JP2012189876A - Image forming apparatus and toner for developing electrostatic charge image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner containing crystalline polyester which suppresses aggregation of the toner in a high temperature and high humidity environment markedly, while suppressing degradation in a filming property and toner fluidity that may occur as a side effect, and stabilizes a charging property of the toner, and to provide an image forming apparatus mounted with the toner.SOLUTION: In an image forming apparatus of this invention, a toner for forming an image is obtained by dispersing an oil phase into an aqueous medium, the oil phase including at least a crystalline polyester resin and at least one kind or more of non-crystalline polyester resins as a binding resin component in an organic solvent and by removing the organic solvent from the thus obtained dispersion liquid. The toner includes, on a surface of toner base particles, an additive containing at least two or more kinds of fine particles of silica. The silica includes both silica A from a sol-gel process and silica B from a dry process, and the silica A from a sol-gel process has an average primary particle diameter of 20 to 120 nm, and the silica A absorbs 0.01 g or more of moisture by allowing the silica A to stand for 1 week.

Description

  The present invention relates to a toner used as a developer and an image forming apparatus using the toner when developing an electrostatic image formed by electrophotography, electrostatic recording, or the like.

  The image forming process using the image forming apparatus includes a charging process for uniformly charging an image forming area on the surface of the image carrier, an exposure process for writing on the image carrier, and an image formed by toner tribocharged on the image carrier. The image is fixed on the printing paper after the development process for forming the image, the transfer process for transferring the image on the image carrier directly to the printing paper or indirectly via the intermediate transfer body. Further, the untransferred toner remaining without being transferred onto the image carrier is scraped off from the image carrier by the cleaning process, and enters the next image forming process.

In recent years, higher image quality and energy saving have been desired for images of image forming apparatuses. For this reason, in order to achieve higher image quality, a polymerization method having a high degree of circularity and a sharp particle size distribution is increasingly used instead of the pulverization method.
In order to improve the image quality, it is necessary to uniformly charge the toner and fly it from the developing unit to the photoreceptor. Therefore, a toner obtained by adding silica obtained by a sol-gel method in addition to silica obtained by a dry method in order to improve the chargeability of the toner (see Japanese Patent Application Laid-Open No. 2002-108001 of Patent Document 1). Proposed.
Patent Document 1 proposes a toner that uses both silica by a sol-gel method and silica by a dry method, so that low chargeability, which is a defect of silica derived from a sol-gel method, is compensated by silica derived from a dry method. In combination with high-water content and high-volume resistance sol-gel silica in combination with dry-type silica with low water content and volume resistance, long-term charge stability can be obtained by suppressing changes in charge distribution. It is said that it is possible.
However, since the silica derived from the sol-gel method used here has a large particle diameter of 120 nm or more, the silica is likely to be liberated due to stress with the developer, and the carrier is likely to be spent. Therefore, it is easy to cause a significant decrease in charge, and it is easy to spend on the photosensitive member.

Further, in order to achieve further energy saving, in order to lower the glass transition temperature, a crystalline polyester is used as a binder resin, and a toner that can be fixed at a lower temperature than before is also produced. However, since it melts at a low temperature, the storage stability tends to deteriorate in a high temperature environment. In addition, since crystalline polyester has high hygroscopicity, a toner used after being left in a high-temperature and high-humidity environment cannot obtain a sufficient charge amount, and it is difficult to obtain a good image density.
The compatibility between low-temperature fixability and storage stability and charging stability are major issues.
In order to solve this problem, a crystalline resin and a silica-containing toner having an average primary particle size of 50 nm or more and 150 nm or less treated with silicone oil (see JP 2009-98194 A) are proposed. Yes.
However, since this range of particle diameter includes silica having a large particle diameter of 120 to 150 nm, it is considered that an abnormal image due to the liberation of silica is likely to occur as described above.
In addition, many studies have been made on a toner having a shell layer containing a resin different from a binder resin on the surface of toner particles (see Japanese Patent Application Laid-Open No. 2006-267950). However, the shell layer for stress resistance has a problem that the image is not clearly displayed because the pigment is not dispersed and is unevenly distributed on the surface.
For this reason, in order to enable low-temperature fixing, it is necessary to make toner that melts quickly at low temperatures during fixing, and that is resistant to environments other than fixing and other stresses, such as toner transport and in machines.
As a future prospect, it is considered that by using both a crystalline polyester resin and an amorphous polyester resin, a toner having excellent low-temperature melting property can be produced and energy saving can be promoted.

  In view of the above-described problems of the prior art, the present invention greatly suppresses toner aggregation under high temperature and high humidity in toners containing crystalline polyester, and in that case, filming property and toner fluidity which are a concern as a side effect. An object of the present invention is to provide a toner in which deterioration is suppressed and charging is stabilized, and an image forming apparatus equipped with the toner.

The above-described problems are solved by the present invention including the following image forming apparatuses (1) to (8) and toners therefor.
(1) “Charging step for charging the surface of the image carrier, an exposure step for forming a latent image on the image carrier by exposing the surface of the image carrier, and developing a toner on the latent image A developing step for forming a visible image, a transfer step for transferring the visible image to a recording medium or an intermediate transfer member, a fixing step for fixing the transferred image transferred to the recording medium, and the recording medium to And a cleaning process for cleaning the transfer residual toner on the image carrier that has not been completely transferred to the intermediate transfer member, the toner used for image formation includes at least a crystalline polyester resin as a binder resin component An oil phase comprising at least one amorphous polyester resin in an organic solvent is dispersed in an aqueous medium, and the organic solvent is removed from the obtained dispersion. The toner has an additive containing at least two or more kinds of silica fine particles on the surface of the toner base particles, and the silica used as the additive is silica A derived from a sol-gel method and silica B derived from a dry method. The average primary particle size of silica A derived from the sol-gel method is in the range of 20 to 120 nm, and the average primary particle size of silica A derived from the sol-gel method is higher than that of silica B derived from the dry method. The relationship between the coverage ratio Ca (%) of silica A derived from the sol-gel method represented by the following formula and the coverage ratio Cb (%) of silica B derived from the dry method satisfies the following formula, and the silica derived from the sol-gel method An image forming apparatus, wherein when A is allowed to stand at 40 ° C. and a relative humidity of 70% for 1 week, it absorbs 0.01 g or more of moisture per 1 g of silica.
Ca (%) <Cb (%) (1)
Here, coverage Ca = (silica A input part [mass wt%] / 100) * silica A projected area [cm ² / g] / ((1- (silica A input part [mass wt%] / 100) * Toner base particle surface area [cm ² / g]) * 100
Toner base particle surface area = 6 / (average toner particle size * toner specific gravity)
Silica A projected area = 3 / (2 * silica A average particle diameter * silica A specific gravity)
Coverage Cb = (silica B input part [mass wt%] / 100) * silica B projected area [cm ² / g] / ((1- (silica B input part [mass wt%] / 100) * toner base particles Surface area [cm ² / g]) * 100
Toner base particle surface area = 6 / (average toner particle size * toner specific gravity)
Silica B projected area = 3 / (2 * silica B average particle diameter * silica B specific gravity).
(2) “The image forming apparatus according to (1), wherein an average primary particle size of the additive is in a range of 20 to 90 nm.”
(3) “The image forming apparatus according to (1) or (2), wherein the additive is used in combination of silica and titanium oxide.”
(4) “Image forming apparatus according to any one of items (1) to (3), wherein the moisture absorption of the dry-derived silica B is less than 0.01 g.”
(5) “Charging step for charging the surface of the image carrier, an exposure step for forming a latent image on the image carrier by exposing the surface of the image carrier, and developing a toner on the latent image. A developing step for forming a visible image, a transfer step for transferring the visible image to a recording medium or an intermediate transfer member, a fixing step for fixing the transferred image transferred to the recording medium, and the recording medium to A toner for use in an image forming apparatus including a cleaning step for cleaning a transfer residual toner on the image carrier that has not been completely transferred to the intermediate transfer body, and the toner used for image formation includes a binder resin component As an example, an oil phase comprising at least one crystalline polyester resin and at least one amorphous polyester resin in an organic solvent is dispersed in an aqueous medium, and the organic solvent is removed from the obtained dispersion. And an additive containing at least two or more types of silica on the surface of the toner base particles. The silica used as the additive is silica A derived from the sol-gel method and silica derived from the dry method. And the average primary particle size of the silica A derived from the sol-gel method is in the range of 20 to 120 nm, and the average primary particle size is the silica A derived from the sol-gel method from the silica B derived from the dry method. The relationship between the coverage ratio Ca (%) of the silica A derived from the sol-gel method and the coverage ratio Cb (%) of the silica B derived from the dry method satisfies the following formula, and the silica A derived from the sol-gel method is 40 A toner which absorbs moisture by 0.01 g or more per gram of silica when left at 1 ° C. and 70% relative humidity for 1 week.
Ca (%) <Cb (%) (1)
Here, coverage Ca = (silica A input part [mass wt%] / 100) * silica A projected area [cm ² / g] / ((1- (silica A input part [mass wt%] / 100) * Toner base particle surface area [cm ² / g]) * 100
Toner base particle surface area = 6 / (average toner particle size * toner specific gravity)
Silica A projected area = 3 / (2 * silica A average particle diameter * silica A specific gravity)
Coverage Cb = (silica B input part [mass wt%] / 100) * silica B projected area [cm ² / g] / ((1- (silica B input part [mass wt%] / 100) * toner base particles Surface area [cm ² / g]) * 100
Toner base particle surface area = 6 / (average toner particle size * toner specific gravity)
Silica B projected area = 3 / (2 * silica B average particle diameter * silica B specific gravity). "
(6) “The toner according to (5), wherein an average primary particle diameter of the additive is in a range of 20 to 90 nm.”
(7) “The toner according to (5) or (6) above, wherein the additive is a combination of silica and titanium oxide.”
(8) “The toner according to any one of (5) to (7) above, wherein the dry-derived silica B has a moisture absorption amount of less than 0.01 g.”

  According to the present invention, toner containing crystalline polyester greatly suppresses toner aggregation under high temperature and high humidity, suppresses deterioration of filming property and toner fluidity, which are feared as side effects, and stabilizes charging. It is possible to provide an image forming apparatus equipped with the toner and the toner.

It is a schematic explanatory drawing which shows an example of the image forming apparatus used by this invention. It is a schematic explanatory drawing which shows the other example of the image forming apparatus used by this invention. It is a schematic explanatory drawing which shows the other example of the image forming apparatus used by this invention. FIG. 4 is a schematic explanatory view showing a part of the image forming apparatus shown in FIG. 3.

