JP2006285100A - Toner for electrostatic image development, method for manufacturing the same, electrostatic image developer using the same, image forming method using the same and formed image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily manufacture a toner so that unnecessary components are not contained, and to provide a toner excellent in toner properties such as stability after long-term use. <P>SOLUTION: A method for manufacturing a toner for electrostatic image development is provided which includes a step of preparing a mixed liquid by mixing at least an aqueous pigment dispersion and an aqueous binding resin particle dispersion containing self-dispersive polyester binding resin particles having carboxylic acid as a hydrophilic group in a backbone and synthesized from at least a polycarboxylic acid having three or more carboxyl groups and/or an acid anhydride thereof and a polyhydric alcohol, and a step of forming agglomerates in which at least the dispersed pigment is bound to the self-dispersive binding resin particles, by adding a polyvalent metal salt as a flocculant while stirring the mixed liquid, wherein the self-dispersive binding resin particles in the aqueous binding resin particle dispersion are formed from two or more self-dispersive binding resins different from each other in number average molecular weight. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a toner for developing an electrostatic image used in an image forming apparatus using an electrophotographic system, a method for producing the same, an electrostatic image developer using the toner, an image forming method using the toner, and a formed image. More specifically, the present invention relates to facilitating the production of toner having excellent reproducibility.

  Along with recent remarkable development of OA equipment, copiers, printers, facsimile machines, and the like that perform printing using an electrophotographic system have become widespread. In general, an image forming apparatus using an electrophotographic system forms an image through a charging process, an exposure process, a development process, a transfer process, a cleaning process, a fixing process, and the like.

  In the charging step, the surface of the photoreceptor is uniformly charged in a dark place. In the exposure step, the original image is projected onto the charged photoconductor, so that the charged portion is removed and an electrostatic latent image is formed on the surface of the photoconductor. In the development step, a toner image (visible image) is formed by attaching toner to the electrostatic latent image formed on the surface of the photoreceptor. In the transfer process, a recording medium such as paper or sheet is brought into contact with the toner image formed on the surface of the photoconductor, and corona discharge is performed from the side opposite to the surface of the recording medium that is in contact with the toner image. The toner image is transferred to the recording medium by applying a charge of the polarity to the recording medium. In the fixing step, the toner image transferred to the recording medium is fixed by means such as heating and pressing. In the cleaning process, the toner remaining on the surface of the photoreceptor without being transferred to the recording medium is collected. An image forming apparatus using an electrophotographic system forms a desired image on a recording medium through the above steps.

  As a method for producing an electrostatic image developing toner used in an image forming apparatus using an electrophotographic system, there are a dry method and a wet method. Examples of the dry method include a pulverization method. The pulverization method is a method for obtaining toner by melting and kneading a resin, pigment (colorant), wax, and the like, and finely pulverizing and classifying the obtained kneaded material with a pulverizer or the like. It is used. The toner is desired to have a small particle size in order to achieve high image quality of the formed image. However, in the pulverization method, energy and time required for pulverization increase, and the manufacturing process becomes complicated. Further, since the yield is further lowered, there is a problem that the manufacturing cost is remarkably increased.

Examples of the wet method include a suspension polymerization method and an emulsion polymerization method. The suspension polymerization method is a method for obtaining a toner by suspension polymerization of a synthetic resin monomer such as a vinyl monomer in an aqueous medium containing a pigment (see Patent Documents 1 and 2).
On the other hand, the emulsion polymerization method is a method in which an aqueous dispersion of synthetic resin particles and a dispersion of pigment are mixed to form aggregated particles of synthetic resin particles and pigment, and the aggregated particles are heated and melted to obtain a toner. (See Patent Documents 3 to 6). Although this method will be described later, since the surfactant is contained in the resin particle dispersion, which is a starting material for toner production, the surfactant remains in the produced toner.

As another wet method, there is a method using phase inversion emulsification (see Patent Document 7). Phase inversion emulsification is a method of dispersing self-water-dispersible resins and pigments in organic solvents, adding a neutralizing agent that neutralizes the dissociation groups of the resin, and adding water while stirring, pigments, etc. In this method, toner particles are obtained by phase inversion emulsification of resin solution droplets encapsulating toner.
Further, as another wet method, there is a method of obtaining toner particles by granulating a solution in which a resin is soluble in an aqueous medium containing an inorganic dispersant, removing the solvent, and drying. Yes (Patent Document 8). In this method for producing a toner for developing an electrostatic charge image, a material containing a polyester resin and a pigment is dispersed in a solvent in which the polyester resin can be dissolved, and the liquid is granulated in an aqueous medium containing an inorganic dispersant. Then, the solvent is removed to produce a toner.

  As other conventional techniques, techniques similar to the technique of Patent Document 8 are described in Patent Documents 9 and 10. The method for producing a negatively charged toner for developing an electrostatic image in Patent Document 9 and the method for producing a positively charged toner for developing an electrostatic image in Patent Document 10 use an inorganic dispersant having an average particle diameter of 0.7 to 5 μm. Except for this, the toner is manufactured in the same manner as the method for manufacturing a toner for developing an electrostatic charge image in Patent Document 8. The method for producing a negative charge toner for developing an electrostatic image in Patent Document 9 uses a negative charge control agent, and the method for producing a positive charge toner for developing an electrostatic image in Patent Document 10 is positively charged. Sex charge control agent is used.

  As another conventional technique, a technique similar to the techniques of Patent Documents 8 to 10 is described in Patent Document 11. In the method for producing a toner for developing an electrostatic charge image in Patent Document 11, a polymerizable vinyl monomer containing styrene, a styrene derivative, a (meth) acrylic acid alkyl ester and a mixture thereof as a main component as a binder resin is polymerized. The toner is produced in the same manner as in the method for producing an electrostatic charge image developing toner disclosed in Patent Document 8, except that a vinyl polymer obtained in this manner is used.

  As another conventional technique, Patent Document 12 describes a technique similar to the techniques of Patent Documents 8 to 11. In the method for producing a toner for developing an electrostatic charge image of Patent Document 12, after toner particles are prepared, the toner is further washed with water until the difference in electric conductivity between water before washing and water after washing becomes 200 μS / cm or less. Except for this, the toner is manufactured in the same manner as the method for manufacturing a toner for developing an electrostatic charge image in Patent Document 8.

As another conventional technique, Patent Document 13 describes a technique similar to the techniques of Patent Documents 8 to 12. The method for producing the toner for developing an electrostatic charge image of Patent Document 13 is produced in the same manner as the method for producing the toner for developing an electrostatic charge image of Patent Document 8, except that a surfactant is further added to the aqueous medium.
As another conventional technique, a technique similar to the techniques of Patent Documents 8 to 13 is described in Patent Document 14. The toner production method of Patent Document 14 is the production of the electrostatic image developing toner of Patent Document 8, except that an aqueous dispersion containing a surfactant and an inorganic dispersant having an average particle size of 0.1 to 2 μm is used. Produced in the same way as the method.

  In the method for producing a toner by the wet method as described above, an organic solvent, a resin monomer, a surfactant and the like remain in the obtained toner. Such components ooze out of the toner and damage members such as a developing roller when the toner is actually used for developing an electrostatic image. Further, the chargeability of the toner varies. Therefore, after the toner is manufactured, a step of removing the organic solvent, the monomer, the surfactant and the like from the toner is required. However, in such a removal step, variations in the shape of the obtained toner and its chargeability tend to occur due to subtle variations in operating conditions such as pressure, temperature, and time. Therefore, in order to obtain a toner having a uniform shape, it is necessary to adjust the operation condition to an optimum condition, and it is very difficult to realize it. Further, since a large amount of an organic solvent, a monomer, a surfactant, and the like that give a large load to the environment are used, facilities for processing these are necessary, and the manufacturing cost of the toner is increased.

Further, the toner obtained by the conventional wet method as described above is used for the image density of the image formed on the recording medium and the image quality such as “fogging”, the dispersibility of the pigment on the recording medium, and the recording medium. Not all of the toner characteristics such as transfer rate to are excellent.
Therefore, as another conventional technique, Patent Document 15 describes a toner manufacturing method that does not use an organic solvent and does not use a polymerization reaction when forming particles that are toner. In the method for producing a toner composition of Patent Document 15, a pigment aqueous dispersion in which a pigment is dispersed in water using sodium sulfonated polyester is added to an emulsion in which sodium sulfonated polyester is dispersed in water. The toner is manufactured by adding an alkali halide solution to form an aggregate.
Similarly, Patent Document 16 describes a method for producing a toner using a self-dispersing resin containing a hydrophilic ethylenically unsaturated monomer. Patent Document 16 discloses that a styrene derivative is a sodium or potassium sulfonate salt as a hydrophilic ethylenically unsaturated monomer. In this document, a sulfonic acid metal salt is a self-dispersing resin having a hydrophilic machine, and a toner is prepared using a polyvalent metal salt as a flocculant.
Further, Patent Document 17 is cited as a patent using a self-dispersing polyester. This discloses a method for producing a toner using a mixture of a vinyl resin dispersion and a self-dispersing polyester. The self-dispersing polyester disclosed therein is preferably a polyester containing no trivalent monomer. Further, it is disclosed that soft flocculation is performed using an ionic surfactant as a flocculant.

