JP5230297B2 - toner - Google Patents

Description

  The present invention relates to a toner for developing an electrostatic latent image using electrophotography, electrostatic recording, toner jet recording, or the like.

  Conventionally, in an electrophotographic system, an electrostatic charge latent image carrier generally made of a photoconductive substance is charged by various means and further exposed to form an electrostatic latent image on the surface of the electrostatic latent image carrier. Next, the electrostatic latent image is developed with toner to form a toner image, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material by heat, pressure, and heat and pressure, and a copy is made. Or to obtain a print. At this time, the toner remaining on the photosensitive member without being transferred to the transfer material after transfer (transfer residual toner) is cleaned by various methods, and the above-described steps are repeated.

  Known cleaning methods include a blade cleaning method in which an elastic rubber blade is pressed onto the electrostatic latent image bearing member to mechanically remove the transfer residual toner, and a brush cleaning method in which a brush roller in which fine fibers are planted is rotated at a high speed. It has been.

  Various methods and apparatuses have been developed as a fixing method, but the most common method at present is a pressure heating method using a heated roller, film or belt. In particular, pressure heating using a film is widely used because it can be fixed with a relatively low amount of heat.

  In recent years, copying machines and printers using electrophotography have been required to have higher speed and higher image quality, and the process speed of the apparatus has to be accelerated while providing high-definition images. However, the load on the toner increases as the speed increases, and problems with development performance such as a decrease in image density due to toner wear tend to occur.

  Further, in the cleaning process, the process speed of the apparatus is accelerated while the fluidity of the high-definition image toner is improved, so that it is difficult for the toner to pass through the cleaning blade and be scraped off. In addition, when the charge of the toner is non-uniform or when the adhesion force with the image carrier is high, there is a problem that a mirror image force acts on the image carrier and is difficult to remove in the cleaning process. In particular, such a problem tends to become remarkable in a low temperature and low humidity environment, and an approach from toner is desired.

  On the other hand, miniaturization of the main body in consideration of energy saving and space saving is required, and in particular, simplification of the fixing device is important. In that case, if the film fixing is as described above, the heat source and the apparatus configuration can be easily simplified and applied. However, with simplification, for example, a fixing bias mechanism for applying a voltage to the fixing film to prevent toner adhesion is often removed, so that an electrostatic offset that causes toner to electrostatically adhere to the fixing film. Such a phenomenon is likely to occur.

  For the purpose of preventing these phenomena and adjusting the charging stability, durability stability, environmental stability, and fluidity of the toner to obtain good developability and cleaning properties, various inorganic fine powders and organic It is generally known to externally add fine powder.

  Specifically, inorganic fine powder and organic fine powder having a small primary particle size are externally added for the purpose of controlling the fluidity of the toner and the mirror image force with the image carrier to improve the cleaning property. In addition, studies have been made to improve the developability and cleaning properties by controlling the free state of inorganic fine powder and organic fine powder added externally.

  For example, Patent Document 1 discloses an invention in which the amount of free external additive released from the toner particle surface is controlled to 7 to 50%. As a result, filming on the photoconductor is prevented, and at the same time, the effect of improving the cleaning property of the photoconductor is seen.

  In Patent Document 2, the liberation rate of Si atoms derived from an additive based on C atoms in the base toner is 0.5 to 20%, and the liberation rate of Ti atoms derived from an additive based on C atoms. A toner in which silica and titania are added so that the ratio is 0.5 to 20% has been invented. As a result, an image without uneven adhesion is obtained.

  In Patent Document 3, the number release rate of the charge control agent with respect to the toner particles is 10% or less, and the number release rate of the charge control agent, inorganic fine particles, and organic fine particles from the toner particles is a relational expression: 30%> There is an invention satisfying inorganic fine particles> organic fine particles> charge control agent> 0%.

  Also, in Patent Document 4, the average particle size of primary particles is 30 nm to 300 nm, the release rate of toner fine particles with inorganic fine powder having a cubic particle shape and / or a rectangular parallelepiped particle shape and having a perovskite crystal. Is 20 volume% or less. This suppresses the occurrence of image flow.

  However, in any of the inventions, the types of fine powder added externally, the particle size, the added state, and the released state are not sufficiently studied, and phenomena that occur during fixing, such as cleaning properties and electrostatic offset, regardless of the environment. There are still some issues to be addressed.

JP 2006-30653 A Japanese Patent Laid-Open No. 2004-240459 JP 2006-259681 A JP 2005-338750 A

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

  That is, an object of the present invention is to provide a toner that can be obtained with a stable image density and excellent in electrostatic offset resistance even when used for a long time in a low temperature and low humidity environment.

  Another object of the present invention is to provide a toner having excellent cleaning resistance regardless of the environment.

The present invention is a toner having toner particles containing a binder resin and a colorant, an inorganic fine powder, and an organic fine powder,
(I) said inorganic fine powder, pieces number average particle diameter (D1) is contained 300nm following inorganic fine powder A over 30 nm, the isolation ratio of the toner particles of the inorganic fine powder A is 10.0 wt% or more 50.0 mass% or less,
(Ii) the organic fine powder, pieces number average particle diameter (D1) is contained 1000nm following organic fine powder B or 50 nm, the isolation ratio of the toner particles of the organic fine powder B is 3.0 mass% or less And
(Iii) The number average particle diameter of the inorganic fine powder A is not more than the number average particle diameter of the organic fine powder B;
(Iv) The toner has an average circularity of 0.960 or more.

  According to the present invention, it is possible to provide a toner that can obtain an image with a high printing ratio at a stable image density even in a low-temperature and low-humidity environment, has excellent electrostatic offset resistance, and excellent cleaning resistance regardless of the environment. can do.

A toner having toner particles containing a binder resin and a colorant, and inorganic fine powder and organic fine powder,
(I) said inorganic fine powder, pieces number average particle diameter (D1) is contained 300nm following inorganic fine powder A over 30 nm, the isolation ratio of the toner particles of the inorganic fine powder A is 10.0 wt% or more 50.0 mass% or less,
(Ii) the organic fine powder, pieces number average particle diameter (D1) is contained 1000nm following fine organic powder B over 50 nm, the isolation ratio of the toner particles of the organic fine powder B is 3.0 mass% or less And
(Iii) The number average particle diameter of the inorganic fine powder A is not more than the number average particle diameter of the organic fine powder B;
(Iv) The average circularity of the toner is 0.960 or more.

  In the case of using a toner with an increased circularity in order to obtain a high-quality and high-density image, the following points are important in order to improve the cleaning property.

  First, in the cleaning process, a cleaning member such as a cleaning blade is pressed against the image carrier with a predetermined pressure. As the process speed increases, the pressure fluctuation tends to increase easily, the cleaning blade may become chattered, and transfer residual toner may slip through. In order to suppress this phenomenon, it is effective to form a blocking layer in the nip portion by retaining the fine powder released in the cleaning nip portion between the photosensitive drum and the cleaning blade. On the other hand, when a mirror image force acts between the toner and the image carrier, cleaning tends to be difficult. In order to reduce this mirror image force, organic fine powder or the like is adhered to the toner surface, a spacer effect is imparted, the contact area between the toner and the image carrier is reduced, and the mirror image force between the toner and the image carrier is reduced. It is effective to reduce.

  That is, in order to improve the cleaning property, a fine fine powder is retained to form a blocking layer in the nip portion, and further, organic fine powder or the like is attached to the toner to give a spacer effect, It is important to reduce the mirror image force with the image carrier. As a result of intensive studies by the present inventors, it has been found that the expression of the blocking layer / spacer effect is suppressed only by adding inorganic fine powder and organic fine powder.

  However, it has been found that the cleaning properties can be improved without adversely affecting the blocking layer / spacer effect by highly controlling the adhesion state of both the inorganic fine powder and the organic fine powder with controlled particle size. In the toner of the present invention, by controlling the liberation rate of inorganic fine powder and organic fine powder with controlled particle size, both the formation of a blocking layer and the spacer effect that cannot be expressed by inorganic fine powder or organic fine powder alone are achieved. I found out that I can do it. That is, when the liberation rate of the inorganic fine powder having a small particle size is increased, a stable blocking layer can be formed without inhibiting the spacer effect. In addition, when the organic fine powder having a larger particle size than that of the inorganic fine powder was controlled so as not to be liberated, no harmful effect on the blocking layer was observed, and both the blocking layer and the spacer effect could be expressed.

  Further, the present inventors have further studied and found that electrostatic offset properties are improved by highly controlling the adhesion state of the inorganic fine powder and the organic fine powder with controlled particle diameters as described above, and have reached the present invention.

  The electrostatic offset is a phenomenon that is not thermally applied at the time of fixing but electrostatically adheres to the fixing film. Therefore, it is a problem that cannot be solved only by improving the thermal melting characteristics of the toner, such as so-called low-temperature fixability and high-temperature offset resistance, and control of the charging property is important. That is, as the charging property at the time of fixing is uniform, the electrostatic offset is less likely to occur. In order to make the charging property uniform, the addition state of the externally added fine powder is highly controlled to make the charging property of the toner uniform, and the external additive is buried even when the toner starts to melt at the time of fixing. In addition, it suppresses changes in shape and suppresses changes in chargeability. The inventors suggest that the adhesive force and electrostatic cohesive force with the fixing film are reduced by this, and electrostatic offset can be suppressed.

  In the toner of the present invention, the adhesion state of the inorganic fine powder and the organic fine powder with controlled particle sizes to the toner is highly controlled. As a result, it was possible to suppress the burying and shape change of external additives at the start of melting, which could not be expressed with inorganic fine powders and organic fine powders alone, and further to suppress the change in chargeability. The present inventors presume that the above has been improved. That is, when the adhesion state of the inorganic fine powder and organic fine powder with controlled particle size to the toner is highly controlled, the details are unknown, but the chargeability is increased from the transfer process to the fixing process even during long-term use. Largely stabilized. Furthermore, organic fine powders with a higher molecular weight can maintain their shape even when the toner starts melting, and the inorganic fine particles and organic fine powders with controlled particle size and added state coexist to charge even when melted. It is believed that the electrostatic offset resistance has improved due to the suppression of changes in properties.

In particular,
1. The inorganic fine powder A having a number average particle diameter (D1) of 30 nm to 300 nm is contained, and the liberation rate from the toner particles is 10.0% by mass to 50.0% by mass.
2. The organic fine powder B having a number average particle diameter (D1) of 50 nm or more and 1000 nm or less is contained, the release rate from the toner particles is 3.0 mass% or less, and the number average particle diameter of the inorganic fine powder A is It is not more than the number average particle size of the organic fine powder B.
3. The average circularity of the toner is 0.960 or more.

  It has been found that a toner satisfying all of the above can achieve both improvement in cleaning property and electrostatic offset resistance.

