the acid value is high, the charge amount is high under low temperature and low humidity, and the charge amount is low under high temperature and high humidity, and the background stain, image density, and color reproducibility are large, and it is difficult to maintain high image quality. When the acid value exceeds 20 KOHmg / g, the charge amount increases and environmental fluctuations worsen. In the polyester resin of the present invention, the acid value is preferably 20 KOHmg / g or less, more preferably 5 KOHmg / g or less.

Further, the binder resin used in the present invention has an apparent viscosity of 10 ³ Pa · s by a flow tester.
It is preferable that the temperature is 95 to 120 ° C. 9
If it is less than 5 ° C, there is no room for hot offset at the time of fixing, and if it is 120 ° C or more, sufficient gloss cannot be obtained. The temperature at which the apparent viscosity was 10 ³ Pa · s was measured using a Shimadzu CFT-500 type as a flow tester.
Load 10 kg / cm ² , orifice diameter 1 mm x length 1 m
m, the viscosity was measured at a temperature rising rate of 5 ° C./min, and the apparent viscosity was 10
^It reads the temperature at ³ Pa · s.

The polyol resin in the present invention is preferably obtained by condensing bisphenol such as bisphenol A or bisphenol F and epichlorohydrin. Although it is a resin for pretreatment of the coloring material, it is present in the toner, so that a resin having substantially the same thermal characteristics as the binder resin (polyester resin of the present invention) is used. This does not impair the properties of the binder resin. Although the reason why the dispersibility of the coloring material is improved by pretreatment with the polyol resin is not clear, the polyol resin according to the present invention has a viscous body and an elastic body in the resin skeleton, and therefore has a unique viscoelasticity. It is considered that the organic pigment having a large molecular weight is subjected to shearing force and finely dispersed while being entangled with the polyol resin. The skeleton of the polyol resin has the same bisphenol as the polyester resin, and the Sp values of the resin are almost equal. Therefore, the colorant pretreated with the polyol resin is easily compatible with the polyester resin, and the dispersion of the colorant becomes extremely uniform.

In order to obtain stable fixing characteristics and gloss, the epoxy resin is at least two kinds of bisphenol A type epoxy resins having different number average molecular weights, and the low molecular weight component has a number average molecular weight of 360 to 2000 and a high molecular weight. The number average molecular weight of the molecular weight component is preferably 3,000 to 10,000. Further, it is preferable that the low molecular weight component is 20 to 50% by weight and the high molecular weight component is 5 to 40% by weight with respect to the polyol resin. When the amount of low-molecular weight component is too large or the molecular weight is lower than 360, the gloss may be too high or the storage stability may be deteriorated. If the amount of the high molecular weight component is too large or the molecular weight is higher than 10,000, the gloss may be insufficient or the fixability may be deteriorated.

Examples of the alkylene oxide adduct of dihydric phenol as the compound used in the present invention include the following. Examples thereof include reaction products of ethylene oxide, propion oxide, butylene oxide, and mixtures thereof with bisphenols such as bisphenol A and bisphenol F. The obtained adduct may be glycidylated with epichlorohydrin or β-methylepichlorohydrin before use. Particularly, diglycidyl ether of an alkylene oxide adduct of bisphenol A represented by the following general formula (1) is preferable.

[0050]

[Chemical 5] (Where R is

[0051]

[Chemical 6] And n and m are the numbers of repeating units, each being 1 or more and n + m = 2 to 6. )

It is preferable that the alkylene oxide adduct of dihydric phenol or its glycidyl ether is contained in an amount of 10 to 40% by weight based on the polyol resin. If the amount is too small, problems such as curling may occur, and if n + m in the general formula (1) is 7 or more, the gloss may be too high or the storage stability may be deteriorated.

The compound having one active hydrogen in the molecule which reacts with the epoxy group and inactivates the terminal of the epoxy resin used in the present invention includes monohydric phenols, secondary amines and carboxylic acids. is there. The following are examples of monohydric phenols. Phenol, cresol, isopropylphenol, amylphenol, nonylphenol, dodecylphenol, xylenol, p
-Cumylphenol and the like. Examples of secondary amines include diethylamine, dipropylamine, dibutylamine, N-methyl (ethyl) piperazine, piperidine and the like. The carboxylic acids are propionic acid,
Caproic acid and the like can be mentioned.

In order to obtain a polyol resin having an epoxy resin part and an alkylene oxide part in the main chain used in the present invention, various raw materials can be combined. For example, it can be obtained by reacting an epoxy resin having a glycidyl group at both ends with an alkylene oxide adduct of a divalent phenol having a glycidyl group at both ends with a dihalide, an isocyanate, a diamine, a diol, a polyhydric phenol or a dicarboxylic acid. Of these, it is most preferable to react a dihydric phenol from the viewpoint of reaction stability. It is also preferable to use polyhydric phenols and polyhydric carboxylic acids in combination with dihydric phenols within the range where gelation does not occur. Here, the amount of polyhydric phenols and polyhydric carboxylic acids is 15 with respect to the total amount.
It is not more than 10% by weight, preferably not more than 10% by weight.

The compound having two or more active hydrogens which react with the epoxy group used in the present invention is 2
Examples thereof include polyhydric phenols, polyhydric phenols, and polyhydric carboxylic acids. Examples of the dihydric phenols include bisphenols such as bisphenol A and bisphenol F. Further, as polyhydric phenols, orthocresol novolacs, phenol novolacs, tris (4
-Hydroxyphenyl) methane, 1- [α-methyl-α
An example is-(4-hydroxyphenyl) ethyl] benzene. As the polycarboxylic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid,
Examples thereof include phthalic acid, terephthalic acid, trimellitic acid and trimellitic anhydride.

The polyol resin in the present invention preferably has a softening point of 90 to 125 ° C. If it is lower than 90 ° C., there is no margin for offset at the time of fixing, and if it exceeds 125 ° C., sufficient gloss cannot be obtained. The following method is used to measure the softening point of the polyol resin in the present invention. (1) As a device for measuring the softening point, a fully automatic dropping point device FP5 / FP53 manufactured by Metra Co., Ltd. is used and the measurement is carried out by the following procedure. (2) After placing the ground sample in the melting pot and leaving it for 20 minutes,
The sample is poured to the edge of the sample cup (droplet diameter 6.35 mm), cooled to room temperature and set in the cartridge. (3) Set a predetermined temperature rising rate (1 ° C./min) and a measurement start temperature (set at 15 ° C. below the expected softening temperature) in the FP5 control unit. (4) The cartridge is attached to the FP53 heating furnace, and after standing for 30 seconds, the start lever is pushed down to start the measurement. Subsequent measurements are performed automatically. (5) Remove the cartridge when the measurement is completed. (6) The softening point (° C) is calculated as follows. [Value of FP5 result display panel A] + [correction value] The above correction value is added to the obtained result to correspond to the result of the Duran mercury method. (7) When the difference between the value of the result display panel A and the measurement start temperature (set in (3), the values of panels B and C) is not 15 ° C. or more, the measurement start temperature is reset and the measurement is performed again.

Examples of the sulfonate group-containing monomer constituting the resin charge control agent used in the present invention include aromatic sulfonate group-containing monomers and aliphatic sulfonate group-containing monomers. Examples of the aromatic sulfonate group-containing monomers include alkali metal salts such as vinyl sulfonic acid, allyl vinyl sulfonic acid, 2-acrylamido-2 methyl propane sulfonic acid, methacryloyloxyethyl sulfonic acid, alkaline earth metal salts, amine salts and 4 Examples thereof include primary ammonium salts. Examples of the aliphatic sulfonate group-containing monomer include alkali metal salts such as styrenesulfonic acid, sulfophenylacrylamide, sulfophenylmaleimide, and sulfophenylitaconimide, alkaline earth metal salts, amine salts, and quaternary ammonium salts. . Heavy metal salts (nickel, copper, zinc, mercury, chromium, etc.) are not preferable in terms of safety.

As the aromatic monomer having an electron-withdrawing group, styrene substitution products such as chlorostyrene, dichlorostyrene, bromostyrene, fluorostyrene, nitrostyrene and cyanstyrene, chlorophenyl (meth) acrylate, bromophenyl (meth) acrylate, Phenyl (meth) acrylate substitution products such as nitrophenyl (meth) acrylate and chlorophenyloxyethyl (meth) acrylate, phenyl (meth) acrylamides such as chlorophenyl (meth) acrylamide, bromophenyl (meth) acrylamide and nitrophenyl (meth) acrylamide Substitute, chlorophenylmaleimide, dichlorophenylmaleimide, nitrophenylmaleimide,
Examples include phenylmaleimide substitution products such as nitrochlorophenylmaleimide, chlorophenylitaconimide, dichlorophenylitaconimide, nitrophenylitaconimide, phenylitaconimide substitution products such as nitrochlorophenylitaconimide, and phenylvinyl ether substitution products such as chlorophenyl vinyl ether and nitrophenyl vinyl ether. .. Particularly, a phenylmaleimide-substituted product and a phenylitaconimide-substituted product substituted with a chlorine atom or a nitro group are preferable in terms of charging property and filming resistance.

