JP2017003779A - Toner for electrostatic charge image development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development that can fix images at a low temperature while suppressing a deterioration in image quality and a reduction in folding strength.SOLUTION: There is provided a toner for electrostatic charge image development comprising toner particles containing at least an amorphous resin and a crystalline resin, wherein on a cross section of the toner particle dyed with ruthenium, the crystalline resin present at a position within 0.3 μm from the surface of the toner particle in the center direction (area A) is 20 area% or less relative to the total crystalline resin, and the crystalline resin present at a position distant from the surface of the toner particle by (Y) μm or more satisfying the following formula in the center direction (area B) is 30 area% or less relative to the total crystalline resin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a toner for developing an electrostatic image.

  In recent years, in an electrophotographic image forming apparatus, in order to further save energy for the purpose of increasing the printing speed and reducing the environmental load, the toner for developing an electrostatic image having a low-temperature fixability that can be fixed with low energy ( Hereinafter, it is simply called “toner”). In order to satisfy this requirement, development of a toner containing a crystalline resin having excellent melting characteristics is underway. By introducing the crystalline resin into the toner, the thermal melting of the toner can be lowered, and as a result, the low-temperature fixability is improved, and the fixing temperature is further lowered by increasing the amount of introduction of the crystalline material. Can be Further, there has been proposed a toner in which crystalline polyester is used as the crystalline resin, and the crystalline polyester is present in 90% or more within 1 μm from the surface of the toner particles (localized on the toner particle surface). The low-temperature fixability can be achieved with a small amount of crystalline polyester (1 to 30 parts by mass with respect to 100 parts by mass of toner) (see, for example, Patent Document 1).

JP 2011-197274 A

  However, in order to improve the low-temperature fixability, the toner in which the amount of the crystalline material introduced is increased or the toner described in Patent Document 1 in which the crystalline material is unevenly distributed on the surface of the toner particles has sufficient powder flowability of the toner. Instead, there is a problem that image defects are likely to occur. That is, in the toner in which the introduction amount of the crystalline material is increased and the toner described in Patent Document 1, on the toner particle surface, the crystalline resin and the toner binder resin (in this case, an amorphous resin other than the crystalline resin). Plasticization occurs due to compatibility with the toner, and the fluidity of the toner particles as powder decreases. When the fluidity is lowered, the toner and carrier mixing properties in the machine are lowered. Lowering the mixing property reduces the frictional chargeability between the toners and between the toner and the carrier, resulting in poor charging, resulting in a decrease in image density (the density of images such as letters on paper becomes lighter) and scattering. Degradation of image quality occurs. The crystalline resin around the center of the toner particles is difficult to melt due to heat from the fixing device (fixing machine) and to be compatible with the toner binder resin (amorphous resin other than the crystalline resin). There is a problem that the toner layer forming an image tends to remain as a domain having a grain boundary, and the toughness is low in the vicinity of the crystalline resin existing in the vicinity of the center of the toner particle, and the bending strength of the image after fixing is deteriorated. Will occur.

  Accordingly, an object of the present invention is to provide a toner for developing an electrostatic charge image that can be fixed at a low temperature while suppressing deterioration in image quality and reduction in the bending strength of an image.

  The present inventors have intensively studied to solve the above problems, and as a result, have found that the above problems can be solved by defining the amount and location of the crystalline resin in the toner particles. It came to be completed. That is, the above object of the present invention is achieved by the following configuration.

1. An electrostatic charge image developing toner comprising toner particles containing at least an amorphous resin and a crystalline resin,
In the cross section of the ruthenium-dyed toner particles, the crystalline resin present at a position (area A) within 0.3 μm in the central direction from the toner particle surface with respect to the entire crystalline resin is 20 area% or less, and A toner for developing an electrostatic charge image, wherein the crystalline resin present at a position (area B) of (Y) μm or more satisfying the following formula in the center direction from the surface of the toner particles is 30 area% or less.

  Here, (X) in the formula represents the volume-based median particle diameter (μm) of the toner particles.

  2. In the cross section of the ruthenium-dyed toner particles, the crystalline resin present in the area A is 10 area% or less and the crystalline resin present in the area B is 20 area% or less with respect to the entire crystalline resin. 2. The toner for developing an electrostatic charge image according to item 1 above.

3. The toner particles of the electrostatic image developing toner further contain a release agent,
In the cross section of the ruthenium-dyed toner particles, the release agent present in the area A is 10 area% or less and the release agent present in the area B is 64 area% or more with respect to the entire release agent. Item 3. The toner for developing an electrostatic charge image according to Item 1 or 2.

  4). The crystalline resin is a resin in which a crystalline resin unit and an amorphous resin unit other than the crystalline resin are chemically bonded to each other. Toner for developing electrostatic images.

  5. 5. The electrostatic charge image developing toner according to any one of items 1 to 4, wherein the toner particles have a volume-based median particle size of 3.0 μm or more and 8.0 μm or less.

  According to the present invention, by defining the amount and location of the crystalline resin in the toner particles, it is possible to achieve both low-temperature fixability of the toner and fluidity of the powder, resulting in deterioration in image quality and bending of the image. An electrostatic charge image developing toner that can be fixed at a low temperature while suppressing a decrease in strength can be provided. In other words, a certain amount (20 area%) or less of the crystalline resin is present on the toner particle surface, specifically, a position within 0.3 μm from the toner particle surface (area A), so that image defects do not occur. The powder fluidity of the toner can be ensured. In addition, a certain amount (30 area%) or less of the crystalline resin is present in the vicinity of the center of the toner particle, which is less effective for low-temperature fixing, specifically, at a position (Y) μm or more (area B) from the toner particle surface. Further, it is possible to suppress a decrease in the bending strength of the image after fixing. Low temperature fixing can be achieved by unevenly distributing the crystalline resin more than a certain amount (50 area%) between the toner particle surface (area A) and the vicinity of the center (area B).

FIG. 3 is a schematic diagram for explaining a cross-sectional structure of a toner particle in which the amount and the position of a crystalline resin in the toner particle of the electrostatic image developing toner of the present invention are defined. A cross-sectional structure of a toner particle in which a crystalline resin is unevenly distributed (90% or more) on a toner particle surface (specifically, within 1 μm from the toner particle surface) of a conventional electrostatic image developing toner (described in Patent Document 1). It is a schematic diagram for demonstrating.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

<Toner>
An electrostatic charge image developing toner according to an aspect of the present invention includes toner particles containing at least an amorphous resin and a crystalline resin. Further, in the cross section of the toner particles dyed with ruthenium, the crystalline resin present at a position (area A) within 0.3 μm in the central direction from the surface of the toner particles with respect to the entire crystalline resin is 20 area%. The crystalline resin present at a position (area B) of (Y) μm or more that satisfies the following formula in the center direction from the surface of the toner particles is 30 area% or less. Here, the formula: (Y) = 0.15 × (X) +0.3 (wherein (X) represents the volume-based median particle size (μm) of the toner particles). By having such a configuration, the above-described effects of the invention can be effectively expressed.

  Hereinafter, components of the electrostatic image developing toner according to the present invention will be described in detail.

(Toner particles)
The toner particles of the electrostatic image developing toner according to the present invention contain an amorphous resin and a crystalline resin as a binder resin (binder resin). Further, the toner particles may contain other toner particle constituents such as a release agent, a colorant, a magnetic powder, and a charge control agent, if necessary. The toner particles of the present invention are preferably those obtained by a wet production method (for example, an emulsion aggregation method) produced in an aqueous medium.

<Binder resin (amorphous resin and crystalline resin)>
The toner particles according to the present invention include an amorphous resin and a crystalline resin as a binder resin (binder resin).

(1) Amorphous resin There is no particular limitation on the amorphous resin, and a conventionally known amorphous resin in this technical field can be used. Among them, the amorphous resin includes an amorphous vinyl-based resin. It is preferable. Since the amorphous resin contains a vinyl resin, there is an advantage that fixing at low cost and low temperature is possible. Here, the “vinyl resin” is a resin obtained by polymerization using at least a vinyl monomer. Specific examples of the amorphous vinyl resin include an acrylic resin and a styrene acrylic copolymer resin. Among these, as the amorphous vinyl resin, a styrene acrylic copolymer resin formed using a styrene monomer and a (meth) acrylic acid ester monomer is preferable.

  As the vinyl monomer that forms the amorphous vinyl resin, one or more selected from the following may be used.

(A) Styrene monomer Examples of the styrene monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-phenyl styrene, p-ethyl styrene, 2,4-dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, and the like And derivatives thereof.

(B) (Meth) acrylic acid ester monomer As (meth) acrylic acid ester monomer, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate , (Meth) acrylate isopropyl, (meth) acrylate isobutyl, (meth) acrylate t-butyl, (meth) acrylate n-octyl, (meth) acrylate 2-ethylhexyl, (meth) acrylate stearyl, ( Examples include lauryl methacrylate, phenyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and derivatives thereof.

(C) Vinyl esters Examples of vinyl esters (monomer thereof) include vinyl propionate, vinyl acetate, and vinyl benzoate.

(D) Vinyl ethers Examples of vinyl ethers (monomers thereof) include vinyl methyl ether and vinyl ethyl ether.

(E) Vinyl ketones Examples of vinyl ketones (monomers thereof) include vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, and the like.

(F) N-vinyl compounds N-vinyl compounds (monomer thereof) include, for example, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidone and the like.

(G) Other Examples of other monomers include vinyl compounds such as vinyl naphthalene and vinyl pyridine, and acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide.

  Moreover, as a vinyl-type monomer, it is preferable to use the monomer which has ionic dissociation groups, such as a carboxy group, a sulfonic acid group, and a phosphoric acid group, for example. Specifically, there are the following.

  Examples of the monomer having a carboxy group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, and the like. Examples of the monomer having a sulfonic acid group include styrene sulfonic acid, allyl sulfosuccinic acid, and 2-acrylamido-2-methylpropane sulfonic acid. Furthermore, examples of the monomer having a phosphate group include acid phosphooxyethyl methacrylate.

  Furthermore, polyfunctional vinyls can be used as the vinyl monomer, and the amorphous vinyl resin can have a crosslinked structure. Polyfunctional vinyls include divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol Examples include diacrylate.

  As described above, the vinyl resin has been described in detail as a preferable form of the amorphous resin. However, an amorphous polyester resin such as a styrene acrylic modified polyester resin may be used as the amorphous resin.

  The glass transition point (Tg) of the amorphous resin is preferably 25 to 60 ° C, more preferably 35 to 55 ° C. When the glass transition point of the amorphous resin is in the above range, sufficient low-temperature fixability and heat-resistant storage properties (and powder fluidity) can be obtained at the same time. The glass transition point (Tg) of the amorphous resin is a value measured using “diamond DSC” (manufactured by PerkinElmer). As a measurement procedure, 3.0 mg of a measurement sample (amorphous resin) is sealed in an aluminum pan and set in a holder. The reference used an empty aluminum pan. The measurement conditions were a measurement temperature of 0 ° C. to 200 ° C., a temperature increase rate of 10 ° C./min, a temperature decrease rate of 10 ° C./min, and heat-cool-heat temperature control. Perform analysis based on the data in Heat, draw a baseline extension before the rise of the first endothermic peak, and a tangent line indicating the maximum slope between the rise of the first peak and the peak apex, Let the intersection be the glass transition point.

