JP2017003861A - Manufacturing method of toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a toner with which a positively-charged toner having high chargeability and a sharp particle size distribution can be obtained.SOLUTION: There is provided a manufacturing method of a toner comprising toner particles, the method including a step of adjusting pH of an aqueous medium in a suspension to 6.0 or more and 9.0 or less and heating to increase the temperature of the aqueous medium to the glass transition temperature of a binder resin or higher.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing toner used in electrophotography, electrostatic recording, magnetic recording, and toner jet recording.

  In recent years, there has been a demand for higher speed and higher image quality in electrophotographic image formation. In a high-speed electrophotographic process, since the charging process is also shortened, the toner is required to have high chargeability that can be charged instantly. For high image quality, a toner having a sharp particle size distribution is required from the viewpoints of dot reproducibility and image stability during long-term use.

  Patent Document 1 describes a toner containing a positively chargeable charge control resin and manufactured by suspension polymerization for the purpose of improving chargeability.

  Patent Document 2 contains a resin containing nitrogen as a positively chargeable charge control agent in order to improve development characteristics including chargeability, and is produced by suspension polymerization under the condition that the pH of an aqueous medium is 5.6. The toner is described.

  Patent Document 3 describes a toner in which silica fine particles having a specific particle diameter and fatty acid zinc fine particles are externally added as external additives in a toner containing a positively chargeable charge control agent in order to improve development characteristics.

JP 2002-108011 A JP 2006-184687 A JP 2014-146054 A

  However, as a result of the study by the present inventors, the toner described in the above document has room for improvement in terms of further improving the chargeability and making the toner particle size distribution sharper. It has been found that the toner described in Patent Document 1 has a problem that, when used in a high-speed electrophotographic process, the charging property is insufficient and fogging or the like occurs. It has been found that the toner described in Patent Document 2 needs to be further improved in the chargeability and particle size distribution of the toner as the development process is further accelerated and the image quality is improved. Although the toner described in Patent Document 3 has excellent characteristics at the beginning, when used for a long period of time, there is a problem that image deterioration such as fogging occurs due to deterioration of the external additive, and improvement is required. I understood it.

  An object of the present invention is to provide a toner production method capable of obtaining a positively chargeable toner having high chargeability and a sharp particle size distribution.

The present invention is a method for producing a toner having toner particles, the method comprising:
A granulating step of forming particles of a composition containing a polymerizable monomer, a colorant and a positively chargeable charge control agent in an aqueous medium to obtain a suspension;
A polymerization step of polymerizing the polymerizable monomer contained in the particles of the composition in the suspension to form a binder resin; and a pH of the aqueous medium in the suspension of 6.0 to 9 The toner production method is characterized in that the toner particles are formed through a step of heating the temperature of the aqueous medium to not less than 0.0 and the glass transition temperature of the binder resin or higher.

  According to the present invention, it is possible to provide a toner manufacturing method capable of obtaining a positively chargeable toner having high chargeability and sharp particle size distribution that can cope with higher speed and higher image quality.

  The toner production method of the present invention has the following two steps as a suspension polymerization method. One is a granulation process in which particles of a composition containing a polymerizable monomer, a colorant, and a positively chargeable charge control agent are formed in an aqueous medium to obtain a suspension. The other is a polymerization step in which a polymerizable monomer contained in the composition particles is polymerized in the suspension to form a binder resin. And in this invention, it has the process of setting pH of the aqueous medium in suspension to 6.0 or more and 9.0 or less, and heating the temperature of an aqueous medium more than the glass transition temperature (Tg) of binder resin. And

  The inventors of the present invention examined the chargeability and particle size distribution of a toner containing a positively chargeable charge control agent and obtained by suspension polymerization. In the case of producing a toner by suspension polymerization, it is possible to produce a toner having good chargeability and a sharp particle size distribution by having a step of bringing the pH and temperature of the aqueous medium within a certain range. I found out. The present inventors presume the mechanism by which the toner having good chargeability and sharp particle size distribution can be manufactured by the above-described features of the present invention as follows.

  Since the charging phenomenon occurs on the toner surface, the chargeability of the toner can be controlled if the amount of the positively chargeable charge control agent present near the toner surface can be controlled. When a toner is obtained by suspension polymerization as in the present invention, it is known that a material having higher polarity is unevenly distributed on the surface of the toner. Therefore, if the polarity of the positively chargeable charge control agent can be controlled, the chargeability of the toner can be controlled.

  It is known that amines and ammonium salts (hereinafter collectively referred to as amines) generally used as positively chargeable charge control agents receive protons and ionize them in an aqueous medium depending on the pH of the aqueous medium. Yes. Specifically, it is easier to ionize when the pH of the aqueous medium is low. And when comparing the ionized state and the non-ionized state, the ionized state has higher polarity. Further, the positively chargeable charge control agent in the ionized state is more likely to be unevenly distributed on the toner surface as compared with the positively chargeable charge control agent in the nonionized state. Therefore, by controlling the pH of the aqueous medium low in the suspension polymerization method and promoting the ionization of the positively chargeable charge control agent, it is possible to promote the uneven distribution of the positively chargeable charge control agent on the toner surface.

  Further, in order to control the position of the positively chargeable charge control agent by controlling the pH, the positively chargeable charge control agent needs to easily move in the toner. For this purpose, it is necessary to sufficiently raise the temperature of the aqueous medium and increase the molecular mobility of the resin (particularly the binder resin) constituting the toner.

  That is, the pH of the aqueous medium is controlled to 6.0 or more and 9.0 or less to promote ionization of the positively chargeable charge control agent, and the aqueous medium is heated to a temperature higher than the glass transition temperature of the binder resin to be positively charged. It is to promote the movement of the neutral charge control agent. As a result, the positively chargeable charge control agent can be unevenly distributed near the toner surface, and as a result, a toner having good chargeability can be manufactured.

  On the other hand, in order to produce a toner having a sharp particle size distribution, a composition containing a polymerizable monomer, a colorant, and a positively chargeable charge control agent is combined with particles suspended in an aqueous medium throughout the toner production process. It is necessary to control one and division. Specifically, when the occurrence frequency of coalescence is high, coarse particles are likely to increase. When the occurrence frequency of splitting is high, fine particles are likely to increase. Therefore, in order to obtain a toner having a sharp particle size distribution, it is necessary to control the coalescence and division of suspended particles within an optimal range. The ease with which the particles of the composition are coalesced and split is affected by the surface charge of the particles of the composition. When the surface charge of the particles of the composition is small, the repulsion between the particles is small, so the occurrence frequency of coalescence is high, and it becomes easy to obtain many coarse particles.