Examples of the acrylic acid ester monomer, the methacrylic acid ester monomer, and the aromatic vinyl monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, stearyl (meth) acrylate, dodecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, styrene, vinyltoluene, α-methylstyrene and the like.

By adding a sulfonate group-containing monomer as a monomer constituting the resin charge control agent in the present invention, the effect of imparting a negative charge to the resin charge control agent is improved, but the environmental stability of the toner ( It is generally known to be used as a copolymer with an aromatic monomer having an electron-withdrawing group, etc., but it may be used in the order of several thousands, but the temperature and humidity stability is reduced. When used for a long period of time, the developing sleeve and layer thickness control members (blades and rollers) are contaminated and filming occurs on the photoconductor, and the toner's charging stability and high image quality are not sufficiently maintained, resulting in reduced productivity. There is a problem of doing.

In order to make up for such defects, polyester resins and polyol resins suitable as binder resins for full-color toners from the viewpoints of color developability and image strength are (a)
Three types of monomers, a sulfonate group-containing monomer, (b) an electron-withdrawing group-containing aromatic monomer, and (c) an acrylic acid ester monomer and / or a methacrylic acid ester monomer, or (a), (b), By using a copolymer containing four kinds of monomers including (c) and (d) an aromatic vinyl monomer as a resin charge control agent, the developing sleeve and the layer thickness are excellent, because they are excellent in charging and environmental stability for a long period of time. It is possible to obtain a toner for electrophotography, which does not contaminate the regulating member (blade or roller), can form a thin layer well, prevents filming on the photoreceptor, maintains high image quality, and has high productivity.

It is presumed that these effects are due to the following reasons. That is, the combined use of a sulfonate group-containing monomer and an aromatic monomer having an electron-withdrawing group enhances the negative charge imparting effect, and uses an acrylic acid ester monomer and / or a methacrylic acid ester monomer and an aromatic vinyl monomer. This further increases the environmental stability of charging and increases the resin hardness,
In addition to improved pulverizability, there is no contamination of the developing sleeve or layer thickness control member (blade or roller), the effect of preventing photoconductor filming is improved, and as a binder resin for full-color toner, from the viewpoint of color developability and image strength. By combining with a suitable polyester resin, an appropriate dispersibility can be obtained, and an electrophotographic toner having a sharp charge amount distribution can be obtained.

The composition ratio of the monomers in the resin charge control agent used in the present invention is 1 to 30% by weight, more preferably 2 to 20% by weight, of the sulfonate group-containing monomer. When the amount of the sulfonate group-containing monomer is less than 1% by weight, the rise of charge and the amount of charge are insufficient and the image is likely to be affected. On the other hand, if it exceeds 30% by weight, the environmental stability of charging is deteriorated, the charging amount at high temperature and high humidity is low, and the charging amount at low temperature and low humidity is high, so that the charging stability of the toner and the maintenance of high image quality are not sufficient. Further, there is a problem that the developing sleeve and the layer thickness regulating member (blade and roller) are apt to be contaminated and the photoconductor filming is generated, and the productivity at the time of toner production by the kneading and pulverizing method is lowered.

The aromatic monomer having an electron-withdrawing group is 1 to
It is 80% by weight, more preferably 20 to 70% by weight. If the amount of the aromatic monomer having an electron-withdrawing group is less than 1% by weight, the amount of charge is insufficient and scumming and toner scattering easily occur. On the other hand, if it exceeds 80% by weight, the dispersion in the toner is poor, the charge amount distribution of the toner is widened, and scumming and toner scattering easily occur, and the maintenance of high image quality is not sufficient.

The amount of acrylic acid ester monomer and / or methacrylic acid ester monomer is 10 to 80% by weight, more preferably 20 to 70% by weight. If the amount of the acrylic acid ester monomer and / or the methacrylic acid ester monomer is less than 10% by weight, sufficient environmental stability of charging cannot be obtained, and the pulverizability at the time of toner production by the kneading / pulverization method is not sufficient. It is not possible to sufficiently prevent contamination of the developing sleeve and the layer thickness regulating member (blade and roller) and filming of the photoconductor. If it exceeds 80% by weight, the rise of electrification and the electrification amount are not sufficient and the image is likely to be affected.

The aromatic vinyl monomer is 0 to 30% by weight,
More preferably, it is 3 to 20% by weight. If the amount of the aromatic vinyl monomer exceeds 30% by weight, the resin becomes hard, the dispersibility in the toner is lowered, the charge distribution is widened, and scumming and toner scattering in the machine are likely to occur. Further, the fixability of the toner, especially the color developability when the color toners are mixed, becomes poor.

The resin charge control agent of these combinations can be used as a binder resin for a full-color toner in combination with a polyester resin suitable from the viewpoints of color developability and image strength, so that appropriate dispersibility can be obtained and the charge amount distribution can be sharp. An electrophotographic toner is obtained, and long-term charge stability and high image quality are obtained.

In the resin charge control agent of the present invention, it is considered that it is caused by residues of a catalyst, a polymerization inhibitor, a solvent, etc. at the time of synthesizing a phenylmaleimide substitution product or a phenylitaconimide substitution product monomer substituted with a chlorine atom or a nitro group. Variation in volume resistance is likely to occur, which affects a desired toner charge amount. Therefore, problems such as rising of charge of the toner containing the resin negative charge control agent and charge-up of saturated charge amount occur. The volume resistance of the resin charge control agent is 9.
When it is less than 5 Log Ω · cm, the toner on the developing roller cannot initially obtain a desired charge amount, and scumming and toner scattering occur. When the volume resistance of the resin charge control agent exceeds 11.5 Log Ω · cm, the toner on the developing roller initially obtains a desired charge amount, but the charge on the developing roller increases with time. The thin layer is not uniform, and color streaks and unevenness occur on the image. In the two-component development method, the image density decreases,
Scumming and toner scattering occur. The volume resistance of the resin charge control agent is preferably 9.5 to 11.5 LogΩ · cm, and 1
It is more preferably 0.0 to 11.0 Log Ω · cm.

The volume resistance is measured according to JIS standard K6911. The resin charge control agent is sized with a mesh to 23 ° C 5
Humidify at 0% RH. This sample is molded with an automatic pressure molding machine at a sample amount of 3 g and a pressure of 500 kg / cm ² to prepare a disc-shaped test piece having a thickness of about 2 mm and a diameter of 4 cm. After measuring the thickness accurately with a caliper, set it on the dielectric loss measuring instrument (TR-10C manufactured by Ando Electric Co., Ltd.) and set the frequency to 1 kHz.
Is applied and the volume resistance is measured.

The resin charge control agent used in the present invention preferably has a temperature of 85 to 110 ° C. at which the apparent viscosity of the flow tester becomes 10 ⁴ Pa · s. If the temperature is lower than 85 ° C., proper dispersibility in the toner cannot be obtained, and not only the charging is lowered but also the storage stability is deteriorated and the solidification is apt to occur. Further, in the method obtained from the production process of kneading, pulverizing and classifying, sticking is likely to occur in the pulverizing process and productivity is lowered. On the other hand, when the temperature exceeds 110 ° C., the dispersibility in the toner is lowered, the charge amount distribution is widened, and scumming and toner scattering in the machine are likely to occur. Further, the fixability of the toner, especially the color developability at the time of color superposition of the color toners becomes poor. The temperature at which the apparent viscosity is 10 ⁴ Pa · s was measured using a Shimadzu CFT-500 type as a flow tester, a load of 10 kg / cm ² , an orifice diameter of 1 mm and a length of 1 m.
m, the viscosity was measured at a temperature rising rate of 5 ° C./min, and the apparent viscosity was 10
^It reads the temperature at ⁴ Pa · s.

The weight average molecular weight of the resin charge control agent used in the present invention is preferably 5 × 10 ³ to 1 × 10 ⁵ . If it is less than 5,000, proper dispersibility in the toner cannot be obtained, and not only the charge is lowered, but also in the method obtained from the kneading, crushing and classifying production process, sticking easily occurs in the crushing process and productivity is improved. Lower. Also 1 ×
When it exceeds 10 ⁵ , the dispersibility in the toner is lowered, the charge amount distribution is widened, and background stain and toner scattering easily occur in the machine, resulting in poor toner fixability and color developability.

The temperature at which the apparent viscosity of the binder resin by the flow tester becomes 10 ³ Pa · s is T1,
When the temperature at which the apparent viscosity of the resin charge control agent by the flow tester becomes 10 ⁴ Pa · s is T2, T1
It is preferable that T2 is 0.9 <T1 / T2 <1.4.

Dispersion of the charge control agent in the binder resin is a major factor that determines the charging performance of the toner. In the present invention, a toner having good chargeability and excellent charge rising property can be obtained by combining a specific binder resin and a specific resin charge control agent. However, it is apparent that the dispersibility of the binder resin and the resin charge control agent affects the charging performance as described above. The inventors of the present invention have solved the problem by paying attention to the apparent viscosity of the binder resin and the resin charge control agent by the individual flow testers and defining the dispersity thereof. When T1 / T2 is 0.9 or less, the apparent viscosities of the binder resin and the resin charge control agent are close to each other, and the binder resin and the resin charge control agent are in a compatible state, resulting in insufficient saturated charge amount, poor charging start-up, and the like. When T1 / T2 is 1.4 or more, the apparent viscosities of the binder resin and the resin charge control agent are too far apart from each other, the resin charge control agent becomes poorly dispersed, and initial scumming and a decrease in charge with time occur.

