Image forming apparatus and image forming method

Abstract

To provide an image forming apparatus in which cleaning property of toner particles is enhanced and occurrence of toner filming is suppressed.SOLUTION: A charging unit, an electrostatic charge forming unit, an electrostatic charge image developing unit, a transfer unit, and a cleaning unit, in which toner particles included in an electrostatic charge image developing toner in the electrostatic charge forming unit contain a metallic pigment having an average equivalent circle diameter of 5 μm to 15 μ m, and an average value of ratios b / a of major axis diameters a to minor axis diameters b in cross sections of the toner particles is in a range of 0.5 to 0.8, in the image forming apparatus, a mean value of areas of the metallic pigments in a projected image of the toner particles when the toner particles are viewed from a thickness direction is 0.5 or more and 0.7 or less, and a breaking energy of a cleaner blade is 5000MPa ·% or more and 15000MPa ·% or less and a 100% modulus of the cleaner blade at a contact portion with the image holding member is 10MPa or more.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an image forming apparatus and an image forming method. [Background technology]

[0002] Conventionally, electrophotographic image forming apparatuses (such as copiers, facsimiles, and printers) have been required to form images with brilliance, and toner particles containing specific pigments with brilliance have been used for this purpose.

[0003] For example, Patent Document 1 discloses "an electrophotographic toner containing at least a binder resin, a colorant, and a release agent, wherein the colorant is a metallic pigment, and the viscoelasticity of the toner is characterized in that the loss tangent, expressed as loss modulus (G") / storage modulus (G')=loss tangent (tanδ), has a peak at 80 to 160°C, and the peak value of the loss tangent is 3 or more."

[0004] Patent Document 2 discloses a toner that, when a solid image is formed, has a ratio (A / B) of reflectance A at a light-receiving angle of +30° to reflectance B at a light-receiving angle of -30°, measured when the image is irradiated with incident light at an incident angle of -45° using a goniophotometer, of 2 or more and 100 or less.

[0005] Furthermore, in image forming apparatuses that use toner, a cleaning blade has conventionally been used to remove toner remaining on the image carrier. For example, Patent Document 3 discloses "an image forming apparatus having an image carrier on which a latent image is formed and which is capable of carrying a toner image, a developing means for developing the latent image formed on the image carrier with toner, and a cleaning means having a blade-shaped elastic body that comes into contact with the surface of the image carrier, wherein the coefficient of friction Ft / Fn between the image carrier and the elastic body is 0.85 or more and 1.1 or less, and the self-excited vibration WRFt(LMH) of the shear force in the LMH band of the elastic body is 1.5 gf or more and 3.5 gf or less." [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-208142 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-032765 [Patent Document 3] Japanese Patent Application Publication No. 2019-164226 Summary of the Invention [Problem to be solved by the invention]

[0007] The present disclosure addresses the problem of providing an image forming apparatus and image forming method in which, compared to an image forming apparatus using a cleaning blade that satisfies at least one of the conditions of a breaking energy exceeding 5000 MPa·% or less than 15000 MPa·% and a 100% modulus at the contact portion with an image carrier being less than 10 MPa, the cleaning ability of toner particles by a cleaning blade is improved and the occurrence of toner filming by a cleaning blade is suppressed, even when using a toner for developing electrostatic images that contains toner particles that contain a metal pigment with an average equivalent circle diameter of 5 μm or more and 15 μm or less, the ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being an average of 0.5 or more and 0.8 or less, and the average area of ​​the metal pigment in the projected image of the toner particles when viewed from the thickness direction being an average of 0.5 or more and 0.7 or less. [Means for solving the problem]

[0008] Means for solving the above problems include the following aspects. <1> an image carrier; a charging means for charging the surface of the image carrier; an electrostatic charge forming means for forming an electrostatic image on the charged surface of the image carrier; an electrostatic image developing means for developing the electrostatic image with the electrostatic image developing toner to form a toner image, the toner particles containing a metal pigment having an average equivalent circular diameter of 5 μm to 15 μm, the average value of the ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section of the toner particles being 0.5 to 0.8, and the average value of the area occupied by the metal pigment in a projected image of the toner particles when viewed from the thickness direction of the toner particles being 0.5 to 0.7; a transfer means for transferring the toner image onto a recording medium; a cleaning means having a cleaning blade that comes into contact with the surface of the image carrier to clean the surface, the cleaning blade having a breaking energy of 5000 MPa·% or more and 15000 MPa·% or less and a 100% modulus of 10 MPa or more at the portion of contact with the image carrier; An image forming apparatus comprising: <2> The cleaning blade has a breaking energy of 7000 MPa·% or more and 12000 MPa·% or less. <1> 2. The image forming apparatus according to claim 1 . <3> the cleaning blade has a 100% modulus of 12 MPa or more and 20 MPa or less at a portion of contact with the image carrier; <1> or <2> 2. The image forming apparatus according to claim 1 . <4> the cleaning blade, the material constituting the contact portion with the image carrier is polyurethane obtained by polymerizing a polyester polyol having a weight average molecular weight of 1,000 or more and 10,000 or less, an isocyanate compound, and a crosslinking agent; <1> ~ <3> 10. The image forming apparatus according to claim 9, <5> The weight average molecular weight of the polyester polyol is 2000 or more and 8000 or less. <4> 2. The image forming apparatus according to claim 1 . <6> the cleaning blade is configured such that the material constituting the contact portion with the image carrier is polyurethane obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and the proportion of the isocyanate compound in the material constituting the contact portion is 10 mol % or more and 40 mol % or less; <1> ~ <5> 10. The image forming apparatus according to claim 9, <7> The ratio of the isocyanate compound to the material constituting the contact portion is 15 mol % or more and 30 mol % or less. <6> 2. The image forming apparatus according to claim 1 . <8> The cleaning blade is made of a material constituting a contact portion with the image carrier, which is obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and has a crosslinking density of 0.90×10 -3 mol / m 3 Over 1.50 x 10 -3 mol / m 3 Polyurethane, <1> ~ <7> 10. The image forming apparatus according to claim 9, <9> The crosslink density is 1.00×10 -3 mol / m 3 Over 1.30 x 10 -3 mol / m 3 Below is the <8> 2. The image forming apparatus according to claim 1 . <10> the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, The back layer has a 100% modulus of 3 MPa or more and 7 MPa or less and a permanent elongation of less than 2.0%. <1> ~ <9> 10. The image forming apparatus according to claim 9, <11> The back layer has a 100% modulus of 4 MPa or more and 6 MPa or less. <10> 2. The image forming apparatus according to claim 1 . <12> The back layer has a permanent elongation of 1.0% or less. <10> or <11> 2. The image forming apparatus according to claim 1 . <13> the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, the material constituting the back surface layer is polyurethane obtained by polymerizing a polyester polyol having a weight average molecular weight of 100 or more and 2000 or less, an isocyanate compound, and a crosslinking agent; <1> ~ <12> 10. The image forming apparatus according to claim 9, <14> The weight average molecular weight of the polyester polyol is 500 or more and 1000 or less. <13> 2. The image forming apparatus according to claim 1 . <15> the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, the material constituting the back surface layer is polyurethane obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and the proportion of the isocyanate compound in the material constituting the back surface layer is 5 mol % or more and 20 mol % or less; <1> ~ <14> 10. The image forming apparatus according to claim 9, <16> The ratio of the isocyanate compound to the material constituting the back surface layer is 5 mol % or more and 15 mol % or less. <15> 2. The image forming apparatus according to claim 1 . <17> the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, The material constituting the back surface layer is a polymer of a polyol, an isocyanate compound, and a crosslinking agent, and has a crosslink density of 1.5×10 -3 mol / m 3 Over 2.5 x 10 -3 mol / m 3 Polyurethane, <1> ~ <16> 10. The image forming apparatus according to claim 9, <18> The crosslink density is 1.8×10 -3 mol / m 3 Over 2.2 x 10 -3 mol / m 3 That is, <17> 2. The image forming apparatus according to claim 1 . <19> the toner particles contain a binder resin including a crystalline resin and an amorphous resin, and the proportion of the crystalline resin in the binder resin is 3% by mass or more and 30% by mass or less; <1> ~ <18> 10. The image forming apparatus according to claim 9, <20> The proportion of the crystalline resin in the binder resin is 5% by mass or more and 25% by mass or less. <19> 2. The image forming apparatus according to claim 1 . <21> a charging step of charging the surface of the image carrier; an electrostatic charge forming step of forming an electrostatic image on the charged surface of the image carrier; an electrostatic image developing step of forming a toner image by developing the electrostatic image with an electrostatic image developing toner containing toner particles, the toner particles containing a metal pigment having an average equivalent circular diameter of 5 μm to 15 μm, an average value of b / a of a major axis diameter a to a minor axis diameter b in a cross section of the toner particles being 0.5 to 0.8, and an average value of an area occupied by the metal pigment in a projected image of the toner particles when viewed from the thickness direction of the toner particles being 0.5 to 0.7; a transfer step of transferring the toner image onto a recording medium; a cleaning step of bringing a cleaning blade into contact with the surface of the image carrier to clean the surface, the cleaning blade having a breaking energy of 5000 MPa·% or more and 15000 MPa·% or less and a 100% modulus of 10 MPa or more at the contact portion with the image carrier; An image forming method comprising: [Effects of the Invention]

[0009] <1> According to the invention, compared to an image forming apparatus using a cleaning blade that satisfies at least one of the conditions of a breaking energy exceeding 5000 MPa·% or less than 15000 MPa·% and a 100% modulus at the contact portion with the image carrier being less than 10 MPa, an image forming apparatus is provided in which the cleaning ability of toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images that contains toner particles that contain a metal pigment with an average equivalent circle diameter of 5 μm or more and 15 μm or less, the ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is an average of 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction is 0.5 or more and 0.7 or less. <2> According to the invention, compared to an image forming apparatus using a cleaning blade that satisfies the condition of a breaking energy exceeding 7000 MPa·% or less than 12000 MPa·%, an image forming apparatus is provided in which the cleaning ability of the toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images containing toner particles that contain a metal pigment with an average equivalent circle diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction is 0.5 or more and 0.7 or less. <3> According to the invention, compared to an image forming apparatus using a cleaning blade that satisfies the condition that the 100% modulus at the contact point with the image carrier is less than 12 MPa or more than 20 MPa, an image forming apparatus is provided in which the cleaning ability of the toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images containing toner particles that contain a metal pigment with an average circular equivalent diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction is 0.5 or more and 0.7 or less. <4> or <5> According to the invention, compared to an image forming device using a cleaning blade in which the material constituting the contact portion with the image carrier is polyurethane obtained by polymerizing a polyester polyol having a weight-average molecular weight of less than 1,000 or more than 10,000, an isocyanate compound, and a crosslinking agent, an image forming device is provided in which the cleaning ability of the toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images containing toner particles that contain a metal pigment having an average equivalent circular diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction is 0.5 or more and 0.7 or less. <6> or <7> According to the invention, compared to an image forming apparatus using a cleaning blade in which the material constituting the contact portion with the image carrier is polyurethane obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and in which the proportion of the isocyanate compound in the material constituting the contact portion is less than 10 mol % or more than 40 mol %, an image forming apparatus is provided in which the cleaning ability of toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images containing toner particles that contain a metal pigment with an average equivalent circle diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area of ​​the metal pigment in the projected image of the toner particle when viewed from the thickness direction is 0.5 or more and 0.7 or less. <8> or <9> According to the invention, the material constituting the contact portion with the image carrier is a polymer of a polyol, an isocyanate compound, and a crosslinking agent, and has a crosslink density of 0.90×10 -3 mol / m 3 Less than or 1.50 x 10 -3 mol / m 3The present invention provides an image forming apparatus in which, compared to an image forming apparatus using a cleaning blade made of polyurethane having a thickness greater than 1000 nm, the cleaning ability of the toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images containing toner particles that contain a metal pigment having an average equivalent circular diameter of 5 μm to 15 μm, an average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 to 0.8, and an average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction being 0.5 to 0.7. <10> According to the invention relating to the above, compared to an image forming device using a cleaning blade having a back layer that has a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier from the surface layer, and that satisfies at least one of the conditions of a 100% modulus of less than 3 MPa or more than 7 MPa and a permanent set elongation of 2.0% or more, an image forming device is provided in which the cleaning ability of toner particles is improved even when using a toner for developing electrostatic images that contains toner particles that contain a metal pigment having an average circle equivalent diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area of ​​the metal pigment in the projected image of the toner particles when viewed from the thickness direction is 0.5 or more and 0.7 or less. <11> According to the invention relating to the above, compared to an image forming device using a cleaning blade having a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier from the surface layer, and having a back layer that satisfies the condition that the 100% modulus is less than 4 MPa or more than 6 MPa, an image forming device is provided in which the cleaning ability of toner particles is improved even when using a toner for developing electrostatic images, the toner particles containing a metal pigment having an average circle equivalent diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction is 0.5 or more and 0.7 or less. <12> According to the invention relating to the above, compared to an image forming device using a cleaning blade having a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier from the surface layer, and having a back layer that satisfies the condition that the permanent set is greater than 1.0%, there is provided an image forming device in which the cleaning ability of toner particles is improved even when using a toner for developing electrostatic images, the toner particles containing a metal pigment having an average equivalent circle diameter of 5 μm to 15 μm, an average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 to 0.8, and an average value of the area of ​​the metal pigment in the projected image of the toner particles when viewed from the thickness direction being 0.5 to 0.7. <13> or <14> According to the invention, compared to an image forming device using a cleaning blade having a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, wherein the material constituting the back layer is polyurethane obtained by polymerizing a polyester polyol having a weight-average molecular weight of 100 to 2000, an isocyanate compound, and a crosslinking agent, there is provided an image forming device that has improved cleanability of toner particles even when using a toner for developing electrostatic images, the toner particles containing a metal pigment having an average circle equivalent diameter of 5 μm to 15 μm, an average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 to 0.8, and an average area occupied by the metal pigment in the projected image of the toner particle when viewed from the thickness direction being 0.5 to 0.7. <15> or <16> According to the invention related to the above, compared to an image forming apparatus using a cleaning blade having a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, wherein the material constituting the back layer is polyurethane obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and wherein the proportion of the isocyanate compound in the material constituting the back layer is 5 mol % or more and 20 mol % or less, an image forming apparatus is provided in which the cleaning ability of toner particles is improved even when using a toner for developing electrostatic images that contains toner particles that contain a metal pigment with an average equivalent circle diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area of ​​the metal pigment in the projected image of the toner particle when viewed from the thickness direction is 0.5 or more and 0.7 or less. <17> or <18> According to the invention, a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer are provided, and the back layer is made of a material that is obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and has a crosslink density of 1.5×10 -3 mol / m 3 Over 2.5 x 10 -3 mol / m 3 The present invention provides an image forming apparatus in which the cleaning ability of toner particles is improved compared to an image forming apparatus using a cleaning blade made of polyurethane having an average equivalent circle diameter of 5 μm to 15 μm, an average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 to 0.8, and an average area of ​​the metal pigment in the projected image of the toner particles when viewed from the thickness direction being 0.5 to 0.7. <19> or <20> According to the present invention, an image forming apparatus is provided which contains a binder resin including a crystalline resin and an amorphous resin, and in which the wear resistance of images is improved compared to an image forming apparatus which uses toner particles in which the proportion of the crystalline resin in the binder resin is less than 3 mass %. <21> According to the invention related to the above, compared to an image forming method using a cleaning blade that satisfies at least one of the conditions of a breaking energy exceeding 5000 MPa·% or less than 15000 MPa·% and a 100% modulus at the contact portion with the image carrier being less than 10 MPa, an image forming method is provided in which the cleaning ability of toner particles by a cleaning blade is improved and the occurrence of toner filming by a cleaning blade is suppressed, even when using a toner for developing electrostatic images, the toner particles containing a metal pigment having an average equivalent circle diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction is 0.5 or more and 0.7 or less. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a cross-sectional view schematically illustrating a toner particle used in the present embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of a layer structure of an electrophotographic photosensitive member used in the present embodiment. [Figure 3] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Figure 4] FIG. 10 is a schematic configuration diagram illustrating another example of an image forming apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present embodiment, which is an example of the present disclosure, will be described below. The description and examples are intended to exemplify the embodiment, and are not intended to limit the scope of the embodiment.

[0012] In the numerical ranges described in this embodiment in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this embodiment, the upper or lower limit value of the numerical range may be replaced with the value shown in the examples. In this embodiment, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. When the present embodiment is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Furthermore, the sizes of the components in each drawing are conceptual, and the relative size relationships between the components are not limited to these. In this embodiment, each component may contain multiple types of corresponding substances. When referring to the amount of each component in the composition in this embodiment, if multiple types of substances corresponding to each component are present in the composition, the amount refers to the total amount of the multiple types of substances present in the composition, unless otherwise specified.

[0013] [Image forming equipment] The image forming apparatus according to this embodiment has an image carrier, a charging means, an electrostatic charge forming means, an electrostatic charge image developing means, a transfer means, and a cleaning means. The charging means charges the surface of the image carrier. The electrostatic charge forming means forms an electrostatic charge image on the charged surface of the image carrier. The electrostatic charge image developing means has a toner for developing an electrostatic charge image containing toner particles. The electrostatic charge image developing means develops the electrostatic charge image with the toner for developing an electrostatic charge image to form a toner image. The transfer means transfers the toner image to a recording medium. The cleaning means has a cleaning blade that contacts the surface of the image carrier to clean the surface. The toner particles contain a metal pigment having an average equivalent circular diameter of 5 μm to 15 μm. The toner particles have an average ratio b / a of the major axis diameter a to the minor axis diameter b in their cross sections of 0.5 to 0.8. The toner particles have an average area of ​​the metal pigment in a projected image of the toner particles when viewed from the thickness direction of 0.5 to 0.7. Hereinafter, toner particles that satisfy these requirements will be referred to as "glossy toner particles." The cleaning blade has a breaking energy of 5000 MPa·% or more and 15000 MPa·% or less. The cleaning blade has a 100% modulus of 10 MPa or more at the contact portion with the image carrier. Hereinafter, a cleaning blade that meets these requirements will be referred to as a "specific cleaning blade."

