JP2012159712A - Toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide toner that is excellent in electrophotographic performance including image quality and transfer efficiency, cost performance, and environmental performance.SOLUTION: Toner has toner particles containing at least a binder resin and a colorant. The binder resin has a first endothermic peak in the temperature range of 55-75°C, and a second endothermic peak in the temperature range of 80-120°C in a DSC curve, which is measured by a differential scanning calorimeter. The toner particle is manufactured through a surface modification step at least by hot air.

Description

  The present invention relates to a toner (developer) used in an image forming method using an electrophotographic method, an electrostatic recording method, a magnetic recording method, or the like. More specifically, the present invention relates to a toner used in an image forming apparatus such as a copying machine, a printer, or a fax machine that forms a toner image on an electrostatic latent image carrier in advance and then transfers the toner image onto a transfer material to form an image. About.

  Conventionally, many methods are known as electrophotographic methods. In general electrophotography, a photoconductive substance is used to form an electrical latent image on an image carrier by various means, and then the toner is charged on the toner carrier by the latent image. Is transferred to the latent image to make a visible image, and after transferring the toner image to a transfer material such as paper as necessary, the toner image is fixed on the transfer material by heat and pressure to obtain a final image. Are known.

In recent years, not only is it required to improve electrophotographic performance such as high speed and high image quality, but also high level of cost performance such as low cost and low running cost, and environmental performance such as low power consumption and low CO ₂ emission. It is required to line up in parallel.

  When designing the manufacturing cost of the image forming apparatus, the toner manufacturing cost, which is a consumable, and the power cost during use, etc. at a high level in total, it is manufactured by a dry manufacturing method in which a release agent is dispersed in the toner. The toner thus prepared is preferably used. The presence of a release agent in the toner eliminates the need for a member such as an oil application unit in the fixing device, and allows the image forming apparatus to be designed more compactly at a lower cost, compared with a wet manufacturing method such as polymerized toner. In many cases, the cost of manufacturing toner can be reduced, such as simplifying the incidental equipment. Furthermore, since the release agent is dispersed in the toner, it is possible to design an image forming apparatus that is excellent in low-temperature fixability and low in fixing power, and has low power consumption during use and excellent environmental performance.

  Furthermore, in response to the demand for improving electrophotographic performance, it is effective to improve the image quality and transfer efficiency by making the toner spherical. As a technique for spheroidizing the dry toner, there are a method of spheronizing with a mechanical impact force when the toner is manufactured by a pulverization method (Patent Document 1), a method of exposing the toner to a hot air stream and sphering (Patent Document 2), and the like. Are known.

  The mechanical impact method is effective for spheroidization to a certain extent, but if the sphericity is increased to a high degree, the toner surface is pulverized by impact and a large amount of ultrafine particles are generated, which adversely affects development. For example, it is difficult to make a sphere having a circularity exceeding 0.980 with a measured value of FPIA 3000 like a suspension polymerization method toner.

  The method of exposing the toner to a hot air stream can achieve a high degree of spheroidization by the amount of heat applied to the toner. However, in a toner in which wax is dispersed as a release agent in the toner, Oozes out on the surface of the toner, and may cause adverse effects such as contamination of the toner carrier, resulting in poor charging of the toner and poor transfer definition. As a release agent, there is disclosed a method (Patent Document 3) in which crystalline polyester is dispersed in a toner resin instead of wax to avoid seepage of the release agent. Since the crystalline polyester is compatible with the toner resin and the toner is rapidly cooled immediately after the thermal spheronization, the storage stability is deteriorated by the low molecular weight molecules that have lost crystallinity due to the rapid cooling.

  As described above, in order to improve electrophotographic performance, cost performance, and environmental performance at a high level, it is necessary to use a toner having a release agent in the toner in a more highly spherical form. It was difficult to achieve because there was no means to avoid the adverse effects of the oozing out.

JP 2004-333824 A JP 2003-177573 A JP 2003-270856 A

  An object of the present invention is to provide a toner that solves the problems of the prior art. That is, an object of the present invention is to provide a toner capable of aligning electrophotographic performance such as image quality and transfer efficiency, cost performance, and environmental performance at a high level.

  When the toner particles containing the wax are processed by the surface modification processing apparatus, the wax oozes out on the toner surface in a hot air stream, causing various harmful effects. If the phenomenon that the wax dispersed in the binder resin oozes out on the toner surface in a hot air stream can be suppressed, the advantages such as higher image quality and lower consumption by thermal spheroidization while maintaining cost performance and environmental performance are provided at the same time. Can be achieved.

In order to achieve the above object, the present invention is as follows.
(1) A toner having toner particles containing at least a binder resin and a colorant, the binder resin having a first temperature of 55 ° C. to 75 ° C. in a DSC curve measured by a differential scanning calorimeter. A toner having an endothermic peak, having a second endothermic peak at a temperature of 80 ° C. or higher and 120 ° C. or lower, and wherein the toner particles are produced through at least a surface modification step using hot air.
(2) The toner according to (1), wherein an endothermic amount of the second endothermic peak of the binder resin is 0.20 J / g or more and 2.00 J / g or less.

  According to the present invention, a toner that contains a binder resin having two endothermic peaks in at least a specific temperature region and is subjected to a surface modification treatment with hot air, whereby a release agent is applied to the toner particles. Even if it contains, the ooze to the surface can be suppressed. Therefore, for example, it is possible to obtain a toner in which the advantages of the dry process toner containing a releasing agent such as development performance and transferability by thermal spheroidization and cost performance and environmental performance are highly aligned without harm. it can.

It is sectional drawing showing an example of the surface modification apparatus which can be used by this invention.

  As a result of intensive studies on the phenomenon that the release agent dispersed in the toner exudes to the toner surface when subjected to a surface modification process with hot air, the present inventors have found that there are two endothermic peaks in a specific temperature range. It was found that the release of the release agent can be suppressed by using a binder resin having the above.

  The mechanism by which the release agent oozes is not clear, but in the surface modification process using hot air, the toner instantaneously melts in the air and becomes spherical due to surface tension. At this time, a release agent having a low viscosity at the time of melting and having a polarity different from that of the binder resin flows out to the toner surface and is cooled and solidified. The toner whose surface is rich in the release agent causes a phenomenon such as contamination of a member such as a toner carrying member and deterioration of charging and transfer performance, and is not preferable for improving the image quality.

  The melting of the toner in the surface modification process is very instantaneous and is immediately cooled. If the release agent can be kept in its original position by some action for a short time in the molten state, it was considered that the release agent can be kept dispersed in the toner.

  A mixture of a release agent whose viscosity becomes extremely low when melted and an amorphous binder resin having a higher viscosity than the release agent is, for example, in a state of water and oil, and when toner particles melt, The release agent compared to can move freely in the oil. So, if you change the part of the oil molecule to make a water-like part that cannot move freely, and keep that part in contact with the mold release agent, the mold release agent can't stay on the spot. As a result, the present invention has been completed.

