JP2009151045A - Electrostatic charge image developing two-component developer, image forming method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing two-component developer which has low dependency of initial image density on environment, can suppress generation of BCO, can suppress fogging on a non-image part under high temperature and high humidity and can be manufactured by a low environmental load process. <P>SOLUTION: The electrostatic charge image developing two-component developer comprises: an electrostatic charge image developing toner including polyester resin which contains a monomer unit originated from a hydroxy acid having hydroxy acid groups and carboxylic acid groups of at least 3 in total and/or a derivative of the hydroxy acid, in an amount of 2 to 20 mol% in total monomer units; and an electrostatic charge image developing carrier which has a magnetic core particle and a cover resin layer of covering the magnetic core particle, wherein resin of the cover resin layer contains nitrogen atom and/or fluorine atom and the coverage of the magnetic core particle with the cover resin layer is 80% or more. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a two-component developer for developing an electrostatic image, an image forming method, and an image forming apparatus.

  A method of visualizing image information through an electrostatic charge image such as electrophotography is currently used in various fields. In electrophotography, an electrostatic charge image is formed on a photoreceptor by charging and exposure processes, the electrostatic latent image is developed with a developer containing toner, and visualized through a transfer and fixing process. As the developer used here, a two-component developer composed of a toner and a carrier, a one-component developer using a magnetic toner or a non-magnetic toner alone, and the like are used. In these toners, if necessary, inorganic and organic particles for improving fluidity and cleaning properties may be added to the toner particle surfaces.

  In recent years, in order to respond to various demands on toner, studies on toner preparation by a wet manufacturing method are in progress. In this production method prepared in an aqueous medium, an aqueous dispersion of a resin for toner is required. There are various methods for preparing an aqueous dispersion of a resin for toner, but water-soluble acrylic copolymer is mainly produced by neutralizing a copolymer containing acrylic acid and methacrylic acid, which are vinyl monomers, with an amine. Examples thereof include a method for obtaining a coalescence, a method in which a water-insoluble resin such as various copolymers, cyclized rubber, and polyamide is dissolved in an organic solvent and dispersed together with a surfactant, and then the solvent is removed. In order to obtain an aqueous dispersion of polyester suitable for fixability and color images, a method of dissolving in the organic solvent described above, then dispersing in water, and then removing the organic solvent from the particles has been used.

On the other hand, the water dispersion of the resin by the solvent-free emulsification method has many advantages that are more current than the solvent solution of the resin in terms of not only the convenience of handling but also the safety of workers and working environment. For example, a high acid value polyester produced by bulk polymerization is dissolved and emulsified in a vinyl monomer, etc., then the vinyl monomer is polymerized (miniemulsion polymerization method), the polyester monomer is dispersed in water, and then polymerized in water. A method (in-water polycondensation method) is disclosed.
Most of the examples found in patent documents and academic reports are aqueous dispersions of crystalline polyesters or starch derivatives, and there are very few examples of aqueous dispersions of amorphous polyesters. There are no examples of solvent-free emulsification using general-purpose polyester, such as cases where the acid value of polyester is set extremely high even if it exists, and it is necessary to set a large amount of vinyl monomer necessary for emulsification. .

Patent Document 1 describes an example of a solvent-free emulsification method in which a polyester is melted and then neutralized with an amine. Patent Document 2 describes an example of a solvent-free emulsification method of polyester having biodegradability and crystallinity.
When preparing an aqueous dispersion of polyurethane without a solvent, there is an example in which a compound containing a carboxy group as a monomer and having reactivity with an isocyanate is used. For example, in Patent Document 3, (A) a polyol component having an average molecular weight of 600 to 2,000 and containing at least 20% by weight of a polyalkylene glycol among polyol components, (B) an organic diisocyanate component, (C) It consists of dihydroxycarboxylic acid represented by the general formula HO—CH ₂ —C (R) (COOH) —CH ₂ —OH (where R is hydrogen or an alkyl group having 1 to 4 carbon atoms) alone or other active hydrogen-containing compound. Examples of water-soluble or water-dispersible polyurethanes obtained by polymerizing each component of the chain extension component and further neutralizing at least a part of the carboxyl group with a base are described, and there are examples of polyvalent hydroxy acids . Furthermore, Patent Document 4 describes an example of an aqueous polyurethane dispersion using a hydroxy acid having a specific chemical structure as a chain extension component.

  Further, as a conventional technique using a polyvalent hydroxy acid as a polyester monomer, Patent Document 5 uses a trivalent or higher valent hydroxy acid in a polyester composition and applies heat together with a monomer capable of reacting with a carboxy group to perform extension polymerization. Patent Document 6 discloses a method for adding a hydroxy acid to an isocyanate-reactive emulsion.

  In addition, although there are examples of obtaining a polyester resin using a hydroxy acid as a monomer as described above, there is no previous example of using it as a polyester resin for toner. In addition, there is no previous example of a developer including a toner using a polyester using a hydroxy acid as a monomer.

JP 2006-18227 A JP 2002-3607 A JP 59-113053 A JP-A-1-104613 JP-A-9-227668 JP 2005-195882 A

  The problem to be solved by the present invention is that the initial image density is less dependent on the environment, and the occurrence of adhesion of a small-diameter carrier to the photoreceptor (hereinafter also referred to as BCO (Bead-Carry-Out)) due to high toner charging. A two-component developer for developing an electrostatic charge image produced by a low environmental load manufacturing method, an image forming method and an image forming apparatus using the developer, Is to provide.

The above-described problems of the present invention have been solved by the following means.
<1> An electrostatic charge image developing toner comprising a polyester resin containing 2 to 20 mol% of monomer units derived from a hydroxy acid and / or a derivative thereof having a total of 3 or more hydroxy groups and carboxy groups, and a magnetic core An electrostatic charge image developing carrier having particles and a coating resin layer that coats the magnetic core particles, wherein the resin of the coating resin layer contains nitrogen atoms and / or fluorine atoms, and the magnetic property of the coating resin layer A two-component developer for developing an electrostatic image, wherein the coverage of the core particles is 80% or more,
<2> The polyester resin has a monomer unit derived from a polycarboxylic acid and / or derivative thereof and a polyol, and 50 to 100 mol% of the monomer unit derived from the polycarboxylic acid and / or derivative thereof is represented by the formula (1 ) And / or formula (2), and the two-component developer for electrostatic image development according to <1>, wherein 50 to 100 mol% of the monomer unit derived from the polyol is represented by formula (3),
R ¹ OOCA ¹ _m B ¹ _n A ¹ _l COOR ¹ (1)
(A ¹ : methylene group, B ¹ : aromatic hydrocarbon group, R ¹ : each independently a hydrogen atom or a monovalent hydrocarbon group, 1 ≦ m + 1 ≦ 12, 1 ≦ n ≦ 3)
R ² OOCA ² _p B ² _q A ² _r COOR ² (2)
(A ² : methylene group, B ² : alicyclic hydrocarbon group, R ² : each independently a hydrogen atom or monovalent hydrocarbon group, 0 ≦ p ≦ 6, 0 ≦ r ≦ 6, 1 ≦ q ≦ 3 )
HOX _h Y _j X _k OH (3)
(X: alkylene oxide group, Y: bisphenol skeleton group, 1 ≦ h + k ≦ 10, 1 ≦ j ≦ 3)
<3> The two-component developer for developing an electrostatic charge image according to <1> or <2>, wherein the coating resin layer contains conductive powder.
<4> An electrostatic latent image forming step for forming an electrostatic latent image on the electrostatic latent image carrier, and developing the latent image on the electrostatic latent image carrier with a developer containing toner to form a toner image. The electrostatic charge image according to any one of <1> to <3>, comprising: an image forming step to form, a step of transferring the toner image, and a fixing step of fixing the toner image. An image forming method using a two-component developer for development;
<5> An electrostatic latent image holding member, a charging unit for charging the electrostatic latent image holding member, and exposing the charged electrostatic latent image holding member to form an electrostatic latent image on the electrostatic latent image holding member. An exposure unit that forms an image; a developing unit that develops the electrostatic latent image with a developer containing toner to form a toner image; and the toner image is transferred from the electrostatic latent image holder to a transfer medium. And an image forming apparatus using the two-component developer for developing electrostatic images according to any one of <1> to <3> as the developer.

According to the means described in <1> above, compared to the case without this configuration, the initial image density is less dependent on the environment, the occurrence of BCO is suppressed, and the fog of the non-image area at high temperature and high humidity is suppressed. Is suppressed, and a two-component developer for developing an electrostatic charge image produced by a low environmental load production method can be provided.
According to the means described in <2>, the environmental dependency of the initial image density due to a change in high temperature / high humidity / low temperature / low humidity, etc. is lower, the generation of BCO is further suppressed, and the non-image portion at high temperature / high humidity is suppressed. It is possible to provide a two-component developer for developing an electrostatic charge image which is suppressed in fog and manufactured by a low environmental load manufacturing method.
According to the means described in <3>, the initial image density is less dependent on the environment, the generation of BCO is further suppressed, the fogging of the non-image area at high temperature and high humidity is suppressed, and the low environmental load manufacturing method is used. The produced two-component developer for developing an electrostatic image can be provided.
According to the means described in <4> above, the environmental dependency of the initial image density is lower than in the case where this configuration is not provided, the occurrence of BCO is suppressed, and fogging of the non-image area at high temperature and high humidity is prevented. A suppressed image forming method can be provided.
According to the means described in <5>, the initial image density is less dependent on the environment than in the case without this configuration, the occurrence of BCO is suppressed, and fogging of the non-image area at high temperature and high humidity is prevented. A suppressed image forming apparatus can be provided.

  The two-component developer for electrostatic image development of the present invention (hereinafter also simply referred to as “developer” or “two-component developer”) is a hydroxy acid having a total of three or more hydroxy groups and carboxy groups and / or derivatives thereof. Electrostatic charge image developing toner (hereinafter also simply referred to as “toner”) containing a polyester resin containing 2 to 20 mol% of derived monomer units in all monomer units, magnetic core particles, and coating for coating the magnetic core particles An electrostatic image developing carrier having a resin layer (hereinafter also simply referred to as “carrier”), the resin of the coating resin layer contains a nitrogen atom and / or a fluorine atom, and the magnetic core formed by the coating resin layer The particle coverage is 80% or more. In addition, “1-20 mol%” or the like, which is a description of a numerical range, is synonymous with “1 mol% or more and 20 mol% or less”, and the same applies to descriptions of other numerical ranges.

The operation and mechanism of the present invention is presumed as follows.
(1): When a halftone image is printed after a copier / printer has been suspended for a day or more for a long period of time, the image density of the first printed matter may vary depending on the environment (high temperature / high humidity / low temperature / low humidity) after the long period of suspension. is there. In order to improve the charge exchange between the toner and the carrier, a hydroxy acid is introduced as a monomer unit of the polyester resin, and a hydroxy group or a carboxy group is introduced into the chain in addition to the terminal carboxy group of the polyester resin. Solved by.
(2) On the other hand, when a polyester resin into which a hydroxy acid is introduced is used, the resistance of the resin is lowered, so that there is a concern that the resistance value of the two-component developer as the toner carrier mixture is lowered and BCO is generated. Therefore, a carrier / developer that reduces the environmental dependency of the initial image density and suppresses the occurrence of BCO is provided.
(3): A toner resin / resin particle dispersion was prepared by a low environmental load manufacturing method that has not been conventionally used. Specifically, a resin / resin particle dispersion for toner was obtained by an emulsification method in which the polymerization was performed at 100 ° C. to 140 ° C., the emulsification was 100 ° C. or less, and a solvent removal step was not required without using a solvent.
Hereinafter, the present invention will be described in detail.

<Toner for electrostatic image development>
In the present invention, the toner for developing an electrostatic image includes a polyester resin containing 2 to 20 mol% of monomer units derived from a hydroxy acid having a total of 3 or more hydroxy groups and carboxy groups and / or derivatives thereof. .

The use of a polyester resin polycondensed at a temperature of 150 ° C. or less using a sulfur acid polycondensation catalyst is preferable in order to reduce the total toner production energy. The significance of realizing low-temperature fixable toners using crystalline and non-crystalline polyester resins obtained by polycondensation at a temperature of 150 ° C. or lower using a sulfur acid polycondensation catalyst has recently been noticed. This is also preferable from the viewpoint of reducing the environmental burden.
Further, when an organic solvent is used for emulsification and particle formation of the polyester resin, not only a great investment is required for the recovery facility but also environmental safety is not preferable. Furthermore, it is difficult to completely remove the solvent used from the toner, and there are problems in quality such as toner storage stability.

In order to improve the water dispersibility of the polyester resin, the hydrophilic group is incorporated into the polyester chain by copolymerizing a monomer such as an alkali metal salt obtained by neutralizing a hydrophilic group such as a sulfo group or a carboxy group with a base. There is a method of introducing or preparing a polyester resin having a sulfo group or a carboxy group and then dispersing it in alkaline water.
However, in order to impart sufficient emulsifiability to the polyester resin obtained by introducing a hydrophilic group in such a chain, it is necessary to introduce a large number of hydrophilic groups. There will be problems with sex.

Furthermore, in order to impart water dispersibility to the polyurethane resin, a method of copolymerizing a hydroxy acid has been proposed. However, when a hydroxy acid is used as a polycondensable monomer for a polyester resin, polymerization control is insufficient. Resulting in gelation or an increase in the viscosity of the polyester resin, it was difficult to produce a resin particle dispersion suitable for toner.
When the hydroxy acid is polycondensed at a temperature of 150 ° C. or lower, crosslinking and branching are suppressed and excessive high molecular weight does not occur, so that the glass transition temperature of the toner does not increase. Therefore, it is preferable because image defects that impair fixing properties, black and white or color image quality can be suppressed.
In the present invention, it is preferable to perform low-temperature polycondensation at 150 ° C. or lower using a sulfur acid catalyst. In this case, the crosslinkability of the hydroxy acid can be reduced. Thereby, gelation of the resin particle dispersion having a particle diameter suitable for toner can be suppressed.

<Polyester resin>
In the present invention, a polyester resin containing 2 to 20 mol% of monomer units derived from a hydroxy acid having a total of 3 or more hydroxy groups and carboxy groups and / or derivatives thereof is used. Hereinafter, such a polyester resin is also referred to as “the polyester resin of the present invention”. The “hydroxy acid and / or derivative thereof having a total of 3 or more hydroxy groups and carboxy groups” is also simply referred to as “hydroxy acid”.
The polyester resin that can be used in the present invention is obtained by polycondensation of a polycondensable monomer (synonymous with “monomer” and “monomer”). Examples of the polycondensable monomer that can be used in the polycondensation reaction include, in addition to the hydroxy acid, for example, polycarboxylic acid, polyol, and hydroxycarboxylic acid containing one carboxy group and one hydroxy group in one molecule. Examples thereof include acids (excluding the hydroxy acid) or a mixture thereof, and it is preferable to use a polycarboxylic acid and a polyol. As the polycondensable monomer, polycarboxylic acids, polyols, and ester compounds (oligomers and / or prepolymers) thereof can be preferably used, and a polyester resin is obtained through a direct ester reaction or transesterification reaction. What can be done.

(1) Hydroxy acid A hydroxy acid refers to a compound having at least one hydroxy group and at least one carboxy group. However, in the present invention, when simply referred to as “hydroxy acid”, it means a hydroxy acid having a total of 3 or more hydroxy groups and carboxy groups and / or derivatives thereof. A “derivative” of a hydroxy acid refers to a hydroxy acid having a group in which at least one of a total of 3 or more hydroxy groups and carboxy groups is protected.
The protecting group that the hydroxy acid may have is a group that can be deprotected under conditions that do not cause a problem in the production of the polyester resin, and a known protecting group can be used. As the protecting group, for example, the protecting group described in “Protective Groups in Organic Synthesis” (3rd Edition, written by Theodora D. Greene and Peter GM Wuts, published by Wiley, John & Sons, 1999) and the like is preferable depending on reaction conditions and the like. You can choose.
In addition, when performing the polyester resin synthesis reaction, it is preferable to remove the protecting group from the hydroxy group and carboxy group at the site where the reaction is carried out, but if there is no problem during the esterification reaction, the reaction is carried out with the protecting group attached. May be.

The number of hydroxy groups in the hydroxy acid and / or derivative thereof having a total of 3 or more hydroxy groups and carboxy groups is preferably greater than the carboxy group, and the compound has one carboxy group and two or three hydroxy groups. Are preferable, and a compound having one carboxy group and two hydroxy groups is more preferable.
In the hydroxy acid and / or derivative thereof having a total of 3 or more hydroxy groups and carboxy groups that can be used in the present invention, the hydroxy acid is preferably a carboxy group-containing diol or triol, and more preferably a carboxy group-containing diol. Preferably, it is a hydroxy acid represented by the formula (1).

In Formula (1), R represents a hydrogen atom or a hydrocarbon group, preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 3 to 8 carbon atoms.
Examples of the hydroxy acid represented by the formula (1) include 2,2-dimethylolacetic acid, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolpentanoic acid, 2,2-dimethyl. Examples include methylolhexanoic acid, 2,2-dimethylolheptanoic acid, 2,2-dimethyloloctanoic acid, among which 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethyl Methylolhexanoic acid and 2,2-dimethyloloctanoic acid are preferred.
In addition to hydroxy acids having a total of 3 or more hydroxy groups and carboxy groups represented by formula (1), hydroxy acids having a total of 3 or more hydroxy groups and carboxy groups that can be used in the present invention include malic acid, tartaric acid, citric acid, and the like. Examples thereof include acid, dihydroxybenzoic acid (such as pyrocatechuic acid, resorcylic acid, and orthoric acid), protocatechuic acid, gentisic acid, and trihydroxybenzoic acid. Among them, malic acid is preferable.
In addition, even when a hydroxy acid having two or more carboxy groups and two or more hydroxy groups such as tartaric acid is used, a crosslinked polyester resin may be obtained depending on the reaction conditions during polycondensation. In some cases.
The hydroxy acid having a total of 3 or more hydroxy groups and carboxy groups that can be used in the present invention preferably has 4 to 30 carbon atoms, more preferably 4 to 20 carbon atoms, It is more preferable that the number is 4 to 12.