The addition amount of the resin charge control agent in the present invention is preferably 0.1 to 20% by weight, and more preferably 0.5 to 10% by weight, based on the toner particles. If it is less than 0.1% by weight, the rising of the charge and the charge amount are not sufficient, and the image is likely to be affected such as scumming and scatter. If it exceeds 20% by weight, the dispersion becomes poor and the charge amount distribution becomes wide.
It is easy for dirt and toner to scatter inside the machine.

The additives used in the present invention include hydrophobized silica having a primary particle size of 0.01 to 0.03 μm, a primary particle size of 0.01 to 0.03 μm, and a specific surface area of 60.
˜140 m ² / g of hydrophobized titanium oxide.

That is, the primary particle diameter is 0.01 to 0.03.
By attaching the hydrophobic-treated silica of μm to the surface of the base toner, the toner is provided with the necessary fluidity and chargeability, and the developability on the developing roller and from the developing roller to the photoreceptor is improved. The addition amount of this type of silica is preferably 2.1 parts by weight or more with respect to 100 parts by weight of the base toner, so that the thin layer of the toner on the developing roller becomes uniform and the unevenness of the thin layer is significantly improved. Further, by stirring the developing roller for a long period of time, the occurrence of white stripes due to the fusion of the toner to the stirring developer coating blade is prevented. If it is less than the above range, the fluidity of the toner may not be sufficiently obtained, so that the required amount of toner may not be supplied to the developing roller, or the required toner charge amount may not be obtained. Further, the thin layer of the toner on the developing roller becomes non-uniform, so that uniform development of the toner and an image cannot be obtained, or white stripes may occur due to the fusion of the toner to the stirring developer coating blade.

Stabilizing the chargeability of the toner by adhering hydrophobically-treated titanium oxide having a primary particle diameter of 0.01 to 0.03 μm and a specific surface area of 60 to 140 m ² / g to the surface of the base toner. In particular, charge rising property and charge up are prevented. The addition amount of this type of titanium oxide is preferably 0.4 to 1.0 part by weight based on 100 parts by weight of the base toner. If the amount is less than 0.4 parts by weight, the toner may have too high a charging property to sufficiently develop the toner. If more than 1.0 part by weight is added, the chargeability of the toner is too low, which may cause the toner to scatter from the developing roller or stain the background.

The toner according to the present invention defines a weight average molecular weight of 5 × 10 ² or less by weight with respect to the molecular weight distribution of the binder resin, and defines the ratio of the weight average molecular weight to the number average molecular weight to provide blades, sleeves, etc. Filming is less likely to occur. Further, regarding the specific resin charge control agent, due to the definition of the constituent monomers, the definition of the apparent viscosity, and the definition of the apparent viscosity ratio with the binder resin to be dispersed, good chargeability is exhibited and filming hardly occurs. Further, by using a specific additive with the resin charge control agent and the binder resin, a toner having stable chargeability can be obtained.

The toner according to the present invention is characterized in that the coloring material is pretreated with a resin. The treatment method may be a conventionally known method, in which a resin and a coloring material are kneaded and dispersed at an appropriate concentration. Besides the melt-kneading, a flushing method using a solvent may be used. The mixing ratio of the resin and the coloring material is, for example, 5: 5.
~ 7: 3 mag. If the resin component is too much, the shearing force applied to the coloring material will be small and the dispersion will not proceed. On the other hand, if the amount of the colorant component is too large, the amount of the colorant that is not treated by the resin increases, and the colorant cannot be dispersed when it is dispersed in the binder resin for toner.

As the coloring material, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (1
0G, 5G, G), cadmium yellow, yellow iron oxide,
Loess, Yellow lead, Titanium yellow, Polyazo yellow, Oil yellow, Hansa yellow (GR, A, RN, R), Pigment yellow L, Benzidine yellow (G, GR), Permanent yellow (NCG), Balkan fast yellow (5G) , R), tartrazine lake, quinoline yellow lake, anthrazan yellow BGL, isoindolinone yellow, red iron oxide, red lead, lead vermilion, cadmium red, cadmium mercury red, antimon vermilion, permanent red 4R, para red, phise red, Parachlor Ortho Nitroaniline Red, Resor Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carnmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4R
H), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B,
Toluidine 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, Pyrazolone Red, Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkali Blue Lake, Peacock Blue Lake, Victoria Blue Rake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC),
Indigo, Ultramarine, Navy Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chromium Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B , Green gold, acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, lithopone and mixtures thereof can be used. Generally, the amount of binder resin is 10
It is 0.1 to 50 parts by weight with respect to 0 parts by weight.

In the present invention, it has been found that the use of a benzimidazolone yellow pigment is more effective, especially in a yellow pigment. Benzimidazolone yellow pigment is C.I. I. Pigment Yellow 180, which is an organic pigment and is represented by the following formula (2).

[0082]

[Chemical 7]

Since the present pigment is excellent in light resistance, heat resistance, color reproducibility and spectral characteristics and does not generate harmful substances during thermal decomposition, it is an effective and well-known material as a coloring material for yellow toner. However, since the molecular structure is large, there is a problem in dispersibility in the binder resin. The low molecular weight type resin used for color toner cannot be sheared by the resin and the dispersion of the pigment does not proceed. If too much shearing force is applied at the time of kneading, the binder resin will be cut into molecules, and the thermal characteristics (fixability, storability, etc.) of the toner will be adversely affected.

As a result of intensive studies, the present inventors have found that the specific polyol resin of the present invention and benzimidazolone yellow have excellent dispersibility and compatibility. It is considered that benzimidazolone yellow, which has a large molecular structure, is entangled with each other due to the expansion and contraction of the viscous portion and the elastic portion of the polyol resin skeleton, resulting in uniform dispersion.

In the present invention, a known charge control agent may be used together with the resin charge control agent. Nigrosine dyes,
Triphenylmethane dye, chromium-containing metal complex dye,
Examples include molybdic acid chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts, fluorine-modified quaternary ammonium salts, alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, and salicylic acid derivative metal salt compounds.

In order to impart releasability to the produced developer, it is preferable to add wax to the produced developer. The melting point of the wax is 40 to 120.
C., preferably 50 to 110.degree. When the melting point of the wax is too high, the fixability at low temperatures may be insufficient, while when the melting point is too low, the offset resistance and durability may deteriorate. The melting point of the wax is the differential scanning calorimetry (DSC).
Can be sought by. That is, the melting peak value when a few mg of sample is aged at a constant temperature rising rate, for example (10 ° C./min), is taken as the melting point.

Examples of the wax which can be used in the present invention include solid paraffin wax, microwax, rice wax, fatty acid amide wax, fatty acid wax, aliphatic monoketones, fatty acid metal salt wax, fatty acid ester wax. , Partially saponified fatty acid ester wax, silicone varnish, higher alcohol, carnauba wax and the like. In addition, polyolefins such as low molecular weight polyethylene and polypropylene can also be used. In particular, a polyolefin having a softening point of 70 to 150 ° C. by the ring and ball method is preferable, and a polyolefin having a softening point of 120 to 150 ° C. is more preferable.

The toner of the present invention may contain a cleaning property improving agent for removing the post-transfer developer remaining on the photoconductor or the primary transfer medium. Examples of the cleaning property improver include zinc stearate, calcium stearate, fatty acid metal salts such as stearic acid, for example, polymer fine particles produced by soap-free emulsion polymerization of polymethyl methacrylate fine particles, polystyrene fine particles and the like. . It is preferable that the fine polymer particles have a relatively narrow particle size distribution and a volume average particle diameter of 0.01 to 1 μm.

The toner of the present invention includes other additives such as colloidal silica, Teflon (registered trademark), fluoropolymers, low molecular weight polyolefins, metal oxides (aluminum oxide, tin oxide, antimony oxide, etc.) and conductivity imparting agents. (Carbon black, tin oxide, etc.), a magnetic material, and those obtained by surface-treating these additives may be contained. These additives may be used alone or in combination of two or more, and the content thereof is generally 0.1 to 10 parts by weight with respect to 100 parts by weight of the toner.

The toner of the present invention may be a magnetic toner containing a magnetic material. As the magnetic material, iron oxide (magnetite, ferrite, hematite, etc.), metal (iron, cobalt, nickel, etc.), the metal and aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, calcium, Examples thereof include alloys or mixtures of cadmium, manganese, selenium, titanium, tungsten, vanadium and the like. These magnetic materials preferably have a volume average particle diameter of about 0.1 to 2 μm, and the amount contained in the toner is 5 to 150 parts by weight with respect to 100 parts by weight of the binder resin content.