Hereinafter, the present invention will be described in detail and specifically. As described above, the present invention includes a charging step for charging the surface of the image carrier, an exposure step for forming a latent image on the image carrier by exposing the surface of the image carrier, and the latent image. A developing process for developing a toner to form a visible image, a transfer process for transferring the visible image to a recording medium or an intermediate transfer member, and a fixing process for fixing the transferred image transferred to the recording medium; In the image forming apparatus including a cleaning process for cleaning the transfer residual toner on the image carrier that has not been completely transferred to the recording medium or the intermediate transfer body, the toner used for image formation is at least as a binder resin component. An oil phase comprising at least one crystalline polyester resin and an amorphous polyester resin in an organic solvent is dispersed in an aqueous medium, and the organic solvent is removed from the obtained dispersion. And the toner base particle surface has an additive containing at least two kinds of silica fine particles, and the silica used as the additive is derived from the silica A derived from the sol-gel method and the dry method. Both silica B and silica A derived from the sol-gel method have an average primary particle size in the range of 20 to 120 nm, and the average primary particle size is a silica derived from the sol-gel method from silica B derived from the dry method. The relationship between the coverage ratio Ca (%) of the silica A derived from the sol-gel method and the coverage ratio Cb (%) of the silica B derived from the dry method represented by the following formula satisfies the following formula, and the sol-gel method Provided is an image forming apparatus characterized in that when the derived silica A is allowed to stand at 40 ° C. and a relative humidity of 70% for 1 week, it absorbs moisture by 0.01 g or more per 1 g of silica.
Ca (%) <Cb (%) (1)

The calculation formulas of the coverage ratios Ca and Cb in the present invention are defined as follows.
Coverage ratio Ca = (silica A charged part [mass wt%] / 100) * silica A projected area [cm ² / g] / ((1- (silica A charged part [mass wt%] / 100) * toner base particles Surface area [cm ² / g]) * 100
Toner base particle surface area = 6 / (average toner particle size * toner specific gravity)
Silica A projected area = 3 / (2 * silica A average particle diameter * silica A specific gravity)
Coverage Cb = (silica B input part [mass wt%] / 100) * silica B projected area [cm ² / g] / ((1- (silica B input part [mass wt%] / 100) * toner base particles Surface area [cm ² / g]) * 100
Toner base particle surface area = 6 / (average toner particle size * toner specific gravity)
Silica B projected area = 3 / (2 * silica B average particle diameter * silica B specific gravity).

By combining the crystalline polyester and the external additive silica, it can be expected to improve the low-temperature fixability of the crystalline polyester and the accompanying deterioration in storage stability.
As a method for producing silica, a technique generally called a sol-gel method or a dry method is used.
Silica produced by the sol-gel method has the characteristics of high moisture content, volume resistance, sharp particle size distribution, and excellent moisture adsorptivity.
Because of this characteristic, silica having a water adsorption amount of 0.01 g or more per gram when sol-gel silica A is left in an environment of 40 ° C. and 70% for one week is water vapor in the atmosphere where the toner is present. It is considered that the solvent can be adsorbed to the pores, and an increase in the adhesion force of the toner base resin can be suppressed. By using crystalline polyester as the binder resin component, it is possible to provide a toner having excellent low-temperature fixability. However, since crystalline polyester is hygroscopic, it absorbs surrounding water under high temperature and high humidity, and aggregates. It becomes easy to do. Therefore, when sol-gel silica A having a hygroscopic property is externally added, it is considered that the porous silica absorbs moisture around the silica and suppresses aggregation under high temperature and high humidity.

On the other hand, silica B produced by the dry method has a characteristic that the particle size distribution is relatively broad, but has a very low water content and a strong negative chargeability, so that the charging ability is high.
The use of both of these two types of silica A and B complement each other's disadvantages, so that it is possible to obtain a toner having high charging ability in addition to excellent storage stability in a high temperature and high humidity environment. Can be expected.
In addition, to improve the storage stability, the amount of silica added is increased to improve storage stability, or silica with a large particle size is added to prevent contact between the toners due to the spacer effect. Deterioration of chargeability and image blur due to photoconductor filming are caused.
However, by setting the particle diameter of the additive covering the toner to 20 to 120 nm as in the present invention, the embedding of the additive in the toner is suppressed, so that the fluidity is improved, and the large particle diameter exceeding 120 nm. Since the release from the toner is reduced as compared with silica, the filming resistance is improved. Further, silica having a particle diameter of less than 20 nm tends to cause aggregation of the silica itself, and it becomes difficult to uniformly coat the toner, so that contact between the toners increases and aggregation tends to occur. If it exceeds 120 nm, the toner tends to come off from the toner due to its own size, and desired spent resistance and filming resistance cannot be obtained.
Further, the average primary particle size is larger in the silica A derived from the sol-gel method than the silica B derived from the dry method, and the coverage is higher in the coverage of the silica B derived from the dry method than in the silica A derived from the sol-gel method. By adding in this manner, the chargeability can be stabilized by the silica B derived from the dry method having high chargeability.

In the toner of the present invention, the binder resin component preferably contains a binder resin precursor.
The toner of the present invention includes an oil obtained by dissolving and dispersing at least a colorant, a release agent, a binder resin precursor composed of a modified polyester resin, and other binder resin components in an organic solvent. In the phase, the binder resin precursor and a compound that extends or crosslinks are dissolved, and then the oil phase is dispersed in an aqueous medium in which a fine particle dispersant is present to obtain an emulsified dispersion, and in the emulsified dispersion A toner obtained by subjecting the binder resin precursor to a crosslinking reaction and / or elongation reaction to remove an organic solvent is preferable.

(Binder resin precursor)
As the binder resin precursor, a binder resin precursor made of a modified polyester resin is preferable, and examples thereof include a polyester prepolymer modified with isocyanate or epoxy. This undergoes an extension reaction with a compound having an active hydrogen group (such as amines), and has an effect of improving the release width (difference between the minimum fixing temperature and the hot offset generation temperature). As a method for synthesizing this polyester prepolymer, it can be easily synthesized by reacting a base polyester resin with a conventionally known isocyanate agent or epoxidizing agent. Isocyanating agents include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic diisocyanates (Tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; block the polyisocyanates with phenol derivatives, oximes, caprolactam, etc. And combinations of two or more of these. Moreover, as an epoxidizing agent, epichlorohydrin etc. can be mentioned as the representative example.

The ratio of the isocyanate agent is usually 5/1 to 1/1, preferably 4/1 to 1 as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the base polyester. 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, the urea content of this polyester prepolymer becomes low, and the hot offset resistance deteriorates.
The content of the isocyanate agent in the polyester prepolymer is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, and more preferably 2 to 20% by weight. If it is less than 0.5% by weight, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40% by weight, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer is usually 1 or more, preferably 1.5 to 3 on average, and more preferably 1.8 to 2.5 on average. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester resin after the elongation reaction is lowered, and the hot offset resistance is deteriorated.
The binder resin precursor preferably has a weight average molecular weight of 1 × 10 ⁴ or more and 3 × 10 ⁵ or less.

(Compound that stretches or crosslinks with binder resin precursor)
Examples of the compound that extends or crosslinks with the binder resin precursor include compounds having an active hydrogen group, and typical examples thereof include amines. Examples of amines include diamine compounds, trivalent or higher polyamine compounds, amino alcohol compounds, amino mercaptan compounds, amino acid compounds, and compounds in which these amino groups are blocked. Examples of diamine compounds include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, isophoronediamine). Etc.); and aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.) and the like. Examples of the trivalent or higher polyamine compound include diethylenetriamine and triethylenetetramine. Examples of amino alcohol compounds include ethanolamine and hydroxyethylaniline. Examples of the amino mercaptan compound include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of amino acid compounds include aminopropionic acid and aminocaproic acid.
Examples of the compounds in which these amino groups are blocked include ketimine compounds and oxazoline compounds obtained from the amines and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines, preferred are a diamine compound and a mixture of a diamine compound and a small amount of a polyamine compound.

(Coloring agent)
As the colorant 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, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Se Red, Para Chlorortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, 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, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, 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 blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russianine green, anthraquinone green, titanium oxide, zinc white, lithopone and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

The colorant used in the present invention can also be used as a master batch combined with a resin.
As the binder resin to be kneaded together with the production of the masterbatch or the masterbatch, in addition to the modified and unmodified polyester resins mentioned above, styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and polymers of substituted products thereof; Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene 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, Tylene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid Styrene copolymers such as acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, poly Acrylic resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. The
This master batch can be obtained by mixing and kneading a resin for a master batch and a colorant under a high shear force to obtain a master batch. In this case, an organic solvent can be used in order to enhance the interaction between the colorant and the resin. Also, a so-called flushing method called watering paste containing water of a colorant is mixed and kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture and organic solvent components. Since it can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shear dispersion device such as a three-roll mill is preferably used.

(Release agent)
The release agent is preferably a wax having a melting point of 50 to 120 ° C.
Since such a wax can effectively act as a release agent between the fixing roller and the toner interface, high temperature offset resistance can be improved without applying a release agent such as oil to the fixing roller. be able to.
In addition, melting | fusing point of wax is calculated | required by measuring the maximum endothermic peak using TG-DSC system TAS-100 (made by Rigaku Corporation) which is a differential scanning calorimeter.
As the mold release agent, the following materials can be used.
As waxes and waxes, plant waxes such as carnauba wax, cotton wax, wood wax, rice wax; animal waxes such as beeswax and lanolin; mineral waxes such as ozokerite and cercin; paraffin, microcrystalline, petrolatum, etc. And petroleum wax.
In addition, examples of mold release agents other than these natural waxes include synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax; and synthetic waxes such as esters, ketones, and ethers.
Furthermore, fatty acid amides such as 1,2-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbons; low molecular weight crystalline polymer, poly (n-stearyl methacrylate), poly (methacrylic acid n) -A crystalline polymer having a long-chain alkyl group in the side chain, such as a homopolymer or copolymer of polyacrylate such as lauryl (for example, n-stearyl acrylate-ethyl methacrylate copolymer) is also used as a release agent. Can do.

(Charge control agent)
The toner of the present invention may contain a charge control agent as necessary. Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salt or compound, tungsten simple substance or compound, fluorine activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like.
Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of a phenol-based condensate (manufactured by Orient Chemical Industry Co., Ltd.), TP-302 of a quaternary ammonium salt molybdenum complex, TP-415 (manufactured by Hodogaya Chemical Industry Co., Ltd.), quaternary ammonium Copy charge PSY VP2038 of salt, 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), copper phthalocyanine, perylene, quinacridone Azo pigments, sulfonate group, carboxyl group, and polymer compounds having a functional group such as a quaternary ammonium salt.
The amount of the charge control agent used is determined by the toner production method including the type of binder resin, the presence or absence of additives used as necessary, and the dispersion method, but is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline. These charge control agents can be dissolved and dispersed after being melt-kneaded with a masterbatch and resin, or of course, may be added when directly dissolving or dispersing in an organic solvent, or may be fixed on the toner surface after preparation of toner particles. May be.