(2) Hydroxycarboxylic acid Hydroxycarboxylic acid is a compound containing one carboxy group and one hydroxy group in one molecule. Needless to say, hydroxy acids having a total of 3 or more hydroxy groups and carboxy groups are excluded.
Specific examples of the hydroxycarboxylic acid that can be used in the present invention include hydroxyoctanoic acid, hydroxynonanoic acid, hydroxydecanoic acid, hydroxyundecanoic acid, hydroxydodecanoic acid, hydroxytetradecanoic acid, hydroxytridecanoic acid, hydroxyhexadecanoic acid, Hydroxypentadecanoic acid, hydroxystearic acid, lactic acid, monohydroxybenzoic acid derivatives (such as salicylic acid and 3-methylsalicylic acid, 4-methylsalicylic acid, 6-methylsalicylic acid and hydroxymethylbenzoic acid such as creosote acid), vanillic acid, syringic acid , Mandelic acid, benzylic acid, atrolactic acid and the like, but are not limited thereto.

In the present invention, the toner for developing an electrostatic image includes a polyester resin containing 2 to 20 mol% of monomer units derived from a hydroxy acid having a total of 3 or more hydroxy groups and carboxy groups and / or derivatives thereof. It is preferable to include a polyester resin containing 2 to 15 mol% of a hydroxy acid in all monomer units.
When the content of the hydroxy acid is less than 2 mol%, the image density of the first printed material after the printer or the like has not been used for a long time tends to vary depending on the environment (high temperature / high humidity / low temperature / low humidity). If the content of hydroxy acid exceeds 20 mol%, the viscosity of the resin becomes too high, low-temperature fixability may be lost, gloss unevenness may occur, or BCO may be generated due to a decrease in toner resistance. There is sex.
The reason why the environmental dependency of the density of the initial image can be reduced within the above numerical range is as follows. That is, when a polyester resin is produced using a hydroxy acid as a polycondensable monomer, the number of carboxy groups in the polyester resin increases. When a toner based on such a polyester resin is prepared, the charge exchange rate between the toner and the carrier is increased by the abundant carboxy group. Therefore, the image density of the first printed matter after the printer or the like has not been used for a long time can be stabilized without variation depending on the environment (high temperature / high humidity / low temperature / low humidity).

(3) Polycarboxylic acid Polycarboxylic acid is a compound having two or more carboxy groups in one molecule. Among these, dicarboxylic acid is a compound having two carboxy groups in one molecule. Specifically, oxalic acid, succinic acid, fumaric acid, maleic acid, glutaric acid, adipic acid, β-methyladipic acid, malonic acid , Pimelic acid, suberic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, citraconic acid, glutaconic acid, n-dodecylsuccinic acid, n-dodecenylsuccinic acid, isododecylsuccinic acid , Isododecenyl succinic acid, n-octyl succinic acid, n-octenyl succinic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, mucoic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid , Chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p Phenylenedipropionic acid, m-phenylenedipropionic acid, m-phenylenediacetic acid, p-phenylenediacetic acid, o-phenylenediacetic acid, diphenyldiacetic acid, diphenyl-p, p'-dicarboxylic acid, 1,1- Cyclopentene dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,2-cyclohexane dicarboxylic acid, 1,2-cyclohexene dicarboxylic acid, norbornene-2,3-dicarboxylic acid, 1,3-adamantane Examples thereof include dicarboxylic acid, 1,3-adamantane diacetic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracene dicarboxylic acid and the like.
Specific examples of polycarboxylic acids other than dicarboxylic acids include trimellitic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, and pyrenetetracarboxylic acid.
The polycarboxylic acid may have a functional group other than a carboxy group, and carboxylic acid derivatives such as acid anhydrides, acid halides, and lower esters can also be used. These polycarboxylic acids may be used alone or in combination of two or more.
In addition, a lower ester shows that the carbon number of the alkoxy part of ester is 1-8. Specific examples include methyl ester, ethyl ester, n-propyl ester, isopropyl ester, n-butyl ester, and isobutyl ester.

  Specific examples of polycarboxylic acids preferably used as the polycondensable monomer include sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, p-phenylenediacetic acid, and m-phenylenediacetic acid. P-phenylene dipropionic acid, m-phenylene dipropionic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid , Naphthalene-2,6-dicarboxylic acid, trimellitic acid, pyromellitic acid.

(4) Polyol A polyol is a compound containing two or more hydroxyl groups in one molecule. Although it does not specifically limit as a polyol which can be used for this invention, Polycondensable monomers, such as following polyols, such as diol, and a polyol which has a cyclic structure, can be mentioned.
Diol is a compound containing two hydroxyl groups in one molecule. Specifically, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propanediol, dipropylene glycol, polypropylene glycol, butanediol, butenediol, polytetra Examples include methylene glycol, pentanediol, neopentyl glycol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol, tetradecanediol, and octadecanediol.
Specific examples of polyols other than diols include propanetriol, pentaerythritol, hexamethylol melamine, hexaethylol melamine, tetramethylol benzoguanamine, and tetraethylol benzoguanamine.
Specific examples of the polyol having a cyclic structure include cyclohexanediol, cyclohexanedimethanol, bisphenol A, bisphenol C, bisphenol E, bisphenol F, bisphenol P, bisphenol S, bisphenol Z, hydrogenated bisphenol, biphenol, and naphthalenediol. 1,3-adamantanediol, 1,3-adamantane dimethanol, 1,3-adamantane diethanol and the like, but are not limited thereto.
In the present invention, the bisphenols preferably have at least one alkylene oxide group. Examples of the alkylene oxide group include, but are not limited to, an ethylene oxide group, a propylene oxide group, and butylene oxide. Preferably, they are ethylene oxide and propylene oxide, and the number of moles added is preferably 1 to 3 per mole of hydroxy group. When it is within this range, the viscoelasticity and glass transition temperature of the produced polyester resin can be appropriately controlled for use as a toner.
Among the above-mentioned polyols, hexanediol, cyclohexanediol, octanediol, decanediol, dodecanediol and bisphenol A, bisphenol C, bisphenol E, bisphenol S, and bisphenol Z alkylene oxide adducts are preferably used. Can be mentioned.

You may use a polycondensable monomer combining 2 or more types by arbitrary ratios. Moreover, an amorphous polyester resin or a crystalline polyester resin can be easily obtained by a combination of these polycondensable monomers.
The polyester resin that can be used in the present invention is preferably a polycondensed hydroxy acid having a total of 3 or more hydroxy groups and carboxy groups and / or derivatives thereof, dicarboxylic acids, and diols. Moreover, it is good also considering dicarboxylic acid as a slight excess and making a molecular terminal a carboxy group. When the dicarboxylic acid is used in a slight excess, the dicarboxylic acid is preferably added in an excess of 0.1 to 2 mol% with respect to the diol. Within the above range, the reactivity is good, no unreacted residual monomer is produced, and when the obtained resin is used for toner, the offset property at the time of fixing in a high temperature region is excellent.

In the present invention, the polyester resin has a monomer unit derived from a polycarboxylic acid and / or derivative thereof and a polyol, and 50 to 100 mol% of the monomer unit derived from the polycarboxylic acid and / or derivative thereof is represented by the formula ( It is preferable to use a polyester resin composed of a compound represented by the formula (3) in which 50 to 100 mol% of the monomer unit represented by 1) and / or the formula (2) is derived from the polyol.
R ¹ OOCA ¹ _m B ¹ _n A ¹ _l COOR ¹ (1)
(A ¹ : methylene group, B ¹ : aromatic hydrocarbon group, R ¹ : each independently a hydrogen atom or a monovalent hydrocarbon group, 1 ≦ m + 1 ≦ 12, 1 ≦ n ≦ 3)
R ² OOCA ² _p B ² _q A ² _r COOR ² (2)
(A ² : methylene group, B ² : alicyclic hydrocarbon group, R ² : each independently a hydrogen atom or monovalent hydrocarbon group, 0 ≦ p ≦ 6, 0 ≦ r ≦ 6, 1 ≦ q ≦ 3 )
HOX _h Y _j X _k OH (3)
(X: alkylene oxide group, Y: bisphenol skeleton group, 1 ≦ h + k ≦ 10, 1 ≦ j ≦ 3)
Here, the monovalent hydrocarbon group represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a hydrocarbon group, or a heterocyclic group containing no nitrogen and sulfur elements, and these groups are optional substituents. You may have. R ¹ and R ² are preferably a hydrogen atom or a lower alkyl group, more preferably a hydrogen atom, a methyl group or an ethyl group, and most preferably a hydrogen atom.
Moreover, the aromatic hydrocarbon group in Formula (1) and the alicyclic hydrocarbon group in Formula (2) may be further substituted.

  In addition to the hydroxy acid having a total of 3 or more hydroxy groups and carboxy groups and / or derivatives thereof, the compound represented by the formula (1) and / or the formula (2) and the compound represented by the formula (3) are polyester. By using the resin as the main component, non-crystalline polyester resins can be esterified at a low temperature without solvent due to the high reactivity that was previously possible only with aliphatic polyester resins. In addition, the aliphatic polyester resin is easily degradable, such as excellent biodegradability, but the polyester resin has high water resistance and heat resistance, high film strength after curing, and high reactivity at low temperatures. The energy required during thermosetting can be suppressed.

  The dicarboxylic acid represented by Formula (1) and Formula (2) and the diol represented by Formula (3) will be described below. In the present invention, “dicarboxylic acid” is meant to include its esterified products and acid anhydrides.

<Dicarboxylic acid represented by Formula (1)>
The dicarboxylic acid represented by the formula (1) has at least one aromatic hydrocarbon group B ¹ , but its structure is not particularly limited. Examples of the aromatic hydrocarbon group B ¹ include benzene, naphthalene, acenaphthylene, fluorene, anthracene, phenanthrene, tetracene, fluoranthene, pyrene, benzofluorene, benzophenanthrene, chrysene, triphenylene, benzopyrene, perylene, anthrene, benzonaphthacene. , Groups containing a skeleton such as benzochrysene, pentacene, pentaphen, and coronene can be exemplified, but the invention is not limited thereto. Further, a substituent may be further added to these structures.

The number of aromatic hydrocarbon groups B ¹ contained in the dicarboxylic acid represented by the formula (1) is preferably 1 to 3. Within the above numerical range, the polyester resin to be produced is non-crystalline, and since the dicarboxylic acid is easily available, the cost and production efficiency are good, and the dicarboxylic acid represented by the formula (1) The melting point and viscosity are appropriate, and there is no decrease in reactivity due to size and bulkiness, which is preferable.

  When the dicarboxylic acid represented by the formula (1) includes a plurality of aromatic hydrocarbon groups, the aromatic hydrocarbon groups may be directly bonded to each other, and other saturated fats may be interposed between the aromatic hydrocarbon groups. A structure having a skeleton such as an aromatic hydrocarbon group can also be taken. Examples of the former include a biphenyl skeleton and the like, and examples of the latter include a bisphenol A skeleton, a benzophenone, a diphenylethene skeleton, and the like, but are not limited thereto.

A group suitable as the aromatic hydrocarbon group B ¹ has a structure having 6 to 18 carbon atoms in the main skeleton. The number of carbon atoms of the main skeleton does not include the number of carbon atoms contained in the functional group bonded to the main skeleton. Specific examples of the main skeleton include benzene, naphthalene, acenaphthylene, fluorene, anthracene, phenanthrene, tetracene, fluoranthene, pyrene, benzofluorene, benzophenanthrene, chrysene, triphenylene, bisphenol A skeleton, and the like. Among these, particularly preferred skeletons include benzene, naphthalene, anthracene, and phenanthrene skeletons. Most preferred are benzene and naphthalene skeletons.
When the main skeleton has 6 or more carbon atoms, the production of the monomer is easy. Further, when the carbon number of the main skeleton is 18 or less, the size of the monomer molecule is appropriate, the molecular motion is limited, and the reactivity is excellent. Furthermore, the ratio of the reactive functional group in the monomer molecule is appropriate, and the reactivity is good.

The dicarboxylic acid represented by the formula (1) contains at least one methylene group A ¹ . The methylene group may be linear or branched, and for example, a methylene chain, a branched methylene chain, a substituted methylene chain and the like can be used. In the case of a branched methylene chain, the structure of the branched part is not limited and may have an unsaturated bond, further branching, a cyclic structure, or the like.
The number of methylene groups A ¹ is preferably 1 to 12, more preferably 2 to 6, and more preferably m and l are the same as the total m + 1 in the molecule. .
Within the above numerical range, the aromatic hydrocarbon group and the carboxy group at both ends are not directly bonded to each other, so the reaction intermediate formed by the catalyst and the dicarboxylic acid represented by the formula (1) resonates. It is not stabilized and has excellent reactivity. In addition, since the linear portion does not become too large with respect to the dicarboxylic acid represented by the formula (1), the produced polymer has non-crystalline characteristics, and the glass transition temperature Tg becomes an appropriate value. .

The bonding site between the methylene group A ¹ or carboxy group and the aromatic hydrocarbon group B ¹ is not particularly limited, and may be any of the o-position, m-position, and p-position.

  Examples of the dicarboxylic acid represented by the formula (1) include 1,4-phenylenediacetic acid, 1,4-phenylenedipropionic acid, 1,3-phenylenediacetic acid, 1,3-phenylenedipropionic acid, 1,2 -Phenylenediacetic acid, 1,2-phenylenedipropionic acid and the like can be mentioned, but are not limited thereto. Preferable examples include 1,4-phenylene dipropionic acid, 1,3-phenylene dipropionic acid, 1,4-phenylene diacetic acid, and 1,3-phenylene diacetic acid.

  Various functional groups may be added to any of the structures of the dicarboxylic acid represented by the formula (1). The carboxylic acid group that is a polycondensation reactive functional group may be an acid anhydride, an acid ester, or an acid chloride. However, since an intermediate between an acid ester and a proton is easily stabilized and tends to suppress reactivity, a carboxylic acid, a carboxylic acid anhydride, or a carboxylic acid chloride is preferably used.

<Dicarboxylic acid represented by formula (2)>
Dicarboxylic acid represented by formula (2) contains an alicyclic hydrocarbon group B ^2. The alicyclic hydrocarbon structure is not particularly limited, and cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, cyclododecane, cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, Examples thereof include, but are not limited to, cyclooctene, norbornene, adamantane, diamantane, triamantane, tetramantane, isean, and twistane skeleton. Further, a substituent may be added to these structures. In view of the stability of the structure, the size and bulkiness of the molecule, cyclobutane, cyclopentane, cyclohexane, norbornene, adamantane skeleton and the like are preferable.

The number of alicyclic hydrocarbon groups contained in this monomer is preferably 1 to 3. Within the above numerical range, the produced polyester resin has non-crystallinity, and is excellent in reactivity because of an appropriate increase in melting point, molecular size and bulkiness.
In the case of containing a plurality of alicyclic hydrocarbon groups, either a structure in which alicyclic hydrocarbon groups are directly bonded to each other or a structure having a skeleton such as other saturated aliphatic hydrocarbons can be taken. Examples of the former include a dicyclohexyl skeleton and the like, and examples of the latter include, but are not limited to, a hydrogenated bisphenol A skeleton.

  The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. The number of carbon atoms of the main skeleton does not include the number of carbon atoms contained in the functional group bonded to the main skeleton. For example, an alicyclic hydrocarbon group having a cyclopropane, cyclobutane, cyclopentane, cyclohexane, norbornene, adamantane skeleton, or the like can be given. Among these, particularly preferable skeletons include cyclobutane, cyclopentane, cyclohexane, norbornene and adamantane skeletons, and cyclohexane is preferable.

The dicarboxylic acid represented by the formula (2) may have a methylene group A ² in its structure. The methylene group may be linear or branched, and for example, a methylene chain, a branched methylene chain, a substituted methylene chain and the like can be used. In the case of a branched methylene chain, the structure of the branched part is not limited and may have an unsaturated bond, further branching, a cyclic structure, or the like.
The number of methylene groups A ² is, p, is preferably r is 6 or less, respectively. When p and r are 6 or less, the straight-chain part has an appropriate size with respect to the dicarboxylic acid represented by the formula (2), the produced polymer is non-crystalline, and the glass transition temperature Tg is appropriate. It is.
The bonding site between the methylene group A ² or carboxy group and the alicyclic hydrocarbon group B ² is not particularly limited, and may be any of o-position, m-position and p-position.

  Examples of the dicarboxylic acid represented by the formula (2) include 1,1-cyclopropanedicarboxylic acid, 1,1-cyclobutanedicarboxylic acid, 1,2-cyclobutanedicarboxylic acid, 1,1-cyclopentenedicarboxylic acid, Examples include cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,2-cyclohexenedicarboxylic acid, norbornene-2,3-dicarboxylic acid, and adamantanedicarboxylic acid. It is not limited. Of these, compounds having a cyclobutane, cyclohexane or cyclohexane skeleton are preferably used, and 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid are particularly preferable.

  The dicarboxylic acid represented by the formula (2) may have various functional groups added to any of its structures. The carboxy group that is a polycondensation reactive functional group may be an acid anhydride, an acid ester, or an acid chloride. However, since an intermediate between an acid ester compound and a proton is easily stabilized and tends to suppress reactivity, a carboxylic acid, a carboxylic acid anhydride, or a carboxylic acid chloride is preferably used.

In the present invention, the compound represented by the above formula (1) and / or formula (2) (dicarboxylic acid) with respect to the whole polycarboxylic acid component excluding the hydroxy acid having a total of 3 or more hydroxy groups and carboxy groups It is preferable to contain 50-100 mol%. The compound represented by the above formula (1) and the compound represented by the formula (2) can be used alone or in combination.
When the ratio of the compound represented by the formula (1) and / or the formula (2) is 50 mol% or more, the reactivity in the low-temperature polycondensation can be sufficiently exhibited, the degree of polymerization is high, and the molecular weight is appropriate. In addition, since there are few residual polycondensation components, performance deterioration such as stickiness of the obtained image at normal temperature does not occur, and viscoelasticity and glass transition temperature are moderate.
The polyester resin that can be used in the present invention is more preferably a resin obtained by using the compound represented by the formula (1) and / or the formula (2) in an amount of 60 to 100 mol%. A resin obtained by using the compound represented by the formula (1) and / or the formula (2) in an amount of 80 to 100 mol% is more preferable.