[0014] The image forming apparatus according to the present embodiment has the above-described configuration, which improves the cleaning performance of the cleaning blade to remove toner particles and also suppresses the occurrence of toner filming due to the cleaning blade. The reasons for this are presumed to be as follows.

[0015] Conventionally, in image formation using toner, it has been desired to form images with a metallic luster (i.e., brilliance). To this end, electrostatic image developing toners containing metal pigments with large equivalent circle diameters in the toner particles have been used. Specifically, a large equivalent circle diameter refers to an average equivalent circle diameter of 5 μm or more and 15 μm or less. The average value of the ratio b / a and the average value of the area of ​​the metal pigment in the projected image of the toner particles when viewed from the thickness direction of the toner particles for the brilliance toner particles in this embodiment are within the aforementioned ranges. In other words, because the brilliance toner particles have a flattened shape, images with superior brilliance are formed.

[0016] However, because the glitter toner particles are flat, they are difficult to clean from the image-bearing surface (i.e., they are difficult to clean). To address this issue, a method of increasing the cleaning ability of the toner particles can be considered, for example, by strongly pressing a cleaning blade against the image-bearing surface. However, if the pressing force of the cleaning blade is increased, the cleaning blade is more likely to chip in a low-temperature, low-humidity environment. When the cleaning blade is chipped, toner particles slip through. Furthermore, in a high-temperature, high-humidity environment, the cleaning blade is more likely to wear, and toner filming is more likely to occur as a result of the wear.

[0017] For this reason, the present embodiment uses the aforementioned specific cleaning blade. The specific cleaning blade has a breaking energy and a 100% modulus at the contact portion with the image carrier within the aforementioned ranges. In other words, the specific cleaning blade has enhanced breaking resistance, and is less likely to break even when the pressing force is increased. This increases the pressing force against the surface of the image carrier while suppressing chipping of the cleaning blade in low-temperature, low-humidity environments. As a result, slippage of toner particles due to chipping of the cleaning blade is suppressed. In addition, the cleaning blade's ability to remove toner particles is improved. Furthermore, blade wear is suppressed in high-temperature, high-humidity environments, and the occurrence of toner filming due to wear is suppressed. The suppression of toner filming suppresses the occurrence of image defects.

[0018] As described above, the image forming apparatus according to this embodiment can improve the cleaning performance of the cleaning blade to remove toner particles, and also suppress the occurrence of toner filming caused by the cleaning blade.

[0019] The configuration of the image forming apparatus according to this embodiment will be described in detail below.

[0020] 〔toner〕 In this embodiment, a toner for developing electrostatic images (also simply referred to as "toner" in this specification) containing a metallic pigment and having an average value of the ratio b / a and a pigment area ratio in the above-mentioned ranges is used. The metallic pigment has an average equivalent circular diameter of 5 μm to 15 μm.

[0021] Average value of the ratio b / a The glitter toner particles have an average ratio b / a of the major axis diameter a to the minor axis diameter b in their cross sections of 0.5 to 0.8, preferably 0.55 to 0.75, and more preferably 0.6 to 0.7. If the average value of the ratio b / a is less than 0.5, the coverage of the metal pigment by the binder resin may decrease, whereas if the average value of the ratio b / a is more than 0.8, the brightness of the fixed image may decrease.

[0022] In this embodiment, the method for measuring the major axis diameter a and minor axis diameter b of the cross section of a toner particle is as follows: The toner particles are placed on a smooth surface and vibrated to disperse them evenly. For 1,000 toner particles, the maximum thickness is measured as the minor axis diameter b under 1,000x magnification using a color laser microscope "VK-9700" (manufactured by Keyence Corporation), and the circle-equivalent diameter of the surface as viewed from above is measured as the major axis diameter a, and the arithmetic mean value of these is calculated.

[0023] Pigment area ratio In the present specification, the average area of ​​the metallic pigment in the projected image of the glitter toner particles when viewed from the thickness direction of the toner particles is also referred to as the "pigment area ratio." The glitter toner particles have a pigment area ratio of 0.5 to 0.7. The pigment area ratio is preferably 0.53 to 0.67, and more preferably 0.57 to 0.63. If the pigment area ratio is less than 0.5, the glitter of the fixed image may decrease. If the pigment area ratio exceeds 0.7, the coverage of the metallic pigment by the binder resin may decrease.

[0024] In this embodiment, the pigment area ratio is measured as follows. The arithmetic average of the pigment area ratios for 1,000 toner particles obtained as follows is taken as the pigment area ratio in this embodiment. Toner particles are dispersed in water using a surfactant. A light transmission image of the 1,000 toner particles obtained using an optical microscope "LABOPHOT2" (Nikon Corporation) is analyzed, and the area A of the entire toner and the area B of the glitter pigment portion inside the toner are determined, and B / A is calculated.

[0025] ·Ratio (X / Y) When a solid image is formed using a toner for developing electrostatic images containing photoluminescent toner particles, the ratio (X / Y) of the reflectance X at a light-receiving angle of +30° to the reflectance Y at a light-receiving angle of -30° measured when the image is irradiated with incident light at an incident angle of -45° using a goniophotometer is preferably 2 or more and 100 or less.

[0026] A ratio (X / Y) of 2 or more indicates that the incident light is reflected more in the direction opposite to the incident side (positive angle side) than in the direction of the incident side (negative angle side), meaning that diffuse reflection of the incident light is suppressed. When diffuse reflection occurs, where incident light is reflected in various directions, the color appears dull when the reflected light is visually inspected. Therefore, if the ratio (X / Y) is less than 2, the gloss cannot be confirmed even when the reflected light is visually inspected, and the brilliance may be poor. On the other hand, if the ratio (X / Y) exceeds 100, the viewing angle at which reflected light can be seen becomes too narrow, and the specular reflection component is large, which may cause the image to appear black depending on the viewing angle.

[0027] The ratio (X / Y) is more preferably 50 or more and 100 or less, further preferably 60 or more and 90 or less, and particularly preferably 70 or more and 80 or less.

[0028] -Measurement of the ratio (X / Y) using a goniophotometer- First, the incident angle and the receiving angle will be explained. In this embodiment, when measuring with a goniophotometer, the incident angle is set to -45°. This is because the measurement sensitivity is high for images with a wide range of gloss levels. The light receiving angles are set to -30° and +30° because these angles provide the highest measurement sensitivity for evaluating images with and without a glittering appearance.

[0029] Next, the method for measuring the ratio (X / Y) will be explained. In this embodiment, when measuring the ratio (X / Y), first, a "solid image" is formed by the following method: The developer to be used as a sample is filled into the developing unit of a DocuCentre-III C7600 manufactured by Fujifilm Business Innovation Co., Ltd., and the solid image is then printed on recording paper (OK topcoat + paper, manufactured by Oji Paper Co., Ltd.) at a fixing temperature of 190°C and a fixing pressure of 4.0 kg / cm. 2 The toner amount is 4.5g / m 2 A solid image is formed. The "solid image" refers to an image with a printing rate of 100%. The image area of ​​the formed solid image is irradiated with light at an incident angle of -45° using a GC5000L spectral variable goniochromator manufactured by Nippon Denshoku Industries Co., Ltd., and the reflectance X at an acceptance angle of +30° and the reflectance Y at an acceptance angle of -30° are measured. Reflectance X and reflectance Y were measured at 20 nm intervals for light with wavelengths ranging from 400 nm to 700 nm, and the average reflectance at each wavelength was used. The ratio (X / Y) was calculated from these measurement results.

[0030] <Toner composition> From the viewpoint of satisfying the above-mentioned ratio (X / Y), it is desirable that the glittering toner particles satisfy the following requirements (1) and (2). (1) The average equivalent circle diameter D is longer than the average maximum thickness C of the glitter toner particles. (2) When observing a cross section of a lustrous toner particle in the thickness direction, the number of metallic pigments for which the angle between the long axis of the toner in the cross section and the long axis of the metallic pigment is in the range of -30° to +30° is 60% or more of all metallic pigments observed. The average maximum thickness C of the toner corresponds to the arithmetic mean of the minor axis diameter b of the cross section of the toner particle, and the average equivalent circle diameter D of the toner corresponds to the arithmetic mean of the major axis diameter a of the cross section of the toner particle.

[0031] Here, a cross-sectional view showing a schematic diagram of a glitter toner particle that satisfies the above requirements (1) and (2) is shown in Fig. 1. The schematic diagram shown in Fig. 1 is a cross-sectional view in the thickness direction of the glitter toner particle. The glitter toner particles 22 shown in FIG. 1 are flat toner particles having a circle-equivalent diameter longer than the thickness L, and contain flaky metal pigment particles 24.

[0032] Consider the case where glitter toner particles 22 are flat, with a circular equivalent diameter longer than the thickness L, as shown in FIG. 1. In this case, when the toner moves to an image carrier, intermediate transfer medium, recording medium, etc. during the development and transfer processes of image formation, it tends to move in a way that maximizes the toner charge cancellation. Therefore, it is thought that the glitter toner particles are aligned to maximize the adhesion area. In other words, on the recording medium to which the toner is ultimately transferred, it is thought that the flat glitter toner particles are aligned so that their flat surfaces face the recording medium surface. Furthermore, during the fixing process of image formation, it is thought that the pressure applied during fixing causes the flat glitter toner particles to align so that their flat surfaces face the recording medium surface. Therefore, among the scaly metallic pigments contained in these glitter toner particles, metallic pigments that satisfy the requirement (2) above, "the angle between the long axis of the cross section of the glitter toner particle and the long axis of the metallic pigment is in the range of -30° to +30°," are considered to be aligned so that the side with the largest area faces the recording medium surface. When light is irradiated onto an image formed in this manner, the proportion of metallic pigment that diffusely reflects the incident light is reduced, and the aforementioned range of the ratio (X / Y) is considered to be achieved. Furthermore, when the proportion of metallic pigment that diffusely reflects the incident light is reduced, the reflected light intensity changes significantly depending on the viewing angle, resulting in more ideal glitter.

[0033] Next, the components constituting the toner used in this embodiment will be described. The toner used in this embodiment contains toner particles and, if necessary, an external additive. The toner particles used are glittering toner particles that satisfy the above-mentioned requirements. The toner particles are composed of, for example, a specific metal pigment, a binder resin, a release agent, and other additives. The binder resin includes, for example, a crystalline resin and an amorphous resin.

[0034] -Metallic pigments- The metallic pigment used in the glitter toner particles of this embodiment has an average equivalent circular diameter of 5 μm to 15 μm. If the average equivalent circular diameter of the metallic pigment is outside the range of 5 μm to 15 μm, the glitter of the image may decrease. The average equivalent circle diameter of the metal pigment is preferably 7 μm or more and 13 μm or less, and more preferably 9 μm or more and 11 μm or less.

[0035] Examples of components of the metal pigment used in this embodiment include the following: metal powders such as aluminum, brass, bronze, nickel, stainless steel, and zinc; mica coated with titanium oxide or yellow iron oxide; flaky inorganic crystalline substrates coated with barium sulfate, layered silicates, layered aluminum silicates, and the like; single-crystal plate-like titanium oxide; basic carbonates; bismuth oxychloride; and metal-deposited flaky glass powder. In this embodiment, "glossiness" refers to a metallic luster that appears when an image formed using the toner of this embodiment is visually observed.

[0036] In this embodiment, the average equivalent circle diameter of the metal pigment refers to a value measured as follows. The metallic pigment is placed on a smooth surface and vibrated to disperse it evenly. The equivalent circle diameter D of 1,000 metallic pigments is measured when viewed from above at 1,000x magnification using a color laser microscope "VK-9700" (manufactured by Keyence Corporation), and the arithmetic mean value is calculated. The method for extracting the metal pigment from the toner is not particularly limited. For example, the metal pigment is extracted from the toner using the following method. The toner is dispersed in an organic solvent such as toluene to dissolve the binder resin, and then the insoluble components are separated using filter paper and dried to extract the metal pigment.

[0037] The content of the metal pigment in the toner of this embodiment is preferably 1 part by mass or more and 70 parts by mass or less, more preferably 5 parts by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the binder resin described below.

[0038] -Binder resin- The toner particles of the present exemplary embodiment may contain a binder resin. Preferably, the binder resin contains a crystalline resin and an amorphous resin. In this embodiment, the proportion of the crystalline resin in the binder resin is preferably 3% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 25% by mass or less, and even more preferably 10% by mass or more and 20% by mass or less. If the proportion of the crystalline resin in the binder resin is 3% by mass or more, the abrasion resistance of the toner image is improved. If the proportion of the crystalline resin in the binder resin is 30% by mass or less, the increase in diffuse reflection of the image due to the presence of the crystalline resin is suppressed.

[0039] Examples of binder resins include homopolymers of monomers such as styrenes (e.g., styrene, parachlorostyrene, α-methylstyrene, etc.), (meth)acrylic acid esters (e.g., methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (e.g., acrylonitrile, methacrylonitrile, etc.), vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), and olefins (e.g., ethylene, propylene, butadiene, etc.), and vinyl resins made of copolymers of two or more of these monomers. Examples of the binder resin include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosin, mixtures of these with the vinyl resins, and graft polymers obtained by polymerizing vinyl monomers in the presence of these.

[0040] As the binder resin, a polyester resin is preferable. The polyester resin may be, for example, a known amorphous polyester resin. The polyester resin may be a crystalline polyester resin in combination with the amorphous polyester resin.

[0041] The "crystalline" nature of a resin refers to the presence of a clear endothermic peak rather than a stepwise change in endothermic heat in differential scanning calorimetry (DSC). Specifically, this refers to the half-width of the endothermic peak being within 10°C when measured at a heating rate of 10°C / min. On the other hand, the term "amorphous" for a resin means that the half-width exceeds 10°C, that the endothermic amount exhibits a stepwise change, or that no clear endothermic peak is observed.

[0042] Amorphous polyester resin Examples of the amorphous polyester resin include a condensation polymer of a polycarboxylic acid and a polyhydric alcohol. Note that, as the amorphous polyester resin, a commercially available product or a synthesized product may be used.

[0043] Examples of polycarboxylic acids include aliphatic dicarboxylic acids (such as oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenylsuccinic acid, adipic acid, and sebacic acid), alicyclic dicarboxylic acids (such as cyclohexanedicarboxylic acid), aromatic dicarboxylic acids (such as terephthalic acid, isophthalic acid, orthophthalic acid, and naphthalenedicarboxylic acid), anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). Among these, aromatic dicarboxylic acids are preferred as polycarboxylic acids. The polycarboxylic acid may be a trivalent or higher carboxylic acid having a crosslinked or branched structure in combination with a dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). The polycarboxylic acids may be used alone or in combination of two or more.

[0044] Examples of polyhydric alcohols include aliphatic diols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (e.g., cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, etc.), and aromatic diols (e.g., ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, preferred polyhydric alcohols are aromatic diols and alicyclic diols, and more preferred are aromatic diols. As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked or branched structure may be used in combination with the diol. Examples of trihydric or higher polyhydric alcohols include glycerin, trimethylolpropane, and pentaerythritol. The polyhydric alcohols may be used alone or in combination of two or more.

[0045] The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50°C or higher and 80°C or lower, and more preferably 50°C or higher and 65°C or lower. The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, is determined from the "extrapolated glass transition onset temperature" described in the method for determining glass transition temperature in JIS K-7121-1987 "Method for measuring transition temperature of plastics."

[0046] The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less. The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 or more and 100,000 or less. The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less. The weight-average molecular weight and number-average molecular weight are measured by gel permeation chromatography (GPC). Molecular weight measurements by GPC are performed using a Tosoh GPC HLC-8120GPC measuring device, a Tosoh TSKgel SuperHM-M (15 cm) column, and tetrahydrofuran (THF) as the solvent. The weight-average molecular weight and number-average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared with monodisperse polystyrene standard samples.

[0047] The amorphous polyester resin can be obtained by a known manufacturing method, for example, by carrying out the reaction at a polymerization temperature of 180°C or higher and 230°C or lower, reducing the pressure in the reaction system as necessary, and removing water and alcohol generated during the condensation. If the raw material monomers are not soluble or compatible at the reaction temperature, a high-boiling solvent may be added as a solubilizer to dissolve them. In this case, the polycondensation reaction is carried out while distilling off the solubilizer. If a monomer with poor compatibility is present in the copolymerization reaction, it is advisable to first condense the poorly compatible monomer with the acid or alcohol to be polycondensed, and then polycondense it with the main component.

[0048] Crystalline polyester resin The crystalline polyester resin may be, for example, a polycondensate of a polycarboxylic acid and a polyhydric alcohol. Note that, as the crystalline polyester resin, a commercially available product or a synthesized product may be used. Here, the crystalline polyester resin is preferably a polycondensate using a polymerizable monomer having a linear aliphatic group rather than a polymerizable monomer having an aromatic group, since it easily forms a crystalline structure.

[0049] Examples of polycarboxylic acids include aliphatic dicarboxylic acids (e.g., oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc.), aromatic dicarboxylic acids (e.g., dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalene-2,6-dicarboxylic acid), anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). The polycarboxylic acid may be a tricarboxylic or higher carboxylic acid having a crosslinked or branched structure in combination with a dicarboxylic acid. Examples of the tricarboxylic acid include aromatic carboxylic acids (e.g., 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.), anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). As the polycarboxylic acid, a dicarboxylic acid having a sulfonic acid group and a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids. The polycarboxylic acids may be used alone or in combination of two or more.

[0050] Examples of polyhydric alcohols include aliphatic diols (for example, straight-chain aliphatic diols having 2 to 20 carbon atoms in the main chain). Examples of aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,20-icosanediol. Among these, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferred as aliphatic diols. The polyhydric alcohol may be a trihydric or higher alcohol having a crosslinked or branched structure, such as glycerin, trimethylolethane, trimethylolpropane, or pentaerythritol, in combination with the diol. The polyhydric alcohols may be used alone or in combination of two or more.

[0051] Here, the polyhydric alcohol has an aliphatic diol content of 80 mol % or more, preferably 90 mol % or more.

[0052] The melting temperature of the crystalline polyester resin is preferably 50°C or higher and 100°C or lower, more preferably 55°C or higher and 90°C or lower, and even more preferably 60°C or higher and 85°C or lower. The melting temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC) by using the "melting peak temperature" described in the method for determining the melting temperature in JIS K7121-1987 "Method for measuring transition temperatures of plastics."