  The binder resin in the present invention has a first endothermic peak at a temperature of 55 ° C. to 75 ° C., and further has a second endothermic peak at a temperature of 80 ° C. to 120 ° C. .

  As will be described in detail later, these endothermic peaks are peaks appearing in the DSC curve at the time of temperature rise in DSC measurement with a differential scanning calorimeter. It is a peak that appears when the resin softens as the temperature rises, but this is thought to be expressed by melting and releasing the energy confined when the resin cools and hardens, that is, it cools and hardens It is thought that it shows the behavior of time.

  When a general binder resin for toner is cooled and solidified from a molten state, it undergoes a phase transition to a glass state through a supercooled liquid state, and solidifies while maintaining excessive energy. Next, when the temperature rises, a phenomenon of relaxing excessive energy (hereinafter referred to as enthalpy relaxation) occurs when the temperature reaches the temperature at which the molecule starts to move, and appears as an endothermic peak in DSC measurement. This is the first endothermic peak in the present invention. When the first endothermic peak temperature P1 is lower than 55 ° C., it indicates that the binder resin starts to move at a temperature close to room temperature. In such a case, the storage stability of the toner is deteriorated. On the other hand, when the endothermic peak temperature P1 is higher than 75 ° C., it indicates that the binder resin starts to move slowly in the toner. In such a case, the low-temperature fixability deteriorates.

  The second endothermic peak in the present invention represents the presence of a crystalline state obtained by orienting part of the molecular chain of the binder resin. Therefore, it shows that the crystal part of the binder resin in the toner is melted by this peak temperature. When the endothermic peak temperature P2 is lower than 80 ° C., the melting speed of the whole toner increases, so that the low-temperature fixability is improved, but the melting state near the surface of the toner layer changes greatly immediately after the toner layer enters the fixing device. Therefore, the offset property at a low temperature deteriorates. On the other hand, when the endothermic peak temperature P2 is higher than 120 ° C., the low-temperature fixability deteriorates.

  When a crystalline polyester resin and an amorphous polyester resin are mixed and used as the toner material, or when a polyester resin whose crystallinity is simply controlled is used, the resin is not melted and mixed in the kneading process. Since the crystal part and the amorphous part are compatible with each other and the crystal structure disappears, it is difficult to maintain the crystal structure in the toner resin that has undergone the cooling process. For example, in the DSC measurement of the raw material resin, the second endothermic peak that appears at the first temperature rise may not appear when the temperature is lowered once and the temperature rises for the second time. Even if the raw material resin is used, it is suggested that the toner that has undergone the kneading process at the time of production does not necessarily contain a crystal part.

  As will be described in detail later, in the present invention, the kneading step is performed by using a binder resin that has a crystal structure by orienting a part of the molecule of the raw material resin instead of mixing the crystalline resin with the raw material resin. The crystal structure can be maintained even after cooling through. Therefore, the second endothermic peak can be obtained even at the second temperature increase after the temperature is decreased once in the DSC measurement.

  The mechanism by which the binder resin in the present invention suppresses the release agent exudation by the surface reformer is not clear, but is considered as follows.

  By using the resin of the present invention, at the time of toner production, when the resin, the release agent, and other internal additives are cooled and solidified from the melted and mixed state in the kneading step, first, the crystal structure and release of the binder resin The higher melting point of the agent solidifies, and the other solidifies. Whichever comes first, it acts as the other nucleating agent, and each domain does not exist independently, but forms a domain in the state where the binder resin crystal structure and the release agent are in contact with each other. The structure is dispersed in the binder resin. When it is further cooled, the amorphous part of the resin is vitrified and the entire toner is fixed.

  To explain with the above-mentioned illustration of water and oil, since the crystal structure of the resin of the present invention is a crystal structure obtained by orienting a part of the molecule of the raw material resin, a water-like portion is present in the oil molecule. It becomes a structure that is incorporated. Even if the crystal part melts like water when it is melted in the surface reformer, only the crystal part moves freely because it is a polymer in which the crystal part and the amorphous part are connected in the molecule. I can't do it. By forming a domain in a state where the crystal part and the release agent are in contact with each other, even when melted, some bonding force acts on the crystal part and the release agent, so the toner is instantaneously melted in a hot air stream. Even so, it is presumed that the release agent is cooled without moving to the toner surface, and the release agent can be kept dispersed in the toner.

  In addition, when a polyester resin is used as the toner binder resin, it generally has a sharp melt characteristic, and particularly when a crystalline polyester resin is used, the viscosity at the time of heat melting is too low and the offset at the time of fixing is a problem. There is a case. The toner of the present invention has a structure in which the crystal part of the polyester resin and the release agent are in contact with each other. Therefore, the release agent exists in contact with the polyester crystal part at the time of heat fixing, and the offset is reduced. It is presumed that the effect of preventing is also exhibited.

  Furthermore, in the present invention, the endothermic amount of the second endothermic peak of the binder resin is preferably 0.20 J / g or more and 2.00 J / g or less.

  The endothermic amount of the second endothermic peak of the binder resin being less than 0.20 J / g means that the number or amount of crystal domains in the binder resin is too small, and the effect of the present invention is obtained. Hateful. Further, when the endothermic amount exceeds 2.00 J / g, it means that the crystal part is excessive, fixing offset is deteriorated, and productivity may be deteriorated in a pulverizing process or the like.

  The endothermic peak and endothermic amount of the DSC curve of the binder resin in the present invention are measured by the following method. The peak temperature of the endothermic peak of the binder resin is measured according to ASTM D3418-82 using a differential scanning calorimeter “Q1000” (manufactured by TA Instruments). The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium.

  Specifically, about 5 mg of binder resin is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference, and the temperature is raised between 30 ° C. and 200 ° C. The measurement is performed at a temperature or a temperature decrease rate of 10 ° C./min. In the measurement, the temperature is once raised to 200 ° C., subsequently lowered to 30 ° C., and then the temperature is raised again. The specific heat change is obtained in the second temperature raising process. At this time, the intersection of the baseline midpoint line and the differential heat curve before and after the change in specific heat occurs is defined as the glass transition temperature Tg of the binder resin. The endothermic peak obtained immediately after the glass transition temperature Tg in the temperature range of 30 ° C. to 200 ° C. in the second temperature raising process is the endothermic peak P1, and the endothermic peak obtained by further raising the temperature is the endothermic peak P2. . On the other hand, the endothermic amount ΔH of these endothermic peaks can be obtained by obtaining the integrated value of the endothermic peaks.

  As the binder resin used in the present invention, a polyester resin is preferable in that a part of the molecule is oriented to give crystallinity, and among them, a linear polyester is particularly preferable.

  Compared with the case where the binder resin is an acrylic resin having good compatibility with the wax, the polyester resin having poor compatibility tends to cause the wax to ooze out. However, there is a recent demand for low power consumption. In view of the above, it is preferable to use a polyester resin that can be designed with a low fixing power.

