JP2005338132A - Dry toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide dry toner which has excellent negative charging property, achieves good electrophotographic properties, and can stably realize high-quality images over a long period of time. <P>SOLUTION: The dry toner comprises a binder resin, a coloring agent, a wax component and a charge control agent and has C.I. Pigment Yellow 155 and C.I. Pigment Yellow 93 as the coloring agent, wherein a mass ratio between contents of the C.I. Pigment Yellow 155 and the C.I.Pigment 93 is 10:90 to 50:50, the circle-equivalent number average diameter D1 (μm) of the toner measured with a flow particle image analyzer is 2-10 μm, an average circularity of the toner is 0.940-0.995, and a standard deviation of circularity is <0.040. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a toner used in a recording method using an electrophotographic method, an electrostatic recording method, a magnetic recording method, a toner jet method, or the like.

  Specifically, the present invention relates to a yellow toner used in an image recording apparatus that can be used in a copying machine, a printer, a facsimile, a plotter, and the like.

  In recent years, digital full-color copiers and printers have been put into practical use, and it has become possible to obtain high-quality images with excellent color reproducibility with no color unevenness as well as resolution and gradation.

  In a digital full-color copying machine, a color image original is color-separated with B (blue), G (green), and R (red) color filters, and then a latent image having a dot diameter of 20 μm to 70 μm corresponding to the original image is formed. Using Y (yellow), M (magenta), C (cyan), and Bk (black) developers, it is necessary to transfer a large amount of developer from the photoreceptor to the transfer material, In order to cope with further higher image quality in the future, a demand for a finer particle size of the developer corresponding to finer dots is expected.

  However, if the toner particle size is reduced in accordance with the demand for higher image quality, the resolution and sharpness of a full-color image will surely be satisfactory. However, as the particle size becomes smaller, various problems such as image fogging and transfer defects will occur. It has been found that there is an impact.

  In addition, when the toner particle size is reduced, the problem is that the charging characteristics are easily affected by the uneven distribution of the colorant.

  Accordingly, there is a demand for a toner having a well-balanced hue and spectral reflection characteristic and sufficient saturation, as compared with the conventional color toner.

  In addition, when the toner particle size is made smaller, light is more easily scattered, so that the chromaticity, brightness, density, etc. of the image changes, and there is a problem that a color configuration different from that of the conventional technique is required. come.

  This remarkably appears when an image is obtained that is new user-oriented with the recent spread of printers, that is, an image that matches the tendency to prefer an image similar to other glossy printed matter such as photolithography.

  That is, in the conventional technology, the toner that has been fixed needs to be in a state of nearly complete melting so that the shape of the toner particles cannot be discriminated so as not to disturb the color reproduction by irregularly reflecting light. In a color image in which several types of toner layers are superimposed, the upper toner layer needs to have transparency so as not to interfere with the lower toner layer.

  Based on this idea, various configurations of each of yellow / magenta / cyan / black and others have been proposed as shown in Patent Documents 1 to 5 and the like.

  However, when trying to obtain an image having no difference in glossiness with other printed materials such as photoengraving, it is necessary to fix it to a value close to the glossiness of paper, and there is no situation where toner particles are not completely melted. Therefore, the influence of the scattered light of the fine particle toner becomes remarkable, and the color space configuration of the present invention has become insufficient.

  Furthermore, if the toner resin is designed so that the toner particles are not completely melted, the transmitted light is scattered because the toner particles cannot be completely melted even on the transparency film (OHP sheet). It has been found that the color reproduction area becomes small. Furthermore, it has also been found that the target color cannot be obtained because the hue angle also changes. In particular, since yellow is highly sensitive to changes in hue angle, the change in the color angle of transmitted light is not preferred.

  On the other hand, it has been proposed that the above problem can be solved by selecting a suitable binder resin to improve the dispersibility of the colorant in the binder resin. For example, in Patent Document 6, a polyester resin having a specified acid value as a binder resin is used as a main component, so that C.I. I. Pigment Yellow 155 also discloses that good dispersibility can be achieved, and transparency, coloring power, and charging characteristics can be improved. However, since it does not contain a wax component, it is difficult to adapt to an image forming method using an oilless fixing method.

  On the other hand, as disclosed in Patent Document 7 and Patent Document 8, C.I. I. Disazo condensed yellow colorants represented by Pigment Yellow 93 are excellent in light resistance and heat resistance, and are suitably used for toners having a polar resin as a binder resin. Such colorants are dispersed in the toner. In this case, the chargeability of the colorant itself is significantly different from the chargeability of the binder resin, so that stable charging characteristics cannot be obtained, and furthermore, electrostatic aggregation occurs between the colorants. Cause various adverse effects such as lowering of

  On the other hand, in Patent Document 9, C.I. I. A toner containing a disazo condensed yellow colorant typified by Pigment Yellow 93 and a metal salicylate has been proposed to improve dispersibility of the colorant and improve transparency.

  Further, in Patent Document 10, C.I. I. Disazo condensed yellow colorant represented by Pigment Yellow 93, or C.I. I. Benzimidazoline colorants represented by Pigment Yellow 180, C.I. I. It has been proposed that a clear color can be obtained by using Solvent Yellow 162 together.

  However, even with these proposals, 1) good transparency, 2) excellent spectral reflection characteristics for color reproduction, a clear yellow color, and 3) good dispersibility of the colorant in the resin It is not possible to obtain a yellow toner that sufficiently satisfies all required characteristics such as 4) having high coloration and 4) having stable triboelectric charging characteristics in the environment.

  By the way, in the printer market, there are many machines that output images with mixed black characters, but in conventional technology, there is a difference in toner amount between black characters and color images, resulting in a difference in glossiness. As a result, a color image having a high glossiness appears to be “protruded”.

  Furthermore, since light on the image surface is scattered and the image density is lowered, it has been found that the fog becomes conspicuous if the coloring power of the toner is increased as a countermeasure.

  That is, since the amount of heat is relatively sufficiently applied to the portion where the toner is scattered during fixing, the glossiness of the image is increased, and as a result, the image density of the scattered portion is increased. For this reason, fog is noticeable.

  As described above, there is no color toner that can satisfy all of the various problems necessary to obtain a glossy printed matter.

  The toner applied to the dry development method is generally colored resin fine particles (toner particles) containing a binder resin, a colorant, and a wax component as main components, and the particle diameter is usually the number average diameter. Is about 6 to 15 μm. As a method for producing a toner comprising such colored resin fine particles, a binder resin, a colorant such as a colorant and / or a magnetic material, a wax component, and the like are melt-pulverized, and the kneaded product is cooled and pulverized. Generally, toner is obtained by a so-called pulverization method in which pulverized material is classified to obtain toner particles.