JP 57-154253 A JP 59-62870 JP-A 63-186253 JP-A 63-282758 JP-A-63-282749 JP-A-10-26842 JP-A-5-66600 JP-A-7-152202 JP-A-7-168395 JP-A-7-168396 JP 7-219267 A JP-A-8-179555 JP-A-8-179556 Japanese Patent Laid-Open No. 9-230624 JP-A-10-39545 JP 2002-131977 A JP 2004-354411 A

It is desirable that the toner for developing an electrostatic charge image does not contain unnecessary components such as an organic solvent and a monomer, can be easily manufactured, and has excellent toner characteristics.
In the toner production method of Patent Document 15, a toner composition is produced by aggregating a pigment dispersed in water with sodium sulfonated polyester as a toner component and sodium sulfonated polyester dispersed in water. The toner composition can be produced so as to contain no unnecessary components such as an organic solvent, a monomer, and a surfactant. However, simply dispersing the pigment using sodium sulfonated polyester results in insufficient dispersibility of the pigment, resulting in agglomeration of only the pigment, and toner properties such as color reproducibility are not satisfactory. In other words, a toner composition having excellent toner characteristics cannot be produced. Further, the toner composition produced by this method has a problem that the charging characteristics become unstable due to environmental conditions, and the use is limited depending on the environmental conditions, which is derived from a sulfonic acid group which is a hydrophilic group. It is considered a thing.
Similarly, in the toner production method disclosed in Patent Document 16, although the dispersibility of the pigment is maintained, the environmental characteristics of the produced toner are the same problems as above because the hydrophilic group is a sulfone metal salt. Is included.
Furthermore, with the toner disclosed in Patent Document 17, it is difficult to first self-disperse the polyester, and it is very difficult to control the particle size because of soft aggregation caused by a surfactant.

Thus, according to the present invention, an aqueous pigment dispersion, a polyvalent carboxylic acid containing at least three carboxyl groups and / or an acid anhydride thereof, and a polyhydric alcohol are synthesized, and the main chain contains a carboxylic acid as a hydrophilic group. A mixed liquid preparation step of preparing a mixed liquid by mixing at least a binder resin particle aqueous dispersion containing self-dispersing polyester binder resin particles, and a polyvalent metal as a flocculant while stirring the mixed liquid A self-dispersing binder in the binder resin particle aqueous dispersion, the method comprising an agglomerate forming step of adding a salt to form an aggregate in which at least a dispersion pigment is bound to the self-dispersing binder resin particles; There is provided a method for producing a toner for developing an electrostatic image, wherein the resin particles are formed from two or more kinds of self-dispersing binder resins having different number average molecular weights.
According to another aspect of the present invention, there is provided an electrostatic image developing toner produced by the method for producing an electrostatic image developing toner.
According to still another aspect of the present invention, there is provided an electrostatic charge image developer comprising the above electrostatic charge image developing toner and a carrier.
According to still another aspect of the present invention, an electrostatic latent image is formed on a photoconductor, and the electrostatic latent image on the photoconductor is developed using the electrostatic image developer to form a toner image. An image forming method including a step of forming and transferring and fixing a toner image onto a recording medium, and a formed image formed by the image forming method are provided.

According to the method for producing a toner for developing an electrostatic charge image of the present invention, an aqueous solution containing an aggregating agent is added to a self-dispersion-type binder while stirring a liquid mixture obtained by mixing at least a pigment and a self-dispersion binder resin in water. A toner is produced by forming an aggregate in which pigments are bound to the resin particles. As a result, it is possible to easily produce a toner without including unnecessary components such as a dispersant for emulsifying and dispersing a resin, an organic solvent, and a binder resin constituent monomer, which are necessary in the prior art. Further, in the conventional method of melt-kneading the pigment and the binder resin, the polymer is cut by shear stress to change the molecular weight, and the desired toner characteristics can be obtained by changing from the molecular weight distribution at the time of preparation. Although it may not be possible, the present invention does not cause such a problem. Further, by using two or more kinds of self-dispersing binder resins having different number average molecular weights, it is possible to improve toner characteristics, and in particular, it is possible to improve toner storage stability and fixability. Further, by using a pigment having excellent dispersibility, the dispersed particle diameter of the pigment in the toner can be reduced, and a toner having excellent toner characteristics such as color reproducibility can be manufactured.
Further, according to the toner for developing an electrostatic charge image of the present invention, since it is produced by the above production method, there are few unnecessary components such as an organic solvent and a binder resin constituting monomer, and the toner characteristics are excellent.
Furthermore, in the electrostatic image developing toner of the present invention, since the hydrophilic group is a carboxylic acid, it is hydrophobized by washing with an acid and has an effect of being excellent in environmental stability compared to a polyester resin containing a sulfonic acid group. is there.

  The present invention provides a mixed liquid preparation step of preparing a mixed liquid by mixing at least a pigment aqueous dispersion and a binder resin particle aqueous dispersion containing self-dispersing binder resin particles, while stirring the mixed liquid An agglomerate forming step of adding an aggregating agent to form an aggregate in which at least a pigment is bound to the self-dispersing binder resin particles, and the self-dispersing binder in the aqueous dispersion of binder resin particles The resin particles are formed from two or more types of self-dispersing binder resins having different number average molecular weights, and are a method for producing a toner for developing electrostatically charged images. It is characterized in that the resin particles are formed from two or more kinds of self-dispersing binder resins having different number average molecular weights.

  FIG. 1 is a process diagram showing an example of a method for producing an electrostatic charge image developing toner of the present invention. In the toner manufacturing method according to the embodiment of the present invention, the mixed liquid preparation step S1, the aggregate formation step S2, the particle formation step S3, and the cleaning step S4 are performed in this order.

In the mixed liquid preparation step S1, toner components such as individually dispersed pigments and self-dispersing binder resins are mixed with water to prepare a mixed liquid. In the agglomerate forming step S2, an aqueous solution containing an aggregating agent is added to the mixed solution to form toner as an agglomerate in an aqueous medium. Further, by performing steps S3 and S4, a toner having more excellent toner characteristics can be obtained. Specifically, in the particle forming step S3, the aqueous medium containing the aggregate is heated to form the aggregate. In the washing step S4, the agglomerated particles are washed and dried.
Hereinafter, the above steps will be described in more detail.

  In the mixed solution preparation step S1, the pigment aqueous dispersion containing the pigment and the self-dispersing binder resin described later are dispersed in water separately using a stirrer (emulsifier or disperser) in advance. A binder resin particle aqueous dispersion containing dispersed binder resin particles was prepared, and the resulting pigment aqueous dispersion and binder resin particle aqueous dispersion were mixed and stirred to prepare a mixed liquid containing a toner component. obtain. Preferably, the binder resin particle aqueous dispersion and the pigment aqueous dispersion are mixed so as to contain a self-dispersing binder resin of 80 to 99% by weight and a pigment of 0.1 to 20% by weight in a solid content concentration, and a stirrer For example, the prepared liquid mixture is obtained by stirring at room temperature for 1 to 5 hours. Furthermore, in the mixed liquid preparation step S1, a wax fine particle aqueous dispersion containing natural and / or synthetic wax fine particles emulsified in water may be mixed with the above mixed liquid, and the amount is 0. It is preferably 1 to 20% by weight.

In the agglomerate forming step S2, a predetermined amount (for example, 0.5 part with respect to 100 parts by weight of the toner component) is added to a mixed solution containing toner components such as pigments and self-dispersing binder resin particles (including wax fine particles in some cases). (About 20 parts by weight) of an aggregating agent is added and mixed by stirring to form an agglomerate containing a toner component. Therefore, unnecessary components other than the toner component such as an organic solvent and a binder resin constituting monomer are not contained in the toner.
This step S2 is preferably performed at room temperature, but may be heated to near the glass transition temperature (Tg) of the lowest self-dispersing binder resin of two or more types. Furthermore, in this step S2, it is preferable to stir the mixed solution by a mechanical shearing force using a stirrer from the viewpoint that it becomes easy to form aggregates into particles having a uniform particle size and shape. .
Furthermore, agglomeration is formed with a resin and pigment having a lower molecular weight, and in some cases wax dispersed particles, and then resin particles with a higher molecular weight are added to bind the previously added resin particles to the surface of the aggregated particles. This is also possible.
By including this operation, the surface of the produced toner has a high molecular weight resin on the surface layer, so that the storage stability of the toner can be ensured, and the low molecular weight resin in the inner shell ensures the fixability. (Especially effective for low-temperature fixing). Further, it is possible to intentionally control the toner surface properties, for example, a toner having a conductive material such as carbon black on the toner surface layer and a toner having a colored pigment (cyan, magenta, yellow, etc.) on the surface layer. In this case, a difference in charge amount is likely to occur, and it is necessary to individually examine the design of the developer. Since the charge characteristics are mainly governed by the toner surface properties, a difference in charging performance due to the pigments can be reduced by providing a layer on which the pigment is not directly exposed. Furthermore, when the resin layer is provided on the surface layer, a secondary effect that the spent of the carrier by the wax can be improved can be expected.
In this agglomerate forming step S2, a predetermined amount (for example, 1 to 5% by weight of the total amount of resin used) of binder resin particle aqueous dispersion containing no pigment and containing self-dispersing binder resin particles can be mixed. It is. In this case, the resin amount in the binder resin particle aqueous dispersion to be mixed in the previous mixed solution preparation step S1 is reduced in advance by a predetermined amount. Moreover, in order to prevent reaggregation of aggregates, a surfactant may be added, or sodium hydroxide or the like may be added to adjust the pH to 8 or more.

