JP2009175284A - Toner, method for manufacturing toner, developer, developing device, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner which can sufficiently maintain mechanical strength and improve fixability to prevent offset, and can obtain high-quality images less in image fogging over a long period of time, and to provide a method for manufacturing the toner, a developer, a developing device for carrying out a development by using the developer, and an image forming apparatus with the developing device. <P>SOLUTION: The toner contains at least a colorant, a binder resin and a wax, wherein the binder resin contains at least one of a polyester resin and a polyether polyol resin, and the wax is included in the toner particles and has a melting point of 70°C to 150°C and a melt viscosity of 50 mPa s to 10,000 mPa s at 140°C. In the image forming apparatus 1, a developing tank 20 of a developing device 14 is filled with the toner to form an image. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a toner, a manufacturing method thereof, a developer, a developing device, and an image forming apparatus including the developing device.

Toner that visualizes a latent image is used in various image forming processes, and as an example, it is known to be used in an electrophotographic image forming process.
An electrophotographic image forming apparatus that forms an image based on an electrophotographic method can easily form an image having good image quality, and is widely used in a copying machine, a printer, a facsimile machine, a multifunction machine, and the like. An electrophotographic image forming apparatus (hereinafter simply referred to as “image forming apparatus”) includes a drum-shaped photosensitive member (hereinafter also referred to as “photosensitive drum”), a charging unit, an exposing unit, a developing unit, and a transferring unit. And fixing means. The photosensitive drum is provided with a photosensitive layer containing a photoconductive substance on its surface, and an electrostatic latent image is formed. The charging means charges the surface of the photosensitive drum to a predetermined potential and polarity. The exposure unit irradiates the charged surface of the photosensitive drum with signal light corresponding to image information to form an electrostatic latent image. The developing means supplies the toner in the developer to the electrostatic latent image on the surface of the photosensitive drum and develops it to form a toner image. The transfer unit transfers the toner image on the surface of the photosensitive drum to the surface of the recording medium. The fixing unit fixes the toner image on the surface of the recording medium to the recording medium by heating, pressing, or the like.

  Examples of the fixing means include a hot plate, a flash fixing device, and a hot roll type fixing device. Among these, a hot roll type fixing device is preferable because the fixing device can be simplified. In a heat roll type fixing device, a recording medium on which an unfixed toner image is formed passes between two pairs of rolls of a fixing roller for heating the toner and a pressure roller, thereby performing fixing. Therefore, the toner is required to have an improved offset property with respect to the fixing roller and an improved adhesive property with respect to the recording medium.

  In order to improve the offset property, it is necessary to make the viscoelasticity of the binder resin contained in the toner appropriate. Therefore, a toner has been proposed in which a cross-linked resin or a metal oxide is added to a carboxyl group-containing resin and a resin cross-linked during kneading is used as a binder resin. In such a toner, the binder resin itself contained in the toner is crosslinked, so that the offset property is good, but the adhesion of the toner to the recording medium is reduced, and the toner is easily peeled off from the recording medium. Occurs. Further, since the adhesiveness of the toner to the recording medium is low, it is not suitable for high-speed fixing, and it is necessary to set the temperature at the time of fixing high, and there is a problem that the reliability of the image forming apparatus is lowered.

  In order to solve such a problem, Patent Document 1 discloses an electrophotographic toner that heats and melts a metallocene wax wall agent on the surface of a microcapsule. According to the electrophotographic toner disclosed in Patent Document 1, it is possible to obtain a toner that enables efficient offset countermeasures.

  Further, there is disclosed a toner particle composition for dry electronic recording, which includes a wax combined with dry toner particles, wherein all waxes are bonded to the toner particles and the surface of the toner particles, and a metallocene wax is used as the wax. 2 is disclosed. According to the toner particle composition for dry electronic recording disclosed in Patent Document 2, the toner particle composition for dry electronic recording has excellent durability in the formed image and excellent in anti-static property even at a low fixing temperature. You can get things.

JP 2006-26457 A JP 2006-126848 A

  Since the toners disclosed in Patent Documents 1 and 2 are made of wax as a shell material, the mechanical strength is weak and the durability of the developer life is insufficient for use as a toner. The shell layer may be peeled off by stirring in the developing device. When the shell layer is peeled off, the core particles are exposed, fixing properties are deteriorated, and offset is likely to occur.

  An object of the present invention is to provide a toner and a toner manufacturing method capable of preventing high-quality images with little image fogging over a long period of time by maintaining sufficient mechanical strength and improving fixability. The present invention provides a developer, a developing device that performs development using the developer, and an image forming apparatus including the developing device.

The present invention is a toner containing at least a colorant, a binder resin and a wax,
The binder resin includes at least one of a polyester resin and a polyether polyol resin,
Wax is contained in toner particles, and has a melting point of 70 ° C. or higher and 150 ° C. or lower, and a melt viscosity at 140 ° C. of 50 mPa · s or higher and 10,000 mPa · s or lower.

Further, the present invention is characterized in that the wax is a metallocene wax in which the melting point x of the wax and the melt viscosity y at 140 ° C. satisfy the relationship of the formula I.
+ 6.05-0.02875 (x)> log (y) (I)

  In the present invention, the binder resin has a hydroxyl value of 30 KOH mg / g or more and 80 KOH mg / g or less, a glass transition temperature of 55 ° C. or more and 65 ° C. or less, and a weight average molecular weight of 50,000 or more and 300,000 or less. It is characterized by.

Further, the present invention is characterized in that the ratio between the addition amount of the binder resin and the addition amount of the wax satisfies the relationship of the formula II.
200> (addition amount of binder resin) / (addition amount of wax)> 10 (II)

  Further, the present invention is a toner comprising core particles made of the toner and having a core-shell structure.

The present invention is also a method for producing the toner,
A melt-kneading step of melt-kneading at least a binder resin, a colorant and a wax;
And a atomization step of atomizing a kneaded product obtained by melt-kneading.

The present invention also relates to a method for producing the toner, comprising: a fine particle preparation step in which at least a binder resin, a colorant, and a wax toner raw material are dispersed in an aqueous medium to obtain a dispersion liquid containing toner fine particles. ,
And a coagulation step of coagulating fine particles of the toner raw material.

  In addition, the present invention is characterized in that it includes an aggregating step of aggregating the finely divided wax by a high-pressure emulsification apparatus equipped with a pressure reducing mechanism.

The present invention also provides a developer comprising the toner.
Further, the present invention is a two-component developer comprising the toner and a carrier.

  According to another aspect of the present invention, there is provided a developing device that develops a latent image formed on an image carrier using the developer to form a toner image.

The present invention also provides an image carrier on which a latent image is formed,
A latent image forming means for forming a latent image on the image carrier;
An image forming apparatus comprising the developing device.

  According to the present invention, the toner contains a colorant, a binder resin containing at least one of a polyester resin and a polyether polyol resin, and a wax. By including at least one of a polyester resin and a polyether polyol resin as the binder resin, it becomes easy to design the relationship between the molecular weight and the glass transition temperature. Compared to the case where no ether polyol resin is contained, the range of toner design can be widened. Further, by incorporating the wax into the toner, the mechanical strength by stirring in the developing device is stronger than the toner using the wax as the shell material, and the durability of the toner can be improved from the beginning to the end of the life.

  The melting point of the wax is 70 ° C. or higher and 150 ° C. or lower, and the melt viscosity of the wax at 140 ° C. is 50 mPa · s or higher and 10,000 mPa · s or lower. When the melting point of the wax is less than 70 ° C., the storage stability in the image forming apparatus is greatly reduced, so that the toner particles are aggregated and the fluidity is lowered, thereby deteriorating the image quality. When the melting point of the wax exceeds 150 ° C., the temperature at which the toner is fixed on the recording medium (hereinafter referred to as “fixing temperature”) increases, and the reliability of the image forming apparatus decreases. If the melt viscosity at 140 ° C. of the wax is less than 50 mPa · s, the melt viscosity of the wax is low, so that the temperature at which low temperature offset occurs is high and the temperature range in which fixing is possible (hereinafter also referred to as “fixing non-offset region”). Narrow. If the melt viscosity of the wax at 140 ° C. exceeds 10,000 mPa · s, the viscosity of the wax is high, so when fixing is performed at a low temperature, the fixability between the toner and the recording medium is deteriorated, and a low temperature offset is likely to occur. Therefore, it is impossible to achieve low-temperature fixability, which is a characteristic that sufficiently fixes a toner image to a recording medium at a relatively low temperature. As described above, the melting point of the wax is 70 ° C. or higher and 150 ° C. or lower, and the melt viscosity of the wax at 140 ° C. is 50 mPa · s or higher and 10000 mPa · s or lower. And low temperature fixability can be achieved.

  Therefore, it is possible to realize a toner having a wide range of toner design, excellent storage stability and durability, and having a wide fixing non-offset region and good adhesion to a recording medium. By using such a toner, excellent low-temperature fixability can be achieved, and high-quality images can be stably formed over a long period of time.

  According to the present invention, the wax is a metallocene wax in which the melting point x of the wax and the melt viscosity y of the wax at 140 ° C. satisfy the formula I. Specifically, the metallocene wax is a low molecular weight polyolefin polymer synthesized by a metallocene catalyst. In general, a wax having a low melting point is plasticized and has a low melt viscosity. A wax having a high melting point has a high melt viscosity. When a toner having a low melting point is contained in the toner, since the melt viscosity of the wax is low, the fixing non-offset region becomes narrow. Further, when a toner having a high melting point is contained in the toner, an excellent low-temperature fixability cannot be achieved because the wax has a high melt viscosity.

  The metallocene wax can be designed such that the melting point and the melt viscosity are independent by defining the amount and molecular weight of the structure-regulating component, and a wax satisfying the relationship of Formula I can be realized. If the melting point x of the wax and the melt viscosity y of the wax at 140 ° C. do not satisfy the relationship of the formula I, the low temperature fixability may be lowered. Since the melting point x of the wax and the melt viscosity y of the wax at 140 ° C. satisfy the relationship of the formula I, the melting point and melt viscosity of the wax can be made to be more suitable values. The dispersibility of the wax is good, and it has a wide fixing non-offset region, and at the same time, the adhesion between the recording medium and the toner can be further improved. Therefore, it is possible to achieve better low-temperature fixability and more stably form a high-quality image over a long period of time.

  According to the invention, the binder resin has a hydroxyl value of 30 KOH mg / g or more and 80 KOH mg / g or less, a glass transition temperature of 55 ° C. or more and 65 ° C., and a weight average molecular weight of 50,000 or more and 300,000 or less. . A certain amount of moisture is required for the toner to make the recording medium and the toner adhere to each other, but if the hydroxyl value of the binder resin is less than 30 KOHmg / g, the toner has insufficient moisture, so the recording medium For example, the adhesiveness between paper and toner is lowered, the mechanical strength of the image after fixing is lowered, and there is a possibility of causing an image omission where the fixed image is peeled off from the recording medium. When the hydroxyl value of the binder resin exceeds 80 KOHmg / g, the toner performance may be changed due to a change in humidity in the usage environment of the toner. When the glass transition temperature of the binder resin is less than 55 ° C., the storage stability in the image forming apparatus is lowered. When the glass transition temperature of the binder resin exceeds 65 ° C., the temperature at which the low temperature offset occurs is increased, and the low temperature fixability may be deteriorated. If the weight average molecular weight of the binder resin is less than 50,000, the mechanical strength of the fixed image after fixing is lowered, and there is a risk of image loss. When the weight average molecular weight of the binder resin exceeds 300,000, the temperature at which the low temperature offset occurs is increased, and the low temperature fixability may be deteriorated.

  The binder resin has a hydroxyl value of 30 KOH mg / g or more and 80 KOH mg / g or less, a glass transition temperature of 55 ° C. or more and 65 ° C., and a weight average molecular weight of 50,000 or more and 300,000 or less. Thus, it is possible to suppress the change in the physical properties of the toner due to a change in the humidity in the usage environment of the toner.

  Further, according to the present invention, the ratio between the addition amount of the binder resin and the addition amount of the wax satisfies the relationship of the formula II. When the value of (addition amount of binder resin) / (addition amount of wax) is 10 or less, since the addition amount of wax is larger than the addition amount of binder resin, the binder resin is plasticized and fixing is not performed. There is a possibility that the offset region becomes narrow. (Binder resin addition amount) / (Wax addition amount) When it is 200 or more, the wax addition amount is smaller than the binder resin addition amount, and the wax concentration in the toner is low. May decrease. By satisfying the relationship of the formula II, the ratio of the binder resin addition amount and the wax addition amount, the amount of the wax is as small as possible, and even better low-temperature fixability and high-quality images can be obtained over a long period of time. It can be formed more stably.

  According to the invention, the toner includes core particles made of the toner of the invention and has a core-shell structure. As a result, it is possible to suppress problems caused by using wax such as the wax is exposed on the toner particle surface and the wax adheres to the photoconductor, and to realize a toner having better fixing property, storage stability and durability. Can do. By using such a toner, a high-quality image can be formed more stably over a long period of time.

  According to the invention, the toner production method includes at least a melt-kneading step of melt-kneading the binder resin, the colorant, and the wax, and a atomization step of atomizing the kneaded material obtained by melt-kneading. Thus, the toner of the present invention having a wide range of toner design, excellent storage stability and durability, and having a wide fixing non-offset region and good adhesion to a recording medium can be produced.

  According to the present invention, the method for producing a toner includes a fine particle preparation step of dispersing a toner raw material of at least a binder resin, a colorant and a wax in an aqueous medium to obtain a dispersion containing fine particles of the toner raw material, An aggregating step for agglomerating fine particles of the toner raw material. By producing by a method including a fine particle preparation step and an agglomeration step, power consumption related to production in the production step can be reduced and energy efficiency can be increased as compared with the case of producing by a pulverization method. In addition, the toner particles can be easily controlled in shape, and a toner with high uniformity of toner particle shapes can be produced. Therefore, the individual toner particles have almost the same characteristics, and the variation in the characteristics of the individual toner particles is small. Therefore, the toner particles have a wider fixing non-offset region than that produced by the pulverization method, and A toner having better adhesion to the toner can be produced.

  According to the invention, the method for producing a toner includes an aggregating step of aggregating the finely divided wax by a high-pressure emulsification apparatus equipped with a pressure reducing mechanism. This makes it possible to uniformly disperse wax particles having a uniform molecular weight distribution in the toner, so that a toner having a wider fixing non-offset region and better adhesion between the recording medium and the toner can be obtained. Can be manufactured.

  According to the invention, the developer contains the toner of the invention. This makes it possible to form a high-quality image with a wide fixing non-offset region and a developer with stable characteristics over a long period of use, thereby obtaining a developer capable of maintaining good developability. It is done.

  According to the invention, the developer is a two-component developer comprising the toner of the invention and a carrier. Since the toner of the present invention is excellent in storage stability and durability, generation of a carrier spent is suppressed, and a two-component developer having good fluidity can be obtained. By using such a two-component developer, it is possible to suppress deterioration in image quality due to toner scattering and fogging and to stably form a high-quality image.

  Further, according to the present invention, since the latent image is developed using the developer of the present invention, adhesion of the wax component to the photoconductor can be prevented, and a good toner image can be stably formed on the photoconductor. Therefore, a high-quality image can be stably formed.

  According to the present invention, the image bearing member on which the latent image is formed, the latent image forming means for forming the latent image on the image bearing member, and the developing device according to the present invention capable of forming a good toner image as described above. The image forming apparatus is realized. By forming an image with such an image forming apparatus, a high-quality image can be stably formed.

  The toner according to the first embodiment of the present invention contains a binder resin, a wax, and a colorant, and the binder resin includes at least one of a polyester resin and a polyether resin.

