JPH11174728A - Electrophotographic toner and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a toner excellent in anti-hot offsetting property and blocking resistance. SOLUTION: Fine particles of a releasing agent compsn. consisting of at least one of gallium and its compd. and a low m.p. material, together with a bonding resin and a colorant, are added and dispersed in an org. solvent and the resultant oily mixture is added to an aq. medium and granulated to produce the objective toner contg. fine particles of the releasing agent compsn. in a colorant-contg. bonding resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used in an electrophotographic process or the like, a method for producing the same, and a developer composition using the same.

[0002]

2. Description of the Related Art Recently, there has been an increasing demand for miniaturizing a copying machine or a printer using an electrophotographic method and performing high-speed copying. To realize this, it is necessary to fix toner with low power consumption. It is important to simplify the fixing method. As a means for fusing and fixing the toner on paper, a fixing method using a hot roll is currently most commonly used. In a monochrome copying machine or a printer, a system that does not need to supply a release agent oil to a hot roll is generally used.However, when a color toner is used, a thermal roll is used to prevent offset to the hot roll. Means for supplying oil to the rolls are essential, and these are obstacles in designing a small and inexpensive system. For this reason, in image formation using color toners, in particular, in a full-color system in which it is necessary to obtain a clear multicolor image using cyan, yellow, and magenta toners, it is necessary to sufficiently heat-melt each toner layer. Because of this, the fixing temperature of the hot roll must be raised sufficiently to a temperature higher than the temperature at which it is usually fixed on paper.

Further, as a toner for electrostatic development used in the field of electrophotography, in order to sufficiently develop a color image, a resin which melts sharply at the time of fixing and makes the image surface smooth is used. Is preferred. For this reason, a resin having a low molecular weight and a narrow molecular weight distribution is preferable, for example,
A polyester having sufficient flexibility even when the molecular weight is reduced is more preferably used. However, the polyester resin for a color toner has a small internal cohesive force and is difficult to peel off from the roll when melted. Therefore, it has been difficult to implement a fixing method that does not require oil application with a color toner using a polyester resin.

[0004] In order to solve such a problem, it has been widely studied to use a toner to which a release agent has been added so that the toner can be easily separated from a roll. However, although the toner containing the release agent has achieved some success in terms of roll releasability, it has not always been satisfactory in all toner characteristics. One of the reasons is that the amount of the release agent contained in the toner and the amount of the release agent present on the toner surface cannot be present in an optimal state. This is because in a toner produced by a kneading and pulverizing method, which is a general method for producing a toner, a release agent, for example, a commonly used wax is exposed at a high concentration together with a pigment on the surface of the toner particles, which is a fracture surface of the pulverization. Also, due to the collision of toner particles in a pulverizer or a classifier, which is a production process, or frictional heat with the wall of the device, the wax exposed on the surface partially melts and spreads, and further covers the toner particle surface. .

Japanese Patent Application Laid-Open No. 2-87159 discloses a toner obtained by applying a mechanical impact force to a kneaded and pulverized toner containing a wax to form a spherical toner. The amount of wax on the surface of the toner particles is determined by ESCA. The result is 10-40% by weight
It is said that there is a degree. Usually, the proportion of the wax present on the surface of the kneaded and pulverized toner particles to which 1 to 10% by weight of wax is added is about 30 to 50% by weight. Alternatively, there has been a problem that the carrier surface is contaminated, causing fluctuations in the development characteristics. In addition, there is a problem that the adhesive force with the photoconductor or the intermediate transfer member increases, and the transfer efficiency of the toner is low, and there is also a problem that image disorder occurs when a color image requiring multiple transfer is created.

[0006] In order to overcome the above-mentioned drawbacks of the toner to which the wax is added, a new toner has been proposed. One of them is a toner having a capsule structure as disclosed in JP-A-8-297376. These toners having a capsule structure can reduce the proportion of low molecular weight components such as wax exposed on the surface of the particles, and the above-mentioned problems relating to blocking property, filming property, and developing property are compared. Less. However, these toners in which the surface wax is not completely present do not always provide sufficient roll release properties. In order to prevent offset to the hot roll, a weak boundary layer (weak) such as a molten wax between the toner melted in the hot roll fixing nip and the hot roll surface is used.
A boundary layer must be formed instantaneously to prevent the toner from directly contacting the binder resin in a very short time. However, when the wax is completely included in the binder resin of the toner, the inside of the binder resin is reduced. Causes a delay for the molten wax to diffuse to the interface, resulting in a weak boundary layer (Wea).
k Boundary Layer) cannot be formed sufficiently. Furthermore, when a color image is produced with a toner having such a capsule structure, a higher temperature is generally required in order to completely melt the toner image due to a hard shell on the surface, and the color toner is fixed at a high speed. In a process or the like, the releasability from a roll becomes more and more difficult.