<Diol represented by Formula (3)>
The polyester resin that can be used in the present invention is a resin obtained by a polycondensation reaction of a hydroxy acid and / or a derivative thereof, a polycarboxylic acid and a polyol having a total of 3 or more hydroxy groups and carboxy groups, excluding the hydroxy acid. It is preferable that 50-100 mol% of a polyol consists of a compound (diol) represented by Formula (3).
HOX _h Y _j X _k OH (3)
(X: alkylene oxide group, Y: bisphenol skeleton group, 1 ≦ h + k ≦ 10, 1 ≦ j ≦ 3)
The diol represented by the above formula (3) includes at least one bisphenol skeleton Y. The bisphenol skeleton is not particularly limited as long as it is a skeleton composed of two phenol groups. Specifically, bisphenol A, bisphenol C, bisphenol E, bisphenol F, bisphenol M, bisphenol P, bisphenol S, bisphenol Z, etc. However, it is not limited to these. Examples of the skeleton preferably used include bisphenol A, bisphenol C, bisphenol E, bisphenol F, bisphenol M, bisphenol P, bisphenol S, and bisphenol Z, and more preferably bisphenol A, bisphenol E, and bisphenol F. is there.
The number j of the bisphenol skeleton is preferably 1 to 3. When j is in the above range, an amorphous polyester resin is obtained, and the viscosity and melting point are moderate, and the reactivity is excellent.

The diol represented by the formula (3) preferably has at least one alkylene oxide group. Examples of the alkylene oxide group include, but are not limited to, an ethylene oxide group, a propylene oxide group, and a butylene oxide group. Preferred are an ethylene oxide group and a propylene oxide group, and particularly preferred is an ethylene oxide group.
The total number h + k of alkylene oxide groups is preferably 1 to 10 in one molecule. Within the above range, an amorphous polyester resin can be obtained, and it is possible to obtain a resin having high reactivity, excellent polymerization and high molecular weight.
Moreover, it is preferable that h and k are the same number in order to promote an equal reaction. The total number of alkylene oxide groups h + k is preferably 6 or less, and the number of alkylene oxide groups h and k is more preferably 2 or 1 respectively. Moreover, when it has 2 or more alkylene oxide groups, it can also have 2 or more types of alkylene oxide groups in 1 molecule.

Examples of the diol represented by the formula (3) include bisphenol A ethylene oxide adduct (h + k is 1 to 10), bisphenol A propylene oxide adduct (h + k is 1 to 10), ethylene oxide propylene oxide adduct (h + k is 2). -10), bisphenol Z ethylene oxide adduct (h + k is 1 to 10), bisphenol Z propylene oxide adduct (h + k is 1 to 10), bisphenol S ethylene oxide adduct (h + k is 1 to 10), bisphenol S Propylene oxide adduct (h + k is 1 to 10), Biphenol propylene oxide adduct (h + k is 1 to 10), Bisphenol F ethylene oxide adduct (h + k is 1 to 10), Bisphenol F propylene oxide adduct (h + k is 1 to 1) 0), bisphenol E ethylene oxide adduct (h + k is 1 to 10), bisphenol E propylene oxide adduct (h + k is 1 to 10), bisphenol C ethylene oxide adduct (h + k is 1 to 10), bisphenol C propylene oxide addition Product (h + k is 1 to 10), bisphenol M ethylene oxide adduct (h + k is 1 to 10), bisphenol M propylene oxide adduct (h + k is 1 to 10), bisphenol P ethylene oxide adduct (h + k is 1 to 10) Bisphenol P propylene oxide adduct (h + k is 1 to 10) and the like, but are not limited thereto.
Particularly preferably, bisphenol A ethylene oxide 1 mol adduct (1 each of h and k), bisphenol A ethylene oxide 2 mol adduct (2 each of h and k), bisphenol A propylene oxide 1 mol adduct (each of h and k). 1), bisphenol A ethylene oxide 1 mol propylene oxide 2 mol adduct, bisphenol E ethylene oxide 1 mol adduct (1 each of h, k), bisphenol E propylene oxide 1 mol adduct (1 each of h, k), bisphenol F ethylene oxide 1 mol adduct (1 each of h and k), bisphenol F propylene oxide 1 mol adduct (1 each of h and k), and the like.

In this invention, it is preferable that 50-100 mol% of diol represented by Formula (3) is contained in all the polyols except the hydroxy acid and / or its derivative which have a total of 3 or more of a hydroxyl group and a carboxy group. When the content is within the above range, the reactivity in low-temperature polycondensation can be sufficiently exerted, a polyester resin having a high degree of polymerization and an appropriate molecular weight can be obtained, and since there are few residual polycondensation components, it is cured. Performance deterioration such as stickiness of objects at room temperature does not occur, and viscoelasticity and glass transition temperature are moderate.
The polyester resin that can be used in the present invention is more preferably a resin obtained by using the diol represented by the formula (3) in an amount of 60 to 100 mol%, and is represented by the formula (3). More preferably, it is a resin obtained by using 80 to 100 mol% of a diol.

In the present invention, the dicarboxylic acid represented by the formula (1) and / or the formula (2) and the diol represented by the formula (3) are each a resin-forming composition in a monomer state, an oligomer state, or a polymer state. Can be used as a thing.
In the case of oligomers and polymers, the preferred molecular weight is Mw 300 to 30,000, more preferably 300 to 25,000.

The weight average molecular weight of the polyester resin obtained by polycondensation of a polycondensable monomer is preferably 1,500 to 55,000, more preferably 5,000 to 45,000. More preferably, it is 10,000-35,000.
When the weight average molecular weight is 1,500 or more, the cohesive force of the binder resin is good and the hot offset property is excellent, and when it is 55,000 or less, the minimum hot offset property fixing temperature is preferable. Further, it may be partially branched or cross-linked by selecting the carboxylic acid valence or alcohol valence of the monomer.

  The polyester resin that can be used in the present invention can take any form such as an amorphous (amorphous) polyester resin (synonymous with an amorphous polyester resin), a crystalline polyester resin, or a mixed form thereof. A non-crystalline polyester resin is preferred. Moreover, it is preferable that the polyester resin which can be used for this invention is a polyester resin which has a terminal carboxy group.

  When the polyester resin that can be used in the present invention is a crystalline polyester resin, the crystal melting point Tm is preferably 50 to 120 ° C, and more preferably 55 to 90 ° C. When the Tm is 50 ° C. or higher, the cohesive force of the binder resin itself in a high temperature range is good, so that it is excellent in peelability and hot offset property during fixing. When Tm is 120 ° C. or lower, sufficient melting is obtained and the minimum fixing temperature is unlikely to rise.

  On the other hand, when the polyester resin that can be used in the present invention is an amorphous polyester resin, the glass transition point Tg is preferably 50 to 80 ° C, more preferably 50 ° C or more and less than 65 ° C, More preferably, it is in the range of 60 ° C. or more and less than 65 ° C. When the Tg is 50 ° C. or more, the cohesive force of the binder resin itself in a high temperature range is good, and thus the hot offset property is excellent at the time of fixing. When Tg is 80 ° C. or lower, sufficient melting is obtained, and the minimum fixing temperature is hardly increased.

Here, for the measurement of the melting point of the crystalline polyester resin, a differential scanning calorimeter (DSC) was used, and JIS K-7121: 87 when the measurement was performed from room temperature to 150 ° C. at a heating rate of 10 ° C. per minute. The melting peak temperature of the input compensation differential scanning calorimetry shown in FIG. The crystalline polyester resin may show a plurality of melting peaks, but in the present invention, the maximum peak is regarded as the melting point.
Here, the glass transition point of an amorphous polyester resin means the value measured by the method (DSC method) prescribed | regulated to ASTMD3418-82.
“Crystallinity” as shown in the above “crystalline polyester resin” means that the differential scanning calorimetry (DSC) has a clear endothermic peak, not a stepwise endothermic change. Means that the half-value width of the endothermic peak when measured at a heating rate of 10 ° C./min is within 6 ° C. On the other hand, a resin in which the half-value width of the endothermic peak exceeds 6 ° C. or a resin in which no clear endothermic peak is observed means that it is amorphous (amorphous).

<Other polyester resins>
In the present invention, in addition to the polyester resin containing monomer units derived from the hydroxy acid, the following crystalline polyester resin and non-crystalline polyester resin can be used in combination as other polyester resins. The same polycarboxylic acid, polyol, and hydroxycarboxylic acid as those described above can be used as the polycarboxylic acid, polyol, and hydroxycarboxylic acid that can be used for the production of other polyester resins. Moreover, it is the same as that of the said polyester resin also about preferable ranges, such as a weight average molecular weight, melting | fusing point, a glass transition temperature. Preferred crystalline polyester resins and non-crystalline polyester resins are exemplified below, but the present invention is not limited thereto.

(Crystalline polyester resin)
For example, the polyvalent carboxylic acid used to obtain the crystalline polyester resin includes oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, Fumaric acid, citraconic acid, itaconic acid, glutaconic acid, n-dodecyl succinic acid, n-dodecenyl succinic acid, isododecyl succinic acid, isododecenyl succinic acid, n-octyl succinic acid, n-octenyl succinic acid, 1,10- Examples include decanedicarboxylic acid, acid anhydrides thereof, and lower esters thereof. Furthermore, the acid chloride is not limited to this.
Furthermore, the polyols that can be used to obtain the crystalline polyester resin include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, , 4-butenediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like.
As such a crystalline polyester resin, a polyester resin obtained by reacting 1,9-nonanediol and 1,10-decanedicarboxylic acid, and obtained by reacting 1,6-hexanediol and sebacic acid. Polyester resin, polyester resin obtained by reacting ethylene glycol and succinic acid, polyester resin obtained by reacting ethylene glycol and sebacic acid, polyester obtained by reacting 1,4-butanediol and succinic acid Resins can be mentioned. Of these, polyester resins obtained by reacting 1,9-nonanediol and 1,10-decanedicarboxylic acid, polyester resins obtained by reacting 1,6-hexanediol and sebacic acid, and the like are more preferable. But this is not the case.

(Non-crystalline polyester resin)
Furthermore, examples of the polyvalent carboxylic acid that can be used for obtaining an amorphous polyester resin include aromatics such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, and mesaconic acid. Examples thereof include group dicarboxylic acids and the like, and lower esters thereof. Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and anhydrides thereof, 2-sulfo Examples include sodium terephthalate, sodium 5-sulfoisophthalate, sodium sulfosuccinate and lower esters thereof, but are not limited thereto.
Examples of polyols that can be used to obtain an amorphous polyester resin include aliphatic, alicyclic, and aromatic polyols. Specifically, 1,4-cyclohexanediol and 1,4-cyclohexane Preferred examples include dimethanol, bisphenol A, bisphenol Z, hydrogenated bisphenol A, and the like, but not limited thereto.

<Polycondensation catalyst>
When a hydroxy acid having a total of 3 or more hydroxy groups and carboxy groups and / or a derivative thereof is used as the polycondensable monomer of the polyester resin, gelation may occur during the polycondensation depending on the conditions of the polycondensation reaction. . In such a case, it is considered that the hydroxy acid moiety serves as a crosslinking point, and the resulting polymer has a crosslinked or branched structure. In the case of preparing an aqueous dispersion of resin particles based on a polyester resin having no such crosslinked or branched structure, it is preferable because the viscosity is appropriate and gelation is difficult, so that emulsification is easy.
Control of specific reaction selectivity between carboxy group and hydroxy group contributing to the reaction when hydroxy acid and / or its derivative having 3 or more total hydroxy groups and carboxy groups are used as polyester resin polycondensable monomer It is preferable to do.
It is preferable to perform the polycondensation reaction at a temperature lower than 200 ° C. because the above selectivity can be obtained. More preferably, by controlling the reaction system such as polymerization at a low temperature of 150 ° C. or lower, the selectivity between the portion to be esterified according to the reactivity of the functional group and the portion remaining in the main chain as a residue is higher. Therefore, it is preferable.

In the present invention, it is preferable to use a polycondensation catalyst in the polycondensation step in the production of the polyester resin in order to increase the reaction rate of the polycondensation reaction. In the polycondensation step, a known polycondensation catalyst can be blended in advance in the polycondensable monomer as necessary. In order to polycondense a polycondensable monomer at a low temperature of 150 ° C. or lower or 100 ° C. or lower, a polycondensation catalyst is preferably used. Examples of the polycondensable catalyst having catalytic activity at a low temperature include an acid catalyst, a rare earth-containing catalyst, or a hydrolase, and among them, an acid catalyst is preferable, and a sulfur acid is more preferable.
As the acid catalyst, Bronsted acid is preferable, and these salt compounds are also included.
Furthermore, an acid having a surface active effect may be used. The acid having a surface-active effect has a chemical structure composed of a hydrophobic group and a hydrophilic group, and has an acid structure in which at least a part of the hydrophilic group is composed of protons.

In the present invention, it is preferable to use sulfur acid as the acid catalyst. Examples of sulfur acids include inorganic sulfur acids and organic sulfur acids.
Examples of inorganic sulfur acids include sulfuric acid, sulfurous acid, and salts thereof, and examples of organic sulfur acids include sulfonic acids such as alkylsulfonic acid, arylsulfonic acid, and salts thereof, alkylsulfuric acid, arylsulfuric acid, and the like. Organic sulfates such as salts can be mentioned. The sulfur acid is preferably an organic sulfur acid, and more preferably an organic sulfur acid having a surface active effect.
Examples of organic sulfur acids having a surface active effect include alkylbenzene sulfonic acid, alkyl sulfonic acid, alkyl disulfonic acid, alkylphenol sulfonic acid, alkyl naphthalene sulfonic acid, alkyl tetralin sulfonic acid, alkyl allyl sulfonic acid, petroleum sulfonic acid, alkyl benzoic acid. Imidazole sulfonic acid, higher alcohol ether sulfonic acid, alkyl diphenyl sulfonic acid, long chain alkyl sulfate, higher alcohol sulfate, higher alcohol ether sulfate, higher fatty acid amide alkylol sulfate, higher fatty acid amide alkylated sulfate, sulfate Fats, sulfosuccinic acid esters, resin acid alcohol sulfuric acid, and all salt compounds thereof may be used, and a plurality of them may be combined as necessary.
Among these, a sulfonic acid having an alkyl group or an aralkyl group, a sulfate ester having an alkyl group or an aralkyl group, or a salt compound thereof is preferable, and the alkyl group or the aralkyl group has 7 to 20 carbon atoms. Is more preferable. Specifically, dodecylbenzenesulfonic acid, octadecylbenzenesulfonic acid, isopropylbenzenesulfonic acid, camphorsulfonic acid, paratoluenesulfonic acid, monobutylphenylphenol sulfate, dibutylphenylphenol sulfate, dodecyl sulfate, naphthenyl alcohol sulfate, etc. Can be mentioned.
Examples of the acid having a surface active effect other than the above include various fatty acids, sulfonated higher fatty acids, higher alkyl phosphate esters, resin acids, naphthenic acids, and all salt compounds thereof.
These polycondensation catalysts may be used alone or in combination. Furthermore, these catalysts can be recovered and regenerated as necessary.

<Emulsification (resin particle dispersion)>
In the present invention, the resin particle dispersion is a resin particle dispersion in which resin particles containing at least a polyester resin are dispersed in a dispersion medium. The resin particle dispersion can be suitably used as a resin particle dispersion for an electrostatic charge image developing toner.

  In the present invention, the resin particle dispersion is preferably a resin particle dispersion in which resin particles are emulsified and dispersed in an aqueous medium with a median diameter of 0.05 to 2.0 μm. Further, the resin particle dispersion comprises the polycondensation catalyst comprising a polyester resin-generated polycondensable monomer such as polycarboxylic acid or polyol, and a hydroxy acid and / or derivative thereof having a total of three or more carboxy groups and hydroxy groups. The polyester resin is preferably obtained by dispersing and granulating the polyester resin in an aqueous medium after polycondensation in the presence to obtain the polyester resin.

  In the present invention, the dispersion medium of the resin particle dispersion is preferably an aqueous medium. Specific examples of the aqueous medium that can be used in the present invention include water such as distilled water and ion exchange water, and alcohols such as ethanol and methanol. Among these, ethanol and water are preferable, and water such as distilled water and ion-exchanged water is particularly preferable. These may be used individually by 1 type and may use 2 or more types together. The aqueous medium may contain a water-miscible organic solvent. Examples of the water-miscible organic solvent include acetone and acetic acid.

In the present invention, the solid content of the resin particle dispersion is preferably 5 to 40 parts by weight, more preferably 10 to 30 parts by weight, and still more preferably 15 to 25 parts by weight with respect to 100 parts by weight of the resin particle dispersion. . When the solid content of the resin particle dispersion is 5 parts by weight or more, the viscosity of the polymer composition does not become too low, the stability of the particles is good, and the transportation cost is also excellent. When the solid content is 40 parts by weight or less, the viscosity is appropriate and the mixture can be stirred uniformly, and the polymerization proceeds sufficiently.
In the polymerization, in addition to the monomer components before the polymerization, a colorant, a wax and the like can be mixed in advance. By carrying out like this, the resin particle dispersion liquid containing the particle | grains which took in the coloring agent and wax can be obtained.

  In the method for producing a resin particle dispersion, when emulsification polycondensation is performed in an aqueous medium, the preferable emulsification temperature is preferably lower in consideration of energy saving, polymer production rate and thermal decomposition rate of the produced polymer. More preferably, it is 40-150 degreeC, More preferably, it is 80-130 degreeC. It is preferable that the emulsification temperature is 150 ° C. or lower because the required energy does not become excessive and the molecular weight is not lowered due to decomposition of the resin due to high heat. Moreover, it is preferable for the temperature to be 40 ° C. or higher because the resin viscosity is moderate and particle formation is easy.

