JP5477709B2 - Image forming toner, one-component developer and two-component developer thereof, and image forming method, image forming apparatus and process cartridge using toner. - Google Patents

Description

  The present invention relates to an electrophotographic toner, and more specifically, an image forming toner used in an image forming apparatus using a so-called electrophotographic method, such as an electrostatic copying machine or a laser beam printer, and a one-component developer thereof. The present invention relates to a two-component developer, an image forming method using an image forming toner, an image forming apparatus, and a process cartridge.

In recent years, the level of image quality demanded by the market has been increasing, and the level of demand for technological development of toners that play a central role in the technology has been increasing year by year.
In particular, in recent years when an electrophotographic system is being used for on-demand digital printing, it is required to have a wide fixing offset band and a wide color reproduction range while maintaining high gloss.

Conventional electrophotographic toners have mainly been manufactured as pulverized toners that are pulverized, classified, and granulated by melting and kneading a resin or a pigment and a release agent, if necessary, in a resin.
However, due to the increasing demand for high image quality in the market in recent years, a toner granulation method using a polymerization method capable of narrowing the particle size distribution with a smaller particle size has become the mainstream.

Granulation by this polymerization method uses a variety of materials such as water, solvents, surfactants, dispersion stabilizers, and so on, and therefore becomes higher than the technical level required for the stability of conventional materials. .
In particular, when granulating toner particles, the dispersibility of the pigment or release agent in the resin dissolved or dispersed in the solvent greatly affects the fixing temperature range, color reproduction range, and developability of the toner. This is one of the most important parts in the toner production method.
Among these, when the color index number PR122 (hereinafter sometimes abbreviated as PR122) is used for magenta toner and the color index number PY74 (hereinafter sometimes abbreviated as PY74) is used for yellow toner, a solvent or a surfactant is used. The pigment is unevenly distributed on the surface in the toner due to the inherent property of the pigment with respect to the dispersion stabilizer, and the dispersion state is deteriorated.
As a result, compared to a state where the pigment dispersion in the toner particles is good, there is a problem that the absorption spectrum intensity per unit weight is lowered and the coloration and chromaticity are inferior to the expected quality.

For this problem, by using a pigment dispersant, the pigment can be uniformly dispersed in the toner, and it is possible to produce a toner with improved coloring and chromaticity quality. Known (see, for example, Patent Documents 1 and 2).
However, depending on the pigment dispersant used, even if the problem is solved and the dispersibility is improved, the viscosity of the resin and the melting point are significantly reduced due to the addition of the pigment dispersant. Solidification may occur.

Patent Document 3 discloses a toner in which a crystalline polyester resin is contained in a binder resin and both heat-resistant storage stability and low-temperature fixability are achieved.
However, since the crystalline polyester resin is difficult to dissolve in a solvent, the pigment cannot be dispersed, and it is difficult to improve the degree of coloring and chromaticity.
Therefore, it has been necessary to design a toner that can disperse the pigment satisfactorily without lowering the viscosity or melting point, has a high degree of coloring, a wide color reproduction range, and has good storage stability.

The present invention relates to an image forming toner having uniform pigment dispersion in toner particles, having a wide color reproduction range, and having both low-temperature fixability and heat-resistant storage stability, and a one-component developer and two-component thereof It is an object of the present invention to provide a developer, an image forming method using the toner, an image forming apparatus, and a process cartridge.

The polyester resin used as a toner binder granulated in an aqueous solvent needs to be dissolved and dispersed in an organic solvent, and the crystalline polyester resin is acetic acid used for granulation of toner particles. Since they are often not dissolved in an organic solvent such as ethyl, those having low crystallinity or amorphous ones are usually used.
In a system in which the resin does not dissolve, it is difficult to disperse various materials such as wax and pigment in the resin, and it is difficult to use a crystalline resin as a binder for toner.

Further, the pigment dispersion state in the toner particles greatly depends on the surface properties of various materials during granulation. For example, a toner granulated in an aqueous solvent uses a surfactant because it is necessary to disperse a non-aqueous material in which a toner material is dissolved. However, depending on the type of the surfactant, although the pigment dispersion in the varnish obtained by adding the pigment to the resin and organic solvent solution is good, the pigment forms aggregates in the toner particles after granulation. Or may be unevenly distributed on the surface of the toner particles, and may not be dispersed well. If the pigment is not uniformly dispersed in the toner particles, it is one of the major factors that reduce the color reproduction range after image formation.

The present inventor has found that the use of a crystalline resin that does not dissolve in an organic solvent in the masterbatch prevents the pigment from agglomerating or being unevenly distributed on the toner particle surface during toner granulation in an aqueous solvent.
By treating the surface of the pigment with a crystalline resin that is not soluble in organic solvents, the pigment comes into direct contact with various materials such as surfactants that are believed to have an adverse effect on pigment dispersion during toner granulation. Disappear. As a result, the resin adsorbed on the pigment surface does not dissolve and the pigment surface is not exposed, and aggregation or uneven distribution of the pigment due to the surfactant is prevented or greatly reduced, and the pigment is satisfactorily incorporated into the toner particles. The present invention has been completed by finding that it can be dispersed and that the viscosity of the binder resin can be reduced and the melting point can be prevented from being lowered.
That is, the said subject is solved by following (1)-(10) of this invention.
(1) “A toner that includes at least a binder resin, a colorant, and a colorant-dispersing resin and is manufactured in an aqueous medium,
The colorant-dispersing resin contains a crystalline resin that is not soluble in an organic solvent and has a density of 1.25 g / cm ³ or more and less than 1.45 g / cm ³ .
A toner having a saturation c * (the square root of the sum of the squares of a * and b *) of the fixed image measured by the following method of 60 or more ;
However, the saturation was measured by forming a toner unfixed image with an adhesion amount of 0.4 mg / cm ^{2 on} an A4 size paper so as to form a 3 cm × 5 cm rectangle, and subsequently setting the fixing member temperature to 180 ° C. The fixed image was prepared by fixing the unfixed image on the paper at a linear speed of 280 mm / sec, and the L * a * b * chromaticity was measured. "
(2) "The image forming toner according to item (1), wherein the binder resin contains a polyester resin";
(3) “The image forming toner according to (1) or (2), wherein the colorant resin includes a crystalline resin obtained by crystallizing the binder resin”. ,
(4) "Two-component developer comprising the image forming toner according to any one of (1) to (3) and a carrier",
(5) A toner raw material solution containing a colorant and a binder resin obtained by melt-kneading a pigment and a colorant-dispersing resin and surface-treating the pigment with the colorant-dispersing resin is dissolved in an aqueous medium. The method for producing a toner for forming an image according to any one of (1) to (3) above, wherein the toner is turbidly and / or emulsified and dispersed, and granulated.
(6) “At least a charging step for charging the surface of the image bearing member, an electrostatic latent image forming step for forming an electrostatic latent image on the image bearing member, and developing the electrostatic latent image with toner. An image forming method comprising: a developing step for forming a visual image; a transfer step for transferring the visible image onto a recording medium to form an unfixed image; and a fixing step for fixing the unfixed image on the recording medium. Because
An image forming method, wherein the toner used to form the visible image is the image forming toner according to any one of the items (1) to (3),
(7) “Image forming method according to item (6), wherein a conveyance speed of the recording medium in the fixing step is 280 mm / second or more”,
(8) “At least the image carrier, charging means for charging the surface of the image carrier, exposure means for exposing the charged image carrier surface to form an electrostatic latent image, and the electrostatic latent image Developing means for developing a visible image by using toner, transfer means for transferring the developed toner image onto a recording medium to form an unfixed image, and the unfixed image on the recording medium An image forming apparatus comprising a fixing unit for fixing,
An image forming apparatus characterized in that the toner used to form the visible image is the image forming toner according to any one of (1) to (3).
(9) “The image forming apparatus according to (8), wherein a conveyance speed of the recording medium at the time of fixing by the fixing unit is 280 mm / second or more”,
(10) “Image carrier, charging means for charging the surface of the image carrier, exposure means for exposing the surface of the charged image carrier to form an electrostatic latent image, and the formed electrostatic latent image At least one means selected from developing means for developing with toner, transfer means for transferring the developed toner image to a recording medium, and cleaning means for removing toner remaining on the surface of the image carrier after transfer. A process cartridge that is integrated and detachable from the main body of the image forming apparatus, wherein the toner used is the image forming toner described in any one of (1) to (3). Process cartridge featuring.

