KR100657414B1 - Polymerized toner with uniform charging characteristics - Google Patents

Abstract

The present invention relates to a polymerized toner having high charge density and high resolution prepared by suspension polymerization, and more particularly, the polymerized toner of the present invention introduces a functional group capable of bonding with a pigment dispersant to the surface of an organic pigment to modify the surface thereof. It is manufactured by controlling the polarity of the bonding functional groups of the pigment dispersant, thereby improving dispersibility of the organic pigment and reducing the phenomenon that the organic pigment accumulates on the surface of the toner and inhibits the role of the charge control agent. Toner can be produced.

Toner, suspension polymerization, charge control agent, surface modifier, charging characteristics

Description

Polymerized Toner Having Uniform Charge

The present invention relates to a high charge density and a high resolution toner, and more particularly, by reducing the charge characteristic inhibition of the organic pigment by controlling the surface affinity of the organic pigment having a size suitable for the toner and the affinity with the pigment dispersant accordingly. By increasing the concentration of the surface charge control agent to a toner produced by suspension polymerization that realizes high charge density and high resolution.

In general, toner is used for electrophotographic development, electrostatic printers, copiers, and the like, and refers to a paint that develops an image on a transfer object during a transfer operation. Recently, as document creation using a computer is becoming more common, the demand for an image forming apparatus such as a printer is rapidly increasing, and thus, the amount of toner is also increasing.

Various methods are known for producing toner, as follows.

The most widely known and common method, the melt-mixing process, involves mixing resin and pigment together, melt-mixing or extruding, pulverizing and classifying to produce toner particles. However, the toner particles produced by this process have a problem of poor chargeability or flowability because the toner particles have a very irregular shape such as a wide particle size distribution and sharp edges.

In order to solve this problem, a method of producing spherical toner particles by a polymerization method has been proposed. As the polymerization method, emulsion polymerization and suspension polymerization are known. In the emulsion polymerization method, since the particle size of the produced toner is very small and a user inhales it, it is very harmful to the human body. The method by is preferred.

A method for preparing by suspension polymerization is disclosed in U.S. Patent No. 6,337,169, which discloses that a pigment must be dissolved in a portion of the wax so that the pigment is contained in the wax because the wax melts rapidly when the toner is hot melted. Discloses that a high quality image can be formed by quickly forming an image together with wax. However, since a high quality image is more dependent on the charge density of the final toner than on the position or density of the pigment, even if the pigment is dispersed in a binder, the high quality image is formed if the toner density of the toner is not high. There was a problem that could not be done.

Therefore, in order to form a high quality shape, it is required to increase the surface concentration of the charge control agent in the toner.

The present invention is a uniform charge characteristics, high-density wheat prepared by the suspension polymerization method including an organic pigment surface-modified with a coupling agent and a pigment dispersant having a functional group capable of reacting effectively with the organic pigment and a pigment dispersant capable of reacting with the pigment dispersant It is an object to provide a toner having a degree and a high resolution.

Accordingly, the present inventors have described the surface of a surface with a specific functional group capable of combining an organic pigment with a pigment dispersant to reduce the toner surface concentration of the organic pigment, which is one of the important factors for reducing the surface concentration of the charge control agent or inhibiting the role of the charge control agent. By dispersing organic pigments uniformly using a pigment dispersant having a functional group that can effectively combine with this functional group, the blocking effect of the charging phenomenon due to organic pigments is blocked, improving the surface concentration of the charge control agent and improving the charging characteristics. It was found to be uniform and completed the present invention.

In order to achieve the above object, the present invention comprises a charge control agent, a monomer, a wax, an aqueous dispersant, a molecular weight control agent and a pigment, in the toner produced by the suspension polymerization method, surface-modified with a coupling agent and combined with a pigment dispersant Provided are a toner comprising an organic pigment and a pigment dispersant having possible functional groups.

The coupling agent uses a compound represented by the following formula (1).

<Formula 1>

X-R-Y

In the above formula, X is a functional group that reacts with an organic pigment, and is a silane-based, epoxy-based, isocyanate-based, or titanium-based functional group, and R is a functional group or polysiloxane-based group containing C ₁ to C ₁₂ linear or branched alkyl, benzene group. And Y is a functional group bonded to the pigment dispersant and includes an acidic functional group of a carboxylic acid group or a sulfonic acid group; Basic functional groups of amines, imines, amides or isocyanates; Or a glycidyl group, the polarity can be adjusted according to the characteristics of the Y.