  The components of the linear polyester resin particularly preferably used in the present invention are as follows.

  Examples of the divalent acid component include the following dicarboxylic acids or derivatives thereof. Benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride or their anhydrides or lower alkyl esters thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid or their anhydrides or lower thereof Alkyl esters; alkenyl succinic acids or alkyl succinic acids such as n-dodecenyl succinic acid, n-dodecyl succinic acid, or anhydrides thereof or lower alkyl esters thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, itaconic acid Or its anhydride or its lower alkyl ester.

  The present invention is characterized by providing crystallinity by orienting a part of the polymer chain of the binder resin. Therefore, an aromatic dicarboxylic acid that has a solid planar structure and is abundant in electrons delocalized by the π-electron system, and is easily molecularly oriented by π-π interaction, is preferable. Particularly preferred are terephthalic acid and isophthalic acid which can easily form a straight chain structure. The content of the aromatic dicarboxylic acid is preferably 50 mol parts or more in 100 mol parts of the acid component constituting the polyester resin in terms of controlling the temperature of the endothermic peak.

  The following are mentioned as a bivalent alcohol component. Ethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 1,4-cyclohexanedimethanol (CHDM) Hydrogenated bisphenol A, bisphenol represented by formula (1) and derivatives thereof:

（式中、Ｒはエチレンまたはプロピレン基であり、ｘ、ｙはそれぞれ０以上の整数であり、かつ、ｘ＋ｙの平均値は０乃至１０である。）
および式（２）で示されるジオール類。

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 0 to 10.)
And diols represented by formula (2).

  Among these, aliphatic alcohols having 2 to 6 carbon atoms, which can easily form a straight chain structure, are preferable from the viewpoint of aligning a part of the molecule and imparting crystallinity. However, by itself, the crystallinity increases and the amorphous nature is lost. Therefore, it is necessary to break the crystal structure of the polyester resin obtained by the combination of the acid and the alcohol so that the endothermic peak P1 due to enthalpy relaxation and the endothermic peak P2 due to molecular orientation are compatible in the same molecule. For this purpose, neopentyl glycol, 2-methyl-1,3-propanediol, 2-ethyl-1,3 having a substituent in the side chain that has a linear structure and is capable of sterically breaking crystallinity. -Use of hexanediol or the like is particularly preferable.

  The polyester resin used in the present invention includes a monovalent carboxylic acid compound, a monovalent alcohol compound, a trivalent or higher carboxylic acid compound, a trivalent, in addition to the above-described divalent carboxylic acid compound and divalent alcohol compound. You may contain the above alcohol compound as a structural component.

  Examples of the monovalent carboxylic acid compound include aromatic carboxylic acids having 30 or less carbon atoms such as benzoic acid and p-methylbenzoic acid, and aliphatic carboxylic acids having 30 or less carbon atoms such as stearic acid and behenic acid. .

  Examples of monovalent alcohol compounds include aromatic alcohols having 30 or less carbon atoms such as benzyl alcohol, and aliphatic alcohols having 30 or less carbon atoms such as lauryl alcohol, cetyl alcohol, stearyl alcohol, and behenyl alcohol. It is done.

  Although it does not restrict | limit especially as a trivalent or more carboxylic acid compound, A trimellitic acid, trimellitic anhydride, pyromellitic acid, etc. are mentioned.

  Examples of the trivalent or higher alcohol compound include trimethylolpropane, pentaerythritol, and glycerin.

  About the manufacturing method of the polyester resin of this invention, it does not restrict | limit in particular, A well-known method can be used. For example, the aforementioned carboxylic acid compound and alcohol compound are charged together and polymerized through an esterification reaction or a transesterification reaction, and a condensation reaction to produce a polyester resin. In the polymerization of the polyester resin, for example, a polymerization catalyst such as titanium tetrabutoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, germanium dioxide or the like can be used. The polymerization temperature is not particularly limited, but is preferably in the range of 180 ° C to 290 ° C.

  Further, the binder resin has at least one peak Mp in a molecular weight region of 5000 to 10,000 in a molecular weight distribution measured by gel permeation chromatography (GPC) of a THF-soluble component, and an area having a molecular weight of 3000 or less. Is preferably 20% by mass or less based on the entire area, and the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is preferably 1 or more and 30 or less. When the peak Mp is less than 5000, the anti-blocking property tends to deteriorate, and when the molecular weight exceeds 10,000, the fixability tends to deteriorate. Further, when the area having a molecular weight of 3000 or less is larger than 20% with respect to the entire area, since the amount of change in the molecule becomes large at a low temperature, the storage stability tends to deteriorate. Further, when the molecular weight distribution is very sharp such that Mw / Mn is less than 1, high temperature offset tends to deteriorate, and when Mw / Mn is greater than 30, low temperature fixability tends to deteriorate.

  The glass transition temperature of the binder resin is 45 ° C. or more and 60 ° C. or less, more preferably 45 ° C. or more and 58 ° C. or less from the viewpoint of fixability and storage stability.

  The acid value of the binder resin is preferably 5 mgKOH / g or more and 50 mgKOH / g or less. When the acid value is less than 5 mgKOH / g, the interaction with other raw materials (especially charge control agents such as organometallic complexes) tends to be reduced, and it may be difficult to maintain the crystalline state after toner formation. is there. When the acid value is larger than 50 mgKOH / g, the fixability may be deteriorated because the interaction between the other raw materials or the binder resin increases. Thus, in the present invention, it is important to control the acid value of the binder resin. It is necessary to adjust the acid value without affecting the structure of the binder resin in order to maintain the crystalline state even after tonerization by interaction with the toner raw material. As a preferable method, after the polymerization reaction is completed, And post-addition of trimellitic anhydride and the like.

  The toner of the present invention may be a magnetic toner or a non-magnetic toner. When used as a magnetic toner, it is preferable to use magnetic iron oxide. As the magnetic iron oxide, iron oxides such as magnetite, maghemite, and ferrite are used. For the purpose of improving the fine dispersibility in the toner particles, the magnetic iron oxide is preferably subjected to a treatment for shearing the slurry during production and temporarily loosening the magnetic iron oxide.

  In the present invention, the amount of magnetic iron oxide contained in the toner is preferably 25% by mass or more and 50% by mass or less, and more preferably 30% by mass or more and 50% by mass in the toner.

These magnetic materials have a magnetic property of 795.8 kA / m applied at a coercive force of 1.6 kA / m to 12.0 kA / m and a saturation magnetization of 50.0 Am ² / kg to 200.0 Am ² / kg (preferably Is 50.0 Am ² / kg or more and 100.0 Am ² / kg or less). Further, the residual magnetization is preferably 2.0 Am ² / kg or more and 20.0 Am ² / kg or less.

