JP4883793B2 - Two-component developer - Google Patents

Description

  The present invention relates to a two-component developer used in an electrophotographic system, an electrostatic recording system, and an electrostatic printing system.

  In recent years, print on demand (POD) has attracted attention. This digital printing technique prints directly without going through the plate making process. Therefore, it is possible to respond to the demand for small lot printing and short delivery time, for printing that changes the contents for each sheet (variable printing), and distributed printing that moves multiple output machines using a communication function from a single data Since it can respond, there is an advantage over conventional offset printing. When considering the application of the electrophotographic image forming method to the POD market, it is necessary to further improve the color stability in addition to the three basic elements of printing: high speed, high image quality, and low running cost. is there. For this reason, it is essential for the performance desired for the toner to achieve a higher image quality and higher definition image than before and to reduce the toner consumption without narrowing the color gamut reproduction range. Furthermore, it is necessary to cope with a reduction in fixing energy and various recording papers such as plain paper, cardboard or coated paper.

High image quality and high-quality color with a stable and wide color reproduction range by reducing the amount of toner applied to 0.35 mg / cm ² or less, reducing toner consumption, and suppressing problems (blisters, etc.) that occur during fixing. There is a proposal to form an image (Patent Document 1). According to this proposal, it is possible to form a high-quality and high-quality color image with little image roughness, excellent fixability, and stably having a wide color reproduction range. However, a certain effect can be expected with respect to the fixing characteristics. However, if the amount of the colorant contained in the toner particles is simply increased, the density stability and gradation are liable to deteriorate during long-term use. In order to explain this specifically, when the potential is plotted on the horizontal axis and the density is plotted on the vertical axis, the conventional toner has a γ characteristic as shown by curve A in FIG. However, when the amount of the colorant is increased, the density can be produced on the recording paper with a smaller amount of toner than before, and a gradation is formed with a potential of development contrast narrower than that of the prior art. At this time, the γ characteristic as shown by the curve B in FIG. 1 is obtained, the γ characteristic becomes steep, and it may be difficult to obtain a wide gradation. In addition, since the γ characteristic is steep, the change in image density due to potential fluctuation is larger than that of conventional toner, and the stability of the image density may be reduced. In the POD market, wide gradation and color stability are essential conditions, and it is necessary to develop the γ characteristic with a gentle slope even with a small amount of toner. . For that purpose, one solution is to increase the triboelectric charge amount of the toner by using the toner having an increased colorant content. In the above proposal, there is no mention of the triboelectric charge amount of the toner in the two-component developer, and it is not recognized that the triboelectric charge amount is positively controlled.
Furthermore, the colorant also has a great influence as a factor for reducing the stability of the image density. That is, increasing the amount of the colorant exposes a large amount of the colorant on the surface of the toner particles, which is easily affected by the colorant. Then, in order to suppress the influence of a coloring agent, the proposal aiming at improving the dispersibility of a coloring agent by a manufacturing process is made | formed (patent document 2). However, this method has a limit to the amount of colorant that can be added, and the color reproducibility of the secondary color is deteriorated.
In addition, a proposal for improving the dispersibility with a colorant has been made (Patent Document 3). If it is a purified colorant, the influence of conductive impurities contained in the colorant on charging can be suppressed. However, in particular, when copper phthalocyanine is used as a colorant, the dispersibility of the colorant deteriorates and a desired image density cannot be obtained. Further, proposals have been made for the purpose of improving the dispersibility by using a cyan colorant in combination. (Patent Document 4) However, what is proposed here is the conventional colorant content. If the colorant amount is further increased, the image density stability can be obtained without further efforts. Can not.

As described above, in order to form an image with a smaller amount of applied toner than conventional toner using a toner having a high colorant content and a high coloring power, it is important to stably develop a toner having a high charge amount. For this purpose, it is necessary to improve the dispersibility of the colorant and further suppress the influence of the colorant on charging. However, no two-component developer has yet been found that can stably form an image with a smaller amount of toner than conventional cyan toner having a high colorant content and high coloring power.
JP 2005-195664 A JP 2004-347774 A JP 2006-113362 A JP-A-6-67468

The present invention provides a two-component developer that solves the above-described problems of the prior art.
That is, the object of the present invention is to achieve a high-definition image with a smaller amount of applied toner than in the past, to have a color gamut comparable to printing, to reduce toner consumption, and to support high speed, An object of the present invention is to provide a two-component developer capable of outputting an image having a stable color even after long-term use.

As a result of intensive studies, the present inventors have determined that a cyan toner containing at least aluminum phthalocyanine has a cyan toner concentration C (mg / ml) in a chloroform solution of the cyan toner and a wavelength of 660 nm or more in the solution. The absolute value of the triboelectric charge amount of the cyan toner measured by the two-component method using the cyan toner and the magnetic carrier is within the range defined by the present invention. By adjusting, it was found that the above requirements can be satisfied, and the present invention has been achieved.
That is, the present invention is as follows.
(1) A two-component developer containing a cyan toner containing at least a binder resin and a colorant and a magnetic carrier,
The cyan toner is
i) at least further containing aluminum phthalocyanine,
ii) When the cyan toner concentration in the chloroform solution of the cyan toner is C [mg / ml], and the absorbance at the wavelength at which the absorbance is 660 nm or more and 760 nm or less in the solution is A, The relationship between C and A satisfies the following formula (1):
2.00 <A / C <8.15 (1),
iii) A two-component system characterized in that the absolute value of the triboelectric charge amount of the cyan toner measured by a two-component method using the cyan toner and the magnetic carrier is 50 mC / kg or more and 120 mC / kg or less. Developer.
(2) The amount of free aluminum contained in the aluminum phthalocyanine measured by a combined induction plasma emission spectrometer (ICP) is 0.1 ppm or more and 10.0 ppm or less. Two-component developer.
(3) The lightness L ^* and saturation C ^* obtained in the powder state of the cyan toner are 25.0 ≦ L ^* ≦ 40.0 and 50.0 ≦ C ^* ≦ 60.0. The two-component developer according to (1) or (2).

  The present invention achieves a high-resolution, high-definition image while reducing the toner consumption by using a toner having a high coloring power and a high coloring power, and does not impair the image color gamut, saturation, and brightness, It is possible to provide a two-component developer capable of outputting good image quality even during continuous use.

The present invention is described in detail below.
The present invention
A two-component developer containing a cyan toner and a magnetic carrier containing at least a binder resin and a colorant,
The cyan toner is
i) at least further containing aluminum phthalocyanine,
ii) When the cyan toner concentration in the chloroform solution of the cyan toner is C [mg / ml], and the absorbance at the wavelength at which the absorbance is 660 nm or more and 760 nm or less in the solution is A, The relationship between C and A satisfies the following formula (1):
2.00 <A / C <8.15 (1),
iii) A two-component system characterized in that the absolute value of the triboelectric charge amount of the cyan toner measured by a two-component method using the cyan toner and the magnetic carrier is 50 mC / kg or more and 120 mC / kg or less. It relates to a developer.

  In the present invention, in order to increase the coloring power of the toner and improve the fixing and transfer performance, studies have been made to increase the content of the colorant. In order to suppress hue change, which is one of the adverse effects that occur at that time, the above object is achieved by developing the toner while maintaining a high charge amount.

[Cyan toner density]
In the cyan toner used in the present invention, the cyan toner concentration in the chloroform solution of the cyan toner is C [mg / ml], and the absorbance at the wavelength at which the absorbance at the wavelength of 660 nm or more and 760 nm or less in the solution is maximum. A cyan toner having an absorbance per unit concentration, which is a value obtained by dividing A by C (hereinafter referred to as absorbance A / C), when A is greater than 2.00 and less than 8.15. Further, the absorbance A / C is more preferably greater than 2.40 and less than 4.90 in order to obtain the necessary coloring power. When the absorbance A / C is 2.00 or less, the degree of coloring per weight of the toner is low, and in order to obtain the required degree of coloring, it is necessary to increase the amount of toner on the recording paper and to increase the thickness of the toner layer. There is. As a result, toner consumption cannot be reduced, dust is generated during transfer / fixing, and only the edge portion is transferred without transferring the center portion of the line image or character image line on the image. May occur. On the other hand, when the absorbance A / C is 8.15 or more, sufficient coloring power can be obtained, but the brightness is lowered, the image is dark, and the vividness is liable to be lowered. In addition, as the amount of the colorant exposed on the toner surface increases, the chargeability of the toner deteriorates, a toner with a weak frictional charge amount is generated, fogging occurs on the white background of the image, and the inside of the apparatus is contaminated by toner scattering. Sometimes.

[Amount of triboelectric charge of cyan toner]
The cyan toner used in the present invention is characterized in that the absolute value of the triboelectric charge amount measured by the two-component method using the cyan toner and the magnetic carrier is 50 mC / kg or more and 120 mC / kg or less. In a developer using a toner having an absolute value of the triboelectric charge amount of less than 50 mC / kg, the color variation increases with long-term use and the stability may be lost. On the other hand, a developer using toner having an absolute value of the triboelectric charge amount exceeding 120 mC / Kg may cause a decrease in density and transfer efficiency. This is presumably because the electrostatic adhesion force with the magnetic carrier and the surface of the photoreceptor increases.
The triboelectric charge amount is adjusted by the charge imparting ability of the magnetic carrier. Specifically, the amount can be adjusted depending on the amount of the magnetic carrier coating material or when the charge control particles are added to the coating material. It can also be adjusted by the charging ability of the toner. Specifically, it can be adjusted by the dispersion state of the colorant and the kind and amount of the external additive.
Further, as a method for measuring the triboelectric charge amount, a general measurement method such as a blow-off measurement method, an electric field separation measurement method, or a suction measurement method may be used.

The reason why a developer having a high triboelectric charge amount is required is explained as follows.
In order to obtain the Dmax density with the conventional toner, for example, a developer in which the charge amount of the conventional toner is −40 μC / g, and the toner on the photoconductor is 0.5 mg / cm ² when Vcont = 500V. And the system. Here, Vcont is a potential difference between the developing bias potential and the latent image potential on the drum. At this time, if the potential generated by the toner layer on the OPC photoreceptor is ΔV, ΔV can be expressed as a function of Q / S (= product of charge amount (q / m) and toner applied amount (m / s)). It is known that this ΔV (the charge of the toner layer developed on the drum) fills the potential of Vcont = 500 V, that is, it is considered that the charge ΔV created by the toner layer fills the latent image potential. it can.
Here, when the horizontal axis represents the contrast potential and the vertical axis represents the image density, the conventional toner has a γ characteristic like the curve A. Development is carried out by filling the contrast potential with toner charge and toner particles. Point a in FIG. 2 is a point at which saturation density can be obtained with the conventional toner.
On the other hand, when a toner having a high coloring power such as the toner of the present invention is used, assuming that the coloring power is twice that of the conventional toner, the loading amount of 0.25 mg / half of the conventional toner is half. A saturated image density is obtained at cm ² , and Vcont = 250V. Necessary toner is developed at point b in FIG. When Vcont is further increased from point B, the applied amount increases, but the image density is saturated and the density does not increase any more. When Vcont = 500V, the applied amount of toner becomes 0.5 mg / cm ² and reaches point a. At point a, the toner with high coloring power becomes excessive, resulting in a darkly sunk image, and the hue changes greatly. FIG. 5 shows the hue profiles of the conventional toner on the a ^* b ^* plane of CIELAB and the toner with high coloring power. The solid line is the conventional toner, and the dotted line is the toner having a high coloring power, and is a hue profile when developing with the toner having a high coloring power beyond the point b in FIG. When reaching a ', the curve is bent to the left side of the figure, to the a ^* axis side of FIG. 5, and the hue changes. A decrease in brightness also occurs at the same time. Therefore, the saturated image density may be output with the minimum amount of toner that saturates the image density. However, considering a system that develops a toner with a high coloring power that is saturated at a loading amount of 0.25 mg / cm ² and Vcont = 250 V, gradation must be formed with half the conventional Vcont (= 250 V), The density variation with respect to the potential variation becomes large, and there remains a problem in the stability of the image. A gradation is obtained with Vcont (= 500 V) equivalent to that of the conventional toner while the applied amount is halved, that is, a curve A ′ (dotted line) is obtained by enlarging the curve C (broken line) in FIG. 4 in the horizontal axis direction. Thus, if the γ characteristic can be made to have a gentle slope like that of the conventional toner, it is possible to suppress a change in hue caused by the presence of an excessive amount of toner having high coloring power, and at the same time, to improve stability against potential fluctuation. For this purpose, it is necessary to increase the charge amount of the toner in order to fill the contrast potential Vcont (= 500 V) equivalent to that of the conventional toner with half the toner amount of the conventional toner. In order to obtain a saturated image density at a contrast potential of a loading amount of 0.25 mg / cm ² and Vcont = 500 V using the toner with increased coloring power of the present invention, the triboelectric charge amount is twice that of the conventional toner and saturated. If toner is developed efficiently with a charge amount of −80 C / kg, gradation can be formed with the same γ characteristics as conventional toners. In order to maintain high gradation and reduce density fluctuation while reducing the applied amount with toner having increased coloring power, it is necessary to efficiently develop it as a toner having a high triboelectric charge amount.