The pigment dispersant is represented by the following formula (2), the molecular weight is a weight average of 1000 ~ 100,000 and the glass transition temperature is used a high molecular compound 40 ~ 110 ℃.

<Formula 2>

(Z) _n- (R ') _m

In the above formula, Z is a functional group that reacts with an organic pigment, and in order to control polarity, an acidic functional group of a carboxylic acid group or a sulfonic acid group; Or using a basic functional group of an amine, imine, amide or isocyanate, located at the end of the polymer chain, in a block structure or in a random structure,

R 'is any one of a linear ester polymer monomer, a styrene polymer, an acrylate polymer or a mixture thereof,

n is 1-10 and m is 10-300.

The toner of the present invention comprises a core layer including the surface-modified organic pigment and a pigment dispersant and a shell layer surrounding the core layer, and surface modification by adding 1-30 parts by weight of the coupling agent to 100 parts by weight of the organic pigment. And 1-50 parts by weight of the pigment dispersant based on 1-10 parts by weight of the surface-modified organic pigment.                     

The charge control agent may be at least one selected from the group consisting of an electron acceptor organic complex, a chlorinated paraffin, a chlorinated polyester, a polyester containing an excess acid, a sulfonylamine of copper phthalocyanine, and a styrene-acrylic polymer including a sulfonic acid group. have.

The monomer may be at least one selected from the group consisting of aromatic vinyl monomers or acrylic monomers, and the monomer may further comprise at least one selected from polyester-based or styrene acrylic polar polymers.

The wax is a petroleum refined wax selected from the group consisting of paraffin wax, microcrystalline wax and ceresin wax; Natural waxes that are carnuba wax; Or at least one selected from synthetic waxes selected from the group consisting of ester waxes, polyethylene, and polypropylene.

The dispersant may be an inorganic dispersant selected from the group consisting of silica, insoluble calcium salts, and insoluble magnesium salts; Anionic surfactants selected from the group consisting of fatty acid salts, alkyl sulfate ester salts, alkylaryl sulfate ester salts, dialkyl sulfosuccinates and alkyl phosphates; Or nonionic selected from the group consisting of polyoxyethylene alkyl ethers, polyoxyalkylene alkyl phenol ethers, sorbitan fatty acid esters, polyoxyalkylene fatty acid esters, glycerin fatty acid esters, polyvinyl alcohols, alkyl celluloses and polyvinyl pyrrolidones It may be one or more selected from surfactants.

The molecular weight modifier may be at least one selected from mercaptan-based compounds such as t-dodecyl mercaptan and n-dodecyl mercaptan.                     

The pigment is an inorganic pigment selected from the group consisting of metal powder type, metal oxide type, carbon type, sulfide type, chromium salt type and ferrocyanide type; Or at least one organic pigment selected from the group consisting of azo type, acid dye type, basic dye type, modant dye type, phthalocyanine, quinacridone type and dioxane type.

Hereinafter, the present invention will be described in detail.

Specifically, the present invention

1) modifying the surface of the organic pigment using 1-30 parts by weight of the coupling agent based on 100 parts by weight of the organic pigment (first step);

2) preparing an aqueous dispersion comprising 0 to 10 parts by weight of an inorganic dispersant or a water-soluble organic polymer dispersant based on an aqueous solution in water and optionally including 0 to 10 parts by weight of anionic surfactant (second step);

3) 30 to 90 parts by weight of an aromatic vinyl monomer, 5 to 70 parts by weight of at least one of an acrylate monomer, a methacrylate monomer and a diene monomer, and 0 to 30 parts by weight of an acidic or basic olefin monomer, based on the total monomer mixture. 1 to 20 parts by weight of the surface-modified pigment, 1 to 50 parts by weight of the surface-modified pigment, 0 to 30 parts by weight of wax, 0.001 to 8.000 parts by weight of molecular weight regulator, 0.001 to 10 parts by weight of crosslinking agent, charge Preparing a monomer mixture including 0 to 20 parts by weight of a regulator and 0.01 to 5 parts by weight of a reaction initiator (third step);

4) preparing a mixture including 1 to 60 parts by weight of the monomer mixture with respect to 100 parts by weight of the aqueous dispersion, and polymerizing while applying a shearing force to the mixture (step 4); And

5) It provides a toner manufacturing method comprising the step (fifth step) of forming a shell on the manufactured toner core.

