JP4546856B2 - Method for evaluating toner kneaded material and method for producing toner for electrostatic charge development using the evaluation method - Google Patents

Description

The present invention relates to a toner kneaded product evaluation method and a method for producing an electrostatic charge developing toner using the evaluation method.

The image quality of copiers and printers has been improved, and recently, the reproducibility of fine dots has become very important. The dot reproducibility is greatly influenced by the fluidity in addition to the charge amount of the toner and developer, and the uniform toner layer or developer layer can be stably supplied to the fine latent image portion and transported. Is needed.
Further, as the image quality is improved, the toner used in the toner is becoming smaller in particle size and higher in function. For this reason, the structure of the toner has become complicated, and finer control than before has been required. In particular, since the toner fluidity affects various image qualities in addition to dot reproducibility, it is necessary to evaluate the toner dispersibility without deteriorating the toner fluidity.
In addition, when the toner production method changes from the pulverization method to another method such as a polymerization method, the change in the flow characteristics with respect to the manufacturing conditions is large. Evaluation is required.
On the other hand, carbon black is usually used as a black pigment, but the problem that this material has carcinogenicity has been pointed out, and examination of a material to replace it is urgent. Metal oxides have been examined as candidates. In the case of a metal oxide, since the specific gravity is large, a new evaluation technique is required in terms of dispersibility when a toner is used.
Further, as the toner is fixed at a low temperature and the oil-less fixing is progressed, the toner base composition and structure become complicated, and the fluidity of the toner is greatly affected. Therefore, structural control with higher accuracy than before is required, and accordingly, a highly sensitive dispersibility evaluation method is required.

  In Patent Document 1, which is a conventional technique related to toner dispersibility, the dispersibility of a toner pigment is evaluated by examining the change in absorbance of a toner fixed image on OHP. However, in this evaluation method, it is necessary to create a toner fixed image on the OHP every time, and this has a problem that it depends on fixing conditions. Patent Document 2 discloses that the specific gravity of pellets made of a toner mixed product is measured to evaluate dispersibility. However, in this method, measurement variation is large and resolution is a problem. In Patent Document 3, the inorganic element of the additive is measured using EPMA-WDS, and the dispersibility of the toner is evaluated based on the X-ray intensity ratio from a reference sample. Cannot be evaluated.

  In particular, the dispersibility of the toner has been highlighted as a problem only after the low temperature fixing of the toner and the oilless fixing have started. Regarding such low-temperature fixing, there is an attempt to add a specific non-olefinic crystalline polymer having sharp melt property at a glass transition temperature in a binder (Patent Document 4). There is also an attempt to use crystalline polyester having sharp melt properties (Patent Documents 5 and 6). However, crystalline polyesters that have sharp melt properties at the glass transition temperature, if the product temperature during kneading is equal to or higher than the glass transition temperature, reduce the kneading shear force, dispersibility of the wax and the dispersibility of the crystalline polyester resin itself. It is easy to worsen. In particular, in a full-color toner using a resin having a small elastic component, the deterioration of dispersibility becomes remarkable. Therefore, it becomes easy to produce the problem of the fall of the fluidity by deterioration of a wax dispersibility, and the transparency fall by the deterioration of the dispersibility of crystalline polyester resin. Further, the crystalline polyester resin has a lower pulverization property than the polyester resin having no crystallinity, and the pulverization method has a problem for reducing the particle size.

JP-A-9-204488 Japanese Patent Laid-Open No. Sho 62-156540 JP 2001-109186 A JP 62-63940 A Japanese Patent No. 2931899 JP 2001-222138 A

The first object of the present invention is to develop an evaluation method with high accuracy and no individual difference as a method for evaluating dispersibility, thereby defining the optimum dispersion conditions for toner using metal oxide, This is to enable stable production of toner that can be obtained at any time with low temperature fixing, no problem in toner transportability, and high image quality with good dot reproducibility.
A second object of the present invention is to provide an electrostatic charge developing toner having a low temperature fixability capable of forming a high-quality image with good dot reproducibility obtained by adopting such an evaluation method. .

In the first aspect of the present invention, a toner kneaded material comprising at least a resin and a pigment is irradiated with X-rays (CuKα rays) having a wavelength of 1.54 mm, and 2θ (θ: Bragg angle) = 32.9 ± 0.5 deg. In particular, the present invention relates to a method for evaluating an electrostatic charge developing toner, characterized by measuring the peak integrated intensity of a peak of an X-ray diffraction pattern in (1) and evaluating the dispersibility of the toner kneaded product by the peak integrated intensity.
The second aspect of the present invention relates to the method for evaluating an electrostatic charge developing toner according to claim 1, wherein the toner kneaded product contains Fe oxide and Ti oxide as pigments.
A third aspect of the present invention relates to a method for producing a toner for developing an electrostatic charge, wherein the method for evaluating a toner kneaded product according to claim 1 or 2 is used.

In this evaluation method, the toner kneaded material is irradiated with X-rays (CuKα rays) having a wavelength of 1.54 mm, the X-ray diffraction pattern is measured, and 2θ (θ: Bragg angle) = 32.9 ± 0.5 deg. The dispersibility is evaluated by the difference in the peak integrated intensity of the peaks inside.
Since X-rays are used, it has excellent permeability and is suitable for nondestructive analysis. Therefore, the toner kneaded product itself can be measured without any adjustment. In other words, it is an evaluation method that can be directly applied to a part to be inspected such as a production line.

  The configuration of one specific apparatus used in the evaluation method of the present invention is shown in FIG. First, X-rays are generated from an X-ray tube. The X-ray tube generates electrons by colliding electrons with a target cathode at high speed. As the target cathode material, Cr, Fe, Co, Ni, Cu, Mo, or the like is used. In the present invention, a Cu target having a short wavelength is used. When a Cu target is used, various characteristic X-rays are generated. In the present invention, Kα rays are used. The wavelength at that time is 1.54 mm. X-rays are irradiated onto the sample surface through a slit (divergence slit). X-rays incident on the sample cause a Bragg diffraction phenomenon corresponding to the internal structure of the toner kneaded product, and enter the counter tube as reflected X-rays through slits (receiving slits, scatter slits). Examples of the counter tube include a Geiger counter tube, a proportional counter tube, and a scintillation counter tube. In the present invention, a scintillation counter tube is used. The pulses generated and amplified in the counter tube are processed by a pulse height analyzer and detected by a counter circuit. As the configuration of the apparatus, this method is an example, and other counters and the like may be adopted. The measurement is performed by changing the incident angle to the sample at a low speed (0.5 to 10 deg / min) using a goniometer, and measuring and evaluating the reflected X-ray intensity from the sample (toner kneaded material) at that time.