[0053] The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

[0054] The crystalline polyester resin can be obtained by a known manufacturing method, for example, in the same manner as the amorphous polyester.

[0055] The content of the binder resin is, for example, preferably 40% by mass to 95% by mass, more preferably 50% by mass to 90% by mass, and even more preferably 60% by mass to 90% by mass, based on the total mass of the toner particles.

[0056] -Mold release agent- Examples of release agents include hydrocarbon waxes, natural waxes such as carnauba wax, rice wax, and candelilla wax, synthetic or mineral / petroleum waxes such as montan wax, and ester waxes such as fatty acid esters and montanic acid esters, but are not limited thereto.

[0057] The melting temperature of the release agent is preferably 50°C or higher and 110°C or lower, and more preferably 60°C or higher and 100°C or lower. The melting temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC) by using the "melting peak temperature" described in the method for determining the melting temperature in JIS K-7121-1987 "Method for measuring transition temperatures of plastics."

[0058] The content of the release agent is, for example, preferably 1% by mass or more and 20% by mass or less, and more preferably 4% by mass or more and 15% by mass or less, based on the total mass of the toner particles.

[0059] -Other additives- Examples of other additives include well-known additives such as magnetic materials, charge control agents, inorganic powders, etc. These additives are contained in the toner particles as internal additives.

[0060] -Characteristics of glitter toner particles- The glitter toner particles may be toner particles having a single layer structure, or may be toner particles having a so-called core-shell structure consisting of a core particle and a coating layer (shell layer) that covers the core. Here, the toner particles having a core-shell structure may preferably be composed of a core containing, for example, a binder resin, a metal pigment (colorant), and, if necessary, other additives such as a release agent, and a coating layer containing the binder resin.

[0061] The volume average particle size (D50v) of the glitter toner particles is preferably 5 μm or more and 30 μm or less.

[0062] The various average particle sizes and particle size distribution indices of the toner particles are measured using a Coulter Multisizer 4e (manufactured by Beckman Coulter), and the electrolyte is measured using an ISOTON-II (manufactured by Beckman Coulter). For the measurement, 0.5 mg to 50 mg of the sample to be measured is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant, and this is then added to 100 ml to 150 ml of the electrolyte. The electrolyte solution containing the suspended sample is dispersed for 1 minute using an ultrasonic disperser, and the particle size distribution of particles with a particle size range of 2 μm to 60 μm is measured using a Coulter Multisizer 4e with an aperture diameter of 100 μm. The number of particles sampled is 50,000. Based on the particle size distribution measured, cumulative distributions of volume and number are drawn for each divided particle size range (channel) from the smallest diameter side, and the particle size at 16% of the cumulative total is defined as the volume particle size D16v, the number particle size D16p, the particle size at 50% of the cumulative total as the volume average particle size D50v, the cumulative number average particle size D50p, and the particle size at 84% of the cumulative total as the volume particle size D84v and the number particle size D84p. Using these, the volume average particle size distribution index (GSDv) is (D84v / D16v) 1 / 2 The number average particle size distribution index (GSDp) is (D84p / D16p) 1 / 2 It is calculated as:

[0063] The shape factor SF1 of the glitter toner particles is preferably 110 or more and 150 or less, and more preferably 120 or more and 140 or less.

[0064] The shape factor SF1 is calculated by the following formula. Formula: SF1=(ML 2 / A)×(π / 4)×100 In the above formula, ML represents the absolute maximum length of the toner, and A represents the projected area of ​​the toner. Specifically, the shape factor SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows: That is, an optical microscope image of particles scattered on the surface of a glass slide is captured by a video camera into a Luzex image analyzer, the maximum length and projected area of ​​100 particles are determined, and the average value is calculated using the above formula.

[0065] The angle between the long axis direction of the cross section of the glitter toner particle and the long axis direction of the metal pigment As described in (2) above, when observing a cross section of a glitter toner particle in the thickness direction, the number of metallic pigment particles for which the angle between the long axis direction of the toner particle in the cross section and the long axis direction of the metallic pigment is in the range of -30° to +30° is preferably 60% or more of all the metallic pigment particles observed.Moreover, this number is more preferably 70% to 95%, and particularly preferably 80% to 90%. When the above number is 60% or more, excellent brilliance can be obtained.

[0066] Here, a method for observing the cross section of a toner particle will be described. After the toner particles are embedded using a bisphenol A liquid epoxy resin and a curing agent, a cutting sample is prepared. Next, the cutting sample is cut at -100°C using a cutting machine with a diamond knife (in this embodiment, a LEICA Ultramicrotome (manufactured by Hitachi Technologies) is used) to prepare an observation sample. The cross section of the toner particle of this observation sample is observed using a transmission electron microscope (TEM) at a magnification of approximately 5000x. For 1000 toner particles observed, the number of metal pigments where the angle between the long axis direction of the toner particle in the cross section and the long axis direction of the metal pigment is in the range of -30° to +30° is counted using image analysis software, and the percentage is calculated.

[0067] The "long axis direction in the cross section of the toner particle" refers to the direction perpendicular to the thickness direction of the toner particle whose average equivalent circle diameter D is longer than the aforementioned average maximum thickness C, and the "long axis direction of the metal pigment" refers to the length direction of the metal pigment.

[0068] (external additives) Examples of external additives include inorganic particles, such as SiO2, TiO2, Al2O3, SrTiO3, CaTiO3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO·SiO2, and K2O·(TiO2). n, Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, MgSO4, etc.

[0069] The surfaces of inorganic particles as external additives are preferably subjected to a hydrophobic treatment. The hydrophobic treatment is carried out, for example, by immersing the inorganic particles in a hydrophobic treatment agent. The hydrophobic treatment agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used alone or in combination of two or more. The amount of the hydrophobic treatment agent is usually, for example, 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic particles.

[0070] Examples of external additives include resin particles (resin particles such as polystyrene, polymethyl methacrylate (PMMA), and melamine resin), cleaning agents (for example, metal salts of higher fatty acids such as zinc stearate, and higher alcohols), and the like.

[0071] The amount of the external additive added is, for example, preferably 0.01% by mass or more and 10.0% by mass or less, and more preferably 0.01% by mass or more and 6.0% by mass or less, based on the toner particles.

[0072] The toner of the present embodiment may be produced by adding an external additive to toner particles after the toner particles are produced. The method for producing toner particles is not particularly limited, and they can be produced by known dry methods such as kneading and pulverization, or wet methods such as aggregation and coalescence, suspension polymerization, and dissolution and suspension. The kneading and grinding method involves mixing various materials, including a binder resin, and then melting and kneading the materials using a kneader, extruder, etc. The resulting molten and kneaded material is coarsely ground, then pulverized using a jet mill, etc., and passed through an air classifier to obtain toner particles of the desired particle size. Among these methods, the aggregation-coalescence method is preferred because it is easy to control the shape and particle size of toner particles and has a wide range of control over the toner particle structure, such as a core-shell structure.Furthermore, the aggregation-coalescence method is preferred from the viewpoints that it is easy to control the shape and particle size of toner particles and that the toner resin can be coated on the pigment in a state where unevenness is suppressed. The method for producing toner particles by the aggregation-coalescence method will be described in detail below.

[0073] The aggregation and coalescence method includes an emulsification step in which the raw materials constituting the toner particles are emulsified to form resin particles (emulsified particles), etc., an aggregation step in which aggregates of the resin particles are formed, and a fusion step in which the aggregates are fused.

[0074] (emulsification process) Resin particle dispersions can be prepared by a general polymerization method, such as emulsion polymerization, suspension polymerization, or dispersion polymerization. Alternatively, a solution of a water-based medium and a binder resin can be emulsified by applying shear force using a disperser. Heating can be used to reduce the viscosity of the resin component and form particles. A dispersant can also be used to stabilize the dispersed resin particles. Furthermore, if the resin is oil-based and dissolves in a solvent with relatively low solubility in water, the resin can be dissolved in the solvent and dispersed in water together with a dispersant and a polymer electrolyte. The solvent can then be evaporated by heating or reducing the pressure to prepare a resin particle dispersion.

[0075] Examples of aqueous media include water such as distilled water and ion-exchanged water; alcohols; and the like, with water being preferred. Examples of dispersants used in the emulsification step include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium polyacrylate, and sodium polymethacrylate; anionic surfactants such as sodium dodecylbenzenesulfonate, sodium octadecyl sulfate, sodium oleate, sodium laurate, and potassium stearate; cationic surfactants such as laurylamine acetate, stearylamine acetate, and lauryltrimethylammonium chloride; zwitterionic surfactants such as lauryldimethylamine oxide; and nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxyethylene alkylamines; and inorganic salts such as tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate, and barium carbonate.

[0076] Examples of dispersing machines used to prepare the emulsion include homogenizers, homomixers, pressure kneaders, extruders, and media dispersers. Regarding the size of the resin particles, the average particle diameter (volume average particle diameter) is preferably 1.0 μm or less, more preferably 60 nm or more and 300 nm or less, and even more preferably 150 nm or more and 250 nm or less. If the resin particles are 60 nm or more, they tend to become unstable in the dispersion, which may lead to aggregation of the resin particles. If the resin particles are 1.0 μm or less, the particle size distribution of the toner may become narrow.

[0077] To prepare the release agent dispersion, the release agent is dispersed in water together with an ionic surfactant and a polymer electrolyte such as a polymer acid or a polymer base, and then the dispersion is heated to a temperature above the melting temperature of the release agent and dispersed using a homogenizer or pressure-discharge disperser that applies strong shear force. This process yields the release agent dispersion. During the dispersion process, an inorganic compound such as polyaluminum chloride may be added to the dispersion. Examples of suitable inorganic compounds include polyaluminum chloride, aluminum sulfate, highly basic polyaluminum chloride (BAC), polyaluminum hydroxide, and aluminum chloride. Among these, polyaluminum chloride and aluminum sulfate are preferred. While the release agent dispersion is used in the aggregation-coalescence method, it may also be used when producing toner by suspension polymerization.

[0078] By the dispersion treatment, a release agent dispersion liquid containing release agent particles having a volume average particle diameter of 1 μm or less is obtained. The volume average particle diameter of the release agent particles is more preferably 100 nm or more and 500 nm or less. When the volume average particle size is 100 nm or more, the release agent component is generally more easily incorporated into the toner, although this is affected by the properties of the binder resin used. On the other hand, when the volume average particle size is 500 nm or less, the release agent is better dispersed in the toner.

[0079] The colorant (metal pigment) dispersion can be prepared using known dispersion methods, including, without limitation, common dispersion means such as a rotary shear homogenizer, a ball mill with media, a sand mill, a Dyno Mill, or an Ultimizer. The colorant is dispersed in water together with an ionic surfactant and a polymer electrolyte such as a polymer acid or a polymer base. The volume-average particle diameter of the dispersed colorant particles should be 20 μm or less, but a range of 3 μm to 16 μm is desirable because it does not impair cohesion and allows for good dispersion of the colorant in the toner. Alternatively, a dispersion of a bright metal pigment coated with a binder resin may be prepared by dispersing or dissolving the bright metal pigment and the binder resin in a solvent, mixing them, and dispersing them in water by phase inversion emulsification or shear emulsification.

[0080] (Agglutination process) In the aggregation process, a resin particle dispersion, a colorant dispersion, a release agent dispersion, etc. are mixed to form a mixture, which is then heated at a temperature below the glass transition temperature of the resin particles to aggregate them and form aggregated particles. The formation of aggregated particles is often achieved by adjusting the pH of the mixture to an acidic value while stirring. The pH is preferably in the range of 2 to 7, and the use of an aggregating agent is also effective in this case. In the aggregation step, the release agent dispersion may be added and mixed together with various dispersions such as the resin particle dispersion at once, or may be added in portions in several times.

[0081] In the aggregation process, for example, by using an agitator blade with two paddles that creates a laminar flow and agitating at a high agitation speed (for example, 500 rpm or more and 1500 rpm or less), the metal pigments align their major axes in the aggregated particles, and the aggregated particles also aggregate toward their major axes, resulting in a smaller toner thickness (i.e., satisfying the requirement (1) above).

[0082] Suitable flocculants include surfactants with polarity opposite to that of the surfactant used in the dispersant, inorganic metal salts, and divalent or higher metal complexes. In particular, metal complexes are particularly desirable because they can reduce the amount of surfactant used and improve charging properties.

[0083] As the inorganic metal salt, particularly, aluminum salts and polymers thereof are suitable. To obtain a narrower particle size distribution, inorganic metal salts with a valence of divalent rather than monovalent, trivalent rather than divalent, and tetravalent rather than trivalent are more suitable, and even if the valence is the same, polymers of inorganic metal salts are more suitable. In this embodiment, it is desirable to use a polymer of a tetravalent inorganic metal salt containing aluminum in order to obtain a narrow particle size distribution.

[0084] Alternatively, when the aggregated particles reach the desired particle size, a resin particle dispersion may be added (coating step) to produce a toner in which the surfaces of the core aggregated particles are coated with resin. In this case, the release agent and colorant are less likely to be exposed on the toner surface, which is desirable from the viewpoint of chargeability and developability. When adding the resin dispersion, an aggregating agent may be added or the pH may be adjusted before the addition.

[0085] (fusion process) In the fusion step, the aggregation is stopped by increasing the pH of the suspension of aggregated particles to a range of 3 to 9 under stirring conditions similar to those in the aggregation step, and the aggregated particles are fused by heating at a temperature equal to or higher than the glass transition temperature of the resin. If the core aggregated particles are coated with the resin, the resin also fuses and coats the core aggregated particles. The heating time is sufficient to achieve fusion, and may be from 0.5 to 10 hours. In the fusing step, by fusing the aggregated particles at a lower temperature (for example, 60°C or higher and 80°C or lower), the movement associated with the rearrangement of the material is reduced, the orientation of the pigment is maintained, and toner particles that satisfy the requirement (2) above are obtained.

[0086] After the fusion, the mixture is cooled to obtain fused particles. Crystallization may be promoted by slowing the cooling rate near the glass transition temperature of the resin (within a range of glass transition temperature ±10°C), i.e., by slow cooling. The fused particles obtained by the fusion are subjected to a solid-liquid separation step such as filtration, and if necessary, a washing step and a drying step to form toner particles.

[0087] To the obtained toner particles, inorganic oxides such as silica, titania, and aluminum oxide are added and attached as external additives for the purposes of charge adjustment, imparting fluidity, imparting charge exchange properties, etc. This can be done using, for example, a V-type blender, a Henschel mixer, or a Loedige mixer, and the addition may be carried out in stages. The amount of external additive added is preferably in the range of 0.1 to 5 parts, more preferably 0.3 to 2 parts, per 100 parts of toner particles. Furthermore, if necessary, coarse particles of the toner may be removed after external addition using an ultrasonic sieving machine, a vibration sieving machine, a wind sieving machine or the like.

[0088] In addition to the inorganic oxides and the like described above, other components (particles) such as a charge control agent, organic particles, lubricants, and abrasives may be added as external additives.

[0089] The charge control agent is not particularly limited, but a colorless or light-colored one is preferably used. Examples include quaternary ammonium salt compounds, nigrosine compounds, complexes of aluminum, iron, chromium, etc., and triphenylmethane pigments.

[0090] Examples of organic particles include particles that are usually used as external additives on the toner surface, such as vinyl resins, polyester resins, and silicone resins. These inorganic and organic particles are used as flow aids, cleaning aids, etc. Examples of the lubricant include fatty acid amides such as ethylene bisstearic acid amide and oleic acid amide, and fatty acid metal salts such as zinc stearate and calcium stearate. Examples of the abrasive include the above-mentioned silica, alumina, and cerium oxide.

[0091] Next, the method for producing toner particles by the solution suspension method will be described in detail. The solution suspension method is a method in which materials containing a binder resin, a colorant, and other components such as a release agent, which are used as needed, are dissolved or dispersed in a solvent capable of dissolving the binder resin, and the solution or dispersion is then granulated in an aqueous medium containing an inorganic dispersant, after which the solvent is removed to obtain toner particles. Other components used in the solution suspension method include various components such as internal additives, charge control agents, inorganic powders (inorganic particles), and organic particles, in addition to release agents.

[0092] In this embodiment, the binder resin, colorant, and other components used as needed are dissolved or dispersed in a solvent capable of dissolving the binder resin. Whether or not a solvent can dissolve the binder resin depends on the binder resin's constituent components, molecular chain length, degree of three-dimensionality, and so on, and therefore cannot be generally stated. However, generally, hydrocarbons such as toluene, xylene, and hexane; halogenated hydrocarbons such as methylene chloride, chloroform, dichloroethane, and dichloroethylene; alcohols or ethers such as ethanol, butanol, benzyl alcohol ethyl ether, benzyl alcohol isopropyl ether, tetrahydrofuran, and tetrahydropyran; esters such as methyl acetate, ethyl acetate, butyl acetate, and isopropyl acetate; and ketones or acetals such as acetone, methyl ethyl ketone, diisobutyl ketone, dimethyl oxide, diacetone alcohol, cyclohexanone, and methylcyclohexanone are used.

[0093] These solvents dissolve the binder resin, but do not necessarily dissolve the colorant and other components. The colorant and other components only need to be dispersible in the binder resin solution. There are no restrictions on the amount of solvent used, as long as the viscosity allows granulation in an aqueous medium. A ratio of the material containing the binder resin, colorant, and other components (the former) to the solvent (the latter) of 10 / 90 to 50 / 50 (mass ratio of the former / the latter) is preferred in terms of ease of granulation and the final yield of toner particles.

[0094] A liquid (toner mother liquor) containing a binder resin, colorant, and other components dissolved or dispersed in a solvent is granulated to a predetermined particle size in an aqueous medium containing an inorganic dispersant. Water is primarily used as the aqueous medium. The mixing ratio of the aqueous medium to the toner mother liquor is preferably 90 / 10 to 50 / 50 (by weight). The inorganic dispersant is preferably selected from tricalcium phosphate, hydroxyapatite, calcium carbonate, titanium oxide, and silica powder. The amount of inorganic dispersant used is determined depending on the particle size of the particles to be granulated, but is generally preferably used in the range of 0.1% to 15% by weight of the toner mother liquor. If the amount is less than 0.1% by weight, granulation may be difficult, while if the amount is more than 15% by weight, unnecessary fine particles may be generated, making it difficult to obtain the desired particles in high yield.