  It contains inorganic fine powder A having a number average particle size (D1) of 30 nm or more and 300 nm or less, and its liberation rate is 10.0% by mass or more and 50.0% by mass or less, so that cleaning properties and electrostatic offset resistance are achieved. It was effective. When inorganic fine powder of 30 nm or more and 300 nm or less is selected, the release rate of the inorganic fine powder can be easily controlled to 10.0 mass% or more and 50.0 mass% or less, so that the inorganic fine powder stays in the cleaning nip. It is possible to form a blocking layer. Further, since the toner charge amount is stabilized, the electrostatic offset resistance is also improved. When the number average particle diameter (D1) is smaller than 30 nm, it becomes difficult to control to a desired liberation rate. In addition, the small particle size makes it easier for fine powder to slip through the cleaning blade, making it difficult to form a blocking layer. On the other hand, when the number average particle diameter (D1) is larger than 300 nm, it becomes difficult to control the liberation rate, and it becomes difficult to stabilize the toner charge amount.

  By setting the liberation rate of the inorganic fine powder A to 10.0% by mass or more and 50.0% by mass or less, the inorganic fine powder is retained in the cleaning nip portion to form a blocking layer. Furthermore, since the charge amount is stable, good cleaning properties are exhibited, and high-quality and high-density images can be formed even after long-term use. In addition, since the components that are not liberated easily maintain the shape of the toner, the shape of the toner is stabilized even during fixing and melting, and an effect is also exerted against electrostatic offset.

  If the liberation rate of the inorganic fine powder A is less than 10.0% by mass, the amount of the liberated inorganic fine powder is small, and it becomes difficult to form a stable blocking layer.

  On the other hand, when the liberation rate of the inorganic fine powder A is greater than 50.0% by mass, since there are few components that are not liberated, it becomes difficult to maintain the shape of the toner, and the electrostatic offset resistance tends to be reduced.

  Examples of the inorganic fine powder A having a number average particle diameter (D1) of 30 nm or more and 300 nm or less include fine powder silica such as wet process silica and dry process silica, fine powder titanium oxide, fine powder alumina, silane compound, titanium Fine powder treated with coupling agent and silicone oil; oxides such as zinc oxide and tin oxide; double oxides such as strontium titanate, barium titanate, calcium titanate, strontium zirconate and calcium zirconate A carbonate compound such as calcium carbonate and magnesium carbonate;

  Among these, preferable inorganic fine powder A includes strontium titanate fine powder, more preferably titanic acid having a cubic particle shape and / or a rectangular parallelepiped particle shape and having a perovskite crystal structure. Strontium fine powder is used. Strontium titanate fine powder having a cubic particle shape and / or a rectangular parallelepiped particle shape and having a perovskite crystal structure is produced mainly in an aqueous medium without going through a sintering step. Since the particle size can be controlled to be uniform, it is easy to achieve the liberation rate and uniform chargeability of the present invention. Moreover, when it is a cube-shaped particle shape and / or a rectangular parallelepiped particle shape, it becomes easy to stay and a stable blocking layer can be formed.

  In order to confirm that the crystal structure of the inorganic fine powder is a perovskite type (a face-centered cubic lattice composed of three different elements), it can be confirmed by performing X-ray diffraction measurement.

  Further, the inorganic fine powder is preferably treated on the surface of the fine powder from the viewpoint of controlling the triboelectric charge polarity and the amount of triboelectric charge depending on the environment in consideration of development characteristics and forming a stable blocking layer.

  Examples of the surface treatment agent include treatment agents such as fatty acids, fatty acid salts, and organosilane compounds.

  By performing the surface treatment, for example, in the case of a coupling agent that is a compound having a hydrophilic group and a hydrophobic group, the hydrophobic group side becomes the outer side by covering the surface of the inorganic fine powder with the hydrophilic group side. Is made. By doing so, fluctuations in the triboelectric charge amount due to the environment can be suppressed. Further, the triboelectric charge amount can be easily controlled by a coupling agent into which a functional group such as an amino group or fluorine is introduced.

  Further, in the case of the surface treatment agent as described above, the shape of the inorganic fine powder is hardly changed due to the surface treatment at the molecular level, and the scraping force by the shape of a roughly cubic or rectangular parallelepiped is maintained. preferable.

  Examples of surface treatment agents include titanate, aluminum, and silane coupling agents. Examples of fatty acid metal salts include zinc stearate, sodium stearate, calcium stearate, zinc laurate, aluminum stearate, and magnesium stearate. The same effect can be obtained with stearic acid, which is a fatty acid.

  The treatment method includes dissolving and dispersing the surface treatment agent to be treated in a solvent, adding an inorganic fine powder therein, removing the solvent with stirring, a wet method, a coupling agent, and a fatty acid metal. Examples thereof include a dry method in which a salt and an inorganic fine powder are directly mixed and treated with stirring.

  Further, regarding the surface treatment, it is not necessary to completely treat and coat the inorganic fine powder, and the inorganic fine powder may be exposed as long as the effect is obtained. That is, the surface treatment may be formed discontinuously.

  Next, when the organic fine powder B having a number average particle diameter (D1) of 50 nm or more and 1000 nm or less is contained and the liberation rate thereof is 3.0% by mass or less, a spacer effect is imparted, and the toner, the image carrier, The mirror image power can be reduced. In addition, even when melting is started at the time of fixing, burying of external additives and shape change can be suppressed and charging can be stabilized, so that an effect can also be exhibited against electrostatic offset. When the number average particle diameter (D1) of the organic fine powder B is 50 nm or more and 1000 nm or less, the adhesion state on the toner particle surface can be easily controlled as desired, and the spacer effect can be exhibited, so that the cleaning property is improved. . Further, since the burying of the external additive and the change in the shape of the toner can be suppressed, it exhibits good developability even after long-term use, and electrostatic offset is also improved. When the number average particle diameter (D1) is smaller than 50 nm, the external additive is easily buried and the spacer effect is lowered, so that the cleaning property cannot be improved. On the other hand, when the number average particle diameter (D1) is larger than 1000 nm, the liberation rate is likely to be higher than 3.0% by mass, and it becomes difficult to reduce the spacer effect and to suppress the toner shape change.

  Specific examples of the organic fine powder B having a number average particle diameter (D1) of 50 nm to 1000 nm include polyolefin resins such as polyethylene and polypropylene; polyvinyl and polyvinylidene resins such as polystyrene and acrylic resins (acrylic heavy resins). , Acrylic copolymer), polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone; vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer A straight silicone resin composed of an organosiloxane bond or a modified product thereof; a fluororesin such as polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene , Polyesters, polycarbonates, and the like. A cured resin particle can be obtained by simultaneously using a crosslinking component such as divinylbenzene together with the resin formation.

  The weight average molecular weight (Mw) of the component soluble in tetrahydrofuran of the organic fine powder B is preferably 300000 or more and 1000000 or less. When the weight average molecular weight (Mw) is 300000 or more, it becomes easy to maintain the hardness and elasticity of the organic fine powder in a suitable state, so that the charge amount and the spacer effect can be obtained stably even in long-term use. When the weight average molecular weight (Mw) of the component soluble in tetrahydrofuran is 1000000 or less, the fixability tends to be improved and the electrostatic offset property tends to be improved.

  The number average particle diameter of the inorganic fine powder A is not more than the number average particle diameter of the organic fine powder B. The inorganic fine powder A is composed of an inorganic component, and when added externally, there is no change in the shape of the inorganic fine powder. In order to suppress liberation, it is effective to reduce the particle size. On the other hand, since the organic fine powder is composed of a resin component, the shape thereof is easily changed when added externally, so that the adsorptivity to the toner particle surface becomes high. Therefore, it becomes easy to suppress liberation, so that the particle size of the organic fine powder B can be made larger than that of the inorganic fine powder A. For this reason, it is important that the number average particle diameter of the inorganic fine powder A is not more than the number average particle diameter of the organic fine powder B, and the free state of both can be controlled.

  It is preferable that the content of the inorganic fine powder A is 1.0% by mass or less, and the content of the organic fine powder B is not more than the content of the inorganic fine powder A. When the content of the inorganic fine powder A is 1.0% by mass or less, the liberation rate can be easily controlled, and the chargeability and cleaning properties can be easily improved.

  Further, when the content of the organic fine powder B is less than or equal to the content of the inorganic fine powder A, the inorganic fine powder A and the organic fine powder B can be easily controlled to have a desired liberation rate, and the chargeability can be easily stabilized.

  As for the number average particle diameter of the inorganic and organic fine powders in the present invention, 100 particle diameters are arbitrarily selected from photographs taken at a magnification of 50,000 times with an electron microscope, the longest side of the primary particles is a, and the shortest When the side is b, (a + b) / 2 is taken as the primary particle size, and the average was calculated from 100 particles.

  Next, the average circularity of the toner is 0.960 or more. In order to reduce toner adhesion to the non-image area on the image carrier and transfer residual toner amount, improve cleaning properties, and improve electrostatic offset resistance, the toner chargeability is sufficient and uniform. It is necessary.

  Further, the closer the toner is to a spherical shape and the uniform the shape, the smaller the toner adhesion area with the image carrier, the mirror image force between the toner and the image carrier is reduced, and the cleaning property can be improved.

  Therefore, in the toner of the present invention, the average circularity of the toner is 0.960 or more, thereby achieving high image quality, improved cleaning properties, and improved electrostatic offset resistance.

  Examples of the binder resin used in the toner of the present invention include styrene such as polystyrene and polyvinyltoluene, and homopolymers of substitution products thereof; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer. Polymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene -Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene -Vinyl ethyl ether copolymer, Styrene copolymers such as lene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate , Polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin can be used, and these can be used alone or in combination. Can do. Of these, styrene copolymers and polyester resins are particularly preferred from the standpoints of development characteristics and fixability.

  In the toner of the present invention, a charge control agent may be blended as necessary to improve charging characteristics. As the charge control agent, a known one can be used, but a charge control agent that has a high charging speed and can stably maintain a constant charge amount is particularly preferable. Further, when the toner is produced using a polymerization method as described later, a charge control agent having a low polymerization inhibition property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. Among the charge control agents, specific compounds as negative charge control agents include metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid; metal salts of azo dyes or azo pigments Or a metal complex; a polymer compound having a sulfonic acid or carboxylic acid group in the side chain; a boron compound; a urea compound; a silicon compound; and a calixarene. Examples of the positive charge control agent include a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, a nigrosine compound, and an imidazole compound.

  As a method for adding a charge control agent to the toner, a method of adding the charge control agent to the inside of the toner particles, and in the case of producing the toner by suspension polymerization, the charge control agent is added to the polymerizable monomer composition before granulation. A method of adding is generally used. Also, during the polymerization by forming oil droplets in water, or after polymerization, seed polymerization is carried out by adding a polymerizable monomer in which the charge control agent is dissolved and suspended, and the toner surface is made uniform. It is also possible to cover. In the case where an organometallic compound is used as the charge control agent, it is also possible to introduce the compound by adding these compounds to the toner particles, and applying a shear and mixing and stirring.

  The amount of these charge control agents used is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method, and is not uniquely limited. However, when it is internally added to the toner particles, it is preferably used in the range of 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin. Further, when externally added to the toner particles, the amount is preferably 0.005 to 1.0 part by mass, more preferably 0.01 to 0.3 part by mass with respect to 100 parts by mass of the toner.