  The magnetic properties of magnetic iron oxide can be measured using a vibration type magnetometer, for example, VSM P-1-10 (manufactured by Toei Kogyo Co., Ltd.).

  When used as a non-magnetic toner, carbon black and other conventionally known pigments and dyes, or one or more of them can be used as the colorant. The colorant is preferably 0.1 parts by mass or more and 60.0 parts by mass or less, and more preferably 0.5 parts by mass or more and 50.0 parts by mass or less with respect to 100.0 parts by mass of the resin component.

  In the present invention, a release agent may be used in order to impart releasability to the toner. Addition of a release agent is not always necessary in the case of an image forming apparatus that does not cause a problem without adding a release agent, or as long as the release property can be secured by other means. This is to prevent the release agent from exuding by the surface modifying device even if the toner is added with the release agent.

  As the release agent, hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, and paraffin wax are preferable from the viewpoint of ease of dispersion in the toner and high releasability. If necessary, two or more kinds of waxes may be used in combination.

  The following are mentioned as an example of the mold release agent used for this invention. Oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax, or block copolymers thereof; waxes based on fatty acid esters such as carnauba wax, sazol wax, and montanate wax; and deoxidation Deoxidized part or all of fatty acid esters such as carnauba wax. In addition, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, and seryl alcohol Saturated alcohols such as melyl alcohol; long-chain alkyl alcohols; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; methylene bisstearic acid amide, ethylene biscaprin Saturated fatty acid bisamides such as acid amide, ethylene bislauric acid amide, hexamethylene bis stearic acid amide; ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, N, N′-dioleyl Unsaturated fatty acid amides such as dipinamide, N, N-dioleyl sebacic acid amide; aromatic bisamides such as m-xylenebisstearic acid amide, N, N-distearylisophthalic acid amide; calcium stearate, laur Fatty acid metal salts such as calcium phosphate, zinc stearate, magnesium stearate (generally referred to as metal soap); waxes grafted to aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid A partially esterified product of a fatty acid such as behenic acid monoglyceride and a polyhydric alcohol; a methyl ester compound having a hydroxyl group obtained by hydrogenation of a vegetable oil.

  Examples of the release agent particularly preferably used in the present invention include aliphatic hydrocarbon waxes. Examples of such aliphatic hydrocarbon waxes include the following. Low molecular weight alkylene polymer obtained by radical polymerization of alkylene under high pressure or Ziegler catalyst under low pressure; alkylene polymer obtained by thermal decomposition of high molecular weight alkylene polymer; synthesis gas containing carbon monoxide and hydrogen Synthetic hydrocarbon waxes obtained from the distillation residue of hydrocarbons obtained from the aging method from the above, and synthetic hydrocarbon waxes obtained by hydrogenating them; press sweating method, solvent method, vacuum distillation of these aliphatic hydrocarbon waxes Sorted according to the use of and the fractional crystallization method.

  Examples of the hydrocarbon as the matrix of the aliphatic hydrocarbon wax include the following. Carbonization synthesized by the reaction of carbon monoxide and hydrogen using a metal oxide-based catalyst (mostly two or more multi-component systems) (for example, the Gintor method, Hydrocol method (using a fluidized catalyst bed)) Hydrogen compounds); hydrocarbons having up to about several hundred carbon atoms obtained by the age method (using an identified catalyst bed) in which a large amount of waxy hydrocarbons can be obtained; hydrocarbons obtained by polymerizing alkylene such as ethylene with a Ziegler catalyst. Among such hydrocarbons, in the present invention, it is preferable that the hydrocarbon is a linear hydrocarbon having a small number of branches and a small length and a long saturation. In particular, hydrocarbons synthesized by a method not based on polymerization of alkylene are also preferred from the molecular weight distribution.

  The timing of adding the release agent may be added at the time of melt-kneading during toner production or may be at the time of binder resin production, and is appropriately selected from existing methods.

  The release agent is preferably added in an amount of 1 part by weight to 20 parts by weight with respect to 100 parts by weight of the binder resin. When the amount is less than 1 part by mass, it is difficult to obtain a desired release effect. When the amount exceeds 20 parts by mass, dispersion in the toner particles is poor, and toner adhesion to the photoreceptor and surface contamination of the developing member / cleaning member are likely to occur, and the toner image tends to deteriorate.

  In the toner of the present invention, it is preferable to use a charge control agent in order to stabilize the charging property. Although the charge control agent varies depending on the type and physical properties of other toner particle constituent materials, it is generally preferable that the toner particles are contained in an amount of 0.1 to 10 parts by mass per 100 parts by mass of the binder resin. More preferably, it is contained in an amount of 0.1 to 5 parts by mass. As such a charge control agent, an organic metal complex or a chelate compound in which an acid group or a hydroxyl group present at the terminal of the binder resin of the present invention and a central metal easily interact is effective. Examples thereof include monoazo metal complexes; acetylacetone metal complexes; metal complexes or metal salts of aromatic hydroxycarboxylic acids or aromatic dicarboxylic acids.

  Specific examples that can be used include Spiron Black TRH, T-77, T-95 (Hodogaya Chemical Co., Ltd.), BONTRON (registered trademark) S-34, S-44, S-54, E-84, E- 88, E-89 (Orient Chemical). Moreover, charge control resin can also be used together with the above-described charge control agent.

In the toner of the present invention, the fluidity imparting ability to the toner particle surface as an inorganic fine powder is high, and the BET specific surface area with a smaller number average particle size of primary particles is 50 m ² / g or more and 300 m ² / g or less. It is preferable to use a property improver. Any fluidity improver can be used as long as the fluidity can be improved by externally adding the toner particles before and after the addition. For example, the following are mentioned. Fluorine resin powders such as vinylidene fluoride fine powder and polytetrafluoroethylene fine powder; wet-process silica, fine-powder silica such as dry-process silica, these silicas by silane coupling agent, titanium coupling agent, or silicone oil Treated silica with surface treatment. A preferred fluidity improver is a fine powder produced by vapor phase oxidation of a silicon halogen compound, and is referred to as dry process silica or fumed silica. For example, it utilizes the thermal decomposition oxidation reaction of silicon tetrachloride gas in oxygen and hydrogen, and the reaction formula is as follows.
SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl

  Further, in this production process, a composite fine powder of silica and another metal oxide obtained by using another metal halogen compound such as aluminum chloride or titanium chloride together with a silicon halogen compound may be used. The average primary particle diameter is preferably in the range of 0.001 μm to 2 μm, and particularly preferably silica fine powder in the range of 0.002 μm to 0.2 μm is used. good.

  Furthermore, it is preferable to use a treated silica fine powder obtained by hydrophobizing a silica fine powder produced by vapor phase oxidation of the silicon halogen compound. Among the treated silica fine powders, those obtained by treating the silica fine powder so that the degree of hydrophobicity titrated by a methanol titration test is in the range of 30 to 80 are particularly preferable.