  As described above, the pH of the aqueous medium is set to 6.0 or more and 9.0 or less, and the temperature of the aqueous medium is further heated to Tg or higher of the binder resin, thereby controlling the surface charge amount of the particles of the composition. It is presumed that a toner having chargeability and a sharper particle size distribution can be obtained.

  When the pH of the aqueous medium in the suspension is 6.0 or more and 9.0 or less, ionization of the positively chargeable charge control agent is promoted. By combining the temperature of the aqueous medium with the glass transition temperature of the binder resin or higher, it is possible to promote the uneven distribution of the positively chargeable charge control agent on the toner surface and obtain a toner having good chargeability. . Further, when the pH is 6.0 or more and 9.0 or less, the surface charge amount of the particles of the composition falls within the optimum range, so that a toner having a sharp particle size distribution can be obtained. When the pH of the aqueous medium is less than 6.0, the surface charge amount of the particles of the composition becomes excessive, and the particle size distribution and chargeability are lowered. Further, when the pH of the aqueous medium is higher than 9.0, good chargeability cannot be obtained because the positively chargeable charge control agent is insufficiently ionized. Furthermore, the pH of a preferable aqueous medium is 6.0 or more and 8.0 or less.

  The pH of the aqueous medium can be controlled by adding a known acid and base to the aqueous medium of the suspension. Specifically, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid; acids such as organic acids such as acetic acid and citric acid; sodium carbonate, sodium hydrogen carbonate, sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. Inorganic bases; bases such as organic bases such as ammonia and amine compounds.

  Moreover, the temperature of an aqueous medium is heating more than the glass transition temperature (Tg) of binder resin. When the temperature of the aqueous medium is equal to or higher than the glass transition temperature of the toner, and when the temperature of the aqueous medium is less than the Tg of the binder resin, the uneven distribution of the positively chargeable charge control agent on the toner surface is suppressed and good chargeability is achieved. It is difficult to get toner with. A preferable temperature of the aqueous medium is 20 ° C. or more higher than the glass transition temperature of the binder resin.

  Moreover, it is preferable to carry out for 1 hour or more as the time of the process of adjusting to the said specific pH and heat-processing, More preferably, it is 3 hours or more. If it is 3 hours or more, the positively chargeable charge control agent in the toner is sufficiently ionized and unevenly distributed on the surface, so that variation in chargeability between toners can be reduced. The treatment may be performed for any number of hours as long as it is 3 hours or more, but 20 hours or less is preferable from the viewpoint of productivity.

  In addition, when the pH of the aqueous medium is adjusted to a range of less than 6.0 or more than 9.0 after the step of adjusting to the above specific pH and heat treatment, the temperature of the aqueous medium is adjusted within 30 minutes after the adjustment. It is preferable to adjust to below the glass transition temperature. Furthermore, it is preferable to adjust the pH to a range of less than 6.0 or more than 9.0 after adjusting the temperature of the aqueous medium to be equal to or lower than the glass transition temperature of the toner.

  Subsequently, the method for producing the toner of the present invention will be specifically described below.

(Granulation process)
The granulation method is a step of obtaining a suspension by forming particles of a composition containing a polymerizable monomer, a colorant and a positively chargeable charge control agent in an aqueous medium. The particle forming method is not particularly limited. For example, (in-line type) emulsifying disperser (trade name “Milder” manufactured by Ebara Manufacturing Co., Ltd.), high-speed emulsifying disperser (manufactured by Special Machine Industries, Ltd., trade name “TK” A device capable of strong agitation such as “Homomixer”) can be used. The aqueous medium preferably contains a dispersion stabilizer. In the granulation step, a polymerization initiator may be further added.

(Polymerization process)
The polymerization step is a step of polymerizing the polymerizable monomer contained in the particles of the composition in the suspension to form a binder resin. In addition, when this step is performed under the condition that the pH of the aqueous medium is 6.0 or more and 9.0 or less and the temperature of the aqueous medium is equal to or higher than the glass transition temperature of the binder resin obtained by polymerization, the effect of the present invention is obtained. It is easy to obtain and more preferable.

(Process of adjusting to a specific pH and heat treatment)
This step includes a step of performing heat treatment under the condition that the pH of the aqueous medium is 6.0 or more and 9.0 or less and the temperature of the aqueous medium is equal to or higher than the glass transition temperature of the binder resin. In addition to performing this process independently, it can also be performed simultaneously with the said polymerization process or the distillation process mentioned later.

  Further, before the granulation step, if necessary, a colorant is dispersed in the presence of a polymerizable monomer to obtain a colorant dispersion liquid, a polymerizable monomer, a colorant, and positive charge control. You may have the mixing process which mixes resin and obtains a polymerizable monomer composition. Moreover, you may have a distillation process, a washing process, a filtration process, a drying process, a classification process, and an external addition process as needed after the polymerization process.

(Dispersion process)
The dispersion step is a step of obtaining a colorant dispersion by dispersing the colorant in the presence of a polymerizable monomer. As a dispersing device in the dispersing step, a conventionally known media type dispersing machine or non-media type dispersing machine can be used. Further, a positively chargeable charge control agent may be added in the dispersion step.

(Mixing process)
The mixing step is a step of obtaining a composition by mixing a polymerizable monomer, a colorant, and a positively chargeable charge control agent. In addition, you may use the coloring agent dispersion liquid obtained by the above-mentioned dispersion | distribution process as a polymerizable monomer, a coloring agent, and a positively chargeable charge control agent. Further, in addition to the colorant dispersion, a polymerizable monomer, a colorant and a positively chargeable charge control agent may be added. In the mixing step, a macromonomer, a molecular weight adjusting agent, a polymerization initiator, a release agent, and other charge control agents may be further added.

(Distillation process)
The distillation step is a step of removing unreacted polymerizable monomer. As the distillation method, known methods such as atmospheric distillation, reduced pressure distillation, and steam distillation can be used. In addition, it is easy to obtain the effect of the present invention, and it is more preferable to perform the distillation step under the condition that the pH of the aqueous medium is 6.0 or more and 9.0 or less and the temperature of the aqueous medium is equal to or higher than the glass transition temperature of the binder resin. .

(Washing process)
The washing step is a step of removing the dispersion stabilizer. For example, when an inorganic dispersant is used, it is preferable to remove the dispersion stabilizer by performing a treatment under conditions where the inorganic dispersant is dissolved using a known acid, base, or the like.