  Moreover, it is preferable that the molecular weight measured by gel permeation chromatography (GPC) of an amorphous resin is 10,000-100,000 in a weight average molecular weight (Mw). In the present invention, the molecular weight of the amorphous resin GPC is a value measured as follows. That is, using an apparatus “HLC-8120GPC” (manufactured by Tosoh Corporation) and a column “TSKguardcolumn + TSKgelSuperHZ-M3 series” (manufactured by Tosoh Corporation), while maintaining the column temperature at 40 ° C., tetrahydrofuran (THF) was used as a carrier solvent at a flow rate. Flow at 0.2 mL / min, and dissolve the measurement sample (amorphous resin) in tetrahydrofuran to a concentration of 1 mg / ml under a dissolution condition in which treatment is performed for 5 minutes using an ultrasonic disperser at room temperature. A sample solution is obtained by processing with a 0.2 μm membrane filter, and 10 μL of this sample solution is injected into the apparatus together with the carrier solvent described above, detected using a refractive index detector (RI detector), and possessed by the measurement sample. The molecular weight distribution was measured using monodisperse polystyrene standard particles. Calculated using a standard curve. Ten polystyrenes are used for calibration curve measurement.

(2) Crystalline resin There is no particular limitation on the crystalline resin, and a conventionally known crystalline resin in this technical field can be used, and among these, the crystalline resin preferably contains a crystalline polyester resin. Here, the “crystalline resin” refers to a known polyester resin obtained by a polycondensation reaction of a divalent or higher carboxylic acid (polyvalent carboxylic acid) and a divalent or higher alcohol (polyhydric alcohol). )) In differential scanning calorimetry (DSC), it refers to a resin having a clear endothermic peak rather than a stepwise endothermic change. The clear endothermic peak specifically means a peak in which the half-value width of the endothermic peak is within 15 ° C. when measured at a rate of temperature increase of 10 ° C./min in differential scanning calorimetry (DSC). To do.

  The polyvalent carboxylic acid is a compound containing two or more carboxy groups in one molecule. Specifically, for example, oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, n-dodecyl succinic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, tetradecanedicarboxylic acid Saturated aliphatic dicarboxylic acids such as cycloaliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid, aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; trivalent or higher polyvalent carboxylic acids such as trimellitic acid and pyromellitic acid Acid; and anhydrides of these carboxylic acid compounds or alkyl esters having 1 to 3 carbon atoms. These may be used individually by 1 type and may be used in combination of 2 or more type.

  A polyhydric alcohol is a compound containing two or more hydroxyl groups in one molecule. Specifically, for example, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol , 1,8-octanediol, 1,9-nonanediol, dodecanediol, neopentylglycol, 1,4-butenediol and other aliphatic diols; glycerin, pentaerythritol, trimethylolpropane, sorbitol A polyhydric alcohol etc. are mentioned. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The melting point (Tm) of the crystalline polyester resin is preferably 50 to 95 ° C, more preferably 55 to 85 ° C. When the melting point of the crystalline polyester resin is in the above range, sufficient low-temperature fixability and excellent hot offset resistance (and powder fluidity) can be obtained. The melting point of the crystalline polyester resin can be controlled by the resin composition.

  In the present invention, the melting point of the crystalline polyester resin is a value measured as follows. That is, using a differential scanning calorimeter “Diamond DSC” (manufactured by PerkinElmer Co., Ltd.), a first temperature raising process in which the temperature is raised from 0 ° C. to 200 ° C. at an elevation rate of 10 ° C./min, and a cooling rate of 10 ° C./min is 200 ° C. It is measured by the measurement conditions (temperature rise / cooling conditions) that pass through the cooling process for cooling from 0 to 0 ° C. and the second temperature raising process for raising the temperature from 0 ° C. to 200 ° C. at a raising / lowering rate of 10 ° C./min. The endothermic peak top temperature derived from the crystalline polyester resin in the first temperature raising process is defined as the melting point (Tm) based on the DSC curve obtained by this measurement. As a measurement procedure, 3.0 mg of a measurement sample (crystalline polyester resin) is sealed in an aluminum pan and set in a diamond DSC sample holder. The reference uses an empty aluminum pan.

  The molecular weight of the crystalline polyester resin measured by gel permeation chromatography (GPC) is 5,000 to 50,000 in terms of weight average molecular weight (Mw) and 1,500 to 25 in terms of number average molecular weight (Mn). , 000 is preferable. The molecular weight measured by GPC of the crystalline polyester resin is measured in the same manner as described above except that the crystalline polyester resin is used as a measurement sample.

  The content of the crystalline resin is preferably in the range of 3 to 30% by mass with respect to the whole toner particles. If the content of the crystalline resin is in the range of 3 to 30% by mass with respect to the whole toner particles, an appropriate decrease in elasticity can be caused when the toner is heated, and good low-temperature fixability can be obtained. Specifically, if the content of the crystalline resin is 3% by mass or more based on the whole toner particles, the main resin (a heat-adhesion resin other than the crystalline resin; an amorphous resin) and the crystalline resin are in phase when the toner is heated. Since it is easy to dissolve, the elasticity can be lowered and the low-temperature fixability is improved. On the other hand, if the amount is 30% by mass or less, the decrease in elasticity at the time of heating the toner does not become too large, and it is possible to effectively prevent the occurrence of a so-called high temperature offset in which the toner or paper is wound around the fixing device. Excellent in terms. From the above points, the content of the crystalline resin is more preferably in the range of 6 to 20% by mass with respect to the whole toner particles.

  The mass ratio of the amorphous resin to the crystalline resin (amorphous resin / crystalline resin) is preferably 97/3 to 70/30, and more preferably 95/5 to 75/25. When the mass ratio (amorphous resin / crystalline resin) is in the above range, the crystalline resin is not exposed on the surface of the toner particles to be formed, or the amount thereof is extremely small even when exposed, and An amount of crystalline resin that can achieve low-temperature fixability can be introduced into the toner particles.

  The crystalline resin is a crystalline resin formed by chemically bonding a polyester polymer segment and another polymer segment, particularly a vinyl polymer segment (hereinafter referred to simply as “hybrid crystal”). It is also preferable that the crystalline resin not having a plurality of segments is also simply referred to as “non-hybrid crystalline resin”). In particular, the use of the same monomer for the hybrid crystalline resin and the amorphous resin is excellent in that the affinity (compatibility) between the two is increased and the image bending strength is improved.

  The crystalline resin is preferably compounded like the above hybrid crystalline resin, and the compounding rate (ratio of the compounded resin (hybrid crystalline resin) in the crystalline resin) is the binder resin (= A range of 5 to 30% by mass is preferable with respect to the whole (amorphous resin + crystalline resin). When the composite ratio is in the range of 5 to 30% by mass, an appropriate compatibility between the main resin (a heat-fusing resin other than the crystalline resin; an amorphous resin) and the crystalline resin in the image after fixing. Is obtained. Specifically, if the above-mentioned composite rate is 5% by mass or more, in the image after fixing, there is an appropriate compatibility between the main resin (a heat-fusing resin other than the crystalline resin; an amorphous resin) and the crystalline resin. Therefore, it is difficult to separate the phase between the main resin (heat-adhesion resin other than the crystalline resin; amorphous resin) and the crystalline resin, and it is possible to effectively prevent the bending strength of the image from being lowered. Moreover, if the said composite rate is 30 mass% or less, compatibility will not become high too much and the glass transition point of main resin (heat-adhesion resin other than crystalline resin; amorphous resin) will become low. This is superior in that it can effectively prevent sticking (so-called tacking) due to fusion of images.

  When the crystalline resin contains the above hybrid crystalline resin, the polyester polymer segment and the other polymer segment (preferably vinyl polymer segment) are a crystal resin bonded via both reactive monomers. It is preferable. In addition, the said polyester polymerization segment is comprised from crystalline polyester resin. When the crystalline resin includes the hybrid resin, the thickness of the layered lamellar crystal structure due to molecular chain folding can be increased to some extent. That is, the crystallinity can be increased. Thereby, it becomes easy to control the aspect ratio of the lamellar crystal structure and the thickness of the lamellar crystal structure described above within a predetermined range. This is because the vinyl polymer segment introduced into the hybrid crystalline resin has a high affinity with the amorphous resin, so that the hybrid crystalline resin is easily compatible with the amorphous resin (immobilized). As a result, it is considered that the molecular chains of the crystalline resin are easily arranged. Here, the “layered lamellar crystal structure” means a layered structure generated by crystallization by folding a molecular chain of a crystalline resin.

(A) Vinyl Polymerization Segment The vinyl polymer segment constituting the hybrid crystalline resin is composed of a resin obtained by polymerizing a vinyl monomer. Here, as the vinyl monomer, those described above as the monomers constituting the vinyl resin can be used in the same manner, and thus detailed description thereof is omitted here. The content of the vinyl polymer segment in the hybrid crystalline resin is preferably in the range of 5 to 30% by mass, more preferably in the range of 5 to 20% by mass, and 5 to 10% by mass. % Is more preferable. Within this range, there are advantages such as affinity (compatibility) with the vinyl-based amorphous resin and stability as crystals.

(B) Polyester polymerization segment The polyester polymerization segment constituting the hybrid resin is composed of a crystalline polyester resin produced by conducting a polycondensation reaction between a polycarboxylic acid and a polyhydric alcohol in the presence of a catalyst. . Here, specific types of the polyvalent carboxylic acid and the polyhydric alcohol are as described above, and thus detailed description thereof is omitted here.

(C) Amphoteric monomer The amphoteric monomer is a monomer that binds a polyester polymer segment and a vinyl polymer segment, and in the molecule, a hydroxy group or a carboxy group that forms a polyester polymer segment. , A monomer having both a group selected from an epoxy group, a primary amino group and a secondary amino group and an ethylenically unsaturated group forming a vinyl polymerized segment. Both reactive monomers are preferably monomers having a hydroxy group or a carboxy group and an ethylenically unsaturated group. More preferably, it is a monomer having a carboxy group and an ethylenically unsaturated group. That is, it is preferably a vinyl carboxylic acid.

  Specific examples of the both reactive monomers include, for example, acrylic acid, methacrylic acid, fumaric acid, maleic acid and the like, and even these hydroxyalkyl (1 to 3 carbon atoms) esters. Acrylic acid, methacrylic acid or fumaric acid is preferred from the viewpoint of reactivity. The polyester polymer segment and the vinyl polymer segment are bonded through the both reactive monomers.

  The amount of the both reactive monomers used is a vinyl monomer constituting the vinyl polymer segment from the viewpoint of improving the low temperature fixability of the toner, the fluidity of the powder, and the high temperature offset resistance and durability. 1-10 mass parts is preferable with respect to 100 mass parts of total amounts (including both reactive monomers), and 4-8 mass parts is more preferable.

(D) Method for Producing Hybrid Crystalline Resin As a method for producing a hybrid crystalline resin, an existing general scheme can be used. The following three methods are listed as typical methods.