Japanese Patent Application Laid-Open No. 8-6283 discloses that gallium metal is contained in a toner for the purpose of controlling the chargeability of the toner for electrophotography. In this toner, gallium acts as a release agent, but the blocking resistance of the toner is not sufficient. The reason is that the melting point of gallium metal is as low as 30 ° C. or less, so that gallium metal existing on the surface of the toner particles may be melted at high temperatures such as in summer and the toner particles may aggregate.

As described above, the above-mentioned conventionally proposed toners do not sufficiently satisfy all of the high-temperature offset resistance and the blocking resistance.

[0009]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems in the prior art, and has the following advantages. It is an object of the present invention to provide a novel toner having excellent blocking resistance and a method for producing the toner.

[0010]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a release agent composition fine particle comprising at least one of gallium and a gallium compound and a low-melting substance is contained in a colorant-containing binder resin. The inventors have found that the above problems can be solved by doing so, and have completed the present invention. That is, the toner of the present invention is characterized in that the release agent composition fine particles comprising at least one of gallium and a gallium compound and a low-melting substance are included in the colorant-containing binder resin.

The method for producing a toner according to the present invention comprises dispersing fine particles of a release agent composition composed of at least one of gallium and a gallium compound and a low-melting substance by adding them to an organic solvent together with a binder resin and a colorant. The obtained oily mixture is added to an aqueous medium and granulated.
Further, the developer composition of the present invention comprises the above toner and a resin-coated carrier.

In the present invention, one or both of gallium and a gallium compound having a low melting point are mixed with a low-melting substance, and the mixture is contained in the toner in the form of fine particles. Exudation from the particle surface can be suppressed. In addition, at the time of fixing the toner, gallium and the gallium compound quickly cause a weak boundary layer (weak boundary L) between the toner melted in the hot roll fixing nip and the roll surface.
ayer), it exhibits high-temperature offset resistance.

Hereinafter, unless otherwise specified, a mixture of at least one of gallium and a gallium compound and a low-melting substance is referred to as a release agent composition.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, gallium alone, a gallium compound, or a mixture of both of them is used for producing release agent composition fine particles. As the gallium compound, for example, GaBr ₃ , GaCl ₃ , Ga (N
O ₃ ) _{3 and the} like can be used. A gallium compound or mixture having a melting point of 25 ° C to 130 ° C can be suitably used.

As the low-melting substance mixed with one or both of gallium and the gallium compound, a substance having a melting point of 70 ° C. to 150 ° C. can be used. For example, waxes and waxes include carnauba wax, vegetable wax such as cotton wax, wood wax, and rice wax; animal wax such as beeswax and lanolin; mineral wax such as ozokerite and celsin; and paraffin and microcrystalline. And petroleum wax such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, 12-hydroxystearic acid amide,
Synthetic waxes such as fatty acid amides such as stearamide, phthalic anhydride, and chlorinated hydrocarbons, esters, ketones, and ethers can also be used. Further, as the low molecular weight crystalline polymer resin, homopolymers and copolymers of acrylates (for example, poly-n-stearyl methacrylate, poly-n-lauryl methacrylate, n-stearyl acrylate-ethyl methacrylate copolymer, etc.) )
And crystalline polymers having a long alkyl group in the side chain. Of these, more preferred are petroleum waxes such as paraffin wax and microcrystalline wax and synthetic waxes.

The amount of gallium and the gallium compound to be mixed with the low-melting substance depends on the average particle diameter of the finely divided gallium and the gallium compound. Although the above can be used, the range of 5 to 500 parts by weight is still more preferable. More preferably, it is in the range of 10 parts by weight to 100 parts by weight.

Although the amount of the release agent contained in the toner also depends on the average particle size of the finely divided release agent, usually 3 parts by weight or more can be used with respect to 100 parts by weight of the toner. A range from 5 parts to 500 parts by weight is even more preferred. More preferably, it is in the range of 10 parts by weight to 300 parts by weight.

The binder resin is not particularly limited, and resins generally used as toner resins can be used. Specifically, polyester resin, styrene resin, acrylic resin, styrene / acrylic resin, silicone resin, epoxy resin, diene resin, phenol resin, ethylene / vinyl acetate resin, and the like are more preferable. It is.