(Filtration process, drying process, classification process, external addition process)
The toner production method of the present invention may further include a filtration step, a drying step, a classification step, and an external addition step as necessary.

  Then, the material used for this invention is demonstrated in detail below.

(Charge control agent)
The positively chargeable charge control agent used in the present invention includes, for example, primary compounds containing amine or ammonium salt structures in amine compounds and resins such as primary amines, secondary amines, tertiary amines and quaternary ammonium salts. Charge control resin and the like.

In the step of heating the temperature of the aqueous medium above the glass transition temperature of the binder resin, it is preferable that the aqueous medium and the positively chargeable charge control agent satisfy the following formula (1).
1.0 ≦ B−A ≦ 5.0 (1)
In the formula (1), A represents the pH value of the aqueous medium, and B represents the pKa of the positively chargeable charge control agent.

  When the above formula (1) is satisfied, the positively chargeable charge control agent is sufficiently ionized, and a toner having better chargeability can be obtained.

  The positively chargeable charge control agent preferably contains an amine or a quaternary ammonium salt. In addition, when a positively chargeable charge control resin is used, the deterioration of the positively chargeable charge control agent existing on the toner surface even in long-term use is less than when a low molecular weight positively chargeable charge control agent is used. It is more preferable that the chargeability is not lowered due to liberation.

  Examples of a method for obtaining a positively chargeable charge control resin include the following methods. A method of copolymerizing a polymerizable monomer containing an amino group or an ammonium base and a polymerizable monomer copolymerizable therewith, or a polymerizable monomer containing an amino group and a polymerizable monomer copolymerizable therewith This is a method in which a copolymer of monomers is ammonium salified. As the positively chargeable charge control resin, a copolymer having a quaternary ammonium base is preferable. From the viewpoint of solubility in the resin, the copolymer should contain a monomer unit having a functional group that provides positive chargeability, a styrene derivative monomer unit, and an unsaturated carboxylic acid monomer unit. preferable.

  As the copolymerizable polymerizable monomer, a known monomer can be used without particular limitation. Specifically, the polymerizable monomers described in the term of polymerizable monomer described later can be used.

  As the amino group-containing polymerizable monomer, a known monomer can be used without particular limitation. Specifically, the following dimethylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminomethyl (meth) acrylate, dipropylaminomethyl (meth) acrylate, diisopropylaminomethyl (meth) acrylate, ethylmethylamino Such as methyl (meth) acrylate, methylpropylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, etc. N, N-disubstituted aminoalkyl (meth) acrylate and the like can be mentioned. The number of carbon atoms in the alkyl group is preferably 1 or more and 3 or less.

  As the quaternary ammonium base-containing polymerizable monomer, known monomers can be used without any particular limitation. Specifically, the following N, N, N-trimethyl-N- (2-methacryloxyethyl) ammonium chloride (DMC; dimethylaminoethyl methyl chloride methacrylate), N-benzyl-N, N-dimethyl-N— (2-methacryloxyethyl) ammonium chloride (DML; dimethylaminoethylbenzyl chloride methacrylate) and the like. These monomers can also be prepared by modifying an amino group-containing (meth) acrylate monomer with a halogenated organic compound to form a halogenated quaternary ammonium base-containing (meth) acrylate monomer. Can do.

As a method for introducing a quaternary ammonium base-containing (meth) acrylate monomer unit into a copolymer, for example,
(I) First, polymerization of the monofunctional monomer and / or monofunctional monomer shown in the explanation of the polymerizable monomer and the N, N-disubstituted aminoalkyl (meth) acrylate monomer is started. Copolymerization is carried out in the presence of the agent. Thereafter, this copolymer is quaternized with an amino group using a quaternizing agent such as a halogenated organic compound or an acid ester compound:
(Ii) Monofunctional monomers and / or monofunctionals shown in the description of the quaternary ammonium chloride monomer and polymerizable monomer of N, N-disubstituted aminoalkyl (meth) acrylate monomer The copolymerizable monomer is copolymerized in the presence of a polymerization initiator. Thereafter, the copolymer is reacted with an organic acid or derivative thereof to form a salt:
(Iii) In the presence of a polymerization initiator, the monofunctional monomer and / or the monofunctional monomer and the quaternary ammonium base-containing (meth) acrylate monomer shown in the explanation of the polymerizable monomer are used. Copolymerization method:
(Iv) Monofunctional monomer and / or copolymer of monofunctional monomer and alkyl halide (meth) acrylate monomer shown in description of polymerizable monomer, and polymerizable monomer The monofunctional monomer and / or the monofunctional monomer and the copolymer of the amino group-containing (meth) acrylate monomer shown in the description of the body are mixed and quaternized between the polymers. Method:
Etc.

  Examples of the quaternizing agent include halogenated organic compounds and acid ester compounds. Specific examples of the halogenated organic compound include the following linear, branched or cyclic alkyl halides having 1 to 6 carbon atoms such as chloromethane, dichloromethane, and trichloromethane; chlorobenzene, 4-chlorotoluene, Aromatic halides such as 1-chloronaphthalene; and the like. Specific examples of the acid ester include alkyl sulfonic acid alkyl esters such as methyl methyl sulfonate and ethyl methyl sulfonate; benzene sulfonic acid alkyl esters such as methyl benzene sulfonate; paratoluene such as methyl paratoluene sulfonate; Sulfonic acid alkyl ester; phosphoric acid ester such as trimethyl phosphate; boric acid ester such as trimethoxyborane;

  The molecular weight of the positively chargeable charge control resin is preferably a number average molecular weight (Mn) of 2,000 to 10,000 and a weight average molecular weight (Mw) of 5,000 to 50,000. Within this range, deterioration and liberation due to long-term use are suppressed, and the ease of movement in the toner is optimized.

  The glass transition temperature of the positively chargeable charge control resin is more preferably 50 ° C. or higher and 80 ° C. or lower because it hardly affects the storability and fixability of the toner.

  The positively chargeable charge control agent is preferably contained in an amount of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  The present invention may further contain a negatively chargeable charge control agent in addition to the above positively chargeable charge control agent for the purpose of chargeability adjustment, surface charge amount adjustment and the like.

  As the negatively chargeable charge control agent that can be used in the present invention, a conventionally known charge control agent can be used without any particular limitation. Specifically, the following metal compounds of aromatic carboxylic acid represented by salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid, etc .; polymer having sulfonic acid group, sulfonic acid group or sulfonic acid ester group Or a copolymer; Metal salt or metal complex of azo dye or azo pigment; Boron compound, silicon compound, calixarene, and the like.

