JP2014038220A - Liquid developer, developer cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid developer that has excellent positive chargeability.SOLUTION: A liquid developer contains a carrier liquid, toner particles including a polyester resin subjected to surface modification with polyamines, and a carboxyl group-containing silicone compound.

Description

  The present invention relates to a liquid developer, a developer cartridge, a process cartridge, an image forming apparatus, and an image forming method.

  A method of visualizing image information through an electrostatic charge image such as electrophotography is currently used in various fields. In electrophotography, a latent image (electrostatic latent image) is formed on an image carrier by a charging and exposure process (latent image forming process), and an electrostatic charge image developing toner (hereinafter simply referred to as “toner”). The electrostatic latent image is developed (development process) with a developer for developing electrostatic images (hereinafter sometimes referred to simply as “developer”), and visualized through a transfer process and a fixing process. The Developers used in the dry development method include a two-component developer composed of a toner and a carrier, and a one-component developer using a magnetic toner or a non-magnetic toner alone.

  On the other hand, the liquid developer used in the wet development system is one in which toner particles are dispersed in an insulating carrier liquid, and a type in which toner particles containing a thermoplastic resin are dispersed in a volatile carrier liquid. A type in which toner particles containing a thermoplastic resin are dispersed in a hardly volatile carrier liquid is known.

For example, Patent Document 1 discloses a liquid developer in which a toner having a charge opposite to that of toner particles is contained in a liquid as a toner particle dispersion promoting substance. The dispersion promoting substance has a carboxyl group or a polar group as a polar group. It describes that a graft copolymer having a hydroxyl group and containing silicone in the graft portion is used.

  Patent Document 2 describes a liquid developer containing an insulating liquid and toner particles obtained by surface-modifying toner particles containing a rosin resin with polyalkyleneimine.

JP 2004-302436 A JP 2010-025971 A

  An object of the present invention is to provide a liquid developer excellent in positive chargeability, a developer cartridge using the liquid developer, a process cartridge, an image forming apparatus, and an image forming method.

  The invention according to claim 1 is a liquid developer containing a carrier liquid, toner particles containing a polyester resin surface-treated with a polymeric amine, and a carboxyl group-containing silicone compound.

The invention according to claim 2 is the liquid developer according to claim 1, wherein the carboxyl group-containing silicone compound is a compound represented by the following general formula (1).

(1)
(In formula (1), X, Y and Z each independently represent a hydrogen atom or a carboxyl group, and at least one of X, Y and Z represents a carboxyl group. N is an integer of 1 to 10. R ¹ , R ² and R ³ are each independently a single bond or a divalent aliphatic carbon atom having 1 to 20 carbon atoms. Indicates a hydrogen group.)

  The invention according to claim 3 is the liquid developer according to claim 1 or 2, wherein the polymeric amine is a polyalkyleneimine.

The invention according to claim 4 is the liquid developer according to claim 1 or 2, wherein the polymeric amine is a polyallylamine represented by the following general formula (2).

(2)
(In Formula (2), R ⁴ and R ⁵ each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and m and n each independently represent 100 or more and 1,000. The following integers are shown.)

  According to a fifth aspect of the invention, the toner particles containing the polyester resin are toner particles obtained by aggregating a dispersion containing the resin particles containing the polyester resin and the colorant particles in an aqueous medium. 5. The liquid developer according to any one of 1 to 4.

  The invention according to claim 6 is a developer cartridge in which the liquid developer according to any one of claims 1 to 5 is accommodated.

  The invention according to claim 7 is a process cartridge in which the liquid developer according to any one of claims 1 to 5 is accommodated.

  According to an eighth aspect of the present invention, there is provided an image carrier, a latent image forming unit that forms a latent image on the surface of the image carrier, and the latent image formed on the surface of the image carrier. A developing means for forming a toner image by developing with the liquid developer according to any one of claims 1 to 5 held on the surface of the toner, and the toner image formed on the surface of the image carrier. An image forming apparatus comprising: transfer means for transferring onto a recording medium; and fixing means for fixing the toner image transferred to the recording medium to the recording medium to form a fixed image.

  According to the ninth aspect of the present invention, the latent image forming step of forming a latent image on the surface of the image holding member and the latent image formed on the surface of the image holding member are held on the surface of the developer holding member. A development step of developing with the liquid developer according to claim 1 to form a toner image, and transferring the toner image formed on the surface of the image carrier onto a recording medium. An image forming method comprising: a transfer step; and a fixing step of fixing the toner image transferred to the recording medium to the recording medium to form a fixed image.

  According to the first aspect of the present invention, there is provided a liquid developer which is excellent in positive chargeability as compared with a case where only toner particles containing a polyester resin and a carboxyl group-containing silicone compound are not surface-treated. The

  According to the second aspect of the present invention, there is provided a liquid developer excellent in positive chargeability as compared with the case where the carboxyl group-containing silicone compound is not the compound represented by the general formula (1).

  According to the third aspect of the present invention, there is provided a liquid developer excellent in positive chargeability as compared with the case where the polymer amine is a polydiallylamine.

  According to the fourth aspect of the present invention, there is provided a liquid developer excellent in positive chargeability as compared with the case where the polymer amine is a polydiallylamine.

  According to the invention of claim 5, the toner particles containing the polyester resin are not toner particles obtained by aggregating a dispersion containing the resin particles containing the polyester resin and the colorant particles in an aqueous medium. As compared with the above, a liquid developer excellent in positive chargeability is provided.

  According to the invention of claim 6, the liquid development is superior in positive chargeability compared to the case where the liquid developer is not surface-treated and contains only toner particles containing a polyester resin and a carboxyl group-containing silicone compound. A developer cartridge containing the agent is provided.

  According to the seventh aspect of the invention, the liquid developer is excellent in positive chargeability as compared with the case where the liquid developer is not surface-treated and contains only toner particles containing a polyester resin and a carboxyl group-containing silicone compound. A process cartridge containing the agent is provided.

  According to the eighth aspect of the present invention, liquid development that is excellent in positive chargeability as compared with a case where the liquid developer is not surface-treated and contains only toner particles containing a polyester resin and a carboxyl group-containing silicone compound. An image forming apparatus using the agent is provided.

