JP2019164196A - Method for manufacturing toner, toner, and developer - Google Patents

Abstract

To provide a method for manufacturing a toner excellent in low-temperature fixability and heat-resistant storage property.SOLUTION: In a method for manufacturing a toner containing an amorphous binder resin, a mold release agent, organic resin fine particles, and an external additive, the toner is manufactured by emulsifying or dispersing an oil phase containing materials forming the toner in an aqueous phase containing the organic resin fine particles to perform granulation. The granulation includes an alkali cleaning step with an alkaline solution and a heating step after the alkali cleaning step, and when the average circularity of toner base particles before heating in the heating step is D1, and the average circularity of the toner base particles after the heating is D2, the following formula is satisfied. 0.002≤(D2-D1)/D1≤0.010.SELECTED DRAWING: None

Description

  The present invention relates to a toner manufacturing method, toner and developer.

  In electrophotographic image formation, an electrostatic charge image (latent image) is formed on an electrostatic latent image carrier, charged toner is conveyed by a developer carrier, and the latent image is developed to form a toner image. After the formation, the toner image is transferred onto a recording medium such as paper and fixed by a method such as heating to obtain an output image. Further, a technique is known in which toner remaining on an electrostatic latent image carrier after transfer is collected from the electrostatic latent image carrier by a cleaning member and discharged to a waste toner storage unit.

  In the heat-fixing type image forming apparatus, since a large amount of electric power is required in the process of heat-melting the toner and fixing it on a recording medium such as paper, the toner has a low-temperature fixability from the viewpoint of energy saving. Is one of the important characteristics. In addition, even in severe usage conditions such as fluctuations in the operating environment temperature and humidity of the image forming apparatus and continuous output of a large number of images, heat-resistant storage stability may be provided in order to continue outputting images with a constant image quality. is important.

  In order to improve the low-temperature fixability of the toner, it is necessary to control the thermal characteristics of the binder resin that occupies most of the toner. For example, Patent Document 1 proposes a method for producing a toner using a crystalline polyester resin that exhibits a thermal melting characteristic that exhibits a sudden decrease in viscosity near the melting start temperature. In this proposal, the heat resistance storage stability is good due to the crystallinity until just before the melting start temperature, and the viscosity rapidly decreases and fixes at the melting start temperature, so that it is possible to design a toner having both heat storage stability and low temperature fixing performance. However, when the crystalline polyester and the amorphous polyester are compatible, the glass transition temperature may be lowered, and the heat resistant storage stability may be deteriorated. In addition, the use of crystalline polyester presents practical difficulties in terms of cost increase and manufacturing process complexity.

  Patent Document 2 proposes to improve low-temperature fixability and environmental stability by removing resin fine particles present on the toner surface and serving as a fixing inhibitor by alkali washing. However, since the high molecular weight resin fine particles are removed from the toner surface, there is a problem that heat resistant storage stability is deteriorated.

On the other hand, as a method of improving the heat-resistant storage stability of the toner, there is a method of preventing fusion between the toners by adding an external additive to the toner base particles and providing a spacer effect. Since it is a substance that inhibits fixing, if it is added in a large amount, fixing ability is inhibited.
In addition, the toner particles preferably have an uneven shape so that the toner particles can be easily scraped off by the cleaning blade, but the external additive added to the toner particles tends to be localized in the recesses of the toner particles. In particular, when the toner is agitated with a carrier in the developing machine and the toner is subjected to mechanical stress, the external additive tends to move on the surface of the toner particles and collect in the concave portions of the toner particles. If the external additive is localized in the concave portions of the toner particles, the effect of the spacer described above is not sufficiently exhibited, and the heat resistant storage stability and fluidity deteriorate.

  In Patent Document 3, the toner particles are heated in the surface treatment step to alleviate minute irregularities on the surface of the toner particles and reduce the toner surface area per unit weight, thereby increasing the effective coverage of the external additive. The effect of reducing non-electrostatic adhesion has been proposed. According to this proposal, the increase in non-electrostatic adhesion force when the toner is subjected to mechanical stress can be suppressed, and high transfer efficiency can be obtained. This is several nanometers to several tens of nanometers on the toner particle surface. Although it is possible to relieve microscopic unevenness of a certain degree, it is not possible to relieve relatively large unevenness of about several hundred nm to several μm. This does not eliminate the localization of the agent, and the heat-resistant storage stability and fluidity have not reached sufficient levels.

  Then, this invention makes it a subject to solve the said problem and to achieve the following objectives. That is, an object of the present invention is to provide a method for producing a toner excellent in low-temperature fixability, heat-resistant storage stability, and stress resistance.

The said subject is solved by the following structure (1).
(1) A method for producing a toner containing an amorphous binder resin, a release agent, organic resin fine particles and an external additive,
The toner is produced by emulsifying or dispersing an oil phase containing a material constituting the toner in an aqueous phase containing organic resin fine particles, and granulating the oil phase.
The granulation includes an alkali washing step using an alkaline solution and a heating step after the alkali washing step. The average circularity of the toner base particles before heating in the heating step is D1, and the toner base particles after heating are heated. A toner production method characterized by satisfying the following formula when the average circularity is D2.
0.002 ≦ (D2-D1) /D1≦0.010

  According to the present invention, it is possible to provide a method for producing a toner excellent in low-temperature fixability, heat-resistant storage stability and stress resistance.

  The toner production method, toner and developer according to the present invention will be described below. The present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art, and any aspect is possible. As long as the functions and effects of the present invention are exhibited, the scope of the present invention is included.

The toner manufacturing method of the present invention is a toner manufacturing method containing an amorphous binder resin, a release agent, organic resin fine particles and an external additive, and the toner contains a material constituting the toner. The oil phase is produced by emulsifying or dispersing in an aqueous phase containing organic resin fine particles and granulated, and includes an alkali washing step with an alkaline solution, and a heating step after the alkali washing step, In the process, when the average circularity of the toner base particles before heating is D1, and the average circularity of the toner base particles after heating is D2, the following formula is satisfied.
0.002 ≦ (D2-D1) /D1≦0.010

(Alkali washing process and heating process)
As an effect of the alkali washing step, only the organic resin fine particles present on the surface of the toner base particles can be removed, and the low-temperature fixability can be improved. The organic resin fine particles contained in the aqueous phase are used for shape control at the time of granulation. However, since they contain a large amount of acidic groups, if they are present on the surface of the toner particles, they will cause fixing to be inhibited. By washing the toner base particles with an alkaline solution, the organic resin fine particles present on the surface of the toner base particles can be removed, and the low-temperature fixability can be improved.
Details of the alkali cleaning step will be described in detail in the section of the toner production method.

  As an effect of the heating process, the organic resin fine particles existing in a position slightly inside the toner base particle surface move in the binder resin softened by heating, thereby exposing the organic resin fine particles to the toner base particle surface. be able to. The organic resin fine particles present at a position slightly submerged from the surface of the toner base particle are not present on the surface of the toner base particle, and therefore are not removed by alkali cleaning. When the average circularity of the toner particles before heating is D1 and the average circularity of the toner particles after heating is D2, heating is performed so that (D2-D1) / D1 is 0.002 or more and 0.010 or less. Thus, the organic resin fine particles can be appropriately exposed on the surface of the toner base particles, and the heat resistant storage stability can be improved.

  When the organic resin fine particles on the surface of the toner base particles are removed by alkali cleaning, and the average circularity of the toner particles before heating is D1, and the average circularity of the toner particles after heating is D2, (D2-D1) By heating so that / D1 is 0.002 or more and 0.010 or less, the organic resin fine particles existing at a position slightly submerged from the surface of the toner base particle are appropriately exposed on the surface of the toner base particle, The organic resin fine particles are appropriately exposed to such an extent that the low temperature fixability is not excluded, and the heat resistant storage stability can be improved while exhibiting the low temperature fixability.

As a further effect of the heating step, when the average circularity of the toner particles before heating is D1, and the average circularity of the toner particles after heating is D2, (D2−D1) / D1 is 0.002 or more, 0. By heating to be 010 or less, the binder resin is softened, and the surface of the particle has a minute unevenness of several nm to several tens of nm, and a relatively large unevenness of several hundred nm to several μm as the particle shape. Can be relaxed.
In particular, relatively large irregularities of several hundred nm to several μm are alleviated and the concave portions of the toner particles are reduced, so that when the toner is subjected to mechanical stress, the external additive is localized in the concave portions of the toner surface. The arrangement of the toner is suppressed and the arrangement of the external additive on the surface of the toner particles is maintained, whereby the heat resistant storage stability and fluidity can be exhibited even when the toner is subjected to mechanical stress.

In the heating step, when the average circularity of the toner particles before heating is D1, and the average circularity of the toner particles after heating is D2, (D2-D1) / D1 is set to 0.002 or more and 0.010 or less. It is necessary and it is preferable that it is 0.002 or more and 0.004 or less.
If it is less than 0.002, the binder resin is not sufficiently softened, and the relief of unevenness of about several hundred nm to several μm as the particle shape is difficult to occur, so the stress resistance may not be improved. Further, since the binder resin is not sufficiently softened, the organic resin fine particles are not sufficiently exposed, and the heat resistant storage stability may not be improved. When it is larger than 0.010, the organic resin fine particles are excessively exposed and the low-temperature fixability is deteriorated.

The heating process needs to be performed after the alkali cleaning process. In the alkali cleaning step, the uneven shape on the surface of the toner base particles is changed by cleaning with an alkaline solution and removing the organic resin fine particles on the surface of the toner base particles. In order to improve the stress resistance of the toner, it is necessary to relieve the unevenness as the toner shape, and therefore it is necessary to relieve the uneven shape caused by the removal of the organic resin fine particles in the heating step.
Details of the heating step will be described in detail in the section of the toner production method.

(Average circularity)
The average circularity was measured using a flow particle image analyzer (“FPIA-2100”, manufactured by Sysmex Corporation), and analyzed using analysis software (FPIA-2100 Data Processing Program for FPIA version 00-10). . Specifically, 0.1 to 0.5 ml of 10% by mass surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a glass 100 ml beaker, and each toner is added in an amount of 0.1%. 1-0.5 g was added and stirred with a micropartel, and then 80 mL of ion-exchanged water was added. The obtained dispersion is subjected to a dispersion treatment for 3 minutes with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.). The shape and distribution of the toner are measured with the FPIA-2100 until the concentration of the dispersion reaches 5,000 to 15,000 / μL.