The monomers constituting the polyester resin include the following. Examples of the alcohol component include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4-hydroxyphenyl) propane, Oxyethylene (2.0)-
2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl)
Diols such as propane, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, isopentylene glycol, hydrogenated bisphenol A, 1,3-butanediol, 1,4-butanediol, neo Pentylene glycol, xylylene glycol, 1,4-cyclohexanedimethanol, glycerin, trimethylolethane, trimethylolpropane,
Pentaerythritol, bis (β-hydroxyethyl)
Terephthalate, tris (β-hydroxyethyl) isocyanurate, 2,2,4-trimethylolpentane
1,3-diol and the like. Further, a hydroxycarboxylic acid component can be further added. For example, p-
Oxybenzoic acid, vanillic acid, dimethylolpropionic acid, malic acid, tartaric acid, 5-hydroxyisophthalic acid and the like can be added. As the acid component, for example, malonic acid, succinic acid, glutaric acid, dimer acid, phthalic acid,
Isophthalic acid, terephthalic acid, dimethyl isophthalate, dimethyl terephthalate, monomethyl terephthalate, tetrahydroterephthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid, dimethyltetrahydrophthalic acid, endomethylenehexahydrophthalic acid, naphthalenetetracarboxylic acid Acid, diphenolic acid, trimellitic acid, pyromellitic acid, trimesic acid, cyclopentanedicarboxylic acid, 3,3 ', 4,4'
-Benzophenonetetracarboxylic acid, 1,2,3,4-
Butanetetracarboxylic acid, 2,2-bis (4-carboxyphenyl) propane, trimellitic anhydride and 4,4
Dimer carboxylic acid obtained from diaminophenylmethane, tris (β-carboxyethyl) isocyanurate, isocyanurate ring-containing polyimide carboxylic acid, trimerization reaction product of tolylene diisocyanate, xylylene diisocyanate or isophorone diisocyanate with trimellitic anhydride And the like, and isocyanate ring-containing polyimide carboxylic acids and the like, which can be used alone or in combination of two or more. Among these, the use of a crosslinking component such as a trivalent or higher polycarboxylic acid and a polyhydric alcohol may be preferable in terms of stability such as fixing strength and offset resistance. The polyester resin can be produced by a usual method using the above components. The glass transition temperature of polyester resin is 40 ° C ~
The temperature is preferably set to 80 ° C, and a more preferable range is 50 ° C to 70 ° C. Table 1 shows preferable specific examples of the polyester resin used in the present invention.

[0020]

[Table 1]

In the binder resin of the present invention, two or more of the above polyester resins may be combined, or another resin may be combined. Other resins include styrene resin, acrylic resin, styrene / acrylic resin, silicone resin, epoxy resin, diene resin, phenol resin, terpene resin, coumarin resin, amide resin, amideimide resin, butyral resin, urethane resin, ethylene -Vinyl acetate resin and the like. In the present invention, when a polyester resin is used as a main component, it is preferable that the other resin is added to the toner in an amount of 0 to 30% by weight.

In the present invention, known organic or inorganic pigments and dyes, and oil-soluble dyes can be used as the colorant dispersed in the thermoplastic resin. For example, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 12
2, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 12,
C. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 15: 3, Lamp Black (CI No. 7
7266), Rose Bengal (CI No. 4543)
2), carbon black, nigrosine dye (CIN)
o. 50415B), metal complex salt dyes, derivatives of metal complex salt dyes, and mixtures thereof. Further, various metal oxides such as silica, aluminum oxide, magnetite and various ferrites, cupric oxide, nickel oxide, zinc oxide, zirconium oxide, titanium oxide, and magnesium oxide, and appropriate mixtures thereof, and the like can be given. . These colorants need to be contained in a sufficient ratio to form a visible image having a sufficient density, and depend on the toner particle size and the development amount, but are generally based on 100 parts by weight of the binder resin. In the range of 1 to 30 parts by weight. When a black colorant is used, it may be used in the range of 30 to 150 parts by weight based on 100 parts by weight of the binder resin.

In the present invention, a charge control agent may be added to the toner if necessary. Examples of charge control agents that can be used include metal salts of benzoic acid, metal salts of salicylic acid, metal salts of alkylsalicylic acid, metal salts of catechol, metal-containing bisazo dyes, tetraphenylborate derivatives, Compounds selected from the group consisting of quaternary ammonium salts and alkylpyridinium salts, and those suitably combined with each other can be preferably used.

The amount of the charge control agent to be added to the toner is generally 0.1% by weight to 10% by weight, preferably
It is in the range of 0.5 to 8% by weight. When the amount is less than 0.1% by weight, the charge control effect is insufficient, and when the amount exceeds 10% by weight, the toner resistance is excessively reduced, which makes it difficult to use.

Further, a metal soap, an inorganic or organic metal salt can be used in combination with the charge control agent. Such metal soaps include aluminum tristearate, aluminum distearate, barium, calcium, lead and zinc salts of stearic acid, cobalt, manganese, lead and zinc salts of linolenic acid, aluminum, calcium and cobalt salts of octanoic acid , Calcium and cobalt salts of oleic acid, zinc palmitate, calcium, cobalt, manganese, lead and zinc salts of naphthenic acid, calcium, cobalt, manganese lead and zinc salts of resinate and the like can be used. In addition, as the inorganic and organic metal salts, for example, the cationic component in the metal salt is selected from the group consisting of metals of Groups Ia, IIa, and IIIa of the periodic table, The components of are halogen, carbonate, acetate, sulfate,
It is a salt selected from the group consisting of borate, nitrate, and phosphate. These charge control or cleaning aids generally comprise 0.1% by weight of the toner.
It is used in the range of 10 to 10% by weight, more preferably 0.1 to 5% by weight. If the amount is less than 0.1% by weight, the desired effect is insufficient, and if it exceeds 10% by weight, the flowability of the toner powder is reduced, and the use becomes difficult. Generally, the particle size of the toner is preferably in the range of 3 to 10 μm.