[Aluminum phthalocyanine]
The cyan toner used in the present invention further contains aluminum phthalocyanine. Currently, copper phthalocyanine is mainly used as a colorant for cyan. This is because the hue is clear and the resistance to heat, light and the like is excellent. The reason is that since the molecular structure is a macrocyclic complex compound, electrons are delocalized and exhibit stable properties. However, due to the stability of the molecular structure, it is difficult to ensure dispersion stability because of the low polarity among organic pigments. In particular, in order to disperse copper phthalocyanine in a resin having polarity such as a polyester resin, materials and manufacturing processes have been devised. For example, adding a master batch process or using a hybrid resin in which a non-polar styrene acrylic resin is mixed with a polyester resin. In the case of the conventional colorant amount, it was possible to make copper phthalocyanine highly dispersed by using such a method. However, in the case of a high colorant amount as in the present invention, there was a quality problem with the conventional method. Thus, as a result of intensive studies, the inventors have found that high dispersion stability can be obtained by containing aluminum phthalocyanine.
The present inventors consider that the reason is that aluminum phthalocyanine functions as a dispersant. That is, aluminum having an ionization potential smaller than that of copper is easily detached by acid or water. For this reason, it is considered that the dissociated aluminum ions make it easier for the copper phthalocyanine and the resin to conform to each other, so that high dispersibility can be obtained even when a high colorant amount is added.

  A well-known thing can be used as aluminum phthalocyanine (AlPc) used for this invention. For example, “Al-phtalocyanine” (manufactured by Sanyo Pigment) One example of the production method is produced by reacting phthalonitrile or 1,3-diiminoisoindoline in a high boiling point organic solvent such as 1-chloronaphthalene or quinoline in the presence of aluminum chloride. The manufacturing method is not particularly limited. AlPc has a structure such as chloro AlPc, hydroxy AlPc, and AlPc dimer depending on the synthesis method and pigmentation method, and is usually used alone or as a mixture thereof. In the present invention, it is preferable to use an AlPc dimer which is most excellent in various fastness properties, but is not limited thereto.

  The produced AlPc has coarse particles and a poor hue. For this reason, a pigment refining step is usually performed for adjusting crystallinity and adjusting the shape and particle diameter of crystal particles to a desired range. The method can be carried out according to a conventionally known method such as a chemical or physical method. As an example of a chemical method, there is a method in which AlPc is dissolved in concentrated sulfuric acid or polyphosphoric acid, and the solution is poured into water to precipitate a solid solution of AlPc into fine particles. Moreover, as a physical method, it can be obtained by a method in which AlPc is ground to form solid solution fine particles. The grinding method includes a salt milling method and a solvent salt milling method, and an inorganic salt such as anhydrous sodium sulfate, sodium chloride, and aluminum sulfate is used as a grinding aid. After the purification step, fine pigment is obtained by further washing and filtering. By passing through the above process, the aluminum phthalocyanine which can improve the dispersibility of copper phthalocyanine can be obtained. As a result, an image having good hue, transparency, etc., and excellent in various fastnesses such as light resistance, heat resistance, solvent resistance, chemical resistance, and water resistance can be obtained.

  For the same purpose as described above, after preparing a composite pigment or at the time of dispersing the pigment, conventionally known pigment treatment agents, dispersants or surfactants such as rosin, aliphatic amines, AlPc derivatives, polymer dispersants, etc. Etc. may be used to treat the pigment.

  The content of aluminum phthalocyanine used in the present invention is preferably 0.1 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the binder resin in the toner particles. More preferably, it is 0.2 parts by mass or more and 4.0 parts by mass or less. When the content of aluminum phthalocyanine is less than 0.1 parts by mass, the dispersibility of the colorant is deteriorated, and a lot of colorant is exposed on the toner surface, so that the toner tends to aggregate. As a result, image defects are likely to occur. Further, when the content of aluminum phthalocyanine exceeds 6.0 parts by mass, the hue changes greatly, and the transparency of the image tends to deteriorate.

  The amount of free aluminum of the aluminum phthalocyanine used in the present invention was measured by a combined induction plasma emission spectrometer (ICP). The amount of free aluminum contained in the aluminum phthalocyanine is preferably 0.1 ppm or more and 10.0 ppm or less. More preferably, it is 0.1 ppm or more and 7.0 ppm or less.

As a specific measurement method, aluminum ions contained in aluminum phthalocyanine can be eluted by dissolving aluminum phthalocyanine in an aqueous hydrochloric acid solution. By measuring the solution using ICP (ICPS-8000: Shimadzu Corporation) according to the attached instruction manual, free aluminum in aluminum phthalocyanine can be obtained. When the amount of free aluminum is less than 0.1 ppm, the dispersion of the colorant such as copper phthalocyanine is insufficient, and toner aggregation tends to occur. When the amount of free aluminum exceeds 10.0 ppm, the triboelectric charge amount becomes unstable and the image density is not stable.
The amount of free aluminum in aluminum phthalocyanine is adjusted by the step of producing aluminum phthalocyanine. Specifically, it can be adjusted by changing the conditions of acid washing during purification.

[Lightness L * and saturation C * of cyan toner]
In the present invention, the lightness L ^* obtained in the powder state of the cyan toner used in the present invention is preferably 25.0 ≦ L ^* ≦ 40.0. More preferably, 28.0 ≦ L ^* ≦ 40.0. The chroma C ^* is preferably 50.0 ≦ C ^* ≦ 60.0. When the lightness L ^* and chroma C ^* obtained in the powder state of the cyan toner are in this range, the dispersibility of the pigment is good and stable durability characteristics are obtained. In addition, the amount of toner on the transfer material can be reduced, and a reduction in fixing energy can be achieved. As a result, various recording papers such as plain paper, thick paper, and coated paper can be handled.
When L ^* is less than 25.0, when a full-color image is formed in combination with other color toners, the dispersibility of the colorant deteriorates, and the charging stability during durability cannot be obtained and fogging occurs. There is. If L ^* exceeds 40.0, the image density cannot be obtained. For this reason, in order to obtain the necessary density, the amount of toner on the recording paper is increased, and the level of dust and voids at the time of transfer fixing is lowered. As a result, the toner level difference becomes large and the image quality may deteriorate.
When C ^* is less than 50.0, it is difficult to obtain an image density. If C ^* exceeds 60.0, the color balance may be lost when a full-color image is formed. A toner having an increased content of colorant usually changes in hue due to a change in the dispersion state of the colorant, and L ^* and C ^* may change. This is presumed that as a result of increasing the content of the colorant, re-aggregation of the pigment occurred, the coloring power was further reduced, and the hue was changed.
The lightness L ^* is an index indicating the dispersion state of the colorant, and can be adjusted by making the addition amount of the colorant and the colorant a master batch. The chroma C ^* is an index indicating the uniformity of the colorant, and can be adjusted by sharpening the particle size distribution of the colorant.

The toner used in the present invention can be obtained by suspension polymerization, emulsion polymerization, associative polymerization, or kneading and pulverization, and the production method is not particularly limited.

The toner manufacturing process used in the present invention includes a heating and kneading process in which a first kneaded product (colorant master batch) is obtained by heating and kneading a mixture containing at least a first binder resin and a colorant, A melt-kneading step of melt-kneading a mixture containing at least the binder resin and the colorant master batch to obtain a second kneaded product, and a pulverizing step of pulverizing the second kneaded product. preferable. By making the colorant into a master batch in this way, the dispersion of the colorant in the toner is in an optimal state, and the chargeability of the toner is stabilized. As a result, excellent developability is exhibited, fogging to the image background portion, which is likely to occur due to non-uniform charging, is very small, and the image density is stable even when a large number of images are output.

  It is also preferable to add aluminum phthalocyanine when the colorant is masterbatched. By making a colorant and aluminum phthalocyanine into a master batch, high dispersion of the colorant is further promoted, and a stable image density can be obtained.

  In this master batch process, for example, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader such as an open roll continuous kneader can be used. In recent years, single-screw or twin-screw extruders have become mainstream due to the advantage of continuous production. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd. -Commonly used are a twin-screw extruder manufactured by Sea Kay, a co-kneader manufactured by Buss, an open roll continuous kneading granulator manufactured by Mitsui Mining.

  The cyan toner used in the present invention contains at least a binder resin and a colorant, and the weight average particle size of the toner is preferably 4.0 μm or more and 8.0 μm or less, preferably 4.0 μm or more, It is more preferably 7.0 μm or less, and further preferably 4.5 μm or more and 6.5 μm or less. When the weight average particle diameter of the toner is 4.0 μm or more and 8.0 μm or less, dot reproducibility and transfer efficiency can be sufficiently improved. The weight average particle diameter of the toner can be adjusted by classification of the toner particles and mixing of classified products at the time of manufacture. If the weight average particle size of the toner is greater than 8.0 μm, there are few toner particles that can contribute to high image quality, it is difficult to adhere to the fine electrostatic image on the photosensitive drum faithfully, and the highlight reproducibility is poor. The resolution is also low. Further, unnecessary development of the toner on the electrostatic charge image occurs, and the toner consumption tends to increase. On the other hand, if the weight average particle diameter of the toner is smaller than 4.0 μm, the charge amount per unit mass of the toner becomes high, and the image density is likely to be thin particularly at low temperature and low humidity. In particular, it is not suitable for developing an image having a high image area ratio such as a graphic image. Further, the chromatic color toner and the transparent toner may have different weight average particle diameters.