  (I) A polyester polymerization segment is preliminarily polymerized, and the polyester polymerization segment is reacted with both reactive monomers, and further an aromatic vinyl monomer and (meth) for forming a vinyl polymerization segment This is a method of forming a hybrid crystalline resin by reacting an acrylate monomer.

  (Ii) A vinyl polymer segment is polymerized in advance, the vinyl polymer segment is reacted with both reactive monomers, and a polyvalent carboxylic acid and a polyhydric alcohol for forming a polyester polymer segment are further reacted. This is a method for forming a polyester polymer segment.

  (Iii) A method in which a polyester polymer segment and a vinyl polymer segment are polymerized in advance, and both reactive monomers are reacted with each other to bond them together.

  In the present invention, any of the above production methods can be used, but the method of the above item (ii) is preferred. Specifically, a polyvalent carboxylic acid and a polyhydric alcohol that form a polyester polymer segment, a vinyl monomer that forms a vinyl polymer segment, and both reactive monomers are mixed, and a polymerization initiator is added. It is preferable to carry out a polycondensation reaction by adding an esterification catalyst after addition polymerization of a vinyl monomer and an amphoteric monomer to form a vinyl polymer segment.

  Here, as a catalyst for synthesizing the polyester polymerization segment, various conventionally known catalysts can be used. Examples of esterification catalysts include tin compounds such as dibutyltin oxide and tin (II) 2-ethylhexanoate, titanium compounds such as titanium diisopropylate bistriethanolamate, and tetrabutoxytitanium. Examples thereof include gallic acid and the like.

(E) Form of Hybrid Crystalline Polyester Resin In the toner according to the present invention, it is preferable that the cross section of the toner particle has a lamellar crystal structure composed of a crystalline resin, particularly a hybrid crystalline polyester resin. . The hybrid crystalline polyester resin has a structure in which a crystalline polyester resin unit (polyester polymer segment) is chemically bonded as a side chain to a styrene acrylic resin unit (vinyl polymer segment) serving as a main chain. As a result, the hybrid crystalline polyester resin has a comb-shaped molecular structure. Such a comb-shaped molecular structure forms a lamellar crystal structure when the crystalline polyester resin unit is folded and crystallized, for example, in a resin different from the polyester resin.

  Further, in the toner according to the present invention, when the cross section of the toner particle has a lamellar crystal structure composed of a crystalline resin, particularly a hybrid crystalline polyester resin, the major axis of the lamellar crystal structure The average value of the aspect ratio (major axis / minor axis) to the minor axis is preferably 1.0 to 3.0, and the average value of the thickness of the lamellar crystal structure is preferably 45 to 300 nm. Here, the “major axis” for calculating the aspect ratio indicates the larger value of the length and thickness of the lamellar crystal structure, and the “minor axis” indicates the smaller value (major axis = minor axis). When the aspect ratio is 1.) The method for measuring the length and thickness of the lamellar crystal structure (and their respective average values) and the method for calculating the aspect ratio (and their average values) are as follows.

  First, the cross section of the toner particles is observed with the following apparatus and conditions.

Apparatus: Transmission electron microscope “JEM-2000FX” (manufactured by JEOL Ltd.)
Sample: section of toner particles stained with ruthenium tetroxide (RuO ₄ ) (section thickness: 60 to 100 nm)
・ Acceleration voltage: 80 kV
-Magnification: 20,000 times, bright field image.

  The observation is performed within 24 hours after dyeing, and at this time, the measurement of the lamellar lamellar crystal structure is performed for 20 domains.

  Here, the field of view is photographed during cross-sectional observation using the transmission electron microscope described above, a photographic image is captured by a scanner, and dispersed on the cross-section of the toner using an image processing analyzer LUZEX AP (manufactured by Nireco Corporation). The length and thickness of the layered lamellar crystal structure is measured for 20 domains, and the average value of each is obtained. Of the length and thickness measured for each domain, the major axis / minor axis value is calculated as the aspect ratio when the larger value is the major axis and the smaller value is the minor axis (major axis = minor axis). When the diameter, the aspect ratio is 1), and the average value of the observed 20 points of the domain is obtained. Further, the number of layered lamellar crystal structures in 20 fields of view is measured, and the number ratio [%] of those having a thickness of 45 to 300 nm is calculated. In the above observation, the lamellar crystal structure having a major axis or a minor axis of less than 40 nm is not subject to observation. In the present invention, when a cross section of 100 toner particles is observed by the above-described method, the aspect ratio (major axis / minor axis) and thickness of the lamellar crystal structure in the cross section are those that satisfy the above range. It is preferable that 60% (60) or more of the whole is present, and more preferably 80% (80) or more. If the toner base particles satisfying the above-mentioned range of the aspect ratio (major axis / minor axis) and thickness of the lamellar crystal structure are 60% or more of the total, low temperature fixability, powder fluidity, and fixing separation Improvements in performance such as heat resistance and heat storage stability are achieved.

  As long as the above definition is satisfied, there is no particular limitation on the other configuration of the lamellar crystal structure in the cross section of the toner base particles, but the aspect ratio value of the lamellar crystal structure is preferably 1 to 15, More preferably, it is 1-5. Moreover, the average value of the length of the layered lamellar crystal structure is preferably 45 to 900 nm, and more preferably 200 to 700 nm. Furthermore, the average value of the thickness of the layered lamellar crystal structure is preferably 45 to 300 nm, and more preferably 300 to 500 nm. Moreover, the number ratio of the layered lamellar crystal structure having a thickness of 45 to 300 nm is preferably 50% or more, more preferably 70% or more, and further preferably 90% or more. When the various configurations of the lamellar crystal structure satisfy the above range, various performances such as low-temperature fixability, powder fluidity, further fixability and heat-resistant storage stability can be exhibited particularly remarkably.

<Release agent (offset prevention agent or wax)>
In the toner according to the present invention, when the toner particles are configured to contain a release agent, the release agent is composed of a matrix phase (amorphous resin indicated by reference numeral 12 in FIG. 1) and a domain phase (in FIG. 1). Although it may be contained in any one of the crystalline resin (symbol 13), it is particularly preferred that it is contained in the matrix phase from the viewpoint of surface exudation of the release agent during fixing.

  As the release agent (wax), particularly, low molecular weight polypropylene, polyethylene, or oxidized wax, polyolefin wax such as polyethylene, and ester wax such as behenate behenate can be suitably used.

  Specifically, polyolefin waxes such as polyethylene wax and polypropylene wax; branched hydrocarbon waxes such as microcrystalline wax; long-chain hydrocarbon waxes such as paraffin wax and sazol wax; dialkyls such as distearyl ketone Ketone wax; carnauba wax, montan wax, behenate behenate, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecanediol di Ester wax such as stearate, trimellitic trimellitic acid, distearyl maleate; ethylenediamine behenylamide, trimellitic acid tristearylamide Such as amide waxes. Among these, from the viewpoint of releasability during low-temperature fixing, it is preferable to use those having a low melting point, specifically, those having a melting point of 40 to 90 ° C.

  The content ratio of the release agent is preferably 1 to 20% by mass in the toner particles, and more preferably 5 to 20% by mass.

<Colorant>
In the toner according to the present invention, when the toner particles are configured to contain a colorant, the colorant includes a matrix phase (amorphous resin indicated by reference numeral 12 in FIG. 1) and a domain phase (reference numeral 13 in FIG. 1). The crystalline resin) may be contained in any of the above, but is preferably contained in the matrix phase from the viewpoint of dispersibility of the colorant.

  Examples of carbon black (colorant for black toner) include channel black, furnace black, acetylene black, thermal black, and lamp black. Examples of black iron oxide include magnetite, hematite, and iron iron trioxide. It is done.

  Examples of the dye (colorant) include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95 and the like.

  Examples of the pigment (colorant) include C.I. I. Pigment Red 5, 48: 1, 48: 3, 53: 1, 57: 1, 81: 4, 122, 139, 144, 149, 150, 166, 177, 178, 222, 238, 269, C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment yellow 14, 17, 74, 93, 94, 138, 155, 156, 158, 180, 185, C.I. I. Pigment green 7, C.I. I. Pigment Blue 15: 3, 60, and the like.

  The colorant for obtaining the toner of each color can be used singly or in combination of two or more for each color. The content ratio of the colorant is preferably 1 to 10% by mass in the toner particles, and more preferably 2 to 8% by mass.

<Charge control agent>
In the toner according to the present invention, when the toner particles are configured to contain a charge control agent, the charge control agent includes a matrix phase (amorphous resin denoted by reference numeral 12 in FIG. 1) and a domain phase (in FIG. 1). Although it may be contained in any one of the crystalline resin 13), it is particularly preferred that it is contained in the matrix phase from the viewpoint of dispersibility of the charge control agent.

  The content ratio of the charge control agent is usually 0.1 to 10 parts by mass, preferably 0.5 to 100 parts by mass of the finally obtained binder resin (including the amorphous resin and the crystalline resin). ˜5 parts by mass.

  In the toner for developing an electrostatic image of the present invention, as described above, at least an amorphous resin and a crystalline resin (including a binder resin), and if necessary, a release agent, a colorant, a charge control agent, and the like are added. Toner particles containing an agent.

  FIG. 1 is a schematic diagram for explaining a cross-sectional structure of a toner particle in which the amount and the position of a crystalline resin in the toner particle of the toner for developing an electrostatic charge image of the present invention are defined. FIG. 2 illustrates a cross-sectional structure of toner particles in which crystalline resin is unevenly distributed (90% or more) on the surface of toner particles of a conventional electrostatic charge image developing toner (specifically, within 1 μm from the surface of the toner particles). It is a schematic diagram for doing.

(Area ratio of crystalline resin existing in area A)
As shown in FIG. 1, in the toner particle 10 containing at least the amorphous resin 12 and the crystalline resin 11 contained in the toner for developing an electrostatic charge image of the present invention, a crystal in the cross section of the ruthenium-stained toner particle. The crystalline resin 11 present at a position (area A) (reference numeral A) within 0.3 μm in the central direction from the surface of the toner particles with respect to the entire crystalline resin is 20 area% or less. is there. If the crystalline resin 11 present in the area A is 20 area% or less, sufficient fluidity of the toner particles as powder that does not cause image defects can be ensured. Specifically, if the crystalline resin 11 is present in the vicinity of the toner particle surface (area A) (reference A) more than the above-mentioned area ratio, plasticization due to the compatibility of the amorphous resin 12 or shape modification of the toner particle 10 surface. Since the powder fluidity is deteriorated, the toner particles 10 may be used as a powder of the toner particles 10 by preventing them from being present in a position (area A) (symbol A) within 0.3 μm from the surface of the toner particles 10 more than the above area ratio. A decrease in fluidity can be suppressed. On the other hand, as in the toner particles 20 included in the conventional electrostatic image developing toner shown in FIG. 2, 90% of the crystalline resin 21 is applied to an area D within 1 μm from the toner particle surface in the cross section of the ruthenium-stained toner particles. In the case where it is present (unevenly distributed) (that is, when the crystalline resin present in area A exceeds 20 area%), the crystalline resin (crystalline polyester resin) 21 and the toner binder are formed on the surface of the toner particles 20. Plasticization due to compatibility with the resin (binder resin, mainly amorphous resin 22) occurs, and the fluidity of the toner particles 20 as powder decreases. When the fluidity is lowered, the mixing property of the toner and the carrier in the machine is lowered. Lowering the mixing property reduces the frictional chargeability between the toners and between the toner and the carrier, resulting in poor charging, resulting in a decrease in image density (the density of images such as letters on paper becomes lighter) and scattering. It is not preferable because the image quality deteriorates. From the above points, in order to further improve the powder fluidity of the toner and provide better image quality (image quality that does not cause fogging or image roughness), the crystalline resin 11 present in the area A (reference A) is 10 area% or less is more preferable. In the cross section of the toner particle 20 in FIG. 2, an area other than the area D within 1 μm from the toner particle surface is an area E (symbol E).