  The method for dispersing and granulating the polyester resin in an aqueous medium can be selected from known methods such as forced emulsification, self-emulsification, and phase inversion emulsification. Of these, the self-emulsification method and the phase inversion emulsification method are preferably applied in consideration of the energy required for emulsification, the particle size controllability of the obtained emulsion, stability, and the like. The self-emulsification method and the phase inversion emulsification method are described in “Application Technology of Ultrafine Particle Polymer (CMC Publishing)”. As the polar group used for self-emulsification, a carboxy group, a sulfo group, and the like can be used. When applied to a polyester resin that can be used in the present invention, a carboxy group is preferably used.

When an organic solvent is used in the dispersion step, the method for producing a resin particle dispersion in the present invention may include a step of removing at least part of the organic solvent and a step of forming resin particles.
For example, it is preferable to solidify as particles by removing a part of the organic solvent after emulsifying the polyester resin-containing material. As a specific method of solidification, the polyester resin-containing material is emulsified and dispersed in an aqueous medium, and then the organic solvent is dried at the gas-liquid interface while sending an inert gas such as air or nitrogen while stirring the solution. (Waste wind drying method) or a method of drying while maintaining a reduced pressure while bubbling an inert gas as needed (a reduced pressure topping method), and further emulsifying and dispersing the polyester resin-containing material in an aqueous medium For example, there is a method of discharging the emulsified dispersion or polyester resin-containing emulsion into a shower-like shape from the pores, dropping it into a dish-shaped receptacle, and drying it repeatedly (shower-type solvent removal method). It is preferable to remove the solvent by selecting or combining these methods as appropriate based on the evaporation rate of the organic solvent to be used, solubility in water, and the like.

When dispersing and emulsifying in an aqueous medium, the above materials are emulsified or dispersed in the aqueous medium using, for example, mechanical shear or ultrasonic waves. It is also possible to add a surfactant, a polymer dispersant, an inorganic dispersant and the like to the aqueous medium as necessary during the emulsification dispersion.
Further, an aqueous medium may be added to a mixture (oil phase) containing the above materials, and the above materials may be finally emulsified and dispersed in the aqueous medium.

  Examples of the surfactant that can be used in the present invention include anionic surfactants such as sulfate ester, sulfonate, and phosphate ester; cationic surfactants such as amine salt type and quaternary ammonium salt type. Agents: Nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, polyhydric alcohols and the like. Among these, anionic surfactants and cationic surfactants are preferable. The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may use 2 or more types together.

  Anionic surfactants include sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, sodium arylalkylpolyethersulfonate, 3,3′-disulfonediphenylurea-4,4′-diazo-bis-amino-8-naphthol Sodium 6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2 ′, 5,5′-tetramethyl-triphenylmethane-4,4′-diazo-bis-β-naphthol-6-sulfone Sodium sulfate, sodium dialkylsulfosuccinate, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, Sodium prong, potassium stearate, and calcium oleate.

  Examples of the cationic surfactant include alkylbenzene dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride and the like.

  Nonionic surfactants include polyethylene oxide, polypropylene oxide, combinations of polypropylene oxide and polyethylene oxide, esters of polyethylene glycol and higher fatty acids, alkylphenol polyethylene oxide, esters of higher fatty acids and polyethylene glycol, higher fatty acids and polypropylene oxide. Examples thereof include esters and sorbitan esters.

  Examples of the polymer dispersant include sodium polycarboxylate and polyvinyl alcohol, and examples of the inorganic dispersant include calcium carbonate. However, these do not limit the present invention.

  Furthermore, in order to prevent the Ostwald Ripping phenomenon of emulsion particles in an aqueous medium, a higher alcohol represented by heptanol or octanol and / or a higher aliphatic hydrocarbon represented by hexadecane is added as a stabilizing aid. Is also preferable.

<Electrostatic image developing toner and method for producing the same>
In the present invention, a method for producing a toner for developing an electrostatic charge image includes an aggregation step of aggregating the resin particles in a dispersion containing at least a resin particle dispersion to obtain aggregated particles, and fusion in which the aggregated particles are heated and fused. It is preferable that a process is included, and it is more preferable that the resin particle dispersion is the above-described resin particle dispersion.

  In the present invention, as a method for producing a toner for developing an electrostatic image, for example, the resin particle dispersion prepared in the present invention is mixed with a colorant particle dispersion and a release agent particle dispersion, and further an aggregating agent is used. Then, agglomerated particles having a toner diameter are formed by causing heteroaggregation, and then heated to a temperature equal to or higher than the glass transition point or the melting point of the resin particles to fuse and coalesce the aggregated particles, and then washed and dried. A manufacturing method is mentioned. By this production method, a toner for developing an electrostatic image suitable for the present invention can be obtained. The toner shape is preferably from irregular to spherical. In addition to surfactants, inorganic salts and divalent or higher metal salts can be suitably used as the flocculant. In particular, when a metal salt is used, it is preferable in terms of aggregation control and toner charging characteristics.

  In the agglomeration step, the resin particle dispersion and the colorant particle dispersion are agglomerated in advance to form first agglomerated particles, and then the resin particle dispersion or another resin particle dispersion is further added. It is also possible to form a second shell layer on the surface of one particle. In this illustration, the colorant dispersion is prepared separately, but naturally the colorant may be blended in advance with the resin particles in the resin particle dispersion.

  The formation method of the aggregated particles in the present invention is not particularly limited, and a known aggregation method conventionally used in the emulsion polymerization aggregation method of toner for developing an electrostatic image, for example, temperature increase, pH change, salt addition For example, a method of reducing the stability of the emulsion by a method such as stirring with a disperser or the like is used. Further, after the agglomeration treatment, the particle surface may be cross-linked by heat treatment or the like for the purpose of suppressing leaching of the colorant from the particle surface. In addition, you may remove the used surfactant etc. by water washing | cleaning, acid washing | cleaning, or alkali washing | cleaning as needed.

In the present invention, a known charge control agent used for this type of toner may be used in the method for producing an electrostatic charge image developing toner, if necessary. You may add as an aqueous dispersion etc. at the time of the manufacture start of emulsion, the polycondensation start, or the aggregation start of the said resin particle.
The addition amount of the charge control agent is preferably 1 to 25 parts by weight, more preferably 5 to 15 parts by weight with respect to 100 parts by weight of the monomer and the polymer.
Examples of the charge control agent include positive charge control agents such as nigrosine dyes, quaternary ammonium salt compounds, triphenylmethane compounds, imidazole compounds, and polyamine resins, or chromium, cobalt, aluminum, Loads of metal-containing azo dyes such as iron, metal salts and metal complexes of hydroxycarboxylic acids such as salicylic acid or akilsalicylic acid and benzylic acid, such as chromium, zinc and aluminum, amide compounds, phenolic compounds, naphtholic compounds and phenolamide compounds Known materials such as an electric charge control agent can be used.

In the method for producing an electrostatic charge image developing toner according to the present invention, known waxes used for this type of toner may be used as a release agent, if necessary. In that case, the release agent may be added as an aqueous dispersion or the like at the start of production of the emulsion, at the start of polymerization, or at the start of aggregation of the polymer particles. The amount of the release agent to be used is preferably 1 to 25 parts by weight, more preferably 5 to 15 parts by weight with respect to 100 parts by weight of the monomer and the polymer.
Examples of the release agent include polyolefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and ethylene-propylene copolymers, plant waxes such as paraffin wax, hydrogenated castor oil, carnauba wax, rice wax, and stearic acid. Higher fatty acid ester waxes such as esters, behenic acid esters and montanic acid esters, higher alcohols such as alkyl-modified silicones and higher fatty acid stearyl alcohols such as stearic acid, higher fatty acid amides such as oleic acid amide and stearic acid amide, distearyl ketone A known product such as a ketone having a long-chain alkyl group such as can be used.

  Furthermore, in the method for producing the toner for developing an electrostatic charge image, various known internal additives such as antioxidants and ultraviolet absorbers used for this type of toner may be used as necessary.

<Addition polymerization resin particle dispersion>
In addition to the resin particle dispersion, addition polymerization resin particle dispersions prepared using conventionally known emulsion polymerization and the like can be used together. The median diameter of the resin particles in the addition polymerization resin particle dispersion that can be used in the present invention is preferably 0.05 to 2.0 μm, similarly to the resin particle dispersion.

  As addition polymerization monomers for preparing these addition polymerization resin particle dispersions, known monomers can be used and are not limited. In the case of an addition polymerization monomer, a resin particle dispersion can be prepared by carrying out emulsion polymerization using an ionic surfactant or the like. If it is an oily resin with relatively low solubility in water and can be dissolved in a solvent, the resin is dissolved in the solvent, and the particles are dispersed in an aqueous medium by a disperser such as a homogenizer together with an ionic surfactant or polymer electrolyte. The resin particle dispersion can be obtained by dispersing and then heating or reducing the pressure to evaporate the solvent. Moreover, a polymerization initiator and a chain transfer agent can also be used at the time of superposition | polymerization of an addition polymerization type monomer.

<Colorant>
In the present invention, examples of the colorant that can be used in the toner for developing an electrostatic image include carbon black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, Watch Young Red, Permanent Red, Brilliantamine 3B, Brilliantamine 6B, Daypon Oil Red, Pyrazolone Red, Risor Red, Rhodamine B Lake, Lake Red C Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Various pigments such as phthalocyanine blue, phthalocyanine green, malachite green oxalate, titanium black, acridine, xanthene , Azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, thioindico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, thiazine And various dyes such as those based on thiazole, thiazole and xanthene. Specific examples of the colorant include carbon black, nigrosine dye (C.I. No. 50415B), aniline blue (C.I.No. 50405), and calco oil blue (C.I.No. azoic). Blue 3), chrome yellow (C.I. No. 14090), ultramarine blue (C.I.No. 77103), DuPont oil red (C.I.No. 26105), quinoline yellow (C.I.No. 47005), methylene blue chloride (C.I.No. 52015), phthalocyanine blue (C.I.No. 74160), malachite green oxalate (C.I.No. 42000), lamp black (C.I.No. 77266), Rose Bengal (C.I. No. 45435), mixtures thereof, etc. It can be used well.

  As a method for dispersing the colorant, an arbitrary method, for example, a general dispersion method such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, or a dyno mill can be used, and the method is not limited at all. These colorant particles may be added to the mixed solvent at the same time as other particle components, or may be divided and added in multiple stages.

The amount of the colorant used is preferably 0.1 to 20 parts by weight, particularly 0.5 to 10 parts by weight, based on 100 parts by weight of the toner.
The amount of the colorant is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 40 parts by weight, and particularly preferably 1 to 25 parts by weight with respect to 100 parts by weight of the polyester resin.

  In the present invention, the electrostatic image developing toner may contain a magnetic material or a property improving agent as required. Examples of the magnetic material include ferritic metals such as ferrite and magnetite, metals such as cobalt and nickel, alloys, and compounds containing these elements. Or, an alloy that does not contain a ferromagnetic element but exhibits ferromagnetism by applying an appropriate heat treatment, such as a Heusler alloy containing manganese and copper such as manganese-copper-aluminum, manganese-copper-tin, etc. Or an alloy of chromium dioxide.

  For example, in the case of obtaining a black toner, it is preferable to use magnetite which is black in itself and also functions as a colorant. In the case of obtaining a color toner, a toner with less blackness such as metallic iron is preferable. Some of these magnetic materials also function as a colorant, and in that case, they may be used as a colorant. When the magnetic toner is used, the content of these magnetic materials is preferably 20 to 70 parts by weight, more preferably 40 to 70 parts by weight per 100 parts by weight of the toner.

Examples of the property improver include a fixability improver and a charge control agent.
Examples of fixing improvers include polyolefins, fatty acid metal salts, fatty acid esters and fatty acid ester waxes, partially saponified fatty acid esters, higher fatty acids, higher alcohols, fluid or solid paraffin waxes, polyamide waxes, and polyhydric alcohol esters. Silicon varnish, aliphatic fluorocarbon, and the like can be used. In particular, a wax having a softening point (ring and ball method: JIS K2531) of 60 to 150 ° C. is preferable.
Known charge control agents can be used, and examples include nigrosine dyes and metal-containing dyes.

Further, in the present invention, the electrostatic image developing toner is preferably used by mixing inorganic particles such as a fluidity improver. The inorganic particles used in the present invention are particles having a primary particle diameter of 5 nm to 2 μm, preferably 5 nm to 500 nm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion mixed with the toner is 0.01 to 5% by weight, preferably 0.01 to 2.0% by weight.
Examples of such inorganic particles include silica powder, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, Examples thereof include chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Silica powder is particularly preferable.

The silica powder here is a powder having a Si—O—Si bond, and includes both those produced by a dry method and a wet method. In addition to anhydrous silicon dioxide, any of aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, zinc silicate, and the like may be used, but those containing SiO _{2 in an amount} of 85% by weight or more are preferable. Specific examples of these silica powders include various commercially available silicas, and those having a hydrophobic group on the surface are preferred. For example, AEROSIL R-972, R-974, R-805, R-812 (above Aerosil) Product), Thalax 500 (manufactured by Talco), and the like.
In addition, silica powder treated with a silane coupling agent, a titanium coupling agent, silicon oil, silicon oil having an amine in the side chain, or the like can be used.

In the present invention, the cumulative volume average particle diameter D ₅₀ of the toner for developing an electrostatic charge image is preferably 3.0 to 9.0 μm, and more preferably 3.0 to 5.0 μm. Within the above numerical range, the adhesion is moderate, the developability is good, and the resolution of the image is excellent.

  Further, the volume average particle size distribution index GSDv of the electrostatic image developing toner is preferably 1.30 or less, more preferably 1.24 or less, and further preferably 1.20 or less. When GSDv is 1.30 or less, the resolution is excellent, and image defects such as toner scattering and fogging are less likely to occur.

Here, the cumulative volume average particle size D ₅₀ and the average particle size distribution index GSDv are measured with a measuring instrument such as Coulter Counter TAII (manufactured by Beckman Coulter, Inc.) or Multisizer II (manufactured by Beckman Coulter, Inc.). The cumulative distribution is drawn from the smaller diameter side to the particle size range (channel) divided on the basis of the particle size distribution, and the cumulative particle size is 16% of the volume D _16v and the number D _16P The particle size to be 50% is _defined as volume D _50v and number D _50P , and the particle size to be accumulated 84% is defined as volume D _84v and number D _84P . Using these, the volume average particle size distribution index (GSDv) is calculated as (D _84v / D _16V ) ^1/2 and the number average particle size distribution index (GSDp) is calculated as (D _84P / D _16P ) ^1/2 .

  The shape factor SF1 of the toner for developing an electrostatic charge image is preferably from 100 to 140, more preferably from 110 to 135, from the viewpoint of image formability. The shape factor SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope image with an image analyzer. For example, the shape factor SF1 is measured by taking an optical microscope image of toner spread on a slide glass into a Luzex image analyzer through a video camera, calculating SF1 of the following formula for 50 or more toners, and obtaining an average value. Is obtained.

  Here, ML is the absolute maximum length of the toner particles, and A is the projected area of the toner particles.

The obtained toner is dried for the purpose of imparting fluidity and improving cleaning properties, and then dried with inorganic particles such as silica, alumina, titania, calcium carbonate, and resin particles such as vinyl resin, polyester resin, and silicon. And added to the surface of the toner particles while being sheared.
Further, when adhering to the toner surface in an aqueous medium, examples of inorganic particles include silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate and the like, which are commonly used as external additives on the toner surface. Can be used by dispersing with an ionic surfactant, polymer acid, or polymer base.

<Carrier for developing electrostatic image>
The two-component developer for developing an electrostatic image of the present invention comprises a carrier for developing an electrostatic image having magnetic core particles and a coating resin layer covering the magnetic core particles in addition to the toner for developing electrostatic images. And the resin of the coating resin layer contains nitrogen atoms and / or fluorine atoms, and the coverage of the magnetic core particles by the coating resin layer is 80% or more.

In the case of using an electrostatic charge image developing toner using a polyester resin containing a hydroxy acid and / or a derivative thereof having a total of 3 or more as a monomer unit, there is a concern that the following problems may occur. .
That is, since the polyester resin contained in the toner for developing an electrostatic charge image is introduced with a hydroxy acid having a total of 3 or more hydroxy groups and carboxy groups, the resistance of the resin is lowered and the toner for developing an electrostatic charge image is mixed with a carrier. This is a problem that the resistance value of the two-component developer for developing an electrostatic charge image is lowered and BCO is generated.
In order to satisfy both the suppression of the initial image density variation and the suppression of the BCO at the same time, it is necessary to take measures from the carrier side.

<Carrier material>
In the present invention, the electrostatic image developing carrier has magnetic core particles and a coating resin layer that covers the magnetic core particles.
With this configuration, it is possible to reduce the environmental dependency of the image density of the first printed matter after a long-term pause of a printer or the like, to prevent the occurrence of BCO, and to perform stable image formation over a long period of time. The materials constituting the carrier are described below.

(Magnetic core particles)
Examples of the material for the magnetic core particles include magnetic metals such as iron, steel, nickel, and cobalt, alloys of these magnetic metals with manganese, chromium, rare earths, and magnetic oxides such as ferrite and magnetite. From the viewpoint of using the magnetic brush development method, since the carrier is preferably a magnetic carrier, the magnetic core particle material is also preferably a magnetic material. In particular, as magnetic core particles suitably used in the present invention, ferrite particles are preferable because surface uniformity is easy and chargeability is stable.

The volume average particle diameter of the magnetic core particles is preferably 10 to 500 μm, more preferably 20 to 150 μm, and further preferably 30 to 100 μm.
Within the above numerical range, when used in a two-component developer for developing an electrostatic charge image, the adhesion between the toner and the carrier is appropriate, so the toner development amount is also an appropriate amount. In addition, a fine image can be formed.

  As for the magnetic force of the magnetic core particle, the saturation magnetization at 1,000 oersted is preferably 50 emu / g or more, and more preferably 60 emu / g or more. A saturation magnetization of 50 emu / g or more is preferable because the carrier and toner are not developed on the photoreceptor.