In the particle forming step S3, by heating the aqueous medium containing the obtained aggregate, the aggregate can be made into particles having a substantially uniform particle size and shape. In this case, it is preferable to heat the glass transition temperature of the two or more types of self-dispersing binder resins having different number average molecular weights to the highest glass transition temperature or more and adjust the particle diameter to be 1 to 20 μm. By doing so, toner particles having a substantially uniform particle size and shape can be easily obtained.
Further, in this particle forming step S3, in order to control the toner shape, it is possible to add a binder resin particle aqueous dispersion containing a self-dispersing binder resin to form an aggregate again. At this time, a surfactant may be added to prevent reaggregation of the aggregates, or sodium hydroxide or the like may be added to adjust the pH to 8 or higher. In this case as well, it is desirable to reduce the amount of resin in the binder resin particle aqueous dispersion mixed in the previous mixed solution preparation step S1 in advance by a predetermined amount.

  In the washing step S4, the mixed solution containing the toner (aggregate) is cooled to, for example, room temperature, the mixed solution is filtered to remove the supernatant, and the separated toner is washed with water. For the cleaning, it is preferable to use pure water having a conductivity of 10 μS / cm or less, and it is preferable to wash the toner until the supernatant of the water from which the toner has been cleaned has a conductivity of 50 μS / cm or less. Cleaning of the toner using pure water may be performed by a batch method or a continuous method. Cleaning of the toner with pure water is performed to remove unnecessary components other than the toner components such as impurities that affect the chargeability of the toner and unnecessary flocculants that did not participate in the aggregation. A toner that does not contain unnecessary components can be easily produced. Further, the step of washing with water having a pH of 6 or less may be included one or more times in the washing step with pure water, whereby impurities are more sufficiently removed. Thereafter, the toner washed in this way may be separated from the washing water by filtration and dried using, for example, a vacuum dryer. A desired additive (for example, a charge control agent, a release agent, an external additive, etc.) may be added to the toner obtained by drying.

[Description of Toner Component]
(Self-dispersing binder resin particles)
In the present invention, as the resin constituting the self-dispersing binder resin particles, it is particularly preferable to use two or more types of resins that are dispersed in water (resin that can be made into particles) and that have different number average molecular weights. It is not limited, A well-known thing can be used, For example, a polyester resin, vinyl-type copolymer resin, a polyurethane resin, an epoxy resin etc. are mentioned, These resin can be used individually or in multiple selection. Moreover, even if it is the same kind of resin, you may use it combining multiple types of resin in which any one or several, such as a number average molecular weight and a monomer composition, differ. Furthermore, as a self-dispersing binder resin, at least two kinds of exemplified resins such as polyester resin, vinyl copolymer resin, polyurethane resin and epoxy resin are contained in an amount of 50% by weight or more, and the remaining less than 50% by weight is exemplified. You may use the resin mixture containing the 1 type (s) or 2 or more types of synthetic resin which can be melt | dissolved by heating other than the resin made. In this case, each resin used is more preferably a synthetic resin that is compatible and can be melted by heating. The self-dispersing binder resin more preferably includes a hydrophilic group in the main chain.

  In the two or more types of self-dispersing binder resins having different number average molecular weights used in the present invention, the smallest number average molecular weight is 2000 or more, preferably 2500 or more, and more preferably 3000 or more. Further, by setting the difference in the number average molecular weight of these resins in the range of 1000 or more, the toner characteristics can be improved, and in particular, the storability and fixability of the toner can be improved. When the minimum number average molecular weight is 2000 or less, the storage stability and the fixability tend to be inferior.

  The self-dispersing binder resin used in the present invention is a polyester resin and a vinyl copolymer, considering that the powder flowability, low-temperature fixability, secondary color reproducibility, etc. of the obtained toner particles are improved. A coalesced resin is preferable, and a resin mainly composed of a polyester resin is particularly preferable. The ratio of the polyester resin to the entire resin constituting the self-dispersing binder resin particles is preferably 50% by weight or more, more preferably 80% by weight or more, and particularly preferably 90% by weight or more. This is to develop the color reproducibility as a toner and the function of adhesion to paper. Hereinafter, the polyester resin will be described.

  The polyester resin used for the self-dispersing binder resin particles is obtained by polycondensation of an acid component and an alcohol component. The acid component mainly uses polyvalent carboxylic acids, and the alcohol component mainly contains polyvalent alcohols. A polyester resin polycondensed using is preferred.

  Examples of the polyvalent carboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, anthracene dipropionic acid, anthracene dicarboxylic acid, diphenic acid, and sulfoterephthalic acid. 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7 dicarboxylic acid, 5 (4-sulfophenoxy) isophthalic acid, aromatic dicarboxylic acids such as metal salts and ammonium salts thereof, p-oxy Aromatic oxycarboxylic acids such as benzoic acid and p- (hydroxyethoxy) benzoic acid, aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid and dodecanedicarboxylic acid, fumaric acid, maleic acid, itaconic acid, Mesaconic acid and citraconic acid Any aliphatic unsaturated polycarboxylic acid, aromatic unsaturated polycarboxylic acid such as phenylene diacrylic acid, alicyclic dicarboxylic acid such as hexahydrophthalic acid, tetrahydrophthalic acid, trimellitic acid, trimesic acid, pyromellitic Examples thereof include trivalent or higher polyvalent carboxylic acids such as acids and / or acid anhydrides thereof, and these can be used alone or in a plurality of selectively.

  In the present invention, the acid component may contain monocarboxylic acids. As monocarboxylic acids, aromatic monocarboxylic acids are preferred. Examples of the aromatic monocarboxylic acid include benzoic acid, chlorobenzoic acid, bromobenzoic acid, parahydroxybenzoic acid, naphthalenecarboxylic acid, anthracenecarboxylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, salicylic acid, thiosalicylic acid, Examples thereof include phenylacetic acid, lower alkyl esters thereof, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoic acid, tertiary butylbenzoic acid, and tertiarybutylnaphthalenecarboxylic acid.

  In the acid component, the content of polyvalent carboxylic acids is 70 mol% or more, preferably 80 mol% or more, particularly preferably 90 mol% or more, and aromatic polyvalent carboxylic acids are preferred as the polyvalent carboxylic acids. Further, the aromatic polyvalent carboxylic acid preferably contains terephthalic acid and isophthalic acid. The content of terephthalic acid is preferably 40 to 95 mol%, more preferably 60 to 95 mol%, and particularly preferably 70 to 90 mol% in the acid component. Moreover, it is preferable that content of isophthalic acid is 5-60 mol% in an acid component. Further, the total content of terephthalic acid and isophthalic acid is preferably 80 mol% or more, more preferably 90 mol% or more in the acid component. In the present invention, the polyvalent carboxylic acids include trivalent or higher polyvalent carboxylic acids such as trimellitic acid, trimesic acid and pyromellitic acid, and acid anhydrides of these polyvalent carboxylic acids, such as pyromellitic anhydride. , Cyclohexane-1,2,3,4-tetracarboxylic acid-3,4-anhydride, ethylene glycol bisanhydro trimellitate, etc. are particularly preferably contained alone or in combination, and the content thereof Is preferably 0.5 to 8 mol%, particularly preferably 0.5 to 20 mol% in the acid component. Moreover, when monocarboxylic acids are contained in an acid component, 2-25 mol% is preferable during acidification, and, as for the content, More preferably, it is 5-20 mol%. This is because the self-dispersibility of the polyester resin is maintained.

In the present invention, examples of the polyhydric alcohols include aliphatic polyhydric alcohols, alicyclic polyhydric alcohols, and aromatic polyhydric alcohols. Examples of the aliphatic polyhydric alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6- Hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, aliphatic diols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, trimethylolethane, trimethylol Triols such as propane, glycerin and pentaelsitol, tetraols and the like can be mentioned. Examples of the alicyclic polyhydric alcohol include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, spiroglycol, hydrogenated bisphenol A, ethylene oxide adduct and propylene oxide adduct of hydrogenated bisphenol A, tri Examples include cyclodecanediol and tricyclodecane dimethanol. Examples of the aromatic polyhydric alcohol include para-xylene glycol, meta-xylene glycol, ortho-xylene glycol, 1,4-phenylene glycol, 1,4-phenylene glycol ethylene oxide adduct, bisphenol A, and bisphenol A ethylene oxide addition. And propylene oxide adducts. Furthermore, examples of the polyester polyol include a lactone polyester polyol obtained by ring-opening polymerization of a lactone such as ε-caprolactone.
In the present invention, monoalcohols may be included in the polyhydric alcohols as the alcohol component. Examples of monoalcohols include aliphatic alcohols, aromatic alcohols, and alicyclic alcohols.

