JP2016224099A - Curable liquid developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable liquid developer that stabilizes an electrophoretic behavior of toner particles to have good developability.SOLUTION: There is provided a curable liquid developer that contains a liquid polymerizable compound, polymerization initiator, charge control agent, and toner particles, wherein when an agent prepared by excluding only the charge control agent from the curable liquid developer is a D1 agent, and an agent prepared by excluding only the polymerization initiator from the curable liquid developer is a D2 agent, the D1 agent and D2 agent have the same electrophoretic polarity as each other.SELECTED DRAWING: None

Description

  The present invention relates to a liquid developer used in an image forming apparatus using an electrophotographic method such as electrophotographic method, electrostatic recording method, and electrostatic printing.

In the electrophotographic system, the surface of an image carrier such as a photoconductor is uniformly charged (charging process), and an electrostatic latent image is formed on the surface of the image carrier by exposure (exposure process). The electrostatic latent image is developed with a developer made of colored resin particles (development process), the developer image is transferred to a recording medium such as paper or plastic film (transfer process), and the transferred developer image is fixed to the recording medium. (Fixing step) to obtain a printed matter.
In this case, the developer is a liquid developer in which colored resin particles composed of a material including a colorant such as a pigment and a binder resin are used in a dry state, and liquid development in which the colored resin particles are dispersed in an electrically insulating liquid. It is roughly divided into agents.
Since dry developers handle solid-state developers, they currently dominate the developers due to their handling advantages. In order to obtain a high-resolution and high-quality image, first, the developer has an appropriate chargeability for attaching an amount of developer corresponding to the charge density of the electrostatic latent image formed on the image carrier. Required. However, in dry developers, there is a problem in the environmental stability of the charging property from the viewpoint of preventing image deterioration due to environmental changes such as temperature and humidity, and the colored resin particles are likely to aggregate during storage. There was a problem in uniformity when dispersed. Moreover, when these characteristics aim at high resolution and the colored resin particle diameter is relatively small, problems caused by the above-described powder become more remarkable.
On the other hand, the liquid developer uses an electrically insulating liquid as a carrier liquid, so that the problem of agglomeration of colored resin particles in the liquid developer during storage is less likely to occur compared to a dry developer, and fine toner particles are used. Can be used. As a result, the liquid developer has better reproducibility of fine line images, better gradation reproducibility, better color reproducibility, and better image forming methods at high speed than dry developers. It has the feature of being.
In recent years, there has been a demand for the development of a liquid developer having better characteristics taking advantage of these excellent features in a high-quality, high-speed digital printing apparatus.
Conventional liquid developers are known in which colored resin particles are dispersed in an electrically insulating liquid such as a hydrocarbon-based organic solvent or silicone oil. However, such a liquid developer needs to remove the electrically insulating liquid because the image quality is significantly deteriorated when the electrically insulating liquid remains on a recording medium such as paper or plastic film. For removing the electrically insulating liquid, a method of volatilizing and removing the electrically insulating liquid by applying heat energy is generally used. However, in that case, the volatile organic solvent vapor may be diffused outside the apparatus, It is not always preferable from an environmental point of view.
As a countermeasure against this, a method of curing an electrically insulating liquid by a polymerization reaction by light or heat has been proposed. For example, a photocurable liquid developer uses a monomer or oligomer having a reactive functional group as an electrically insulating liquid, and is further dissolved by adding a photopolymerization initiator. This photo-curable liquid developer is cured by a polymerization reaction when irradiated with light such as ultraviolet rays, so that the speed of image formation can be increased.
In order to meet the recent demands for higher image quality and higher speed, there is known a method of adding a large charge to toner particles by adding a charge control agent to a liquid developer (Patent Document 1).

Japanese Patent No. 3442406

However, in the prior art, the influence of the polymerization initiator, which is a unique and essential material for the curable liquid developer, on the charging has not been considered. Therefore, if a charge control agent that has been used in the past to improve the developability of toner particles in a curable liquid developer is used, the electrophoretic behavior of the toner particles becomes unstable depending on the combination with the polymerization initiator. An issue was found.
That is, the present invention provides a curable liquid developer that stabilizes the electrophoretic behavior of toner particles and has good developability.

The present invention is a curable liquid developer containing a liquid polymerizable compound, a polymerization initiator, a charge control agent, and toner particles,
D1 agent was prepared by removing only the charge control agent from the curable liquid developer,
When the D2 agent was prepared by removing only the polymerization initiator from the curable liquid developer,
The curable liquid developer is characterized in that the electrophoretic polarities of toner particles in the D1 agent and the D2 agent are the same polarity.

  According to the present invention, it is possible to provide a curable liquid developer that stabilizes the electrophoretic behavior of toner particles and has good developability.

The curable liquid developer of the present invention is a curable liquid developer containing a liquid polymerizable compound, a polymerization initiator, a charge control agent, and toner particles,
D1 agent was prepared by removing only the charge control agent from the curable liquid developer,
When the D2 agent was prepared by removing only the polymerization initiator from the curable liquid developer,
The electrophoretic polarities of the toner particles in the D1 agent and the D2 agent are the same polarity.

As described above, the electrophoretic behavior of toner particles may become unstable depending on the combination with a polymerization initiator when a charge control agent that has been used in the past is used to improve the developability of toner particles in a curable liquid developer. become.
Although this reason is not necessarily clear, it can be considered as follows.
In order to initiate the polymerization reaction of the liquid polymerizable compound, a reaction called an initiation reaction is required. A substance used for this purpose is a polymerization initiator.
However, when the polymerization initiator is mixed with the liquid polymerizable compound, the volume resistivity tends to decrease, and it is considered that some ionic dissociation occurs.
When ions generated by the dissociation are selectively adsorbed on the toner particles, the toner particles are charged, and thus can move (that is, electrophoresis) in the electric field.
On the other hand, the charge control agent is for improving the chargeability of the toner particles, and is considered to charge the toner particles by selective adsorption of ions to the toner particles.
That is, the polymerization initiator unintentionally functions in the same manner as the charge control agent. Therefore, if the polarity that the ion derived from the polymerization initiator gives to the toner particles and the polarity that the ion derived from the charge control agent gives to the toner particles are opposite, the charge distribution on the surface of the toner particles will be mixed and the electrophoresis will be mixed. It is thought that the behavior becomes unstable.
Therefore, in the present invention, the electrophoretic polarities of the toner particles in the D1 agent and D2 agent are the same, thereby stabilizing the electrophoretic behavior of the toner particles and realizing good developability of the liquid developer. Yes.

The curable liquid developer of the present invention includes a liquid polymerizable compound, a polymerization initiator, a charge control agent, and toner particles. The curable liquid developer preferably has excellent curability, high volume resistivity, and low viscosity near room temperature.
Hereinafter, the material used for this invention is demonstrated in detail.