Image forming toner having uniform pigment dispersion in toner particles, having a wide color reproduction range, and having both low-temperature fixability and heat-resistant storage stability, and one-component developer and two-component containing the toner An image forming method, an image forming apparatus, and a process cartridge using a developer and toner can be provided.

This is a toner image in which pigments are unevenly distributed on the surface. It is a toner image using a pigment treated with crystalline polyester. 1 is a schematic view of a tandem full-color image forming apparatus. It is the schematic of a process cartridge.

Details of the present invention will be described below.

(Coloring agent dispersion resin)
As the colorant-dispersing resin used in the present invention, all those conventionally used as binder resins for image forming toners can be used. For example, homopolymers of styrene such as polystyrene, polychlorostyrene, and polyvinyltoluene, and substituted products thereof; styrene / p-chlorostyrene copolymer, styrene / propylene copolymer, styrene / vinyltoluene copolymer, styrene / vinyl Naphthalene copolymer, styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer, styrene / methyl methacrylate copolymer, Styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene / α-chloromethyl methacrylate copolymer, styrene / acrylonitrile copolymer, styrene / vinyl ethyl ether copolymer, styrene / vinyl methyl Ketone copolymer, steel Styrene copolymers such as styrene / butadiene copolymer, styrene / isoprene copolymer, styrene / acrylonitrile / indene copolymer, styrene / maleic acid copolymer, styrene / maleic acid ester copolymer; polymethyl methacrylate , Polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyvinyl butyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic Group petroleum resins, chlorinated paraffin, paraffin wax and the like can be mentioned. The colorant-dispersing resin does not dissolve in the aqueous medium, and preferably contains a resin obtained by crystallizing the resin.
The resin having crystallinity is preferably a polyester resin. Polyester resin is excellent in low-temperature fixability, can easily obtain resin strength, can reduce the molecular weight, can form a high gloss image, and the toner is finely pulverized or agglomerated while stirring the toner. Therefore, it is more advantageous than a general vinyl polymer resin for toner.
Since the crystalline polyester resin contains the same monomer component as that obtained by crystallizing the polyester resin contained in the binder resin, the crystalline polyester resin has a high affinity with the binder resin and is highly dispersible.

Monomers constituting the crystalline polyester resin include, but are not limited to, the following.
In addition, the following alcohol and acid-modified monomers dehydrogenated with appropriate functional group portions to achieve desired physical properties can be used for the purpose of providing crosslinking points in the resin. Care must be taken not to reduce the density.
Specifically, as the divalent alcohol component, for example, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5 -Obtained by polymerization of cyclic ethers such as ethylene oxide and propylene oxide on pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, or bisphenol A Diols, and the like.
Examples of trihydric or higher polyhydric alcohols that can be used in combination include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, such as dipentaerythritol, tripentaerythritol, 1,2, 4-butanetriol, 1,2,5-pentatriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-triol Hydroxybenzene, and the like.

Examples of acid components that form polyester polymers include benzene dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid, or anhydrides thereof, alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid, or the like. Unsaturated dibasic acids such as anhydride, maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid, maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride, etc. Unsaturated dibasic acid anhydrides, and the like.
Trivalent or higher polyvalent carboxylic acid components that can be used in combination include trimetic acid, pyrometic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, and 2,5,7-naphthalenetricarboxylic acid. 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, tetra ( Methylenecarboxy) methane, 1,2,7,8-octanetetracarboxylic acid, empole trimer acid, or anhydrides thereof, partial lower alkyl esters, and the like.

  The crystalline polyester can be obtained by heating a solution having a resin concentration of 10% or less in which a polyester resin is dissolved in an organic solvent, and removing it in a calm state. The crystallinity can be adjusted by the resin concentration. it can. When the resin concentration is low, orientation is easy and crystallinity can be increased. The crystalline polyester in the present invention is preferably a linear polyester, and more preferably an aromatic linear polyester.

Here, the degree of crystallinity represents a state between a state where a certain polymer exists as 100% crystal and a case where it exists as 100% non-crystal, but there are various crystal states. In addition, since it is difficult to reproduce 100% crystalline and non-crystalline states, it should be considered as an approximate value. In general, since a material having higher crystallinity has a higher density, the present invention employs density measurement as an index of crystallinity.
Since the colorant-dispersing resin for the masterbatch is a crystalline resin, it is preferably higher in density than the resin used for the binder resin.
The crystalline resin for the colorant is preferably 1.25 g / cm ³ or more and less than 1.45 g / cm ³ . When the density is lower than 1.25 g / cm ³ , the crystallinity is insufficient, the resin that has been subjected to the pigment surface treatment is dissolved in the solvent, the pigment surface is exposed, and the surfactant during granulation When the interaction is increased, the dispersibility of the pigment is lowered, which may cause a decrease in image quality. Also, if it is larger than 1.45 g / cm ³ , when fixing the toner at the time of image formation, excessive melting occurs and an offset image is output to the non-image area, or some materials may not melt. And it becomes difficult to maintain the fixing property appropriately.