[0095] In order to granulate the toner mother liquid well in the aqueous medium containing the inorganic dispersant, an auxiliary agent may be added to the aqueous medium. Such auxiliary agents include known cationic, anionic, and nonionic surfactants, with anionic ones being particularly preferred. For example, sodium alkylbenzenesulfonate, sodium α-olefinsulfonate, sodium alkylsulfonate, etc. are used in an amount of 1×10 based on the toner mother liquid. -4 It is preferably used in the range of 0.1% by mass or more and 0.1% by mass or less.

[0096] Granulation of the toner mother liquid in an aqueous medium containing an inorganic dispersant is preferably carried out under shear. The toner mother liquid dispersed in the aqueous medium is desirably granulated to an average particle size of 20 μm or less, particularly preferably 3 μm or more and 15 μm or less. There are various types of dispersers equipped with a shearing mechanism, with homogenizers being preferred. By using a homogenizer, incompatible materials (in this embodiment, an aqueous medium containing an inorganic dispersant and a toner mother liquid) can be passed through the gap between a casing and a rotating rotor, dispersing the incompatible material into particles in a liquid. Examples of such homogenizers include the TK Homomixer, Line Flow Homomixer, and Auto Homomixer (all manufactured by Tokushu Kika Kogyo Co., Ltd.), Silverson Homogenizer (manufactured by Silverson), and Polytron Homogenizer (manufactured by Kinematica AG).

[0097] The stirring conditions using a homogenizer are preferably a rotor blade peripheral speed of 2 m / s or more. If it is less than this, the granulation tends to be insufficient. In this embodiment, the toner mother liquid is granulated in an aqueous medium containing an inorganic dispersant, and then the solvent is removed. The solvent removal may be carried out at room temperature (25°C) and atmospheric pressure, but since this takes a long time, it is preferable to carry out the removal at a temperature lower than the boiling point of the solvent and within a range of 80°C or less from the boiling point. The pressure may be atmospheric pressure or reduced pressure, but when reduced pressure is used, it is preferable to carry out the removal at a temperature of 20 mmHg or more and 150 mmHg or less.

[0098] In this embodiment, after removing the solvent, it is preferable to wash the toner particles with hydrochloric acid or the like. This removes the inorganic dispersant remaining on the surface of the toner particles, returning them to their original composition and improving their properties. Then, by dehydrating and drying, powder toner particles are obtained. As in the case of the aggregation-coalescence method, inorganic oxides such as silica, titania, and aluminum oxide are added and attached as external additives to the toner particles obtained by the solution-suspension method for the purpose of charge adjustment, imparting fluidity, imparting charge exchangeability, etc. In addition to the inorganic oxides described above, other components (particles) such as charge control agents, organic particles, lubricants, and abrasives may also be added as external additives.

[0099] In this embodiment, the average value of the ratio b / a of the glitter toner particles can be set to the range of 0.5 to 0.8 by adjusting the amount of binder resin used relative to the metallic pigment, the heating time during the fusion process in the case of the aggregation-coalescence method, etc. For example, increasing the amount of binder resin used relative to the metallic pigment makes it easier to increase the average value of the ratio b / a of the toner particles. Also, extending the heating time during the fusion process makes it easier to increase the average value of the ratio b / a of the toner particles. The ratio b / a can be adjusted to a preferred range by adjusting the stirring conditions in the aggregation step. More specifically, the ratio b / a can be reduced by stirring at high speed and heating at a constant temperature in the stage of forming aggregated particles, and the ratio b / a can be increased by stirring at a lower speed and heating more. Furthermore, to adjust the ratio b / a to a preferred range, the toner particles may be treated with a ball mill. In this embodiment, the pigment area ratio can be adjusted to a range of 0.5 to 0.7 by adjusting the average equivalent circle diameter of the metallic pigment, the amount of binder resin used relative to the metallic pigment, and the heating time during the fusion process in the case of the aggregation-coalescence method. For example, increasing the average equivalent circle diameter of the metallic pigment increases the pigment area ratio. Furthermore, increasing the amount of binder resin used relative to the metallic pigment makes it easier to reduce the pigment area ratio. Furthermore, extending the heating time during the fusion process makes it easier to increase the pigment area ratio.

[0100] <Electrostatic image developer> The electrostatic image developer used in this embodiment contains at least the toner of this embodiment. The electrostatic image developer used in this embodiment may be a one-component developer containing only the toner of this embodiment, or may be a two-component developer containing a mixture of the toner and a carrier.

[0101] The carrier is not particularly limited, and examples thereof include known carriers, such as coated carriers in which the surface of a core material made of magnetic powder is coated with a coating resin, magnetic powder dispersion carriers in which magnetic powder is dispersed and blended in a matrix resin, and resin-impregnated carriers in which porous magnetic powder is impregnated with a resin. The magnetic powder dispersion type carrier and the resin impregnated type carrier may be a carrier in which the constituent particles of the carrier are used as a core material and are coated with a coating resin.

[0102] Examples of magnetic powders include magnetic metals such as iron, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite. Magnetite and ferrite are particularly preferred. The magnetic powder can also be used as particles dispersed in a resin.

[0103] Examples of coating resins and matrix resins include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid ester copolymer, straight silicone resins containing organosiloxane bonds or modified products thereof, fluororesins, polyesters, polycarbonates, phenolic resins, and epoxy resins. The coating resin and the matrix resin may contain other additives such as conductive particles.

[0104] Examples of conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

[0105] Here, the method of coating the surface of the core material with a coating resin includes a method of coating with a solution for forming a coating layer, in which the coating resin and, if necessary, various additives are dissolved in an appropriate solvent. The solvent is not particularly limited and may be selected taking into consideration the coating resin to be used, its applicability, etc. Specific resin coating methods include an immersion method in which the core material is immersed in a solution for forming a coating layer, a spray method in which the solution for forming a coating layer is sprayed onto the surface of the core material, a fluidized bed method in which the solution for forming a coating layer is sprayed onto the core material while it is suspended in flowing air, and a kneader coater method in which the core material of the carrier and the solution for forming a coating layer are mixed in a kneader coater and the solvent is removed.

[0106] In the two-component developer, the mixing ratio (mass ratio) of toner to carrier is preferably toner:carrier=1:100 to 30:100, and more preferably 3:100 to 20:100.

[0107] [Cleaning blade] The cleaning blade used in the image forming apparatus according to this embodiment will be described. The cleaning blade is made of, for example, a resin (preferably a polyurethane resin). The breaking energy of the cleaning blade is 5000 MPa·% or more and 15000 MPa·% or less, and the 100% modulus at the contact portion with the image carrier is 10 MPa or more.

[0108] The cleaning blade may be a single-layer blade, a two-layer blade consisting of a surface layer (i.e., the layer that comes into contact with the image carrier) and a back layer, or a blade having a laminated structure of three or more layers.

[0109] 100% Modulus (M100) The 100% modulus of the cleaning blade at the surface (contact portion) that contacts the image carrier is 10 MPa or more, preferably 12 MPa or more, and more preferably 14 MPa or more. A 100% modulus of 10 MPa or more enhances the breakage resistance of the cleaning blade, suppressing breakage even when the pressing force against the image carrier is increased. This increases the pressing force against the surface of the image carrier while suppressing chipping of the cleaning blade in low-temperature, low-humidity environments. As a result, slippage of toner particles due to chipping of the cleaning blade is suppressed, and the cleaning performance of the cleaning blade for removing toner particles is improved. Furthermore, blade wear in high-temperature, high-humidity environments is easily suppressed, and the occurrence of toner filming due to wear is easily suppressed. Furthermore, suppressing toner filming suppresses the occurrence of image defects.

[0110] The 100% modulus of the cleaning blade at the contact portion is preferably 20 MPa or less, and more preferably 18 MPa or less. By having a 100% modulus of 20 MPa or less, the contact posture of the contact portion of the cleaning blade with the image carrier is maintained well, and the pressing force against the surface of the image carrier can be increased. As a result, the cleaning ability of the cleaning blade to remove toner particles can be improved.

[0111] The 100% modulus of the cleaning blade at the contact portion with the image carrier is 10 MPa or more, preferably 12 MPa or more and 20 MPa or less, and more preferably 14 MPa or more and 18 MPa or less.

[0112] The 100% modulus is measured at 23°C using a dumbbell-shaped No. 3 test piece at a tensile speed of 500 mm / min in accordance with JIS K6251 (2010), and is the value determined from the stress at 100% strain. The measurement device used is a Strograph AE Elastomer manufactured by Toyo Seiki Co., Ltd. The test piece is taken from the surface (contact portion) of the cleaning blade that comes into contact with the image carrier.

[0113] Methods for adjusting the 100% modulus within the above range include adjusting the composition of the member of the cleaning blade that comes into contact with the image carrier (hereinafter also referred to as the "contact member"). Specific examples include adjusting the content of the polyisocyanate component when the contact member contains a polyurethane resin, selecting at least one of the type and amount of crosslinking agent when a crosslinking agent is used in the production of the contact member, and combinations of these. The 100% modulus increases with increasing weight-average molecular weight of the polyester polyol used in synthesizing the polyurethane resin contained in the contact member, increasing the amount of the polyisocyanate component in the polyurethane resin, and increasing the crosslinking density.

[0114] Breaking energy The cleaning blade has a breaking energy of 5000 MPa·% or more and 15000 MPa·% or less. It is preferably 7000 MPa·% or more and 12000 MPa·% or less, and more preferably 8000 MPa·% or more and 10000 MPa·% or less. A breaking energy of 5000 MPa·% or more enhances the breaking resistance of the cleaning blade, suppressing breakage even when the pressing force against the image carrier is increased. This increases the pressing force against the surface of the image carrier while suppressing chipping of the cleaning blade in low-temperature, low-humidity environments. As a result, slippage of toner particles due to chipping of the cleaning blade is suppressed, and the cleaning blade's ability to remove toner particles is improved. A breaking energy of 15000 MPa·% or less ensures that the contact position of the contact portion of the cleaning blade with the image carrier is maintained properly, increasing the pressing force against the surface of the image carrier. As a result, the cleaning blade's ability to remove toner particles is improved.

[0115] The breaking energy is determined by the following measurement at 23°C. Using a tensile tester MODEL-1605N (manufactured by Aiko Engineering Co., Ltd.), a cleaning blade sample cut to a width of 5 mm and a length of 25 mm is measured at a pulling speed of 20 mm / min using a load cell with a rated load of 5 kgf. The test piece is taken from the surface (contact portion) of the cleaning blade that comes into contact with the image carrier.

[0116] The breaking energy can be adjusted to the above range by adjusting the composition of the cleaning blade contact member (i.e., contact member). Specifically, when the contact member contains a polyurethane resin, the breaking energy increases as the weight-average molecular weight of the polyester polyol used in synthesizing the polyurethane resin increases.

[0117] Dual-layer cleaning blade The cleaning blade may have a two-layer structure consisting of a surface layer and a back layer. A cleaning blade having a surface layer and a back layer (hereinafter also simply referred to as a "two-layer cleaning blade") is produced, for example, by producing the surface layer and the back layer by the polyurethane resin production method described below, and then laminating the obtained surface layer and back layer together. Alternatively, the two-layer cleaning blade can be produced by pouring a raw material composition for the back layer into a mold and curing it, and then pouring a raw material composition for the surface layer into the remaining area of ​​the mold and curing it.

[0118] In addition, when the physical properties of the surface layer and the back layer are to be made different, one method is to change the material of the polyurethane resin.

[0119] The surface layer of the two-layer cleaning blade has a 100% modulus and breaking energy in the contact area with the image carrier within the above-mentioned ranges.

[0120] Next, the back layer in the two-layer cleaning blade will be described.

[0121] (Back layer) 100% modulus (M100) The 100% modulus of the back layer is preferably 3 MPa or more and 7 MPa or less, and more preferably 4 MPa or more and 6 MPa or less. When the 100% modulus of the back layer is 3 MPa or more, the rigidity of the cleaning blade can be increased, and the pressing force against the image carrier can be increased. As a result, the cleaning ability of the cleaning blade to remove toner particles can be improved. When the 100% modulus of the back layer is 7 MPa or less, the cleaning ability of the cleaning blade to remove toner particles can be improved.

[0122] The 100% modulus of the back layer is measured in the same manner as in the above-mentioned method for measuring the 100% modulus. Note that the dumbbell-shaped No. 3 test piece is taken from the back layer of the cleaning blade.

[0123] Methods for adjusting the 100% modulus of the back layer within the above range include adjusting the composition of the back layer. Specifically, if the back layer contains a polyurethane resin, adjusting the content of the polyisocyanate component is one example. If a crosslinking agent is used in the production of the back layer, selecting at least one of the type and amount of the crosslinking agent, or a combination of these methods is one example. The 100% modulus increases with increasing weight-average molecular weight of the polyester polyol used in synthesizing the polyurethane resin contained in the back layer, increasing the amount of the polyisocyanate component in the polyurethane resin, and increasing the crosslinking density.

[0124] Permanent elongation The backing layer preferably has a permanent elongation of less than 2.0%, more preferably 1.0% or less, which improves the ability of the cleaning blade to block toner particles and the like, thereby improving the cleaning performance of the toner particles.

[0125] The permanent elongation of the backing layer is determined in accordance with JIS K6262 (1997) by applying 100% tensile strain to a rectangular test piece, leaving it for 24 hours, and calculating the distance between the gauge lines according to the following formula: The test piece is taken from the backing layer of the cleaning blade. Ts = (L2 - L0) / (L1 - L0) × 100 In the above formula, Ts represents permanent elongation, L0 represents the gauge length before tensioning, L1 represents the gauge length during tensioning, and L2 represents the gauge length after tensioning.

[0126] Examples of methods for adjusting the permanent elongation of the back layer within the above range include adjusting the composition of the back layer. Specifically, if the back layer contains a polyurethane resin, adjusting the content of the polyisocyanate component is one example. If a crosslinking agent is used in the production of the back layer, selecting at least one of the type and amount of the crosslinking agent, or a combination of these methods is one example. The higher the weight-average molecular weight of the polyester polyol used to synthesize the polyurethane resin contained in the back layer, the greater the amount of the polyisocyanate component in the polyurethane resin, and the higher the crosslinking density, the higher the 100% modulus.

[0127] The thickness of the cleaning blade is preferably 1.0 mm or more and 3.0 mm or less, and more preferably 1.5 mm or more and 2.5 mm or less. In a cleaning blade having a two-layer structure of a surface layer and a back layer, the thickness of the surface layer is preferably 0.2 mm to 1.0 mm, more preferably 0.4 mm to 0.8 mm, and the thickness of the back layer is preferably 0.6 mm to 2.6 mm, more preferably 0.8 mm to 1.8 mm.

[0128] -composition- The cleaning blade is made of, for example, a resin, and preferably a polyurethane resin. Here, a cleaning blade made of a polyurethane resin will be described. In a cleaning blade having a two-layer structure consisting of a surface layer and a back layer, it is preferable that both the surface layer and the back layer are made of a resin (preferably a polyurethane resin).

[0129] Polyurethane resin The polyurethane resin is a polyurethane resin obtained by polymerizing at least a polyol component and a polyisocyanate component. If necessary, the polyurethane resin may be a polyurethane resin obtained by polymerizing a resin having a functional group capable of reacting with an isocyanate group of the polyisocyanate in addition to the polyol component.

[0130] The polyurethane resin preferably has a hard segment and a soft segment. The terms "hard segment" and "soft segment" refer to segments in which the material constituting the former is relatively harder than the material constituting the latter, and the material constituting the latter is relatively softer than the material constituting the former, in a polyurethane resin material. Examples of materials constituting the hard segments (hard segment materials) include low-molecular-weight polyol components among polyol components, resins having functional groups capable of reacting with the isocyanate groups of polyisocyanates, etc. On the other hand, examples of materials constituting the soft segments (soft segment materials) include high-molecular-weight polyol components among polyol components.

[0131] Here, the average particle size of the hard segment aggregates is preferably 1 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less. By setting the average particle size of the hard segment aggregates to 1 μm or more, the friction resistance on the surface of the contacting member is likely to be reduced, which stabilizes blade behavior and makes it easier to suppress localized wear. On the other hand, by setting the average particle size of the hard segment aggregates to 10 μm or less, the occurrence of chipping is easily suppressed.

[0132] The average particle size of the hard segment aggregates is measured as follows: Using a polarizing microscope (Olympus BX51-P), images are taken at a magnification of ×20, and the images are binarized by image processing. The particle diameters (circle-equivalent diameters) of the aggregates are measured at five points per cleaning blade (the particle diameters of five aggregates per point are measured) for 20 cleaning blades, and the average particle diameter is calculated from a total of 500 particles. The images were binarized using the image processing software OLYMPUS Stream essentials (Olympus Corporation), and the hue / saturation / brightness thresholds were adjusted so that the crystalline portion and hard segment aggregates were black and the amorphous portion (corresponding to the soft segment) was white.

[0133] Polyol component The polyol component includes a high molecular weight polyol and a low molecular weight polyol.

[0134] The polymer polyol component is a polyol having a number average molecular weight of 500 or more (preferably 500 or more and 5000 or less). Examples of the polymer polyol component include well-known polyols such as polyester polyols obtained by dehydration condensation of low molecular weight polyols and dibasic acids, polycarbonate polyols obtained by reaction of low molecular weight polyols with alkyl carbonates, polycaprolactone polyols, and polyether polyols. Commercially available polymer polyols include PLACCEL 205 and PLACCEL 240 manufactured by Daicel Corporation.

[0135] Here, the number average molecular weight is a value measured by gel permeation chromatography (GPC). The same applies hereinafter.

[0136] These polymer polyols may be used alone or in combination of two or more.

[0137] The polymerization ratio of the high molecular weight polyol component is preferably 30 mol % or more and 50 mol % or less, and more preferably 40 mol % or more and 50 mol % or less, based on the total polymerization components of the polyurethane resin.

[0138] The low-molecular-weight polyol component is a polyol having a molecular weight (number average molecular weight) of less than 500. The low-molecular-weight polyol is a material that functions as a chain extender and a crosslinking agent.

[0139] Examples of low molecular weight polyol components include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,20-eicosanediol. Among these, 1,4-butanediol is preferably used as the low molecular weight polyol component.