  The toner obtained by such a method needs to be configured to have a positive or negative charge according to the charge polarity of the electrostatic image to be developed. In order to retain the charge in the toner, the triboelectric charging property of the binder resin, which is the main component of the toner, can be used. However, the charging property of the toner is low only by this. Therefore, a charge control agent is added to the toner in order to impart a desired triboelectric chargeability to the toner. Although a toner containing such a charge control agent may exhibit a relatively high triboelectric charge amount, generally, the toner charge amount under high humidity and the charge rate under low humidity are reduced.

  One reason for this is the adsorption / desorption of moisture near the charge control agent present in the toner particles or on the surface of the toner particles. It is thought that it has influenced.

  Today, as charge control agents known in the technical field, as a negatively chargeable one, a metal complex salt of a monoazo dye, a metal complex salt of salicylic acid, a metal complex salt of naphthoic acid, a metal complex salt of dicarboxylic acid, a copper phthalocyanine colorant Etc.

  On the other hand, Patent Document 11 discloses a technique relating to a toner containing a charge control resin having acrylamidomethylpropanesulfonic acid as a constituent monomer. However, since the charge control resin has good dispersibility with respect to the binder resin, it is necessary to increase the amount of addition in order to exhibit the charge control ability efficiently. Further, since the coloring power of the toner is not taken into consideration at all, it is difficult to adapt to the toner.

  In contrast, Patent Document 12 proposes application to a polymerization method color toner, which is produced by a suspension polymerization method and uses a charge control resin having an appropriate weight average molecular weight, thereby developing characteristics and coloring. It is disclosed that the dispersibility of the agent is improved. However, the toner has not been designed in consideration of transferability, transparency and color tone, and there remains room for studying the adaptability of the charge control resin to the color toner.

JP 59-26757 A JP-A-63-70271 JP-A-1-230072 JP-A-2-293860 Japanese Patent Laid-Open No. 6-11898 JP 11-242357 A JP-A-2-210360 JP-A-3-269068 JP 2000-75552 A JP 2000-162824 A JP 63-184762 A Japanese Patent Laid-Open No. 11-327208

  An object of the present invention is to provide a dry toner that solves the above-mentioned problems.

  A further object of the present invention is to provide a dry toner that is excellent in negative chargeability, achieves good electrophotographic characteristics, and can stably realize a high-quality image over a long period of time.

  A further object of the present invention is to provide a dry toner in which a very clear color is obtained at a high image density.

  A further object of the present invention is to provide a dry toner that has a wide color space of a projected image and has excellent transparency in a fixed image of an OHP sheet.

The present invention is a dry toner containing at least a binder resin, a colorant represented by Structural Formula [1] and a colorant represented by Structural Formula [2], a wax component, and a charge control agent,
The mass ratio of the content of the colorant represented by the structural formula [1] and the structural formula [2] is 10:90 to 50:50, and a flow type particle image analyzer (Flow Particle Image Analyzer) is used. The toner has a circle equivalent number average diameter D1 (μm) of 2 to 10 μm, the toner has an average circularity of 0.940 to 0.995, and a circularity standard deviation of less than 0.040. And a dry toner.

〔Ｒ₁、Ｒ₂は、水素原子、塩素原子、又はメチル基を示し、Ｒ₃は下記の群

[R ₁ and R ₂ represent a hydrogen atom, a chlorine atom, or a methyl group, and R ₃ represents the following group:

より選ばれる置換基を示す。〕

The substituent chosen from is shown. ]

  According to the present invention, in a dry toner containing at least a binder resin, a yellow colorant, and a charge control agent, the colorant in the toner is appropriately selected / blended, and the toner particle shape is preferably controlled. Makes it possible to improve the color developability and dispersibility of the colorant in the toner particles, and has extremely clear color and transparency, coloring power, and stable triboelectric charging characteristics, developability, transferability, and A toner having excellent durability is provided.

  The dry toner of the present invention is a dry toner containing at least a binder resin, a colorant represented by the structural formula [1] and a colorant represented by the structural formula [2], a wax component, and a charge control agent. The mass ratio of the content of the colorant represented by the structural formula [1] and the structural formula [2] is 10:90 to 50:50, and the flow type particle image analyzer (Flow Particle Image Analyzer). The average equivalent circle diameter D1 (μm) of the toner measured by Analyzer) is 2 to 10 μm, the average circularity of the toner is 0.940 to 0.995, and the circularity standard deviation is less than 0.040. It is characterized by being.

〔Ｒ₁、Ｒ₂は、水素原子、塩素原子、又はメチル基を示し、Ｒ₃は下記の群

[R ₁ and R ₂ represent a hydrogen atom, a chlorine atom, or a methyl group, and R ₃ represents the following group:

より選ばれる置換基を示す。〕

The substituent chosen from is shown. ]

  As a result of intensive studies, the inventors have selected / blended the colorant in the toner as described above, the colorant and the charge control agent coexist, and the particle shape of the toner satisfies the above conditions. As a result, it has been found that the charging characteristics, developing characteristics, durability, coloring power, transparency, and color tone of the toner can be improved in a balanced manner, and the present invention has been completed.

  According to the knowledge of the present inventors, by selecting / blending the colorant in the toner as described above and coexisting it, the dispersibility of the colorant in the toner particles is remarkably improved, and the charging characteristics, development characteristics, Durability, coloring power, transparency, color tone, etc. are improved in a well-balanced manner. Although these reasons are not necessarily clear, the colorant represented by the structural formula [1] suppresses the electrostatic reaggregation of the colorant represented by the structural formula [2] generated in the toner particles. , I believe that it is caused by creating a situation where those colorants themselves can greatly demonstrate their inherent abilities. In the toner of the present invention, the colorant represented by the structural formula [1] and the colorant represented by the structural formula [2] are mixed in the toner particles by mixing the colorant represented by the structural formula [1]. Re-aggregation is suppressed, and a coherent effect based on the interaction between the colorants produces a relatively slow reaggregation state between the two colorants. As a result, it is presumed that the toner particles are provided with desirable color development and charging characteristics.

  Furthermore, according to the knowledge of the present inventors, the colorant in the toner is selected / blended as described above, the charge control agent is allowed to coexist and the toner particle shape satisfies the above conditions. Therefore, the dispersibility of the colorant in the toner particles is remarkably improved, and the colorant and the charge control agent in the toner particles are placed in a desired position, that is, the charge control agent is on the toner particle surface and in the vicinity of the surface, and the colorant is in the toner. It can be controlled to be present in the intermediate layer from the vicinity of the surface, and the color tone, coloring power, charging characteristics, and durability of the toner can be made excellent.