Next, a method for producing a toner according to the present invention will be described. First, one or both of gallium and a gallium compound having a low melting point and a low melting substance are mixed in advance, and the mixture is added to an organic solvent and dispersed together with a binder resin and a colorant. One or both of gallium and a gallium compound are mixed in advance with a low-melting substance, and the obtained release agent composition fine particles are encapsulated in a binder resin. Seepage is suppressed.

The mixing method for preparing the release agent composition fine particles is not particularly limited, but the mixing must be performed at a temperature higher than a temperature at which gallium and the gallium compound are sufficiently dissolved. For example, the following manufacturing method is adopted. That is, one or both of gallium and a gallium compound and a low-melting substance are melted and kneaded using a Banbury-type kneader or the like, and the mixture is melted with liquid nitrogen or the like so that the gallium and the gallium compound are not melted by frictional heat during grinding. Coarsely pulverized while maintaining the following. Furthermore, it is frozen and pulverized by a jet mill in the same manner as described above, and has an average particle diameter of 0.1 to
The release agent composition fine particles of 5 μm, for example, about 1 to 2 μm are obtained.

The toner of the present invention is produced by a wet process. According to the wet manufacturing method, a component having a polar group and a non-polar component such as a general wax contained in a toner composition in an aqueous phase are mixed with a gallium-containing release agent composition fine particle due to a hydrophilic-hydrophobic affinity difference. With the nucleus as a nucleus, a toner is formed by an aggregation effect.

In the present invention, as a toner component, a binder resin such as a polyester resin, a coloring agent, and other additives used as necessary are used. Dissolve or disperse in an insoluble organic solvent. The organic solvent that can be used depends on the components of the binder resin and the low-melting substance contained in the release agent composition fine particles, but generally, hydrocarbons such as toluene, xylene, and hexane, methylene chloride, chloroform, Halogenated hydrocarbons such as dichloroethane, alcohols or ethers such as ethanol, butanol, benzyl alcohol ether and tetrahydrofuran, esters such as methyl acetate, ethyl acetate, butyl acetate and isopropyl acetate, acetone, methyl ethyl ketone, diisobutyl ketone, cyclohexanone, And ketones such as methylcyclohexane. These organic solvents include:
It is necessary to mainly dissolve the binder resin, but the colorant and other additives may or may not be dissolved. The weight ratio of the toner component to the organic solvent used in the oil phase is from 10:90 to 8
A range of 0:20 is preferred in terms of ease of granulation or final toner yield.

The oil phase produced as described above is then suspended in an aqueous phase and granulated to a predetermined particle size. In this case, the main medium of the aqueous phase is water. In the aqueous phase,
If necessary, inorganic and organic dispersion stabilizers that form hydrophilic colloids may be added. Examples of the inorganic dispersion stabilizer include calcium carbonate, magnesium carbonate, barium carbonate, tricalcium phosphate, hydroxyapatite, silicic acid, diatomaceous earth, and clay. The average particle size of these inorganic dispersion stabilizers is preferably 2 μm or less, more preferably 0.1 μm or less. These are desirably pulverized to a desired particle size by a wet disperser such as a ball mill, a sand mill, and an attritor, and then used. If the particle diameter of these inorganic dispersion stabilizers exceeds 2 μm, the particle size distribution of the granulated toner becomes wide and cannot be used as a toner.

Specific examples of the organic dispersion stabilizer which may be used in combination with these inorganic dispersion stabilizers include gelatin and gelatin derivatives (eg, acetylated gelatin, phthalated gelatin, succinated gelatin, etc.). ,albumin,
Proteins such as casein, collodion, gum arabic, agar, alginic acid, cellulose derivatives (eg, carboxymethylcellulose alkyl ester, hydroxymethylcellulose, carboxymethylcellulose, etc.), synthetic polymers (polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, polyacrylic acid) Salts, polymethacrylates, polymaleates, polystyrenesulfonates) and the like. These organic dispersion stabilizers
They may be used alone or as a mixture of two or more. The dispersion stabilizer is preferably used in an amount of 0.001 to 5 parts by weight based on 100 parts by weight of the main medium in the aqueous phase.

A dispersion stabilizing aid may be used in combination with the aqueous phase. Various surfactants can be used as the dispersion stabilizing aid. Examples of the surfactant include ionic and nonionic surfactants. Specific examples of the anionic surfactant include alkyl benzene sulfonate, alkyl phenyl sulfonate, alkyl naphthalene sulfonate, and higher surfactants. Fatty acid salts, sulfate salts of higher fatty acid esters, sulfonic acid of higher fatty acid esters, and the like can be used. As the cationic activator, primary to tertiary amine salts, quaternary ammonium salts and the like can be used. Non-ionic activators include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester And fatty acid alkylolamides. These dispersion stabilizing aids may be used alone or as a mixture of two or more. The dispersion stabilizing adjuvant is 0.1% based on the main medium of the aqueous phase.
It is preferably used in the range of 001 parts by weight to 5 parts by weight.