  The toner of the present invention contains a colorant that matches the target color. As the colorant used in the toner of the present invention, any of known organic pigments or dyes, carbon black, magnetic powder, and the like can be used.

  Specifically, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used as cyan colorants. Specifically, C.I. I. Pigment blue 1, C.I. I. Pigment blue 7, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 60, C.I. I. Pigment blue 62, C.I. I. And CI Pigment Blue 66.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment red 7, C.I. I. Pigment violet 19, C.I. I. Pigment red 23, C.I. I. Pigment red 48: 2, C.I. I. Pigment red 48: 3, C.I. I. Pigment red 48: 4, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 81: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 144, C.I. I. Pigment red 146, C.I. I. Pigment red 166, C.I. I. Pigment red 169, C.I. I. Pigment red 177, C.I. I. Pigment red 184, C.I. I. Pigment red 185, C.I. I. Pigment red 202, C.I. I. Pigment red 206, C.I. I. Pigment red 220, C.I. I. Pigment red 221, C.I. I. And CI Pigment Red 254.

  As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 62, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 110, C.I. I. Pigment yellow 111, C.I. I. Pigment yellow 120, C.I. I. Pigment yellow 127, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 129, C.I. I. Pigment yellow 147, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 168, C.I. I. Pigment yellow 174, C.I. I. Pigment yellow 175, C.I. I. Pigment yellow 176, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 181, C.I. I. Pigment yellow 191, C.I. I. And CI Pigment Yellow 194.

  These colorants can be used singly or in combination of two or more, and also in a solid solution state. The colorant used in the toner of the present invention is appropriately selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in the toner. Further, the addition amount of the colorant is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  Further, as the black colorant, carbon black, magnetic powder, and a color toned to black using the yellow / magenta / cyan colorant are used. When carbon black is used as the black colorant, the addition amount is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  When the toner of the present invention is used as a magnetic toner, magnetic powder can be used as a colorant. When magnetic powder is used as the black colorant, the magnetic powder is preferably used in an amount of 20 to 150 parts by mass with respect to 100 parts by mass of the binder resin. When the added amount of the magnetic powder is 20 parts by mass or more, the coloring power of the toner is improved and fogging is easily suppressed. On the other hand, when the amount is 150 parts by mass or less, the fixability is improved and the balance with the holding force by the magnetic force of the toner carrier is easily maintained, and the developability is improved.

  In particular, when a magnetic powder is used as a colorant, the magnetic powder is preferably used because it can suppress excessive embedding of inorganic and organic fine powders and easily achieve a desired release rate.

  Note that the content of the magnetic powder in the toner can be measured using a thermal analyzer manufactured by PerkinElmer, TGA7. The measuring method is as follows. The toner is heated from room temperature to 900 ° C. at a temperature rising rate of 25 ° C./min in a nitrogen atmosphere. The weight loss mass% between 100 ° C. and 750 ° C. is defined as the binder resin amount, and the remaining mass is approximately defined as the magnetic powder amount.

  In the present invention, when a toner is produced using a polymerization method, it is necessary to pay attention to the polymerization inhibition property and water phase transfer property of the colorant. Therefore, the colorant is preferably subjected to surface modification, for example, a hydrophobic treatment with a substance that does not inhibit polymerization. In particular, since dyes and carbon black have many polymerization-inhibiting properties, care must be taken when using them.

  About carbon black, you may process with the substance which reacts with the surface functional group of carbon black, for example, polyorganosiloxane.

When magnetic powder is used in the toner of the present invention, the magnetic powder is mainly composed of magnetic iron oxide such as triiron tetroxide and γ-iron oxide, and phosphorus, cobalt, nickel, copper, magnesium, Elements such as manganese, aluminum, and silicon may be included. These magnetic powders preferably have a BET specific surface area of 2 to 30 m ² / g by nitrogen adsorption method, and more preferably 3 to 28 m ² / g. A Mohs hardness of 5 to 7 is preferred. The shape of the magnetic powder includes polyhedron, octahedron, hexahedron, spherical shape, needle shape, scale shape, etc., but those having low anisotropy such as polyhedron, octahedron, hexahedron, spherical shape, etc. It is preferable in terms of enhancement.

  The magnetic powder preferably has a volume average particle size of 0.10 μm to 0.40 μm. When the volume average particle size is 0.10 μm or more, the dispersibility in the toner tends to be improved, and the blackness is improved. On the other hand, when the volume average particle size is 0.40 μm or less, the coloring power is easily improved.

  The volume average particle size of the magnetic powder can be measured using a transmission electron microscope. Specifically, after sufficiently dispersing the toner particles to be observed in the epoxy resin, a cured product obtained by curing in an atmosphere at a temperature of 40 ° C. for 2 days is obtained. The obtained cured product is used as a flaky sample by a microtome, and the diameter of 100 magnetic powder particles in the field of view is measured with a transmission electron microscope (TEM) at a magnification of 10,000 to 40,000 times. Then, the volume average particle diameter is calculated based on the equivalent diameter of a circle equal to the projected area of the magnetic powder. It is also possible to measure the particle size with an image analyzer.

In the present invention, when the magnetic toner is dissolved at 5 mol / l hydrochloric acid, the dissolution amounts S ₃ and S ₁₅ (mass%) with respect to the total magnetic powder content at 3 minutes and 15 minutes satisfy the following formula. Is preferred.
・ 0.5 ≦ S ₃ ≦ 10 Formula (4)
・ 40 ≦ S ₁₅ ≦ 80 Formula (5)

This indicates that the dissolved amounts S ₃ and S ₁₅ (% by mass) satisfy the formulas (4) and (5), that is, the magnetic powder forms a stable shell in the toner particles. For this reason, the magnetic powder in the external addition step or the like is a particularly preferable form because it can suppress excessive embedding of inorganic and organic fine powders and easily achieve a desired release rate.

  In the present invention, the presence state of the magnetic powder from the outermost surface of the toner to the inside can be estimated by changing the time for extracting the magnetic toner with hydrochloric acid. At this time, the magnetic powder extracted at 5 mol / l hydrochloric acid for 3 minutes is the magnetic powder existing on the outermost surface portion of the toner, and the magnetic powder amount extracted at 15 minutes is the magnetic powder existing from the vicinity of the surface toward the toner center. This is considered to represent the abundance of the powder.

In the present invention, the amount of magnetic powder (S ₃ ) obtained by extracting the magnetic toner with 5 mol / l hydrochloric acid for 3 minutes is 0.5% by mass or more and 10% by mass or less, preferably 5% by mass or less. Since only a small amount of magnetic powder is present in the vicinity of the outermost surface in this manner, there is almost no influence of moisture absorption by the magnetic powder, so that charging characteristics excellent in environmental stability can be obtained. When S ₃ is 0.5% by mass or more, magnetic powder is appropriately present on the outermost surface, so that charge-up in a low-humidity environment is easily suppressed, and stable charging characteristics are easily obtained. Moreover, when it is 10 mass% or less, it becomes easy to suppress the improvement of the charge amount in a high-humidity environment, the environmental stability, and the increase in the amount of free magnetic powder.

In the present invention, the amount of magnetic powder (S ₁₅ ) extracted with 5 mol / l hydrochloric acid for 15 minutes is 40% by mass to 80% by mass, preferably 45% by mass to 75% by mass. S ₁₅ corresponds to the amount of magnetic powder existing near the surface. In the present invention, the stress resistance can be improved by distributing the magnetic powder so as to be unevenly distributed in the vicinity of the toner surface.

  The magnetic powder used for the toner of the present invention can be produced, for example, by the following method. An aqueous solution containing ferrous hydroxide is prepared by adding an alkali such as sodium hydroxide in an amount equivalent to or greater than the iron component to the ferrous salt aqueous solution. Air was blown in while maintaining the pH of the prepared aqueous solution at pH 7 or higher, and ferrous hydroxide was oxidized while heating the aqueous solution to 70 ° C. or higher. Generate.

  Next, an aqueous solution containing about 1 equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals based on the amount of alkali added previously. While maintaining the pH of the solution at 5 to 10, the reaction of ferrous hydroxide proceeds while blowing air to grow magnetic iron oxide powder with the seed crystal as the core. At this time, it is possible to control the shape and magnetic properties of the magnetic powder by selecting an arbitrary pH, reaction temperature, and stirring conditions. As the oxidation reaction proceeds, the pH of the liquid shifts to the acidic side, but the pH of the liquid is preferably not less than 5. The magnetic powder can be obtained by filtering, washing and drying the magnetic powder thus obtained by a conventional method.

  In the present invention, when the toner is produced by a polymerization method, it is very preferable to subject the surface of the magnetic powder to a hydrophobic treatment. When the surface treatment is performed by a dry method, the coupling agent treatment is performed on the magnetic powder that has been washed, filtered, and dried. When wet surface treatment is performed, after the oxidation reaction is completed, the dried product is redispersed, or after completion of the oxidation reaction, the iron oxide body obtained by washing and filtering is not dried but in another aqueous medium. The dispersion is redispersed and a coupling treatment is performed. Specifically, a silane coupling agent is added while stirring the redispersion sufficiently, and the temperature is increased after hydrolysis, or the coupling is performed by adjusting the pH of the dispersion to an alkaline region after hydrolysis. . Among these, from the viewpoint of performing a uniform surface treatment, it is preferable to carry out the surface treatment by reslurry as it is without drying after filtration and washing after completion of the oxidation reaction.

  In order to treat the surface of the magnetic powder wet, that is, to treat the magnetic powder with a coupling agent in an aqueous medium, first, the magnetic powder is sufficiently dispersed in the aqueous medium to have a primary particle size, and then settled. Stir with a stirring blade to prevent aggregation. Next, an arbitrary amount of coupling agent is added to the dispersion, and the surface treatment is carried out while hydrolyzing the coupling agent. At this time, the dispersion is sufficiently dispersed so as not to aggregate while using a device such as a pin mill or a line mill. More preferably, the surface treatment is carried out.

  Here, the aqueous medium is a medium containing water as a main component. Specific examples include water itself, water added with a small amount of surfactant, water added with a pH adjuster, and water added with an organic solvent. As the surfactant, nonionic surfactants such as polyvinyl alcohol are preferable. The surfactant is preferably added in an amount of 0.1% by mass to 5.0% by mass with respect to water. Examples of the pH adjuster include inorganic acids such as hydrochloric acid. Examples of the organic solvent include alcohols.

Examples of the coupling agent that can be used in the surface treatment of the magnetic powder in the present invention include a silane coupling agent and a titanium coupling agent. More preferably used is a silane coupling agent, which is represented by the general formula (I).
R _m SiY _n (I)
[Wherein, R represents an alkoxy group, m represents an integer of 1 to 3, Y represents a functional group such as an alkyl group, a vinyl group, an epoxy group, or a (meth) acryl group, and n represents 1 to 3] Indicates an integer. However, m + n = 4. ]

  Examples of the silane coupling agent represented by the general formula (I) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, Vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyl Diethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, trimethylmethoxysilane, n-hexyltrimethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, hydroxypropyl Examples include trimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.