The sample of the toner kneaded product is measured by fixing the sample directly on the sample table using an adhesive means or the like. The difference in the dispersion state of the sample is measured as a change in the X-ray diffraction peak intensity characteristic at the Bragg angle θ inherent to the sample (corresponding to the structure). As the toner kneaded material sample, one having a smooth surface with no irregularities on the surface, and having no deformation such as curling is suitable. The measurement is performed by changing the scan angle 2θ in the range of 10 deg to 50 deg and measuring the X-ray diffraction intensity. In the present invention, the dispersion state of the metal oxide in the toner kneaded product is examined. The diffraction peak of the metal oxide composed of Fe oxide and Ti oxide appears at 2θ = 32.9 ± 0.5 deg. Therefore, the scan angle 2θ may be measured by narrowing it to a range of 10 deg to 40 deg. The X-ray diffraction peak of the metal oxide composed of Fe oxide and Ti oxide appearing at 2θ = 32.9 ± 0.5 deg depends on the state of dispersion in the resin constituting the toner kneaded product. The X-ray diffraction peak becomes large when the state of dispersion is poor, such as when there is a large lump in some places, and the X-ray diffraction peak becomes small when it is very finely and uniformly dispersed. The evaluation of the size of the X-ray diffraction peak uses the integrated value of the peak. This is because when the peak intensity is used, the variation in data becomes large, causing problems in measurement accuracy and reproducibility. When the peak integrated intensity of the X-ray diffraction peak was used for evaluation, the variation in measurement was small, and stable evaluation could be realized. The measurement may be performed once, but it is more appropriate to repeat the measurement twice or more and evaluate the average. When the sample of the toner kneaded material is thin, X-rays are transmitted and affected by the base of the sample holder, so care must be taken.
However, the measurement system and measurement conditions are not limited to this.

  The toner particles for electrostatic charge development of the present invention require that the toner particles have a weight average particle diameter of 4 to 8 μm in order to realize a high-quality image with good dot reproducibility. The toner particles have a weight average particle diameter of 4 to 8 μm, more preferably 5 to 7 μm. If the weight average particle size is less than 4 μm, problems such as contamination in the machine due to toner particle scattering during long-term use, image density reduction in a low-humidity environment, poor photoconductor cleaning, and the like are likely to occur, and there are concerns about the effects on the human body. When the weight average particle size exceeds 8 μm, the resolution of minute spots of 100 μm or less is not sufficient, and the image quality tends to be inferior due to many scattering to non-image areas.

  The developer using the toner particles needs to have an average particle diameter of the carrier of 20 to 70 μm in order to realize a high quality image. When the average particle diameter of the carrier is in the range of 20 to 70 μm, the charge amount of the toner particles can be made more uniform when the toner concentration in the developing machine is in the range of 2 to 10% by weight. When it is smaller than 20 μm, carrier particles are likely to adhere to the photoreceptor, and the stirring efficiency with the toner particles is deteriorated, so that it is difficult to obtain a uniform charge amount of the toner. On the other hand, when the average particle diameter of the carrier exceeds 70 μm, fine image reproducibility deteriorates and high image quality cannot be obtained.

  Details of the toner particles and the developer are shown below.

  The resin used for producing the toner of the present invention is not particularly limited, but polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene acrylic resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol There are resin, polyethylene resin, silicon resin, butyral resin, terpene resin, polyol resin and the like.

  Examples of the vinyl resin such as polystyrene resin include styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and homopolymers of substitution products thereof: styrene-p-chlorostyrene copolymer, styrene-propylene copolymer. Styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer Polymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene -Vinyl methyl ether copolymer Styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene -Styrene copolymers such as maleate ester copolymers: polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate and the like. These resins may be used alone or in combination.

The polyester resin is composed of a dihydric alcohol as shown in the following group A and a dibasic acid salt as shown in the group B, and further a trihydric or higher alcohol as shown in the group C or Carboxylic acid may be added as a third component.
Group A: ethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,4-bis (hydroxymethyl) ) Cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylene (2,2) -2,2'-bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3)- 2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2,0) -2,2'-bis (4-hydroxyphenyl) propane and the like.
Group B: maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, malonic acid, linolenic acid, or These acid anhydrides or esters of lower alcohols.
Group C: Trivalent or higher alcohols such as glycerin, trimethylolpropane and pentaerythritol, and trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid. As the polyol resin, an alkylene oxide adduct of an epoxy resin and a dihydric phenol, or a compound having one active hydrogen in the molecule that reacts with the glycidyl ether and the epoxy group, and an active hydrogen that reacts with the epoxy resin in the molecule. There are those obtained by reacting two or more compounds.

  As the polyester resin, crystalline polyester may be used. An aliphatic polyester having crystallinity, having a sharp molecular weight distribution, and increasing the absolute amount of the low molecular weight as much as possible is preferable. This resin undergoes a crystal transition at the glass transition temperature (Tg), and at the same time, the melt viscosity suddenly decreases from the solid state and exhibits a fixing function to paper. By using this crystalline polyester resin, low-temperature fixing can be achieved without excessively reducing the Tg and molecular weight of the resin. Therefore, there is no decrease in storage stability associated with a decrease in Tg. Further, there is no excessively high gloss and offset resistance deterioration due to the low molecular weight. Therefore, the introduction of the crystalline polyester resin is very effective for improving the low-temperature fixability of the toner.

  In the toner of the present invention, the content of the crystalline polyester is 1 to 50 with respect to the total amount of the resin and the release agent in the toner in order to exhibit low-temperature fixability and ensure hot offset resistance. The content of the release agent is preferably 2 to 15% by weight. When the content of the crystalline polyester is less than 1% by weight, there is no effect on the low-temperature fixability, and when it exceeds 50% by weight, the hot offset property is deteriorated. When the release agent content is less than 2% by weight, the offset resistance may not be effective, and when it exceeds 15% by weight, the toner fluidity decreases.

  Examples of the resin include a polyester resin and / or a polyol resin conventionally used for color toners. Polyester resins and polyol resins are suitable because they have better low-temperature fixability and relatively better heat-resistant storage stability than the styrene-acrylic resins that have been widely used. However, polyester resins and polyol resins have poor dispersibility of the release agent compared to styrene-acrylic resins. If the dispersibility is poor, the crushing stress tends to concentrate at the interface between the resin and the wax at the time of crushing, so it is easy to crush at the interface between the resin and the release agent. The release agent was exposed to the toner and the fluidity of the toner was deteriorated.