The mixing ratio of the oil phase and the aqueous phase varies depending on the final particle size of the toner and the production equipment, but is usually preferably in the range of 10/90 to 90/10 by weight. The granulation of the oil phase in the aqueous phase is preferably performed under high-speed shearing.
In particular, when setting the average particle diameter of the toner to 5 to 9 μm, it is necessary to pay attention to the selection of a disperser having a high-speed shearing mechanism to be used. Among them, it is preferable to use a high-speed blade rotation type or forced interval passage type emulsifier such as various homomixers, homogenizers and colloid mills.

The solvent is removed during the granulation step or after the granulation step. The removal of the solvent may be performed at normal temperature or may be performed under reduced pressure. To perform at room temperature,
It is necessary to perform at a temperature lower than the boiling point of the solvent and taking into account the Tg of the binder resin. At temperatures significantly above the Tg of the binder resin, undesirable toner coalescence may occur.
Usually, it is preferable to stir at about 40 ° C. for 3 to 24 hours.
When the pressure is reduced, it is preferably performed at 20 to 150 mmHg.

In a toner in which an inorganic dispersion stabilizer and an organic dispersion stabilizer remain on the toner surface, the humidity dependency of the toner deteriorates due to the hygroscopicity of the residual deposits. It is necessary to remove the dispersion stabilizer and minimize the influence on the chargeability and powder fluidity of the toner. Therefore, after removing the solvent, the obtained toner is preferably subjected to an acid or alkali treatment. Specifically, it is preferable to wash with an acid that makes the inorganic dispersion stabilizer water-soluble, such as hydrochloric acid, nitric acid, formic acid, and acetic acid. As a result, the inorganic dispersion stabilizer remaining on the toner surface is removed. The acid- or alkali-treated toner may be washed again with an alkaline water such as sodium hydroxide if necessary. As a result, some ionic substances on the surface of the toner particles insolubilized by being placed in an acidic atmosphere are again
It is solubilized and removed, which is advantageous in terms of improvement in chargeability and powder flowability.

Further, the washing with the acid and the alkaline water has an effect of washing and removing the low-melting-point substance liberated and adhered to the surface of the toner particles. In addition to setting conditions such as pH at the time of washing, the number of washings, and temperature at the time of washing, it is preferable to use a stirrer, an ultrasonic dispersion device, or the like because washing is effectively performed. Thereafter, if necessary, the toner of the present invention can be obtained by subjecting it to a treatment such as filtration, decantation, or centrifugation, and drying.

A known external additive may be added to the toner of the present invention to control fluidity and developability. As the external additive, various inorganic oxide fine particles such as silica, alumina, titania, and cerium oxide, and if necessary, hydrophobicized fine particles, a vinyl polymer, and zinc stearate can be used. The external addition amount is based on 100 parts by weight of the toner before addition.
A range of 0.01 to 1 part by weight is preferred.

The toner obtained by the production method of the present invention can be used without limitation in the known dry electrostatic developing method. For example, a two-component developing method such as a cascade method, a magnetic brush method, or a microtoning method, a one-component developing method such as a conductive one-component developing method, an insulating one-component developing method, and a non-magnetic one-component developing method. As a carrier used in the component development method, a resin-coated carrier is used. As the carrier core, any one may be used as long as it is generally used, and specific examples thereof include various ferrites such as ferric oxide, γ-iron sesquioxide, MnZn ferrite, and NiZn ferrite, and chromium oxide. . Examples of the resin for coating these carrier cores include polyvinylidene fluoride, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene copolymer, acrylate ester polymer and copolymer. Examples include coalesced, methacrylic acid polymers and copolymers. These resins are usually used in an amount of 0.
It is used in amounts ranging from 0.05 to 3.0% by weight. The coating can be performed by a conventional method, for example, a method in which a solution in which a resin is dissolved in an organic solvent is added to a carrier core, and the coating is performed by a fluid coating apparatus, or the like can be used. The carrier generally has a particle size in the range of 10 to 200 μm.

[0039]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited by the following Examples and Comparative Examples. In Examples and Comparative Examples, “parts” means “parts by weight”.

Example 1-1 (A) Preparation of Pigment Dispersion 1. Polyester resin R-1 (described in Table 1): 50 parts (Tg; 63 ° C., softening point; 102 ° C., weight average molecular weight; 9000) 2. Copper phthalocyanine pigment: 50 parts (CI Pigment Blue 15: 3, Cyanine Blue 4933M; manufactured by Dainichi Seika Co., Ltd.) Ethyl acetate 100 parts Glass beads were added to the above material, and the mixture was placed in a sand mill disperser. While cooling the periphery of the dispersion container, the mixture was stirred and dispersed in a high-speed stirring mode for 3 hours. Since ethyl acetate volatilized during stirring, ethyl acetate was added to adjust to finally obtain a pigment dispersion having a pigment concentration of 10% by weight.