[0140] Examples of the low molecular weight polyol component include diols (2 functional), triols (3 functional), and tetraols (4 functional), which are well known as chain extenders and crosslinking agents. These polyols may be used alone or in combination of two or more.

[0141] The polymerization ratio of the low molecular weight polyol component is preferably more than 50 mol% and 75 mol% or less, more preferably 52 mol% or more and 75 mol% or less, more preferably 55 mol% or more and 75 mol% or less, and even more preferably 55 mol% or more and 60 mol% or less, relative to the total polymerization components of the polyurethane resin.

[0142] The material constituting the contact portion of the cleaning blade with the image carrier is preferably polyurethane obtained by polymerizing a polyester polyol having a weight-average molecular weight of 1,000 to 10,000, an isocyanate compound (i.e., a polyisocyanate component), and a crosslinking agent. The weight-average molecular weight of the polyester polyol is more preferably 2,000 to 8,000. By using a polyester polyol having a weight-average molecular weight within the above range, it becomes easier to control the 100% modulus and breaking energy at the contact portion within the aforementioned ranges. Note that the material constituting the contact portion of the cleaning blade with the image carrier refers to the cleaning blade itself when the cleaning blade is composed of only one layer, or to the surface layer in contact with the image carrier when the cleaning blade is a two-layer cleaning blade having a surface layer and a back layer.

[0143] When the cleaning blade has a two-layer structure, the back layer is preferably polyurethane obtained by polymerizing a polyester polyol having a weight-average molecular weight of 100 to 2000, an isocyanate compound, and a crosslinking agent. The weight-average molecular weight of the polyester polyol is more preferably 500 to 1000. By using a polyester polyol having a weight-average molecular weight within the above range, it becomes easier to control the 100% modulus and permanent set elongation of the back layer within the above ranges.

[0144] Polyisocyanate component Examples of the polyisocyanate component include 4,4'-diphenylmethane diisocyanate (MDI), 2,6-toluene diisocyanate (TDI), 1,6-hexane diisocyanate (HDI), 1,5-naphthalene diisocyanate (NDI), and 3,3-dimethylbiphenyl-4,4'-diisocyanate (TODI).

[0145] As the polyisocyanate component, 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), and hexamethylene diisocyanate (HDI) are more preferable.

[0146] These polyisocyanate components may be used alone or in combination of two or more.

[0147] The polymerization ratio of the polyisocyanate component is preferably 5 mol % or more and 25 mol % or less, and more preferably 10 mol % or more and 20 mol % or less, based on the total polymerization components of the polyurethane resin.

[0148] The cleaning blade is preferably made of a polyurethane material constituting the contact portion with the image carrier, which is a polymer of a polyol, an isocyanate compound (i.e., a polyisocyanate component), and a crosslinking agent, and the proportion of the isocyanate compound in the material constituting the contact portion is 10 mol % to 40 mol %. The proportion of the isocyanate compound in the material constituting the contact portion is more preferably 15 mol % to 30 mol %. By having the proportion of the isocyanate compound in the material constituting the contact portion within the above range, it becomes easier to control the 100% modulus and breaking energy at the contact portion within the above range.

[0149] When the cleaning blade has a two-layer structure, the material constituting the back layer is preferably polyurethane obtained by polymerizing a polyol, an isocyanate compound (i.e., a polyisocyanate component), and a crosslinking agent, and the proportion of the isocyanate compound in the material constituting the back layer is preferably 5 mol % or more and 20 mol % or less. Furthermore, the proportion of the isocyanate compound in the material constituting the back layer is more preferably 5 mol % or more and 15 mol % or less. By having the proportion of the isocyanate compound in the material constituting the back layer within the above range, it becomes easier to control the 100% modulus and permanent elongation of the back layer within the above range.

[0150] Resins with functional groups that can react with isocyanate groups A resin having a functional group capable of reacting with an isocyanate group (hereinafter referred to as a "functional group-containing resin") is preferably a flexible resin. From the viewpoint of flexibility, an aliphatic resin having a linear structure is more preferable. Specific examples of functional group-containing resins include acrylic resins containing two or more hydroxyl groups, polybutadiene resins containing two or more hydroxyl groups, and epoxy resins containing two or more epoxy groups.

[0151] Commercially available acrylic resins containing two or more hydroxyl groups include, for example, Actflow (grades: UMB-2005B, UMB-2005P, UMB-2005, UME-2005, etc.) manufactured by Soken Chemical & Engineering Co., Ltd.

[0152] Commercially available polybutadiene resins containing two or more hydroxyl groups include, for example, R-45HT manufactured by Idemitsu Kosan Co., Ltd.

[0153] The epoxy resin having two or more epoxy groups is preferably one that is not hard and brittle like conventional general epoxy resins, but is more flexible and tougher than conventional epoxy resins. For example, in terms of molecular structure, the epoxy resin preferably has a structure (flexible skeleton) in its main chain structure that can increase the mobility of the main chain. Examples of flexible skeletons include alkylene skeletons, cycloalkane skeletons, and polyoxyalkylene skeletons, and polyoxyalkylene skeletons are particularly preferred. In terms of physical properties, epoxy resins with a lower viscosity relative to their molecular weight than conventional epoxy resins are preferred. Specifically, the weight-average molecular weight is preferably within the range of 900±100, and the viscosity at 25°C is preferably within the range of 15,000±5,000 mPa·s, and more preferably within the range of 15,000±3,000 mPa·s. Commercially available epoxy resins with these properties include, for example, EPICLON EXA-4850-150 manufactured by DIC.

[0154] The polymerization ratio of the functional group-containing resin is preferably set within a range that does not impair the properties of the cleaning blade.

[0155] -Method of manufacturing polyurethane resin The polyurethane resin can be produced by a general polyurethane production method such as a prepolymer method or a one-shot method. The prepolymer method is suitable for this embodiment because it can produce polyurethane with excellent abrasion resistance and chipping resistance, but the production method is not limited thereto. The cleaning blade is produced by forming the cleaning blade composition prepared by the above method into a sheet using, for example, centrifugal molding or extrusion molding, and then cutting the sheet.

[0156] Examples of catalysts used in the production of polyurethane resins include amine compounds such as tertiary amines, quaternary ammonium salts, and organometallic compounds such as organotin compounds. Examples of the tertiary amine include trialkylamines such as triethylamine, tetraalkyldiamines such as N,N,N',N'-tetramethyl-1,3-butanediamine, aminoalcohols such as dimethylethanolamine, ethoxylated amines, ethoxylated diamines, ester amines such as bis(diethylethanolamine) adipate, triethylenediamine (TEDA), cyclohexylamine derivatives such as N,N-dimethylcyclohexylamine, morpholine derivatives such as N-methylmorpholine and N-(2-hydroxypropyl)-dimethylmorpholine, and piperazine derivatives such as N,N'-diethyl-2-methylpiperazine and N,N'-bis-(2-hydroxypropyl)-2-methylpiperazine.

[0157] Examples of quaternary ammonium salts include 2-hydroxypropyltrimethylammonium octylate, 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) octylate, 1,8-diazabicyclo[5.4.0]undecene-7 (DBU) octylate, DBU-oleate, DBU-p-toluenesulfonate, DBU-formate, and 2-hydroxypropyltrimethylammonium formate.

[0158] Examples of organotin compounds include dialkyltin compounds such as dibutyltin dilaurate and dibutyltin di(2-ethylhexoate), stannous 2-ethylcaproate, and stannous oleate.

[0159] Among these catalysts, the tertiary ammonium salt triethylenediamine (TEDA) is used due to its hydrolysis resistance, while quaternary ammonium salts are preferred due to their processability. Among quaternary ammonium salts, 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) octylate, 1,8-diazabicyclo[5.4.0]undecene-7 (DBU) octylate, and DBU formate are preferred due to their high reactivity.

[0160] The content of the catalyst is preferably in the range of 0.0005% by mass to 0.03% by mass, and particularly preferably 0.001% by mass to 0.01% by mass, of the total polyurethane resin constituting the contact member. These may be used alone or in combination of two or more.

[0161] The cleaning blade is made of a material constituting the contact portion with the image carrier, which is a polymer of polyol, an isocyanate compound (i.e., a polyisocyanate component), and a crosslinking agent, and has a crosslinking density of 0.90×10 -3 mol / m 3 Over 1.50 x 10 -3 mol / m 3 Preferably, the crosslink density is 1.00×10 or less. -3 mol / m 3 Over 1.30 x 10 -3 mol / m 3 It is more preferable that the crosslink density is not more than 100%. When the crosslink density is in the above range, it becomes easier to control the 100% modulus and breaking energy at the contact portion to fall within the above ranges.

[0162] When the cleaning blade has a two-layer structure, the material constituting the back layer is a polymer of a polyol, an isocyanate compound (i.e., a polyisocyanate component), and a crosslinking agent, and the crosslinking density is 1.5×10 -3 mol / m 3 Over 2.5 x 10 -3 mol / m 3 Preferably, the crosslink density is 1.8×10 or less. -3 mol / m 3 Over 2.2 x 10 -3 mol / m 3 When the crosslink density is within the above range, it becomes easier to control the 100% modulus and permanent set elongation of the back layer within the above ranges.

[0163] [Image holder] An image carrier used in the image forming apparatus according to this embodiment will now be described. In this embodiment, an electrophotographic photoreceptor (hereinafter also referred to as "photoreceptor") is preferably used as the image carrier on whose surface a toner image is formed. The photoreceptor may have, for example, a configuration including a conductive substrate and a photosensitive layer provided on the conductive substrate.

[0164] The electrophotographic photosensitive member will be described below with reference to the drawings. 2 may be, for example, a photoreceptor 7 having a structure in which an undercoat layer 1, a charge generation layer 2, and a charge transport layer 3 are laminated in this order on a conductive support 4. The charge generation layer 2 and the charge transport layer 3 constitute a photosensitive layer 5.

[0165] The electrophotographic photoreceptor 7 may have a layer structure in which the undercoat layer 1 is not provided. The electrophotographic photoreceptor 7 may also be a photoreceptor having a single-layer photosensitive layer in which the functions of the charge generating layer 2 and the charge transport layer 3 are integrated. In the case of a photoreceptor having a single-layer photosensitive layer, the single-layer photosensitive layer constitutes the outermost surface layer. The electrophotographic photoreceptor 7 may also be a photoreceptor having a surface protective layer on the charge transport layer 3 or on the single-layer photoreceptor layer. In the case of a photoreceptor having a surface protective layer, the surface protective layer constitutes the outermost surface layer.

[0166] Each layer of the electrophotographic photoreceptor will be described in detail below, with the reference numerals omitted.

[0167] (Conductive substrate) Examples of conductive substrates include metal plates, metal drums, and metal belts containing metals (aluminum, copper, zinc, chromium, nickel, molybdenum, vanadium, indium, gold, platinum, etc.) or alloys (stainless steel, etc.). Other examples of conductive substrates include paper, resin films, belts, etc. coated, vapor-deposited, or laminated with conductive compounds (e.g., conductive polymers, indium oxide, etc.), metals (e.g., aluminum, palladium, gold, etc.), or alloys. Here, "conductive" refers to a material having a volume resistivity of 10 13 This means that the resistance is less than Ωcm.

[0168] When the electrophotographic photoreceptor is used in a laser printer, the surface of the conductive substrate is preferably roughened to a center line average roughness Ra of 0.04 μm to 0.5 μm inclusive in order to suppress interference fringes that occur when irradiated with laser light. When incoherent light is used as the light source, roughening to prevent interference fringes is not particularly necessary, but it is suitable for extending the life of the conductive substrate by suppressing defects caused by surface irregularities.

[0169] Examples of methods for roughening the surface include wet honing, which involves spraying an abrasive suspended in water onto the conductive substrate; centerless grinding, which involves pressing the conductive substrate against a rotating grinding wheel and continuously grinding the substrate; and anodizing.

[0170] As a method for roughening the surface, there may be mentioned a method in which, without roughening the surface of the conductive substrate, conductive or semiconductive powder is dispersed in a resin to form a layer on the surface of the conductive substrate, and the surface is roughened by the particles dispersed in the layer.

[0171] Anodizing is a surface roughening treatment that uses a metallic (e.g., aluminum) conductive substrate as the anode and anodizes it in an electrolyte solution to form an oxide film on the surface of the conductive substrate. Examples of electrolyte solutions include sulfuric acid solution and oxalic acid solution. However, the porous anodic oxide film formed by anodizing is chemically active in its original state, easily contaminated, and exhibits large resistance fluctuations depending on the environment. Therefore, it is preferable to perform a sealing treatment on the porous anodic oxide film, in which the micropores of the oxide film are sealed by volume expansion caused by hydration in pressurized steam or boiling water (with the addition of a metal salt such as nickel), converting the film into a more stable hydrated oxide.

[0172] The thickness of the anodic oxide film is preferably, for example, from 0.3 μm to 15 μm, inclusive, and within this range, the film tends to exhibit barrier properties against injection and also tends to suppress an increase in residual potential due to repeated use.

[0173] The conductive substrate may be subjected to a treatment with an acidic treatment solution or a boehmite treatment. Treatment with an acidic treatment solution is carried out, for example, as follows. First, an acidic treatment solution containing phosphoric acid, chromic acid, and hydrofluoric acid is prepared. The compounding ratios of phosphoric acid, chromic acid, and hydrofluoric acid in the acidic treatment solution are, for example, in the range of 10% by mass to 11% by mass for phosphoric acid, 3% by mass to 5% by mass for chromic acid, and 0.5% by mass to 2% by mass for hydrofluoric acid, with the total concentration of these acids preferably in the range of 13.5% by mass to 18% by mass. The treatment temperature is preferably, for example, 42°C to 48°C. The film thickness of the coating is preferably 0.3 μm to 15 μm.

[0174] The boehmite treatment is carried out, for example, by immersing the steel sheet in pure water at 90°C to 100°C for 5 to 60 minutes, or by contacting the steel sheet with heated steam at 90°C to 120°C for 5 to 60 minutes. The coating film preferably has a thickness of 0.1 μm to 5 μm. This may be further anodized using an electrolyte solution with low coating solubility, such as adipic acid, boric acid, borate, phosphate, phthalate, maleate, benzoate, tartrate, or citrate.

[0175] (subbing layer) The undercoat layer is, for example, a layer containing inorganic particles and a binder resin.

[0176] As inorganic particles, for example, powder resistance (volume resistivity) 10 2 Ωcm or more 10 11 Examples include inorganic particles with a particle size of Ωcm or less. Among these, inorganic particles having the above resistance value are preferably metal oxide particles such as tin oxide particles, titanium oxide particles, zinc oxide particles, and zirconium oxide particles, with zinc oxide particles being particularly preferred.

[0177] The specific surface area of ​​inorganic particles measured by the BET method is, for example, 10 m 2 / g or more is preferable. The volume average particle size of the inorganic particles is, for example, 50 nm or more and 2000 nm or less (preferably 60 nm or more and 1000 nm or less).

[0178] The content of the inorganic particles is, for example, preferably 10% by mass or more and 80% by mass or less, more preferably 40% by mass or more and 80% by mass or less, relative to the binder resin.

[0179] The inorganic particles may be surface-treated, and two or more types of inorganic particles having different surface treatments or different particle sizes may be used in combination.

[0180] Examples of the surface treatment agent include a silane coupling agent, a titanate-based coupling agent, an aluminum-based coupling agent, a surfactant, etc. In particular, a silane coupling agent is preferred, and a silane coupling agent having an amino group is more preferred.

[0181] Examples of silane coupling agents having an amino group include, but are not limited to, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, and N,N-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane.

[0182] Two or more silane coupling agents may be used in combination. For example, a silane coupling agent having an amino group may be used in combination with another silane coupling agent. Examples of other silane coupling agents include, but are not limited to, vinyltrimethoxysilane, 3-methacryloxypropyl-tris(2-methoxyethoxy)silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N,N-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, and 3-chloropropyltrimethoxysilane.

[0183] The surface treatment method using the surface treatment agent may be any known method, and may be either a dry method or a wet method.

[0184] The amount of the surface treatment agent to be used is preferably, for example, 0.5% by mass or more and 10% by mass or less relative to the inorganic particles.

[0185] Here, it is preferable that the undercoat layer contains an electron-accepting compound (acceptor compound) together with the inorganic particles, from the viewpoint of improving the long-term stability of the electrical properties and the carrier blocking property.

[0186] Examples of electron-accepting compounds include electron-transporting substances such as compounds having an anthraquinone structure; quinone compounds such as chloranil and bromoanil; tetracyanoquinodimethane compounds; fluorenone compounds such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitro-9-fluorenone; oxadiazole compounds such as 2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole, 2,5-bis(4-naphthyl)-1,3,4-oxadiazole, and 2,5-bis(4-diethylaminophenyl)-1,3,4-oxadiazole; xanthone compounds; thiophene compounds; diphenoquinone compounds such as 3,3',5,5'-tetra-t-butyldiphenoquinone; and benzophenone compounds. In particular, the electron-accepting compound is preferably a compound having an anthraquinone structure, such as a hydroxyanthraquinone compound, an aminoanthraquinone compound, or an aminohydroxyanthraquinone compound, and specifically, for example, anthraquinone, alizarin, quinizarin, anthrarphine, purpurin, or a derivative thereof.

[0187] The electron-accepting compound may be contained in the undercoat layer in a dispersed state together with the inorganic particles, or may be contained in a state of being attached to the surfaces of the inorganic particles.

[0188] The electron-accepting compound can be attached to the surface of the inorganic particles by, for example, a dry method or a wet method.

[0189] The dry method is a method in which, while stirring inorganic particles using a mixer or the like with high shear force, an electron-accepting compound is added dropwise, either directly or dissolved in an organic solvent, or sprayed together with dry air or nitrogen gas to adhere the electron-accepting compound to the surface of the inorganic particles. The electron-accepting compound is preferably added dropwise or sprayed at a temperature below the boiling point of the solvent. After the electron-accepting compound has been added dropwise or sprayed, baking may be performed at 100°C or higher. The baking temperature and time are not particularly limited as long as they achieve electrophotographic properties.