The molecular structure of the crystalline polyester resin is not limited, but from the viewpoint of the crystallinity and softening point of the polyester resin, a diol compound having 2 to 6 carbon atoms, particularly 1,4-butanediol and 1,6-hexane. Crystalline polyester represented by the following general formula (1) synthesized using an alcohol component containing a diol and derivatives thereof, and an acid component containing maleic acid, fumaric acid, succinic acid, and derivatives thereof
(In the formula, n and m are the number of repeating units, and R ¹ and R ² are groups independently selected from the group consisting of hydrogen and hydrocarbon groups.)
It is preferable to contain. From the viewpoint of the crystallinity and softening point of the polyester resin, a trihydric or higher polyhydric alcohol such as glycerin is added to the alcohol component to synthesize a non-linear polyester, and trimellitic anhydride or the like is added to the acid component. Polycondensation may be carried out by adding a trivalent or higher polyvalent carboxylic acid. R ¹ and R ² are groups selected from the group consisting of hydrogen, alkyl groups, and hydrocarbon groups such as aromatic groups, as described in Group B of [0016].

  The glass transition temperature (Tg) of the crystalline polyester resin is desirably low so long as the heat resistant storage stability does not deteriorate, and is preferably in the range of 80 to 130 ° C. When the glass transition temperature (Tg) is less than 80 ° C., the heat resistant storage stability is deteriorated, and blocking tends to occur at the temperature inside the developing device. Sex cannot be obtained. The glass transition temperature (Tg) of the crystalline polyester resin is an endothermic peak temperature at the time of 2nd temperature increase by a differential thermal analyzer (DSC).

The following pigments are used in the present invention, and at least one of the pigments is a metal oxide composed of Fe oxide and Ti oxide.
Examples of black pigments include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and composite metal oxides.
As the metal oxide pigment, a metal oxide composed of Fe oxide and Ti oxide, a metal oxide composed of Gd oxide or Fe oxide, a metal oxide composed of Mn oxide and Fe oxide, or the like is used. These metal oxides have a spinel structure and basically have the following composition.
(AO) · Fe ₂ O ₃
(A: an element selected from the group consisting of Ti, Gd, Mn and Fe)
However, the reaction is actually inadequate and Ti oxides, Gd oxides, Mn oxides, Fe oxides, etc. are often segregated at grain boundaries. Even if it can be used as this material.

In the case of a metal oxide composed of Fe oxide and Ti oxide, it is demagnetized by increasing the amount of FeO or TiO ₂ and used as a black pigment.
(AO) x. (Fe ₂ O ₃ ) _2-x
(A: Ti or Fe)
In the above formula, it is necessary to satisfy the condition of 1 ≦ X <2. The manufacturing method was as follows.
Ti oxide and Fe oxide are weighed and mixed using a ball mill. Next, it was calcined at 600 to 1000 ° C. for 2 to 5 hours with an electric furnace or the like, and the calcined product was put into a ball mill and pulverized. The obtained powder was pressure-molded with a powder press to form a plate, and the molded product was fired at 1100 to 1300 ° C. for 2 to 5 hours in an electric furnace or the like. This fired product was cut with a cutter, coarsely pulverized, finely pulverized, and classified into a predetermined particle size by a classifier to obtain metal oxide particles composed of Ti oxide and Fe oxide.
The average particle diameter of the metal oxide particles made of Ti oxide and Fe oxide is 0.01 to 0.2 μm. When the average particle diameter of the metal oxide particles composed of Ti oxide and Fe oxide is smaller than 0.01 μm, it is not suitable for aggregation and the like, and when it is larger than 0.2 μm, the coloring power decreases. Not suitable.

In the case of a metal oxide composed of Fe oxide and Gd oxide, GdxFe _(3-x) O ₄
(In the formula, 0.25 ≦ x ≦ 2)
When the Gd composition is less than 0.5, strong magnetic properties are obtained, and the particles tend to aggregate, which is not suitable for high image quality. When the Gd composition is larger than 2, the spinel structure is broken and a stable material cannot be obtained.
A feature of the present invention is that the magnetic characteristics change according to the Gd composition, so that both a one-component and two-component non-magnetic toner can be produced from a one-component magnetic toner. As the Gd composition increases, the magnetic properties decrease and change from ferromagnetic to non-magnetic. When used as a magnetic toner, the Gd composition x needs to satisfy 0.25 ≦ x <0.5. When used as a non-magnetic toner, it is necessary that 0.5 ≦ x ≦ 2. Examples of a method for producing a metal oxide composed of a Gd oxide and an Fe oxide include the following methods.

  Gd oxide and Fe oxide are weighed and mixed using a ball mill. Next, it was calcined at 600 to 1000 ° C. for 2 to 5 hours with an electric furnace or the like, and the calcined product was put into a ball mill and pulverized. The obtained powder was pressure-molded with a powder press to form a plate, and the molded product was fired at 1100 to 1300 ° C. for 2 to 5 hours in an electric furnace or the like. The fired product was cut with a cutter, coarsely pulverized, finely pulverized, and classified into a predetermined particle size by a classifier to obtain metal oxide particles composed of Gd oxide and Fe oxide.

The average particle diameter of the metal oxide particles composed of Gd oxide and Fe oxide is 0.01 to 0.2 μm. When the average particle diameter of the metal oxide particles composed of Gd oxide and Fe oxide is smaller than 0.01 μm, it is not suitable for aggregation and the like, and when it is larger than 0.2 μm, the coloring power decreases. Not suitable.
Gd oxide is a stable material, is known to be safe for the human body, and is used for medical purposes. Therefore, a metal oxide composed of Gd oxide and Fe oxide is a material that is safe for the human body.

Moreover, you may add the 3rd additive shown by a following formula to these materials.
_{Gdx (Fe 1-y B y} ) 3-x O 4
(In the formula, 0.25 ≦ x ≦ 2, 0 ≦ y ≦ 0.5.)
The third additive is added when the magnetic properties are too strong, or added to reinforce durability. The additive amount corresponds to the y amount in the above formula. If the amount added is increased, a separated phase may be formed, making it difficult to produce a structurally stable material. Therefore, the addition amount y needs to be 0.5 or less.