  According to the ninth aspect of the present invention, the liquid developer is excellent in positive chargeability as compared with the case where the liquid developer is not surface-treated and contains only toner particles containing a polyester resin and a carboxyl group-containing silicone compound. An image forming method using an agent is provided.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

<Liquid developer>
The liquid developer according to the exemplary embodiment includes a carrier liquid, toner particles containing a polyester resin that has been surface-treated with polymer amines, and a carboxyl group-containing silicone compound. A liquid developer in which toner particles containing a polyester resin as a binder resin are dispersed in a carrier liquid has been studied. However, since a polyester resin is a material that has a strong tendency to be negatively charged, a liquid developer is used. It was difficult to charge positively.

  In this embodiment, in a liquid developer in which toner particles containing a polyester resin as a binder resin are dispersed in a carrier liquid, toner particles surface-treated with polymer amines are used as toner particles, and a carboxyl group-containing material is used. By including a silicone compound, a liquid developer having excellent positive charging characteristics is realized. Further, the liquid developer according to this embodiment is excellent in dispersion stability.

  The reason why the positive chargeability is excellent by using the liquid developer according to this embodiment is because, for example, in this liquid developer, high-cationic polymer amines are firmly attached to the surface of the toner particles. it is conceivable that.

  Hereinafter, the components of the liquid developer according to this embodiment will be described in detail.

Examples of the carboxyl group-containing silicone compound include a compound represented by the following general formula (1), a compound represented by the following general formula (3), etc. Among these, points such as high cationicity and easy positive charging Therefore, a compound represented by the following general formula (1) is preferable.

(1)
(In formula (1), X, Y and Z each independently represent a hydrogen atom or a carboxyl group, and at least one of X, Y and Z represents a carboxyl group. N is an integer of 1 to 10. R ¹ , R ² and R ³ are each independently a single bond or a divalent aliphatic carbon atom having 1 to 20 carbon atoms. Indicates a hydrogen group.)

(3)
(In the formula (3), R ⁶ represents a divalent aliphatic hydrocarbon group, j represents an integer of 1 to 100, k represents an integer of 10 to 1000, and l represents 1 to 1000. R ⁷ represents an aliphatic hydrocarbon group.

  In formula (1), even if one of X, Y and Z is a carboxyl group, or two of X, Y and Z are carboxyl groups, all of X, Y and Z are carboxyl groups. May be.

In Formula (1), R ¹ , R ² and R ³ are each independently a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, and a single bond or 3 to 12 carbon atoms. These divalent aliphatic hydrocarbon groups are preferred. Examples of the divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, an octamethylene group, a decamethylene group, an undecamethylene group, and a dodecamethylene group. Hexadecamethylene group, octadecamethylene group and the like, and trimethylene group, tetramethylene group, hexamethylene group, octamethylene group, decamethylene group, undecamethylene group, dodecamethylene group and the like are preferable.

  In Formula (1), m is an integer of 1 or more and 1,000 or less, and an integer of 5 or more and 100 or less is preferable. In the formula (1), n is an integer of 1 to 10, and preferably an integer of 1 to 5.

  The amount of the carboxyl group-containing silicone compound in the liquid developer is, for example, preferably in the range of 0.001 to 10 parts by mass with respect to 100 parts by mass of the liquid developer, and 0.01 to 1 part by mass. More preferably, it is in the range of less than or equal to parts by mass. When the amount of the carboxyl group-containing silicone compound relative to the liquid developer is less than 0.001 part by mass with respect to 100 parts by mass of the liquid developer, the chargeability may be inferior. When the amount exceeds 10 parts by mass, the conductivity is high. In some cases, the chargeability may be lowered.

  The weight average molecular weight of the carboxyl group-containing silicone compound is preferably in the range of 100 to 100,000, and more preferably in the range of 1,000 to 10,000. If the weight average molecular weight of the carboxyl group-containing silicone compound is less than 100, the compatibility with the liquid developer may not be sufficient, and if it exceeds 100,000, the fixability of the developer may be inhibited.

[Toner particles]
The toner particles contained in the liquid developer according to the exemplary embodiment include a binder resin, and may include other components such as a colorant and a release agent as necessary. The toner particles are surface-treated with high molecular amines.

  Examples of the polymer amines include polyalkyleneimines, polyallylamines, polydiallylamines and the like. Of these, polyalkylenimines and polyallylamines are preferred from the viewpoints of high cationicity and easy positive charging.

  Examples of the polyalkyleneimines include polyethyleneimine.

Examples of polyallylamines include polyallylamines represented by the following general formula (2).

(2)
(In Formula (2), R ⁴ and R ⁵ each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and m and n each independently represent 100 or more and 1,000. The following integers are shown.)

R ⁴ and R ⁵ are a hydrogen atom or an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and preferably an aliphatic hydrocarbon group having 1 to 20 carbon atoms. Examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a linear or branched propyl group, a butyl group, a pentyl group, a hexyl group, and an octyl group, and a methyl group is preferable.

  m and n are each independently an integer of 1 to 10,000, preferably an integer of 5 to 1,000.

  The amount of the polymeric amine with respect to the toner particles is preferably in the range of 0.01 parts by weight to 100 parts by weight, for example, in the range of 0.1 parts by weight to 10 parts by weight with respect to 100 parts by weight of the toner particles. A range is more preferable. When the amount of the polymeric amine with respect to the toner particles is less than 0.01 parts by weight with respect to 100 parts by weight of the toner particles, the chargeability may be inferior. When the amount exceeds 100 parts by weight, the chargeability is too high. Transferability may decrease.

  The weight average molecular weight of the polymeric amines is preferably in the range of 100 to 1,000,000, more preferably in the range of 1,000 to 100,000. When the weight average molecular weight of the polymeric amine is less than 100, the adsorptivity to the toner surface is low, and the target charging performance may not be obtained. Adhesion may occur.