Circle equivalent diameter (number basis) of 2.0 μm measured by a flow type particle image measuring apparatus having a toner image processing resolution of 512 × 512 pixels (0.37 μm × 0.37 μm per pixel).
The average circularity of the cyan toner at m to 200 μm is preferably 0.945 or more and 0.970 or less. When the average circularity is less than 0.945, the contact point between the toner and the carrier is increased and the adhesion is increased, so that the developability may be lowered. Therefore, it is not preferable in a system in which a high triboelectric charge amount toner as in the present invention must be developed efficiently. Furthermore, when an image is output on a large number of sheets, the external additive is embedded to cause deterioration of the toner, which may be unsatisfactory in transferability. Further, if the average circularity is greater than 0.970, the shape of the toner particles becomes too spherical, and image defects due to poor cleaning may occur, such as transfer residual toner slipping through the cleaning blade when the photosensitive drum is cleaned. is there.

  Preferable embodiments of the toner used in the present invention include the toner of the following first embodiment and the toner of the second embodiment.

  The toner of the first aspect used in the two-component developer of the present invention is a toner having toner particles containing a resin mainly composed of a polyester unit and a colorant (hereinafter also referred to as “the toner of the first aspect”). ). “Polyester unit” refers to a part derived from polyester, and “resin mainly composed of polyester unit” means a resin in which many of the repeating units constituting the resin are repeating units having an ester bond. However, these will be described in detail later.

The polyester unit is formed by condensation polymerization of ester monomers. Examples of the ester-based monomer include a polyhydric alcohol component and a carboxylic acid component such as a polyvalent carboxylic acid, a polyvalent carboxylic acid anhydride, or a polyvalent carboxylic acid ester having two or more carboxyl groups.

  The following are mentioned as a dihydric alcohol component among a polyhydric alcohol component. 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) -polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) Bisphenol A alkylene oxide adducts such as -2,2-bis (4-hydroxyphenyl) propane; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1 , 4-butanediol, neopentyl glycol, 1,4-butenedio , 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A.

  Examples of the trihydric or higher alcohol component among the polyhydric alcohol components include the following. Sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene.

  The following are mentioned as a carboxylic acid component which comprises a polyester unit. Aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or their anhydrides; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or their anhydrides; substituted with an alkyl group having 6 to 12 carbon atoms Succinic acid or anhydride thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or anhydrides thereof.

  Preferable examples of the resin having a polyester unit contained in the toner particles of the first aspect include the following. That is, a bisphenol derivative typified by the structure represented by the chemical formula (1) as an alcohol component, a carboxylic acid component (for example, fumaric acid, a carboxylic acid having two or more valences or an acid anhydride thereof, or a lower alkyl ester thereof) This is a polyester resin obtained by polycondensation of maleic acid, maleic anhydride, phthalic acid, terephthalic acid, dodecenyl succinic acid, trimellitic acid, pyromellitic acid) as carboxylic acid components. This polyester resin has good charging characteristics. The charging characteristics of this polyester resin work more effectively when used as a resin contained in a color toner contained in a two-component developer.

〔式中、Ｒはエチレン基及びプロピレン基から選ばれる１種以上であり、ｘ及びｙはそ
れぞれ１以上の整数であり、且つｘ＋ｙの平均値は２以上、１０以下である。〕

[In the formula, R is at least one selected from an ethylene group and a propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 or more and 10 or less. ]

  A preferred example of the resin having a polyester unit contained in the toner particles of the first aspect includes a polyester resin having a cross-linked site. The polyester resin having a crosslinking site can be obtained by subjecting a polyhydric alcohol and a carboxylic acid component containing a trivalent or higher polyvalent carboxylic acid to a condensation polymerization reaction. Examples of the trivalent or higher polyvalent carboxylic acid component include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 2,5,7. -Naphthalene tricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, and acid anhydrides and ester compounds thereof. The content of the trivalent or higher polyvalent carboxylic acid component contained in the ester-based monomer to be polycondensed is preferably 0.1 mol% or more and 1.9 mol% or less based on the total monomers.

Further, preferable examples of the resin having a polyester unit contained in the toner particles of the first aspect include (a) a hybrid resin having a polyester unit and a vinyl polymer unit, and (b) a hybrid resin and a vinyl type. A mixture of a polymer, (c) a mixture of a polyester resin and a vinyl polymer, (d) a mixture of a hybrid resin and a polyester resin, and (e) a mixture of a polyester resin, a hybrid resin and a vinyl polymer. It is done.
The hybrid resin is formed by a transesterification reaction between a polyester unit and a vinyl polymer unit obtained by polymerizing a monomer component having a carboxylic ester group such as an acrylic ester. Examples of the hybrid resin include a graft copolymer or a block copolymer having a vinyl polymer as a trunk polymer and a polyester unit as a branch polymer. The vinyl polymer unit refers to a portion derived from a vinyl polymer. A vinyl polymer unit or a vinyl polymer is obtained by polymerizing a vinyl monomer described later.

  The toner of the second embodiment used in the two-component developer of the present invention is a toner having toner particles obtained from a direct polymerization method or in an aqueous medium (hereinafter also referred to as “the toner of the second embodiment”). is there. The toner according to the second aspect may be produced by a direct polymerization method, or may be produced by previously forming emulsified fine particles and then aggregating together with a colorant and a release agent. The toner having toner particles produced by the latter is also referred to as “a toner obtained from an aqueous medium” or “a toner obtained by an emulsion polymerization method”.

  The toner of the second aspect preferably has toner particles having a resin mainly composed of a vinyl resin, obtained by a direct polymerization method or an emulsion polymerization method. The vinyl resin that is the main component of the toner particles is produced by polymerization of a vinyl monomer. The following are mentioned as a vinyl-type monomer. Styrenic monomers, acrylic monomers; methacrylic monomers; monomers of ethylenically unsaturated monoolefins; monomers of vinyl esters; monomers of vinyl ethers; monomers of vinyl ketones; monomers of N-vinyl compounds: other vinyl monomers.

The following are mentioned as a styrene-type monomer. Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethyl Styrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene . The following are mentioned as an acryl-type monomer. Methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, dimethylaminoethyl acrylate,
Acrylic esters such as phenyl acrylate, acrylic acid and acrylic amides. Examples of methacrylic monomers include the following. Ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, methacryl Methacrylic acid esters such as diethylaminoethyl acid and methacrylic acid and methacrylic acid amides. Examples of the monomer of the ethylenically unsaturated monoolefins include ethylene, propylene, butylene, and isobutylene. Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl benzoate. Examples of vinyl ether monomers include vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether. Examples of the vinyl ketone monomers include vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone. Examples of the monomer of the N-vinyl compound include N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, and N-vinyl pyrrolidone. Other vinyl monomers include acrylic acid derivatives or methacrylic acid derivatives such as vinyl naphthalenes, acrylonitrile, methacrylonitrile and acrylamide. These vinyl monomers can be used alone or in combination of two or more.

  The following are mentioned as a polymerization initiator used when manufacturing a vinyl-type resin. 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis Azo or diazo polymerization initiators such as -4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butyl hydroperoxide, Di-t-butyl peroxide, dicumyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis (4,4-t-butylperoxycyclohexyl) propane, tris- (t-butylperoxy) triazine Peroxidation Initiator having a system initiator or a peroxide in the side chain; potassium persulfate, such as ammonium persulfate persulfate; hydrogen peroxide.

  Examples of the radical polymerizable trifunctional or higher polymerization initiator include the following. Tris (t-butylperoxy) triazine, vinyltris (t-butylperoxy) silane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 2,2-bis (4,4 -Di-t-amylperoxycyclohexyl) propane, 2,2-bis (4,4-di-t-octylperoxycyclohexyl) propane, 2,2-bis (4,4-di-t-butylperoxy) Radical polymerizable polyfunctional polymerization initiators such as (cyclohexyl) butane.

  The toner used in the present invention is preferably the toner of the first aspect. As the resin having a polyester unit used at that time, two or more kinds of the above-described resins may be used.

  Examples of the colorant for the toner used in the present invention include the following. C. I. Pigment Blue 2, 3, 15, 15: 1, 15: 2, 15: 3, 16, 17; I. Acid Blue 6; I. A copper phthalocyanine pigment having 1 to 5 phthalimidomethyl groups substituted on Acid Blue 45 or a phthalocyanine skeleton. These pigments may be used alone or in combination. As the colorant preferably used, C.I. I. Pigment Blue 15: 3.

As an example of a method for producing a colorant, copper phthalocyanine (CuPc) is shown as an example. In a high-boiling organic solvent such as 1-chloronaphthalene or quinoline, phthalonitrile or 1,3-diiminoisoindoline is used. It is produced by reacting in the presence. The manufacturing method is not particularly limited. CuPc has a structure such as chloro CuPc, hydroxy CuPc, and CuPc dimer depending on the synthesis method and pigmentation method, and is usually used alone or as a mixture thereof. In the present invention, it is preferable to use a CuPc dimer that is most excellent in various fastness properties, but is not limited thereto.

  The produced colorant has coarse particles and poor hue. For this reason, a pigment refining step is usually performed for adjusting crystallinity and adjusting the shape and particle diameter of crystal particles to a desired range. The method can be carried out according to a conventionally known method such as a chemical or physical method. As an example of a chemical method, there is a method in which CuPc is dissolved in concentrated sulfuric acid or polyphosphoric acid, and the solution is poured into water to precipitate a solid solution of CuPc into fine particles. As a physical method, CuPc is ground to obtain solid solution fine particles. The grinding method includes a salt milling method and a solvent salt milling method, and an inorganic salt such as anhydrous sodium sulfate, sodium chloride, and aluminum sulfate is used as a grinding aid. After the purification step, fine pigment is obtained by further washing and filtering. By passing through the above steps, a colorant having good hue, transparency and the like, and excellent in various fastnesses such as light resistance, heat resistance, solvent resistance, chemical resistance and water resistance can be obtained.

  Furthermore, for the same purpose as described above, after preparation of the composite pigment or at the time of dispersion of the pigment, conventionally known pigment treatment agents, dispersants or surfactants such as rosin, aliphatic amines, CuPc derivatives, polymer dispersants, etc. Etc. may be used to treat the pigment.

  The content of the colorant in the toner used in the present invention is preferably 5.0 parts by mass or more and 25.0 parts by mass or less with respect to 100 parts by mass of the binder resin in the toner particles. More preferably, it is 5.5 parts by mass or more and 20.0 parts by mass or less. If the content of the colorant is less than 5.0 parts by mass, the toner consumption cannot be reduced, and dust is generated at the time of transfer and fixing, or the central part of the line image and the character image line is transferred. In some cases, “transfer skipping” occurs in which only the edge portion is transferred. Moreover, when content of a coloring agent exceeds 25.0 mass parts, although sufficient coloring power is obtained, the brightness falls, an image is dark and vividness tends to fall. Also, the increased amount of colorant exposed to the toner surface adversely affects the chargeability of the toner, resulting in weakly charged toner, fogging on the white background of the image, and contamination of the device due to toner scattering. Sometimes.

Further, when the content of the colorant of the toner used in the present invention is X parts by mass and the content of aluminum phthalocyanine is Y parts by mass, it is preferable that the following formula (2) is satisfied.
1.0 ≦ (Y / X) × 100 ≦ 50.0 (2)
When ((Y / X) × 100) is less than 1.0, the dispersibility of the colorant deteriorates and a large amount of colorant is exposed on the toner surface, so that the toner is likely to aggregate. As a result, image defects are likely to occur. When ((Y / X) × 100) exceeds 50.0, the hue changes greatly, and the transparency of the image tends to deteriorate. More preferably, 2.0 ≦ (Y / X) × 100 ≦ 30.0.