(Non-crystalline polyester resin)
In the present invention, an amorphous unmodified polyester resin is used as the binder resin component.
It is preferable that at least a part of the modified polyester resin obtained by crosslinking and / or elongation reaction of the binder resin precursor made of the modified polyester resin is compatible with the unmodified polyester resin. Thereby, low temperature fixability and hot offset resistance can be improved. For this reason, it is preferable that the polyol and polycarboxylic acid of the modified polyester resin and the unmodified polyester resin have similar compositions. Further, as the unmodified polyester resin, the non-modified polyester resin used in the crystalline polyester dispersion can also be used as long as it is unmodified.
The acid value of the unmodified polyester resin is usually 1 to 50 KOHmg / g, preferably 5 to 30 KOHmg / g. Thereby, since the acid value is 1 KOHmg / g or more, the toner is likely to be negatively charged, and further, the affinity between the paper and the toner is improved at the time of fixing to the paper, and the low-temperature fixability can be improved. . However, if the acid value exceeds 50 KOHmg / g, the charging stability, particularly the charging stability against environmental fluctuations, may be reduced. In the present invention, the unmodified polyester resin preferably has an acid value of 1 to 50 KOHmg / g.
The hydroxyl value of the unmodified polyester resin is preferably 5 KOHmg / g or more.

The hydroxyl value is measured using a method based on JIS K0070-1966.
Specifically, first, 0.5 g of a sample is precisely weighed into a 100 ml volumetric flask, and 5 ml of an acetylating reagent is added thereto. Next, after heating in a 100 ± 5 ° C. warm bath for 1-2 hours, the flask is removed from the warm bath and allowed to cool. Furthermore, acetic anhydride is decomposed by adding water and shaking.
Next, in order to completely decompose acetic anhydride, the flask is again heated in a warm bath for 10 minutes or more and allowed to cool, and then the wall of the flask is thoroughly washed with an organic solvent.
Furthermore, the hydroxyl value was measured at 23 ° C. using an automatic potentiometric titrator DL-53 Titrator (manufactured by METTLER TOLEDO) and electrode DG113-SC (manufactured by METTLER TOLEDO), and analysis software LabX Light Version 1.00 Analyze using .000. For calibration of the apparatus, a mixed solvent of 120 ml of toluene and 30 ml of ethanol is used.
At this time, the measurement conditions are as follows.
Stir
Speed [%] 25
Time [s] 15
EQP titration
Titrant / Sensor
Titrant CH3ONa
Concentration [mol / L] 0.1
Sensor DG115
Unit of measurement mV
Predispensing to volume
Volume [mL] 1.0
Wait time [s] 0
Titrant addition Dynamic
dE (set) [mV] 8.0
dV (min) [mL] 0.03
dV (max) [mL] 0.5
Measurement mode Equilibrium controlled
dE [mV] 0.5
dt [s] 1.0
t (min) [s] 2.0
t (max) [s] 20.0
Recognition
Threshold 100.0
Steppes jump only No
Range No
Tendency None
Termination
at maximum volume [mL] 10.0
at potential No
at slope No
after number EQPs Yes
n = 1
comb. termination conditions No
Evaluation
Procedure Standard
Potential1 No
Potentialial No
Stop for revaluation No

The urea-modified polyester resin can be used in combination with a polyester resin modified with a chemical bond other than a urea bond, for example, a polyester resin modified with a urethane bond, in addition to an unmodified polyester resin.
When the toner composition contains a modified polyester resin such as a urea-modified polyester resin, the modified polyester resin can be produced by a one-shot method or the like.

As an example, a method for producing a urea-modified polyester resin will be described.
First, a polyol and a polycarboxylic acid are heated to 150 to 280 ° C. in the presence of a catalyst such as tetrabutoxy titanate or dibutyltin oxide, and if necessary, water generated while removing pressure is removed to have a hydroxyl group. A polyester resin is obtained. Next, a polyester resin having a hydroxyl group is reacted with polyisocyanate at 40 to 140 ° C. to obtain a polyester prepolymer having an isocyanate group. Furthermore, the polyester prepolymer having an isocyanate group is reacted with amines at 0 to 140 ° C. to obtain a urea-modified polyester resin.
The number average molecular weight of the urea-modified polyester resin is usually 1000 to 10000, preferably 1500 to 6000.
In addition, when making the polyester resin which has a hydroxyl group and polyisocyanate react, and when making the polyester prepolymer which has an isocyanate group, and amines react, a solvent can also be used as needed.
Solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.); ethers (tetrahydrofuran) And the like which are inert with respect to the isocyanate group.

In addition, when using unmodified polyester resin together, you may mix to the solution after reaction of the urea modified polyester resin what was manufactured similarly to the polyester resin which has a hydroxyl group.
In the present invention, as the binder resin component contained in the oil phase, a crystalline polyester resin, an amorphous polyester resin, a binder resin precursor, and an unmodified resin may be used in combination. The binder resin component may be contained. The binder resin component preferably contains a polyester resin, and more preferably contains 50% by weight or more of the polyester resin. If the content of the polyester resin is less than 50% by weight, the low-temperature fixability may be lowered. It is particularly preferable that all of the binder resin components are polyester resins.

  Examples of binder resin components other than polyester resins include polystyrene, poly (p-chlorostyrene), styrene-substituted polymers such as polyvinyltoluene, styrene-substituted polymers, styrene-p-chlorostyrene copolymers, and styrene-propylene copolymers. Polymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-acrylic acid Octyl copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer , Styrene-vinyl methyl ketone copolymer Styrene copolymers such as styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; Methyl acid, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, epoxy resin, epoxy polyol resin, polyurethane resin, polyamide resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax and the like.

(Toner production method in aqueous medium)
The aqueous medium used in the present invention may be water alone, or a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohols (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (eg, methyl cellosolv (registered trademark)), lower ketones (eg, acetone, methyl ethyl ketone), and the like.
The binder resin precursor, colorant, release agent, crystalline polyester dispersion, charge control agent, unmodified polyester resin, etc. that form toner particles are mixed when forming the dispersion in an aqueous medium. However, it is more preferable to mix these toner raw materials in advance and then add and disperse the mixture in an aqueous medium. In the present invention, other toner raw materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium. It may be added later. For example, after forming particles containing no colorant, the colorant can be added by a known dyeing method.
The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferable. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 60 minutes. The temperature during dispersion is usually 0 to 80 ° C. (under pressure), preferably 10 to 40 ° C.
The amount of the aqueous medium used is usually 100 to 1000 parts by weight with respect to 100 parts by weight of the toner composition. If the amount is less than 100 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 1000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

  As a method of reacting the polyester prepolymer and the compound having active hydrogen groups, the compound having active hydrogen groups may be added and reacted before dispersing the toner composition in the aqueous medium, or dispersed in the aqueous medium. Then, a compound having an active hydrogen group may be added to cause a reaction from the particle interface. In this case, a polyester modified with a polyester prepolymer is preferentially produced on the surface of the toner to be produced, and a concentration gradient can be provided inside the particles.

  Anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamines, etc. as dispersants for emulsifying and dispersing the oil phase in which the toner composition is dispersed in a liquid containing water Amine salts such as salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, etc. Nonionic surfactants such as quaternary ammonium salt type cationic surfactants, fatty acid amide derivatives, polyhydric alcohol derivatives such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl- Amphoteric surfactants such as N- dimethyl ammonium betaine and the like.

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts thereof, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl ) Perfluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate Etc.
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (Daikin Kogyo Co., Ltd.), Mega-Fac F-l0, F-l20, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), Xtop EF-102 , 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fagento F-100, F150 (manufactured by Neos).

  Examples of cationic surfactants include aliphatic primary, secondary or tertiary amine acids having a fluoroalkyl group, aliphatic quaternary ammonium salts such as perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts, and benzaza. Luconium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass), Florard FC-135 (Sumitomo 3M), Unidyne DS-202 (Daikin Industries) , Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products Co., Ltd.), Footgent F-300 (Neos Co., Ltd.), and the like.

Further, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite and the like can be used as an inorganic compound dispersant which is hardly soluble in water.
Further, the dispersed droplets may be stabilized by a polymer protective colloid or water-insoluble organic fine particles. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-acrylate Chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N- Methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc., or esters of compounds containing vinyl alcohol and carboxyl groups, eg acetic acid Vinyl, vinyl propionate, vinyl butyrate, etc., acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, etc. Homopolymers or copolymers such as those having a nitrogen atom or its heterocyclic ring, polyoxyethylene, polyoxypropylene, poly Xylethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl Polyoxyethylenes such as esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

In addition, when an acid such as calcium phosphate salt or an alkali-soluble one is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as washing with water after dissolving the calcium phosphate salt with an acid such as hydrochloric acid. To do. It can also be removed by operations such as enzymatic degradation.
When a dispersant is used, the dispersant can remain on the surface of the toner particles. However, it is preferable from the charged surface of the toner to wash away after the reaction.

Further, in order to lower the viscosity of the toner composition, a solvent in which the polyester prepolymer reacts and is modified with a modified polyester can be used. The use of a solvent is preferable in that the particle size distribution becomes sharp. The solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate and the like. These can be used alone or in combination of two or more water-miscible solvents such as methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran and methanol.
In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of the solvent with respect to 100 parts of polyester prepolymers is 0-300 parts normally, Preferably it is 0-100 parts, More preferably, it is 25-70 parts. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after elongation and / or crosslinking reaction.

The elongation and / or crosslinking reaction time is selected depending on the reactivity depending on the combination of the polyester prepolymer and the compound having an active hydrogen group, and is usually 10 minutes to 40 hours, preferably 30 minutes to 24 hours. The reaction temperature is usually 0 to 100 ° C., preferably 10 to 50 ° C. Moreover, a well-known catalyst can also be used as needed. Specific examples include tertiary amines such as triethylamine and imidazoles.
In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the entire system is gradually raised to completely evaporate and remove the organic solvent in the droplets can be employed. Alternatively, the emulsified dispersion can be sprayed into a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and the aqueous dispersant can be removed by evaporation together. . As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air currents heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. Sufficient quality can be obtained by short-time treatment such as spray dryer, belt dryer, rotary kiln.

When the particle size distribution at the time of emulsification dispersion is wide, and washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classification into a desired particle size distribution.
In the classification operation, the fine particle portion can be removed in the liquid by a cyclone, a decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder as a powder after drying. The unnecessary fine particles or coarse particles obtained can be returned to the kneading step and used for the formation of particles. At that time, fine particles or coarse particles may be wet.
The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.

By mixing the resulting dried toner powder with dissimilar particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, or by giving mechanical impact force to the mixed powder By immobilizing and fusing on the surface, it is possible to prevent the detachment of the foreign particles from the surface of the resulting composite particle.
Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture in a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) has been modified to lower the pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar, etc.

(Cleaning improver)
The cleaning improver is an agent added to the toner in order to remove the developer after transfer remaining on the photoreceptor or the primary transfer medium. For example, fatty acid such as zinc stearate, calcium stearate, stearic acid Examples thereof include polymer fine particles produced by soap-free emulsion polymerization such as metal salts, polymethyl methacrylate fine particles, and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 to 1 μm are suitable.