  As a hydrophobizing method, it is applied by chemically treating with an organosilicon compound that reacts or physically adsorbs with silica fine powder. As a preferred method, silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with an organosilicon compound. Examples of such organosilicon compounds include the following. Hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α- Chlorethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilyl mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, 1 -Hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyl Ludisiloxane and dimethylpolysiloxane containing 2 to 12 siloxane units per molecule and containing hydroxyl groups bonded to one Si at each terminal unit. These may be used alone or as a mixture of two or more.

  The inorganic fine powder may be treated with silicone oil, or may be treated in combination with the hydrophobic treatment.

As a preferable silicone oil, one having a viscosity at 25 ° C. of 30 mm ² / s or more and 1000 mm ² / s or less is used. For example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, and fluorine modified silicone oil are particularly preferred.

  Examples of the method for treating silicone oil include the following methods. A method in which silica fine powder treated with a silane coupling agent and silicone oil are directly mixed using a mixer such as a Henschel mixer; a method in which silicone oil is sprayed on a silica fine powder as a base; or silicone in an appropriate solvent A method in which after dissolving or dispersing oil, silica fine powder is added and mixed to remove the solvent. More preferably, the silicone oil-treated silica is heated to 200 ° C. or higher (more preferably 250 ° C. or higher) in an inert gas to stabilize the surface coating after the silicone oil treatment. A preferred silane coupling agent is hexamethyldisilazane (HMDS).

  In the present invention, the silica is preferably treated by a method in which silica is previously treated with a coupling agent and then treated with silicone oil, or a method in which silica is treated with a coupling agent and silicone oil at the same time.

  The inorganic fine powder is used in an amount of 0.01 to 8 parts by weight, preferably 0.1 to 4 parts by weight, based on 100 parts by weight of the toner particles.

  Other external additives may be added to the toner of the present invention as necessary. Examples thereof include resin fine particles and inorganic fine particles that function as charging aids, conductivity imparting agents, fluidity imparting agents, anti-caking agents, mold release agents at the time of heat roller fixing, lubricants, and abrasives.

  Examples of the lubricant include polyfluorinated ethylene powder, zinc stearate powder, and polyvinylidene fluoride powder. Of these, polyvinylidene fluoride powder is preferred. Examples of the abrasive include cerium oxide powder, silicon carbide powder, and strontium titanate powder. These external additives can be sufficiently mixed using a mixer such as a Henschel mixer to obtain the toner of the present invention.

  In order to produce the toner of the present invention, binder resin, colorant, other additives, etc. are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill and then heat kneaded such as a heating roll, a kneader or an extruder. Melt and knead using a machine, cool and solidify after grinding and classification as necessary, after grinding or classification, perform surface modification treatment with hot air, and if necessary, add desired additives to a mixer such as a Henschel mixer The toner of the present invention can be obtained by sufficiently mixing.

  As the kneader used in the melt-kneading step, a biaxial kneader is preferably used for the reason that continuous production is possible. In the present invention, it is preferable that the ratio Ln / L of the kneading portion occupying the distance L from the raw material inlet to the paddle downstream end is 0.40 or more and 0.70 or less (where L is from the raw material inlet). Distance to paddle downstream end, Ln indicates length of all kneading parts). By configuring the kneading part to occupy the most part of the extruder, it becomes possible to continue to share as much as possible to the kneaded product. As a result, it becomes possible to control the compatibility of the binder resin in which a portion existing in the toner has crystallinity.

  The surface modification apparatus in the present invention performs surface modification of toner with hot air. Toner that has a smooth surface by spraying high-temperature hot air on the toner particles dispersed in the airflow to instantly melt the toner, making the toner surface uneven and spherical by surface tension, and then cooling instantaneously Particles can be obtained. For example, toner particles having a smooth surface and a spherical shape are preferably used as a toner that has uniform charging characteristics, improved development characteristics and transfer characteristics, and can obtain high image quality.

  FIG. 1 is a sectional view showing an example of a surface modification apparatus used in the present invention. The toner particles or toner accelerated by the airflow A from the powder / airflow A supply zone (100) is directed to the airflow C ejecting unit (102) below. The airflow C is ejected from the airflow C injection section (102) to the airflow A, and the particles riding on the airflow A are repelled upward and outward by the airflow C. A cooling jacket (106) is provided on the outer periphery of the powder / airflow A supply zone (100). At this time, an air flow F supply zone (111) for the purpose of preventing condensation may be provided between (100) and (106). A cooling jacket (106) is also provided on the outer surface of the surface reformer and the outer periphery of the transfer pipe for the purpose of preventing toner fusion.

  The surface of the particles repelled by the airflow C is subjected to heat melting treatment by the airflow B having a temperature of 160 ° C. to 450 ° C. supplied from the air flow B supply zone (101). At this time, when the temperature is lower than 160 ° C., there may be a variation in processing in the powder particles, which is not preferable. Moreover, when it exceeds 450 degreeC, coalescence of particle | grains will advance because a molten state advances too much, and the coarsening and fusion | melting of a powder particle may arise, and it is unpreferable. The particles treated by the airflow B are cooled by the airflow D supplied from the airflow D supply zone (103) provided on the upper outer periphery of the surface treatment apparatus. At this time, the airflow E may be introduced from the airflow E supply zone (104) provided on the side surface of the main body of the surface reforming device for the purpose of controlling the temperature in the apparatus and controlling the surface treatment state. A slit shape, a louver shape, a perforated plate shape, a mesh shape, or the like can be used for the airflow E outlet, and the introduction direction can be selected horizontally according to the purpose and the direction along the apparatus wall surface according to the purpose.

  When the toner particles or toner is spheroidized by the surface modifying apparatus in the present invention, the flow rate and temperature of the air currents A, B, C, D, and E are controlled according to the desired sphericity. Specifically, for example, when it is desired to reduce the degree of circularity relatively, for example, by increasing the airflow A, lowering the temperature of the airflow B, lowering the temperature of the airflow C · D, or increasing the flow rate. Can be adjusted. Conversely, when it is desired to obtain a high degree of circularity, it can be adjusted by, for example, reducing the airflow A, increasing the temperature of the airflow B, increasing the temperature of the airflows C and D, or decreasing the flow rate.

Prior to the surface modification step with hot air, the toner particles and the inorganic fine powder may be mixed with a mixer such as a Henschel mixer. For example, by mixing a fluidity-imparting agent, toner dispersion in the surface modification device is improved, and the generation of coalesced particles in the surface modification process can be suppressed and the circularity distribution can be sharply controlled. It is preferable. Examples of the fluidity imparting agent to be mixed before the surface modification step include silica fine powder having a specific surface area of 100 m ² / g to 400 m ² / g, or silica having a specific surface area of 10 m ² / g to 100 m ² / g. A fine powder can be preferably used. Two or more kinds of inorganic fine powders and the like may be added simultaneously. When the surface modified fine powder obtained by mixing before the surface modification step sufficiently satisfies the performance as a toner, the external additive mixing step after the surface modification step can be omitted.