  In the alcohol component forming the polyester resin of the present invention, the content of polyhydric alcohol is 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, particularly preferably 90 mol% or more. The alcohols preferably include aliphatic diols and / or alicyclic diols. As the aliphatic diol, ethylene glycol, propylene glycol, and 2,3-butanediol are preferable. Among these, ethylene glycol and propylene glycol are preferable. As the alicyclic diols, tricyclodecane dimethanol, cyclohexane diol, and cyclohexane dimethanol are preferable. In particular, in the present invention, it is preferable that ethylene alcohol and / or propylene glycol is contained in the alcohol component in an amount of 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more.

  The polyester resin constituting the self-dispersing binder resin fine particles is obtained mainly by polycondensation of a raw material divalent or higher polyvalent carboxylic acid and a divalent or higher polyhydric alcohol as described above. The purpose is to broaden the molecular weight distribution of the polyester resin, not to gel the resin. The gelation of the resin makes it difficult to take out the resin from the polymerization apparatus and significantly reduces the productivity. The polyester resin used in the present invention is substantially free of gelation, more specifically, the chloroform insoluble content of the polyester resin is 0.5% by weight or less, preferably 0.25% by weight or less, and The acid value of the polyester resin is 40 mgKOH / g or less, preferably 30 mgKOH / g or less.

  In the present invention, the glass transition temperature (or softening point) of the polyester resin constituting the self-dispersing binder resin particles is preferably 40 to 80 ° C. (80 to 150 ° C.), more preferably 45 to 45 ° C. It is 80 degreeC (85-150 degreeC), Most preferably, it is 50-75 degreeC (80-145 degreeC). When the glass transition temperature is 40 ° C. or the softening point is lower than 80 ° C., the toner formed using the polyester resin particles tends to block and causes a problem in storage stability. On the other hand, when the glass transition temperature exceeds 80 ° C., it tends to be offset, and this problem is more remarkable particularly when printing with overlapping colors like a color. When the softening point exceeds 150 ° C., the polyester resin particles The toner formed by using the toner causes a problem in fixability, and the fixing roll needs to be heated to a high temperature. Therefore, the material of the fixing roll and the material of the substrate to be transferred are limited.

  The molecular weight of the polyester resin within the above glass transition temperature and softening point can be selected from a wide range, but the obtained toner particles can be used as a color toner, the fixability to an OHP sheet, etc. can be improved. Considering that the region shifts to a high temperature side to prevent poor fixing of toner particles to a transfer material, it is preferably 2000 to 200000, more preferably 2000 to 50000, and a number average The molecular weight is 2000 to 30000, preferably 3000 to 25000, and more preferably 3000 to 20000. If the number average molecular weight is larger than 200,000, it is difficult to self-disperse, and if it is smaller than 2000, there is a disadvantage that the fixing property as a toner is inferior.

  As the hydrophilic group contained in the main chain of the self-dispersing binder resin, an ionic group is preferable, and among them, an anionic group is particularly preferable. Specific examples of preferred hydrophilic groups include carboxyl groups, sulfonic acid groups, phosphoric acid groups, phosphonic acid groups, phosphinic acid groups, ammonium salts and metal salts of the above groups. Among these, alkali metal carboxylates More preferred are salts and ammonium carboxylate. In the case of a polyester resin, for example, when introducing an alkali metal carboxylate and an ammonium carboxylate, a polyvalent carboxylic acid such as trimellitic acid and / or an acid anhydride thereof is used at the end of polymerization of the polyester. It is possible to use a method in which a carboxyl group is added to a polymer terminal and / or a molecular chain by introducing it into the polymer chain, and this is further neutralized with ammonia, sodium hydroxide or the like to exchange for a carboxylate. The ionic group has a function of imparting water dispersibility to the polyester resin, but the counter cation of these ionic group-containing monomers in polymerizing the polyester is preferably a monovalent cation. A self-dispersing polyester resin having a carboxylate as a hydrophilic group has an advantage that it can be hydrophobized by a subsequent washing method.

Next, a method for obtaining particles having a predetermined average particle size and particle size distribution from a self-dispersing resin containing an ionic group will be described. In the case of a polyester resin, the ionic group-containing polyester resin has water dispersibility. An aqueous fine dispersion of a polyester resin containing an ionic group can be produced by a known method. For example, there is a method in which a polyester resin containing an ionic group and a water-soluble organic compound are preliminarily adjusted to 50 to 200 ° C., mixed, and water is added thereto.
As another method, a method of producing by adding a mixture of a polyester resin containing an ionic group and a water-soluble organic compound (for example, a counter cation) to water and further heating to 40 to 120 ° C. and dispersing. There is.
As another method, there is a method in which a polyester resin containing an ionic group is added to a mixed solution of water and a water-soluble organic compound, and the mixture is further heated to 40 to 100 ° C. and stirred.
As the water-soluble organic compound, solvents such as ethanol, butanol, isopropanol, ethyl cellosolve, butyl cellosolve, dioxane, tetrahydrofuran, acetone and methyl ethyl ketone can be used.
The average particle size of self-dispersing binder resin particles such as an aqueous fine dispersion of a polyester resin is 0.2 μm or less, preferably 0.01 to 0.15 μm, more preferably 0.01 to 0.1 μm. . When the average particle size of the self-dispersing binder resin particles is larger than 0.2 μm, the aggregated particles are coarsened and cannot be formed into a desired toner particle size.

(Pigment)
In the present invention, known pigments can be used, and any of blue, brown, cyan, green, violet, magenta, red and yellow pigments or a mixture thereof may be used. Specifically, anthraquinone pigments, phthalocyanine blue pigments, phthalocyanine green pigments, diazo pigments, monoazo pigments, pyranthrone pigments, perylene pigments, heterocyclic yellow, quinacridone, indigoid pigments and thioindigoid pigments, etc. Is mentioned. Examples of the anthraquinone pigment include pigment red 43, pigment red 194 (perinone red), pigment red 216 (brominated pyrantrone red), and pigment red 226 (pyrantron red). Examples of the phthalocyanine blue pigment include copper phthalocyanine blue and pigment blue 15 which is a derivative thereof. Examples of the pyrerin pigment include pigment red 123 (bell million), pigment red 149 (scarlet), pigment red 179 (maroon), pigment red 190 (red), pigment violet, pigment red 189 (yellow shade red), and pigment red 224. Etc. Examples of the heterocyclic yellow include pigment yellow 117 and pigment yellow 138. Examples of the quinacridone pigment include Pigment Orange 48, Pigment Orange 49, Pigment Red 122, Pigment Red 192, Pigment Red 202, Pigment Red 206, Pigment Red 207, Pigment Red 209, Pigment Violet 19 and Pigment Violet 42. Examples of the thioindigoid pigment include Pigment Red 86, Pigment Red 87, Pigment Red 88, Pigment Red 181, Pigment Red 198, Pigment Violet 36, and Pigment Violet 38. As the black pigment, carbon black produced by various methods can be used.

  The pigment may be dispersed in water using a dispersant such as a surfactant. In this case, as the dispersant, an anionic surfactant and a nonionic surfactant are preferable, and an anionic surfactant is particularly preferable. By using the dispersant, the pigment can be easily dispersed in water, the dispersed particle diameter of the pigment in the toner can be reduced, and a toner having more excellent toner characteristics can be produced. Further, it is possible to remove unnecessary dispersant by the washing step.

  A pigment may be used individually by 1 type and may use 2 or more types together. Moreover, when using 2 or more types of pigments together, the pigment of the same color may be used together, and the pigment of multiple colors may be used together. In the present invention, the content of the pigment can be selected from a wide range according to the required toner characteristics, but is 0.1 to 20% by weight with respect to 100% by weight of the self-dispersing binder resin. It is preferable that it is 0.1 to 15 weight%. When the amount is less than 0.1% by weight, the image density of the formed image is unlikely to be excellent, and when the amount exceeds 20% by weight, it is difficult to ensure the dispersibility of the pigment in the formed image.

(Wax fine particles)
In the present invention, wax fine particles that may be one of the toner components may be included. As the fine particles, known waxes can be used. For example, natural waxes such as carnauba wax and rice wax, polypropylene waxes, polyethylene waxes, synthetic waxes such as Fischer and Lopush wax, and coal-based waxes such as montan wax. , Alcohol waxes and ester waxes. One type of wax may be used alone, or two or more types may be used in combination. The wax fine particles are mixed with the liquid mixture in the mixed liquid preparation step S1. At this time, the wax fine particle aqueous dispersion prepared by previously mixing and emulsifying the wax in water or the encapsulated wax in which the surface of the wax is encapsulated with a resin. Is preferably mixed in the mixed solution. For this reason, inclusion of encapsulated wax is preferable in that the spent on the carrier can be improved because the wax is not exposed on the toner surface in the toner of the production method in which the resin layer is not provided on the toner surface. When the toner component contains a wax, the content thereof is preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight with respect to 100% by weight of the self-dispersing binder resin.

(Additive)
In the present invention, in addition to the above-described toner components, additives generally added to the toner as necessary, for example, a charge control agent and a release agent may be added in an appropriate amount to the dried toner after the washing step. Good.
Further, the toner particles may be surface-modified by adding an external additive to the dried toner after the washing step. As the external additive, known external additives can be used, and examples thereof include water-dispersible inorganic particles such as silica and titanium oxide. These inorganic particles have an average particle diameter of 1 μm or less, preferably 0.01 to 0.8 μm, and one or more kinds can be used in combination. Furthermore, surface modification may be performed by adding a silicone resin or the like to the external additive. The addition amount of the external additive is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the toner particles.