(Career)
Hereinafter, the carrier used in the present invention will be specifically described.
As the basic structure of the carrier in the present invention, the basic structure of the carrier in the present invention is composed of a core material particle having magnetism and a resin layer covering the surface thereof. The selection of the particle size is important. The carrier used in the developing method of the present invention has a weight average particle diameter Dw in the range of 20 to 45 μm. When the weight average particle diameter Dw is larger than the above range, carrier adhesion is less likely to occur, but the toner is not developed faithfully with respect to the electrostatic latent image, and the variation in the dot diameter increases and graininess (roughness). Decreases.
In addition, when a carrier having a weight average particle diameter Dw smaller than 20 μm is used, particles with small magnetization are present throughout the magnetic brush, and the carrier adhesion is rapidly deteriorated.
Further, in the carrier particles having a weight average particle diameter Dw of 22 to 32 μm, sharp particles in which particles smaller than 36 μm are 80% by weight or more, more preferably 82% by weight or more and the content of particles smaller than 44 μm are 90% by weight or more. A carrier coated with a resin having a particle size distribution has a small variation in magnetization of each carrier particle, and carrier adhesion can be greatly improved by a developing method in which a DC bias is applied.
In particular, the content of particles having a particle size smaller than 20 μm is in the range of 0-7 wt%, the content of particles smaller than 36 μm is 80-100 wt%, and the content of particles smaller than 44 μm is 90-100 wt%. A carrier coated with a resin having a sharp particle size distribution becomes smaller in variation in magnetization of each carrier particle, and can greatly improve carrier adhesion.
Further, in the carrier particles having a weight average particle diameter Dw of 22 to 32 μm, sharp particles in which particles smaller than 36 μm are 80% by weight or more, more preferably 82% by weight or more and the content of particles smaller than 44 μm are 90% by weight or more. A carrier coated with a resin having a particle size distribution has a small variation in magnetization of each carrier particle, and carrier adhesion can be greatly improved by a developing method in which a DC bias is applied.

Further, the carrier used in the present invention is preferably a carrier having a sharper particle size distribution and uniform particle size, and in addition to the above-mentioned regulation of the weight average particle diameter Dw, the carrier and the carrier regulated by the number average particle diameter Dp. Preferably, core material particles are used.
As a particle size analyzer for measuring the particle size distribution in the present invention, a Microtrac particle size analyzer (model HRA9320-X100: manufactured by Honeywell) was used.
Further, in the carrier according to the present invention, a predetermined magnetization is required because it is necessary to form a magnetic brush, and the amount of magnetization of such a carrier is the amount of magnetization when a magnetic field of 1000 oersted (Oe) is applied. 40 to 100 emu / g, more preferably 50 e to 90 mu / g. When it becomes less than 40 emu / g, carrier adhesion tends to occur, and when it becomes 100 emu / g or more, the head trace of the magnetic brush becomes strong.

The amount of magnetization can be measured as follows. A BH tracer (BHU-60 / manufactured by Riken Denshi Co., Ltd.) is used, and 1 g of carrier core particles are packed in a cylindrical cell and set in an apparatus. The magnetic field is gradually increased and changed to 3000 oersted, then gradually reduced to zero, and then the opposite magnetic field is gradually increased to 3000 oersted. Further, after gradually reducing the magnetic field to zero, a magnetic field is applied in the same direction as the first. In this way, a BH curve is drawn, and a magnetic moment of 1000 Oersted is calculated from the drawing.
The amount of magnetization of such carriers is basically determined by the magnetic material that becomes the core particles. Examples of the core particles that are 40 emu / g or more when a magnetic field of 1000 oersted used in the carrier of the present invention is applied include, for example, ferromagnetic materials such as iron and cobalt, magnetite, hematite, Li-based ferrite, and MnZn-based materials. Examples thereof include ferrite, CuZn ferrite, NiZn ferrite, Ba ferrite, and Mn ferrite.

The core particles used in the carrier of the present invention are crushed particles of magnetic material, or in the case of core materials such as ferrite and magnetite, the primary granulated product before classification is classified, and the sintered particles are classified. It can be obtained by mixing a plurality of particle powders after classification into particle powders having different particle size distributions by treatment.
As a method of classifying the core particles, conventionally known classification methods such as a sieving machine, a gravity classifier, a centrifugal classifier, and an inertia classifier can be used, but the productivity is easy and the classification point can be easily changed. Therefore, it is preferable to use an air classifier such as a gravity classifier, a centrifugal classifier, or an inertia classifier.

  In the carrier of the present invention, the electrical resistivity (log R) is preferably in the range of 11.0 to 17.0 Ω · cm, and more preferably in the range of 11.5 to 16.5 Ω · cm. When the resistivity logR of the carrier is less than 11.0 Ω · cm, when the developing gap (the closest distance between the photosensitive member and the developing sleeve) is narrowed, charges are induced in the carrier and carrier adhesion is likely to occur. When it is larger than 17.0 Ω · cm, the edge effect becomes strong and the image density of the solid image portion becomes low. On the other hand, when LogR is greater than 17.0 Ω · cm, charges having the opposite polarity to the toner are likely to be accumulated, and the carrier is charged and carrier adhesion is likely to occur.

The resistivity of the carrier can be adjusted by adjusting the resistance of the coating resin on the core particles and controlling the thickness of the coating layer. Moreover, it is also possible to add conductive fine powder to the coating resin layer for carrier resistance adjustment. Examples of the conductive fine powder include conductive metals such as ZnO and Al, or cerium oxide, alumina, for example, metal oxides such as SiO2 and TiO2 whose surfaces are hydrophobized, SnO2 prepared by various methods, and various elements. Conductive polymers such as doped borides such as SnO2, TiB2, ZnB2, and MoB2, silicon carbide, polyacetylene, polyparaphenylene, poly (para-phenylene sulfide) polypyrrole, polyethylene, furnace black, acetylene black, channel black, etc. Examples thereof include carbon black.
These conductive fine powders can be obtained by the following methods: a dispersing machine using a medium such as a ball mill or a bead mill after the conductive fine powder is put into a solvent used for coating or a resin solution for coating, or a blade rotating at high speed. The dispersion for forming a coating layer is prepared by uniformly dispersing by using a stirrer equipped with, and the carrier can be prepared by applying the dispersion for forming a coating layer to the core material particles.

As the resin used for the carrier coating layer, various conventionally known resins can be used, and a silicone resin is preferably used.
In the present invention, a straight silicone resin can be used as the silicone resin. Examples thereof include KR271, KR272, KR282, KR252, KR255, KR152 (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2400, SR2406 (manufactured by Toray Dow Corning Silicone).
In the present invention, a modified silicone resin can be used as the silicone resin. Examples of such materials include epoxy-modified silicone, acrylic-modified silicone, phenol-modified silicone, urethane-modified silicone, polyester-modified silicone, and alkyd-modified silicone. Specific examples of the modified silicone resin include epoxy modified product: ES-1001N, acrylic modified silicone: KR-5208, polyester modified product: KR-5203, alkyd modified product: KR-206, urethane modified product: KR-305 ( As mentioned above, Shin-Etsu Chemical Co., Ltd.), epoxy-modified product: SR2115, alkyd-modified product: SR2110 (manufactured by Toray Dow Corning Silicone), and the like.

Furthermore, in this invention, it is also possible to use the resin shown below individually or in mixture with the said silicone resin.
Polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, Styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer) Polymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylate copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, Styrene-phenyl methacrylate copolymer, etc.) Styrenic resins such as styrene-α-chloroacrylic acid methyl copolymer, styrene-acrylonitrile-acrylic acid ester copolymer, epoxy resin, polyester resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, ketone resin, ethylene -An ethyl acrylate copolymer, a xylene resin, a polyamide resin, a phenol resin, a polycarbonate resin, a melamine resin, a fluorine resin, or the like can be suitably mixed with the silicone resin.

In the present invention, a carrier having good durability can be obtained by adding an aminosilane coupling agent to the coating layer made of the silicone resin.
The aminosilane coupling agent used in the present invention is preferably 0.001 to 30% by weight.
As a method for forming the resin coating layer on the surface of the carrier core material particles, a known method such as a spray drying method, a dipping method, or a powder coating method can be used. In particular, the method using a fluidized bed type coating apparatus is effective for forming a uniform coating layer.
The thickness of the coating layer on the surface of the carrier core particles is usually 0.02-1 μm, preferably 0.03-0.8 μm. Since the thickness of the coating layer is very small, the carrier having the coating layer formed on the surface of the core particle and the carrier core particle have substantially the same particle size.
In this case, the carrier bulk density affects the carrier adhesion, but the carrier bulk density recommended in the present invention is 2.15 to 2.70 g / cm ³ , more preferably 2.25 to 2.60 g / cm ³ . When the carrier is porous, or the surface irregularities are large and the bulk density is less than 2.15, the substantial magnetization per particle is increased even if the amount of magnetization (emu / g) of 1 KOe of the core particle is large. Since the value is small, it is disadvantageous for carrier adhesion.
To increase the bulk density, it is possible to increase the firing temperature. However, it is preferable that the core particles are less than 2.7 g / cm ³ because the core particles are easily fused and difficult to disintegrate. More preferably, it is less than 6 g / cm ³ .

According to the metal powder-apparent density test method (JIS-Z-2504), the carrier according to the present invention has a bulk density of 25 cm ³ made of stainless steel, which is allowed to flow naturally from an orifice having a diameter of 2.5 mm. After pouring the carrier into the cylindrical container until it overflows, the upper surface of the container is scraped flat with a single operation along the upper end of the container using a nonmagnetic horizontal spatula. If it is difficult to flow with an orifice having a diameter of 2.5 mm, the carrier naturally flows out from the orifice having a diameter of 5 mm. By this operation, the weight of the carrier per cm ^{3 is} obtained by dividing the weight of the carrier flowing into the container by the volume of the container 25 cm ³ . This is defined as the bulk density of the carrier.

The image forming apparatus of the present invention includes an electrostatic latent image forming process (charging process and exposure process), a developing process, a transfer process, a fixing process, and a cleaning process. You may further have processes, such as a process and a control process.
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the image carrier. The material, shape, structure, size and the like of the image carrier can be appropriately selected from known ones. Examples of the material include inorganic substances such as amorphous silicon and selenium, and organic substances such as polysilane and phthalopolymethine. Amorphous silicon is preferable because of its long life. Further, the shape is preferably a drum shape. The electrostatic latent image can be formed by uniformly charging the surface of the image carrier and then exposing it imagewise, and can be performed by electrostatic latent image forming means.
The electrostatic latent image forming unit preferably has a charger (charging unit) that uniformly charges the surface of the image carrier and an exposure unit (exposure unit) that exposes the surface of the image carrier.

Charging can be performed by applying a voltage to the surface of the image carrier using a charger.
The charger can be appropriately selected according to the purpose, but a known contact charger equipped with a conductive or semiconductive roll, brush, film, rubber blade, etc., or corona discharge such as corotron or scorotron is used. Non-contact chargers and the like.

  The exposure can be performed by exposing the surface of the image carrier using an exposure device. The exposure device can be appropriately selected according to the purpose, but various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used. It should be noted that an optical back side system in which exposure is performed from the back side of the image carrier may be employed.