(Binder resin)
The binder resin contains a polyester resin as a main component. The polyester resin is synthesized from an acid (polyhydric carboxylic acid) component and an alcohol (polyhydric alcohol) component. In the present embodiment, the “acid-derived constituent component” The component part which was an acid component is pointed out, and the "alcohol-derived component" refers to the component part which was an alcohol component before the synthesis of the polyester resin. The main component means 50 parts by mass or more with respect to 100 parts by mass of the binder resin in the toner particles.

[Acid-derived components]
The acid-derived component is not particularly limited, and aliphatic dicarboxylic acids and aromatic carboxylic acids are preferably used. Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decanedicarboxylic acid. 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc. Or lower alkyl esters and acid anhydrides thereof, but are not limited thereto. Examples of the aromatic carboxylic acid include lower alkyl esters and acid anhydrides of aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, and naphthalenedicarboxylic acid. Moreover, alicyclic carboxylic acids, such as cyclohexane dicarboxylic acid, etc. are mentioned. In order to secure better fixing properties, it is preferable to use a trivalent or higher carboxylic acid (trimellitic acid or acid anhydride thereof) together with a dicarboxylic acid in order to form a crosslinked structure or a branched structure. Specific examples of the alkenyl succinic acid include dodecenyl succinic acid, dodecyl succinic acid, stearyl succinic acid, octyl succinic acid, octenyl succinic acid and the like.

[Alcohol-derived components]
The alcohol-derived constituent component is not particularly limited, and examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol and the like can be mentioned. In addition, diethylene glycol, triethylene glycol, neopentyl glycol, glycerin, alicyclic diols such as cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A Aromatic diols such as are used. Further, in order to ensure good fixability, a trihydric or higher polyhydric alcohol (glycerin, trimethylolpropane, pentaerythritol) may be used in combination with the diol in order to take a crosslinked structure or a branched structure.

  The method for producing the polyester resin is not particularly limited, and may be produced by a general polyester polymerization method in which an acid component and an alcohol component are reacted. Examples thereof include direct polycondensation and transesterification. What is necessary is just to produce it properly according to a kind. The molar ratio (acid component / alcohol component) when the acid component reacts with the alcohol component varies depending on the reaction conditions and the like, and cannot be generally stated, but is usually about 1/1.

  The polyester resin may be produced, for example, at a polymerization temperature of 180 ° C. or higher and 230 ° C. or lower, and may be reacted while removing the water and alcohol generated during condensation by reducing the pressure in the reaction system as necessary. . When the monomer is not dissolved or compatible at the reaction temperature, the polymerization reaction may be partially accelerated or delayed, and many uncolored particles may be generated. It may be added and dissolved as a solubilizer. The polycondensation reaction may be carried out while distilling off the solubilizing solvent. If there is a monomer with poor compatibility in the copolymerization reaction, the monomer with poor compatibility is preliminarily condensed with the acid or alcohol to be polycondensed and then polymerized together with the main component. It may be condensed.

  Catalysts that may be used in the production of the polyester resin include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; metals such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium Compound; Phosphorous acid compound, phosphoric acid compound, amine compound and the like. Among these, for example, it is preferable to use a tin-containing catalyst such as tin, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, and diphenyltin oxide.

  In the present embodiment, a compound having a hydrophilic polar group may be used as long as it is copolymerizable as a resin for an electrostatic charge image developing toner. Specific examples include dicarboxylic acid compounds in which an aromatic ring such as sulfonyl-terephthalic acid sodium salt or 3-sulfonylisophthalic acid sodium salt is directly substituted when the resin used is a polyester.

  The weight average molecular weight Mw of the polyester resin is preferably 5,000 or more, and more preferably 5,000 or more and 50,000 or less. When this polyester resin is included, it is excellent in rubbing property. When the weight average molecular weight Mw of the polyester resin is less than 5,000, it may be easily separated in some cases, and thus problems derived from the released resin (filming, increase in fine powder due to brittleness, deterioration in powder fluidity, etc.) May occur.

  The toner according to the exemplary embodiment may include a resin other than the polyester resin. Although it does not restrict | limit especially as resin other than a polyester resin, Specifically, Styrenes, such as styrene, parachlorostyrene, (alpha) -methylstyrene; Methyl acrylate, ethyl acrylate, acrylic acid n-propyl, butyl acrylate, Acrylic monomers such as lauryl acrylate and 2-ethylhexyl acrylate; methacrylic monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; and further acrylic Ethylenic unsaturated acid monomers such as acid, methacrylic acid and sodium styrenesulfonate; vinyl nitriles such as acrylonitrile and methacrylonitrile; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl methyl ketone and vinyl Vinyl ketones such as ruethyl ketone and vinyl isopropenyl ketone; homopolymers of olefin monomers such as ethylene, propylene and butadiene, copolymers obtained by combining two or more of these monomers, or mixtures thereof; , Epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, etc., non-vinyl condensation resin, or a mixture of these with the vinyl resin, and vinyl monomers in the presence of these resins. Examples thereof include a graft polymer obtained by polymerization. These resins may be used alone or in combination of two or more.

  The content of the binder resin is, for example, in the range of 80% by mass to 95% by mass with respect to the entire toner particles.

  The toner particles according to the exemplary embodiment may contain other additives such as a colorant, a release agent, a charge control agent, silica powder, and a metal oxide as necessary. These additives may be added internally by, for example, kneading into a binder resin, or may be added externally by, for example, mixing the particles after obtaining toner particles.

  There is no restriction | limiting in particular as a coloring agent, A well-known pigment is used, A well-known dye may be included as needed. Specifically, the following pigments such as yellow, magenta, cyan, and black (black) are used.

  As yellow pigments, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complex compounds, methine compounds, allylamide compounds and the like are used.

  As the magenta pigment, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds, and the like are used.

  Examples of cyan pigments include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like.

  As the black pigment, carbon black, aniline black, acetylene black, iron black and the like are used.

  The content of the colorant is, for example, in the range of 5% by mass to 20% by mass with respect to the entire toner particles.