The toner provided by the present invention has a core-shell structure and is produced through the following suspension polymerization step.

(1) Modification of organic pigment surface

After dispersing the pigment in a suitable solvent, using a coupling agent having a functional group in the amount of about 1 to 30% of the organic pigment, the surface is modified, the organic pigment is separated, washed several times with a solvent and dried to surface-modified pigment Prepare.

(2) toner core manufacturing step

Preparing from 0 to 10 parts by weight of an inorganic dispersant or a water-soluble organic polymer dispersant based on an aqueous solution, and optionally from 0 to 10 parts by weight of an anionic surfactant; 30 to 90 parts by weight of the aromatic vinyl monomer as a monomer with respect to the entire monomer mixture, 5 to 70 parts by weight with respect to the whole of the monomer mixture and at least one of acrylate monomer, methacrylate monomer and diene monomer Or 0 to 30 parts by weight of the basic olefinic monomer based on the entire monomer mixture, 1 to 20 parts by weight of the surface modified pigments relative to the entire monomer mixture, 1 to 50 parts by weight of the pigment that is surface modified with the pigment dispersant, wax 0 to 30 parts by weight with respect to the whole monomer mixture, 0.001 to 8.000 parts by weight with respect to the whole monomer mixture, 0.001 to 10 parts by weight with respect to the whole monomer mixture, and 0 to 20 charges to the whole monomer mixture Parts by weight, including 0.01 to 5 parts by weight of the reaction initiator based on the whole monomer mixture A monomer mixture is prepared, and the monomer mixture is prepared by using 1 to 60 parts by weight of the aqueous dispersion to form a reaction mixture, and polymerization is performed while applying a shear force to the reaction mixture to form a toner core.

(3) shell forming step

A monomer, a charge control agent and a crosslinking agent are added to the core prepared above to form a shell. At this time, the monomers and charge control agents used are the same as those used in the core forming step, and the crosslinking agent uses divinylbenzene and the like having no polarity.

(4) post-processing step

In the solution containing the core-shell toner prepared above, the aqueous dispersant is removed by adding an appropriate basic aqueous solution or an acidic aqueous solution according to the type of aqueous dispersant, and the cleaning and filtering processes are repeated to separate the toner, and then, the vacuum dispersant is removed. It is dried for 48 hours at room temperature to obtain the final toner particles.

In the above, the monomers are aromatic vinyl-based, acrylate-based, methacrylate-based, diene-based monomers are used for polymerization, and optionally acidic or basic olefinic monomers are used.

Styrene, monochlorostyrene, methyl styrene, dimethyl styrene, etc., which are aromatic vinyl monomers, are preferably used in an amount of 30 to 90 parts by weight based on the entire monomer mixture, and methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl Acrylate monomers such as acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, and the like; Methacrylate monomers such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, and the like; And at least one monomer of a diene monomer such as butadiene, isoprene, etc., is used in an amount of 5 to 70 parts by weight based on the whole monomer mixture.

?,? -Ethylene compounds having a carboxyl group as the acidic olefin monomer, and methacrylic acid esters, methacrylic amides, vinyl amines, diallyl amines of aliphatic alcohols having amine groups or quaternary ammonium groups as basic olefin monomers. It is preferable that at least 1 monomer is used in 0-30 weight part with respect to the whole monomer mixture among monomers, such as a system or its ammonium salt.

As wax, Petroleum refined extract wax, such as paraffin wax; Natural product waxes such as carnuba wax; The wax selected from synthetic waxes such as esters, polyethylenes, and polypropylenes is preferably used in an amount of 0 to 30 parts by weight based on the whole monomer mixture.

As the reaction initiator, an oil-soluble initiator and a water-soluble initiator can be used. Azo initiators such as azobisisobutyronitrile and azobisvaleronitrile; Organic peroxides such as benzoyl peroxide and lauroyl peroxide; And commonly used water-soluble initiators such as potassium persulfate and ammonium persulfate. The amount of the reaction initiator is used in an amount of 0.01 to 5.00 parts by weight based on the whole monomer mixture, and more preferably 0.1 to 2.0 parts by weight.