  Since the colorant used in the present invention has a hydrophilic functional group, when the toner particles are formed by polymerizing the granulated particles of the polymerizable monomer composition in an aqueous dispersion medium, the colorant is used. When the agent is present alone, it moves toward the interface between the polymerizable monomer composition that is a dispersoid and the aqueous medium, and as a result, reaggregation occurs in the vicinity of the toner particle surface. Such a colorant re-aggregate has an adverse effect on the charge amount and charge speed of the toner particles obtained.

  On the other hand, the colorant is appropriately adjusted within the range of the blending amount satisfying the relationship as described above, and then dispersed / mixed together with a part of the polymerizable monomer composition to produce a toner by suspension polymerization. By doing so, re-aggregation of the colorant alone is prevented, and a situation in which the ability of the colorant itself can be exerted greatly can be created, and between the two colorants in the toner particles. Since it is possible to encapsulate while maintaining the interaction, the coexistence effect based on the interaction between the colorants creates a relatively slow re-aggregation state between the two colorants, which is desirable for the resulting toner. Characteristics and color developability can be imparted.

  In particular, when the toner of the present invention is produced by a suspension polymerization method or an emulsion polymerization method, not only the problems due to poor dispersion of the colorant as described above can be prevented, but also the coexisting charge control agent is present on the toner particle surface. Orientation in the vicinity, imparting excellent charging characteristics, and preventing the colorant from moving to the vicinity of the toner particle surface, further improving the charging characteristics, and further caused by the colorant present on the toner particle surface For example, C.I. I. C., a photoconductor that is caused by the presence of needle-like crystals such as a colorant represented by the structural formula [2] classified as Pigment Yellow 95 on the surface of the toner particles; I. Prevents contamination of the photoreceptor or sticking to the photoreceptor due to the presence of a colorant having high tinting strength, such as the colorant represented by Structural Formula [2] classified as Pigment Yellow 93, on the toner particle surface. And high-quality images can be stably realized over a long period of time. Further, in the suspension polymerization method, the charge control agent is uniformly oriented in the vicinity of the toner particle surface, and the particle surface is uniformly covered with the dispersant by attracting with the dispersant in water. Is prevented, shows excellent granulation stability, and brings about a favorable effect in terms of production.

  The colorant represented by Structural Formula [1] contained in the toner of the present invention is C.I. I. Pigment Yellow 155 (according to the name described in the color index 4th edition). The colorant is preferable from the viewpoint of physical stability such as transparency and compatibility with the binder resin.

  On the other hand, the colorant represented by Structural Formula [2] contained in the toner of the present invention can be used alone or in combination.

〔Ｒ₁、Ｒ₂は、水素原子、塩素原子、又はメチル基を示し、Ｒ₃は下記の群

[R ₁ and R ₂ represent a hydrogen atom, a chlorine atom, or a methyl group, and R ₃ represents the following group:

より選ばれる置換基を示す。〕

The substituent chosen from is shown. ]

  For example, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 95, C.I. I. Pigment Yellow 128, and C.I. I. Pigment Yellow 166 (each according to the name described in the color index 4th edition) and the like. I. Pigment Yellow 93 is preferably used from the viewpoints of improving dispersibility by suppressing reaggregation of the colorant represented by the structural formula [1], and further improving color developability, color tone, and charging characteristics.

  The total content of the colorant represented by the structural formula [1] and the colorant represented by the structural formula [2] in the dry toner of the present invention is preferably 1 to 20% by mass, more preferably 3 to 10%. % By mass. The mass ratio of the content of the colorant represented by Structural Formula [1] and the colorant represented by Structural Formula [2] in the dry toner (colorant represented by Structural Formula [1]: Structural Formula [2] ] Is added so as to satisfy 10:90 to 50:50.

  The mass ratio of the content of the colorant represented by the structural formula [1] and the colorant represented by the structural formula [2] is represented by the colorant represented by the structural formula [1]: structural formula [2]. When the colorant is outside the range of 10:90 to 50:50, not only does the coexistence effect disappear, but the content ratio of the colorant represented by the structural formula [2] is less than 50% by mass. Can not obtain sufficient coloring power, and if it exceeds 90% by mass, in addition to a decrease in transparency, damage to the photoreceptor caused by excessive colorant represented by the structural formula [2] or fixation to the photoreceptor This causes problems.

  In addition, when the total content of the colorant in the toner is less than 1% by mass, the function as the colorant may not be sufficiently achieved. On the other hand, when the amount exceeds 20% by mass, the presence of the colorant in the toner particles becomes excessive, the coexistence effect of both colorants disappears, and re-aggregation of the colorant proceeds, so that transparency and charging characteristics are increased. May be adversely affected.

  In the toner of the present invention, both colorants having the same content are encapsulated in each toner particle by precisely controlling the toner particle shape so that the toner particle shape satisfies the above conditions. The influence of the charging characteristics due to the agent is also uniform, whereby the developability and transferability are improved in a balanced manner, and problems such as image fog and toner scattering can be avoided.

That is, by reducing the particle equivalent number average diameter D ₁ (μm) of the toner to 2 to 10 μm, preferably 2 to 7 μm, more preferably 2 to 5 μm, the contour portion of an image, particularly a character image or a line. The reproducibility of pattern development is good.

  On the other hand, there are concerns about various effects such as image fogging and transfer failure as the toner particle size is reduced, but the average circularity of the circularity frequency distribution of the toner is 0.940 to 0.995, preferably 0.955. By setting it to ˜0.995, more preferably 0.970 to 0.990, image fogging and transferability of toner having a small particle diameter, which has been difficult in the past, are greatly improved.

  Furthermore, the toner of the present invention has a developability by making the circularity standard deviation of the circularity frequency distribution of the toner less than 0.040, preferably less than 0.035, more preferably 0.015 or more and less than 0.035. The problem about can be greatly improved.

Further, by setting the toner having an average circularity of less than 0.955 in the circularity frequency distribution to 15% or less, the development efficiency in image formation becomes a sufficient level, and the image formation is also good.
The equivalent-circle diameter, circularity, and frequency distribution of the toner in the present invention are used as a simple method for quantitatively expressing the shape of the toner particles. In the present invention, the flow-type particle image measuring device “ Measurement was carried out using "FPIA-1000 type" (manufactured by Toa Medical Electronics Co., Ltd.), and calculation was performed using the following formula.

  Here, the “particle projected area” is the area of the binarized toner particle image, and the “peripheral length of the particle projected image” is the length of the contour line obtained by connecting the edge points of the toner particle image. Define.

  The circularity in the present invention is an index indicating the degree of unevenness of toner particles, and is 1.000 when the toner particles are perfectly spherical, and the circularity becomes smaller as the surface shape becomes more complicated.

  In the present invention, the circle-equivalent number average diameter D1 (μm) and the particle size standard deviation SDd, which mean the average value of the particle number frequency distribution based on the number of toners, are the particle size (central value) at the dividing point i of the particle size distribution. Is di, and the frequency is fi.