The development step is a step of forming a visible image by developing the electrostatic latent image using the toner of the present invention. The visible image can be formed using a developing unit. The developing means can be appropriately selected from known ones, and preferably has a developing unit that accommodates the toner of the present invention and can apply the toner to the electrostatic latent image in a contact or non-contact manner. Further, it may be a single color developer or a multicolor developer. Specifically, a stirrer for charging the developer by friction stirring and a developer having a rotatable magnet roller can be used.
In the developing device, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and is held on the surface of the rotating magnet roller in a raised state, thereby forming a magnetic brush.
Since the magnet roller is disposed in the vicinity of the image carrier, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the image carrier by an electric attractive force. As a result, the electrostatic latent image is developed with toner, and a visible image is formed with toner on the surface of the image carrier.

The transfer step is a step of transferring a visible image to a recording medium. The intermediate transfer member is used to primarily transfer the visible image onto the intermediate transfer member, and then the secondary transfer of the visible image onto the recording medium. It is preferable. At this time, the toner used is usually two or more colors, and it is preferable to use a full-color toner. For this reason, it is more preferable to have a primary transfer process in which a visible image is transferred onto an intermediate transfer member to form a composite transfer image, and a secondary transfer process in which the composite transfer image is transferred onto a recording medium.
The transfer can be performed by charging the image carrier using a transfer unit. The transfer means preferably has a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. The intermediate transfer member can be appropriately selected from known transfer members according to the purpose, and a transfer belt or the like can be used.

  The transfer means preferably has a transfer device that peels and charges the visible image formed on the image carrier to the recording medium side. There may be one transfer means or a plurality of transfer means. Specific examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device. The recording medium can be appropriately selected from known recording media, and recording paper or the like can be used.

  The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing unit, and may be fixed each time the toner of each color is transferred to the recording medium, or each color toner is laminated. You may fix at once in the state. The fixing unit can be appropriately selected according to the purpose, but a known heating and pressing unit can be used. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt. The heating in the heating and pressurizing means is usually preferably 80 ° C to 200 ° C. A known optical fixing device may be used together with or instead of the fixing unit depending on the purpose.

  The neutralization step is a step of neutralizing by applying a neutralization bias to the image carrier, and can be performed using a neutralization unit. The neutralization means can be appropriately selected from known neutralizers, and a neutralization lamp or the like can be used.

  The cleaning step is a step of removing the toner remaining on the image carrier, and can be performed using a cleaning unit. The cleaning means can be appropriately selected from known cleaners, and a magnetic brush cleaner, electrostatic brush cleaner, magnetic roller cleaner, blade cleaner, brush cleaner, web cleaner, or the like can be used. It is preferable to use a blade cleaner.

  The recycling process is a process in which the toner removed by the cleaning process is recycled by the developing unit, and can be performed using the recycling unit. The recycling means can be appropriately selected according to the purpose, and a known conveying means or the like can be used.

  A control process is a process of controlling each process, and can be performed using a control means. The control means can be appropriately selected according to the purpose, and devices such as a sequencer and a computer can be used.

The process cartridge of the present invention is used in the image forming apparatus of the present invention, and integrally supports an image carrier and at least one unit selected from a charging unit, a developing unit, and a cleaning unit to form the image of the present invention. It is detachable from the main body.
FIG. 1 shows an example of an image forming apparatus used in the present invention.
The image forming apparatus (100A) includes a drum-shaped photoconductor (10) as an increasing carrier, a charging roller (20) as a charging unit, an exposure device (30) as an exposure unit, and development as a developing unit. An apparatus (40), an intermediate transfer member (50), a cleaning device (60) as a cleaning means, and a static elimination lamp (70) as a static elimination means are provided.
The intermediate transfer member (50) is an endless belt, and is stretched by three rollers (51) so as to be movable in the direction of the arrow. A part of the three rollers (51) also functions as a transfer bias roller that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer member (50). A cleaning device (90) having a cleaning blade is disposed in the vicinity of the intermediate transfer member (50). Further, a transfer roller (80) as a transfer means capable of applying a transfer bias for transferring (secondary transfer) a visible image (toner image) to a recording paper (95) as a recording medium is opposed to the recording paper (95). Has been placed. Around the intermediate transfer member (50), there is a corona charger (58) for applying a charge to the toner image on the intermediate transfer member (50) in the rotational direction of the intermediate transfer member (50). 10) and the intermediate transfer member (50) and the contact portion between the intermediate transfer member (50) and the transfer paper (95).
The developing device (40) includes a developing belt (41) as a developer carrying member, a black developing device (45K), a yellow developing device (45Y), and a magenta developing device (45M) provided around the developing belt (41). And a cyan developing unit (45C). The black developing device (45K) includes a developer accommodating portion (42K), a developer supply roller (43K), and a developing roller (44K), and the yellow developing device (45Y) includes a developer accommodating portion (42Y). ), A developer supply roller (43Y), and a development roller (44Y). The magenta developer (45M) includes a developer accommodating portion (42M), a developer supply roller (43M), and a development roller (44M). The cyan developing device (45C) includes a developer container (42C), a developer supply roller (43C), and a developing roller (44C). Further, the developing belt (41) is an endless belt, is stretched by a plurality of belt rollers so as to be movable in the direction of the arrow, and a part thereof is in contact with the photoreceptor (10).

  In the image forming apparatus (100A), the charging roller (20) uniformly charges the photoconductor (10), and then exposes the photoconductor (10) using the exposure device (30), thereby electrostatic latent. Form an image. Next, the electrostatic latent image formed on the photoreceptor (10) is developed by supplying a developer from the developing device (40) to form a toner image. Further, the toner image is transferred (primary transfer) onto the intermediate transfer member (50) by the voltage applied by the roller (51), and further transferred (secondary transfer) onto the recording paper (95). As a result, a transfer image is formed on the recording paper (95). The toner remaining on the photoconductor (10) is removed by a cleaning device (60) having a cleaning blade, and the charged charge on the photoconductor (10) is removed by a static elimination lamp (70).

FIG. 2 shows another example of the image forming apparatus used in the present invention.
The image forming apparatus (100B) does not include the developing belt (41), and a black developing unit (45K), a yellow developing unit (45Y), a magenta developing unit (45M), and a cyan developing unit are provided around the photoreceptor (10). Except that (45C) is arranged to face each other, it has the same configuration as that of the image forming apparatus (100A) and exhibits the same functions and effects. In FIG. 4, the same components as those in FIG. 3 are denoted by the same reference numerals.

FIG. 3 shows another example of the image forming apparatus used in the present invention.
The image forming apparatus (100C) is a tandem color image forming apparatus. The image forming apparatus (100C) includes a copying apparatus main body (150), a paper feed table (200), a scanner (300), and an automatic document feeder (400). The copying machine main body (150) is provided with an endless belt-like intermediate transfer member (50) at the center. The intermediate transfer member (50) is stretched around the support rollers (14), (15) and (16) so as to be able to move clockwise in the drawing. An intermediate transfer body cleaning device (17) for removing toner remaining on the intermediate transfer body (50) is disposed in the vicinity of the support roller (15). The intermediate transfer member (50) stretched by the support rollers (14) and (15) is opposed to image forming means (18) of four colors of yellow, cyan, magenta, and black along the conveyance direction. A tandem developing device (120) juxtaposed in parallel is arranged. An exposure device (21) is disposed in the vicinity of the tandem developing device (120). A secondary transfer device (22) is arranged on the opposite side of the intermediate transfer member (50) from the side where the tandem developing device (120) is arranged. In the secondary transfer device (22), a secondary transfer belt (24), which is an endless belt, is stretched between a pair of rollers (23), and the recording paper conveyed on the secondary transfer belt (24) is intermediate to the recording paper. The transfer bodies (50) can contact each other. A fixing device (25) is disposed in the vicinity of the secondary transfer device (22). The fixing device (25) includes a fixing belt (26) that is an endless belt, and a pressure roller (27) that is arranged to be pressed against the fixing belt (26).
In the image forming apparatus (100C), a sheet reversing device (28) for reversing the transfer paper is disposed in the vicinity of the secondary transfer device (22) and the fixing device (25). Thereby, images can be formed on both sides of the recording paper.

Next, full color image formation (color copying) using the tandem developing device (120) will be described. First, the document is set on the document table (130) of the automatic document feeder (400), or the automatic document feeder (400) is opened and the document is set on the contact glass (32) of the scanner (300). The automatic document feeder (400) is closed.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder (400), the document is conveyed on the contact glass (32) and then on the contact glass (32). When is set, the scanner (300) is immediately driven, and the first traveling body (33) and the second traveling body (34) travel. At this time, the reflected light from the original surface of the light irradiated by the first traveling body (33) is reflected by the mirror in the second traveling body (34), and passes through the imaging lens (35) to read the sensor (36). ). As a result, a color original (color image) is read and used as image information for each color of black, yellow, magenta, and cyan. The image information of each color is transmitted to the image forming means (18) for each color in the tandem developing device (120), and a toner image for each color is formed.
The toner image on the black photoconductor (10K), the toner image on the yellow photoconductor (10Y), the toner image on the magenta photoconductor (10M), and the toner image on the cyan photoconductor (10C) are intermediate. Transfer (primary transfer) is sequentially performed on the transfer body (50). Then, the toner images of the respective colors are superimposed on the intermediate transfer member (50) to form a composite color image (color transfer image).

As shown in FIG. 4, each color image forming means (18) in the tandem developing device (120) includes a photoreceptor (10) and a charger (59) for uniformly charging the photoreceptor (10). And an exposure device (21) that forms an electrostatic latent image on the photoconductor (10) by exposing the photoconductor (10) based on image information of each color (L in the figure), and toner of each color Is used to develop the electrostatic latent image to form a toner image of each color on the photoreceptor (10), and a transfer for transferring the toner image of each color onto the intermediate transfer member (50). A charger (62), a photoreceptor cleaning device (63), and a static eliminator (64) are provided.
On the other hand, in the paper feed table (200), one of the paper feed rollers (142a) is selectively rotated to feed the recording paper from one of the paper feed cassettes (144) provided in multiple stages in the paper bank (143). The sheet is separated one by one by the separation roller (145a), sent to the sheet feeding path (146), conveyed by the conveying roller (147) and guided to the sheet feeding path (148) in the copying machine main body (150), and the registration roller Stop at (49). Alternatively, the recording paper on the manual feed tray (52) is fed out by rotating the paper feed roller (142b), separated one by one by the separation roller (145b), and put into the manual paper feed path (53). 49) and stop. The registration roller (49) is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet.
Then, the registration roller (49) is rotated in time with the color transfer image formed on the intermediate transfer member (50), and the recording paper is interposed between the intermediate transfer member (50) and the secondary transfer device (22). , A color transfer image is formed on the recording paper. The toner remaining on the intermediate transfer body (50) after the transfer is cleaned by the intermediate transfer body cleaning device (17).
The recording paper on which the color transfer image is formed is conveyed to the fixing device (25) by the secondary transfer device (22), and the color transfer image is fixed on the recording paper by heat and pressure. Thereafter, the recording paper is switched by the switching claw (55), discharged by the discharge roller (56), and stacked on the discharge tray (57). Alternatively, the sheet is switched by the switching claw (55), reversed by the sheet reversing device (28) and led to the transfer position again, and after the image is formed on the back surface, the sheet is discharged by the discharge roller (56) and discharged by the discharge tray (57 ) Is stacked on top.