<Liquid polymerizable compound>
In the present invention, the liquid polymerizable compound is not particularly limited as long as it has a high volume resistivity and is electrically insulating, and has a low viscosity near room temperature.
The viscosity of the liquid polymerizable compound at 25 ° C. is preferably 0.5 mPa · s to 200 mPa · s, and more preferably 0.5 mPa · s to 100 mPa · s.
The volume resistivity of the liquid polymerizable compound is preferably 1 × 10 ⁹ Ω · cm to 1 × 10 ¹³ Ω · cm, and preferably 1 × 10 ¹⁰ Ω · cm to 1 × 10 ¹³ Ω · cm. It is more preferable that
The liquid polymerizable compound is preferably selected from liquids that do not dissolve the binder resin contained in the toner particles. Specifically, it is preferably selected from a combination of a liquid polymerizable compound and a binder resin such that the binder resin to be dissolved is 1 part by mass or less with respect to 100 parts by mass of the liquid polymerizable compound at a temperature of 25 ° C.
The liquid polymerizable compound is preferably a component that can be polymerized by a photopolymerization reaction. The photopolymerization reaction may be any type of light reaction, but is more preferably an ultraviolet light reaction.
As the liquid polymerizable compound, there are those having radical polymerizability, those having cationic polymerizability, and those having both, and any of them can be suitably used.
Examples thereof include vinyl ether compounds, urethane compounds, styrene compounds, acrylic compounds, and cyclic ether compounds such as epoxy compounds and oxetane compounds.
In this invention, this liquid polymeric compound may contain the said compound individually by 1 type, and may contain it in combination of 2 or more type.

In the present invention, the liquid polymerizable compound preferably includes a cationic polymerizable compound, and more preferably includes a vinyl ether compound. Since the vinyl ether compound has little deviation in electron density in the molecule, a curable liquid developer having high resistance, low viscosity and high sensitivity can be obtained by using the vinyl ether compound.
Here, the vinyl ether compound refers to a compound having a vinyl ether structure (—CH═CH—O—C—).
The vinyl ether structure is preferably represented by R—CH═CH—O—C— (R is hydrogen or alkyl having 1 to 3 carbon atoms, preferably hydrogen or methyl).
In the present invention, it is also one of preferred embodiments that the vinyl ether compound is a compound having no hetero atom other than the vinyl ether structure.
Here, the hetero atom means an atom other than a carbon atom and a hydrogen atom.
When a heteroatom is contained in a vinyl ether compound, the electron density is likely to be biased in the molecule due to the difference in electronegativity between the heteroatom and the carbon atom. The resistance tends to decrease because the trajectory tends to be a path of conduction electrons or holes.
Furthermore, in this invention, it is also one of the preferable aspects that a vinyl ether compound does not have carbon-carbon double bonds other than a vinyl ether structure in a vinyl ether compound. A carbon-carbon double bond has an electron occupied orbital with a high energy level and a non-electron occupied orbital with a low energy level, but these tend to be a path for electrons and holes, and easily reduce resistance. When a carbon-carbon double bond other than the vinyl ether structure is contained in the vinyl ether compound, the resistance is likely to decrease due to such a mechanism.
In the present invention, the vinyl ether compound is preferably represented by the following formula (C).

［式（Ｃ）中、ｎは、一分子中のビニルエーテル構造の数を示し、１以上４以下の整数である。Ｒはｎ価の炭化水素基である。］
上記ｎは、１以上３以下の整数であることが好ましい。
Ｒは、好ましくは、炭素数１以上２０以下の直鎖又は分岐の飽和又は不飽和の脂肪族炭化水素基、炭素数５以上１２以下の飽和又は不飽和の脂環式炭化水素基、及び炭素数６以上１４以下の芳香族炭化水素基から選択される基であり、該脂環式炭化水素基及び該芳香族炭化水素基は、炭素数１以上４以下の飽和又は不飽和の脂肪族炭化水素基を有していてもよい。
上記Ｒは、より好ましくは炭素数４以上１８以下の直鎖又は分岐の飽和脂肪族炭化水素基である。
以下に、ビニルエーテル化合物の具体例〔例示化合物Ｂ−１〜Ｂ−３０〕を挙げるが、本発明はこれらの例に制限されるものではない。

[In the formula (C), n represents the number of vinyl ether structures in one molecule and is an integer of 1 or more and 4 or less. R is an n-valent hydrocarbon group. ]
N is preferably an integer of 1 or more and 3 or less.
R is preferably a linear or branched saturated or unsaturated aliphatic hydrocarbon group having 1 to 20 carbon atoms, a saturated or unsaturated alicyclic hydrocarbon group having 5 to 12 carbon atoms, and carbon. A group selected from an aromatic hydrocarbon group having 6 to 14 carbon atoms, the alicyclic hydrocarbon group and the aromatic hydrocarbon group having a saturated or unsaturated aliphatic carbon group having 1 to 4 carbon atoms You may have a hydrogen group.
R is more preferably a linear or branched saturated aliphatic hydrocarbon group having 4 to 18 carbon atoms.
Specific examples of the vinyl ether compound [Exemplary Compounds B-1 to B-30] are shown below, but the present invention is not limited to these examples.

  Among these, preferred are dodecyl vinyl ether (B-3), dicyclopentadiene vinyl ether (B-8), cyclohexanedimethanol divinyl ether (B-17), tricyclodecane vinyl ether (B-10), dipropylene glycol. Divinyl ether (B-19), trimethylolpropane trivinyl ether (B-24), 2-ethyl-1,3-hexanediol divinyl ether (B-25), 2,4-diethyl-1,5-pentanediol di Vinyl ether (B-26), 2-butyl-2-ethyl-1,3-propanediol divinyl ether (B-27), neopentyl glycol divinyl ether (B-23), pentaerythritol tetravinyl ether (B-28), 1,2-decanediol Like ether (B-30).