(Area ratio of crystalline resin existing in area B)
As shown in FIG. 1, in the toner particle 10 containing at least the amorphous resin 12 and the crystalline resin 11 contained in the toner for developing an electrostatic charge image of the present invention, a crystal in the cross section of the ruthenium-stained toner particle. The crystalline resin 11 present at a position (area B) (reference symbol B) of (Y) μm or more that satisfies the following formula in the center direction from the surface of the toner particles with respect to the entire crystalline resin is 30 area% or less. It is characterized by. If the crystalline resin 11 present in the area B (symbol B) is 30 area% or less, the crystalline resin 11 present in the vicinity of the toner particle center (area B) (symbol B) having a small effect on low-temperature fixing is constant. The amount can be reduced to less than the amount, and a decrease in the bending strength of the image after fixing can be suppressed. Specifically, the crystalline resin 11 existing around the center (area B) (reference numeral B) of the toner particles 10 is melted by heat of the fixing device and a toner binder resin (a binder resin other than the crystalline resin 11, mainly a non-resin). Since it is difficult to be compatible with the crystalline resin 12), it tends to remain as a domain having a grain boundary in the toner layer for forming a fixed image, and the crystalline resin 11 itself is fragile. The vicinity of the crystalline resin 11 existing in the vicinity of the center (area B) (symbol B) of the toner is not preferable because the toughness becomes low and the problem that the bending strength of the image after fixing deteriorates occurs. From the above points, in order to further increase the bending strength of the image after fixing, the crystalline resin 11 present in the area B (reference B) is more preferably 20 area% or less.

  Here, (X) in the formula represents the volume-based median particle diameter (μm) of the toner particles.

(Area ratio of crystalline resin existing in area C between area A and area B)
As shown in FIG. 1, in the toner particle 10 containing at least the amorphous resin 12 and the crystalline resin 11 contained in the toner for developing an electrostatic charge image of the present invention, a crystal in the cross section of the ruthenium-stained toner particle. The crystalline resin 11 existing in the area C (reference C) between the area A (reference A) and the area B (reference B) with respect to the entire crystalline resin is 50 area% or more. Is. If the crystalline resin 11 present in the area C (reference C) is 50 area% or more, it is between the vicinity of the toner particle 10 surface (area A) (reference A) and the vicinity of the center (area B) (reference B). The crystalline resin 11 can be unevenly distributed in the area C (reference C), which is excellent in that low-temperature fixing can be achieved. In other words, when the crystalline resin 11 present in the area C (symbol C) is less than 50% by area, low-temperature fixing is difficult and relatively present in the area A (symbol A) and the area B. As the area ratio of the crystalline resin 11 increases, it becomes difficult to ensure sufficient fluidity so that image defects do not occur as described above, and it is difficult to suppress a decrease in the bending strength of the image after fixing. Therefore, it is not preferable. From the above points, in order to further improve the image quality and the bending strength of the image, the crystalline resin 11 existing in the area C (reference C) is more preferably 70 area% or more.

(Area ratio of release agent in area A)
As shown in FIG. 1, when the toner particle 10 containing at least the amorphous resin 12 and the crystalline resin 11 contained in the toner for developing an electrostatic charge image of the present invention further contains a release agent 13, ruthenium In the cross section of the dyed toner particles, the release agent (not shown) present in the area A (reference A) with respect to the entire release agent is preferably 26 area% or less, and preferably 10 area% or less. More preferably. If the release agent present in area A (symbol A) is 10 area% or less, sufficient fluidity of the toner particles 10 as powder that does not cause image defects can be ensured. Specifically, if the release agent is present in the vicinity (area A) (reference A) of the toner particles 10 in the vicinity of the toner particles 10, the release agent is not compatible with the crystalline resin 11. The fluidity of the toner particles 10 as a powder deteriorates due to the plasticization due to the compatibility of the amorphous resin 11 and the amorphous resin 12 and the irregular shape of the surface of the toner particles 10 (because of the rugged shape and flattening). By preventing the toner particles 10 from being present in a position (area A) (symbol A) within 0.3 μm from the surface of the toner particles 10 more than the above area ratio, it is possible to suppress a decrease in fluidity of the toner particles 10 as a powder. It is. That is, if the release agent present in the area A (reference A) is 10 area% or less with respect to the entire release agent, the release agent (not shown) and the crystalline resin are formed on the surface of the toner particles 10. 11 is incompatible with the toner particles 10, so that the shape of the toner particles 10 is prevented from being deformed. The crystalline resin 11 and the toner binder resin (binder resin other than the crystalline resin, mainly the amorphous resin 12) Suppressing the occurrence of plasticization due to compatibility, ensuring the fluidity of the toner particles 10 as powder, improving the mixing property of the toner and the carrier in the machine, and the triboelectric chargeability between the toners and between the toner and the carrier To prevent the occurrence of charging defects and effectively prevent deterioration of image quality (fogging and image roughness) such as a decrease in image density (the density of images such as letters on paper is reduced) and scattering. It is something that can be done.

(Area ratio of release agent in area B)
As shown in FIG. 1, when the toner particle 10 containing at least the amorphous resin 12 and the crystalline resin 11 contained in the toner for developing an electrostatic charge image of the present invention further contains a release agent 13, ruthenium In the cross section of the dyed toner particles, the release agent 13 present in the area B (reference B) with respect to the entire release agent is preferably 50 area% or more, more preferably 64 area% or more. preferable. If the release agent 13 existing in the area B (reference B) is 64 area% or more, when the fixing temperature is low at the time of toner fixing, the exudation of the release agent (wax) 13 is suppressed and the fixing is performed. It is excellent in that the image folding strength is improved and the image bending strength is increased (note that even when the fixing temperature is high, the paper separation property (releasability) can be secured to the same level as in the past).

(Area ratio of release agent present in area C between area A and area B)
As shown in FIG. 1, when the toner particle 10 containing at least the amorphous resin 12 and the crystalline resin 11 contained in the toner for developing an electrostatic charge image of the present invention further contains a release agent 13, ruthenium The release agent (not shown) present in the area C (reference C) between the area A (reference A) and the area B (reference B) with respect to the entire release agent in the section of the dyed toner particles However, it is preferable that it is 36 area% or less. If the release agent present in area C (symbol C) is 36 area% or less, the amount of release agent (not shown) near the surface of toner particle 10 (area A) (symbol A) is reduced, and the center The release agent 13 can be unevenly distributed in the vicinity (area B) (symbol B), and sufficient fluidity of the toner particles 10 as a powder that does not cause image defects can be secured. The fixing property is improved, the image bending strength can be improved, and low temperature fixing can be achieved. From the above points, in order to further improve the image quality and the bending strength of the image, the release agent present in area C (reference C) is more preferably in the range of 20 to 30 area%.

(Volume-based median particle diameter of toner particles; (X) in the above formula)
The volume-based median particle size of the toner particles 10 of the present invention is preferably 3 μm or more and 8 μm or less. When the volume-based median particle size of the toner particles 10 is in the range of 3 μm or more and 8 μm or less, the properties (particularly fluidity) of the toner particles are improved, and the adhesion between the toner and the carrier is appropriate and good. This is because an accurate image can be output. Specifically, when the volume-based median particle size of the toner particles 10 is 3 μm or more, an appropriate adhesion force can be maintained without the adhesion force between the toner and the carrier becoming too strong. Therefore, it is excellent in that it is possible to prevent the developability from being lowered and to effectively prevent the image density from being lowered. On the other hand, if the volume-based median particle size of the toner particles 10 is 8 μm or less, the adhesion force between the toner and the carrier can be maintained without being excessively reduced. Therefore, it is excellent in that image defects such as fog can be effectively prevented. From the above points, in order that the adhesion between the toner and the carrier is more appropriate and a better image is output, the volume-based median particle size of the toner particles 10 is more preferably in the range of 4 μm to 7.5 μm. preferable.

  By substituting (X) in the above formula as a preferable range of the volume-based median particle size of the toner particles 10, a region (range) of area B (reference symbol B) that satisfies the above formula (Y) is obtained. . For example, when the volume-based median particle size of the toner particles 10 is 3 μm, the area B (reference numeral B) is 0.75 (= 0.15 × 3 + 0.3) μm or more in the central direction from the toner particle 10 surface. It becomes the position. Further, when the volume-based median particle size of the toner particles 10 is 8 μm, the area B is located at a position of 1.5 (= 0.15 × 8 + 0.3) μm or more in the center direction from the surface of the toner particles 10. .

(Volume-based median particle size of area B and area B + C constituting toner particles)
Further, as shown in the following method for producing toner particles 10, in the present invention, the amorphous resin 12, the crystalline resin 11, the release agent 13 and the colorant (not shown) constituting the areas B, C and A, respectively. 1), the volume-based median particle size of the associated particles corresponding to area B (symbol B) in the production stage, and area B (symbol B) + area Volume-based median particle size of associated particles (= associated particles excluding area A (reference A)) corresponding to C (reference C), and toner particles 10 (area B (reference B) + area C (reference C) The toner particles 10 as designed can be freely produced by controlling (controlling) the volume-based median particle diameter of the associated particles corresponding to the area A (reference A) (see each example). . Specifically, the volume-based median particle diameter (diameter) of area B (reference symbol B) is 1.5 from the viewpoint of achieving both low temperature fixing property and fixing separation property by inclusion of a release agent in the toner. The range of -3.0 micrometers is preferable, and the range of 1.5-2.5 micrometers is more preferable. The volume-based median particle diameter (diameter) of area B (symbol B) + area C (symbol C) (= particles excluding area A (symbol A)) is a dispersion of crystalline resin domains in the toner. From the viewpoint of improving properties, a range of 2.0 to 7.5 μm is preferable, and a range of 4.0 to 5.5 μm is more preferable. In the production stage, these are volume-based median particle diameters (D50) (D50) obtained by a particle size distribution measuring apparatus described below (for example, a precision particle size distribution measuring apparatus Coulter “Multisizer 3”; manufactured by Coulter Beckman). μm). Further, when the toner particle 10 is obtained based on the volume-based median particle size (X) of the manufactured toner particle 10, the particle size (X) of the toner particle 10 is substituted into the above formula, and an area (area) that satisfies (Y) B (diameter of B) can be obtained. By removing a region of 0.3 μm from the particle size (X) of the toner particles 10 (area A (reference A)), area B (reference B) + area C (reference C) (= area A (reference A) ), The diameter of the particles excluding).