The glass transition temperature (Tg) of the polyester for a binder resin preferably used in the present invention is desirably low so long as the heat resistant storage stability of the toner is not deteriorated. In general, the Tg is preferably 40 to 70 ° C. Is 60-65 ° C. When Tg is higher than the above range, the lower limit fixing temperature of the toner is increased, so that the low temperature fixing property of the toner is deteriorated.
The glass transition temperature (Tg) can be measured using a TG-DSC system (TAS-100) manufactured by Rigaku Corporation in the same manner as the Tg of the toner described later.

(Binder resin)
As the binder resin used in the present invention, the same resin as the colorant-dispersing resin can be used, and a polyester resin is preferable. These may be used alone or in admixture of two or more. As the monomer constituting the polyester resin, the same monomers as the colorant-dispersing resin can be used.
The density of the binder resin is preferably 1.1 to 1.3 g / cm ³ .
When the density of the binder resin is 1.1 g / cm ³ or less, there is a possibility that when the toner is fixed at the time of image formation, excessive melting occurs and an offset image is output to the non-image portion. When the density is not less than / cm ³ , the crystallinity is increased, so that poor dissolution occurs in the dissolution process of the toner material before toner granulation, and toner granulation in an aqueous solvent may be difficult.

(Pigment)
As the colorant used in the image forming toner of the present invention, all known dyes and pigments can be used.
For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthracene Yellow BGL , Isoindolinone yellow, bengara, red lead, red lead, cadmium red, cadmium mercury red, antimony red, permanent red 4R, para red, phise red, parachlor ortho nitroaniline red, risor fast scarlet G, Reliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon , Oil red, quinacridone red, pyrazolone red, polyazo red, chrome vermilion, benzidine Range, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo , Ultramarine, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt violet, manganese violet, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridiane, emerald green, pigment green B, naphthol green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Oxidized Chi Tan, zinc white, lithopone and mixtures thereof.
The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the image forming toner.

  The image forming toner according to the present invention may contain a charge control agent, a magnetic powder, an external additive, and the like as required, as long as the effects of the present invention are not impaired.

(Charge control agent)
As the charge control agent used in the present invention, any conventionally known charge control agent can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus Simple substance or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like.
Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts.
The content of the charge control agent is appropriately determined according to desired charging characteristics.

(External additive)
As the external additive used in the present invention, inorganic fine particles are preferably used for the purpose of imparting fluidity, chargeability and developability. The primary particle diameter of the inorganic fine particles is preferably 5 × 10 ^-3 ~2μm, it is particularly preferably 5 × 10 ^-3 ~0.5μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The amount of the inorganic fine particles added is preferably 0.01 to 5 wt% of the image forming toner.
Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, Examples thereof include diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
Such external additives can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .

Next, a method for producing the toner of the present invention will be described.
The toner of the present invention is a toner containing a colorant obtained by surface-treating a pigment with a colorant-dispersing resin, and has a colorant-soluble resin present so as to cover the pigment surface.
Here, the surface treatment means a state in which the colorant-dispersing resin is adsorbed, adhered, and coordinated to the pigment.
As the surface treatment method, first, the above-described resin for dispersing the colorant and the colorant, or if necessary, a binder resin, a dye, a release agent, and if necessary, a charge control agent and other additives Is thoroughly mixed with a mixer such as a Henschel mixer.
The blended mixture is converted into a continuous twin screw extruder (for example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd., PCM type twin screw extruder manufactured by Ikekai Tekko Co., Ltd.) KEX type twin screw extruder manufactured by Kurimoto Iron Works Co., Ltd., continuous single screw kneader (for example, Kousida manufactured by Buss Co., Ltd., KCK kneader), direct open roll type continuous kneader Needex (open roll) A master batch is obtained by melting and kneading using a thermal kneader such as a continuous kneading granulator (Mitsui Mining Co., Ltd.).
At this time, as a method for increasing the specific energy, a method of decreasing the kneading amount or a method of lowering the kneader setting temperature and kneading the kneaded material in a high viscosity state is used.
The kneaded product (master batch) thus obtained is cooled and then roughly pulverized using a hammer mill or the like and used as a colorant.

Unlike a pigment treated with a binder resin for toner, a pigment that has been masterbatch-treated with a crystalline resin is difficult to dissolve in an organic solvent such as ethyl acetate. Then, it disperse | distributes with a ball mill or a paint shaker using a medium, and it is set as a coloring agent dispersion liquid.
In addition, without using media, known dispersion machines for liquids (for example, colloid mills, stone mills, caddy mills, flow jet mixers, slasher mills, various multi-axis mixers, various sand mills and bead mills such as attritors) are used. You may do it. Moreover, the media used in that case can use all the existing materials, such as a glass bead, an alumina bead, a zirconia bead, a zircon bead, and a steel bead.

Next, a mixture of a colorant dispersion, a binder resin, and a wax dispersion mixed in a solvent used for toner granulation is charged into a disperser and dissolved, and the resultant is dissolved in an aqueous solvent in which a surfactant and the like are dissolved in advance. The image formation of the present invention is accomplished by evaporating the solvent from the emulsified and granulated product, washing the surfactant, drying the moisture, passing through a sieve of 250 mesh or more, and removing coarse particles and aggregated particles. Get toner for use.
Furthermore, the inorganic fine particles as the external additive and the toner after the classification may be sufficiently mixed by a mixer such as a Henschel mixer.

In the image forming toner of the present invention, in order to achieve both low-temperature fixability and heat-resistant storage stability and appropriate glossiness (glossiness), the weight average molecular weight (Mw) of the resin (for example, polyester resin) in the toner is 1000. It is desirable to be about ˜500000. Note that the number average molecular weight (Mn) may be measured instead of the weight average molecular weight.

The weight average particle diameter of the toner is not particularly limited and can be appropriately selected according to the purpose. However, in order to obtain a high-quality image with excellent granularity, sharpness, and fine line reproducibility, the weight average particle diameter Is preferably 3.5 μm to 10 μm. The smaller the particle size, the better the image sharpness and fine line reproducibility. In particular, in a color image forming apparatus, a demand for image quality is strict and a toner of 10 μm or less is required. In particular, 7.5 μm or less is preferable for image quality. On the other hand, if the toner particle size becomes too small, the fluidity and transferability of the toner deteriorate.

The Tg of the image forming toner of the present invention is preferably 60 to 65 ° C. When Tg is higher than the above range, the lower limit fixing temperature of the toner is increased, so that the low temperature fixing property of the toner is deteriorated.

(Developer)
The image forming toner of the present invention can be used as a one-component developer or a two-component developer. That is, the one-component developer is composed of only the image forming toner, and the two-component developer is composed of the image forming toner and the carrier.
[One-component developer]
In the one-component developer, it can be used as a non-magnetic one-component toner or a magnetic one-component toner (magnetic toner).
When used as a magnetic toner, a known magnetic material can be used. That is, magnetic materials contained in the magnetic toner include iron oxides such as magnetite, hematite, and ferrite, metals such as iron, cobalt, and nickel, or aluminum, cobalt, copper, lead, magnesium, tin, and the like of these metals. Examples include alloys of metals such as zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, and mixtures thereof. These ferromagnetic materials desirably have an average particle size of about 0.1 to 2 μm. The amount of the ferromagnetic material contained in the toner is 20 to 200 parts by weight, particularly preferably 100 parts by weight of the resin component, with respect to 100 parts by weight of the binder resin. 40 to 150 parts by weight per part.