Examples of the epoxy compound having cationic polymerizability include the following aromatic epoxides, alicyclic epoxides, and aliphatic epoxides.
Aromatic epoxides include di- or polyglycidyl ethers produced by reaction of polyphenols having at least one aromatic nucleus or their alkylene oxide adducts with epichlorohydrin.
Specific examples include di- or polyglycidyl ethers of bisphenol A or alkylene oxide adducts thereof, di- or polyglycidyl ethers of hydrogenated bisphenol A or alkylene oxide adducts thereof, and novolak-type epoxy resins.
Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.
The alicyclic epoxide is obtained by epoxidizing a compound having at least one cycloalkene ring such as cyclohexene ring or cyclopentene ring with a suitable oxidizing agent such as hydrogen peroxide or peracid. Can be mentioned.
Specifically, a cyclohexene oxide or a cyclopentene oxide-containing compound can be exemplified.
Examples of the aliphatic epoxide include dihydric polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof.
Specifically, diglycidyl ether of ethylene glycol, diglycidyl ether of propylene glycol or diglycidyl ether of alkylene glycol such as diglycidyl ether of 1,6-hexanediol, di- or triglycidyl of glycerin or its alkylene oxide adduct Polyglycidyl ethers of polyhydric alcohols such as ethers, diglycidyl ethers of polyethylene glycol or alkylene oxide adducts thereof, diglycidyl ethers of polyalkylene glycols such as polypropylene glycol or diglycidyl ethers of alkylene oxide adducts thereof, and the like.
Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.
Moreover, it is also preferable to use an epoxy-modified silicone oil compound or the like as the epoxy compound having cationic polymerizability.
On the other hand, as the above-mentioned compound having radical polymerizability, monofunctional compounds include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl acroyl phosphate, tetrahydrofurfuryl acrylate, indecyl. Examples thereof include monomers such as acrylate and polymers thereof.
For bifunctional ones, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, tripropylene glycol diacrylate, neopentyl glycol diacrylate, gin Examples thereof include monomers such as kudiacrylate and ethoxylated bisphenol A diacrylate and polymers thereof.
Trifunctional monomers include monomers such as trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, and polymers thereof.
Examples of tetra- or higher functional monomers include monomers such as pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hydroxypentaacrylate, dipentaerythritol hexaacrylate, and polymers thereof.

<Polymerization initiator>
In order to initiate the polymerization reaction of the liquid polymerizable compound, a reaction called an initiation reaction is required. A substance used for this purpose is a polymerization initiator.
In the present invention, examples of the polymerization initiator include the following.
Cationic polymerization initiators include, but are not limited to, onium salt compounds; nonionic compounds such as sulfonyldiazomethane compounds, oxime sulfonate compounds, imide sulfonate compounds, and trichloromethyltriazine compounds.
Examples of onium salt compounds include iodonium compounds (for example, IRGACURE (registered trademark) 250 manufactured by BASF, WPI-113, WPI-116, WPI-169, WPI-170, WPI-124 or more, Wako Pure Chemical Industries, Ltd.), And sulfonium-based compounds (triarylsulfonium salt-based compounds CPI-110P, CPI-210S or more, manufactured by San Apro, aromatic sulfonium salt-based compounds, Adekaoptomer SP-150 ADEKA Corporation).
Examples of the nonionic compound include the following compounds.
As sulfonyldiazomethane-based compounds, WPAG-145 (Bis (cyclohexylsulfonyl) diazomethane), WPAG-170 (Bis (t-butylsulfonyl) diazomethane), WPAG-199 (Bis (f-toluene)), WPAG-199 (Bis (f-toluene))
ane)).
As an oxime sulfonate-based compound, IRGACURE (registered trademark) PAG103 [(5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitryl], IRGACURE (registered trademark) PAG108 [(5-octimyloxy) 5] -2-ylidene)-(2-methylphenyl) acetontrile)], IRGACURE (registered trademark) PAG121 [(5-p-toluenesulfonyloxyimino-5H-thiophene-2-ylidene)-(2-methylphenyl) acetonitrileBA, above Made It is below.
Examples of imide sulfonate compounds include N-trifluoromethylsulfuccinimide, N-Hydroxyphthalmide triflate, N-Hydroxy-5-norbornenene-2, 3-dicarboxene-2, 3-dicarboxenebide.
As a trichloromethyltriazine compound, 2- [2- (Furan-2-yl) ethylene] -4,6-bis (trichloromethyl) -s-triazine, 2- [2- (5-Methylfuran) manufactured by Sanwa Chemical Co., Ltd. -2-yl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine, 2- (methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- [2- (3,4- Dimethylphenethyl) ethyl] -4,6-bis (trichloromethyl) -s-triazine.

Of the cationic polymerization initiators, nonionic compounds such as sulfonyldiazomethane compounds, oxime sulfonate compounds, imide sulfonate compounds, and trichloromethyltriazine compounds are preferred. This is because even when the nonionic compound and the liquid polymerizable compound are mixed, the volume resistivity of the liquid polymerizable compound is extremely low.
About the said imide sulfonate type compound, a specific example is shown and further demonstrated.
As this imide sulfonate type compound, the photoinitiator represented by following formula (1) is mentioned.

［式（１）中、Ｒ_８とＲ_９は互いに結合して環構造を形成し、ｘは１〜８の整数を表し、ｙは３〜１７の整数を表す。］

[In Formula (1), R ₈ and R ₉ are bonded to each other to form a ring structure, x represents an integer of 1 to 8, and y represents an integer of 3 to 17. ]

The photopolymerization initiator represented by the above formula (1) is photolyzed by ultraviolet irradiation to generate a sulfonic acid that is a strong acid. It is also possible to use a sensitizer together and cause the polymerization initiator to decompose and sulfonic acid to be generated by using the sensitizer to absorb ultraviolet rays as a trigger.
Examples of the ring structure formed by combining R ₈ and R ₉ include 5-membered rings and 6-membered rings. Specific examples of the ring structure formed by combining R ₈ and R ₉ include succinimide structure, phthalimide structure, norbornene dicarboximide structure, naphthalene dicarboximide structure, cyclohexanedicarboximide structure, epoxy Examples thereof include a cyclohexene dicarboximide structure.
The ring structure may have an alkyl group, an alkyloxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, or the like as a substituent.

CxFy in the above formula (1) includes a linear alkyl group (RF1) in which a hydrogen atom is substituted with a fluorine atom, a branched alkyl group (RF2) in which a hydrogen atom is substituted with a fluorine atom, and a hydrogen atom in a fluorine atom And an aryl group (RF4) in which a hydrogen atom is substituted with a fluorine atom.
Examples of the linear alkyl group (RF1) in which a hydrogen atom is substituted with a fluorine atom include a trifluoromethyl group (x = 1, y = 3), a pentafluoroethyl group (x = 2, y = 5), and hepta. Fluoro n-propyl group (x = 3, y = 7) nonafluoro n-butyl group (x = 4, y = 9), perfluoro n-hexyl group (x = 6, y = 13), and perfluoro n- An octyl group (x = 8, y = 17) etc. are mentioned.
Examples of the branched alkyl group (RF2) in which a hydrogen atom is substituted with a fluorine atom include a perfluoroisopropyl group (x = 3, y = 7) and a perfluoro-tert-butyl group (x = 4, y = 9). ), And a perfluoro-2-ethylhexyl group (x = 8, y = 17).
Examples of the cycloalkyl group (RF3) in which a hydrogen atom is substituted with a fluorine atom include a perfluorocyclobutyl group (x = 4, y = 7), a perfluorocyclopentyl group (x = 5, y = 9), Examples include a fluorocyclohexyl group (x = 6, y = 11) and a perfluoro (1-cyclohexyl) methyl group (x = 7, y = 13).
Examples of the aryl group (RF4) in which a hydrogen atom is substituted with a fluorine atom include a pentafluorophenyl group (x = 6, y = 5) and a 3-trifluoromethyltetrafluorophenyl group (x = 7, y = 7).
Of the CxFy in the above formula (1), from the viewpoint of availability and decomposability of the sulfonic acid ester moiety, preferably a linear alkyl group (RF1), a branched alkyl group (RF2), and aryl Group (RF4). More preferably, they are a linear alkyl group (RF1) and an aryl group (RF4). Particularly preferably, trifluoromethyl group (x = 1, y = 3), pentafluoroethyl group (x = 2, y = 5), heptafluoro n-propyl group (x = 3, y = 7), nonafluoro n- A butyl group (x = 4, y = 9), and a pentafluorophenyl group (x = 6, y = 5).

