JP2005084468A - Method for manufacturing toner, toner and image forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing toner by which no unevenness in charge amount between toner lots is ensured, a toner excellent in storage stability of the toner is obtained, and a toner image having good fixability and no emission of a foul odor during heat fixation are achieved, and to provide a toner. <P>SOLUTION: In the method for manufacturing a toner including a step of forming particles in an aqueous medium, a step of treating a toner composition or toner particles in the aqueous medium with ozonized water is included. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a toner manufacturing method used for a copying machine, a printer, and the like, a toner, and an image forming method using the toner.

  In recent years, digital image formation has become mainstream in electrophotographic image forming methods due to progress in digital technology. The digital image forming method is based on visualizing a small dot image of one pixel such as 1200 dpi (dpi is the number of dots per inch, that is, 2.54 cm). High image quality technology that reproduces the image is required.

  From the viewpoint of such high image quality, toner particle size is being reduced. So far, so-called pulverized toner, in which toner powder obtained by mixing a binder resin and a pigment, kneading and pulverizing, is classified in a classification process has been mainly used for forming an electrophotographic image. However, the toner obtained through such a manufacturing process has limitations in reducing the toner particle size and making the particle size distribution uniform. Accordingly, it is difficult to achieve sufficient image quality in an electrophotographic image using such pulverized toner.

  In recent years, a polymerized toner obtained by a suspension polymerization method or an emulsion polymerization method has attracted attention as a means for achieving a reduction in the particle size of toner particles, a uniform particle size distribution, and a uniform shape.

  In this polymerization method, resin particles and, if necessary, colorant particles are associated or salted out / fused to produce an irregularly shaped toner, or a radically polymerizable monomer is mixed and dispersed. Then, there is a method in which the obtained dispersion liquid is dispersed into droplets having a desired toner particle size in a solution, and this is subjected to suspension polymerization. Among these, the former polymerization method is a preferable method for forming an amorphous toner. In this polymerization method, polymerization is performed using a water-soluble polymerization initiator in a solution. At this time, a chain transfer agent is used to control the molecular weight distribution, and a mercaptan-based compound is used as a suitable chain transfer agent.

  However, it is difficult to completely remove volatile substances such as residual polymerizable monomers and degradation products such as chain transfer agents from the toner particles during toner production.

  Toner in which a large amount of volatile substances such as polymerizable monomers and chain transfer agents remain, toner aggregation is likely to occur during storage of the toner, and with the developer using the aggregated toner, the image quality deteriorates during image formation, Problems such as the inability to obtain good quality images and the occurrence of odor due to volatilization of polymerizable monomers and volatile substances remaining in the toner at the time of heat fixing occur.

  The problem caused by the remaining volatile substances such as polymerizable monomers and chain transfer agents in the toner is a problem with so-called pulverized toner obtained by melt-kneading and pulverizing a binder resin and a colorant. There was no particular problem. The reason is that the binder resin used in the pulverized toner can be produced at 100 ° C. or higher, and even if it contains residual polymerizable monomers or volatile substances, the toner is produced. It was not regarded as a problem because it was removed by heating in the melt-kneading process.

  However, since the polymerized toner does not have a melt-kneading process at the time of manufacture, the opportunity to remove the polymerizable monomer and volatile substance remaining in the toner is less than that of the pulverized toner. As a result, it is considered that the polymerizable monomer and the volatile substance remain in the toner to cause the above problem.

In response to the above problems, attempts have been made to reduce the amount of polymerizable monomers and volatile substances by regulating the amount of residual styrene monomer in the toner and by regulating the amount of residual monomer. However, the problem that odor is generated at the time of heat fixing cannot be solved, and the performance is not sufficient (see, for example, Patent Document 1 and Patent Document 2).
JP 2002-251037 A JP 2002-49176 A

  The present invention has been proposed in view of the above circumstances, and the object of the present invention is to obtain a toner having no variation in charge amount between toner lots and having excellent storage stability and good fixing during image formation. It is an object of the present invention to provide a toner production method, toner, and an image forming method using the same, which do not generate property and odor.

The object of the present invention is achieved by adopting the following configuration.
(Claim 1)
A toner production method comprising a step of forming particles in an aqueous medium, the method comprising the step of treating the toner composition or toner particles in the aqueous medium with ozone water.
(Claim 2)
In the toner manufacturing method including a step of solid-liquid separation of a toner particle dispersion containing toner particles in which particles are formed in an aqueous medium, the step of treating with ozone water forms the particles in the aqueous medium. The toner manufacturing method according to claim 1, wherein the toner manufacturing method is performed in
(Claim 3)
In the toner manufacturing method including a step of solid-liquid separation of a toner particle dispersion containing toner particles in which particles are formed in an aqueous medium, the step of treating with ozone water dehydrates or concentrates the toner particle dispersion. The toner manufacturing method according to claim 1, wherein the toner manufacturing method is performed in a step of dispersing in a post-cleaning medium.
(Claim 4)
In the toner manufacturing method including a step of solid-liquid separation of a toner particle dispersion containing toner particles in which particles are formed in an aqueous medium, the step of treating with ozone water is performed in the step of solid-liquid separation. The toner production method according to claim 1, wherein the toner production method is used.
(Claim 5)
In the toner manufacturing method including a step of solid-liquid separation of a toner particle dispersion containing toner particles in which particles are formed in an aqueous medium, the step of treating with ozone water forms the particles in the aqueous medium. The toner production method according to claim 1, wherein the toner production method is performed in at least two steps of a step of dehydrating or concentrating and then dispersing in a cleaning medium and a step of solid-liquid separation.
(Claim 6)
A toner produced through the process according to claim 1.
(Claim 7)
The peak of a volatile substance by a head space gas chromatograph method exists between n-hexane and n-hexadecane, and the total area of those peaks is 0.5-20 ppm in terms of toluene, The toner described in 1.
(Claim 8)
A toner image is formed on the electrostatic latent image carrier using the toner according to claim 6, and the toner image transferred onto the transfer member is heated and fixed to form an image. Image forming method.

  According to the present invention, it is possible to provide a toner having no variation in charge amount between toner lots and having excellent storage stability. Further, when an image is formed using the toner obtained in the present invention, it is possible to provide a toner that exhibits good fixability and does not cause odor problems during the heat fixing process. As a result, it has become possible to realize a comfortable printing work environment without odor during image formation.

  The present inventors have considered that it is important to control the residual amount of volatile substances in the toner. This is because the inventors analyzed the deposits on the carrier in the two-component developer and the deposits on the developer transport member and the developer layer regulating member, and as a result, toner with a large residual amount of volatile substances adhered. It was a knowledge gained from doing this.

  Volatile substances remaining in the toner may cause problems such as toner aggregation when the toner is stored, and odor when the toner image is heat-fixed on the transfer body (transfer paper) during image formation. Was.

  Further, the volatile substance in the gas state generated in the fixing process has not only a problem of odor but also a problem of deteriorating the resin parts of the image forming apparatus and making it difficult to reuse the parts.

  In order to solve these problems, there is a method of reducing the residual amount of volatile substances by sufficiently carrying out the polymerization reaction, but this method increases the molecular weight of the binder resin, increases the softening point of the toner, and fixes the fixing property. Therefore, the polymerization reaction is not allowed to proceed unnecessarily.

  Therefore, the present inventors have studied the specific residual amount level of volatile substances that do not cause the above-mentioned problems including odor problems, etc., and considered solving these problems by controlling the residual amount. did.

  From the examination results of the present inventors, it was confirmed that the above problem can be solved by setting the residual amount of the volatile substance to 0.5 to 20 ppm, preferably 1.0 to 10 ppm. The residual amount of volatile substances referred to here is measured by a head space gas chromatograph method described later.