  In this measurement method, it is important that the concentration of the dispersion is 5,000 to 15,000 / μL from the viewpoint of measurement reproducibility of average circularity. In order to obtain the concentration of the dispersion, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant to be added and the amount of toner. The amount of the surfactant varies depending on the hydrophobicity of the toner as in the measurement of the toner particle diameter described above. If it is added in a large amount, noise due to bubbles is generated, and if it is too small, the toner cannot be sufficiently wetted. It will be enough. The amount of toner added varies depending on the particle size, and is small when the particle size is small, and needs to be increased when the particle size is large. By adding 5 g, the dispersion concentration can be adjusted to 5,000 / μL to 15,000 / μL.

<Toner component>
The toner of the present invention is a toner base containing at least an amorphous binder resin, a release agent, and organic resin fine particles, containing other components as necessary, and further adding an external additive.

<< Binder resin >>
As the binder resin, it is preferable to use only an amorphous binder resin. When a crystalline binder resin is contained, the crystalline resin and the non-crystalline resin are compatible in the heating step, and the glass transition temperature of the toner is lowered, which may deteriorate the heat resistant storage stability.
There is no restriction | limiting in particular as said non-crystalline binder resin, According to the objective, it can select suitably. For example, polyester resin, silicone resin, styrene / acrylic resin, styrene resin, acrylic resin, epoxy resin, diene resin, phenol resin, terpene resin, coumarin resin, amidoimide resin, butyral resin, urethane resin, ethylene vinyl acetate resin, etc. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, polyester resins and resins obtained by combining polyester resins with the above other binder resins are preferable because they are excellent in low-temperature fixability and have sufficient flexibility even when the molecular weight is reduced. Moreover, it is preferable that the said binder resin is polyester and / or a polyester derivative.

-Polyester resin-
There is no restriction | limiting in particular as said polyester resin, Although it can select suitably according to the objective, An unmodified polyester resin and a modified polyester resin are preferable. These may be used individually by 1 type and may use 2 or more types together.

--Unmodified polyester resin--
There is no restriction | limiting in particular as said unmodified polyester resin, According to the objective, it can select suitably. Examples thereof include resins obtained by polyesterification of a polyol represented by the following general formula (1) and a polycarboxylic acid represented by the following general formula (2), a crystalline polyester resin, and the like.

However, in the said General formula (1), A represents the aromatic group or heterocyclic aromatic group which may have a C1-C20 alkyl group, an alkylene group, and a substituent, m is 2- Represents an integer of 4.
In the general formula (2), B represents an alkyl group having 1 to 20 carbon atoms, an alkylene group, an aromatic group that may have a substituent, or a heterocyclic aromatic group, and n represents 2 to 2 Represents an integer of 4.

  There is no restriction | limiting in particular as a polyol represented by the said General formula (1), According to the objective, it can select suitably. For example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, Pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2, -Butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, bisphenol A, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, hydrogenated bisphenol A, hydrogenated bisphenol A oxidation Examples include ethylene adducts, hydrogenated bisphenol A propylene oxide adducts, and the like. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as polycarboxylic acid represented by the said General formula (2), According to the objective, it can select suitably. For example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isooctyl succinic acid , Isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, 1,2,4-benzenetricarboxylic acid, 2, , 5,7-Naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl- 2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, te La (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, etc., cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, butanetetracarboxylic acid, diphenylsulfonetetracarboxylic acid, And ethylene glycol bis (trimellitic acid). These may be used alone or in combination of two or more.

--Modified polyester resin--
There is no restriction | limiting in particular as said modified polyester resin, According to the objective, it can select suitably. For example, an active hydrogen group-containing compound, a resin obtained by subjecting a polyester capable of reacting with the active hydrogen group-containing compound (hereinafter sometimes referred to as “polyester prepolymer”) to an extension reaction and / or a crosslinking reaction, etc. Can be mentioned. The extension reaction and / or the cross-linking reaction may be stopped by a reaction terminator (blocked monoamine such as diethylamine, dibutylamine, butylamine, laurylamine, ketimine compound, etc.) as necessary.

--- Active hydrogen group-containing compound ---
The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent or the like when the polyester prepolymer undergoes an elongation reaction, a crosslinking reaction, or the like in an aqueous phase.

  The active hydrogen group-containing compound is not particularly limited as long as it has an active hydrogen group, and can be appropriately selected according to the purpose. However, when the polyester prepolymer is an isocyanate group-containing polyester prepolymer described later. An amine is preferable in that a high molecular weight can be obtained.

  There is no restriction | limiting in particular as said active hydrogen group, According to the objective, it can select suitably, For example, a hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group etc. are mentioned. These may be contained singly or in combination of two or more.

  There is no restriction | limiting in particular as said amines which are the said active hydrogen group containing compound, According to the objective, it can select suitably. Examples thereof include diamine, trivalent or higher polyamine, amino alcohol, amino mercaptan, amino acid, and those obtained by blocking the amino group of these amines.

Examples of the diamine include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine, etc.); aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like.
Examples of the trivalent or higher polyamine include diethylenetriamine and triethylenetetramine.
Examples of the amino alcohol include ethanolamine and hydroxyethylaniline.
Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of the amino acid include aminopropionic acid and aminocaproic acid.
In addition, examples of those in which the amino group of these amines is blocked include, for example, any of these amines (diamine, trivalent or higher polyamine, amino alcohol, amino mercaptan, amino acid, etc.) and ketones (acetone, Methyl ethyl ketone, methyl isobutyl ketone and the like) and ketimine compounds, oxazolyson compounds and the like.

  These may be used individually by 1 type and may use 2 or more types together. Among these, the amines are particularly preferably diamine and a mixture of a diamine and a small amount of a trivalent or higher polyamine.

--- Polymer capable of reacting with active hydrogen group-containing compound ---
The polymer that can react with the active hydrogen group-containing compound is not particularly limited as long as it is a polymer having at least a group that can react with the active hydrogen group-containing compound, and can be appropriately selected according to the purpose. Among them, a urea-bond-forming group-containing polyester resin (RMPE) is excellent in that it has excellent fluidity and transparency when melted, easily adjusts the molecular weight of the polymer component, and is excellent in oilless low-temperature fixability and releasability in dry toners. ) Is preferred, and an isocyanate group-containing polyester prepolymer is more preferred.

  There is no restriction | limiting in particular as said isocyanate group containing polyester prepolymer, According to the objective, it can select suitably. Examples thereof include polycondensates of polyols and polycarboxylic acids, and those obtained by reacting active hydrogen group-containing polyester resins with polyisocyanates.

  There is no restriction | limiting in particular as said polyol, According to the objective, it can select suitably. For example, alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.), alkylene ether glycol (diethylene glycol, triethylene glycol, dipropylene) Glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.), alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.), bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.), Alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the alicyclic diol, alkylene oxide of the bisphenol Diols such as adducts (ethylene oxide, propylene oxide, butylene oxide, etc.); polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.), trivalent or higher phenols (phenol novolac) , Cresol novolac, etc.) trihydric or higher polyols such as alkylene oxide adducts of trihydric or higher polyphenols; mixtures of diols and trihydric or higher polyols.

These may be used individually by 1 type and may use 2 or more types together.
Among these, the polyol is preferably the diol alone or a mixture of the diol and a small amount of the trivalent or higher polyol.

  Examples of the diol include alkylene glycols having 2 to 12 carbon atoms, alkylene oxide adducts of bisphenols (bisphenol A ethylene oxide 2 mol adduct, bisphenol A propylene oxide 2 mol adduct, bisphenol A propylene oxide 3 mol adduct, etc.) Is preferred.

  There is no restriction | limiting in particular as content in the isocyanate group containing polyester prepolymer of the said polyol, According to the objective, it can select suitably. For example, 0.5 mass%-40 mass% are preferable, 1 mass%-30 mass% are more preferable, and 2 mass%-20 mass% are more preferable. When the content is 0.5% by mass or more, the hot offset resistance is good, and it is possible to achieve both the storage stability of the toner and the low-temperature fixability. When the content is 40% by mass or less, the low-temperature fixability is good.

  There is no restriction | limiting in particular as said polycarboxylic acid, According to the objective, it can select suitably. For example, alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid (terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, etc.); Examples thereof include polycarboxylic acids (such as aromatic polycarboxylic acids having 9 to 20 carbon atoms such as trimellitic acid and pyromellitic acid). These may be used individually by 1 type and may use 2 or more types together.

  Among these, the polycarboxylic acid is preferably an alkenylene dicarboxylic acid having 4 to 20 carbon atoms and an aromatic dicarboxylic acid having 8 to 20 carbon atoms. In place of the polycarboxylic acid, an anhydride of polycarboxylic acid, a lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) may be used.

  There is no restriction | limiting in particular as a mixing ratio of the said polyol and the said polycarboxylic acid, According to the objective, it can select suitably. The equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] of the polyol and the carboxyl group [COOH] of the polycarboxylic acid is preferably 2/1 to 1/1, and 1.5 / 1 to 1/1. Is more preferable, and 1.3 / 1 to 1.02 / 1 is more preferable.

  There is no restriction | limiting in particular as said polyisocyanate, According to the objective, it can select suitably. For example, aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, tetramethylhexane Diisocyanates, etc.); cycloaliphatic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, diphenylene-4,4′-diisocyanate, 4,4 '-Diisocyanato-3,3'-dimethyldiphenyl, 3-methyl Diphenylmethane-4,4′-diisocyanate, diphenyl ether-4,4′-diisocyanate, etc.); araliphatic diisocyanate (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates (Tris-isocyanate) Natoalkyl-isocyanurate, triisocyanatocycloalkyl-isocyanurate, etc.); these phenol derivatives; those blocked with oxime, caprolactam and the like. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as a mixing ratio of the said polyisocyanate and the said active hydrogen group containing polyester resin (hydroxyl group containing polyester resin), According to the objective, it can select suitably. The equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] of the polyisocyanate and the hydroxyl group [OH] of the hydroxyl group-containing polyester resin is preferably 5/1 to 1/1, and 4/1 to 1.2. / 1 is more preferable, and 3/1 to 1.5 / 1 is particularly preferable. The equivalent ratio [NCO] / [OH] is 1/1 or higher, offset resistance is good, and 5/1 or less, and low-temperature fixability is good.