[0190] The wet method involves dispersing inorganic particles in a solvent using, for example, stirring, ultrasonic waves, a sand mill, an attritor, or a ball mill, while adding an electron-accepting compound. The mixture is stirred or dispersed, and then the solvent is removed to adhere the electron-accepting compound to the surfaces of the inorganic particles. The solvent can be removed, for example, by filtration or distillation. After solvent removal, baking may be performed at 100°C or higher. The baking temperature and time are not particularly limited as long as electrophotographic properties are obtained. In the wet method, moisture contained in the inorganic particles may be removed before adding the electron-accepting compound. Examples of such methods include a method of removing the moisture by stirring and heating in a solvent, and a method of removing the moisture by azeotropy with the solvent.

[0191] The attachment of the electron-accepting compound may be carried out before or after the inorganic particles are surface-treated with a surface-treating agent, or the attachment of the electron-accepting compound and the surface treatment with a surface-treating agent may be carried out simultaneously.

[0192] The content of the electron-accepting compound is, for example, 0.01% by mass or more and 20% by mass or less, and preferably 0.01% by mass or more and 10% by mass or less, based on the inorganic particles.

[0193] Examples of binder resins used in the undercoat layer include known polymer compounds such as acetal resins (e.g., polyvinyl butyral, etc.), polyvinyl alcohol resins, polyvinyl acetal resins, casein resins, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, unsaturated polyester resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate-maleic anhydride resins, silicone resins, silicone-alkyd resins, urea resins, phenolic resins, phenol-formaldehyde resins, melamine resins, urethane resins, alkyd resins, and epoxy resins; zirconium chelate compounds; titanium chelate compounds; aluminum chelate compounds; titanium alkoxide compounds; organic titanium compounds; and silane coupling agents. Examples of binder resins used in the undercoat layer include charge transporting resins having charge transporting groups, conductive resins (such as polyaniline), and the like.

[0194] Among these, the binder resin used in the undercoat layer is preferably a resin that is insoluble in the coating solvent of the upper layer, and in particular, a resin obtained by reacting at least one resin selected from the group consisting of thermosetting resins such as urea resins, phenolic resins, phenol-formaldehyde resins, melamine resins, urethane resins, unsaturated polyester resins, alkyd resins, and epoxy resins, and polyamide resins, polyester resins, polyether resins, methacrylic resins, acrylic resins, polyvinyl alcohol resins, and polyvinyl acetal resins with a curing agent is preferred. When two or more of these binder resins are used in combination, the mixing ratio is set as necessary.

[0195] The undercoat layer may contain various additives to improve electrical properties, environmental stability, and image quality. Examples of additives include known materials such as polycyclic condensation and azo electron transport pigments, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, and silane coupling agents. Silane coupling agents are used for the surface treatment of inorganic particles as described above, and may also be added to the undercoat layer as an additive.

[0196] Examples of silane coupling agents as additives include vinyltrimethoxysilane, 3-methacryloxypropyl-tris(2-methoxyethoxy)silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N,N-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, and 3-chloropropyltrimethoxysilane.

[0197] Examples of zirconium chelate compounds include zirconium butoxide, zirconium ethyl acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate zirconium butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octanoate, zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, and isostearate zirconium butoxide.

[0198] Examples of titanium chelate compounds include tetraisopropyl titanate, tetra-normal-butyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate ethyl ester, titanium triethanolamine, and polyhydroxytitanium stearate.

[0199] Examples of aluminum chelate compounds include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethylacetoacetate aluminum diisopropylate, and aluminum tris(ethylacetoacetate).

[0200] These additives may be used alone or as a mixture or polycondensate of a plurality of compounds.

[0201] The undercoat layer preferably has a Vickers hardness of 35 or more. The surface roughness (ten-point average roughness) of the undercoat layer is preferably adjusted to between 1 / (4n) (n is the refractive index of the upper layer) and 1 / 2 of the wavelength λ of the exposure laser used to suppress moiré images. Resin particles or the like may be added to the undercoat layer to adjust the surface roughness. Examples of resin particles include silicone resin particles and crosslinked polymethyl methacrylate resin particles. The surface of the undercoat layer may be polished to adjust the surface roughness. Examples of polishing methods include buffing, sandblasting, wet honing, and grinding.

[0202] The formation of the undercoat layer is not particularly limited, and a well-known formation method can be used. For example, the undercoat layer can be formed by forming a coating film of a coating liquid for forming the undercoat layer in which the above components are added to a solvent, drying the coating film, and heating it as necessary.

[0203] Examples of solvents for preparing the coating liquid for forming the undercoat layer include known organic solvents, such as alcohol-based solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, ketone-based solvents, ketone alcohol-based solvents, ether-based solvents, and ester-based solvents. Specific examples of these solvents include ordinary organic solvents such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene.

[0204] Examples of a method for dispersing inorganic particles when preparing a coating liquid for forming an undercoat layer include known methods such as using a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker.

[0205] Examples of methods for applying the coating liquid for forming the undercoat layer onto the conductive substrate include conventional methods such as blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, and curtain coating.

[0206] The thickness of the undercoat layer is set, for example, preferably at least 15 μm, more preferably in the range of 20 μm to 50 μm.

[0207] (middle class) Although not shown, an intermediate layer may be further provided between the undercoat layer and the photosensitive layer. The intermediate layer is, for example, a layer containing a resin. Examples of the resin used in the intermediate layer include polymer compounds such as acetal resins (such as polyvinyl butyral), polyvinyl alcohol resins, polyvinyl acetal resins, casein resins, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate-maleic anhydride resins, silicone resins, silicone-alkyd resins, phenol-formaldehyde resins, and melamine resins. The intermediate layer may be a layer containing an organometallic compound. Examples of the organometallic compound used in the intermediate layer include organometallic compounds containing metal atoms such as zirconium, titanium, aluminum, manganese, and silicon. The compounds used in the intermediate layer may be used alone or as a mixture or polycondensation product of a plurality of compounds.

[0208] Among these, the intermediate layer is preferably a layer containing an organometallic compound containing zirconium atoms or silicon atoms.

[0209] The formation of the intermediate layer is not particularly limited, and a well-known formation method can be used. For example, the intermediate layer can be formed by forming a coating film of a coating liquid for forming an intermediate layer in which the above components are added to a solvent, drying the coating film, and heating it if necessary. The intermediate layer can be formed by any of the usual coating methods, such as dip coating, push-up coating, wire bar coating, spray coating, blade coating, air knife coating, and curtain coating.

[0210] The thickness of the intermediate layer is preferably set in the range of, for example, 0.1 μm to 3 μm. The intermediate layer may also be used as an undercoat layer.

[0211] (charge generation layer) The charge generation layer is, for example, a layer containing a charge generation material and a binder resin. Alternatively, the charge generation layer may be a vapor-deposited layer of the charge generation material. A vapor-deposited layer of the charge generation material is suitable for use with an incoherent light source such as an LED (Light Emitting Diode) or an organic EL (Electro-Luminescence) image array.

[0212] Examples of the charge generating material include azo pigments such as bisazo and trisazo; fused-ring aromatic pigments such as dibromoanthanthrone; perylene pigments; pyrrolopyrrole pigments; phthalocyanine pigments; zinc oxide; and trigonal selenium.

[0213] Among these, in order to be compatible with laser exposure in the near-infrared region, it is preferable to use a metal phthalocyanine pigment or a metal-free phthalocyanine pigment as the charge generating material, specifically, for example, hydroxygallium phthalocyanine, chlorogallium phthalocyanine, dichlorotin phthalocyanine, or titanyl phthalocyanine.

[0214] On the other hand, in order to accommodate laser exposure in the near ultraviolet region, preferred charge generating materials include fused ring aromatic pigments such as dibromoanthanthrone; thioindigo pigments; porphyrazine compounds; zinc oxide; trigonal selenium; and bisazo pigments.

[0215] The above charge generating material may also be used when an incoherent light source such as an LED or organic EL image array having a central emission wavelength of 450 nm or more and 780 nm or less is used.

[0216] In contrast, when an n-type semiconductor such as a fused ring aromatic pigment, perylene pigment, or azo pigment is used as the charge generating material, dark current is less likely to occur, and image defects known as black spots can be suppressed even when the material is made into a thin film. The n-type is determined by the polarity of the photocurrent that flows using the commonly used time-of-flight method, and those that flow more easily as electrons than holes as carriers are considered to be n-type.

[0217] The binder resin used in the charge generating layer may be selected from a wide range of insulating resins, and may also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane. Examples of binder resins include polyvinyl butyral resin, polyarylate resin (polycondensation product of bisphenols and aromatic dicarboxylic acids, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin, polyacrylamide resin, polyvinylpyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinylpyrrolidone resin, etc. Here, "insulating" means a resin having a volume resistivity of 10 13 This means that the resistance is Ωcm or more. These binder resins may be used alone or in combination of two or more.

[0218] The compounding ratio of the charge generating material to the binder resin is preferably within the range of 10:1 to 1:10 by mass.

[0219] The charge generating layer may contain other well-known additives.

[0220] The formation of the charge generation layer is not particularly limited, and a well-known formation method can be used. For example, the charge generation layer can be formed by forming a coating film of a coating liquid for forming the charge generation layer by adding the above components to a solvent, drying the coating film, and heating it as necessary. The charge generation layer can also be formed by vapor deposition of the charge generation material. Formation of the charge generation layer by vapor deposition is particularly suitable when a fused ring aromatic pigment or a perylene pigment is used as the charge generation material.

[0221] Examples of solvents for preparing the coating liquid for forming the charge generating layer include methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene, etc. These solvents may be used alone or in combination of two or more.

[0222] Methods for dispersing particles (e.g., charge generating material) in the coating liquid for forming the charge generating layer include, for example, media dispersers such as ball mills, vibration ball mills, attritors, sand mills, and horizontal sand mills, and medialess dispersers such as stirrers, ultrasonic dispersers, roll mills, and high-pressure homogenizers. Examples of high-pressure homogenizers include a collision method in which the dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision under high pressure, and a penetration method in which the dispersion liquid is dispersed by passing through a fine flow path under high pressure. During this dispersion, it is effective to adjust the average particle size of the charge generating material in the coating liquid for forming the charge generating layer to 0.5 μm or less, preferably 0.3 μm or less, and more preferably 0.15 μm or less.

[0223] Examples of methods for applying the coating liquid for forming the charge generating layer onto the undercoat layer (or onto the intermediate layer) include conventional methods such as blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, and curtain coating.

[0224] The thickness of the charge generating layer is set, for example, preferably in the range of 0.1 μm to 5.0 μm, more preferably 0.2 μm to 2.0 μm.

[0225] (charge transport layer) The charge transport layer is, for example, a layer containing a charge transport material and a binder resin, or may be a layer containing a polymer charge transport material.

[0226] Examples of charge transport materials include electron transport compounds such as quinone compounds such as p-benzoquinone, chloranil, bromanil, and anthraquinone; tetracyanoquinodimethane compounds; fluorenone compounds such as 2,4,7-trinitrofluorenone; xanthone compounds; benzophenone compounds; cyanovinyl compounds; and ethylene compounds. Examples of charge transport materials also include hole transport compounds such as triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, and hydrazone compounds. These charge transport materials may be used alone or in combination, but are not limited to these.

[0227] As the charge transport material, triarylamine derivatives represented by the following structural formula (a-1) and benzidine derivatives represented by the following structural formula (a-2) are preferred from the viewpoint of charge mobility.

[0228] [ka]

[0229] In structural formula (a-1), Ar T1 , Ar T2 , and Ar T3 each independently represents a substituted or unsubstituted aryl group, -C6H4-C(R T4 )=C(R T5 )(R T6 ), or -C6H4-CH=CH-CH=C(R T7 )(R T8 ) indicates R T4 , R T5 , R T6 , R T7 , and R T8 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Examples of the substituents on the above groups include halogen atoms, alkyl groups having from 1 to 5 carbon atoms, and alkoxy groups having from 1 to 5 carbon atoms. Examples of the substituents on the above groups also include substituted amino groups substituted with alkyl groups having from 1 to 3 carbon atoms.

[0230] [ka]

[0231] In structural formula (a-2), R T91 and R T92 R each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. T101 , R T102 , R T111 and R T112 each independently represents a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, a substituted or unsubstituted aryl group, -C(R T12 )=C(R T13 )(R T14 ), or -CH=CH-CH=C(R T15 )(R T16 ) and R T12 , R T13 , R T14 , R T15 and R T16 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Tm1, Tm2, ​​Tn1, and Tn2 each independently represent an integer of 0 or more and 2 or less. Examples of the substituents on the above groups include halogen atoms, alkyl groups having from 1 to 5 carbon atoms, and alkoxy groups having from 1 to 5 carbon atoms. Examples of the substituents on the above groups also include substituted amino groups substituted with alkyl groups having from 1 to 3 carbon atoms.

[0232] Among the triarylamine derivatives represented by the structural formula (a-1) and the benzidine derivatives represented by the structural formula (a-2), in particular, "-C6H4-CH=CH-CH=C(R T7)(R T8 )" and triarylamine derivatives having "-CH=CH-CH=C(R T15 )(R T16 ) is preferred from the viewpoint of charge mobility.

[0233] As the polymer charge transport material, known materials having charge transport properties such as poly-N-vinylcarbazole and polysilane are used. In particular, polyester polymer charge transport materials are particularly preferred. The polymer charge transport material may be used alone or in combination with a binder resin.

[0234] Examples of binder resins used in the charge transport layer include polycarbonate resins, polyester resins, polyarylate resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl acetate resins, styrene-butadiene copolymers, vinylidene chloride-acrylonitrile copolymers, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, silicone resins, silicone alkyd resins, phenol-formaldehyde resins, styrene-alkyd resins, poly-N-vinylcarbazole, and polysilanes. Among these, polycarbonate resins or polyarylate resins are preferred as binder resins. These binder resins may be used alone or in combination of two or more. The compounding ratio of the charge transport material to the binder resin is preferably from 10:1 to 1:5 by mass.

[0235] The charge transport layer may contain other well-known additives.

[0236] The formation of the charge transport layer is not particularly limited, and a well-known formation method can be used. For example, the charge transport layer can be formed by forming a coating film of a coating liquid for forming the charge transport layer in which the above components are added to a solvent, drying the coating film, and heating it if necessary.

[0237] Examples of solvents for preparing the coating solution for forming the charge transport layer include ordinary organic solvents such as aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene; ketones such as acetone and 2-butanone; halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, and ethylene chloride; and cyclic or linear ethers such as tetrahydrofuran and ethyl ether. These solvents may be used alone or in combination.

[0238] Examples of a coating method for applying the coating liquid for forming the charge transport layer onto the charge generating layer include common methods such as blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, and curtain coating.

[0239] The thickness of the charge transport layer is set, for example, preferably in the range of 5 μm to 50 μm, more preferably 10 μm to 30 μm.

[0240] (protective layer) A protective layer may be provided on the photosensitive layer as needed, for example, to prevent chemical changes in the photosensitive layer when charged, or to further improve the mechanical strength of the photosensitive layer. Therefore, it is preferable to apply a layer made of a cured film (crosslinked film) as the protective layer. Examples of such a layer include the following layers 1) and 2).

[0241] 1) A layer composed of a cured film of a composition containing a reactive group-containing charge transport material having a reactive group and a charge transport skeleton in the same molecule (i.e., a layer containing a polymer or crosslinked product of the reactive group-containing charge transport material). 2) A layer composed of a cured film of a composition containing a non-reactive charge transport material and a reactive group-containing non-charge transport material that does not have a charge transport skeleton and has a reactive group (i.e., a layer containing a non-reactive charge transport material and a polymer or crosslinked product of the reactive group-containing non-charge transport material).

[0242] The reactive group of the reactive group-containing charge transport material may be a chain polymerizable group, an epoxy group, -OH, -OR (wherein R represents an alkyl group), -NH2, -SH, -COOH, or -SiR. Q1 3-Qn (OR Q2 ) Qn [However, R Q1 represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group, and R Q2 represents a hydrogen atom, an alkyl group, or a trialkylsilyl group; Qn represents an integer of 1 to 3.

[0243] The chain polymerizable group is not particularly limited as long as it is a functional group capable of radical polymerization, and is, for example, a functional group having a group containing at least a carbon double bond. Specific examples include groups containing at least one selected from a vinyl group, a vinyl ether group, a vinyl thioether group, a styryl group (vinylphenyl group), an acryloyl group, a methacryloyl group, and derivatives thereof. Among these, a group containing at least one selected from a vinyl group, a styryl group (vinylphenyl group), an acryloyl group, a methacryloyl group, and derivatives thereof is preferred as the chain polymerizable group because of its excellent reactivity.

[0244] The charge transport skeleton of the reactive group-containing charge transport material is not particularly limited as long as it has a known structure in electrophotographic photoreceptors, and examples thereof include a skeleton derived from a nitrogen-containing hole transport compound such as a triarylamine compound, a benzidine compound, or a hydrazone compound, and having a conjugated structure with a nitrogen atom. Among these, a triarylamine skeleton is preferred.

[0245] The reactive group-containing charge transport material having a reactive group and a charge transporting skeleton, the non-reactive charge transport material, and the reactive group-containing non-charge transport material may be selected from known materials.

[0246] The protective layer may also contain other well-known additives.

[0247] The formation of the protective layer is not particularly limited, and a well-known formation method can be used. For example, the protective layer can be formed by forming a coating film of a coating liquid for forming the protective layer in which the above components are added to a solvent, drying the coating film, and, if necessary, subjecting it to a curing treatment such as heating.

[0248] Examples of solvents for preparing the coating liquid for forming the protective layer include aromatic solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ester solvents such as ethyl acetate and butyl acetate, ether solvents such as tetrahydrofuran and dioxane, cellosolve solvents such as ethylene glycol monomethyl ether, and alcohol solvents such as isopropyl alcohol and butanol. These solvents may be used alone or in combination. The protective layer-forming coating liquid may be a solvent-free coating liquid.

[0249] Examples of a method for applying the protective layer-forming coating liquid onto a photosensitive layer (e.g., a charge transport layer) include conventional methods such as dip coating, push-up coating, wire bar coating, spray coating, blade coating, air knife coating, and curtain coating.

[0250] The thickness of the protective layer is set, for example, preferably in the range of 1 μm or more and 20 μm or less, more preferably 2 μm or more and 10 μm or less.