  Specific methods for bringing the residual amount of the volatile substance into the above range include various methods such as heating, extending the polymerization time, and increasing the amount of the polymerization initiator. It was intended to promote the process and was not preferable. Therefore, as a result of intensive studies, the present inventors have established a treatment process with ozone water during the toner production process, and the toner composition and toner particles in the aqueous medium are treated with ozone water, so that the volatile substance is effective. As a result, the present invention was found.

  Examples of volatile substances remaining in the toner include unreacted polymerizable monomers and chain transfer agents, by-products at the time of toner production, and organic solvents used for the production.

  Examples of the polymerizable monomer include polymerizable monomers such as styrene, acrylic acid, methacrylic acid, acrylic acid, ethyl acrylate, and butyl acrylate, or decomposition products thereof.

  Examples of the chain transfer agent include n-octyl mercaptan and n-decyl mercaptan, and examples of the by-products at the time of toner production include butanol, dodecanol, dodecanal, acrylic acid ester, and benzaldehyde.

  Examples of the organic solvent when an organic solvent is used for production include butanol, xylene, ethylbenzene, ethyl acetate, butyl acetate and the like.

  The toner according to the present invention can be obtained by a production method including a step of treating a toner composition or toner particles in an aqueous medium with ozone water.

  Specifically, as the step of treating with ozone water, a step of adding and stirring as an additive liquid to a reaction vessel for forming toner particles, a diluting liquid to a stirring tank for concentrating and redispersing the toner particle dispersion liquid Examples include a step of adding and stirring, a step of washing a toner cake formed by solid-liquid separation with a washing solution, or a step of combining two or more of the above steps. The toner composition or toner particles are contacted with ozone water to volatilize. There is no particular limitation as long as the active substance can be decomposed and removed from the system.

  The ozone water treatment referred to in the present invention is completed by decomposing and washing the low molecular weight organic compound in the system with ozone water (water containing ozone), and further removing the decomposition products by a drying process.

  Ozone water has a strong oxidizing power and is preferable for efficiently decomposing volatile substances. In addition, ozone water returns to oxygen when left unattended, so there is no danger of remaining in the toner particles, and the toner treated with ozone water expresses a stable toner image during image formation and considers the user and the environment. Is.

  Examples of the ozone water production apparatus include a method of directly electrolyzing water, a silent discharge method, an electrolysis method or a method of blowing ozone gas generated by an ultraviolet lamp method into water, and ozone produced by any method. There is no problem with water, and among these, the method of blowing ozone gas generated by the silent discharge method into water is preferable because high-concentration ozone water can be obtained at low cost.

  A commercially available device can be used as the ozone water production device, such as “D-OZONE Super 500” (manufactured by Shinko Plant Construction Co., Ltd.), “Ozex Water FZW”, “Ozex Water ZW” (manufactured by Rokienji Co., Ltd.) And the like.

  The present inventors examined using ozone gas that oxidatively decomposes organic compounds as a means for effectively removing only volatile substances that are low molecular weight organic compounds from the system. However, since ozone gas is processed at a high concentration, it has been found that the toner composition in the system is decomposed and is not preferable.

  Therefore, the inventors of the present invention used ozone water in which the reaction of ozone was relaxed and performed processing in liquid for a long time. As a result, only low molecular weight volatile substances in the system were obtained without damaging the toner composition. It was found that it can be selectively decomposed.

  The higher the ozone concentration in the ozone water, the stronger the oxidizing power and the more volatile substances can be decomposed in a short time. At the same time, however, the toner composition (for example, resin component) also decomposes, causing a problem. A range in which only volatile substances can be decomposed without decomposing them is preferable.

  Specifically as ozone concentration contained in ozone water, 5-150 ppm is preferable and 10-60 ppm is more preferable.

The treatment time with ozone water is preferably 30 seconds to 2 hours. The amount of ozone water required for the toner particles to process ozone water is preferably toner particles 1kg per 0.1~30m ^3, 1~10m ³ is more preferable. Moreover, it is preferable to adjust pH of ozone water to 8-12, and it has been confirmed that the effect of this invention is fully expressed by setting it as pH of this range.

  In addition, the ozone concentration in ozone water is the unbuffered KI method introduced in “Ozone concentration measurement guidelines in ozone generators” published by the Japan Ozone Association (Iodine is liberated by the reaction between ozone and potassium iodide in ozone water). Can be measured.

  Next, a method for producing a toner particle dispersion will be described.

  Examples of the method for producing the toner particle dispersion include, but are not limited to, an emulsion association method, a suspension polymerization method, a dispersion polymerization method, a dissolution suspension method, and a continuous emulsion dispersion method.

  Hereinafter, a method for producing a toner particle dispersion by an emulsion association method and a dispersion polymerization method, which are excellent in that the particle size distribution is sharp, will be described.

  A method for producing a toner particle dispersion by emulsion polymerization is a method for forming toner particles in an aqueous medium, and is disclosed in, for example, JP-A-2002-351142.

  In addition, the resin particles disclosed in JP-A-5-265252, JP-A-6-329947, and JP-A-9-15904 are salted out / fused in an aqueous medium to produce a toner particle dispersion. A method can be mentioned.

  Specifically, after resin particles are dispersed in water using an emulsifier, a coagulant having a critical coagulation concentration or higher is added for salting out, and at the same time, heat fusion is performed at or above the glass transition temperature of the formed polymer itself. Gradually grow the particle size while forming fused particles, stop the particle size growth by adding a large amount of water when the desired particle size is reached, and further smooth the particle surface while heating and stirring The shape is controlled to prepare a toner particle dispersion.

  The method for producing a toner particle dispersion by dispersion polymerization is to dissolve a monomer and a polymerization initiator simultaneously in a good solvent in which the monomer is soluble, and precipitate the polymer component that is no longer soluble in the solvent as the polymerization proceeds. It is a method of forming. As the solvent, methanol is generally used, and solid-liquid separation is generally performed in an alcohol medium, or in an aqueous medium in which water and alcohol are mixed.

  The amount of the volatile substance can be measured by a head space gas chromatograph method. The peak of the volatile substance by a head space gas chromatograph method exists between n-hexane and n-hexadecane, and the total area of those peaks is 0.5-20 ppm in toluene conversion, It is characterized by the above-mentioned.

  By setting the amount of volatile substances measured by headspace gas chromatography within this range, there is no variation in charge amount between toner lots, excellent toner storage stability, good toner image fixability, and thermal fixing. It is possible to obtain a toner that sometimes does not generate odor.

  In the present invention, the head space type used for the determination of the volatile substance remaining in the toner means that the toner is sealed in an open / close container and heated at the time of heat fixing such as a copying machine, and the volatile component is contained in the container. In a state where the gas is filled, the gas in the container is quickly injected into the gas chromatograph to measure the amount of volatile components, and in the headspace method of the present invention, MS (mass spectrometry) is also performed. As a method for measuring the amount of impurities derived from the binder resin and a small amount of additive, a method in which the binder resin or toner is dissolved in a solvent and injected into a gas chromatograph is well known. In some cases, the peaks of impurities and trace amounts of additive components to be measured may be hidden, which is not suitable for measuring the total amount of volatile substances. In the headspace method used in the present invention, it is possible to observe all peaks of volatile substances by gas chromatograph, and by using an analysis method utilizing electromagnetic interaction, it is possible to quantify residual components with high accuracy. Has been achieved.