  A method for measuring physical properties of the toner of the present invention is as follows. Examples described later are also based on this method.

<Measurement method of weight average particle diameter (D4)>
The weight average particle diameter (D4) of the toner is calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) equipped with a 100 μm aperture tube by a pore electrical resistance method was used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) was used. The measurement was performed with 25,000 effective measurement channels.

  As the electrolytic aqueous solution used for the measurement, a special grade sodium chloride dissolved in ion exchange water to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50,000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.

  In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic solution is put in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.
(3) An ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikkaki Bios Co., Ltd.) having an electrical output of 120 W is prepared by incorporating two oscillators having an oscillation frequency of 50 kHz with the phases shifted by 180 degrees. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of electrolyte aqueous solution in a beaker may become the maximum.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker (1) installed in the sample stand, the electrolyte aqueous solution (5) in which the toner is dispersed is dropped using a pipette, and the measured concentration is adjusted to about 5%. To do. The measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) is calculated. The “average diameter” on the “analysis / volume statistics (arithmetic average)” screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

<Measuring method of average circularity>
The average circularity of the toner particles was measured with a flow type particle image analyzer “FPIA-3000” (manufactured by Sysmex Corporation) under the measurement and analysis conditions during the calibration operation.

  A specific measurement method is as follows. First, about 20 ml of ion-exchanged water from which impure solids are removed in advance is put in a glass container. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.2 ml of a diluted solution obtained by diluting the solution with ion exchange water about 3 times by mass. Further, about 0.02 g of a measurement sample is added, and a dispersion treatment is performed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of a dispersion liquid may become 10 to 40 degreeC. As the ultrasonic disperser, a desktop ultrasonic cleaner disperser (for example, “VS-150” (manufactured by VervoCrea)) having an oscillation frequency of 50 kHz and an electric output of 150 W is used. Ion exchange water is added, and about 2 ml of the above-mentioned Contaminone N is added to this water tank.

  For the measurement, the above-mentioned flow type particle image analyzer equipped with “LUCPLFLN” (magnification 20 ×, numerical aperture 0.40) as an objective lens is used, and particle sheath “PSE-900A” (manufactured by Sysmex Corporation) is used as the sheath liquid. It was used. The dispersion prepared in accordance with the above procedure is introduced into the flow type particle image analyzer, and 2000 toner particles are measured in the HPF measurement mode and in the total count mode. Then, the binarization threshold at the time of particle analysis was set to 85%, the analysis particle diameter was limited to a circle equivalent diameter of 1.977 μm or more and less than 39.54 μm, and the average circularity of the toner particles was determined.

  In the measurement, automatic focus adjustment is performed using standard latex particles (for example, “RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5100A” manufactured by Duke Scientific) diluted with ion-exchanged water before starting the measurement. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement.

  In the examples of the present application, a flow-type particle image analyzer that has been issued a calibration certificate issued by Sysmex Corporation, which has been calibrated by Sysmex Corporation, was used. The measurement was performed under the measurement and analysis conditions when the calibration certificate was received, except that the analysis particle diameter was limited to a circle equivalent diameter of 1.977 μm or more and less than 39.54 μm.

  The measurement principle of the flow-type particle image analyzer “FPIA-3000” (manufactured by Sysmex Corporation) is to capture flowing particles as a still image and perform image analysis. The sample added to the sample chamber is fed into the flat sheath flow cell by a sample suction syringe. The sample fed into the flat sheath flow is sandwiched between sheath liquids to form a flat flow. The sample passing through the flat sheath flow cell is irradiated with stroboscopic light with a nucleus for 1/60 second, and the flowing particles can be photographed as a still image. Further, since the flow is flat, the image is taken in a focused state. The particle image is captured by a CCD camera, and the captured image is subjected to image processing at an image processing resolution of 512 × 512 (0.19 μm × 0.19 μm per pixel), and the contour of each particle image is extracted, The projected area S, the peripheral length L, and the like are measured.

Next, the equivalent circle diameter and the circularity are obtained using the area S and the peripheral length L. The equivalent circle diameter is the diameter of a circle having the same area as the projected area of the particle image, and the circularity C is a value obtained by dividing the circumference of the circle obtained from the equivalent circle diameter by the circumference of the projected particle image. And is calculated by the following formula.
Circularity C = 2 × (π × S) ^1/2 / L

  When the particle image is circular, the degree of circularity is 1, and the degree of unevenness on the outer periphery of the particle image increases, and the degree of circularity decreases. After calculating the circularity of each particle, the arithmetic average value of the obtained circularity is calculated, and the value is defined as the average circularity.

<Measurement of magnetic properties of magnetic iron oxide particles>
Using a vibrating sample magnetometer VSM-P7 manufactured by Toei Industry Co., Ltd., measurement was performed at a sample temperature of 25 ° C. and an external magnetic field of 795.8 kA / m.

<Measurement of average primary particle diameter of magnetic iron oxide particles>
The average primary particle diameter is obtained by observing magnetic iron oxide particles with a scanning electron microscope (magnification 40000 times), measuring the ferret diameter of 200 particles, and determining the number average particle diameter. In this example, S-4700 (manufactured by Hitachi, Ltd.) was used as the scanning electron microscope.

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

<Binder Resin Production Example 1>
-100 mol part of terephthalic acid-60 mol part of ethylene glycol-40 mol part of neopentyl glycol The above-mentioned polyester monomer is charged into a 5-liter autoclave together with an esterification catalyst (dibutyltin oxide). A reflux condenser, a water separator, an N ₂ gas introduction pipe, a thermometer, and a stirring device were attached thereto, and a polycondensation reaction was performed at 230 ° C. while introducing N ₂ gas into the autoclave. The progress of the reaction was monitored by the viscosity, and when the reaction approached late, trimellitic anhydride: 5 mol parts was added to adjust the acid value. Thus, the acid value can be adjusted without affecting the basic structure of the polyester by adding it in the late stage of the reaction. After completion of the reaction, the reaction product was taken out from the container, cooled and pulverized to obtain a binder resin B1. Each physical property of the obtained binder resin was measured and shown in Table 1.

<Binder Resin Production Examples 2 to 13>
Binder resins B2 to B13 were obtained in the same manner as in Binder resin production example 1 except that the monomers used as raw materials were changed as shown in Table 1. At this time, the monomers described as post-addition in Table 1 are added in the latter stage of the polycondensation reaction in the same manner as in Production Example 1 of the binder resin in order to adjust the acid value or the hydroxyl value. Further, the molecular weight at the end of the reaction was adjusted while monitoring the progress of the reaction by viscosity. Each physical property of the obtained binder resin was measured and shown in Table 1. Among these, the binder resins B9 and B12 were resins having only one endothermic peak of DSC measurement, and the binder resins B11 and 13 were resins having no endothermic peak of DSC measurement.