[Toner characteristics measurement method]
<Weight average particle diameter (Dw), volume average particle diameter (Dv), and number average particle diameter (Dn)>
The weight average particle diameter (Dw), volume average particle diameter (Dv), and number average particle diameter (Dn) of the toner are measured with a particle size measuring device (manufactured by Multisizer III Beckman Coulter, Inc.) with an aperture diameter of 100 μm. Analysis was performed with analysis software (Beckman Coulter Multisizer 3 Version 3.51). Specifically, 0.5 ml of 10 wt% surfactant (alkylbenzene sulfonate Neogen SC-A; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added to a glass 100 ml beaker, 0.5 g of each toner was added, and the mixture was stirred with a micropartel. Subsequently, 80 ml of ion-exchanged water was added. The obtained dispersion was subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion was measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter, Inc.) as the measurement solution. In the measurement, the toner sample dispersion was dropped so that the concentration indicated by the apparatus was 8 ± 2%. In this measurement method, it is important that the concentration is 8 ± 2% from the viewpoint of the reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.

The ratio (Dw / Dn) of the weight average particle diameter (Dw) to the number average particle diameter (Dn) in the toner manufactured by the manufacturing method of the present invention is preferably 1.30 or less, for example, 1.00 to 1 .30 is more preferred. When the ratio of the weight average particle diameter to the number average particle diameter (Dw / Dn) is less than 1.00, in the two-component developer, the toner is fused to the surface of the carrier during long-term agitation in the developing device, and the carrier It tends to lead to a decrease in charging ability and deterioration in cleaning performance. In the case of a one-component developer, toner filming on the developing roller and toner fusion to a member such as a blade are likely to occur because the toner is thinned. Further, if Dw / Dn exceeds 1.30, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the fluctuation of the toner particle diameter increases. Sometimes.
Further, when the ratio of the weight average particle diameter to the number average particle diameter (Dw / Dn) of the toner is 1.00 to 1.30, any of storage stability, low-temperature fixability, and hot offset resistance can be obtained. Also tends to be an excellent toner. In particular, when used in a full-color copying machine, the glossiness of the image is excellent.
Even if the toner balance for a long time is carried out with a two-component developer, the toner particle diameter in the developer is little changed, and good and stable developability can be obtained even with long-term stirring in the developing device. With toner balance, the toner particle size fluctuations are reduced, and there is no toner filming on the developing roller and no toner fusion to a member such as a blade for thinning the toner. Good and stable developability can be obtained even during long-term use (stirring) of the apparatus, and high-quality images can be obtained.

<Average circularity>
The average circularity of the toner is defined by the average circularity SR = (peripheral length of a circle having the same area as the particle projection area / perimeter length of the particle projection image) × 100%. Measurement was performed using a flow type particle image analyzer (“FPIA-2100”; manufactured by Sysmex Corporation), and analysis was performed using analysis software (FPIA-2100 Data Processing Program for FPIA version 00-10). Specifically, 0.1 to 0.5 ml of 10 wt% surfactant (alkylbenzene sulfonate Neogen SC-A; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a glass 100 ml beaker, and each toner 0.1 0.5 g was added and stirred with microspatel, and then 80 ml of ion-exchanged water was added. The obtained dispersion was subjected to a dispersion treatment for 3 minutes with an ultrasonic disperser (Honda Electronics). The shape and distribution of the toner were measured using the FPIA-2100 until the density of the dispersion was 5000 to 15000 / μl. In this measurement method, it is important that the concentration of the dispersion liquid is 5000 to 15000 / μl from the viewpoint of measurement reproducibility of the average circularity. In order to obtain the dispersion concentration, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant to be added and the amount of toner. The amount of the surfactant varies depending on the hydrophobicity of the toner as in the measurement of the toner particle diameter described above, and if it is added in a large amount, noise due to bubbles is generated. If the amount is too small, the toner cannot be sufficiently wetted and dispersion is not achieved. It will be enough. Further, the toner addition amount differs from the particle size, and it is necessary to decrease the small particle size and increase the large particle size. When the toner particle size is 3 to 7 μm, the toner amount is 0.1 to 0. By adding 0.5 g, the dispersion concentration can be adjusted to 5000 to 15000 / μl.

<Acid value>
In the present invention, the acid value is measured using a method based on JIS K0070-1992.
Specifically, first, 0.5 g of a sample (0.3 g in the case where ethyl acetate is soluble) is added to 120 ml of toluene and dissolved by stirring at 23 ° C. for about 10 hours. Next, 30 ml of ethanol is added to prepare a sample solution. When the sample does not dissolve, a solvent such as dioxane or tetrahydrofuran is used. Furthermore, the acid value was measured at 23 ° C. using an automatic potentiometric titrator DL-53 Titrator (manufactured by METTLER TOLEDO) and electrode DG113-SC (manufactured by METTLER TOLEDO), and analysis software LabX Light Version 1.00 Analyze using .000.

For calibration of the apparatus, a mixed solvent of 120 ml of toluene and 30 ml of ethanol is used.
At this time, the measurement conditions are the same as in the case of the hydroxyl value.
The acid value can be measured as described above. Specifically, the acid value is titrated with a 0.1N potassium hydroxide / alcohol solution standardized in advance, and from the titration, the formula acid value [KOHmg / g] = Titrate [ml] x N x 56.1 [mg / ml] / sample weight [g] (where N is a factor of 0.1 N potassium hydroxide / alcohol solution).

The acid value of the toner of the present invention is an important index for low-temperature fixability and high-temperature offset resistance, and is derived from the terminal carboxyl group of the unmodified polyester resin. In order to control the offset generation temperature and the like, it is preferably 0.5 to 40 KOH mg / g.
When the acid value exceeds 40 KOH mg / g, the extension reaction and / or the cross-linking reaction of the reactive modified polyester resin become insufficient, and the high temperature offset resistance may be lowered. On the other hand, if the acid value is less than 0.5 KOHmg / g, the effect of improving the dispersion stability by the base at the time of production cannot be obtained, or the elongation reaction and / or the crosslinking reaction of the reactive modified polyester resin can easily proceed. As a result, the production stability may be reduced.

<Glass transition temperature>
In the present invention, the polyester resin preferably has a glass transition point of 40 to 70 ° C. When the glass transition point is less than 40 ° C., the heat-resistant storage stability may be lowered, and when it exceeds 70 ° C., the low-temperature fixability may be lowered.
In the present invention, the glass transition point is measured using Rigaku THRMOFLEX TG8110 (manufactured by Rigaku Corporation) and 10TG-DSC system TAS-100 (manufactured by Rigaku Corporation).
Specifically, first, an aluminum sample container containing about 10 mg of sample is placed on a holder unit and set in an electric furnace. Next, after heating from room temperature to 150 ° C. at a rate of temperature increase of 10 ° C./min, let stand at 150 ° C. for 10 minutes, cool the sample to room temperature and leave it for 10 minutes, then raise the temperature to 150 ° C. again under a nitrogen atmosphere The DSC measurement is performed by heating at a rate of 10 ° C./min.
The glass transition point is calculated from the tangent line of the endothermic curve near the glass transition point and the base line using the analysis system in the TAS-100 system.

(1 component developer, 2 component developer)
When the toner of the present invention is used for a two-component developer, it may be used by mixing it with a magnetic carrier. Part is preferred. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used.
Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, and polyamide resin.
Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resins such as vinyl, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride Fluoro such as terpolymers of non-fluoride monomers including, and silicone resins, epoxy resins, and the like and.
Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.
The toner of the present invention can also be used as a one-component magnetic toner that does not use a carrier or a non-magnetic toner.

[Method for Producing Toner of the Present Invention]
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, this invention is not limited to the Example and comparative example which are illustrated here. In addition, the part in an Example represents a mass part unless there is particular description.

~ Synthesis of crystalline polyester resin ~
Into a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, 2,300 g of 1,6-alkanediol, 2530 g of fumaric acid, 291 g of trimellitic anhydride, and 4.9 g of hydroquinone were added. After making it react at 5 degreeC for 5 hours, it heated up at 200 degreeC, made it react for 1 hour, and also made it react at 8.3 kPa for 1 hour, and obtained the crystalline polyester resin 1.

-Synthesis of non-crystalline polyester (low molecular polyester) resin-
A 5-liter four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple, 229 parts of bisphenol A ethylene oxide side 2 mol adduct, 529 parts of bisphenol A propylene oxide 3 mol adduct, terephthalic acid 208 parts, 46 parts of adipic acid and 2 parts of dibutyltin oxide were added, reacted at 230 ° C. at normal pressure for 7 hours, further reacted at reduced pressure of 10-15 mmHg for 4 hours, and then 44 parts of trimellitic anhydride was added to the reaction vessel. The mixture was reacted at 180 ° C. and normal pressure for 2 hours to obtain [Amorphous Polyester 1].

~ Synthesis of polyester prepolymer ~
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].
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].

~ Synthesis of master batch (MB) ~
1200 parts of water, carbon black (printex 35 manufactured by Dexa) [DBP oil absorption = 42 ml / 100 mg, pH = 9.5] 540 parts, polyester resin 1200 parts are added, and the mixture is mixed with a Henschel mixer (manufactured by Mitsui Mining). Was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch 1].

~ Creation of oil phase ~
378 parts of [Non-crystalline polyester 1], 110 parts of Carnauba WAX, 22 parts of CCA (salicylic acid metal complex E-84: Orient Chemical Industry), and 947 parts of ethyl acetate were placed in a container equipped with a stir bar and a thermometer. The temperature was raised to 80 ° C., kept at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution 1].
[Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. Carbon black and WAX were dispersed under conditions of filling and 3 passes. Next, 1042.3 parts of a 65% ethyl acetate solution of [Amorphous Polyester 1] was added, followed by one pass with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion 1].

~ Preparation of crystalline polyester dispersion ~
100 g of [Crystalline Polyester Resin 1] and 400 g of ethyl acetate were placed in a metal 2 L container, heated and dissolved at 75 ° C., and then rapidly cooled in an ice water bath at a rate of 27 ° C./min. To this, 500 ml of glass beads (3 mmφ) was added, and pulverized for 10 hours with a batch type sand mill (manufactured by Campehapio) to obtain [Crystalline Polyester Dispersion 1].

~ 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), 138 parts of styrene, 138 parts of methacrylic acid, When 1 part of ammonium persulfate was charged 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 an aqueous 1% ammonium persulfate solution was added, and the mixture was aged at 75 ° C. for 5 hours. Dispersion 1] was obtained.