The molecular weight modifier may use one or more molecular weight modifiers of mercaptans such as t-dodecyl mercaptan and n-dodecyl mercaptan, and the amount of the molecular weight modifier is preferably used in an amount of 0.001 to 8.000 parts by weight based on the entire monomer mixture. .

As pigments, inorganic pigments such as metal powder type, metal oxide type, carbon type, sulfide type, chromium salt type, ferrocyanide type, azo type, acid dye type, basic dye type, modal dye type, phthalocyanine and quinacrylic Organic pigments such as pig type and dioxane type are used in an amount of 1 to 100 parts by weight based on the whole monomer mixture.

The charge control agent is a cationic charge control agent such as an electron acceptor dye of a nigrosine type, a high aliphatic metal salt, an alkoxy amine, a chelate, a quaternary ammonium salt, an alkylamide, a fluorine treatment active agent, a metal salt of naphthalene acid, or an electron acceptor organic compound as an anionic charge control agent. Complexes, chlorinated paraffins, chlorinated polyesters, polyesters containing excess acid, sulfonylamines of copper phthalocyanine, styrene-acrylic polymers including sulfonic acid groups, and the like. It is preferred that 20 parts by weight to be used.

Crosslinking agent divinylbenzene, ethylene dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, 1,6-hexamethylene diacrylate, allyl methacrylate, 1,1,1-trimethylolpropane Triacrylate, triallylamine, tetraallyloxyethane and the like are used, and the crosslinking agent is preferably used in an amount of 0.001 to 10 parts by weight based on the monomer.

The dispersant may be calcium phosphate salt, magnesium salt, hydrophilic silica, hydrophobic silica, colloidal silica, and the like as an inorganic dispersant, and a water-soluble organic polymer dispersant may be used. These are preferably used in 0.001 to 20 parts by weight based on the whole aqueous solution.

The water-soluble organic polymer dispersant includes a nonionic polymer dispersant and an ionic polymer dispersant, and anionic surfactants include at least one of fatty acid salts, alkyl sulfate ester salts, alkylaryl sulfate ester salts, dialkyl sulfosuccinate salts and alkyl phosphates. It is preferable to use 0.001-20 weight part with respect to the whole aqueous solution.

Nonionic polymeric dispersants include polyoxyethylene alkyl ethers, polyoxyalkylene alkylphenol ethers, sorbitan fatty acid esters, polyoxyalkylene fatty acid esters, glycerin fatty acid esters, polyvinyl alcohols, alkyl celluloses, and polyvinyl pyrrolidones. It is preferable that the above is used in 0-10 weight part with respect to the whole aqueous solution.

Ionic polymer dispersants include polyacrylamide, polyvinyl amine, polyvinyl amine N-oxide, polyvinyl ammonium salt, polydialkyldiallyl ammonium salt, polyacrylic acid, polystyrene sulfonic acid, polyacrylate, polystyrene sulfonate, polyaminoalkyl It is preferable that at least one of the acrylates is used at 0.001 to 20 parts by weight based on the entire aqueous solution.

As the anionic surfactant, at least one of fatty acid salt, alkyl sulfate ester salt, alkylaryl sulfate ester salt, dialkyl sulfosuccinate salt and alkyl phosphate salt is preferably used in an amount of 0.001 to 20 parts by weight based on the total aqueous solution.

In order to describe the present invention in more detail, the following Preparation Examples and Examples are described, but the present invention is not limited thereto.                     

<Example 1>

1) Surface modification of organic pigment

C.I. 1 g of gamma-aminopropyltrimethoxysilane, a silane coupling agent having an amine functional group in 10 g of Pigment Red 269, was reacted at 50 ° C. in an acid catalyst at 50 g of toluene, and the pigment was separated by drying through filtering / washing.