The toner of the present invention may be used as a two-component developer using a carrier. The carrier used here may be any conventional system such as iron powder, ferrite, magnetite, glass beads and the like. Further, these carriers may be resin-coated. The resin used in this case is a known one such as polyfluorocarbon, polyvinyl chloride, polyvinylidene chloride, phenol resin, polyvinyl acetal, acrylic resin, and silicone resin, but the silicone-coated carrier is excellent from the viewpoint of developer life. There is. If necessary, conductive powder or the like may be contained in the coating resin. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. It is preferable that these conductive powders have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control the electric resistance. The mixing ratio of the toner of the two-component developer and the carrier is generally 0.
5 to 20.0 parts by weight.

The method for producing the toner of the present invention may be any conventionally known method, including a step of mechanically mixing at least a developer component containing a binder resin, a charge control agent and a colorant, and a step of melt-kneading. A toner manufacturing method including a pulverizing step and a classifying step can be applied. Further, in the mechanical mixing step and the melt-kneading step, a manufacturing method of returning powders other than particles to be the product obtained in the pulverizing or classifying step and reusing them is also included.

After the step of melting and kneading with the powder (sub-product) other than the particles to be the product here, fine particles or coarse particles other than the components to be the product of the desired particle size obtained in the pulverizing step, and subsequent processing are carried out. It means fine particles or coarse particles other than the components that become the product of the desired particle size generated in the classification step. It is preferable to mix 1 to 20 parts by weight of the by-product with 100 parts by weight of the raw material and preferably 100 parts by weight of the main raw material in the step of mixing or melt-kneading such by-product.

At least a binder resin, a charge control agent,
The mixing step of mechanically mixing the colorant and the developer component including the by-product may be carried out under ordinary conditions using an ordinary mixer having rotating blades and is not particularly limited.

Upon completion of the above mixing steps, the mixture is then placed in a kneader and melt-kneaded. As the melt kneader, a uniaxial or biaxial continuous kneader or a batch type kneader using a roll mill can be used. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by KCK, PCM twin screw extruder manufactured by Ikegai Iron Works, Buss manufactured by Bus Co. A co-kneader or the like is preferably used.

It is important that this melt-kneading is carried out under appropriate conditions so as not to cause the breakage of the molecular chain of the binder resin. Specifically, the melt-kneading temperature should be determined with reference to the softening point of the binder resin. If the temperature is lower than the softening point, the cutting will be severe, and if it is too high, the dispersion will not proceed.

After the above melt-kneading process is completed, the kneaded product is then pulverized. In this pulverizing step, it is preferable to first coarsely pulverize and then finely pulverize. At this time, a method of colliding with a collision plate in a jet stream to pulverize, colliding particles in a jet stream to pulverize, or pulverizing with a narrow gap between a rotor and a stator rotating mechanically is preferably used. After the completion of this pulverizing step, the pulverized product is classified in an air stream by centrifugal force or the like to produce toner particles having a predetermined particle size, for example, an average particle size of 5 to 20 μm.

When preparing the toner, in order to improve the fluidity, storability, developability and transferability of the developer, the above-mentioned hydrophobic property of the toner particles produced as described above is used. Inorganic fine particles such as silica fine powder are added and mixed. A general powder mixer is used for mixing the external additives, but it is preferable to equip a jacket or the like to control the internal temperature. To change the history of the load applied to the external additive, the external additive may be added midway or gradually. Of course, the rotation speed, rolling speed, time, temperature, etc. of the mixer may be changed. A strong load may be applied first, and then a relatively weak load may be applied, or vice versa. Examples of mixing equipment that can be used include a V-type mixer, a rocking mixer, a Loedige mixer, a Nauta mixer, a Henschel mixer, and the like.

FIG. 1 shows an example of a one-component developing device of the image forming apparatus according to the present invention. This apparatus is an apparatus including a developer carrying member 1, a developer transporting member 2, a developer layer thickness regulating member 3, and a developer replenishing auxiliary member 4, and the developer carrying body 1 has the developer layer thickness regulating member. 3 is in contact with the developer transport member 2, the developer transport member 2 is rotatably movable, and the developer layer thickness regulating member 3 is rotatably movable, fixed or intermittently rotatable. The developer transport member 2 is located upstream of the developer layer thickness regulating member 3 in the rotation direction of the developer carrier, and the developer transport member 2
The surface is moved in the forward direction at the contact portion with the developer carrying member 1, and the developer transport member 2 is rotated at 160 mm / sec or more and 280 mm / sec or less. If the developer conveying member 2 is slower than 160 mm / sec, the toner is not sufficiently supplied and the charge amount cannot be sufficiently obtained. If it exceeds 280 mm / sec, the toner supply becomes excessive and the toner layer on the developer carrying member cannot be made uniform.

[0100]

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples, parts and% are based on weight unless otherwise specified.

(Synthesis Example of Polyester Resin) Synthesis Example 1 Stirrer, thermometer, nitrogen inlet, flow-down condenser,
In a 4-neck separable flask equipped with a cooling tube, 740 g of polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2
2) -2,2-bis (4-hydroxyphenyl) propane 300 g, dimethyl terephthalate 466 g, isododecenyl succinic anhydride 80 g, and tri-n-butyl 1,2,4-benzenetricarboxylate 114 g were added together with the esterification catalyst. In a nitrogen atmosphere, the atmospheric pressure was raised to 210 ° C. in the first half, and the reaction was performed while stirring at 210 ° C. in the latter half under reduced pressure. This gives a content of 3.5% with a molecular weight of 5 × 10 ² or less, a main molecular weight of 7.5 × 10 ³ , Tg of 62 ° C. and Mw / M.
n = 5.1, acid value 2.3 KOHmg / g, temperature 112 at which apparent viscosity by flow tester reaches 10 ³ Pa · s
A polyester resin (hereinafter referred to as polyester resin A) containing no THF insoluble component at 0 ° C. was obtained.

Synthesis Example 2 Polyoxypropylene (2,2) -2,2-bis (4-)
Hydroxyphenyl) propane 1225 g, polyoxyethylene (2,2) -2,2-bis (4-hydroxyphenyl) propane 165 g, terephthalic acid 500 g, isododecenyl succinic anhydride 130 g, 1,2,4-benzenetricarboxylic acid triisopropyl 170 g was added to the flask along with the esterification catalyst. Synthesis Example 1
Molecular weight of 5 × 1
Content of 0 ² or less 3.0%, molecular weight main peak 8 × 1
0 ³ , Tg 62 ° C., Mw / Mn = 4.7, acid value 0.5K
OHmg / g, apparent viscosity 10 ³ by flow tester
A polyester resin (hereinafter polyester resin B) containing no THF-insoluble component was obtained at a temperature of Pa · s of 116 ° C.

Synthesis Example 3 Polyoxypropylene (2,2) -2,2-bis (4-)
Ester of 650 g of hydroxyphenyl) propane, 650 g of polyoxyethylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, 515 g of isophthalic acid, 70 g of isooctenylsuccinic acid and 80 g of 1,2,4-benzenetricarboxylic acid It was added to the flask together with the oxidization catalyst. These were reacted with the same apparatus and the same formulation as in Synthesis Example 1, and the content was 2.1% with a molecular weight of 5 × 10 ² or less,
Molecular weight main peak 8.2 × 10 ³ , Tg 61 ° C., Mw
/Mn=4.6, acid value 10.0 KOHmg / g, temperature 1 at which apparent viscosity by flow tester becomes 10 ³ Pa · s
A polyester resin (hereinafter polyester resin C) containing no THF insoluble component at 17 ° C. was obtained.

Synthesis Example 4 Polyoxypropylene (2,2) -2,2-bis (4-)
Ester of 714 g of hydroxyphenyl) propane, 663 g of polyoxyethylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, 648 g of isophthalic acid, 150 g of isooctenylsuccinic acid and 120 g of 1,2,4-benzenetricarboxylic acid It was added to the flask together with the oxidization catalyst. These were reacted with the same apparatus and the same formulation as in Synthesis Example 1 to give a content of 4.8 with a molecular weight of 5 × 10 ² or less.
%, Molecular weight main peak 9.5 × 10 ³ , Tg 67 ° C.,
A THF-insoluble component-free polyester resin (hereinafter polyester resin D) having an Mw / Mn = 8.5, an acid value of 23.2 KOHmg / g and an apparent viscosity of 10 ³ Pa · s by a flow tester at a temperature of 126 ° C. was obtained. .

(Synthesis Example of Polyol Resin) Synthesis Example 1 In a separable flask equipped with a stirrer, thermometer, nitrogen inlet, and cooling tube, 252.6 g of high molecular weight bisphenol A epoxy resin (number average molecular weight of about 360), high Molecular bisphenol A type epoxy resin (number average molecular weight about 1000
0) 112.0 g, a diglycidyl compound of a bisphenol A-type ethylene oxide adduct (n + m is about 5.9 in the general formula (1)) 336.0 g, bisphenol A 255.3 g, p-cumylphenol 44.1 g, xylene. 200g was charged. 70 to 10 under nitrogen atmosphere
The temperature was raised to 0 ° C., 0.183 g of lithium chloride was added, the temperature was further raised to 160 ° C., xylene was distilled off under reduced pressure, and polymerization was performed at a reaction temperature of 180 ° C. for 6 to 9 hours to give a softening point of 1
1000 g of a polyol resin having a temperature of 100 ° C. at which the apparent viscosity by a flow tester was 10 ³ Pa · s was obtained at 09 ° C., Tg 58 ° C. (hereinafter referred to as polyol resin a).