  In electrostatic charge developing toner, uniform dispersion of good pigment is indispensable, and instead of putting the pigment directly into a large amount of resin, a master batch in which the pigment is once dispersed at a high concentration is prepared and diluted. The method of throwing in the form is used. In this case, a solvent is generally used to assist dispersibility. However, there is a problem of environment and the like, and in the present invention, water is used for dispersion. When water is used, temperature control is important so that residual moisture in the masterbatch does not become a problem.

  In the electrostatic charge developing toner of the present invention, a charge control agent may be blended (internally added) inside the toner particles, but may be used by mixing (externally adding) the toner particles in some cases. An external additive may be used in combination. When adhering or fixing to the surface, it is necessary to use a charge control agent having an average particle size of 20 to 200 nm. The charge control agent enables optimal charge amount control according to the development system.

  For controlling the toner particles to be positively charged, nigrosine and quaternary ammonium salts, triphenylmethane dyes, imidazole metal complexes and salts can be used alone or in combination of two or more. Further, salicylic acid metal complexes, salts, organic boron salts, calixarene compounds, and the like are used for controlling toner particles to be negatively charged.

  Further, a release agent can be internally added to the electrostatic developing toner in the present invention in order to prevent offset at the time of fixing. Release agents include natural waxes such as candelilla wax, carnauba wax, rice wax, montan wax and derivatives thereof, paraffin wax and derivatives thereof, polyolefin wax and derivatives thereof, sazol wax, low molecular weight polyethylene, and low molecular weight polypropylene. And alkyl phosphate esters. The melting point of these release agents is preferably 65 to 90 ° C. When the temperature is lower than this range, blocking during storage of the toner tends to occur, and when the temperature is higher than this range, an offset is likely to occur in a region where the fixing roller temperature is low.

  For the purpose of improving the dispersibility of the release agent or the like, an additive for dispersing the release agent may be added. Examples of the release agent dispersing additive include styrene acrylic resin, polyethylene resin, polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol resin, butyral There are resins, terpene resins, polyol resins, etc., and a mixture of two or more of these resins may be used.

Further, a grinding aid may be included in the toner particles in order to improve the grindability. Examples of the material include a resin containing a polymer of at least one monomer selected from the group consisting of vinyltoluene, α-methylstyrene, and isopropenyltoluene. This polymer may be a homopolymer of vinyltoluene, α-methylstyrene or isopropenyltoluene, or a copolymer of these monomers. These polymers are preferably not copolymerized with a monomer other than styrene, but may be copolymerized with a monomer other than styrene as long as the object of the present invention is not impaired.
The content of styrene is 50 mol% or less, preferably 40 to 20 mol%, as a proportion of styrene in all monomers constituting the copolymer. Since these resins are brittle, when used in combination with crystalline polyester, insufficient crushability resulting from the crystallinity of the crystalline polyester can be improved.

  Examples of the method for producing the toner particles according to the present invention include a pulverization method and a polymerization method (suspension polymerization, emulsion polymerization dispersion polymerization, emulsion aggregation, emulsion association, etc.), but are not limited to these production methods.

  As an example of the pulverization method, first, the above-mentioned resin, pigment or dye as a colorant, charge control agent, release agent, other additives, etc. are sufficiently mixed by a mixer such as a Henschel mixer, and then batch type. The constituent materials are well kneaded using a two-roll, Banbury mixer, continuous twin-screw extruder, continuous single-screw kneader, or the like, and cut after rolling and cooling. The dispersibility of the toner kneaded product thus obtained is evaluated using this evaluation method. In this case, the sample is directly attached to the sample holder of the evaluation apparatus shown in FIG. The scan angle 2θ is measured while changing in the range of 10 deg to 40 deg. The number of measurements is two, and the average value is used for evaluation. After that, the toner kneaded product after cutting is crushed, coarsely pulverized using a hammer mill or the like, and further pulverized by a fine pulverizer or mechanical pulverizer using a jet stream, The toner particles are classified into toner particles of a predetermined particle size by a classifier using the Coanda effect. Thereafter, an additive composed of inorganic particles or the like is adhered or fixed to the toner particle surface by a mixer.

  In the X-ray diffraction pattern, the peak integrated intensity in the range of 2θ (θ: Bragg angle) = 32.9 ± 0.5 deg has a correlation with the dispersion state of the toner kneaded material made of resin, pigment, etc., and the peak integral By evaluating the change in strength, the change in the dispersion state of the toner kneaded product can be examined. That is, when the metal oxide composed of Fe oxide and Ti oxide is finely and uniformly dispersed in the toner kneaded product, the Bragg reflection intensity is reduced because the individual fine particles are randomly oriented, When the metal oxide consisting of Fe oxide and Ti oxide is unevenly dispersed in the toner mixture in the form of coarse and large clusters, large Bragg reflection intensity due to regular orientation from the clusters Is obtained.

The characteristics of the evaluation method using X-ray diffraction are as follows, and it is possible to perform non-destructive, quick evaluation and easy measurement, and therefore measurement without individual differences is possible.
(I) Non-destructive analysis is possible.
(Ii) Non-contact analysis is possible.
(Iii) The sample can be measured as it is.
Therefore, online measurement is also possible, and it can be installed between each process in the manufacturing process to evaluate the quality during the process. For example, after passing through the kneading / rolling cooling process as shown in FIG. 3, a sample zone is extracted in the middle of transporting the kneaded sample to the next process, and a measurement zone such as a measurement chamber or an X-ray diffraction measurement device is provided. Open and close the shutter to transport a certain amount of sample to the measurement unit. The sample is mounted on the sample holder inside the sample chamber of the measurement unit, the toner sample is irradiated with X-rays, the reflected light is detected, and the peak integrated intensity in the range of 2θ = 32.9 ± 0.5 deg. Measure. When the measurement is completed, the sample is returned to the original sample by another route. As a result of the evaluation, if the numerical value is out of the predetermined setting range, the sample is not sent to the pulverization step but is sent to the toner reprocessing step. It is also possible to independently use a toner evaluation apparatus having these functions as an evaluation apparatus in the development stage.

  In the case of the toner kneaded product, as shown in FIG. 4, several diffraction peaks appear in the range of the scan angle 2θ = 10 deg to 50 deg. These diffraction peaks are peaks inherent to the substance constituting the toner kneaded product (particularly, a substance having a crystal structure), and a change in peak integrated intensity of the diffraction peak at the diffraction peak position (2θ) is examined. The diffraction angle 2θ of the metal oxide composed of Fe oxide and Ti oxide constituting the toner kneaded product is present at around 33 deg, around 35.5 deg, around 40.5 deg, around 49 deg, and around 53.5 deg. Either diffraction peak may be used, but evaluation was performed using a diffraction peak near 33 deg with high peak intensity and high sensitivity. However, any diffraction peak may be used for the evaluation, and the entire diffraction pattern may be used.