  Specific examples [Exemplary compounds A-1 to A-27] of the photopolymerization initiator represented by the above formula (1) are listed below, but the present invention is not limited to these examples.

On the other hand, examples of the radical polymerization initiator include, but are not limited to, α-aminoalkylphenone compounds, α-hydroxyalkylphenone compounds, acylphosphine oxide compounds, and oxime ester compounds.
As an α-aminoalkylphenone compound, IRGACURE (registered trademark) 369 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, IRGACURE (registered trademark) 379 (EG) manufactured by BASF ) 2-Dimethylamino-2- (4methylbenzyl) -1- (4-morpholin-4-ylphenyl) butan-1-one, IRGACURE® 907 2-methyl-1 [4-methylthiophenyl] -2-morpholinopropan-1-one.
As an α-hydroxyalkylphenone compound, IRGACURE (registered trademark) 127 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2 manufactured by BASF -Methyl-propan-1-one, IRGACURE (R) 184 1-hydroxy-cyclohexyl-phenyl-ketone, DAROCUR (R) 1173 2-hydroxy-2-methyl-1-phenyl-propan-1-one, IRGACURE (Registered trademark) 2959 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one.
As an acylphosphine oxide compound, IRGACURE (registered trademark) 819 bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, IRGACURE (registered trademark) 1800 bis (2,6-dimethoxybenzoyl) manufactured by BASF -2,4,4-trimethyl-pentylphosphine oxide, Lucirin TPO 2,4,6-trimethylbenzoyldiphenylphosphine oxide, Lucirin TPO-L 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide.
As oxime ester compounds, IRGACURE (registered trademark) OXE01 1,2-octanedione, 1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime), IRGACURE (registered trademark) OXE02 manufactured by BASF Corporation And ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime).

The said polymerization initiator can be used individually by 1 type or in combination of 2 or more types.
The content of the polymerization initiator is not particularly limited, but is preferably 0.01 parts by mass or more and 5 parts by mass or less, more preferably 0.05 parts by mass or more with respect to 100 parts by mass of the liquid polymerizable compound. 1 part by mass or less, more preferably 0.1 part by mass or more and 0.5 part by mass or less.

<Charge control agent>
In the present invention, a charge control agent is used for the purpose of improving the chargeability of the toner particles.
As the charge control agent, any known one can be used without particular limitation as long as the volume resistivity of the curable liquid developer is small and the increase in viscosity is small.
Specific examples of the compound include the following.
Oils and fats such as linseed oil and soybean oil; Alkyd resins, halogen polymers, aromatic polycarboxylic acids, acidic group-containing water-soluble dyes, oxidative condensates of aromatic polyamines; zirconium naphthenate, cobalt naphthenate, nickel naphthenate, naphthene Metal soaps such as iron oxide, zinc naphthenate, cobalt octylate, nickel octylate, zinc octylate, cobalt dodecylate, nickel dodecylate, zinc dodecylate, aluminum stearate, cobalt 2-ethylhexanoate; petroleum sulfone Sulfonic acid metal salts such as acid metal salts and metal salts of sulfosuccinic acid esters; phospholipids such as lecithin; salicylic acid metal salts such as t-butylsalicylic acid metal complexes; polyvinylpyrrolidone resins, polyamide resins, sulfonic acid-containing resins, hydroxybenzoic acid Derivatives etc. That.
Further, the curable liquid developer of the present invention also includes a polymer compound having a structural unit represented by the following formula (2) as a charge control agent.

［上記式（２）中、Ｒ_１〜Ｒ_４はそれぞれ独立して、水素原子及びアルキル基のいずれかを表し、Ａは単結合、カルボニル基、アルキレン基、アリーレン基及び−ＣＯＯＲ_７−（ただし、−ＣＯＯＲ_７−中のカルボニル基はＲ_１が結合した炭素原子に結合し、Ｒ_７は炭素数１以上４以下のアルキレンを表す）のいずれかを表し、Ｂはアルキレン基及びアリーレン基のいずれかを表す。］

[In the above formula (2), R _{1 to} R ₄ each independently represent either a hydrogen atom or an alkyl group, and A represents a single bond, a carbonyl group, an alkylene group, an arylene group, and —COOR ₇ — (provided that , -COOR _7- is bonded to the carbon atom to which R ₁ is bonded, and R ₇ represents alkylene having 1 to 4 carbon atoms, and B represents any of an alkylene group and an arylene group. Represents ]

In the above formula (2), the alkyl group in R _1, preferably an alkyl group having 1 to 4 carbon atoms. Examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group.
R ₁ in the above formula (2) can be arbitrarily selected from the substituents and hydrogen atoms listed above, but is preferably a hydrogen atom or a methyl group from the viewpoint of production (polymerizability) of the polymer compound. .

In the above formula _(2), the alkyl group in R 2 to R _4, preferably an alkyl group having 1 to 18 carbon atoms. Examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an n-octyl group, a 2-ethylhexyl group, a dodecyl group, and an octadecyl group. These alkyl groups may be further substituted and may be bonded to each other to form a ring.

In the above formula (2), A is a linking group that bonds the polymer main chain and the phosphate ester moiety, and is a carbonyl group, an alkylene group, an arylene group, and —COOR ₇ — (wherein the carbonyl group in —COOR ₇ — Is bonded to the carbon atom to which R ₁ is bonded, and R ₇ represents alkylene having 1 to 4 carbon atoms. Further, it may be directly connected to the polymer main chain by a single bond.
The alkylene group in the linking group A may be either linear or branched and is preferably an alkylene group having 1 to 4 carbon atoms.
For example, a methylene group, ethylene group, propylene group, various butylene groups, etc. are mentioned.
Examples of the arylene group in the linking group A include 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, naphthalene-1,4-diyl group, naphthalene-1,5-diyl group, And naphthalene-2,6-diyl group.
As —COOR ₇ — in the linking group A, the carbonyl group in —COOR ₇ — is bonded to the carbon atom to which R ₁ is bonded, and R ₇ is alkylene having 1 to 4 carbon atoms. The alkylene may be either linear or branched.
These linking groups may be further substituted, and the substitution is not particularly limited as long as the charging property of the polymer compound is not significantly lowered.
The linking group A is not particularly limited as described above, but a carbonyl group or —COOR ₇ — (wherein the carbonyl group in —COOR ₇ — is R in terms of availability of raw materials and ease of production. _More preferably, ₁ is bonded to a bonded carbon atom, and R ₇ represents an alkylene having 1 to 4 carbon atoms.