  The wax is contained in the toner, and has a melting point of 70 ° C. or higher and 150 ° C. or lower, and a melt viscosity at 140 ° C. of 50 mPa · s or higher and 10,000 mPa · s or lower. When the melting point of the wax is less than 70 ° C., the storage stability in the image forming apparatus is greatly reduced, so that the toner particles are aggregated and the fluidity is lowered, thereby deteriorating the image quality. When the melting point of the wax exceeds 150 ° C., the temperature at which the toner is fixed on the recording medium (hereinafter referred to as “fixing temperature”) increases. If the melt viscosity at 140 ° C. of the wax is less than 50 mPa · s, the melt viscosity of the wax is low, so that the temperature at which low temperature offset occurs is high and the temperature range in which fixing is possible (hereinafter also referred to as “fixing non-offset region”). Narrow. If the melt viscosity of the wax at 140 ° C. exceeds 10,000 mPa · s, the viscosity of the wax is high, so when fixing is performed at a low temperature, the fixability between the toner and the recording medium is deteriorated, and a low temperature offset is likely to occur. Therefore, it is impossible to achieve low-temperature fixability, which is a characteristic that sufficiently fixes a toner image to a recording medium at a relatively low temperature. As described above, the melting point of the wax is 70 ° C. or higher and 150 ° C. or lower, and the melt viscosity of the wax at 140 ° C. is 50 mPa · s or higher and 10000 mPa · s or lower. And low temperature fixability can be achieved.

  Therefore, it is possible to realize a toner having a wide range of toner design, excellent storage stability and durability, and having a wide fixing non-offset region and good adhesion to a recording medium. By using such a toner, excellent low-temperature fixability can be achieved, and high-quality images can be stably formed over a long period of time.

  In the present exemplary embodiment, other toner additives may be included as necessary. Examples of other additives include a charge adjusting agent.

[Binder resin]
By including at least one of a polyester resin and a polyether polyol resin as the binder resin, it becomes easy to design the relationship between the molecular weight and the glass transition temperature. Compared to the case where neither of the polyether polyol resins is contained, the width of the toner design can be widened. In addition, by including wax in the toner, the mechanical strength by stirring in the developing device is stronger than the toner using the wax as the shell material, and the durability of the toner can be improved from the beginning to the end of the life. .

  The polyester resin is not particularly limited, and known resins can be used. Examples thereof include polycondensation products of polybasic acids and polyhydric alcohols. Polybasic acids are polybasic acids and derivatives of polybasic acids, such as acid anhydrides or esterified products of polybasic acids. Polyhydric alcohols are compounds containing two or more hydroxyl groups, and include both alcohols and phenols.

  As polybasic acids, those commonly used as monomers of polyester resins can be used, for example, aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid and naphthalenedicarboxylic acid, And aliphatic carboxylic acids such as maleic anhydride, fumaric acid, succinic acid and adipic acid. Polybasic acids may be used alone or in combination of two or more.

  Polyhydric alcohols that are commonly used as monomers of polyester resins can be used, for example, aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol and glycerin, cyclohexanediol, Examples include alicyclic polyhydric alcohols such as cyclohexanedimethanol and hydrogenated bisphenol A, and aromatic diols such as ethylene oxide adduct of bisphenol A and propylene oxide adduct of bisphenol A.

  “Bisphenol A” is 2,2-bis (p-hydroxyphenyl) propane. Examples of the ethylene oxide adduct of bisphenol A include polyoxyethylene-2,2-bis (4-hydroxyphenyl) propane. Examples of the propylene oxide adduct of bisphenol A include polyoxypropylene-2,2-bis (4-hydroxyphenyl) propane. Polyhydric alcohols may be used alone or in combination of two or more.

  Polyester resins can be synthesized by a condensation polymerization reaction. For example, polycondensation reaction between polybasic acids and polyhydric alcohols in the presence of a catalyst in an organic solvent or in the absence of a solvent, specifically dehydration condensation. It can be synthesized by reacting. At this time, a demethanol polycondensation reaction may be carried out using a methyl esterified product of a polybasic acid as part of the polybasic acid. The polycondensation reaction between polybasic acids and polyhydric alcohols may be terminated when the acid value and softening temperature of the produced polyester resin reach the values in the polyester resin to be synthesized. In this polycondensation reaction, the mixing ratio of polybasic acids and polyhydric alcohols, reaction rate, polymerization time, polymerization temperature, trifunctional or higher functional components used in the polycondensation reaction, such as trivalent or higher polybasic acids, 3 By appropriately changing the reaction conditions such as selection of polyhydric alcohols having a value higher than the valence, for example, the content of carboxyl groups bonded to the terminal of the obtained polyester resin, and thus the acid value, hydroxyl value, softening of the obtained polyester resin The temperature, glass transition temperature, weight average molecular weight and other physical property values can be adjusted.

  A known polyether polyol resin can be used, for example, a polyether polyol which is a reaction product of an epoxy resin and a compound having active hydrogen having reactivity with an epoxy group (hereinafter referred to as “active hydrogen compound”). Resin. The polyether polyol resin preferably has a number average molecular weight of 1,000 or more and 10,000 or less, more preferably 2,000 or more and 5,000 or less, according to a gel permeation (GPC) method.

  As the epoxy resin, for example, a bisphenol type epoxy resin represented by the following general formula (1) (hereinafter referred to as “bisphenol type epoxy resin (1)”) can be used.

(In the formula, R ₁ and R ₂ may be the same or different, and are a hydrogen atom, a methyl group, an ethyl group, or a phenyl group, and n is an integer of 0 or more.)

  In the general formula (1), the symbol n indicates the degree of polymerization. As the bisphenol type epoxy resin (1), those in which n is 0 or more and 2 or less are preferable. The number average molecular weight of the bisphenol type epoxy resin (1) by the gel permeation method is preferably 300 or more and 1000 or less, more preferably 350 or more and 800 or less. The epoxy equivalent of the bisphenol-type epoxy resin (1) is preferably 150 g / eq or more and 500 g / eq or less, more preferably 170 g / eq or more and 400 g / eq or less.

  Examples of the active hydrogen compound include monohydric phenols, dihydric phenols, carboxylic acids, alcohols, and alkylene oxide adducts of dihydric phenols (hereinafter referred to as “alkylene oxide adducts”).

  Examples of monohydric phenols include phenol, cresol, isopropylphenol, aminophenol, nonylphenol, dodecylphenol, xylenol, p-cumylphenol, p-octylphenol, and t-butylphenol. Monohydric phenols can be used alone or in combination of two or more.

  Examples of the divalent phenols include divalent phenols represented by the following general formula (2) (hereinafter referred to as “divalent phenol (2)”).

(In the formula, R ₃ and R ₄ may be the same or different and are a hydrogen atom, a methyl group, an ethyl group or a phenyl group.)

  Specific examples of the dihydric phenol (2) include mononuclear dihydric phenols such as hydroquinone and resorcin, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 2,2-bis (4 -Hydroxyphenyl) methane (bisphenol F), 2,2-bis (4-hydroxyphenyl) ethane (bisphenol AD), and the like. A dihydric phenol can be used individually by 1 type, or can use 2 or more types together.

Examples of the carboxylic acids include carboxylic acids represented by the following general formula (3) (hereinafter referred to as “carboxylic acid (3)”).
R ₅ (COOH) _m (3)
(In the formula, R ₅ represents an alkyl group having 1 to 20 carbon atoms or a phenyl group. M is an integer of 1 to 4.)

  In the general formula (3), the symbol m represents the degree of polymerization. In the carboxylic acid (3), m is preferably 1 or more and 4 or less, and more preferably 1 or more and 3 or less. When m is 1 or more and 4 or less, reaction control during production becomes easy.

  Specific examples of the carboxylic acid (3) include, for example, acetic acid, propionic acid, lauric acid, myristic acid, palmitic acid, stearic acid, acrylic acid, oleic acid, arachidic acid, linoleic acid, castor oil fatty acid, tall oil fatty acid and Monovalent carboxylic acids such as benzoic acid, phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, succinic acid, fumaric acid, adipic acid, maleic acid, sebacic acid, decamethylenedicarboxylic acid, mesaconic acid, citraconic acid, itaconic acid , Glutaconic acid, maconic acid, 1,3-cyclohexanedicarboxylic acid, divalent carboxylic acids such as hexahydrophthalic acid and tetrahydrophthalic acid, and 1,2,3-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid 1,2,4-cyclohexanetricarboxylic acid, 2 5,7-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) And trivalent or higher polyvalent carboxylic acids such as methane, 1,2 and 7,8-octanetetracarboxylic acid. Carboxylic acids can be used alone or in combination of two or more.

Examples of the alcohols include alcohols represented by the following general formula (4) (hereinafter referred to as “alcohol (4)”).
R ₆ (OH) _q (4)
(R ₆ represents an alkyl group having 1 to 10 carbon atoms or an alkylene group. Q represents an integer of 1 to 20)

  In general formula (4), the symbol q indicates the degree of polymerization. As alcohols (4), q is preferably 1 or more and 20 or less, and more preferably 1 or more and 3 or less. When q is 1 or more and 20 or less, reaction control during production becomes easy.

  Specific examples of the alcohol (4) include, for example, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, t-butyl alcohol, monohydric alcohols such as pentanol, hexanol, heptanol and octanol, ethylene glycol, diethylene glycol, polyethylene glycol 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, dihydric alcohols such as neopentyl glycol and 1,4-butenediol, and sorbitol, 1,2,3,6-hexane Tetrol, 1,4-sorbitan, pentaerthritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerine Phosphorus, 2-methylpropane triol, 2-methyl-1,2,4-butane triol, trimethylol propane, polyvalent alcohols such as trimethylol butane and 1,3,5-trihydroxy methyl benzene. Alcohols can be used alone or in combination of two or more.

  Examples of the alkylene oxide adduct include an alkylene oxide adduct represented by the following general formula (5) (hereinafter referred to as “alkylene oxide adduct (5)”).

(In the formula, R ₇ and R ₈ may be the same or different and each represents an ethylene group or a propylene group. R ₉ and R ₁₀ may be the same or different, and a hydrogen atom, a glycidyl group or an acid anhydride is added. In the general formula (5), the symbols x and y represent the degree of polymerization, and as the alkylene oxide adduct (5), x and y represent an integer of 1 or more, and x + y is 2 or more and 10 or less. is there.)

  Specific examples of the alkylene oxide adduct (5) include, for example, polyoxyethylene- (2,0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2,2) -2, 2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (1,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (1,1) -2,2-bis ( 4-hydroxyphenyl) propane, polyoxypropylene- (2,2) -polyoxyethylene- (2,0) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene- (3,3)- 2,2-bis (4-hydroxyphenyl) propane and the like can be mentioned. In this embodiment, aromatic diols such as p-xylene glycol and m-xylene glycol can also be used. An alkylene oxide adduct can be used individually by 1 type, or can use 2 or more types together.

  An acid addition type polyether polyol resin can be used as the polyether polyol resin. The acid addition type polyether polyol resin can be produced by reacting a polyether polyol resin and an acid anhydride. Alternatively, it can be produced by reacting a secondary hydroxyl group of a polyether polyol resin with a lactone and then adding an acid anhydride. The acid addition type polyether polyol resin contains a carboxylic acid half ester group in the molecule. The amount is preferably from 2 KOH mg / g to 50 KOH mg / g as the acid value, more preferably from 5 KOH mg / g to 30 KOH mg / g. When the acid value is in the range of 2 KOHmg / g or more and 50 KOHmg / g or less, it is preferable in that the toner can be easily charged without using a large amount of a charge adjusting agent when it is made into a toner. In addition, by including an acid addition type polyether polyol resin in the shell layer, it is possible to obtain a capsule toner with little deterioration in charging performance under high humidity.

  The softening temperature of the acid addition type polyether polyol resin is preferably 80 ° C. or higher and 140 ° C. or lower, and more preferably 85 ° C. or higher and 130 ° C. or lower. When the softening temperature is within this range, the temperature at the start of fixing can be lowered, which is preferable from the viewpoint of improving low-temperature fixability. The glass transition temperature (Tg) of the acid-added polyether polyol resin is preferably 50 or more and 90 ° C. or less, and more preferably 55 or less and 60 ° C. or less. When the glass transition temperature (Tg) is in this range, the blocking resistance under high temperature and high humidity is improved. The acid addition type polyether polyol resin has a number average molecular weight (GPC method) of usually about 1000 to 10000, preferably about 2000 to 5000. The weight average molecular weight is preferably about 2000 to 80000, more preferably about 5000 to 50000. The average molecular weight within this range is preferable because the fixing non-offset region can be adjusted.

  An acid anhydride is a compound obtained by dehydration condensation of two carboxyl groups of a polybasic acid, such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bisglycerol tris (anhydrous). Trimellitate), maleic anhydride, succinic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylnadic anhydride, alkenyl succinic anhydride, methylhexahydrophthalic anhydride methylcyclohexenetetracarboxylic acid Anhydride, chlorendic anhydride, tetrabromophthalic anhydride, etc. are mentioned. An acid anhydride can be used individually by 1 type, or can use 2 or more types together. Although the ratio of the acid anhydride to the polyether polyol resin is not particularly limited, it is preferably 1 to 20 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the polyether polyol resin. Thereby, an acid addition type polyether polyol having an acid value of 2 to 50 KOHmg / g is obtained.

  Examples of lactones include β-propiolactone, dimethylpropiolactone, butyrolactone, γ-valerolactone, γ-caprolactone, γ-caprolactone, γ-laurolactone, γ-palmilactone, and γ-stearolo. Examples include lactone, crotraclone, α-angelilactone, β-angelilactone, σ-valerolactone, σ-caprolactone, and ε-caprolactone. Lactones can be used alone or in combination of two or more.

  In addition, in the synthesis of the polyether polyol resin and the acid addition type polyether polyol resin, in addition to the above-described essential compounds, bifunctional epoxy resins other than the bisphenol type epoxy resin (1), epoxy resins such as polyfunctional epoxy resins, One or more selected from dihydric phenols other than dihydric phenol (2), phenolic compounds such as polyhydric phenol, and the like can be used. These epoxy resins and phenol compounds are preferably included in the polyether polyol resin in a total amount of 30% by weight or less based on the total weight of the obtained polyether polyol resin.

  Examples of the bifunctional epoxy resin other than the bisphenol type epoxy resin (1) include diglycidylated etherified diphenols, glycerol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and polypropylene. Aliphatic bifunctional epoxy resins such as glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, adipic acid diglycidyl ester, diglycidyl p -Diglycidyl esters such as oxybenzoic acid. A bifunctional epoxy resin can be used individually by 1 type, or can use 2 or more types together.

  Examples of the polyfunctional epoxy resin include polyglycidylated polyhydric phenols, glycerol polyglycidyl ether, sorbitol polyglycidyl ether, polyglycerin polyglycidyl ether, pentaerythritol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate. Examples thereof include aliphatic polyfunctional epoxy resins such as nerate and trimethylolpropane polyglycidyl ether, and glycidylamines such as tetraglycidyldiaminodiphenylmethane, triglycidyl m-aminophenol, and tetraglycidyl m-xylylenediamine. A polyfunctional epoxy resin can be used individually by 1 type, or can use 2 or more types together.

  Examples of dihydric phenols other than dihydric phenol (2) include mononuclear dihydric phenols such as hydroquinone and resorcin, 1,4-bis [α- (4-hydroxyphenyl) -α-methylethyl] benzene, and the like. And trinuclear dihydric phenols. Divalent phenols other than the divalent phenol (2) can be used alone or in combination of two or more.

  Examples of the polyhydric phenol include phenol / formalin condensates such as phenol novolac resin and cresol novolac resin, tetra (4-hydroxyphenyl) ethane, 1,1,3-tris (4-hydroxyphenyl) propane, 1,1. , 3-tris (3,5-dimethyl-4-hydroxyphenyl) propane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1- [α-methyl- (4′-hydroxyphenyl) ethyl] -4- [α ′, α′-bis (4 ″ -hydroxyphenyl) ethyl] benzene, etc. The polyphenol can be used alone or in combination of two or more. Can be used together.

  The polyether polyol resin and the acid addition type polyether polyol resin can be produced by one-step polymerization and addition reaction (hereinafter referred to as “polyaddition reaction”) using the aforementioned epoxy resin and compound as raw material compounds. The polyaddition reaction is performed in a suitable solvent in the presence of a catalyst.