Synthesis Example 2 In the apparatus of Synthesis Example 1, 289.9 g of low molecular weight bisphenol A type epoxy resin (number average molecular weight of about 360) and high molecular weight bisphenol A type epoxy resin (number average molecular weight of about 100) were used.
00) 232.0 g, a bisphenol A-type ethylene oxide adduct diglycidyl compound (n + m in the general formula (1) is about 6.0) 309.0 g, bisphenol A 117.5 g, p-cumylphenol 51.6.
g and 200 g of xylene were charged. 70 in a nitrogen atmosphere
Up to 100 ° C., 0.183 g of lithium chloride is added, the temperature is further raised to 160 ° C., xylene is distilled off under reduced pressure, polymerization is carried out at a reaction temperature of 180 ° C. for 6 to 9 hours, and a softening point of 116 ° C. , Tg 61 ° C., and 1000 g of a polyol resin having an apparent viscosity of 10 ³ Pa · s by a flow tester at a temperature of 106 ° C. (hereinafter referred to as polyol resin b).

Synthesis Example 3 421.5 g of low molecular weight bisphenol A type epoxy resin (number average molecular weight of about 680) and high molecular weight bisphenol A type epoxy resin (number average molecular weight of about 650) were added to the apparatus of Synthesis Example 1.
0) 107.0 g, diglycidylation product of bisphenol A-type ethylene oxide adduct (n + m is about 2.0 in the general formula (1)) 214.0 g, bisphenol F 210.0 g, p-cumylphenol 47.5 g, xylene. 200g was charged. 70 to 10 under nitrogen atmosphere
The temperature was raised to 0 ° C., 0.183 g of lithium chloride was added, the temperature was further raised to 160 ° C., xylene was distilled off under reduced pressure, and polymerization was performed at a reaction temperature of 180 ° C. for 6 to 9 hours to give a softening point of 1
1000 g of a polyol resin having a temperature of 104 ° C. at a temperature of 14 ° C., a Tg of 60 ° C. and an apparent viscosity of 10 ³ Pa · s by a flow tester was obtained (hereinafter referred to as a polyol resin c).

Synthesis Example 4 In the apparatus of Synthesis Example 1, 370.6 g of low molecular weight bisphenol A type epoxy resin (number average molecular weight: about 680), high molecular weight bisphenol A type epoxy resin (number average molecular weight: about 650) were used.
0) 306.0 g, bisphenol A type ethylene oxide adduct diglycidyl compound (n + m in the general formula (1) is about 5.8) 102.0 g, bisphenol A 110.2 g, p-cumylphenol 111.2 g,
200 g of xylene was charged. 70 to 1 under nitrogen atmosphere
The temperature was raised to 00 ° C., 0.183 g of lithium chloride was added, the temperature was further raised to 160 ° C., xylene was distilled off under reduced pressure, and polymerization was performed at a reaction temperature of 180 ° C. for 6 to 9 hours to give a softening point of 118 ° C. 1000 g of a polyol resin having a Tg of 62 ° C. and an apparent viscosity of 10 ³ Pa · s by a flow tester of 115 ° C. was obtained (hereinafter referred to as polyol resin d).

(Synthesis Example of Resin Charge Control Agent) Synthesis Example 1 350 parts of 3,4-dichlorophenylmaleimide and 2-
Acrylamide-2-methylpropanesulfonic acid 100
A part was copolymerized in dimethylformaldehyde (DMF) at a boiling point for 8 hours using di-t-butyl peroxide as an initiator. Next, after adding 500 parts of n-butyl acrylate and 50 parts of styrene and graft-polymerizing for 4 hours with di-t-butyl peroxide as an initiator, DMF was distilled off under reduced pressure to obtain a volume resistance of 10.5 LogΩ · cm. A resin charge control agent 1 having a weight average molecular weight of 1 × 10 ⁴ and an apparent viscosity of 10 ⁴ Pa · s and a temperature of 96 ° C. was obtained.

Synthesis Example 2 3,4-dichlorophenylmaleimide 500 parts and 2-
Acrylamide-2-methylpropanesulfonic acid 150
Part was copolymerized in DMF at a boiling point for 8 hours using di-t-butyl peroxide as an initiator. Then acrylic acid n-
After adding 350 parts of butyl and 250 parts of α-methylstyrene and graft-polymerizing for 4 hours with di-t-butyl peroxide as an initiator, DMF was distilled off under reduced pressure to obtain a volume resistance of 11.5 LogΩ · cm, A resin charge control agent 2 having a weight average molecular weight of 9.6 × 10 ⁴ and an apparent viscosity of 10 ⁴ Pa · s at a temperature of 110 ° C. was obtained.

Synthesis Example 3 400 parts of 3,4-dichlorophenylmaleimide and 200 parts of perfluorooctane sulfonic acid were copolymerized in DMF at a boiling point for 8 hours with di-t-butyl peroxide as an initiator. Next, 300 parts of n-butyl acrylate was added, and di-t-butyl peroxide was used as an initiator to prepare 4 parts.
After graft polymerization for a period of time, DMF was distilled off under reduced pressure to obtain a resin having a volume resistance of 10.4 Log Ω · cm, a weight average molecular weight of 1.5 × 10 ⁴ and an apparent viscosity of 10 ⁴ Pa · s at a temperature of 105 ° C. Control agent 3 was obtained.

Synthesis Example 4 400 parts of 3,4-dichlorophenylmaleimide and 2-
Acrylamide-2-methylpropanesulfonic acid 100
Part was copolymerized in DMF at a boiling point for 8 hours using di-t-butyl peroxide as an initiator. Then acrylic acid n-
After adding 500 parts of butyl and 100 parts of styrene and dissolving, graft polymerization was carried out for 4 hours with di-t-butyl peroxide as an initiator, DMF was distilled off under reduced pressure, and volume resistance was 9.3 Log Ω · cm, weight average. Molecular weight 3 × 1
0 ⁴ , the temperature at which the apparent viscosity is 10 ⁴ Pa · s is 101 ° C
Thus, a resin charge control agent 4 was obtained.

Synthesis Example 5 3,4-dichlorophenylmaleimide 400 parts and 2-
Acrylamide-2-methylpropanesulfonic acid 200
Part was copolymerized in DMF at a boiling point for 8 hours using di-t-butyl peroxide as an initiator. Then acrylic acid n-
200 parts of butyl and 400 parts of styrene were added and dissolved, followed by graft polymerization with di-t-butyl peroxide as an initiator for 4 hours, and then DMF was distilled off under reduced pressure to obtain a volume resistance of 11.6 LogΩ · cm and a weight average. Molecular weight 11.6
× 10 ³ , the temperature at which the apparent viscosity is 10 ⁴ Pa · s is 11
A resin charge control agent 5 having a temperature of 0 ° C. was obtained.

(Example of Additive) (I) Hydrophobized silica having a primary particle diameter of 0.01 to 0.03 μm

[0115]

[Table 1] (II) Primary particle size 0.01 to 0.03 μm and specific surface area 6
Hydrophobized titanium oxide of 0 to 140 m ² / g

[0116]

[Table 2]

Example 1 A coloring material was treated according to the following formulation. Yellow colorant formulation: Polyol resin a 200 parts by weight C.I. I. Pigment Yellow 180 100 parts by weight Red colorant formulation: 200 parts by weight of polyol resin a C.I. I. Pigment Red 146 100 parts by weight Blue colorant formulation: 200 parts by weight of polyol resin a C.I. I. Pigment Blue 15: 3 100 parts by weight Black colorant formulation: Polyol resin a 200 parts by weight Carbon black 100 parts by weight The above materials are put into a Henschel mixer for each color and mixed, and then the mixture is heated to 100 ° C. in a two-roll mill. The mixture was melted and kneaded for 30 minutes. Thereafter, the kneaded product was rolled and cooled, and coarsely pulverized with a hammer mill to obtain a polyol resin a-treated coloring material.

Then, toner particles were prepared by the following formulation. Yellow toner particle formulation: Polyester resin A 88 parts by weight Polyol resin a treated yellow colorant 18 parts by weight Resin charge control agent 1 3 parts by weight Magenta toner particle formulation: Polyester resin A 90 parts by weight Polyol resin a treated red colorant 15 Parts by weight Resin charge control agent 1 3 parts by weight Cyan toner particle formulation: Polyester resin A 94 parts by weight Polyol resin a treated blue colorant 9 parts by weight Resin charge control agent 1 3 parts by weight Black toner particle formulation: Polyester resin A 86 parts by weight Part Polyol resin a treated black colorant 18 parts by weight Polyol resin a treated blue colorant 3 parts by weight Resin charge control agent 1 3 parts by weight The above materials were put into a Henschel mixer and mixed, and the resulting mixture was mixed with 110 parts. The mixture was put into a roll mill heated to ℃ and melted and kneaded for 30 minutes after the addition. Then, the kneaded product was rolled and cooled, coarsely pulverized by a hammer mill and finely pulverized by an air jet mill pulverizer. Further, fine powder was removed by an air classifier to obtain toner particles of each color. The ratio (T1) of the temperature (T1) at which the apparent viscosity of the polyester resin A by the flow tester becomes 10 ³ Pa · s and the temperature (T2) at which the apparent viscosity of the resin charge control agent 1 by the flow tester becomes 10 ⁴ Pa · s (T1). / T2) was 1.17.