(Dispersion stabilizer)
In the production method of the present invention, it is preferable to contain a dispersion stabilizer in the aqueous medium. Examples of the dispersion stabilizer include, as inorganic dispersion stabilizers, phosphates represented by the following magnesium phosphate, aluminum phosphate, hydroxyapatite, tricalcium phosphate, dicalcium phosphate, zinc phosphate and the like; water Metal hydroxides represented by magnesium oxide, aluminum hydroxide, calcium hydroxide, etc .; carbonates represented by calcium carbonate, magnesium carbonate, etc .; sulfates represented by calcium sulfate, barium sulfate, etc., calcium metasilicate, Examples thereof include bentonite, silica, and alumina. Examples of organic dispersion stabilizers include polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, polyacrylic acid and salts thereof, and starch.

  Among these, it is preferable to use an inorganic dispersant because the toner particle size can be easily controlled and can be easily washed. In addition, among inorganic dispersants, it can stably exist in the region of pH 6.0 or more and pH 9.0 or less, and it is easy to obtain a toner having a sharp particle size distribution. Therefore, an aluminum phosphate compound, a magnesium phosphate compound, An aluminum hydroxide compound is particularly preferred. It is preferable to use at least one selected from the group consisting of these three compounds. These dispersion stabilizers can be almost completely removed by adding an acid or an alkali after the polymerization and dissolving them.

(Polymerizable monomer)
As the polymerizable monomer used in the present invention, a vinyl monomer capable of radical polymerization can be used. As the vinyl monomer, a monofunctional monomer or a polyfunctional monomer can be used. Specifically, as a monofunctional monomer, the following styrene derivatives represented by styrene, α-methylstyrene, etc .; methyl acrylate, butyl acrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, methacrylic acid unsaturated carboxylic acid esters represented by t-butyl, 2-ethylhexyl methacrylate, etc .; unsaturated carboxylic acids represented by acrylic acid, methacrylic acid, etc .; unsaturated dicarboxylic acids represented by maleic acid; maleic anhydride Unsaturated dicarboxylic acid anhydrides typified by products; nitrile vinyl monomers typified by acrylonitrile; halogen-containing vinyl monomers typified by vinyl chloride; nitro series typified by nitrostyrene Vinyl monomer; and the like. These monofunctional monomers may be used alone or in combination of two or more.

  Further, in the present invention, a polyfunctional monomer may be used for the purpose of improving the durability, storage stability and hot offset resistance of the toner. Specifically, as the polyfunctional monomer, the following polyfunctional styrene derivatives represented by divinylbenzene and the like; represented by 1,6-hexanediol diacrylate, 1,10-decanediol diacrylate and the like Polyfunctional unsaturated carboxylic acid ester; and the like. Among these, it is preferable to use a bifunctional monomer from the viewpoint of easy control of the polymerization reaction. The polyfunctional monomer is preferably 0.05 parts by weight or more and 5.0 parts by weight or less, more preferably 0.1 parts by weight or more and 1.0 parts by weight, with respect to 100 parts by weight of the monofunctional monomer. It is preferable to use less than or equal to parts by mass.

  In the present invention, the binder resin is obtained by polymerizing the above polymerizable monomer, and specifically, is preferably a styrene acrylic resin.

(Polymerization initiator)
In the present invention, a polymerization initiator may be further used. Examples of the polymerization initiator used in the present invention include the following: 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1 ′ An azo or diazo polymerization initiator represented by azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and the like; Benzoyl peroxide, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, methyl ethyl ketone peroxide , Diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauro Examples thereof include peroxide-based polymerization initiators represented by irperoxide and the like.

  In addition, when using a polymerization initiator in this invention, it is preferable to add a polymerization initiator in the mixing process or granulation process mentioned above.

(Molecular weight regulator)
In the present invention, it is preferable to further use a molecular weight modifier. As the molecular weight regulator, a conventionally known molecular weight regulator can be used without particular limitation. Specifically, the following mercaptan compounds such as t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, and 2,2,4,6,6-pentamethylheptane-4-thiol; tetramethylthiuram monosulfide , Tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram tetrasulfide, N, N′-dimethyl-N, N′-diphenylthiuram disulfide, N, N′-dioctadecyl-N, N ′ -Thiuram compounds such as diisopropyl thiuram disulfide; piperidine salt of pentamethylene dithiocarbamate, pipecolyl dithiocarbamate, pipecoline, dimethyldithiocarbamate, sodium diethyldithiocarbamate And dithiocarbamate compounds such as sodium dibutyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, zinc N-ethyl-N-phenyldithiocarbamate, and tellurium diethyldithiocarbamate. Of these molecular weight regulators, mercaptan compounds and thiuram compounds are preferred. These can be used alone or in combination of two or more.

  The amount of the molecular weight modifier added is 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 100 parts by weight of the polymerizable monomer. 0.2 parts by mass or more and 3 parts by mass or less.

  In addition, when using a molecular weight regulator in this invention, it is preferable to add a molecular weight regulator in the mixing process, granulation process, or polymerization process mentioned above.

(Coloring agent)
As the colorant used in the present invention, conventionally known black, yellow, magenta, and cyan colors and pigments and dyes of other colors, magnetic substances, and the like can be used without particular limitation.

  As the black colorant, specifically, a black pigment represented by carbon black or the like is used.

  Specific examples of the yellow colorant include monoazo compounds, disazo compounds, condensed azo compounds, isoindolinone compounds, benzimidazolone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. And yellow pigments and yellow dyes. More specifically, the following C.I. I. Pigment yellow 74, 93, 95, 109, 111, 128, 155, 174, 180, 185, C.I. I. Solvent yellow 162 etc. are mentioned.

  Specific examples of the magenta colorant include the following monoazo compounds; condensed azo compounds; diketopyrrolopyrrole compounds; anthraquinone compounds; quinacridone compounds; basic dye lake compounds; naphthol compounds: benzimidazolone compounds; thioindigo compounds; And magenta pigments and magenta dyes. More specifically, the following C.I. I. Pigment Red 2,3,5,6,7,23,48: 2,48: 3,48: 4,57: 1,81: 1,122,144,146,150,166,169,177,184, 185, 202, 206, 220, 221, 238, 254, 269, C.I. I. And CI Pigment Bio Red 19.

  Specific examples of cyan colorants include the following copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds; cyan pigments and cyan dyes represented by basic dye lake compounds and the like. More specifically, the following C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66, and the like.