<Binder Resin Production Example 14>
Binder resin B11 (70 mol parts) (mol parts are calculated using the peak molecular weight as a representative molecular weight), a mixture of 1,3-propanediol (15 mol parts) and terephthalic acid (15 mol parts), and esterification condensation Charge to a 5 liter autoclave with catalyst (dibutyltin oxide). A reflux condenser, a water separator, an N ₂ gas introduction pipe, a thermometer, and a stirring device were attached thereto, and a polycondensation reaction was performed at 230 ° C. while introducing N ₂ gas into the autoclave. After completion of the reaction, it was taken out from the container, cooled and pulverized to obtain a binder resin B14. Each physical property of the obtained binder resin was measured and shown in Table 1. The binder resin B14 was a resin having only one endothermic peak in DSC measurement.

<Toner Production Example 1>
・ Binder resin B1 100 parts by mass. Release agent (paraffin wax, Tm: 75 ° C.) 4 parts by mass. Charge control agent (azo-based iron complex compound) 2 parts by mass. Magnetic iron oxide 90 parts by mass (octahedral shape) (Magnetite, average particle size 0.19 μm, coercive force 11.2 KA / m, remanent magnetization 14.8 Am ² / kg, saturation magnetization 81.3 Am ² / kg)
The above materials were sufficiently premixed with a Henschel mixer and then melt-kneaded with a biaxial kneader heated to 170 ° C. The obtained mixture was cooled and coarsely pulverized with a hammer mill, and then finely pulverized using a fine pulverizer using a jet stream. The resulting finely pulverized product was further classified with an air classifier, and the weight average particle diameter ( D4) A 7.5 μm classified fine powder was obtained.

The obtained classified fine powder was supplied with a raw material supply amount of 2 kg / hr, an airflow A of 25 ° C./2.5 m ³ / min, and an air flow B of 350 ° C./5.0 m ³ using the surface modification apparatus shown in FIG. / Min, airflow C is 25 ° C./2.0 m ³ / min, air flows D and C are pushed from a liquid nitrogen cylinder through a blower, and −5 ° C./3.0 m ³ / min. The blower air volume was 18.0 m ³ / min, the valve between the supply air supplies was opened, and surface reforming treatment with hot air was performed under the condition that water at 20 ° C. was passed through the cooling jacket.

Next, 0.8 parts by mass of hydrophobic dry silica (BET specific surface area 300 m ² / g) was added to 100 parts by mass of fine powder whose surface was modified, and Henschel with a stirring blade rotation speed of 18.33 S ⁻¹ . The toner FM1 (made by Mitsui Miike Co., Ltd.) was rotated for 4 minutes and externally added.

<Toner Production Examples 2 to 13>
As shown in Table 2, toners T2 to T13 were obtained in the same manner as in Toner Production Example 1 except that the binder resin to be added was changed to B1 to B14. Of these, the binder resin to be added for toner T12 is 100 parts by mass of B11: B12 mixed at a mass ratio of 9: 1, and for toner T13, B13: B14 is mass ratio of 3: 7. The mixture was taken as 100 parts by mass. Table 2 shows the average circularity and average particle diameter of the obtained toners.

<Toner Production Example 14>
-100 parts by weight of the above binder resin B1-3 parts by weight of release agent (paraffin wax, Tm: 75 ° C)-6 parts by weight of charge control agent (aromatic oxycarboxylic acid Al compound)-5 parts by weight of pigment (copper phthalocyanine) The above materials were sufficiently premixed with a Henschel mixer and then melt-kneaded with a biaxial kneader heated to 170 ° C. The obtained mixture was cooled and coarsely pulverized with a hammer mill, and then finely pulverized using a fine pulverizer using a jet stream. The resulting finely pulverized product was further classified with an air classifier, and the weight average particle diameter ( D4) A 7.8 μm classified fine powder was obtained.

The obtained classified fine powder was supplied with a raw material supply amount of 3 kg / hr, an airflow A of 25 ° C./2.5 m ³ / min, and an air flow B of 300 ° C./5.0 m ³ using the surface modification apparatus shown in FIG. / Min, airflow C is 25 ° C./2.0 m ³ / min, air flows D and C are pushed from a liquid nitrogen cylinder through a blower, and −5 ° C./3.0 m ³ / min. The blower air volume was 18.0 m ³ / min, the valve between the supply air supplies was opened, and surface reforming treatment with hot air was performed under the condition that water at 20 ° C. was passed through the cooling jacket.

Next, 1.3 parts by mass of hydrophobic dry silica (BET specific surface area 300 m ² / g) is added to 100 parts by mass of fine powder whose surface has been modified, and Henschel with a stirring blade rotational speed of 21.67 S ⁻¹ . The toner FM14 (manufactured by Mitsui Miike Co., Ltd.) was rotated for 10 minutes and externally added, and sieved with a mesh having a mesh size of 300 μm to obtain toner T14 of the present invention.

<Toner Production Examples 15 to 16>
As shown in Table 2, toners T15 to T16 were obtained in the same manner as in Toner Production Example 14 except that the binder resin to be added was changed to B5 or B7. Table 2 shows the average circularity and average particle diameter of the obtained toners.

<Example 1>
A commercially available monochrome multifunction device iR2230 (manufactured by Canon Inc.), which is a jumping development method using magnetic one-component toner, was modified to increase the frequency of the alternating current component applied as a developing bias by 1.2 times and the process speed by 1.2 times It was. By this modification, the toner carrier and the toner are rubbed more strongly, and the release agent contamination to the toner carrier appears more remarkably.

This modified machine is filled with the toner T1 of the present invention and allowed to blend in an environment of 25 ° C./60% RH for 24 hours, and then an original document having a printing rate of 8% composed of a solid area, a halftone area, and text is prepared. The copy image was output to plain paper for copying machines (basis weight 75 g / m ² ), and the solid image density was measured.

  The solid image density was averaged by measuring five solid portions of the original image with a color reflection densitometer (for example, X-RITE 404A: manufactured by X-Rite Co.). The obtained image density was ranked in five stages, and rank 3 or higher was regarded as acceptable.

<Image density evaluation rank>
Rank 5: Reflection density 1.40 or more Rank 4: Reflection density 1.35 or more and less than 1.40 Rank 3: Reflection density 1.30 or more and less than 1.35 Rank 2: Reflection density 1.25 or more and less than 1.30 Rank 1 : Reflection density less than 1.24

Next, the fixing device of the evaluation machine is modified so that the fixing temperature is set in a temperature range of 150 ° C. to 240 ° C., and the original is a horizontal line pattern with a width of 100 μm and solid black, and the lower half is solid white. Was used to output a copy image on plain paper for copying machines (basis weight: 60 g / m ² ) where offset is likely to occur. The contamination on the image due to the high temperature offset was visually confirmed, and the generated temperature was ranked as a high temperature offset property, and was ranked in five stages.