The following additives were mixed with 100 parts by weight of the obtained toner particles of each color in a Henschel mixer to prepare a toner (one-component developer). I-1 hydrophobic silica 2.4 parts by weight II-1 hydrophobic titanium oxide 0.8 parts by weight

A commercially available digital full-color printer (IPSiO Colo manufactured by Ricoh Co., Ltd.) was used as the obtained one-component developer.
r 4100N) to form an image. The image obtained was clear and no abnormalities such as scumming were observed. When the developing roller was visually observed, the thin layer on the roller was uniform. The amount of charge on the developing roller was measured by a suction method. As a result, the yellow developer was -32 µC / g, the magenta developer was -28 µC / g, and the cyan developer was -30 µC.
C / g, and the black developer was -29 μC / g. Three
Even under high temperature and high humidity of 0 ° C 90% RH, 10 ° C 15% R
The image was similarly formed and the charge amount was measured under the low temperature and low humidity condition of H.
No significant change was observed, and good images were formed in all cases. When a full-color image was formed on an OHP sheet at room temperature and projected by an overhead projector, an extremely clear full-color image was projected. Further, when the yellow toner was dissolved in toluene and the dispersibility of the pigment was visually confirmed, no aggregate of the pigment was found. When a durability test was performed on a full-color image up to 30,000 sheets at room temperature, no significant change was found in the fixed image, and the 30,000th image was a clear image without background stain. Visual observation of the developing roller after printing the 30,000th sheet showed no remarkable change in the thin layer on the roller. At this time, the charge amount of the developer was yellow developer -30 μC / g, magenta developer-
It was stable at 27 μC / g, cyan developer-29 μC / g, and black developer-27 μC / g. The developing roller, blade, and photoreceptor were visually observed after 30,000 sheets, but there was no filming. A storage test was conducted in which 10 g of each color toner was placed in a heat-resistant glass container of 30 cc and allowed to stand in a constant temperature bath at 50 ° C. for 5 days. As a result, the toner did not show agglomeration or the like and good fluidity was maintained. .

Example 2 A coloring material was treated according to the following formulation. Yellow colorant formulation: Polyol resin b 100 parts by weight C.I. I. Pigment Yellow 180 100 parts by weight Red colorant formulation: Polyol resin b 100 parts by weight C.I. I. Pigment Red 57: 1 100 parts by weight Blue-based colorant formulation: Polyol resin b 100 parts by weight C.I. I. Pigment Blue 15: 3 100 parts by weight Black colorant formulation: 100 parts by weight of polyol resin b 100 parts by weight of carbon black 100 parts by weight of each color The above materials are put into a Henschel mixer and mixed, and then the mixture is put into an air-cooled two-roll mill. After the addition, the mixture was kneaded for 20 minutes. After that, the kneaded product was rolled and cooled, and coarsely pulverized by a hammer mill to obtain a polyol resin b-treated coloring material.

Next, toner particles were prepared by the following formulation. Yellow toner particle formulation: Polyester resin B 94 parts by weight polyol resin b treated yellow colorant 12 parts by weight Resin charge control agent 2 3 parts by weight Magenta toner particle formulation: polyester resin B 95 parts by weight Polyol resin b treated red colorant 10 Parts by weight Resin charge control agent 2 4 parts by weight Cyan toner particle formulation: Polyester resin B 96 parts by weight Polyol resin b treated blue colorant 8 parts by weight Resin charge control agent 2 3 parts by weight Black toner particle formulation: Polyester resin B 93 parts by weight Part Polyol resin b-treated blue colorant 2 parts by weight Polyol resin b-treated black colorant 12 parts by weight Resin charge control agent 2 3 parts by weight The above materials are put into a Henschel mixer and mixed, and the resulting mixture is mixed with 80 parts. The mixture was charged into a twin-screw continuous kneader heated to ° C and melt-kneaded. After that, the kneaded product is rolled and cooled,
Coarse pulverization was performed with a hammer mill and fine pulverization was performed with an airflow pulverizer. Further, fine powder was removed by an air classifier to obtain toner particles of each color. The polyester resin B and T1 of the resin charge control agent 2
/ T2 was 1.05.

The following additives were mixed with 100 parts by weight of the obtained toner particles of each color by a Henschel mixer to prepare a toner (one-component developer). I-2 Hydrophobic silica 2.3 parts by weight II-2 Hydrophobic titanium oxide 0.5 parts by weight

A commercially available digital full color printer (Ricoh Co., Ltd. I
PSiO Color 4100N), and an image was formed in the same manner as in Example 1. The obtained image was clear without scumming. When the developing roller was visually observed, the thin layer on the roller was uniform. The amount of charge on the developing roller was measured by a suction method. As a result, the yellow developer was -32 μC / g, the magenta developer was -29 μC / g,
Cyan developer is -30 μC / g, black developer is -2
It was 9 μC / g. The projected image on the OHP sheet was also vivid. No abnormal image was observed under high temperature and high humidity and low temperature and low humidity, and no significant change was observed in both image and charge in the durability test of 30,000 sheets. The developing roller, blade, and photoreceptor were visually observed after 30,000 sheets, but there was no filming. The thin layer on the developing roller was also uniform. Further, a storage test was conducted in which each color toner was allowed to stand in a constant temperature bath of 50 ° C. for 5 hours. As a result, no agglomeration was observed in the toner after standing and good fluidity was maintained.

Example 3 A coloring material was treated according to the following formulation. Yellow colorant formulation: Polyol resin c 200 parts by weight C.I. I. Pigment Yellow 180 100 parts by weight Red colorant formulation: Polyol resin c 200 parts by weight C.I. I. Pigment Red 57: 1 100 parts by weight Blue colorant formulation: Polyol resin c 200 parts by weight C.I. I. Pigment Blue 15: 3 100 parts by weight Black colorant formulation: Polyol resin c 200 parts by weight Carbon black 100 parts by weight The above materials for each color are put into a Henschel mixer and mixed, and then the mixture is heated to 110 ° C. in a two-roll mill. And kneaded for 30 minutes after the addition. Thereafter, the kneaded product was rolled and cooled, and coarsely pulverized with a hammer mill to obtain a polyol resin c-treated coloring material.

Then, toner particles were prepared by the following formulation. Yellow toner particle formulation: Polyester resin C 88 parts by weight Polyol resin c-treated yellow colorant 18 parts by weight Resin charge control agent 3 2 parts by weight Magenta toner particle formulation: Polyester resin C 90 parts by weight Polyol resin c-treated red colorant 15 Parts by weight Resin charge control agent 3 3 parts by weight Cyan toner particle formulation: Polyester resin C 94 parts by weight Polyol resin c treated blue colorant 9 parts by weight Resin charge control agent 3 2 parts by weight Black toner particle formulation: Polyester resin C 86 parts by weight Parts Polyol resin c-treated black colorant 18 parts by weight Polyol resin c-treated blue colorant 3 parts by weight Resin charge control agent 3 2 parts by weight The above materials are put into a Henschel mixer and mixed, and the resulting mixture is mixed with 80 parts. The mixture was charged into a twin-screw continuous kneader heated to ° C and melt-kneaded. After that, the kneaded product is rolled and cooled,
Coarse pulverization was performed with a hammer mill and fine pulverization was performed with a mechanical pulverizer. Further, fine powder was removed by an air classifier to obtain toner particles of each color. The polyester resin C and T1 of the resin charge control agent 3
/ T2 was 1.11.

The following additives were mixed with 100 parts by weight of the obtained toner particles of each color by a Henschel mixer to obtain toners of each color. I-3 Hydrophobic silica 2.1 parts by weight II-3 Hydrophobic titanium oxide 0.4 parts by weight

Then, 7 parts by weight of each color toner and 93 parts by weight of a silicone resin-coated magnetite carrier were mixed to prepare a two-component developer for each color. The charge amount of the obtained developer was measured by the blow-off method. As a result, the yellow developer was -23 μC / g, the magenta developer was −22 μC / g, the cyan developer was −23 μC / g, and the black developer was −21 μC / g.
It was μC / g.

A commercially available digital full-color printer (IPSiO Color 8 manufactured by Ricoh Co., Ltd.) was used as the obtained developer.
000) and an image was formed in the same manner as in Example 1. The obtained image was clear without scumming. OHP
The projected image on the sheet was also vivid. No significant change was observed in both images and charging at high temperature and high humidity, low temperature and low humidity. No abnormal image was observed in the 30,000-sheet durability test. Three
The photoreceptor was visually observed after 10,000 sheets, but there was no filming. Further, a storage test was conducted in which each color toner was allowed to stand in a constant temperature bath of 50 ° C. for 5 hours. As a result, no agglomeration was observed in the toner after standing and good fluidity was maintained.