  The release agent is not particularly limited, and examples thereof include plant waxes such as carnauba wax, wood wax and rice bran wax; animal waxes such as bees wax, insect wax, whale wax and wool wax; minerals such as montan wax and ozokerite. Synthetic waxes, synthetic fatty acid solid ester waxes such as Fischer-Tropsch wax (FT wax) having ester side chains, special fatty acid esters, polyhydric alcohol esters; paraffin wax, polyethylene wax, polypropylene wax, polytetrafluoroethylene wax, polyamide wax And synthetic waxes such as silicone compounds. Only one type of release agent may be used, or two or more types may be used.

  The content of the release agent is, for example, in the range of 0.1% by mass to 10% by mass with respect to the entire toner particles.

  There is no restriction | limiting in particular as a charge control agent, A conventionally well-known charge control agent is used. For example, positively chargeable charge control agents such as nigrosine dyes, fatty acid-modified nigrosine dyes, carboxyl group-containing fatty acid-modified nigrosine dyes, quaternary ammonium salts, amine compounds, amide compounds, imide compounds, organometallic compounds; oxycarboxylic acids And negatively chargeable charge control agents such as metal complexes of azo compounds, metal complex dyes and salicylic acid derivatives. Only one type of charge control agent may be used, or two or more types may be used.

  The metal oxide is not particularly limited, and examples thereof include titanium oxide, aluminum oxide, magnesium oxide, zinc oxide, strontium titanate, barium titanate, magnesium titanate, and calcium titanate. Only one type of metal oxide may be used, or two or more types may be used.

(Method for producing toner particles)
The method for producing the toner particles used in the present embodiment is not particularly limited, and is obtained by, for example, pulverizing toner produced by a production method such as pulverized toner, emulsion-dried toner in liquid, or polymerized toner in a carrier liquid. It is done.

  For example, binder resin, and if necessary, colorant, other additives, etc. are put into a mixing device such as a Henschel mixer and mixed, and this mixture is melted with a twin screw extruder, Banbury mixer, roll mill, kneader, etc. After kneading, cooling with a drum flaker, etc., coarsely pulverizing with a pulverizer such as a hammer mill, etc., further pulverizing with a pulverizer such as a jet mill, etc. can get.

  Also, the binder resin, if necessary, the colorant and other additives were dissolved in a solvent such as ethyl acetate, and emulsified and suspended in water to which a dispersion stabilizer such as calcium carbonate was added, and the solvent was removed. Thereafter, particles obtained by removing the dispersion stabilizer are filtered and dried to obtain an in-liquid emulsified dry toner.

  In addition, a polymerizable monomer, a colorant, and a polymerization initiator (for example, benzoyl peroxide, lauroyl peroxide, isopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichloroylbenzoyl peroxide) that form a binder resin , Methyl ethyl ketone peroxide, etc.) and other additives are added to the aqueous phase under stirring and granulated. After the polymerization reaction, the particles are filtered and dried to obtain a polymerized toner.

  The mixing ratio of each material (binder resin, colorant, other additives, etc.) for obtaining the toner may be set in consideration of required characteristics, low temperature fixability, color, and the like. The obtained toner is pulverized in carrier oil using a known pulverizer such as a ball mill, a bead mill, a high-pressure wet atomizer, etc., thereby obtaining toner particles for the liquid developer of this embodiment.

  In the present embodiment, from the viewpoint of ease of surface treatment with polymeric amines, toner particles containing a polyester resin agglomerate a dispersion containing resin particles containing a polyester resin and colorant particles in an aqueous medium. It is preferable that the toner particles are obtained as described above.

(Characteristics of toner particles)
The volume average particle diameter D50v of the toner particles is preferably 0.5 μm or more and 5.0 μm or less. By being in the said range, adhesive force is high and developability is improved. In addition, the resolution of the image can be improved. The volume average particle diameter D50v of the toner particles is more preferably in the range of 0.8 μm or more and 4.0 μm or less, and further preferably in the range of 1.0 μm or more and 3.0 μm or less.

For the volume average particle size D50v, number average particle size distribution index (GSDp), volume average particle size distribution index (GSDv), etc. of the toner particles, a laser diffraction / scattering type particle size distribution measuring device such as LA920 (manufactured by Horiba Ltd.) is used. Measured. Draw a cumulative distribution from the smaller diameter side for each particle size range (channel) divided based on the particle size distribution, and particles with a cumulative particle size of 16%, volume D16v, number D16p, and cumulative 50% The diameter is defined as volume D50v, number D50p, and the particle diameter at 84% cumulative is defined as volume D84v, number D84p. Using these, the volume average particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 and the number average particle size distribution index (GSDp) is calculated as (D84p / D16p) ^1/2 .

[Carrier liquid]
The carrier liquid is an insulating liquid for dispersing the toner particles and is not particularly limited. For example, the carrier liquid is an aliphatic hydrocarbon solvent mainly containing an aliphatic hydrocarbon such as paraffin oil (in a commercial product, Moresco White MT-30P, Moresco White P40, Moresco White P70 manufactured by Matsumura Oil Co., Ltd. Hydrocarbon solvents such as Exon Chemical Co. Isopar L and Isopar M), naphthenic oils, etc. Exol D80, Exol D110, Exol D130 manufactured by Nippon Petrochemicals, Inc. Further, silicone oils (silicone solvents) such as dimethyl silicone oil and methylphenyl silicone oil can be used. Of these, silicone oil is preferable from the viewpoints of safety and non-volatility.

  The carrier liquid contained in the liquid developer according to the exemplary embodiment may be only one type or two or more types. When the carrier liquid is used as a mixed system of two or more kinds, for example, a mixed system of paraffinic solvent and vegetable oil, a mixed system of silicone solvent and vegetable oil, or the like can be used.

Examples of the volume resistivity of the carrier liquid include a range of 1.0 × 10 ¹⁰ Ω · cm to 1.0 × 10 ¹⁴ Ω · cm, and 1.0 × 10 ¹⁰ Ω · cm to 1.0 × It may be in a range of 10 ¹³ Ω · cm or less.

  The carrier liquid is made of various auxiliary materials such as dispersants, emulsifiers, surfactants, stabilizers, wetting agents, thickeners, foaming agents, antifoaming agents, coagulants, gelling agents, anti-settling agents, charging agents. It may contain a control agent, an antistatic agent, an anti-aging agent, a softening agent, a plasticizer, a filler, a flavoring agent, an anti-tacking agent, a release agent and the like.