2) Core Synthesis Using Acidic Pigment Dispersant

400 g of distilled water and 10 g of colloidal silica as a dispersant were dissolved in a 500 ml reactor, and the reaction mixture was prepared by raising the temperature to 70 ° C. As monomer, 160g of styrene, 36g of butyl acrylate, 4g of acrylic acid, 4g of allyl methacrylate as crosslinking, and 0.02g of n-dodecyl mercaptan as a molecular weight regulator were added, and 10g of surface-modified pigment was added thereto. A styrene-acrylate copolymer polymer (weight average molecular weight: 10,000, glass transition temperature: 60 ° C.) of 20 mgKOH / g was added thereto, stirred at 2000 rpm for 2 hours using a bead mill, and beads were removed to prepare 105 g of a monomer and pigment mixture.

The mixture was placed in a 70 ° C. water bath to raise the temperature, and then 1 g of styrene-acrylic polymer charge control agent including sulfonic acid group and 5 g of paraffin wax were added thereto, followed by stirring for 20 minutes to sufficiently dissolve. 2 g of azobisisobutyronitrile was added to the final monomer mixture as a polymerization initiator, followed by stirring for 5 minutes. The reaction was placed in an aqueous solution prepared above, and the reaction was continued while stirring at 10000 rpm for 20 minutes with a homogenizer, followed by reaction at 600 rpm with a general stirrer for 15 hours to prepare a core.

3) shell synthesis                     

In a 500 ml reactor, a core was prepared by dissolving 20 g of styrene as a monomer, 0.12 g of divinylbenzene as a crosslinking agent and 0.4 g of azobisisobutyronitrile as an initiator to prepare a final toner. The final toner was sufficiently washed and filtered with water to remove the dispersant and dried in vacuo to prepare a toner. The size and shape of the produced toner particles were all measured by using a multisizer cooler counter and SEM.

<Example 2>

1) Surface modification of organic pigment

C.I. 1 g of gamma-aminopropyltrimethoxysilane, a silane coupling agent having an amine functional group in 10 g of Pigment Red 269, was reacted at 50 ° C. in an acid catalyst at 50 g of toluene, and the pigment was separated by drying through filtering / washing.

2) Core synthesis using basic pigment dispersant

400 g of distilled water and 10 g of silica colloid were dissolved as a dispersant in a 500 ml reactor, and the reaction temperature was raised to 70 ° C. to prepare. As monomer, 160 g of styrene, 36 g of butyl acrylate, 4 g of acrylic acid, 4 g of ethylene dimethacrylate as a crosslinking agent, 0.02 g of n-dodecyl mercaptan as a molecular weight control agent, 10 g of surface-modified pigment was added thereto, and the amine number was 20 mgKOH / g of a styrene-acrylate copolymer (weight average molecular weight: 10,000, glass transition temperature: 60 ° C.) was added thereto, stirred at 2000 rpm with a bead mill for 2 hours, and beads were removed to prepare 105 g of a monomer and pigment mixture.

The mixture was placed in a 70 ° C. water bath to raise the temperature, and then 1 g of styrene-acrylic polymer charge control agent including sulfonic acid group and 5 g of paraffin wax were added thereto, followed by stirring for 20 minutes to sufficiently dissolve. 2 g of azobisisobutyronitrile was added to the final monomer mixture as a polymerization initiator, followed by stirring for 5 minutes. The reaction was then added to an aqueous solution prepared above, and the reaction was continued at 10000 rpm for 20 minutes with a homogenizer. Thereafter, the cores were prepared by reacting at 600 rpm for 15 hours using a general stirrer.

3) shell synthesis

In a 500 ml reactor, a core was prepared by dissolving 20 g of styrene as a monomer, 0.12 g of divinylbenzene as a crosslinking agent and 0.4 g of azobisisobutyronitrile as an initiator to prepare a final toner. The final toner was sufficiently washed and filtered with water to remove the dispersant and dried in vacuo to prepare a toner. The size and shape of the produced toner particles were all measured and observed using a multisizer cooler counter and SEM.

<Example 3>

1) Surface modification of organic pigment

C.I. 1 g of glycidoxypropyltrimethoxysilane, a silane coupling agent having a glycidyl functional group in 10 g of Pigment Yellow 17, was reacted at 50 ° C. in an acid catalyst in 50 g of toluene, and the pigment was separated by drying through filtering / washing.