Below, the measuring method by a head space method is demonstrated in detail.
<Measuring method>
1. Sample collection A 0.8 g sample is collected in a 20 ml headspace vial. The sample amount is weighed to 0.01 g (necessary for calculating the area per unit mass). Seal the vial with a septum using a dedicated crimper.
2. Heating the sample Place the sample in a 170 ° C constant temperature bath and heat for 30 minutes.
3. Setting of gas chromatographic separation conditions A column coated with silicon oil SE-30 so as to have a mass ratio of 15% and packed in a column having an inner diameter of 3 mm and a length of 3 m is used as a separation column. The separation column is attached to a gas chromatograph, and He is used as a carrier to flow at 50 ml / min. The temperature of the separation column is set to 40 ° C., and measurement is performed while the temperature is increased to 260 ° C. at 15 ° C./min. Hold for 5 minutes after reaching 260 ° C.
4). Sample introduction Remove the vial from the thermostat and immediately inject 1 ml with a gas tight syringe.
5). Calculation In this invention, the substance detected between the peak of n-hexane and the peak of n-hexadecane is quantified as the total amount of volatile substances.

For quantitative determination of the polymerizable monomer, a calibration curve is prepared in advance using the polymerizable monomer used for the polymerization as a reference substance, and the concentration of each component is determined.
6). Equipment (1) Headspace conditions Headspace device HP7694 manufactured by Hewlett-Packard Co., Ltd.
"Head Space Sampler"
Temperature conditions Transfer line: 200 ° C
Loop temperature: 200 ° C
Sample amount: 0.8 g / 20 ml vial (2) GC / MS condition GC HP 890 manufactured by GC Hewlett-Packard Co., Ltd.
HP 5971 made by MS Hewlett-Packard Co., Ltd.
Column: HP-624 30m x 0.25mm
Oven temperature: held at 40 ° C. for 3 minutes, and then heated up to 200 ° C. at 10 ° C./min in 16 minutes. Thereafter, the temperature is maintained at 200 ° C.

Measurement mode: SIM
In the actual measurement in the present invention, pre-measurement of n-hexane and n-hexadecane of the reference sample is performed with the above oven temperature program, and the detection times of the peaks of both substances are confirmed in advance. Then, sample measurement is performed with the said oven temperature program, and the peak total area of the substance detected between the peak detection time of n-hexane to the peak detection time of n-hexadecane is converted with a toluene calibration curve. The peak of 0.1 ppm or more in terms of toluene equivalent per peak is targeted. The volatile substances and polymerizable monomers detected during this time are quantified.

  Next, a toner manufacturing method having a process of treating with ozone water will be described in detail.

  The toner according to the present invention has a step of solid-liquid separating a toner particle dispersion containing toner particles formed in an aqueous medium, in which the toner composition or toner particles are treated with ozone water. The toner particles can be produced by a production method in which an external additive is added to and mixed with the toner particles as necessary.

  Examples of the aqueous medium include, but are not particularly limited to, water, methanol, ethanol, isopropanol, butanol, 2-methyl-2-butanol, acetone, methyl ethyl ketone, tetrahydrofuran, or a mixture thereof. . A suitable toner can be selected from among these.

  A method for producing a dispersion of toner particles can be prepared by a known production method. Specifically, an emulsion association method, a suspension polymerization method, a dispersion polymerization method, a dissolution suspension method, a continuous emulsion dispersion method, etc. Can be mentioned.

  Hereinafter, a method for producing a toner particle dispersion by an emulsion association method and a dispersion polymerization method will be described.

  A method for producing a toner particle dispersion by emulsion polymerization is a method for forming toner particles in an aqueous medium, and is disclosed in, for example, JP-A-2002-351142.

  In addition, the resin particles disclosed in JP-A-5-265252, JP-A-6-329947, and JP-A-9-15904 are salted out / fused in an aqueous medium to produce a toner particle dispersion. A method can be mentioned.

  Specifically, after resin particles are dispersed in water using an emulsifier, a coagulant having a critical coagulation concentration or higher is added for salting out, and at the same time, heat fusion is performed at or above the glass transition temperature of the formed polymer itself. Gradually grow the particle size while forming fused particles, stop the particle size growth by adding a large amount of water when the desired particle size is reached, and further smooth the particle surface while heating and stirring The shape is controlled to prepare a toner particle dispersion. Here, a solvent that is infinitely soluble in water, such as alcohol, may be added simultaneously with the flocculant.

  The method for producing a toner particle dispersion by dispersion polymerization is to dissolve a monomer and a polymerization initiator simultaneously in a good solvent in which the monomer is soluble, and precipitate the polymer component that is no longer soluble in the solvent as the polymerization proceeds. It is a method of forming. As the solvent, methanol is generally used, and solid-liquid separation is generally performed in an alcohol medium, or in an aqueous medium in which water and alcohol are mixed.

  Even if the toner particle dispersion liquid produced by any of the above production methods is used, the volatile substance can be brought into the above range by ozone water treatment, but in the above production method, the toner particle dispersion produced by emulsion polymerization is used. The liquid is suitable for ozone water treatment.

  Examples of the solid-liquid separator include a rotary cylindrical dehydrator, a horizontal belt dehydrator, and the like. Among these, the rotary cylindrical dehydrator is preferable in terms of space.

  FIG. 1 is a production flow diagram showing an example of a method for producing toner particles preferably used in the present invention (adding ozone water as an additive liquid into a reaction vessel).

  In FIG. 1, 701 is a reaction vessel, 702 is a concentration device, 703 is a stirring tank, 704 is a solid-liquid separation device, 705 is a stock tank, 705 is a drying device, 601 is an ozone water tank for the reaction vessel, and 604 is a toner cake. Show.

  The ozone water in the reaction vessel ozone water tank 601 is added as an additive to the reaction vessel 701 in which the toner particle dispersion shown in FIG. 1 is formed, and stirred to decompose the volatile substances in the reaction vessel. Thereafter, the toner particle dispersion is concentrated from the reaction vessel 701 by the concentration device 702 and then sent to the agitation tank 703. In the agitation tank 702, a diluted solution is added to the concentrated toner particles and redispersed to adjust the toner particle dispersion to a concentration suitable for solid-liquid separation. Thereafter, the toner particle dispersion in the agitation tank 703 is put into a solid-liquid separator 704 and solid-liquid separated to form a toner cake 604. The toner cake 604 is washed with water and then dehydrated by rotating the basket of the solid-liquid separator 704 at a high speed and taken out from the toner cake discharge port by a scraping device. The taken-out toner cake 604 is stored in a stock tank 705, and is preferably unwound and then sent to a drying device 706 to be dried to obtain toner particles.

  FIG. 2 is a production flow diagram showing an example of a method for producing toner particles (adding ozone water into a stirring vessel) preferably used in the present invention.

  In FIG. 2, 701 is a reaction vessel, 702 is a concentration device, 703 is a stirring tank, 704 is a solid-liquid separation device, 705 is a stock tank, 705 is a drying device, 602 is an ozone water tank for the stirring tank, and 604 is a toner cake. Show.

  The toner particle dispersion in the reaction vessel 701 shown in FIG. 2 is sent to the concentrating device 702, concentrated by the concentrating device 702, and then sent to the stirring tank. In the agitation tank 702, the toner particles concentrated and solidified are added with the ozone water in the ozone water tank 602 for the agitation tank and agitated and redispersed to decompose the volatile substances and disperse the toner particles at a concentration suitable for solid-liquid separation. Adjust to. Thereafter, the toner particle dispersion in the agitation tank 703 is put into a solid-liquid separator 704 and solid-liquid separated to form a toner cake 604. The toner cake 604 is washed with water and then dehydrated by rotating the basket of the solid-liquid separator 704 at a high speed and taken out from the toner cake discharge port by a scraping device. The taken-out toner cake 604 is stored in a stock tank 705, and preferably is unwound and then sent to a drying device 706 to be dried to obtain toner particles.