  In the toner of the present invention, a charge control agent is added from the standpoint of improving the dispersibility and chargeability of the colorant. However, the negative charge control is capable of maintaining a constant charge amount in a colorless or light color with a high toner charge speed. Agents are preferred. In particular, a sulfur-containing polymer is preferable, leading to good dispersibility and charging characteristics of the colorant, and improving developability, transferability, and coloring power in a balanced manner.

  Examples of the sulfur-containing polymer used in the present invention include polymer-type compounds having a sulfonic acid group in the side chain, and particularly a sulfonic acid group-containing (meth) acrylamide monomer in a copolymerization ratio of 2% by mass or more. Styrene containing preferably 5% by mass or more and having a glass transition temperature (Tg) of 40 to 90 ° C., a peak average molecular weight of 10,000 to 30,000, and preferably a weight average molecular weight of 25,000 to 40,000 And / or a polymer compound comprising a styrene (meth) acrylic acid copolymer. When this is used, preferred charging characteristics can be enjoyed without affecting the thermal characteristics required of the toner particles. Further, since the charge control agent contains a sulfonic acid group, the dispersibility of the charge control agent itself in the binder resin and the dispersibility of the colorant are improved, and coloring power, transparency, and charging characteristics are improved. Significantly improved.

  As said sulfonic-acid-group-containing (meth) acrylamide type monomer, what is represented by the following general formula [3] is preferable, and 2-acrylamide-2-methylpropanoic acid and 2-methacrylamide-2 are specifically mentioned. -Methyl propanoic acid etc. are mentioned.

〔上記一般式［３］中、Ｒ₉は水素原子、又はメチル基を示し、Ｒ₁₀ とＲ₁₁は、それぞれ水素原子、Ｃ₁〜Ｃ₁₀のアルキル基、アルケニル基、アリール基、又はアルコキシ基を示し、ｎは１〜１０の整数を示す。〕

[In the general formula [3], R ₉ represents a hydrogen atom or a methyl group, and R ₁₀ and R ₁₁ represent a hydrogen atom, a C _{1 to} C ₁₀ alkyl group, an alkenyl group, an aryl group, or an alkoxy group, respectively. N represents an integer of 1-10. ]

  Further, a dialkyl salicylic acid derivative may be used as the charge control agent. Examples of the dialkyl salicylic acid derivative used in the present invention include a metal complex of di-tert-butyl salicylic acid, specifically, an aluminum complex of di-tert-butyl salicylic acid. Since the charge control agent has a salicylic acid structure, it is easy to orient uniformly in the vicinity of the toner particle surface, exhibits an efficient charge imparting ability, suppresses migration of the colorant to the toner surface, and exists on the toner particle surface. The problem caused by the colorant to be avoided can be avoided. In particular, in the suspension polymerization method, the surface of the particles is uniformly covered with the dispersant by attracting with the dispersant in water, so that the coalescence of the particles is prevented, and excellent granulation stability is exhibited. preferable.

  When the charge control agent used in the present invention is contained in an amount of 2 to 10 parts by mass with respect to 100 parts by mass of the binder resin, the toner particles are less likely to hold a reverse charge, and the charged state is further improved. Can do.

  Moreover, the surface of the colorant according to the present invention can be treated by a conventionally known method. By using the surface-treated colorant, re-aggregation of the colorant can be prevented, dispersibility of the colorant in the toner particles can be improved, and further, the chargeability of the toner can be brought into a preferable state. The characteristics as described above can be further improved.

  As a method for producing the toner according to the present invention, the binder resin, the colorant according to the present invention, the wax component and the like are melt-kneaded with a pressure kneader or the like, and then the cooled kneaded product is pulverized to a desired toner particle size. Further, a finely pulverized product is classified to prepare a toner by adjusting the particle size distribution to obtain a toner; described in JP-B-36-10231, JP-A-59-53856, and JP-A-59-61842. A direct toner production method using the suspension polymerization method; a spherical toner is produced by atomizing a melt-kneaded product in air using a disk or a multi-fluid nozzle described in JP-B-56-13945 Known methods such as an emulsion polymerization method represented by a soap-free polymerization method can be used. To precisely control the particle shape of a toner that satisfies the above conditions, By law Concrete it is desirable.

  Control of the toner average circularity, circularity standard deviation, and the number of toners having a circularity of less than 0.950 as described above is performed during the polymerization reaction from the granulation step to the polymerization step in the toner production method by suspension polymerization. This is possible depending on the pH of the aqueous dispersion medium.

  A toner produced by the suspension polymerization method is prepared by mixing a binder resin, the colorant according to the present invention, a polar resin, a wax component, a charge control resin, and a polymerization initiator to prepare a polymerizable monomer composition. The polymerizable monomer composition is dispersed in an aqueous medium to produce particles of the polymerizable monomer composition, and the styrene monomer in the particles of the polymerizable monomer composition is polymerized in the aqueous medium. Generated.

  The toner of the present invention contains a binder resin as an essential component. Examples of the binder resin for the toner used in the present invention include commonly used styrene- (meth) acrylic copolymers, polyester resins, epoxy resins, and styrene-butadiene copolymers. In a method for directly obtaining toner particles by a polymerization method, a monomer for forming them is used. Specifically, styrene; styrene monomers such as o- (m-, p-) methylstyrene, m- (p-) ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, acrylic acid Propyl, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acryl (Meth) acrylic acid ester monomers such as dimethylaminoethyl acrylate and diethylaminoethyl (meth) acrylate; ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile and acrylamide are preferably used. . These may be used alone or in general so that the theoretical glass transition temperature (Tg) described in the publication Polymer Handbook 2nd edition III-p139-192 (John Wiley & Sons) is 40-75 ° C. It is used by appropriately mixing the monomer. When the theoretical glass transition temperature is less than 40 ° C., problems are likely to occur in terms of storage stability and durability stability of the toner. On the other hand, when it exceeds 75 ° C., the transparency of the OHP image in the case of full-color image formation of toner. Decreases.

  In the present invention, a polar resin such as a polyester resin or a polycarbonate resin can be used in combination with the above-described binder resin.

  For example, when a toner is directly produced by suspension polymerization or the like, when a polar resin is added during the polymerization reaction from the dispersion step to the polymerization step, a polymerizable monomer composition that becomes toner particles and an aqueous dispersion medium are exhibited. Depending on the balance of polarity, the added polar resin can be controlled to form a thin layer on the surface of the toner particles or to have a gradient from the toner particle surface toward the center. At this time, by using a polar resin that interacts with the colorant or sulfur-containing polymer according to the present invention, the state of the colorant in the toner can be brought into a desired form.