Among these, from the viewpoint of imparting high hydrophobicity to the magnetic powder, it is preferable to use an alkyltrialkoxysilane coupling agent represented by the following general formula (II).
_{C p H 2p + 1 -Si- (} OC q H 2q + 1) 3 (II)
[Wherein, p represents an integer of 2 to 20, and q represents an integer of 1 to 3. ]

  When p in the above formula is 2 or more, it becomes easy to impart hydrophobicity to the magnetic powder. Further, when p is 20 or less, the coalescence of the magnetic powders is easily suppressed. Furthermore, q is preferably 3 or less because the reactivity of the silane coupling agent is easily improved. It is preferable to use an alkyltrialkoxysilane coupling agent in which p represents an integer of 2 to 20 and q represents an integer of 1 to 3.

  When using the said silane coupling agent, it is possible to process independently or to process in combination of several types. When using several types together, you may process separately with each coupling agent, and may process simultaneously.

  The total amount of coupling agent used is preferably 0.9 to 3.0 parts by mass with respect to 100 parts by mass of the magnetic powder, depending on the surface area of the magnetic powder, the reactivity of the coupling agent, etc. It is important to adjust the amount of the treatment agent.

  When using magnetic powder as a colorant in the present invention, other colorants may be used in combination with the magnetic powder. Examples of the colorant that can be used in combination include magnetic or nonmagnetic inorganic compounds in addition to the above-described known dyes and pigments. Specifically, ferromagnetic metal particles such as cobalt and nickel, or alloys obtained by adding chromium, manganese, copper, zinc, aluminum, rare earth elements and the like to these. Examples thereof include particles such as hematite, titanium black, nigrosine dye / pigment, carbon black, and phthalocyanine. These are also preferably used by treating the surface.

  The glass transition temperature (Tg) of the toner of the present invention is preferably 40 ° C to 70 ° C. Storage stability improves that a glass transition temperature is 40 degreeC or more, and it becomes easy to control the liberation rate of an external additive in long-term use. Further, when the temperature is 70 ° C. or lower, the fixability tends to be improved. Therefore, the glass transition temperature of the toner is preferably 40 ° C. to 70 ° C. in view of the balance between the fixing property, the storage stability, and the developability.

  The toner of the present invention preferably has a core-shell structure in order to improve storage stability and developability. This is because by having the shell layer, the surface property of the toner becomes uniform, the fluidity improves and the charging property becomes uniform.

  Further, since the high molecular weight shell uniformly covers the surface layer, the low-melting-point substance does not ooze out even during long-term storage, and the storage stability is improved.

  For this reason, it is preferable to use an amorphous high molecular weight material for the shell layer, and the acid value is preferably 5.0 to 20.0 mgKOH / g from the viewpoint of charging stability.

  Specific methods for forming the shell include embedding the fine particles for the shell in the core particles, or attaching the ultra fine particles for the shell to the core particles when the toner is produced in an aqueous medium which is a preferred production method of the present invention. The shell layer can be formed by drying and drying. In addition, in the suspension suspension method and suspension polymerization method, the acid value and hydrophilicity of the high molecular weight polymer for the shell are utilized to make the shell unevenly distributed at the interface with water, that is, near the toner surface. Is possible. Furthermore, a shell can be formed by swelling a monomer on the surface of the core particle by a so-called seed polymerization method and polymerizing the monomer.

  Examples of the high molecular weight material for the shell layer include styrene such as polystyrene and polyvinyltoluene, and homopolymers of substituted styrene; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, Styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-meta Methyl acrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl Ethyl ether copolymer, styrene Styrene copolymers such as vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, poly Butyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, styrene-polyester copolymer, poly (meth) acrylate-polyester copolymer, polyamide resin, epoxy resin, polyacrylic acid resin, terpene There exist resin, a phenol resin, etc., These can be used individually or in mixture of 2 or more types. Moreover, you may introduce | transduce functional groups, such as an amino group, a carboxyl group, a hydroxyl group, a sulfonic acid group, a glycidyl group, a nitrile group, in these polymers.

  The addition amount of these resins is preferably 1 to 30 parts by mass in total with respect to 100 parts by mass of the polymerizable monomer. When the amount is 1 part by mass or more, the effect of addition is easily exhibited, and when it is 30 parts by mass or less, various physical properties of the toner can be easily designed.

  Among these resins, polyester is particularly preferable because the above effect is greatly expressed. As the polyester resin used in the present invention, a saturated polyester resin, an unsaturated polyester resin, or both can be appropriately selected and used.

  As the polyester resin used in the present invention, a normal resin composed of an alcohol component and an acid component can be used, and both components are exemplified below.

  As alcohol components, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexane Diol, neopentyl glycol, 2-ethyl-1,3-hexanediol, cyclohexanedimethanol, butenediol, octenediol, cyclohexenedimethanol, hydrogenated bisphenol A, and bisphenol derivatives represented by formula (I);

［式中、Ｒはエチレンまたはプロピレン基であり、ｘ，ｙはそれぞれ１以上の整数であり、かつｘ＋ｙの平均値は２から１０である。］、あるいは式（Ｉ）の化合物の水添物、

[Wherein, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10. Or hydrogenated compounds of the formula (I),

  A diol represented by the formula (II);

、あるいは式（ＩＩ）の化合物の水添物のジオールが挙げられる。

Or diols of hydrogenated compounds of the formula (II).

  Divalent carboxylic acids include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride or anhydrides thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid, or anhydrides thereof; Further, succinic acid substituted with an alkyl or alkenyl group having 6 to 18 carbon atoms or an anhydride thereof; unsaturated dicarboxylic acid such as fumaric acid, maleic acid, citraconic acid, itaconic acid or the anhydride thereof may be used.

  In addition, polyhydric alcohols such as glycerin, pentaerythritol, sorbit, sorbitan, and oxyalkylene ethers of novolac type phenol resins can be cited as the alcohol component, and trimellitic acid, pyromellitic acid, 1,2,3,4- Examples thereof include polyvalent carboxylic acids such as butanetetracarboxylic acid, benzophenonetetracarboxylic acid and anhydrides thereof.

  Among the polyester resins, the alkylene oxide adduct of bisphenol A, which is excellent in charging characteristics and environmental stability and balanced in other electrophotographic characteristics, is preferably used. In the case of this compound, the average number of added moles of alkylene oxide is preferably 2 to 10 in terms of fixability and toner durability.

  In the polyester resin of the present invention, it is preferable that 45 mol% to 55 mol% of all components are alcohol components and 55 to 45 mol% are acid components.

  Further, the number average molecular weight of the high molecular weight body forming the shell is preferably 2500 to 10,000. When the number average molecular weight is 2500 or more, developability, blocking resistance and durability tend to be improved. On the other hand, when the number average molecular weight is 10,000 or less, the low-temperature fixability tends to be improved. The number average molecular weight can be measured by GPC described later.

  The toner of the present invention can be produced by any known method. First, in the case of producing by a pulverization method, for example, binder resin, colorant, ester compound, low melting point substance, charge control agent and other necessary components, and other additives are added to Henschel mixer, ball mill, etc. Mix thoroughly with a mixer. Thereafter, the toner material is dispersed or dissolved by using a heat kneader such as a heating roll, a kneader, or an extruder to disperse or dissolve the toner material, and after cooling and solidification, pulverization, and surface treatment as necessary to obtain toner particles. be able to. Either the classification or the surface treatment may be performed first. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency.

  The pulverization step can be performed by a method using a known pulverizer such as a mechanical impact type or a jet type. Further, in order to obtain a toner having a preferable circularity of the present invention, it is preferable to further heat and pulverize, or to perform a process of applying a mechanical impact as an auxiliary. Further, a hot water bath method in which finely pulverized (classified as necessary) toner particles are dispersed in hot water, a method of passing in a hot air stream, or the like may be used.

  Examples of means for applying a mechanical impact force include a method using a mechanical impact pulverizer such as a kryptron system manufactured by Kawasaki Heavy Industries, Ltd. or a turbo mill manufactured by Turbo Industry. Also, like devices such as Hosokawa Micron's Mechano-Fusion System and Nara Machinery's Hybridization System, the toner is pressed against the inside of the casing by centrifugal force with high-speed rotating blades, and the force of compression force, friction force, etc. There is a method of applying a mechanical impact force to the toner.

  The toner of the present invention can be produced by the pulverization method as described above, but the toner particles obtained are generally indefinite. For this reason, in order to obtain the physical property that the average circularity of the present invention is 0.960 or more, it is necessary to perform mechanical / thermal or some special treatment, resulting in poor productivity. Therefore, the toner of the present invention is preferably produced in an aqueous medium such as a dispersion polymerization method, an association aggregation method, a dissolution suspension method, or a suspension polymerization method. In particular, the suspension polymerization method is a suitable physical property of the present invention. It is easy to satisfy and is very preferable.

  The suspension polymerization method is a polymerizable monomer in which a polymerizable monomer and a colorant (in addition, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives as necessary) are uniformly dissolved or dispersed. A composition is obtained. Thereafter, the polymerizable monomer composition is dispersed in a continuous layer (for example, an aqueous phase) containing a dispersion stabilizer by using a suitable stirrer, and a polymerization reaction is simultaneously performed to obtain a toner having a desired particle size. To get. Since the toner obtained by this suspension polymerization method (hereinafter also referred to as “polymerized toner”) has individual toner particle shapes that are substantially spherical, the physical property requirement suitable for the present invention that the average circularity is 0.960 or more. It is easy to obtain a toner that satisfies the requirements. Furthermore, since the toner has a relatively uniform charge amount distribution, an improvement in image quality can be expected.

  In the production of the polymerized toner according to the present invention, examples of the polymerizable monomer constituting the polymerizable monomer composition include the following.

  Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; methyl acrylate, ethyl acrylate, Acrylate esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate , Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, Methacrylic acid dimethyl aminoethyl methacrylic acid esters such as diethylaminoethyl methacrylate; and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide. These monomers can be used alone or in combination. Among the above-mentioned monomers, styrene or a styrene derivative is preferably used alone or mixed with other monomers from the viewpoint of developing characteristics and durability of the toner.

  The polymerization initiator used in the production of the toner according to the present invention by polymerization is preferably one having a half-life of 0.5 to 30 hours during the polymerization reaction. Further, when a polymerization reaction is carried out using an addition amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer, a polymer having a maximum between 5,000 and 50,000 is obtained. The toner can be provided with desirable strength and suitable melting characteristics.

  Specific examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1- Carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo or isoazo polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxide Peroxide polymerization initiators such as oxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy 2-ethylhexanoate, t-butylperoxypivalate, etc. Can be mentioned.

  When the toner of the present invention is produced by a polymerization method, a crosslinking agent may be added, and a preferable addition amount is 0.001 to 15 parts by mass with respect to 100 parts by mass of the polymerizable monomer. .

  Here, as the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; for example, ethylene glycol diacrylate, ethylene glycol diester Carboxylic acid ester having two double bonds such as methacrylate, 1,3-butanediol dimethacrylate, etc .; Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, etc .; and having three or more vinyl groups Are used alone or as a mixture of two or more.