  There is no restriction | limiting in particular as content of the said polyisocyanate in the said isocyanate group containing polyester prepolymer, According to the objective, it can select suitably. 0.5 mass%-40 mass% are preferable, 1 mass%-30 mass% are more preferable, 2 mass%-20 mass% are especially preferable. When the content is 0.5% by mass or more, hot offset resistance is good, and both storage stability and low-temperature fixability are achieved. When the content is 40% by mass or less, low-temperature fixability is good.

  The average number of isocyanate groups contained in one molecule of the isocyanate group-containing polyester prepolymer is preferably 1 or more, more preferably 1.2 to 5, and more preferably 1.5 to 4. A polyester resin (RMPE) having an average number of 1 or more and modified with a urea bond-forming group has a high molecular weight and good hot offset resistance.

  There is no restriction | limiting in particular as a mixing ratio of the said isocyanate group containing polyester prepolymer and the said amines, According to the objective, it can select suitably. The mixing equivalent ratio [NCO] / [NHx] of the isocyanate group [NCO] in the isocyanate group-containing polyester prepolymer and the amino group [NHx] in the amines is preferably 1/3 to 3/1. / 2 to 2/1 is more preferable, and 1 / 1.5 to 1.5 / 1 is particularly preferable. When the mixing equivalent ratio ([NCO] / [NHx]) is 1/3 or more, the low-temperature fixability is good, and when it is 3/1 or less, the urea-modified polyester resin has a high molecular weight and good hot offset resistance.

--- Method for synthesizing polymer capable of reacting with active hydrogen group-containing compound ---
There is no restriction | limiting in particular as a synthesis method of the polymer which can react with the said active hydrogen group containing compound, According to the objective, it can select suitably. For example, in the case of the isocyanate group-containing polyester prepolymer, the polyol and the polycarboxylic acid are heated to 150 ° C. to 280 ° C. in the presence of a known esterification catalyst (titanium tetrabutoxide, dibutyltin oxide, etc.). And a method of synthesizing by reacting the polyisocyanate with the hydroxyl group-containing polyester at 40 ° C. to 140 ° C. after the water is distilled off to obtain the hydroxyl group-containing polyester. .

  There is no restriction | limiting in particular as a weight average molecular weight (Mw) of the polymer which can react with the said active hydrogen group containing compound, According to the objective, it can select suitably. The molecular weight distribution by GPC (gel permeation chromatography) of the soluble portion of tetrahydrofuran (THF) is preferably 3,000 to 40,000, more preferably 4,000 to 30,000. When the weight average molecular weight (Mw) is 3,000 or more, the storage stability is good, and when the weight average molecular weight (Mw) is 40,000 or less, the low-temperature fixability is good.

  The weight average molecular weight (Mw) can be measured, for example, as follows. First, the column was stabilized in a 40 ° C. heat chamber, and at this temperature, tetrahydrofuran (THF) as a column solvent was flowed at a flow rate of 1 mL / min, and the sample concentration was adjusted to 0.05 to 0.6% by mass. Measurement is performed by injecting 50 μL to 200 μL of a tetrahydrofuran sample solution.

In measuring the molecular weight of the sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of the calibration curve prepared by several monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, Pressure Chemical co. The molecular weights are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3 manufactured by Toyo Soda Kogyo Co., Ltd. It is preferable to use 1.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples. An RI (refractive index) detector can be used as the detector.

<< Releasing agent >>
There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably. For example, plant wax (carnauba wax, cotton wax, wood wax, rice wax, etc.), animal wax (beeswax, lanolin, etc.), mineral wax (ozokerite, cercin etc.), petroleum wax (paraffin, microcrystalline, petrolatum, etc.) ) Waxes and waxes; synthetic hydrocarbon waxes (Fischer-Tropsch wax, polyethylene wax, etc.), synthetic waxes other than natural waxes (esters, ketones, ethers, etc.); 1,2-hydroxystearic acid amide, Fatty acid amides such as stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbons; homopolymers or copolymers of polyacrylates such as poly (n-stearyl methacrylate) and poly (n-lauryl methacrylate) which are low molecular weight crystalline polymers ( Acrylic acid n- Crystalline polymer having a stearyl over long chain alkyl group in the side chain of ethyl methacrylate copolymer, etc.) and the like; and the like.

  Among these, Fischer-Tropsch wax, paraffin wax, microcrystalline wax, monoester wax, and rice wax are preferable because less unnecessary volatile organic compounds are generated during fixing.

  A commercial item can be used for the mold release agent. Examples of the microcrystalline wax include “HI-MIC-1045”, “HI-MIC-1070”, “HI-MIC-1080”, “HI-MIC-1090” manufactured by Nippon Seiki Co., Ltd. “Bsquare 180 White”, “Bsquare 195” manufactured by WAX Petrolife, “CAREVALAC WN-1442” manufactured by Cray Valley, and the like.

  There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 60 to 100 degreeC is preferable and 65 to 90 degreeC is more preferable. When the melting point is 60 ° C. or more, even when stored at a high temperature of about 30 to 50 ° C., it is possible to suppress the exudation of the release agent from the toner base material and maintain good heat-resistant storage stability. When the temperature is 100 ° C. or lower, it is preferable because cold offset hardly occurs during fixing at a low temperature.

  The melting point is measured by DSC. For example, it can be measured under the following measurement conditions using TA-60WS and DSC-60 manufactured by Shimadzu Corporation.

[Measurement condition]
Sample container: Aluminum sample pan (with lid)
Sample amount: 5mg
Reference: Aluminum sample pan (alumina 10mg)
Atmosphere: Nitrogen (flow rate 50 mL / min)
Temperature conditions 1st. Temperature rise Start temperature: 20 ° C., Temperature rise rate: 10 ° C./min, End temperature: 150 ° C., Holding time: None 1st. Temperature drop Temperature drop: 10 ° C./min, end temperature: 20 ° C., retention time: none 2nd. Temperature rise Temperature rise rate: 10 ° C / min, end temperature: 150 ° C
The measurement results are analyzed using data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation.
The melting point is 2nd. The temperature at the top of the endothermic peak measured at elevated temperature is used.

  The release agent is preferably present in a dispersed state in the toner base particles, and for this purpose, the release agent and the binder resin are preferably incompatible with each other. The method for finely dispersing the release agent in the toner base particles is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method of dispersing by applying a shearing force of kneading at the time of toner production may be mentioned.

  The dispersion state of the release agent can be confirmed by observing a thin film slice of toner particles with a transmission electron microscope (TEM). The dispersion diameter of the release agent is preferably small, but if it is too small, there are cases where bleeding during fixing is insufficient. Therefore, if the release agent can be confirmed at a magnification of 10,000, the release agent is present in a dispersed state. When the release agent cannot be confirmed at 10,000 times, even when finely dispersed, the dyeing at the time of fixing becomes insufficient.

  There is no restriction | limiting in particular as content in the said toner of the said mold release agent, According to the objective, it can select suitably. Especially, 3 mass%-15 mass% are preferable, and 5 mass%-10 mass% are more preferable. When the content is 3% by mass or more, the hot offset resistance is good, and when the content is 15% by mass or less, the exudation amount of the release agent at the time of fixing is not excessive, and the heat resistant storage stability is good.

<< Other ingredients >>
-Colorant-
There is no restriction | limiting in particular as a coloring agent used for the said toner, According to the objective, it can select suitably from a well-known coloring agent.

  The color of the colorant of the toner is not particularly limited and may be appropriately selected depending on the purpose, and may be at least one selected from black toner, cyan toner, magenta toner, and yellow toner. The toner of each color can be obtained by appropriately selecting the type of the colorant, but is preferably a color toner.

  Examples of black products include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, copper, iron (CI pigment black 11), titanium oxide, and the like. And organic pigments such as aniline black (CI Pigment Black 1).

  Examples of the magenta color pigment include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48: 1, 49, 50, 51, 52, 53, 53: 1, 54, 55, 57, 57: 1, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 150, 163, 177, 179, 184, 202, 206, 207, 209, 211, 269; I. Pigment violet 19; C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, etc. are mentioned.

  Examples of the color pigment for cyan include C.I. I. Pigment Blue 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 60; I. Bat Blue 6; C.I. I. Acid Blue 45 and copper phthalocyanine pigments in which 1 to 5 phthalimidomethyl groups are substituted on the phthalocyanine skeleton, Green 7, Green 36, and the like.

  Examples of the color pigment for yellow include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 55, 65, 73, 74, 83, 97, 110, 139, 151, 154, 155, 180, 185; I. Bat yellow 1, 3, 20, orange 36 and the like.

  The content of the colorant in the toner is preferably 1% by mass to 15% by mass, and more preferably 3% by mass to 10% by mass. When the content is 1% by mass or more, the coloring power of the toner is good, and when the content is 15% by mass or less, poor dispersion of the pigment in the toner does not occur, and the coloring power and the electrical characteristics of the toner do not decrease.

  The colorant may be used as a master batch combined with a resin. Such a resin is not particularly limited, but it is preferable to use a binder resin or a resin having a structure similar to the binder resin from the viewpoint of compatibility with the binder resin.

  The masterbatch can be produced by applying a high shear force and mixing or kneading the resin and the colorant. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the colorant and the resin. Also, the so-called flushing method is preferable in that the wet cake of the colorant can be used as it is, and there is no need to dry it. The flushing method is a method in which an aqueous paste containing water of a colorant is mixed or kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove water and the organic solvent. For mixing or kneading, for example, a high shear dispersion device such as a three-roll mill can be used.

-Charge control agent-
Any known charge control agent can be used as the charge control agent. Since the color tone may change when a colored material is used, a colorless or nearly white material is preferable. For example, a triphenylmethane dye, a molybdate chelate pigment, a rhodamine dye, an alkoxyamine, a quaternary ammonium salt (fluorine) Modified quaternary ammonium salts), alkylamides, phosphorus alone or compounds thereof, tungsten alone or compounds thereof, fluorine-based activators, metal salts of salicylic acid, metal salts of salicylic acid derivatives, and the like. These may be used individually by 1 type and may use 2 or more types together.