In said formula (2), B is a coupling group which couple | bonds a phosphate ester site | part and a quaternary ammonium site | part, and represents either an alkylene group or an arylene group.
The alkylene group in the linking group B may be linear or branched and is preferably an alkylene group having 1 to 4 carbon atoms.
For example, a methylene group, ethylene group, propylene group, various butylene groups, etc. are mentioned.
As the arylene group in the linking group B, for example, 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, naphthalene-1,4-diyl group, naphthalene-1,5-diyl group, And naphthalene-2,6-diyl group.
These linking groups may be further substituted, and the substitution is not particularly limited as long as the charging property of the polymer compound is not significantly lowered.
The linking group B is not particularly limited as described above, but is more preferably a simple alkylene group such as a methylene group and an ethylene group from the viewpoint of availability of raw materials and ease of production.

  The curable liquid developer of the present invention preferably contains a copolymer having a structural unit represented by the above formula (2) and a structural unit represented by the following formula (3) as a charge control agent. It is mentioned as an aspect.

［上記式（３）中、Ｒ_５は水素原子及びアルキル基のいずれかを表し、Ｒ_６はアルキル基、カルボン酸エステル基、カルボン酸アミド基、アルコキシ基及びアリール基のいずれかを表す。］

[In the above formula (3), R ₅ represents any one of a hydrogen atom and an alkyl group, and R ₆ represents any one of an alkyl group, a carboxylic acid ester group, a carboxylic acid amide group, an alkoxy group, and an aryl group. ]

In the formula (3), the alkyl group in _{R 5,} preferably an alkyl group having 1 to 4 carbon atoms. Examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group.
In the above formula (3), R ₅ can be arbitrarily selected from the substituents listed above and a hydrogen atom, but is preferably a hydrogen atom or a methyl group from the viewpoint of production (polymerizability) of the copolymer. .
In the above formula (3), the alkyl group in _{R 6,} preferably an alkyl group having 1 to 30 carbon atoms. Examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-hexyl group, an n-decyl group, an n-hexadecyl group, an octadecyl group, a docosyl group, and a triacontyl group.
In the above formula (3), examples of the aryl group for R ₆ include aryl groups such as a phenyl group, a 1-naphthyl group, and a 2-naphthyl group.
In the above formula (3), the carboxylate group in R ₆ is —COOR ₁₀ (where R ₁₀ is any one of an alkyl group having 1 to 30 carbon atoms, a phenyl group, and a hydroxyalkyl group having 1 to 30 carbon atoms). Represents.). Specifically, methyl ester group, ethyl ester group, n-propyl ester group, isopropyl ester group, n-butyl ester group, tert-butyl ester group, octyl ester group, 2-ethylhexyl ester group, dodecyl ester group, octadecyl Examples include ester groups such as ester groups, docosyl ester groups, triacontyl ester groups, phenyl ester groups, and 2-hydroxyethyl ester groups.
In the above formula (3), as the carboxylic acid amide group in R ₆ , —CO—NR ₁₁ R ₁₂ (wherein R ₁₁ and R ₁₂ are each independently hydrogen, an alkyl group having 1 to 30 carbon atoms, and phenyl. Represents any of the groups.). Specifically, N-methylamide group, N, N-dimethylamide group, N, N-diethylamide group, N-isopropylamide group, N-tert-butylamide group, Nn-decylamide group, Nn-hexa Examples include amide groups such as decylamide group, N-octadecylamide group, N-docosylamide group, N-triacontylamide group, and N-phenylamide group.
In said formula (3), as an alkoxyl group in R < ₆ >, a C1-C30 alkoxy group or a C1-C30 hydroxy alkoxy group is mentioned. Specifically, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, n-hexyloxy group, cyclohexyloxy group, n-octyloxy group, 2-ethylhexyloxy group, dodecyloxy group And alkoxy groups such as octadecyloxy group, docosyloxy group, triacontyloxy group, and 2-hydroxyethoxy group.

In the above formula (3), the substituent of R ₆ may be further substituted, and is not particularly limited as long as it does not significantly reduce the charging characteristics of the copolymer. In this case, examples of the substituent which may be substituted include alkoxy groups such as methoxy group and ethoxy group, amino groups such as N-methylamino group and N, N-dimethylamino group, acyl groups such as acetyl group, and fluorine atoms. And halogen atoms such as chlorine atom.
In the present invention, the copolymer composition ratio in the copolymer is not particularly limited, but the molar ratio of the structural unit represented by the formula (2) to the structural unit represented by the formula (3) is 0.00. It is preferably 01: 99.99 to 50:50, and more preferably 1:99 to 30:70.

The weight average molecular weight (Mw) of the polymer compound or copolymer is not particularly limited, but the weight average molecular weight (Mw) is preferably about 3000 to 300,000, more preferably 3000 to 150,000, Preferably they are 3000 or more and 50,000 or less, Most preferably, they are 3000 or more and 20,000 or less.
In this invention, this charge control agent may be contained individually by 1 type, and may be contained in combination of 2 or more type.
In the present invention, the content of the charge control agent is preferably 0.01 parts by mass or more and 10 parts by mass or less, and 0.05 parts by mass or more and 5 parts by mass with respect to 100 parts by mass of the toner particles (solid content). It is more preferable that the amount is not more than parts.

<Toner particles>
The toner particles preferably contain a binder resin and a colorant as constituent components.
In the present invention, as the binder resin contained in the toner particles, a known binder resin having fixability to an adherend such as paper, plastic and film can be used.
For example, resins such as epoxy resins, polyester resins, (meth) acrylic resins, styrene- (meth) acrylic resins, alkyd resins, polyethylene resins, ethylene- (meth) acrylic resins, and rosin-modified resins can be used. Moreover, these can be used individually or in combination of 2 or more types as needed.
Although it does not specifically limit as content of binder resin, It is preferable that it is 50-1000 mass parts with respect to 100 mass parts of coloring agents.