[Method for producing liquid developer]
In the liquid developer according to the exemplary embodiment, the toner particles and the carrier liquid are mixed and pulverized using a dispersing machine such as a ball mill, a sand mill, an attritor, or a bead mill, and the toner particles are mixed in the carrier liquid. Obtained by dispersing. The dispersion of the toner particles in the carrier liquid is not limited to a disperser, and may be dispersed by rotating a special stirring blade at a high speed like a mixer, or by the shearing force of a rotor / stator known as a homogenizer. Alternatively, it may be dispersed by ultrasonic waves.

  The concentration of the toner particles in the carrier liquid should be in the range of 0.5% by mass or more and 40% by mass or less from the viewpoint of controlling the viscosity of the developer appropriately and facilitating the circulation of the developer in the developing machine. Is preferable, and the range of 1% by mass to 30% by mass is more preferable.

  Thereafter, the obtained dispersion liquid may be filtered using, for example, a filter such as a membrane filter having a pore diameter of about 100 μm to remove dust, coarse particles, and the like.

<Developer cartridge, process cartridge, image forming apparatus>
The image forming apparatus according to the present embodiment includes, for example, an image carrier (hereinafter sometimes referred to as “photosensitive member”), a charging unit that charges the surface of the image carrier, and a latent image ( The latent image forming means for forming the electrostatic latent image) and the latent image formed on the surface of the image holding member are developed with the liquid developer according to the embodiment held on the surface of the developer holding member. Developing means for forming a toner image, transfer means for transferring the toner image formed on the surface of the image carrier onto the recording medium, and fixing the toner image transferred to the recording medium onto the recording medium Fixing means to be formed.

  In the image forming apparatus, for example, the part including the developing unit may have a cartridge structure (process cartridge) that is detachable from the main body of the image forming apparatus. The process cartridge is not particularly limited as long as it contains the liquid developer according to the present embodiment. The process cartridge includes, for example, a developing unit that stores the liquid developer according to the present embodiment and develops a latent image formed on the image carrier with the liquid developer to form a toner image. It is to be attached to and detached from.

  The developer cartridge according to the present embodiment is not particularly limited as long as it contains the liquid developer according to the present embodiment. The developer cartridge contains, for example, the liquid developer according to the present embodiment, and includes an image forming apparatus including a developing unit that forms a toner image by developing the latent image formed on the image holding member with the liquid developer. It is to be attached to and detached from.

  Hereinafter, an image forming apparatus using a liquid developer in the present embodiment will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present embodiment. The image forming apparatus 100 includes a photosensitive member (image holding member) 10, a charging device (charging unit) 20, an exposure device (latent image forming unit) 12, a developing device (developing unit) 14, and an intermediate transfer member (transfer). Means) 16, a cleaner (cleaning means) 18, and a transfer fixing roller (transfer means, fixing means) 28. The photosensitive member 10 has a cylindrical shape, and a charging device 20, an exposure device 12, a developing device 14, an intermediate transfer member 16, and a cleaner 18 are sequentially provided on the outer periphery of the photosensitive member 10.

  Hereinafter, the operation of the image forming apparatus 100 will be described.

  The charging device 20 charges the surface of the photoconductor 10 to a predetermined potential (charging process), and based on the image signal, the exposure device 12 exposes the charged surface with, for example, a laser beam to form a latent image (static image). Electrostatic latent image) is formed (latent image forming step).

  The developing device 14 includes a developing roller 14a and a developer storage container 14b. The developing roller 14a is provided such that a part thereof is immersed in the liquid developer 24 stored in the developer storage container 14b. The liquid developer 24 includes an insulating carrier liquid, toner particles containing a binder resin, and the charge control agent.

  In the liquid developer 24, the toner particles are dispersed. For example, the liquid developer 24 is further stirred by a stirring member provided in the developer container 14b. Variation in the position of the concentration of is reduced. Thus, the liquid developer 24 with reduced toner particle density variation is supplied to the developing roller 14a rotating in the direction of arrow A in the figure.

  The liquid developer 24 supplied to the developing roller 14a is conveyed to the photoconductor 10 in a state where the liquid supply 24 is limited to a constant supply amount by the regulating member, and at a position where the developing roller 14a and the photoconductor 10 are close (or in contact). It is supplied to the electrostatic latent image. As a result, the electrostatic latent image is visualized to become a toner image 26 (development process).

  The developed toner image 26 is conveyed to the photosensitive member 10 that rotates in the direction of arrow B in the figure, and is transferred to a paper (recording medium) 30. In this embodiment, the photosensitive member 26 is transferred before being transferred to the paper 30. The toner image is temporarily transferred to the intermediate transfer body 16 in order to improve the transfer efficiency to the recording medium including the separation efficiency of the toner image from the toner 10, and to perform fixing simultaneously with the transfer to the recording medium (intermediate transfer step). . At this time, a peripheral speed difference may be provided between the photosensitive member 10 and the intermediate transfer member 16.

  Next, the toner image conveyed in the direction of arrow C by the intermediate transfer body 16 is transferred to the paper 30 and fixed at the position of contact with the transfer and fixing roller 28 (transfer process, fixing process). The transfer fixing roller 28 sandwiches the paper 30 together with the intermediate transfer body 16, and causes the toner image on the intermediate transfer body 16 to adhere to the paper 30. As a result, the toner image is transferred to the paper 30, and the toner image is fixed on the paper to form a fixed image 29. The fixing of the toner image is preferably performed by applying a heating element to the transfer fixing roller 28 and applying pressure and heating. The fixing temperature is usually in the range of 120 ° C. or higher and 200 ° C. or lower.