  FIG. 3 is a manufacturing flow diagram (manufacturing process diagram) showing an example of a toner particle manufacturing method (a toner cake in a solid-liquid separator is washed with ozone water) preferably used in the present invention.

  In FIG. 3, 701 is a reaction vessel, 702 is a concentrating device, 703 is a stirring tank, 704 is a solid-liquid separation device, 705 is a stock tank, 705 is a drying device, 603 is an ozone water tank for cleaning toner cake, and 604 is a toner cake. Indicates.

  The toner particle dispersion in the reaction vessel 701 shown in FIG. 3 is sent to the concentrating device 702, concentrated by the concentrating device 702, and then sent to the stirring tank. In the agitation tank 702, a diluted liquid is added to the concentrated toner particles, and the mixture is stirred and redispersed to adjust the toner particle dispersion to a concentration suitable for solid-liquid separation. Thereafter, the toner particle dispersion in the agitation tank 703 is put into a solid-liquid separator 704 and solid-liquid separated to form a toner cake 604. The toner cake 604 is washed with ozone water in a toner cake cleaning ozone water tank 603, and the remaining volatile substances are decomposed. Thereafter, the basket of the solid-liquid separator 704 is rotated at high speed for dehydration, and is taken out from the toner cake discharge port by the scraping device. The taken-out toner cake 604 is stored in a stock tank 705, and preferably is unwound and then sent to a drying device 706 to be dried to obtain toner particles.

  In the present invention, two or more treatments with ozone water described in FIGS. 1, 2 and 3 can be combined.

  The toner according to the present invention may be used as it is with the toner particles produced as described above, but for the purpose of improving fluidity and cleaning properties, a so-called external additive is added to the toner particles. be able to. These external additives are not particularly limited, and various inorganic fine particles, organic fine particles and lubricants can be used.

  Examples of inorganic fine particles that can be used as an external additive include conventionally known fine particles. Specifically, silica fine particles, titanium fine particles, alumina fine particles and the like can be preferably used. These inorganic fine particles are preferably hydrophobic.

  Specific examples of the silica fine particles include commercially available products R-805, R-976, R-974, R-972, R-812, R-809 manufactured by Nippon Aerosil Co., Ltd., HVK-2150, H manufactured by Hoechst Co., Ltd. -200, commercially available products TS-720, TS-530, TS-610, H-5, MS-5, spherical monodispersed silica manufactured by Cabot Corporation.

  Specific examples of the titanium fine particles include, for example, commercial products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., and commercial products MT-100S, MT-100B, MT-500BS, MT-600, and MT manufactured by Teika Co., Ltd. -600SS, JA-1, commercial products TA-300SI, TA-500, TAF-130, TAF-510, TAF-510T manufactured by Fuji Titanium Co., Ltd., commercial products IT-S, IT-OA manufactured by Idemitsu Kosan Co., Ltd. , IT-OB, IT-OC, rutile titanium oxide and the like.

  Specific examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd., and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

  Examples of the organic fine particles that can be used as the external additive include spherical fine particles having a number average primary particle diameter of about 10 to 2000 nm. Examples of the constituent material of the organic fine particles include polystyrene, polymethyl methacrylate, styrene-methyl methacrylate copolymer and the like.

  Examples of the lubricant that can be used as an external additive include metal salts of higher fatty acids. Specific examples of such higher fatty acid metal salts include: stearic acid metal salts such as zinc stearate, aluminum stearate, copper stearate, magnesium stearate, calcium stearate; zinc oleate, manganese oleate, iron oleate, olein Oleic acid metal salts such as acid copper and magnesium oleate; palmitate metal salts such as zinc palmitate, copper palmitate, magnesium palmitate and calcium palmitate; linoleic acid metal salts such as zinc linoleate and calcium linoleate; ricinol Examples include ricinoleic acid metal salts such as zinc acid and calcium ricinoleate.

  The addition amount of the external additive is preferably about 0.1 to 5% by mass with respect to the toner particles.

  Examples of the apparatus for adding and mixing the external additive into the toner particles include various known mixing apparatuses such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer.

  Next, the developer will be described.

  The developer preferably used in the present invention is a mixture of toner and carrier and used as a two-component developer.

  As the carrier, known magnetic particles made of metals such as iron, ferrite, and magnetite, alloys of these metals with metals such as aluminum and lead, and the like can be used. Among these, ferrite particles are preferable. The volume average particle diameter of the magnetic particles is preferably 15 to 100 μm, more preferably 25 to 80 μm.

  The volume average particle diameter of the carrier can be measured by a laser diffraction particle size distribution measuring apparatus “Heros” (manufactured by Sympathic Co., Ltd.) equipped with a wet disperser.

  As the carrier, a carrier in which magnetic particles are further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in a resin can be used. The resin for coating is not particularly limited, and known resins can be used. Specifically, olefin resins, styrene resins, styrene-acrylic resins, silicone resins, ester resins, or fluorine-containing resins can be used. Polymer based resins and the like are used. In addition, the resin for constituting the resin-dispersed carrier is not particularly limited, and known resins can be used. Specifically, styrene-acrylic resins, polyester resins, fluorine resins, phenol resins, etc. Can be used.

  Next, an image forming method will be described.

  The image forming method used in the present invention is a method using heat fixing for fixing a toner image.

  The heat fixing method is not particularly limited, and any of a contact fixing (human roll) method and a non-contact fixing (oven fixing, flash fixing, microwave fixing, etc.) method can be used.

  FIG. 4 is a cross-sectional configuration diagram of an image forming apparatus showing an example of an image forming method using toner according to the present invention.

  The image forming apparatus shown in FIG. 4 is a digital image forming apparatus, and includes an image reading unit A, an image processing unit B (not shown), an image forming unit C, and a transfer paper transport unit D as a transfer paper transport unit. It is configured.

  The upper part of the image reading unit A is provided with automatic document feeding means for automatically conveying the document. The document placed on the document placing table 111 is separated and conveyed by the document conveying roller 112 to the reading position 113a. The image is read. The document after the document reading is completed is discharged onto the document discharge tray 114 by the document transport roller 112.

  On the other hand, the image of the original when placed on the platen glass 113 is read at a speed v of the first mirror unit 115 including the illumination lamp and the first mirror constituting the scanning optical system, and the V-shaped first image is located. Reading is performed by moving the second mirror unit 116 composed of the two mirrors and the third mirror in the same direction at the speed v / 2.

  The read image is formed on the light receiving surface of the image sensor CCD, which is a line sensor, through the projection lens 117. The line-shaped optical image formed on the image sensor CCD is sequentially photoelectrically converted into an electric signal (luminance signal) and then A / D converted, and the image processing unit B performs processing such as density conversion and filter processing. Then, the image data is temporarily stored in the memory.

  In the image forming unit C, as an image forming unit, a drum-shaped photosensitive member (hereinafter also referred to as a photosensitive drum) 121 that is an electrostatic latent image carrier, a charger 122 that is a charging unit, and a developing unit are provided on the outer periphery thereof. Developing device 123, transfer device 124 as transfer means, separator 125 as separation means, cleaning device 126 and PCL (precharge lamp) 127 are arranged in the order of operation. The photoconductor 121 is formed by coating a photoconductive compound on a drum base. For example, an organic photoconductor (OPC) is preferably used, and is driven to rotate in the clockwise direction shown in the drawing.

  After the rotating photosensitive member 121 is uniformly charged by the charger 122, the exposure optical system 130 performs image exposure based on the image signal called from the memory of the image processing unit B. The exposure optical system 130 as writing means uses a laser diode (not shown) as a light source, passes through a rotating polygon mirror 131, an fθ lens (no symbol), and a cylindrical lens (no symbol), and the optical path is bent by a reflection mirror 132 to perform main scanning. Thus, image exposure is performed on the photoconductor 121 at the position Ao, and a latent image is formed by rotation (sub-scanning) of the photoconductor 121. In one example of the present embodiment, the character portion is exposed to form a latent image.