The colorant contained in the toner particles is not particularly limited, and all commercially available organic pigments, inorganic pigments, or pigments dispersed in an insoluble resin as a dispersion medium, or pigments A resin grafted on the surface can be used.
Examples of pigments that can be used include “Pigment Dictionary” (2000), edited by Seijiro Ito. Herbst, K.M. Hunger “Industrial Organic Pigments”, JP 2002-12607 A, JP 2002-188025 A, JP 2003-26978 A, and JP 2003-342503 A3.
Specific examples of the pigment include, for example, the following ones exhibiting a yellow color.
C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185; I. Bat yellow 1, 3, 20
Examples of those exhibiting red or magenta color include the following.
C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48: 2, 48: 3, 48: 4, 49, 50, 51, 52, 53, 54, 55, 57: 1, 58, 60, 63, 64, 68, 81: 1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269; I. Pigment violet 19; C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35.
Examples of the pigment exhibiting blue or cyan include the following.
C. I. Pigment blue 2, 3, 15: 2, 15: 3, 15: 4, 16, 17; I. Bat Blue 6; C.I. I. Acid Blue 45, a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted on the phthalocyanine skeleton.
Examples of the green pigment include the following.
C. I. Pigment Green 7, 8, 36.
Examples of the orange pigment include the following.
C. I. Pigment Orange 66, 51.
Examples of black pigments include the following.
Carbon black, titanium black, aniline black.
Specific examples of the white pigment include the following.
Basic lead carbonate, zinc oxide, titanium oxide, strontium titanate.
For the dispersion of the pigment in the toner particles, a dispersing means corresponding to the toner particle production method may be used. Examples of the apparatus that can be used as the dispersing means include a ball mill, a sand mill, an attritor, a roll mill, a jet mill, a homogenizer, a paint shaker, a kneader, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, and a wet jet mill. There is.
It is also possible to add a pigment dispersant when dispersing the pigment. Examples of the pigment dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long-chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a high molecular weight unsaturated acid ester, a high molecular weight copolymer, a modified polyacrylate, a fatty acid An aromatic polyvalent carboxylic acid, naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester, pigment derivative and the like can be mentioned. It is also preferable to use a commercially available polymer dispersant such as Solsperse series manufactured by Lubrizol.
Moreover, it is also possible to use the synergist according to various pigments as a pigment dispersion aid.
These pigment dispersants and pigment dispersion aids are preferably added in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the pigment.

In the present invention, the method for producing the curable liquid developer is not particularly limited, and examples thereof include known methods such as a coacervation method and a wet pulverization method.
As a general production method, a pigment, a binder resin, other additives, and a dispersion medium are mixed and pulverized using a bead mill or the like to obtain a dispersion of toner particles. A production method for obtaining a liquid developer by mixing the obtained dispersion of toner particles, a polymerizable initiator, a charge control agent, a liquid polymerizable compound and the like can be exemplified.
Details of the coacervation method are described in, for example, JP-A No. 2003-241439, International Publication No. 2007/000974, or International Publication No. 2007/000975.
In the coacervation method, a pigment, a resin, a solvent that dissolves the resin, and a solvent that does not dissolve the resin are mixed, the solvent that dissolves the resin is removed from the mixed solution, and the solution in a dissolved state is obtained. By precipitating the resin, the toner particles embedded with the pigment can be dispersed in a solvent that does not dissolve the resin.
On the other hand, details of the wet pulverization method are described in, for example, International Publication No. 2006/126666 or International Publication No. 2007/108485.
In the wet pulverization method, the toner particles are electrically pulverized by kneading the pigment and the binder resin at a melting point of the binder resin or higher and then dry pulverizing the resulting pulverized material in an electrically insulating medium. Can be dispersed in.
In the present invention, such a known method can be used.
The toner particles preferably have a volume average particle size of 0.05 μm or more and 5 μm or less, more preferably 0.05 μm or more and 1 μm or less from the viewpoint of obtaining a high-definition image.
In the present invention, the toner particle concentration in the curable liquid developer is preferably about 1% by mass to 70% by mass.

<Charge aid>
The toner particles can contain a charge auxiliary agent for the purpose of adjusting the chargeability of the toner particles. As the charge auxiliary agent, known ones can be used.
Specific compounds include zirconium naphthenate, cobalt naphthenate, nickel naphthenate, iron naphthenate, zinc naphthenate, cobalt octylate, nickel octylate, zinc octylate, cobalt dodecylate, nickel dodecylate, zinc dodecylate. , Metal soaps such as aluminum stearate, aluminum tristearate and cobalt 2-ethylhexanoate; metal sulfonates such as petroleum metal sulfonates and metal salts of sulfosuccinates; phospholipids such as lecithin; t- Salicylic acid metal salts such as butylsalicylic acid metal complexes; polyvinylpyrrolidone resins, polyamide resins, sulfonic acid-containing resins, hydroxybenzoic acid derivatives, and the like.

<Other additives>
In the curable liquid developer of the present invention, in addition to the above description, various known additions may be made depending on the purpose of recording medium compatibility, storage stability, image storage stability, and other various performances, as necessary. An agent may be used. For example, a sensitizer, a polymerization inhibitor, a surfactant, a lubricant, a filler, an antifoaming agent, an ultraviolet absorber, an antioxidant, a discoloration inhibitor, an antifungal agent, and a rust inhibitor are appropriately selected and used. be able to.

<Characteristics of curable liquid developer>
The curable liquid developer of the present invention is preferably used by adjusting so as to have the following physical property values. That is, the viscosity of the curable liquid developer is from 0.5 mPa · s to 100 mPa · s at 25 ° C. at a toner particle concentration of 2% by mass from the viewpoint of obtaining appropriate electrophoretic mobility of toner particles. The following is preferable.
The volume resistivity of the curable liquid developer is preferably 1 × 10 ⁹ Ω · cm or more and 1 × 10 ¹³ Ω · cm or less from the viewpoint of not lowering the potential of the electrostatic latent image.

The measurement method and evaluation method used in the present invention are shown below.
<Composition analysis>
The following method was used to determine the structure of the compound.
Using ECA-400 (400 MHz) manufactured by JEOL Ltd., ¹ H-NMR and ¹³ C-NMR spectra were measured.
Measurement was performed at 25 ° C. in a deuterated solvent containing tetramethylsilane as an internal standard substance. The chemical shift value was shown as a ppm shift value (δ value) with tetramethylsilane as an internal standard substance being zero.

<Molecular weight distribution measurement>
The molecular weight distribution of the resin and the like was calculated in terms of monodispersed polymethyl methacrylate by gel permeation chromatography (GPC). The molecular weight was measured by GPC as shown below.
The sample solution was added to the eluent below so that the sample concentration was 1% by mass, and the solution was allowed to stand at room temperature for 24 hours and dissolved, and then filtered through a solvent-resistant membrane filter with a pore diameter of 0.45 μm. And measured under the following conditions.
Equipment: High-speed GPC GPC-104 (made by Showa Denko)
Column: GPC HFIP-603, 604 double series (Showa Denko)
Eluent: hexafluoroisopropanol (HFIP) (containing 10 mmol / l sodium trifluoroacetate)
Flow rate: 0.2 ml / min
Oven temperature: 40 ° C
Sample injection volume: 20 μL
In calculating the molecular weight distribution of the sample, a molecular weight calibration curve prepared with a standard polymethyl methacrylate resin (EasiVial PM Polymer Standard Kit manufactured by Agilent Technologies) was used.