  The addition amount of the polar resin is preferably 1 to 25 parts by mass, more preferably 2 to 15 parts by mass with respect to 100 parts by mass of the binder resin. If the amount is less than 1 part by mass, the presence state of the polar resin in the toner particles becomes non-uniform. Conversely, if the amount exceeds 25 parts by mass, the thin layer of the polar resin formed on the surface of the toner particles becomes thick.

  Specific examples of the polar resin used in the present invention include polyester resins, epoxy resins, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, and styrene-maleic acid copolymers. In particular, a polyester resin having a peak molecular weight of 3,000 to 10,000 is preferable because it can improve the fluidity, negative triboelectric charging characteristics, and transparency of toner particles.

  The toner of the present invention has a wax component as an essential component. Specific examples of wax components that can be used in the present invention include paraffin wax, microcrystalline wax, petroleum waxes such as petrolactam and derivatives thereof, montan wax and derivatives thereof, hydrocarbon waxes and derivatives thereof according to the Fischer-Tropsch method. , Polyolefin waxes typified by polyethylene and derivatives thereof, natural waxes such as carnauba wax and candelilla wax, and derivatives thereof, and the like include oxides, block copolymers with vinyl monomers, and graft modified products. Is also included. Examples thereof include alcohols such as higher aliphatic alcohols; aliphatics such as stearic acid and palmitic acid or compounds thereof; acid amides, esters, ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes, and animal waxes. These can be used alone or in combination. In particular, it is preferable to use a low melting point wax such as paraffin wax and a high melting point wax such as a hydrocarbon wax obtained by the Fischer-Tropsch method because the fixability and coloring power can be improved.

  The wax component used in the present invention is a compound having a main endothermic peak temperature (melting point) in a DSC curve measured according to “ASTM D3418-82” in the range of 30 to 120 ° C., more preferably 40 to 90 ° C. However, the fixability and further the transparency can be improved, which is preferable.

  Furthermore, in the present invention, it is preferable to use a crosslinking agent during the synthesis of the binder resin in order to increase the mechanical strength of the toner particles and control the molecular weight of the toner molecules.

  Examples of the crosslinking agent used in the toner of the present invention include divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1, bifunctional crosslinking agent. 4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 200, # 400, # 600 diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester diacrylate (MAN A Nippon Kayaku), and include those instead dimethacrylate above diacrylate.

  Polyfunctional crosslinkers include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis (4-methacryloxy, polyethoxy Phenyl) propane, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate and triallyl trimellitate.

  These crosslinking agents are preferably used in an amount of 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, with respect to 100 parts by mass of the monomer.

  When the toner of the present invention is produced by suspension polymerization, specific examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile) and 2,2′-azobisiso. Azo or diazo such as butyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile A polymerization initiator such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide; Although the usage-amount of these polymerization initiators changes with the target degree of polymerization, generally 5-20 mass parts is used with respect to 100 mass parts of polymerizable vinylic monomers. The type of the polymerization initiator is slightly different depending on the polymerization method, but is used alone or in combination with reference to the 10-hour half-life temperature.

  When the toner of the present invention is produced by the suspension polymerization method, known inorganic and organic dispersants can be used as the dispersant used when preparing the aqueous dispersion medium. Specifically, as the inorganic dispersant, for example, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, Examples include calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina. Examples of organic dispersants that can be used include polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, carboxymethylcellulose sodium salt, and starch.

  Commercially available nonionic, anionic and cationic surfactants can also be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate can be used.

  When the toner of the present invention is produced by the suspension polymerization method, the inorganic dispersant is preferably a water-insoluble dispersant as the dispersant used in preparing the aqueous dispersion medium, and the acid-soluble inorganic water-soluble inorganic dispersant. Should be used. Moreover, in this invention, when preparing a water-based dispersion medium using a slightly water-soluble inorganic dispersing agent, these dispersing agents are 0.2-2. It is preferable to use it in such a ratio that it becomes 0 parts by mass. Moreover, in this invention, it is preferable to prepare an aqueous dispersion medium using 300-3,000 mass parts water with respect to 100 mass parts of polymerizable monomer compositions.

  In the present invention, when preparing an aqueous dispersion medium in which the above-mentioned poorly water-soluble inorganic dispersant is dispersed, a commercially available dispersant may be used as it is, but a dispersion having a fine uniform particle size may be used. In order to obtain agent particles, a slightly water-soluble inorganic dispersant as described above may be prepared in a liquid medium such as water under high-speed stirring. For example, when tricalcium phosphate is used as a dispersant, a preferred dispersant can be obtained by mixing aqueous sodium phosphate solution and aqueous calcium chloride solution at high speed to form fine particles of tricalcium phosphate. .

  Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited thereto.

(Toner Production Example 1)
In a 4-liter flask for 2 liters equipped with a high-speed stirring device TK type homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), 700 parts by mass of ion-exchanged water and 800 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution were added. The rotation speed of the high-speed stirrer was set to 12,000 rpm, and the mixture was heated to 65 ° C. To this, 70 parts by mass of a 1.0 mol / liter-CaCl ₂ aqueous solution was added to prepare an aqueous dispersion medium containing a minute hardly water-soluble dispersion stabilizer Ca ₃ (PO ₄ ) ₂ . Further, the pH of the aqueous dispersion medium was adjusted again to 5.2 with dilute hydrochloric acid.

on the other hand,
・ C. I. Pigment Yellow 155 1.2 parts by mass / C.I. I. Pigment Yellow 93 4.8 parts by mass, styrene monomer 47 parts by mass, charge control agent (sulfur-containing polymer R-1) 3 parts by mass (Mp = 13,000, Tg = 58 ° C.)
-Polyester resin (peak molecular weight = 7,000) K. A colorant dispersion composition was prepared by dispersing for 1 hour using a homodisper (manufactured by Tokushu Kika Kogyo Co., Ltd.).

In a separate container,
-Styrene monomer 36 parts-N-butyl acrylate 17 parts-Divinylbenzene monomer 0.3 part-Ester wax (melting point = 50 ° C) 8 parts-Acid-modified polyethylene wax (melting point = 120 ° C) After adding 63 parts by mass of the colorant dispersion composition to a mixture of 5 parts by mass, dispersing and dissolving while heating at 65 ° C., 2,2′-azobis (2,4-dimethylvaleronitrile) 5 A part by mass was added to prepare a polymerizable vinyl monomer composition as a dispersoid.