  The volume-based median particle size of the toner particles is a volume-based median particle size (D50) obtained by a particle size distribution measuring device (for example, a precision particle size distribution measuring device Coulter “Multisizer 3”; manufactured by Coulter Beckman). μm). Specifically, the volume-based median particle size of toner particles is connected to a computer system equipped with data processing software “Software V3.51” to the Coulter “Multisizer 3” (manufactured by Beckman Coulter, Inc.). It is measured and calculated using the measuring device. Specifically, 0.02 g of a measurement sample (toner particles; not including external additive particles) is added to 20 mL of a surfactant solution (for example, a neutral detergent containing a surfactant component is purified for the purpose of dispersing toner particles). (Surfactant solution diluted 10 times with water) and acclimatized, followed by ultrasonic dispersion for 1 minute to prepare a dispersion of toner particles. Pipette into a beaker containing ISOTON II (Beckman Coulter, Inc.) until the display concentration of the measuring device is 8%. Here, a reproducible measurement value can be obtained by setting the concentration range. In the measuring apparatus, the measurement particle count number is 25000, the aperture diameter is 100 μm, and the frequency value is calculated by dividing the range of 2 to 60 μm, which is the measurement range, into 256 parts. % Particle size is defined as the volume-based median particle size.

(Measurement method of area ratio of crystalline resin and release agent of toner cross section stained with ruthenium)
The area ratio of the crystalline resin and the release agent in the cross section of the toner particles stained with ruthenium can be measured according to the following procedures 1 to 4. However, the materials, reagents, conditions (staining conditions, etc.) used in the measurement, measuring apparatus, etc. may be changed as appropriate as long as those skilled in the art can easily conceive.

1. Method for Producing Section of Toner Particles After exposing toner particles in a ruthenium tetroxide (RuO ₄ ) vapor atmosphere for 10 minutes, the toner particles are dispersed in a photocurable resin “D-800” (manufactured by JEOL Ltd.). Photocuring to form blocks. Next, using a microtome equipped with diamond teeth, a flaky sample having a thickness of about 60 nm to 100 nm is cut out from the block and placed on a grid with a support film for transmission electron microscope observation. A filter paper is laid on a plastic petri dish having a diameter of 5 cm (5 cmφ), and a grid on which the slice is placed is placed on the plastic petri dish with the surface on which the slice is placed facing up.

2. Ruthenium tetroxide dyeing conditions The dyeing conditions (time, temperature, and concentration and amount of the dye) are different from each resin (mainly amorphous resin, crystalline resin, and release agent) when observed with a transmission electron microscope. Adjust to the conditions that you can. For example, 2 to 3 drops of 0.5 mass% RuO ₄ staining solution is dropped on two points in the petri dish, covered, and after 10 minutes, the petri dish lid is removed and left until the staining solution is free of moisture.

3. Toner particle cross-section observation method (conditions)
Apparatus: Transmission electron microscope “JEM-2000FX” (manufactured by JEOL Ltd.)
Sample: A section of toner particles stained with ruthenium tetroxide (RuO ₄ ) (section thickness of about 60 nm to 100 nm)
・ Magnification: 10,000 times.

4). Analysis of cross-sectional image of toner particles First, an image obtained by cross-sectional observation is divided into an area (area A) of 0.3 μm from the toner particle surface and an area (area B) of (Y) μm or more from the toner particle surface. To do.

  Here, (Y) = 0.15 × (X) +0.3 (μm) is satisfied, and (X) is a volume-based toner particle obtained by “Coulter Multisizer 3” (manufactured by Coulter Beckman). The median particle size (D50) (μm).

  In the toner particles, the crystalline resin (crystalline polyester resin) and the release agent are determined from the contrast and shape. Those present in the form of rods or lumps are determined as release agents, and crystals scattered in the non-crystalline resin of the toner particles with a linear, needle-like or lamellar crystal structure (lamellar layer shape) are judged as crystalline resins. In contrast, a whiter contrast portion is determined as a release agent. Binder resins (non-crystalline resins, crystalline resins) other than mold release agents have many double bond parts and are dyed with ruthenium tetroxide, so the mold release part and resin parts other than the mold release agent are distinguished. it can. That is, the release agent is dyed lightest by ruthenium dyeing, then the crystalline resin (crystalline polyester resin) is dyed, and the amorphous resin (amorphous polyester resin) is dyed most intensely. The analysis is an average value performed on the cross section of 20 toner particles. Here, the layered lamellar crystal structure is as defined above. The cross-sectional area of the lamellar lamellar crystal structure is that of a structure that exists as an island-like phase having a closed interface (boundary between phases) in a matrix part that is a lamellar lamellar crystal structure (ie, a matrix that is a continuous phase). Part)).

(External additive particles, lubricant)
The toner for developing an electrostatic charge image according to the present invention may include external additive particles in addition to the toner particles described above. The external additive particles are not particularly limited, but inorganic fine particles having a number average primary particle size of about 2 to 800 nm are preferable. As the external additive particles, conventionally known external additive particles can be used. Examples of such external additive particles include inorganic oxide fine particles such as silica fine particles, alumina fine particles, and titania fine particles, inorganic stearate compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, or titanic acid. Examples thereof include fine particles of inorganic titanate compounds such as strontium and zinc titanate. These can be used individually by 1 type or in combination of 2 or more types. These inorganic fine particles are preferably subjected to a gloss treatment with a silane coupling agent, a titanium coupling agent, a higher fatty acid, a silicone oil or the like in order to improve heat-resistant storage stability and environmental stability.

  In addition to the toner particles described above, the toner for developing an electrostatic charge image according to the present invention can use a lubricant to further improve the cleaning property and the transfer property. For example, there are metal salts of higher fatty acids as follows. That is, salts of zinc stearate, aluminum, copper, magnesium, calcium, etc., zinc oleate, salts of manganese, iron, copper, magnesium, etc., zinc palmitate, salts of copper, magnesium, calcium, etc., linoleic acid And salts of zinc and calcium of ricinoleic acid.

  The addition amount of the external additive particles and the lubricant other than the toner particles is preferably in the range of 0.1 to 10.0 parts by mass with respect to 100 parts by mass of the toner.

(Toner glass transition point)
The glass transition point (Tg) of the toner for developing an electrostatic charge image according to the present invention is preferably 25 to 65 ° C., more preferably 35 to 55 ° C. When the glass transition point of the toner of the present invention is in the above range, sufficient low-temperature fixing property and heat-resistant storage property (and powder fluidity) can both be obtained. The glass transition point of the toner is measured in the same manner as described above except that the toner is used as a measurement sample.

(Toner particle size)
The average particle diameter of the toner for developing an electrostatic charge image according to the present invention is preferably 3 to 8 μm, and more preferably 4 to 7.5 μm, for example, on a volume basis median diameter. This average particle diameter can be controlled by the concentration of the coagulant used in the production, the amount of the organic solvent added, the fusing time, the composition of the binder resin (binder resin), and the like. When the volume-based median diameter is in the above range, a very small dot image of 1200 dpi level can be faithfully reproduced. The volume-based median diameter of the toner is measured and calculated using a measuring apparatus in which a computer system equipped with data processing software “Software V3.51” is connected to “Multisizer 3” (manufactured by Beckman Coulter). Is. Specifically, 0.02 g of a measurement sample (toner) is mixed with 20 mL of a surfactant solution (for example, a neutral detergent containing a surfactant component with pure water for the purpose of dispersing toner particles including external additive particles in pure water. After adding to the diluted surfactant solution), ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion, and this toner dispersion is added to “ISOTON II” (Beckman Coulter, Inc.) in the sample stand. Pipette into the beaker containing the product until the displayed concentration of the measuring device is 8%. Here, a reproducible measurement value can be obtained by setting the concentration range. In the measuring apparatus, the measurement particle count number is 25000, the aperture diameter is 100 μm, and the frequency value is calculated by dividing the range of 2 to 60 μm, which is the measurement range, into 256 parts. % Particle diameter is defined as the volume-based median diameter.

(Average circularity of toner)
In the toner for developing an electrostatic charge image according to the present invention, the individual toner particles constituting the toner have an average circularity from the viewpoints of stability of charging characteristics, powder fluidity, and low-temperature fixability. 0.930 to 1.000 is preferable, and 0.950 to 0.995 is more preferable. When the average circularity is within the above range, the individual toner particles are less likely to be crushed, the contamination of the frictional charge imparting member is suppressed, the toner chargeability is stabilized, and the image quality of the formed image is high. It will be a thing. The average circularity of the toner is a value measured using “FPIA-2100” (manufactured by Sysmex). Specifically, the measurement sample (toner) was blended with an aqueous solution containing a surfactant, dispersed by performing ultrasonic dispersion for 1 minute, and then subjected to measurement conditions HPF by “FPIA-2100” (manufactured by Sysmex). In the (high magnification imaging) mode, images are taken at an appropriate density of 3,000 to 10,000 HPF detections, and the circularity of each toner particle is calculated according to the following formula, and the circularity of each toner particle is added. And a value calculated by dividing by the total number of toner particles. If the number of HPF detections is in the above range, reproducibility can be obtained.

<Toner production method>
<Method for producing toner particles>
The toner particles of the present invention can be produced, for example, by an emulsion aggregation method. The production method when the toner particles of the present invention are produced by the emulsion aggregation method includes, for example, adding a dispersion liquid (a) containing amorphous resin fine particles and a dispersion liquid (b) containing crystalline resin fine particles to an aqueous medium. Preparing a mixed dispersion, and heating the mixed dispersion to agglomerate the amorphous resin particles and the crystalline resin particles to form toner particles. Further, toner particles having a core-shell structure can be obtained by using the toner particles as a core and providing a shell layer on the surface thereof. By adopting the core-shell structure, the heat-resistant storage property and the low-temperature fixability, and further the powder fluidity can be further improved. In the present specification, the “aqueous medium” refers to a medium containing at least 50% by mass of water, and examples of components other than water include organic solvents that dissolve in water. For example, methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, dimethylformamide, methyl cellosolve, tetrahydrofuran and the like can be mentioned. Among these, it is preferable to use an organic organic solvent such as methanol, ethanol, isopropanol, and butanol, which is an organic solvent that does not dissolve the resin. Preferably, only water is used as the aqueous medium.

  The said manufacturing method can be comprised as what includes each following process, for example. Here, the following examples describe the case where the toner particles contain an amorphous resin, a crystalline resin, a release agent, and a colorant, and the technical scope of the present invention is in these forms. It is not limited to.

  (1) A step of preparing an amorphous resin dispersion (a) for preparing an aqueous dispersion (a) containing amorphous resin fine particles is performed.

  (2) Crystalline resin fine particles by dissolving a crystalline resin (preferably a crystalline polyester resin, more preferably a hybrid crystalline polyester resin) in an organic solvent, emulsifying and dispersing in an aqueous dispersion medium, and removing the organic solvent. The crystalline resin dispersion (b) is prepared by preparing an aqueous dispersion (b) containing.