  Both of the two-component developer using the toner of the first aspect and the toner of the second aspect of the present invention are preferably used in an electrophotographic process employing oilless fixing. Therefore, the toner (the toner of the first aspect and the toner of the second aspect) used for the two-component developer of the present invention preferably contains a release agent.

Examples of the release agent include the following. Low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, aliphatic hydrocarbon wax such as Fischer-Tropsch wax; oxide of aliphatic hydrocarbon wax such as oxidized polyethylene wax, Or block copolymers thereof; waxes based on fatty acid esters such as carnauba wax, montanic acid ester wax, and behenyl behenate; partially or fully deoxidized fatty acid esters such as deoxidized carnauba wax . Suitable release agents include hydrocarbon waxes and paraffin waxes.
The toner used in the two-component developer of the present invention has one or more endothermic peaks in the temperature range of 30 ° C. or higher and 200 ° C. or lower in the endothermic curve of the toner in differential scanning calorimetry (DSC). The maximum endothermic peak temperature in the endothermic peak is desirably 50 ° C. or higher and 110 ° C. or lower. This is because the toner can have good low-temperature fixability and durability.
Examples of the differential scanning calorimetry (DSC) apparatus include DSC-7 manufactured by PerkinElmer, DSC2920 manufactured by TA Instruments, and Q1000 manufactured by TA Instruments. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium. Use an aluminum pan as the measurement sample, set an empty pan for control, and measure according to the attached instruction manual.

  The content of the release agent for the toner used in the present invention is preferably 1 part by mass or more and 15 parts by mass or less, with respect to 100 parts by mass of the binder resin in the toner particles. It is more preferable that the amount is not more than parts. When the content of the release agent is 1 part by mass or more and 15 parts by mass or less, good transferability can be exhibited during oilless fixing.

  The toner used in the present invention may contain a charge control agent. Examples of the charge control agent include organometallic complexes, metal salts, and chelate compounds. Examples of the organometallic complex include a monoazo metal complex, an acetylacetone metal complex, a hydroxycarboxylic acid metal complex, a polycarboxylic acid metal complex, and a polyol metal complex. Other examples include carboxylic acid derivatives such as metal salts of carboxylic acids, carboxylic acid anhydrides, and esters, and condensates of aromatic compounds. Also, phenol derivatives such as bisphenols and calixarenes can be used as the charge control agent. The charge control agent contained in the toner in the present invention is preferably an aluminum compound of an aromatic carboxylic acid from the viewpoint of improving the charge rising of the toner and the dispersibility of the pigment.

  The content of the charge control agent in the toner used in the present invention is preferably 0.1 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the binder resin in the toner particles. More preferably, it is at least 5.0 parts by mass. The toner has a charge control agent of 0.1 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the binder resin in the toner particles, so that the toner can be used in a wide range of environments from high temperature and high humidity to low temperature and low humidity. The change in the charge amount can be reduced.

  The toner used in the present invention may be externally added with external additives which are fine particles. When the fine particles are externally added, fluidity and transferability can be improved. The external additive externally added to the toner particle surface preferably contains inorganic fine particles of titanium oxide, alumina oxide, and silica fine particles. The surface of the inorganic fine particles contained in the external additive is preferably subjected to a hydrophobic treatment. The hydrophobizing treatment is preferably carried out by a hydrophobizing agent such as various titanium coupling agents and coupling agents such as silane coupling agents; fatty acids and metal salts thereof; silicone oils; or combinations thereof.

  Examples of the titanium coupling agent for hydrophobizing the inorganic fine particles contained in the external additive include the following. Tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate.

  Moreover, the following are mentioned as a silane coupling agent. γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ -Aminopropyltrimethoxysilane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyl Trimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane.

  Examples of the fatty acid for hydrophobizing the inorganic fine particles include the following. Examples include long-chain fatty acids such as undecyl acid, lauric acid, tridecyl acid, dodecyl acid, myristic acid, palmitic acid, pentadecyl acid, stearic acid, heptadecylic acid, arachidic acid, montanic acid, oleic acid, linoleic acid, and arachidonic acid. Zinc, iron, magnesium, aluminum, calcium, sodium, lithium are the metals of these fatty acid metal salts.

  Examples of the silicone oil for performing the hydrophobizing treatment include dimethyl silicone oil, methylphenyl silicone oil, and amino-modified silicone oil.

  The content of the external additive of the toner used in the present invention is preferably 0.1 parts by mass or more and 5.0 parts by mass or less, and 0.5 parts by mass or more and 4.0 parts by mass with respect to the toner particles. It is more preferable that the amount is not more than parts. The external additive may be a combination of a plurality of types of fine particles.

  The magnetic carrier used in the present invention is not particularly limited, but metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium and rare earths whose surface is oxidized or not oxidized. , Their alloy particles, oxide particles and ferrite. The magnetic carrier may be a so-called resin-impregnated carrier in which a porous magnetic material (including porous ferrite) is impregnated with a resin, and the magnetic material-containing resin in which the magnetic material is dispersed in the resin. It may be a carrier. In the present invention, among the above magnetic carriers, it is preferable to use a magnetic substance-containing resin carrier in which a magnetic substance is dispersed in a resin.

  Examples of the method for producing the magnetic substance-containing resin carrier include a method obtained by polymerizing a monomer constituting the resin in the presence of the magnetic substance. In the above method, the monomers used for the polymerization include vinyl monomers, bisphenols and epichlorohydrin for forming epoxy resins; phenols and aldehydes for forming phenol resins; urea resins. Examples include urea and aldehydes for forming, and melamine and aldehydes for forming melamine resin.

  As another method for producing the above magnetic substance-containing resin carrier, a vinyl-type or non-vinyl-type thermoplastic resin, a magnetic substance, and other additives are sufficiently mixed by a mixer, and then a heating roll, a kneader, and an extruder. A method of obtaining a magnetic substance-containing resin carrier core by melting and kneading using a kneader such as the above, cooling, and then pulverizing and classifying can be mentioned. At this time, it is preferable that the obtained magnetic substance-containing resin carrier core is thermally or mechanically spheroidized and used as a magnetic substance-containing resin carrier.

The content of the magnetic substance used for the magnetic substance-containing resin carrier is 70% by mass or more and 95% by mass or less (more preferably 80% by mass or more and 92% by mass or less) with respect to the magnetic substance-containing resin carrier. However, it is preferable for reducing the true specific gravity of the magnetic carrier and ensuring sufficient mechanical strength. Furthermore, in order to adjust the magnetic properties of the magnetic carrier, a part of the magnetic substance contained in the magnetic substance-containing resin carrier may be replaced with a nonmagnetic inorganic compound. When a part of the magnetic material is replaced with a nonmagnetic inorganic compound, the magnetic material is contained in an amount of 30% by mass or more and 99% by mass or more based on the total amount of the magnetic material and the nonmagnetic inorganic compound. It is preferable for adjusting the strength of magnetization of the body-containing resin carrier to prevent carrier adhesion, and further for adjusting the specific resistance value of the magnetic body-containing resin carrier.

In the magnetic substance-containing resin carrier, the magnetic substance is preferably magnetite fine particles or magnetic ferrite fine particles containing at least an iron element, and the nonmagnetic inorganic compound is hematite (α-Fe ₂ O ₃ ). Fine particles are more preferable in terms of making the dispersibility in the carrier uniform and adjusting the magnetic properties and true specific gravity of the carrier.

  The number average particle diameter of the magnetic material is preferably 0.02 μm or more and 2.00 μm or less from the viewpoint of making the state of the particle surface of the magnetic carrier uniform. The nonmagnetic inorganic compound preferably has a number average particle size of 0.05 μm or more and 5.00 μm or less, and the nonmagnetic inorganic compound has a larger particle size than the magnetic material. It is preferable for increasing the surface resistance value.

  The surface of the magnetic substance-containing resin carrier is preferably coated with a coating material from the viewpoint of charge imparting properties and releasability. As a resin for forming the coating material, an insulating resin is preferably used. The insulating resin may be a thermoplastic resin or a thermosetting resin.

Specific examples of the resin for forming the coating material include thermoplastic resins such as polystyrene, polymethyl methacrylate and acrylic resins such as styrene-acrylic acid copolymer, styrene-butadiene copolymer, and ethylene-acetic acid. Vinyl copolymer, polyvinyl chloride, polyvinyl acetate, polyvinylidene fluoride resin, fluorocarbon resin, perfluorocarbon resin, solvent-soluble perfluorocarbon resin, polyvinyl alcohol, polyvinyl acetal, polyvinylpyrrolidone, petroleum resin, cellulose, cellulose acetate, cellulose nitrate , Cellulose derivatives such as methylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, novolak resin, low molecular weight polyethylene, saturated alkyl polyester Le resin, polyethylene terephthalate, polybutylene terephthalate, polyarylates such aromatic polyester resins, polyamide resins, polyacetal resins, polycarbonate resins, polyethersulfone resins, polysulfone resins, polyphenylene sulfide resins, polyether ketone resins.
Examples of thermosetting resins include phenolic resins, modified phenolic resins, maleic resins, alkyd resins, epoxy resins, acrylic resins, or unsaturated polyesters obtained by polycondensation of maleic anhydride, terephthalic acid, and polyhydric alcohols. , Urea resin, melamine resin, urea-melamine resin, xylene resin, toluene resin, guanamine resin, melamine-guanamine resin, acetoguanamine resin, gliptal resin, furan resin, silicone resin, polyimide, polyamideimide resin, polyetherimide resin, Polyurethane resin. These resins can be used alone or in combination. In addition, a curing agent or the like can be mixed with a thermoplastic resin and cured for use. A particularly preferred mode of use is to use a resin having a higher release property for a toner having a small particle diameter and containing a release agent.

Further, the coating material preferably contains conductive particles or charge controllable particles. As such a coating material, for example, a resin that forms the coating material or a monomer that forms the resin contains conductive particles or charge controllable particles, and the resin or monomer is appropriately used. It is preferable to coat the magnetic substance-containing resin carrier by a method. These particles are important in terms of soft and quick charging to a toner having a small particle size and low temperature fixability.

The particles having conductivity are preferably those having a specific resistance of 1 × 10 ⁸ Ωcm or less, and more preferably those having a specific resistance of 1 × 10 ⁶ Ωcm or less. Specifically, the conductive particles are preferably particles containing at least one kind of particles selected from carbon black, magnetite, graphite, zinc oxide, and tin oxide. In particular, as the particles having conductivity, carbon black having good conductivity is preferable in terms of improving the charge imparting property (rise of charge amount) to the toner.

  It is preferable that the conductive particles have a number average particle size of 1 μm or less in order to prevent the particles from falling off from the carrier and to function as a uniform conductive site.

  The particles having charge controllability include organometallic complex particles, organometallic salt particles, chelate compound particles, monoazo metal complex particles, acetylacetone metal complex particles, hydroxycarboxylic acid metal complex particles, and polycarboxylic acid. Examples include metal complex particles and polyol metal complex particles. The particles may be a charge control agent dispersed in the toner particles. However, it is preferable to use inorganic particles treated with resin particles having a functional group or a treatment agent having a functional group to improve the charge imparting property to the toner. It is preferable to make it. Specifically, the particles having charge controllability include polymethyl methacrylate resin particles, polystyrene resin particles, melamine resin particles, phenol resin particles, nylon resin particles, silica particles, titanium oxide particles, And particles containing at least one kind of particles selected from alumina particles. Moreover, when using inorganic particle | grains as said particle | grain, it is preferable to process and use various coupling agents, in order to express charge control property and electroconductivity.