  If the intermediate transfer member 16 has a roller shape as shown in FIG. 1, it forms a roller pair with the transfer fixing roller 28. Therefore, the intermediate transfer member 16 and the transfer fixing roller 28 conform to the fixing roller and the pressing roller in the fixing device, respectively. It shows a fixing function. That is, when the sheet 30 passes through the nip formed between the intermediate transfer body 16 and the transfer fixing roller 28, the toner image is transferred and heated and pressed against the intermediate transfer body 16 by the transfer fixing roller 28. The As a result, the binder resin in the toner particles constituting the toner image is softened, and the toner image is infiltrated into the fibers of the paper 30 to form a fixed image 29 on the paper 30.

  In this embodiment, fixing is performed simultaneously with the transfer to the paper 30. However, the transfer process and the fixing process may be performed separately, and the fixing may be performed after the transfer. In this case, the transfer roller for transferring the toner image from the photoconductor 10 has a function according to the intermediate transfer body 16.

  On the other hand, in the photoreceptor 10 that has transferred the toner image 26 to the intermediate transfer member 16, the toner particles remaining without being transferred are conveyed to a contact position with the cleaner 18 and collected by the cleaner 18. If the transfer efficiency is close to 100% and residual toner is not a problem, the cleaner 18 may not be provided.

  The image forming apparatus 100 may further include a neutralization device (not shown) that neutralizes the surface of the photoconductor 10 after the transfer and before the next charging.

  For example, the charging device 20, the exposure device 12, the developing device 14, the intermediate transfer member 16, the transfer fixing roller 28, and the cleaner 18 that are provided in the image forming apparatus 100 are all synchronized with the rotational speed of the photosensitive member 10. May be operated.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail more concretely, this invention is not limited to a following example.

[Example 1]
(Preparation of liquid developer)
40 parts by mass of cyan pigment (CI Pigment Blue 15: 3, manufactured by Clariant) was added to 60 parts by mass of a polyester resin (manufactured by Kao Corporation, weight average molecular weight: 15,000). Kneaded. The kneaded product was coarsely pulverized to prepare a cyan pigment master batch.

Next, a mixture having the following composition was dissolved and dispersed in a ball mill for 24 hours.
Polyester resin (manufactured by Kao Corporation, weight average molecular weight: 15,000): 70 parts by mass Cyan pigment master batch: 25 parts by mass Ethyl acetate: 100 parts by mass

On the other hand, 50 parts by mass of calcium carbonate (manufactured by Maruo Calcium Co., Ltd., Luminous) as an aqueous dispersion prepared by dissolving 60 parts by mass of sodium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) in 400 parts by mass of ion-exchanged water. And dispersed with a ball mill for 24 hours to obtain a dispersion medium. 100 parts by mass of the mixture was added to 170 parts by mass of this dispersion medium, and the mixture was emulsified at 10,000 rpm or more for 1 minute using an emulsifying apparatus (manufactured by IKA, Ultratax T-50) to obtain a suspension. The suspension was put into a separable flask equipped with a stirrer, thermometer, cooling and a nitrogen introduction tube, and stirred for 3 hours at 60 ° C. while flowing nitrogen through the nitrogen introduction tube to distill off ethyl acetate. .
After allowing to cool, 5% hydrochloric acid aqueous solution was added to the mixture to decompose calcium carbonate, solids were separated by a centrifuge, washed 3 times with 1 L of ion exchange water, and a volume average particle size of 3.5 μm was obtained. A slurry of toner particles was obtained.

  100 parts by mass of the cyan toner particle slurry obtained above was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 20 parts by mass of a 5% by weight aqueous solution of polyethyleneimine (weight average molecular weight 70,000; manufactured by Alfa Aeser) was gradually added dropwise, and stirring was continued for 1 hour after completion of the addition. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 57 parts by mass of dried cyan toner particles.

20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) and an average one-terminal carboxyl-modified silicone oil (X-22-3710; Manufactured by Shin-Etsu Chemical Co., Ltd., in the above formula (1), X is COOH, Y and Z are hydrogen atoms, R ¹ is an alkylene group (details unknown), R ² and R ³ are-(single bond) Number average molecular weight: 1,450) Mixed with 0.1 part by mass to obtain a liquid developer having a solid content concentration of 20% by mass.

<Evaluation of charging characteristics>
(Charge polarity)
Two glass substrates with ITO processed by 5cm x 1cm (EHC: 100Ω / □) are sandwiched with a Naflon sheet (Azwan: 1cm x 1cm x 1.0mm) as an insulating spacer, and the electrode faces inward It was fixed to become. Place 1 mL of liquid developer sample in a disposable cell (Azwan: 12 × 12 × 45 mm), immerse the electrode substrate above, apply a DC voltage of 250 V for 30 seconds, and keep the voltage applied. The polarity of the charge was determined by observing the adhesion state of the particles on the ITO electrode surfaces of the positive electrode and the negative electrode. The results are shown in Table 1.
+: Adheres only to the negative electrode-: adheres only to the positive electrode ±: adheres to both electrodes-: does not adhere to both electrodes

(Positive charge)
For the liquid developers obtained in each Example and each Comparative Example, the potential difference was measured using a “microscopic laser zeta electrometer” ZC-3000 manufactured by Microtick Nithion, and evaluated according to the following five-stage criteria. did. The measurement is performed by diluting the liquid developer with a diluting solvent, putting it in a 10 mm transparent cell, applying a voltage of 300 V at 9 mm between the electrodes, and simultaneously observing the moving speed of the particles in the cell with a microscope. The calculation was performed by calculating the zeta potential from the value. The results are shown in Table 1.
A: Potential difference is +100 mV or more (very good)
B: Potential difference is +85 mV or more and less than +100 mV (good)
C: Potential difference is +70 mV or more and less than +85 mV (normal)
D: Potential difference is +50 mV or more and less than +70 mV (somewhat bad)
E: Potential difference is less than +50 mV (very bad)

  The toner particles can be collected from the liquid developer by the following method. The liquid developer is sedimented by centrifugation (1,000 rpm × 5 minutes), the supernatant is removed by decantation, and the toner particles are removed. The removed toner particles are washed with hexane, isopar or the like (the mixed solvent may be appropriately changed depending on the toner resin).