  (3) A step of preparing the release agent dispersion (c) is performed, in which an aqueous dispersion (c) containing release agent fine particles is prepared.

  (4) A step of preparing the colorant dispersion (d) is performed to prepare the aqueous dispersion (d) containing the colorant fine particles.

  (5) Amorphous resin dispersion (a) “a1” parts by mass (solid content conversion), crystalline resin dispersion (b) “b1” parts by mass (solid) prepared in (1) to (4) above Component conversion), release agent dispersion (c) “c1” parts by mass (solids conversion), and colorant dispersion (d) “d1” parts by mass (solids conversion) are added to the aqueous medium to form a mixed dispersion. The step of preparing the mixed dispersion for area B is performed. Here, each of the input amounts “a1” to “d1” is controlled to be within a range satisfying the area ratio of the crystalline resin and the release agent in the area B of the toner particles of the present invention as defined above. (Control)

  (6) The mixed dispersion prepared in (5) above is heated to agglomerate and associate the amorphous resin fine particles and the crystalline resin fine particles to form associated particles having a volume-based median particle size [e1]. An associated particle forming step corresponding to area B is performed. Here, the volume-based median particle diameter [e1] of the associated particles may be controlled so as to have the volume-based median particle diameter of the area B of the toner particles of the present invention as defined above.

  (7) Amorphous resin dispersion (a) “a2” parts by mass (in terms of solid content) prepared in the above (1) to (4) in the dispersion containing the associated particles of (6) above, crystallinity Resin dispersion (b) “b2” parts by mass (solid content conversion), release agent dispersion (c) “c2” parts by mass (solid content conversion), Colorant dispersion (d) “d2” parts by mass (solid) The step of preparing a mixed dispersion for area B + C is performed, in which a mixed dispersion is prepared by adding (minute conversion). Here, each of the input amounts “a2” to “d2” is controlled to be within a range satisfying the area ratio of the crystalline resin and the release agent in the area C of the toner particles of the present invention as defined above. (Control)

  (8) The mixed dispersion prepared in (7) above is heated to agglomerate and associate the amorphous resin fine particles and the crystalline resin fine particles to form associated particles having a volume-based median particle size [e2]. An associated particle (= associated particle excluding area A) forming step corresponding to area B + C is performed. Here, the volume-based median particle size [e2] of the associated particles may be controlled so as to have the volume-based median particle size of the area B + C of the toner particles of the present invention defined above.

  (9) Amorphous resin dispersion (a) “a3” parts by mass (in terms of solid content) prepared in the above (1) to (4) in the dispersion containing the associated particles of (8) above, crystallinity Resin dispersion (b) “b3” parts by mass (solid content conversion), release agent dispersion (c) “c3” parts by mass (solid content conversion), colorant dispersion (d) “d3” parts by mass (solids) The step of preparing a mixed dispersion for area B + C + A (= toner particles) is prepared by adding a component). Here, each of the input amounts “a3” to “d3” is controlled so as to be within a range satisfying the area ratio of the crystalline resin and the release agent in the area A of the toner particles of the present invention defined above. (Control)

  (10) The mixed dispersion prepared in (9) above is heated to agglomerate and associate the amorphous resin particles and the crystalline resin particles to form associated particles having a volume-based median particle size [e3]. An associated particle (= associated particle of toner particles) forming step corresponding to the area B + C + A is performed. Here, the volume-based median particle size [e3] of the associated particles may be controlled so as to have the volume-based median particle size of the toner particles of the present invention defined above.

  (11) An aging step is carried out to obtain toner particles whose shape is controlled by aging the aggregated particles formed in (10) above by thermal energy.

  (12) A cooling step of cooling the toner particle dispersion is performed.

  (13) A filtration / washing process is performed in which the toner particles are separated from the aqueous medium, and the surfactant and the like are removed from the toner particles.

  (14) A drying step of drying the washed toner particles is performed.

  As described above, the toner particles of the present invention can include those consisting of the steps (11) to (14) that can be added to the essential steps (1) to (10) as necessary. Preferably, the steps (1) to (14) are preferably performed. Note that the order of the steps (1) to (4) is not limited at all, and may be performed in any order or simultaneously.

  In carrying out the above-described steps, conventionally known knowledge can be referred to as appropriate. For example, the dispersion liquid (a) containing the amorphous resin fine particles described above, the dispersion liquid (b) containing the crystalline resin fine particles, the dispersion liquid (c) containing the release agent fine particles, and the dispersion liquid (d) containing the colorant fine particles (d) In particular, the dispersion liquid (a) containing amorphous resin fine particles and the dispersion liquid (b) containing crystalline resin fine particles are prepared using various emulsification methods such as a method of emulsifying by mechanical shearing force. However, it is preferable to prepare using a method called a phase inversion emulsification method. In particular, with respect to the dispersion (b), by using a dispersion prepared by a phase inversion emulsification method, there is an advantage that a dispersion that is monodispersed and has a small particle diameter and that is suitable for introduction into a toner can be obtained. In the “phase inversion emulsification method”, a resin is dissolved in an organic solvent to obtain a resin solution, a neutralization step in which a neutralizer is added to the resin solution, and the neutralized resin solution is dispersed in an aqueous system. By passing through an emulsification step of emulsifying and dispersing in a medium to obtain a resin emulsion, and a desolvation step of removing the organic solvent from the resin emulsion, a dispersion of resin fine particles is obtained. The particle size of the resin fine particles in the dispersion can be controlled by changing the amount of neutralizing agent added.

<Method for producing toner for developing electrostatic image>
(External additive addition process)
The external additive adding step is a step of preparing an electrostatic image developing toner by adding and mixing the external additive particles to the dried toner particles. Examples of the method for adding the external additive include a dry method in which the external additive is added in powder form to the dried toner particles, and examples of the mixing device include mechanical mixing devices such as a Henschel mixer and a coffee mill. .

<Developer for developing electrostatic image>
The toner for developing an electrostatic image according to the present invention can be used as a magnetic or non-magnetic one-component developer, but may be mixed with a carrier and used as a two-component developer. In the case where the toner for developing an electrostatic image is used as a two-component developer, the carrier may be a conventionally known material such as a metal such as iron, ferrite, or magnetite, or an alloy of such a metal with a metal such as aluminum or lead. In particular, ferrite particles are preferable. As the carrier, a coated carrier in which the surface of magnetic particles is coated with a coating agent such as a resin, a dispersion type carrier in which magnetic fine powder is dispersed in a binder resin, or the like may be used.

  The volume-based median diameter of the carrier is preferably 20 to 100 μm, more preferably 25 to 80 μm. The volume-based median diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

  The “(toner for developing electrostatic image)” according to the present invention contains “toner particles” as described above. The “toner particles” are referred to as “toner (for electrostatic image development)” by adding external additive particles. “Toner for (electrostatic image development)” refers to an aggregate of toner particles (innumerable) containing external additive particles.

<Electrophotographic image forming method>
The developer for developing an electrostatic charge image according to the present invention can be used in various known electrophotographic image forming methods. For example, it can be used in a monochrome image forming method or a full color image forming method. In the full-color image forming method, four types of color developing devices for yellow, magenta, cyan, and black, and one electrostatic charge image carrier (also referred to as “electrophotographic photoreceptor” or simply “photoreceptor”). 4 cycle type image forming method and tandem type image forming method in which a color developing device for each color and an image forming unit having an electrostatic charge image carrier are mounted for each color. Methods can also be used.

  Specifically, as the electrophotographic image forming method, the electrostatic charge image developing developer according to the present invention is used, for example, the electrostatic charge image carrier is charged with a charging device (charging process), and image exposure is performed. The electrostatic image formed electrostatically (exposure process) is developed by charging the toner with a carrier in the developer for developing an electrostatic image according to the present invention and developing the image in the developing device. To obtain a toner image (development process). Then, the toner image is transferred to a sheet (transfer process), and then the toner image transferred onto the sheet is fixed on the sheet (fixing process) by a contact heating type fixing process to obtain a visible image.

  Examples of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

[Synthesis of Crystalline Polyester Resin [1]]
The following raw material monomers for the polycondensation resin were placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and heated to 170 ° C. to dissolve.

-278 mass parts of sebacic acid-280 mass parts of dodecanediol.

Thereafter, 0.8 part by mass of Ti (OBu) ₄ was added as an esterification catalyst, the temperature was raised to 235 ° C., and the reaction was performed for 5 hours under normal pressure (101.3 kPa) and further for 1 hour under reduced pressure (8 kPa). went.

  Next, after cooling to 200 ° C., the reaction was performed under reduced pressure (20 kPa) for 1 hour to obtain a crystalline polyester resin [1]. The obtained crystalline polyester resin [1] had a number average molecular weight (Mn) of 5,000 and a melting point of 78 ° C.

[Synthesis of Hybrid Crystalline Polyester Resin [2]]
The following raw material monomers for addition polymerization resin, both reactive monomers and a radical polymerization initiator were placed in a dropping funnel.

-Styrene 35 mass parts-Butyl acrylate 9 mass parts-Acrylic acid 4 mass parts-Polymerization initiator (di-t-butyl peroxide) 7 mass parts.

  Moreover, the following raw material monomers for the polycondensation resin were placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and heated to 170 ° C. to be dissolved.

-278 mass parts of sebacic acid-280 mass parts of dodecanediol.

Next, the raw material monomer of the addition polymerization resin was added dropwise over 90 minutes with stirring, and after aging for 60 minutes, the unreacted addition polymerization monomer was removed under reduced pressure (8 kPa). Thereafter, 0.8 part by mass of Ti (OBu) ₄ was added as an esterification catalyst, the temperature was raised to 235 ° C., and the reaction was performed for 5 hours under normal pressure (101.3 kPa) and further for 1 hour under reduced pressure (8 kPa). went.

  Next, after cooling to 200 ° C., a hybrid crystalline polyester resin [2] was obtained by reacting under reduced pressure (20 kPa) for 1 hour. The obtained hybrid crystalline polyester resin [2] had a number average molecular weight (Mn) of 4,000 and a melting point of 75 ° C.

[Preparation of aqueous dispersion [x1] of crystalline polyester resin fine particles]
30 parts by mass of the crystalline polyester resin [1] was melted and transferred in a molten state to the emulsification disperser “Cavitron CD1010” (manufactured by Eurotech Co., Ltd.) at a transfer rate of 100 parts by mass. Simultaneously with the transfer of the crystalline polyester resin [1] in the molten state, 70 mass parts of reagent ammonia water was diluted with ion-exchanged water in an aqueous solvent tank with respect to the emulsifying disperser, and the concentration was 0.37 mass%. The diluted ammonia water was transferred at a transfer rate of 0.1 liter per minute while being heated to 100 ° C. with a heat exchanger. Then, by operating this emulsification disperser under the conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² , the volume-based median particle size is 200 nm and the solid content is 30 parts by mass (30% by mass in the dispersion). Aqueous dispersion [x1] of crystalline polyester resin fine particles (1) was prepared.