  The content of the charge control agent is determined by the toner production method including the type of the binder resin and the dispersion method, and is not uniquely limited. 01 mass%-5 mass% are preferable, and 0.02 mass%-2 mass% are more preferable. When the addition amount is 5% by mass or less, the chargeability of the toner is not too high, the effect of the charge control agent is not diminished, the electrostatic attraction force with the developing roller is increased, and the flowability of the developer is reduced. There is no reduction in density, and when it is 0.01% by mass or more, the charge rise and charge amount are sufficient, and the toner image is not affected.

<< External additive >>
There is no restriction | limiting in particular as said external additive, According to the objective, it can select suitably from well-known things. For example, silica fine particles, hydrophobized silica fine particles, fatty acid metal salts (eg, zinc stearate, aluminum stearate, etc.); metal oxides (eg, titania, alumina, tin oxide, antimony oxide, etc.) or their hydrophobized products, fluoro Examples thereof include polymers. Among these, hydrophobized silica fine particles, titania particles, and hydrophobized titania fine particles are preferable.

  Examples of the hydrophobized silica fine particles include HDK H2000T, HDK H2000 / 4, HDK H2050EP, HVK21, HDK H1303VP (all manufactured by Clariant Japan); R972, R974, RX200, RY200, R202, R805, R812, NX90G (all manufactured by Nippon Aerosil Co., Ltd.) and the like.

  Examples of the titania fine particles include P-25 (manufactured by Nippon Aerosil Co., Ltd.); STT-30, STT-65C-S (both manufactured by Titanium Industry Co., Ltd.); TAF-140 (manufactured by Fuji Titanium Industry Co., Ltd.); MT-150W. , MT-500B, MT-600B, MT-150A (all of which are manufactured by Teica).

  Examples of the hydrophobized titanium oxide fine particles include T-805 (manufactured by Nippon Aerosil Co., Ltd.); STT-30A, STT-65S-S (both manufactured by Titanium Industry Co., Ltd.); TAF-500T, TAF-1500T (any Also, manufactured by Fuji Titanium Industry Co., Ltd.); MT-100S, MT-100T (both manufactured by Teika); IT-S (produced by Ishihara Sangyo Co., Ltd.).

  There is no restriction | limiting in particular as content of the said external additive, Although it can select suitably according to the objective, 0.3 mass part-3.0 mass parts are preferable with respect to 100 mass parts of toner base particles. 0.5 parts by mass to 2.0 parts by mass is more preferable.

  The total coverage of the external additive with respect to the toner base particles is not particularly limited, but is preferably 50% to 90%, and more preferably 60% to 80%.

<Toner production method>
The toner manufacturing method in the present invention is preferably a so-called chemical method in which toner particles are granulated in an aqueous medium.

  As the chemical method, for example, there is a solution suspension method in which a resin or a resin precursor is dissolved in an organic solvent and dispersed or emulsified in an aqueous medium, and in particular, in the solution suspension method, it can react with active hydrogen groups. An oil phase composition containing a resin precursor having a functional group (reactive group-containing prepolymer) is emulsified or dispersed in an aqueous medium containing organic resin fine particles. In the aqueous medium, an active hydrogen group-containing compound and And a method of reacting with the reactive group-containing prepolymer (production method (I)).

  Among these, the toner obtained by the production method (I) is preferable from the viewpoint of granulation properties (particle size distribution control, particle shape control, etc.). In the following, a detailed description of these production methods will be given.

  In the dissolution suspension method, for example, an oil phase composition in which a toner composition containing at least a binder resin or a resin precursor, a colorant, and a release agent is dissolved or dispersed in an organic solvent is used. This is a method for producing toner base particles by dispersing or emulsifying in a medium.

The organic solvent used for dissolving or dispersing the toner composition is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal of the solvent later.
Examples of the organic solvent include ester solvents such as ethyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, diethyl ether, tetrahydrofuran, dioxane, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl. Ether solvents such as ether, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, cyclohexanone, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 2 -Alcohol solvents, such as ethyl hexyl alcohol and benzyl alcohol, and these 2 or more types of mixed solvents are mentioned.

In the dissolution suspension method, when the oil phase composition is dispersed or emulsified in an aqueous medium, an emulsifier or a dispersant may be used as necessary.
As the emulsifier or dispersant, known surfactants, water-soluble polymers and the like can be used. The surfactant is not particularly limited, and is an anionic surfactant (alkyl benzene sulfonic acid, phosphate ester, etc.), a cationic surfactant (quaternary ammonium salt type, amine salt type, etc.), an amphoteric surfactant (carbon carboxyl). Acid salt type, sulfate ester type, sulfonate salt type, phosphate ester salt type, etc.), nonionic surfactants (AO addition type, polyhydric alcohol type, etc.) and the like. One surfactant may be used alone, or two or more surfactants may be used in combination.

Examples of the water-soluble polymer include cellulose compounds (for example, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose and saponified products thereof), gelatin, starch, dextrin, gum arabic, chitin, chitosan. , Polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polyethyleneimine, polyacrylamide, acrylic acid (salt) -containing polymer (sodium polyacrylate, potassium polyacrylate, ammonium polyacrylate, partially neutralized sodium hydroxide of polyacrylic acid) , Sodium acrylate-acrylic acid ester copolymer), sodium hydroxide of styrene-maleic anhydride copolymer ( Min) neutralized product water-soluble polyurethane (polyethylene glycol, reaction products of polycaprolactone diol with polyisocyanate and the like) and the like.
Moreover, said organic solvent, a plasticizer, etc. can also be used together as an auxiliary | assistant of emulsification or dispersion | distribution.

  The toner according to the present invention includes at least a binder resin, a binder resin precursor having a functional group capable of reacting with an active hydrogen group (reactive group-containing prepolymer), a colorant, a release agent, in a dissolution suspension method. And the oil phase composition containing the charge control agent is dispersed or emulsified in the aqueous medium containing the organic resin fine particles, and the reaction with the active hydrogen group-containing compound contained in the oil phase composition and / or the aqueous medium is performed. The toner base particles are preferably obtained by granulation by a method of reacting with a functional group-containing prepolymer (production method (I)).

(Organic resin fine particles)
The organic resin fine particles can be formed using a known polymerization method, but is preferably obtained as an aqueous dispersion of resin fine particles. Examples of the method for preparing an aqueous dispersion of resin fine particles include the methods shown in the following (a) to (h).
(A) A method of directly preparing an aqueous dispersion of organic resin fine particles by a polymerization reaction of any one of a suspension polymerization method, an emulsion polymerization method, a seed polymerization method and a dispersion polymerization method using a vinyl monomer as a starting material.
(B) After dispersing a precursor of polyaddition or condensation resin such as polyester resin, polyurethane resin, epoxy resin (monomer, oligomer, etc.) or a solvent solution thereof in an aqueous medium in an aqueous medium, A method of preparing an aqueous dispersion of organic resin fine particles by heating or adding a curing agent to cure.
(C) Polyaddition or condensation resin precursors (monomers, oligomers, etc.) such as polyester resins, polyurethane resins, and epoxy resins, or solvent solutions thereof (preferably liquids, which may be liquefied by heating). A method of preparing an aqueous dispersion of fine organic resin particles by dissolving a suitable emulsifier in the mixture and then adding water to effect phase inversion emulsification.
(D) A resin synthesized in advance by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) is pulverized and classified using a mechanical rotary type or jet type fine pulverizer. A method of preparing an aqueous dispersion of organic resin fine particles by obtaining organic resin fine particles by dispersing in water in the presence of an appropriate dispersant.
(E) Finely spraying organic resin fine particles by spraying a resin solution prepared by previously dissolving a resin synthesized in a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent. A method of preparing an aqueous dispersion of organic resin fine particles by forming and then dispersing organic resin fine particles in water in the presence of a suitable dispersant.
(F) A poor solvent is added to a resin solution prepared by previously dissolving a resin synthesized by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent, or heated to a solvent in advance. The organic resin fine particles are precipitated by cooling the dissolved resin solution, the solvent is removed to form the organic resin fine particles, and then the organic resin fine particles are dispersed in water in the presence of a suitable dispersing agent. A method of preparing an aqueous dispersion of fine particles.
(G) A resin solution obtained by dissolving a resin previously synthesized by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent in the presence of an appropriate dispersant. A method of preparing an aqueous dispersion of organic resin fine particles by dispersing in a solvent and then removing the solvent by heating, decompression or the like.
(H) A suitable emulsifier is dissolved in a resin solution prepared by previously dissolving a resin synthesized by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent, and then water To prepare an aqueous dispersion of organic resin fine particles by phase inversion emulsification.

  The organic resin fine particles have a volume average particle size of preferably 10 nm to 300 nm, more preferably 30 nm to 120 nm. When the volume average particle size of the organic resin fine particles is 10 nm or more and when it is 300 nm or less, the particle size distribution of the toner does not deteriorate.

  The content of the organic resin fine particles is preferably 1.2% or more and less than 2.4% with respect to the solid content of the oil phase. If it is 1.2% or more, the deforming at the time of granulation is sufficiently performed, and if it is 2.4% or less, the organic resin fine particles can be sufficiently removed by alkali washing, and the low-temperature fixability is sufficiently exhibited.

  The solid content concentration of the oil phase is preferably about 40 to 80%. If the concentration is not too high, dissolution or dispersion does not become difficult, and the viscosity does not become difficult to handle, and if the concentration is not too low, toner productivity is good.

  The toner composition other than the binder resin such as the colorant, the release agent, and the charge control agent, and the masterbatch thereof are individually dissolved or dispersed in an organic solvent, and then the binder resin solution or dispersion. You may mix with a liquid.

  As the aqueous medium, water alone may be used, but a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like.

  If the amount of the active hydrogen group-containing compound added is too large, the particle size distribution of the toner may deteriorate, and the variation in surface potential between the toner particles may increase. is there.

  The dispersion or emulsification method in the aqueous medium is not particularly limited, and known equipment such as a low-speed shearing type, a high-speed shearing type, a friction type, a high-pressure jet type, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable from the viewpoint of reducing the particle size of the particles. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 20 to 80 ° C.