  The particles having charge controllability preferably have a number average particle diameter of 0.01 μm or more and 1.50 μm or less in order to work as a uniform charging site. The coating amount of the resin forming the coating material on the magnetic substance-containing resin carrier is 0.1 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the magnetic substance-containing resin carrier core. It is preferable for enhancing the charge imparting property to the toner and the durability of the magnetic carrier.

  The blending amount of the conductive particles and charge controllable particles in the coating material is 0.1 parts by mass or more and 30.0 masses in total with respect to 100 parts by mass of the resin forming the coating material. Part or less. When the conductive particles and the charge controllable particles are added to the coating material in an amount exceeding 30.0 parts by mass, the particles are difficult to disperse in the resin forming the coating material, and the magnetic substance-containing resin carrier Therefore, the particles tend to be detached. In particular, when carbon black is added, the toner tends to cause contamination of the toner and components due to carbon black as it is durable. If the amount of the conductive particles or the charge controllable particles is less than 0.1 parts by mass, a desired charge amount may not be obtained.

The magnetic carrier preferably has a volume-based 50% particle size (D50) of 15 μm or more and 70 μm or less (more preferably 25 μm or more and 50 μm or less) in relation to the weight average particle size of the toner. As a method for preparing the volume-based 50% particle size (D50) of the magnetic carrier in the above range, for example, classification can be performed by using a sieve. In particular, in order to classify with high accuracy, it is preferable to repeat a plurality of times using a sieve having an appropriate opening. It is also an effective means to use a mesh opening whose shape is controlled by plating or the like. When the volume-based 50% particle size (D50) of the magnetic carrier is less than 15 μm, the rising of the developer due to the magnetic force on the developing carrier is not uniform, and the uniformity of the solid image tends to be lost. is there. Further, the fluidity of the developer is deteriorated and the rising of the charge tends to be deteriorated. On the other hand, the volume-based 50% particle size (D50) of the magnetic carrier is 70 μm.
In the case where it exceeds 1, the developer standing due to magnetism is high, and the developer is unevenly swept by the ears, so the image quality tends to deteriorate.

The true specific gravity of the magnetic carrier is preferably 2.5 g / cm ³ or more and 4.2 g / cm ³ or less. The true specific gravity of the magnetic carrier is 2.5 g / cm ³
If it is smaller, frictional charging of the toner with the magnetic carrier is not easily performed in the developing unit, and image defects such as fogging may occur. Further, when the true specific gravity of the magnetic carrier exceeds 4.2 g / cm ³ , the shearing force on the carrier and the toner is increased in the developing device, the toner spent on the carrier is easily generated, and the durability tends to be inferior. Become.

  When preparing a two-component developer in the present invention, the mixing ratio is usually such that the toner concentration in the developer is 2% by mass or more and 15% by mass or less, preferably 4% by mass or more and 13% by mass or less. Good results are obtained. If the toner concentration is less than 2% by mass, the image density tends to decrease, and if it exceeds 15% by mass, fogging and in-machine scattering tend to occur.

When preparing a two-component developer in the present invention, a predetermined amount of toner and magnetic carrier are weighed and mixed in a mixer. Examples of the mixing apparatus include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, and a Nauta mixer. Among these, the V-type mixer is preferable in consideration of the dispersibility of the magnetic carrier and the charge rising of the toner.

The image forming method of the present invention comprises a charging step for charging the image carrier, a latent image forming step for forming an electrostatic latent image on the image carrier charged in the charging step, and a formation on the image carrier. A developing step of developing the electrostatic latent image formed with toner to form a toner image, a transfer step of transferring the toner image on the image carrier to a transfer material with or without an intermediate transfer member, and the toner An image forming method including a fixing step of fixing an image on a transfer material, wherein the amount of the cyan toner applied to the single-color solid image portion formed on the transfer material is 0.10 mg / cm ² or more and 0.35 mg / cm A range of ² or less is preferred. When the amount of the cyan toner applied is less than 0.10 mg / cm ² , the toner particle number is insufficient even if the coloring power of one toner particle is increased, and the density increases due to the influence of the formation of the recording paper. There may not be. On the other hand, if it exceeds 0.35 mg / cm ² , the toner level difference becomes conspicuous, which may cause a problem in image quality. Also, dust during transfer / fixing may become noticeable.

In the present invention, an auto-refresh (ACR) developing system that uses the two-component developer as a replenishment developer can be used. It is also possible. By developing while supplying the developer for replenishment to the developing device, and discharging the excess magnetic carrier inside the developing device from the developing device, it is easy to maintain the performance of the two-component developer in the developing device. That is, it becomes possible to insert a new magnetic carrier, and it is possible to achieve a long life of the developer. As described above, when the two-component developer of the present invention is used as a replenishment developer, the replenishment developer contains 2% by mass or more and 50% by mass or less of the toner with respect to 1 part by mass of the magnetic carrier. It is preferable to contain in the compounding ratio. By using a replenishment developer having a blending ratio in this range, it is easy to maintain a stable developer performance over a long period of time, there is little fluctuation in toner chargeability, dot reproducibility is good, and an image with little fog is obtained. Easy to get.
Note that the two-component developer (hereinafter also referred to as a “starting developer”) that is initially charged in the developing device and the toner and magnetic carrier used in the replenishing developer are the same or different. It does not matter.

  The measurement method according to the present invention will be described below.

<Measurement method of absorbance per unit concentration of toner>
The absorbance per unit concentration of toner in the present invention was determined as follows. The toner chloroform solution was adjusted to a concentration of mg / mL, and specifically, it was subjected to measurement as a chloroform solution of about 0.1 mg / mL.
The solution was used as a sample for UV-visible spectrophotometry. For the measurement, a UV-visible spectrophotometer V-500V (manufactured by JASCO Corporation) is used. The measurement was performed according to the attached instruction manual, and the absorbance of the solution was measured in a wavelength range of 350 nm to 800 nm using a quartz cell having an optical path length of 10 mm. The absorbance A / C per unit concentration is calculated by reading the absorbance (A) at the wavelength at which the absorbance of the solution at the wavelength of 660 nm or more and 760 nm or less is maximum and dividing by the toner concentration (C) of the chloroform solution. did.

<Lightness L ^* and Saturation C ^* of Toner in Powder State>
L ^* and C ^* in cyan toner in a powder state are D50 as an observation light source and 2 as an observation field using a spectroscopic color difference meter “SE-2000” (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS Z-8722. Measure in degrees. The measurement is performed according to the attached instruction manual. For standard adjustment of the standard plate, it is preferable to perform the measurement through a glass of 2 mm thickness and Φ30 mm in an optional powder measurement cell. More specifically, the measurement is performed in a state where a cell filled with the sample powder is placed on the sample table (attachment) for the powder sample of the spectral color difference meter. Before installing the cell on the sample table for the powder sample, fill the powder sample with 80% or more with respect to the internal volume of the cell, and apply vibration once per second on the vibration table for 30 seconds. Measure with

<True specific gravity of magnetic carrier>
The true specific gravity of the magnetic carrier was measured using a dry automatic densimeter autopycnometer (manufactured by Yuasa Ionics) according to the attached instruction manual.
Cell SM cell (10 mL)
Sample amount 2.0g
This measurement method measures the true density of a solid / liquid based on a gas phase substitution method. Similar to the liquid phase replacement method, it is based on Archimedes' principle, but uses a gas as the replacement medium, and therefore has high precision for micropores.

<Method for measuring free aluminum contained in aluminum phthalocyanine>
The amount of free aluminum can be determined by measuring the amount of aluminum ions contained in the colorant. The measuring method can be obtained by dissolving a colorant in an aqueous hydrochloric acid solution and measuring the amount of eluted aluminum ions with a combined induction plasma emission spectrometer (ICP).
(Create sample)
50 cc sample bottle in which aluminum phthalocyanine S (specifically 2.0 g) and 0.1 mol / l hydrochloric acid aqueous solution C (specifically 30.0 g) were weighed and the interior was washed with distilled water. Put in. The sample bottle is shaken at 150 rpm for 1 hour with a shaker (Yaoi-type shaker) and left to stand for 14 hours or more. A solution obtained by filtering the solution that had been allowed to stand through a disk filter (aperture 0.45 μm) was used as an elution sample.
(Device) ICPS-8000 (Shimadzu Corporation)
(Plasma conditions)
High frequency output 1.2 kW, torch observation height 11 mm, coolant gas 14.0 L / min, plasma gas 1.2 L / min, carrier gas 0.7 L / min,
(Measurement)
Under the above conditions, the amount of aluminum ions (ppm) in the eluted sample and the aqueous hydrochloric acid solution used is measured by ICP. When the amount of aluminum ions contained in the eluted sample is A (ppm) and the amount of aluminum ions contained in the hydrochloric acid aqueous solution is B (ppm), the amount of free aluminum can be obtained by the following formula (3).
Free aluminum content (ppm) = {(A / C) -B} / S (3)

A: The amount of aluminum ions contained in the eluted sample B: The amount of aluminum ions contained in the used hydrochloric acid aqueous solution C: The amount of the hydrochloric acid aqueous solution used in preparing the eluted sample S: The colorant used in preparing the eluted sample Amount of

<Method for Measuring Toner Weight Average Particle Size (D4)>
The weight average particle diameter (D4) of the toner used in the present invention can be measured using a Coulter Counter TA-II or Coulter Multisizer II (manufactured by Beckman Coulter, Inc.) according to the attached instruction manual. The electrolytic solution is an approximately 1% NaCl aqueous solution, which may be prepared using primary sodium chloride, or a commercial product of ISOTON (registered trademark) -II (manufactured by Coulter Scientific Japan). The method for measuring the weight average particle diameter (D4) of the toner will be specifically described below. A surfactant (preferably alkylbenzenesulfone hydrochloric acid) as a dispersant is added in an amount of 0.1 ml to 5 ml, and further a measurement sample (toner) is added in an amount of 2 mg to 20 mg. The electrolyte solution in which the sample is suspended is dispersed for about 1 minute with an ultrasonic disperser to obtain a measurement sample. The aperture is a 100 μm aperture. The volume and number of samples are measured for each of the following channels, and the volume distribution and number distribution of the samples are calculated. From the calculated distribution, the weight average particle diameter of the sample is obtained.
The channel includes 2.00 μm to 2.52 μm; 2.52 μm to 3.17 μm; 3.17 μm to 4.00 μm; 4.00 μm to 5.04 μm; 5.04 μm to 6.35 μm; .35 μm to 8.00 μm; 8.00 μm to 10.08 μm; 10.08 μm to 12.70 μm; 12.70 μm to 16.00 μm; 16.00 μm to 20.20 μm; 13 channels of 40 μm or less; 25.40 μm or more and 32.00 μm or less; 32 μm or more and 40.30 μm or less are used.