The dispersion state of the toner kneaded material is closely related to the fluidity of the powder, and when the dispersibility of the toner kneaded material is good, the metal oxide, crystalline PES, and release agent that inhibit the fluidity are fine. Since the toner particles are present in the toner particles in a state, they do not exist greatly on the surface of the toner particles, and each powder particle is easy to move, so that the fluidity is improved. That is, since the toner particle transportability is improved, the reproducibility and the like in a fine developing portion is improved, and high image quality can be realized. On the contrary, when the dispersibility of the toner kneaded material is poor, the metal oxide, crystalline PES, and release agent that inhibit the fluidity often exist as part of a large lump on the toner particle surface. Since the individual powder particles are difficult to move, the fluidity is deteriorated. As a result, the transportability of the toner in the developing unit is deteriorated, and the image quality is deteriorated. As described above, in the evaluation method of the present invention, the dispersibility can be evaluated in the following relationship.
When dispersibility is good → In the X-ray diffraction pattern of the toner kneaded product, the X-ray diffraction peak integrated intensity in the range of 2θ = 32.9 ± 0.5 deg becomes small.
When the dispersibility is poor → In the X-ray diffraction pattern of the toner kneaded product, the integrated intensity of the X-ray diffraction peak in the range of 2θ = 32.9 ± 0.5 deg increases.

The dispersibility of the toner kneaded product is almost determined by the kneading step in the toner preparation step. In other words, depending on the state in which the pigment, the charge control agent, etc. are dispersed in the resin, the fluidity and charging characteristics of the toner particles that can be produced in the subsequent steps vary greatly.
The dispersion state of the toner kneaded product varies depending on kneading conditions (amount of charge, rotation speed, temperature, kneading time, etc.) in the kneading step. Therefore, kneading conditions play an important role in dispersibility, and evaluation of dispersibility after the kneading step is important.

As a result of evaluating the dispersibility of the toner kneaded product by this method using X-ray diffraction and investigating the relationship with dot reproducibility, a toner having good dot reproducibility is in the range of “2θ = 32.9 ± 0.5 deg. The peak integrated intensity of the X-ray diffraction peak within the range is 1000 to 15000 counts, preferably 7000 to 14000 counts, and particularly preferably 8000 to 13000 counts.
When the peak integrated intensity of the X-ray diffraction peak within the range of 2θ = 32.9 ± 0.5 deg is less than 1000 counts, the charging characteristics other than the dispersibility of the toner are deteriorated, the image quality is deteriorated, and if it is larger than 15000 counts. Dispersibility decreases, image density decreases, toner fluidity deteriorates, and image quality decreases.
The evaluation may be performed using a diffraction peak around 2θ = 35 to 36 deg, or the entire diffraction pattern may be used.
After the kneading step, the toner kneaded product after cutting is crushed, coarsely pulverized using a hammer mill or the like, and further pulverized by a fine pulverizer or a mechanical pulverizer using a jet stream, and classified using a swirling airflow And classifying using a classifier using the Coanda effect. Thereafter, an additive composed of inorganic particles or the like is adhered or fixed to the particle surface by a mixer. Further, the toner particles of the present invention are obtained by passing through a sieve of 250 mesh or more to remove coarse particles and aggregated particles.

  In order to achieve high image quality, the average circularity of the electrostatic charge developing toner needs to be 0.9 to 0.99. The shape of the toner particles also greatly affects the fluidity of the electrostatic charge developing toner, and those having an average circularity in the range of 0.9 to 0.99 are close to the fluidity of the electrostatic charge developing toner. Excellent image quality. The circularity of the toner particles was measured as an average circularity using a flow particle image analyzer FPIA-1000 (Toa Medical Electronics Co., Ltd.).

This evaluation method can also be used to evaluate the dispersibility of particles produced by other polymerization methods.
For example, the toner kneaded product of the present invention can be produced as follows. For example, an oily dispersion in which at least a polyester-based prepolymer containing an isocyanate group is dissolved in an organic solvent, a pigment-based colorant is dispersed, and a release agent is dissolved or dispersed is dispersed in an aqueous medium with inorganic fine particles and And / or dispersing in the presence of polymer fine particles, and reacting the prepolymer with a polyamine and / or a monoamine having an active hydrogen-containing group in the dispersion to form a urea-modified polyester resin having a urea group, It can be obtained by removing the liquid medium contained in the dispersion containing the urea-modified polyester resin.
In the urea-modified polyester resin, the Tg is 40 to 65 ° C, preferably 45 to 60 ° C. The number average molecular weight Mn is 2500 to 50000, preferably 2500 to 30000. The weight average molecular weight Mw is 10,000 to 500,000, preferably 30,000 to 100,000.
This toner contains, as a binder resin, a urea-modified polyester resin having a urea bond that has been increased in molecular weight by the reaction between the prepolymer and the amine. The colorant is highly dispersed in the binder resin.
The obtained toner particle powder after drying is air-classified, and an additive composed of inorganic fine particles or the like is adhered or fixed to the particle surface by a mixer under the optimum mixing conditions. Alternatively, the charge control agent may be applied to the surface of the toner powder after drying and fixedly injected. Further, thereafter, an additive made from inorganic fine particles or the like may be adhered or fixed to the particle surface. By placing the charge control agent on the surface, the charge amount of the toner can be easily controlled.

Specific means for mixing and fixing and injecting are as follows: a method of applying an impact force to the powder mixture with blades rotating at high speed; For example, there is a method of causing the particles to collide with an appropriate collision plate. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) has been modified to reduce the pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar, etc.
In these cases, it can be applied to inspection after granulation.

  Further, when the electrostatic charge developing toner of the present invention is used as a two-component developer, it is made into a two-component developer by mixing with a magnetic carrier described later at a predetermined mixing ratio.

  The electrostatic charge developing toner of the present invention is used as a one-component or two-component developer used in a contact or non-contact development system. As the contact or non-contact development method, various known ones are used. For example, there are a contact development method using an aluminum sleeve, a contact development method using a conductive rubber belt, and a non-contact development method using a development sleeve in which a conductive resin layer containing carbon black or the like is formed on the surface of an aluminum base tube. . In addition, when an AC bias voltage component is applied during development using the electrostatic charge developing toner of the present invention, development efficiency is improved and image characteristics are improved.