2) Core synthesis using acidic pigment dispersant

400 g of distilled water and 10 g of colloidal silica as a dispersant were dissolved in a 500 ml reactor, and the reaction mixture was prepared by raising the temperature to 70 ° C. As monomer, 160 g of styrene, 36 g of butyl acrylate, 4 g of acrylic acid, 4 g of allyl methacrylate as a crosslinking agent, 0.02 g of n-dodecyl mercaptan as a molecular weight control agent, 10 g of surface-modified pigment was added thereto, and the acid value was 20 mgKOH / g of a styrene-acrylate copolymer (weight average molecular weight: 10,000, glass transition temperature: 60 ° C.) was added thereto, stirred at 2000 rpm with a bead mill for 2 hours, and beads were removed to prepare 105 g of a monomer and pigment mixture.

The mixture was placed in a 70 ° C. water bath to raise the temperature, and then 5 g of paraffin wax was added thereto, followed by stirring for 20 minutes to sufficiently dissolve. 2 g of azobisisobutyronitrile was added to the final monomer mixture as a polymerization initiator, followed by stirring for 5 minutes. The reaction was placed in an aqueous solution prepared above, and the reaction was continued while stirring at 10000 rpm for 20 minutes with a homogenizer, followed by reaction at 600 rpm with a general stirrer for 15 hours to prepare a core.

3) shell synthesis

In a 500 ml reactor, a core was prepared by dissolving 20 g of styrene as a monomer, 0.12 g of divinylbenzene as a crosslinking agent, and 0.4 g of azobisisobutyronitrile as an initiator to prepare a final toner. The final toner was sufficiently washed and filtered with water to remove the dispersant and dried in vacuo to prepare a toner. The size and shape of the produced toner particles were all measured and observed using a multisizer cooler counter and SEM.

<Example 4>

1) Surface modification of organic pigment

C.I. 1 g of glycidoxypropyltrimethoxysilane, a silane coupling agent having a glycidyl functional group on 10 g of Pigment Yellow 17, was reacted at 50 ° C. in an acid catalyst at 50 g of toluene, and then the pigment was separated by drying through filtering / washing.

2) Core synthesis using basic pigment dispersant

400 g of distilled water and 10 g of silica colloid were dissolved as a dispersant in a 500 ml reactor, and the reaction temperature was raised to 70 ° C. to prepare. As monomer, 160 g of styrene, 36 g of butyl acrylate, 4 g of acrylic acid, 4 g of ethylene dimethacrylate as a crosslinking agent, 0.02 g of n-dodecyl mercaptan as a molecular weight control agent, 10 g of surface-modified pigment was added thereto, and the amine number was 20 mgKOH / g of a styrene-acrylate copolymer (weight average molecular weight: 10,000, glass transition temperature: 60 ° C.) was added thereto, stirred at 2000 rpm with a bead mill for 2 hours, and beads were removed to prepare 105 g of a monomer and pigment mixture.

The mixture was placed in a 70 ° C. water bath to raise the temperature, and then 5 g of paraffin wax was added thereto, followed by stirring for 20 minutes to sufficiently dissolve. 2 g of azobisisobutyronitrile was added to the final monomer mixture as a polymerization initiator, followed by stirring for 5 minutes. The reaction was placed in an aqueous solution prepared above, and the reaction was continued while stirring at 10000 rpm for 20 minutes with a homogenizer, followed by reaction at 600 rpm with a general stirrer for 15 hours to prepare a core.

3) shell synthesis

In a 500 ml reactor, a core was prepared by dissolving 20 g of styrene as a monomer, 0.12 g of divinylbenzene as a crosslinking agent, and 0.4 g of azobisisobutyronitrile as an initiator to prepare a final toner. The final toner was sufficiently washed and filtered with water to remove the dispersant and dried in vacuo to prepare a toner. The size and shape of the produced toner particles were all measured and observed using a multisizer cooler counter and SEM.

Comparative Example 1

1) Core Synthesis

400 g of distilled water and 10 g of silica colloid were dissolved as a dispersant in a 500 ml reactor, and the reaction temperature was raised to 70 ° C. to prepare. As monomer, 160 g of styrene, 36 g of butyl acrylate, 4 g of acrylic acid, 4 g of ethylene dimethacrylate as a crosslinking agent, and 0.02 g of n-dodecyl mercaptan as a molecular weight control agent were added thereto. 10 g of Pigment Yellow 17 was added thereto, stirred at 2000 rpm for 2 hours using a bead mill, and beads were removed to prepare 105 g of a monomer and pigment mixture.