<Measuring method of average circularity of toner>
The average circularity of the toner was measured using a flow type particle image analyzer “FPIA-3000 type” (manufactured by Sysmex Corporation) under the same measurement and analysis conditions as in the calibration operation according to the attached instruction manual.
As a specific measurement method, an appropriate amount of a surfactant, preferably an alkylbenzene sulfonate, is added to 20 ml of ion-exchanged water, 0.02 g of a measurement sample (toner) is added, an oscillation frequency of 50 kHz, electrical Dispersion treatment was performed for 2 minutes using a desktop ultrasonic cleaner / disperser with an output of 150 W (for example, “VS-150” (manufactured by Velvo Crea Co., Ltd.)) to obtain a dispersion for measurement. The temperature is 10 ° C. or more and 40 ° C. or less, and the flow type particle image analyzer equipped with a standard objective lens (10 ×) is used for the measurement. 900A "(manufactured by Sysmex Corporation) The dispersion prepared in accordance with the above procedure was introduced into the flow type particle image analyzer, and the total count was measured in the HPF measurement mode. 3,000 toner particles were measured with a particle, the binarization threshold at the time of particle analysis was set to 85%, the analysis particle diameter was limited to the equivalent circle diameter of 2.00 μm to 200.00 μm, and the average toner The circularity was determined.
In the measurement, automatic focus adjustment is performed using standard latex particles (for example, Duke Scientific 5200A diluted with ion-exchanged water) before the measurement is started. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement.
In this embodiment, a flow type particle image analyzer which has been issued a calibration certificate issued by Sysmex Corporation, which has been calibrated by Sysmex Corporation, has an analysis particle diameter of 2.00 μm in equivalent circle diameter. The measurement was performed under the measurement and analysis conditions when the calibration certificate was received, except that it was limited to 200.00 μm or less.
The measurement principle of the flow-type particle image analyzer “FPIA-3000 type” (manufactured by Sysmex Corporation) is to take a flowing particle as a still image and perform image analysis. The sample added to the sample chamber is fed into the flat sheath flow cell by a sample suction syringe. The sample fed into the flat sheath flow is sandwiched between sheath liquids to form a flat flow. The sample passing through the flat sheath flow cell is irradiated with strobe light at 1/60 second intervals, and the flowing particles can be photographed as a still image. Further, since the flow is flat, the image is taken in a focused state. The particle image is captured by a CCD camera, and the captured image is subjected to image processing at an image processing resolution of 512 × 512 (0.37 × 0.37 μm per pixel), and the contour of each particle image is extracted, Projected area, perimeter, etc. are measured.
Next, the projected area S and the perimeter L of each particle image are obtained. Using the area S and the perimeter L, the equivalent circle diameter and the circularity are obtained. The equivalent circle diameter is the diameter of a circle having the same area as the projected area of the particle image, and the circularity is a value obtained by dividing the circumference of the circle obtained from the equivalent circle diameter by the circumference of the projected particle image. Defined and calculated by the following equation (4).
C = 2 × (π × S) ^1/2 / L (4)
When the particle image is circular, the degree of circularity is 1, and the degree of unevenness on the outer periphery of the particle image increases, and the degree of circularity decreases. After calculating the circularity of each particle, the range of the circularity of 0.2 to 1.0 is divided into 800, and the average circularity is calculated by dividing by the number of measured particles.

<Method for measuring molecular weight distribution of binder resin>
The molecular weight of the binder resin by gel permeation chromatography (GPC) is measured under the following conditions. In this application, HLC-8120GPC (manufactured by Tosoh Corporation) was used for the measurement.
The column is stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (THF) as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 ml / min. The sample concentration is 0.05% by mass or more and 0.6% by mass or less. 100 μl of the prepared binder resin THF sample solution is injected and measured. In measuring the molecular weight distribution of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts (retention time). Examples of standard polystyrene samples for preparing a calibration curve include those manufactured by Tosoh Corporation or Pressure Chemical Co. The molecular weights manufactured are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8 .6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ are used. It is appropriate to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.
As a column, in order to accurately measure a molecular weight region of 1 × 10 ³ or more and 2 × 10 ⁶ or less, it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, shodex GPC KF-801 manufactured by Showa Denko KK , 802, 803, 804, 805, 806, and 807, and a combination of μ-styragel 500, 10 ³ , 10 ⁴ , and 10 ⁵ manufactured by Waters.

<Two-component charge measurement method>
As a device for measuring the charge amount, a suction separation type charge amount measuring device Sepasoft STC-1-C1 type (manufactured by Sankyo Piotech) is used. A mesh (metal mesh) with an opening of 20 μm is placed on the bottom of the sample folder (Faraday gauge), and about 0.1 g of developer is placed on the mesh and covered. The mass of the entire sample folder at this time is weighed and is defined as W1 (g). Next, the sample folder is installed in the main body, and the air volume control valve is adjusted so that the suction pressure is 4 kPa. In this state, the toner is removed by suction for 2 minutes. The charge at this time is Q (μC). Further, the mass of the entire sample folder after suction is weighed and is defined as W2 (g). The charge amount (mC / kg) of the developer is calculated as follows. The charge Q is the charge of the carrier and has the opposite polarity as the charge of the toner. The measurement was performed in a normal temperature and normal humidity environment (23 ° C., 60%). The developer is sampled from the developing device sleeve.
Charge amount (mC / kg) = Q / (W1-W2)

<Measurement method of specific resistance of magnetic carrier>
The specific resistance of the magnetic carrier used in the present invention is measured using a measuring apparatus schematically shown in FIG. A resistance measurement cell E is filled with a magnetic carrier 47, a lower electrode 41 and an upper electrode 42 are arranged so as to be in contact with the filled magnetic carrier, a voltage is applied between these electrodes, and a current flowing at that time is measured. Thus, the specific resistance of the magnetic carrier is obtained.
The measurement conditions of the specific resistance are such that the contact area S between the filled magnetic carrier and the electrode is 2.3 cm ² , and the sample thickness L of the filled magnetic carrier is within the range of 0.8 mm to 1.0 mm. The sample is placed in the cell, and the load of the upper electrode 42 is 180 g.

<Measuring method of magnetization and residual magnetization of magnetic carrier>
As a measuring device, a BHU-60 type magnetization measuring device (manufactured by Riken Measurement) is used. Specifically, about 1.0 g of a measurement sample is weighed and packed in a cell having an inner diameter of 7 mm and a height of 10 mm, and set in the above-described apparatus. In the measurement, the applied magnetic field is changed to 79.6 kA / m (1000 oersted). Next, the applied magnetic field is decreased, and finally a hysteresis curve of the sample is obtained on the recording paper. From this, the magnetization and residual magnetization of the magnetic carrier are obtained.

  Hereinafter, the present invention will be described more specifically with reference to specific production examples and examples. However, the present invention is not limited to these examples.

[Production Example 1 of Hybrid Resin]
As a vinyl polymer, 2.0 mol of styrene, 0.22 mol of 2-ethylhexyl acrylate, 0.15 mol of fumaric acid, 0.05 mol of α-methylstyrene dimer, and 0.05 mol of dicumyl peroxide were put into a dropping funnel. . In addition, 7.0 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane; 3 mol, 3.3 mol of terephthalic acid, 2.2 mol of trimellitic anhydride, 5.0 mol of fumaric acid and 0.2 g of dibutyltin oxide are placed in a 4-liter 4-neck flask made of glass, a thermometer, a stir bar, a condenser and nitrogen The introduction tube was installed and placed in a mantle heater. Next, after the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and while stirring at a temperature of 145 ° C., the monomer of the vinyl resin, the crosslinking agent and the polymerization initiator were added from the previous dropping funnel for 5 hours. It was dripped over. Subsequently, the temperature was raised to 200 ° C. and reacted at 200 ° C. for 4.2 hours to obtain a hybrid resin 1. Table 1 shows the measurement results of molecular weight distribution by GPC (gel permeation chromatography). In Table 1, Mw is a weight average molecular weight, Mn is a number average molecular weight, and Mp is a peak molecular weight.

[Production example 1 of aluminum phthalocyanine]
A reaction vessel was charged with 52.0 parts by mass of phthalonitrile, 350.0 parts by mass of 1-chloronaphthalene and 15.0 parts by mass of aluminum chloride, and reacted at 250 ° C. for 5 hours. The reaction product was separated by filtration, washed successively with methanol and 2% dilute sulfuric acid aqueous solution, filtered and dried. Next, the total amount of the reaction product obtained was dissolved in 500.0 parts by mass of concentrated sulfuric acid, and then injected into 3,000 parts by mass of ice water at a temperature of 10 ° C. or less to precipitate and crystallize AlPc fine particles. After filtration, the product was sufficiently washed with water to obtain an AlPc press cake. Then, it prepared so that water might become 1,000 mass parts with the water | moisture content in this press cake, 20 mass parts of butyl cellosolve was added, and it stirred and mixed at 90 degreeC for 6 hours. The mixture is poured into 5 liters of warm water to which 50 g of 10% dilute sulfuric acid is added, stirred, filtered, washed with water until no dilute sulfuric acid remains in the filtrate, water is removed with a filter, dried and crushed and pressed. Aluminum phthalocyanine 1 having an aluminum phthalocyanine content of 40% by mass present in the cake was obtained. The amount of free aluminum of aluminum phthalocyanine 1 measured by the method described above was 5.0 ppm.

[Production example 2 of aluminum phthalocyanine]
Aluminum phthalocyanine 2 was obtained in the same manner as in Production Example 1 of aluminum phthalocyanine except that the amount of 10% dilute sulfuric acid added was 100 g. The amount of free aluminum of aluminum phthalocyanine 2 measured by the method described above was 0.1 ppm.

[Production Example 3 of aluminum phthalocyanine]
Aluminum phthalocyanine 3 was obtained in the same manner as in Production Example 1 of aluminum phthalocyanine except that the amount of 10% dilute sulfuric acid added was 25 g. The amount of free aluminum of aluminum phthalocyanine 3 measured by the method described above was 10.0 ppm.

[Production Example 4 of aluminum phthalocyanine]
Aluminum phthalocyanine 4 was obtained in the same manner as in Production Example 1 of aluminum phthalocyanine except that 10% dilute sulfuric acid was not added. The amount of free aluminum of aluminum phthalocyanine 4 measured by the method described above was 15.0 ppm.

[Cyan Masterbatch Production Example 1]
Hybrid resin 1 60.0 parts by weight Cyan pigment (Pigment Blue 15: 3) 36.0 parts by weight Aluminum phthalocyanine 1 4.0 parts by weight Heating kneader (Moriyama) with 100 parts by weight of water added to the above formulation Then, the mixture was mixed and steam-heated while being mixed to carry out melt flushing. Bring the temperature of the kneaded resin to 90 ° C,
Flushing was continued for about an hour to separate the water. The separated water was discharged and the remaining water was removed by steam while heating and kneading. Thereafter, the kneaded product was taken out from the kneader, cooled, and pulverized by a pin mill (manufactured by Hadano Sangyo) to obtain a cyan master batch 1. The constituent materials are shown in Table 2.

[Cyan Masterbatch Production Examples 2 to 5]
Cyan master batches 2 to 5 were obtained in the same manner as in Cyan Master Batch Production Example 1 except that the addition amounts of cyan pigment and aluminum phthalocyanine 1 were changed as shown in Table 2. The constituent materials are shown in Table 2.

[Production Examples 6-8 of Cyan Masterbatch]
Cyan master batches 6 to 8 were obtained in the same manner as in Cyan Master Batch Production Example 3 except that the type of aluminum phthalocyanine used was changed as shown in Table 2. The constituent materials are shown in Table 2.

[Cyan Masterbatch Production Example 9]
The same formulation as in Cyan Masterbatch Production Example 1 was charged into an open roll kneader (Mitsui Mine) and melt kneaded. After kneading at 120 ° C., the kneaded product was taken out, cooled, and pulverized by a pin mill (manufactured by Hadano Sangyo) to obtain a cyan master batch 9. The constituent materials are shown in Table 2.