  Catalysts include, for example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, alkali metal alcoholates such as sodium methylate, tertiary such as N, N-dimethylbenzylamine, triethylamine and pyridine. Quaternary ammonium salts such as amines, tetramethylammonium chloride and benzyltriethylammonium chloride, organophosphorus compounds such as triphenylphosphine and triethylphosphine, alkali metal salts such as lithium chloride and lithium bromide, and boron trifluoride, chloride Lewis acids such as aluminum and tin tetrachloride are mentioned. Although the amount of the catalyst used is not particularly limited, it is preferably 1 ppm or more and 1000 ppm or less, more preferably 5 ppm or more and 500 ppm or less with respect to the total weight of the raw material compound.

  Solvents include aromatic compounds such as xylene and toluene, ketones such as 2-butanone, methyl isobutyl ketone and cyclohexanone, ethers such as ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, dioxane and anisole, and N , N-dimethylformamide, dimethyl sulfoxide and aprotic polar solvents such as 1-methyl-2-pyrrolidinone. These solvents can be used alone or in combination of two or more. Although the amount of the solvent used is not particularly limited, it is preferably 1% or more and 100% or less, more preferably 5% or more and 50% or less of the total weight of the raw material compound. The reaction temperature of the polyaddition reaction is appropriately selected depending on the amount of catalyst, but is usually about 120 to 180 ° C.

  The polyaddition reaction can be followed by measuring, for example, epoxy equivalent, softening temperature, number average molecular weight by GPC method. In this embodiment, the time when the epoxy group substantially disappears, that is, the time when the epoxy equivalent becomes 20000 g / equivalent or more is defined as the reaction end point. This method is simple. The measuring method of epoxy equivalent is as follows.

[Measurement of epoxy equivalent]
After putting 0.2 to 5 g of a sample into a 200 ml Erlenmeyer flask, 25 ml of dioxane was added and dissolved. To this was added 25 ml of a 0.2N dioxane solution of hydrochloric acid, which was sealed and mixed well, and then allowed to stand for 30 minutes. Next, 50 ml of a toluene-ethanol mixed solution (1: 1 volume ratio) was added, and a 1/10 N aqueous sodium hydroxide solution was titrated using cresol red as an indicator. Based on the titration result, the epoxy equivalent (g / equivalent) was calculated according to the following formula.
Epoxy equivalent (g / equivalent) = 1000 × W / [(B−S) × N × F]
W: Amount of sample collected (g)
B: Amount of sodium hydroxide aqueous solution required for the blank test (ml)
S: Amount of normal sodium hydroxide aqueous solution required for sample test (ml)
N: Normality of aqueous sodium hydroxide solution F: Potency of aqueous sodium hydroxide solution

  In the polyaddition reaction, the polymerization conditions, the polymerization temperature, and the reaction conditions such as selection of a trifunctional or higher functional component used in the polyaddition reaction, such as a trifunctional or higher polyfunctional epoxy resin, a trivalent or higher polyvalent carboxylic acid, are appropriately changed By doing so, for example, the content of the carboxyl group bonded to the terminal of the obtained polyether polyol resin and acid addition type polyether polyol resin, and consequently the acid value of the obtained polyether polyol resin and acid addition type polyether polyol resin, The hydroxyl value, softening temperature, glass transition temperature, weight average molecular weight and other physical property values can be adjusted.

  As the binder resin used in the present invention, in addition to polyester resin and polyether polyol resin, one or more known binder resins for toner can be used in combination. For example, polystyrene and styrene-acrylic acid ester Examples include styrene resins such as polymer resins, acrylic resins such as polymethyl methacrylate, polyolefin resins such as polyethylene, polyurethane, epoxy resins, etc. Also, a release agent is mixed with the raw material monomer mixture and polymerized. Resin that can be used may be used. These binder resins may be used in combination of two or more.

  In the present embodiment, the hydroxyl value of the binder resin is preferably 30 KOHmg / g or more and 80 KOHmg / g or less, and more preferably 30 KOHmg / g or more and 50 KOHmg / g or less. A certain amount of moisture is required for the toner to make the recording medium and the toner adhere to each other, but if the hydroxyl value of the binder resin is less than 30 KOHmg / g, the toner has insufficient moisture, so the recording medium For example, the adhesiveness between paper and toner is lowered, the mechanical strength of the image after fixing is lowered, and there is a possibility of causing an image omission where the fixed image is peeled off from the recording medium. When the hydroxyl value of the binder resin exceeds 80 KOHmg / g, the toner performance may be changed due to a change in humidity in the usage environment of the toner.

  In the present embodiment, the glass transition temperature of the binder resin is preferably 55 ° C. or higher and 65 ° C. or lower, and more preferably 55 ° C. or higher and 60 ° C. or lower. When the glass transition temperature of the binder resin is less than 55 ° C., the storage stability in the image forming apparatus is lowered. When the glass transition temperature of the binder resin exceeds 65 ° C., the temperature at which the low temperature offset occurs is increased, and the low temperature fixability may be deteriorated.

  In this embodiment, the weight average molecular weight of the binder resin is preferably 50,000 or more and 300,000 or less, and more preferably 80,000 or more and 200,000 or less. If the weight average molecular weight of the binder resin is less than 50,000, the mechanical strength of the fixed image after fixing is lowered, and there is a risk of image loss. When the weight average molecular weight of the binder resin exceeds 300,000, the temperature at which the low temperature offset occurs is increased, and the low temperature fixability may be deteriorated.

  The weight average molecular weight of the binder resin can be controlled by adjusting the degree of polymerization of the binder resin. That is, polymerization time, polymerization temperature, trifunctional or higher component, for example, in the case of polyester resin, tribasic or higher polybasic acid, trivalent or higher polyhydric alcohol, in the case of polyether polyol resin, trifunctional. It can control by selecting the above polyfunctional epoxy resin and trivalent or more polyvalent carboxylic acid.

  By using a binder resin having physical properties in the above range, it is possible to further improve the adhesion between the recording medium and the toner, and to suppress changes in the physical properties of the toner due to changes in humidity in the toner usage environment. .

[wax]
As described above, the toner of this embodiment contains wax. By including the wax, the fixing property can be improved.

The wax is not particularly limited. For example, polyester wax and derivatives thereof, paraffin wax and derivatives thereof, petroleum wax such as microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax and Derivatives thereof, low molecular weight polypropylene wax and derivatives thereof, hydrocarbon-based synthetic waxes such as polyolefin polymer waxes (such as low molecular weight polyethylene wax) and derivatives thereof, carnauba wax and derivatives thereof, rice wax and derivatives thereof, candelilla wax and Derivatives, plant waxes such as wood wax, animal waxes such as beeswax and spermaceti, fats and oils such as fatty acid amides and phenol fatty acid esters Synthetic waxes, long-chain carboxylic acids and their derivatives, long-chain alcohols and derivatives thereof, silicon-based polymers, and the higher fatty acid and the like. Derivatives include oxides, block copolymers of vinyl monomers and the above wax, graft modified products of vinyl monomers and the above wax, and the like. Among these, it is preferable to use a metallocene wax in which the melting point x of the wax and the melt viscosity y of the wax at 140 ° C. satisfy the relationship of the following general formula (I).
+ 6.05-0.02875 (x)> log (y) (I)

  Specifically, the metallocene wax is a low molecular weight polyolefin polymer synthesized by a metallocene catalyst. In general, a wax having a low melting point is plasticized and has a low melt viscosity, and a wax having a high melting point has a high melt viscosity. When a toner having a low melting point is contained in the toner, since the melt viscosity of the wax is low, the fixing non-offset region becomes narrow. Further, when a toner having a high melting point is contained in the toner, an excellent low-temperature fixability cannot be achieved because the wax has a high melt viscosity.

  Unlike ordinary olefin waxes that regulate the structural skeleton, metallocene waxes are the ones that decouple the relationship between viscosity and melting point. Waxes that can be designed as independent and satisfy the relationship of Formula I can be realized. If the melting point x of the wax and the melt viscosity y of the wax at 140 ° C. do not satisfy the relationship of the formula I, the low temperature fixability may be lowered. Since the melting point x of the wax and the melt viscosity y of the wax at 140 ° C. satisfy the relationship of the formula I, the melting point and melt viscosity of the wax can be made to be more suitable values. The dispersibility of the wax is good, and it has a wide fixing non-offset region, and at the same time, the adhesion between the recording medium and the toner can be further improved. Therefore, it is possible to achieve better low-temperature fixability and more stably form a high-quality image over a long period of time.

  As the metallocene wax, a wax having a polar group (hereinafter referred to as “nonpolar metallocene wax” unless otherwise specified) than a wax having a polar group (hereinafter referred to as “polar metallocene wax” unless otherwise specified). Is preferred. Since the polar metallocene wax easily absorbs moisture in the toner, there is a possibility that the toner characteristics may be deteriorated, for example, the toner charge amount is decreased under high humidity. “Nonpolar metallocene-based wax” means not having any polarity but having no polar group.

  Low molecular weight polyolefins include homopolymers such as polyethylene, polypropylene, polybutene, polypentene, polyhexene and polyoctene, and copolymers using two or more monomers such as ethylene-propylene copolymer and ethylene-butene copolymer. Can be mentioned. Among these, polypropylene, polyethylene, ethylene-propylene copolymer and ethylene-butene copolymer are preferable.

  The metallocene catalyst uses a main catalyst in which a cyclopentadiene ring and a transition metal compound are bonded, and methylalumoxane or an anionic species as a cocatalyst. Examples of the main catalyst in which the cyclopentadiene ring and the transition metal compound are bonded include, for example, the main catalyst in which the cyclopentadiene ring and the transition metal compound that are represented by the following general formulas (6), (7), and (8) are bonded. It is done.

  Examples of the co-catalyst methylalumoxane or anionic species include anionic species represented by the following general formula (9).

  As a polymerization method of the low molecular weight polyolefin polymer, any of a high pressure polymerization method, a gas polymerization method, and a solution polymerization method can be used. As for the molecular weight of the polyolefin-based polymer, the weight average molecular weight (Mw) is preferably 3000 or more and 50000 or less, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.0. More preferably, it is -2.0.

  Commercially available products of these metallocene waxes include, for example, polyolefin wax PP1302, PP1502, PP1602, PE2301 manufactured by Clariant, Evolue SP2020, SP2320, SP2520, SP2510, SP3010, SP1520, SP0540, SP1540, SP2040, SP2540 manufactured by Mitsui Chemicals, Inc. , SP4030, Wintech WFX4T, WFX4TA, WFX6 manufactured by Nippon Polychem Corporation.

The amount of the wax added to the toner is not particularly limited and can be appropriately selected from a wide range, but it is preferable that the ratio of the binder resin addition amount and the wax addition amount satisfy the relationship of Formula II.
200> (addition amount of binder resin) / (addition amount of wax)> 10 (II)

  When the value of (addition amount of binder resin) / (addition amount of wax) is 10 or less, since the addition amount of wax is larger than the addition amount of binder resin, the binder resin is plasticized and fixing is not performed. There is a possibility that the offset region becomes narrow. (Binder resin addition amount) / (Wax addition amount) When it is 200 or more, the wax addition amount is smaller than the binder resin addition amount, and the wax concentration in the toner is low. May decrease. By satisfying the relationship of the formula II, the ratio of the binder resin addition amount and the wax addition amount satisfies the relationship of Formula II. It can be formed more stably.

[Colorant]
The colorant contained in the toner of the present invention is not particularly limited, and for example, organic dyes, organic pigments, inorganic dyes, inorganic pigments and the like can be used. Specific examples of the colorant for black toner include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, magnetic ferrite, and magnetite.

  Examples of the colorant for yellow toner include chrome yellow, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 180 and C.I. I. And CI Pigment Yellow 185.

  Examples of the colorant for the orange toner include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK, C.I. I. Pigment orange 31, C.I. I. And CI Pigment Orange 43.

  Examples of the colorant for red toner include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, risol red, pyrazolone red, watching red, calcium salt, lake red C, lake red D, and brilliant carmine. 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178 and C.I. I. And CI Pigment Red 222.

  Examples of purple colorants include manganese purple, fast violet B, and methyl violet lake.

  Examples of the colorant for blue toner include bitumen, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated, first sky blue, induslen blue BC, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16 and C.I. I. And CI Pigment Blue 60.

  Examples of the green colorant include chrome green, chromium oxide, pigment green B, micalite green lake, final yellow green G, and C.I. I. And CI Pigment Green 7.

  Examples of the white colorant include compounds such as zinc white, titanium oxide, antimony white, and zinc sulfide.

  One colorant can be used alone, or two or more different colorants can be used in combination. Moreover, even if it is the same color, 2 or more types can be used together.

[Charge control agent]
Examples of the charge control agent include Copy Charge N4P VP 2481 (trade name, manufactured by Clariant Japan Co., Ltd.) and Copy Charge N5P (trade name, manufactured by Clariant Japan Co., Ltd.).

  The toner of the exemplary embodiment preferably includes core particles made of the toner of the present invention and has a core-shell structure. As a result, it is possible to suppress problems caused by using wax such as the wax is exposed on the toner particle surface and the wax adheres to the photoconductor, and to realize a toner having better fixing property, storage stability and durability. Can do. By using such a toner, a high-quality image can be formed more stably over a long period of time. The method for forming the shell is not particularly limited, and for example, it can be formed by an agglomeration method.

  Examples of the resin that can be used as the shell agent include styrene acrylic resin, epoxy resin, melamine resin, and urethane resin.

[Toner Production Method]
The toner of this embodiment can be manufactured by, for example, a pulverization method. The pulverization method includes a melt-kneading process, an atomization process, and a classification process. In the melt-kneading step, the raw material containing at least the binder resin, the colorant and the wax is melt-kneaded, and in the atomization step, the kneaded material obtained in the melt-kneading step is atomized, and the kneaded material atomized in the classification step Classify. Thus, the toner of the present invention having a wide range of toner design, excellent storage stability and durability, and having a wide fixing non-offset region and good adhesion to a recording medium can be produced.

  Specifically, for example, the toner raw material is melt-kneaded, and the obtained melt-kneaded product is cooled and then roughly pulverized by a hammer mill or a cutter mill. Next, the coarsely pulverized product is further finely pulverized by a jet mill or an ong mill, and then classified so as to have a preferable volume average particle size range.

  In the melt-kneading step, for example, the toner raw material containing the binder resin, the colorant, the wax, and the charge preparation agent described above is dry-mixed in a mixer, and then the temperature is higher than the softening temperature of the binder resin and lower than the thermal decomposition temperature. The mixture is heated and melt-kneaded to melt or soften the binder resin and to disperse the toner raw material other than the binder resin in the binder resin. The toner material containing the binder resin and the colorant may be melt-kneaded as it is without being dry-mixed, but is preferably melt-kneaded after dry-mixing. Melting and kneading after dry mixing improves the dispersibility of the raw material other than the binder resin such as the colorant in the binder resin, and makes it possible to make the characteristics such as the charging performance of the resulting toner uniform.

  As a mixer used for dry mixing, for example, Henschel mixer (trade name, manufactured by Mitsui Mining Co., Ltd.), super mixer (trade name, manufactured by Kawata Co., Ltd.), mechano mill (trade name, manufactured by Okada Seiko Co., Ltd.), etc. Examples include a Henschel type mixing apparatus, Ong mill (trade name, manufactured by Hosokawa Micron Corporation), hybridization system (trade name, manufactured by Nara Machinery Co., Ltd.), and Cosmo system (trade name, manufactured by Kawasaki Heavy Industries, Ltd.).

  For melt kneading, a kneader such as a kneader, a twin-screw extruder, a two-roll mill, a three-roll mill, or a lab blast mill can be used. As such a kneader, for example, TEM-100B (trade name, manufactured by Toshiba Machine Co., Ltd.), PCM-65 / 87, PCM-30 (all of which are trade names, manufactured by Ikegai Co., Ltd.) or the like Examples thereof include open-roll kneaders such as biaxial extruders and kneedex (trade name, manufactured by Mitsui Mining Co., Ltd.). Melt kneading may be performed using a plurality of kneaders.

  In the atomization step, the melt-kneaded product obtained by melt-kneading is cooled and solidified to obtain a resin composition containing a binder resin and a colorant. The resin composition obtained by melt kneading is pulverized into a coarsely pulverized product having a particle size of, for example, about 100 μm to 5 mm by a hammer mill or a cutter mill. Thereafter, the coarsely pulverized product is further pulverized until it becomes a fine powder having a particle size of, for example, 15 μm or less. For pulverization of the coarsely pulverized product, for example, a jet type pulverizer that pulverizes using a supersonic jet stream or a space formed between a rotor (rotor) and a stator (liner) that rotate at a high speed is roughly used. An impact pulverizer that introduces and pulverizes the pulverized product can be used.