  As a magnetic property measuring device, a vibration sample type magnetic measuring device VSMP10-15 (manufactured by Toei Industry Co., Ltd.) can be preferably used. The measurement sample is packed in a cell having an inner diameter of 7 mm and a height of 5 mm and set in the apparatus. The measurement applies an applied magnetic field and sweeps up to 1,000 oersted. Next, the applied magnetic field is decreased to create a hysteresis curve on the recording paper. Saturation magnetization, residual magnetization, and coercive force are obtained from the curve data. In the present invention, saturation magnetization refers to magnetization measured in a 1,000 oersted magnetic field.

The volume electrical resistance (volume resistivity) of the magnetic core particles is preferably in the range of 10 ⁵ to 10 ^9.5 Ω · cm, and more preferably in the range of 10 ⁷ to 10 ⁹ Ω · cm. When the volume electric resistance is within the above numerical range, even when the toner concentration in the developer is reduced by repeated copying, no charge is injected into the carrier, and the carrier itself is developed. It is preferable because it is not present. In addition, it is preferable because an outstanding edge effect and pseudo contour can be suppressed.

The volume electrical resistance (Ω · cm) of the magnetic core particles is measured as follows. The measurement environment is a temperature of 20 ° C. and a humidity of 50% RH. A measurement object is placed flat on the surface of a circular jig having a 20 cm ² electrode plate so as to have a thickness of about 1 to 3 mm to form a layer. A 20 cm ² electrode plate similar to that described above is placed thereon and the layer is sandwiched. In order to eliminate gaps between objects to be measured, a thickness (cm) of the layer is measured after a load of 4 kg is applied on the electrode plate placed on the layer. Both electrodes above and below the layer are connected to an electrometer and a high voltage power generator. A high voltage is applied to both electrodes so that the electric field is 10 ^3.8 V / cm, and the current value (A) flowing at this time is read to calculate the volume electrical resistance (Ω · cm) of the measurement object. The calculation formula of the volume electrical resistance (Ω · cm) of the measurement object is as shown in the following formula.
Formula: R = E × 20 / (I−I ₀ ) / L
In the above formula, R is the volume electric resistance (Ω · cm) of the measurement object, E is the applied voltage (V), I is the current value (A), I ₀ is the current value (A) at the applied voltage of 0 V, and L is Each layer thickness (cm) is expressed. A coefficient of 20 represents the area (cm ² ) of the electrode plate.

(Coating resin layer)
In the present invention, the coating resin layer covering the magnetic core particles used for the electrostatic image developing carrier is not particularly limited as long as it contains nitrogen atoms and / or fluorine atoms and has thermoplasticity. It can be appropriately selected depending on the case. The thermoplastic resin may be a polymer of a single monomer or a copolymer with other monomers as long as the resulting resin is thermoplastic.

In the present invention, it is preferable to use a copolymer of a compound having an ethylenically unsaturated group and a compound having an ethylenically unsaturated group containing a nitrogen atom and / or a fluorine atom as the resin forming the coating resin layer. it can.
Examples of the compound having an ethylenically unsaturated group include methyl (meth) acrylate, styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2 , 4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, 2,4,5-trimethylstyrene, 2,4,6-trimethylstyrene, pn-butyl Styrene, pt-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, 3,4-di Examples include chlorostyrene and potassium styrenesulfonate.
A compound having two or more ethylenically unsaturated groups can also be used. For example, divinylbenzene, divinyltoluene, ethylene glycol di (meth) acrylate, ethylene oxide di (meth) acrylate, tetraethylene oxide di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) Acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, and the like. Among them, a compound having a (meth) acryloyl group is preferable, and methyl (Meth) acrylate is more preferred.
Examples of the compound having an ethylenically unsaturated group containing a nitrogen atom and / or a fluorine atom include dimethylaminoethyl (meth) acrylate, dimethylamino (meth) acrylate, dimethylaminomethyl (meth) acrylate, and diethylaminomethyl (meth). Compounds having nitrogen atoms including nitrogen atom-containing (meth) acrylic monomers such as acrylate, dimethyl (meth) acrylamide, isopropyl (meth) acrylamide, (meth) acryloylmorpholine and derivatives thereof, and perfluorooctylethyl (meth) ) Compounds having a fluorine atom such as acrylate, polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene and the like can be mentioned.
Among them, a compound having a methacryloyl group is preferable, and dimethylaminoethyl methacrylate and perfluorooctylethyl methacrylate can be preferably used.

The compound having an ethylenically unsaturated group containing a nitrogen atom and / or a fluorine atom is preferably contained in an amount of 0.1 to 80% by weight, and 0.5 to 60% by weight, based on the entire resin forming the coating resin layer. It is more preferable that it is contained, and it is further more preferable that 1 to 40% by weight is contained.
Within the above numerical range, the charge amount of the carrier due to the friction between the toner and the carrier can be stably obtained on the positive electrode side. As a result, since the negative charge amount of the toner can be stably obtained, the image density during printing can be easily made constant, and the occurrence of fogging in the non-image portion can be prevented. In addition, since the surface energy of the coating resin layer can be kept low, the adhesion of the toner to the resin-coated carrier is reduced, and toner impact can be prevented. This is preferable because it is possible to prevent a decrease in image density, to make it easy to make the image density constant during printing, and to prevent the occurrence of fogging in the non-image area.

As a method for polymerizing the compound having an ethylenically unsaturated group, a known polymerization method such as a method using a radical polymerization initiator, a self-polymerization method by heat, or a method using ultraviolet irradiation can be employed. In this case, as a method using a radical polymerization initiator, radical polymerization initiators include oil-soluble and water-soluble ones, but both initiators can be used.
As the radical polymerization initiator, known radical polymerization initiators can be appropriately selected and used. Specifically, 2,2′-azobis (2-methylpropionitrile), 2,2′-azobis ( 2-methylbutyronitrile), 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4) -Methoxyvaleronitrile), 1,1′-azobis (cyclohexanecarbonitrile), azobisnitriles such as 2,2′-azobis (2-amidinopropane) hydrochloride, acetyl peroxide, octanoyl peroxide, 3, Diacyl such as 5,5-trimethylhexanoyl peroxide, decanoyl peroxide, lauroyl peroxide, benzoyl peroxide Dialkyl peroxides such as peroxide, di-t-butyl peroxide, t-butyl-α-cumyl peroxide, dicumyl peroxide, t-butyl peroxyacetate, α-cumyl peroxypivalate, t-butylperoxide Peroxy octoate, t-butyl peroxyneodecanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, di-t-butyl peroxyphthalate, di-t-butyl peroxyisophthalate, etc. Hydroperoxides such as oxyesters, t-butyl hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, cumene hydroperoxide, di-isopropylbenzene hydroperoxide, t-butyl peroxyisopropyl carbonate Radical polymerization initiators such as organic peroxides such as peroxycarbonates, inorganic peroxides such as hydrogen peroxide, persulfates such as potassium persulfate, sodium persulfate, ammonium persulfate, etc. Azobisnitriles are preferred, and 2,2′-azobisisobutyronitrile is more preferred. A redox polymerization initiator may be used in combination.

  The coating resin layer preferably contains conductive powder as needed for the purpose of controlling resistance or the like. Examples of the conductive powder include metal particles such as gold, silver and copper, carbon black such as ketjen black and acetylene black, semiconductive oxide particles such as titanium oxide and zinc oxide, and titanium oxide, zinc oxide, barium sulfate and boron. Examples thereof include particles whose surfaces such as aluminum oxide and potassium titanate powders are covered with tin oxide, carbon black, metal and the like. These may be used individually by 1 type and may use 2 or more types together. As the conductive powder, carbon black is preferable in terms of good production stability, cost, conductivity, and the like. The type of carbon black is not particularly limited, but carbon black having a DBP oil absorption of about 50 to 250 ml / 100 g is preferable because of excellent production stability.

  The conductive powder preferably has a volume average particle size of 0.5 μm or less, more preferably 0.05 to 0.5 μm, and still more preferably 0.05 to 0.35 μm. It is preferable that the value is within the above numerical range because the conductive powder is less likely to fall off from the coating resin layer and stable chargeability is obtained.

  The volume average particle diameter of the conductive powder can be measured using a laser diffraction particle size distribution measuring device (LA-920: manufactured by Horiba, Ltd.). As a measurement method, 2 g of a measurement sample is added to a surfactant, preferably 50 ml of a 5% aqueous solution of sodium alkylbenzene sulfonate, and dispersed for 2 minutes with an ultrasonic disperser (1,000 Hz) to prepare a sample for measurement. To do. The obtained volume average particle diameter for each channel is accumulated from the smaller volume average particle diameter, and the volume average particle diameter is defined as 50%.

The volume electric resistance of the conductive powder is preferably 10 ¹ to 10 ¹¹ Ω · cm, and more preferably 10 ³ to 10 ⁹ Ω · cm. The volume electrical resistance of the conductive powder can be measured in the same manner as the volume electrical resistance of the magnetic core particles.

  1-50 volume% is preferable with respect to the whole coating resin layer, and, as for content of electroconductive powder, 3-20 volume% is more preferable. Within the above numerical range, the carrier resistance is appropriate, and therefore it is preferable because image loss due to carrier adhesion to the developed image can be suppressed. In addition, since the carrier is not insulated, the carrier easily works as a developing electrode during development. Therefore, it is preferable because the reproducibility of the solid image is excellent, for example, the edge effect can be suppressed when a black solid image is formed.

  Further, the coating resin layer may contain resin particles. Examples of the resin particles include thermoplastic resin particles and thermosetting resin particles. Among these, a thermosetting resin is preferable from the viewpoint of easily increasing the hardness, and from the viewpoint of imparting negative chargeability to the toner, resin particles made of a nitrogen-containing resin containing nitrogen atoms are preferable. In addition, these resin particles may be used individually by 1 type, and may use 2 or more types together.

  The volume average particle diameter of the resin particles is preferably 0.1 to 2.0 μm, more preferably 0.2 to 1.0 μm. Within the above numerical range, it is preferable because the dispersibility of the resin particles in the coating resin layer is good and the resin particles do not fall off from the coating resin layer. The volume average particle diameter of the resin particles can be obtained by performing the same measurement as the volume average particle diameter of the conductive powder.

  The content of the resin particles is preferably 1 to 50% by weight, more preferably 1 to 30% by weight, and still more preferably 1 to 20% by weight with respect to the entire coating resin layer. Within the above numerical range, it is preferable because the effect of the resin particles can be exhibited, and the resin particles do not drop out and stable chargeability is obtained.

  The method for forming the coating resin layer on the surface of the magnetic core particle is not particularly limited. For example, the coating resin layer is formed by containing conductive powder, nitrogen atom and / or fluorine atom-containing (meth) acrylic resin, polycarbonate resin or the like in a solvent. And a method using a working solution. For example, a dipping method in which magnetic core particles are immersed in a film forming liquid, a spray method in which a film forming liquid is sprayed on the surface of the magnetic core particles, and a magnetic core particle is mixed with the film forming liquid in a state of being suspended by flowing air. And a kneader coater method for removing the solvent. Among these, the kneader coater method is preferable in the present invention.

  The solvent used in the coating resin layer forming liquid is not particularly limited as long as it can dissolve only the resin, and can be selected from known solvents. For example, aromatic hydrocarbons such as toluene and xylene; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane;

When resin particles are dispersed in the coating resin layer, since the resin particles are uniformly dispersed in the thickness direction and the tangential direction of the carrier surface, the coating resin layer is worn out by using the carrier for a long period of time. However, it is possible to always maintain the same surface formation as when it is not used, and to maintain a good charge imparting ability for the toner over a long period of time.
In addition, when conductive powder is dispersed in the coating resin layer, the conductive powder is uniformly dispersed in the thickness direction and the tangential direction of the carrier surface. Even if it does, it can always maintain the same surface formation as when it is not used, and carrier deterioration can be prevented for a long time.
In the case where resin particles and conductive powder are dispersed in the coating resin layer, the above-described effects can be achieved simultaneously.
Further, the coating resin layer is not limited to a single layer, and may be composed of two or more layers.

  In the present invention, the content of the coating resin layer in the carrier is preferably in the range of 0.5 to 10 parts by weight, more preferably in the range of 1 to 5 parts by weight, with respect to 100 parts by weight of the magnetic core particles. A range of parts by weight is more preferred. When the content of the coating resin layer is within the range of the above numerical values, the surface exposure of the magnetic core particles is appropriate and the development charge is difficult to be injected. Further, since the resin powder released from the coating resin layer can be reduced, the carrier resin powder peeled off from the initial stage in the developer is not contained.

  The coverage of the surface of the magnetic core particles by the coating resin layer is 80% or more, preferably 85% or more, and is preferably as close as possible to 100%. When the coverage is less than 80%, charge injection into the carrier occurs when used for a long period of time, and the carrier in which the charge injection has occurred moves onto the photoconductor, resulting in white spots on the image. .

In addition, the coverage of a coating resin layer can be calculated | required by XPS measurement. As the XPS measuring apparatus, for example, JPS80 (manufactured by JEOL Ltd.) can be used. The measurement was performed using MgKα ray as an X-ray source, setting the acceleration voltage to 10 kV, and the emission current to 20 mV, and the main elements (usually carbon) constituting the coating resin layer and the main cores constituting the magnetic core particles. Element (for example, iron and oxygen when the magnetic core particle is an iron oxide-based material such as magnetite) is measured.
Hereinafter, a case where the magnetic core particles are iron oxide-based will be described. Here, the C1s spectrum is measured for carbon, the Fe2p _3/2 spectrum is measured for iron, and the O1s spectrum is measured for oxygen.
Based on the spectrum of each of these elements, the number of elements of carbon, oxygen, and iron (A _C + A _O + A _Fe ) is obtained, and the following formula (I) is obtained from the obtained number ratio of the elements of carbon, oxygen, and iron. Based on this, the iron content rate after the magnetic core particles and the magnetic core particles were coated with the coating resin layer (carrier) was determined. Subsequently, the coverage was determined by the following formula (II).
Formula (I): Iron content rate (atomic%) = A _Fe / (A _C + A _O + A _Fe ) × 100
Formula (II): Coverage rate (%) = {1- (iron content rate of carrier) / (iron content rate of magnetic core particle alone)} × 100
When a material other than iron oxide is used as the magnetic core particle, the spectrum of the metal element constituting the magnetic core particle in addition to oxygen is measured, and according to the above formulas (I) and (II) If a similar calculation is performed, the coverage can be obtained.

The average film thickness of the coating resin layer is preferably 0.1 to 10 μm, more preferably 0.1 to 3.0 μm, and still more preferably 0.1 to 1.0 μm.
It is preferable for it to be within the above numerical value range since peeling of the coating resin layer can be suppressed during long-time use. Moreover, it is preferable because the time required to reach the saturation charge amount can be shortened.

The average film thickness (μm) of the coating resin layer is such that the true specific gravity of the magnetic core particles is ρ (dimensionless), the volume average particle diameter of the magnetic core particles is d (μm), the average specific gravity of the coating resin layer is ρ _C , and magnetic When the total content of the coating resin layer with respect to 100 parts by weight of the core particles is W _C (parts by weight), it can be obtained as in the following formula (III).
Formula (III): Average film thickness (μm) = [amount of coating resin per carrier (including all additives such as conductive powder) / surface area per carrier] / average specific gravity of coating resin layer = {[ 4 / 3π · (d / 2) ³ · ρ · W _C ] / [4π · (d / 2) ² ]} / ρ _C
= (1/6) · (d · ρ · W _C / ρ _C )

<Characteristics for electrostatic image development>
An electrostatic charge image developing carrier is obtained using the magnetic core particles and the coating resin, and the weight average particle diameter of the carrier is preferably 15 to 50 μm, and more preferably 25 to 40 μm. It is preferable that the weight average particle diameter of the carrier is in the above numerical range because carrier contamination can be suppressed. Further, it is preferable because toner deterioration due to stirring can be suppressed.

  The weight average particle diameter of the carrier can be measured using a laser diffraction / scattering particle size distribution analyzer (LS Particle Size Analyzer: LS13 320, manufactured by Beckman Coulter, Inc.). For the particle size range (channel) obtained by dividing the obtained particle size distribution, the volume cumulative distribution is subtracted from the small particle size side, and the particle size at 50% cumulative is taken as the volume average particle size.

Also, the shape factor SF1 of the carrier is preferably 100 to 145. This is to achieve both high image quality and developer agitation efficiency. The carrier shape factor SF1 means a value obtained by the following equation.
SF1 = 100π × (ML) ² / (4 × A)
Here, ML is the maximum length of the carrier particles, and A is the projected area of the carrier particles. The maximum carrier particle length and projected area are determined by observing the carrier particles sampled on the slide glass with an optical microscope and importing them into an image analyzer (LUZEX III, manufactured by Nireco Corporation) through a video camera. It is obtained by doing. The number of samplings at this time is 100 or more, and the shape factor is obtained using the average value.

The saturation magnetization of the carrier is preferably 40 emu / g or more, and more preferably 50 emu / g or more.
As a magnetic property measuring device, a vibrating sample type magnetic measuring device VSMP10-15 (manufactured by Toei Industry Co., Ltd.) can be used. The measurement sample is packed in a cell having an inner diameter of 7 mm and a height of 5 mm and set in the apparatus. The measurement applies an applied magnetic field and sweeps up to 1,000 oersted. Next, the applied magnetic field is decreased to create a hysteresis curve on the recording paper. From the curve data, saturation magnetization, residual magnetization, and coercive force can be obtained. In the present invention, saturation magnetization refers to magnetization measured in a 1,000 oersted magnetic field.

The volume electric resistance of the carrier is preferably controlled in the range of 1 × 10 ⁷ to 1 × 10 ¹⁵ Ω · cm, more preferably in the range of 1 × 10 ⁸ to 1 × 10 ¹⁴ Ω · cm, More preferably, it is in the range of 1 × 10 ⁸ to 1 × 10 ¹³ Ω · cm.
If the volume electrical resistance of the carrier is within the above numerical range, the volume electrical resistance will be appropriate, and it will be easier to work as a developing electrode during development. Excellent. In addition, since the charge is not injected from the developing roll into the carrier when the toner concentration in the developer is lowered, a problem that the carrier itself is developed is less likely to occur. The volume electrical resistance of the carrier can be measured in the same manner as the volume electrical resistance of the magnetic core particles.