  In order to remove the organic solvent from the obtained emulsified dispersion, there is no particular limitation, and a known method can be used. For example, the whole system is gradually raised while stirring the whole system under normal pressure or reduced pressure. A method of warming and completely evaporating and removing the organic solvent in the droplets can be employed.

(Alkali cleaning process)
The toner base particles obtained by dispersion or emulsification in an aqueous medium are then subjected to an alkali washing step.
Examples of a method for alkali-washing toner base particles dispersed in an aqueous medium with an alkaline solution include, for example, adjusting the pH by adding an alkaline solution to the toner base particles dispersed in an aqueous medium, and then a centrifugal separator. There is a method in which solid-liquid separation is performed with a filter press or the like, and then the obtained toner cake is redispersed in ion-exchanged water at room temperature to about 40 ° C.

  The pH is preferably 10 or more and 12 or less. If it is 10 or more, the organic resin fine particles are sufficiently removed, and the low-temperature fixability is sufficiently exhibited. When it is 12 or less, the binder resin does not hydrolyze.

  The alkali washing time is not particularly limited as long as the binder resin is not hydrolyzed, and can be appropriately selected according to the purpose, but is preferably 30 minutes or more and less than 12 hours.

  The alkaline solution is not particularly limited as long as it is an alkaline aqueous solution, and can be appropriately selected from known compounds. For example, an alkali metal salt such as sodium hydroxide or potassium hydroxide, or an aqueous solution such as ammonia can be used. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, a sodium hydroxide aqueous solution is preferable.

  As a method for cleaning the base particles of the toner after the alkali cleaning, a known technique is used. That is, after solid-liquid separation with a centrifuge, a filter press or the like, the obtained toner cake is redispersed in ion-exchanged water at room temperature to about 40 ° C., and the pH is adjusted with acid or alkali as necessary. Thereafter, the process of solid-liquid separation again is repeated several times to remove impurities and surfactants.

(Heating process)
The washed toner base particles are then subjected to a heating step. As a method for heating the toner base particles, for example, there is a method in which the temperature of the toner base particles dispersed in the aqueous medium is raised using a plate heat exchanger or the like and then cooled. At this time, it is preferable to continue applying a shearing force so that the toner base particles are not fused until the toner base particles are heated and cooled.
Further, when the toner base particles are heated, when the average circularity of the toner base particles before heating is D1 and the average circularity of the toner base particles after heating is D2, the following formula is satisfied.
0.002 ≦ (D2-D1) /D1≦0.010

  The value of the formula (D2-D1) / D1 needs to be 0.002 or more and 0.010 or less, and is preferably 0.002 or more and 0.004 or less. By setting it to 0.002 or more, the binder resin is sufficiently softened, the unevenness of about several hundred nm to several μm occurs as the particle shape, and the stress resistance is improved. Further, since the binder resin is sufficiently softened, the organic resin fine particles are sufficiently exposed, and the heat resistant storage stability is improved. By setting it to 0.010 or less, the organic resin fine particles are not excessively exposed, and the low-temperature fixability is not deteriorated.

The temperature for heating the toner base particles is preferably a glass transition temperature of the toner base particles + 21 ° C. or higher and a glass transition temperature of the toner base particles before the heating + 30 ° C. or lower. By setting the glass transition temperature of the toner base particles to 21 ° C. or higher, the binder resin is sufficiently softened, and the stress resistance and the heat resistant storage stability are improved. By setting the glass transition temperature of the toner base particles to 30 ° C. or lower, the organic resin fine particles are not excessively exposed and the low-temperature fixability is not deteriorated.
The time for heating the base particles is not particularly limited as long as the toners are not fused, and can be appropriately selected according to the purpose, but is preferably less than 60 minutes.

  The glass transition temperature is measured by DSC. For example, it can be measured under the following measurement conditions using TA-60WS and DSC-60 manufactured by Shimadzu Corporation.

[Measurement condition]
Sample container: Aluminum sample pan (with lid)
Sample amount: 5mg
Reference: Aluminum sample pan (alumina 10mg)
Atmosphere: Nitrogen (flow rate 50 mL / min)
Temperature conditions 1st. Temperature rise Start temperature: 20 ° C., Temperature rise rate: 10 ° C./min, End temperature: 150 ° C., Holding time: None 1st. Temperature drop Temperature drop: 10 ° C./min, end temperature: 20 ° C., retention time: none 2nd. Temperature rise Temperature rise rate: 10 ° C / min, end temperature: 150 ° C
The measurement results are analyzed using data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation. Analysis of the glass transition temperature is 2nd. A range of ± 5 ° C. is designated centering on the point showing the maximum peak on the lowest temperature side of the DrDSC curve which is the DSC differential curve at the temperature rise, and the peak temperature is obtained using the peak analysis function of the analysis software. Next, the maximum endothermic temperature of the DSC curve is determined using the peak analysis function of the analysis software in the range of the peak temperature + 5 ° C. and −5 ° C. in the DSC curve. The temperature shown here corresponds to the glass transition temperature.

  A known technique is used as a method of drying the toner base particles dispersed in the aqueous medium. That is, the toner powder is obtained by drying with an air flow dryer, a circulation dryer, a vacuum dryer, a vibration fluid dryer, or the like. At this time, the fine particle component of the toner may be removed by centrifugation or the like, and a desired particle size distribution can be obtained using a known classifier after drying, if necessary.

(Addition of external additives)
Further, in order to improve the fluidity, storage stability, developability, and transferability of the toner, inorganic fine particles such as hydrophobic silica fine powder are added and mixed with the toner base particles produced as described above.
For mixing the additives, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. In order to change the load history applied to the additive, the additive may be added midway or gradually. In this case, you may change the rotation speed, rolling speed, time, temperature, etc. of a mixer. Alternatively, a strong load may be applied first, then a relatively weak load, or vice versa. Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a Ladige mixer, a Nauter mixer, and a Henschel mixer. Next, the toner is obtained by passing through a sieve of 250 mesh or more to remove coarse particles and aggregated particles.

(Developer)
The developer of the present invention contains at least the toner and contains other components such as a carrier selected as appropriate. The developer may be a one-component developer or a two-component developer. However, when it is used for a high-speed printer or the like corresponding to the recent improvement in information processing speed, the life is improved. In view of the above, the two-component developer is preferable.

In the case of the one-component developer using the toner, toner agglomeration hardly occurs over time even against stress due to the developing means, and toner filming on the developing roller as the developer carrying member, The toner is not fused to a layer thickness regulating member such as a blade for reducing the thickness of the toner, and a good and stable image quality can be obtained by maintaining good image density stability and transferability.
In addition, in the case of the two-component developer using the toner, toner agglomeration is less likely to occur over time with respect to agitation stress by the developing unit, and the occurrence of abnormal images is suppressed and image density stability is achieved. In addition, by maintaining good transferability, good and stable image quality can be obtained.

<Career>
There is no restriction | limiting in particular as said carrier, Although it can select suitably according to the objective, What has a core particle and the resin layer (coating layer) which coat | covers this core particle is preferable.

<< Core particle >>
The core particles are not particularly limited as long as they are magnetic core particles, and can be appropriately selected according to the purpose. Examples thereof include ferromagnetic metals such as iron and cobalt; iron oxides such as magnetite, hematite and ferrite; and resin particles in which magnetic materials such as various alloys and compounds are dispersed in the resin. Among these, Mn-based ferrite, Mn-Mg-based ferrite, Mn-Mg-Sr-based ferrite and the like are preferable from the viewpoint of environmental considerations.

-Weight average particle diameter Dw of core particles-
The weight average particle diameter Dw of the core particles refers to the particle diameter at an integrated value of 50% in the particle size distribution of the core particles obtained by a laser diffraction or scattering method. There is no restriction | limiting in particular as the weight average particle diameter Dw of the said core particle, Although it can select suitably according to the objective, 10 micrometers-80 micrometers are preferable, and 20 micrometers-65 micrometers are more preferable.

The weight average particle diameter Dw of the core particles is measured by using a microtrac particle size distribution meter (HRA9320-X100, manufactured by Honeywell) as a particle diameter distribution (relationship between number frequency and particle diameter) of particles measured on a number basis. Measured under the conditions described below using the following formula (I). Each channel represents a length for dividing the particle size range in the particle size distribution chart into measurement width units, and the lower limit value of the particle size stored in each channel is adopted as the representative particle size.
Dw = {1 / Σ (nD ₃ )} × {Σ (nD ₄ )} (I)
However, in said formula (I), D represents the representative particle size (micrometer) of the core particle which exists in each channel, and n represents the total number of the core particle which exists in each channel.

[Measurement condition]
[1] Particle size range: 100 μm to 8 μm
[2] Channel length (channel width): 2 μm
[3] Number of channels: 46
[4] Refractive index: 2.42

<< Coating layer >>
The coating layer contains at least a resin, and may contain other components such as a filler as necessary.

-Resin-
There is no restriction | limiting in particular as resin for forming the coating layer of a carrier, According to the objective, it can select suitably. For example, a crosslinkable copolymer containing polyolefin (for example, polyethylene, polypropylene, etc.) or a modified product thereof, polystyrene, acrylic resin, acrylonitrile, vinyl acetate, vinyl alcohol, vinyl chloride, vinyl carbazole, vinyl ether, etc .; consisting of an organosiloxane bond Silicone resins or modified products thereof (for example, modified products by alkyd resin, polyester resin, epoxy resin, polyurethane, polyimide, etc.); polyamide; polyester; polyurethane; polycarbonate; urea resin; melamine resin; benzoguanamine resin; Examples thereof include polyimide resins and derivatives thereof. These may be used individually by 1 type and may use 2 or more types together. Among these, a silicone resin is preferable.

  There is no restriction | limiting in particular as said silicone resin, According to the objective, it can select suitably from the silicone resin generally known. For example, a straight silicone resin composed only of an organosiloxane bond, a silicone resin modified with alkyd, polyester, epoxy, acrylic, urethane, or the like can be used.

  Examples of the straight silicone resin include KR271, KR272, KR282, KR252, KR255, KR152 (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2400, SR2405, SR2406 (manufactured by Toray Dow Corning Silicone).