Hereinafter, the curable liquid developer will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these.
In the following description, unless otherwise specified, “part” and “%” mean “part by mass” and “% by mass”, respectively.

<Preparation of liquid polymerizable compound>
The following three types of liquid polymerizable compounds were prepared.
(Liquid polymerizable compound A)
As a vinyl ether compound having cationic polymerizability, a mixture of cyclohexane dimethanol divinyl ether (CHDVE) and dodecyl vinyl ether (DDVE) at 1: 9 (mass ratio) was prepared.
(Liquid polymerizable compound B)
An epoxy-modified silicone oil compound (MCR-E1, manufactured by AMAX Co.) was prepared as an epoxy compound having cationic polymerizability.
(Liquid polymerizable compound C)
1,6-hexanediol diacrylate was prepared as an acrylic compound having radical polymerizability.

The following toner particles were prepared.
In a reaction vessel equipped with a thermometer, 25 parts of Nucrel N1525 (ethylene-methacrylic acid resin, manufactured by Mitsui DuPont Polychemical Co., Ltd.) and 75 parts of the above liquid polymerizable compound A were introduced, using a three-one motor at 200 rpm. While stirring, the temperature was raised to 130 ° C. over 1 hour in an oil bath. After being held at 130 ° C. for 1 hour, it was gradually cooled at a temperature drop rate of 15 ° C. per hour to prepare a binder resin dispersion. The obtained binder resin dispersion was a white paste.
59.40 parts of the above binder resin dispersion, Pigment Blue 15: 3 (4.95 parts) as a pigment, 0.20 parts of aluminum tristearate as a charge auxiliary agent, and 35.45 parts of a liquid polymerizable compound A Is packed in a planetary bead mill (Classic Line P-6, Fritsch) together with zirconia beads having a diameter of 0.5 mm, and pulverized at 200 rpm for 4 hours at room temperature to obtain a toner particle dispersion (solid content 20 mass%). Obtained.
The toner particle dispersion thus prepared was designated as toner particle dispersion A. Further, a toner particle dispersion B was obtained by using the liquid polymerizable compound B instead of the liquid polymerizable compound A, and a toner particle dispersion C was obtained by using the liquid polymerizable compound C.

The following three types were prepared as polymerization initiators.
(Polymerization initiator A)
A compound represented by the following formula (A-1), which is an imide sulfonate compound, was prepared as a cationic polymerizable initiator.

(Polymerization initiator B)
As a cationic polymerization initiator, a triarylsulfonium salt (CPI-210S, manufactured by San Apro), which is an onium salt compound, was prepared.
(Polymerization initiator C)
IRGACURE (registered trademark) 907 (manufactured by BASF), which is an α-aminoalkylphenone compound, was prepared as a radical polymerization initiator.
(Polymerization initiator D)
IRGACURE (registered trademark) 127 (manufactured by BASF), which is an α-hydroxyalkylphenone compound, was prepared as a radical polymerization initiator.

The following were prepared as charge control agents.
(Charge control agent A)
The following compounds were prepared as the charge control agent A.
17.9 parts 2- (methacryloyloxy) ethyl 2- (trimethylammonio) ethyl phosphate, 82.1 parts octadecyl methacrylate, azobis in a reaction vessel equipped with a condenser, stirrer, thermometer and nitrogen inlet tube 4.1 parts of isobutyronitrile and 900 parts of n-butanol were charged, and nitrogen bubbling was performed for 30 minutes. The resulting reaction mixture was heated at 65 ° C. for 8 hours under a nitrogen atmosphere to complete the polymerization reaction. After cooling the reaction solution to room temperature, the solvent was distilled off under reduced pressure. The obtained residue was dissolved in chloroform and purified by dialysis using a dialysis membrane (Spectra / Por7 MWCO 1 kDa manufactured by Spectrum Laboratories). After the solvent was distilled off under reduced pressure, the charge control agent A was obtained by drying under reduced pressure at 50 ° C. and 0.1 kPa or less.
When the obtained charge control agent A was analyzed by the above analysis method, the weight average molecular weight (Mw) was 11800, and the structural unit represented by the above formula (2) was 21 mol% in all monomer units. Contained.
Next, in a reaction vessel equipped with a stirrer and a thermometer, 6.2 parts of charge control agent A and 68.2 parts of tetrahydrofuran (THF) are charged, and the temperature is raised to 60 ° C. Was dissolved. After 71.3 parts of the liquid polymerizable compound A was added thereto, THF was distilled off under reduced pressure at 50 ° C. and 4 kPa to obtain a solution containing the charge control agent A as a transparent reverse micelle solution.
The resulting solution containing the charge control agent A was designated as charge control agent A solution-a. Moreover, what used the liquid polymeric compound B and the liquid polymeric compound C instead of the liquid polymeric compound A in the above was used as the charge control agent A solution-b and the charge control agent A solution-c, respectively.

(Charge control agent B)
As the charge control agent B, zirconium naphthenate was prepared.
Next, 6.7 parts of the zirconium naphthenate (manufactured by Kishida Chemical Co., Ltd.) was dissolved in 24.3 parts of the liquid polymerizable compound A to obtain a solution containing the charge control agent B.
The resulting solution containing the charge control agent B was designated as charge control agent B solution-a. Moreover, what used the liquid polymeric compound B and the liquid polymeric compound C instead of the liquid polymeric compound A in the above was used as the charge control agent B solution-b and the charge control agent B solution-c, respectively.

Various curable liquid developers were prepared by the following procedure.
<Example 1>
100 parts of the liquid polymerizable compound A, 0.334 parts of the polymerization initiator A, 0.0284 parts of the charge control agent A solution-a, and 13.644 parts of the toner particle dispersion A are mixed, and curable liquid development is performed. An agent was prepared.

<Example 2>
100 parts of the liquid polymerizable compound A, 0.334 parts of the polymerization initiator B, 0.0284 parts of the charge control agent A solution-a, and 13.644 parts of the toner particle dispersion A are mixed and cured liquid development. An agent was prepared.

<Example 3>
100 parts of the liquid polymerizable compound B, 0.334 parts of the polymerization initiator A, 0.0284 parts of the charge control agent A solution-b, and 13.644 parts of the toner particle dispersion B are mixed, and curable liquid development is performed. An agent was prepared.