(B) Preparation of Release Agent Composition Dispersion 1. Polypropylene wax: 67 parts (melting point: 140 ° C., latent heat of fusion: 290 mJ / mg) Gallium (simple) 33 parts (melting point 29.8 ° C., latent heat of fusion: 80 mJ / mg) The above materials were kneaded with a Banbury kneader, and then pulverized to produce fine particles. The obtained fine particles were dispersed in toluene at the following ratio to prepare a release agent composition dispersion liquid. 3. Fine particles: 50 parts 4. Toluene: 17 parts The average particle size of the fine particles of the obtained release agent composition dispersion was measured using a laser diffraction / scattering particle size distribution analyzer LA-700 (manufactured by Horiba, Ltd.). It was confirmed that there was.

(C) Preparation of Oil Phase 1. Polyester resin R-1 (described in Table 1): 85 parts (Tg; 63 ° C, softening point; 102 ° C, weight average molecular weight; 9000) 2. Pigment dispersion liquid: (Pigment concentration: 10% by weight) 50 parts 3. Release agent composition dispersion liquid: (release agent concentration: 75% by weight) 33 parts Ethyl acetate 32 parts The above materials were mixed, and after confirming that the polyester resin was sufficiently dissolved, the mixture was charged into a homomixer (Ace Homogenizer, manufactured by Nippon Seiki Co., Ltd.) and stirred at 15,000 rpm for 2 minutes. A fresh oil phase was prepared.

(D) Preparation of Aqueous Phase Two types of aqueous phases were prepared by the following procedure. D-1) Calcium carbonate aqueous solution 1. Calcium carbonate: (average particle size 0.03 micron) 60 parts 40 parts of pure water The above-mentioned material was stirred with a ball mill for 4 days. When the average particle size of calcium carbonate was measured using the above-mentioned laser diffraction / scattering particle size distribution analyzer LA-700 (manufactured by Horiba Ltd.), it was confirmed to be about 0.08 μm. D-2) Carboxymethylcellulose aqueous solution 1. Carboxymethylcellulose 2 parts (Cellogen BSH; Daiichi Kogyo Pharmaceutical) 98 parts of pure water was dissolved to obtain an aqueous phase.

(E) Toner Production Method Oil phase (C): 60 parts 2. 2. Calcium carbonate aqueous solution (D-1): 10 parts Carboxymethylcellulose aqueous solution (D-2): 30 parts The above materials were charged into a colloid mill (manufactured by Nippon Seiki Co., Ltd.), and emulsified at 8000 rotations per minute at a gap interval of 1.5 mm for 20 minutes. Next, the above emulsion was put into a rotary evaporator, and the solvent was removed under reduced pressure of 30 mmHg at room temperature for 3 hours. Then add 12N hydrochloric acid until pH2,
Calcium carbonate was removed from the toner surface. Then 1
0N sodium hydroxide was added until the pH reached 10, and stirring was continued for one hour with a stirrer in an ultrasonic cleaning tank. After further centrifugal sedimentation, the supernatant was exchanged three times and washed, and then dried to take out toner particles. The average particle size of the obtained toner particles was 7.1 μm. To the obtained toner particles, 3% by weight of hydrophobic silica powder (R972, manufactured by Nippon Aerosil Co., Ltd.) was added to prepare a toner.

Example 1-2 In preparing the release agent composition dispersion of Example 1-1, polypropylene and gallium chloride (GaCl ₃ ) were used in place of polypropylene and gallium, and the release agent composition was prepared according to the following procedure. Example 1-1 except that a product dispersion was prepared.
A toner was produced in the same manner as described above. (B) Preparation of release agent composition dispersion liquid 86 parts of polypropylene wax (melting point: 110 ° C.) Gallium chloride (GaCl ₃ ) (melting point: 78 ° C.) 14 parts The above materials were kneaded by a Banbury-type kneader, and then pulverized to produce fine particles. The obtained fine particles were dispersed in toluene at the following ratio to prepare a release agent composition dispersion liquid. 3. Fine particles: 50 parts 4. Toluene: 17 parts The average particle diameter of the fine particles in the obtained release agent composition dispersion is
When measured using a laser diffraction / scattering particle size distribution analyzer LA-700 (manufactured by Horiba, Ltd.), about 1.20 μm
Was confirmed.

Example 2-1 In preparing the release agent composition dispersion of Example 1-1, a release agent composition dispersion was prepared by the following procedure (B) using carnauba wax and gallium. Further, a toner was prepared in the same manner as in Example 1-1 except that a polyester resin R-2 (described in Table 1) was used instead of the polyester resin R-1 in preparing the pigment dispersion and the oil phase. . (B) Preparation of release agent composition dispersion liquid 1. Carnauba wax: 67 parts Gallium (simple) 33 parts (melting point 29.8 ° C., latent heat of fusion: 80 mJ / mg) The above materials were kneaded with a Banbury kneader, and then pulverized to produce fine particles. The obtained fine particles were dispersed in toluene at the following ratio to prepare a release agent composition dispersion liquid. 3. Fine particles: 50 parts 4. Toluene: 17 parts The average particle diameter of the fine particles in the obtained release agent composition dispersion is
When measured using a laser diffraction / scattering particle size distribution analyzer LA-700 (manufactured by Horiba, Ltd.), about 1.50 μm
Was confirmed.