  Specific examples of the modified silicone resin include epoxy-modified product: ES-1001N, acrylic-modified silicone: KR-5208, polyester-modified product: KR-5203, alkyd-modified product: KR-206, and urethane-modified product: KR-. 305 (manufactured by Shin-Etsu Chemical Co., Ltd.), epoxy-modified product: SR2115, alkyd-modified product: SR2110 (manufactured by Toray Dow Corning Silicone), and the like.

The silicone resin can be used alone, but a crosslinking reactive component, a charge amount adjusting component, and the like can be used at the same time.
Examples of the crosslinking reactive component include a silane coupling agent. Examples of the silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, octyltrimethoxysilane, aminosilane coupling agent, and the like.

-Filler-
There is no restriction | limiting in particular as said filler, According to the objective, it can select suitably, For example, a conductive filler, a nonelectroconductive filler, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, it is preferable to contain a conductive filler and a non-conductive filler in the coating layer.

The conductive filler refers to a filler having a powder specific resistance value of 100 Ω · cm or less.
The said nonelectroconductive filler points out the filler whose powder specific resistance value exceeds 100 ohm * cm.
The powder specific resistance value of the filler is measured by a powder resistance measurement system (MCP-PD51, manufactured by Dia Instruments) and a resistivity meter (4-terminal 4-probe system, Loresta GP, manufactured by Mitsubishi Chemical Analytech). Can be measured under the conditions of a sample of 1.0 g, an electrode interval of 3 mm, a sample radius of 10.0 mm, and a load of 20 kN.

--Conductive filler--
There is no restriction | limiting in particular as said electroconductive filler, According to the objective, it can select suitably. For example, a conductive filler formed as a layer of tin dioxide or indium oxide on a substrate such as aluminum oxide, titanium oxide, zinc oxide, barium sulfate, silicon oxide, zirconium oxide, etc .; a conductive filler formed using carbon black, etc. It is done. Among these, a conductive filler containing aluminum oxide, titanium oxide, and barium sulfate is preferable.

--Non-conductive filler--
There is no restriction | limiting in particular as said nonelectroconductive filler, According to the objective, it can select suitably, For example, it forms using aluminum oxide, titanium oxide, barium sulfate, zinc oxide, silicon dioxide, zirconium oxide etc. Non-conductive filler etc. are mentioned. Among these, non-conductive fillers containing aluminum oxide, titanium oxide, and barium sulfate are preferable.

<< Carrier manufacturing method >>
There is no restriction | limiting in particular as a manufacturing method of the said carrier, Although it can select suitably according to the objective, The said resin and the said filler are contained in the surface of the said core particle using a fluid bed type coating apparatus. The method of manufacturing by apply | coating a coating layer forming solution is preferable. In addition, when apply | coating the said coating layer forming solution, you may advance condensation of the resin contained in the said coating layer, and after apply | coating the said coating layer forming solution, condensation of the resin contained in the said coating layer You may proceed. There is no restriction | limiting in particular as the condensation method of the said resin, According to the objective, it can select suitably, For example, the method etc. which give a heat | fever, light, etc. to the said coating layer formation solution, etc. are mentioned. .

-Weight average particle diameter Dw of carrier-
The weight average particle diameter Dw of the carrier refers to the particle diameter at an integrated value of 50% in the particle size distribution of the core particles obtained by a laser diffraction / scattering method. There is no restriction | limiting in particular as the weight average particle diameter Dw of the said carrier, Although it can select suitably according to the objective, 10 micrometers-80 micrometers are preferable, and 20 micrometers-65 micrometers are more preferable.

For the measurement of the weight average particle diameter Dw of the carrier, the particle size distribution (relationship between the number frequency and the particle diameter) of the particles measured on the basis of the number is used using a Microtrac particle size distribution meter (HRA9320-X100, manufactured by Honeywell). Measured under the conditions described below and calculated using the following formula (II). Each channel represents a length for dividing the particle size range in the particle size distribution chart into measurement width units, and the lower limit value of the particle size stored in each channel is adopted as the representative particle size.
Dw = {1 / Σ (nD ₃ )} × {Σ (nD ₄ )} (II)
However, in said formula (II), D represents the representative particle size (micrometer) of the carrier which exists in each channel, and n represents the total number of the carriers which exist in each channel.

[Measurement condition]
[1] Particle size range: 100 μm to 8 μm
[2] Channel length (channel width): 2 μm
[3] Number of channels: 46
[4] Refractive index: 2.42

  When the developer is a two-component developer, the mixing ratio of the toner and the carrier in the two-component developer is preferably such that the mass ratio of the toner to the carrier is 2.0 to 12.0% by mass, More preferably, it is 2.5-10.0 mass%.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example. In the description in the examples, [%] indicates% by weight, and unless otherwise specified, when “part” is simply indicated, it means “part by mass”.

(Synthesis of non-crystalline polyester resin)
In a reaction vessel equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, bisphenol A propylene oxide 2 mol adduct and bisphenol A propylene oxide 3 mol adduct in a molar ratio of 80/20, isophthalic acid and adipine The acid was adjusted to a molar ratio of 72/28, OH / COOH = 1.44, and reacted with 500 ppm of titanium tetraisopropoxide at 230 ° C. for 10 hours at normal pressure. Subsequently, after reacting under reduced pressure of 10 mmHg to 15 mmHg for 5 hours, 11 parts of trimellitic anhydride was put into a reaction vessel and reacted at 180 ° C. and normal pressure for 3 hours to obtain [Non-crystalline polyester resin].

(Synthesis of crystalline polyester resin)
In a reaction vessel equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, 241 parts of sebacic acid, 55 parts of adipic acid, 314 parts of 1,4-butanediol and titanium dihydroxybis (triethanolamino) as a condensation catalyst. Nate) 0.75 part was put, and it was made to react for 4 hours, distilling off the water produced | generated at 180 degreeC under nitrogen stream. Next, while gradually raising the temperature to 225 ° C., the reaction was carried out for 3 hours while distilling off the generated water and 1,4-butanediol in a nitrogen stream, and then under reduced pressure of 5 to 20 mmHg, the Mw (weight average The reaction was continued until the molecular weight reached about 1200.
218 parts of the obtained crystalline resin was transferred into a reaction vessel equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, and 250 parts of ethyl acetate, 40 parts of hexamethylene diisocyanate (HDI), 25 parts of maleic anhydride The mixture was added and reacted at 80 ° C. for 5 hours under a nitrogen stream. Subsequently, ethyl acetate was distilled off under reduced pressure to obtain [Crystalline Polyester Resin].

(Preparation of masterbatch)
1,200 parts of water, carbon black (manufactured by Printex 35 Dexa) [DBP oil absorption = 42 mL / 100 mg, pH = 9.5] 540 parts, and [non-crystalline polyester resin] 1,200 parts were added, and a Henschel mixer (Mitsui (Mine Co., Ltd.) and the mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch].

(Synthesis of graft modified polymer)
In an autoclave reaction vessel equipped with a thermometer and a stirrer, 480 parts of xylene and 100 parts of low molecular weight polyethylene (Sanwax 151P manufactured by Sanyo Chemical Industries, Ltd .: melting point 108 ° C., weight average molecular weight 1,000) are sufficiently dissolved. After substitution with nitrogen, a mixed solution of 805 parts of styrene, 50 parts of acrylonitrile, 45 parts of butyl acrylate, 36 parts of di-t-butyl peroxide, and 100 parts of xylene was added dropwise at 170 ° C. for 3 hours for polymerization, and this temperature was further increased. For 30 minutes. Subsequently, the solvent was removed to obtain [graft-modified polymer].

(Manufacture of organic resin fine particle dispersion)
In an autoclave equipped with a thermometer and a stirrer, 562 parts of bisphenol A ethylene oxide 2 mol addition, 90 parts of bisphenol A propylene oxide 2 mol addition, 90 parts of bisphenol A propylene oxide 3 mol addition, 143 parts terephthalic acid, Add 126 parts of adipic acid and 2 parts of dibutyltin oxide, react at 230 ° C. for 8 hours at normal pressure, and then react for 6 hours under reduced pressure of 10-15 mmHg, and then add 60 parts of trimellitic anhydride to the reaction vessel. The mixture was reacted at 180 ° C. and normal pressure for 2 hours to obtain [Polyester 1]. 200 g of this [Polyester 1] was dissolved in 300 g of tetrahydrofuran at room temperature. Subsequently, 10 g of 40 wt% aqueous KOH solution was added. While stirring this mixture, 1800 ml of a 1% nonionic surfactant (Neugen EM230D manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) aqueous solution was added at room temperature. In order to remove tetrahydrofuran, the temperature was raised to 65 ° C. with nitrogen flow, and the temperature was maintained for 1 hour. This was cooled to room temperature to obtain [organic resin fine particle dispersion].

(Synthesis of polyester prepolymer)
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introduction tube, 682 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts by mass of terephthalic acid, 22 parts by mass of merit acid and 2 parts by mass of dibutyltin oxide were added and reacted at 230 ° C. for 8 hours under normal pressure. Furthermore, [intermediate polyester] was synthesized by reacting under reduced pressure of 10 mmHg to 15 mmHg for 5 hours. Next, 410 parts by mass of the synthesized [intermediate polyester], 89 parts by mass of isophorone diisocyanate, and 500 parts by mass of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and 100 ° C. Was reacted for 5 hours to synthesize [Polyester Prepolymer].

(Example 1)
<Preparation of toner>
-Preparation of pigment / wax dispersion-
In a container in which a stir bar and a thermometer are set, 378 parts by mass of [amorphous polyester resin], 110 parts by mass of wax (carnauba wax WA-05 made by Celalica Noda), and 88 parts by mass of [graft-modified polymer] Part, a charge control agent (CCA, salicylic acid metal complex E-84, manufactured by Orient Chemical Industry Co., Ltd.), 22 parts by mass, and 947 parts by mass of ethyl acetate were added, the temperature was raised to 80 ° C. with stirring, and the temperature was maintained at 80 ° C. for 5 hours. After holding, it was cooled to 30 ° C. at 1 hour. Next, 500 parts by mass of [Masterbatch] and 500 parts by mass of ethyl acetate were charged into the container and mixed for 1 hour to obtain a raw material solution. 1,324 parts by mass of the resulting raw material solution was transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads were added. Carbon black and wax were dispersed under the conditions of 80% by volume filling and 3 passes. As a result, [Pigment / Wax Dispersion] was obtained.