  The content of the colorant is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer.

  Furthermore, the toner of the present invention can be made into a magnetic toner by containing a magnetic substance. In this case, the magnetic material can also serve as a colorant. Magnetic materials include the following iron oxides typified by magnetite, hematite, ferrite, etc .; metals typified by iron, cobalt, nickel, etc. or these metals and aluminum, cobalt, copper, lead, magnesium, tin, zinc , Alloys with metals such as antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, and mixtures thereof.

  In addition, when using a pigment as a coloring agent in this invention, it is preferable to perform the dispersion process mentioned above and to add a pigment in a dispersion process.

(Release agent)
In the present invention, a release agent may be further used. As the release agent used in the present invention, a conventionally known release agent can be used without any particular limitation. Specifically:
Monofunctional ester waxes represented by behenyl behenate, stearyl stearate, palmityl palmitate, etc. (esters of monohydric alcohol and aliphatic monocarboxylic acid);
Bifunctional ester waxes represented by dibehenyl sebacate, hexanediol dibehenate, etc. (ester of dihydric alcohol and aliphatic monocarboxylic acid, or ester of divalent carboxylic acid and aliphatic monoalcohol);
Trifunctional ester waxes typified by glycerin tribehenate (ester of trihydric alcohol and aliphatic monocarboxylic acid, or ester of trivalent carboxylic acid and aliphatic monoalcohol);
Tetrafunctional ester waxes represented by pentaerythritol tetrastearate, pentaerythritol tetrapalmitate, etc. (esters of tetravalent alcohol and aliphatic monocarboxylic acid, or esters of tetravalent carboxylic acid and aliphatic monoalcohol);
Hexafunctional ester waxes represented by dipentaerythritol hexastearate, dipentaerythritol hexapalmitate, etc. (esters of hexavalent alcohol and aliphatic monocarboxylic acid, or esters of hexavalent carboxylic acid and aliphatic monoalcohol);
Polyfunctional ester waxes represented by polyglycerin behenate (esters of polyhydric alcohol and aliphatic monocarboxylic acid, or esters of polyhydric carboxylic acid and aliphatic monoalcohol);
Natural ester waxes typified by carnauba wax, rice wax, etc .; paraffin wax, microcrystalline wax, petroleum wax such as petrolatum and derivatives thereof; hydrocarbon wax and derivatives thereof by Fischer-Tropsch method; polyethylene wax, polypropylene wax, etc. Polyolefin wax and derivatives thereof; higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid; and acid amide waxes.

  It is preferable that the compounding quantity of a mold release agent is 1 to 30 mass parts with respect to 100 mass parts of polymerizable monomers.

  In addition, when using a mold release agent in this invention, it is preferable to perform the mixing process mentioned above and to add a mold release agent in a mixing process.

(External additive)
In the present invention, an external additive is preferably used for the purpose of improving the fluidity of the toner. As the external additive used in the present invention, a conventionally known external agent can be used without any particular limitation. Specifically, the following: raw silica fine particles typified by wet process silica, dry process silica or the like, or surface of these raw silica fine particles by a treatment agent typified by a silane coupling agent, a titanium coupling agent, and silicone oil Treated silica fine particles; metal oxide fine particles represented by titanium oxide fine particles, aluminum oxide fine particles, zinc oxide fine particles, etc. or metal oxide fine particles obtained by hydrophobizing the above metal oxide; zinc stearate, calcium stearate, stearin Fatty acid metal salts typified by zinc acid, etc .; metal complexes of aromatic carboxylic acids typified by salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid, etc .; clay minerals typified by hydrotalcite; Vinylidene fine particles, polytetrafluoroethylene fine particles Fluoric resin particles and the like typified by. Among these, from the viewpoint of excellent fluidity and chargeability, it is preferable to use silica fine particles obtained by subjecting the raw silica fine particles to a surface treatment with a silane coupling agent, a titanium coupling agent, and a treatment agent typified by silicone oil.

  The amount of the external additive is preferably 0.1 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particles. In addition, when using an external additive in this invention, it is preferable to perform the external addition process mentioned above and to use an external additive in an external addition process.

  The toner of the present invention can be used as it is as a one-component developer or as a two-component developer by mixing with a magnetic carrier.

  Then, the measuring method used for this invention is described in detail below.

<Measurement method of glass transition point of binder resin and positively chargeable charge control resin>
The glass transition temperature Tg (° C.) of the binder resin and the positively chargeable charge control resin is measured according to ASTM D3418-82 using a differential scanning calorimeter “Q1000” (manufactured by TA Instruments). The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium. Specifically, 2 mg of a measurement sample is precisely weighed and placed in an aluminum pan, and an empty aluminum pan is used as a reference. The measurement range is 0 ° C. to 100 ° C., and the heating rate is 10 ° C. / The temperature is raised at a rate of minutes. Hold at 100 ° C. for 15 minutes, and then cool between 100 ° C. and 0 ° C. at a rate of temperature decrease of 10 ° C./min. Hold at 0 ° C. for 10 minutes, and then measure between 0 ° C. and 100 ° C. at a rate of temperature increase of 10 ° C./min. Let Tg (° C.) be the intersection of the baseline intermediate line and the differential heat curve before and after the specific heat change of the specific heat change curve in the second temperature raising process. The Tg of the binder resin is measured by polymerizing the polymerizable monomer used in the polymerization step to form the binder resin, and only the obtained binder resin is used as a measurement sample.

<Measurement method of pKa of positively chargeable charge control agent>
0.100 g of the measurement sample is precisely weighed in a 250 ml tall beaker, 150 ml of THF is added and dissolved over 30 minutes. A pH electrode is placed in this solution, and the pH of the sample THF solution is read. Thereafter, 10 μl of 3 w / v% ethyl alcohol solution (manufactured by Kishida Chemical Co., Ltd.) is added, and the pH is read and titrated each time. Add 3 w / v% ethyl alcohol solution in hydrochloric acid until the pH is 4 or less and there is no change in pH even when 30 μl is added. From the obtained results, the pH is plotted against the addition amount of the 3 w / v% hydrochloric acid ethyl alcohol solution to obtain a titration curve. The point where the slope of pH change is greatest from the obtained titration curve is taken as the neutralization point. Since pKa is the same value as the pH in half of the 3 w / v% hydrochloric acid ethyl alcohol solution required up to the neutralization point, the pH in half is read from the titration curve.