In addition, in the one-component development system, the electrostatic charge developing toner of the present invention is applied to a development system in which a roller blade for making the toner layer uniform and a supply roller for supplying toner are provided at the outlet of the toner supply unit. It is characterized by using. In the case of such a system, not only filming on the photoconductor but also filming on the doctor roller and the supply roller occurs. For this reason, the toner layer cannot be formed uniformly, the toner charge becomes non-uniform, and the toner charge amount becomes small. For this reason, poor development occurs.
However, when the electrostatic charge developing toner of the present invention is used, filming to the doctor roller and the supply roller does not occur, stable development is performed, and the system has excellent durability characteristics. (See Figure 5)

  Since the electrostatic charge developing toner of the present invention is excellent in fluidity, it can be stored in a cartridge container and is suitable for an apparatus configured to convey toner from the cartridge container to the developing unit. .

  Examples of the cartridge container include a toner cartridge that is filled with electrostatic charge developing toner, and a process cartridge that includes at least a photosensitive member and a developing means and fills the toner storage portion of the developing means with electrostatic charge developing toner. Usually, these toner cartridges or process cartridges are mounted on an image forming apparatus to form an image.

  Further, when the magnetic toner is used, magnetic particles may be internally added to the toner particles. Examples of the magnetic material include ferromagnetic materials such as ferrite, magnetite, iron, nickel, cobalt, and alloys thereof. The average particle size of the magnetic material is preferably 0.1 to 1 μm. The content of the magnetic material is preferably 10 to 70 parts by weight with respect to 100 parts by weight of the toner.

  As the carrier used in the two-component developer, known ones can be used. For example, magnetic particles such as iron powder, ferrite powder, nickel powder, and magnetite powder, or the surface of these magnetic particles are made of fluorine resin or vinyl resin. And those treated with a silicone-based resin or the like, or magnetic particle-dispersed resin particles in which magnetic particles are dispersed in the resin. The average particle size of these magnetic carriers is preferably 20 to 70 μm. When the particle size is 20 μm or less, carrier particles are likely to adhere to the photoreceptor, and the stirring efficiency with the toner is deteriorated, so that uniform charging of the toner is difficult to obtain. On the other hand, if it exceeds 70 μm, fine image reproducibility deteriorates.

As described above, the two-component developer of the present invention can be used by adding (externally adding) inorganic fine powder to the toner as a fluidity improver. The average particle size of the inorganic fine powder is preferably 20 to 200 nm. When the average particle size is less than 20 nm, it becomes difficult to control the treatment, and when it exceeds 200 nm, the fluidity is deteriorated.
As the inorganic fine powder of the present invention, Si, Ti, Al, Mg, Ca, Sr, Ba, In, Ga, Ni, Mn, W, Fe, Co, Zn, Cr, Mo, Cu, Ag, V, Zr, etc. And oxides and composite oxides. Of these, fine particles of silicon dioxide (silica), titanium dioxide titania) and alumina are preferably used.

  The inorganic fine powder is preferably used in an amount of 0.1 to 2% by weight based on the toner. If it is less than 0.1% by weight, the effect of improving toner aggregation is poor, and if it exceeds 2% by weight, problems such as toner scattering between fine wires, contamination in the machine, scratches and abrasion of the photoreceptor tend to occur. is there.

Furthermore, it is effective to perform a surface modification treatment with a hydrophobizing agent or the like. Typical examples of the hydrophobizing agent include the following.
Dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, allyldimethyldichlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, p-chloroethyltrichlorosilane, Chloromethyldimethylchlorosilane, chloromethyltrichlorosilane, hexaphenyldisilazane, hexatolyldisilazane, etc.

  Further, the developer of the present invention may further contain other additives, for example, a lubricant powder such as Teflon (registered trademark) powder, zinc stearate powder, and polyvinylidene fluoride powder; Abrasives such as cerium powder, silicon carbide powder, and strontium titanate powder; or a conductivity-imparting agent such as carbon black powder, zinc oxide powder, and tin oxide powder can be used in small amounts as a developability improver.

(1) Dispersibility of the toner kneaded product is measured by measuring the peak integrated intensity of a diffraction peak within the range of 2θ = 32.9 ± 0.5 deg by irradiating the X-ray (CuKα ray) having a wavelength of 1.54 mm. However, due to the difference in peak integrated intensity, we have developed a measurement method that can measure quickly, accurately, and without individual differences. (2) When the electrostatic charge developing toner of the present invention produced by utilizing this measurement method is used, a high-quality product with high image density and good dot reproducibility can be obtained. (3) According to the present invention, it is possible to stably produce a human-friendly toner.

Hereinafter, although an Example is described, this does not limit this invention at all. In this case, toners with different compositions and kneading conditions were prepared and evaluated using this evaluation method as the toner dispersibility (evaluation conditions are shown below), and the image density and dot reproducibility were evaluated as the roughness of the image. A five-step evaluation (rank 1: bad → rank 5: good) was made. Further, a running durability test of 20,000 sheets was performed to evaluate defects in toner transportability such as blocking in the developing unit. The case where there was no defect was evaluated as ◯, and the case where there was a defect was evaluated as x.
・ X-ray source: CuKα ray ・ Tube voltage: 40 kV
・ Tube current: 40 mA
Scan angle 2θ: 10-50deg
Scan speed: 2 deg / min
In addition, all the parts in the following mixing | blending are a weight part.

Example 1
Resin Polyester resin 90 parts
10 parts of crystalline polyester resin (Tg = 110 ° C.)
Pigment (Ti-O) .Fe ₂ O ₃ 25 parts Charge control agent Salicylic acid zinc salt 5 parts Mold release agent Low molecular weight polyethylene 5 parts After thoroughly mixing the above raw materials with a mixer, a twin screw extruder is used under the following conditions: Melt kneaded.
Kneading temperature: 125 ° C
Kneading rotation speed: 80rpm
Thereafter, the kneaded product was cooled and rolled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then classified into a particle size distribution with a weight average particle size of 6.5 μm using a swirling air classifier. . To 100 parts of the toner particles (matrix coloring particles) thus obtained, an additive was mixed under the following mixing conditions to prepare an electrostatic charge developing toner.
Additives Silica fine powder (20 nm) 1.2 parts
Titanium oxide fine powder (60nm) 0.3 parts Mixing rotation speed 800rpm
Mixing time 120sec
Mixer Supermixer On the other hand, the X-ray diffraction measurement of the toner kneaded product was performed, and the peak integrated intensity value of the peak within the range of 2θ = 32.9 ± 0.5 deg was obtained. It was. The obtained electrostatic charge developing toner was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and image evaluation and running experiments were performed. The results are shown in Table 1. The average circularity of the toner particles was 0.93.