Example 2-2 The following procedure (B) was used to prepare the release agent composition dispersion of Example 2-1 except that carnauba wax and gallium chloride (GaCl ₃ ) were used instead of carnauba wax and gallium.
A toner was prepared in the same manner as in Example 2-1 except that a release agent composition dispersion was prepared as described above. (B) Preparation of release agent composition dispersion liquid 86 parts of carnauba wax 2. Gallium chloride (GaCl ₃ ) (melting point: 78 ° C.) 14 parts The above materials were kneaded by a Banbury-type kneader, and then pulverized to produce fine particles. The obtained fine particles were dispersed in toluene at the following ratio to prepare a release agent composition dispersion liquid. 3. Fine particles: 50 parts 4. Toluene: 17 parts The average particle diameter of the fine particles of the obtained release agent composition dispersion was measured using a laser diffraction / scattering particle size distribution analyzer LA-700 (manufactured by Horiba, Ltd.). It was confirmed that there was.

Example 3-1 In preparing the release agent composition dispersion of Example 1-1, a release agent composition dispersion was prepared by the following procedure (B) using polyethylene and gallium. In preparing a pigment dispersion and an oil phase, a polyester resin R-3 (described in Table 1) was used instead of the polyester resin R-1.
A toner was produced in the same manner as in Example 1-1. (B) Preparation of release agent composition dispersion liquid 1. Polyethylene wax: 67 parts (melting point: 110 ° C.) Gallium (simple) 33 parts (melting point 29.8 ° C., latent heat of fusion: 80 mJ / mg) The above materials were kneaded with a Banbury kneader, and then pulverized to produce fine particles. The obtained fine particles were dispersed in toluene at the following ratio to prepare a release agent composition dispersion liquid. 3. Fine particles: 50 parts 4. Toluene: 17 parts The average particle size of the fine particles of the obtained release agent composition dispersion was measured using a laser diffraction / scattering particle size distribution analyzer LA-700 (manufactured by Horiba, Ltd.). It was confirmed that there was.

Example 3-2 In preparing the dispersion of the release agent composition of Example 3-1, carnauba wax and gallium chloride (GaCl ₃ ) were used in place of polyethylene and gallium, and the following procedure (B) was used. A toner was prepared in the same manner as in Example 3-1 except that a release agent composition dispersion was prepared. (B) Preparation of release agent composition dispersion liquid 86 parts of polyethylene wax Gallium chloride (GaCl ₃ ) (melting point: 78 ° C.) 14 parts The above materials were kneaded by a Banbury-type kneader, and then pulverized to produce fine particles. The obtained fine particles were dispersed in toluene at the following ratio to prepare a release agent composition dispersion liquid. 3. Fine particles: 50 parts 4. Toluene: 17 parts The average particle diameter of the fine particles of the obtained release agent composition dispersion was measured using a laser diffraction / scattering particle size distribution analyzer LA-700 (manufactured by Horiba, Ltd.). It was confirmed that there was.

Comparative Example 1-1 Example 1 was repeated except that the materials in "(B) Preparation of release agent composition dispersion" in Example 1-1 were changed to the following materials.
In the same manner as in -1, a toner was produced. 1. 1. Polypropylene wax: 15 parts (melting point: 140 ° C., latent heat of fusion: 290 mJ / mg) Toluene: 85 parts Comparative Example 1-2 Instead of the polypropylene wax in Comparative Example 1-1, gallium fine particles (melting point: 29.8 ° C., latent heat of fusion: 80)
mJ / mg), except that a toner was produced in the same manner as in Comparative Example 1-1.

Comparative Example 2-1 Example 2 was repeated except that the materials in "(B) Preparation of release agent composition dispersion" in Example 2-1 were changed to the following.
In the same manner as in -1, a toner was produced. 1. 1. Carnauba wax: 15 parts Toluene: 85 parts Comparative Example 2-2 Instead of carnauba wax in Comparative Example 2-1, gallium fine particles (melting point: 29.8 ° C., latent heat of fusion: 80 mJ /
mg)) to prepare a toner in the same manner as in Comparative Example 2-1.

Comparative Example 3-1 Example 3 was repeated except that the materials in "(B) Preparation of release agent composition dispersion" in Example 3-1 were changed to the following.
In the same manner as in -1, a toner was produced. 1. 1. Polyethylene wax: (melting point: 110 ° C.) 15 parts Toluene: 85 parts Comparative Example 3-2 Instead of polyethylene wax in Comparative Example 3-1, gallium fine particles (melting point: 29.8 ° C., latent heat of fusion: 80)
mJ / mg), except that a toner was prepared in the same manner as in Comparative Example 3-1.