<Measuring method of weight average particle diameter (D4) and number average particle diameter (D1) of toner>
The weight average particle diameter (D4) and number average particle diameter (D1) of the toner are calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. Note that the measurement is performed with 25,000 effective measurement channels.

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

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

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

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

The specific measurement method is as follows.
(1) In a glass 250 ml round bottom beaker for exclusive use of Multisizer 3, 200 ml of the electrolytic aqueous solution is placed and set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) Put 30 ml of the aqueous electrolytic solution into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetra 150” (manufactured by Nikkaki Bios Co., Ltd.) having an electrical output of 120 W is prepared. Into the water tank of the ultrasonic disperser, 3.3 l of ion-exchanged water is added, and 2 ml of Contaminone N is added to the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker (1) installed in the sample stand, the electrolyte aqueous solution (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to 5%. The measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. The “average diameter” on the “analysis / volume statistic (arithmetic average)” screen when the graph / volume% is set in the dedicated software is the weight average particle size (D4). When the number% is set, the “average diameter” on the “analysis / number statistics (arithmetic average)” screen is the number average particle diameter (D1).

<Calculation method of coarse powder amount (ratio of particles having a weight average particle diameter (D4) of 10.0 μm or more)>
In the present invention, the amount of coarse powder (% by volume) means the ratio of particles having a weight average particle diameter (D4) of 10.0 μm or more. The volume-based coarse powder amount (volume%) in the toner is calculated by analyzing the data after measuring the Multisizer 3 described above.

  Specifically, first, graph / volume% is set with the dedicated software, and the measurement result chart is displayed in volume%. Then, check “>” in the particle size setting portion on the “format / particle size / particle size statistics” screen, and enter “10” in the particle size input section below. When the “analysis / volume statistic (arithmetic average)” screen is displayed, the numerical value in the “> 10 μm” display portion indicates the amount of coarse powder (the volume of particles having a weight average particle diameter (D4) in the toner of 10.0 μm or more). %).

  The present invention will be specifically described with reference to the following examples. However, this does not limit the present invention in any way. The toner and the method for producing the toner are described below. In the examples and comparative examples, “part” and “%” are all based on mass unless otherwise specified.

[Production example of positively chargeable charge control resin]
[Manufacture of positively chargeable charge control resin 1]
In a 2 L flask equipped with a stirrer, condenser, thermometer and nitrogen inlet tube, 100 parts of a monomer mixture consisting of 82% styrene, 16% n-butyl acrylate, and 2% diethylaminoethyl methacrylate was added to 900 parts of toluene. The polymerization reaction was carried out at 75 ° C. for 8 hours in the presence of 4 parts of azobisdimethylvaleronitrile. After completion of the polymerization reaction, toluene was distilled off, and then dried under reduced pressure at 40 ° C., and then roughly crushed with a hammer mill, and the crushed product was further dried under reduced pressure at 40 ° C. for 48 hours. The physical properties of the obtained positively chargeable charge control resin 1 were pKa = 9.7 and Tg = 61 ° C.

[Manufacture of positively chargeable charge control resin 2]
In a 2 L flask equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube, 100 parts of a monomer mixture consisting of 82% styrene, 16% n-butyl acrylate, and 2% t-butylaminoethyl methacrylate was added to toluene 900. The polymerization reaction was carried out at 75 ° C. for 8 hours in the presence of 4 parts of azobisdimethylvaleronitrile. After completion of the polymerization reaction, toluene was distilled off, and then dried under reduced pressure at 40 ° C., and then roughly crushed with a hammer mill, and the crushed product was further dried under reduced pressure at 40 ° C. for 48 hours. The physical properties of the resulting positively chargeable charge control resin 2 were pKa = 11.2 and Tg = 60 ° C.

[Manufacture of positively chargeable charge control resin 3]
In a 2 L flask equipped with a stirrer, condenser, thermometer and nitrogen inlet tube, 100 parts of a monomer mixture consisting of 82% styrene, 16% n-butyl acrylate, and 2% dimethylaminoethyl methacrylate in 900 parts of toluene. And polymerized at 75 ° C. for 8 hours in the presence of 4 parts of azobisdimethylvaleronitrile. After completion of the polymerization reaction, toluene was distilled off, and then dried under reduced pressure at 40 ° C., and then roughly crushed with a hammer mill, and the crushed product was further dried under reduced pressure at 40 ° C. for 48 hours. The physical properties of the resulting positively chargeable charge control resin 3 were pKa = 9.3 and Tg = 62 ° C.

[Preparation example of aqueous medium]
[Preparation of aqueous medium 1]
In a three-necked flask, an aqueous solution in which 3.8 parts of trisodium phosphate (anhydride) was dissolved in 250 parts of ion-exchanged water was heated to 65 ° C. T.A. K. Using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), while stirring at 12,000 rpm, an aqueous solution in which 2.3 parts of magnesium chloride (anhydride) is dissolved in 50 parts of ion-exchanged water is gradually added, and phosphoric acid is added. An aqueous medium containing magnesium colloid was prepared. Then, 1N sodium hydroxide aqueous solution was added, pH was adjusted to 9.5, and it was set as the aqueous medium 1.

[Preparation of aqueous medium 2]
In a three-necked flask, an aqueous solution in which 6.9 parts of sodium hydroxide (anhydride) was dissolved in 250 parts of ion-exchanged water was heated to 65 ° C. T.A. K. An aqueous medium containing aluminum hydroxide colloid is prepared by gradually adding an aqueous solution in which 10.8 parts of aluminum chloride (anhydride) is dissolved in 50 parts of ion-exchanged water while stirring at 12000 rpm using a homomixer. did. Then, 1N sodium hydroxide aqueous solution was added, pH was adjusted to 9.5, and it was set as the aqueous medium 2.

[Preparation of aqueous medium 3]
In a three-necked flask, an aqueous solution in which 4.0 parts of trisodium phosphate (anhydride) was dissolved in 250 parts of ion-exchanged water was heated to 65 ° C. T.A. K. An aqueous medium containing aluminum phosphate colloid was prepared by gradually adding an aqueous solution in which 2.3 parts of aluminum chloride was dissolved in 50 parts of ion-exchanged water while stirring at 12000 rpm using a homomixer. Then, 1N sodium hydroxide aqueous solution was added, pH was adjusted to 9.5, and it was set as the aqueous medium 3.