<Example 4>
100 parts of the liquid polymerizable compound B, 0.334 parts of the polymerization initiator B, 0.0284 parts of the charge control agent A solution-b, and 13.644 parts of the toner particle dispersion B are mixed, and curable liquid development is performed. An agent was prepared.

<Example 5>
100 parts of the liquid polymerizable compound C, 0.334 parts of the polymerization initiator C, 0.0284 parts of the charge control agent A solution-c, and 13.644 parts of the toner particle dispersion C are mixed, and curable liquid development is performed. An agent was prepared.

<Example 6>
100 parts of the liquid polymerizable compound C, 0.334 parts of the polymerization initiator D, 0.0106 parts of the charge control agent B solution-c, and 13.68 parts of the toner particle dispersion C are mixed, and curable liquid development is performed. An agent was prepared.

<Comparative Example 1>
100 parts of the liquid polymerizable compound A, 0.334 parts of the polymerization initiator A, 0.0106 parts of the charge control agent B solution-a, and 13.68 parts of the toner particle dispersion A are mixed, and curable liquid development is performed. An agent was prepared.

<Comparative example 2>
100 parts of the liquid polymerizable compound A, 0.334 parts of the polymerization initiator B, 0.0106 parts of the charge control agent B solution-a, and 13.68 parts of the toner particle dispersion A are mixed, and curable liquid development is performed. An agent was prepared.

<Comparative Example 3>
100 parts of the liquid polymerizable compound B, 0.334 parts of the polymerization initiator A, 0.0106 parts of the charge control agent B solution-b, and 13.68 parts of the toner particle dispersion B are mixed, and curable liquid development is performed. An agent was prepared.

<Comparative example 4>
100 parts of the liquid polymerizable compound B, 0.344 parts of the polymerization initiator B, 0.0106 parts of the charge control agent B solution-b, and 13.68 parts of the toner particle dispersion B are mixed, and curable liquid development is performed. An agent was prepared.

<Comparative Example 5>
100 parts of the liquid polymerizable compound C, 0.344 parts of the polymerization initiator C, 0.0106 parts of the charge control agent B solution-c, and 13.68 parts of the toner particle dispersion C are mixed, and curable liquid development is performed. An agent was prepared.

<Comparative Example 6>
100 parts of the liquid polymerizable compound C, 0.344 parts of the polymerization initiator D, 0.0284 parts of the charge control agent A solution-c, and 13.644 parts of the toner particle dispersion C are mixed, and curable liquid development is performed. An agent was prepared.

In order to examine in detail the electrophoretic polarity of the toner particles contained in the curable liquid developers prepared in the above Examples and Comparative Examples, the following experiment was conducted.
<Preparation of D1 agent and D2 agent>
In the preparation of the curable liquid developer used in each of Examples and Comparative Examples, a charge control agent is not added (hereinafter referred to as “D1 agent”), and a polymerization initiator is not added (hereinafter referred to as “D2 agent”). ")".
<Evaluation of Electrophoretic Properties of Toner Particles in D1 and D2 Agent>
The electrophoretic properties of the toner particles in the prepared D1 agent and D2 agent were evaluated according to the following procedure.
The D1 agent and the D2 agent were held by a capillary force between parallel plate electrodes in which a metal electrode having a thickness of 300 μm and a width of 20 mm was opposed to each other by 100 μm.
A high-speed camera (FASTCAM SA-1 manufactured by Photoron Co., Ltd.) connected to an optical microscope shows the state of electrophoresis of toner particles when a potential difference of 100 V is applied between parallel plate electrodes (electric field strength 1 × 10 ⁶ V / m). )
The electrophoresis polarity of the toner particles was determined based on the state of electrophoresis of the toner particles.
The electrophoresis polarity was negative when the toner particles migrated to the positive electrode and positive when the toner particles migrated to the negative electrode. In addition, when the electrophoretic polarity was not clear, it was determined by which electrode a large amount of toner particles adhered.

<Developability evaluation of curable liquid developer>
The developability of the obtained curable liquid developer was evaluated according to the following procedure and evaluated according to the following criteria.
The developing roller whose surface layer was covered with conductive rubber and a metal roller were pressed to face each other to form a nip of about 3 mm. After dropping a few drops of the curable liquid developer to be evaluated on the surface of the developing roller, development is performed while being transported so as to be sandwiched between the rollers and the electrostatic recording paper on which the electrostatic pattern image is formed at a surface potential of 150V or 500V. It was.
However, the electrostatic pattern image side was made to face the developing roller. During development, the core of the developing roller was set to 300V, and the metal roller was set to 0V. By doing so, an image is formed on the electrostatic recording paper according to the polarity of the toner particles.
The quality of the obtained image was judged by means of a magnifying glass and visual observation of the so-called fog which is the density of the non-image forming part (white background part).
(Evaluation criteria)
A: Fog is not found even when viewed with a loupe (10 times, manufactured by PEAK) B: Fog is visible when viewed with a loupe, but is not noticeable visually C: Visually visible fog D: Clearly visible Can be confirmed

Table 1 summarizes the results of the evaluation of the electrophoretic properties of the toner particles and the evaluation of the developability of the curable liquid developer.
From the results in Table 1, it can be seen that toner particles having the same electrophoretic polarity (ie, the same polarity) in the D1 agent and D2 agent have good developability evaluation of the curable liquid developer.

  By using the curable liquid developer of the present invention, the electrophoretic behavior of the toner particles is stabilized and good developability is obtained.

Claims (5)

A curable liquid developer containing a liquid polymerizable compound, a polymerization initiator, a charge control agent, and toner particles,
D1 agent was prepared by removing only the charge control agent from the curable liquid developer,
When the D2 agent was prepared by removing only the polymerization initiator from the curable liquid developer,
A curable liquid developer, wherein the electrophoretic polarities of toner particles in the D1 agent and the D2 agent are the same.   The curable liquid developer according to claim 1, wherein the liquid polymerizable compound contains a cationic polymerizable compound.   The curable liquid developer according to claim 1, wherein the liquid polymerizable compound contains a vinyl ether compound. The curable liquid developer according to claim 1, wherein the polymerization initiator contains a compound represented by the following formula (1).

[In the formula (1), R ₈ and R ₉ are bonded to each other to form a ring structure, x represents an integer of 1 to 8, and y represents an integer of 3 to 17. ] The curable liquid developer according to claim 1, wherein the charge control agent contains a polymer compound having a structural unit represented by the following formula (2).

[In the formula (2), R _{1 to} R ₄ each independently represent any of a hydrogen atom and an alkyl group, and A represents a single bond, a carbonyl group, an alkylene group, an arylene group, and —COOR ₇ — (provided that , -COOR _7- is bonded to the carbon atom to which R ₁ is bonded, and R ₇ represents alkylene having 1 to 4 carbon atoms, and B represents any of an alkylene group and an arylene group. Represents ]