Next, the polymerizable monomer composition is put into the aqueous dispersion medium and stirred for 5 minutes in an N ₂ atmosphere at an internal temperature of 65 ° C. while maintaining the rotation speed of the high-speed stirring device at 15,000 rpm. The polymerizable monomer composition was granulated. Thereafter, the stirring device was changed to one equipped with a paddle stirring blade, and the same temperature was maintained while stirring at 200 rpm. When the temperature reached 90%, the first reaction step was completed. A 0.1 mol / liter sodium hydroxide aqueous solution was added thereto to change the pH of the aqueous dispersion medium to 10. Further, the reaction temperature was raised to 80 ° C., and when the polymerization conversion rate was almost 100%, the second reaction step was completed, and the polymerization step was completed.

  After completion of the polymerization, the residual monomer was distilled off under reduced pressure by heating, and after cooling, diluted hydrochloric acid was added to dissolve the hardly water-soluble dispersant. Further, water washing was repeated several times, and then a drying process was performed using a conical ribbon dryer (manufactured by Okawara Seisakusho) to obtain polymer particles (A).

100 parts by mass of the polymer particles (A) and 1.5 parts by mass of silicone oil-treated silica fine powder (BET; 200 m ^{2 /} g) were dry-mixed with a Henschel mixer (manufactured by Mitsui Kinzoku Co., Ltd.), and the toner (A) and did.

  The toner (A) has a circle-equivalent number average diameter of 4.1 μm, a circularity frequency distribution with an average circularity of 0.987, a circularity standard deviation of 0.025, and the number of toner particles having a circularity of less than 0.950. Was 5.4% by number.

(Toner Production Examples 2 to 5)
Except for changing the type and addition amount of the yellow colorant, the type and addition amount of the charge control agent, and the type and addition amount of the wax component, the polymer particles (B) to After obtaining (E), toners (B) to (E) were prepared.

(Toner Production Example 6)
The following materials are mixed in advance, melt kneaded with a twin screw extruder, the cooled kneaded product is coarsely pulverized with a hammer mill, the coarsely pulverized product is finely pulverized with a jet mill, and the resulting finely pulverized product is classified and classified. It was set as the powder (F).
-Binder resin 100 parts by mass [styrene-n-butyl acrylate copolymer resin (Tg = 65 ° C.)]
・ C. I. Pigment Yellow 155 0.75 part by mass, C.I. I. Pigment Yellow 166 4.25 parts by mass / charge control agent 3 parts by mass (aluminum compound of dialkyl salicylic acid)
・ 10 parts by mass of paraffin wax (melting point = 65 ° C.)

  Using the classified powder (F), a toner (F) was prepared in the same manner as in Toner Production Example 1.

(Comparative Toner Production Example 1)
4.2 parts by weight of “CI Pigment Yellow 155” as a colorant, 1.8 parts by weight of “CI Pigment Yellow 128”, 3 parts by weight of a boron compound of benzyl acid as a charge control agent, and an ester as a wax component Comparative polymer particles (a) were obtained in the same manner as in the toner production example 1 except that 10 parts by weight of a wax (melting point = 60 ° C.) was used. Then, a comparative toner (a) was prepared. did.

(Comparative toner production example 2)
1.2 parts by weight of “CI Pigment Yellow 62” as a colorant, 4.8 parts by weight of “CI Pigment Yellow 139”, 2 parts by weight of calixarene as a charge control agent, and ester wax (melting point) (= 60 ° C.) Comparative polymer particles (b) were obtained in the same manner as in Toner Production Example 1 except that 10 parts by mass was used. Comparative toner (b) was then prepared.

(Comparative toner production example 3)
Styrene monomer 83 parts by mass n-butyl acrylate 17 parts by mass C.I. I. Pigment Yellow 155 5 parts by mass / charge control agent (sulfur-containing polymer R-4) 1 part by mass (Mp = 15,000, Tg = 42 ° C.)
The above materials were stirred and mixed with a normal stirring device, and then uniformly dispersed with a media type dispersing machine. To this, 4 parts by mass of pentaerythritol stellar myristate was added, mixed and dissolved to obtain a polymerizable monomer composition.

  On the other hand, to an aqueous solution in which 9.5 parts by mass of magnesium chloride was dissolved in 250 parts by mass of ion-exchanged water, an aqueous solution in which 5.8 parts by mass of sodium hydroxide was dissolved in 50 parts by mass of ion-exchanged water was gradually added with stirring. A magnesium hydroxide colloidal dispersion was prepared. Into this dispersion, the polymerizable monomer composition was added and stirred until the droplets were stabilized. After adding 6 parts by mass of a polymerization initiator t-butylperoxy-2-ethylhexanoate, Using an Eva Milder (MDN303V type manufactured by Ebara Seisakusho Co., Ltd.), high shear stirring was performed for 30 minutes at a rotation speed of 15,000 rpm to granulate droplets of the monomer mixture. This granulated monomer mixture aqueous dispersion was put into a 10 liter reactor equipped with a stirring blade, the polymerization reaction was started at 90 ° C., the polymerization was continued for 8 hours, the reaction was stopped, and pH 9 While stirring the aqueous dispersion of polymer particles of .5, acid wash (25 ° C., 10 minutes) with sulfuric acid to a pH of about 5.5, followed by filtration, dehydration and washing, and drying After the comparative polymer particles (c) were obtained, a comparative toner (c) was prepared.

(Comparative toner production example 4)
Polyester resin 70 parts by mass [polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane terephthalic acid / fumaric acid / trimellitic acid (Tg = 56 ° C.)]
・ C. I. Pigment Yellow 155 30 parts by mass The above materials were charged into a kneader-type mixer, heated while being mixed with no pressure, and sufficiently premixed.

-16.7 parts by weight of the above mixture-88.3 parts by weight of the above colorant polyester resin-4 parts by weight of the zirconium dialkyl salicylate compound The above materials are sufficiently premixed with a Henschel mixer, melt-mixed with a biaxial extruder, and cooled. It was coarsely pulverized by about 1 to 2 mm using a post-hammer mill, and then finely pulverized by an air jet type fine pulverizer. Further, fine powder and coarse powder were removed from the resulting finely pulverized product with a multi-part pulverizer to obtain comparative polymer particles (d), and then comparative toner (d) was prepared.

(Comparative Toner Production Example 5)
Only 2.5 parts by mass of “CI Pigment Yellow 93” as a colorant, 1.5 parts by mass of an aluminum dialkylsalicylate compound as a charge control agent, and 10 parts by mass of an ester wax (melting point = 64 ° C.) as a wax component A comparative polymer particle (e) was obtained in the same manner as in Toner Production Example 1 except that the comparative toner (e) was prepared.

(Comparative Toner Production Example 6)
Except for changing to using 5 parts by weight of “CI Pigment Yellow 168” as a colorant, 3 parts by weight of calixarene as a charge control agent, and 10 parts by weight of an ester wax (melting point = 60 ° C.) as a wax component. Comparative polymer particles (f) were obtained in the same manner as in Toner Production Example 5, and then comparative toner (f) was prepared.