[Preparation of aqueous dispersion [x2] of crystalline polyester resin fine particles]
30 parts by mass of the hybrid crystalline polyester resin [2] was melted and transferred to the emulsification disperser “Cavitron CD1010” (manufactured by Eurotech) at a transfer rate of 100 parts by mass per minute. Simultaneously with the transfer of the hybrid crystalline polyester resin [2] in the molten state, 70 mass parts of reagent ammonia water was diluted with ion-exchanged water in an aqueous solvent tank with respect to the emulsifying disperser, and the concentration was 0.37 mass. % Dilute aqueous ammonia was transferred at a transfer rate of 0.1 liter per minute while being heated to 100 ° C. with a heat exchanger. Then, by operating this emulsification disperser under the conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² , the volume-based median particle size is 200 nm and the solid content is 30 parts by mass (30% by mass in the dispersion). Aqueous dispersion [x2] of crystalline polyester resin fine particles (1) was prepared.

[Preparation of aqueous dispersion of amorphous resin fine particles]
A reaction vessel equipped with a stirrer, a temperature sensor, a condenser, and a nitrogen introducing device was charged with 8 parts by mass of sodium dodecyl sulfate and 2983 parts by mass of ion-exchanged water, and the internal temperature was increased while stirring at a stirring speed of 230 rpm under a nitrogen stream. The temperature was raised to 80 ° C. After raising the temperature, 10 parts by mass of potassium persulfate dissolved in 200 parts by mass of ion-exchanged water was added, and the liquid temperature was again set to 80 ° C.
Styrene 544 parts by mass n-butyl acrylate 188 parts by mass methacrylic acid 85 parts by mass n-octyl mercaptan 7 parts by mass of a monomer mixture dropwise over 1 hour and then heated at 80 ° C for 2 hours, After the polymerization by stirring, the mixture was cooled to 20 ° C. to prepare an aqueous dispersion of amorphous resin fine particles made of vinyl resin.

  With respect to the obtained aqueous dispersion of amorphous resin fine particles, the volume-based median particle size of the amorphous resin fine particles is 200 nm, the glass transition point (Tg) is 55 ° C., and the weight average molecular weight (Mw) is 32,000. there were.

(Preparation of release agent dispersion)
-Behenyl behenate (melting point 73 ° C) 200 parts by mass-Sodium dodecyl sulfate 20 parts by mass-Ion-exchanged water 2200 parts by mass.

  A solution in which the above components are mixed is heated to 95 ° C. and sufficiently dispersed with IKA Ultra Turrax T50, and then dispersed with a pressure discharge type gorin homogenizer to disperse a release agent having a volume-based median particle size of 100 nm. A liquid was prepared.

[Preparation Example of Aqueous Dispersion of Colorant Fine Particles [Bk]]
90 parts by mass of sodium dodecyl sulfate was added to 1600 parts by mass of ion-exchanged water. While stirring this solution, 420 parts by mass of carbon black “Regal 330R” (Cabot Corp.) is gradually added, and then dispersed using a stirring device “Cleamix” (M Technique Corp.). An aqueous dispersion [Bk] of fine colorant particles was prepared.

  With respect to the aqueous dispersion [Bk] of the obtained colorant fine particles, the average particle size (volume-based median particle size) of the colorant fine particles was 110 nm.

[Example 1: Production example of black toner [1] and developer [1] using the same]
In a reaction vessel equipped with a stirrer, a temperature sensor, and a cooling pipe, an aqueous dispersion “a1” of amorphous resin fine particles (solid content), an aqueous dispersion of crystalline polyester resin fine particles [x1] “b1” 5 parts by weight (solid content conversion), release agent dispersion “c1” mass part (solid content conversion), aqueous dispersion of colorant fine particles [Bk] “d1” (solid content conversion) The pH was adjusted to 10 by adding a mol / liter aqueous sodium hydroxide solution. Here, the input amounts “a1” to “d1” in Example 1 are all as shown in Table 1 below.

  Next, an aqueous solution in which 60 parts by mass of magnesium chloride was dissolved in 60 parts by mass of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. The temperature was started, the system was heated to 80 ° C. over 60 minutes, the particle size of the associated particles was measured with “Coulter Multisizer 3” (manufactured by Coulter Beckman), and the volume-based median particle size The stirring speed was controlled so that (the diameter of area B) was [e1] μm. The volume-based median particle size (area B diameter) [e1] of the associated particles of Example 1 is as shown in Table 1 below.

  Thereafter, an aqueous dispersion of amorphous resin fine particles “a2” by mass (solid content conversion), an aqueous dispersion of crystalline polyester resin fine particles [x1] “b2” by mass (solid content conversion), a release agent dispersion “C2” parts by mass (converted to solid content) and an aqueous dispersion of colorant fine particles [Bk] “d2” by weight (converted to solids) were added, and stirring was continued while maintaining the temperature. “Coulter Multisizer 3 ”(Manufactured by Coulter Beckman), the particle size of the associated particles was measured, and when the volume-based median particle size (diameter excluding area A) reached [e2] μm, the amorphous resin fine particles Aqueous dispersion “a3” parts by mass (solid content), crystalline polyester resin fine particle aqueous dispersion [x1] “b3” parts by mass (solids equivalent), release agent dispersion “c3” parts by mass (solids) Conversion), aqueous dispersion of colorant fine particles [Bk] d3 "parts by weight (in solid equivalent) was added. Here, each of the addition amounts “a2” to “d2” and “a3” to “d3” in Example 1 are as shown in Table 1 below. The volume-based median particle size (diameter excluding area A) [e2] of Example 1 is as shown in Table 1 below.

  Thereafter, stirring was further continued, and when the volume-based median particle size (toner particle size) of the associated particles reached [e3] μm, an aqueous solution in which 190 parts by mass of sodium chloride was dissolved in 760 parts by mass of ion-exchanged water was obtained. Addition to stop grain growth. Further, the temperature is raised and the particles are fused by heating and stirring at 80 ° C., and the average circularity measuring device “FPIA-2100” (manufactured by Sysmex) is used (HPF detection). When the average circularity reached 0.945, it was cooled to 30 ° C. at a cooling rate of 2.5 ° C./min. Here, the volume-based median particle diameter (toner particle diameter) [e3] of the associated particles of Example 1 is as shown in Table 1 below. That is, the volume-based median particle size of the toner particles is the same as the volume-based median particle size [e3] of the associated particles in the example = then, the particle fusion proceeds, and the average circularity of the toner is 0.945. It is the same as the particle size of the toner particles.

  Next, the operation of solid-liquid separation and re-dispersing the dehydrated toner cake in ion-exchanged water and solid-liquid separation was washed three times, and then dried at 40 ° C. for 24 hours, whereby black toner particles [1X] were obtained. Obtained.

  To 100 parts by mass of the obtained black toner particles [1X], 0.6 part by mass of hydrophobic silica (number average primary particle size = 12 nm, degree of hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle size = 20 nm). Hydrophobic degree = 63) 1.0 part by mass was added, and after mixing for 20 minutes at 32 ° C. with a rotating blade peripheral speed of 35 mm / sec by “Henschel mixer” (manufactured by Mitsui Miike Chemical Co., Ltd.), an opening of 45 μm A toner [1] was produced by applying an external additive treatment to remove coarse particles using a sieve of No. 1.

  A developer [1] was produced by adding and mixing a ferrite carrier having a volume average particle diameter of 60 μm coated with a silicone resin so as to have a toner concentration of 6% by mass with respect to the toner [1].

[Examples 2 to 10 and Comparative Examples 1 and 2: Black toner [2] to [10], [12] to [13] and developers [2] to [10], [12] to [13] Production Example]
The input amounts “a1” to “d1”, “a2” to “d2” and “a3” to “d3” of Example 1 and the volume-based median particle sizes [e1] to [e3] of each associated particle Instead, the input amounts “a1” to “d1”, “a2” to “d2” and “a3” to “d3” in Examples 2 to 10 and Comparative Examples 1 and 2 shown in Table 1 below, and each meeting Black toners [2] to [10], [12] to [13] and the same are used in the same manner as in Example 1 except that the volume-based median particle size [e1] to [e3] is used. Developers [2] to [10] and [12] to [13] were produced.

[Example 11: Production example of black toner [11] and developer [11] using the same]
In Example 11, instead of the aqueous dispersion [x1] of the crystalline polyester resin fine particles used in Example 1, an aqueous dispersion [x2] of the crystalline polyester resin fine particles was used. In place of “a1” to “d1”, “a2” to “d2”, “a3” to “d3”, and volume-based median particle sizes [e1] to [e3] of each associated particle, Each input amount “a1” to “d1”, “a2” to “d2” and “a3” to “d3” of Example 11 shown, and the volume-based median particle size [e1] to [e3] of each associated particle A black toner [11] and a developer [11] using the same were produced in the same manner as in Example 1 except that was used.

(Measurement method of area ratio of crystalline resin and release agent of toner cross section stained with ruthenium)
The area ratio of the crystalline resin and the release agent on the cross section of the toner particles stained with ruthenium was measured according to the following procedures 1 to 4. The obtained results are shown in Table 2.

1. Preparation Method of Toner Particle Section After the toner particles obtained in Examples 1 to 11 and Comparative Examples 1 and 2 were exposed for 10 minutes in a ruthenium tetroxide (RuO ₄ ) vapor atmosphere, the photocurable resin “D- 800 ”(manufactured by JEOL Ltd.) and then photocured to form a block. Next, using a microtome equipped with diamond teeth, a flaky sample having a thickness of about 60 nm to 100 nm was cut out from the above block and placed on a grid with a support film for transmission electron microscope observation. A filter paper was laid on a 5 cmφ plastic petri dish, and a grid on which the slice was placed was placed thereon with the surface on which the slice was placed facing up.

2. Ruthenium tetroxide dyeing conditions The dyeing conditions (time, temperature, and concentration and amount of the dye) are different from each resin (mainly amorphous resin, crystalline resin, and release agent) when observed with a transmission electron microscope. The conditions were adjusted to be possible. For example, 2 to 3 drops of 0.5 mass% RuO ₄ staining solution was dropped on two points in the petri dish, covered, and after 10 minutes, the petri dish lid was removed and left until the water in the staining solution was free of moisture.

3. Toner particle cross-section observation method (conditions)
Apparatus: Transmission electron microscope “JEM-2000FX” (manufactured by JEOL Ltd.)
Sample: A section of toner particles stained with ruthenium tetroxide (RuO ₄ ) (section thickness of about 60 nm to 100 nm)
-Magnification: 10,000 times.

4). Analysis of cross-sectional image of toner particles First, an image obtained by cross-sectional observation is divided into an area (area A) of 0.3 μm from the toner particle surface and an area (area B) of (Y) μm or more from the toner particle surface. did.

  Here, (Y) = 0.15 × (X) +0.3 (μm) is satisfied, and (X) is a volume-based toner particle obtained by “Coulter Multisizer 3” (manufactured by Coulter Beckman). The median particle size (D50) (μm).