  The toner obtained by the above production method of the present invention preferably has an average particle size of 10 μm or less, more preferably 2 to 9 μm, and particularly preferably 3 to 8 μm. When the average particle diameter exceeds 10 μm, the particle size distribution becomes broad in the toner production process, and the chargeability variation is large, which causes the image to be disturbed.

The toner obtained by the production method of the present invention can be used as a one-component developer or a two-component developer. When used as a one-component developer, a carrier is not used, only toner is used, a blade and a fur brush are used, a toner is frictionally charged by a developing sleeve, and the toner is attached onto the sleeve to form an image. .
When used as a two-component developer, toner is used together with a carrier. As the carrier, a known carrier can be used, and examples thereof include a single or composite ferrite composed of iron, copper, zinc, nickel, cobalt, manganese, chromium and the like and a carrier core particle whose surface is coated with a coating substance. As the coating material, known materials can be used. For example, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, metal compound of ditertiary butylsalicylic acid, styrene resin, acrylic resin , Polyacid, polyvinyllar, nigrosine, aminoacrylate resin, basic dye, basic dye lake, silica fine powder, alumina fine powder, and the like, which are preferably selected according to the toner component. Moreover, a coating substance may be used individually by 1 type, and may be used in combination of 2 or more type. The average particle size of the carrier is preferably 10 to 100 μm, more preferably 20 to 80 μm.

[Description of flocculant]
As the aggregating agent used in the agglomerate forming step in the toner production method of the present invention, known ones can be used, for example, electrolytes, organic substances having ions opposite to the pigments, and the like can be used. As described above, since the self-dispersing binder resin and the pigment preferably have an ionic group and / or an ionizable group on the surface, the self-dispersing binder resin and the pigment are ionized. Polyvalent metal salts capable of binding are preferred. Further, magnesium sulfate and aluminum sulfate, which are easily dissolved in water so as to be easily washed with pure water, are more preferable. Among these, magnesium sulfate is particularly preferable. The reason for this is that the magnesium salt has a ionic valence of 2 and, when used as an aggregating agent, compared to a trivalent aluminum salt, the agglomeration rate is slow and is optimal for controlling the particle size. . Further, as the flocculant, an organic flocculant such as dimethylaminoethyl (2,2 dimethylol) propionate can be used.
The amount of the flocculant used is 0.5 to 20 parts by weight, preferably 0.5 to 18 parts by weight, and more preferably 1.0 to 18 parts by weight with respect to 100 parts by weight of the toner component. If the amount of the flocculant used is less than 0.5 parts by weight, no aggregation occurs and particles cannot be formed. If the amount exceeds 20 parts by weight, the aggregated particles become too large.

[Description of pure water]
The pure water used in the cleaning step in the toner production method of the present invention preferably has an electrical conductivity of 20 μS / cm or less. Such pure water can be obtained by a known method such as an activated carbon method, an ion exchange method, a distillation method, or a reverse osmosis method, and a plurality of methods may be combined. The temperature of pure water at the time of washing is preferably not more than the lowest glass transition temperature among the glass transition temperatures of two or more kinds of self-dispersing binder resins having different number average molecular weights from the viewpoint of reaggregation.

[Description of agitator]
In the agglomerate forming step in the toner production method of the present invention, it is preferable to use a stirrer for stirring the mixture. As the stirrer, known emulsifiers and dispersers can be used, but the toner component and the aqueous medium can be received batchwise or continuously, have a heating means, and the toner component and the aqueous medium are heated. An apparatus capable of producing toner which is binder resin particles containing a pigment by mixing and discharging the toner in a batch type or a continuous type is preferable. In addition, the emulsifier and the disperser can impart a shearing force to the mixture of the toner and the aqueous medium, which makes it easier to form the formed aggregate into particles having a uniform particle size and shape. This is preferable. Further, the emulsifier and the disperser preferably have at least one of a stirring unit and a rotating unit, and can mix the toner and the aqueous medium under stirring or rotation. In the emulsifier and the disperser, the mixing container for mixing the toner and the aqueous medium preferably has a heat retaining means.
Specifically, for example, Ultra Thalax (trade name: manufactured by IKA Japan Co., Ltd.), Polytron homogenizer (trade name: manufactured by Kinematica Co., Ltd.) and TK Auto Homo Mixer (trade name: manufactured by Special Machine Industries Co., Ltd.) Batch type emulsifiers such as Max Blend (trade name: manufactured by Sumitomo Heavy Industries, Ltd.), Ebara Milder (trade name: manufactured by Ebara Corporation), TK Pipeline Homo Mixer (trade name: Special Machine Industries ( Co., Ltd.), TK homomic line flow (trade name: manufactured by Tokushu Kika Kogyo Co., Ltd.), Philmix (trade name: manufactured by Tokushu Kika Kogyo Co., Ltd.), colloid mill (trade name: Shinko Pantech ( Co., Ltd.), Thrasher (trade name: Mitsui Miike Kako Co., Ltd.), Trigonal wet milling machine (trade name: Mitsui Miike Kako Co., Ltd.), Cavitron (trade name: Eurotech Co., Ltd.) ) And Fine Flow Mill (trade name: Taiheiyo Kiko Co., Ltd.) and other continuous emulsifiers, Claremix (trade name: M Technique Co., Ltd.) and Fillmix (trade name: Tokushu Kika Kogyo Co., Ltd.) ))).

  EXAMPLES Examples and comparative examples of the present invention will be specifically described below, but the present invention is not limited to these examples unless it exceeds the gist.

[Synthesis of copolymerized polyester resin used as self-dispersing binder resin particles]
(Copolymerized polyester resin 1)
In an autoclave equipped with a thermometer and a stirrer, 137 parts by weight of dimethyl terephthalate, 55 parts by weight of dimethyl isophthalate, 68 parts by weight of ethylene glycol, 175 parts by weight of bisphenol A ethylene oxide adduct (average molecular weight 350) and tetrabutoxy titanate as a catalyst 0.1 part by weight was charged, and the ester exchange reaction was performed by heating at 150 to 220 ° C. for 180 minutes, and then the temperature was raised to 240 ° C. Then, the pressure of the reaction system was gradually reduced to 10 mmHg after 30 minutes, The reaction was continued for a minute. Thereafter, the inside of the autoclave was replaced with nitrogen gas to obtain atmospheric pressure. While maintaining the temperature at 200 ° C., 2 parts by weight of trimellitic anhydride was added and reacted for 70 minutes to obtain a copolyester resin 1.
It was 15 KOHmg when the acid value of the obtained copolyester resin 1 was measured.

(Copolymerized polyester resin 2)
In a reaction vessel equipped with a stirrer, condenser and thermometer, 199 parts of terephthalic acid, 465 parts of isophthalic acid, 468 parts of 2,2-dimethyl-1,3-propanediol, 156 parts of 1,5-pentanediol, tetrabutyl as a catalyst 0.41 part of titanate was charged, and esterification reaction was performed from 160 ° C. to 230 ° C. over 4 hours. Next, the pressure in the system was gradually reduced, the pressure was reduced to 5 mmHg over 20 minutes, and a polycondensation reaction was performed at 260 ° C. for 40 minutes under a vacuum of 0.3 mmHg or less. Under a nitrogen stream, the mixture was cooled to 220 ° C., 23 parts of trimellitic anhydride and 16 parts of ethylene glycol bisanhydro trimellitate were added, and reacted for 30 minutes to obtain polyester resin 2. It was 22 mgKOH / g when the acid value of the obtained copolyester resin 1 was measured.

(Copolymerized polyester resin 3)
In an autoclave equipped with a thermometer and a stirrer, 1,5-naphthalenedicarboxylic acid methyl ester 38 parts by weight, dimethyl terephthalate 96 parts by weight, dimethyl isophthalate 58 parts by weight, ethylene glycol 136 parts by weight and tetrabutoxy titanate 0 as a catalyst .1 part by weight was charged and transesterified by heating at 150 to 220 ° C. for 180 minutes. Next, after the temperature was raised to 240 ° C., the pressure in the reaction system was gradually reduced to 30 mm after 30 minutes, and the reaction was continued for 70 minutes. Thereafter, the inside of the autoclave was replaced with nitrogen gas to obtain atmospheric pressure. While maintaining the temperature at 200 ° C., 10 parts by weight of trimellitic anhydride was added and reacted for 70 minutes to obtain a copolyester resin 2. It was 14KOHmg when the acid value of the obtained copolyester resin 3 was measured.

(Copolymerized polyester resin 4)
In an autoclave equipped with a thermometer and a stirrer, 96 parts by weight of dimethyl terephthalate, 96 parts by weight of dimethyl phthalate, 72 parts by weight of ethylene glycol, 103 parts by weight of neopentyl glycol, and A transesterification reaction was carried out by charging 0.1 parts by weight of tetrabutoxy titanate and heating at 150 to 220 ° C. for 180 minutes. Subsequently, after raising the temperature to 240 ° C., the pressure of the system was gradually reduced to 30 mm after 10 minutes, and the reaction was continued for 60 minutes. Thereafter, the inside of the autoclave was replaced with nitrogen gas to obtain atmospheric pressure. The temperature was maintained at 200 ° C., 4 parts by weight of trimellitic anhydride was added, and the reaction was performed for 60 minutes to obtain a copolyester resin 4. It was 25 KOHmg when the acid value of the obtained copolyester resin 4 was measured.