[Two-component developer]
As the carrier used in the two-component developer of the present invention, conventionally known ones for two-component developers can be used.
For example, a carrier made of magnetic particles such as iron or ferrite, a resin-coated carrier in which such magnetic particles are coated with a resin, or a binder-type carrier in which magnetic fine powder is dispersed in a binder resin. Can be used.
Magnetic materials include iron oxides such as magnetite, hematite, and ferrite, metals such as iron, cobalt, and nickel, or aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, Metal alloys such as calcium, manganese, selenium, titanium, tungsten, vanadium and mixtures thereof can be used.

Among these carriers, a silicone resin, a copolymer resin (graft resin) of an organopolysiloxane and a vinyl monomer, or a resin-coated carrier using a polyester resin can be used as a coating resin, such as toner spent. A carrier coated with a resin obtained by reacting an isocyanate with a copolymer resin of an organopolysiloxane and a vinyl monomer is preferable from the viewpoint of durability, environmental stability, and spent resistance. .
As the vinyl monomer, it is necessary to use a monomer having a substituent such as a hydroxyl group reactive with isocyanate. In addition, it is preferable to use a magnetic carrier having a volume average particle diameter of 20 to 100 μm, preferably 20 to 60 μm from the viewpoint of ensuring high image quality and preventing carrier fogging.

  In addition to the above, examples of carrier coating materials used for carriers include amino resins such as urea-formaldehyde resins, melamine resins, benzoguanamine resins, urea resins, polyamide resins, and epoxy resins. Polyvinyl and polyvinylidene resins, acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and polystyrene resins such as styrene-acrylic copolymer resins, poly Halogenated olefin resins such as vinyl chloride, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoropropylene Resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and fluoride Vinylidene fluoro such as terpolymers of non-fluorinated monomer, and silicone resins.

  Moreover, you may make conductive powder etc. contain as a filler in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide, aluminum oxide, silica and the like can be used. These preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it is difficult to control electric resistance in the case of conductive powder.

(Image forming method)
The image forming method of the present invention comprises at least a charging step for charging the surface of an image carrier, an electrostatic latent image forming step for forming an electrostatic latent image on the image carrier, and the electrostatic latent image for image formation. A development process for forming a visible image by developing with toner, a transfer process for transferring the visible image onto a recording medium to form an unfixed image, and fixing the unfixed image on the recording medium The image forming method includes a fixing step, and the image forming toner used for forming the visible image is the image forming toner described above. Here, the toner for image formation can be satisfactorily fixed even if the conveyance speed of the recording medium in the fixing step is 280 mm / second or more.

  According to the image forming method of the present invention, an image forming toner that has excellent low-temperature fixability and heat-resistant storage stability even at high speed and is fixed only at a desired position on a recording medium without causing an offset phenomenon is used. Therefore, even when an image is formed by an electrophotographic image forming apparatus having a high output speed, it is excellent in glossiness, and it is possible to stably output a high-quality image without generating a ghost or the like.

(Image forming device)
The image forming apparatus of the present invention includes at least an image carrier, a charging unit that charges the surface of the image carrier, and an exposure unit that exposes the charged image carrier surface to form an electrostatic latent image. Developing means for developing the electrostatic latent image using an image forming toner to form a visible image; and transfer means for transferring the developed toner image onto a recording medium to form an unfixed image; An image forming apparatus comprising fixing means for fixing the unfixed image to the recording medium,
The image forming toner used to form the visible image is the image forming toner described above.

According to the image forming apparatus of the present invention, an image forming toner that has excellent low-temperature fixability and heat-resistant storage stability even at a high speed and is fixed only at a desired position on a recording medium without causing an offset phenomenon is used. Therefore, even if the process line speed is high, an abnormal image is not generated and the image can be fixed stably. For example, if a tandem full-color image forming apparatus is used, a higher-quality image can be output at a higher speed.
The image forming method and the image forming apparatus of the present invention can be widely applied to electrophotographic application fields using electrophotography (for example, electrostatic copying machines, laser beam printers, etc.).

Hereinafter, a tandem full-color image forming apparatus will be described as an example of the image forming apparatus of the present invention, and will be described with reference to the drawings.
FIG. 3 is a schematic diagram for explaining the tandem-type full-color image forming apparatus of the present invention. In FIG. 3, reference numerals (1C, 1M, 1Y, 1K) denote drum-shaped image carriers (hereinafter referred to as “photosensitive members”). This photosensitive member (1C, 1M, 1Y, 1K) rotates in the direction of the arrow in the figure, and at least around that is a charging member (2C, 2M, 2Y, 2K) as a charging means and a developing member as a developing means. (4C, 4M, 4Y, 4K) and cleaning members (5C, 5M, 5Y, 5K) are arranged. The charging members (2C, 2M, 2Y, 2K) are charging members that constitute a charging device for uniformly charging the surface of the photoreceptor.

  From the back side of the photoreceptor between the charging member (2C, 2M, 2Y, 2K) and the developing member (4C, 4M, 4Y, 4K), laser light (3C, 3M, 3Y, 3K) is irradiated, and electrostatic latent images are formed on the photoreceptors (1C, 1M, 1Y, 1K). Then, four image forming elements (6C, 6M, 6Y, 6K) centering on such a photoreceptor (1C, 1M, 1Y, 1K) are along a transfer conveyance belt (10) which is a transfer material conveyance means. Are juxtaposed. The transfer / conveying belt (10), which is a transfer unit, includes a developing member (4C, 4M, 4Y, 4K) of each image forming unit (6C, 6M, 6Y, 6K) and a cleaning member (5C, 5M, 5Y, 6K) that is a cleaning unit. 5K), and a transfer brush (for applying a transfer bias) to the surface (back surface) of the transfer conveyance belt (10) which is in contact with the back side of the photoconductor side (back surface) (which is in contact with the photoconductor (1C, 1M, 1Y, 1K)). 11C, 11M, 11Y, 11K). Each image forming element (6C, 6M, 6Y, 6K) is different in the color of the toner inside the developing device, and the others are the same in configuration.

  In the color electrophotographic apparatus having the configuration shown in FIG. 3, the image forming operation is performed as follows. First, in each image forming element (6C, 6M, 6Y, 6K), the charging member (2C, 2M, 2Y) in which the photoconductor (1C, 1M, 1Y, 1K) rotates in the direction of the arrow (direction along with the photoconductor). , 2K), and then an electrostatic latent image corresponding to each color image to be created by laser light (3C, 3M, 3Y, 3K) by an exposure unit (not shown) disposed outside the photoconductor. It is formed.