Comparative Examples 4-1 to 4-6 50 parts of a binder resin shown in Table 3 and a release agent (not mixed in advance) shown in Table 3 (gallium alone in the weight of the release agent, The weight ratio of gallium is 50% each
And 17%. ) And 4 parts of a cyan pigment (Cyanine Blue 4933M, manufactured by Dainichi Seika Co., Ltd.) were melt-kneaded with a Banbury mixer type kneader. The kneaded material is formed into a plate having a thickness of about 1 cm by a rolling roll, coarsely pulverized to about several millimeters by a Fitz mill type pulverizer, finely pulverized by an IDS type pulverizer, and classified by an elbow type classifier to obtain toner particles. I got A hydrophobic silica powder (R97) is added to the obtained toner particles.
2, manufactured by Nippon Aerosil Co., Ltd.) to prepare a toner.

Preparation Example of Developer A two-component developer for electrophotography was prepared by mixing 7% by weight of each of the toners obtained in the above Examples and Comparative Examples with 93% by weight of a carrier. Note that the carrier used for A-Color 635 (manufactured by Fuji Xerox Co., Ltd.) was used as it was.

(Evaluation Method of Developer) The developer obtained as described above was evaluated as follows. As the image output evaluation device, a device modified from A color 635 (manufactured by Fuji Xerox Co., Ltd.) was used. The evaluation was performed by preparing an image without supplying a release agent oil to the heat fixing roll. The specific experimental conditions are as follows. Photoreceptor: Organic photoreceptor (OPC) (φ84 mm) ROS: LED (400 dpi) Process speed: 160 mm / s Latent image potential: Background portion = −550 V, Image portion = −150 V Developing roll (common to first to fourth developing units) ): Magnet fixing, sleeve rotation, magnet magnetic flux density = 500 G (on the sleeve), sleeve diameter = φ25 mm, sleeve rotation speed = 300 mm / s Distance between the photoconductor and the developing roll (common to the first to fourth developing devices): 0.5 mm Distance between developer layer thickness regulating member and developing roll (common to first to fourth developing devices): 0.5 mm Development bias: (common to first to fourth developing devices) DC component = −500 V, AC Component = 1.5 kVP-P (8 kHz) Transfer condition: Corotron transfer (wire diameter = 85 μm) Fixing condition: Fluorine roll, no oil supply, fixing roll and pressure roll Le of two-up is 6.0mm evaluation environment: normal temperature and normal humidity (23 ℃, 50% RH) and high temperature and high humidity (23 ℃, 5 0% RH)

(1) Offset resistance evaluation: Plain paper (J
0.65 unfixed toner on paper (manufactured by Fuji Xerox)
mg / cm ² , and fixed by heat and pressure using the above apparatus. The test was performed by adjusting the temperature from 120 ° C. to 210 ° C. every 5 ° C. The offset resistance was determined by visually observing the state of occurrence of the offset. That is, the lowest temperature at which no offset occurs visually was determined as the lowest fixing temperature, and the temperature was increased. The highest temperature at which no offset occurred was defined as the highest fixing temperature.

(2) Evaluation of Blocking Resistance 5 g of the toner was left in a chamber at 45 ° C. and 50% RH for 17 hours. After the temperature is returned to room temperature, 2 g of toner is
It was thrown into a micron mesh and vibrated under certain conditions. The weight of the toner remaining on the mesh was measured, and the weight ratio was calculated. This value was taken as the toner heat blocking index.

The evaluation results are shown in Tables 2 and 3.

[Table 2]

[0059]

[Table 3]

As is clear from Tables 2 and 3, the toner of the present invention using a mixture of at least one of gallium and a gallium compound and a low-melting substance as a releasing agent is a gallium compound, a gallium compound or a low-melting substance. It can be seen that the anti-blocking property is remarkably improved and the anti-high-temperature offset property is also excellent as compared with the case where only the release agent is used.

Using the same production method as in Example 1-1 and Comparative Example 1-1, only the pigment type was changed (magenta pigment: CI Pigment Red 57: 1, yellow pigment: CI
Pigment Yellow 17, black pigment: carbon black # 25, manufactured by Mitsubishi Kasei Co., Ltd.), magenta toner, yellow toner, and black toner were prepared and evaluated in the same manner. It turned out that it was excellent in blocking property.

[0062]

As described above, the toner of the present invention is excellent in peeling from the fixing roll, and is excellent in high-temperature offset resistance and blocking resistance even when the surface of the fixing roll is oilless. Further, according to the toner manufacturing method of the present invention, a low melting point release agent that was difficult to use in the conventional kneading and pulverizing method, a resin that was difficult to use as a binder resin in the conventional polymerization method, for example, It can be dispersed in a polyester resin.

Continued on the front page (72) Inventor Seiichi Takagi 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd.

Claims (3)

[Claims] 1. A toner comprising a colorant-containing binder resin containing release agent composition fine particles comprising at least one of gallium and a gallium compound and a low-melting substance. 2. A release agent composition fine particle comprising at least one of gallium and a gallium compound and a low-melting substance is added to an organic solvent together with a binder resin and a colorant to be dispersed, and the obtained oily mixture is dissolved in an aqueous solvent. A method for producing a toner, which comprises adding the mixture to a medium and granulating the mixture. 3. A developer composition comprising the toner according to claim 1 and a resin-coated carrier.