  In the method for producing the toner of the present invention by a polymerization method, generally, the above-described toner composition or the like is added as appropriate, and the polymerizable single particle is uniformly dissolved or dispersed by a disperser such as a homogenizer, a ball mill, or an ultrasonic disperser. The meter composition is suspended in an aqueous medium containing a dispersion stabilizer. At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to obtain a desired toner particle size at a stretch. The polymerization initiator may be added at the same time when other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Also, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction.

  After granulation, stirring may be performed using a normal stirrer to such an extent that the particle state is maintained and the particles are prevented from floating and settling.

  When the toner of the present invention is produced, known surfactants, organic dispersants and inorganic dispersants can be used as the dispersion stabilizer. Among them, inorganic dispersants are less likely to produce ultrafine powder, and because of their steric hindrance, dispersion stability is obtained, so even if the reaction temperature is changed, stability is not easily lost, and cleaning is easy and does not adversely affect the toner. It can be preferably used. Examples of such inorganic dispersants include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, phosphate polyvalent metal salts such as hydroxyapatite, carbonates such as calcium carbonate and magnesium carbonate, calcium metasuccinate, calcium sulfate, Examples thereof include inorganic salts such as barium sulfate and inorganic compounds such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide.

  These inorganic dispersants are desirably used in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. Moreover, the said dispersion stabilizer may be used independently and may use multiple types together. Furthermore, you may use 0.001 mass part-0.1 mass part surfactant together.

  When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated and used in an aqueous medium. For example, in the case of tricalcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution can be mixed under high-speed stirring to produce water-insoluble calcium phosphate, which enables more uniform and fine dispersion. At the same time, water-soluble sodium chloride salt is produced as a by-product. However, if water-soluble salt is present in the aqueous medium, dissolution of the polymerizable monomer in water is suppressed, and ultrafine toner is generated by emulsion polymerization. This is more convenient.

  Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

  In the step of polymerizing the polymerizable monomer, the polymerization temperature is set to 40 ° C. or higher, generally 50 ° C. to 90 ° C. When the polymerization is carried out in this temperature range, the low melting point substance to be sealed inside is precipitated by phase separation, and the encapsulation is more complete.

  After the polymerization of the polymerizable monomer is completed, the obtained polymer particles are filtered, washed and dried by a known method to obtain toner particles. The toner of the present invention can be obtained by mixing the toner particles with an inorganic fine powder and an organic fine powder as necessary and externally adding to the surface of the toner particles (also referred to as an external addition step).

  In particular, as in the present invention, in order to highly control the free state of inorganic fine powder and organic fine powder from toner particles, for example, external addition conditions such as external addition of organic fine powder after external addition of inorganic fine powder It is necessary to devise. Further, regarding the mixing conditions of the apparatus, it is preferable to highly control the rotation speed, time, etc. of the apparatus.

  It is also possible to insert a classification step in the manufacturing process (before the external addition step) to cut coarse powder and fine powder contained in the toner particles.

  In the present invention, in addition to the inorganic fine powder A and the organic fine powder B, an inorganic fine powder having a number average primary particle size of 4 nm to 80 nm, more preferably 6 nm to 40 nm is added to the toner particles as a fluidizing agent. It is also a preferable form. The inorganic fine powder is added to improve the fluidity of the toner and to make the charge of the toner particles uniform. However, adjustment of the charge amount of the toner, improvement of environmental stability, etc. by treatment such as hydrophobizing the inorganic fine powder. It is also a preferable form to provide the function.

  In the present invention, the number average primary particle size of the inorganic fine powder is measured using a photograph of the toner magnified by a scanning electron microscope.

Silica, titanium oxide, alumina, etc. can be used as the inorganic fine powder used in the present invention. As the fine silica powder, for example, both a so-called dry method produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and so-called wet silica produced from water glass or the like can be used. is there. However, dry silica having fewer silanol groups on the surface and in the silica fine powder and less production residue such as Na ₂ O and SO ₃ ²⁻ is more preferable. In dry silica, it is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process, They are also included.

  Among the above-mentioned treatment agents, those treated with silicone oil are preferred, and those treated with silicone oil are more preferred at the same time as or after the hydrophobic treatment of the inorganic fine powder with the silane compound. As a method for treating such inorganic fine powder, for example, as a first-stage reaction, a silanization reaction is performed with a silane compound and silanol groups are eliminated by chemical bonds, and then a hydrophobic reaction is performed on the surface with silicone oil as a second-stage reaction. The thin film can be formed.

The silicone oil may have a viscosity from 10 mm ² / s of 200,000 mm ² / s at 25 ° C., and more preferably those from 3,000 mm ² / s of 80,000mm ² / s. The intensity | strength with respect to a heat | fever and mechanical external force improves that it is 10 mm < ² > / s or more. Further, when the viscosity of the silicone oil is 200,000 mm ² / s or less, the inorganic fine powder tends to be easily treated uniformly.

  As the silicone oil used, for example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, fluorine modified silicone oil and the like are particularly preferable.

  Examples of the method of treating the inorganic fine powder with silicone oil include a method of directly mixing the inorganic fine powder treated with the silane compound and the silicone oil using a mixer such as a Henschel mixer, or a method of treating the inorganic fine powder with the silicone oil. The method of spraying is mentioned. Alternatively, after dissolving or dispersing silicone oil in an appropriate solvent, an inorganic fine powder may be added and mixed to remove the solvent. A spraying method is more preferred in that the formation of inorganic fine powder aggregates is relatively small.

  The treatment amount of the silicone oil is 1 to 40 parts by mass, preferably 3 to 35 parts by mass with respect to 100 parts by mass of the inorganic fine powder.

Inorganic fine powder used in the present invention, in order to impart good fluidity to the toner, the specific surface area measured by the BET method by nitrogen adsorption of preferably those in 350 meters ² / g range 20 m ² / g, 25 m More preferable is ² / g to 300 m ² / g. The specific surface area is calculated using the BET multipoint method by adsorbing nitrogen gas to the sample surface using a specific surface area measuring device Autosorb 1 (manufactured by Yuasa Ionics) according to the BET method.

  Next, a method for measuring each physical property related to the toner of the present invention will be described.

(1) Calculation method of free rate of inorganic fine powder
Sample preparation
Toner before release : Various toners prepared in Examples described later were used as they were.
Toner after release : Weigh 20 g of a 2% by weight aqueous solution of neutral detergent for cleaning a pH7 precision measuring instrument consisting of non-ionic surfactant, anionic surfactant and organic builder in a 50 ml vial. Set with “KM Shaker” (model: V.SX) manufactured by Iwaki Sangyo Co., Ltd., and shake for 30 seconds with speed set to 50. Then, centrifuge (1000 rpm for 5 minutes) The toner and the aqueous solution are separated by separating the supernatant and the precipitated toner is vacuum-dried to dryness.
External additive-removed toner : The external additive-removed toner means a state in which the external additive is removed, and can be regarded as toner particles. In the sample preparation method, the toner is put in a solvent that does not dissolve the toner, such as isopropanol, and vibration is applied for 10 minutes with an ultrasonic cleaner. Thereafter, the toner and the solution are separated by a centrifugal separator (1000 rpm for 5 minutes). The supernatant is separated and the precipitated toner is dried by vacuum drying.

  As for the abundance of these elements, after removing external additives, the above elements are quantified using a known analysis method such as fluorescent X-ray analysis or plasma emission analysis (ICP) on the toner particles. I can do it.

  In the examples described later, the measurement of each element is performed using fluorescent X-ray analysis, and the details are in accordance with JIS-KO119.

(I) Equipment used X-ray fluorescence analyzer 3080 (Rigaku Corporation)
Sample press molding machine MAEKAWA Testing Machine (manufactured by MFG Co, LTD)

(Ii) Measurement conditions Measurement potential, voltage 50 kV, 50 to 70 mA
2θ angle a
Crystal plate LiF
Measurement time 60 seconds

(Iii) Method for calculating release rate from toner particles First, the element strengths of the pre-release toner, the post-release toner, and the external additive-removed toner are obtained by the above-described method. Thereafter, the liberation rate is calculated based on the following formula.
[Expression] Free rate = 100− (strength of toner element after free-strength of external additive-removed toner element) / (strength of pre-release toner element−strength of external additive-removed toner element) × 100

(2) Method for calculating the liberation rate of organic fine powder “Contaminone N” (2 of neutral detergent for cleaning precision instruments with a pH of 7 consisting of nonionic surfactant, anionic surfactant, and organic builder in a 50 ml vial Weigh 20 g of mass% aqueous solution and mix with 1 g of toner Set a 50 ml vial in “KM Shaker” (model: V.SX) manufactured by Iwaki Sangyo Co., Ltd., set speed to 50 and shake for 30 seconds. Thereafter, the toner and the aqueous solution are separated by a centrifuge (1000 rpm * 5 min), 40 g of the separated aqueous solution is weighed into a vial, left in a fume hood, and dried at 40 ° C. under reduced pressure to dryness. Thereafter, 10 mg of a standard polystyrene resin (F-10, manufactured by Tosoh Corporation) having a molecular weight of 98900 was added to the dried vial, and further THF was added. 0 ml was added, and the polystyrene and free resin particles in the vial were dissolved over 24 hours at room temperature, and the resulting solution was dissolved in a solvent-resistant membrane filter “Maescho Disc” with a pore size of 0.2 μm. A sample solution is obtained by filtration through Tosoh Corp. The sample solution is measured under the following conditions.
Apparatus: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)
Column: Seven series of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection volume: 0.10 ml

  In calculating the molecular weight of the sample, standard polystyrene resin (for example, trade name “TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F— 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500 ", manufactured by Tosoh Corporation) are used.

  Of the molecular weight distribution obtained by the measurement, the peak area and the resin particle peak area of a standard polystyrene resin having a molecular weight of 98900 are calculated. The obtained peak areas are designated PS (1) and RP (1), respectively.

  Further, 10 mg of a standard polystyrene resin having a molecular weight of 98900 and 10 mg of resin particles used are mixed, and GPC is measured in the same manner as above. The peak areas of the resin particles obtained here are PS (ref) and RP (ref), respectively.

Further, the release rate of the resin particles is calculated by the following formula, where A (part by mass) is the amount of the resin particles contained in the magnetic toner.
(Formula) Residual rate of resin particles (%)
= {RP (1) / PS (1) × 1.25} / {RP (ref) / RP (ref)} × 10/5000 × 100 × 1 / A × 100

(3) Average particle size and particle size distribution of toner The weight average particle size (D4) and the number average particle size (D1) of the toner are measured by a precise particle size distribution measuring apparatus “Coulter by a pore electrical resistance method equipped with an aperture tube of 100 μm.・ Counter Multisizer 3 ”(registered trademark, manufactured by Beckman Coulter) and attached dedicated software“ Beckman Coulter Multisizer 3 Version 3.51 ”(manufactured by Beckman Coulter) for measurement condition setting and measurement data analysis The measurement was performed with 25,000 effective measurement channels, and the measurement data was analyzed and calculated.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, dedicated software was set up as follows.

  In the “Standard Measurement Method (SOM) Change Screen” of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using The threshold and noise level are automatically set by pressing the threshold / noise level measurement button. Also, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the aperture tube flash after measurement is checked.