-Adjustment of aqueous phase-
990 parts of water, 83 parts of [fine particle dispersion 1], 37 parts of a 48.5% aqueous solution of dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries) and 90 parts of ethyl acetate were mixed and stirred. A liquid [aqueous phase 1] was obtained.

-Emulsification / solvent removal-
[Pigment / WAX Dispersion 1] 664 parts, [Prepolymer 1] 109.4 parts, [Crystalline Polyester Dispersion 1] 73.9 parts, [Ketimine Compound 1] 4.6 parts, After mixing for 1 minute at 5,000 rpm with a TK homomixer (manufactured by Tokushu Kika Co., Ltd.), add 1200 parts of [Aqueous Phase 1] to the container and mix with a TK homomixer at 13,000 rpm for 20 minutes [emulsification Slurry 1] was obtained.
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 4 hours to obtain [Dispersion slurry 1].

~ Washing and drying ~
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (10 minutes at 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): Add 300 parts of ion-exchanged water to the filter cake of (3), mix with a TK homomixer (10 minutes at 12,000 rpm) and then filter twice to obtain [Filter cake 1]. It was.
[Filtration cake 1] was dried at 45 ° C. for 48 hours in a circulating drier, and sieved with a mesh of 75 μm to obtain [Toner Intermediate 1].

~ Creation of silica A ~
[Silica A (1)]
In a 3 liter glass reactor equipped with a stirrer, a dropping funnel and a thermometer, 693.0 g of methanol, 46.0 g of water, and 55.3 g of 28% aqueous ammonia were added and mixed.
While this solution was adjusted to 42 ° C. and stirred, 1293.0 g (8.5 mol) of tetramethoxysilane and 464.5 g of 5.4% aqueous ammonia were simultaneously added, the former being 6 hours and the latter being 4 hours. And dripped.
Stirring was continued for 0.5 hour after the tetramethoxysilane was dropped to obtain a silica fine particle suspension.
To the obtained suspension, 547.4 g (3.39 mol) of hexamethyldisilazane was added at room temperature, heated to 120 ° C. and reacted for 3 hours to trimethylsilylate the silica fine particles.
Thereafter, the solvent was distilled off under reduced pressure to obtain 553.0 g of [silica A (1)] having an average particle diameter of 80 nm.

[Silica A (2)]
Further, silica A was prepared in the same manner except that the stirring temperature was changed to 50 ° C., and 553.0 g of [silica A (2)] having an average particle diameter of 30 nm was obtained.

[Silica A (3)]
Similarly, the stirring temperature was changed to 47 ° C. to obtain 553.0 g of [silica A (3)] having an average particle diameter of 50 nm.

~ Additive mixing ~
[Toner Intermediate 1] 100 parts of silica produced by the sol-gel method is Silica A, 1.0 part of [Additive 1], silica produced by the dry process (H1303; average primary particle size 23 nm, Clariant Japan) 1.2 parts of silica B was added, and 0.5 part of hydrophobized titanium oxide was mixed with a Henschel mixer to obtain [Toner 1].

(Evaluation item)
(Heat resistant storage stability)
The toner was stored for 2 weeks in an environment of 40 ° C. and 70%, and then sieved by hand vibration using a 75 mesh sieve, and the residual rate on the wire mesh was measured.
In addition, the heat-resistant storage stability was determined by setting the case where the residual ratio was less than 1% as ◯ and the case where it was 1% or more as x.

(Fixability)
A copying test was performed on type 6200 paper (manufactured by Ricoh) using an apparatus in which a fixing unit of a copying machine MF2200 (manufactured by Ricoh) using a Teflon (registered trademark) roller as a fixing roller was modified.
Specifically, the cold offset temperature (fixing lower limit temperature) and the hot offset temperature (fixing upper limit temperature) were determined by changing the fixing temperature.
The evaluation conditions for the minimum fixing temperature were a paper feed linear velocity of 120 to 150 mm / second, a surface pressure of 1.2 kgf / cm ² , and a nip width of 3 mm.
The evaluation conditions for the upper limit fixing temperature were a paper feed linear velocity of 50 mm / second, a surface pressure of 2.0 kgf / cm ² , and a nip width of 4.5 mm.
The lower limit fixing temperature of the conventional low-temperature fixing toner is about 140 ° C.
At this time, the fixing lower limit temperature was judged as ◎ when the temperature was less than 120 ° C, ◯ when the temperature was 120 ° C or more and less than 140 ° C, and x when the temperature was 140 ° C or more and less than 150 ° C.

(Liquidity)
The fluidity was judged by the degree of toner aggregation. The degree of toner aggregation is an index representing the adhesive force between toners. If the value is large, the adhesive force between toners is large, and the development flyability deteriorates. To measure the degree of toner aggregation, a powder tester (manufactured by Hosokawa Micron Corporation) is used, and sieves with openings of 75 μm, 45 μm and 22 μm are arranged in this order from above. The vibration was given for 30 seconds, the toner weight on each sieve was measured after the vibration, and the weights of 0.5, 0.3 and 0.1 were added to each and added, and the percentage was calculated.
When this value was 15% or less, ◎, 15 to 20% were taken as ○, and when it exceeded 20%, it was judged as ×.

(Chargeability)
In a room temperature and humidity room (temperature: 23.5 ° C, humidity: 60% RH), the humidity is adjusted for 30 minutes or more in an open system. After adding 6.000 g of initial carrier and 0.452 g of toner to a stainless steel container, the container is sealed. , YS-LD (shaking machine manufactured by Yayoi Co., Ltd.) was operated for 1 minute at a scale of 150, and a sample which was triboelectrically charged with an amplitude of about 1100 times was subjected to a general blow-off method [manufactured by Toshiba Chemical Co., Ltd. : TB-200].
When this value was 35 (−μc / g) or more, ◎, 25 to 35 were evaluated as ◯, and less than 25 (−μc / g) were determined as ×.

  The additive in the production process of [Toner 1] in Example 1 described above was the same except that the additive, silica B (UFP-35; average primary particle size 78 nm, manufactured by Denki Kagaku) was changed to 4.0 parts. I went to.

The additive in the production process of [Toner 1] of Example 1 was performed in the same manner except that Silica A (1) was changed to 0.6 part of [Silica A (3)] (50 nm).

The additive in the production process of [Toner 1] in Example 1 was performed in the same manner except that Silica A (1) was changed to 0.4 part of [Silica A (2)] (30 nm).

[Comparative Example 1]
Regarding the additive in the production process of [Toner 1] of Example 1 described above, silica A (1) 0.4 parts [silica A (2)] (30 nm), silica B UFP-35 (average primary particle size) 78 nm, manufactured by Denki Kagaku Co., Ltd.).

[Comparative Example 2]
The additive in the production process of [Toner 1] of Example 1 was performed in the same manner except that Silica A (1) was changed to 0.6 part of Sciqas (50 nm).

[Comparative Example 3]
The additive in the production process of [Toner 1] of Example 1 was performed in the same manner except that Silica A (1) was changed to 2.2 parts of X24 (average primary particle size 170 nm, manufactured by Shin-Etsu Chemical Co., Ltd.). .

[Comparative Example 4]
The additives in the production process of [Toner 1] of Example 1 described above are the same except that 3.2 parts of silica A (1) [silica A (3)] (50 nm) and silica B are not added. It was.

[Comparative Example 5]
The additives in the production process of [Toner 1] of Example 1 were performed in the same manner except that 1.5 parts of silica B and no silica A were added.

[Comparative Example 6]
The additive in the production process of [Toner 1] of Example 1 was performed in the same manner except that Silica A (1) was changed to 4.1 parts.

[Comparative Example 7]
<Oil-in-water dispersion preparation process>
An oil-in-water dispersion in which dispersed particles are dispersed was prepared as follows.
-Dissolution of toner material or preparation of dispersion-
-Synthesis of polyester resin (1)-
229 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 529 parts by mass of bisphenol A propion oxide 3-mole adduct, 208 parts by mass of terephthalic acid, 46 parts by mass of adipic acid And 2 parts by mass of dibutyltin oxide were allowed to react at 230 ° C. under normal pressure for 8 hours, and further reacted under reduced pressure of 10 to 15 mmHg for 5 hours. Then, trimellitic anhydride 44 was added to the reaction vessel. The polyester resin (1) was synthesize | combined by putting a mass part and making it react at 180 degreeC under a normal pressure for 2 hours.
The obtained polyester resin (1) had a number average molecular weight (Mn) of 3,200, a mass average molecular weight (Mw) of 6,700, a glass transition temperature (Tg) of 43 ° C., and an acid value of 25 mgKOH / g. It was.

-Synthesis of unmodified polyester (low molecular weight polyester)-
682 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 81 parts by mass of bisphenol A propion oxide 2-mole adduct, 283 parts by mass of terephthalic acid, trimellitic anhydride 22 parts by mass and 2 parts by mass of dibutyltin oxide were added and reacted at 230 ° C. for 5 hours under normal pressure to synthesize an unmodified polyester.
The resulting unmodified polyester has a number average molecular weight (Mn) of 2,100, a weight average molecular weight (Mw) of 9,500, a glass transition temperature (Tg) of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl group. The value was 51.

-Preparation of masterbatch (MB)-
1200 parts by mass of water, 540 parts by mass of carbon black (“Printex35”; manufactured by Degussa, DBP oil absorption = 42 ml / 100 g, pH = 9.5) as the colorant, and 1200 parts by mass of the polyester resin (1) And Henschel mixer (Mitsui Mining Co., Ltd.).
The mixture was kneaded for 30 minutes at 150 ° C. with two rolls, rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron) to prepare a master batch.

-Preparation of organic solvent phase-
In a reaction vessel in which a stir bar and a thermometer are set, 378 parts by mass of the polyester resin (1), 110 parts by mass of carnauba wax, 22 parts by mass of CCA (“salicylic acid metal complex E-84”; manufactured by Orient Kogyo Co., Ltd.), and 947 parts by mass of ethyl acetate was charged, the temperature was raised to 80 ° C. with stirring, the temperature was maintained at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour.
Next, 500 parts by mass of the master batch and 500 parts by mass of ethyl acetate were charged into the reaction vessel and mixed for 1 hour to obtain a raw material solution.
1324 parts by mass of the obtained raw material solution was transferred to a reaction vessel, and using a bead mill (“Ultra Visco Mill”; manufactured by Imex Co., Ltd.), the liquid feeding speed was 1 kg / hr, the disk peripheral speed was 6 m / sec, and 0.5 mm zirconia. The carbon black and the carnauba wax were dispersed in 3 passes under the condition of 80% by volume of beads.
Subsequently, 1213 parts by mass of a 65% by mass ethyl acetate solution of the unmodified polyester and 350 parts by mass of the crystalline polyester dispersion were added to the dispersion.
An organic solvent phase (pigment / wax dispersion) was prepared by passing through a bead mill under the same conditions as described above for dispersion.
The solid content concentration (measurement conditions: 130 ° C., 30 minutes) of the obtained organic solvent phase was 50% by mass.