[Preparation of aqueous medium 4]
In a three-necked flask, an aqueous solution in which 10.2 parts of magnesium chloride (anhydride) was dissolved in 250 parts of ion-exchanged water was heated to 65 ° C. T.A. K. While stirring at 12,000 rpm using a homomixer, an aqueous solution in which 6.2 parts of sodium hydroxide (anhydride) is dissolved in 50 parts of ion-exchanged water is gradually added to form an aqueous medium containing magnesium hydroxide colloid. Prepared. Then, 1N sodium hydroxide aqueous solution was added, pH was adjusted to 9.5, and it was set as the aqueous medium 4.

[Preparation of aqueous medium 5]
In a three-necked flask, an aqueous solution in which 4.2 parts of trisodium phosphate (anhydride) was dissolved in 250 parts of ion-exchanged water was heated to 65 ° C. T.A. K. An aqueous medium containing calcium phosphate colloid was prepared by gradually adding an aqueous solution in which 2.4 parts of calcium chloride (anhydride) was dissolved in 50 parts of ion-exchanged water while stirring at 12000 rpm using a homomixer. Thereafter, 10% hydrochloric acid was added to adjust the pH to 5.6, whereby an aqueous medium 5 was obtained.

[Preparation of aqueous medium 6]
The pH of the aqueous medium 1 was adjusted to 7.0 by adding 10.0% hydrochloric acid to obtain an aqueous medium 6.

[Example of toner production]
[Production Example of Toner 1]
-Styrene: 60 parts-Colorant (CI Pigment Blue 15: 3): 7 parts-Positively chargeable charge control resin 1: 1.2 parts The above materials are put into an attritor (Mitsui Miike Chemical Co., Ltd.). Further, using a zirconia particle having a diameter of 1.7 mm, it was dispersed at 220 rpm for 5 hours to obtain a composition.

Styrene: 18 parts n-butyl acrylate: 22 parts Paraffin wax (manufactured by Nippon Seiwa Co., Ltd., trade name “HNP-9”): 5 parts were added to the above composition. The material was kept at 65 ° C. K. Using a homomixer, it was uniformly dissolved and dispersed at 500 rpm. 4.4 parts of t-butyl peroxy-2-ethylhexanoate (manufactured by NOF Corporation, trade name “Perbutyl O”) was dissolved in this to prepare a polymerizable monomer composition.

  While adding the polymerizable monomer composition to the aqueous medium 1 and maintaining the temperature at 65 ° C., T.W. K. The mixture was stirred with a homomixer at 8000 rpm for 5 minutes to perform a granulation step. Thereafter, a reflux tube was attached to the three-necked flask, and a polymerization process was performed at 65 ° C. for 6 hours while stirring with a paddle stirring blade.

  After completion of the polymerization step, 10% hydrochloric acid was added to adjust the pH of the aqueous medium to 7.0. Thereafter, the reflux tube was replaced with a distillation tube, and a distillation step was performed at a temperature of 98 ° C. for 3 hours.

  After completion of the distillation step, the reaction vessel was cooled, 10% hydrochloric acid was added to adjust the pH of the aqueous medium to 2 or less, and the dispersion stabilizer was dissolved while stirring for 2 hours. The emulsion was filtered under pressure and further washed with 2000 parts or more of ion exchange water. Then, after sufficiently ventilating with a pressure filter, it was dried to obtain toner particles.

  100 parts of toner particles and 1.6 parts by mass of silica fine particles (primary particle size: 10 nm) treated with dimethyl silicone oil (20% by mass) are 4000 rpm using a Mitsui Henschel mixer (manufactured by Mitsui Miike Chemical Co., Ltd.). Was mixed for 5 minutes to obtain toner 1. The physical properties of the toner 1 are shown in Table 2. In these toner production examples 1, the step of adjusting to a specific pH and heat treatment corresponds to a distillation step.

[Production Examples of Toner 2 to Toner 14, Toner 17, Toner 18 and Toner 21 to Toner 25]
In the toner 1 manufacturing example, toner 2 to toner 14, toner 17, toner 18 and toner 21 to toner 25 are the same as in the toner 1 manufacturing example except that the manufacturing conditions and materials used are changed as shown in Table 1. Got. As the positively chargeable charge control agent for the toner 21, commercially available P-51 (manufactured by Orient Chemical Industry Co., Ltd .: pKa = 9.7) was used. The physical properties of toner 2 to toner 14, toner 17, toner 18 and toner 21 to toner 25 are shown in Table 2. In the production examples of the toner 2 to the toner 14, the toner 17, and the toner 21 to the toner 25, the process of adjusting the specific pH and performing the heat treatment corresponds to the distillation process. In the production example of the toner 18, the process of adjusting to a specific pH and performing the heat treatment corresponds to the polymerization process.

[Production Example of Toner 15]
In the production example of the toner 1, after completion of the distillation process, the pH of the aqueous medium is adjusted to 9.5 using sodium hydroxide before cooling, and the process after cooling is performed after stirring at 98 ° C. for 30 minutes. In the same manner as in the production example of toner 1, toner 15 was obtained. The physical properties of the toner 15 are described in Table 2.

[Production Example of Toner 16]
In the production example of the toner 1, after completion of the distillation step, the pH of the aqueous medium is adjusted to 9.5 using sodium hydroxide before cooling, and the subsequent steps after cooling are performed after stirring at 98 ° C. for 60 minutes. In the same manner as in the production example of toner 1, toner 16 was obtained. The physical properties of the toner 16 are described in Table 2.

[Production Example of Toner 19]
In the production example of the toner 11, except that the amount of styrene added to the polymerizable monomer composition is changed from 18 parts to 26 parts and the amount of n-butyl acrylate is changed from 22 parts to 14 parts, Similarly, toner 19 was obtained. The physical properties of the toner 19 are described in Table 2.

[Production Example of Toner 20]
In the production example of toner 12, the production example of toner 11 except that the amount of styrene added to the polymerizable monomer composition is changed from 18 parts to 26 parts and the amount of n-butyl acrylate is changed from 22 parts to 14 parts. Similarly, toner 20 was obtained. The physical properties of the toner 20 are shown in Table 2.

(Examples 1 to 19 and Comparative Examples 1 to 6)
The toners 1 to 25 were evaluated according to the combinations shown in Table 3. The evaluation results are shown in Table 3.

  The evaluation method and evaluation criteria of the present invention will be described below.

[1] Particle size distribution and coarse powder amount The particle size distribution and coarse powder amount of the obtained toner were evaluated based on the following evaluation criteria. As the particle size distribution index, a value (D4 / D1) obtained by dividing the weight average particle size (D4) by the number average particle size (D1) was used.