  Next, the latent image is developed by a developing member (4C, 4M, 4Y, 4K) to form a toner image. The developing members (4C, 4M, 4Y, and 4K) are C (cyan), M (magenta), Y (yellow), and K (black) image forming toners of the present invention (hereinafter referred to as “toners”). )), The color toner images formed on the four photoconductors (1C, 1M, 1Y, 1K) are superimposed on the transfer paper. The transfer paper (7) is fed out from the tray by the paper feed roller (8), temporarily stopped by the pair of registration rollers (9), and then transferred to the transfer conveyance belt (10) in synchronization with the image formation on the photosensitive member. Sent. The transfer paper (7) held on the transfer / conveying belt (10) is conveyed, and the toner images of the respective colors are transferred at the contact positions (transfer portions) with the respective photoreceptors (1C, 1M, 1Y, 1K). It is.

  The toner image on the photosensitive member is transferred onto the transfer paper (by the electric field formed by the potential difference between the transfer bias applied to the transfer brush (11C, 11M, 11Y, 11K) and the photosensitive member (1C, 1M, 1Y, 1K). 7) Transferred on top. Then, the recording paper (7) on which the toner images of four colors are superimposed through the four transfer portions is conveyed to the fixing device (12), where the toner is fixed, and is discharged to a paper discharge portion (not shown). Further, the residual toner remaining on the respective photoconductors (1C, 1M, 1Y, 1K) without being transferred by the transfer unit is collected by the cleaning device (5C, 5M, 5Y, 5K).

In the example of FIG. 3, the image forming elements are arranged in the order of C (cyan), M (magenta), Y (yellow), and K (black) from the upstream side to the downstream side in the transfer paper conveyance direction. However, it is not limited to this order, and the color order is arbitrarily set. Further, when a black-only document is created, it is particularly effective to use the present invention to provide a mechanism for stopping the image forming elements (6C, 6M, 6Y) other than black. Further, although the charging member is in contact with the photosensitive member in FIG. 3, by providing an appropriate gap (for example, about 10 to 200 μm) between them, the wear amount of both can be reduced and the charging member Less toner filming and good use.
The above-described tandem image forming apparatus can transfer a plurality of toner images at a time, so that high-speed full-color printing is realized.

  The image forming means as described above may be fixedly incorporated in the copying apparatus, facsimile, or printer, but may be incorporated in these apparatuses in the form of a process cartridge.

The process cartridge is an apparatus (part) that contains an image carrier (photoconductor) and further includes a means selected from a charging unit, an exposure unit, a developing unit, a transfer unit, and a cleaning unit. If necessary, other means such as a static elimination means may be included. There are many shapes and the like of the process cartridge, but a general example is shown in FIG.
Here, the process cartridge includes a photosensitive member (101), and includes a charging unit (102), an exposure unit (103), a developing unit (104), and a cleaning unit (107). It has the means of. In the figure, (105) is a recording medium (transfer body), and (108) is a transfer means.

  That is, the process cartridge of the present invention includes an image carrier, a charging unit that charges the surface of the image carrier, an exposure unit that exposes the charged image carrier surface to form an electrostatic latent image, and a formed static member. It is selected from developing means for developing the electrostatic latent image using image forming toner, transfer means for transferring the developed toner image to the recording medium, and cleaning means for removing the toner remaining on the surface of the image carrier after the transfer. A process cartridge which can be attached to and detached from an image forming apparatus main body integrated with at least one means, and the image forming toner used is the image forming toner of the present invention. It is. It should be noted that other means (for example, static elimination means) may be included as necessary as at least one means to be selected.

  In the process cartridge of the present invention, since the image forming toner of the present invention is supplied from the developing unit, the fixing unit is stably fixed only at a desired position on the recording medium without causing an offset phenomenon due to an unfixed image. High quality images can be output. In addition, it is easy to store and transport and has excellent handling properties.

Next, a method for measuring the image forming toner of the present invention will be described.
(Density measurement method)
The density of the resin in the present invention was measured according to JIS industry standard K7112-1999, and was measured by an underwater substitution method. The resin was heated and melted, poured into a 10 cm long, 10 cm wide, 1 cm deep mold, the weight of the cooled test piece was measured, the volume was immersed in water, and this was repeated three times to obtain a density g / cm ³ was determined.

(Toner storage stability measurement method)
The heat resistant storage stability of the produced toner was measured by storing it in a commercially available dryer. 10g of toner is put into a 30ml glass vial bottle, and the dryer is kept at 50 ° C in a laboratory where humidity is controlled at 25 ° C and 50% without lid (manufactured by Yamato Scientific Co., Ltd.) ) For 24 hours. After that, the sample is transferred to a mesh with an opening of 75 μm, and it is visually judged whether or not there is an aggregate of 1 mm or more by applying vibration. When less than 10 were observed, the heat resistant storage stability test was made by ◯, and the case where more aggregates were recognized as x.

(Molecular weight of the resin used)
The weight average molecular weight (Mw) or the number average molecular weight (Mn) can be measured as follows.
[Measurement of weight average molecular weight (Mw)]
The mass average molecular weight of the binder resin is measured by GPC (gel permeation chromatography) under the following conditions.
・ Apparatus: GPC-150C (manufactured by Waters)
Column: KF801-807 (manufactured by Shodex)
・ Temperature: 40 ℃
・ Solvent: THF (tetrahydrofuran)
・ Flow rate: 1.0 mL / min ・ Sample: 0.1 mL injection of a sample with a concentration of 0.05 to 0.6% Molecular weight prepared from a monodisperse polystyrene standard sample from the molecular weight distribution of the binder resin measured under the above conditions The mass average molecular weight of the binder resin is calculated using the calibration curve.
[Measurement of Number Average Molecular Weight (Mn)]
The number average molecular weight of the binder resin is measured by GPC under the following conditions.
・ Apparatus: GPC-150C (manufactured by Waters)
Column: KF801-807 (manufactured by Shodex)
・ Temperature: 40 ℃
・ Solvent: THF (tetrahydrofuran)
Flow rate: 1.0 mL / min Sample: Inject 0.1 mL of a sample having a concentration of 0.05 to 0.6%.
Further, when the insoluble content when 1 g of a sample (binder resin) is added to 100 ml of THF is 75% by weight or more, DMF (dimethylformamide) is used as a solvent. The number average molecular weight is calculated from a molecular weight calibration curve prepared using a monodisperse polystyrene standard sample.

(Weight average particle diameter of toner)
The weight average particle diameter of the toner can be determined as follows.
As an apparatus for measuring the particle size distribution of toner particles by the Coulter counter method, there are Coulter Counter TA-II and Coulter Multisizer III (both manufactured by Coulter). In the present invention, measurement was performed using a Coulter Multisizer III. The measurement method is described below.