Example 2
The raw materials similar to those in Example 1 were sufficiently mixed with a mixer, and then melt-kneaded with a twin screw extruder under the following conditions.
Kneading temperature: 125 ° C
Kneading rotation speed: 120rpm
Thereafter, the kneaded product was cooled and rolled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then classified into a particle size distribution with a weight average particle size of 6.5 μm using a swirling air classifier. . To 100 parts of the toner particles (matrix coloring particles) thus obtained, an additive was mixed under the following mixing conditions to prepare an electrostatic charge developing toner.
Additives Silica fine powder (20 nm) 1.2 parts
Titanium oxide fine powder (60nm) 0.3 parts Mixing rotation speed 800rpm
Mixing time 120sec
Mixer Supermixer On the other hand, the X-ray diffraction measurement of the toner kneaded product was performed, and the peak integrated intensity value of the peak within the range of 2θ = 32.9 ± 0.5 deg was obtained. It was. The obtained electrostatic charge developing toner was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and image evaluation and running experiments were performed. The results are shown in Table 1. The average circularity of the toner particles was 0.93.

Example 3
The raw materials similar to those in Example 1 were sufficiently mixed with a mixer, and then melt-kneaded with a twin screw extruder under the following conditions.
Kneading temperature: 90 ° C
Kneading rotation speed: 160rpm
Thereafter, the kneaded product was cooled and rolled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then classified into a particle size distribution with a weight average particle size of 6.5 μm using a swirling air classifier. . To 100 parts of the toner particles (matrix coloring particles) thus obtained, an additive was mixed under the following mixing conditions to prepare an electrostatic charge developing toner.
Additives Silica fine powder (20 nm) 1.2 parts
Titanium oxide fine powder (60nm) 0.3 parts Mixing rotation speed 800rpm
Mixing time 120sec
Mixer Supermixer On the other hand, the X-ray diffraction measurement of the toner kneaded product was performed, and the peak integrated intensity value of the peak within the range of 2θ = 32.9 ± 0.5 deg was obtained. It was. The obtained electrostatic charge developing toner was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and image evaluation and running experiments were performed. The results are shown in Table 1. The average circularity of the toner particles was 0.93.

Example 4
The raw materials similar to those in Example 1 were sufficiently mixed with a mixer, and then melt-kneaded with a twin screw extruder under the following conditions.
Kneading temperature: 125 ° C
Kneading rotation speed: 160rpm
Thereafter, the kneaded product was cooled and rolled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then classified into a particle size distribution with a weight average particle size of 6.5 μm using a swirling air classifier. . To 100 parts of the toner particles (matrix coloring particles) thus obtained, an additive was mixed under the following mixing conditions to prepare an electrostatic charge developing toner.
Additives Silica fine powder (20 nm) 1.2 parts
Titanium oxide fine powder (60nm) 0.3 parts Mixing rotation speed 800rpm
Mixing time 120sec
Mixer Supermixer On the other hand, the X-ray diffraction measurement of the toner kneaded product was performed, and the peak integrated intensity value of the peak within the range of 2θ = 32.9 ± 0.5 deg was obtained. It was. The obtained electrostatic charge developing toner was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and image evaluation and running experiments were performed. The results are shown in Table 1. The average circularity of the toner particles was 0.93.

Comparative Example 1
The raw materials similar to those in Example 1 were sufficiently mixed with a mixer, and then melt-kneaded with a twin screw extruder under the following conditions.
Kneading temperature: 160 ° C
Kneading rotation speed: 160rpm
Thereafter, the kneaded product was cooled and rolled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then classified into a particle size distribution with a weight average particle size of 6.5 μm using a swirling air classifier. . To 100 parts of the toner particles (matrix coloring particles) thus obtained, an additive was mixed under the following mixing conditions to prepare an electrostatic charge developing toner.
Additives Silica fine powder 1.2 parts
Titanium oxide fine powder 0.3 part Mixing rotation speed 800rpm
Mixing time 120sec
Mixer Supermixer On the other hand, X-ray diffraction measurement was performed on the toner kneaded product, and the peak integrated intensity value of the peak in the range of 2θ = 32.9 ± 0.5 deg was obtained. It was outside the scope of the invention. The obtained electrostatic charge developing toner was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and image evaluation and running experiments were performed. The results are shown in Table 1.

Example 5
Resin Polyester resin 80 parts
20 parts of crystalline polyester resin
(Tg = 110 ° C.)
Pigment (Ti-O) .Fe ₂ O ₃ 25 parts Charge control agent Salicylic acid zinc salt 5 parts Mold release agent Low molecular weight polyethylene 5 parts After thoroughly mixing the above raw materials with a mixer, a twin screw extruder is used under the following conditions: Melt kneaded.
Kneading temperature: 125 ° C
Kneading rotation speed: 80rpm
Thereafter, the kneaded product was cooled and rolled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then classified into a particle size distribution with a weight average particle size of 6.5 μm using a swirling air classifier. . To 100 parts of the toner particles (matrix coloring particles) thus obtained, an additive was mixed under the following mixing conditions to prepare an electrostatic charge developing toner.
Additives Silica fine powder (20 nm) 1.2 parts
Titanium oxide fine powder (60nm) 0.3 parts Mixing rotation speed 800rpm
Mixing time 120sec
Mixer Supermixer On the other hand, the X-ray diffraction measurement of the toner kneaded product was performed, and the peak integrated intensity value of the peak within the range of 2θ = 32.9 ± 0.5 deg was obtained. It was.
The toner for electrostatic charge development obtained by the above production method and the carrier were mixed at a ratio of 2.5 parts with respect to 97.5 parts of the carrier to prepare a two-component developer. The obtained developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and image evaluation and running experiments were performed. The results are shown in Table 1. The average circularity of the toner particles was 0.93.