<Two-component developer for electrostatic image development>
The electrostatic image developing toner obtained by the method for producing an electrostatic image developing toner described above is used as one component of the two-component developer for developing an electrostatic image. As the electrostatic image developing toner, an electrostatic image developing toner based on a polyester resin containing a monomer unit derived from a hydroxy acid and / or a derivative thereof having a total of 3 or more hydroxy groups and carboxy groups is used.
This two-component developer for developing an electrostatic charge image contains not only the toner for developing an electrostatic charge image but also a two-component developer for developing an electrostatic charge image by using it in combination with the carrier for developing an electrostatic charge image. Is done.

  The mixing ratio of the electrostatic image developing toner and the electrostatic image developing carrier is preferably 2 to 10 parts by weight of the electrostatic image developing toner with respect to 100 parts by weight of the electrostatic image developing carrier. The method for preparing the two-component developer for developing an electrostatic charge image is not particularly limited, and examples thereof include a method of mixing with a V blender or the like.

<Image Forming Method, Image Forming Apparatus>
The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and developing the latent image on the electrostatic latent image carrier with a developer containing toner. A two-component developer for developing an electrostatic charge image according to the present invention, comprising: an image forming step for forming a toner image; a step for transferring the toner image; and a fixing step for fixing the toner image. It is characterized by using.
The image forming apparatus of the present invention includes an electrostatic latent image holding member, a charging unit that charges the electrostatic latent image holding member, and the charged electrostatic latent image holding member (synonymous with an electrophotographic photosensitive member). An exposure unit that exposes and forms an electrostatic latent image on the electrostatic latent image holding member; a developing unit that develops the electrostatic latent image with a developer containing toner to form a toner image; and the toner image And a transfer means for transferring the toner from the electrostatic latent image holding member to the transfer medium, and the two-component developer for developing an electrostatic charge image of the present invention is used as the developer.

The image forming method and the image forming apparatus of the present invention will be described below with reference to FIGS.
FIG. 1 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of an image forming apparatus of the present invention. An image forming apparatus 200 illustrated in FIG. 1 includes an electrophotographic photosensitive member 207, a charging device 208 that charges the electrophotographic photosensitive member 207, a power source 209 connected to the charging device 208, and an electrophotographic image that is charged by the charging device 208. An exposure device 210 that exposes the photosensitive member 207 to form an electrostatic latent image, a developing device 211 that develops the electrostatic latent image formed by the exposure device 210 with toner, and forms a toner image, and a developing device 211 The image forming apparatus includes a transfer device 212 that transfers the formed toner image to a transfer medium (image output medium) 500, a cleaning device 213, a static eliminator 214, and a fixing device 215. In this case, the static eliminator 214 may not be provided.

  Here, the charging device 208 is of a type (contact charging type) in which the surface of the electrophotographic photosensitive member 207 is brought into contact with a charging roll as a conductive member to charge the surface of the photosensitive member 207.

  In the present invention, when the photosensitive member is charged using the charging roll, a voltage is applied to the charging roll. The applied voltage may be a DC voltage or a DC voltage in which an AC voltage is superimposed.

  As the exposure apparatus 210, an optical system apparatus that can expose a light source such as a semiconductor laser, an LED (light emitting diode), and a liquid crystal shutter on the surface of the electrophotographic photosensitive member in a desired image-like manner can be used.

  As the developing device 211, the two-component developer for developing an electrostatic image of the present invention is used as a two-component developer.

  Examples of the transfer device 212 include a roller-type contact charging member, a contact-type transfer charger using a belt, a film, a rubber blade, or the like, or a scorotron transfer charger or a corotron transfer charger using corona discharge. It is done.

The transfer device 212 is capable of supplying a current having a predetermined current density toward the electrophotographic photosensitive member when the toner image formed on the electrophotographic photosensitive member 207 is transferred to the transfer medium 500. Is preferred.
Examples of the transfer medium 500 that can be used in the image forming apparatus of the present invention include neutral paper, resin-coated paper, plastic films such as polyethylene and PET, among which neutral paper and resin-coated paper are preferable.

  The cleaning device 213 is for removing residual toner adhering to the surface of the electrophotographic photosensitive member after the transfer process. The cleaned electrophotographic photosensitive member is repeatedly used for the image forming process described above. . As the cleaning device, brush cleaning, roll cleaning, and the like can be used in addition to the cleaning blade. Among these, it is preferable to use the cleaning blade. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicon rubber.

  Further, the image forming apparatus of the present invention may further include a light irradiation device as the static eliminator 214 as shown in FIG. As a result, when the electrophotographic photosensitive member is repeatedly used, the phenomenon that the residual potential of the electrophotographic photosensitive member is brought into the next cycle is prevented, so that the image quality can be further improved.

  FIG. 2 is a sectional view schematically showing the basic configuration of another preferred embodiment of the image forming apparatus of the present invention. The image forming apparatus 201 shown in FIG. 2 transfers the toner image formed on the electrophotographic photosensitive member 207 to the primary transfer member 212a and then supplies it between the primary transfer member 212a and the secondary transfer member 212b. A transfer device of an intermediate transfer system for transferring to a transfer medium (image output medium) 500 to be transferred, and at the time of such transfer, a current having a predetermined current density from the primary transfer member 212a toward the electrophotographic photosensitive member. Can be supplied. Although not shown in FIG. 2, the image forming apparatus 201 may further include a static eliminator similarly to the image forming apparatus 200 shown in FIG. 1. Other configurations of the image forming apparatus 201 are the same as those of the image forming apparatus 200.

  In such an image forming apparatus 201, when a toner image formed on the electrophotographic photosensitive member 207 is transferred to the primary transfer member 212a, a predetermined current density is transferred from the primary transfer member 212a toward the electrophotographic photosensitive member 207. By supplying this current, fluctuations in the transfer current due to the type and material of the transfer medium 500 can be suppressed, so that the amount of charge flowing into the electrophotographic photosensitive member 207 can be accurately controlled. Become. As a result, it is possible to achieve higher image quality and reduced environmental burden at a higher level.

  FIG. 3 is a sectional view schematically showing the basic configuration of another preferred embodiment of the image forming apparatus of the present invention. An image forming apparatus 220 shown in FIG. 3 is an intermediate transfer type image forming apparatus. In the housing 400, four electrophotographic photoreceptors 401a to 401d (for example, the electrophotographic photoreceptor 401a is yellow and the electrophotographic photoreceptor 401b is magenta). The electrophotographic photosensitive member 401c can form an image of cyan and the electrophotographic photosensitive member 401d can form a black color) are arranged in parallel along the intermediate transfer belt 409. Here, the electrophotographic photoreceptors 401a to 401d mounted on the image forming apparatus 220 are respectively electrophotographic photoreceptors.

  Each of the electrophotographic photosensitive members 401a to 401d can be rotated in a predetermined direction (counterclockwise on the paper surface), and the charging rolls 402a to 402d, the developing devices 404a to 404d, and the primary transfer roll 410a along the rotation direction. 410d and cleaning blades 415a to 415d are arranged. Each of the developing devices 404a to 404d can be supplied with toners of four colors of black, yellow, magenta and cyan accommodated in toner cartridges 405a to 405d. Further, the primary transfer rolls 410a to 410d are in contact with the electrophotographic photosensitive members 401a to 401d via the intermediate transfer belt 409, respectively.

  Further, a laser light source (exposure device) 403 is disposed at a predetermined position in the housing 400, and the surfaces of the electrophotographic photoreceptors 401a to 401d after charging are irradiated with laser light emitted from the laser light source 403. Is possible. Accordingly, charging, exposure, development, primary transfer, and cleaning are sequentially performed in the rotation process of the electrophotographic photoreceptors 401a to 401d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 409 in an overlapping manner.

  The intermediate transfer belt 409 is supported with a predetermined tension by a drive roll 406, a backup roll 408, and a tension roll 407, and can rotate without causing deflection due to the rotation of these rolls. Further, the secondary transfer roll 413 is disposed so as to contact the backup roll 408 via the intermediate transfer belt 409. The intermediate transfer belt 409 passing between the backup roll 408 and the secondary transfer roll 413 is cleaned by, for example, a cleaning blade 416 disposed in the vicinity of the drive roll 406 and then repeatedly used for the next image forming process. Is done.

  A tray (transfer medium tray) 411 is provided at a predetermined position in the housing 400, and the transfer medium 500 such as paper in the tray 411 is moved by the intermediate transfer belt 409 and the secondary transfer roll by the transfer roll 412. Then, the paper is sequentially transferred between the two fixing rolls 414 that are in contact with each other and the two fixing rolls 414, and then discharged to the outside of the housing 400.

  In the above description, the case where the intermediate transfer belt 409 is used as the intermediate transfer member has been described. However, the intermediate transfer member may have a belt shape or a drum shape like the intermediate transfer belt 409. Also good. Conventionally known resins can be used as the resin material used as the base material of the intermediate transfer member in the belt shape. For example, polyimide resin, polycarbonate resin (PC), polyvinylidene fluoride (PVDF), polyalkylene terephthalate (PAT), ethylenetetrafluoroethylene copolymer (ETFE) / PC, ETFE / PAT, PC / PAT blend material, polyester Examples thereof include resin materials such as resin, polyether ether ketone, and polyamide, and resin materials using these as main raw materials. Furthermore, a resin material and an elastic material can be blended and used.

  Elastic materials include polyurethane, chlorinated polyisoprene, NBR (nitrile rubber), chloropyrene rubber, EPDM (ethylene-propylene-diene rubber), hydrogenated polybutadiene, butyl rubber, silicone rubber, etc., or a blend of two or more. The material formed can be used. If necessary, a conductive agent imparting electronic conductivity or a conductive agent having ionic conductivity is added to the resin material and elastic material used for these base materials in combination of one kind or two or more kinds. Among these, it is preferable to use a polyimide resin in which a conductive agent is dispersed from the viewpoint of excellent mechanical strength. As the conductive agent, a conductive polymer such as carbon black, metal oxide, or polyaniline can be used.

  When a belt-shaped configuration such as the intermediate transfer belt 409 is employed as the intermediate transfer member, the thickness of the belt is generally preferably 50 to 500 μm and more preferably 60 to 150 μm, but is appropriately selected according to the hardness of the material. be able to.

  For example, a belt made of a polyimide resin in which a conductive agent is dispersed is 5 to 20% by weight as a conductive agent in a polyamic acid solution as a polyimide precursor, as described in JP-A-63-111263. After the carbon black is dispersed, the dispersion is cast on a metal drum and dried, and then the film peeled off from the drum is stretched at a high temperature to form a polyimide film. Can be produced.

The film forming is generally performed by injecting a polyamic acid solution film-forming stock solution in which a conductive agent is dispersed into a cylindrical mold and, for example, heating at 100 to 200 ° C. and rotating at a rotational speed of 500 to 2,000 rpm. While rotating the mold, the film was formed into a film by a centrifugal molding method. Then, the obtained film was demolded in a semi-cured state and covered with an iron core, and a polyimide reaction (polyamide) was performed at a high temperature of 300 ° C. It can be carried out by proceeding the acid ring-closing reaction) and carrying out the main curing.
Also, the stock solution is cast on a metal sheet to a uniform thickness and heated to 100 to 200 ° C. in the same manner as above to remove most of the solvent, and then gradually raised to a high temperature of 300 ° C. or higher. There is also a method of forming a polyimide film. Further, the intermediate transfer member may have a surface layer.

  When a drum-shaped configuration is adopted as the intermediate transfer member, it is preferable to use a cylindrical substrate formed of aluminum, stainless steel (SUS), copper, or the like as the substrate. If necessary, an elastic layer can be coated on the cylindrical substrate, and a surface layer can be formed on the elastic layer.

  FIG. 4 is a cross-sectional view schematically showing a preferred embodiment of the cartridge. The cartridge 300 is provided with an electrophotographic photosensitive member 207, a charging device 208 having a charging roll, a cleaning device (cleaning means) 213, an opening portion 218 for exposure, and an opening portion 217 for static elimination exposure together with the developing device 211. 216 is combined and integrated.

  The cartridge 300 is detachable from an image forming apparatus main body including a transfer device 212, a fixing device 215, and other components not shown. The image forming apparatus is mounted together with the image forming apparatus main body. It constitutes.

  EXAMPLES Hereinafter, although this invention is explained in full detail based on an Example, this invention is not limited to this. In the following examples, “parts” means “parts by weight” unless otherwise specified.

<Preparation of Resin P1 and Resin Particle Dispersion L1>
(Preparation of resin P1)
-Bisphenol A ethylene oxide 2 mol adduct 834.3 parts-Bisphenoxyethanol fluorene (BPEF) 326.7 parts-Dimethylol butanoic acid 55.9 parts-1,4-cyclohexanedicarboxylic acid 649.4 parts-Dodecylbenzenesulfonic acid 4.92 parts The above materials were mixed, charged into a reactor equipped with a stirrer, and subjected to polycondensation in an open system for 16 hours so that the resin temperature was 120 ° C. As a result, uniform transparent amorphous polyester resin P1 Got. Thereafter, a small amount of a resin sample was collected, and the following physical properties were measured.
・ GPC weight average molecular weight 22,640
・ Glass transition temperature (onset) 64 ℃

  2.13 parts of triethanolamine was added to the resin P1 obtained as described above, and the mixture was stirred at 120 ° C. for 10 minutes to obtain a resin P1 ′.

The weight average molecular weight Mw and the number average molecular weight Mn were measured by gel permeation chromatography (GPC) under the conditions described below. At a temperature of 40 ° C., a solvent (tetrahydrofuran) was flowed at a flow rate of 1.2 ml / min, and 3 mg of a tetrahydrofuran sample solution having a concentration of 0.2 g / 20 ml was injected as a sample weight for measurement. In measuring the molecular weight of the sample, the measurement conditions were selected so that the molecular weight of the sample was included in a range in which the logarithm of the molecular weight of the calibration curve prepared by several monodisperse polystyrene standard samples and the count number were linear. In addition, the reliability of the measurement results is that the NBS706 polystyrene standard sample performed under the above measurement conditions is
Weight average molecular weight Mw = 28.8 × 10 ⁴
Number average molecular weight Mn = 13.7 × 10 ⁴
Can be confirmed.
As the GPC column, TSK-GEL and GMH (manufactured by Tosoh Corporation) satisfying the above conditions were used. A differential scanning calorimeter (Shimadzu Corporation, DSC-50) was used to measure the glass transition temperature Tg of the polyester resin.

(Preparation of resin particle dispersion L1)
After 11 parts of sodium dodecylbenzenesulfonate and 200 parts of 10% ammonia water were added dropwise to 1,000 parts of the resin P1 ′ obtained as described above, the resin was heated to 90 ° C., 1.5 times the weight of the resin. Heated ion exchange water was added to the resin, and stirring was continued for 2 hours to obtain an aqueous dispersion of polyester resin particles.
Then, the presence or absence of resin dispersion residue in the resin particle dispersion after stirring for 3 minutes was confirmed with a homogenizer (IKA's Ultra Turrax T50). There was no residue, and a resin particle dispersion having a solid content of 40% by weight was obtained.
By the above method, an amorphous polyester resin particle dispersion L1 having a particle central diameter of 180 nm and a pH of 8.1 was obtained. In addition, the particle diameter of the obtained resin particle dispersion was measured with a laser diffraction particle size distribution measuring apparatus (LA-920, manufactured by Horiba, Ltd.).

<Preparation of resin P2 and resin particle dispersion L2>
(Preparation of resin P2)
-Bisphenol A propylene oxide 2-mole adduct 906.7 parts-Dimethylolpropionic acid 153.6 parts-1,4-phenylenediacetic acid 730.5 parts-Octadecylbenzenesulfonic acid 6.18 parts The above materials are mixed and stirred. When the polycondensation was carried out in an open system for 16 hours so that the resin temperature was 120 ° C. in an open system, a uniform transparent amorphous polyester resin P2 was obtained.
A small amount of resin sample was taken and the following physical properties were measured.
・ GPC weight average molecular weight 32,560
・ Glass transition temperature (onset) 64 ℃
2.13 parts of triethanolamine was added to the resin P2 obtained as described above, and the mixture was stirred at 1200 ° C. for 10 minutes to obtain a resin P2 ′.

(Preparation of resin particle dispersion L2)
After 11 parts of sodium dodecylbenzenesulfonate and 200 parts of 10% aqueous ammonia were added dropwise to 1,000 parts of the resin P2 ′ obtained as described above, the mixture was added to 90 ° C., which is 1.5 times the weight of the resin. Warm ion-exchanged water was added to the resin, and stirring was continued for 2 hours to obtain an aqueous dispersion of polyester resin particles. Then, the presence or absence of resin dispersion residue in the resin particle dispersion after stirring for 3 minutes was confirmed with a homogenizer (IKA's Ultra Turrax T50). There was no residue, and a resin particle dispersion having a solid content of 40% by weight was obtained.
By the above method, an amorphous polyester resin particle dispersion L2 having a particle central diameter of 170 nm and a pH of 8.40 was obtained.

<Preparation of resin P3 and resin particle dispersion L3>
(Preparation of resin P3)
-Bisphenol Z ethylene oxide 2 mol adduct 1,286.9 parts-Dimethylol hexanoic acid 26.81 parts-Phenylenediacetic acid 730.5 parts-Dodecyl fluorobenzene sulfonic acid 5.19 parts The polycondensation was carried out for 16 hours so that the resin temperature was 120 ° C. in an open system, and a uniform transparent amorphous polyester resin P3 was obtained. A small amount of resin sample was taken and the following physical properties were measured.
-Weight average molecular weight by GPC 14,950
・ Glass transition temperature (onset) 60 ℃
2.13 parts of triethanolamine was added to the resin P3 obtained as described above, and the mixture was stirred for 10 minutes at 120 ° C. to obtain a resin P3 ′.