  In the classification step, classification is performed in order to remove fine powder from the toner particles after pulverization by a pulverizer. In the toner according to another embodiment of the present invention, classification may not be performed.

  The toner production method of the present invention is preferably produced by a method including an aqueous treatment step, that is, a chemical toner treatment step. By producing by a method including an aqueous treatment process, power consumption related to production in the production process can be reduced and energy efficiency can be increased as compared with the case of producing by a pulverization method. In addition, the toner particles can be easily controlled in shape, and a toner with high uniformity of toner particle shapes can be produced. Therefore, the individual toner particles have almost the same characteristics, and the variation in the characteristics of the individual toner particles is small. Therefore, the toner particles have a wider fixing non-offset region than that produced by the pulverization method, and A toner having better adhesion to the toner can be produced.

  Examples of the method including an aqueous treatment step include suspension polymerization and agglomeration, but the toner obtained by suspension polymerization is spherical and causes cleaning failure, so that the aggregation of the toner can be controlled. The method is more preferred.

  FIG. 1 is a flowchart showing an example of the procedure of the toner production method of the present invention by the aggregation method. The toner production method of the present invention by the aggregation method includes a binder resin fine particle preparation step S1, a colorant fine particle preparation step S2, a wax fine particle preparation step S3, an aggregation step S4, and a cleaning step S5.

[Binder resin fine particle preparation step S1]
In the binder resin fine particle preparation step of Step S1, a dispersion in which the binder resin fine particles are dispersed in an aqueous medium (hereinafter referred to as “binder resin fine particle dispersion”) is prepared. At this time, the above-described binder resin is used as the binder resin.

  The method for preparing the binder resin fine particle dispersion is not particularly limited, but it is preferable to use a high-pressure emulsification apparatus equipped with a decompression mechanism. By preparing using the said apparatus, the binder resin fine particle dispersion containing the binder resin fine particles with uniform distribution can be prepared.

  As a high-pressure emulsification apparatus provided with a pressure reduction mechanism, for example, NANO3000 (trade name, manufactured by Migrain Co., Ltd.) and the like can be mentioned. The high-pressure emulsification apparatus includes a tank, a pressurizing unit, a heater, a pulverizing nozzle, a decompression module, and a cooler. The tank is a container-like member having an internal space, and stores a dispersion liquid (hereinafter referred to as “coarse slurry”) in which the coarse powder of the binder resin is dispersed in an aqueous medium. The pressurizing unit pressurizes the coarse powder slurry. The heater heats the coarse powder slurry pressurized by the pressure unit. The crushing nozzle pulverizes the binder resin coarse powder into binder resin fine particles by allowing the coarse powder slurry in a heated and pressurized state to flow through the flow path formed therein, thereby dispersing the binder resin fine particles. Make a liquid. The decompression module decompresses the binder resin fine particle dispersion in a heated and pressurized state so that bubbles are not generated due to bumping. The cooler cools the binder resin fine particle dispersion in a heated state.

  As a preparation of the binder resin fine particle dispersion using the high-pressure emulsifier, first, the dispersion containing the binder resin is stored in the tank of the high-pressure emulsifier. Although it does not restrict | limit especially as an aqueous medium, Water is preferable when the ease of process control, the waste liquid treatment after all the processes, the ease of handling, etc. are considered. As water, ion-exchanged water, distilled water, pure water, or the like can be used.

  It is preferable to add a dispersant to the aqueous medium. The dispersant is preferably added to the aqueous medium before the toner composition such as the binder resin monomer is added to the aqueous medium.

  As the dispersant, those commonly used in this field can be used. Among these, a water-soluble polymer dispersant is preferable. Examples of the water-soluble polymer dispersant include acrylic monomers such as (meth) acrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, and maleic anhydride. Body, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-chloro-acrylate Hydroxyl group-containing acrylic monomers such as 2-hydroxypropyl and 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Ester monomers such as stealth, vinyl alcohol monomers such as N-methylol acrylamide and N-methylol methacrylamide, ethers with vinyl alcohol, vinyl alkyl such as vinyl methyl ether, vinyl ethyl ether and vinyl propyl ether Ether monomers, vinyl alkyl ester monomers such as vinyl acetate, vinyl propionate and vinyl butyrate, aromatic vinyl monomers such as styrene, α-methylstyrene and vinyltoluene, acrylamide, methacrylamide, di Acetone acrylamide, amide monomers such as these methylol compounds, nitrile monomers such as acrylonitrile and methacrylonitrile, acid chloride monomers such as acrylic acid chloride and methacrylic acid chloride, vinylpyridine, vinyl One or two selected from vinyl nitrogen-containing heterocyclic monomers such as lupyrrolidone, vinylimidazole, and ethyleneimine, and crosslinkable monomers such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, allyl methacrylate, and divinylbenzene (Meth) acrylic polymers containing various hydrophilic monomers, polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxy Polyoxyethylene such as ethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonyl phenyl ester Cellulose polymers such as methyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, polyoxyethylene lauryl phenyl ether sodium sulfate, polyoxyethylene lauryl phenyl ether potassium sulfate, polyoxyethylene nonyl phenyl ether sodium sulfate, polyoxyethylene oleyl phenyl Polyoxyalkylene alkyl aryl ether sulfates such as sodium ether sulfate, polyoxyethylene cetyl phenyl ether sodium sulfate, polyoxyethylene lauryl phenyl ether ammonium sulfate, polyoxyethylene nonylphenyl ether ammonium sulfate, polyoxyethylene oleyl phenyl ether ammonium sulfate, polyoxyethylene Laurylate Sodium sulfate, polyoxyethylene lauryl ether potassium sulfate, polyoxyethylene oleyl ether sodium sulfate, polyoxyethylene cetyl ether sodium sulfate, polyoxyethylene lauryl ether ammonium sulfate, polyoxyalkylene alkyl ether sulfate such as polyoxyethylene oleyl ether ammonium sulfate, etc. Is mentioned. A dispersing agent can be used individually by 1 type, or can use 2 or more types together. The addition amount of the dispersant is not particularly limited, but is preferably 0.1 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the binder resin.

  A thickener, a surfactant and the like may be added to the binder resin fine particle dispersion together with the dispersant. The thickener is effective for further atomizing the binder resin fine particles. The thickener is preferably a polysaccharide thickener selected from synthetic polymer polysaccharides and natural polymer polysaccharides. As the synthetic polymer polysaccharide, known ones can be used, and examples thereof include cationized cellulose, hydroxyethyl cellulose, starch, ionized starch derivatives, and a block polymer of starch and synthetic polymer. Examples of the natural polymer polysaccharide include hyaluronic acid, carrageenan, locust bean gum, xanthan gum, guar gum, gellan gum and the like. A thickener can be used individually by 1 type, or can use 2 or more types together. The addition amount of the thickener is not particularly limited, but is preferably 0.01 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the binder resin.

  The surfactant further improves the dispersibility of the binder resin fine particles in the aqueous medium. Examples of the surfactant include lauryl sulfosuccinate disodium, polyoxyethylene sulfosuccinate lauryl disodium, polyoxyethylene alkyl (C12 to C14) sulfosuccinic acid disodium, sulfosuccinic acid polyoxyethylene lauroyl ethanolamide 2 Examples include sodium and sulfosuccinic acid ester salts such as dioctyl sodium sulfosuccinate. Surfactant can be used individually by 1 type, or can use 2 or more types together. The addition amount of the surfactant is not particularly limited, but is preferably 0.1 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the binder resin.

  A method for mixing a dispersant, a thickener, a surfactant, and the like with an aqueous medium is not particularly limited and can be performed by a known method. When the water-soluble polymer dispersant and the aqueous medium are mixed, the addition and dispersion may be performed by any method as long as the dispersant can be uniformly dissolved in water.

  The dispersion liquid containing the binder resin stored in the tank is pressurized by the pressure unit, heated by the heater, and passed through the flow path formed in the pulverizing nozzle, so that the binder resin is coarsely crushed. Is done. The conditions for pressurizing and heating the melt-kneaded dispersion at this time are not particularly limited, but it is preferably 15 to 120 MPa and 10 ° C. or higher and lower than the melting point of the binder resin. The dispersion in which the wax is coarsely pulverized is further passed through a flow path formed in the pulverizing nozzle so that the binder resin is atomized to obtain a binder resin fine particle dispersion. Although the pressure heating conditions at this time are not particularly limited, it is preferable that the pressure is increased to 50 MPa to 250 MPa and heated to 50 ° C. or higher. By crushing the binder resin under such pressure and heating conditions, binder resin fine particles having a uniform distribution can be obtained efficiently.

  The average particle diameter of the binder resin fine particles in the resulting binder resin fine particle dispersion is preferably 1 μm or less, and more preferably 0.01 μm or more and 1 μm or less. When the average particle size exceeds 1 μm, the particle size distribution of the finally obtained toner particles becomes wide and free particles are generated, so that the performance and reliability of the toner may be easily lowered.

[Colorant fine particle preparation step S2]
In the colorant fine particle preparation step of Step S2, a dispersion liquid in which the colorant fine particles are dispersed in an aqueous medium (hereinafter referred to as “colorant fine particle dispersion liquid”) is prepared.

  The method for preparing the colorant fine particle dispersion is not particularly limited, but it is preferable to use a high-pressure emulsification apparatus equipped with a decompression mechanism. By preparing using the said apparatus, the colorant microparticles | fine-particles dispersion liquid containing the colorant microparticles | fine-particles with uniform distribution can be prepared. The high-pressure emulsifying device is the same device as the high-pressure emulsifying device used in the binder resin fine particle dispersion preparing step in step S1, and the colorant fine particles are added by adding the coarse colorant powder instead of the coarse powder of the binder resin. A dispersion can be prepared. By preparing using the said apparatus, the colorant microparticle dispersion liquid containing the binder resin microparticles with uniform distribution can be prepared.

  As a preparation of the colorant fine particle dispersion using the high-pressure emulsifier, first, the dispersion containing the colorant is stored in the tank of the high-pressure emulsifier. Although it does not restrict | limit especially as an aqueous medium, Water is preferable when the ease of process control, the waste liquid treatment after all the processes, the ease of handling, etc. are considered. As water, ion-exchanged water, distilled water, pure water or the like can be used.

  The colorant is preferably used in a proportion of 5 to 50 parts by weight, more preferably 20 to 40 parts by weight, based on 100 parts by weight of the aqueous medium. When the use ratio of the colorant is less than 5 parts by weight, the amount of the colorant with respect to the aqueous medium is too small, so that the dispersion uniformity is lowered. If the proportion of the colorant used exceeds 50 parts by weight, the amount of the colorant relative to the aqueous medium is too large, so that the viscosity of the aqueous medium becomes too high, and this also reduces the dispersibility.

  A dispersant is preferably added to the aqueous medium used for the preparation of the colorant fine particle dispersion. An inorganic or organic dispersant can be used as the dispersant. The dispersant is preferably added to the aqueous medium before the colorant is added to the aqueous medium.

  The inorganic dispersant is preferably a hydrophilic inorganic dispersant. By using a hydrophilic inorganic dispersant, the particle size of the fine powder of the colorant in the liquid medium can be made more uniform. Examples of the hydrophilic inorganic dispersant include silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, clay, diatomaceous earth, and bentonite. Among these, calcium carbonate is preferable.

  The number average particle diameter of the primary particles of the inorganic dispersant is preferably 1 nm or more and 1000 nm or less, more preferably 5 nm or more and 500 nm or less, and further preferably 10 nm or more and 300 nm or less. When the number average particle diameter of the primary particles of the inorganic dispersant is less than 1 nm, it is difficult to disperse the inorganic dispersant in the aqueous medium. If the number average particle size of the primary particles of the inorganic dispersant exceeds 1000 nm, the difference between the particle size of the colorant coarse powder and the particle size of the inorganic dispersant becomes small, and the colorant coarse powder is stable in the liquid. Thus, it becomes difficult to maintain the dispersion.

  The inorganic dispersant is preferably used in the range of 1 part by weight to 300 parts by weight and more preferably in the range of 4 parts by weight to 100 parts by weight with respect to 100 parts by weight of the colorant. When the amount of the inorganic dispersant used is less than 1 part by weight, it is difficult to disperse the inorganic dispersant in the aqueous medium. When the usage-amount of an inorganic dispersing agent exceeds 300 weight part, there exists a possibility that the viscosity of a liquid medium may become high too much and a dispersibility may fall.

  Further, a polymer dispersant may be added to the aqueous medium together with the inorganic dispersant. As the polymer dispersant, for example, a hydrophilic one is preferably used, one having a carboxyl group is more preferable, and one having no lipophilic group such as a hydroxypropoxyl group or a methoxyl group is particularly preferable. Examples of such a polymer dispersant include water-soluble cellulose ethers such as carboxymethyl cellulose and carboxyethyl cellulose. Among these, carboxymethyl cellulose is particularly preferable. The polymer dispersant is preferably used in a proportion of 0.1 to 5.0 parts by weight with respect to 100 parts by weight of the colorant.

  The organic dispersant is preferably an anionic dispersant. Anionic dispersants are excellent in the ability to improve the dispersibility of colorant particles in water. Examples of the anionic dispersant include a sulfonic acid type anionic dispersant, a sulfate ester type anionic dispersant, a polyoxyethylene ether type anionic dispersant, a phosphate ester type anionic dispersant, and a polyacrylate. Can be mentioned. As specific examples of the anionic dispersant, for example, sodium dodecylbenzenesulfonate, sodium polyacrylate, polyoxyethylene phenyl ether and the like can be preferably used. An anionic dispersing agent can be used individually by 1 type, or can use 2 or more types together.

  The organic dispersant is not limited to an anionic dispersant and may be a cationic dispersant. Examples of the cationic dispersant include alkyltrimethylammonium type cationic dispersants, alkylamidoamine type cationic dispersants, alkyldimethylbenzylammonium type cationic dispersants, cationized polysaccharide type cationic dispersants, and alkylbetaine type cationic dispersants. Dispersants, alkylamide betaine type cationic dispersants, sulfobetaine type cationic dispersants, amine oxide type cationic dispersants, metal salts and the like are preferable. Examples of the metal salt include chlorides such as sodium, potassium, calcium, and magnesium, and sulfates. Among these, alkyltrimethylammonium cationic dispersants are more preferable. Specific examples of the alkyl trimethyl ammonium type cationic dispersant include stearyl trimethyl ammonium chloride, tri (polyoxyethylene) stearyl ammonium chloride, lauryl trimethyl ammonium chloride and the like. A cationic dispersing agent can be used individually by 1 type, or can use 2 or more types together.

  The addition amount of the organic dispersant is not particularly limited and can be appropriately selected from a wide range, but is preferably 0.1 parts by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the colorant. When the addition amount is less than 0.1 parts by weight, the effect of dispersing the colorant by the dispersant becomes insufficient and aggregation may occur. Even if the organic dispersant is added in an amount exceeding 5 parts by weight, the dispersion effect is not further improved, and the dispersibility of the colorant is lowered by increasing the viscosity of the colorant slurry. As a result, aggregation may occur.

  A commercially available thing can also be used as a dispersing agent. Examples of commercially available dispersants include BYK-182, BYK-161, BYK-116, BYK-111, BYK-2000 (manufactured by Big Chemie Japan Co., Ltd.), Solsperse-2000, Solsperse-38500 (above Avicia Corporation). Product), EFKA-4046, EFKA-4047 (manufactured by Efcar Chemicals), Surfynol GA (manufactured by Air Products), and the like. One of these commercially available dispersants may be used alone, or two or more thereof may be mixed and used.

  Such a commercially available dispersant is preferably used in a ratio of 10 parts by weight or more and 100 parts by weight or less, and in a ratio of 20 parts by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the colorant. Is more preferable. If the ratio of the commercially available dispersant used is less than 10 parts by weight, the effect of dispersing the colorant by the dispersant becomes insufficient, and aggregation may occur. When the use ratio of the commercially available dispersant exceeds 100 parts by weight, the dispersibility of the colorant is lowered due to an increase in the viscosity of the colorant slurry. As a result, aggregation may occur.