(Copolymerized polyester resin 5)
In an autoclave equipped with a thermometer and a stirrer, 49.8 parts by weight of terephthalic acid, 116.2 parts by weight of isophthalic acid, 58.5 parts by weight of 2-methyl-1,3-propanediol, 1,4 -Cyclohexanedimethanol 51.1 parts by weight Titanium tetrabutoxide 0.1 part was charged into a 3 L four-necked flask and gradually heated to 235 ° C over 4 hours for esterification. Thereafter, initial polymerization under reduced pressure was performed, and the temperature was raised to 250 ° C. to perform polymerization. When the target molecular weight was reached, it was cooled to 220 ° C. under a nitrogen atmosphere. Next, 2 parts of ethylene glycol bistrimellitate dianhydride and 1.8 parts of trimellitic anhydride were successively added, and stirring was continued at 200 ° C. to 230 ° C. for 1 hour in a nitrogen atmosphere to obtain polyester resin 5. The acid value of the obtained copolyester resin 4 was measured and found to be 23 KOHmg.
(Copolymerized polyester resin 6)
In an autoclave equipped with a thermometer and a stirrer, 112 parts by weight of dimethyl terephthalate, 76 parts by weight of dimethyl isophthalate, 6 parts by weight of 5 sodium sulfodimethyl isophthalate, ethylene glycol 96 parts by weight, 50 parts by weight of propylene glycol, and 0.1 parts by weight of tetrabutoxy titanate were charged and heated at 180 to 230 ° C. for 120 minutes to conduct a transesterification reaction. Next, the temperature of the reaction system was raised to 250 ° C., and the reaction was continued for 60 minutes at a system pressure of 1 to 10 mmHg. As a result, a copolyester resin 3 was obtained.
The acid value of the obtained copolyester resin 3 was measured and found to be 0.1 KOHmg.

  Table 1 shows the glass transition temperatures and number average molecular weights of the obtained copolyester resins 1-6. The glass transition temperature was determined by DSC (differential scanning calorimeter) measurement, and the number average molecular weight was determined by GPC (gel permeation chromatography) measurement.

[Preparation of water dispersion of copolymerized polyester resin]
(Copolymerized polyester resin water fine dispersion 1)
100 parts by weight of the above copolyester resin 1, 48 parts by weight of butanol, 12 parts by weight of methyl ethyl ketone and 20 parts by weight of isopropanol are put into a four-necked 10 liter separable flask equipped with a thermometer, a condenser and a stirring blade. And dissolved at 70 ° C. with stirring. Further, 270 parts by weight of 1N ammonia aqueous solution was added so as to be equal to the acid value of the copolyester resin 1, and after stirring for 30 minutes while maintaining 70 ° C., 300 parts by weight of 70 ° C. water was added while stirring. A water fine dispersion of the copolyester resin 1 was obtained. Further, the obtained water fine dispersion was put into a distillation flask, and the organic solvent was removed by reducing the pressure with a vacuum pump at a temperature of 70 ° C. Finally, the solid content was adjusted with deionized water to obtain a copolyester resin water fine dispersion 1 having a solid content concentration of 30%, which was finally desolvated. The average particle diameter of the polyester resin water finely dispersed particles was 0.095 μm.

(Copolymerized polyester resin water fine dispersion 2)
A copolyester resin water fine dispersion 2 was obtained in the same manner as the preparation of the copolyester resin water fine dispersion 1 except that the copolyester 2 was used. The average particle diameter of the polyester resin water finely dispersed particles was 0.073 μm.

(Copolymerized polyester resin water fine dispersion 3)
A copolyester resin water fine dispersion 3 was obtained in the same manner as in the preparation of the copolyester resin water fine dispersion 1 except that the copolyester 3 was used. The average particle diameter of the polyester resin water finely dispersed particles was 0.080 μm.

(Copolymerized polyester resin water fine dispersion 4)
A copolyester resin water fine dispersion 4 was obtained in the same manner as in the preparation of the copolyester resin water fine dispersion 1 except that the copolyester 4 was used. The average particle diameter of the polyester resin water finely dispersed particles was 0.043 μm.

(Copolymerized polyester resin water fine dispersion 5)
A copolyester resin water fine dispersion 5 was obtained in the same manner as in the preparation of the copolyester resin water fine dispersion 1 except that the copolyester 5 was used. The average particle size of the polyester resin water finely dispersed particles was 0.037 μm.

(Copolymerized polyester resin water fine dispersion 6)
A copolyester resin water fine dispersion 6 was obtained in the same manner as in the preparation of the copolyester resin water fine dispersion 1 except that the copolyester 6 was used. The average particle diameter of the polyester resin water finely dispersed particles was 0.2 μm.

[Preparation of aqueous pigment dispersion]
(Pigment aqueous dispersion 1)
50 parts by weight of a cyan pigment (manufactured by BASF: Eupolene Blue 69-1501), 5 parts by weight of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) and 223 parts by weight of ion-exchanged water are zirconia beads having a diameter of 0.5 mm. For 40 minutes with a planetary ball mill (manufactured by Fritsch), and then put into a homogenizer (manufactured by Polytron, PT3000) and stirred for 20 minutes at room temperature to disperse the pigment. In addition, an ultrasonic homogenizer (Japan) And a blue pigment aqueous dispersion 1 having an average particle size of 0.10 μm was obtained.
In addition, the measurement of the average particle diameter of the pigment of the pigment aqueous dispersion 1 and the pigment aqueous dispersions 2 to 5 described later was measured with Microtrac UPA-ST150 (manufactured by Nikkiso Co., Ltd.).

(Pigment aqueous dispersion 2)
50 parts by weight of magenta pigment 1 (manufactured by BASF: Eupolen Red 47-9001), 5 parts by weight of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) and 223 parts by weight of ion-exchanged water are zirconia having a diameter of 0.5 mm. Use beads to disperse in a planetary ball mill (manufactured by Fritsch) for 40 minutes, then add to a homogenizer (manufactured by Polytron, PT3000), stir at room temperature for 20 minutes to disperse the pigment, and add with an ultrasonic homogenizer. Dispersion was carried out for 20 minutes to obtain a red pigment aqueous dispersion 2 having an average particle size of 0.09 μm.

(Pigment aqueous dispersion 3)
Zirconia beads having a diameter of 0.5 mm containing 50 parts by weight of a yellow pigment (manufactured by BASF: Eupole Yellow 09-6101), 5 parts by weight of an anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 223 parts by weight of ion-exchanged water. And then dispersed in a planetary ball mill (manufactured by Fritsch) for 40 minutes, and then placed in a homogenizer (manufactured by Polytron, PT3000) and stirred for 20 minutes at room temperature to disperse the pigment. In addition, an ultrasonic homogenizer was used for 20 Dispersing for a minute, a yellow pigment aqueous dispersion 3 having an average particle size of 0.08 μm was obtained.

(Pigment aqueous dispersion 4)
Using zirconia beads having a diameter of 0.5 mm, 50 parts by weight of carbon black (manufactured by Cabot, Mogal L), 5 parts by weight of a nonionic surfactant (manufactured by Sanyo Chemical Co., Ltd., Nonipol 400) and 223 parts by weight of ion-exchanged water are used. Carbon black having an average particle size of 0.13 μm is dispersed with a planetary ball mill (Fritsch) for 40 minutes, then charged into a homogenizer (Polytron, PT3000) and stirred for 20 minutes at room temperature to disperse the pigment. A pigment aqueous dispersion 4 was obtained.

(Pigment aqueous dispersion 5)
50 parts by weight of magenta pigment 2 (manufactured by BASF: Eupolen Red 47-9001), 5 parts by weight of a cationic surfactant (manufactured by Kao Corporation, SANISOL B50) and 223 parts by weight of ion-exchanged water are used with zirconia beads having a diameter of 0.5 mm. Disperse for 40 minutes with a planetary ball mill (manufactured by Fritsch), and then put into a homogenizer (PT3000, manufactured by Polytron) to stir at room temperature for 20 minutes to disperse the pigment. In addition, disperse with an ultrasonic homogenizer for 20 minutes. Thus, a red pigment aqueous dispersion 5 having an average particle size of 0.09 μm was obtained.

[Preparation of wax fine particle dispersion]
Stainless steel beaker with a jacket containing 50 parts by weight of paraffin wax (Nippon Seiwa Co., Ltd., HNP10, melting point 72 ° C.), 5 parts by weight of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) and 161 parts by weight of ion-exchanged water And dispersed for 30 minutes while heating at 95 ° C. with a homogenizer (manufactured by Polytron, PT3000), then transferred to a pressure discharge type homogenizer (manufactured by Nippon Seiki Co., Ltd.) and subjected to a dispersion treatment at 90 ° C. for 20 minutes. An aqueous wax fine particle dispersion having a particle size of 0.4 μm was obtained. The average particle diameter of the wax fine particles was measured with Microtrac UPA-ST150 (manufactured by Nikkiso Co., Ltd.).