  Table 1 summarizes the main prescription contents and toner particle shapes of the toner production examples and comparative toner production examples.

(Toner Production Example 7)
Except for changing to using 5 parts by weight of “CI Pigment Blue 15: 3” as a colorant and 10 parts by weight of ester wax (melting point = 60 ° C.) as a wax component, the same as in Production Example 1 of the toner described above. After obtaining polymer particles, a cyan toner was prepared.

(Toner Production Example 8)
Similar to the toner production example 1 except that 7 parts by weight of “CI Pigment Red 122” is used as the colorant and 10 parts by weight of ester wax (melting point = 60 ° C.) is used as the wax component. After obtaining coalesced particles, a magenta toner was prepared.

[Example 1]
With respect to the toner (A) obtained in Production Example 1, when the triboelectric charge amount was measured under normal temperature and normal humidity and high temperature and high humidity, no significant difference was observed, and the environmental charge stability was excellent.

A laser beam printer (Canon: LBP-2160) was modified and used as the image forming apparatus. The toner (A) obtained in Toner Production Example 1 is put into this process cartridge, plain paper for copying machines (75 g / m ² ) is used as a transfer material, and a character image with a printing area ratio of 4% in the monochrome mode. After printing out 10,000 sheets at a printout speed of 28 sheets (A4 size) / min and evaluating the printout image, dot reproducibility and transferability are good, and image fogging and toner scattering are observed. As a result, a good image equivalent to the initial printing was obtained. With respect to this, when the surface of the photoconductor was observed, filming of the photoconductor surface, adhesion of residual toner, and damage did not occur, and it was in a very good state.

Further, several types of solid images having different toner amounts on the transfer paper in the range of 0.1 mg / cm ² to 1.0 mg / cm ² were created, and the relationship between the toner amount on the transfer paper and the image density was evaluated. Even with a relatively small amount of toner, an image having a sufficient image density was obtained, and the high coloring power could be confirmed.

Using the cyan toner obtained in Toner Production Example 7 and the magenta toner obtained in Toner Production Example 8 in addition to yellow toner (A), plain paper for copying machines (75 g / m ²⁾ was used in the same manner as described above. When a full-color image was printed out on (), an image with excellent secondary color superposition and excellent color reproducibility was obtained. In addition, when printed on an OHP sheet “CG3700” (manufactured by 3M) and evaluated for an OHP projection image, the projection was excellent in transparency, and also excellent in overlaying secondary colors and having a wide color space. An image was obtained.

  These evaluation results are summarized in Table 3.

  In addition, the evaluation method and its evaluation criteria are as follows, and Examples 2 to 6 and Comparative Examples 1 to 6 described later also follow these.

(Evaluation methods)
(1) Environmental Charging Stability of Toner FIG. 1 is a schematic explanatory diagram of an apparatus for measuring the triboelectric charge amount of toner. The mixture of toner (without external additives) and carrier is put into a polyethylene bottle having a capacity of 50 to 100 ml, and is shaken and charged by shaking 500 times. As the carrier, a ferrite carrier coated with a silicone resin (average particle size 35 μm) is used, and the mixing mass ratio of the toner and the carrier is 7:93. The mixture (toner and carrier) W0 (g: about 0.5 to 1.5 g) is placed in a metal measuring container 2 having a 500 mesh screen 3 at the bottom, and a metal lid 4 is formed. The total mass of the measurement container 2 at this time is weighed and is defined as W1 (g). Next, in the suction machine 1 (the part in contact with the measurement container 2 is at least insulative), suction from the suction port 7 and adjustment of the air volume control valve 6 are performed to set the pressure of the vacuum gauge 5 to 2450 (hpa). In this state, suction is performed for 2 minutes to remove the toner by suction. At this time, the triboelectric charge amount Q (mC / kg) of the toner is defined as follows when the toner is 100% corrected.

（Ｖ（ボルト）は電位計９の電位を示し、Ｃ（μＦ）はコンデンサー８の容量を示し、Ｗ２（ｇ）は吸引後の測定容器２の質量を示し、Ｔはトナー／キャリアの質量比を示す）

(V (volt) indicates the potential of the electrometer 9, C (μF) indicates the capacity of the capacitor 8, W2 (g) indicates the mass of the measurement container 2 after suction, and T indicates the toner / carrier mass ratio. Indicate)

  The environmental charge stability of the toner was measured by measuring the triboelectric charge quantity Q of the toner at normal temperature and normal humidity (23 ° C., 60% RH) and high temperature and high humidity (35 ° C., 90% RH).

<Frictional charge Q (normal temperature and humidity)>
A: Less than −35 mC / kg B: −35 mC / kg or more, less than −30 mC / kg C: −30 mC / kg or more, less than −25 mC / kg D: −25 mC / kg or more

<Frictional charge Q (high temperature and high humidity)>
A: The difference from the triboelectric charge amount Q at normal temperature and humidity is less than 5 B: The difference from the triboelectric charge amount Q at normal temperature and normal humidity is 5 or more and less than 10 C: The difference from the triboelectric charge amount Q at normal temperature and normal humidity 10 or more and less than 15 D: The difference from the triboelectric charge Q at normal temperature and humidity is 15 or more

(2) Dot reproducibility An image of an isolated dot pattern having a small diameter (35 μm) as shown in FIG. 2 was printed out, and the dot reproducibility was evaluated.
A: 2 or less defects in 100 B: 3 to 5 defects in 100 C: 6 to 10 defects in 100 D: 11 or more defects in 100

(3) Image fog The residual toner on the photosensitive member at the time of solid white image formation is taped and peeled off with Mylar tape, and the reflection density is measured with “X-Rite 504” on the paper. The obtained reflection density was evaluated using a value obtained by subtracting the reflection density when the Mylar tape was stuck on paper as it was. The smaller the numerical value, the more image fog is suppressed.
A: Less than 0.03 B: 0.03 or more, less than 0.07 C: 0.07 or more, less than 0.15 D: 0.15 or more

(4) Toner Scattering Toner scattering pays attention to toner scattering due to deterioration of charging property, and when the endurance of 10000 sheets, the toner contamination on the outer surface of the upstream side toner scattering suppression unit and the downstream side toner scattering suppression unit of the developing container, In addition, the contamination by toner other than the developing container was visually observed and evaluated based on the following evaluation criteria.
A: Not recognized at all B: Stain is slightly observed on the outer surface of the upstream toner scattering suppression portion of the developing container, but no contamination is observed on the outer surface of the downstream toner scattering suppressing portion C: Toner on the upstream side of the developing container Dirt is observed on the outer surface of the scattering control part and the outer surface of the downstream side toner scattering prevention, but no dirt is observed except in the developing container.