[Weight average particle diameter (Dw) of toner]
First, 0.1 to 5 ml of a surfactant, preferably polyoxyethylene alkyl ether, is added as a dispersant to 100 to 150 ml of an electrolytic aqueous solution. Here, the electrolytic solution is prepared by preparing an about 1% NaCl aqueous solution using primary sodium chloride, and for example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measurement device is used to measure the volume and number of toner particles or toner using a 100 μm aperture as an aperture. Volume distribution and number distribution are calculated. From the obtained distribution, the weight average particle diameter (Dw) and the number average particle diameter (Dn) of the toner can be obtained.

  The channel in the above measurement is as follows: 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to 6.35 μm Less than 6.35 to less than 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; ≦ 25.40 μm; 25.40 to less than 32.00 μm; 13 channels of 32.00 to less than 40.30 μm are used, and particles having a particle diameter of 2.00 μm to less than 40.30 μm are targeted.

(Tg of toner)
The Tg (DSC maximum endothermic peak) of the toner for image formation is tangent to the endothermic curve near the melting point using a TG-DSC system (TAS-100) manufactured by Rigaku Corporation and using an analysis system in the TAS-100 system. And calculated from the point of contact with the baseline.
That is, about 10 mg of a toner sample is placed in an aluminum sample container, which is placed on a holder unit and set in an electric furnace. Heating was performed from room temperature to 180 ° C. at a heating rate of 10 ° C./min, and calculation was performed based on the obtained endothermic curve.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

(Synthesis of polyester resin 1)
443 parts of PO adduct of bisphenol A (propylene oxide added to bisphenol A: hydroxyl value 320) in a reaction vessel equipped with a thermometer, stirrer, cooler and nitrogen introduction tube, 135 parts of diethylene glycol, 422 parts of terephthalic acid And 2.5 parts of dibutyltin oxide were allowed to react at 230 ° C. until the acid value reached 7, and 410 parts of the resin was put into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate were added and reacted at 100 ° C. for 5 hours to obtain [Polyester resin (hereinafter referred to as Pes) 1]. This [Pes1] had a weight average molecular weight peak of 9000 and a density of 1.183 g / cm ³ .

(Production of crystalline polyester resin 1)
10 parts of [Pes1] is added to 90 parts of ethyl acetate so as to have a concentration of 10% in ethyl acetate, and heated to 60 ° C. in a hot water bath. Then, the hot water bath was turned off and the mixture was left for 1 day while slowly cooling to room temperature. The cloudy solution thus obtained was further dried in a draft for 1 day to obtain [Crystalline Polyester Resin (hereinafter referred to as Cpes) 1]. The peak molecular weight of [Cpes1] was 9000, and the density was 1.261 g / cm ³ .

(Preparation of masterbatch 1)
Next, a colorant (masterbatch 1) in which a colorant was uniformly dispersed in a part of [Pes1] used for toner formulation was prepared as follows.
The materials shown in the following formula (Masterbatch 1) were mixed at 1500 rpm for 3 minutes using a Henschel mixer (Henschel 20B; manufactured by Mitsui Mining Co., Ltd.), and the resulting mixture was mixed at 110 ° C. using two rolls. After kneading for 45 minutes, rolling and cooling, pulverizing with a pulverizer, and adding 50 parts of [Masterbatch 1] and 50 parts of ethyl acetate to a polypropylene container with 300 parts of zirconia balls (3 mmφ, manufactured by Nikkato) Stir for 24 hours to obtain [Masterbatch Dispersion 1].

(Master batch 1 prescription)
Water: 30 parts Quinacridone pigment PR122 (manufactured by DIC): 50 parts Pes1: 25 parts Cpes1: 25 parts

(Synthesis of organic fine particle emulsion)
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 83 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate and 1 part of ammonium persulfate were added and stirred at 400 rpm for 15 minutes, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion [fine particle dispersion 1] was obtained. The average particle diameter of the [fine particle dispersion 1] measured by LA-920 (Laser diffraction / scattering particle size distribution measuring device manufactured by Horiba, Ltd.) was 105 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The weight average molecular weight of this resin was 150,000.

(Preparation of aqueous phase)
990 parts of water, 99 parts of [fine particle dispersion 1], 35 parts of a 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries) and 70 parts of ethyl acetate are mixed and stirred. A milky white liquid was obtained. This is designated as [Aqueous Phase 1].

(Synthesis of intermediate polyester)
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. for 8 hours at normal pressure, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5, and a hydroxyl value of 51.

(Synthesis of Prepolymer 1)
Next, 410 parts of [Intermediate polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Polymer 1] was obtained.

(Synthesis of ketimine)
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1].

(Production of oil phase)
[Pes1] 160 parts, carnauba wax 32 parts, ethyl acetate 400 parts were charged in a container equipped with a stir bar and a thermometer, heated to 80 ° C. with stirring, and kept at 80 ° C. for 5 hours. Cooled to 30 ° C. over time. Next, 90 parts of the same [Masterbatch Dispersion 1] used in Example 1 was charged in the container and mixed for 1 hour to obtain [Raw Material Solution 1] having a solid content of 50 wt%.
[Material solution 1] 464 parts were transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feed speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads were 80% by volume. The pigment and WAX were dispersed under the conditions of filling and 3 passes. Next, 420 parts of a 50% ethyl acetate solution of [Pes1] was added, and one pass was performed with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion 1].

(Emulsification ⇒ Solvent removal)
[Pigment / WAX Dispersion 1] 885 parts, [Prepolymer 1] 115 parts, [Ketimine Compound 1] 2.9 parts in a container and mixed for 1 minute at 5000 rpm with a TK homomixer (made by Tokushu Kika Co., Ltd.) After that, 1200 parts of [Aqueous Phase 1] was added to the container and mixed with a TK homomixer at a rotational speed of 12500 rpm for 30 minutes to obtain [Emulsified Slurry 1].
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 35 ° C. for 7 hours, aging was carried out at 45 ° C. for 4 hours to obtain [Dispersion slurry 1]. In the middle of solvent removal, the sample was transferred to a TK homomixer and stirred at a rotational speed of 12,500 rpm for 40 minutes to deform the toner.

(Washing ⇒ drying)
[Dispersion Slurry 1] After 100 parts were filtered under reduced pressure, (1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (10 minutes at a rotation speed of 12,000 rpm), and then filtered. (2): 100 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure. (3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered. (4): 300 parts of ion-exchanged water was added to the filter cake of (3), and the mixture was mixed with a TK homomixer (rotation speed: 12000 rpm for 10 minutes) and then filtered twice to obtain [Filter cake 1].