[Example 1]
(Mixed liquid preparation process)
In the solid content concentration (parts by weight) shown in Table 2, the pigment aqueous dispersion 1 containing pigment cyan, the copolymer polyester resin aqueous dispersion 1 prepared by the method described above (85% of the amount shown in Table 2), The copolymerized polyester resin water fine dispersion 2 and the wax fine particle dispersion were mixed to obtain a mixed solution. At this time, the mixed solution was adjusted with pure water so that the solid content concentration was 10% by weight.

(Aggregate formation process)
While stirring the obtained mixed solution at 500 rpm using a Max blend stirrer, 270 parts by weight of a 1 wt% magnesium chloride aqueous solution was added dropwise little by little as a flocculant, and then the mixed solution was stirred for 1 hour. By doing so, the aggregate which is a toner was formed in the aqueous medium. Next, the remaining copolyester resin aqueous fine dispersion 1 (15% of the amount shown in Table 2) was mixed, and 30 parts by weight of a 1% strength by weight aqueous magnesium chloride solution was added dropwise little by little. Was stirred for 1 hour. By doing so, the aggregate which is a toner was further formed in the aqueous medium.
(Particle formation process)
The aqueous medium containing the aggregate that has undergone the aggregate formation process is heated to 75 ° C., and stirring is further continued for 30 minutes, and further stirred at 94 ° C. for 20 minutes to uniformize the particle size and shape of the aggregate. It was. At this time, in order to prevent reaggregation, the pH was adjusted to 10 and 1 part by weight of linear sodium alkylbenzene sulfonate was added.

(Washing process)
Next, the supernatant liquid in which the aggregates are precipitated is removed, the aggregates are washed with pure water three times (the supernatant liquid is exchanged three times), then washed with an aqueous HCl solution adjusted to pH 2, and further purified. After washing with water three times, it was filtered and dried using a vacuum dryer to prepare a magenta toner.
In addition, the pure water used for washing | cleaning used the 0.5 micro S / cm water prepared from the tap water using the ultrapure water manufacturing apparatus (ADVANTEC company_made: Ultra pure water system CPW-102). The pH and conductivity of water were measured using a Lacom tester (manufactured by Inoue Seieido: EC-PHCON10).

[Example 2]
The pigment aqueous dispersion 2, the copolyester resin water fine dispersion 1, the copolyester resin water fine dispersion 3, and the wax fine particle dispersion containing the pigment magenta 1 at a solid content concentration (parts by weight) shown in Table 2 were prepared. After mixing to obtain a mixed solution, a toner was produced in the same manner as in Example 1 to obtain a magenta toner of Example 2. In addition, the copolymer polyester resin water fine dispersion 1 used 85% by weight of the amount shown in Table 2 in the mixed liquid preparation step, and 15% by weight of the amount shown in Table 2 in the next aggregate formation step. .

[Example 3]
The pigment aqueous dispersion 3 containing pigment yellow, the copolyester resin water fine dispersion 1, the copolyester resin water fine dispersion 4 and the wax fine particle dispersion were mixed at a solid content concentration (parts by weight) shown in Table 2. After obtaining a mixed solution, a toner was manufactured in the same manner as in Example 1 to obtain a yellow toner of Example 3. In addition, the copolymer polyester resin water fine dispersion 1 used 85% by weight of the amount shown in Table 2 in the mixed liquid preparation step, and 15% by weight of the amount shown in Table 2 in the next aggregate formation step. .

[Example 4]
The pigment aqueous dispersion 4 containing pigment black, the copolyester resin water fine dispersion 1, the copolyester resin water fine dispersion 2, and the wax fine particle dispersion were mixed at the solid content concentration (parts by weight) shown in Table 2. Thus, a mixed liquid was obtained, and then a toner was manufactured in the same manner as in Example 1 to obtain a black toner of Example 4. In addition, the copolymer polyester resin water fine dispersion 1 used 85% by weight of the amount shown in Table 2 in the mixed liquid preparation step, and 15% by weight of the amount shown in Table 2 in the next aggregate formation step. .

[Example 5]
The pigment aqueous dispersion 1 containing pigment cyan, the copolyester resin water fine dispersion 3, the copolyester resin water fine dispersion 4 and the wax fine particle dispersion were mixed at the solid content concentration (parts by weight) shown in Table 2. Thus, a mixed liquid was obtained, and a toner was manufactured in the same manner as in Example 1 to obtain a cyan toner of Example 5. In addition, the copolymer polyester resin water fine dispersion 3 used 85% by weight of the amount shown in Table 2 in the mixed liquid preparation step, and 15% by weight of the amount shown in Table 2 in the next aggregate formation step. .

[Example 6]
The pigment aqueous dispersion 4 containing pigment black, the copolymerized polyester resin aqueous fine dispersion 2, and the wax fine particle dispersion were mixed at a solid content concentration (parts by weight) shown in Table 2 to obtain a mixed liquid. A coagulant was added to this mixed solution in the same manner as in Example 1 to form an aggregate, and then the copolyester resin aqueous fine dispersion 1 was added, and further the coagulant was added to produce a toner. Thus, the black toner of Example 5 was obtained. In addition, the copolyester resin water fine dispersion 2 uses the total weight of the amount shown in Table 2 in the mixed liquid preparation step, and uses the total weight of the copolyester 1 shown in Table 2 in the next aggregate formation step. did. Therefore, the polyester resin 2 is coated on the inner shell, and the polyester resin 1 is coated on the outer shell.

[Comparative Example 1]
Pigment aqueous dispersion 5 containing pigment magenta 2 dispersed in a solid content concentration (parts by weight) shown in Table 2 using a cationic surfactant (manufactured by Kao Corporation: Sanisol B50), as a self-dispersing binder resin Copolymerized polyester resin water fine dispersion 1, copolymerized polyester resin water fine dispersion 2 and wax fine particle dispersion were mixed to obtain a mixed solution. At this time, when the polyester resin and the dispersed pigment liquid were mixed and stirring was continued, aggregates were formed and the viscosity was increased. For this reason, the subsequent aggregation process was not performed.

[Comparative Example 2]
Pigment cyan-containing pigment aqueous dispersion 1 having a solid content concentration (parts by weight) shown in Table 2, self-dispersing binder resin as copolyester resin water fine dispersion 1, copolyester resin water fine dispersion 5 and After the wax fine particle dispersion was mixed to obtain a mixed liquid, a toner was produced in the same manner as in Example 1 to obtain a cyan toner of Comparative Example 2. In addition, the copolymer polyester resin water fine dispersion 1 used 85% by weight of the amount shown in Table 2 in the mixed liquid preparation step, and 15% by weight of the amount shown in Table 2 in the next aggregate formation step. .

[Comparative Example 3]
Aggregates were produced in the same manner as in Example 1. In the subsequent cleaning step, not only the step of cleaning with an aqueous HCl solution having a pH of 2, but the subsequent steps were carried out in the same manner as in Example 1 to prepare a cyan toner.

[Comparative Example 4]
The copolyester resin water fine dispersion 1 and the copolyester resin water fine dispersion 6 were mixed separately as self-dispersing binder resins at a solid content concentration (parts by weight) shown in Table 2, and 88 of the mixed solution. A pigment aqueous dispersion 1 containing% by weight and pigment cyan and a wax fine particle dispersion were mixed to obtain a mixed liquid, and then an agglomerate was produced in the same manner as in Example 1, and then the remaining copolymerized polyester resin water was used. 12% by weight of a mixture of the fine dispersion 1 and the copolyester resin water fine dispersion 6 was mixed, and a flocculant was added again in the same manner as in Example 1 to produce a toner, whereby a cyan toner of Comparative Example 4 was obtained.

[Comparative Example 5]
A toner was produced in the same manner as in Comparative Example 5 except that the flocculant of Example 2 was changed to Sanisol 50B (alkyldimethylbenzylammonium chloride) manufactured by Kao Corporation at the solid content concentration (parts by weight) shown in Table 2. A magenta toner was obtained.

[Comparative Example 6]
A pigment aqueous dispersion 1 containing pigment cyan, a copolymerized polyester resin aqueous fine dispersion 5 and a wax fine particle dispersion were mixed at a solid content concentration (parts by weight) shown in Table 2 to obtain a mixed liquid. A coagulant was added to this mixed solution in the same manner as in Example 1 to form an aggregate, and then the copolyester resin aqueous fine dispersion 4 was added, and further the coagulant was added to produce a toner. Thus, a cyan toner of Comparative Example 6 was obtained. The copolyester resin aqueous fine dispersion 5 uses the total weight of the amount shown in Table 2 in the mixed liquid preparation step, and uses the total weight of the copolyester 4 shown in Table 2 in the next aggregate formation step. did. Therefore, the polyester resin 5 is coated on the inner shell, and the polyester resin 4 is coated on the outer shell.

  In Examples 1-6 and Comparative Examples 1-6, 85 wt% of the amount shown in Table 2 was used in the mixed liquid preparation step in one specific type of copolyester resin aqueous dispersion, In the agglomerate forming step, 15% by weight of the amount shown in Table 2 was used, but a mixture of two or three types of copolyester resin aqueous fine dispersions may be used in the above proportion by dividing into the above two steps. .