  The latent image on the photoconductor 121 is reversely developed by the developing device 123, and a visible toner image is formed on the surface of the photoconductor 121. In the transfer paper transport section D, paper feed units 141 (A), 141 (B), and 141 (C) are provided below the image forming unit as transfer paper storage means for storing transfer paper P of different sizes. Further, a manual paper feeding unit 142 that performs manual paper feeding is provided on the side, and the transfer paper P selected from any of them is fed along the transport path 140 by the guide roller 143 and fed. The transfer paper P is temporarily stopped by a pair of registration rollers 144 that corrects the inclination and bias of the transfer paper to be transferred, and then fed again, and is guided to the transport path 140, the pre-transfer roller 143a, and the transfer entrance guide plate 146. The toner image on the photoconductor 121 is transferred to the transfer paper P by the transfer device 124 at the transfer position Bo, and then the charge is removed by the separator 125, so that the transfer paper P is transferred from the surface of the photoconductor 121. Separated, it is conveyed to the fuser 150 by a conveying device 145.

  The heat fixing device 150 includes a heat fixing roller 151 and a pressure roller 152. By passing the transfer paper P between the heat fixing roller 151 and the pressure roller 152, the toner is heated and pressed. Weld. After the toner image is heated and fixed, the transfer paper P is cooled by the cooler 163 and discharged onto the paper discharge tray 164. The transfer paper P discharged to the paper discharge tray 164 is aligned and used by hand. At this time, it is preferable to cool the transfer paper immediately after paper discharge during continuous printing by a cooler so that the temperature becomes 80 ° C. or lower.

  The present invention will be specifically described below with reference to examples, but the embodiments of the present invention are not limited to these examples.

<Manufacture of toner>
<Preparation of Toner Particle Dispersion 1 (Example of Emulsion Association Method)>
(Preparation of latex (1HML))
(1) Preparation of core particles (first stage polymerization)
An anionic surfactant in a 7000 ml separable flask equipped with a stirrer, temperature sensor, condenser, and nitrogen inlet
C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₂ OSO ₃ Na
A surfactant solution (aqueous medium) in which 7.08 g was dissolved in 3010 g of ion-exchanged water was charged, and the temperature in the flask was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.

To this surfactant solution, an initiator solution prepared by dissolving 9.2 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water was added, the temperature was adjusted to 75 ° C., and then 70.1 g of styrene, n -A monomer mixture consisting of 19.9 g of butyl acrylate and 10.9 g of methacrylic acid was added dropwise over 1 hour, and this system was polymerized by heating and stirring at 75 ° C for 2 hours (first stage polymerization). And a latex (a dispersion of resin particles made of a high molecular weight resin) was prepared. This is referred to as “latex (1H)”.
(2) Formation of intermediate layer (second stage polymerization)
In a flask equipped with a stirrer, a monomer mixture consisting of 105.6 g of styrene, 30.0 g of n-butyl acrylate, 6.2 g of methacrylic acid, and 5.6 g of n-octyl-3-mercaptopropionic acid ester was separated. As a mold, 98.0 g of a compound represented by the following formula (hereinafter referred to as “Exemplary Compound (19)”) was added, heated to 90 ° C. and dissolved to prepare a monomer solution.

Exemplary compound (19)
_{CH 3 (CH 2) 20 COOCH} 2 C (CH 2 OCO (CH 2) 20 CH 3) 3
On the other hand, a surfactant solution obtained by dissolving 1.6 g of an anionic surfactant (the above formula (101)) in 2700 ml of ion-exchanged water is heated to 98 ° C., and a dispersion of core particles is added to the surfactant solution. After adding 28 g of the above-mentioned “latex (1H)” in terms of solid content, a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path is used to The monomer solution was mixed and dispersed for 8 hours to prepare a dispersion (emulsion) containing emulsified particles (oil droplets) having a dispersed particle diameter of 284 nm.

  Next, an initiator solution prepared by dissolving 5.1 g of a polymerization initiator (KPS) in 240 ml of ion-exchanged water and 750 ml of ion-exchanged water are added to this dispersion (emulsion). Polymerization (second-stage polymerization) was carried out by heating and stirring over time to obtain a latex (a dispersion of composite resin particles having a structure in which the surface of resin particles made of a high molecular weight resin was coated with an intermediate molecular weight resin). This is referred to as “latex (1HM)”.

The “latex (1HM)” was dried and observed with a scanning electron microscope. As a result, particles (400 to 1000 nm) mainly composed of the exemplary compound (19) not surrounded by the latex were observed.
(3) Formation of outer layer (third stage polymerization)
An initiator solution in which 7.4 g of a polymerization initiator (KPS) is dissolved in 200 ml of ion-exchanged water is added to the “latex (1HM)” obtained as described above, and styrene is added at a temperature of 80 ° C. A monomer mixed liquid consisting of 300 g, 95 g of n-butyl acrylate, 15.3 g of methacrylic acid, and 10.4 g of n-octyl-3-mercaptopropionic acid ester was added dropwise over 1 hour. After completion of the dropwise addition, polymerization (third stage polymerization) was performed by heating and stirring for 2 hours, followed by cooling to 28 ° C. and latex (a central part made of a high molecular weight resin, an intermediate layer made of an intermediate molecular weight resin, A dispersion of composite resin particles) having an outer layer made of a molecular weight resin and containing the exemplified compound (19) in the intermediate layer was obtained. This latex is referred to as “latex (1HML)”.

The composite resin particles constituting this “latex (1HML)” have peak molecular weights (weights) at 138,000, 80,000 and 13,000, and the weight average particle diameter of the composite resin particles is It was 122 nm.
(Preparation of toner particle dispersion)
Anionic surfactant (sodium dodecyl sulfate) 59.0 g was dissolved in 1600 ml of ion-exchanged water with stirring, and 420.0 g of “CI Pigment Blue 15: 3” was gradually added while stirring this solution. A “colorant particle dispersion” was prepared by dispersion treatment using “CLEARMIX” (manufactured by M Technique Co., Ltd.).

  Reaction in which 420.7 g of “latex (1HML)” (converted to solid content), 900 g of ion-exchanged water, and 166 g of “dispersion of colorant particles” were attached with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device. It stirred in the container (four necked flask). After adjusting the temperature in the container to 30 ° C., 5 mol / L sodium hydroxide aqueous solution was added to this solution to adjust the pH to 8.

  Next, an aqueous solution obtained by dissolving 12.1 g of magnesium chloride hexahydrate in 1000 ml of ion-exchanged water was added at 30 ° C. over 10 minutes with stirring. After standing for 3 minutes, the temperature was started to rise, and the system was heated to 90 ° C. over 6 to 60 minutes to produce associated particles. In this state, the particle size of the associated particles was measured with “Coulter Counter TA-II” (manufactured by Coulter Counter Co., Ltd.). When the volume average particle size reached 6.4 μm, 80.4 g of sodium chloride was ionized. An aqueous solution dissolved in 1000 ml of exchange water was added to stop the particle growth, and further, the particles were fused by heating and stirring at a liquid temperature of 98 ° C. for 2 hours as an aging treatment.

  Thereafter, the mixture was cooled to 30 ° C., hydrochloric acid was added to adjust the pH to 4.5, and “Toner Particle Dispersion 1” was produced.