[Cyan Masterbatch Production Example 10]
-Hybrid resin 1 60.0 parts by mass-Cyan pigment (Pigment Blue 15: 3) 40.0 parts by mass-Aluminum compound of 3,5-di-tert-butylsalicylic acid 5.0 parts by mass Heating 100 parts by mass of water to the above formulation The mixture was charged into a mold kneader (manufactured by Moriyama), heated with steam while mixing, and melted and flushed. The temperature of the kneaded resin was set to 90 ° C., and flushing was continued to separate water. The separated water was discharged and the remaining water was removed by steam while heating and kneading. Thereafter, the kneaded product was taken out from the kneader, cooled, and pulverized by a pin mill (manufactured by Hadano Sangyo) to obtain a cyan master batch 10. The constituent materials are shown in Table 2.

[Cyan Masterbatch Production Example 11]
A cyan master batch 11 was obtained in the same manner as in Cyan Master Batch Production Example 10 except that a boron compound of a benzylic acid derivative (LR147: Nippon Carlit) was used instead of the aromatic oxycarboxylate aluminum. The constituent materials are shown in Table 2.

[Cyan Masterbatch Production Example 12]
A cyan master batch 11 was obtained in the same manner as in Cyan Master Batch Production Example 10 except that no aromatic aluminum oxycarboxylate was used. The constituent materials are shown in Table 2.

[Cyan Masterbatch Production Example 13]
A cyan master batch 13 was obtained in the same manner as in Cyan Master Batch Production Example 1 except that metal-free phthalocyanine (manufactured by Sanyo Dye) was used in place of aluminum phthalocyanine 1. The constituent materials are shown in Table 2.

[Magnetic Carrier Production Example 1]
Magnetic material-containing resin carrier cores were produced using the materials shown below.
-Phenol 10 parts by mass-Formaldehyde solution (37% by mass aqueous solution) 6 parts by mass-Magnetite particles (number average particle diameter (D1) 0.28 μm, magnetization strength 75 Am ² / kg, specific resistance 5.5 × 10 ⁵ Ω · cm) 84 parts by mass The above material, 5 parts by mass of 28% by mass ammonia water, and 10 parts by mass of water were placed in a flask, heated to 85 ° C. over 30 minutes while stirring and mixing, and 3 at 85 ° C. It was cured by polymerization for a time. Then, after cooling to 30 degreeC and adding water, the supernatant liquid was removed, the precipitate was washed with water, and then air-dried. Subsequently, this was dried under reduced pressure (5 hPa or less) at a temperature of 60 ° C. to obtain a magnetic substance-containing resin carrier core in which magnetic fine particles were dispersed.
Subsequently, 4 parts by mass of a methyl methacrylate macromer having an ethylenically unsaturated group at one end and a weight average molecular weight of 5,000, 52 parts by mass of methyl methacrylate, and 51 parts by mass of cyclohexyl methacrylate were added to a reflux condenser, a thermometer, and nitrogen suction. Add to a four-necked flask equipped with a tube and a rubbing method stirrer, add 100 parts by mass of toluene, 100 parts by mass of methyl ethyl ketone, and 2.5 parts by mass of azobisisovaleronitrile, and keep at 80 ° C. for 8 hours under a nitrogen stream A resin solution for a coating material (solid content: 35% by mass) was obtained.
2 parts by mass of melamine particles (number average particle size 0.1 μm), 1 part by mass of carbon black (number average particle size 35 nm, DBP oil absorption 50 ml / 100 g) with respect to 30 parts by mass of the obtained resin solution for a coating material, 70 parts by mass of toluene was added to a bead mill (RMH-03 type, Imex (
Co., Ltd.) was dispersed using glass beads having a bead diameter of 0.5 mm to obtain a coating material.
Subsequently, using a fluidized bed coating apparatus (Spiraflow, manufactured by Freund Sangyo Co., Ltd.), 100 parts by mass of the magnetic substance-containing resin carrier core was flowed at 80 ° C., and 2.0 parts by mass of the coating material was sprayed on the spray nozzle. Then, the solvent was volatilized and dried at 100 ° C. while flowing to coat the core surface. This coated magnetic substance-containing resin carrier core is classified with a sieve having an opening of 75 μm, and the average particle diameter (D50) is 35 μm, the specific resistance is 3.0 × 10 ⁹ Ω · cm, the true specific gravity is 3.6 g / cm ³ , A magnetic carrier 1 having a magnetization intensity (σ1000) of 55.5 Am ² / kg and a residual magnetization of 5.5 Am ² / kg was obtained.

[Production example 2 of magnetic carrier]
The same magnetic substance-containing resin carrier core and coating material resin solution as in Magnetic Carrier Production Example 1 are used. And 4 parts by mass of melamine particles (number average particle size 0.1 μm), 1 part by mass of carbon black (number average particle size 35 nm, DBP oil absorption 50 ml / 100 g), 30 parts by mass of the resin solution for coating material, toluene 70 parts by mass was dispersed with a bead mill (RMH-03 type, manufactured by Imex Co., Ltd.) using glass beads having a bead diameter of 0.5 mm to obtain a coating material.
Subsequently, using a fluidized bed coating apparatus (Spiraflow, manufactured by Freund Sangyo Co., Ltd.), while spraying 100 parts by mass of the magnetic substance-containing resin carrier core at 80 ° C., 3.0 parts by mass of the coating material is sprayed. Then, the solvent was volatilized and dried at 100 ° C. while flowing to coat the core surface. The coated magnetic fine particle-dispersed core is classified with a sieve having an opening of 75 μm, and has an average particle diameter (D50) of 35 μm, a specific resistance of 3.0 × 10 ¹⁰ Ω · cm, a true specific gravity of 3.5 g / cm ³ , and a magnetization. Magnetic carrier 2 having a strength (σ1000) of 55.1 Am ² / kg and a residual magnetization of 5.2 Am ² / kg was obtained.

[Magnetic Carrier Production Example 3]
The same magnetic substance-containing resin carrier core and coating material resin solution as in Magnetic Carrier Production Example 1 are used. And 1 part by mass of melamine particles (number average particle size 0.1 μm) and 1.5 parts by mass of carbon black (number average particle size 35 nm, DBP oil absorption 50 ml / 100 g) with respect to 30 parts by mass of the resin solution for coating material Then, 70 parts by mass of toluene was dispersed with a bead mill (RMH-03 type, manufactured by Imex Co., Ltd.) using glass beads having a bead diameter of 0.5 mm to obtain a coating material.
Subsequently, using a fluidized bed coating apparatus (Spiraflow, manufactured by Freund Sangyo Co., Ltd.), 100 parts by mass of the magnetic substance-containing resin carrier core was allowed to flow at 80 ° C., and 1 part by mass of the coating material was sprayed with a spray nozzle. After spraying, the solvent was volatilized and dried at 100 ° C. while flowing to coat the core surface. This coated magnetic substance-containing resin carrier core is classified with a sieve having an opening of 75 μm, and an average particle diameter (D50) of 35 μm, a specific resistance of 3.0 × 10 ⁷ Ω · cm, a true specific gravity of 3.8 g / cm ³ , A magnetic carrier 3 having a magnetization intensity (σ1000) of 52.5 Am ² / kg and a residual magnetization of 5.4 Am ² / kg was obtained.

[Cyan toner production example 1]
Hybrid resin 1 90.7 parts by mass Cyan master batch 1 15.5 parts by mass Wax A (refined paraffin wax maximum endothermic peak = 70 ° C., Mw = 450, Mn = 32) 4.0 parts by mass -Aluminum compound of di-tertiarybutylsalicylic acid (charge control agent)

3.0 parts by mass Preliminarily mixed with a Henschel mixer with the above formulation, melt-kneaded so that the kneaded material temperature becomes 150 ° C. with a twin-screw extrusion kneader, and after cooling, a particle size of about 1 to Roughly pulverized to about 2 mm, the hammer shape was changed again, and a coarsely pulverized product having a particle diameter of about 0.3 mm was made using a hammer mill with fine mesh. Further, using a turbo mill (RS rotor / SNB liner) manufactured by Turbo Industry, a medium pulverized product having a particle diameter of about 11 μm was prepared. Furthermore, using a turbo mill (RSS rotor / SNNB liner) manufactured by Turbo Industry, 5 μm
Medium crushed material was made to the extent. Using a turbo mill (RSS rotor / SNNB liner) again, a finely pulverized product having a particle diameter of about 5 μm was prepared. Next, using a Faculty made by Hosokawa Micron with an improved hammer shape and the like, spheronization was performed simultaneously with classification to obtain a particle size of 5.3 μm, and cyan toner particles 1 were obtained.
0.5 parts by mass of anatase-type titanium oxide fine powder (BET specific surface area of 80 m ² / g, isobutyltrimethoxysilane 12% by mass) and 100% by mass of cyan toner particles 1 and oil-treated silica (BET ratio) A cyan toner 1 was prepared by externally adding 1.0 part by mass of a surface area of 95 m ² / g and a silicone oil of 15% by mass and mixing with a Henschel mixer. The average circularity of the cyan toner was 0.953, and the weight average particle size was 5.5 μm. Table 3 summarizes toner physical properties such as lightness and saturation in the powder state of cyan toner 1.

[Cyan toner production examples 2 to 20]
Cyan toners 2 to 20 were obtained in the same manner as in cyan toner production example 1 except that the materials and blending ratios shown in Table 3 were followed. Table 3 shows the constituent materials and physical property values.

[Example 1]
A developer for start and a developer for replenishment were prepared using the combinations shown in Table 4 for the magnetic carrier and cyan toner, and the actual machine was evaluated using a full color copier iRC5180 manufactured by Canon Inc.
The starting developer is V-type in an environment of room temperature and normal humidity (23 ° C., 50% RH) by adding 10 parts by mass of cyan toner to 90 parts by mass of the magnetic carrier so that the cyan toner density becomes 10% by mass. The mixture was mixed with a mixer to obtain a starting developer, which was introduced into the developing device. Further, the replenishment developer is obtained by adding 90 parts by mass of cyan toner to 10 parts by mass of the magnetic carrier and mixing the mixture in a V-type mixer in an environment of normal temperature and normal humidity (23 ° C., 50% RH). did. The replenishment developer was filled in a replenishment developer container for supplying the replenishment developer to the developing device.
Using these developers, evaluation was performed using a full color copying machine iRC3200 manufactured by Canon Inc. On the transfer material (paper: GLC glossy thick paper NS-701: manufactured by Canon), a 16-tone image is formed, and the applied toner amount (Dmax 1.6) at which the reflection density of the single-color solid image is 1.6. Asked. A color reflection densitometer (for example, X-RITE 404A: manufactured by X-Rite Co.) was used for density measurement at this time. Subsequently, the image saturation of the monochromatic solid image portion was measured. A chart in which the image area is 5% under normal temperature and low humidity (23 ° C., 5% RH) while replenishing the replenishment developer under the condition that the toner density is 1.6 so that the reflection density of the monochrome solid image is 1.6. Using this, a 50,000-sheet durability image output test was conducted. Subsequently, a durability image output test of 50,000 sheets was further performed using a chart in which the image area was 25% under a high temperature and high humidity environment (30 ° C., 80% RH).
The evaluation items and evaluation criteria are shown below. The obtained evaluation results are shown in Table 4.