[0251] (single-layer photosensitive layer) The single-layer photosensitive layer (charge generation / charge transport layer) is a layer containing, for example, a charge generation material, a charge transport material, and, if necessary, a binder resin and other well-known additives. Note that these materials are the same as those described for the charge generation layer and the charge transport layer. The content of the charge generating material in the single-layer photosensitive layer is preferably 0.1% by mass to 10% by mass, and more preferably 0.8% by mass to 5% by mass, based on the total solid content. The content of the charge transport material in the single-layer photosensitive layer is preferably 5% by mass to 50% by mass, based on the total solid content. The method for forming the single-layer photosensitive layer is the same as the method for forming the charge generating layer and the charge transport layer. The thickness of the single-layer photosensitive layer is, for example, 5 μm or more and 50 μm or less, and preferably 10 μm or more and 40 μm or less.

[0252] [Configuration of Image Forming Apparatus (and Process Cartridge)] The image forming apparatus according to this embodiment includes an image carrier, a charging means for charging the surface of the image carrier, an electrostatic image forming means for forming an electrostatic image on the surface of the charged image carrier, a developing means that contains an electrostatic image developer containing a toner having toner particles and develops the electrostatic image formed on the surface of the image carrier by the electrostatic image developer into a toner image, a transfer means that transfers the toner image formed on the surface of the image carrier to the surface of a recording medium, and a cleaning device that has a cleaning blade that comes into contact with and cleans the outer peripheral surface of the image carrier. The toner particles and cleaning blade have the above-described configuration.

[0253] The image forming apparatus according to this embodiment may be any of known image forming apparatuses, such as an apparatus equipped with a transfer means for transferring a toner image on an image carrier onto a recording medium via a secondary transfer body (e.g., a secondary transfer belt); an apparatus equipped with a fixing means for fixing the toner image transferred onto the surface of the recording medium; an apparatus equipped with a cleaning device for cleaning the surface of the image carrier after the toner image is transferred but before it is charged; an apparatus equipped with a static elimination device for irradiating the surface of the image carrier with static elimination light to eliminate static electricity after the toner image is transferred but before it is charged; and an apparatus equipped with an image carrier heating member for increasing the temperature of the image carrier and reducing the relative temperature.

[0254] The image forming apparatus according to this embodiment may be either a dry development type image forming apparatus or a wet development type image forming apparatus (a development type using a liquid developer).

[0255] In the image forming apparatus according to the present embodiment, for example, the portion including the image carrier may have a cartridge structure (process cartridge) that is detachably attached to the image forming apparatus. As the process cartridge, for example, a process cartridge including a toner image forming device and a transfer device is preferably used.

[0256] (Image forming method) The image forming method according to this embodiment includes a charging step of charging the surface of an image carrier, an electrostatic charge forming step of forming an electrostatic image on the charged surface of the image carrier, an electrostatic image developing step of developing the electrostatic image with a toner containing toner particles to form a toner image, a transfer step of transferring the toner image to a recording medium, and a cleaning step of contacting a cleaning blade with the surface of the image carrier to clean the surface. The toner particles and cleaning blade have the above-described configuration.

[0257] An example of an image forming apparatus and an image forming method according to the present embodiment will be described below with reference to the drawings. However, the image forming apparatus and the image forming method according to the present embodiment are not limited to this. Note that the main parts shown in the drawings will be described, and descriptions of other parts will be omitted.

[0258] FIG. 3 is a schematic diagram showing an example of the configuration of an image forming apparatus according to this embodiment. As shown in FIG. 3 , the image forming apparatus 100 according to the present embodiment includes a process cartridge 300 having an electrophotographic photosensitive member 7 (an example of an image carrier), an exposure device 9 (an example of an electrostatic charge image forming means), a transfer device 40 (a primary transfer device), and an intermediate transfer member 50. In the image forming apparatus 100, the exposure device 9 is disposed at a position where it can expose the electrophotographic photosensitive member 7 through the opening of the process cartridge 300, and the transfer device 40 is disposed at a position facing the electrophotographic photosensitive member 7 via the intermediate transfer member 50, with a portion of the intermediate transfer member 50 being in contact with the electrophotographic photosensitive member 7. Although not shown, the image forming apparatus 100 also includes a secondary transfer device that transfers the toner image transferred onto the intermediate transfer member 50 onto a recording medium (e.g., paper). The intermediate transfer member 50, the transfer device 40 (a primary transfer device), and the secondary transfer device (not shown) correspond to examples of transfer means.

[0259] 3 integrally supports, within a housing, an electrophotographic photosensitive member 7, a charging device 8 (an example of a charging means), a developing device 11 (an example of a developing means), and a cleaning device 13. The cleaning device 13 has a cleaning blade 131, which is disposed so as to come into contact with the surface of the electrophotographic photosensitive member 7. The cleaning member may not be in the form of the cleaning blade 131, but may be a conductive or insulating fibrous member, which may be used alone or in combination with the cleaning blade 131.

[0260] Note that FIG. 3 shows an example of an image forming apparatus equipped with a fibrous member 132 (roll-shaped) that supplies lubricant 14 to the surface of electrophotographic photosensitive member 7, and a fibrous member 133 (flat brush-shaped) that assists cleaning, but these may be arranged as needed.

[0261] Hereinafter, each configuration of the image forming apparatus according to this embodiment will be described.

[0262] -Charging device- The charging device 8 may be, for example, a contact-type charger using a conductive or semi-conductive charging roller, charging brush, charging film, charging rubber blade, charging tube, etc. Also usable are non-contact type roller chargers, scorotron chargers and corotron chargers that utilize corona discharge, and other known chargers.

[0263] -Exposure equipment- The exposure device 9 may be, for example, an optical system that exposes the surface of the electrophotographic photosensitive member 7 to light such as semiconductor laser light, LED light, or liquid crystal shutter light in a predetermined image. The wavelength of the light source is within the spectral sensitivity range of the electrophotographic photosensitive member. The wavelength of semiconductor lasers is mainly near-infrared, with an oscillation wavelength around 780 nm. However, this wavelength is not limited to this, and lasers with an oscillation wavelength in the 600 nm range or blue lasers with an oscillation wavelength of 400 nm to 450 nm may also be used. Furthermore, for color image formation, a surface-emitting laser light source capable of outputting multiple beams is also effective.

[0264] -Developing device- The developing device 11 may be, for example, a general developing device that develops by contact or non-contact application of a developer. The developing device 11 is not particularly limited as long as it has the above-mentioned functions, and may be selected depending on the purpose. For example, it may be a known developing device that has a function of applying a one-component developer or a two-component developer to the electrophotographic photosensitive member 7 using a brush, roller, or the like. Among these, a developing roller that holds a developer on its surface is preferred.

[0265] The developer used in the developing device 11 may be a one-component developer containing only toner, or a two-component developer containing toner and a carrier. The developer may be magnetic or non-magnetic. Well-known developers are used.

[0266] -Cleaning device- The cleaning device 13 is a cleaning blade type device equipped with a cleaning blade 131 .

[0267] -Transfer device- Examples of the transfer device 40 include a contact type transfer charger using a belt, roller, film, rubber blade, etc., and a known transfer charger such as a scorotron transfer charger or corotron transfer charger that utilizes corona discharge.

[0268] -Intermediate transfer body- A belt-like intermediate transfer belt containing semiconductive polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber, etc. is used as the intermediate transfer body 50. The intermediate transfer body may be in the form of a drum other than a belt.

[0269] FIG. 4 is a schematic diagram showing another example of the configuration of the image forming apparatus according to the present embodiment. The image forming apparatus 120 shown in Fig. 4 is a tandem-type multi-color image forming apparatus equipped with four process cartridges 300. In the image forming apparatus 120, the four process cartridges 300 are arranged in parallel on the intermediate transfer member 50, and one electrophotographic photosensitive member is used per color. The image forming apparatus 120 has the same configuration as the image forming apparatus 100, except that it is a tandem-type apparatus.

[0270] Although the present embodiment has been described above, it should not be construed as being limited to the above embodiment, and various modifications, changes, and improvements may be made. [Example]

[0271] Examples of the present disclosure will be described below, but the present disclosure is not limited to the following examples. In the following description, unless otherwise specified, all "parts" and "%" are by mass.

[0272] [Example 1] - Developer production - <Preparation of Metal Pigment Dispersion> Aluminum pigment (Showa Aluminum Powder Co., Ltd., 2173EA): 100 parts Anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen R): 1.5 parts Ion-exchanged water: 400 parts The solvent was removed from the aluminum pigment paste, and the pigment was mechanically pulverized and classified using a Star Mill (LMZ, manufactured by Ashizawa Finetech Co., Ltd.). The resulting mixture was then mixed with the surfactant and ion-exchanged water and dispersed for approximately one hour using a Cavitron emulsifier / disperser (CR1010, manufactured by Pacific Machinery Co., Ltd.) to prepare a metal pigment dispersion containing dispersed metal pigment particles (aluminum pigment) (solids concentration: 20%). The average equivalent circular diameter of the dispersion was 15 μm.

[0273] <Synthesis of amorphous polyester resin> Bisphenol A ethylene oxide 2.2 mole adduct: 40 mole% Bisphenol A propylene oxide 2.2 mole adduct: 60 mole% Terephthalic acid: 47 mol% Fumaric acid: 40 mol% Dodecenylsuccinic anhydride: 15 mol% Trimellitic anhydride: 3 mol%

[0274] A reaction vessel equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with the above monomer components other than fumaric acid and trimellitic anhydride, and 0.25 parts of tin dioctanoate per 100 parts of the total monomer components. After reacting for 6 hours at 235°C under a nitrogen gas stream, the temperature was lowered to 200°C, and the above fumaric acid and trimellitic anhydride were added and reacted for 1 hour. The temperature was further raised to 220°C over 4 hours, and polymerization was continued under a pressure of 10 kPa until the desired molecular weight was reached, yielding a pale yellow, transparent amorphous polyester resin. The obtained amorphous polyester resin had a glass transition temperature Tg of 59°C measured by DSC, a mass average molecular weight Mw of 25,000 measured by GPC, a number average molecular weight Mn of 7,000 measured by GPC, a softening temperature of 107°C measured by a flow tester, and an acid value AV of 13 mgKOH / g.

[0275] <Preparation of amorphous polyester resin dispersion> A 3-liter jacketed reactor (Tokyo Rikakikai Co., Ltd.: BJ-30N) equipped with a condenser, thermometer, water dripping device, and anchor blade was maintained at 40 ° C. in a water-circulating thermostatic bath, and a mixed solvent of 160 parts of ethyl acetate and 100 parts of isopropyl alcohol was added to the reactor, and 300 parts of the amorphous polyester resin was added to the reactor, and stirred at 150 rpm using a three-one motor to dissolve the resin and obtain an oil phase. 14 parts of 10% aqueous ammonia was added dropwise to the stirred oil phase over a 5-minute period, and after mixing for 10 minutes, 900 parts of ion-exchanged water was added dropwise at a rate of 7 parts per minute to cause phase inversion, resulting in an emulsion. Immediately, 800 parts of the resulting emulsion and 700 parts of ion-exchanged water were placed in a 2-liter recovery flask and placed in an evaporator (Tokyo Rikakikai Co., Ltd.) equipped with a vacuum control unit via a trap bulb. While rotating the recovery flask, the flask was heated in a 60°C hot water bath and, while taking care to prevent bumping, the pressure was reduced to 7 kPa to remove the solvent. When the amount of recovered solvent reached 1,100 parts, the pressure was returned to normal and the recovery flask was water-cooled to obtain a dispersion. The resulting dispersion had no solvent odor. The volume-average particle size D50 of the resin particles in this dispersion was 130 nm. Hereinafter, the volume-average particle size D50 was determined by averaging three measurements out of five taken using a Microtrac, excluding the maximum and minimum values. Thereafter, ion-exchanged water was added to adjust the solid content concentration to 20%, and this was used as an amorphous polyester resin dispersion.

[0276] <Synthesis of crystalline polyester resin> 1,10-dodecanedioic acid: 50 mol% 1,9-nonanediol: 50 mol% The above monomer components were placed in a reaction vessel equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube, and after the atmosphere in the reaction vessel was replaced with dry nitrogen gas, 0.25 parts of titanium tetrabutoxide (reagent) was added per 100 parts of the monomer components. After stirring and reacting for 3 hours at 170°C under a nitrogen gas stream, the temperature was further raised to 210°C over 1 hour, the pressure inside the reaction vessel was reduced to 3 kPa, and stirring and reacting were continued under reduced pressure for 13 hours to obtain a crystalline polyester resin. The resulting crystalline polyester resin had a melting temperature of 73.6°C as measured by DSC, a mass average molecular weight Mw of 25,000, a number average molecular weight Mn of 10,500 and an acid value AV of 10.1 mgKOH / g as measured by GPC.

[0277] <Preparation of Crystalline Polyester Resin Dispersion> 300 parts of the crystalline polyester resin, 160 parts of methyl ethyl ketone (solvent), and 100 parts of isopropyl alcohol (solvent) were placed in a jacketed 3-liter reaction vessel (Tokyo Rikakikai Co., Ltd.: BJ-30N) equipped with a condenser, a thermometer, a water dropping device, and an anchor blade, and the resin was dissolved by stirring and mixing at 100 rpm while maintaining the temperature at 70°C in a water-circulating thermostatic bath (solution preparation process). Thereafter, the stirring speed was increased to 150 rpm, the water circulation type thermostatic bath was set to 66°C, and 17 parts of 10% aqueous ammonia (reagent) was added over 10 minutes, followed by adding a total of 900 parts of ion-exchanged water maintained at 66°C dropwise at a rate of 7 parts / min to cause phase inversion and obtain an emulsion. Immediately, 800 parts of the obtained emulsion and 700 parts of ion-exchanged water were placed in a 2-liter recovery flask and set in an evaporator (Tokyo Rikakikai Co., Ltd.) equipped with a vacuum control unit via a trap bulb. While rotating the recovery flask, it was heated in a hot water bath at 60°C, and the pressure was reduced to 7 kPa while taking care to prevent bumping, to remove the solvent. When the amount of recovered solvent reached 1,100 parts, the pressure was returned to normal, and the recovery flask was cooled with water to obtain a dispersion. The obtained dispersion had no solvent odor. The volume average particle diameter D of the resin particles in this dispersion was 50 Thereafter, ion-exchanged water was added to adjust the solid concentration to 20%, and this was used as a crystalline polyester resin dispersion.

[0278] <Toner Production> Amorphous polyester resin dispersion: 263 parts Crystalline polyester resin dispersion: 12 parts Metal pigment dispersion: 100 parts Nonionic surfactant (IGEPAL CA897): 2.5 parts

[0279] The raw materials were placed in a 2-liter cylindrical stainless steel container and dispersed and mixed for 10 minutes using a homogenizer (Ultra Turrax T50, manufactured by IKA) at 4,000 rpm while applying shear force. Next, 60 parts of a 10% aqueous solution of polyaluminum chloride in nitric acid was gradually added dropwise as a flocculant, and the homogenizer was rotated at 5,000 rpm for 15 minutes to disperse and mix the materials, yielding a raw material dispersion. The raw material dispersion was then transferred to a polymerization kettle equipped with a stirrer using two paddle stirrers and a thermometer, and the stirring speed was set to 857 rpm and heating was started using a mantle heater to promote the growth of aggregated particles at 54°C. The pH of the raw material dispersion was controlled in the range of 2.2 to 3.5 using 0.3 N nitric acid or a 1 N aqueous solution of sodium hydroxide. The pH was maintained in this range for approximately 2 hours to form aggregated particles.

[0280] Next, 125 parts of the amorphous polyester resin dispersion liquid was further added to adhere the resin particles of the binder resin to the surfaces of the aggregated particles. The mixture was then heated to 56°C, and the aggregated particles were adjusted while checking the particle size and morphology using an optical microscope and a Multisizer II. 4.25 parts of a chelating agent (HIDS, manufactured by Nippon Shokubai Co., Ltd.) was then added, and the pH was adjusted to 7.8 using a 5% aqueous sodium hydroxide solution and maintained for 15 minutes. The pH was then increased to 8.0 to fuse the aggregated particles, and the mixture was heated to 66.5°C. After confirming that the aggregated particles had fused using an optical microscope, the pH was lowered to 6.0 while maintaining the temperature at 66.5°C. After 1 hour, heating was stopped and the mixture was cooled at a rate of 1.0°C / min. The particles were then sieved through a 20 μm mesh, washed repeatedly with water, and dried in a vacuum dryer to obtain toner particles. The resulting toner particles had a volume average particle diameter of 17.2 μm, an average b / a ratio of 0.5, and a pigment area ratio of 0.7. 100 parts of the toner particles were mixed with 1.5 parts of silica particles (RY50 manufactured by Nippon Aerosil Co., Ltd.) using a Henschel mixer (manufactured by Mitsui Miike Co., Ltd.) at a peripheral speed of 30 m / s for 3 minutes, and then sieved through a vibrating sieve with 45 μm openings to prepare a toner.

[0281] <Creating the carrier> Ferrite particles (volume average particle size: 35 μm): 100 parts Toluene: 14 parts Perfluoroacrylate copolymer (critical surface tension: 24 dyn / cm): 1.6 parts Carbon black (product name: VXC-72, manufactured by Cabot Corporation, volume resistivity: 100 Ω cm or less): 0.12 parts Cross-linked melamine resin particles (average particle size: 0.3 μm, insoluble in toluene): 0.3 parts

[0282] First, carbon black diluted with toluene was added to the perfluoroacrylate copolymer and dispersed using a sand mill. Next, the above components except for the ferrite particles were dispersed therein using a stirrer for 10 minutes to prepare a coating layer forming solution. Next, this coating layer forming solution and the ferrite particles were placed in a vacuum degassing kneader and stirred at a temperature of 60°C for 30 minutes, after which the pressure was reduced and the toluene was distilled off to form a resin coating layer, thereby obtaining a carrier.

[0283] <Preparation of developer> 36 parts of the toner and 414 parts of the carrier were placed in a 2-liter V blender, stirred for 20 minutes, and then sieved through a 212 μm sieve to prepare a developer.