<Preparation of Toner Particle Dispersion 2 (Example of Emulsion Association Method)>
(Preparation of resin particle dispersion)
A mixture of 370 g of styrene, 30 g of n-butyl acrylate, 8 g of acrylic acid, 24 g of dodecanethiol, and 4 g of carbon tetrabromide was dissolved in 6 g of a nonionic surfactant “nonylphenyl ether” and an anionic surfactant “ Emulsion polymerization was carried out in a flask in which 10 g of sodium dodecylbenzenesulfonate was dissolved in 550 g of ion-exchanged water, and 50 g of ion-exchanged water in which 4 g of ammonium persulfate was dissolved was added thereto while slowly mixing for 10 minutes. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the contents reached 70 ° C., and emulsion polymerization was continued for 5 hours. As a result, “resin fine particle dispersion 2” in which resin particles having a volume average particle diameter = 150 nm, a glass transition temperature = 58 ° C., and a weight average molecular weight = 11500 was dispersed was obtained. The solid content concentration of this dispersion was 40% by mass.

(Preparation of colorant dispersion)
Colorant “CI Pigment Blue 15: 3” 60 parts by weight Nonionic surfactant “Noniphenyl ether” 5 parts by weight Ion-exchanged water 240 parts by weight After mixing and dissolving the above components, the homogenizer “Ultra Turrax T50” (IKA Co., Ltd.) was stirred for 10 minutes, and then dispersed with an optimizer to prepare a colorant dispersion in which colorant particles having a volume average particle diameter of 250 nm were dispersed. This colorant dispersion was treated with air bubbles for 5 minutes to obtain "Colorant Dispersion 2".

(Preparation of release agent dispersion)
Paraffin wax (melting point 97 ° C.) 100 parts by weight Cationic surfactant “alkyl ammonium salt” 5 parts by weight Ion-exchanged water 240 parts by weight The above components are mixed in a round stainless steel flask with a homogenizer “Ultra Turrax T50” (IKA The product was dispersed for 10 minutes using a pressure discharge type homogenizer, and “release agent dispersion 2” in which release agent particles having a volume average particle size of 550 nm were dispersed was prepared.
(Preparation of aggregated particles)
Resin fine particle dispersion 2 234 parts by weight Colorant dispersion 2 30 parts by weight Release agent dispersion 2 40 parts by weight Polyaluminum chloride 1.8 parts by weight Ion-exchanged water 600 parts by weight In the round stainless steel flask After mixing and dispersing using a homogenizer “Ultra Turrax T50” (manufactured by IKA Corporation), the mixture was heated to 55 ° C. while stirring the inside of the flask in a heating oil bath. After maintaining at 55 ° C. for 30 minutes, it was confirmed that aggregated particles having D50 of 4.8 μm were formed in the solution. Further, when the temperature of the heating oil bath was raised and held at 56 ° C. for 2 hours, D50 was 5.9 μm. Thereafter, 32 parts by mass of “resin fine particle dispersion 2” was added to the dispersion containing the aggregated particles, and then the temperature of the heating oil bath was raised to 55 ° C. and maintained for 30 minutes to prepare aggregated particles. The aggregated particles were treated with air bubbles for 5 minutes to obtain “aggregated particles 2”. After adding 1 mol / L sodium hydroxide to the dispersion containing “aggregated particles 2” and adjusting the pH of the system to 5.0, the stainless steel flask was sealed with a magnetic seal and stirring was continued. The mixture was heated to 95 ° C. and held for 6 hours to prepare a toner particle dispersion. This toner particle dispersion was treated with air bubbles for 5 minutes to obtain "Toner Particle Dispersion 2".

<Preparation of Toner Particle Dispersion 3 (Example of Polyester Association Method)>
(Preparation of polyester resin)
715.0 g of dimethyl terephthalate, 95.8 g of sodium dimethyl 5-sulfoisophthalate, 526.0 g of propanediol, 48.0 g of diethylene glycol, 247.1 g of dipropylene glycol, and 1.5 g of butyltin hydroxide catalyst Placed in polycondensation reactor. The mixture was heated to 190 ° C. and slowly raised to about 200-202 ° C. while collecting methanol by-product in the distillation receiver. Next, the temperature was raised to about 210 ° C. while reducing the pressure from atmospheric pressure to about 1067 Pa over about 4.5 hours. The product was taken out to prepare “Polyester Resin 3” having a glass transition temperature of 53.8 ° C.

(Preparation of polyester resin emulsion)
Next, 168 g of the above-mentioned “polyester resin 3” was added to 1,232 g of deionized water and stirred at 92 ° C. for 2 hours to prepare “polyester resin emulsion 3”.

(Meeting process)
1,400 g of “Polyester Resin Emulsion 3” and 14.22 g of “CI Pigment Blue 15: 3” were added to the reactor to prepare “Emulsion / Dispersion 3”.

  Next, zinc acetate was dissolved in deionized water to prepare a 5 mass% zinc acetate solution. This solution was placed in a reservoir placed on a balance and connected to a pump capable of accurately supplying a zinc acetate solution at 0.01-9.9 ml / min. The amount of zinc acetate required for emulsion association is 10% of the resin mass in the emulsion.

  After “Emulsion / Dispersion 3” was heated to 56 ° C., the zinc acetate solution was pumped at 9.9 ml / min to initiate association. After adding 60% by weight of the total amount of zinc acetate (205 g for a 5% by weight solution), the pump addition rate was reduced to 1.1 ml / min and the amount of zinc acetate was equal to 10% by weight of the resin in the emulsion (5 The addition was continued until 335 g in a mass% solution, and the mixture was stirred at 80 ° C. for 9 hours to prepare “Toner Particle Dispersion 3”.

<Preparation of Toner Particle Dispersion 4 (Example of Suspension Polymerization Method)>
Styrene 165 g, n-butyl acrylate 35 g, “CI Pigment Blue 15: 3” 10 g, di-t-butyl salicylic acid metal compound 2 g, styrene-methacrylic acid copolymer 8 g, paraffin wax (mp = 70 ° C.) 20 g The mixture was heated to 60 ° C., and uniformly dissolved and dispersed at 12000 rpm with a “TK homomixer” (manufactured by Tokushu Kika Kogyo Co., Ltd.). To this, 10 g of 2,2′-azobis (2,4-valeronitrile) as a polymerization initiator was added and dissolved to prepare “polymerizable monomer composition 4”. Next, 450 g of 0.1 M sodium phosphate aqueous solution was added to 710 g of ion-exchanged water, and 68 g of 1.0 M calcium chloride was gradually added while stirring at 13,000 rpm with a “TK homomixer” to disperse the tricalcium phosphate. Liquid 4 "was prepared. The above-mentioned “polymerizable monomer composition 4” is added to this “suspension 4” and stirred at 10,000 rpm for 20 minutes with “TK homomixer” to granulate “polymerizable monomer composition 4”. did. Then, it was made to react at 75-95 degreeC for 5 to 15 hours using the reaction apparatus. The tricalcium phosphate was dissolved and removed with hydrochloric acid to prepare “Toner Particle Dispersion 4”.

<Preparation of toner particle dispersion 5 (example of dissolution suspension method)>
(Preparation of pigment dispersion)
50 parts by mass of polyester resin (Tg: 60 ° C., softening point: 98 ° C., weight average molecular weight: 9500)
C. I. Pigment Blue 15: 3 50 parts by mass Ethyl acetate 100 parts by mass A container obtained by adding glass beads to the dispersion having the above material composition was attached to a sand mill disperser. While cooling around the vessel, the dispersion was carried out for 8 hours in a high-speed stirring mode, and then diluted with ethyl acetate to prepare “Pigment Dispersion Liquid 5” having a pigment concentration of 15% by mass.