-Synthesis of prepolymer-
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 410 parts by mass of the unmodified polyester, 89 parts by mass of isophorone diisocyanate, and 500 parts by mass of ethyl acetate were charged and reacted at 100 ° C. for 5 hours. A prepolymer (polymer capable of reacting with the active hydrogen group-containing compound) was synthesized.
The free isocyanate content of the obtained prepolymer was 1.53% by mass.

-Synthesis of ketimine (the active hydrogen group-containing compound)-
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts by mass of isophoronediamine and 75 parts by mass of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to synthesize a ketimine compound (the active hydrogen group-containing compound).
The amine value of the obtained ketimine compound (the active hydrogen machine-containing compound) was 418.
In a reaction vessel, 749 parts by mass of the organic solvent phase, 115 parts by mass of the prepolymer, 2.9 parts by mass of the ketimine compound, and a tertiary amine compound (“U-CAT 660M”; manufactured by San Apro Co., Ltd.) 3 Then, 5 parts by mass was charged, and a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) was used for 1 minute at 7.5 m / s to prepare a toner material solution or dispersion.

-Preparation of aqueous medium phase-
990 parts by weight of water, 45 parts by weight of a 48.5% by weight aqueous solution of sodium dodecyl diphenyl ether disulfonate (“Eleminol MON-7”, manufactured by Sanyo Chemical Industries), and 90 parts by weight of ethyl acetate were mixed and stirred to give a milky white liquid (Aqueous medium phase) was obtained.

-Emulsification or dispersion-
1200 parts by mass of the aqueous medium phase is added to the dissolved or dispersed liquid of the toner material, and mixed for 20 minutes at a peripheral speed of 15 m / s with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). A mold dispersion (emulsified slurry) was prepared.
The volume average particle size (Mv) of the dispersed particles in the obtained oil-in-water dispersion (emulsified slurry) was measured using a particle size distribution measuring device (“nanotrac UPA-150EX”; manufactured by Nikkiso Co., Ltd.). 0.401 μm.

<Toner granulation process>
-Controlling the particle size of dispersed particles-
Using a paddle type stirring device, the oil-in-water dispersion (emulsified slurry) was stirred at a peripheral speed of 0.7 m / s, and 120 parts by mass of a 10% by mass sodium chloride solution was added.
This was charged into a reaction vessel equipped with a stirrer and a thermometer, and 10 parts by mass of a 20% by mass aqueous solution of sodium dodecylbenzenesulfonate (Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added. The particle size of the dispersed particles therein was controlled.
It was 4.4 micrometers when the volume average particle diameter (Mv) of this dispersed particle was measured using the said particle size distribution measuring apparatus (Nanotrac UPA-150EX Nikkiso Co., Ltd. product).

-Removal of organic solvent-
The emulsified slurry after controlling the particle size was charged into a reaction vessel equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 4 hours to obtain a dispersed slurry.
When the volume average particle size and number average particle size of the obtained dispersion slurry were measured by Multisizer III (manufactured by Beckman Coulter, Inc.), the volume average particle size was 4.3 μm, and the number average particle size was 3.8 μm. It was.

-Cleaning and drying-
After 100 parts by mass of the dispersion slurry was filtered under reduced pressure, 100 parts by mass of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (10 minutes at a rotation speed of 10.0 m / s), and then filtered.
100 parts by mass of ion-exchanged water was added to the obtained filter cake, mixed with a TK homomixer (at a rotation speed of 10.0 m / s for 10 minutes), and then filtered under reduced pressure.
To the obtained filter cake, 100 parts by mass of a 10% by mass aqueous sodium hydroxide solution was added, mixed with a TK homomixer (10 minutes at a rotation speed of 10.0 m / s), and then filtered.
To the obtained filter cake, 300 parts by mass of ion-exchanged water was added, mixed with a TK homomixer (at a rotation speed of 10.0 m / s for 10 minutes), and then filtered twice to obtain a final filter cake. It was.
The obtained final filter cake was dried with a circulating dryer at 45 ° C. for 48 hours, and sieved with a mesh of 75 μm to obtain toner base particles of Comparative Example 6.

-External additive treatment-
The same external additive treatment as that of Example 1 was performed on 100 parts by mass of the obtained toner base particles of Comparative Example 7 to produce the toner of Comparative Example 7.
It has been clarified that the toner within the scope of the present invention is a toner excellent in storage stability, fixability, spent resistance, fluidity and chargeability.
Tables 1 and 2 show physical property values of the toners of Examples and Comparative Examples of the present invention.

DESCRIPTION OF SYMBOLS 10 Photoconductor 10K Black photoconductor 10Y Yellow photoconductor 10M Magenta photoconductor 10C Cyan photoconductor 14, 15, 16 Support roller 17 Intermediate transfer body cleaning device 18 Image forming means 20 Charging roller 21 Exposure device 22 Secondary transfer Device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure belt 28 Sheet reversing device 30 Exposure device 32 Contact glass 33 First traveling member 34 Second traveling member 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing Belt 42K, 42Y, 42M, 42C Developer container 43K, 43Y, 43M, 43C Developer supply roller 44K, 44Y, 44M, 44C Developer roller 45K Black developer 45Y Yellow developer 45M Magenta developer 45C Cyan Present Device 49 Registration roller 50 Intermediate transfer member 51 Roller 52 Manual feed tray 53 Manual feed path 55 Switching claw 56 Discharge roller 57 Discharge tray 58 Corona charger 59 Charger 60 Cleaning device 61 Developer 62 Transfer charger 63 Photoconductor cleaning device 64 Static eliminator 70 Static elimination lamp 80 Transfer roller 90 Cleaning device 95 Recording paper 100A, 100B, 100C Image forming device 110 Belt type fixing device 120 Tandem type developer 130 Document table 142a, 142b Paper feed roller 143 Paper bank 144 Paper feed cassette 145a, 145b Separating roller 146 Feeding path 147 Conveying roller 148 Feeding path 150 Copier main body 200 Feeding table 300 Scanner 400 Automatic document feeder L Exposure

JP 2002-108001 A JP 2009-98194 A JP 2006-267950 A

Claims (8)

A charging step for charging the surface of the image carrier; an exposure step for forming a latent image on the image carrier by exposing the surface of the image carrier; and developing a visible image by developing toner on the latent image. A developing process for forming a visible image, a transfer process for transferring the visible image to a recording medium or an intermediate transfer body, a fixing process for fixing the transfer image transferred to the recording medium, and a recording medium or an intermediate transfer body. In an image forming apparatus including a cleaning step for cleaning transfer residual toner on the image carrier that has not been completely transferred,
A toner used for image formation was obtained by dispersing an oil phase containing at least one crystalline polyester resin and an amorphous polyester resin in an organic solvent as a binder resin component in an aqueous medium. A toner obtained by removing an organic solvent from a dispersion,
The toner base particle surface has an additive containing at least two kinds of silica fine particles, and the silica used as the additive has both silica A derived from the sol-gel method and silica B derived from the dry method. And the average primary particle size of the silica A derived from the sol-gel method is in the range of 20 to 120 nm, and the average primary particle size of the silica A derived from the sol-gel method is larger than the silica B derived from the dry method, and The relationship between the coverage Ca (%) of the silica A derived from the sol-gel method represented by the formula and the coverage Cb (%) of the silica B derived from the dry method satisfies the following formula, and the silica A derived from the sol-gel method is 40 ° C. An image forming apparatus that absorbs moisture by 0.01 g or more per gram of silica when left at a relative humidity of 70% for 1 week.
Ca (%) <Cb (%) (1)
Here, coverage Ca = (silica A input part [mass wt%] / 100) * silica A projected area [cm ² / g] / ((1- (silica A input part [mass wt%] / 100) * Toner base particle surface area [cm ² / g]) * 100
Toner base particle surface area = 6 / (average toner particle size * toner specific gravity)
Silica A projected area = 3 / (2 * silica A average particle diameter * silica A specific gravity)
Coverage Cb = (silica B input part [mass wt%] / 100) * silica B projected area [cm ² / g] / ((1- (silica B input part [mass wt%] / 100) * toner base particles Surface area [cm ² / g]) * 100
Toner base particle surface area = 6 / (average toner particle size * toner specific gravity)
Silica B projected area = 3 / (2 * silica B average particle diameter * silica B specific gravity).   The image forming apparatus according to claim 1, wherein an average primary particle size of the additive is in a range of 20 to 90 nm.   The image forming apparatus according to claim 1, wherein the additive uses silica and titanium oxide.   The image forming apparatus according to claim 1, wherein the dry-type silica B has a moisture absorption amount of less than 0.01 g. A charging step for charging the surface of the image carrier; an exposure step for forming a latent image on the image carrier by exposing the surface of the image carrier; and developing a visible image by developing toner on the latent image. A developing process for forming a visible image, a transfer process for transferring the visible image to a recording medium or an intermediate transfer body, a fixing process for fixing the transfer image transferred to the recording medium, and a recording medium or an intermediate transfer body. A toner used in an image forming apparatus including a cleaning step of cleaning a transfer residual toner on the image carrier that has not been completely transferred,
The toner used for image formation was obtained by dispersing an oil phase comprising at least one crystalline polyester resin and at least one amorphous polyester resin in an organic solvent as a binder resin component in an aqueous medium. Obtained by removing the organic solvent from the dispersion,
The toner base particle surface has an additive containing at least two or more types of silica, and the silica used as the additive has both silica A derived from the sol-gel method and silica B derived from the dry method. The average primary particle size of the silica A derived from the sol-gel method is in the range of 20 to 120 nm, and the average primary particle size of the silica A derived from the sol-gel method is larger than the silica B derived from the dry method, and the sol-gel method The relationship between the coverage ratio Ca (%) of the silica A derived from the coating ratio Cb (%) of the silica B derived from the dry process satisfies the following formula, and the silica A derived from the sol-gel process is 1 at 40 ° C. and 70% relative humidity A toner that absorbs moisture by 0.01 g or more per gram of silica when left for a week.
Ca (%) <Cb (%) (1)
Here, coverage Ca = (silica A input part [mass wt%] / 100) * silica A projected area [cm ² / g] / ((1- (silica A input part [mass wt%] / 100) * Toner base particle surface area [cm ² / g]) * 100
Toner base particle surface area = 6 / (average toner particle size * toner specific gravity)
Silica A projected area = 3 / (2 * silica A average particle diameter * silica A specific gravity)
Coverage Cb = (silica B input part [mass wt%] / 100) * silica B projected area [cm ² / g] / ((1- (silica B input part [mass wt%] / 100) * toner base particles Surface area [cm ² / g]) * 100
Toner base particle surface area = 6 / (average toner particle size * toner specific gravity)
Silica B projected area = 3 / (2 * silica B average particle diameter * silica B specific gravity).   The toner according to claim 5, wherein an average primary particle diameter of the additive is in a range of 20 to 90 nm.   The toner according to claim 5 or 6, wherein the additive is one using silica and titanium oxide.   The toner according to claim 5, wherein the dry-derived silica B has a moisture absorption amount of less than 0.01 g.

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