<High temperature offset resistance evaluation rank>
Rank 5: Generation temperature 240 ° C does not occur Rank 4: Generation temperature 220 ° C to 240 ° C Rank 3: Generation temperature 200 ° C to less than 220 ° C Rank 2: Generation temperature 180 ° C to 200 ° C Rank 1: Generation temperature 180 Less than ℃

Next, the fixing temperature is set in the temperature range of 150 ° C. to 240 ° C., and the toner development amount on the paper becomes 0.6 mg / cm ² by using plain paper for copying machines (basis weight 75 g / m ² ). Was output. The obtained image is rubbed 5 times with sylbon paper with a load of 4.9 kPa, and the fixing temperature is 10% or less before and after the rubbing. The rank 3 or higher, which does not cause any practical problems, was accepted.

<Low-temperature fixability evaluation rank>
Rank 5: Fixing temperature 150 ° C. or less Rank 4: Fixing temperature 150 ° C. or more and 160 ° C. or less Rank 3: Fixing temperature 160 ° C. or more and 170 ° C. or less Rank 2: Fixing temperature 170 ° C. or more and 180 ° C. or less Rank 1: Fixing temperature 180 ° C. or less

  Next, in order to confirm the contamination during long-term use, the developer and drum unit are idled for 30 minutes without outputting an image, and then the same image as the initial image density evaluation is output, and the toner on the toner carrier is further removed. The surface of the toner carrying member was removed by suction, and the surface of the toner carrying member was visually observed, and the adhesion of the release agent and the filming state were ranked in five levels.

<Evaluation rank of toner carrier contamination>
Rank 5: The toner carrier is not contaminated by the release agent and there is no image defect. Rank 4: The toner carrier is slightly contaminated but no image defect is observed. Rank 3: The image defect is slightly observed. Acceptable level Rank 2: Image defects may occur and may not be acceptable in some cases Rank 1: Significant image defects caused by contamination with release agent

  As a result of these evaluations, even when the toner T1 of the present invention is a toner that has undergone a surface modification step with hot air, the image density is good without causing contamination of the toner carrier due to the exudation of the release agent, and the release Due to the inclusion of the agent, the low-temperature fixability and high-temperature offset resistance were also good.

<Examples 2 to 6 and Comparative Examples 1 to 7>
Using the toners T2 to T13, evaluation of initial density and evaluation of high temperature offset property, low temperature fixability, and toner carrier contamination were performed in the same manner as in Example 1. The evaluation results are shown in Table 3.

<Examples 7 to 8 and Comparative Example 8>
Each of toners T14 to T16 and magnetic ferrite carrier particles (average particle diameter of 50 μm) coated with a silicon resin were mixed so that the toner concentration was 6% by mass to obtain a two-component developer.

  Two-component development using toners T14 to T16, respectively, using a modified machine with a process speed of 1.1 times that of a commercially available color multifunction peripheral iR C2550 (manufactured by Canon Inc.), which is a development method using a non-magnetic two-component developer. The initial image density, low temperature fixability, and high temperature offset were evaluated in the same manner as in Example 1 using the agent.

Next, using super economy paper (basis weight 64 g / m ² ), which tends to cause transfer bulging, the secondary transfer pressure was remodeled to 80% of the specification, and the image density was adjusted using a solid black original. An image having a toner development amount on paper of 1.1 mg / cm ² was output. This image was visually observed, and the transfer bow state was ranked in five stages, and rank 3 or higher, which does not cause a problem in practice, was accepted.

<Evaluation rank of transfer boss>
Rank 5: A uniform solid image is output. Rank 4: When the image is held over a strong light, a slight transfer margin can be confirmed. Rank 3: A slight level of transfer margin can be confirmed with normal light, but an acceptable level. Rank 2: There is a possibility that the transfer margin is confirmed and may not be acceptable. Rank 1: A noticeable transfer margin occurs and the image is uneven.

  From the above evaluation results, the effect of the present invention was confirmed.

  The toners mentioned in the examples are all good in terms of image density, low-temperature fixability, and high-temperature offset resistance, and have no or slight contamination due to exudation of a release agent and transfer bulge, confirming the effects of the present invention. It was done.

  Regarding Example 4 and Example 3 in which the second peak ΔH2 due to the crystal portion of the binder resin is small, the effect of the present invention is somewhat small among the examples, and the concentration is considered to be caused by the exudation of the release agent. The decrease has occurred from the beginning, and it is considered that the presence of the crystal part of the binder resin in the toner suggests that the effect of suppressing the release of the release agent is expressed.

  On the contrary, in Examples 2 and 6 in which ΔH2 is large, although it was slight, a high temperature offset was observed, and a preferable range of ΔH2 representing the amount of the crystal component was 0.40 J / g to 1.75 J / g.

  The low-temperature fixability and the high-temperature offset resistance are considered to be mainly influenced by the peak temperatures of P1 and P2, but if the peak temperatures of P1 and P2 are within the range of the present invention, the fixability is practical. The evaluation confirmed that there was no problem.

  Also, in Examples 7 to 8, which are two-component toners containing pigment instead of the magnetic material added to the toner, the results are the same as those of the magnetic toner, so that the toner of the present invention is magnetic and non-magnetic. Regardless, it was confirmed to be effective.

  The comparative example 2 and comparative example 8 in which the second peak ΔH2 due to the crystal component of the binder resin is excessively small, and the comparative examples 5 to 7 having no crystal peak have little or no effect of the present invention. I couldn't. When the surface modification process is performed in the hot air surface modification process, the release agent oozes out to the surface of the toner particles, and the leached release agent causes a decrease in image density, contamination of the toner carrier, two-component developer. In Comparative Example 8, it is considered that the transfer was caused.

  According to these evaluations, according to the present invention, even when a toner having a release agent in the toner is used in a highly spheroidized form, it does not cause adverse effects on the development and transfer due to the release of the release agent, and the spheroidization It has been confirmed that it is possible to provide a toner that can improve the electrophotographic performance and provide a high level of cost performance and environmental performance.

DESCRIPTION OF SYMBOLS 100 Powder / airflow A supply zone, 101 Airflow B supply zone, 102 Airflow C injection part, 103 Airflow D supply zone, 104 Airflow E supply zone, 105 Conveyance air supply pipe, 106 Cooling jacket, 107 Support member, 108 Clear flow member 109 airflow A, 110 toner supply zone, 111 airflow F supply zone

Claims (2)

  A toner having toner particles containing at least a binder resin and a colorant, the binder resin having a first endothermic peak at a temperature of 55 ° C. or higher and 75 ° C. or lower in a DSC curve measured by a differential scanning calorimeter. And a toner having a second endothermic peak at a temperature of 80 ° C. or higher and 120 ° C. or lower, wherein the toner particles are produced through a surface modification step using at least hot air.   2. The toner according to claim 1, wherein an endothermic amount of the second endothermic peak of the binder resin is 0.20 J / g or more and 2.00 J / g or less.

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