The mixture was placed in a 70 ° C. water bath to raise the temperature, and then 5 g of paraffin wax was added thereto, followed by stirring for 20 minutes to sufficiently dissolve. 2 g of azobisisobutyronitrile was added to the final monomer mixture as a polymerization initiator, followed by stirring for 5 minutes. The reaction was placed in an aqueous solution prepared above, and the reaction was continued while stirring at 10000 rpm for 20 minutes with a homogenizer, followed by reaction at 600 rpm with a general stirrer for 15 hours to prepare a core.

3) shell synthesis

In a 500 ml reactor, a core was prepared by dissolving 20 g of styrene as a monomer, 0.12 g of divinylbenzene as a crosslinking agent, and 0.4 g of azobisisobutyronitrile as an initiator to prepare a final toner. The final toner was sufficiently washed and filtered with water to remove the dispersant and dried in vacuo to prepare a toner. The size and shape of the produced toner particles were all measured and observed using a multisizer cooler counter and SEM.

Experimental Example 1

The toner prepared in Examples 1 to 4 was added to 2 parts by weight of the surface-treated silica RY200S, mixed at a blender for 3 minutes at 3000 rpm for surface treatment, and sucked in a HP4500 printer (Hewlett-Packard Co.). The charge was measured by the (suction method), and the charge amount and the transfer rate at this time are shown in Table 1 below.

TABLE 1

Sample number Transcription rate (%) Charge amount (μC / g) Example 1 85 -30 Example 2 60 To 0 Example 3 77 -20 Example 4 70 -5 Comparative Example 1 65 -5

As can be seen from Table 1, in the toners of Examples 1 to 4 according to the present invention, the charge control agent was relatively changed depending on the degree of interaction between the polar functional group on the surface of the organic pigment and the functional group of the pigment dispersant according to the surface treatment. The surface concentration was influenced by the transfer rate and the charge amount. In Examples 1 and 3, the pigment dispersion effect is increased due to the affinity between the functional groups on the surface of the pigment and the functional group of the polymer dispersant, thereby increasing the pigment dispersing effect, thereby improving the charging property. It became. As a result, the transfer rate and the charge amount were high. In the case of Example 2, since the functional groups meet with base and base pairs, the charging property is lowered rather than without surface modification as in Comparative Example 1. In Example 4, the glycidyl group was weak in the functional group having an amine number, but was able to react, and thus showed a slightly good effect on the charging characteristics.

As described above, the toner of the present invention may combine the organic pigment with the pigment dispersant to reduce the surface concentration of the organic pigment, which is one of the important factors that reduce the surface concentration of the charge control agent or inhibit the role of the charge control agent. Since the surface is modified with a specific functional group, and a pigment dispersant having a functional group that can effectively combine with the functional group is used, the surface charge density is higher than that of the conventional toner, which is very useful for securing high charge density and high resolution.

Claims (14)