  In addition, the crystalline resin (crystalline polyester resin or hybrid crystalline polyester resin) and the release agent were determined from the contrast and shape in the toner particles. A rod-like or lump-like one is a release agent, and a crystal dispersed in a non-crystalline resin of toner particles with a linear, needle-like, or lamellar crystal structure (lamellar layer shape) is judged as a crystalline resin ( (See FIG. 1). In contrast, a whiter contrast portion was determined as a release agent. Binder resins (non-crystalline resins, crystalline resins) other than mold release agents have many double bond parts and are dyed with ruthenium tetroxide, so the mold release part and resin parts other than the mold release agent are distinguished. it can. That is, the release agent is dyed lightest by ruthenium dyeing, then the crystalline resin (crystalline polyester resin) is dyed, and the amorphous resin (amorphous polyester resin) is dyed most intensely. The analysis is an average value performed on the cross section of 20 toner particles. Here, the layered lamellar crystal structure is as defined above. The cross-sectional area of the lamellar lamellar crystal structure is that of a structure that exists as an island-like phase having a closed interface (boundary between phases) in a matrix part that is a lamellar lamellar crystal structure (ie, a matrix that is a continuous phase). Part)).

  CPes in Table 2 is an abbreviation for crystalline polyester resin. Moreover, [%] in each column of the presence position of the crystalline resin and the presence position of the release agent represents [area%]. Wax (wax) in each column of the location of the release agent is synonymous with the release agent. In the crystalline resin type column, “Presence / absence of compounding” is set to “Yes” when a compounded hybrid crystalline polyester resin is used as the crystalline resin, and the hybrid crystallinity accounting for the entire binder resin. The content ratio of the polyester resin is shown in parentheses as a composite rate (%). In addition, when the hybrid crystalline polyester resin compounded as the crystalline resin is not used, it is “None”. Further, “toner volume-median particle size” refers to the volume-based median particle size of toner particles.

[Evaluation method]
(1) Evaluation of low-temperature fixability In the copying machine “bizhub PRESS C1070” (manufactured by Konica Minolta Co., Ltd.), the surface temperature (fixing temperature) of the heating roller can be changed within the range of 120 to 200 ° C. The developers [1] to [13] obtained as described above were loaded into the remodeled parts as described above.

A solid image with a toner adhesion amount of 8 mg / cm ² is fixed on A4 size high-quality paper “CF paper” (manufactured by Konica Minolta Co., Ltd.) in an environment of normal temperature and humidity (temperature 20 ° C., humidity 50% RH). The fixing experiment was repeated up to 200 ° C. while changing the set fixing temperature from 120 ° C. in increments of 5 ° C.

  Among fixing experiments in which image peeling due to low-temperature offset is not visually observed, the fixing temperature of the fixing experiment relating to the lowest fixing temperature was evaluated as the minimum fixing temperature. Table 3 shows the minimum fixing temperature obtained. Those having a minimum fixing temperature of 150 ° C. or lower are determined to be acceptable for low-temperature fixability. A toner having a temperature of 150 ° C. or lower was regarded as acceptable for low-temperature fixability, but it can be determined that a toner having a lower minimum fixing temperature has better low-temperature fixability.

(2) Evaluation of bendability of image The printed matter obtained in the fixing experiment relating to each fixing temperature in the low temperature fixability evaluation described above is folded by a folding machine so as to apply a load to the solid image, and compressed to 0.35 MPa. Air was blown, the limit sample was referred to, and the folds were ranked in five stages shown in the following evaluation criteria, and the fixing temperature in the fixing experiment of rank 3 was defined as the lower limit fixing temperature. The obtained lower limit fixing temperature is shown in Table 3.

  When the temperature reaching the rank 3 (lower limit fixing temperature) is within + 20 ° C. from the minimum fixing temperature according to the low temperature fixing property evaluation, it is determined that the image bendability is acceptable.

-Evaluation criteria for image bendability-
Rank 5: No crease.

  Rank 4: There is peeling according to some creases.

  Rank 3: There is fine linear peeling according to the crease.

  Rank 2: There is a thick linear peeling according to the crease.

  Rank 1: There is large peeling.

(3) Evaluation of image quality (toner scattering / fogging and image density reduction) A commercially available copying machine bizhub PRESS C1070 (manufactured by Konica Minolta Co., Ltd.) is used as an image forming apparatus, and the developer obtained above is used as a developer. Each of [1] to [13] is mounted, and 100,000 character images with a printing rate of 10% are continuously printed on high-quality A4 size paper in a high-temperature and high-humidity environment (temperature 30 ° C., humidity 80% RH). After printing, test images including white images, halftone images, and solid images are printed, image roughness of fog and halftone images and image density of solid images are observed, and judged according to the following evaluation criteria. An unacceptable level (greater than Δ) was accepted for image quality (toner scattering / fogging and image density reduction). The results determined according to the following evaluation criteria are shown in Table 3.

-Evaluation criteria for image quality (toner scattering, fogging and image density reduction)-
A: Image density reduction, image roughness, and fog are not visually observed.

  ○: Image density reduction, image roughness, and / or fog are slightly observed with a 20-fold magnifier, but there is no practical problem.

  (Triangle | delta): Image density fall, image roughness, and / or fog are observed visually, but a level which does not have a problem in practical use.

  X: Level at which image density reduction, image roughness, and fog are visually observed and have practical problems.

(4) Evaluation of Fixing Separation The commercially available copying machine bizhub PRESS C1070 (manufactured by Konica Minolta Co., Ltd.) is used as an image forming apparatus, and the developers [1] to [13] obtained above are used as developers. Amount of toner adhering on A4-sized coated paper “OK Top Coat (105 g / m ² )” (manufactured by Oji Paper Co., Ltd.) in an environment of normal temperature and humidity (temperature 20 ° C., humidity 50% RH). A fixing experiment for fixing a solid image of 8 mg / cm ² was carried out in the same manner as the procedure of “-Evaluation of low-temperature fixing property”, and at the fixing temperature of + 10 ° C. from the minimum fixing temperature confirmed, the leading edge was set from the setting of the copying machine. The margin was increased from 0 mm to 1 mm, and the fixing separation property was evaluated by setting the shortest leading margin that does not cause defective discharge due to the winding of the image to the fixing device as the separating leading margin.

  The results determined according to the following evaluation criteria are shown in Table 3.

−Evaluation criteria for separable tip margin−
○: Separable tip margin is 3 mm or less, which is a practically sufficient level.

  Δ: Separable tip margin 4 to 7 mm, practically no problem.

  ×: Separable tip margin of 8 mm or more, practically problematic level.

  From the results shown in Tables 1 to 3, the toner and developer using the toner particles of Examples 1 to 11 have a low temperature fixability as compared with the toner and developer using the toner particles of Comparative Examples 1 and 2. It was confirmed that the image was more excellent (the minimum fixing temperature was lower) and excellent in both the bendability of the image and the image quality (toner scattering / fogging and image density reduction). That is, by controlling (controlling) the amount and location of the crystalline resin in the toner particles as well as the release agent, it is possible to achieve both low-temperature fixability of the toner and fluidity of the powder. It has been found that an electrostatic charge image developing toner that can be fixed at a low temperature while suppressing deterioration and a decrease in the bending strength of the image can be provided.

  Further, in Examples 1 to 11, compared with Examples 1 and 2 in which the crystalline resin at a position (area A) within 0.3 μm from the toner particle surface is in the range of 10 to 20% by area, In Examples 3 to 11 in which the crystalline resin of A is 10 area% or less, sufficient powder flowability of the toner without causing image defects can be secured, and toner scattering / fogging and image density reduction can be achieved. It was found that the image quality performance is less and less.

  Further, the vicinity of the center of the toner particle, which is less effective for low-temperature fixing, more specifically, the crystalline resin at a position (area B) of (Y) μm or more from the surface of the toner particle is made 30 area% or less, so Example 4 in which the crystalline resin between the area A and the area B is 80 area% or more as compared with Examples 1 to 3 in which the crystalline resin in the vicinity (area B) is 55 to 76 area%. In -11, the minimum fixing temperature is lower, the low-temperature fixing property is more excellent, the lower limit fixing temperature is lower, and the bending strength of the image after fixing is also excellent.

  Furthermore, compared with Examples 1 to 3 in which the crystalline resin in area A is 10 to 20 area% or the crystalline resin in area B is 20 to 30 area%, the crystalline resin in area A is 10 area% or less and In Examples 4 to 11 in which the area B crystalline resin is 20 area% or less, the minimum fixing temperature is lower, the low-temperature fixing property is more excellent, the lower limit fixing temperature is lower, and the image after fixing is bent. It can be seen that the strength is excellent and the image quality is also excellent.

  Furthermore, among Examples 4 to 11 in which the area A crystalline resin was 10 area% or less and the area B crystalline resin was 20 area% or less, the amount and location of the release agent were controlled. In Examples, specifically, Examples 8 to 11 in which the release agent present in area A is 10 area% or less and the release agent present in area B is 64 area% or more, the minimum fixing temperature is lower. It can be seen that the low-temperature fixability is more excellent, the lower limit fixing temperature is lower, the folding strength of the image after fixing is better, and the image quality is extremely excellent.

  Furthermore, the area A crystalline resin is 10 area% or less, the area B crystalline resin is 20 area% or less, and the mold release agent present in the area A is 10 area% or less and is present in the area B. Among Examples 8 to 11 in which the release agent is 64% by area or more, Example 11 using a hybrid crystalline polyester resin as the crystalline resin has the lowest minimum fixing temperature and the best low-temperature fixing property. The lower limit fixing temperature is the lowest, the folding strength of the image after fixing is the highest, and the image quality is extremely excellent.

10 Toner particles of the present invention,
11 crystalline resin,
12 Amorphous resin,
13 mold release agent,
20 conventional toner particles,
21 crystalline resin (crystalline polyester resin),
22 Amorphous resin,
A Area A,
B Area B,
C Area C,
D Area (area D) within 1 μm from the toner particle surface,
E Area E.

Claims (5)

An electrostatic charge image developing toner comprising toner particles containing at least an amorphous resin and a crystalline resin,
In the cross section of the ruthenium-dyed toner particles, the crystalline resin present at a position (area A) within 0.3 μm in the central direction from the toner particle surface with respect to the entire crystalline resin is 20 area% or less, and A toner for developing an electrostatic charge image, wherein the crystalline resin present at a position (area B) of (Y) μm or more satisfying the following formula in the center direction from the surface of the toner particles is 30 area% or less.
Here, (X) in the formula represents the volume-based median particle diameter (μm) of the toner particles.   In the cross section of the toner particles dyed with ruthenium, the crystalline resin present in the area A is 10 area% or less and the crystalline resin present in the area B is 20 area% or less with respect to the entire crystalline resin. The toner for developing an electrostatic charge image according to claim 1, wherein: The toner particles further contain a release agent,
In the cross section of the ruthenium-dyed toner particles, the release agent present in the area A is 10 area% or less and the release agent present in the area B is 64 area% or more with respect to the entire release agent. The electrostatic image developing toner according to claim 1, wherein the toner is for electrostatic image development.   4. The electrostatic image developing toner according to claim 1, wherein the crystalline resin is a resin formed by chemically bonding a polyester polymer segment and a vinyl polymer segment. 5. .   5. The electrostatic charge image developing toner according to claim 1, wherein a volume-based median particle diameter of the toner particles is 3.0 μm or more and 8.0 μm or less.