  In the “pulse to particle size conversion setting screen” of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

  The specific measurement method is as follows.

  1) About 200 ml of the electrolytic solution is placed in a 250 ml round bottom beaker made exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the analysis software.

  2) About 30 ml of the electrolytic aqueous solution is put in a glass 100 ml flat bottom beaker, and 10% by weight aqueous solution of “Contaminone N” (manufactured by Wako Pure Chemical Industries, Ltd.) as a dispersant is tripled by ion exchange water. Add about 0.3 ml of diluted dilution.

  3) Two oscillators with an oscillation frequency of 50 kHz are incorporated in a state where the phase is shifted by 180 degrees, and a predetermined amount is placed in a water tank of an ultrasonic disperser “Ultrasonic Dissipation System Tetora150” (manufactured by Nikkiki Bios) with an electrical output of 120 W Of ion-exchanged water, and about 2 ml of the above-mentioned Contaminone N is added to this water tank.

  4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.

  5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.

  6) To the round bottom beaker (1) installed in the sample stand, the electrolyte aqueous solution (5) in which the toner is dispersed is dropped using a pipette, and the measured concentration is adjusted to about 5%. The measurement is performed until the number of measured particles reaches 50,000.

  7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. When the graph / volume% is set with the dedicated software, the “average diameter” on the analysis / volume statistics (arithmetic average) screen is the weight average particle size (D4), and the graph / number% is set with the dedicated software. The “average diameter” on the analysis / number statistic (arithmetic average) screen is the number average particle diameter (D1).

(4) Average circularity of toner The average circularity of the toner is measured using a flow type particle image measuring device “FPIA-2100” (manufactured by Sysmex Corporation). Details are as follows.

First, the circularity is calculated from the following equation.
Circularity = (perimeter of a circle having the same area as the particle projection area) / (perimeter of the particle projection image)

  Here, the “particle projected area” is the area of the binarized 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 particle image. . The measurement uses the perimeter of the particle image when image processing is performed at an image processing resolution of 512 × 512 (0.3 μm × 0.3 μm pixels).

  In the present invention, the degree of circularity is an index indicating the degree of unevenness of particles, and is 1.00 when the particles are perfectly spherical. The more complicated the surface shape, the smaller the degree of circularity.

  The average circularity C, which means the average value of the circularity frequency distribution, is calculated from the following formula (1), where ci is the circularity at the dividing point i of the particle size distribution and m is the number of measured particles.

  The circularity standard deviation SD is calculated from the following equation (2) where the average circularity C, the circularity ci of each particle, and the number of measured particles are m.

  As a specific measurement method, 10 ml of ion-exchanged water from which impure solids have been previously removed is prepared in a container, and after adding a surfactant as a dispersant, preferably sodium dodecylbenzenesulfonate, Further, 0.02 g of a measurement sample is added and dispersed. As a means for dispersion, two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150 type” (manufactured by Nikkei Bios Co., Ltd.) having an electrical output of 120 W is used. Use it for 2 minutes to make a dispersion for measurement. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more. In order to suppress variation in circularity, the installation environment of the apparatus is controlled at 23 ° C. ± 0.5 ° C. so that the temperature inside the flow type particle image analyzer FPIA-2100 is 26 to 27 ° C. Preferably, autofocus is performed using 2 μm latex particles every 2 hours.

To measure the circularity of the toner particles, the flow type particle image measuring device is used, and the concentration of the dispersion is readjusted so that the toner particle concentration at the time of measurement is about 5000 particles / μl. After the measurement, using this data, data having an equivalent circle diameter of less than 2 μm is cut to determine the average circularity of the toner. The equivalent circle diameter is a value calculated as follows.
Equivalent circle diameter = (particle projected area / π) 1/2 × 2

  “FPIA-2100”, which is a measuring apparatus used in the present invention, has a thinner sheath flow (7 μm → 4 μm) than “FPIA-1000” which has been used for observing the shape of a conventional toner. ) And the magnification of the processed particle image, and further the processing resolution of the captured image is improved (256 × 256 → 512 × 512), and the accuracy of toner shape measurement is improved.

(5) Measurement of molecular weight of THF soluble content of toner and organic fine powder The molecular weight distribution of the THF soluble content of toner and organic fine powder is measured by gel permeation chromatography (GPC) as follows.

First, the toner and organic fine powder are dissolved in tetrahydrofuran (THF) at room temperature over 24 hours. The obtained solution is filtered through a solvent-resistant membrane filter “Maescho Disc” (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of the component soluble in THF is about 0.8% by mass. Using this sample solution, measurement is performed under the following conditions.
Apparatus: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)
Column: Seven series of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection volume: 0.10 ml

  In calculating the molecular weight of the sample, standard polystyrene resin (for example, trade name “TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F— 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500 ", manufactured by Tosoh Corporation) are used.

(6) Measuring method of magnetic substance dissolution amount In the present invention, the magnetic substance dissolution amount when dissolving 5 mol / l hydrochloric acid is measured as follows.
(I) Toner 25 mg (4 times) is precisely weighed.
(Ii) A sample is put in a sample bottle, and 4 samples are prepared by adding 100 ml of 5 mol / l hydrochloric acid. While stirring with a stirrer, dissolve each for 3 minutes, 15 minutes and overnight.
(Iii) Each solution after dissolution is filtered with a sample processing filter (pore size 0.2 to 0.5 μm, for example, Mysori Disc H-25-2 (manufactured by Tosoh Corporation) can be used), and then the filtrate is used. Absorbance at a wavelength of 338 nm is measured with a spectrophotometer (for example, Shimadzu Corporation UV-3100PC). At this time, 10 mol / l hydrochloric acid in which the toner is not dissolved is put in the control cell. The absorbance of the present invention is the common logarithm of the reciprocal of the transmittance I / I ₀ which is the ratio of the intensity I ₀ of the incident light when the light enters the sample cell and the intensity I of the transmitted light, ie, Log (I ₀ / I)
Measurement conditions: scan speed (medium speed), slit width (0.5 nm), sampling pitch (2 nm), measurement range (600 to 250 nm)

  In the present invention, the amount dissolved in 3 minutes and 15 minutes with respect to the total content of the magnetic material is the solution sampled at 3 minutes and 15 minutes with respect to the absorbance after standing overnight (the magnetic material is completely dissolved). It is calculated by the ratio of absorbance.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. “Part” and “%” are based on mass unless otherwise specified.

<Magnetic powder 1>
In ferrous sulfate aqueous solution, l. 0 to 1.1 equivalent of caustic soda solution, P ₂ O _{5 in} an amount of 0.15% in terms of phosphorus with respect to iron element, SiO in an amount of 0.50% by mass in terms of silicon with respect to iron element ₂ was mixed to prepare an aqueous solution containing ferrous hydroxide. The pH of the aqueous solution was 8.0, and an oxidation reaction was performed at 85 ° C. while blowing air to prepare a slurry liquid having seed crystals.

  Then, after adding ferrous sulfate aqueous solution to this slurry liquid so that it may become 0.9 to 1.2 equivalent with respect to the original alkali amount (sodium component of caustic soda), the slurry liquid is maintained at pH 7.6, The oxidation reaction was promoted while blowing air to obtain a slurry liquid containing magnetic iron oxide. After filtration and washing, the water-containing slurry was once taken out. At this time, a small amount of water-containing sample was collected and the water content was measured. Next, this water-containing sample is put into another aqueous medium without being dried, stirred and redispersed with a pin mill while circulating the slurry, and the pH of the redispersed liquid is adjusted to about 4.8. Then, 1.6 parts of n-hexyltrimethoxysilane coupling agent was added to 100 parts of magnetic iron oxide with stirring (the amount of magnetic iron oxide was calculated as a value obtained by subtracting the water content from the water-containing sample), and water was added. Decomposition was performed. Thereafter, the mixture was sufficiently stirred and dispersed with a pin mill while circulating the slurry, and the pH of the dispersion was set to 8.6 to perform a coupling treatment. The produced hydrophobic magnetic powder is filtered with a filter press, washed with a large amount of water, dried at 100 ° C. for 15 minutes, and then at 90 ° C. for 30 minutes. Of 0.22 μm was obtained.

<Magnetic powder 2>
In magnetic powder production example 1, magnetic iron oxide particles produced after the oxidation reaction were washed and subjected to the same treatment until filtration, then dried and then slightly agglomerated particles were crushed to obtain a volume average particle size. Of 0.23 μm was obtained.

<External additives 1 to 3>
The silica fine powder of each particle size was hydrophobized with 15% hexamethyldisilazane and 15% by mass dimethyl silicone oil.

<External additives 4 to 8>
The hydrous titanium oxide obtained by hydrolyzing the titanyl sulfate aqueous solution was washed with pure water until the electric conductivity of the filtrate reached 2200 μS / cm. NaOH was added to the hydrous titanium oxide slurry, and the sulfate radical adsorbed was washed with SO ₃ until it became 0.24%. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH of the slurry to 1.0 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was 6.0, and the supernatant was washed by decantation with pure water until the electrical conductivity of the supernatant reached 120 μS / cm.

533 g (0.6 mol) of metatitanic acid having a moisture content of 91% obtained as described above was put into a SUS reaction vessel, and nitrogen gas was blown into the vessel and left for 20 minutes to replace the inside of the reaction vessel with nitrogen gas. 183.6 g (0.66 mol) of Sr (OH) ₂ .8H ₂ O (purity 95.5%) was added, and distilled water was further added to add 0.3 mol / liter (SrTiO ₃ equivalent), SrO / TiO _2. A slurry with a molar ratio of 1.10 was prepared.

  The slurry was heated to 90 ° C. in a nitrogen atmosphere to carry out the reaction. After the reaction, the reaction solution is cooled to 40 ° C., the supernatant is removed under a nitrogen atmosphere, and the operation of adding 2.5 liters of pure water and decanting is repeated twice, followed by filtration with Nutsche. It was. The obtained cake was dried in the atmosphere at 110 ° C. for 4 hours to obtain fine strontium titanate powder.

  100 parts of strontium titanate fine powder was added to a sodium stearate aqueous solution (7 parts of sodium stearate and 100 parts of water) which is a fatty acid metal salt. While stirring, an aqueous aluminum sulfate solution was dropped to deposit strontium titanate treated with stearic acid by precipitating and adsorbing aluminum stearate on the surface of the fine strontium titanate powder. Further, the temperature of the slurry was raised to 90 ° C., and then the reaction time was lengthened to increase the particle size and adjust the target particle size.

<External additive 9>
Zinc stearate having a number average particle diameter of 4.5 μm, a metal content of 11%, and a melting point of 120 ° C. was used.

<External additives 10 and 11>
External additive 10: Titanium oxide having a primary particle size of 50 nm, a BET specific surface area of 90 m ² / g, and a hydrophobization degree of 60% was used.