  Mixing with an aqueous medium and a dispersing agent can be performed by a well-known method, without being specifically limited. When mixing an inorganic dispersant and an aqueous medium, the inorganic dispersant can be dispersed in water in an aqueous medium using a disperser containing a medium such as a ball mill or a sand mill, a high-pressure disperser, an ultrasonic disperser, or the like. . When the organic dispersant and the aqueous medium are mixed, the addition and dispersion may be performed by any method as long as the dispersant can be uniformly dissolved in water.

  It is preferable to add a dispersant to the aqueous medium used for the preparation of the colorant fine particle dispersion. The dispersant is preferably added to the aqueous medium before adding the wax to the aqueous medium.

  As the dispersant, those commonly used in this field can be used, and a thickener and a surfactant may be used in combination. As the dispersant, thickener and surfactant, the dispersant, thickener and surfactant described in the binder resin fine particle preparation step S1 can be used. Further, a dispersion liquid in which other additives are dispersed in an aqueous medium may be used for the purpose of improving toner physical properties.

  The dispersion liquid containing the colorant stored in the tank is pressurized by the pressurizing unit, heated by the heater, and passed through the flow path formed in the pulverizing nozzle, so that the colorant is coarsely pulverized. . The pressurizing and heating conditions of the colorant dispersion at this time are not particularly limited, but are preferably 15 MPa or more and 120 MPa or less and preferably 10 ° C. or more and less than the melting point of the colorant. The dispersion liquid in which the colorant is coarsely pulverized is further passed through a flow path formed in the pulverizing nozzle, whereby the colorant is atomized to obtain a colorant fine particle dispersion liquid. Although the pressure heating conditions at this time are not particularly limited, it is preferable that the pressure is increased to 50 MPa to 250 MPa and heated to 50 ° C. or higher. By finely pulverizing the colorant under such pressure and heating conditions, it is possible to obtain fine colorant particles having a uniform distribution.

  The average particle diameter of the colorant fine particles is preferably 1 μm or less, and more preferably 0.01 μm or more and 1 μm or less. When the average particle diameter exceeds 1 μm, the particle size distribution of the finally obtained toner particles becomes wide and free particles are generated, which may tend to cause deterioration in toner performance and reliability.

[Wax Fine Particle Preparation Step S3]
In the wax fine particle preparation step of step S3, a dispersion in which wax fine particles are dispersed in an aqueous medium (hereinafter referred to as “wax fine particle dispersion”) is prepared.

  Although the wax fine particles can be produced according to a known wax granulation method, it is preferable to use a high-pressure emulsification apparatus equipped with a decompression mechanism. By including an agglomeration step in which the wax is agglomerated by a high-pressure emulsification device equipped with a decompression mechanism, wax particles with a uniform molecular weight distribution can be uniformly dispersed in the toner, so a wider fixing non-offset It is possible to manufacture a toner having a region and having a better adhesion between the recording medium and the toner. The high-pressure emulsifying device is the same device as the high-pressure emulsifying device used in the binder resin fine particle dispersion preparing step in step S1, and the colorant fine particles are added by adding the coarse colorant powder instead of the coarse powder of the binder resin. A dispersion can be prepared.

  As a high-pressure emulsification apparatus provided with a pressure reduction mechanism, for example, NANO3000 (trade name, manufactured by Migrain Co., Ltd.) and the like can be mentioned. The high-pressure emulsification apparatus includes a tank, a pressurizing unit, a heater, a pulverizing nozzle, a decompression module, and a cooler. The tank is a container-like member having an internal space, and stores a dispersion liquid (hereinafter referred to as “wax slurry”) in which wax is dispersed in an aqueous medium. The pressure unit pressurizes the wax slurry. The heater heats the wax slurry that is pressurized by the pressure unit. The crushing nozzle pulverizes the wax into fine wax particles by causing the wax slurry in a heated and pressurized state to flow through a flow path formed therein, thereby producing a wax fine particle dispersion. The decompression module decompresses the wax fine particle dispersion in a heated and pressurized state so that bubbles are not generated due to bumping. The cooler cools the wax fine particle dispersion in a heated state.

  For the preparation of the wax fine particle dispersion using the high-pressure emulsifier, first, the dispersion containing wax is stored in the tank of the high-pressure emulsifier. Although it is not particularly limited as an aqueous medium, water is preferable in consideration of easiness of process management, waste liquid treatment after all processes and easiness of handling, and as water, ion exchange water, distilled water, pure water, or the like is used. be able to.

  It is preferable to add a dispersant to the aqueous medium used for the preparation of the wax fine particle dispersion. The dispersant is preferably added to the aqueous medium before adding the wax to the aqueous medium.

  As the dispersant, those commonly used in this field can be used, and a thickener and a surfactant may be used in combination. As the dispersant, thickener and surfactant, the dispersant, thickener and surfactant described in the binder resin fine particle preparation step S1 can be used. Further, a dispersion liquid in which other additives are dispersed in an aqueous medium may be used for the purpose of improving toner physical properties.

  The dispersion liquid containing the wax stored in the tank is pressurized by the pressurizing unit, heated by the heater, and passed through the flow path formed in the pulverizing nozzle, so that the wax is roughly pulverized. The pressure and heating conditions of the melt-kneaded dispersion at this time are not particularly limited, but are preferably 15 MPa or more and 120 MPa or less and preferably 10 ° C. or more and less than the melting point of the wax. The dispersion in which the wax is coarsely pulverized is further passed through a flow path formed in the pulverizing nozzle, whereby the wax is atomized to obtain a wax fine particle dispersion. Although the pressure heating conditions at this time are not particularly limited, it is preferable that the pressure is increased to 50 MPa to 250 MPa and heated to 50 ° C. or higher. By pulverizing the wax under such pressure and heating conditions, it is possible to obtain wax fine particles having a uniform distribution efficiently.

  When other additives such as a charge control agent are included in the toner as necessary, a dispersion containing additive fine particles (hereinafter referred to as “additive fine particle dispersion”) is prepared by the same method as described above. To do.

[Aggregating step S4]
In the aggregation step of Step S4, the binder resin fine particles obtained in Steps S1 to S3, the colorant fine particles, the wax fine particles, and the additive fine particles in an aqueous medium containing a dispersant, a surfactant, a thickener and the like. A dispersion liquid in which aggregated particles that are aggregates are dispersed (hereinafter referred to as “aggregated particle dispersion liquid”) is obtained. In the aggregation step S4, the binder fine particle dispersion obtained in steps S1 to S3, the colorant fine particle dispersion, the wax fine particle dispersion, and the additive fine particle dispersion are mixed, and the flocculant is added thereto. A thing is stored in a stirring container, and each fine particle is aggregated by stirring.

  In the agglomeration step S4, a granulating apparatus including a stirring container for storing the fine particle dispersion and a stirring means provided in the stirring container for stirring the fine particle dispersion is used. As such a granulating apparatus, it is preferable to use an emulsifier or a disperser capable of applying a shearing force from one mechanical direction. Thereby, the particle diameter and shape of the toner particles to be formed can be made more uniform. Specific examples of the emulsifier and the disperser include, for example, Ultra Tarrax (trade name, manufactured by IKA Japan Co., Ltd.), Polytron homogenizer (trade name, manufactured by Kinematica Co., Ltd.), TK Auto Homo Mixer (trade name, manufactured by Primix Co., Ltd.). ), Max Blend (Sumitomo Heavy Industries, Ltd.) and other batch emulsifiers, Ebara Milder (trade name, manufactured by Ebara Corporation), TK Pipeline Homomixer (trade name, manufactured by Primix Corporation), TK Homomic Lineflow (trade name, manufactured by Primix Co., Ltd.), Fillmix (trade name, manufactured by Primix Co., Ltd.), colloid mill (trade name, manufactured by Shinko Pantech Co., Ltd.), Thrasher (trade name, manufactured by Mitsui Miike Chemical Industries, Ltd.) ), Trigonal wet pulverizer (trade name, manufactured by Mitsui Miike Chemical Co., Ltd.), Cabi Continuous emulsifiers such as Ron (trade name, manufactured by Eurotech Co., Ltd.), Fine Flow Mill (trade name, manufactured by Taiheiyo Kiko Co., Ltd.), Claremix (trade name, manufactured by M Technique Co., Ltd.), Fillmix (product) Name, manufactured by Primix Co., Ltd.).

  In the mixing of each fine particle dispersion of the toner raw material and the aggregating agent, the stirring speed and stirring temperature of the granulating device may be appropriately selected from values at which toner particles having a desired particle size, particle size distribution and shape can be obtained. The stirring time can be appropriately selected according to various conditions such as binder resin, colorant, wax, other toner additive components, types of flocculant and dispersant, and concentration.

  Examples of the flocculant include cationic dispersants and polyvalent metal salts. Examples of the cationic dispersant include alkyltrimethylammonium type cationic dispersants, alkylamidoamine type cationic dispersants, alkyldimethylbenzylammonium type cationic dispersants, cationized polysaccharide type cationic dispersants, and alkylbetaine type cationic dispersants. Examples thereof include a dispersant, an alkylamide betaine type cationic dispersant, a sulfobetaine type cationic dispersant, an amine oxide type cationic dispersant, and a metal salt. Examples of the metal salt include chlorides and sulfates such as sodium, potassium, calcium, and magnesium.

  The polyvalent metal salt is a divalent or higher metal salt. The divalent or higher metal is preferably an alkaline earth metal such as magnesium, calcium or barium, a Group 13 element of the periodic table such as aluminum, and particularly preferably magnesium or aluminum. Specific examples of the divalent or higher metal salt include magnesium sulfate, aluminum sulfate, barium chloride, magnesium chloride, calcium chloride, aluminum chloride, aluminum hydroxide, and magnesium hydroxide. Among these flocculants, sodium chloride is preferred because of its relatively high solubility in water and a slow flocculation rate. The amount of the flocculant used is preferably 0.5 to 20 parts by weight, more preferably 0.5 to 18 parts by weight, and particularly preferably 1 to 100 parts by weight of the resin fine particle slurry. 0.0 parts by weight to 18 parts by weight. If the amount is less than 0.5 part by weight, the agglomeration effect may be insufficient. If the amount exceeds 20 parts by weight, the agglomerated particles may become too large due to overaggregation.

[Washing step S5]
In the cleaning step of step S5, after the aggregated particle dispersion is cooled, the aggregated particles contained in the aggregated particle dispersion are washed. Washing of the agglomerated particles is performed in order to remove a surfactant, a dispersant, a thickener, impurities derived therefrom, and the like. If the surfactant, dispersant, thickener and the impurities remain in the aggregated particles, the charging performance of the resulting toner may become unstable. In addition, the toner charge amount may decrease due to the influence of moisture in the air.

  Washing of the agglomerated particles can be performed, for example, by adding water to the agglomerated particle dispersion, stirring, and removing the supernatant liquid separated by centrifugation or the like. Washing of the agglomerated particles is preferably repeated until the conductivity of the supernatant measured with a conductivity meter or the like is 100 μS / cm or less, preferably 10 μS / cm or less. As a result, it is possible to more reliably prevent surfactants, dispersants, thickeners, and the like, and impurities derived therefrom, from remaining, and to stabilize the charging performance of the toner particles more uniformly.

  The water used for washing is preferably water having a conductivity of 20 μS / cm or less. Such washing water can be prepared, for example, by an activated carbon method, an ion exchange method, a distillation method, a reverse osmosis method, or the like. Moreover, you may prepare water combining 2 or more types among these methods. The temperature of the washing water is not particularly limited, but is preferably 10 ° C. or higher and a glass transition temperature (Tg) or lower. When the melt-kneaded material contains two or more kinds of binder resins, the glass transition temperature (Tg) or lower here is the lowest glass transition temperature among the glass transition temperatures (Tg) of the two or more kinds of binder resins. Below the value of temperature (Tg). The water washing of the agglomerated particles may be carried out either batchwise or continuously.

  Next, the aggregated particles are separated and recovered from the aqueous medium mixture containing the aggregated particles after washing. Separation of the aggregated particles from the aqueous medium is not particularly limited, and can be performed by, for example, filtration, suction filtration, centrifugation, or the like.

  Finally, the aggregated particles after washing and separation are dried. The method for drying the agglomerated particles is not particularly limited, and examples thereof include a freeze drying method and an airflow drying method. The aggregated particles are dried, and the production of the toner particles is finished.

  The toner particles produced as described above are responsible for functions such as powder flowability improvement, triboelectric chargeability improvement, heat resistance, long-term storage stability improvement, cleaning property improvement and photoreceptor surface wear property control. An additive may be externally added.

  As the external additive, those commonly used in this field can be used, and examples thereof include fine silica powder, fine titanium oxide powder and fine alumina powder. These inorganic fine powders are silicone varnishes, various modified silicone varnishes, silicone oils, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, etc. It is preferably treated with a treating agent such as an organosilicon compound. External additives can be used alone or in combination of two or more.

  The amount of the external additive added is 1 weight with respect to 100 parts by weight of the toner particles in consideration of the charge amount necessary for the toner, the influence of the external additive on the abrasion of the photoreceptor and the environmental characteristics of the toner. The amount is preferably from 10 to 10 parts by weight, more preferably 5 parts by weight or less.

  The external additive preferably has a number average particle diameter of primary particles of 10 nm to 500 nm. By externally adding such an external additive having a number average particle diameter to the toner particles, the effect of improving the fluidity of the toner is more easily exhibited.

  As described above, the toner in which the external additive is externally added to the toner particles as necessary can be used as it is as a one-component developer, or can be mixed with a carrier and used as a two-component developer. . The developer contains the toner of the present invention. This makes it possible to form a high-quality image with a wide fixing non-offset region and a developer with stable characteristics over a long period of use, thereby obtaining a developer capable of maintaining good developability. It is done.

  When used as a one-component developer, the toner is used only without using a carrier. When used as a one-component developer, a blade and a fur brush are used, frictionally charged by a developing sleeve, and the toner is transported by adhering the toner onto the sleeve to form an image.

  The toner of the present invention is suitably used for a two-component developer comprising a toner and a carrier. Since the toner of the present invention is excellent in storage stability and durability, generation of a carrier spent is suppressed, and a two-component developer having good fluidity can be obtained. By using such a two-component developer, it is possible to suppress deterioration in image quality due to toner scattering and fogging and to stably form a high-quality image.

When used as a two-component developer, the toner of the present invention is used with a carrier.
As the carrier, a known carrier can be used, for example, a single or composite ferrite composed of iron, copper, zinc, nickel, cobalt, manganese, chromium, etc., a resin-coated carrier whose carrier core particles are coated with a coating substance, and a resin And a resin-dispersed carrier in which magnetic particles are dispersed.

  Known coating materials for coating the carrier core particles can be used, such as polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicon resin, polyester resin, metal compound of ditertiary butyl salicylic acid, styrene Resin, acrylic resin, polyacid, polyvinyllar, nigrosine, aminoacrylate resin, basic dye, lake of basic dye, fine silica powder, fine alumina powder, and the like.

  Although it does not restrict | limit especially as resin used for a resin dispersion type carrier, For example, a styrene acrylic resin, a polyester resin, a fluorine resin, a phenol resin, etc. are mentioned. Either of them is preferably selected according to the toner component, and one kind can be used alone or two or more kinds can be used in combination.

  The shape of the carrier is preferably a spherical shape or a flat shape. The particle size of the carrier is not particularly limited, but is preferably 10 μm or more and 100 μm or less, more preferably 20 μm or more and 50 μm or less in consideration of high image quality.

The volume resistivity of the carrier is preferably 10 ⁸ Ω · cm or more, and more preferably 10 ¹² Ω · cm or more. The volume resistivity of the carrier is determined by placing the carrier in a container having a cross-sectional area of 0.50 cm ² and tapping it, and then applying a load with a weight of 1 kg / cm ² to the particles packed in the container. It is a value obtained by reading a current value when a voltage that generates an electric field of 1000 V / cm is applied during the period. When the volume resistivity is low, when a bias voltage is applied to the developing sleeve, charges are injected into the carrier, and carrier particles easily adhere to the photoreceptor. Further, breakdown of the bias voltage is likely to occur.