Example 4 A coloring material was treated according to the following formulation. Yellow colorant formulation: Polyol resin c 100 parts by weight C.I. I. Pigment Yellow 180 100 parts by weight Red colorant formulation: Polyol resin c 100 parts by weight C.I. I. Pigment Red 146 100 parts by weight Blue colorant formulation: Polyol resin c 100 parts by weight C.I. I. Pigment Blue 15: 3 100 parts by weight Black colorant formulation: 100 parts by weight of polyol resin c 100 parts by weight of carbon black 100 parts by weight of each color The above materials are put into a Henschel mixer and mixed, and then the mixture is put into an air-cooled two-roll mill. After the addition, the mixture was kneaded for 20 minutes. Then, the kneaded product was rolled and cooled, and coarsely pulverized with a hammer mill to obtain a polyol resin c-2 treated colorant.

Then, toner particles were prepared by the following formulation. Yellow toner particle formulation: Polyester resin C 91 parts by weight Polyol resin c-2 treated yellow colorant 18 parts by weight Resin charge control agent 12 parts by weight Magenta toner particle formulation: Polyester resin C 94 parts by weight Polyol resin c-2 treated red Colorant 12 parts by weight Resin charge control agent 1 3 parts by weight Cyan toner particle formulation: Polyester resin C 96 parts by weight Polyol resin c-2 treated blue colorant 8 parts by weight Resin charge control agent 1 3 parts by weight Black toner particle formulation : Polyester resin C 93 parts by weight Polyol resin c-2 treated black colorant 12 parts by weight Polyol resin c-2 treated blue colorant 2 parts by weight Resin charge control agent 1 3 parts by weight The above materials are added to a Henschel mixer for each color. The mixture was added and mixed, and the obtained mixture was put into a twin-screw continuous kneader heated to 80 ° C. and melt-kneaded. After that, the kneaded product is rolled and cooled,
Coarse pulverization was performed with a hammer mill and fine pulverization was performed with a mechanical pulverizer. Further, fine powder was removed by an air classifier to obtain toner particles of each color. The polyester resin C and T1 of the resin charge control agent 1
/ T2 was 1.22.

To 100 parts by weight of the obtained toner particles of each color, the following additives were mixed by a Henschel mixer to obtain a toner (one-component developer). I-4 Hydrophobic silica 2.7 parts by weight II-4 Hydrophobic titanium oxide 1.0 part by weight

A commercially available digital full color printer (IPSiO Color manufactured by Ricoh Co., Ltd.) was used as the obtained one-component developer.
4100 N) and an image was formed in the same manner as in Example 1. The obtained image was clear without scumming. When the developing roller was visually observed, the thin layer on the roller was uniform. When the amount of charge on the developing roller was measured by the suction method, it was -36 μC /
g, magenta developer was −31 μC / g, cyan developer was −33 μC / g, and black developer was −32 μC / g. The projected image on the OHP sheet was also vivid.
No significant change was observed in both images and charging at high temperature and high humidity, low temperature and low humidity. No abnormal image was observed in the 30,000-sheet durability test. The developing roller and the photoconductor were visually observed after 30,000 sheets, but there was no filming. In addition, each color toner 50 ℃
When a storage test was carried out by leaving the toner in the constant temperature tank for 5 hours, no agglomeration was observed in the toner after the toner was left and good fluidity was maintained.

Example 5 A coloring material was treated according to the following formulation. Yellow colorant formulation: Polyol resin b 100 parts by weight C.I. I. Pigment Yellow 180 100 parts by weight Red colorant formulation: Polyol resin b 100 parts by weight C.I. I. Pigment Red 122 100 parts by weight Blue-based colorant formulation: Polyol resin b 100 parts by weight C.I. I. Pigment Blue 15: 3 100 parts by weight Black colorant formulation: Polyol resin b 100 parts by weight Carbon black 100 parts by weight The above materials for each color are put into a Henschel mixer and mixed, and then the mixture is heated to 90 ° C. in a two-roll mill. And kneaded for 30 minutes after the addition. Thereafter, the kneaded product was rolled and cooled, and coarsely pulverized with a hammer mill to obtain a polyol resin b-2 treated colorant.

Then, toner particles were prepared by the following formulation. Yellow toner particle formulation: 93 parts by weight of polyester resin B Polyol resin b-2 treated yellow colorant 14 parts by weight Resin charge control agent 3 4 parts by weight Magenta toner particle formulation: 94 parts by weight of polyester resin B Polyol resin b-2 treated red Colorant 12 parts by weight Resin charge control agent 3 5 parts by weight Cyan toner particle formulation: Polyester resin B 96 parts by weight Polyol resin b-2 treated blue colorant 8 parts by weight Resin charge control agent 3 4 parts by weight Black toner particle formulation Polyester resin B 91 parts by weight Polyol resin b-2 treated black colorant 16 parts by weight Polyol resin b-2 treated blue colorant 2 parts by weight Resin charge control agent 3 4 parts by weight The above materials are added to a Henschel mixer for each color. The mixture was put and mixed, and the obtained mixture was put into a twin-screw continuous kneader heated to 80 ° C. and melt-kneaded. After that, the kneaded product is rolled and cooled,
Coarse pulverization was performed with a hammer mill and fine pulverization was performed with a mechanical pulverizer. Further, fine powder was removed by an air classifier to obtain toner particles of each color. The polyester resin B and T1 of the resin charge control agent 3
/ T2 was 1.10.

The following additives were mixed with 100 parts by weight of the obtained toner particles of each color by a Henschel mixer to obtain toners of each color. I-1 Hydrophobic silica 2.2 parts by weight II-1 Hydrophobic titanium oxide 0.5 parts by weight

Then, 7 parts by weight of each color toner and 93 parts by weight of a silicone resin coated magnetite carrier were mixed to prepare a two-component developer for each color. The charge amount of the obtained developer was measured by the blow-off method. As a result, the yellow developer was -28 μC / g, the magenta developer was -25 μC / g, the cyan developer was -29 C / 28 g, and the black developer was -2.
It was 6 μC / g. A commercially available digital full-color copying machine (Imagio Colo manufactured by Ricoh Co., Ltd.)
r 5105) and an image was formed in the same manner as in Example 1. The obtained image was clear without scumming. O
The projected image on the HP sheet was also vivid. No significant change was observed in both images and charging at high temperature and high humidity, low temperature and low humidity. No abnormal image was observed in the 30,000-sheet durability test. Visual observation of the photoreceptor after 30,000 sheets showed no filming. Further, a storage test was conducted in which each color toner was allowed to stand in a constant temperature bath of 50 ° C. for 5 hours. As a result, no agglomeration was observed in the toner after standing and good fluidity was maintained.

Comparative Example 1 Toner particles were prepared according to the following formulation without pretreatment of the coloring material. Yellow toner particle formulation: Polyester resin A 100 parts by weight C.I. I. Pigment Yellow 180 6 parts by weight Resin charge control agent 1 3 parts by weight Magenta toner particle formulation: Polyester resin A 100 parts by weight C.I. I. Pigment Red 146 5 parts by weight Resin charge control agent 1 3 parts by weight Cyan toner particle formulation: Polyester resin A 100 parts by weight C.I. I. Pigment Blue 15: 3 3 parts by weight Resin Charge Control Agent 1 3 parts by weight Black toner particle formulation: Polyester resin A 100 parts by weight Carbon black 6 parts by weight C.I. I. Pigment Blue 15: 3 1 part by weight Resin charge control agent 1 3 parts by weight The above materials for each color are put into a Henschel mixer and mixed, and the resulting mixture is put into a roll mill heated to 110 ° C. and melted and kneaded for 30 minutes after the addition. did. Thereafter, the kneaded product was cooled, coarsely pulverized with a hammer mill, and finely pulverized with an air jet mill pulverizer. Further, fine powder was removed by an air classifier to obtain toner particles of each color. The T1 / T2 of the polyester resin A and the resin charge control agent 1 was 1.17.

To 100 parts by weight of the obtained toner particles of each color, the following additives were mixed by a Henschel mixer to prepare a toner (one-component developer). I-1 hydrophobic silica 2.4 parts by weight II-1 hydrophobic titanium oxide 0.8 parts by weight

A commercially available digital full-color printer (IP manufactured by Ricoh Co., Ltd.) was used in the same manner as in Example 1 to obtain the obtained one-component developer.
An image was formed by setting on SiO Color 4100N). In the obtained image, dust was conspicuous and stains were conspicuous. When the developing roller was visually observed, unevenness was found in the toner layer on the roller. When the amount of charge on the developing roller was measured by the suction method, it was −22 for the yellow developer.
μC / g, -18 μC / g for magenta developer, -20 μC / g for cyan developer, -18 μC / g for black developer
It was a low g. Under high temperature and high humidity of 30 ° C. and 90% RH, the ground stain became more severe. Further, when a full color image was formed on an OHP sheet and projected by an overhead projector, the transparency was poor and only a darkened full color image was projected. Further, when a durability test was performed on a full-color image up to 30,000 sheets at room temperature, the image density was low and the background stain was severe after about 5,000 sheets.
When the developing roller was visually observed, the toner layer on the roller had streaks, the unevenness was severe, and the toner was dropped from the roller in some places. When the charge amount on the developing roller was measured, it was found that the yellow developer was -10 μC /
g, magenta developer -8 μC / g, cyan developer-
The deterioration was 11 [mu] C / g and the black developer was -8 [mu] C / g.