  External additive 11: 100 g of titania CR-EL (Ishihara Sangyo Co., Ltd., average primary particle size: 0.3 μm) washed with water was added to a methanol-water (95: 5) mixed solvent in which 40 g of methyltrimethoxysilane was dissolved. And ultrasonically dispersed. Next, after evaporating methanol and the like in the dispersion with an evaporator and drying, heat-treat with a dryer set at 120 ° C., pulverize with a mortar, and titania surface-treated with 40% methyltrimethoxysilane. Using.

<External additives 12 to 17>
Polymethyl methacrylate (PMMA) resin fine particles having respective number average particle diameters shown in Table 1 were used.

<Production Example 1 of Toner Particles>
After adding 451 parts of a 0.1 mol / liter-Na ₃ PO ₄ aqueous solution to 709 parts of ion-exchanged water and heating to 60 ° C., 68 parts of 1.0 mol / liter-CaCl ₂ aqueous solution was gradually added and Ca ₃ ( An aqueous medium containing PO ₄ ) ₂ was obtained.

on the other hand,
Styrene 72 parts n-butyl acrylate 28 parts saturated polyester resin (monomer composition; bisphenol A propylene oxide adduct / terephthalic acid, acid value 12 mg KOH / g, Tg = 72 ° C., Mn = 3900, Mw = 10000) 5 parts negative charge Property control agent (T-77; manufactured by Hodogaya Chemical Co., Ltd.) 2 parts magnetic powder 1 80 parts The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.). This monomer composition was heated to 60 ° C., 10 parts of ester wax (melting point: 72 ° C.) was mixed and dissolved therein, and polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) was added thereto. [T1 / 2 = 140 minutes, 60 ° C.] 5 parts were dissolved.

The polymerizable monomer system was put into the aqueous medium, and the mixture was granulated by stirring at 10,000 rpm for 15 minutes in Claremix (manufactured by M Technique) in an N ₂ atmosphere at 60 ° C. Thereafter, the mixture was reacted at 60 ° C. for 6 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was raised to 80 ° C. and stirring was continued for 4 hours. After completion of the reaction, the suspension was cooled and hydrochloric acid was added to dissolve the dispersant, followed by filtration, washing with water and drying to obtain toner particles 1. The physical properties are shown in Table 2.

<Production Example 2 of Toner Particles>
Polyester resin 100 parts (peak molecular weight = 6100, acid value = 18.5 mgKOH / g)
・ Magnetic powder 2 90 parts ・ Monoazo iron complex (T-77: Hodogaya Chemical Co., Ltd.) 2 parts ・ Ester wax (melting point: 72 ° C.) 4 parts The above mixture was premixed with a Henschel mixer and heated to 110 ° C. Then, the mixture was melt-kneaded with a biaxial extruder, and the cooled kneaded product was coarsely pulverized with a hammer mill to obtain a coarsely pulverized toner product. The obtained coarsely pulverized product was coated with a mechanical pulverizer turbo mill (manufactured by Turbo Kogyo Co., Ltd .; coated with chromium alloy plating containing chromium carbide on the rotor and stator surfaces (plating thickness 150 μm, surface hardness HV1050)). Then, the finely pulverized product and the finely pulverized product were classified and removed at the same time using a multi-division classifier (Elbow Jet Classifier manufactured by Nittetsu Mining Co., Ltd.) using the Coanda effect.

  The raw material toner particles were subjected to surface modification by Meteole Inbo (manufactured by Nippon Pneumatic Kogyo Co., Ltd.) which is a device for modifying the surface of the toner particles by blowing hot air to obtain toner particles 2. The conditions for the surface modification were a raw material supply rate of 2 kg / hr, a hot air flow rate of 700 L / min, and a discharge hot air temperature of 300 ° C. The physical properties are shown in Table 2.

<Production Example 3 of Toner Particles>
Polyester resin (acid value = 18.5 mgKOH / g, Tg = 60 ° C., Ts = 110 ° C.)
100 parts Magnetic powder 2 80 parts Charge control agent (zirconium complex of di-t-butylsalicylic acid) 1 part Rice wax 4 parts are thoroughly premixed with a Henschel mixer, melt kneaded with a twin screw extruder and cooled After that, coarsely pulverized by a hammer mill, finely pulverized by an air jet fine pulverizer, and further classified to obtain toner particles 3 having an average particle diameter of 7.9 μm. The physical properties are shown in Table 2.

<Toner Particle Production Example 4>
Polyester resin (condensate of bisphenol A-ethylene oxide adduct and terephthalic acid) 100 parts magnetic powder 2 80 parts zinc compound of salicylic acid 2 parts 2. Mix the above raw materials with a Henschel mixer and melt knead them with a twin screw extruder set at 2.130 ° C. 3. Cool the kneaded product and finely pulverize it with a pulverizer using a jet stream. Classification using an air classifier,
Number average diameter: 5.7μm
Volume average particle size: 11.0 μm
Volume average particle diameter / number average particle diameter: 1.9
Toner particles 4 were obtained. The physical properties are shown in Table 2.

<Toner particle production example 5>
~ Synthesis of organic fine particle emulsion ~
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 166 parts of methacrylic acid, 110 butyl acrylate Parts and 1 part of ammonium persulfate were added and stirred at 3800 rpm for 30 minutes to obtain a white emulsion. The system was heated to raise the system temperature to 75 ° C. and reacted for 3 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 70 ° C. for 5 hours, and an aqueous dispersion of vinyl resin (methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt copolymer). [Fine particle dispersion 1] was obtained. The volume average particle diameter of [fine particle dispersion 1] measured by LA-920 was 75 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The Tg of the resin was 60 ° C., and the weight average molecular weight was 110,000.

~ Preparation of aqueous phase ~
990 parts of water, 83 parts of [fine particle dispersion 1], 37 parts of a 48.3% aqueous solution of dodecyl diphenyl ether disulfonate ((Eleminol MON-7): Sanyo Chemical Industries) and 90 parts of ethyl acetate are mixed and stirred. As a result, a milky white liquid was obtained. This is designated as [Aqueous Phase 1].

~ Synthesis of low molecular weight polyester ~
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 46 parts adipic acid and dibutyl Add 2 parts of tin oxide, react at 230 ° C for 7 hours at normal pressure, and further react for 5 hours at a reduced pressure of 10 to 15 mmHg, and then add 44 parts of trimellitic anhydride to the reaction vessel and add 3 parts at 180 ° C and normal pressure. The reaction was performed for a while to obtain [Low molecular weight polyester 1]. [Low molecular polyester 1] had a number average molecular weight of 2,300, a weight average molecular weight of 6,700, Tg of 43 ° C., and an acid value of 25.

~ Synthesis of intermediate polyester ~
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. at normal pressure for 7 hours, and further reacted at reduced pressure of 10 to 15 mmHg for 5 hours to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2200, a weight average molecular weight of 9700, Tg of 54 ° C., an acid value of 0.5, and a hydroxyl value of 52.

  Next, 410 parts of [Intermediate Polyester 1], 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Polymer 1] was obtained. [Prepolymer 1] had a free isocyanate weight% of 1.53%.

~ Synthesis of ketimine ~
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 4 and a half hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 417.

~ Synthesis of master batch (MB) ~
Add 600 parts of water, 960 parts of magnetic powder 1 and 1200 parts of polyester resin, mix with a Henschel mixer (Mitsui Mining Co., Ltd.), knead the mixture at 120 ° C. for 45 minutes using two rolls, cool by rolling. By crushing with a pulverizer, [Masterbatch 1] was obtained.

~ Creation of oil phase ~
In a container in which a stir bar and a thermometer were set, 378 parts of [Low molecular weight polyester 1], 100 parts of Carnauba WAX, and 947 parts of ethyl acetate were charged, heated to 80 ° C. with stirring, and kept at 80 ° C. for 5 hours. It was cooled to 30 ° C at 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution 1].

  [Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. The pigment and WAX were dispersed under the conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] was added, followed by two passes with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion 1]. The solid content concentration of [Pigment / WAX Dispersion 1] (130 ° C., 30 minutes) was 50%.

~ Emulsification⇒Desolvation ~
[Pigment / WAX Dispersion 1] 749 parts, [Prepolymer 1] 115 parts, and [Ketimine Compound 1] 2.9 parts were put in a container and mixed with a TK homomixer (manufactured by Tokushu Kika) at 5000 rpm for 2 minutes. Thereafter, 1200 parts of [Aqueous Phase 1] was added to the container, and mixed with a TK homomixer at a rotational speed of 13,000 rpm for 25 minutes to obtain [Emulsified Slurry 1].

  [Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 7 hours to obtain [Dispersion slurry 1].

~ Washing⇒Drying ~
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
1: 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12000 rpm for 10 minutes), and then filtered.
100 parts of a 10% aqueous sodium hydroxide solution was added to a 2: 1 filter cake, mixed with a TK homomixer (rotation speed: 12000 rpm for 30 minutes), and then filtered under reduced pressure.
100 parts of 10% hydrochloric acid was added to the 3: 2 filter cake, mixed with a TK homomixer (rotation speed: 12000 rpm for 10 minutes), and then filtered.
300 parts of ion-exchanged water was added to the 4: 3 filter cake, mixed with a TK homomixer (rotation speed: 12000 rpm for 10 minutes), and then filtered twice to obtain [Filter cake 1].

  [Filter cake 1] was dried at 45 ° C. for 48 hours in a circulating dryer to obtain toner particles 5. The physical properties are shown in Table 2.

<Production Example 6 of Toner Particles>
After adding 451 parts of a 0.1 mol / liter-Na ₃ PO ₄ aqueous solution to 709 parts of ion-exchanged water and heating to 60 ° C., 68 parts of 1.0 mol / liter-CaCl ₂ aqueous solution was gradually added and Ca ₃ ( An aqueous medium containing PO ₄ ) ₂ was obtained.

on the other hand,
Styrene 72 parts n-butyl acrylate 28 parts saturated polyester resin (monomer composition; bisphenol A propylene oxide adduct / terephthalic acid, acid value 12 mg KOH / g, Tg = 72 ° C., Mn = 3900, Mw = 10000) 5 parts negative charge Property control agent (T-77; manufactured by Hodogaya Chemical Co., Ltd.) 2 parts C.I. I. Pigment Blue 15: 3 7 parts The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.). This monomer composition was heated to 60 ° C., 10 parts of ester wax (melting point: 72 ° C.) was mixed and dissolved therein, and polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) was added thereto. [T1 / 2 = 140 minutes, 60 ° C.] 5 parts were dissolved.

The polymerizable monomer system was put into the aqueous medium, and the mixture was granulated by stirring at 10,000 rpm for 15 minutes in Claremix (manufactured by M Technique) in an N ₂ atmosphere at 60 ° C. Thereafter, the mixture was reacted at 60 ° C. for 6 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was raised to 80 ° C. and stirring was continued for 4 hours. After completion of the reaction, the suspension was cooled and hydrochloric acid was added to dissolve the dispersant, followed by filtration, washing with water and drying to obtain toner particles 6. The physical properties are shown in Table 2.