  The magnetization strength (maximum magnetization) of the carrier is preferably 10 emu / g or more and 60 emu / g or less, more preferably 15 emu / g or more and 40 emu / g or less. The magnetization strength depends on the magnetic flux density of the developing roller, but under the general magnetic flux density conditions of the developing roller, if it is less than 10 emu / g, the magnetic binding force does not work and causes carrier scattering. There is a fear. On the other hand, if the magnetization strength exceeds 60 emu / g, the rising of the carrier becomes too high, and it becomes difficult to maintain the non-contact state between the image carrier and the carrier in non-contact development. Further, in the contact development, there is a risk that a sweep is likely to appear in the toner image.

The use ratio of the toner and the carrier in the two-component developer is not particularly limited, and can be appropriately selected according to the type of the toner and the carrier. If a resin-coated carrier having a density of 5 to 8 g / cm ² is taken as an example, Preferably, the toner may be used so that the developer contains 2 to 30% by weight, more preferably 2 to 20% by weight of the total amount of the developer. In the two-component developer, the coverage of the carrier with the toner is preferably 40% or more and 80% or less.

  FIG. 2 is a schematic cross-sectional view schematically showing the configuration of the image forming apparatus 1 according to the embodiment of the present invention. The image forming apparatus 1 is a multifunction machine having both a copying function, a printer function, and a facsimile function, and forms a full-color or monochrome image on a recording medium in accordance with transmitted image information. That is, the image forming apparatus 1 has three types of printing modes, ie, a copier mode (copying mode), a printer mode, and a FAX mode. Operation input from an operation unit (not shown), a personal computer, a portable terminal device, and information recording A print mode is selected by a control unit (not shown) in response to reception of a print job from an external device using a storage medium or a memory device.

  The image forming apparatus 1 includes a toner image forming unit 2, an intermediate transfer unit 3, a transfer unit 7, a fixing unit 4, a recording medium supply unit 5, and a discharge unit 6. Each member constituting the toner image forming unit 2 and some members included in the intermediate transfer unit 3 are black (b), cyan (c), magenta (m), and yellow (y) included in the color image information. In order to correspond to the image information of each color, four each are provided. Here, each member provided by four according to each color is distinguished by attaching an alphabet representing each color to the end of the reference symbol, and when referring collectively, only the reference symbol is used.

  The toner image forming unit 2 includes a photosensitive drum 11 that is an image carrier, a charging unit 12, an exposure unit 13, a developing device 14, and a cleaning unit 15. The charging unit 12, the developing device 14, and the cleaning unit 15 are arranged around the photosensitive drum 11 in this order. The charging unit 12 is disposed below the developing device 14 and the cleaning unit 15 in the vertical direction. The charging unit 12 and the exposure unit 13 function as a latent image forming unit that forms a latent image on the photosensitive drum 11.

  The photosensitive drum 11 is supported by a driving unit (not shown) so as to be rotatable around an axis, and includes a conductive substrate (not shown) and a photosensitive layer formed on the surface of the conductive substrate. The conductive substrate can take various shapes, and examples thereof include a cylindrical shape, a columnar shape, and a thin film sheet shape. Among these, a cylindrical shape is preferable.

  The conductive substrate is formed of a conductive material. As the conductive material, those commonly used in this field can be used, for example, metals such as aluminum, copper, brass, zinc, nickel, stainless steel, chromium, molybdenum, vanadium, indium, titanium, gold, platinum, and the like. A conductive layer made of one or more of aluminum, aluminum alloy, tin oxide, gold, indium oxide, etc. is formed on a film-like substrate such as a synthetic resin film, a metal film, or paper. And a resin composition containing a conductive film, conductive particles and / or a conductive polymer. As the film-like substrate used for the conductive film, a synthetic resin film is preferable, and a polyester film is particularly preferable. Moreover, as a formation method of the electroconductive layer in an electroconductive film, vapor deposition, application | coating, etc. are preferable.

  The photosensitive layer is formed, for example, by laminating a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. In that case, it is preferable to provide an undercoat layer between the conductive substrate and the charge generation layer or the charge transport layer. By providing an undercoat layer, the scratches and irregularities present on the surface of the conductive substrate are coated to smooth the surface of the photosensitive layer, to prevent deterioration of the chargeability of the photosensitive layer during repeated use. Alternatively, an advantage of improving the charging characteristics of the photosensitive layer in a low humidity environment can be obtained. Further, it is also possible to use a laminated photoreceptor having a three-layer structure having a large durability and having a photoreceptor surface protective layer as the uppermost layer.

  The charge generation layer is mainly composed of a charge generation material that generates a charge when irradiated with light, and contains a known binder resin, plasticizer, sensitizer and the like as necessary. As the charge generation material, those commonly used in this field can be used. Phthalocyanine pigments such as metal-free phthalocyanine, squalium dye, azulenium dye, thiapyrylium dye, carbazole skeleton, styryl stilbene skeleton, triphenylamine skeleton, dibenzothiophene skeleton, oxadiazole skeleton, fluorenone skeleton, bis stilbene skeleton, distyryl oxa And azo pigments having a diazole skeleton or a distyrylcarbazole skeleton. Among these, metal-free phthalocyanine pigments, oxotitanyl phthalocyanine pigments, bisazo pigments containing a fluorene ring and / or a fluorenone ring, bisazo pigments composed of aromatic amines, trisazo pigments, etc. have high charge generation ability and high sensitivity. Suitable for obtaining a photosensitive layer. One type of charge generating material can be used alone, or two or more types can be used in combination. The content of the charge generation material is not particularly limited, but is preferably 5 to 500 parts by weight, more preferably 10 to 200 parts by weight with respect to 100 parts by weight of the binder resin in the charge generation layer. As the binder resin for the charge generation layer, those commonly used in this field can be used. For example, melamine resin, epoxy resin, silicone resin, polyurethane, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polycarbonate, phenoxy resin , Polyvinyl butyral, polyarylate, polyamide, polyester and the like. Binder resin can be used individually by 1 type, or can use 2 or more types together as needed.

  The charge generation layer generates charge by dissolving or dispersing appropriate amounts of charge generation materials, binder resins and, if necessary, plasticizers and sensitizers in an appropriate organic solvent capable of dissolving or dispersing these components. It can be formed by preparing a layer coating solution, applying this charge generation layer coating solution to the surface of the conductive substrate and drying. The film thickness of the charge generation layer thus obtained is not particularly limited, but is preferably 0.05 to 5 μm, more preferably 0.1 to 2.5 μm.

  The charge transport layer laminated on the charge generation layer has a charge transport material having the ability to accept and transport the charge generated from the charge generation material and a binder resin for the charge transport layer as essential components. Contains known antioxidants, plasticizers, sensitizers, lubricants and the like.

  As the charge transport material, those commonly used in this field can be used, for example, poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensation product and derivatives thereof, Polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, pyrazoline Derivatives, phenylhydrazones, hydrazone derivatives, triphenylamine compounds, tetraphenyldiamine compounds, triphenylmethane compounds, stilbene compounds, 3-methyl-2-benzothiazoline -Donating substances such as azine compounds, fluorenone derivatives, dibenzothiophene derivatives, indenothiophene derivatives, phenanthrenequinone derivatives, indenopyridine derivatives, thioxanthone derivatives, benzo [c] cinnoline derivatives, phenazine oxide derivatives, tetracyano Examples include electron-accepting substances such as ethylene, tetracyanoquinodimethane, promanyl, chloranil, and benzoquinone. The charge transport materials can be used alone or in combination of two or more. The content of the charge transport material is not particularly limited, but is preferably 10 to 300 parts by weight, more preferably 30 to 150 parts by weight with respect to 100 parts by weight of the binder resin in the charge transport material.

  As the binder resin for the charge transport layer, those commonly used in this field and capable of uniformly dispersing the charge transport material can be used. For example, polycarbonate, polyarylate, polyvinyl butyral, polyamide, polyester, polyketone, epoxy resin, polyurethane , Polyvinyl ketone, polystyrene, polyacrylamide, phenol resin, phenoxy resin, polysulfone resin, and copolymer resins thereof. Among these, in consideration of film formability, wear resistance of the resulting charge transport layer, electrical characteristics, etc., polycarbonate containing bisphenol Z as a monomer component (hereinafter referred to as “bisphenol Z type polycarbonate”), bisphenol Z type polycarbonate And a mixture of polycarbonate with other polycarbonates are preferred. Binder resin can be used individually by 1 type, or can use 2 or more types together.

  The charge transport layer preferably contains an antioxidant together with the charge transport material and the binder resin for the charge transport layer. As the antioxidant, those commonly used in this field can be used, and examples thereof include vitamin E, hydroquinone, hindered amine, hindered phenol, paraphenylenediamine, arylalkane and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds. It is done.

  One antioxidant can be used alone, or two or more antioxidants can be used in combination. The content of the antioxidant is not particularly limited, but is 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on the total amount of components constituting the charge transport layer. The charge transport layer is dissolved or dispersed in a suitable organic solvent that can dissolve or disperse these components in an appropriate amount such as a charge transport material and a binder resin, and if necessary, an antioxidant, a plasticizer, and a sensitizer. The charge transport layer coating liquid is prepared, and the charge transport layer coating liquid is applied to the surface of the charge generation layer and dried. The film thickness of the charge generation layer thus obtained is not particularly limited, but is preferably 10 to 50 μm, more preferably 15 to 40 μm. Note that a photosensitive layer in which a charge generation material and a charge transport material are present can be formed in one layer. In that case, the type, content, binder resin, and other additives of the charge generation material and the charge transport material may be the same as in the case of separately forming the charge generation layer and the charge transport layer.

  In this embodiment, the photosensitive drum formed by forming the organic photosensitive layer using the charge generation material and the charge transport material as described above is used. Instead, an inorganic photosensitive layer using silicon or the like is formed. Can be used.

  The charging unit 12 faces the photosensitive drum 11 and is arranged so as to be separated from the surface of the photosensitive drum 11 along the longitudinal direction of the photosensitive drum 11 with a gap, and the surface of the photosensitive drum 11 has a predetermined polarity and Charge to potential. As the charging unit 12, a charging brush type charger, a charger type charger, a sawtooth type charger, an ion generator, or the like can be used. In the present embodiment, the charging unit 12 is provided so as to be separated from the surface of the photosensitive drum 11, but is not limited thereto. For example, a charging roller may be used as the charging unit 12 and the charging roller may be disposed so that the charging roller and the photosensitive drum are in pressure contact with each other, or a contact charging type charger such as a charging brush or a magnetic brush may be used. .

  The exposure unit 13 is arranged such that light of each color information emitted from the exposure unit 13 passes between the charging unit 12 and the developing device 14 and is irradiated on the surface of the photosensitive drum 11. The exposure unit 13 branches the image information into light of each color information of b, c, m, and y in the unit, and the surface of the photosensitive drum 11 charged to a uniform potential by the charging unit 12 is light of each color information. To form an electrostatic latent image on the surface. As the exposure unit 13, for example, a laser scanning unit including a laser irradiation unit and a plurality of reflecting mirrors can be used. In addition, a unit in which an LED array, a liquid crystal shutter, and a light source are appropriately combined may be used.

  The cleaning unit 15 removes the toner remaining on the surface of the photosensitive drum 11 after transferring the toner image to the recording medium, and cleans the surface of the photosensitive drum 11. For the cleaning unit 15, for example, a plate-like member such as a cleaning blade is used. In the image forming apparatus of the present invention, an organic photosensitive drum is mainly used as the photosensitive drum 11, and the surface of the organic photosensitive drum is mainly composed of a resin component. Deterioration of the surface is likely to proceed due to the chemical action of ozone generated by. However, the deteriorated surface portion is worn by receiving a rubbing action by the cleaning unit 15 and is gradually but surely removed. Therefore, the problem of surface deterioration due to ozone or the like is practically solved, and the charging potential by the charging operation can be stably maintained over a long period of time. Although the cleaning unit 15 is provided in this embodiment, the present invention is not limited to this, and the cleaning unit 15 may not be provided.

  According to the toner image forming unit 2, the surface of the photosensitive drum 11 that is uniformly charged by the charging unit 12 is irradiated with signal light corresponding to the image information from the exposure unit 13 to form an electrostatic latent image. Toner is supplied from the developing device 14 to form a toner image. After the toner image is transferred to the intermediate transfer belt 25, the toner remaining on the surface of the photosensitive drum 11 is removed by the cleaning unit 15. This series of toner image forming operations is repeatedly executed.

  The intermediate transfer unit 3 is disposed above the photosensitive drum 11, and includes an intermediate transfer belt 25, a driving roller 26, a driven roller 27, an intermediate transfer roller 28 (b, c, m, y), and a transfer belt cleaning. A unit 29 and a transfer roller 30. The intermediate transfer belt 25 is an endless belt-like member that is stretched by a driving roller 26 and a driven roller 27 to form a loop-shaped movement path, and is driven to rotate in the direction of an arrow B. When the intermediate transfer belt 25 passes through the photosensitive drum 11 while being in contact with the photosensitive drum 11, an intermediate transfer roller 28 disposed on the surface of the photosensitive drum 11 is opposed to the photosensitive drum 11 via the intermediate transfer belt 25. A transfer bias having a polarity opposite to the charging polarity of the toner is applied, and the toner image formed on the surface of the photosensitive drum 11 is transferred onto the intermediate transfer belt 25. In the case of a full-color image, each color toner image formed on each photoconductor drum 11 is sequentially transferred onto the intermediate transfer belt 25 to form a full-color toner image. The driving roller 26 is provided so as to be rotatable around its axis by driving means (not shown), and the intermediate transfer belt 25 is driven to rotate in the direction of arrow B by the rotational driving. The driven roller 27 is provided so as to be able to be driven and rotated by the rotational drive of the driving roller 26, and applies a certain tension to the intermediate transfer belt 25 so that the intermediate transfer belt 25 does not loosen. The intermediate transfer roller 28 is provided in pressure contact with the photosensitive drum 11 via the intermediate transfer belt 25 and capable of being driven to rotate about its axis by a driving unit (not shown). The intermediate transfer roller 28 is connected to a power source (not shown) for applying a transfer bias as described above, and has a function of transferring the toner image on the surface of the photosensitive drum 11 to the intermediate transfer belt 25. The transfer belt cleaning unit 29 is provided so as to face the driven roller 27 through the intermediate transfer belt 25 and to contact the outer peripheral surface of the intermediate transfer belt 25. Since the toner adhering to the intermediate transfer belt 25 due to contact with the photosensitive drum 11 causes the back surface of the recording medium to be contaminated, the transfer belt cleaning unit 29 removes and collects the toner on the surface of the intermediate transfer belt 25. The transfer roller 30 is provided in pressure contact with the drive roller 26 via the intermediate transfer belt 25, and can be driven to rotate about an axis by a drive unit (not shown). At the pressure contact portion (transfer nip portion) between the transfer roller 30 and the drive roller 26, the toner image carried and conveyed by the intermediate transfer belt 25 is transferred to the recording medium fed from the recording medium supply means 5 described later. Is done. The recording medium carrying the toner image is fed to the fixing unit 4. According to the intermediate transfer unit 3, the toner image transferred from the photosensitive drum 11 to the intermediate transfer belt 25 at the pressure contact portion between the photosensitive drum 11 and the intermediate transfer roller 28 is moved in the direction of arrow B of the intermediate transfer belt 25. The sheet is conveyed to the transfer nip portion by rotation and transferred to a recording medium there.