(Preparation of micronized wax dispersion)
Paraffin wax (melting point: 85 ° C.) 15 parts by mass Toluene 85 parts by mass The above materials were placed in a dispersing machine equipped with a stirring blade and having a function of circulating a heat medium around the container. The temperature was gradually raised while stirring at 83 rpm, and finally the mixture was stirred for 3 hours while maintaining at 100 ° C. Next, while continuing stirring, the mixture was cooled to room temperature at a rate of about 2 ° C. per minute to precipitate finely divided wax. This wax dispersion was dispersed again at a pressure of 550 × 10 ⁵ Pa using a high-pressure emulsifier “APV Gorin homogenizer” (manufactured by APV Gorin Co., Ltd.). At the same time, the viscosity of the wax was measured and found to be 0.69 μm. The prepared fine particle wax dispersion was diluted with ethyl acetate so that the mass concentration of the wax was 15% by mass to prepare “fine particle wax dispersion 5”.

(Preparation of oil phase)
85 parts by mass of polyester resin (Tg: 60 ° C., softening point: 98 ° C., weight average molecular weight: 9500)
Pigment dispersion 5 (pigment concentration 15% by mass) 50 parts by mass Fine particle wax dispersion 5 (wax concentration 15% by mass) 33 parts by mass Ethyl acetate 32 parts by mass The polyester resin in the material composition was sufficiently dissolved. After confirmation, this solution was put into a homomixer “ACE Homogenizer” (manufactured by Nippon Seiki Co., Ltd.) and stirred at 16000 rpm for 2 minutes to prepare a uniform “oil phase 5”.

(Preparation of aqueous phase)
Calcium carbonate (average particle size: 0.03 μm) 60 parts by mass Pure water 40 parts by mass An aqueous calcium carbonate solution obtained by stirring the above materials with a ball mill for 4 days was referred to as “aqueous phase (calcium carbonate aqueous solution) 5”. When the average particle diameter of calcium carbonate was measured using “Laser diffraction / scattering particle size distribution measuring apparatus A-700” (manufactured by Horiba, Ltd.), it was about 0.08 μm.

Carboxymethylcellulose 2 parts by mass Pure water 98 parts by mass An aqueous solution of carboxymethylcellulose obtained by stirring the above materials with a ball mill was designated as “aqueous phase (carboxymethylcellulose aqueous solution) 5”.

(Preparation of spherical particles)
Oil phase 5 55 parts by mass Aqueous phase (calcium carbonate aqueous solution) 5 15 parts by mass Aqueous phase (carboxymethylcellulose aqueous solution) 5 30 parts by mass The above materials were put into a “colloid mill” (manufactured by Nippon Seiki Co., Ltd.). Emulsification was performed at 5 mm, 9400 rpm for 40 minutes. Next, the emulsion was put into a rotary evaporator, and the solvent was removed under reduced pressure at room temperature of 4,000 Pa for 3 hours.

  Thereafter, 12 mol / L hydrochloric acid was added until the pH reached 2, and calcium carbonate was removed from the toner surface. Thereafter, 10 mol / L sodium hydroxide was added until the pH reached 10, and stirring was continued for 1 hour while stirring in an ultrasonic cleaning tank to prepare “toner particle dispersion 5”.

<Preparation of Toner Particle Dispersion 6 (Example of Continuous Emulsion Dispersion Method)>
(Synthesis of polyether resin (A))
In a high-pressure reactor equipped with a stirrer, a nitrogen inlet tube, a thermometer, a raw material inlet, etc., 0.5 parts by mass of potassium hydroxide and 200 parts by mass of toluene as a solvent are placed, and the pressure in the system is 10 × 10 ⁵ Pa, while maintaining the temperature at 40 ° C., a mixture of 10.8 parts by mass of propylene oxide and 89.2 parts by mass of styrene oxide was injected little by little, and the state of molecular weight change was traced by end group determination. The reaction was terminated when the number average molecular weight reached 7,000. The total amount of the monomer injected at this time was 8.64 parts by mass of propylene oxide and 71.4 parts by mass of styrene oxide. Toluene and unreacted monomers were distilled off from the resulting polymer solution under a reduced pressure of 4,000 Pa to obtain “polyether resin (A)”.

(Synthesis of polyester resin (B) having no ether bond)
In a flask having an internal volume of 5 liters equipped with a stirrer, a nitrogen introduction tube, a thermometer, and a rectifying column, 67.85 parts by mass of terephthalic acid, 3.34 parts by mass of neopentyl glycol, 25.58 parts by mass of propylene glycol, 3.22 parts by mass of trimethylolpropane and 0.3 parts by mass of dibutyltin oxide were added, and the reaction was allowed to stir at 240 ° C. under a nitrogen stream. The reaction was terminated when the softening point by the ring and ball method reached 130 ° C. to obtain “polyester resin (B)”. The obtained “polyester resin (B)” was a light yellow solid, and the weight average molecular weight in terms of polystyrene by GPC measurement was 96,000.

18 parts by mass of “polyether resin (A)”, 72 parts by mass of “polyester resin (B)” and 10 parts by mass of “CI Pigment Blue 15: 3” were used using a biaxial continuous kneader. A colored resin melt heated to 180 ° C. was transferred to a rotary continuous dispersion apparatus “Cabitron CD1010” (manufactured by Eurotech) at a rate of 100 g / min. Separately prepared aqueous medium tank is filled with 0.37 mass% diluted ammonia water diluted with ion-exchanged water and heated at 150 ° C. with a heat exchanger at a rate of 0.1 liter per minute. The colored resin melt is transferred to the Cavitron at the same time, and a dispersion liquid having a temperature of 160 ° C. in which the colored resin spherical fine particles are dispersed is obtained under operating conditions of a rotor rotation speed of 7500 rpm and a pressure of 5 × 10 ⁵ Pa. The mixture was cooled to a temperature of 40 ° C. in 10 seconds to prepare “Toner Particle Dispersion 6”.

<Production of toner particles by ozone water treatment>
(Treatment in reaction vessel)
According to the production flow in which the “toner particle dispersion 1” prepared above is treated by adding ozone water to the reaction vessel shown in FIG. 1, 2000 ml of ozone water adjusted to pH 9 with a sodium hydroxide solution is added and stirred for 30 minutes. Processing was performed to prepare “toner particle 1”.

(Treatment in stirring tank)
The “toner particle dispersion 1” produced above was treated by adding ozone water as a diluent in the stirring tank shown in FIG. 2 (2000 ml of ozone water adjusted to pH 10 with sodium hydroxide solution was added and stirred for 40 minutes) The “toner particles 2” were produced according to the production flow.

(Processing in solid-liquid separator)
For the “toner particle dispersions 1 to 6” produced above, the toner cake in the solid-liquid separator shown in FIG. 3 was treated with ozone water (ozone adjusted to pH 9 with 1 m ³ sodium hydroxide solution per kg of toner cake). “Toner particles 3 to 10” were produced by a production flow in which water was washed for 30 minutes.

(Treatment in reaction vessel, stirring tank, solid-liquid separator)
According to the manufacturing flow in which the “toner particle dispersion 1” prepared above is processed in the reaction vessel shown in FIG. 1, processed in the stirring tank shown in FIG. 2, and processed in the solid-liquid separator shown in FIG. In the same manner as described above, ozone water treatment was performed to produce “toner particles 11”.

(No processing)
As a comparative example, the “toner particle dispersion 1” produced above was produced in the production flow shown in FIG. 1 to produce “toner particles 12” without using ozone water.

  As the solid-liquid separator, a rotary cylindrical dehydrator “MARK III Model No. 60 × 40” (Matsumoto Kikai Co., Ltd.) is used. To dry the toner cake, a “flash jet dryer” (Seishin Enterprise Co., Ltd.) is used. The toner particles were dried until the water content of the toner particles was 0.5% by mass.