-Preparation of aqueous phase-
808 parts by weight of water, 63 parts by weight of [organic resin fine particle dispersion], 248 parts by weight of a 48.5% by weight aqueous solution of linear sodium dodecylbenzenesulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries), and ethyl acetate 81 parts by mass were mixed to obtain a milky white liquid. This is designated as [Aqueous Phase 1].

-Oil phase adjustment-
714 parts by mass of the prepared [pigment / wax dispersion], 78 parts by mass of [polyester prepolymer], and 8 parts by mass of 5-amino-1,3,3-trimethylcyclohexanemethylamine (manufactured by Sigma Aldrich Japan) It put into the container and mixed for 1 minute at 5,000 rpm using TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.), and it was set as [oil phase 1].

-Emulsification and desolvation step-
Next, 800 parts by mass of the prepared [Oil Phase 1] and 1,200 parts by mass of the prepared [Aqueous Phase 1] are placed in a container, and mixed at 13,000 rpm for 20 minutes using a TK homomixer. [Emulsified slurry 1] was obtained. At this time, the content of the organic resin fine particles with respect to the solid content of the oil phase was 1.8%. After adding 400 parts by mass of ion-exchanged water to 2,000 parts by mass of the obtained [emulsified slurry 1], the mixture was put into a container equipped with a stirrer and a thermometer and desolvated at 30 ° C. for 8 hours. And aged at 45 ° C. for 4 hours to obtain [Dispersion Slurry 1].

-Alkali cleaning process-
To the obtained [Dispersion Slurry 1], a 1% by mass aqueous sodium hydroxide solution was added so that the pH was 11, and the mixture was mixed with a stirrer for 30 minutes, followed by filtration under reduced pressure. 100 parts by mass of ion-exchanged water was added to the filter cake, and the mixture was mixed for 10 minutes at 12,000 rpm using a TK homomixer and then filtered. Further, 100 parts by mass of ion-exchanged water was added to the filter cake, and the mixture was mixed at 12,000 rpm for 10 minutes using a TK homomixer to obtain [Slurry 1 after alkali washing].

-Acid cleaning process-
1% by mass hydrochloric acid was added to the obtained [Slurry 1 after alkali washing] so as to have a pH of 4, and mixed with a stirrer for 30 minutes, followed by filtration under reduced pressure. 100 parts by mass of ion-exchanged water was added to the filter cake, and the mixture was mixed for 10 minutes at 12,000 rpm using a TK homomixer and then filtered. Further, 100 parts by mass of ion-exchanged water was added to the filter cake, and mixed at 12,000 rpm for 10 minutes using a TK homomixer to obtain [Slurry 1 after acid cleaning]. The average circularity of the toner base particles in [Slurry 1 after acid cleaning] was 0.975. In addition, a part of [Slurry 1 after acid cleaning] was filtered under reduced pressure, and dried at 35 ° C. for 48 hours with a circulating air dryer. The glass transition temperature was measured and found to be 43 ° C.

-Heating process-
The obtained [Slurry 1 after acid cleaning] was heated to 68 ° C. using a plate heat exchanger while being mixed with a stirrer, and held for 20 minutes. Immediately after that, it was cooled to 25 ° C. using a plate heat exchanger to obtain [Slurry 1 after heating]. The average circularity of the toner base particles in [Slurry 1 after heating] was 0.978.

-Drying process-
The obtained [Slurry 1 after heating] was filtered under reduced pressure, then 300 parts by mass of ion-exchanged water was added, and the mixture was mixed at 12,000 rpm for 10 minutes using a TK homomixer, followed by filtration, and [Filter cake 1 ] Was obtained. The obtained [Filtration cake 1] was dried at 35 ° C. for 48 hours with a circulating drier, and sieved with a mesh of 75 μm to prepare [Toner base particle 1].

-Mixing process-
Hydrophobic silica (HDK-2000, manufactured by Wacker Chemie) is added to 100 parts of [Toner Base Particles 1] to [Toner Base Particles 1], and a 20 L Henschel mixer (Mitsui Mining Co., Ltd.) is added. Manufactured at a peripheral speed of 33 m / s for 5 minutes. The above was air sieved through a 500 mesh sieve to produce [Toner 1].

(Example 2)
[Post-heating slurry 2] was obtained in the same manner as in Example 1 except that the temperature was raised to 68 ° C. and held for 10 minutes in the heating step of Example 1. The average circularity of the toner base particles in [Slurry 2 after heating] was 0.977.
[Toner 2] was prepared in the same manner as in Example 1 in the drying step and the mixing step.

(Example 3)
[Post-heating slurry 3] was obtained in the same manner as in Example 1 except that the temperature was raised to 68 ° C. and maintained for 40 minutes in the heating step of Example 1. The average circularity of the toner base particles in [Slurry 3 after heating] was 0.979.
[Toner 3] was produced in the same manner as in Example 1 in the drying step and the mixing step.

Example 4
[Post-heating slurry 4] was obtained in the same manner as in Example 1 except that the temperature was raised to 70 ° C. and held for 20 minutes in the heating step of Example 1. The average circularity of the toner base particles in [Post-heating slurry 4] was 0.980.
[Toner 4] was prepared in the same manner as in Example 1 in the drying step and the mixing step. Further, when air sieving in the mixing step, a small amount of toner aggregates were found on the sieving.

(Example 5)
[Post-heating slurry 5] was obtained in the same manner as in Example 1 except that the temperature was raised to 72 ° C. and held for 60 minutes in the heating step of Example 1. The average circularity of the toner base particles in [Slurry 5 after heating] was 0.985.
[Toner 5] was prepared in the same manner as in Example 1 in the drying step and the mixing step. Further, when air sieving in the mixing step, a small amount of toner aggregates were found on the sieving.

(Example 6)
[Slurry 6 after heating] was obtained in the same manner as in Example 1 except that the temperature was raised to 63 ° C. and held for 90 minutes in the heating step of Example 1. The average circularity of the toner base particles in [Slurry 6 after heating] was 0.978.
[Toner 6] was prepared in the same manner as in Example 1 in the drying step and the mixing step.

(Example 7)
[Post-heating slurry 7] was obtained in the same manner as in Example 1 except that the temperature was raised to 64 ° C. and held for 30 minutes in the heating step of Example 1. In [Slurry 7 after heating], the average circularity of the toner base particles was 0.978.
[Toner 7] was produced in the same manner as in Example 1 in the drying step and the mixing step.

(Example 8)
[Slurry 8 after heating] was obtained in the same manner as in Example 1 except that the temperature was raised to 73 ° C. and held for 5 minutes in the heating step of Example 1. In [Slurry 8 after heating], the average circularity of the toner base particles was 0.979.
[Toner 8] was produced in the same manner as in Example 1 in the drying step and the mixing step. Further, when air sieving in the mixing step, a small amount of toner aggregates were found on the sieving.

Example 9
[Post-heating slurry 9] was obtained in the same manner as in Example 1, except that the temperature was raised to 74 ° C in the heating step of Example 1 and immediately cooled to 25 ° C. In [Slurry 9 after heating], the average circularity of the toner base particles was 0.979.
[Toner 9] was prepared in the same manner as in Example 1 in the drying step and the mixing step. Further, when air sieving in the mixing step, a small amount of toner aggregates were found on the sieving.

(Example 10)
[Toner 10] was produced in the same manner as in Example 1, except that a 1% by mass aqueous sodium hydroxide solution was added so that the pH was 9 in the alkali washing step of Example 1.

(Example 11)
[Toner 11] was produced in the same manner as in Example 1, except that a 1% by mass aqueous sodium hydroxide solution was added so that the pH was 10 in the alkali washing step of Example 1.

Example 12
[Toner 12] was produced in the same manner as in Example 1, except that a 1% by mass aqueous sodium hydroxide solution was added so that the pH was 12 in the alkali washing step of Example 1.

(Example 13)
[Toner 13] was produced in the same manner as in Example 1, except that a 1% by mass aqueous sodium hydroxide solution was added so that the pH was 13 in the alkali washing step of Example 1.

(Example 14)
[Aqueous phase 14] was prepared in the same manner as in Example 1 except that 833 parts by weight of water and 38 parts by weight of [organic resin fine particle dispersion] were prepared by adjusting the aqueous phase. Thus, [Dispersed slurry 14] was obtained in the same manner as in Example 1 except that [Aqueous phase 14] was used instead of [Aqueous phase 1]. At this time, the content of the organic resin fine particles with respect to the solid content of the oil phase was 1.1%.
The alkali washing step and the acid washing step were carried out in the same manner as in Example 1 to obtain [Slurry 14 after acid washing]. The average circularity of the toner base particles in [Slurry 14 after acid cleaning] was 0.959. A part of [Slurry 14 after acid cleaning] was filtered under reduced pressure and dried at 35 ° C. for 48 hours with a circulating drier, and the glass transition temperature was measured. As a result, it was 43 ° C.
[Slurry 14 after heating] was obtained in the same manner as in Example 1 except that the temperature was raised to 68 ° C. and held for 10 minutes in the heating step. The average circularity of the toner base particles in [After-heated slurry 14] was 0.962.
[Toner 14] was prepared in the same manner as in Example 1 in the drying step and the mixing step.

(Example 15)
[Aqueous phase 15] was prepared in the same manner as in Example 1 except that 829 parts by mass of water and 42 parts by mass of [organic resin fine particle dispersion] were prepared by adjusting the aqueous phase. Thus, [Dispersion slurry 15] was obtained in the same manner as in Example 1 except that [Water phase 15] was used instead of [Water phase 1]. At this time, the content of the organic resin fine particles with respect to the solid content of the oil phase was 1.2%.
The alkali washing step and the acid washing step were carried out in the same manner as in Example 1 to obtain [Slurry 15 after acid washing]. The average circularity of the toner base particles in [Slurry 15 after acid cleaning] was 0.961. Further, a part of [Slurry 15 after acid cleaning] was filtered under reduced pressure and dried at 35 ° C. for 48 hours with a circulating drier, and the glass transition temperature was measured. As a result, it was 43 ° C.
[Post-heating slurry 15] was obtained in the same manner as in Example 1 except that the temperature was raised to 68 ° C. and maintained for 10 minutes in the heating step. The average circularity of the toner base particles in [Post-heating slurry 15] was 0.964.
[Toner 15] was prepared in the same manner as in Example 1 in the drying step and the mixing step.