  The fixing unit 4 is provided downstream of the intermediate transfer unit 3 in the recording medium conveyance direction, and includes a fixing roller 31 and a pressure roller 32. The fixing roller 31 is rotatably provided by a driving unit (not shown), and heats and melts the toner constituting the unfixed toner image carried on the recording medium to fix it on the recording medium. A heating unit (not shown) is provided inside the fixing roller 31. The heating unit heats the fixing roller 31 so that the surface of the fixing roller 31 reaches a predetermined temperature (heating temperature). For example, a heater or a halogen lamp can be used as the heating means. The heating means is controlled by fixing condition control means described later. The control of the heating temperature by the fixing condition control means will be described in detail later. A temperature detection sensor is provided near the surface of the fixing roller 31 to detect the surface temperature of the fixing roller 31. The detection result by the temperature detection sensor is written in the storage unit of the control means described later. The pressure roller 32 is provided so as to be in pressure contact with the fixing roller 31 and is supported so as to be driven to rotate by the rotation drive of the pressure roller 32. The pressure roller 32 assists fixing of the toner image on the recording medium by pressing the toner and the recording medium when the toner is melted and fixed on the recording medium by the fixing roller 31. A pressure contact portion between the fixing roller 31 and the pressure roller 32 is a fixing nip portion. According to the fixing unit 4, the recording medium on which the toner image is transferred by the intermediate transfer unit 3 is sandwiched between the fixing roller 31 and the pressure roller 32, and the toner image is heated while passing through the fixing nip portion. By being pressed against the recording medium, the toner image is fixed on the recording medium and an image is formed.

  The recording medium supply unit 5 includes an automatic paper feed tray 35, a pickup roller 36, a transport roller 37, a registration roller 38, and a manual paper feed tray 39. The automatic paper feed tray 35 is a container-like member that is provided in the lower portion of the image forming apparatus in the vertical direction and stores a recording medium. Recording media include plain paper, color copy paper, overhead projector sheets, postcards, and the like. The pick-up roller 36 takes out the recording medium stored in the automatic paper feed tray 35 one by one and feeds it to the paper transport path S1. The conveyance rollers 37 are a pair of roller members provided so as to be in pressure contact with each other, and convey the recording medium toward the registration rollers 38. The registration rollers 38 are a pair of roller members provided so as to be in pressure contact with each other, and the recording medium fed from the conveyance roller 37 is used to convey the toner image carried on the intermediate transfer belt 25 to the transfer nip portion. Synchronously, it is fed to the transfer nip. The manual paper feed tray 39 is a device that takes a recording medium into the image forming apparatus by manual operation. The recording medium taken from the manual paper feed tray 39 passes through the paper conveyance path S200 by the conveyance roller 37, and It is fed to the registration roller 38. According to the recording medium supply means 5, the toner image carried on the intermediate transfer belt 25 is conveyed to the transfer nip portion of the recording medium supplied one by one from the automatic paper feed tray 35 or the manual paper feed tray 39. In synchronism with this, the sheet is fed to the transfer nip portion.

  The discharge unit 6 includes a conveyance roller 37, a discharge roller 40, and a discharge tray 41. The conveyance roller 37 is provided downstream of the fixing nip portion in the sheet conveyance direction, and conveys the recording medium on which the image is fixed by the fixing unit 4 toward the discharge roller 40. The discharge roller 40 discharges the recording medium on which the image is fixed to a discharge tray 41 provided on the upper surface in the vertical direction of the image forming apparatus. The discharge tray 41 stores a recording medium on which an image is fixed.

  The image forming apparatus 1 includes a control unit (not shown). For example, the control unit is provided in an upper part of the internal space of the image forming apparatus 1 and includes a storage unit, a calculation unit, and a control unit. In the storage unit of the control means, various setting values via an operation panel (not shown) arranged on the upper surface of the image forming apparatus, detection results from sensors (not shown) arranged at various locations inside the image forming apparatus, Image information and the like are input. In addition, programs for executing various means are written. Examples of the various means include a recording medium determination unit, an adhesion amount control unit, and a fixing condition control unit. As the storage unit, those commonly used in this field can be used, and examples thereof include a read only memory (ROM), a random access memory (RAM), and a hard disk drive (HDD). As the external device, an electric / electronic device that can form or acquire image information and can be electrically connected to the image forming apparatus can be used. For example, a computer, a digital camera, a television, a video recorder, a DVD recorder, HDDVD (High-Definition Digital Versatile Disc), Blu-ray disc recorder, facsimile device, portable terminal device, and the like. The arithmetic unit takes out various data (image formation command, detection result, image information, etc.) written in the storage unit and programs of various means, and performs various determinations. The control unit sends a control signal to the corresponding device according to the determination result of the calculation unit, and performs operation control. The control unit and the calculation unit include a processing circuit realized by a microcomputer, a microprocessor, or the like provided with a central processing unit (CPU). The control means includes a main power supply together with the processing circuit described above, and the power supply supplies power not only to the control means but also to each device in the image forming apparatus.

  FIG. 3 is a schematic cross-sectional view schematically showing the configuration of the developing device 14. The developing device 14 develops the latent image formed on the image carrier to form a toner image. The developing device 14 includes a developing tank 20 and a toner hopper 21. The developing tank 20 is disposed so as to face the surface of the photosensitive drum 11, and is a container that supplies toner to the electrostatic latent image formed on the surface of the photosensitive drum 11 and develops it to form a visible toner image. It is a shaped member. The developing tank 20 accommodates toner in its internal space and accommodates a roller member such as the developing roller 110, a supply roller, and a stirring roller, or a screw member, and rotatably supports it. An opening is formed in a side surface of the developing tank 20 facing the photosensitive drum 11, and a developing roller 110 is rotatably provided at a position facing the photosensitive drum 11 through the opening. The developing roller 110 is a roller-like member that supplies toner to the electrostatic latent image on the surface of the photoconductor 11 at the pressure contact portion or the closest portion with the photoconductor drum 11.

  When supplying the toner, a potential having a polarity opposite to the charging potential of the toner is applied to the surface of the developing roller 110 as a developing bias voltage (hereinafter simply referred to as “developing bias”). As a result, the toner on the surface of the developing roller 110 is smoothly supplied to the electrostatic latent image. Further, by changing the developing bias value, the amount of toner (toner adhesion amount) supplied to the electrostatic latent image can be controlled. The supply roller is a roller-like member that faces the developing roller 110 and can be driven to rotate, and supplies toner around the developing roller 110. The agitation roller is a roller-like member that faces the supply roller and can be driven to rotate, and feeds toner newly supplied from the toner hopper 21 into the developing tank 20 to the periphery of the supply roller. The toner hopper 21 is provided so that a toner replenishing port (not shown) provided at the lower part in the vertical direction communicates with a toner receiving port (not shown) provided at the upper part in the vertical direction of the developing tank 20. The toner is replenished according to the toner consumption status of 20. Further, the toner hopper 21 may not be used, and the toner may be directly supplied from each color toner cartridge.

  As described above, since the developing device of the present invention develops a latent image using the developer of the present invention, it prevents the wax component from adhering to the photoreceptor and stably forms a good toner image on the photoreceptor. be able to. Therefore, a high-quality image can be stably formed. The image forming apparatus of the present invention also includes an image carrier on which a latent image is formed, a latent image forming unit that forms a latent image on the image carrier, and a toner image that can form a good toner image as described above. An image forming apparatus is realized. By forming an image with such an image forming apparatus, a high-quality image can be stably formed.

  The hydroxyl value (OHV) of the binder resin in Examples and Comparative Examples, the glass transition point (Tg) of the binder resin, the weight average molecular weight (Mw) of the binder resin, the melting point of the wax, the melt viscosity of the wax at 140 ° C., The volume average particle diameter and coefficient of variation (CV value) of the toner particles were measured as follows.

[Hydroxyl value of binder resin (OHV)]
The hydroxyl value was measured by a back titration method. As a specific measurement method, 2 g of a binder resin as a sample was added to 5 mL of an acetylating reagent and dissolved, and then the obtained sample solution was allowed to stand for 1 hour while maintaining the liquid temperature at 100 ° C. The acetylating reagent was prepared by mixing 500 mL of pyridine, 70 g of phthalic acid and 10 g of imidazole. Next, 1 mL of water, 70 mL of tetrahydrofuran and several drops of phenolphthalein in ethanol were added to the sample solution, and titration was performed with a 0.4 mol / L sodium hydroxide (NaOH) aqueous solution. The point at which the color of the sample solution changed from colorless to purple was used as the end point, and the hydroxyl value (KOHmg / g) was calculated from the amount of sodium hydroxide aqueous solution required to reach the end point and the amount of sample used for titration. .

[Glass transition temperature of binder resin (Tg)]
Using a differential scanning calorimeter (trade name: DSC220, manufactured by Seiko Denshi Kogyo Co., Ltd.), according to Japanese Industrial Standard (JIS) K7121-1987, 1 g of the binder resin as a sample was heated at a heating rate of 10 ° C. per minute. DSC curve was measured. Draw the endothermic peak corresponding to the glass transition of the obtained DSC curve at a point where the slope is maximum with respect to the straight line that extends the base line on the high temperature side to the low temperature side and the curve from the rising part of the peak to the vertex. The temperature at the intersection with the tangent was determined as the glass transition temperature (Tg).

[Weight average molecular weight of binder resin (Mw)]
Using a GPC apparatus (trade name: HLC-8220GPC, manufactured by Tosoh Corporation), a sample solution is a 0.25 wt% tetrahydrofuran (tetrahydrofuran; THF) solution of a binder resin as a sample solution at a temperature of 40 ° C. The molecular weight distribution curve was obtained with an injection amount of 200 μL. The molecular weight at the peak of the obtained molecular weight distribution curve was determined as the peak top molecular weight. Moreover, the weight average molecular weight Mw was calculated | required from the obtained molecular weight distribution curve. The molecular weight calibration curve was prepared using standard polystyrene.

[Melting point of wax]
Using a differential scanning calorimeter (trade name: DSC220, manufactured by Seiko Denshi Kogyo Co., Ltd.), 1 g of the wax as a sample is heated from a temperature of 20 ° C. to 200 ° C. at a heating rate of 10 ° C. per minute, and then from 200 ° C. to 20 ° C. The operation of rapidly cooling to ° C. was repeated twice and the DSC curve was measured. The temperature at the top of the endothermic peak corresponding to the melting of the DSC curve measured in the second operation was determined as the melting point of the wax.

[Melt viscosity at 140 ° C. of wax]
The standard is to measure the sample without diluting with a solvent. The rotor and the number of rotations specified for each measurement sample are used. Put a proper amount of sample, rotor, guard, and 0.1 ° C scale thermometer in a specified beaker (inner diameter 55mm, height 110mm), and keep it at a specified temperature (specified temperature in units of 0.1 ° C) Soak the sample gently, and check that the temperature is 140 ± 0.2 ° C. Join the rotor and guard to the body of a B-type viscometer (BH type, manufactured by Tokimec), immerse the rotor in the sample between the immersion marks, and adjust the position so that the rotor is at the center of the beaker. Determine the level of the meter correctly, and check that there is no temperature and no bubbles. Remove the clamp lever and set the power to the specified speed before turning on the power. When the pointer was stabilized after several rotations, the clamp lever was pressed and the power was turned off so that the pointer stopped in the field of view. The reading was read to 0.1 and the melt viscosity was measured.

[Volume average particle diameter and coefficient of variation CV of toner]
50 ml of electrolyte solution (trade name: ISOTON-II, manufactured by Beckman Coulter, Inc.) was placed in a 100 ml beaker. As a sample, 20 mg of toner and 1 ml of sodium alkyl ether sulfate (dispersant, manufactured by Kishida Chemical Co., Ltd.) were added as samples, and 3 at a frequency of 20 kHz using an ultrasonic dispersing device (trade name: UH-50, manufactured by STM). A sample for ultrasonic dispersion was used as a measurement sample. For this measurement sample, the particle size distribution measuring device (trade name: Multisizer 3, manufactured by Beckman Coulter, Inc.) is used to measure the volume particle size distribution of the sample particles under the conditions of an aperture diameter of 100 μm and the number of measured particles of 50000 counts. From the results, the particle size D _{50V at} which the cumulative volume from the large particle size side in the cumulative volume distribution becomes 50% was calculated as the volume average particle size (μm). Moreover, the standard deviation in volume particle size distribution was calculated | required, and the variation coefficient (CV value,%) was computed based on the following formula. The coefficient of variation means that the smaller the value, the narrower the particle size distribution width.
CV value (%) = {standard deviation in volume particle size distribution / volume average particle size (μm)} × 100

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited to the following examples unless it exceeds the gist.

Example 1
[Preparation of binder resin fine particle dispersion]
Polyester resin (Mitsubishi Rayon Co., Ltd., hydroxyl value (OHV) 45 KOHmg / g, glass transition temperature (Tg) 59 ° C., weight average molecular weight (Mw) 150,000) 100 parts by weight, sodium dodecylbenzenesulfonate (DBS) 2 parts by weight Particulates and 898 parts by weight of ion-exchanged water were mixed and treated with NANO3000 (trade name, manufactured by Miki Co., Ltd.) at 150 MPa, and a binder resin fine particle dispersion containing fine particles of a binder resin having a volume average particle diameter of 1 μm was obtained. Prepared.

[Preparation of colorant fine particle dispersion]
As a colorant, 5 parts by weight of phthalocyanine blue (trade name: copper phthalocyanine 15: 3, manufactured by Clariant Japan KK), 3 parts by weight of sodium dodecylbenzene sulfonate (DBS), and 100 parts by weight of ion-exchanged water are mixed. Then, it was treated at 200 MPa with NANO3000 (trade name, manufactured by Miki Co., Ltd.) to prepare a colorant fine particle dispersion containing colorant fine particles having a volume average particle diameter of 0.6 μm.

[Preparation of wax fine particle dispersion]
Mixing 20 parts by weight of metallocene wax (melting point: 70 ° C., melt viscosity: 9500 mPa · s at 140 ° C.) as a wax, 2 parts by weight of SANISOL B50 (trade name, manufactured by Kao Corporation) as a surfactant, and 100 parts by weight of ion-exchanged water Then, it was treated at 160 MPa and 150 ° C. with NANO3000 (trade name, manufactured by Miki Co., Ltd.) to prepare a wax fine particle dispersion containing wax fine particles having a volume average particle size of 0.4 μm.

[Preparation of charge control agent fine particle dispersion]
A charge control agent (trade name: Copy Charge N4P VP 2481, manufactured by Clariant Japan Co., Ltd.), 20 parts by weight, 2 parts by weight of sodium dodecylbenzenesulfonate (DBS), and 100 parts by weight of ion-exchanged water were mixed, and NANO3000 (trade name, The product was treated at 180 MPa, and a charge control agent fine particle dispersion containing charge control agent fine particles having a volume average particle size of 0.3 μm was prepared.

[Preparation of Aggregated Particle Dispersion]
A binder resin fine particle dispersion, a colorant fine particle dispersion, and a composition such that the binder resin is 100 parts by weight, the colorant is 5.0 parts by weight, the wax is 3.3 parts by weight, and the charge control agent is 1.0 part by weight. The wax fine particle dispersion and the charge control agent dispersion are mixed uniformly, 2 parts by weight of sodium chloride is added, and a single motion type emulsifier (trade name: CLEARMIX, manufactured by M Technique Co., Ltd.) By mixing at 80 ° C. for 6 hours, an aggregated particle dispersion containing aggregated particles was prepared.

  Water (temperature 20 ° C., conductivity 0.5 μS / cm) was added to the aggregated particle dispersion obtained as described above to prepare a solid content of 10% by weight, and a turbine type stirring blade (trade name: H- 701FR (manufactured by Kokusan Co., Ltd.) for 30 minutes and agitating blade rotation speed was 300 rpm. By repeating this operation until the electrical conductivity of the supernatant liquid separated from the stirred mixture by centrifugation is 10 μS / cm or less, the aggregated particles in the aggregated particle dispersion were washed. Centrifugal separation (trade name: H-122, manufactured by Kokusan Co., Ltd.) was performed from the mixture of the aggregated particle-containing aqueous medium after the washing step, and the solid content including the aggregated particles was collected. The solid content collected in the separation step was freeze-dried to obtain toner particles that are aggregated particles obtained by aggregating the toner raw materials. The volume average particle diameter of the toner particles was 5.7 μm, and the coefficient of variation (CV value) was 24%.

  The toner of Example 1 was obtained by externally adding 1.2 parts by weight of silica fine particles (trade name: R972, manufactured by Nippon Aerosil Co., Ltd.) as an external additive to 100 parts by weight of the obtained toner particles.

(Example 2)
In place of the metallocene wax used in Example 1, a metallocene wax having a melting point of 85 ° C. and a melt viscosity of 9100 mPa · s at 140 ° C. was used in the same manner as in Example 1 except that the metallocene wax was used. Toner (volume average particle diameter: 5.5 μm, CV value: 23%) was obtained.