Example 6
The raw materials similar to those in Example 5 were sufficiently mixed with a mixer, and then melt kneaded with a twin screw extruder under the following conditions.
Kneading temperature: 125 ° C
Kneading rotation speed: 120rpm
Thereafter, the kneaded product was cooled and rolled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then classified into a particle size distribution with a weight average particle size of 6.5 μm using a swirling air classifier. . To 100 parts of the toner particles (matrix coloring particles) thus obtained, an additive was mixed under the following mixing conditions to prepare an electrostatic charge developing toner.
Additives Silica fine powder (20 nm) 1.2 parts
Titanium oxide fine powder (60nm) 0.3 parts Mixing rotation speed 800rpm
Mixing time 120sec
Mixer Supermixer On the other hand, the X-ray diffraction measurement of the toner kneaded product was performed, and the peak integrated intensity value of the peak within the range of 2θ = 32.9 ± 0.5 deg was obtained. It was.
The toner for electrostatic charge development obtained by the above production method and a carrier (65 μm) were mixed at a ratio of 2.5 parts with respect to 97.5 parts of the carrier to prepare a two-component developer. The obtained developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and image evaluation and running experiments were performed. The results are shown in Table 1. The average circularity of the toner particles was 0.93.

Example 7
The raw materials similar to those in Example 5 were sufficiently mixed with a mixer, and then melt kneaded with a twin screw extruder under the following conditions.
Kneading temperature: 90 ° C
Kneading rotation speed: 160rpm
Thereafter, the kneaded product was cooled and rolled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then classified into a particle size distribution with a weight average particle size of 6.5 μm using a swirling air classifier. . To 100 parts of the toner particles (matrix coloring particles) thus obtained, an additive was mixed under the following mixing conditions to prepare an electrostatic charge developing toner.
Additives Silica fine powder (20 nm) 1.2 parts
Titanium oxide fine powder (60nm) 0.3 parts Mixing rotation speed 800rpm
Mixing time 120sec
Mixer Supermixer On the other hand, the X-ray diffraction measurement of the toner kneaded product was performed, and the peak integrated intensity value of the peak within the range of 2θ = 32.9 ± 0.5 deg was obtained. It was.
The toner for electrostatic charge development obtained by the above production method and a carrier (65 μm) were mixed at a ratio of 2.5 parts with respect to 97.5 parts of the carrier to prepare a two-component developer. The obtained developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and image evaluation and running experiments were performed. The results are shown in Table 1. The average circularity of the toner particles was 0.93.

Example 8
The raw materials similar to those in Example 5 were sufficiently mixed with a mixer, and then melt kneaded with a twin screw extruder under the following conditions.
Kneading temperature: 125 ° C
Kneading rotation speed: 160rpm
Thereafter, the kneaded product was cooled and rolled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then classified into a particle size distribution with a weight average particle size of 6.5 μm using a swirling air classifier. . To 100 parts of the toner particles (matrix coloring particles) thus obtained, an additive was mixed under the following mixing conditions to prepare an electrostatic charge developing toner.
Additives Silica fine powder (20 nm) 1.2 parts
Titanium oxide fine powder (60nm) 0.3 parts Mixing rotation speed 800rpm
Mixing time 120sec
Mixer Supermixer On the other hand, the X-ray diffraction measurement of the toner kneaded product was performed, and the peak integrated intensity value of the peak within the range of 2θ = 32.9 ± 0.5 deg was obtained. It was.
The toner for electrostatic charge development obtained by the above production method and a carrier (65 μm) were mixed at a ratio of 2.5 parts with respect to 97.5 parts of the carrier to prepare a two-component developer. The obtained developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and image evaluation and running experiments were performed. The results are shown in Table 1. The average circularity of the toner particles was 0.93.

Comparative Example 2
The raw materials similar to those in Example 5 were sufficiently mixed with a mixer, and then melt kneaded with a twin screw extruder under the following conditions.
Kneading temperature: 160 ° C
Kneading rotation speed: 160rpm
Thereafter, the kneaded product was cooled and rolled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and then classified into a particle size distribution with a weight average particle size of 6.5 μm using a swirling air classifier. . To 100 parts of the toner particles (matrix coloring particles) thus obtained, an additive was mixed under the following mixing conditions to prepare an electrostatic charge developing toner.
Additives Silica fine powder 1.2 parts
Titanium oxide fine powder 0.3 part Mixing rotation speed 800rpm
Mixing time 120sec
Mixer Supermixer On the other hand, X-ray diffraction measurement was performed on the toner kneaded product, and the peak integrated intensity value of the peak in the range of 2θ = 32.9 ± 0.5 deg was obtained. It was outside the scope of the invention.
The toner for electrostatic charge development obtained by the above production method and the carrier were mixed at a ratio of 2.5 parts with respect to 97.5 parts of the carrier to prepare a two-component developer. The obtained developer was set in a copying machine in which the latent image carrier is an OPC drum photoreceptor and the cleaning method is blade cleaning, and image evaluation and running experiments were performed. The results are shown in Table 1.

  As can be seen from the results in Table 1, there is a correlation between the peak integrated intensity of the X-ray diffraction peak in the range of 2θ = 32.9 ± 0.5 deg of the toner kneaded product and the dot reproducibility and running characteristics. Even if the result of FIG. 2 is taken into consideration, in order to obtain a toner with good dispersibility necessary for obtaining a high image quality with good dot reproducibility, it is in the range of 2θ = 32.9 ± 0.5 deg. The peak integrated intensity of the X-ray diffraction peak needs to be 1000 to 15000 counts. It can be said that when the peak integrated intensity is large, both the dot reproducibility and the running characteristics are deteriorated.

FIG. 2 is a schematic view of one measuring apparatus used in the toner kneaded product evaluation method used in the present invention. In Figure irradiated with X-rays with a wavelength of 1.54 Å, showing the relationship between the dot reproducibility through the peak integrated intensity and The variability sense of the X-ray diffraction pattern in the range of 2 [Theta] = 32.9 ± 0.5 deg is there. It is a model diagram showing an example of a toner manufacturing apparatus using the evaluation method of the present invention. It is a figure which shows the X-ray diffraction pattern which one toner kneaded material of this invention shows. 1 is a schematic diagram of a developing device used in the present embodiment.

Claims (3)

  At least a resin kneaded mixture composed of a resin and a pigment is irradiated with X-rays (CuKα rays) having a wavelength of 1.54 mm, and an X-ray diffraction pattern within a range of 2θ (θ: Bragg angle) = 32.9 ± 0.5 deg A method for evaluating a toner for electrostatic charge development, comprising measuring a peak integrated intensity of a peak and evaluating dispersibility of the toner kneaded product based on the peak integrated intensity.   2. The electrostatic charge developing toner evaluation method according to claim 1, wherein the toner kneaded product contains Fe oxide and Ti oxide as pigments. A method for producing a toner for developing an electrostatic charge, wherein the method for evaluating a toner kneaded product according to claim 1 or 2 is used.