  Table 1 shows the toner particle dispersion used for preparing “toner particles 1 to 12”, the process of ozone water treatment, the ozone concentration of ozone water, the average particle diameter of toner, and the residual amount of volatile substances. . The residual amount of volatile substances is a value measured by the above-mentioned head space method, and the ozone concentration of ozone water is a value measured by the above-mentioned non-buffered KI method.

<Production of toner>
To 100 parts by mass of the “toner particles 1 to 12” produced above, 0.8 parts by mass of rutile titanium oxide (volume average particle size = 20 nm, n-decyltrimethoxysilane treatment), spherical monodispersed silica (sol-gel method) The silica sol obtained in HMDS was subjected to HMDS treatment, dried and pulverized and mixed with 1.8 parts by mass of “Henschel mixer” (circumferential speed 30 m / s) (Mitsui Miike Chemical Co., Ltd.) For 15 minutes. Thereafter, coarse particles were removed using a filter having an opening of 45 μm to produce “Toners 1 to 12”, which were designated as “Examples 1 to 11” and “Comparative Example 1”.

<< Preparation of developer >>
Each of “Toners 1 to 12” produced above was mixed with a ferrite carrier having a volume average particle diameter of 60 μm to prepare “Developers 1 to 12” having a toner concentration of 6%.

<Evaluation>
<Live-action evaluation>
In the evaluation of actual images, the toner and the developer were set in a developing unit of a commercially available digital copying machine “7065” (manufactured by Konica Corporation) adopting an electrophotographic method, and printing was performed. The detailed conditions were set according to the following evaluation items and evaluated.

"Evaluation results"
(Charge amount variation between toner lots)
Ten batches of “toners 1 to 12” were prepared, and the variation in charge amount between toner lots was evaluated.

  The variation in the charge amount is determined by mixing each of the 10 toner batches prepared above with the carrier to prepare a measurement sample having a toner concentration of 6% by mass, and the charge amount in an environment of a temperature of 30 ° C. and a relative humidity of 80% RH. Was measured. The charge amount was measured by the blow-off method.

Evaluation Criteria A: Charge of 10 batches is centered ± 0.3 μC / g and the variation is very small and judged to be practically acceptable ○: Charge of 10 batches is center value ± 0.6 μC / g and the variation is small and practical △: Charge amount of 10 batches is center value ± 1.0 μC / g, and the variation is slightly large, but practically no problem is determined. ×: Charge amount of 10 batches is center value ± 1.0 μC / g Since it was not within the range and the variation was large, it was judged that there was a problem in practical use.

(Storage stability of toner)
2 g of each toner prepared above was taken in a sample tube, shaken 500 times with a tapping denser, and allowed to stand in an environment of 55 ° C. and 35% RH for 2 hours. Next, it is put into a sieve of 48 μm mesh, sieved under a constant vibration condition, the ratio (mass%) of the remaining toner amount on the mesh is measured, this is taken as the toner aggregation rate, and the toner is stored according to the criteria described below. The stability was evaluated.

A: The toner aggregation rate is less than 15% by mass (the storage stability of the toner is very good, and there is no problem during image formation).
○: toner aggregation rate of 15 to 45% by mass (good toner storage stability, no problem during image formation)
Δ: Toner agglomeration ratio 46 to 60% by mass (the storage stability of the toner is slightly poor and there are some problems during image formation, but the acceptable range of use)
X: The toner aggregation rate exceeds 60% by mass (cannot be used because the storage stability of the toner is poor and a problem occurs during image formation).

(Fixability of toner image)
Toner image fixability was evaluated based on the fixability of extremely thick paper.

  Continuous printing was carried out using 500 postcards (thickness 0.4 mm) made by Heart Inc. using a digital copying machine “7065” (manufactured by Konica Corporation).

  A gray frame with a relative density of 0.5 was attached to the frame of the postcard. The ranks of the obtained prints were evaluated as follows.

◎: The toner does not come off at all even if the characters are strongly written with a pen attached to the gray frame. ○: The toner is peeled off when the characters are strongly written with a pen attached on the gray frame, but the toner is peeled off when using the ballpoint pen. Not good x: Insufficient fixing, just holding the gray frame in the hand, the toner is peeled off and the hand becomes dirty.

(Odor)
In a sealed room with a floor of 5m x 5m and a height of 2m, the digital copying machine "7065" (manufactured by Konica Corporation) was remodeled, and the fixing temperature of the heat fixing device was set to 175 ° C. A cooler that cools the transfer paper was attached, and the surface temperature of the discharged transfer paper was adjusted to 75 ° C., and 1000 images of 50% solid black were printed continuously.

  The evaluation of odor was carried out by 30 evaluators at the end of printing 1000 sheets by the number of persons who felt odor.

◎: One evaluator did not feel odor ○: Three or less evaluators felt odor ×: Four or more evaluators felt odor.

  The evaluation results are shown in Table 2.

  As is apparent from Table 2, “Examples 1 to 11” produced by the toner manufacturing method of the present invention have no variation in charge amount between toner lots compared to “Comparative Example 1”, and toner storage stability. In addition, a toner image having excellent fixability can be obtained, and a toner image having good fixability can be formed when an image is formed using the toner. It was confirmed that there was an excellent effect of being obtained.

FIG. 3 is a production flow diagram showing an example of a toner particle production method (adding ozone water into a reaction vessel) preferably used in the present invention. FIG. 5 is a production flow diagram showing an example of a toner particle production method (adding ozone water into a stirring vessel) preferably used in the present invention. FIG. 3 is a production flow diagram (production process diagram) showing an example of a method for producing toner particles preferably used in the present invention (washing the toner cake in the solid-liquid separator with ozone water). 1 is a cross-sectional configuration diagram of an image forming apparatus showing an example of an image forming method using toner according to the present invention.

Explanation of symbols

601 Ozone water tank for reaction vessel 602 Ozone water tank for stirring tank 603 Ozone water tank for cleaning toner cake 604 Toner cake 701 Reaction vessel 702 Concentration device 703 Stirring vessel 704 Solid-liquid separator 705 Stock tank 706 Drying device

Claims (8)

A toner production method comprising a step of forming particles in an aqueous medium, the method comprising the step of treating the toner composition or toner particles in the aqueous medium with ozone water. In the toner manufacturing method including a step of solid-liquid separation of a toner particle dispersion containing toner particles in which particles are formed in an aqueous medium, the step of treating with ozone water forms the particles in the aqueous medium. The toner production method according to claim 1, wherein the toner production method is performed in the process. In the toner manufacturing method including a step of solid-liquid separation of a toner particle dispersion containing toner particles in which particles are formed in an aqueous medium, the step of treating with ozone water dehydrates or concentrates the toner particle dispersion. The toner manufacturing method according to claim 1, wherein the toner manufacturing method is performed in a step of dispersing in a post-cleaning medium. In the toner manufacturing method including a step of solid-liquid separation of a toner particle dispersion containing toner particles in which particles are formed in an aqueous medium, the step of treating with ozone water is performed in the step of solid-liquid separation. The toner production method according to claim 1, wherein the toner production method is used. In the toner manufacturing method including a step of solid-liquid separation of a toner particle dispersion containing toner particles in which particles are formed in an aqueous medium, the step of treating with ozone water forms the particles in the aqueous medium. The toner production method according to claim 1, wherein the toner production method is performed in at least two steps of a step of dehydrating or concentrating and then dispersing in a cleaning medium and a step of solid-liquid separation. A toner produced through the process according to claim 1. The peak of a volatile substance by a head space gas chromatograph method exists between n-hexane and n-hexadecane, and the total area of those peaks is 0.5-20 ppm in terms of toluene, The toner described in 1. A toner image is formed on the electrostatic latent image carrier using the toner according to claim 6, and the toner image transferred onto the transfer member is heated and fixed to form an image. Image forming method.

Images