[Evaluation of fog]
The average reflectance Dr (%) of the paper was measured using a reflectometer ("REFLECTOMETER MODEL TC-6DS" manufactured by Tokyo Denshoku Co., Ltd.) according to the instruction manual.
Next, after a durability image output test of 50,000 sheets, a solid white image was printed (set to Vback 150V), and the reflectance Ds (%) of the solid white image was measured.
The fog (%) was calculated using the following formula (5). The obtained fog was evaluated according to the following evaluation criteria.
Fog (%) = Dr (%)-Ds (%) (5)
A: Less than 0.5% B: 0.5 or more and less than 1.0% C: 1.0 or more and less than 2.0% (no problem in actual use)
D: 2.0% or more (problems in actual use)

[Evaluation of color fluctuation (color difference) before and after durability]
The development voltage was adjusted so that the amount of toner on the paper was 0.6 mg / cm ² . The amount of toner on the paper is calculated from the weight and suctioned image area after the power is turned off at the timing before the paper passes through the fuser to obtain an unfixed image. To do.
Before the endurance image output test, a solid image (3 cm × 3 cm) having an image area of 100% was output at 400 lines / inch at a developing voltage at which the applied amount of toner was 0.6 mg / cm ² . Next, after a durability image output test of 50,000 sheets, a solid image having an image area of 100% was printed at 400 lines / inch at the same development voltage as that before the durability image output test. Subsequently, the chromaticity of the output image was measured. A chromaticity meter (Spectrolino, manufactured by GRETAGMACBETH) was used for chromaticity measurement, the observation light source was D50, the observation visual field was 2 °, and ΔE was calculated and evaluated.
The color reproducibility is based on the color system definition standardized by the International Commission on Illumination (CIE) in 1976, and the color variation (color difference) (ΔE: Formula (6) )) Was evaluated quantitatively as follows and evaluated based on the following evaluation criteria.
^{ΔE = {(L1 * -L2 *} ) 2+ (a1 * -a2 *) 2+ (b1 * -b2 *) 2} 1/2 ······ (6)
[L1 ^* : Lightness of image before endurance image output test a1 ^* , b1 ^* : Chromaticity indicating hue and saturation of image before endurance image output test L2 ^* : Lightness of image after endurance image output test a2 ^* , b2 ^* : Chromaticity indicating hue and saturation of image after endurance image output test]
A: A slight color difference is felt. 0.0 or more and less than 1.5 B: A slight color difference is felt. 1.5 or more and less than 3.0 C: The color difference can be considerably felt. 3.0 or more and less than 6.0 (no problem in actual use)
D: A color difference is noticeable. 6.0 or more (problems in actual use)

[Fixing temperature limit]
When a 16-gradation image was formed, the applied toner amount at which the reflection density of the single-color solid fixed image was 1.6 was determined, the development voltage was adjusted so as to be the applied toner amount, and an unfixed image was output. The fixing roller temperature was raised from 120 ° C. every 5 ° C., and after passing through an external fixing device, the density reduction rate was obtained by a rubbing test. The reduction rate was 20% or less, and the density reduction rate exceeded 20%. The boundary between the point and the point of 20 or less was defined as the minimum fixing temperature. In the rubbing test, the toner image portion of the passed image was folded open into a cross by reciprocating a cylindrical roller (brass: 798 g) of φ60 mm × 40 mm 5 times, and then a square columnar weight of 22 mm × 22 mm × 47 mm Silbon paper (Dasper K3-half cut, manufactured by Ozu Sangyo Co., Ltd.) was wrapped around the cross section of brass (made of 198 g) and rubbed 10 times, and the temperature at which the toner image peeling rate was 25% or less was defined as the fixing temperature. An image processing system (Personal IAS) was used for the measurement of the peeling rate.

[Gradation]
An original image having 40 gradations from a white image to a solid image is formed on a transfer material (paper: glossy thick-mouthed paper for CLC NS-701: manufactured by Canon). At that time, the applied toner amount at which the reflection density of the single-color solid fixed image is 1.6 is obtained, and the development voltage is adjusted so as to be the applied toner amount. This original image was output and the gradation was evaluated. As an evaluation method, the image density of each gradation is measured, and when the difference from the gradation density is 0.05 or more from the lower density, the gradation level is determined, and the gradation property is determined by the number of the level differences. Was evaluated. A color reflection densitometer (for example, X-RITE 404A: manufactured by X-Rite Co.) was used for density measurement at this time.
A: Extremely excellent gradation (gradation step is 30 steps or more: good)
B: Excellent gradation (gradient level difference is 20 steps or more and less than 30 steps: no practical problem)
C: Slightly inferior in gradation (gradation step is 10 steps or more and less than 20 steps: practical for image quality where gradation is not important)
D: Inferior in gradation (gradation step is less than 10 steps: practically problematic)

[Evaluation method of halftone lines]
A halftone image was output after a durability image output test of 50,000 sheets in a normal temperature and low humidity environment (23 ° C./5%). As the recording material, glossy thick paper for CLC (NS-701: manufactured by Canon) was used. Incidentally, the obtained image was subjected to density measurement with a densitometer X-Rite 500 type, and an average value of 6 points was taken as an image density. An image having an image density of 0.5 to 0.7 was output, three A4 images were output, and streaks were visually confirmed.
(Evaluation criteria)
A: Very good with uniform images without streaks B: Within 1 / sheet is good C: Within 3 / sheet Practical level D: 3 or more / sheet Impractical level

[Image dropout evaluation]
A full color copier iRC3200 remodeled machine manufactured by Canon Inc. was used for evaluation of image dropout. The iRC3200 remodeled machine is remodeled as follows. First, a carrier recovery member such as a discharge screw was attached in order to discharge the excess carrier inside the developing device from the developing device so as to be compatible with the ACR developing system.
When a 16-tone image is formed after outputting 50,000 images in a high-temperature and high-humidity environment (30 ° C./80%), the amount of applied toner is such that the reflection density of a monochrome solid-fixed image is 1.6. Adjust the development voltage as follows. An image is formed so that fine lines are present in both the vertical and horizontal directions, two, four, six, eight, and ten dot lines are printed, and the non-latent image portion width between each line is printed to be about 1 mm. The result of observation with a magnifying glass was used as an evaluation of hollowness.
A: Image with almost no voids even by magnified observation in 2 dot lines B: Image with slight voids observed by magnified observation in 2 dot lines and not visually observed C: Image voids visually observed in 2 dot lines An image in which a void is not visually observed in a 4-dot line.
D: An image in which a hollow is visually observed in a 4-dot line. Very problematic for practical use.

[Examples 2 to 5]
Examples 2 to 5 were performed in the same manner as Example 1 except that the cyan toner was changed.
In Example 2, since A / C was small, the transferability tended to deteriorate. Further, since the amount of applied toner is large, the fixability tends to be inferior.
In Example 3, although the gradation was slightly inferior, the overall balance was achieved.
In Examples 4 and 5, since A / C is high and L * tends to be small, fluctuations in image density and fogging tend to be deteriorated.

[Examples 6 to 9]
In Examples 6 to 9, evaluation was performed in the same manner as in Example 1 except that cyan toners 6 to 9 were used. The evaluation results are shown in Table 4.
In Example 6, since the value of (Y / X × 100) was small, the gradation property tended to be slightly inferior, but it was at a level that was not a problem for practical use.
In Examples 7 and 8, performance was balanced and good evaluation results were obtained.
In Example 9, as Y / X × 100 increased, gradation and image streaks tended to occur. However, the level was practically no problem.

[Examples 10 to 12]
In Examples 10 to 12, evaluation was made in the same manner as in Example 1 except that cyan toners 10 to 12 were used. The evaluation results are shown in Table 4.
When the amount of free aluminum contained in aluminum phthalocyanine increases, the image streak and gradation tend to be inferior. However, even in Example 12, there was no problem in practical use.

[Example 13]
In Example 13, the evaluation was performed in the same manner as in Example 3 except that the method for producing the cyan master batch was changed. The evaluation results are shown in Table 4. Good results were obtained even when the masterbatch production equipment was changed.

[Example 14]
In Example 14, aluminum oxycarboxylate aluminum was added during the production of the cyan master batch, and aluminum phthalocyanine was added during the subsequent toner production. Since the pigment dispersion effect of aluminum phthalocyanine is reduced, image streaks and color variations are slightly inferior.

[Example 15]
In Example 15, a boron compound of a benzylic acid derivative was used instead of the aromatic aluminum oxycarboxylate. Since the dispersion of the pigment deteriorated, the fog was slightly inferior in addition to the image streak and the color variation.

[Example 16]
In Example 16, the toner was manufactured by adding aluminum phthalocyanine at the time of manufacturing the toner. The image streak and the color fluctuation were slightly inferior because of the worse dispersion than when added to the masterbatch process, but it was at a level that is practically acceptable.

[Comparative Example 1]
In Comparative Example 1, no aluminum phthalocyanine was added. In this case, in the present invention in which the amount of pigment added is large, image streaks are generated due to inferior pigment dispersibility.

[Comparative Example 2]
In Comparative Example 2, metal-free phthalocyanine was added instead of aluminum phthalocyanine. As a result, image streaks occurred due to poor dispersibility of the pigment, and gradation was not practical.

[Comparative Example 3]
Comparative Example 3 is a conventional toner having a coloring power, and a large amount of toner is applied to obtain a predetermined image density.

[Comparative Example 4]
In Comparative Example 4, toner was formed without adding aluminum phthalocyanine and without further forming a masterbatch. The gradation was further deteriorated as compared with Comparative Example 1.

[Comparative Examples 5 and 6]
In Comparative Examples 5 and 6, the magnetic carrier was changed from Examples 1 and 2, respectively. In Comparative Example 5, evaluation was impossible because the charge amount was too high. Further, in Comparative Example 6, since the charge amount was too small, the color variation was large, the gradation was poor, and the level was not practical.

It is a figure which shows the (gamma) characteristic at the time of only increasing the quantity of the coloring agent contained in a toner particle. It is a figure which shows the (gamma) characteristic in the case where the amount of the conventional toner and the colorant increased, and each having the same charge amount. FIG. 6 is a diagram illustrating γ characteristics when the contrast potential is increased with toner having an increased amount of colorant. FIG. 6 is a diagram illustrating γ characteristics when a toner having an increased amount of colorant and a high charge amount is used. It is a figure which shows the profile of the hue of the conventional toner of a ^* b ^* plane of CIELAB, and the toner with high coloring power. It is a schematic diagram of the measuring apparatus which measures the specific resistance of a magnetic carrier.

Claims (3)

A two-component developer containing a cyan toner and a magnetic carrier containing at least a binder resin and a colorant,
The cyan toner is
i) at least further containing aluminum phthalocyanine,
ii) When the cyan toner concentration in the chloroform solution of the cyan toner is C [mg / ml], and the absorbance at the wavelength where the absorbance at the wavelength of 660 nm to 760 nm is the maximum in the solution is A, The relationship between C and A satisfies the following formula (1):
2.00 <A / C <8.15 (1),
iii) A two-component system characterized in that an absolute value of the triboelectric charge amount of the cyan toner measured by a two-component method using the cyan toner and the magnetic carrier is 50 mC / kg or more and 120 mC / kg or less. Developer. 2. The two-component system according to claim 1, wherein the amount of free aluminum contained in the aluminum phthalocyanine measured by a coupled induction plasma emission spectrometer (CP) is 0.1 ppm or more and 10.0 ppm or less. Developer. The lightness L ^* and saturation C ^* obtained in the powder state of the cyan toner satisfy 25.0 ≦ L ^* ≦ 40.0 and 50.0 ≦ C ^* ≦ 60.0, respectively. The two-component developer according to 1 or 2.

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