[Example 2]
100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, polyallylamine PAA-15C (15 wt% solution; manufactured by Nitto Bo Medical Co., Ltd., in the above formula (2), m is about 300, and n is 0. Weight average molecular weight: 15,000 ) 10 parts by mass were gradually added dropwise, and stirring was continued for 1 hour after completion of the addition. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 53 parts by mass of dried cyan toner particles.

20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) and side chain carboxyl-modified silicone oil (X-22-3701E; Shin-Etsu Chemical). In the above formula (1) manufactured by Kogyo Co., Ltd., X and Y are hydrogen atoms, Z is COOH, R ¹ and R ² are-(single bond), and R ³ is an alkylene group (details unknown). (Number average molecular weight: 40,000) 0.2 parts by mass was mixed to obtain a liquid developer having a solid content concentration of 20% by mass. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, polyallylamine PAA-1112 (15 wt% solution; manufactured by Nitto Bo Medical Co., Ltd., in the above formula (2), m is 5 or more and 10 or less, n is 5 or more and 10 or less, and R ⁴ And R ⁵ is a methyl group, 10 parts by weight of a weight average molecular weight: 1,000) were gradually added dropwise, and stirring was continued for 1 hour after the addition was completed. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 58 parts by mass of dried cyan toner particles.

20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.), and both-end carboxyl-modified silicone oil (BY16-750; Toray Dow Corning). In the above formula (1), X and Y are COOH, Z is a hydrogen atom, R ¹ and R ² are alkylene groups (details are unknown), and R ³ is-(single bond). (Average molecular weight: 1,500) Mixed with 0.05 part by mass, a liquid developer having a solid concentration of 20% by mass was obtained. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]
100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 10 parts by mass of polyamine PAS-21 (15% by weight solution; manufactured by Nitto Bo Medical Co., Ltd., weight average molecular weight: 4,000) was gradually added dropwise, and stirring was continued for 1 hour after completion of the addition. . After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 58 parts by mass of dried cyan toner particles.

20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) and carboxyl-modified silicone oil (X-22-162C; Shin-Etsu Chemical ( In the above formula (1), X and Y are COOH, Z is a hydrogen atom, R ¹ and R ² are alkylene groups (details unknown), and R ³ is-(single bond). (Molecular weight: 4,600) 0.05 parts by mass was mixed to obtain a liquid developer having a solid content concentration of 20% by mass. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Example 5]
100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 20 parts by mass of a 5% by weight aqueous solution of polyethyleneimine (weight average molecular weight 70,000; manufactured by Alfa Aeser) was gradually added dropwise, and stirring was continued for 1 hour after completion of the addition. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 57 parts by mass of dried cyan toner particles.

  20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.), and both-end carboxyl-modified silicone oil (BY16-750; Toray Dow Corning). Mixed with 0.05 parts by mass to obtain a liquid developer having a solid content concentration of 20% by mass. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Example 6]
100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 10 parts by mass of polyallylamine PAA-1112 (15 wt% solution; manufactured by Nitto Bo Medical Co., Ltd.) was gradually added dropwise, and stirring was continued for 1 hour after the addition was completed. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 58 parts by mass of dried cyan toner particles.

  20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) and an average one-terminal carboxyl-modified silicone oil (X-22-3710; Mixing with 0.1 part by mass of Shin-Etsu Chemical Co., Ltd.), a liquid developer having a solid content concentration of 20% by mass was obtained. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Example 7]
100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 10 parts by mass of polyallylamine PAA-1112 (15 wt% solution; manufactured by Nitto Bo Medical Co., Ltd.) was gradually added dropwise, and stirring was continued for 1 hour after the addition was completed. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 58 parts by mass of dried cyan toner particles.

  20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) and side chain carboxyl-modified silicone oil (X-22-3701E; Shin-Etsu Chemical). This was mixed with 0.2 parts by mass of Kogyo Co., Ltd. to obtain a liquid developer having a solid concentration of 20% by mass. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Example 8]
100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 10 parts by mass of polyallylamine PAA-1112 (15 wt% solution; manufactured by Nitto Bo Medical Co., Ltd.) was gradually added dropwise, and stirring was continued for 1 hour after the addition was completed. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 58 parts by mass of dried cyan toner particles.

  20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) and carboxyl-modified silicone oil (X-22-162C; Shin-Etsu Chemical ( Co., Ltd.) and mixed with 0.05 part by mass to obtain a liquid developer having a solid concentration of 20% by mass. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Example 9]
100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 10 parts by mass of polyallylamine PAA-15C (15% by weight solution; manufactured by Nitto Bo Medical Co., Ltd.) was gradually added dropwise, and stirring was continued for 1 hour after completion of the addition. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 53 parts by mass of dried cyan toner particles.

  20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) and an average one-terminal carboxyl-modified silicone oil (X-22-3710; Mixing with 0.1 part by mass of Shin-Etsu Chemical Co., Ltd.), a liquid developer having a solid content concentration of 20% by mass was obtained. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Example 10]
100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 10 parts by mass of polyamine PAS-21 (15% by weight solution; manufactured by Nitto Bo Medical Co., Ltd.) was gradually added dropwise, and stirring was continued for 1 hour after the addition was completed. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 58 parts by mass of dried cyan toner particles.

  20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) and an average one-terminal carboxyl-modified silicone oil (X-22-3710; Mixing with 0.1 part by mass of Shin-Etsu Chemical Co., Ltd.), a liquid developer having a solid content concentration of 20% by mass was obtained. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Example 11]
(Synthesis of soluble polymer containing carboxyl group)
1 part by weight of methacrylic acid and 50 parts by weight of methacryloxy-modified silicone FM0711 (manufactured by Chisso) were dissolved in 100 parts by weight of toluene and purged with nitrogen, followed by azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.). 2 parts by mass were added and reacted at 80 ° C. for 20 hours. After completion of the reaction, toluene was distilled off under reduced pressure, the residue was washed with methanol, and concentrated under reduced pressure to obtain a soluble polymer compound represented by the following formula (carboxyl group-containing silicone compound, in the above formula (3), R ⁷ is aliphatic. A hydrocarbon group (details are unknown), l is about 10.).