(Preparation of resin particle dispersion L3)
After 11 parts of sodium dodecylbenzenesulfonate and 200 parts of 10% aqueous ammonia were added dropwise to 1,000 parts of the resin P3 ′ obtained as described above, the mixture was added to 90 ° C. of 1.5 times the weight of the resin. Warm ion-exchanged water was added to the resin, and stirring was continued for 2 hours to obtain an aqueous dispersion of polyester resin particles.
Then, the presence or absence of resin dispersion residue in the resin particle dispersion after stirring for 3 minutes was confirmed with a homogenizer (IKA's Ultra Turrax T50). There was no residue, and a resin particle dispersion having a solid content of 40% by weight was obtained.
By the above method, an amorphous polyester resin particle dispersion L3 having a particle central diameter of 240 nm and a pH of 7.20 was obtained.

<Preparation of resin P4 and resin particle dispersion L4>
(Preparation of resin P4)
・ Bisphenol A propylene oxide 2 mol adduct 1,165.8 parts ・ Dimethylol octanoic acid 77.57 parts ・ Phenylenediacetic acid 730.5 parts ・ Pentadecyl benzene sulfonic acid 5.57 parts The polycondensation was carried out for 16 hours so that the resin temperature was 120 ° C. in an open system, and a uniform transparent amorphous polyester resin P4 was obtained. A small amount of resin sample was taken and the following physical properties were measured.
・ GPC weight average molecular weight 18,290
・ Glass transition temperature (onset) 60 ℃
2.13 parts of triethanolamine was added to the resin P4 obtained as described above, and the mixture was stirred at 100 ° C. for 10 minutes to obtain a resin P4 ′.

(Preparation of resin particle dispersion L4)
After 11 parts of sodium dodecylbenzenesulfonate and 200 parts of 10% ammonia water were added dropwise to 1,000 parts of the resin P4 ′ obtained as described above, the mixture was added to 90 ° C., which is 1.5 times the weight of the resin. Warm ion-exchanged water was added to the resin, and stirring was continued for 2 hours to obtain an aqueous dispersion of polyester resin particles. Then, the presence or absence of resin dispersion residue in the resin particle dispersion after stirring for 3 minutes was confirmed with a homogenizer (IKA's Ultra Turrax T50). There was no residue, and a resin particle dispersion having a solid content of 40% by weight was obtained.
By the above method, an amorphous polyester resin particle dispersion L4 having a particle central diameter of 180 nm and a pH of 8.0 was obtained.

<Preparation of resin particle dispersion for comparative example>
<Preparation of resin P5 and resin particle dispersion L5>
(Preparation of resin P5)
・ Bisphenol Z ethylene oxide 2 mol adduct 1,313.7 parts ・ Dimethylol hexanoic acid 13.41 parts ・ Phenylenediacetic acid 730.5 parts ・ Dodecylbenzenesulfonic acid 4.91 parts When the polycondensation was carried out for 16 hours so that the resin temperature was 190 ° C. in an open system, a uniform transparent amorphous polyester resin P5 was obtained. A small amount of resin sample was taken and the following physical properties were measured.
・ GPC weight average molecular weight 17,770
・ Glass transition temperature (onset) 65 ℃
2.13 parts of triethanolamine was added to the resin P5 obtained as described above, and the mixture was stirred for 10 minutes at 120 ° C. to obtain a resin P5 ′.

(Preparation of resin particle dispersion L5)
11 parts of sodium dodecylbenzenesulfonate and 200 parts of 10% ammonia water were added dropwise to 1,000 parts of the resin P5 ′ obtained as described above, and then added to 90 ° C. of 1.5 times the weight of the resin. Warm ion-exchanged water was added to the resin, and stirring was continued for 2 hours. Thereafter, stirring was performed for 3 minutes with a homogenizer (manufactured by IKA, Ultra Tarrax T50). The presence or absence of the resin dispersion residue in the resin particle dispersion was confirmed, but not all of the resin was dispersed in water, and a resin dispersion residue was generated. Since the resin particle dispersion could not be prepared by the above method, solvent phase inversion emulsification was performed by the following method to obtain an emulsion.

  After adding 150 parts of ethyl acetate to 300 parts of resin P5 'and dissolving the resin while heating to 50 ° C, 30 parts of isopropyl alcohol was added to obtain a solvent solution of the resin. Thereafter, 14 parts of 10% ammonia water was added dropwise, and then ion-exchanged water was added dropwise at a dropping rate of 8.0 g / min. As a result of solvent phase inversion emulsification, the particle diameter was 150 nm and the pH was 7.4. An amorphous polyester resin particle dispersion L5 was obtained.

<Preparation of Resin P6 and Resin Particle Dispersion L6>
(Preparation of resin P6)
-Bisphenol Z ethylene oxide 2 mol adduct 804.3 parts-Dimethylol hexanoic acid 268.1 parts-Phenylene dipropionic acid 813.4 parts-Dodecylbenzenesulfonic acid 4.91 parts The above materials are mixed and equipped with a stirrer. The polycondensation was carried out for 16 hours so that the resin temperature was 140 ° C. in an open system, and a translucent amorphous polyester resin P6 that was turbid in brown color was obtained. A small amount of resin sample was taken and the following physical properties were measured.
・ GPC weight average molecular weight 44,770
・ Glass transition temperature (onset) 68 ℃
2.13 parts of triethanolamine was added to the resin P6 obtained as described above, and the mixture was stirred at 120 ° C. for 10 minutes to obtain a resin P6 ′.

(Preparation of resin particle dispersion L6)
11 parts of sodium dodecylbenzenesulfonate and 200 parts of 10% aqueous ammonia are added dropwise to 1,000 parts of the resin P6 ′ obtained as described above, and then heated to 90 ° C., which is twice the weight of the resin. The ion-exchanged water was added to the resin, and stirring was continued for 2 hours to obtain an aqueous dispersion of polyester resin particles. Then, after stirring for 3 minutes with a homogenizer (IKA, Ultra Tarrax T50), the presence or absence of resin dispersion residue in the resin particle dispersion was confirmed. There was no residue, and a resin particle dispersion having a solid content of 40% by weight was obtained.
By the above method, an amorphous polyester resin particle dispersion L6 having a particle central diameter of 140 nm and a pH of 7.20 was obtained.

(Preparation of resin P7)
The same material as P4 was used except that 4.21 parts of dibutyltin oxide was used instead of dodecylbenzenesulfonic acid when obtaining the resin P4.
The above materials were mixed, put into a reactor equipped with a stirrer, and subjected to polycondensation in an open system for 28 hours so that the resin temperature was 220 ° C. As a result, a translucent non-crystalline polyester resin clouded in brown P7 was obtained. A small amount of resin sample was taken and the following physical properties were measured.
・ GPC weight average molecular weight 19,770
・ Glass transition temperature (onset) 64 ℃
2.13 parts of triethanolamine was added to the resin P7 obtained as described above, and the mixture was stirred for 10 minutes at 120 ° C. to obtain a resin P7 ′.

(Preparation of resin particle dispersion L7)
11 parts of sodium dodecylbenzenesulfonate and 200 parts of 10% aqueous ammonia are added dropwise to 1,000 parts of the resin P7 ′ obtained as described above, and then heated to 90 ° C., which is twice the weight of the resin. The ion-exchanged water was added to the resin, and stirring was continued for 2 hours to obtain an aqueous dispersion of polyester resin particles. Then, the presence or absence of resin dispersion residue in the resin particle dispersion after stirring for 3 minutes was confirmed with a homogenizer (IKA's Ultra Turrax T50). There was no residue, and a resin particle dispersion having a solid content of 40% by weight was obtained.
By the above method, an amorphous polyester resin particle dispersion L7 having a particle central diameter of 180 nm and a pH of 7.40 was obtained.

In preparing the toner using the resin particle dispersions L1 to L7 prepared as described above as raw materials, the following release agent particle dispersion W1 and colorant dispersions C1 and Y1 were prepared.
(Preparation of release agent particle dispersion W1)
・ 30 parts of polyethylene wax (Toyo Petrolite Co., Ltd., Polywax 725, melting point 103 ° C.)
・ Cationic surfactant (manufactured by Kao Corporation, Sanizol B50) 3 parts ・ Ion-exchanged water 67 parts After thoroughly dispersing the above ingredients while heating to 95 ° C. with a homogenizer (IKA, Ultra Turrax T50) Then, dispersion treatment was performed using a pressure discharge type homogenizer (Gorin homogenizer manufactured by Gorin Co., Ltd.) to prepare a release agent particle dispersion (W1). The number average particle diameter D _50n of the release agent particles in the obtained dispersion was 460 nm. Thereafter, ion exchange water was added to adjust the solid content concentration of the dispersion to 30% by weight.

(Preparation of magenta pigment dispersion M1)
・ Magenta pigment 20 parts (Daiichi Ink Chemical Co., Ltd., CI Pigment Red)
-Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) 2 parts-78 parts of ion-exchanged water The above components were prepared to obtain a magenta pigment dispersion M1. The number average particle diameter D _50n of the pigment in the dispersion was 165 nm. Thereafter, ion exchange water was added to adjust the solid content concentration to 15% by weight.

(Preparation of cyan pigment dispersion C1)
20 parts of cyan pigment (Daiichi Seika Kogyo Co., Ltd., CI Pigment Blue 15: 3)
-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) 2 parts-Ion-exchanged water 78 parts The above components were prepared in the same manner as the magenta pigment dispersion M1 to obtain a cyan pigment dispersion. . The number average particle diameter D _50n of the pigment in the dispersion was 121 nm. Thereafter, ion exchange water was added to adjust the solid content concentration of the dispersion to 15% by weight.

(Preparation of yellow pigment dispersion Y1)
20 parts of yellow pigment (Clariant Japan Co., Ltd., CI Pigment Yellow 74)
-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) 2 parts-Ion-exchanged water 78 parts The above ingredients were prepared in the same manner as the magenta pigment dispersion M1 to obtain a yellow pigment dispersion Y1. It was. The number average particle diameter D _50n of the pigment in the dispersion was 118 nm. Thereafter, ion exchange water was added to adjust the solid content concentration of the dispersion to 15% by weight.

<Toner Example>
(Production of toner particles)
(Toner Example 1: Preparation of toner using resin particle dispersion L1)
・ Resin particle dispersion (L1) 160 parts ・ Releasing agent particle dispersion (W1) 33 parts ・ Cyan pigment dispersion (C1) 60 parts ・ Polyaluminum chloride 10 wt% aqueous solution 15 parts (manufactured by Asada Chemical Co., Ltd.) , PAC100W)
1% nitric acid aqueous solution 3 parts The above components were dispersed in a round stainless steel flask for 3 minutes at 5,000 rpm using a homogenizer (manufactured by IKA, Ultra Turrax T50), and then magnetically sealed to the flask. The lid is equipped with a stirring device, a thermometer and a pH meter, and a heating mantle heater is set, and the whole dispersion in the flask is appropriately adjusted to the minimum number of revolutions to be stirred and stirred. The mixture was heated to 1 ° C. at 1 ° C./1 min, held at 62 ° C. for 30 minutes, and the particle size of the aggregated particles was confirmed with a Coulter counter (TA II, manufactured by Beckman Coulter). Immediately after the temperature increase was stopped, 50 parts of the resin particle dispersion (L1) was added and held for 30 minutes. Then, an aqueous sodium hydroxide solution was added until the pH in the system reached 6.5, and then 97 ° C. at 1 ° C./1 min. Heated to ° C. After the temperature rise, an aqueous nitric acid solution was added to adjust the pH in the system to 5.0, and the aggregated particles were heated and fused by maintaining for 10 hours.

  Thereafter, the temperature in the system was lowered to 50 ° C., an aqueous sodium hydroxide solution was added to adjust the pH to 12.0, and the mixture was maintained for 10 minutes. After removing from the flask, sufficiently filtering with ion-exchanged water, washed with water, dispersed in ion-exchanged water so that the solid content is 10% by weight, added with nitric acid, and stirred at pH 3.0 for 10 minutes. Then, the slurry obtained by sufficiently filtering and washing with water through ion exchange water again was freeze-dried to obtain a cyan toner (toner C1).

The cyan toner particles are made of silica (SiO ₂ ) particles having a primary particle average particle size of 40 nm and subjected to surface hydrophobization treatment with hexamethyldisilazane (hereinafter sometimes abbreviated as “HMDS”), metatitanic acid and isobutyltrimethoxysilane. 1 wt% each of the metatitanic acid compound particles having an average primary particle diameter of 20 nm, which is a reaction product of the above reaction product, was mixed with a Henschel mixer to prepare a cyan externally added toner.
Thus, when the particle diameter of the toner particles was measured with a Coulter counter,
The cumulative volume average particle diameter D ₅₀ is 4.67 μm, and the volume average particle size distribution index GSDv is 1.20. The shape factor SF1 of the toner particles determined from the shape observation with Luzex was 130 potato shapes.

(Toner Example 2: Preparation of toner using resin particle dispersion L2)
In Toner Example 1, except for changing the resin particle dispersion L2 is prepared cyan toner in a similar manner, the cumulative volume-average particle diameter D ₅₀ and the volume average particle size distribution index GSDv, the shape factor were measured. An external additive was externally added to this toner in the same manner as in Toner Example 1 to obtain a cyan externally added toner.
As a result, in Example 2, D ₅₀ was 4.61 μm, and the volume average particle size distribution index GSDv was 1.20. The shape factor SF1 was a slight potato shape of 124.

Thereafter, the following toners were obtained in the same manner.
In Toner Example 3 using resin particle dispersion L3, D ₅₀ is 4.71, GSDv of 1.20, a shape factor SF1 of the toner 129 was obtained.
In Toner Example 4 using resin particle dispersion L4, D ₅₀ is 4.63, GSDv of 1.20, a shape factor SF1 is obtained toner 130.

(Toner Comparative Examples 1 to 4: Preparation of toner using resin particle dispersions L5, L6, L4, and L7)
In Toner Example 1, except that instead of each resin particle dispersion L4~L7 obtain a cyan colored particles in a similar manner, the cumulative volume-average particle diameter D ₅₀ and the volume average particle size distribution index GSDv, and measuring the shape factor . An external additive was externally added to the toner in the same manner as in Toner Example 1 to obtain an external additive toner. as a result,
In Toner Comparative Example 1 using the resin particle dispersion L5, a toner having a D ₅₀ of 4.69 μm, a GSDv of 1.21, and a shape factor SF1 of 129 was obtained.
In Toner Comparative Example 2 using the resin particle dispersion L6, a toner having a D ₅₀ of 4.81 μm, a GSDv of 1.24, and a shape factor SF1 of 133 was obtained.
In Comparative Example 3 using the resin particle dispersion L4, a toner having a D ₅₀ of 4.79 μm, a GSDv of 1.26, and a shape factor SF1 of 135 was obtained.
In Comparative Example 4 using the resin particle dispersion L7, a toner having a D ₅₀ of 5.01 μm, a GSDv of 1.25, and a shape factor SF1 of 130 was obtained.

<Career evaluation method and production>
Examples of carrier production are shown below, but the present invention is not limited to the examples.

[Measuring method]
(Measurement method of BET specific surface area)
Using a BET specific surface area meter (SA3100, manufactured by Beckman Coulter, Inc.) as a measurement device, 0.1 g of porous silicon nitride powder as a measurement sample is precisely weighed and placed in a sample tube, and then degassed. The numerical value obtained by the automatic measurement by the multipoint method is defined as the BET specific surface area A of the magnetic core particles.

(Measurement method of volume average particle diameter of magnetic core particles)
The volume average particle size of the magnetic core particles was measured using a laser diffraction / scattering type particle size distribution analyzer (LS Particle Size Analyzer: LS13 320, manufactured by Beckman Coulter, Inc.). For the particle size range (channel) obtained by dividing the obtained particle size distribution, the volume cumulative distribution was subtracted from the small particle size side, and the particle size at 50% cumulative was taken as the volume average particle size.

(Measurement method of true specific gravity of magnetic core particles)
The true specific gravity of the magnetic core particles was measured using a Le Chatelier specific gravity bottle according to JIS-K-0061 5-2-1. The operation was performed as follows.
(1) About 250 ml of ethyl alcohol is put into a Lechatelier specific gravity bottle and adjusted so that the meniscus is at the position of the scale.
(2) The specific gravity bottle is immersed in a constant temperature water bath, and when the liquid temperature reaches 20.0 ± 0.2 ° C., the position of the meniscus is accurately read with the scale of the specific gravity bottle. (Accuracy 0.025ml)
(3) About 100 g of a sample is weighed and its mass is defined as W (g).
(4) Put the weighed sample in a specific gravity bottle to remove bubbles.
(5) The specific gravity bottle is immersed in a constant temperature water bath, and when the liquid temperature becomes 20.0 ± 0.2 ° C., the position of the meniscus is accurately read with the scale of the specific gravity bottle. (Accuracy 0.025ml)
(6) The true specific gravity is calculated by the following formula.
D = W / (L2-L1)
ρ = D / 0.9982
In the formula, D is the density of the sample (20 ° C.) (g / cm ³ ), ρ is the true specific gravity of the sample (20 ° C.), W is the apparent mass (g) of the sample, and L1 is before the sample is placed in the specific gravity bottle. Meniscus reading (20 ° C.) (ml), L2 is the meniscus reading (20 ° C.) (ml) after the sample is placed in the density bottle, 0.9982 is the density of water at 20 ° C. (g / cm ³ ) It is.

<Measurement method of magnetic properties>
A vibration sample type magnetic measuring device VSMP10-15 (manufactured by Toei Kogyo Co., Ltd.) is used as a magnetic property measuring device. The measurement sample is packed in a cell having an inner diameter of 7 mm and a height of 5 mm and set in the apparatus. The measurement applies an applied magnetic field and sweeps up to 3,000 Oersted. Next, the applied magnetic field is decreased to create a hysteresis curve on the recording paper. Saturation magnetization, residual magnetization, and coercive force are obtained from the curve data. In the present invention, saturation magnetization refers to magnetization measured in a 1,000 oersted magnetic field.