(Example 16)
[Aqueous phase 16] was prepared in the same manner as in Example 1 except that 787 parts by mass of water and 84 parts by mass of [organic resin fine particle dispersion] were prepared by adjusting the aqueous phase. Thus, [Dispersed slurry 16] was obtained in the same manner as in Example 1, except that [Aqueous phase 16] was used instead of [Aqueous phase 1]. At this time, the content of the organic resin fine particles with respect to the solid content of the oil phase was 2.4%.
The alkali cleaning step and the acid cleaning step were performed in the same manner as in Example 1 to obtain [Slurry 16 after acid cleaning]. The average circularity of the toner base particles in [Slurry 16 after acid cleaning] was 0.980. A part of [Slurry 16 after acid cleaning] was filtered under reduced pressure, and dried at 35 ° C. for 48 hours with a circulating drier, and the glass transition temperature was measured. As a result, it was 43 ° C.
[Post-heating slurry 16] was obtained in the same manner as in Example 1 except that the temperature was raised to 68 ° C. and maintained for 40 minutes in the heating step. In [Slurry 16 after heating], the average circularity of the toner base particles was 0.983.
[Toner 16] was produced in the same manner as in Example 1 in the drying step and the mixing step.

(Example 17)
[Aqueous phase 17] was prepared in the same manner as in Example 1 except that 784 parts by weight of water and 87 parts by weight of [organic resin fine particle dispersion] were prepared by adjusting the aqueous phase. Thus, [Dispersed slurry 17] was obtained in the same manner as in Example 1 except that [Aqueous phase 17] was used instead of [Aqueous phase 1]. At this time, the content of the organic resin fine particles with respect to the solid content of the oil phase was 2.5%.
The alkali washing step and the acid washing step were performed in the same manner as in Example 1 to obtain [Slurry 17 after acid washing]. The average circularity of the toner base particles in [Slurry 17 after acid cleaning] was 0.981. A part of [Slurry 17 after acid cleaning] was filtered under reduced pressure and dried at 35 ° C. for 48 hours with a circulating dryer, and the glass transition temperature was measured. As a result, it was 43 ° C.
[Post-heating slurry 17] was obtained in the same manner as in Example 1 except that the temperature was raised to 68 ° C. and maintained for 40 minutes in the heating step. The average circularity of the toner base particles in [Post-heating slurry 17] was 0.984.
[Toner 17] was produced in the same manner as in Example 1 in the drying step and the mixing step.

(Comparative Example 1)
[Post-heating slurry 18] was obtained in the same manner as in Example 1 except that the temperature was raised to 66 ° C. and held for 5 minutes in the heating step of Example 1. The average circularity of the toner base particles in [Post-heating slurry 18] was 0.976.
[Toner 18] was prepared in the same manner as in Example 1 in the drying step and the mixing step.

(Comparative Example 2)
[Post-heating slurry 19] was obtained in the same manner as in Example 1 except that the temperature was raised to 72 ° C. and held for 80 minutes in the heating step of Example 1. In [Slurry 19 after heating], the average circularity of the toner base particles was 0.986.
[Toner 19] was produced in the same manner as in Example 1 in the drying step and the mixing step. Further, when air sieving in the mixing step, a large amount of toner aggregates were found on the sieving.

(Comparative Example 3)
-Preparation of pigment, wax, and crystalline polyester dispersions-
341 parts by mass of [Non-crystalline polyester resin], 37 parts by mass of [Crystalline polyester resin], and 110 of wax (carnauba wax WA-05 made by Celalica Noda) were placed in a container in which a stir bar and a thermometer were set. 80 parts by mass, 80 parts by mass of [Graft-modified polymer], 22 parts by mass of a charge control agent (CCA, salicylic acid metal complex E-84, manufactured by Orient Chemical Industries) and 947 parts by mass of ethyl acetate The temperature was kept at 80 ° C. for 5 hours and then cooled to 20 ° C. over 1 hour. Next, 500 parts by mass of [Masterbatch] and 500 parts by mass of ethyl acetate were charged into the container and mixed for 1 hour to obtain a raw material solution. 1,324 parts by mass of the resulting raw material solution was transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads were added. Carbon black and wax were dispersed under the conditions of 80% by volume filling and 3 passes. As a result, [Pigment / Wax / Crystalline Polyester Dispersion] was obtained.

[Oil phase 20] was obtained in the same manner as in Example 1 except that [pigment / wax / crystalline polyester dispersion] was used instead of [pigment / wax dispersion] in the adjustment of the oil phase. . [Dispersion slurry 20] was obtained in the same manner as in Example 1 except that [oil phase 20] was used instead of [oil phase 1] in the emulsification and solvent removal step. At this time, the content of the organic resin fine particles with respect to the solid content of the oil phase was 1.8%.
The alkali washing step and the acid washing step were carried out in the same manner as in Example 1 to obtain [Slurry 20 after acid washing]. The average circularity of the toner base particles in [Slurry 20 after acid cleaning] was 0.970. A part of [Slurry 20 after acid cleaning] was filtered under reduced pressure, and dried at 35 ° C. for 48 hours with a circulating air dryer. The glass transition temperature was measured and found to be 39 ° C.
[Post-heating slurry 20] was obtained in the same manner as in Example 1 except that the temperature was raised to 62 ° C. and held for 5 minutes in the heating step. The average circularity of the toner base particles in [Post-heating slurry 20] was 0.971.
[Toner 20] was prepared in the same manner as in Example 1 in the drying step and the mixing step.

(Comparative Example 4)
[Toner 21] was produced in the same manner as in Example 1 except that the 1% by mass sodium hydroxide aqueous solution was not added in the alkali washing step of Example 1.

(Evaluation method and evaluation results)
The following evaluation was performed using the obtained toner. The evaluation results are shown in Table 1.
<Low temperature fixability>
The image is a cardboard ("copy printing paper <135>"; manufactured by NBS Ricoh Co., Ltd.) using an evaluation machine that has been tuned by modifying the image forming apparatus ("IPSIO Color 8100"; manufactured by Ricoh) to the oilless fixing system. ) And the toner was adjusted so that 1.0 ± 0.1 mg / cm ² of toner was developed with a solid image. The fixing roll temperature at which the residual ratio of the image density after rubbing the obtained fixed image with a pad was 70% or more was determined as the minimum fixing temperature.

[Evaluation criteria]
A: Fixing lower limit is less than 130 ° C. ○: Fixing lower limit is 130 ° C. or more and less than 135 ° C. Δ: Fixing lower limit is 135 ° C. or more and less than 145 ° C. ×: Fixing lower limit is 145 ° C. or more.

<Heat resistant storage stability>
The toner was stored at 50 ° C. for 24 hours, and then sieved with a 42 mesh screen for 2 minutes. The residual rate on the wire mesh was used as an index for heat resistant storage stability. The heat resistant storage stability was evaluated in the following four stages. “◎” and “◯” are levels that have no problem at all, “Δ” is a level that is slightly poor in storability, but has no practical problem, and “×” is a level that has a problem in practical use.

[Evaluation criteria]
◎: Less than 5% ○: 5-10%
Δ: 10 to 20%
×: 20% or more

<Stress resistance>
7 parts of toner and 93 parts of carrier were mixed with a tumbler mixer at 100 rpm for 60 minutes, then filled into a glass bottle and stored at 50 ° C. for 48 hours. The developer after storage was evaluated for ease of discharge from the glass bottle and the degree of solidification of the developer after discharge.

[Evaluation criteria]
◎: Evacuated without structure and no clumping ○: Discharge takes a little time and there is a weak lump △: Drained when tapping the bottle lightly, and there is a slightly hard lump ×: Ejected when the bottle is tapped hard, hard There is a mass

<Aggregate amount>
The amount of residual toner on the sieve when air-sieving with a 500-mesh sieve in the mixing step in the toner preparation was used as an index of the aggregate amount. “◯” indicates that there is almost no residual toner, “Δ” indicates that there is some residual toner, and “X” indicates that there is a large amount of residual toner.

[Evaluation criteria]
○: Almost no residual toner Δ: Some residual toner ×: There is a large amount of residual toner

  As is apparent from the evaluation results of Table 1, Examples 1 to 17 produced by the method of the present invention are excellent in heat-resistant storage stability, low-temperature fixability, stress resistance, and aggregate amount. The result of 3 is particularly excellent. On the other hand, with respect to the toners of Comparative Examples 1 to 4, any one of heat-resistant storage stability, low-temperature fixability, stress resistance, and aggregate amount has a practically problematic result.

Japanese Patent No. 5467505 Japanese Patent No. 4494317 Japanese Patent No. 5423226

Claims (7)

A method for producing a toner containing an amorphous binder resin, a release agent, organic resin fine particles and an external additive,
The toner is produced by emulsifying or dispersing an oil phase containing a material constituting the toner in an aqueous phase containing organic resin fine particles, and granulating the oil phase.
The granulation includes an alkali washing step using an alkaline solution and a heating step after the alkali washing step. The average circularity of the toner base particles before heating in the heating step is D1, and the toner base particles after heating are heated. A toner production method characterized by satisfying the following formula when the average circularity is D2.
0.002 ≦ (D2-D1) /D1≦0.010 2. The toner according to claim 1, wherein the toner satisfies the following formula, where D1 is an average circularity of the toner base particles before heating in the heating step and D2 is an average circularity of the toner base particles after heating. Manufacturing method.
0.002 ≦ (D2-D1) /D1≦0.004   3. The heating temperature in the heating step is a glass transition temperature of the toner base particles before heating + 21 ° C. or more and a glass transition temperature of the toner base particles before heating + 30 ° C. or less. 2. A method for producing the toner according to 1.   The method for producing a toner according to claim 1, wherein the alkali cleaning step is performed at a pH of 10 or more and 12 or less.   5. The toner according to claim 1, wherein the content of the organic resin fine particles is 1.2% or more and 2.4% or less with respect to the solid content of the oil phase. Production method.   A toner produced by the production method according to claim 1.   A developer comprising the toner according to claim 6.