Comparative Example 2 A coloring material was pretreated by the following formulation. Yellow colorant formulation: Polyester resin D 200 parts by weight C.I. I. Pigment Yellow 180 100 parts by weight Red colorant formulation: Polyester resin D 200 parts by weight C.I. I. Pigment Red 146 100 parts by weight Blue colorant formulation: Polyester resin D 200 parts by weight C.I. I. Pigment Blue 15: 3 100 parts by weight Black colorant formulation: 200 parts by weight of polyester resin D 100 parts by weight of carbon black 100 parts by weight of each color The above materials are put into a Henschel mixer and mixed, and then the mixture is heated to 100 ° C. in a two-roll mill. The mixture was melted and kneaded for 30 minutes. Thereafter, the kneaded product was rolled and cooled, and coarsely pulverized with a hammer mill to obtain a resin D-treated coloring material.

Next, toner particles were prepared by the following formulation. Yellow toner particle formulation: 88 parts by weight of polyester resin D Resin D-treated yellow colorant 18 parts by weight Resin charge control agent 4 3 parts by weight Magenta toner particle formulation: 90 parts by weight of polyester resin D Resin D-treated red colorant 15 parts by weight Resin charge control agent 4 3 parts by weight Cyan toner particle formulation: Polyester resin D 94 parts by weight Resin D treated blue colorant 9 parts by weight Resin charge control agent 4 3 parts by weight Black toner particle formulation: Polyester resin D 86 parts by weight Resin D Treated black colorant 18 parts by weight Resin D Treated blue colorant 3 parts by weight Resin charge control agent 4 3 parts by weight The above materials were put in a Henschel mixer for each color and mixed, and the resulting mixture was heated to 110 ° C. The mixture was placed in a roll mill and, after the introduction, was melted and kneaded for 30 minutes. Thereafter, the kneaded product was cooled, coarsely pulverized with a hammer mill, and finely pulverized with an air jet mill pulverizer. Further, fine powder was removed by an air classifier to obtain toner particles of each color. The T1 / T2 of the polyester resin D and the resin charge control agent 4 was 1.25.

The following additives were mixed with 100 parts by weight of the obtained toner particles of each color by a Henschel mixer to prepare a toner (one-component developer). I-1 Hydrophobic silica 2.3 parts by weight II-1 Hydrophobic titanium oxide 0.6 parts by weight

A commercially available digital full color printer (IP manufactured by Ricoh Co., Ltd.) was used in the same manner as in Example 1 except that the obtained one-component developer was used.
An image was formed by setting on SiO Color 4100N). The image obtained was clear and no abnormalities such as scumming were observed. When the developing roller was visually observed, the thin layer on the roller was uniform. When the amount of charge on the developing roller was measured by the suction method, the yellow developer was -3.
3 μC / g, -27 μC / g for magenta developer, -29 μC / g for cyan developer, -28 μC for black developer
/ G. An image was similarly formed and the charge amount was measured under a high temperature and high humidity condition of 30 ° C. and 90% RH, and under a low temperature and low humidity condition of 10 ° C. and 15% RH, but no remarkable change was observed and good images were formed in both cases. . When a full-color image was formed on an OHP sheet at room temperature and projected by an overhead projector, the full-color image was projected, but the image was slightly darkened as a whole. When the yellow toner was dissolved in toluene and the dispersibility of the pigment was visually confirmed, aggregates of the pigment were found.

[0145]

According to the present invention, in both the two-component and one-component color developing systems, there is no filming on the photoconductor, the developer layer thickness regulating member or the developing sleeve after continuous printing for a long time. It is possible to obtain an electrophotographic toner capable of stabilizing the charging and conveyance of the toner and maintaining an image density equivalent to that of the initial image and a high-quality output image. Further, an electrophotographic toner excellent in coloring power and transparency can be obtained. Further, since there is little reduction in charging during continuous use, there are no problems such as fluctuations in image density, low developability, background stains, and toner scattering in the developing device, and an image with good color development and color reproducibility can be obtained. Due to such long-term durability, it is possible to extend the life of the developing unit, photoconductor unit, etc., and reduce the amount of recycled materials and waste generated after use, which is much more labor for the user to replace those image forming units. Can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of a one-component developing device of an image forming apparatus of the present invention.

[Explanation of symbols]

1 developer carrier 2 Developer transport member 3 Developer layer thickness control member 4 Developer supply auxiliary member

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 9/08 361 333 F term (reference) 2H005 AA01 AA06 AA08 CA02 CA04 CA07 CA08 CA20 CA21 CA30 CB13 DA02 EA01 EA03 EA05 EA06 EA07

Claims (6)

[Claims] 1. A dry electrophotographic toner mainly containing at least a binder resin, a coloring material, a charge control agent and an additive, wherein the coloring material is pretreated with a resin different from the binder resin. Dry type electrophotographic toner. 2. The binder resin is made of one or more kinds of polyester resins and has the following characteristics, and the colorant pretreatment resin different from the binder resin is a polyol resin having the following components. 2. The dry electrophotographic toner according to claim 1, wherein the charge control agent is a resin charge control agent having the following characteristics, and the additive has the following configuration. Binder resin; polyester resin, containing no THF insoluble component, and having a weight average molecular weight of 5 × 10 ² or less in the molecular weight distribution in gel permeation chromatography (GPC), 4% by weight or less, It has a main peak in the region where the weight average molecular weight is 3 × 10 ³ or more and 9 × 10 ³ or less. Polyol resin: A polyol having an epoxy resin part and an alkylene oxide part in the main chain and having an inactive resin terminal. A polyol obtained by reacting an epoxy resin, an alkylene oxide adduct of a dihydric phenol or a glycidyl ether thereof with a compound having two or more active hydrogens that react with an epoxy group in the molecule. Alternatively, the epoxy resin forming the polyol is at least two kinds of bisphenol A type epoxy resins having different number average molecular weights. At least 2 having different number average molecular weights
The low molecular weight component of the one or more bisphenol A type epoxy resins has a number average molecular weight of 360 to 2000, and the high molecular weight component has a number average molecular weight of 3000 to 10,000. In the above, the low molecular weight component and the high molecular weight component of at least two kinds of bisphenol A type epoxy resins having different number average molecular weights are 20 to 50% by weight and 5 to 40% by weight with respect to the polyol. In the above, the glycidyl ether of the alkylene oxide adduct of the dihydric phenol constituting the polyol is a diglycidyl ether of the alkylene oxide adduct of bisphenol A and is represented by the following general formula (1). [Chemical 1] (Here, R is And n and m are the numbers of repeating units, each being 1 or more and n + m = 2 to 6. ) Or, the alkylene oxide adduct of dihydric phenol or its glycidyl ether constituting the polyol is 10 to 40 with respect to the polyol.
Contains% by weight. Charge control agent: a resin charge control agent, and at least (a) a sulfonate group-containing monomer as a monomer, (b) an aromatic monomer having an electron-withdrawing group, (c) an acrylic acid ester monomer, and / or methacrylic acid. An ester monomer and (d) an aromatic vinyl monomer, or (a), (b), and (c) as a constituent unit, and the resin charge control agent has a volume resistance of 9.5 to 11.5 Log Ω · cm.
Is. Additives; hydrophobized silica having a primary particle diameter of 0.01 to 0.03 μm and primary particle diameter of 0.01 to 0.03 μm
And titanium oxide having a specific surface area of 60 to 140 m ² / g that has been hydrophobized. 3. The colorant having one or more types of yellow colorants, at least one of which is a benzimidazolone yellow pigment.
The dry electrophotographic toner according to item 1. 4. The temperature at which the apparent viscosity of the binder resin by the flow tester becomes 10 ³ Pa · s is T1, and the temperature at which the apparent viscosity of the resin charge control agent by the flow tester is 10 ⁴ Pa · s is T2. When T1, T
2. The toner for dry electrophotography according to claim 1, wherein 2 is 0.9 <T1 / T2 <1.4. 5. A latent image forming step of forming a latent image on a latent image holding body, a developing step of developing the latent image with a developer on a developer carrying body, and a developed toner image on a transfer body. An image forming method having a transfer step of transferring the toner image on a transfer body and a fixing step of heating and fixing a toner image on a transfer body, wherein the developer contains the dry electrophotographic toner according to any one of claims 1 to 4. An image forming method characterized by using. 6. A container holding a developer containing the dry electrophotographic toner according to claim 1, an apparatus having the developing step, an apparatus having the transferring step, and the fixing step. An image forming apparatus having a device.