  100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 20 parts by mass of a 5% by weight aqueous solution of polyethyleneimine (weight average molecular weight 70,000; manufactured by Alfa Aeser) was gradually added dropwise, and stirring was continued for 1 hour after completion of the addition. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 57 parts by mass of dried cyan toner particles.

  20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.05 of the above soluble polymer compound (carboxyl group-containing silicone compound). A liquid developer having a solid content of 20% by mass was obtained by mixing with parts by mass. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Example 12]
100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 10 parts by mass of polyallylamine PAA-1112 (15 wt% solution; manufactured by Nitto Bo Medical Co., Ltd.) was gradually added dropwise, and stirring was continued for 1 hour after the addition was completed. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 58 parts by mass of dried cyan toner particles.

  20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) and the soluble polymer compound (carboxyl group-containing silicone) used in Example 11. Compound) mixed with 0.05 part by mass to obtain a liquid developer having a solid concentration of 20% by mass. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Example 13]
Cyan toner particles were obtained by the method described in Example 1 of JP-A-11-7156.

  100 parts by mass of the resulting toner particle slurry was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 10 parts by mass of polyallylamine PAA-1112 (15 wt% solution; manufactured by Nitto Bo Medical Co., Ltd.) was gradually added dropwise, and stirring was continued for 1 hour after the addition was completed. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 58 parts by mass of dried cyan toner particles.

  20 parts by mass of the cyan toner particles obtained above were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) and an average one-terminal carboxyl-modified silicone oil (X-22-3710; Mixing with 0.1 part by mass of Shin-Etsu Chemical Co., Ltd.), a liquid developer having a solid content concentration of 20% by mass was obtained. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
The slurry of cyan toner particles used in Example 1 was lyophilized as it was at 20 ° C. for 24 hours to recover 60 parts by mass of the dried cyan toner particles.

  20 parts by mass of the obtained dry cyan toner particles were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) to obtain a liquid developer having a solid content concentration of 20% by mass. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 2]
20 parts by mass of the dry cyan toner particles used in Comparative Example 1, 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.), and one-end carboxyl-modified silicone oil (X-22-3710; Mixing with 0.1 part by mass of Shin-Etsu Chemical Co., Ltd.), a liquid developer having a solid content concentration of 20% by mass was obtained. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3]
100 parts by mass of the cyan toner particle slurry used in Example 1 was dispersed in 300 parts by mass of distilled water, and adjusted to pH 2 by adding 4 parts by mass of 1N hydrochloric acid. While stirring this mixture, 20 parts by mass of a 5% by weight aqueous solution of polyethyleneimine (weight average molecular weight 70,000; manufactured by Alfa Aeser) was gradually added dropwise, and stirring was continued for 1 hour after completion of the addition. After completion of the stirring, the dispersion was subjected to suction filtration and repeatedly washed with water, and then the obtained cake was freeze-dried at 20 ° C. for 24 hours to recover 57 parts by mass of dried cyan toner particles.

  20 parts by mass of the obtained dry cyan toner particles were mixed with 80 parts by mass of silicone oil (KE-96L-20cs; manufactured by Shin-Etsu Chemical Co., Ltd.) to obtain a liquid developer having a solid content concentration of 20% by mass. Thereafter, the charging characteristics were determined in the same manner as in Example 1. The results are shown in Table 1.

  As described above, the example using the liquid developer containing the toner particles containing the polyester resin and the carboxyl group-containing silicone compound, which is surface-treated with the polymer amines, has a positive chargeability as compared with the comparative example. Excellent.

  DESCRIPTION OF SYMBOLS 10 Photosensitive body (image holding body), 12 Exposure apparatus (latent image forming means), 14 Developing apparatus (developing means), 14a Developing roller (developer holding body), 14b Developer accommodating container, 16 Intermediate transfer body (transfer means) ), 18 cleaner (cleaning means), 20 charging device (charging means), 24 liquid developer, 26 toner image, 28 transfer fixing roller (transfer means, fixing means), 29 fixed image, 30 paper (recording medium), 100 Image forming apparatus.

Claims (9)

Carrier liquid,
Toner particles surface-treated with polymeric amines and containing polyester resin;
A carboxyl group-containing silicone compound;
A liquid developer comprising: The liquid developer according to claim 1, wherein the carboxyl group-containing silicone compound is a compound represented by the following general formula (1).

(1)
(In formula (1), X, Y and Z each independently represent a hydrogen atom or a carboxyl group, and at least one of X, Y and Z represents a carboxyl group. N is an integer of 1 to 10. R ¹ , R ² and R ³ are each independently a single bond or a divalent aliphatic carbon atom having 1 to 20 carbon atoms. Indicates a hydrogen group.)   The liquid developer according to claim 1, wherein the high molecular amine is a polyalkyleneimine. The liquid developer according to claim 1, wherein the high molecular amine is a polyallylamine represented by the following general formula (2).

(2)
(In Formula (2), R ⁴ and R ⁵ each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and m and n each independently represent 100 or more and 1,000. The following integers are shown.)   The toner particles containing the polyester resin are toner particles obtained by aggregating a dispersion containing resin particles containing a polyester resin and colorant particles in an aqueous medium. The liquid developer according to any one of the above.   A developer cartridge in which the liquid developer according to claim 1 is contained.   A process cartridge in which the liquid developer according to claim 1 is contained. An image carrier,
Latent image forming means for forming a latent image on the surface of the image carrier;
The toner image is formed by developing the latent image formed on the surface of the image carrier with the liquid developer according to any one of claims 1 to 5 held on the surface of the developer carrier. Developing means,
Transfer means for transferring the toner image formed on the surface of the image carrier onto a recording medium;
Fixing means for fixing the toner image transferred to the recording medium to the recording medium to form a fixed image;
An image forming apparatus comprising: A latent image forming step of forming a latent image on the surface of the image carrier;
The toner image is formed by developing the latent image formed on the surface of the image carrier with the liquid developer according to any one of claims 1 to 5 held on the surface of the developer carrier. A development process to
A transfer step of transferring the toner image formed on the surface of the image carrier onto a recording medium;
A fixing step of fixing the toner image transferred to the recording medium to the recording medium to form a fixed image;
An image forming method comprising: