JP2013068686A - Toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner being excellent in low temperature fixing property, offset resistance and uneven fixation without affecting long-term storage stability.SOLUTION: A toner particle is obtained by an emulsion aggregation method, of which binder resin contains at least polyester resin as a main component, and the polyester resin has a first endothermic peak P1 at a temperature of 55 or 75°C and a second endothermic peak P2 at a temperature of 80 or 120°C in a DSC curve measured with a differential scanning calorimeter.

Description

  The present invention relates to an electrophotographic image forming method for developing an electrostatic image and a toner used in a toner jet.

  In recent years, in image output devices for multifunction devices, printers, and fax machines in the field of electrophotography, the toner particles have been made smaller in size due to the demand for energy savings by improving the quality of printed images and lowering the fixing temperature. Control is becoming important.

  An emulsion aggregation method has been proposed as a means for producing toner particles that has a wide range of selection of materials for improving the fixing characteristics and can intentionally control the reduction in particle size and shape.

  When aiming at further low-temperature fixability by this emulsion aggregation method, a method using a crystalline polyester resin that melts sharply at a low temperature in the core portion has been proposed for toner particles having a core-shell structure (Patent Documents). 1). Patent Document 1 describes that a low-temperature fixability is improved by using a non-crystalline polyester resin having a different molecular weight compatible with a crystalline polyester resin as a binder resin and promoting the melting of the binder resin. Yes. However, when the crystalline polyester resin and the amorphous polyester resin are excessively compatibilized, the binder resin is plasticized (decrease in glass transition temperature), and storage stability and high temperature offset resistance are reduced.

  In view of this, toner particles that are phase-separated from the amorphous polyester resin by forming a structure with the crystalline polyester resin and the release agent and allowing the crystalline polyester resin to exist as domains have been proposed (patents). Reference 2). However, in such toner particles, the domain of the crystalline polyester resin becomes too large, and as a result, fixing unevenness may occur due to a difference in melting rate from the amorphous polyester resin portion.

  In addition, a proposal has been made to control the compatibility by ion-crosslinking a crystalline polyester resin and an amorphous polyester resin during a fusion process using a titanium catalyst (Patent Document 3). Maintaining the storage stability and high-temperature offset resistance while improving the low-temperature fixability by maintaining the domain of the crystalline polyester resin and dispersing it uniformly in the amorphous polyester resin and dispersing it uniformly. Is intended. However, in this method, it is difficult to control the reaction, and the above-described plasticization and fixing unevenness may occur due to a difference in the degree of compatibilization.

  There is a need for a toner that can improve the fixability, maintain storage stability and high-temperature offset resistance, and obtain an image free from uneven fixing.

JP 2005-266565 A JP 2008-033057 A JP 2008-191260 A

  An object of the present invention is to provide a toner that solves the above-mentioned problems.

  An object of the present invention is to provide a toner that is excellent in long-term storage stability, excellent in low-temperature fixability and high-temperature offset resistance, and hardly causes uneven fixing.

The present invention relates to a toner having toner particles containing a binder resin, a colorant, and a release agent.
The toner particles are prepared by mixing a dispersion of resin fine particles, a dispersion of the colorant, and a dispersion of the release agent to prepare a mixed solution, and the resin fine particles, the colorant, and the release agent are mixed in the mixture. Toner particles produced by producing aggregated particles containing a mold agent to prepare a dispersion of the aggregated particles, heating the dispersion and fusing the aggregated particles;
The binder resin is produced from the resin fine particles,
The resin particles contain a polyester resin as a main component,
The polyester resin has a first endothermic peak P1 at a temperature of 55 to 75 ° C. and a second endothermic peak P2 at a temperature of 80 to 120 ° C. in a DSC endothermic curve measured by a differential scanning calorimeter. It relates to a characteristic toner.

  The present invention can provide a toner that is excellent in long-term storage stability, excellent in low-temperature fixability and high-temperature offset resistance, and hardly causes uneven fixing.

It is a DSC curve showing the glass transition temperature Tg in this invention. It is a DSC curve of the binder resin 1 of the present invention. It is a DSC curve of the binder resin 9 of the present invention.

  A toner having good low-temperature fixability is rapidly melted in a short time after passing through the nip of the heat and pressure fixing device. Generally, it is necessary to control the melting characteristics of the binder resin, which is the main component of the toner, in order to melt the toner quickly at the time of fixing. However, when the melting property of the binder resin itself is controlled, the influence on high temperature offset resistance and storage stability is great. Therefore, a method for controlling the melting property of the binder resin by a plastic effect using a fixing aid (additives such as low melting point wax and crystalline polyester) has been studied.

  Further, in order to obtain a good image with no fixing unevenness, it is necessary to make the melting rate in the toner particles uniform. For that purpose, it is important that the molecules constituting the binder resin move more uniformly at the molecular level.

  When toner particles are formed by an emulsion aggregation method using a crystalline polyester resin as a part of the binder resin, it is difficult to control the compatibility of the crystalline polyester resin with the binder resin. In the case of compatibilization, the binder resin is plasticized and storage stability and offset resistance are lowered. Also, in the case of phase separation, the melting rate of the crystalline domain and the melting rate of the amorphous resin are different, so the melting rate in the toner particles at the time of heat and pressure fixing is different and fixing unevenness occurs. There is.

  The inventors of the present invention have achieved further low-temperature fixability in the emulsion aggregation method, and as a result of earnestly studying a toner that is less likely to cause fixing unevenness without deteriorating storage stability, a binder resin has never been considered before. I found it necessary to design with. Specifically, it has been found that this problem can be solved by making the polyester resin have two endothermic peaks by aligning the orientation of part of the molecular chains of the molecules constituting the polyester resin.

  A general binder resin undergoes a phase transition from a glass state to a supercooled state at a glass transition temperature, and its melting characteristics slightly change. Accordingly, when this temperature is low, the storage stability is lowered. The present inventors paid attention to a phenomenon (hereinafter referred to as “enthalpy relaxation”) in which the energy excessively held by the polymer is higher than the glass transition temperature that affects storage stability. The enthalpy relaxation affects the state of the toner layer immediately after entering the heat and pressure fixing device, and affects the subsequent melting state of the toner. Moreover, it has been found that the melting rate of the toner can be controlled by having an endothermic peak after the temperature at which enthalpy relaxation occurs. In addition, the molecular motion can be controlled stepwise in the polyester resin as described above, and uniform melting of the toner can be promoted.

  That is, the present invention has a first endothermic peak P1 at a temperature of 55 to 75 ° C. (preferably 55 to 70 ° C.) in a DSC endothermic curve measured by a differential scanning calorimeter, and a temperature of 80 to 120 ° C. (preferably Is characterized in that the resin constituting the binder resin further has a second endothermic peak P2 at 85 to 115 ° C.). The endothermic peak P1 represents enthalpy relaxation. Enthalpy relaxation refers to a phenomenon in which molecules attempt to move further immediately after the binder resin in the toner particles undergoes a phase transition from the glass state to the supercooled liquid. When the enthalpy relaxation occurs in this temperature range, the melted state of the toner layer immediately after entering the heat and pressure fixing device changes favorably. It is possible to promote the subsequent melting of the toner by trying to move a part of the molecular chain of the resin constituting the binder resin, and the molecules move more uniformly at the temperature at which the resin actually melts. It is possible to promote When the endothermic peak P1 is lower than 55 ° C., it indicates that the molecules of the resin constituting the binder resin start to move at a temperature close to room temperature. In such a case, the storage stability of the toner decreases. On the other hand, when the endothermic peak 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 is lowered. Further, since the movement of the molecules is slow, more uniform molecular movement at the actual melting temperature is not promoted and fixing unevenness may occur.

  Next, the second endothermic peak P2 at a temperature of 80 to 120 ° C. is derived from thermal motion when the resin starts to melt, and does not appear in a normal amorphous resin. This occurs because there is a portion where the molecular orientation of the resin is aligned, so that a portion of the crystalline portion is formed in the resin, and this crystalline portion is present. When the endothermic peak P2 is lower than 80 ° C., the melting rate of the entire toner increases, so that the low-temperature fixability is improved, but the melt viscosity near the surface of the toner layer immediately after the toner layer enters the heat-pressure fixing device. High temperature offset resistance decreases due to rapid increase. Furthermore, since the melt viscosity rapidly rises at a stage where the melting of the toner due to the endothermic peak P1 is not sufficiently promoted, uniform molecular motion may not be performed and fixing unevenness may occur. On the other hand, when the endothermic peak P2 exceeds 120 ° C., melting of the toner is not promoted in the fixing temperature region, so that the low temperature fixability is deteriorated.

  The toner of the present invention preferably has an endothermic amount of the second endothermic peak P2 obtained in the DSC curve measured by a differential scanning calorimeter of the binder resin of 0.20 J / g to 2.00 J / g. More preferably, it is 0.50 J / g to 1.80 J / g. When it is less than 0.20 J / g, the acceleration of toner melting at the time of fixing is lowered, and when it is more than 2.00 J / g, the storage stability of the toner tends to be lowered.

  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 quantity uses the heat of fusion of indium.

  Specifically, about 5 mg of a measurement sample is accurately weighed, put in an aluminum pan, and an empty aluminum pan is used as a reference. Measure at room temperature and humidity for 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 point of intersection between the baseline halfway line and the differential thermal curve before and after the specific heat change obtained in this temperature raising process is expressed as the glass transition temperature Tg of the binder resin (FIG. 1). An endothermic peak obtained immediately after the glass transition temperature Tg in the temperature range of 30 to 200 ° C. in the second temperature raising process is defined as an endothermic peak P1, and an endothermic peak obtained by further raising the temperature is defined as P2. On the other hand, the endothermic amount ΔH of the second endothermic peak is obtained from the integrated value of the second endothermic peak.

  Toner particles are prepared by mixing a dispersion of resin fine particles, a dispersion of a colorant and a dispersion of a release agent to prepare a mixed solution, and aggregating particles containing resin fine particles, a colorant and a release agent in the mixture. It can be produced by preparing a dispersion of aggregated particles and heating the dispersion to fuse the aggregated particles.

  For example, the toner particles are generated by an emulsion aggregation method. The emulsion aggregation method includes an aggregation step in which aggregated particles are formed in a dispersion in which at least resin particles are dispersed (hereinafter sometimes referred to as “emulsified liquid”) to prepare a dispersion of the aggregated particles, and dispersion of the aggregated particles It is a manufacturing method including a fusion step of fusing the aggregated particles by heating the liquid. In addition, there is a step (adhesion step) for forming adhering particles between the aggregating step and the fusing step by adding and mixing the dispersion in which the particles are dispersed in the aggregating particle dispersion to adhere the particles to the agglomerated particles. You may do it.

  When the temperature in the fusing step is a temperature between the peak temperature P1 of the endothermic peak P1 and the peak temperature P2 of the endothermic peak P2, it is possible to obtain toner particles with better performance. By performing the fusion at a temperature higher than the peak temperature P1 of the endothermic peak P1, the molecules move appropriately and the crystalline parts are uniformly dispersed in the resin. On the other hand, by performing the fusion at a temperature lower than the peak temperature P2 of the endothermic peak P2, the molecules do not move too much and are fused without breaking the orientation of the crystalline part. Therefore, it is uniformly dispersed in the resin while maintaining the crystalline state. While maintaining the domain of the crystalline portion, it can be uniformly dispersed in the amorphous resin while being appropriately compatible. As a result, the contribution of the crystalline part to the low-temperature fixability is more effective, and the occurrence of uneven fixing can be suppressed.

  Moreover, these peaks exist also in the second temperature rising process in DSC, indicating that an amorphous part and a crystalline part exist stably. In addition, since there are crystalline and amorphous parts in the same molecule, it is possible to easily control the abundance of crystalline parts by controlling the monomer ratio during resin preparation. Become.

  In the toner of the present invention, since the resin itself has a crystalline part and an amorphous part, the resin may be used alone without taking the core-shell structure. This resin may be used for the core portion of the core-shell structure in place of a composite resin in which a crystalline polyester resin and an amorphous polyester resin are combined. In particular, when this resin is used alone, it is not necessary to use an amorphous polyester resin with a high softening point that may impair fixing properties in the shell portion. It is possible to suppress the occurrence of uneven fixing.

  As the resin of the resin particles used in the present invention, a polyester resin is preferable in that a portion between molecules is oriented to give crystallinity, and among them, a linear polyester is particularly preferable.

  The components for producing 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 in that crystallinity is imparted by orienting a part between the polymer chains 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 aromatic dicarboxylic acid content is preferably 50 mol% or more in 100 mol% of the acid component constituting the polyester resin from the viewpoint 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 are easy to have a straight chain structure, are preferred in order to orient some of the molecules and to provide crystallinity. However, since the crystallinity may become too high by itself, it is preferable to use an aliphatic alcohol having a branched structure. In order to adjust the crystal structure between the molecules of the polyester resin and to achieve both endothermic peak P1 due to enthalpy relaxation and endothermic peak P2 due to molecular orientation in the same molecule, neopentyl glycol having a methyl group or an ethyl group in the side chain, It is particularly preferred to use methyl-1,3-propanediol or 2-ethyl-1,3-hexanediol.

  The polyester resin used in the present invention includes a monovalent carboxylic acid, a monovalent alcohol, a trivalent or higher carboxylic acid, and a trivalent or higher alcohol in addition to the above divalent carboxylic acid and divalent alcohol. You may use when producing | generating a polyester resin.

  Examples of monovalent carboxylic acids include aromatic carboxylic acids having 7 to 30 carbon atoms such as benzoic acid and p-methylbenzoic acid, and aliphatic carboxylic acids having 16 to 30 carbon atoms such as stearic acid and behenic acid. .

  Examples of monohydric alcohols include aromatic alcohols having 7 to 30 carbon atoms such as benzyl alcohol, and aliphatic alcohols having 10 to 30 carbon atoms such as lauryl alcohol, cetyl alcohol, stearyl alcohol, and behenyl alcohol. It is done.

  The trivalent or higher carboxylic acid compound is not particularly limited, and examples thereof include trimellitic acid, trimellitic anhydride, and pyromellitic acid.

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

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

  It is preferable that the binder resin has at least one peak in a molecular weight region of 5000 to 10,000 in a molecular weight distribution measured by gel permeation chromatography (GPC) of THF-soluble matter. When the peak maximum molecular weight is less than 5000, the blocking resistance is lowered. When the molecular weight at the peak maximum value exceeds 10,000, the fixability is lowered.

  The toner particles may have a core-shell structure. In that case, it is preferable to use a resin having crystallinity for the core part and an amorphous resin for the shell part. An amorphous resin is a resin that does not have an endothermic peak associated with crystal melting in differential thermal analysis using differential scanning calorimetry (DSC), is a solid at room temperature, and is thermoplastic at temperatures above the glass transition temperature. It is resin which has.

  Examples of the amorphous resin include polyamide resin, polycarbonate resin, polyether resin, polyacrylonitrile resin, polyarylate resin, polyester resin, and styrene-acrylic resin. Among these, the amorphous polyester resin can be synthesized usually by selecting and combining suitable ones from a dicarboxylic acid component and a diol component, and using a transesterification method or a polycondensation method.

  Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, cyclohexanedicarboxylic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid; biphenyldicarboxylic acid; succinic acid, glutaric acid, adipic acid, speric acid, Dibasic acids such as azelaic acid, sebacic acid, phthalic acid, malonic acid, mesaconic acid, and their anhydrides and their lower alkyl esters; aliphatic unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid Examples include acids. In addition, trivalent or higher carboxylic acids such as 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, anhydrides thereof, and lower alkyl esters thereof. Can be used in combination. For the purpose of adjusting the acid value or hydroxyl value, a monovalent acid such as acetic acid or benzoic acid may be used as necessary.

  Divalent alcohol components include ethylene glycol, propylene glycol, neopentyl glycol, cyclohexanedimethanol, ethylene oxide adduct of bisphenol A, trimethylene oxide adduct of bisphenol A, and bisphenol A, hydrogenated Bisphenol A, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, diethylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexane Examples include diol and neopentyl glycol. Moreover, if it is trace amount, trivalent or more alcohols, such as glycerol, a trimethylol ethane, a trimethylol propane, and a pentaerythritol, can be used together. These may be used individually by 1 type and may use 2 or more types together. Monovalent alcohols such as cyclohexanol and benzyl alcohol may also be used.

  In producing the amorphous polyester resin, for example, a polymerization catalyst such as titanium tetrabutoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, or germanium dioxide may be used.

  Examples of the colorant used in the toner of the present invention include phthalocyanine pigments, monoazo pigments, bisazo pigments, magnetic powders, and quinacridone pigments. Specific examples include the following. Carbon Black, Chrome Yellow, Hansa Yellow, Benzidine Yellow, Slen Yellow, Quinoline Yellow, Permanent Orange GTR, Pyrazolone Orange, Vulcan Orange, Watch Young Red, Permanent Red, Brilliantamine 3B, Brilliantamine 6B, Dupont Oil Red, Pyrazolone Red, Resol red, rhodamine B lake, lake red C, rose bengal, aniline blue, ultramarine blue, chalcoil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxalate; pigments such as acridine, xanthene, azo Benzoquinone, azine, anthraquinone, dioxazine, thiazine, azomethine, Zico, thioindigo, phthalocyanine, aniline black, polymethine, triphenylmethane dyes, diphenylmethane dyes, thiazine, thiazole, xanthene such dyes. These colorants may be used alone or in combination of two or more.

  In the present invention, the content of the colorant in the toner is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin. When the amount is less than 1 part by mass, the coloring power may decrease. On the other hand, when the amount is more than 20 parts by mass, the color space tends to be small.

  The toner of the present invention has a release agent. As the mold release agent, those having a melting point of 40 ° C. to 150 ° C. or less are preferably used, more preferably 40 ° C. to 130 ° C., and particularly preferably 40 ° C. to 110 ° C. Specific examples include the following. Low molecular weight polyolefins such as polyethylene; silicones that melt or soften upon heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, stearic acid amide; ester waxes such as stearyl stearate; carnauba Plant waxes such as wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; minerals such as montan wax, ozokerite, ceresin wax, microcrystalline wax, Fischer-Tropsch wax, ester wax Petroleum-based waxes; and their modified products.

  In the present invention, the content of the release agent in the toner is preferably 4 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the binder resin. When the amount is less than 4 parts by mass, the releasability of the toner cannot be maintained, and the transfer paper is likely to be wound when the fixing body is at a low temperature. When the amount is more than 25 parts by mass, the release agent is likely to be exposed on the toner surface, and the heat resistant storage stability may be deteriorated. Furthermore, it is liable to cause harmful effects such as fogging and fusion.

  If necessary, inorganic particles or organic particles can be added to the toner particles. By adding these particles to the toner particles, the storage elastic modulus of the toner increases, and offset resistance and releasability from the fixing device are improved. Moreover, these particles may improve the dispersibility of internal additives such as colorants and release agents.

  Inorganic particles include silica, hydrophobized silica, alumina, titanium oxide, calcium carbonate, magnesium carbonate, tricalcium phosphate, colloidal silica, alumina-treated colloidal silica, cationic surface-treated colloidal silica, anion surface-treated colloidal silica, etc. Is mentioned. These particles may be used alone or in combination. Of these, colloidal silica is preferably used from the viewpoint of dispersibility in the toner. The number average particle size is preferably 5 to 50 nm. It is also possible to use particles having different particle sizes in combination. The particles can be added directly when the toner particles are produced, but it is preferable to use particles dispersed in an aqueous medium in advance using an ultrasonic disperser in order to improve dispersibility. In the dispersion, the dispersibility may be improved by using an ionic surfactant, a polymer acid, or a polymer base.

  In addition, a charge control agent may be added to the toner. The number average particle diameter of the material added at that time is preferably 1 μm or less, and more preferably 0.01 to 1 μm. When the number average particle diameter exceeds 1 μm, the particle size distribution of the finally obtained toner particles may be widened, or free particles may be generated, which may lead to a decrease in performance and reliability. On the other hand, when the number average particle diameter is within the above range, the uneven distribution among the toner particles is reduced, the dispersion in the toner is improved, and the variation in performance and reliability is advantageous.

  In the present invention, a preferable blending amount of the charge control agent is 0.01 parts by mass or more and 20 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin.

  Further, the toner of the present invention will be described in detail together with its production method.

  The toner particles according to the present invention are prepared by mixing a dispersion of resin fine particles, a dispersion of the colorant, and a dispersion of the release agent to prepare a mixed solution, and the resin fine particles and the colorant are mixed in the mixture. And agglomerated particles containing the releasing agent are produced to prepare a dispersion of the agglomerated particles, and the dispersion is heated to fuse the agglomerated particles. Hereinafter, this generation method may be referred to as an “emulsion aggregation method”. Hereinafter, a toner manufacturing method will be described.

  In the emulsion aggregation method, between the aggregation process and the fusion process, the dispersion liquid of the particles dispersed in the dispersion liquid of the aggregated particles is added and mixed, and the adhered particles are formed by attaching the particles to the aggregated particles. You may have the process (attachment process) to do. In the attaching step, the added particles may be referred to as “additional particles”.

  By adding additional particles, a core-shell structure can be formed in the toner particles. The binder resin that is the main component of the additional particles is a resin for forming the shell layer.

  In the emulsion aggregation method, when a polyester resin or an amorphous resin is used, an emulsification step of emulsifying the amorphous polyester resin to form emulsion particles (droplets) of the amorphous polyester resin is preferably used.

  In the emulsification step, for example, the emulsified particles (droplets) of the amorphous polyester resin give a shearing force to a solution (polymer liquid) containing an aqueous medium, the amorphous polyester resin, and, if necessary, a colorant. Is formed. At that time, the viscosity of the polymer liquid can be lowered to form emulsified particles by heating to a temperature equal to or higher than the glass transition temperature of the amorphous polyester resin. Further, a dispersant may be used for stabilizing the emulsified particles and increasing the viscosity of the aqueous medium. Hereinafter, such a dispersion of emulsified particles may be referred to as a “resin fine particle dispersion”.

  Examples of the emulsifier used when forming the emulsified particles include a homogenizer, a homomixer, a pressure kneader, an extruder, and a media disperser. The size of the emulsified particles (droplets) of the polyester resin is preferably 0.005 to 0.5 μm, more preferably 0.01 to 0.3 μm in volume average particle diameter (Dv). If it is less than 0.005 μm, it is almost dissolved in water, making it difficult to produce particles. If it exceeds 0.5 μm, it is difficult to obtain particles having a desired particle size of 3.0 to 7.5 μm. There is a case.

  Also, when the melt viscosity of the resin during emulsification is high, it is difficult to reduce the particle size to the desired particle size, so the temperature was raised using an emulsifier that can pressurize to a pressure higher than atmospheric pressure, and the resin viscosity was lowered. By emulsifying in a state, a resin particle dispersion having a desired particle size can be obtained.

  In the emulsification step, a method in which a solvent is previously added to the resin may be used for the purpose of improving the emulsifiability by lowering the viscosity of the resin. The solvent used is not particularly limited as long as it dissolves the polyester resin, but tetrahydrofuran (THF); methyl acetate; ethyl acetate; ketone solvents such as methyl ethyl ketone; benzene solvents such as benzene, toluene and xylene Can be mentioned. From the viewpoints of solubility and solvent removal, it is preferable to use tetrahydrofuran (THF) or ethyl acetate.

  Further, for the purpose of improving the affinity with water as a medium and controlling the particle size distribution, an alcohol solvent such as ethanol or isopropyl alcohol may be added to water or the resin.

  Further, for the purpose of controlling the particle size distribution, a salt such as sodium chloride or potassium chloride, or ammonia may be added.

  Further, a dispersant may be added for the purpose of controlling the particle size distribution. Examples of the dispersant include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, and sodium polyacrylate; anions such as sodium dodecylbenzenesulfonate, sodium octadecyl sulfate, sodium oleate, sodium laurate, and potassium stearate. Surfactants; cationic surfactants such as laurylamine acetate and lauryltrimethylammonium chloride; zwitterionic surfactants such as lauryldimethylamine oxide; polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene Nonionic surfactant mistaken for alkylamine; tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate, charcoal Such inorganic compounds barium. Among these, anionic surfactants are preferably used. The amount of the dispersant used is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the polyester resin (binder resin).

  Further, a phase inversion emulsification method may be used for forming the emulsified particles. The phase inversion emulsification method is obtained by dissolving a polyester resin in an organic solvent, adding a neutralizing agent and a dispersion stabilizer as necessary, dropping an aqueous solvent under stirring to obtain emulsified particles, In this method, the organic solvent in the resin dispersion is removed to obtain an emulsion. At this time, the order of adding the neutralizing agent and the dispersion stabilizer may be changed.

  Examples of the organic solvent for dissolving the polyester resin include formic acid esters, acetic acid esters, butyric acid esters, ketones, ethers, benzenes, and halogenated carbons. Specifically, methyl esters, ethyl esters, n-propyl esters, isopropyl esters, n-butyl esters, isobutyl esters, sec-butyl esters, t-butyl esters of carboxylic acids such as formic acid, acetic acid and butyric acid; acetone, MEK , Methyl ketones such as MPK, MIPK, MBK, MIBK; ethers such as diethyl ether and diisopropyl ether; heterocyclic substituents such as toluene, xylene and benzene; carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1 , 1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene and the like. These can be used alone or in combination of two or more. Acetic acid esters, methyl ketones and ethers, which are low boiling solvents, are usually preferably used from the viewpoints of availability, ease of recovery during solvent removal, and environmental considerations, and in particular, acetone, methyl ethyl ketone, acetic acid, ethyl acetate, Butyl acetate is preferred. When the organic solvent remains in the resin particles, it becomes a VOC causative substance, and it is preferable to use a relatively volatile organic solvent. The amount of these organic solvents used is preferably 20 to 200% by mass, more preferably 30 to 100% by mass, based on the amount of resin.

  As the aqueous solvent, ion-exchanged water is basically used, but a water-soluble organic solvent may be included so as not to destroy the oil droplets. Examples of water-soluble organic solvents include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, and short carbon chain alcohols; ethylene glycol monomethyl ether, ethylene glycol Examples thereof include ethylene glycol monoalkyl ethers such as monoethyl ether and ethylene glycol monobutyl ether; ethers, diols, THF and acetone. In particular, ethanol and 2-propanol are preferably used. The amount of these water-soluble organic solvents used is 1 to 60% by mass, more preferably 5 to 40% by mass, based on the amount of resin. In addition, the water-soluble organic solvent may be added to the resin solution and used in addition to the ion-exchanged water to be added. When a water-soluble organic solvent is added, the wettability between the resin and the resin dissolving solvent can be adjusted, and the liquid viscosity after dissolving the resin can be reduced.

  Moreover, you may add a dispersing agent to a resin solution and an aqueous component as needed so that an emulsion may maintain a dispersed state stably. Dispersants are those that form hydrophilic colloids in aqueous components, especially cellulose derivatives such as hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose; polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, polyacrylate, poly Synthetic polymers such as methacrylate, gelatin, gum arabic, and agar. Solid fine powders such as silica, titanium oxide, alumina, tricalcium phosphate, calcium carbonate, calcium sulfate, and barium carbonate can also be used. These dispersion stabilizers are usually added so that the concentration in the aqueous component is 0 to 20% by mass, preferably 0 to 10% by mass. As the dispersant, a surfactant can also be used. As examples of the surfactant, those according to those used in the colorant dispersion described later can be used. For example, in addition to natural surfactant components such as saponins, cationic surfactants such as alkylamine hydrochlorides, acetates, quaternary ammonium salts, glycerins; fatty acid soaps, sulfates, alkylnaphthalene sulfonates, Examples thereof include anionic surfactants such as sulfonates, phosphoric acid, phosphate esters, and sulfosuccinates. Anionic surfactants and nonionic surfactants are preferably used. In order to adjust the pH of the emulsion, a neutralizing agent may be added. As the neutralizing agent, an acid such as nitric acid, hydrochloric acid, sodium hydroxide, ammonia, or an alkali can be used.

  Examples of the method for removing the organic solvent from the emulsion include a method in which the organic solvent is volatilized at a temperature of 15 to 70 ° C., and a method in which reduced pressure is combined with this is preferably used.

  Examples of the dispersion method of the colorant and the release agent include a dispersion method using a high-pressure homogenizer, a rotary shearing homogenizer, an ultrasonic disperser, a high-pressure impact disperser, a ball mill having a medium, a sand mill, and a dyno mill. .

  If necessary, an aqueous dispersion of these colorants can be prepared using a surfactant, or an organic solvent dispersion of these colorants can be prepared using a dispersant. Hereinafter, the dispersion of the colorant and the release agent may be referred to as “colorant dispersion” and “release agent dispersion”, respectively.

  The dispersant used for the colorant dispersion or the release agent dispersion is generally a surfactant. Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol Preferred examples include nonionic surfactants such as polyphenols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, an ionic surfactant is preferable, and an anionic surfactant and a cationic surfactant are more preferable. The nonionic surfactant is preferably used in combination with an anionic surfactant or a cationic surfactant. Surfactant may be used individually by 1 type and may use 2 or more types together. Moreover, it is preferable that a mold release agent dispersion liquid is the same polarity as the dispersing agent used for another dispersion liquid.

  Anionic surfactants include fatty acid soaps such as potassium laurate, sodium oleate, sodium castor oil; sulfates such as octyl sulfate, lauryl sulfate, lauryl ether sulfate, nonylphenyl ether sulfate; lauryl sulfonate, dodecyl sulfonate, Sodium alkylnaphthalene sulfonate such as dodecylbenzene sulfonate, triisopropyl naphthalene sulfonate, dibutyl naphthalene sulfonate, naphthalene sulfonate formalin condensate, monooctyl sulfosuccinate, dioctyl sulfosuccinate, lauric acid amide sulfonate, sulfonic acid such as oleic acid amide sulfonate Salts: lauryl phosphate, isopropyl phosphate, noni Phosphoric acid esters such as phenyl ether phosphates; dialkyl sodium sulfosuccinates such as sodium dioctyl sulfosuccinate, sodium lauryl sulfosuccinate 2, polyoxyethylene sulfo such sulfosuccinic acid salts of succinic acid lauryl disodium and the like. Among these, alkylbenzene sulfonate compounds such as dodecylbenzene sulfonate and its branched products are preferable.

  Cationic surfactants include laurylamine hydrochloride, stearylamine hydrochloride, oleylamine acetate, stearylamine acetate, amine salts such as stearylaminopropylamine acetate; lauryltrimethylammonium chloride, dilauryldimethylammonium chloride, distearyl Ammonium chloride, distearyldimethylammonium chloride, lauryl dihydroxyethylmethylammonium chloride, oleylbispolyoxyethylenemethylammonium chloride, lauroylaminopropyldimethylethylammonium ethosulphate, lauroylaminopropyldimethylhydroxyethylammonium perchlorate, alkylbenzenedimethylammonium chloride, alkyl Trimethyla Mo chloride such as quaternary ammonium salts.

  Nonionic surfactants include alkyl ethers such as polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether, polyoxyethylene nonylphenyl Alkyl phenyl ethers such as ether; alkyl esters such as polyoxyethylene laurate, polyoxyethylene stearate, polyoxyethylene oleate; polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether, polyoxyethylene oleyl amino ether , Alkylamines such as polyoxyethylene soybean amino ether and polyoxyethylene beef tallow amino ether; Alkyl amides such as ethylene lauric acid amide, polyoxyethylene stearic acid amide, polyoxyethylene oleic acid amide; vegetable oil ethers such as polyoxyethylene castor oil ether, polyoxyethylene rapeseed oil ether; lauric acid diethanolamide, stearic acid Alkanolamides such as diethanolamide and oleic acid diethanolamide; sorbitan ester ethers such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate Is mentioned.

  The addition amount of the dispersant used is preferably 2% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less with respect to the colorant or the release agent. If the amount of the dispersant is too small, the particle size may not be reduced, or the storage stability of the dispersion may be reduced. On the other hand, when the amount is too large, the amount of the dispersant remaining in the toner particles increases, and the triboelectric chargeability and powder fluidity of the toner may be reduced.

  The aqueous dispersion medium to be used is preferably one having few impurities such as metal ions such as distilled water and ion exchange water. Moreover, you may add alcohol for the purpose of defoaming or surface tension adjustment. In order to adjust the viscosity, polyvinyl alcohol or cellulose polymer can be added, but if it remains in the toner particles, the triboelectric chargeability is lowered.

  The means for preparing various additive dispersions is not particularly limited. For example, ball mills, sand mills, dyno mills having rotary shearing homogenizers and media, colorant dispersions and release agent dispersions. The dispersion apparatus used for the production of the above is mentioned.

  In the aggregation step, it is preferable to use an aggregating agent in order to form aggregated particles. Examples of the flocculant used include a surfactant having a polarity opposite to that of the surfactant used for the dispersant, an inorganic metal compound (inorganic metal salt), or a polymer thereof. The metal element constituting the inorganic metal salt has a divalent or higher charge belonging to the 2A, 3A, 4A, 5A, 6A, 7A, 8, 1B, 2B, 3B group in the periodic table (long periodic table). There may be any resin that dissolves in the form of ions in the resin particle aggregation step.

  Examples of inorganic metal salts include calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide Is mentioned. Among these, an aluminum salt and a polymer thereof are particularly preferable. In general, in order to obtain a sharper particle size distribution, even if the valence of the inorganic metal salt is divalent to monovalent, bivalent to trivalent or higher, and even to the same valence, the polymerization type inorganic metal salt weight Combined is more suitable.

  The amount of the flocculant added varies depending on the type and valence of the flocculant, but is preferably in the range of 0.05 to 0.1% by mass. The aggregating agent does not always remain in the toner particles by flowing out into the aqueous medium or forming coarse powder during the aggregating step. In particular, when the amount of solvent in the resin is large in the flocculation step, the solvent and the flocculating agent interact and easily flow out into the aqueous medium. Therefore, it is necessary to adjust the amount according to the residual solvent amount.

  In the fusing step, the agglomeration suspension is brought to a pH range of 5 to 10 under stirring in accordance with the agglomeration step to stop the agglomeration, and a temperature equal to or higher than the glass transition temperature (Tg) of the resin. The aggregated particles are fused by heating at. The heating time is preferably 0.2 to 10 hours for desired melting. Thereafter, when the temperature is lowered to Tg or less of the resin to solidify the particles, the particle shape and surface properties change depending on the temperature lowering rate. For example, when the temperature is lowered at a high speed, spheroidization and surface irregularities tend to decrease, and conversely, when the temperature is lowered slowly, the particle shape becomes irregular and irregularities are likely to occur on the particle surface. Therefore, it is preferable to lower the temperature to at most Tg of the resin at a rate of at least 0.5 ° C./min, more preferably at a rate of 1.0 ° C./min or more.

  After completing the fusing step, the particles are washed and dried to obtain toner particles. Considering the triboelectric chargeability of the toner, it is preferable to wash with ion-exchanged water, and the degree of washing is monitored by the electrical conductivity of the filtrate so that the conductivity is finally 25 μS / cm or less. preferable. The washing may include a step of neutralizing ions with an acid or an alkali. The treatment with an acid preferably has a pH of 4.0 or less, and the treatment with an alkali preferably has a pH of 8.0 or more. The solid-liquid separation after washing is not particularly limited, but pressure filtration such as suction filtration or filter press is preferably used from the viewpoint of productivity. Further, the drying method is not particularly limited, but freeze drying, flash jet drying, fluidized drying, and vibration type fluidized drying are preferably used from the viewpoint of productivity, and the moisture content of the final toner particles is 1% by mass or less. More preferably, drying is performed so that the content is 0.7% by mass or less.

  In addition, a shearing force is applied to the surface of the obtained toner particles in a dry state on inorganic particles such as silica, alumina, titania and calcium carbonate, and particles of resin such as vinyl resin, polyester resin and silicone resin. May be added. These inorganic particles and resin particles function as fluidity aids and cleaning aids.

  In the toner of the present invention, other additives may be used as long as they do not have a substantial adverse effect. For example, the following are mentioned. Lubricant powders such as polyfluorinated ethylene powder, zinc stearate powder and polyvinylidene fluoride powder; abrasives such as cerium oxide powder, silicon carbide powder and strontium titanate powder; fluidity imparting agents such as titanium oxide powder and aluminum oxide powder; Anti-caking agent; conductivity imparting agent such as carbon black powder, zinc oxide powder and tin oxide powder; developability improver such as organic fine particles and inorganic fine particles of opposite polarity. As the external addition method, a conventionally known method using a Henschel mixer can be used.

  The weight average particle diameter (D4) of the toner in the present invention is preferably in the range of 4 to 9 μm, more preferably in the range of 4.5 to 8.5 μm, and still more preferably in the range of 5 to 8 μm. When the weight average particle diameter (D4) is smaller than 4 μm, the toner fluidity is lowered, the triboelectric chargeability of each particle is liable to be lowered, and the triboelectric charge distribution is widened. The toner scatters easily from the container. If the weight average particle diameter of the toner is smaller than 4 μm, cleaning may be difficult. When the weight average particle diameter (D4) is larger than 9 μm, the resolution is lowered, and it may be difficult to obtain a high-quality image.

  The particle size distribution is performed using a Coulter counter.

  As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is 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.) is used. The measurement is performed with 25,000 effective measurement channels.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as 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 is set as follows.

  On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter, Inc.) 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 electrolytic solution is put into 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, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) About 30 ml of electrolytic 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) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W is prepared. 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 the electrolyte 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 the ultrasonic dispersion, the water temperature of the water tank is adjusted 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 measurement concentration is adjusted to about 5% by mass. To do. The measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. When the graph / volume% is set in the dedicated software, the “average diameter” on the “Analysis / volume statistics (arithmetic average)” screen is the weight average particle diameter (D4), and the graph / number% in the dedicated software. The “average diameter” on the “analysis / number statistics (arithmetic mean)” screen is the number average particle diameter (D1).

  The toner of the present invention is used as a one-component toner and also used as a two-component toner in combination with a carrier. Since the toner of the present invention exhibits excellent properties in high-speed developability, it is preferably used as a two-component toner used in combination with a magnetic carrier.

  An example of the magnetic carrier is a resin-coated magnetic carrier.

  The resins may be used alone or in combination of two or more. The amount of the coating resin is 0.1 part by mass or more and 10 parts by mass or less, and preferably 0.5 part by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the magnetic carrier core particles.

  The mixing ratio (mass ratio) of the toner and the magnetic carrier in the two-component developer is in the range of toner: magnetic carrier = 1: 100 to 30: 100, and more preferably in the range of 3: 100 to 20: 100.

  Although the basic configuration and features of the present invention have been described above, the present invention will be specifically described below based on examples. However, this does not limit the embodiment of the present invention. The number of parts in the examples is part by mass.

<Example of production of binder resin 1>
Terephthalic acid: 100 mol part Ethylene glycol: 60 mol part Neopentyl glycol: 40 mol part The above polyester monomer is charged into an autoclave together with an esterification catalyst (dibutyltin oxide), reflux condenser, moisture separator, N ₂ gas introduction pipe, thermometer and stirring The apparatus was installed and a polycondensation reaction was performed at 230 ° C. while introducing N ₂ gas into the autoclave. While the progress of the reaction was monitored by viscosity, when the reaction approached late, 5 mol parts of trimellitic anhydride was added into the autoclave to adjust the acid value of the polyester resin. By adding trimellitic anhydride at the late stage of the reaction, the acid value was adjusted without affecting the basic structure of the polyester resin. After completion of the reaction, the polyester resin was taken out from the autoclave, cooled and pulverized to obtain a binder resin 1. Table 2 shows the physical properties of the binder resin 1. FIG. 2 shows a DSC chart of the binder resin 1.

<Example of production of binder resins 2 to 13 and 15>
The monomers listed in Table 1 are charged into a 5 liter autoclave together with an esterification catalyst (dibutyltin oxide), equipped with a reflux condenser, moisture separator, N ₂ gas inlet tube, thermometer and stirrer, and N ₂ gas in the autoclave. The polycondensation reaction was carried out at 230 ° C. while introducing. At this time, the monomers described as post-addition in Table 1 are added in the latter stage of the polycondensation reaction to adjust the acid value or hydroxyl value. After completion of the reaction, it was taken out from the container, cooled and pulverized to obtain binder resins 2 to 13 and 15. Various physical properties of these resins are as shown in Table 2. FIG. 3 shows a DSC chart of the binder resin 9.

<Example of production of binder resin 14>
1,10-decanedicarboxylic acid: 100 mol parts 1,9-nonanediol: 100 mol parts The above polyester monomer is charged into a 5 liter autoclave together with an esterification catalyst (titanium tetrabutoxide), reflux condenser, moisture separator, N ₂ gas introduction A tube, a thermometer and a stirrer were attached, and a polycondensation reaction was carried out at 170 ° C. while introducing N ₂ gas into the autoclave. Furthermore, the temperature was raised to 220 ° C., the pressure in the reaction vessel was reduced, and a polycondensation reaction was performed under reduced pressure. After completion of the reaction, it was taken out from the container, cooled and pulverized to obtain a binder resin 14. Various physical properties of the resin are as shown in Table 2.

<Preparation of resin dispersion 1>
200 parts of the binder resin 1 was dissolved in 250 parts of tetrahydrofuran, and 5 parts of potassium hydroxide was dissolved in 10 parts of ion-exchanged water and added. While stirring this tetrahydrofuran solution at room temperature, 1000 parts of ion-exchanged water was added dropwise. The mixed solution was heated to about 75 ° C. to remove tetrahydrofuran. A resin dispersion 1 having a volume average particle diameter of resin particles in the dispersion of 0.09 μm was obtained. Then, it adjusted with ion-exchange water and solid content concentration was 20 mass%.

<Preparation of resin dispersions 2 to 13, 15>
200 parts of the binder resins 2 to 13 and 15 were dissolved in 250 parts of tetrahydrofuran, and 5 parts of potassium hydroxide were dissolved in 10 parts of ion-exchanged water and added. While stirring this tetrahydrofuran solution at room temperature, 1000 parts of ion-exchanged water was added dropwise. The mixed solution was heated to about 75 ° C. to remove tetrahydrofuran. The volume average particle size of the resin particles in these dispersions is as shown in Table 2. Then, it adjusted with ion-exchange water and solid content concentration was 20 mass%.

<Preparation of resin dispersion 14>
200 parts of the binder resin 14 was put in 800 parts of distilled water, heated to 85 ° C., adjusted to pH 9.0 with ammonia, and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK). 0.4 parts (as an active ingredient) was added and dispersed at 8000 rpm for 5 minutes with a homogenizer (IKA Japan: Ultra Tarax T50) while heating to 85 ° C., and then using a pressure discharge type gorin homogenizer. A dispersion process corresponding to 10 passes was performed at 110 ° C. to obtain a resin dispersion 14. The volume average particle size of the particles in this dispersion was 0.15 μm, and the solid content was 20% by mass.

<Preparation of additional particle dispersion>
An anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK, active ingredient amount: 60% by mass) is added to 210 parts of the resin dispersion 15 so as to be 2% by mass with respect to the resin solid content. After mixing, the additional particle dispersion 1 was prepared by adjusting the pH to 3.0 with a 2 mass% aqueous nitric acid solution.

<Preparation of release agent dispersion>
Carnauba wax (melting point 84 ° C.) 50.0 parts Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 5.0 parts Ion-exchanged water 200 parts The above was heated to 95 ° C. and homogenizer (manufactured by IKA) : Ultra-Turrax T50), and then dispersed with a pressure discharge type homogenizer to prepare a release agent dispersion liquid in which a release agent having an average particle size of 0.5 μm is dispersed.

<Preparation of colorant dispersion>
Carbon black 20.0 parts Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 2.0 parts Ion-exchanged water 78.0 parts The above materials were mixed and dispersed using a sand grinder mill. When the particle size distribution in this colorant particle dispersion was measured using a particle size measuring device (LA-700, manufactured by Horiba, Ltd.), the average particle size of the colorant particles contained was 0.2 μm and 1.0 μm. No coarse particles exceeding were observed.

<Preparation of charge control agent dispersion>
Di-alkyl-salicylic acid metal compound (charge control agent, Bontron E-84, manufactured by Orient Chemical Industries) 20.0 parts Anionic surfactant (Neogen SC Daiichi Kogyo Seiyaku Co., Ltd.) 2.0 parts ion-exchanged water 78.0 parts The above materials were mixed and dispersed using a sand grinder mill. When the number particle size distribution in the charge control particle dispersion was measured using a particle size measuring device (LA-700, manufactured by Horiba, Ltd.), the number average particle size of the colorant particles contained was 0.2 μm. Coarse particles exceeding 0 μm were not observed.

[Example 1]
(Production of toner)
Resin dispersion 1 360.0 parts Release agent dispersion 40.0 parts Colorant dispersion 40.0 parts The above materials were put into a 3 liter reaction vessel equipped with a stirrer, condenser, and thermometer and stirred. . To this mixed solution, a 1.0% by mass aqueous nitric acid solution was added to adjust the pH to 3.0.

  As a flocculant, 1.5 parts of a 10% by mass polyaluminum chloride aqueous solution (manufactured by Asada Chemical Co., Ltd.) was added dropwise to this mixed solution, and the mixture was heated to a temperature of 50 ° C. while stirring in the heating oil bath. At this temperature, 3 parts of resin dispersion 1 and 10 parts of dispersion of charge control agent particles were added and held for 2 hours.

  5 mass% sodium hydroxide aqueous solution was added here and pH was set to 9.0. Thereafter, while adjusting the pH to 9.0 every 5 ° C., the temperature was increased to 90 ° C. at a temperature increase rate of 1 ° C./min, and the temperature was maintained at 90 ° C. for 3 hours. After cooling, the reaction product is filtered, washed thoroughly with ion-exchanged water, then fluidized bed dried at a temperature of 45 ° C, and dispersed in a gas phase at a temperature of 200 ° C to 300 ° C with a spray dryer. And toner particles 1 were obtained. The average particle size of the toner particles 1 was about 6.8 μm.

To 100 parts of this toner, 1.7 parts of hydrophobic silica having a BET specific surface area value of 200 (m ² / g) was externally added with a Henschel mixer to obtain toner 1.

(Creation of carrier)
After atomization using 15 parts of MgO, 10 parts of MnO, and 75 parts of Fe ₂ O ₃ , water was added and granulated, followed by firing at 1200 ° C., particle size adjustment, and a volume average particle diameter of 35.8 μm. A ferrite carrier core material was obtained.

  The volume average particle diameter of the carrier was measured by a laser diffraction particle size distribution analyzer SALD-300V (manufactured by Shimadzu Corporation), and a volume-based 50% particle diameter (D50) was calculated.

On the other hand, 20 parts of toluene, 20 parts of butanol, 20 parts of water, 40 parts of ice is taken up in a four-necked flask, with stirring and CH ₃ SiCl ₂ 15 parts by mole (CH _{3) 2} mixture 40 parts of SiCl ₂ 10 molar parts After stirring for 30 minutes, a condensation reaction was performed at 60 ° C. for 1 hour. Thereafter, the siloxane was thoroughly washed with water and dissolved in a toluene-methyl ethyl ketone-butanol mixed solvent to prepare a silicone varnish having a solid content of 10%.

  In this silicone varnish, 2.0 parts of ion-exchanged water and 2.0 parts of the following curing agent (2), 1.0 part of the following aminosilane coupling agent (11) and 5 parts per 100 parts of the siloxane solid form 0.0 parts of the following silane coupling agent (18) and 1% by mass of carbon black were simultaneously added to prepare a carrier coating solution I. This solution I was applied to 100 parts of the above-mentioned carrier core material with an applicator (Okada Seiko Co., Ltd .: Spiracoater) so that the resin coating amount was 1 part, and carrier A was obtained.

  The obtained toner 1 and carrier A were mixed at a toner concentration of 8%, and image evaluation was performed using a color composite machine (image RUNNER iRC3580, manufactured by Canon Inc.). Below, the evaluation method and evaluation criteria of this invention are demonstrated.

The fixing device of the color multifunction device was taken out, and the external fixing device modified so that the fixing temperature and the process speed can be arbitrarily set is also operated outside the color multifunction device. Using “Color Laser Copier Paper CS-814 (81.4 g / m ² ) (Canon Marketing Japan Co., Ltd.)” as a transfer for room temperature and normal humidity (N / N: temperature 23.5 ° C., humidity 60% RH) Paper was passed under the environment. Low-temperature fixability is a solid black unfixed image (toner loading amount of 0.45 mg / cm ² ), high-temperature offset resistance is A4 horizontal, the entire 5 cm from the tip is a halftone with an image density of 0.5, and the rest is solid Evaluation was made by passing an unfixed image of white. Unevenness of fixing was evaluated by passing an unfixed image in which a solid patch image having a size of 10 mm × 10 mm was written at 10 positions on the front end of the paper and evenly in a horizontal row. The evaluation results are shown in Table 3.

For low-temperature fixability, the solid black image created by the above method is temperature-regulated every 5 ° C. in the temperature range of 100 to 180 ° C. with a heating device of the fixing device, the process speed is 300 mm / sec, and the nip width is 13 mm. Set and fix. A load of 4.9 kPa was applied to the obtained fixed image, and the fixed image was rubbed back and forth with Sylbon paper 5 times, and the temperature at which the image density reduction rate before and after the rub was 10% or less was evaluated as the fixing start temperature. did. The image density was measured using a Macbeth densitometer (RD-914; manufactured by Macbeth) using an SPI auxiliary filter.
A: Fixing start temperature is less than 120 ° C. B: Fixing start temperature is between 120 ° C. and less than 125 ° C. C: Fixing start temperature is between 125 ° C. and less than 130 ° C. D: Fixing start temperature is between 130 ° C. and less than 135 ° C. E: Fixing start temperature Is over 135 ℃

For high-temperature offset resistance, the unfixed image created by the above method is temperature-regulated every 5 ° C. in the temperature range of 180 to 200 ° C. with a heating device of the fixing device, the process speed is 50 mm / sec, and the nip width is 13 mm. Set and fix. The level of the offset appearing on the white background at this time was visually confirmed.
A: No offset occurs at all. B: At a fixing temperature of 200 ° C., it is slightly off at the end other than the part that has passed through A4 portrait.
A set occurred.
C: An offset occurred in the entire longitudinal direction at a fixing temperature of 200 ° C.
D: At a fixing temperature of 190 ° C., it is slightly off at the end other than the part that has passed through A4 portrait.
A set occurred.
E: Offset occurred at the fixing temperature of 190 ° C. throughout the longitudinal direction.

For storage stability, 5 g of developer was measured in a 100 cc polycup, and the blocking resistance after standing in a constant temperature and humidity chamber at 45 ° C. and 95% RH for 30 days was evaluated visually using the following evaluation criteria. .
A: There is no solidified state B: When the cup is turned, it is loosened immediately. C: There is a lump, but it becomes smaller and loosens as the cup is turned. D: A lump remains even if the cup is turned. E: Large There is a lump and it won't unravel when you turn the cup

For fixing unevenness, an unfixed image created by the above method is fixed by setting the heating device of the fixing device to 180 ° C., setting the process speed to 280 mm / sec, and the nip width to 13 mm, and patch images at 10 locations. The difference between the maximum and minimum gross values was evaluated. The gloss value was measured using a handy gloss meter gloss checker (trade name IG-310, manufactured by Horiba, Ltd.) for the image in the fixed image area.
A: Gloss difference is less than 3 B: Gloss difference is 3 or more and less than 6 C: Gloss difference is 6 or more and less than 9 D: Gloss difference is 9 or more and less than 12 E: Gloss difference is 12 or more

[Examples 2 to 8]
In the preparation of the toner of Example 1, toners 2 to 8 were prepared and a developer was prepared according to Example 1, except that the resin dispersions 2 to 8 were used instead of the resin dispersion 1. Evaluation according to 1 was performed.

[Example 9]
(Production of toner)
Resin dispersion 1 400.0 parts Release agent dispersion 40.0 parts Colorant dispersion 40.0 parts The above materials were put into a 3 liter reaction vessel equipped with a stirrer, a condenser, and a thermometer and stirred. . To this mixed solution, a 1.0% by mass aqueous nitric acid solution was added to adjust the pH to 3.0.

  As a flocculant, 1.5 parts of a 10% by mass polyaluminum chloride aqueous solution (manufactured by Asada Chemical Co., Ltd.) was added dropwise to the mixed solution, and the flask was heated to a temperature of 50 ° C. while stirring the inside of the flask. At this temperature, 3 parts of resin dispersion 1 and 10 parts of dispersion of charge control agent particles were added and held for 30 minutes. Thereafter, the total amount of the additional particle dispersion prepared previously was added over 3 minutes and held for 30 minutes.

  5 mass% sodium hydroxide aqueous solution was added here and pH was set to 9.0. Thereafter, an operation according to Example 1 was performed to prepare toner 9 and a developer, and evaluation according to Example 1 was performed.

[Comparative Examples 1 to 5]
In preparation of the toner of Example 1, toners 10 to 14 and preparation of a developer were prepared according to Example 1, except that the resin dispersions 9 to 13 were used instead of the resin dispersion 1. Evaluation according to 1 was performed.

[Comparative Example 6]
(Production of toner)
Resin dispersion 14 40.0 parts Resin dispersion 15 360.0 parts Release agent dispersion 40.0 parts Colorant dispersion 40.0 parts 3 liters of the above materials equipped with a stirrer, cooling tube and thermometer The reaction vessel was charged and stirred. To this mixed solution, a 1.0% by mass aqueous nitric acid solution was added to adjust the pH to 3.0.

  As a flocculant, 1.5 parts of a 10% by mass polyaluminum chloride aqueous solution (manufactured by Asada Chemical Co., Ltd.) was added dropwise to this mixed solution, and the mixture was heated to a temperature of 50 ° C. while stirring in the heating oil bath. At this temperature, 3 parts of resin dispersion 15 and 10 parts of dispersion of charge control agent particles were added and held for 30 minutes. Thereafter, the total amount of the additional particle dispersion prepared previously was added over 3 minutes and held for 30 minutes.

  5 mass% sodium hydroxide aqueous solution was added here and pH was set to 9.0. Thereafter, an operation according to Example 1 was performed to prepare toner 15 and a developer, and evaluation according to Example 1 was performed.

Claims (4)

A toner having toner particles containing a binder resin, a colorant and a release agent,
The toner particles are prepared by mixing a dispersion of resin fine particles, a dispersion of the colorant, and a dispersion of the release agent to prepare a mixed solution, and the resin fine particles, the colorant, and the release agent are mixed in the mixture. Toner particles produced by producing aggregated particles containing a mold agent to prepare a dispersion of the aggregated particles, heating the dispersion and fusing the aggregated particles;
The binder resin is produced from the resin fine particles,
The resin fine particles contain a polyester resin as a main component,
The polyester resin has a first endothermic peak P1 at a temperature of 55 to 75 ° C. and a second endothermic peak P2 at a temperature of 80 to 120 ° C. in a DSC endothermic curve measured by a differential scanning calorimeter.
Toner characterized by the above.   The toner according to claim 1, wherein the endothermic amount of the second endothermic peak P2 is 0.20 J / g to 2.00 J / g.   The toner particles contain 1 to 20 parts by mass of the colorant and 4 to 25 parts by mass of the release agent with respect to 100 parts by mass of the binder resin. The toner according to claim 1, wherein the toner is a toner.   The toner according to claim 1, wherein the binder resin is generated from the resin fine particles and other resin fine particles.

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