(Preparation of base toner)
[Filter cake 1] was dried at 45 ° C. for 48 hours in a circulating drier, sieved with a mesh of 75 μm, and a charge control agent (salicylic acid metal salt E-84: 0.6 parts of (Orient Chemical Co., Ltd.) was mixed at 1000 rpm using a Henschel mixer, and then mixed at 5500 rpm with a Q-type mixer (Mitsui Kinzoku Kogyo Co., Ltd.) to fix the charge control agent on the toner surface. Base toner 1] was obtained.

(Addition of external additives)
Next, 100 parts of [base toner 1] was mixed with 0.7 parts of hydrophobic titanium oxide using a Henschel mixer to complete the production of [polymerized toner 1]. [Polymerized toner 1] had a weight average particle diameter (Dw) of 5.2 μm, a number average particle diameter (Dn) of 4.6 μm, and a glass transition temperature Tg of 56 ° C.

(Manufacture of Cpes2)
[Cpes2] was produced under the same conditions except that the production conditions of [Cpes1] produced in Example 1 were changed to 10% resin concentration of 1%. The weight average molecular weight peak of [Cpes2] 9000 and a density of 1.402g / cm ^3.

(Preparation of polymerization toner 2)
A toner was prepared under the same conditions as in Example 1 except that [Cpes2] was used instead of [Cpes1] in [Masterbatch dispersion 1] produced in Example 1 to obtain [Polymerized toner 2]. It was. [Polymerized toner 2] had a weight average particle diameter (Dw) of 5.3 μm, a number average particle diameter (Dn) of 4.7 μm, and a glass transition temperature Tg of 59 ° C.

(Manufacture of Cpes3)
[Cpes3] was produced under the same conditions except that the production conditions of [Cpes1] produced in Example 1 were changed to 10% resin concentration of 0.1%. [Cpes3] had a weight average molecular weight peak of 9000 and a density of 1.430 g / cm ³ .

(Preparation of polymerization toner 3)
A toner was prepared under the same conditions as in Example 1 except that [Cpes3] was used instead of [Cpes1] in [Masterbatch dispersion 1] produced in (Example 1), and [Polymerized toner 2] Got. [Polymerized toner 1] had a weight average particle diameter (Dw) of 5.3 μm, a number average particle diameter (Dn) of 4.7 μm, and a glass transition temperature Tg of 55 ° C.

(Synthesis of Pes2)
443 parts of PO adduct of bisphenol A (propylene oxide added to bisphenol A: hydroxyl value 320) in a reaction vessel equipped with a thermometer, stirrer, cooler and nitrogen introduction tube, 135 parts of diethylene glycol, 422 parts of terephthalic acid And 2.5 parts of dibutyltin oxide were allowed to react at 230 ° C. until the acid value reached 7, and 410 parts of the resin was put into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 44 parts of isophorone diisocyanate and 500 parts of ethyl acetate were added and reacted at 100 ° C. for 5 hours to obtain [Pes2]. The weight average molecular weight peak of [Pes2] was 8000, and the density was 1.209 g / cm ³ .

(Preparation of polymerization toner 4)
A toner was prepared under the same conditions as in Example 1 except that [Pes2] was used instead of [Pes1] used in the preparation of the oil phase of Example 1 to obtain [Polymerized toner 4]. [Polymerized toner 4] had a weight average particle diameter (Dw) of 5.3 μm, a number average particle diameter (Dn) of 4.7 μm, and a glass transition temperature Tg of 56 ° C.

A toner was prepared under the same conditions as in Example 2 except that [Pes2] was used instead of [Pes1] used in the preparation of the oil phase of Example 2 to obtain [Polymerized toner 5]. [Polymerized toner 5] had a weight average particle diameter (Dw) of 5.7 μm, a number average particle diameter (Dn) of 4.8 μm, and a glass transition temperature Tg of 57 ° C.

A toner was prepared under the same conditions as in Example 3 except that [Pes2] was used instead of [Pes1] used in the preparation of the oil phase of Example 3 to obtain [Polymerized toner 6]. [Polymerized toner 6] had a weight average particle diameter (Dw) of 5.8 μm, a number average particle diameter (Dn) of 5.1 μm, and a glass transition temperature Tg of 55 ° C.

(Synthesis of Pes3)
443 parts of PO adduct of bisphenol A (propylene oxide added to bisphenol A: hydroxyl value 320) in a reaction vessel equipped with a thermometer, stirrer, cooler and nitrogen introduction tube, 135 parts of diethylene glycol, 422 parts of terephthalic acid And 2.5 parts of dibutyltin oxide were allowed to react at 230 ° C. until the acid value reached 7, and 410 parts of the resin was put into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 22 parts of isophorone diisocyanate and 500 parts of ethyl acetate were added and reacted at 100 ° C. for 5 hours to obtain [Pes3]. This [Pes3] had a weight average molecular weight peak of 8,000 and a density of 1.274 g / cm ³ .

(Preparation of polymerization toner 7)
A toner was prepared under the same conditions as in Example 2 except that [Pes3] was used instead of [Pes1] used in the preparation of the oil phase of Example 2 to obtain [Polymerized toner 7]. [Polymerized toner 7] had a weight average particle diameter (Dw) of 6.3 μm, a number average particle diameter (Dn) of 5.4 μm, and a glass transition temperature Tg of 57 ° C.

A toner was prepared under the same conditions as in Example 3 except that [Pes3] was used instead of [Pes1] used in the preparation of the oil phase of Example 3 to obtain [Polymerized toner 8]. [Polymerized toner 8] had a weight average particle diameter (Dw) of 6.1 μm, a number average particle diameter (Dn) of 5.3 μm, and a glass transition temperature Tg of 56 ° C.

[Prepolymer 1] and [ketimine compound 1] of Example 1 were not used, and only 1000 parts of [Pigment / WAX Dispersion 1] were put in a container, and 1 at 5000 rpm with a TK homomixer (manufactured by Tokushu Kika). After mixing for 1 minute, 1200 parts of [Aqueous Phase 1] was added to the container and mixed with a TK homomixer at 15000 rpm for 30 minutes to obtain [Emulsion Slurry 2]. Thereafter, [Polymerized toner 9] was obtained in the same manner as in Example 1. [Polymerized toner 9] had a weight average particle diameter (Dw) of 6.9 μm, a number average particle diameter (Dn) of 6.1 μm, and a glass transition temperature Tg of 55 ° C.

(Comparative Example 1)
A toner was prepared under the same conditions as in Example 1 except that [Pes1] was used instead of [Cpes1] in [Masterbatch dispersion 1] used in Example 1 to obtain [Polymerized toner 10]. It was. [Polymerized toner 10] had a weight average particle diameter (Dw) of 4.9 μm, a number average particle diameter (Dn) of 4.2 μm, and a glass transition temperature Tg of 60 ° C.