An organic pigment and a pigment containing a charge control agent, a monomer, a wax, an aqueous dispersant, a molecular weight regulator, and an organic pigment and which are prepared by a suspension polymerization method, which are surface-modified with a coupling agent and have a functional group bondable with the pigment dispersant. A toner comprising a dispersant. The toner of claim 1, wherein the coupling agent is a compound represented by the following Chemical Formula 1. <Formula 1> X-R-Y In the above formula, X is a functional group that reacts with the organic pigment, and is a functional group of silane, epoxy, isocyanate or titanium, R is C ₁ to C ₁₂ linear or branched alkyl, a functional group or polysiloxane containing a benzene group, Y is a functional group which bonds with the pigment dispersant and includes an acidic functional group of a carboxylic acid group or a sulfonic acid group; Basic functional groups of amines, imines, amides or isocyanates; Or a glycidyl group. The toner of claim 1, wherein the pigment dispersant is represented by the following Chemical Formula 2, wherein the pigment dispersant is a polymer compound having a molecular weight of 1000 to 100,000 as a weight average and a glass transition temperature of 40 to 110 ° C. <Formula 2> (Z) _n- (R ') _m In the above formula, Z is a functional group that reacts with the organic pigment, and an acidic functional group of a carboxylic acid group or a sulfonic acid group; Or a basic functional group of an amine, imine, amide or isocyanate, located at the end of a polymer chain, in a block structure or in a random structure, R 'is any one of a linear ester polymer monomer, a styrene polymer, an acrylate polymer or a mixture thereof, n is 1-10 and m is 10-300. The toner according to claim 1, comprising a core layer comprising the surface-modified organic pigment and a pigment dispersant and a shell layer surrounding the core layer. The toner according to claim 1, wherein 1-30 parts by weight of the coupling agent is added to 100 parts by weight of the organic pigment to perform surface modification. The toner of claim 1, wherein the pigment dispersant comprises 1-50 parts by weight based on 1-20 parts by weight of the surface-modified organic pigment. The toner according to claim 1, wherein the charge control agent is at least one selected from the group consisting of chlorinated paraffin, chlorinated polyester, sulfonylamine of copper phthalocyanine, and styrene-acrylic polymer containing sulfonic acid group. The toner according to claim 1, wherein the monomer is at least one selected from aromatic vinyl, acrylate, methacrylate, diene monomers or acidic or basic olefinic monomers. 9. The toner of claim 8, wherein the monomer further comprises one or more selected from polyester-based or styrene acrylic polar polymers. The method of claim 1, wherein the wax is petroleum refined wax selected from the group consisting of paraffin wax, microcrystalline wax and ceresin wax; Natural waxes that are carnuba wax; Or at least one selected from synthetic waxes selected from the group consisting of ester waxes, polyethylene, and polypropylene. The method of claim 1, wherein the dispersing agent is an inorganic dispersant selected from the group consisting of silica, insoluble calcium salt and insoluble magnesium salt; Anionic surfactants selected from the group consisting of fatty acid salts, alkyl sulfate ester salts, alkylaryl sulfate ester salts, dialkyl sulfosuccinates and alkyl phosphates; Or nonionic selected from the group consisting of polyoxyethylene alkyl ethers, polyoxyalkylene alkyl phenol ethers, sorbitan fatty acid esters, polyoxyalkylene fatty acid esters, glycerin fatty acid esters, polyvinyl alcohols, alkyl celluloses and polyvinyl pyrrolidones Toner, characterized in that at least one selected from surfactants. The toner according to claim 1, wherein the molecular weight modifier is at least one selected from t-dodecyl mercaptan or n-dodecyl mercaptan. The method of claim 1, wherein the pigment is an inorganic pigment selected from the group consisting of metal powder type, metal oxide type, carbon type, sulfide type, chromium salt type and ferrocyanide type; Or at least one organic pigment selected from the group consisting of azo type, acid dye type, basic dye type, modant dye type, phthalocyanine, quinacridone type and dioxane type. 1) modifying the surface of the organic pigment using 1-30 parts by weight of the coupling agent based on 100 parts by weight of the organic pigment (first step); 2) preparing an aqueous dispersion comprising 0 to 10 parts by weight of an inorganic dispersant or a water-soluble organic polymer dispersant based on an aqueous solution in water and optionally including 0 to 10 parts by weight of anionic surfactant (second step); 3) 30 to 90 parts by weight of an aromatic vinyl monomer, 5 to 70 parts by weight of at least one of an acrylate monomer, a methacrylate monomer and a diene monomer, and 0.017 to 30 parts by weight of an acidic or basic olefin monomer, based on the total monomer mixture. Part, 1 to 20 parts by weight of the surface-modified pigment, 1 to 50 parts by weight of the surface-modified pigment, 0.021 to 30 parts by weight of wax, 0.001 to 8.000 parts by weight of molecular weight regulator, 0.001 to 10 parts by weight of crosslinking agent, charge control agent Preparing a monomer mixture including 0.004 to 20 parts by weight and 0.01 to 5 parts by weight of a reaction initiator (third step); 4) preparing a mixture including 1 to 60 parts by weight of the monomer mixture with respect to 100 parts by weight of the aqueous dispersion, and polymerizing while applying a shear force to the mixture (step 4); And 5) The toner manufacturing method of claim 1, comprising forming a shell on the manufactured toner core (step 5).