(Example 3)
Example 3 was carried out in the same manner as in Example 1 except that a metallocene wax was used as a wax having a melting point of 85 ° C. and a melt viscosity of 3200 mPa · s at 140 ° C. instead of the metallocene wax used in Example 1. Toner (volume average particle diameter: 5.4 μm, CV value: 24%) was obtained.

Example 4
In the same manner as in Example 3 except that the amount of wax added was changed from 3.3 parts by weight to 6.7 parts by weight when preparing the aggregated particle dispersion, the toner (volume average particle diameter) of Example 4 was changed. : 5.6 μm, CV value: 22%).

(Example 5)
The toner (volume average particle diameter) of Example 5 was the same as Example 3 except that the amount of wax added was changed from 3.3 parts by weight to 0.67 parts by weight when preparing the aggregated particle dispersion. : 5.8 μm, CV value: 26%).

(Example 6)
Instead of the polyester resin used in Example 1, the hydroxyl value (OHV) is 30 KOHmg / g, the glass transition temperature (Tg) is 59 ° C., and the weight average molecular weight (Mw) is 50,000. A toner (volume average particle size: 5.4 μm, CV value: 24)%) of Example 6 was obtained in the same manner as Example 3 except that Mitsubishi Rayon Co., Ltd. was used.

(Example 7)
Instead of the polyester resin used in Example 1, the hydroxyl value (OHV) is 80 KOH mg / g, the glass transition temperature (Tg) is 59 ° C., and the weight average molecular weight (Mw) is 300,000. The toner of Example 7 (volume average particle diameter: 5.8 μm, CV value: 25%) was obtained in the same manner as in Example 3 except that Mitsubishi Rayon Co., Ltd. was used.

(Example 8)
In place of the metallocene wax used in Example 1, a metallocene wax having a melting point of 85 ° C. and a melt viscosity at 140 ° C. of 160 mPa · s was used in the same manner as in Example 1, except that Example 8 Toner (volume average particle diameter: 5.3 μm, CV value: 25%) was obtained.

Example 9
The toner of Example 9 was used in the same manner as in Example 1 except that a metallocene wax having a melting point of 150 ° C. and a melt viscosity of 120 mPa · s at 140 ° C. was used instead of the metallocene wax used in Example 1. (Volume average particle diameter: 5.6 μm, CV value: 25%) was obtained.

(Example 10)
Instead of the polyester resin used in Example 3, a polyether polyol having a hydroxyl value (OHV) of 65 KOHmg / g, a glass transition temperature (Tg) of 60 ° C., and a weight average molecular weight (Mw) of 110,000 A toner of Example 10 (volume average particle size: 5.3 μm, CV value: 23%) was obtained in the same manner as in Example 3 except that the resin (manufactured by Mitsui Chemicals) was used.

Example 11
The toner (volume average particle) of Example 11 was prepared in the same manner as in Example 3 except that when the wax fine particle dispersion was prepared, it was treated using Claremix W Motion (M Technique Co., Ltd.) instead of NANO3000. (Diameter: 5.8 μm, CV value: 29%).

Example 12
The toner of Example 12 (volume average particle diameter) was prepared in the same manner as in Example 3 except that after the aggregated particle dispersion was prepared, the core particles as aggregated particles were coated with a styrene acrylic resin to form a core-shell structure. : 5.3 μm, CV value: 24%).

(Example 13)
Polyester resin (manufactured by Mitsubishi Rayon Co., Ltd., hydroxyl value (OHV) 45 KOH mg / g, glass transition temperature (Tg) 59 ° C., weight average molecular weight (Mw) 150,000) 100 parts by weight, phthalocyanine blue (trade name: copper phthalocyanine 15: 3, 5 parts by weight of Clariant), metallocene wax (melting point 70 ° C., melt viscosity 9140 mPa · s at 140 ° C.) 3.3 parts by weight, charge control agent (trade name: Copy Charge N4P VP 2481, manufactured by Clariant Japan KK ) The toner particles were obtained by uniformly mixing with a Henschel mixer at a composition of 1.0 part by weight, and kneading and pulverizing the mixture with a twin screw extruder.

  By adding 1.2 parts by weight of silica fine particles (trade name: R972, manufactured by Nippon Aerosil Co., Ltd.) as an external additive to 100 parts by weight of the obtained toner particles, the toner of Example 13 (volume average particle diameter: 5.5 μm, CV value: 22%).

(Example 14)
The toner of Example 14 (volume average particle diameter: 5) was prepared in the same manner as in Example 1 except that the amount of wax added was changed from 3.3 parts by weight to 15 parts by weight when preparing the aggregated particle dispersion. 0.7 μm, CV value: 24%).

(Example 15)
Polyester resin (manufactured by Mitsubishi Rayon Co., Ltd., hydroxyl value (OHV) 45 KOH mg / g, glass transition temperature (Tg) 59 ° C., weight average molecular weight (Mw) 150,000) 100 parts by weight, phthalocyanine blue (trade name: copper phthalocyanine 15: 3. 5.0 parts by weight of Clariant Co., Ltd., 1.0 parts by weight of charge control agent (trade name: Copy Charge N4P VP 2481, Clariant Japan KK), metallocene wax (melting point: 85 ° C., melt viscosity at 140 ° C .: 3200 mPa S) After 3.3 parts by weight were mixed with a Henschel mixer for 10 minutes, the mixture was melt-kneaded with a twin-screw extrusion kneader (trade name: PCM65, manufactured by Ikegai Co., Ltd.). The melt-kneaded product is coarsely pulverized with a cutting mill (trade name: VM-16, manufactured by Ryoxing Industrial Co., Ltd.), then finely pulverized with a counter jet mill, and then the excessively pulverized toner is classified and removed with a rotary classifier. Toner particles were prepared. To 100 parts by weight of the obtained toner particles, 1.2 parts by weight of silica fine particles (trade name: R972, manufactured by Nippon Aerosil Co., Ltd.) were externally added, and the toner of Example 15 (volume average particle diameter: 5.5 μm, CV value: 26%) was obtained.

(Comparative Example 1)
Comparative Example 1 was carried out in the same manner as in Example 1 except that a metallocene wax having a melting point of 85 ° C. and a melt viscosity of 12000 mPa · s at 140 ° C. was used instead of the metallocene wax used in Example 1. Toner (volume average particle size: 5.6 μm, CV value: 27%) was obtained.

(Comparative Example 2)
A styrene acrylic resin having a hydroxyl value (OHV) of 0 KOHmg / g, a glass transition temperature (Tg) of 58 ° C., and a weight average molecular weight (Mw) of 150,000 instead of the polyester resin used in Example 3. A toner of Comparative Example 2 (volume average particle size: 5.4 μm, CV value: 24%) was obtained in the same manner as Example 3 except that (Mitsui Chemicals Co., Ltd.) was used.

(Comparative Example 3)
A styrene acrylic resin (manufactured by Mitsui Chemicals) having a glass transition temperature (Tg) of 57 ° C. and a weight average molecular weight (Mw) of 300,000 was used instead of the polyester resin used in Example 3. In the same manner as in Example 3, the toner of Comparative Example 3 (volume average particle size: 5.6 μm, CV value: 25%) was obtained.

(Comparative Example 4)
In place of the metallocene wax used in Example 1, the melting point was 82 ° C., and a polyethylene wax having a melt viscosity of 3550 mPa · s at 140 ° C. was used in the same manner as in Example 1, except that Comparative Example 4 A toner (volume average particle diameter: 5.4 μm, CV value: 24%) was obtained.

(Comparative Example 5)
Comparative Example 5 was carried out in the same manner as in Example 1 except that a metallocene wax having a melting point of 65 ° C. and a melt viscosity at 140 ° C. of 4000 mPa · s was used instead of the metallocene wax used in Example 1. Toner (volume average particle diameter: 5.8 μm, CV value: 26%) was obtained.

(Comparative Example 6)
The toner (volume average particle size) of Comparative Example 6 was used in the same manner as in Example 1 except that a metallocene wax having a melting point of 152 ° C. and not melted at 140 ° C. was used instead of the metallocene wax used in Example 1. (Diameter: 5.5 μm, CV value: 23%).

  The compositions of the wax and binder resin in the toners of Examples 1 to 15 and Comparative Examples 1 to 6 are summarized in Table 1.

  The production methods and physical properties of the toners of Examples 1 to 15 and Comparative Examples 1 to 6 are summarized in Table 2. In the “fine particle preparation step and agglomeration step”, when the fine particle preparation step and the agglomeration step are included, “○” is indicated, and when not included, “x” is indicated. In the case of including an agglomeration step for agglomerating the finely divided wax, “○” is indicated. It expresses by.

  Using the toners of Examples 1 to 15 and Comparative Examples 1 to 6 and the ferrite core carrier having a volume average particle diameter of 45 μm as the carrier, the coverage of the toners of Examples 1 to 15 and Comparative Examples 1 to 6 with respect to the carrier Were mixed for 20 minutes in a V-type mixer / mixer (trade name: V-5, manufactured by Tokuju Kakujo Co., Ltd.) to prepare a two-component developer.

Using the obtained two-component developer, the fixability and environmental resistance were evaluated by the following methods.
[Fixability]
A recording medium (trade name: PPC paper SF-4AM3, manufactured by Sharp Corporation), which is a recording medium using a modified color multifunction machine (trade name: MX-2700, manufactured by Sharp Corporation) as an evaluation machine In addition, a sample image including a rectangular solid image portion having a length of 20 mm and a width of 50 mm is adjusted so that the adhesion amount of toner to the recording medium in an unfixed state in the solid image portion is 0.5 mg / cm ^2. Then, an unfixed image was formed, and a fixed image was prepared using an external fixing device prepared using a fixing unit of a color multifunction peripheral. The fixing process speed was 124 mm / second, the temperature of the fixing roller was increased from 130 ° C. in increments of 5 ° C., and the temperature range in which neither low temperature offset nor high temperature offset occurred was defined as the non-fixing offset region. The definition of high temperature and low temperature offset is that the toner does not fix to the recording medium at the time of fixing but adheres to the recording medium after the roller makes a full rotation while adhering to the fixing roller.

The toner was evaluated based on the following criteria, with a value obtained by subtracting the temperature at which the low temperature offset occurred from the temperature at which the high temperature offset occurred, as a fixing non-offset region.
A: Very good. The fixing non-offset region is 60 ° C. or higher.
○: Good. The fixing non-offset region is 45 ° C. or higher and lower than 60 ° C.
Δ: No problem in actual use. The fixing non-offset region is 35 ° C. or higher and lower than 45 ° C.
X: Defect. The fixing non-offset region is less than 35 ° C.

[Fixing strength]
An image bending test with a weight of 1 kg was performed, and the degree of white streaks in the image was judged by comparison with a reference sample. As a reference sample, an output image of MX7001N (manufactured by Sharp Corporation) was used.

Judgment was made based on the following criteria from the results of the image folding test with a weight of 1 kg.
○: Good. Compared to the reference sample, the white lines are almost inconspicuous and there is no problem.
Δ: No problem in actual use. Compared to the reference sample, it is confirmed that there are white streaks, but it does not cause extreme image degradation.
X: Defect. There is a white streak, and it is a level to be worried about compared to the reference sample.

[Environmental resistance]
Each developer was exposed for one week in an HH environment (35 ° C., 85% RH) and an NN environment (25 ° C., 50% RH), then the charge amount was measured and judged by the ratio of the values. The toner charge amount was measured using a charge amount measuring device (trade name: 210HS-2A, manufactured by Trek Japan Co., Ltd.) as follows. Each developer is put in a metal container having a 500 mesh conductive screen at the bottom, and only the toner is sucked at a suction pressure of 250 mmHg by a suction machine. The weight of the developer before suction and the developer after suction The toner charge amount Q [μC / g] was determined from the difference in weight with respect to the weight of the toner and the potential difference between the capacitor electrode plates connected to the container by the following formula III.
Q [μC / g] = Measured amount of charge [μC] / {Developer amount before suction [g] −Developer amount after suction [g]} (III)
A: Very good. Q (HH) / Q (NN)> 0.9
○: Good. 0.9 ≧ Q (HH) / Q (NN)> 0.7
X: Defect. Q (HH) / Q (NN) ≦ 0.7
Table 3 shows the evaluation results of the toners obtained in Examples 1 to 15 and Comparative Examples 1 to 6.

  From the results of Table 3, the toner of Comparative Example 5 in which the melting point of the wax is less than 70 ° C. has a narrow fixing non-offset region, and Comparative Example 1 in which the melt viscosity of the wax at 140 ° C. is 12000 mPa · s is low-temperature offset. It can be seen that the generation temperature is high. It can also be seen that Comparative Examples 2 to 4 using resins other than the polyester resin and the polyether polyol resin as the binder resin have a high low temperature offset generation temperature and a low fixing strength. It can be seen that Comparative Example 6 in which the melting point of the wax exceeds 150 ° C. and the melt viscosity of the wax at 140 ° C. is less than 50 mPa · s has poor fixability and fixing strength. From the above, the toner of the present invention can achieve excellent low-temperature fixability, and can achieve both significant improvement in fixability and maintenance of environmental resistance.

  In this embodiment and the comparative example, cyan toner is exemplified as the toner, but the toner is not limited to cyan toner.

5 is a flowchart illustrating a toner manufacturing method according to the exemplary embodiment. 1 is a schematic diagram schematically showing a configuration of an image forming apparatus 1 according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing the developing device 14 shown in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Toner image forming means 3 Intermediate transfer means 4 Fixing means 5 Recording medium supply means 6 Ejecting means 11 Photosensitive drum 12 Charging means 13 Exposure unit 14 Developing device 15 Cleaning unit 25 Intermediate transfer belt 26 Drive roller 27 Follower roller 28 Intermediate transfer roller 29 Transfer belt cleaning unit 30 Transfer roller 31 Fixing roller 32 Pressure roller 35 Automatic paper feed tray 36 Pickup roller 37 Conveying roller 38 Registration roller 39 Manual feed tray 40 Discharge roller 41 Discharge tray

Claims (12)

A toner containing at least a colorant, a binder resin and a wax,
The binder resin includes at least one of a polyester resin and a polyether polyol resin,
The toner is characterized in that the wax is contained in toner particles, the melting point thereof is 70 ° C. or higher and 150 ° C. or lower, and the melt viscosity at 140 ° C. is 50 mPa · s or higher and 10,000 mPa · s or lower. 2. The toner according to claim 1, wherein the wax is a metallocene wax satisfying the relationship of the formula I: the melting point x of the wax and the melt viscosity y at 140 ° C. of the wax.
+ 6.05-0.02875 (x)> log (y) (I)   The binder resin has a hydroxyl value of 30 KOHmg / g or more and 80 KOHmg / g or less, a glass transition temperature of 55 ° C or more and 65 ° C or less, and a weight average molecular weight of 50,000 or more and 300,000 or less. Item 3. The toner according to Item 1 or 2. The toner according to claim 1, wherein the ratio of the addition amount of the binder resin and the addition amount of the wax satisfies the relationship of Formula II.
200> (addition amount of binder resin) / (addition amount of wax)> 10 (II)   A toner comprising core particles made of the toner according to claim 1 and having a core-shell structure. A method for producing the toner according to any one of claims 1 to 5,
A melt-kneading step of melt-kneading at least a binder resin, a colorant and a wax;
And a atomization step of atomizing a kneaded product obtained by melt-kneading. A method for producing the toner according to any one of claims 1 to 5,
A fine particle preparation step in which a toner raw material of at least a binder resin, a colorant and a wax is dispersed in an aqueous medium to obtain a dispersion containing fine particles of the toner raw material;
And a coagulation step of coagulating the fine particles of the toner raw material.   The toner production method according to claim 7, further comprising an aggregating step of aggregating the finely divided wax by a high-pressure emulsification apparatus including a pressure reducing mechanism.   A developer comprising the toner according to claim 1.   The developer according to claim 9, wherein the developer is a two-component developer including the toner and a carrier.   A developing device, comprising: developing a latent image formed on an image carrier using the developer according to claim 9 to form a toner image. An image carrier on which a latent image is formed;
A latent image forming means for forming a latent image on the image carrier;
An image forming apparatus comprising: the developing device according to claim 11.

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