<Measurement method of volumetric electrical resistance of magnetic core particles, conductive powder, carrier>
The volume electrical resistance (Ω · cm) of the magnetic core particles, conductive powder, and carrier is measured as follows. The measurement environment is a temperature of 20 ° C. and a humidity of 50% RH.
A measurement object is placed flat on the surface of a circular jig having a 20 cm ² electrode plate so as to have a thickness of about 1 to 3 mm to form a layer. A 20 cm ² electrode plate similar to the above is placed on this and the layers are sandwiched. In order to eliminate gaps between objects to be measured, a thickness (cm) of the layer is measured after a load of 4 kg is applied on the electrode plate placed on the layer. Both electrodes above and below the layer are connected to an electrometer and a high voltage power generator. A high voltage is applied to both electrodes so that the electric field is 10 ^3.8 V / cm, and the current value (A) flowing at this time is read to calculate the volume electrical resistance (Ω · cm) of the measurement object. The calculation formula of the volume electrical resistance (Ω · cm) of the measurement object is as shown in the following formula.
Formula: R = E × 20 / (I−I ₀ ) / L
In the above formula, R is the volume electric resistance (Ω · cm) of the measurement object, E is the applied voltage (V), I is the current value (A), I ₀ is the current value (A) at the applied voltage of 0 V, and L is Each layer thickness (cm) is expressed. A coefficient of 20 represents the area (cm ² ) of the electrode plate.

<Measurement method of volume average particle diameter in conductive powder and resin particles>
The volume average particle diameter of the conductive powder and the resin particles is measured using a laser diffraction particle size distribution analyzer (LA-920: manufactured by Horiba, Ltd.).
As a measuring method, the sample in the state of dispersion is adjusted so as to have a solid content of about 2 g, and ion exchange water is added thereto to make about 40 ml. This is put into the cell until an appropriate concentration is reached, and after waiting for 2 minutes, the concentration is measured when the concentration in the cell becomes almost stable.
The obtained volume average particle diameter for each channel is accumulated from the smaller volume average particle diameter, and the volume average particle diameter is defined as 50%.

<Measurement method of coverage>
The coverage of the coating resin layer can be determined by XPS measurement. As the XPS measuring apparatus, JPS80 manufactured by JEOL Ltd. was used. The measurement is performed using MgKα ray as an X-ray source, setting the acceleration voltage to 10 kV and the emission current to 20 mV, and the main elements (usually carbon) constituting the coating resin layer and the main cores constituting the magnetic core particles. Element (for example, iron and oxygen when the magnetic core particle is an iron oxide-based material such as magnetite) is measured (hereinafter, description will be made on the assumption that the magnetic core particle is an iron oxide-based material). Here, the C1s spectrum is measured for carbon, the Fe2p _3/2 spectrum is measured for iron, and the O1s spectrum is measured for oxygen.
Based on the spectrum of each of these elements, the number of elements of carbon, oxygen, and iron (A _C + A _O + A _Fe ) is obtained, and the following formula (I) is obtained from the obtained number ratio of the elements of carbon, oxygen, and iron. Based on this, the iron content rate after coating the magnetic core particles alone and the magnetic core particles with the coating resin layer (carrier) was determined, and then the coverage was determined by the following formula (II).
Formula (I): Iron content rate (atomic%) = A _Fe / (A _C + A _O + A _Fe ) × 100
Formula (II): Coverage rate (%) = {1- (iron content rate of carrier) / (iron content rate of magnetic core particle alone)} × 100
When a material other than iron oxide is used as the magnetic core particle, the spectrum of the metal element constituting the magnetic core particle in addition to oxygen is measured and conforms to the above formula (I) or formula (II). If the same calculation is performed, the coverage can be obtained.
The average film thickness (μm) of the coating resin layer is such that the true specific gravity of the magnetic core particles is ρ (dimensionless), the volume average particle diameter of the magnetic core particles is d (μm), the average specific gravity of the coating resin layer is ρ _C , and magnetic When the total content of the coating resin layer with respect to 100 parts by weight of the core particles is W _C (parts by weight), it can be obtained as in the following formula (III).
Formula (III): Average film thickness (μm) = [amount of coating resin per carrier (including all additives such as conductive powder) / surface area per carrier] / average specific gravity of coating resin layer = {[ 4 / 3π · (d / 2) ³ · ρ · W _C ] / [4π · (d / 2) ² ]} / ρ _C
= (1/6) · (d · ρ · W _C / ρ _C )

<Measuring method of weight average particle diameter of carrier and volume average particle diameter of toner>
The weight average particle diameter of the carrier and the volume average particle diameter of the toner were measured using Coulter Multisizer II (manufactured by Beckman Coulter, Inc.). As the electrolytic solution, ISOTON-II (manufactured by Beckman Coulter, Inc.) was used.

As a measuring method, 0.5 to 50 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant, and this is added to 100 to 150 ml of the electrolytic solution. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size is 2.0 to 60 μm by the Coulter Multisizer II using an aperture having an aperture diameter of 100 μm. Measure the particle size distribution of the range of particles. The number of particles to be measured is 50,000.
For the divided particle size range (channel), draw the cumulative distribution from the small diameter side with respect to the divided particle size range (channel), and define the 50% cumulative particle size as the weight average particle size or volume average particle size, respectively. To do.

<How to find the shape factor>
The shape factor SF1 is obtained by the following equation.
Formula: SF1 = 100π × (ML) ² / (4 × A)
Here, ML is the maximum length of the particle, and A is the projected area of the particle. The maximum length and projected area of the particles are obtained by observing the particles sampled on the slide glass with an optical microscope, taking them into an image analyzer (LUZEX III, manufactured by Nireco Corporation) through a video camera, and performing image analysis. be able to. The number of samplings at this time is 100 or more, and the shape factor shown in the equation is obtained using the average value.

<Measurement method of glass transition point of resin>
The glass transition point (Tg) of the resin is measured using a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC-50) under a temperature rising rate of 3 ° C./min. The temperature at the intersection of the extension line with the rising line was taken as the glass transition point.
A method for producing the magnetic core particles of the carrier, the resin of the coating resin layer, and the carrier will be described below.

<Manufacture of magnetic core particle A>
The production of the magnetic core particle A was performed as follows.
After mixing 70 parts of Fe ₂ O ₃ , 22 parts of MnO _{2 and} 7 parts of Mg (OH) ₂ , mixing / pulverizing with a wet ball mill for 30 hours, granulating and drying with a spray dryer, 850 ° C. using a rotary kiln, Pre-baking 1 for 7 hours was performed. The calcined product 1 thus obtained was pulverized for 2 hours with a wet ball mill to a volume average particle size of 2.1 μm, further granulated and dried with a spray dryer, and then at 910 ° C. for 6 hours using a rotary kiln. The preliminary firing 2 was performed. The calcined product 2 thus obtained was pulverized with a wet ball mill for 5 hours to have a volume average particle size of 5.4 μm, granulated and dried with a spray dryer, and then heated at a temperature of 905 ° C. using an electric furnace. The main baking was performed for 12 hours. Through the crushing step and the classification step, magnetic core particles A having a volume average particle size of 33.8 μm were prepared. The BET specific surface area was 0.224 (m ² / g). The following table summarizes these characteristics.

<Manufacture of resin used as material for coating resin layer>
(Production of resin A)
Production of the resin A of the coating resin layer was performed as follows.
Methyl methacrylate 297 parts Dimethylaminoethyl methacrylate (dimethylaminoethyl methacrylate) 3 parts benzene 300 parts azobisisobutyronitrile 0.6 parts The above ingredients were mixed, heated to 60 ° C, shaken for 6 hours, and polymerized. . The reaction product was dissolved in methyl ethyl ketone and precipitated with 7 times the amount of hexane to obtain Resin A.
The resulting resin is
Weight average molecular weight Mw = 110,000,
Glass transition temperature 102 ° C.,
The volume electric resistance was 10 ¹⁶ (Ω · cm).
Table 2 shows the composition and characteristics of the obtained resin A.

(Production of resin B)
Methyl methacrylate 180 parts Perfluorooctyl ethyl methacrylate 120 parts benzene 300 parts azobisisobutyronitrile 0.6 part The above components were mixed, heated to 60 ° C., shaken for 6 hours, and polymerized. The reaction product was dissolved in methyl ethyl ketone and precipitated with 7 times the amount of hexane to obtain Resin B.
The resulting resin is
Weight average molecular weight Mw = 110,000,
Glass transition temperature 102 ° C.,
The volume electric resistance was 10 ¹⁶ (Ω · cm).
Table 2 shows the composition and characteristics of the obtained resin B.

[Manufacture of carriers]
(Manufacture of carrier C1)
Magnetic core particles A: 100 parts Toluene: 20 parts Resin A: 3 parts Carbon black (VXC-72; manufactured by Cabot Corporation): 0.3 parts

  Of the above materials, resin A was diluted with toluene, carbon black was added, and the mixture was stirred with a homogenizer for 5 minutes to prepare a resin solution. The resin solution and the magnetic core particle A are put in a vacuum degassing type kneader, stirred for 30 minutes at 80 ° C., then left at 100 Pa for 30 minutes, and further depressurized to remove toluene, and on the ferrite particle surface. A film was formed to obtain a carrier C1. The carrier particle size is almost the same as the magnetic core particle size.

(Manufacture of carrier C2)
Carrier C2 was produced in the same manner as carrier C1, except that resin B was used instead of resin A when obtaining carrier C1. The carrier particle size is almost the same as the magnetic core particle size.

(Manufacture of carrier C3)
Magnetic core particles A: 100 parts Toluene: 20 parts Resin A: 2 parts Carbon black (VXC-72; manufactured by Cabot Corporation): 0.3 parts

  Of the above materials, resin A was diluted with toluene, carbon black was added, and the mixture was stirred with a homogenizer for 5 minutes to prepare a resin solution. The resin solution and the magnetic core particle A are placed in a vacuum degassing kneader and stirred at 80 ° C. for 30 minutes, and the pressure is reduced as it is to remove toluene to form a film on the ferrite particle surface. C3 was obtained. The carrier particle size is almost the same as the magnetic core particle size.

<Production of developer>
To 100 parts of the obtained C1 to C3 carrier, 8 parts of each toner prepared as described above was charged and mixed in a V blender to prepare a two-component developer for developing an electrostatic image.

  The following toner evaluation and image quality evaluation were performed using the two-component developers for developing electrostatic images prepared as described above.

<Two-component developer for developing electrostatic image and evaluation of image quality>
(1) Evaluation of image density A Docu Center Color 500CP remodeling machine manufactured by Fuji Xerox Co., Ltd. was used as an image forming apparatus. Resin-coated paper (CX paper manufactured by Fuji Xerox Co., Ltd.) was used as the transfer medium.
Using the two-component developers for developing electrostatic images obtained in Examples and Comparative Examples, a predetermined number of sheets were used in a high-temperature and high-humidity environment (30 ° C./85% RH) and a low-temperature low-humidity environment (10 ° C./15% RH). After taking a copy, it was left overnight, and further an image having a 2 cm × 5 cm patch was copied. I took the value.
The evaluation standard for image density is the difference between the image density measurement value in a high temperature and high humidity environment and the minimum image density measurement value in a low temperature and low humidity environment.
○ less than 0.05,
0.05 or more and less than 0.06 △,
0.06 or more was set as x.

  Regarding the two-component developer examples 1 to 4 for electrostatic image development and the two-component developer comparative examples 2 to 3 for electrostatic image development, there is a difference in density between the image obtained at high temperature and high humidity and the image obtained at low temperature and low humidity. The density difference of the two-component developers for developing electrostatic images of Comparative Examples 1 and 4 was 0.06 or more, whereas it was less than 0.05.

(2) BCO Evaluation It is known that image quality defects due to BCO have a correlation with the number of carriers developed on the non-image background portion. Therefore, the BCO is evaluated by a carrier developed on the background portion when the difference between the latent image background portion potential and the developing bias potential is 400 V after 50,000 copies are made with the above-mentioned modified machine (Fuji Xerox Co., Ltd.). The number was evaluated by visual observation.
The number of carriers developed on the background is 10 or less.
The number of carriers developed on the background area is 11 or more and 15 or less.
The number of carriers developed on the background is 16 or more ×
It was.
In the two-component developer examples 1 to 4 for electrostatic image development and the two-component developer comparative examples 1 and 4 for electrostatic image development, the number of carriers was 10 or less, whereas in the comparative examples 2 and 3, In the two-component developer for developing an electrostatic image, the number of carriers was 20 or more.

(3): Evaluation of fogging of non-image area under high temperature and high humidity About the non-image part between fine lines of image quality in which the fine line image is fixed using the two-component developer for electrostatic image development described above and a remodeling machine. It was measured with a reflection densitometer (X-Rite 404, manufactured by X-Rite, USA).
If there was a density increase greater than 0.01 at the ground fog, the mark was x.
As a result of performing the above evaluation on each obtained two-component developer for developing electrostatic images, when the two-component developers for developing electrostatic images of Examples 1 to 4 and Comparative Examples 1 to 3 were used, there was no fog. It was not seen, and the density measurement of the non-image area by X-Rite 404 was less than 0.01.
On the other hand, when the two-component developer for developing an electrostatic charge image of Comparative Example 4 was used, a density of 0.01 was confirmed in the density measurement of the non-image area by X-Rite 404, and slight fogging occurred visually. Was recognized.

Abbreviations in Table 3 represent the following compounds.
BPA-2EO: Bisphenol A ethylene oxide 2 mol adduct BPA-2PO: Bisphenol A propylene oxide 2 mol adduct BPZ-2EO: Bisphenol Z ethylene oxide 2 mol adduct BPEF: Bisphenoxyethanol fluorene DMPA: Dimethylolpropanoic acid DMBA: Di Methylolbutanoic acid DMHA: dimethylolhexanoic acid DMOA: dimethyloloctanoic acid CHDA: 1,4-cyclohexanedicarboxylic acid PDAA: 1,4-phenylenediacetic acid PDPA: 1,4-phenylenedipropionic acid DBSA: dodecylbenzenesulfonic acid P- DBSA: pentadecylbenzenesulfonic acid O-DBSA: octadecylbenzenesulfonic acid F-DBSA: dodecylfluorobenzenesulfonic acid SnB O: dibutyl tin oxide

  The structural formula of each catalyst is shown below.

1 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of an image forming apparatus of the present invention. It is sectional drawing which shows schematically the basic composition of other suitable one Embodiment of the image forming apparatus of this invention. It is sectional drawing which shows schematically the basic composition of other suitable one Embodiment of the image forming apparatus of this invention. 1 is a cross-sectional view schematically showing a preferred embodiment of a cartridge according to the present invention.

Explanation of symbols

200 Image forming apparatus 201 Image forming apparatus 207 Electrophotographic photosensitive member 208 Charging apparatus 209 Power supply 210 Exposure apparatus 211 Developing apparatus 212 Transfer apparatus 212a Primary transfer member 212b Secondary transfer member 213 Cleaning apparatus 214 Static eliminator 215 Fixing apparatus 216 Mounting rail 217 Opening part 218 for static elimination exposure Opening part 220 for exposure Image forming apparatus 300 Cartridge 400 Housing 401a, 401b, 401c, 401d Electrophotographic photoreceptors 402a, 402b, 402c, 402d Charging roll 403 Laser light source (exposure apparatus)
404a, 404b, 404c, 404d Developing devices 405a, 405b, 405c, 405d Toner cartridge 406 Drive roll 407 Tension roll 408 Backup roll 409 Intermediate transfer belt 410a, 410b, 410c, 410d Primary transfer roll 411 Tray (transfer medium tray)
412 Transfer roll 413 Secondary transfer roll 414 Fixing rolls 415a, 415b, 415c, 415d Cleaning blade 416 Cleaning blade 500 Transfer medium (image output medium)

Claims (5)

An electrostatic charge image developing toner comprising a polyester resin containing 2 to 20 mol% of monomer units derived from hydroxy acid and / or a derivative thereof having a total of 3 or more of hydroxy groups and carboxy groups, and
An electrostatic charge image developing carrier having magnetic core particles and a coating resin layer covering the magnetic core particles;
The resin of the covering resin layer contains nitrogen atoms and / or fluorine atoms, and
A two-component developer for developing an electrostatic charge image, wherein the coverage of the magnetic core particles by the coating resin layer is 80% or more. The polyester resin has a polycarboxylic acid and / or a derivative thereof, and a monomer unit derived from a polyol,
50 to 100 mol% of monomer units derived from the polycarboxylic acid and / or derivative thereof are represented by formula (1) and / or formula (2),
The two-component developer for developing an electrostatic charge image according to claim 1, wherein 50 to 100 mol% of the monomer unit derived from the polyol is represented by the formula (3).
R ¹ OOCA ¹ _m B ¹ _n A ¹ _l COOR ¹ (1)
(A ¹ : methylene group, B ¹ : aromatic hydrocarbon group, R ¹ : each independently a hydrogen atom or a monovalent hydrocarbon group, 1 ≦ m + 1 ≦ 12, 1 ≦ n ≦ 3)
R ² OOCA ² _p B ² _q A ² _r COOR ² (2)
(A ² : methylene group, B ² : alicyclic hydrocarbon group, R ² : each independently a hydrogen atom or monovalent hydrocarbon group, 0 ≦ p ≦ 6, 0 ≦ r ≦ 6, 1 ≦ q ≦ 3 )
HOX _h Y _j X _k OH (3)
(X: alkylene oxide group, Y: bisphenol skeleton group, 1 ≦ h + k ≦ 10, 1 ≦ j ≦ 3)   The two-component developer for electrostatic image development according to claim 1 or 2, wherein the coating resin layer contains conductive powder. An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier;
An image forming step of developing the latent image on the electrostatic latent image carrier with a developer containing toner to form a toner image;
Transferring the toner image;
A fixing step of fixing the toner image,
An image forming method using the two-component developer for developing an electrostatic charge image according to any one of claims 1 to 3 as the developer. An electrostatic latent image carrier;
Charging means for charging the electrostatic latent image holding member;
Exposure means for exposing the charged electrostatic latent image holding member to form an electrostatic latent image on the electrostatic latent image holding member;
Developing means for developing the electrostatic latent image with a developer containing toner to form a toner image;
Transfer means for transferring the toner image from the electrostatic latent image holding member to a transfer medium;
An image forming apparatus using the two-component developer for developing an electrostatic image according to claim 1 as the developer.

Images