[Toner preparation]
Toners of various colors were obtained by mixing (externally adding) 0.7 parts by weight of silica particles having an average primary particle diameter of 20 nm that had been subjected to a hydrophobic treatment with a silane coupling agent to the toners obtained in Examples and Comparative Examples.
[Preparation of developer]
70 g of externally added toner prepared as described above and 1400 g of ferrite carrier coated with a thermoplastic resin were mixed in a V-type mixer to prepare a developer.

[Evaluation methods]
About Examples 1-6 and Comparative Examples 1-6, each evaluation of average particle diameter, coefficient of variation, average circularity, image density, fog and fixability and their overall evaluation are performed by the evaluation methods shown below. The results are shown in Table 3. In Table 3, the following “◯” symbols mean that evaluation is very excellent in each item, and “x” symbols mean that it is difficult to put into practical use.

(Average particle size and coefficient of variation)
The average particle size and variation coefficient of the toner particles were measured using Coulter Multisizer II (manufactured by Coulter Inc.), and evaluated based on the following criteria based on the variation coefficient. The number of measured particles was 50,000 counts, and the aperture diameter was 100 μm. In addition, the unit of the average particle diameter in Table 3 is μm.
○: The coefficient of variation is 40 or less.
X: The coefficient of variation is less than 40.

(Average circularity)
The average circularity of the toner particles was measured using a flow particle image analyzer (manufactured by Toa Medical Electronics Co., Ltd .: FPIA-2000). The average circularity is defined by the following formula in the projected image of the particles detected by the flow type particle image analyzer, and has a value of 1 or less.
Average circularity = (perimeter of a circle having the same area as the projected image) / (perimeter of the projected image)

(Image density)
The image density was evaluated by measuring the optical density of the evaluation image using a spectrocolorimetric densitometer (manufactured by Nippon Planographic Printing Equipment Co., Ltd .: X-Rite 938) and based on the optical density based on the following criteria. The evaluation image shows the amount of toner particles deposited on a full-color paper (Sharp: PP106A4C) using a developer in a modified device of a digital full-color multifunction peripheral (Sharp: AR-C150). Was adjusted to 0.6 mg / cm ² , printed, and prepared using an external fixing machine.
○: Optical density is 1.2 or more.
X: The optical density is less than 1.2.

(Fog)
The fog was evaluated as follows. In the case of black toner, the whiteness of A4 size full color paper (manufactured by Sharp Corporation: PP106A4C) is measured in advance using a whiteness meter (manufactured by Nippon Denshoku Industries Co., Ltd .: Z-Σ90 COLOR MEASURING SYSTEM). Is the first measured value W1. Next, three originals including a white circle with a diameter of 55 mm are copied, and the whiteness of the obtained white portion is measured with a whiteness meter, and this value is set as a second measurement value W2. The fog density W (%) was calculated from the following formula, and evaluated according to the following criteria based on the fog density.
W = {100 × (W1-W2) / W1}
○: The fog density W is 2.0% or less.
X: The fog density W is higher than 2.0%.

(Fixability)
The fixability was evaluated by fixing the toner on the paper on which a predetermined chart was copied with an external fixing machine, obtaining the temperature range in which hot offset occurred from the temperature at which cold offset occurred, and evaluating the case where the non-offset area is the following area. .
○: The non-offset region is 40 ° C. or higher.
X: Non-offset area | region is less than 40 degreeC.

(Storability)
As for storability, 5 g of toner was weighed into a 50 ml sample bottle, tapped, and then stored in a high temperature bath at 50 ° C. for 24 hours. The stored sample was taken out, left to room temperature, tapped again, and the degree of aggregation was visually confirmed. The case where the pieces were loosened immediately after tapping and became the same as the initial state was marked with ◯, and the aggregated pieces were marked with X.

(Environmental assessment)
A predetermined amount of the developer is put into a developing tank and stored for one day in each environment ((a) temperature 5 ° C., humidity 10%, (b) temperature 35 ° C., humidity 80%). Rotate at the same rotation speed for 2 minutes, measure the charge amount of the toner at that time, and based on the relative ratio of the charge amount of the toner under the high temperature and high humidity condition of (b) to the low temperature and low humidity condition of (a) Evaluation was made according to the following criteria.
○: Change rate is within 60%. X: The rate of change is less than 60%.

  As is apparent from Table 3, the toners produced by the toner production method of the present invention (Examples 1 to 6) are toners having excellent toner characteristics such as particle size distribution, image density, fog and fixability. It has been found that it can be produced and is excellent in fog, fixability, storage stability and environmental characteristics. Comparing Examples 4 and 6, Example 6 coated with a higher molecular weight resin improved the fixing property slightly. On the other hand, in the toner of Comparative Example 1, since the cationic surfactant was used as the pigment dispersant, aggregation started in the mixed liquid of the pigment aqueous dispersion and the copolymerized polyester resin aqueous fine dispersion before adding the flocculant. A toner having an excessive average particle diameter has been produced. Therefore, it was determined that measurement of average circularity, image density, fog and fixability was unnecessary. Moreover, in the system using a polyester resin having a number average molecular weight of 2000 or less as in Comparative Example 2, problems of fixability and storage stability occurred. In Comparative Example 3, since the washing step of pH 6 or less was not performed, the environmental characteristics became unstable. Similarly, in Comparative Example 4, since a polyester resin having a sulfonic acid group was used, environmental stability was unstable. In Comparative Example 5, since the metal salt was not used as the flocculant, the particle diameter of the generated particles could not be controlled, large particles were generated, and other evaluations were not performed. In Example 5 and Comparative Example 6, the encapsulation was performed with a resin having a molecular weight of 2000 or more. However, in Comparative Example 6 in which the difference in molecular weight of the resin used was 1000 or less, the non-offset region was narrow and the properties as a toner were inferior. all right.

  The electrostatic image developing toner of the present invention can be suitably used for a copying machine or a printer.

FIG. 3 is a flowchart showing a method for producing an electrostatic image developing toner of the present invention.

Claims (17)

Self-dispersing polyester binder resin particles synthesized from an aqueous pigment dispersion, a polyvalent carbo containing at least three carboxyl groups and / or an acid anhydride thereof and a polyhydric alcohol, and having a carboxylic acid as a hydrophilic group in the main chain A mixed liquid preparation step of preparing a mixed liquid by mixing at least a binder resin particle aqueous dispersion containing
An agglomerate forming step of adding a polyvalent metal salt as an aggregating agent while stirring the mixed solution to form an aggregate in which at least a dispersed pigment is bound to the self-dispersing binder resin particles;
Self-dispersing binder resin particles in the aqueous dispersion of binder resin particles are formed of two or more types of self-dispersing binder resins having different number average molecular weights, respectively. Toner manufacturing method.   2. The electrostatic image developing toner according to claim 1, wherein the two or more types of self-dispersing binder resins have a smallest number average molecular weight of 2000 or more and a difference in number average molecular weight of the resins of 1000 or more. Production method.   3. The electrostatic charge image development according to claim 1, wherein in the aggregate formation step, the binder resin particle aqueous dispersion containing the self-dispersing binder resin particles is further mixed while stirring the mixed liquid containing the aggregate. Of manufacturing toner.   The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 3, wherein the average particle diameter of the aggregate is 10 µm or less.   The method for producing a toner for developing an electrostatic image according to claim 1, wherein the self-dispersing binder resin particles have an average particle size of 0.2 μm or less.   The method for producing a toner for developing an electrostatic image according to claim 1, wherein the metal of the polyvalent metal salt is a magnesium or aluminum metal salt.   The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 6, further comprising a washing step of washing the aggregate with pure water and drying after the aggregate formation step.   The method for producing a toner for developing an electrostatic image according to claim 7, wherein the washing step includes a step of washing with water having a pH of 6 or less once or more.   The electrostatic charge image according to any one of claims 1 to 8, wherein the pigment aqueous dispersion is a dispersion dispersed using a dispersant composed of an anionic surfactant and / or a nonionic surfactant. A method for producing a developing toner.   The electrostatic charge image according to any one of claims 1 to 9, further comprising a particle forming step of heating the mixed solution containing the aggregate to uniformize the particle diameter and shape of the aggregate after the aggregate forming step. Development toner.   The static liquid according to any one of claims 1 to 10, wherein in the mixed liquid preparation step, a wax fine particle aqueous dispersion containing natural and / or synthetic wax fine particles to be bound to the self-dispersing binder resin particles is further mixed. A method for producing a toner for developing a charged image.   The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 11, wherein in the aggregate formation step, an aqueous solution containing an aggregating agent is mixed while stirring the mixed liquid by a mechanical shearing force.   An electrostatic image developing toner produced by the method for producing an electrostatic image developing toner according to claim 1.   The electrostatic image developing toner according to claim 13, wherein one or more kinds of inorganic particles having an average particle diameter of 1 μm or less are bound to the surface of the toner particles.   15. An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 13 and a carrier.   An electrostatic latent image is formed on the photoreceptor, and the electrostatic latent image on the photoreceptor is developed using the electrostatic image developer according to claim 19 to form a toner image, and the toner image is recorded on the recording medium. An image forming method comprising a step of transferring and fixing to an image.   A formed image produced by the image forming method according to claim 16.

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