<Manufacture of toner 1>
100 parts of toner particles 1, 0.8 part of external additive 1, 0.3 part of external additive 6 , and 0.2 part of external additive 15 are Henschel mixer 10B (Mitsui Miike Chemical Co., Ltd.) Were mixed to prepare toner 1. The mixing conditions of the Henschel mixer were: 100 parts of toner particles 1 and 0.3 part of external additive 6 were mixed at 4000 rpm for 3 minutes, and once stopped, 0.8 part of external additive 1 and 0 part of external additive 15 were mixed. 2 parts were added and further mixed at 4000 rpm for 3 minutes. The external addition conditions of Toner 1 are shown in Table 3, and the physical properties are shown in Table 4.

<Manufacture of Toners 2 to 16 and Toner 20>
Toners 2 to 16 and toner 20 were prepared by adding inorganic or organic fine powder to 100 parts of each toner particle under the conditions shown in Table 3 and changing the mixing conditions of the Henschel mixer. Table 3 shows the external addition conditions of the toners 2 to 16 and the toner 20, and Table 4 shows the physical properties.

<Manufacture of toner 17>
100 parts of toner particles 3, 2.5 parts of external additive 2, 0.25 parts of external additive 9, and 0.5 parts of external additive 10 were mixed at 30 m / s for 6 minutes with a Henschel mixer. Toner 17 was adjusted. Table 3 shows external addition conditions of the toner 17, and Table 4 shows physical properties.

<Manufacture of Toner 18>
To 100 parts of toner particles 4, 3.0 parts of external additive 2 and 0.2 parts of external additive 11 were added and mixed thoroughly with a Henschel mixer (Mitsui Miike Co., Ltd.) to obtain toner 18. . The external addition conditions of the toner 18 are shown in Table 3, and the physical properties are shown in Table 4.

<Manufacture of Toner 19>
100 parts of toner particles 5, 1.5 parts of external additive 1, 1 part of external additive 3, and 0.5 part of external additive 11 were mixed with a Henschel mixer (FM20C manufactured by Mitsui Mining Co., Ltd.). Toner 19 was obtained. Mixing conditions were set by repeating a set of 30 second rotation and 60 second rotation stop at a peripheral speed of 30 m / sec 12 times. Table 3 shows external addition conditions of the toner 17, and Table 4 shows physical properties.

<Example 1>
(Image forming device)
As the image forming apparatus, LBP-3000 (manufactured by Canon) was used with modification as shown in FIG.

  As shown in FIG. 2, the image forming apparatus includes a photoconductor 100, a conductive charging roller 117 that is disposed in contact with the photoconductor 100 and charges the photoconductor 100, and a laser beam corresponding to an image to be formed. A laser generator 121, which is an exposure device that forms an electrostatic latent image on the photosensitive member 100 by irradiating the charged photosensitive member 100 with 123, and the toner image is developed by developing the formed electrostatic latent image with toner. And a developing unit 140 formed in the unit 100. Further, the transfer material P is brought into contact with the photoreceptor 100. A conductive transfer roller 114 that transfers the formed toner image to the transfer material P, a fixing device 126 that fixes the toner image on the transfer material P to the transfer material P, and the surface of the photoreceptor 100 after transfer. A cleaner 116 having a cleaning blade for removing transfer residual toner, a register roller 124 for conveying the transfer material P between the photoconductor 100 and the transfer roller 114, and a transfer material P on which the toner image is transferred. A conveying belt 125 for conveying to the fixing device 126.

  As shown in FIG. 1, the developing device 140 includes a developing container that stores a developer, a developing sleeve 102 that is rotatably disposed in an opening of the developing container, and a stationary inside the developing sleeve 102. A magnet roller 104 that is in contact with the developing sleeve 102, an elastic blade 103 that regulates the toner carried on the developing sleeve 102 and regulates the thickness of the toner layer on the developing sleeve 102, and the inside of the developing container And a stirring member 141 that stirs the toner. The developing device 140 is disposed at a position where the developing sleeve 102 and the photoconductor 100 are not in contact with the photoconductor 100.

  As shown in FIG. 3, the transfer roller 114 includes a cored bar 114a and a conductive elastic layer 114b that covers the peripheral surface of the cored bar 114a. A transfer bias power source 115 for applying a transfer bias applied from the back surface of the transfer material P when the toner image is transferred is connected to the metal core 114a. The charging roller 117 can be configured in the same manner as the transfer roller 114. It should be noted that the devices and members shown in FIGS. 1 to 3 can all be constituted by known members.

First, toner 1 was used as a toner, and an image forming test was performed in a low temperature and low humidity environment (15 ° C., 10% RH) and in a 0 ° C. low humidity environment (0 ° C., 10% RH). As the transfer material, A4 paper of 75 g / m ² was used. As a result, an image having high density and dot reproducibility in the initial stage and excellent cleaning property and electrostatic offset was obtained.

  Next, durability was evaluated by printing an image pattern consisting only of horizontal lines with a printing area ratio of 2% in intermittent mode up to 2000 prints. Image evaluation and toner durability evaluation were performed as follows.

a) Image density A solid image portion was formed and evaluated after the initial and 2000 printouts were completed. The image density was measured by using a “Macbeth reflection densitometer” (manufactured by Macbeth Co.), which is an image density measuring device, to measure a relative density with respect to a printout image of a white background portion having a document density of 0.00. If the image density is 1.40 or more, the image has no practical problem.

b) Dot reproducibility The dot reproducibility was evaluated by performing an image formation test using a checker pattern of 80 μm × 50 μm shown in FIG.
A: 2 or less defects in 100 B: 3 or more and 5 or less defects in 100 C: 6 or more and 10 or less defects in 100 D: 11 or less defects in 100

c) Electrostatic offset test A solid white image was continuously passed through 75 sheets of A4 paper of 75 g / m ² . Thereafter, 100 images were continuously drawn using an electrostatic offset test chart in which the first half of the image was solid black and the second half was white, and the electrostatic offset resistance was visually evaluated.

In addition, the evaluation criteria of the electrostatic offset resistance in 1) and 2) were determined as follows.
A: Not seen at all.
B: It is faintly seen on a white background part.
C: A level that can be seen in a white background but has no practical problem.
D: A level that is clearly seen in a white background and is not preferable for practical use.

d) Poor cleaning The cleaning performance was evaluated based on the degree of contamination on the solid white image in a low-temperature and low-humidity environment and at 0 ° C and low-humidity environment, and the contamination of the electrostatic image carrier after the solid white image was printed. The degree was evaluated.
A: Clean image quality with no problem on the image and no stain on the image carrier.
B: A cleaning property in which an image having no problem on the image can be obtained, but the image carrier is slightly stained.
C: Cleanability with no problem in practical use.
D: Dirt is observed on the image and the image bearing member, and cleaning properties which are not preferable for practical use.

<Examples 2 to 11>
Toners 2 to 11 were used as shown in Table 3, respectively, and an image forming test and a durability test were performed using the same image forming apparatus as in Example 1. As a result, practically satisfactory results were obtained with respect to image characteristics, cleanability, and electrostatic offset.

<Comparative Examples 1 to 8>
Evaluation was performed in the same manner as in Example 1 using the comparative toners 12 to 19. The evaluation results are shown in Table 3. As a result, practically undesirable results were obtained with respect to image characteristics, cleaning properties, and electrostatic offset.

<Example 12>
Using a commercially available full color laser beam printer “LBP-5100” (manufactured by Canon Inc., printout speed: A4 size 12 sheets / min) as the image forming apparatus, toner 20 was charged instead of the toner in the cyan toner cartridge, The image output test was performed in the single color mode.
In the low temperature and low humidity environment (15 ° C., 10% RH) and in the 0 ° C. low humidity environment (0 ° C., 10% RH), image evaluation and toner durability evaluation were performed in the same manner as in Example 1. As a result, an image having high density and dot reproducibility in the initial and durability tests, and good cleaning property and electrostatic offset was obtained. The results are shown in Table 6.

FIG. 3 is a schematic diagram illustrating a configuration of a developing device 140 in the image forming apparatus illustrated in FIG. 2. 1 is a schematic diagram illustrating a configuration of an image forming apparatus used in an embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a transfer roller 114 in the image forming apparatus illustrated in FIG. 2. It is explanatory drawing of the checker pattern used for dot reproducibility evaluation.

Explanation of symbols

21a to 21d Photosensitive drums 24a to 24d, 140 Developing device 27 Transport charger 29a to 29d Image forming unit 30a to 30d Transfer discharging unit 31 Charger 32 Discharge port 100 Photoconductor 102 Developing sleeve (magnetic toner carrier)
103 Elastic blade (regulator blade)
104 Magnet roller 114 Transfer roller 114a Core metal 114b Conductive elastic layer 115 Transfer bias power supply 116 Charge amount adjusting member (cleaner)
117 Charging roller 121 Laser generator (laser beam scanner)
123 Laser light 124 Register roller 125 Conveying belt 126 Fixing device 140 Developing device 141 Stirring member P Transfer material (recording medium)

Claims (11)

A toner having toner particles containing a binder resin and a colorant, and inorganic fine powder and organic fine powder,
(I) said inorganic fine powder, pieces number average particle diameter (D1) is contained 300nm following inorganic fine powder A over 30 nm, the isolation ratio of the toner particles of the inorganic fine powder A is 10.0 wt% or more 50.0 mass% or less,
(Ii) the organic fine powder, pieces number average particle diameter (D1) is contained 1000nm following organic fine powder B or 50 nm, the isolation ratio of the toner particles of the organic fine powder B is 3.0 mass% or less And
(Iii) The number average particle diameter of the inorganic fine powder A is not more than the number average particle diameter of the organic fine powder B;
(Iv) A toner having an average circularity of 0.960 or more.   The toner according to claim 1, wherein the organic fine powder B has a liberation rate from toner particles of 1.0% by mass or less.   The content of the inorganic fine powder A with respect to the toner particles is 1.0% by mass or less, and the content of the organic fine powder B is less than or equal to the content of the inorganic fine powder A. Item 3. The toner according to Item 1 or 2. The main component of the organic fine powder B is, toner according to either the claims 1 to 3, characterized in that an acrylic polymer or an acrylic copolymer.   5. The toner according to claim 1, wherein the organic fine powder B has a weight average molecular weight (Mw) of a component soluble in tetrahydrofuran of 300000 or more and 1000000 or less. The toner according to Izu Re one of claims 1 to 5 wherein the inorganic fine powder A is characterized in that it is a strontium titanate fine powder.   The toner according to claim 6, wherein the strontium titanate fine powder is a particle having a cubic particle shape and / or a rectangular parallelepiped particle shape and having a perovskite crystal.   The toner according to claim 6 or 7, wherein the strontium titanate fine powder contains a fatty acid, a fatty acid salt, or an organosilane compound.   The toner according to claim 1, wherein the colorant is a magnetic powder. Before the Quito toner of 5 mol / l during hydrochloric acid dissolved, and the dissolved amount of the magnetic powder is 10 mass% or less than 0.5 wt% with respect to the magnetic powder total content of 3 min time point, at 15 min time point The toner according to claim 9, wherein the dissolved amount of the magnetic powder with respect to the total content of the magnetic powder is 40% by mass or more and 80% by mass or less. The toner according to any one of claims 1 to 10, wherein the toner particles are toner particles produced by suspension polymerization.

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