(Comparative Example 2)
A toner was prepared under the same conditions as in Example 1 except that [Pes2] was used instead of [Cpes1] in [Masterbatch dispersion 1] used in Example 1 to obtain [Polymerized toner 11]. It was. [Polymerized toner 11] had a weight average particle diameter (Dw) of 4.8 μm, a number average particle diameter (Dn) of 4.1 μm, and a glass transition temperature Tg of 61 ° C.

(Comparative Example 3)
A toner was prepared under the same conditions as in Example 1 except that [Pes3] was used instead of [Cpes1] in [Masterbatch dispersion 1] used in Example 1 to obtain [Polymerized toner 12]. It was. [Polymerized toner 12] had a weight average particle diameter (Dw) of 5.1 μm, a number average particle diameter (Dn) of 4.4 μm, and a glass transition temperature Tg of 59 ° C.

(Comparative Example 4)
Except that [Pes1] was used instead of [Cpes1] of [Master batch dispersion 1] used in Example 1, and [Cpes1] was used instead of [Pes1] used in the production of the oil phase, A toner was prepared under the same conditions as in Example 1 to obtain [Polymerized toner 13]. [Polymerized toner 13] had a weight average particle diameter (Dw) of 7.1 μm, a number average particle diameter (Dn) of 5.4 μm, and a glass transition temperature Tg of 53 ° C.

(Comparative Example 5)
Example 2 except that [Cpes2] was used instead of [Pes1] used in the preparation of the oil phase of Example 2, and [Pes1] was used instead of [Cpes2] of [Masterbatch Dispersion 2] [Polymerized toner 14] was produced under the same conditions. However, the toner could not be granulated.
Tables 1 and 2 show the formulations of Examples and Comparative Examples.

(Fixed image evaluation method)
The evaluation of the fixed image was carried out using an image Neo Neo C600 manufactured by Ricoh Co., Ltd., and each [polymerized toner] was mixed with a carrier used in the copying machine, and the following image evaluation test was performed.
A toner sample having an adhesion amount of 0.4 mg / cm ² was prepared on an A4 size paper (T6000 70W T, manufactured by Ricoh), and a 3 cm × 5 cm rectangular image was formed at a position 3 cm from the front end of the paper surface. The fixing member was fixed at a linear velocity of 280 mm / sec after always controlling the temperature of the fixing member to 180 ° C. Next, this image is evaluated by X-Rite (manufactured by X-Rite) for L * a * b * chromaticity in the status A mode, and the saturation c * (the sum of the squares of a * and b * is calculated). When the square root was 60 or more, it was judged as good (◯), and when it was less than 60, it was judged as bad (x). In addition, the storage stability of the toner was also evaluated.
The evaluation results are shown in Tables 3 and 4.

(Comprehensive evaluation)
As described above, the conditions satisfying the present invention are satisfied (acceptance: ◯) only when the saturation c * and the storage stability are both ◎ or ◯, and the others are determined to be disqualified (×). As a result, the toner produced as in the claims of the present invention was judged acceptable, but the toner of the comparative example outside the scope of claims was judged unacceptable.

(Figure 3)
1C, 1M, 1Y, 1K: drum-shaped image carriers 2C, 2M, 2Y, 2K: charging members 3C, 3M, 3Y, 3K: laser beams 4C, 4M, 4Y, 4K: developing members 5C, 5M, 5Y, 5K: Cleaning members 6C, 6M, 6Y, 6K: Image forming element 7: Transfer paper 8: Paper feed roller 9: Registration roller 10: Transfer conveyance belt 11C, 11M, 11Y, 11K: Transfer brush 12: Fixing device

(Fig. 4)
101: photoconductor 102: charging unit 103: exposure unit 104: developing unit 105: recording medium (transfer body),
107: Cleaning means 108: Transfer means

Japanese Patent No. 4079257 JP 2009-116313 JP Japanese Patent No. 4213067

Claims (10)

A toner comprising at least a binder resin, a colorant, and a colorant-dispersing resin, and produced in an aqueous medium,
The colorant-dispersing resin contains a crystalline resin that is not soluble in an organic solvent and has a density of 1.25 g / cm ³ or more and less than 1.45 g / cm ³ .
A toner having a saturation c * (the square root of the sum of squares of a * and b *) of a fixed image measured by the following method of 60 or more .
However, the saturation was measured by forming a toner unfixed image with an adhesion amount of 0.4 mg / cm ^{2 on} an A4 size paper so as to form a 3 cm × 5 cm rectangle, and subsequently setting the fixing member temperature to 180 ° C. The unfixed image was fixed on a sheet at a linear speed of 280 mm / sec, and the L * a * b * chromaticity was measured.   2. The image forming toner according to claim 1, wherein the binder resin contains a polyester resin.   The image forming toner according to claim 1, wherein the colorant resin includes a crystalline resin obtained by crystallizing the binder resin.   A two-component developer comprising the image forming toner according to any one of claims 1 to 3 and a carrier.   A toner raw material solution containing a colorant and a binder resin obtained by melt-kneading a pigment and a colorant-dispersing resin and surface-treating the pigment with the colorant-dispersing resin is dissolved and suspended in an aqueous medium and / or 4. The method for producing an image forming toner according to claim 1, wherein the toner is emulsified and dispersed and granulated. A charging step for charging at least the surface of the image carrier, an electrostatic latent image forming step for forming an electrostatic latent image on the image carrier, and developing the electrostatic latent image with toner to form a visible image An image forming method comprising: a developing step, a transfer step of transferring the visible image onto a recording medium to form an unfixed image, and a fixing step of fixing the unfixed image on the recording medium,
The image forming method according to claim 1, wherein the toner used to form the visible image is the image forming toner according to claim 1.   The image forming method according to claim 6, wherein a conveyance speed of the recording medium in the fixing step is 280 mm / second or more. At least an image carrier, a charging unit that charges the surface of the image carrier, an exposure unit that exposes the charged image carrier surface to form an electrostatic latent image, and the electrostatic latent image using toner Developing means for forming a visible image by developing, transfer means for transferring the developed toner image onto a recording medium to form an unfixed image, and fixing means for fixing the unfixed image to the recording medium An image forming apparatus comprising:
The image forming apparatus according to claim 1, wherein the toner used to form the visible image is the image forming toner according to claim 1.   9. The image forming apparatus according to claim 8, wherein a conveyance speed of the recording medium at the time of fixing by the fixing unit is 280 mm / second or more.   An image carrier, a charging unit for charging the surface of the image carrier, an exposure unit for exposing the charged surface of the image carrier to form an electrostatic latent image, and the formed electrostatic latent image using toner At least one means selected from a developing means for developing, a transferring means for transferring the developed toner image to a recording medium, and a cleaning means for removing toner remaining on the surface of the image carrier after transfer is integrated with the image. A process cartridge that is detachable from a main body of the forming apparatus, wherein the toner to be used is the image forming toner according to claim 1.

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