[1-1] Particle size distribution (D4 / D1)
A: D4 / D1 is 1.25 or less, and the particle size distribution is very sharp.
B: D4 / D1 is 1.30 or less, and the particle size distribution is sharp.
C: D4 / D1 is 1.35 or less.
D: D4 / D1 exceeds 1.35, and the particle size distribution is broad.

[1-2] Coarse powder amount A: Coarse powder amount is 3.0% or less, and the amount of coarse powder is very small.
B: The amount of coarse powder is 4.0% or less, and the amount of coarse powder is small.
C: The amount of coarse powder is 5.0% or less.
D: The amount of coarse powder exceeds 5.0%, and the amount of coarse powder is large.

[2] Image evaluation As the image forming apparatus, a commercially available laser printer LBP-7700C (Canon) modified machine and a commercially available process cartridge Toner Cartridge 323 (Cyan) (Canon) modified cartridge were used. The product toner was extracted from the inside of the cartridge, cleaned by air blow, and then filled with 150 g of the toner of the present invention.

The laser printer was remodeled so that the potential of each process was reversed from the normal sign for evaluation of positively chargeable toner. Also, the process cartridge has been modified so that members such as a photosensitive drum and a charging roller are charged with the opposite sign from the normal one.
[2-1] Initial fog and durable fog Initial fog and durable fog were evaluated by the following methods.

LBP-7700C modified machine, modified cyan cartridge filled with toner of the present invention and evaluation paper (plain paper “Canon Color Laser Copier Paper” (Canon: 81.4 g / m ² ), high gloss paper “HP Laser Photo” Paper 220 g ”(manufactured by HP: 220 g / m ² )) was allowed to stand in a high temperature and high humidity environment (30 ° C./80% RH) for 24 hours.

  Thereafter, one image with a printing rate of 0% was output on high gloss paper that was partially covered and protected so as not to be printed. Subsequently, the whiteness of the image and the protected portion was measured with a reflectometer equipped with an amber filter ("REFECTOMETER MODEL TC-6DS" manufactured by Tokyo Denshoku Co., Ltd.), and the fog was calculated from the difference in whiteness. . The initial fog was evaluated based on the following evaluation criteria.

[2-1-1] Initial fog A: The fog is 1.0% or less, which is a very excellent level.
B: Fog is 1.5% or less, and an excellent level.
C: Fog is 3.0% or less, which is good.
D: The fog is over 3.0% and the initial fog is inferior.

  After evaluation of initial fogging, 7000 images with a printing rate of 1% were output on plain paper. Thereafter, the modified LBP-7700C with the cartridge mounted was left in the same environment for 60 hours. Subsequently, in the same way as the evaluation of initial fogging, one image with a printing rate of 0% was output on high gloss paper that was partially covered and protected from printing. Subsequently, the whiteness of the image and the protected portion was measured with a reflectometer equipped with an amber filter ("REFECTOMETER MODEL TC-6DS" manufactured by Tokyo Denshoku Co., Ltd.), and the fog was calculated from the difference in whiteness. . Durability fog was evaluated based on the following evaluation criteria.

[2-1-2] Durability fog A: The fog is 1.0% or less and is a very excellent level.
B: Fog is 1.5% or less, and an excellent level.
C: Fog is 3.0% or less, which is good.
D: The fog is over 3.0% and the durability fog is inferior.

[2-2] Bad regulation / dot reproducibility Bad regulation and dot reproducibility were evaluated by the following methods.

LBP-7700C modified machine, modified cyan cartridge filled with toner of the present invention and evaluation paper (plain paper “Canon Color Laser Copier Paper” (Canon: 81.4 g / m ² )) at low temperature and low humidity environment (15 ° C. / 10% RH) for 24 hours.

Thereafter, 7000 images with a printing rate of 1% were output on plain paper. Subsequently, a halftone image (toner loading amount of 0.20 mg / cm ² ) was output on plain paper. Regulation failure was evaluated by observing the output image and the toner coat state on the developing roller in the cartridge. Subsequently, while outputting the same halftone image, the power of the main body was forcibly turned off, and the developed photosensitive drum was observed at a magnification of 100 using an optical microscope to evaluate dot reproducibility. In addition, a halftone image was also visually evaluated.

[2-2-1] Poor regulation A: The toner coat state and the image are uniform and very excellent.
B: Although the toner coat at the end of the developing roller is slightly thicker than the center, the image is uniform and has an excellent level.
C: Although the toner coat at the end of the developing roller is thicker than the center, the image is uniform and has a good level.
D: The toner coat at the end of the developing roller is thicker than the center, and the end of the image is also dark.

[2-2-2] Dot reproducibility A: The dot reproducibility is good and the image is uniform.
B: Although the image reproducibility is slightly disturbed, the image is uniform.
C: Although the dot reproducibility is largely disturbed, the image is uniform.
D: The reproducibility of dot reproducibility is very large, and part of the image is also rough.

Claims (7)

A method for producing a toner having toner particles, the method comprising:
A granulating step of forming particles of a composition containing a polymerizable monomer, a colorant and a positively chargeable charge control agent in an aqueous medium to obtain a suspension;
A polymerization step of polymerizing the polymerizable monomer contained in the particles of the composition in the suspension to form a binder resin, and a pH of the aqueous medium in the suspension of 6.0 to 9. A method for producing toner, comprising forming toner particles through a step of heating to 0 or less and heating the temperature of the aqueous medium to a glass transition temperature or higher of the binder resin. The aqueous medium includes a dispersion stabilizer;
The method for producing a toner according to claim 1, wherein the dispersion stabilizer contains at least one selected from the group consisting of an aluminum phosphate compound, a magnesium phosphate compound, and an aluminum hydroxide compound. In the step of heating the temperature of the aqueous medium above the glass transition temperature of the binder resin,
The toner production method according to claim 1, wherein the aqueous medium and the positively chargeable charge control agent satisfy the following formula (1).
1.0 ≦ B−A ≦ 5.0 (1)
(In the formula (1), A represents the pH value of the aqueous medium, and B represents the pKa of the positively chargeable charge control agent.)   The method for producing a toner according to claim 1, wherein the positively chargeable charge control agent contains an amine or a quaternary ammonium salt.   4. The toner production method according to claim 1, wherein the positively chargeable charge control agent is a positively chargeable charge control resin. 5.   The method for producing a toner according to any one of claims 1 to 5, wherein a time for performing the step of heating the temperature of the aqueous medium to a glass transition temperature or higher of the binder resin is 1 hour or longer.   The method for producing a toner according to claim 1, wherein the binder resin is a styrene acrylic resin.