(5) Transferability The residual toner on the photosensitive member at the time of solid image formation is removed by taping with a Mylar tape, and the reflection density of the toner stuck on paper is measured by “X-Rite 504”. The obtained reflection density was evaluated using a value obtained by subtracting the reflection density when the Mylar tape was stuck on paper as it was. The smaller the value, the better the transferability.
A: Less than 0.03 B: 0.03 or more, less than 0.07 C: 0.07 or more, less than 0.10 D: 0.10 or more

(6) Matching with Photoreceptor Filming on the surface of the photoreceptor, sticking of residual toner, damage occurrence, and influence on the printout image were visually evaluated.
A: Not generated B: Scratches are slightly observed, but there is no effect on the image C: There is fixing or scratching, but there is little effect on the image D: There is much fixing, and vertical streak-like image defects Arise

(7) Coloring power Several types of solid images with different toner amounts were created on the transfer paper in the range of 0.1 mg / cm ² to 1.0 mg / cm ² , and the image density was determined using “X-Rite 504”. After measuring and determining the relationship between the toner amount on the transfer paper and the image density, the coloring power was relatively evaluated with the image density corresponding to the case where the toner amount on the transfer paper was 0.5 mg / cm ^{2 in} particular.
A: Toner amount on transfer paper is 0.5 mg / cm ² and image density is 1.4 or more B: Toner amount on transfer paper is 0.5 mg / cm ² , image density is 1.35 or more, 1.40 Less than C: Toner amount on transfer paper is 0.5 mg / cm ² , image density is 1.20 or more, less than 1.35 D: Toner amount on transfer paper is 0.5 mg / cm ² and image density is Less than 1.20

(8) Color reproducibility and transparency of full-color projection image A full-color image on an OHP sheet “CG3700” (manufactured by 3M) is converted into a transmission image by OHP “95550” (manufactured by 3M company), and an image projected on a white wall surface In addition to visual evaluation, L ^* a ^* b ^* c ^* standardized by the International Commission on Illumination was measured with a spectral radiance meter “PR650” (manufactured by Photo Research) for the yellow monochromatic part, and the brightness (L ^* ) and Saturation (c ^* ) was evaluated.

<L ^* value, c ^* value>
A: L ^* value is 85 or more and c ^* value is 70 or more B: L ^* value is 85 or more and c ^* value is 60 or more and less than 70 C: L ^* value is 80 or more and less than 85 and c ^* Value is less than 70 D: L ^* Value is less than 80 and c ^* value is less than 70

<Visual evaluation>
A: Vivid and excellent in transparency B: Excellent in transparency and excellent in color reproducibility of yellow, but secondary colors (red and green) are slightly inferior C: Transparency is slightly inferior, yellow, secondary Color (red, green) is slightly inferior in color reproducibility D: Dull and yellow, secondary colors (red, green) are inferior in color reproducibility

(9) Color reproducibility of images on plain paper A full color image on plain paper for copying machines (75 g / m ² ) is visually evaluated and measured with “X-Rite SP68” (manufactured by X-Rite). The volume of the color space solid determined by L ^* a ^* b ^* color system brightness L ^* , red or green degree a ^* , yellow or blue degree b ^* specified by the Lighting Committee Asked. A larger value means a wider color space, and a smaller value means poor color reproducibility.

<Color space volume>
A: More than 2.5 million B: More than 2 million and less than 2.5 million C: More than 1.5 million and less than 2 million D: Less than 1.5 million

<Visual evaluation>
A: Yellow and secondary colors (red and green) are excellent in color reproducibility B: Yellow color reproducibility is excellent, but secondary colors (red and green) are slightly inferior C: Yellow and secondary colors (red) , Green) Any color reproducibility is slightly inferior D: Yellow, secondary colors (red, green) any color reproducibility is also inferior

[Examples 2 to 6 and Comparative Examples 1 to 6]
Evaluation was performed in the same manner as in Example 1 except that toners (B) to (F) and comparative toners (a) to (f) were used as toners. The results are shown in Table 3.

FIG. 6 is an explanatory diagram of an apparatus for measuring the frictional charge amount of toner. It is explanatory drawing of the pattern image used for dot reproducibility evaluation.

Explanation of symbols

1. 1. Suction machine 3. Measuring device 3.500 mesh screen Lid 5. Vacuum gauge 6. 6. Air flow control valve Suction port 8. Capacitor 9. Electrometer

Claims (10)

A dry toner containing at least a binder resin, a colorant represented by Structural Formula [1] and a colorant represented by Structural Formula [2], a wax component, and a charge control agent,
The mass ratio of the content of the colorant represented by the structural formula [1] and the structural formula [2] is 10:90 to 50:50, and a flow type particle image analyzer (Flow Particle Image Analyzer) is used. The toner has a circle equivalent number average diameter D1 (μm) of 2 to 10 μm, the toner has an average circularity of 0.940 to 0.995, and a circularity standard deviation of less than 0.040. Dry toner.

[R ₁ and R ₂ represent a hydrogen atom, a chlorine atom, or a methyl group, and R ₃ represents the following group:

The substituent chosen from is shown. ]   The dry toner according to claim 1, wherein the charge control agent is a sulfur-containing polymer.   The dry toner according to claim 2, wherein the sulfur-containing polymer is a polymer having a sulfonic acid group.   The sulfur-containing polymer contains a sulfonic acid group-containing (meth) acrylamide monomer in a copolymerization ratio of 2% by mass or more, a glass transition temperature (Tg) of 40 to 90 ° C., and a peak average molecular weight of 10,000 to 30, 4. The dry toner according to claim 1, wherein the dry toner is a polymer compound composed of styrene and / or a styrene (meth) acrylic acid copolymer.   5. The dry toner according to claim 1, wherein the toner has an average circularity of 0.955 to 0.995 and a circularity standard deviation of less than 0.035.   The dry toner according to claim 1, wherein the toner has an average circularity of 0.970 to 0.990 and a circularity standard deviation of 0.015 or more and less than 0.035.   In the equivalent circle diameter-circularity scattergram based on the number of toners measured by the flow type particle image measuring device, the toner contains 15% by number or less of toner particles having a circularity of less than 0.950. Item 7. The dry toner according to any one of Items 1 to 6.   The colorant represented by Structural Formula [2] is C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 95, C.I. I. Pigment Yellow 128, and C.I. I. The dry toner according to claim 1, wherein the dry toner is selected from the group of Pigment Yellow 166 (each according to a name described in the color index fourth edition).   The colorant represented by Structural Formula [2] is C.I. I. The dry toner according to claim 1, which is Pigment Yellow 93 (according to the name described in the color index fourth edition).   The dry toner according to claim 1, wherein the dry toner is a yellow toner that is supplied to form a yellow toner image when a full-color image is formed.

Images