[0284] -Cleaning blade manufacturing- <Surface layer composition> Adipic acid (HOOC-CH-COOH) and 1,4-butanediol were polymerized and treated to have -OH groups at the terminals, yielding a polyester polyol (PEPO) polymerized with a linear diol (butanediol) having four carbon atoms. The weight-average molecular weight of the resulting polyester polyol was as shown in Table 1. The polyester polyol as the polyol component, 4,4'-diphenylmethane diisocyanate (MDI, polyisocyanate, manufactured by Nippon Polyurethane Industry Co., Ltd., Millionate MT) as the isocyanate component, and a crosslinking agent (TMP, trimethylolpropane, manufactured by Mitsubishi Gas Chemical Company, Inc.) were adjusted to the molar ratios shown in Table 1 and reacted at 80°C for 2 hours under a nitrogen atmosphere to prepare a surface layer composition A1 for forming a cleaning blade.

[0285] <Back layer composition> In addition, in the surface layer composition A1, the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO), 4,4'-diphenylmethane diisocyanate (MDI), and crosslinking agent (TMP) were changed to those shown in Table 1 to prepare a back layer composition A2.

[0286] <Cleaning Blade Production> Next, the back layer composition A2 was poured into the center of the mold, and the mold temperature was adjusted to 140°C by raising the temperature of the mold. After 10 minutes, the surface layer composition A1 was poured in and then cured for 1 hour. Next, it was heated and aged at 110°C for 24 hours, cooled, and then cut to obtain a cleaning blade with a width of 8 mm and a thickness of 2 mm (surface layer thickness 0.5 mm, back layer thickness 1.5 mm) formed of a surface layer that comes into contact with the member to be cleaned (i.e., image carrier) and a back layer.

[0287] [Example 2] - Developer production - A toner was produced in the same manner as in Example 1, except that the metal pigment used had an average equivalent circular diameter adjusted to 5 μm, and then the produced toner was spread using a ball mill. The resulting toner particles had a volume average particle diameter of 7.5 μm, an average ratio b / a of 0.5, and a pigment area ratio of 0.5.

[0288] -Cleaning blade manufacturing- In Example 1, a cleaning blade was produced in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 1.

[0289] [Example 3] - Developer production - The average circular equivalent diameter of the metal pigment is adjusted to 10 μm, and the toner manufacturing method is Amorphous polyester resin dispersion: 215 parts Crystalline polyester resin dispersion: 60 parts Metal pigment dispersion: 100 parts Nonionic surfactant (IGEPAL CA897): 2.5 parts A toner was produced in the same manner as in Example 1, except that the above-mentioned formula was changed to: The volume average particle diameter of the obtained toner particles was 12.3 μm, the average value of the ratio b / a was 0.65, and the pigment area ratio was 0.6.

[0290] -Cleaning blade manufacturing- In Example 1, a cleaning blade was produced in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 1.

[0291] [Example 4] - Developer production - How to make toner Amorphous polyester resin dispersion: 155 parts Crystalline polyester resin dispersion: 120 parts Metal pigment dispersion: 100 parts Nonionic surfactant (IGEPAL CA897): 2.5 parts A toner was produced in the same manner as in Example 1, except that the above-mentioned conditions were changed to the following: The volume average particle diameter of the obtained toner particles was 17.5 μm, the average value of the ratio b / a was 0.8, and the pigment area ratio was 0.7.

[0292] -Cleaning blade manufacturing- In Example 1, a cleaning blade was produced in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 1.

[0293] [Example 5] - Developer production - The average circular equivalent diameter of the metal pigment is adjusted to 5 μm, and the toner manufacturing method is Amorphous polyester resin dispersion: 155 parts Crystalline polyester resin dispersion: 120 parts Metal pigment dispersion: 100 parts Nonionic surfactant (IGEPAL CA897): 2.5 parts A toner was produced in the same manner as in Example 1, except that the above-mentioned formula was changed to: The volume average particle diameter of the obtained toner particles was 7.6 μm, the average value of the ratio b / a was 0.8, and the pigment area ratio was 0.5.

[0294] -Cleaning blade manufacturing- In Example 1, a cleaning blade was produced in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 1.

[0295] [Example 6] - Developer production - Except for using a metal pigment whose average equivalent circle diameter was adjusted to 10 μm, a toner was produced in the same manner as in Example 1. The volume average particle diameter of the obtained toner particles was 12.1 μm, the average value of the ratio b / a was 0.5, and the pigment area ratio was 0.6.

[0296] -Cleaning blade manufacturing- In Example 1, a cleaning blade was produced in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 1.

[0297] [Example 7] - Developer production - A toner was prepared in the same manner as in Example 4.

[0298] -Cleaning blade manufacturing- In Example 1, a cleaning blade was produced in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 1.

[0299] [Example 8] - Developer production - A toner was prepared in the same manner as in Example 4.

[0300] -Cleaning blade manufacturing- In Example 1, a cleaning blade was prepared in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 2.

[0301] [Example 9] - Developer production - A toner was prepared in the same manner as in Example 2.

[0302] -Cleaning blade manufacturing- In Example 2, a cleaning blade was prepared in the same manner as in Example 2, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO), 4,4'-diphenylmethane diisocyanate (MDI), and crosslinking agent (TMP) in the surface layer composition A1 were changed to those shown in Table 2.

[0303] [Examples 10 to 20] - Developer production - A toner was prepared in the same manner as in Example 1.

[0304] -Cleaning blade manufacturing- In Example 1, a cleaning blade was prepared in the same manner as in Example 1, except that either the weight average molecular weight of the polyester polyol (PEPO) or the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, or the weight average molecular weight of the polyester polyol (PEPO) or the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 was changed to those shown in Table 2 or Table 3.

[0305] [Example 21] - Developer production - Toners were prepared in the same manner as in Example 1, except that the amount of crystalline resin in Example 1 was changed as shown in Table 3.

[0306] -Cleaning blade manufacturing- A cleaning blade was produced in the same manner as in Example 1. [Comparative Example 1] - Developer production - A toner was prepared in the same manner as in Example 1.

[0307] -Cleaning blade manufacturing- In Example 1, a cleaning blade was prepared in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 4.

[0308] Comparative Example 2 - Developer production - A toner was prepared in the same manner as in Example 4.

[0309] -Cleaning blade manufacturing- In Example 1, a cleaning blade was prepared in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 4.

[0310] Comparative Example 3 How to make toner Amorphous polyester resin dispersion: 271 parts Crystalline polyester resin dispersion: 4 parts Metal pigment dispersion: 100 parts Nonionic surfactant (IGEPAL CA897): 2.5 parts A toner was produced in the same manner as in Example 1, except that the above-mentioned conditions were changed to the following: The volume average particle diameter of the obtained toner particles was 17.3 μm, the average value of the ratio b / a was 0.4, and the pigment area ratio was 0.7.

[0311] -Cleaning blade manufacturing- In Example 1, a cleaning blade was prepared in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 4.

[0312] Comparative Example 4 The average circular equivalent diameter of the metal pigment is adjusted to 5 μm, and the toner manufacturing method is Amorphous polyester resin dispersion: 271 parts Crystalline polyester resin dispersion: 4 parts Metal pigment dispersion: 100 parts Nonionic surfactant (IGEPAL CA897): 2.5 parts A toner was produced in the same manner as in Example 1 except for changing the ratio b / a to 0.5, and then the produced toner was spread using a ball mill. The volume average particle diameter of the obtained toner particles was 7.4 μm, the average value of the ratio b / a was 0.4, and the pigment area ratio was 0.5.

[0313] -Cleaning blade manufacturing- In Example 1, a cleaning blade was prepared in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 4.

[0314] Comparative Example 5 - Developer production - A toner was prepared in the same manner as in Comparative Example 3.

[0315] -Cleaning blade manufacturing- In Example 1, a cleaning blade was prepared in the same manner as in Example 1, except that the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the surface layer composition A1, and the weight average molecular weight of the polyester polyol (PEPO) and the molar ratio of the polyester polyol (PEPO) to 4,4'-diphenylmethane diisocyanate (MDI) and the crosslinking agent (TMP) in the back layer composition A2 were changed to those shown in Table 4.

[0316] [Comparative Examples 6 and 7] - Developer production - A toner was prepared in the same manner as in Example 2.

[0317] -Cleaning blade manufacturing- A cleaning blade was prepared in the same manner as in Example 2, except that the molar ratio of polyester polyol (PEPO), 4,4'-diphenylmethane diisocyanate (MDI), and crosslinking agent (TMP) in the surface layer composition A1 was changed to that shown in Table 4.

[0318] [Cleaning blade properties] For the cleaning blades obtained in each Example and Comparative Example, the breaking energy, 100% modulus at the contact portion with the image carrier, and crosslink density of the surface layer were measured by the methods described above. The 100% modulus, permanent set, and crosslink density of the back layer were also measured by the methods described above. The results are shown in Tables 1 to 4. In the crosslink densities shown in Tables 1 to 4, for example, "1.00E-03" means "1.00 x 10 -3 " and similarly for other values.

[0319] [evaluation] -Formation of evaluation image- An evaluation image was formed by the following method. The developer sample was filled into the developing unit of a DocuCentre-III C7600 manufactured by Fujifilm Business Innovation Co., Ltd., and the developer was applied to recording paper (C2 paper, manufactured by Fujifilm Business Innovation Japan Co., Ltd., smoothness measured according to JIS P8119:1998 is 90 seconds) at a fixing temperature of 190°C and a fixing pressure of 4.0 kg / cm. 2 The toner amount is 4.5g / m 2 A solid image of 1000 ppm was formed.

[0320] -Brilliance evaluation- The resulting solid images were visually evaluated for brilliance under color observation lighting (natural daylight) in accordance with JIS K5600-4-3:1999 "General Test Methods for Paints - Part 4: Visual Properties of Coatings - Section 3: Visual Comparison of Color." The evaluation included particle appearance (the effect of sparkling brilliance) and optical effect (change in hue depending on the viewing angle) according to the following criteria. A score of 2 or higher is considered practically usable. 5: The graininess and optical effect are in harmony. 4: Slightly grainy and has an optical effect. 3: Normal feelings 2: It feels a little blurry 1: No graininess or optical effect at all.

[0321] -Evaluation of image abrasion resistance- Twenty-five sheets of recording paper (C2 paper, manufactured by Fuji Xerox Interfield Co., Ltd.) were placed on the side of the recording paper with a solid image formed thereon, and 25 sheets of recording paper (C2 paper, manufactured by Fujifilm Business Innovation Japan Co., Ltd.) were placed on the opposite side of the solid image, resulting in a stack of 51 sheets of recording paper. This stack was placed in the automatic document feeder of a modified Fujifilm Business Innovation DocuCentre C7550, and the documents were fed one by one to apply a rubbing load to the image. After all 51 sheets of recording paper had been fed, the sheets were bundled together again, and the rubbing load was applied to the image in the same manner using the automatic document feeder. After applying a rubbing load a total of 50 times, the brilliance of the solid image after the rubbing load was evaluated based on the following criteria, similar to the above-mentioned gloss evaluation. Note that when the recording paper was transported by the automatic document feeder, the method of transporting the recording paper was adjusted so that the solid image contacted the rollers of the automatic document feeder. A level of 2 or above is practically usable. 5: The image surface is smooth, and the graininess and optical effect are in harmony. 4: The image surface is almost free of scratches, and has a grainy, optical effect. 3: There are some scratches on the surface of the image, but it is normal. 2: The image surface is slightly scratched and blurred. 1: The image surface is heavily scratched, with no graininess or optical effect.

[0322] -Measuring blade wear- The cleaning blade obtained in each example was mounted on a DocuCentre-IV C5575 manufactured by Fujifilm Business Innovation Japan Co., Ltd., and 200,000 images were formed in a high-temperature, high-humidity environment (28°C / 85% RH) with the NF (Normal Force) set to 2.0 gf / mm and the W / A (Working Angle) set to 11°. Then, 200,000 images were formed in a low-temperature, low-humidity environment (10°C / 15%), for a total of 400,000 images. The amount of wear at the tip of the cleaning blade was measured by observing the cross-sectional profile with a Keyence VK-9500 laser microscope. Cleaning blade wear is 3μm2 It is preferable that the thickness is less than 3 μm (for example, toner slippage is suppressed), 2 Anything above this is not preferable (for example, toner slip-through is observed).

[0323] -Evaluation of toner slip-through- As an index of toner slip-through, the presence or absence of toner remaining on the image carrier after forming a total of 400,000 images in the "blade wear amount measurement" was confirmed, and judged according to the following evaluation criteria. A: No toner is found on the image carrier B: Toner is found on the image carrier, but within the acceptable range C: Toner is clearly visible on the image carrier, and is unacceptable.

[0324] -Image evaluation- In the "Formation of Evaluation Images" solid image formation, the recording paper was changed to "C2r paper, manufactured by Fujifilm Business Innovation Japan Co., Ltd." and 200,000 images were formed. After that, the state of deformation of the cleaning blade and the occurrence of image defects such as color streaks were observed and evaluated visually according to the following criteria. A: No color streaks are observed B: A slight color streak is observed in the image, but it is within the acceptable range. C: Color streaks are observed in the image and are unacceptable.

[0325] [Table 1]

[0326] [Table 2]

[0327] [Table 3]

[0328] [Table 4]

[0329] As shown in Tables 1 to 4, in Examples 1 to 21, both the toner particles and the cleaning blade satisfy the requirements of the present embodiment. Examples 1 to 21 exhibited excellent glitter (i.e., toners with high brightness, high reflectivity, and high hiding power that reproduced a metallic appearance were obtained). In addition, the cleaning blade exhibited excellent mechanical strength and abrasion resistance, and good cleaning performance was obtained over a long period of time even with the toner, which is difficult to clean due to its flat shape.

[0330] In Comparative Example 1, the breaking energy and 100% modulus of the cleaning blade were low, which led to accelerated wear of the cleaning blade and weak mechanical rigidity. In Comparative Example 1, the blade behavior became unstable, toner slipped through, and the image evaluation was poor.

[0331] In Comparative Example 2, the breaking energy of the cleaning blade was high, which increased the contact pressure with the image carrier and accelerated the wear of the cleaning blade. In Comparative Example 2, toner slipped through and the image evaluation was poor.

[0332] In Comparative Examples 3 and 4, the average value of the ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section of the toner particles was low. In Comparative Examples 3 and 4, the coverage and abrasion resistance of the metal pigment by the binder resin in the toner particles was low, and the abrasion resistance of the image was poor.

[0333] In Comparative Example 5, the breaking energy and 100% modulus of the cleaning blade were low, leading to accelerated wear of the cleaning blade and weak mechanical rigidity. Furthermore, in Comparative Example 5, the average value of the ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section of the toner particles was low. In Comparative Example 5, the blade behavior became unstable, toner slip-through occurred, and the image evaluation was poor. Furthermore, the coverage and abrasion resistance of the metal pigment by the binder resin in the toner particles were low, resulting in poor abrasion resistance of the image.

[0334] In Comparative Example 6, the breaking energy of the cleaning blade was low, and the wear of the cleaning blade progressed. In Comparative Example 6, the blade behavior became unstable, toner slipped through, and the image evaluation was also poor.

[0335] In Comparative Example 7, the 100% modulus of the cleaning blade was low, the blade behavior was unstable, toner slipped through, and the image evaluation was poor.

[0336] (Addendum) (((1))) an image carrier; a charging means for charging the surface of the image carrier; an electrostatic charge forming means for forming an electrostatic image on the charged surface of the image carrier; an electrostatic image developing means for developing the electrostatic image with the electrostatic image developing toner to form a toner image, the toner particles containing a metal pigment having an average equivalent circular diameter of 5 μm to 15 μm, the average value of the ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section of the toner particles being 0.5 to 0.8, and the average value of the area occupied by the metal pigment in a projected image of the toner particles when viewed from the thickness direction of the toner particles being 0.5 to 0.7; a transfer means for transferring the toner image onto a recording medium; a cleaning means having a cleaning blade that comes into contact with the surface of the image carrier to clean the surface, the cleaning blade having a breaking energy of 5000 MPa·% or more and 15000 MPa·% or less and a 100% modulus of 10 MPa or more at the portion of contact with the image carrier; An image forming apparatus comprising: (((2))) The image forming apparatus according to (((1))), wherein the cleaning blade has a breaking energy of 7000 MPa·% or more and 12000 MPa·% or less. (((3))) The image forming apparatus according to (((1))) or (((2))), wherein the cleaning blade has a 100% modulus of 12 MPa or more and 20 MPa or less at the contact portion with the image carrier. (((4))) The image forming apparatus according to any one of (((1))) to (((3))), wherein the material constituting the contact portion of the cleaning blade with the image carrier is polyurethane obtained by polymerizing a polyester polyol having a weight average molecular weight of 1,000 or more and 10,000 or less, an isocyanate compound, and a crosslinking agent. (((5))) The image forming apparatus according to (((4))), wherein the weight average molecular weight of the polyester polyol is 2,000 or more and 8,000 or less. (((6))) The image forming apparatus according to any one of (((1))) to (((5))), wherein the material constituting the contact portion of the cleaning blade with the image carrier is polyurethane obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and the proportion of the isocyanate compound in the material constituting the contact portion is 10 mol % or more and 40 mol % or less. (((7))) The image forming apparatus according to (((6))), wherein the isocyanate compound accounts for 15 mol % or more and 30 mol % or less of the material constituting the contact portion. (((8))) The cleaning blade is made of a material constituting a contact portion with the image carrier, which is obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and has a crosslinking density of 0.90×10 -3 mol / m 3 Over 1.50 x 10 -3 mol / m 3 The image forming apparatus according to any one of (((1))) to (((7))), wherein the polyurethane is one of the following: (((9))) The crosslink density is 1.00×10 -3 mol / m 3 Over 1.30 x 10 -3 mol / m 3 The image forming apparatus according to (((8))) below. (((10))) the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, The image forming apparatus according to any one of (((1))) to (((9))), wherein the backing layer has a 100% modulus of 3 MPa or more and 7 MPa or less, and a permanent set of less than 2.0%. (((11))) The image forming apparatus according to (((10))), wherein the back surface layer has a 100% modulus of 4 MPa or more and 6 MPa or less. (((12))) The image forming apparatus according to (((10))) or (((11))), wherein the back surface layer has a permanent set of 1.0% or less. (((13))) the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, The image forming apparatus according to any one of (((1))) to (((12))), wherein the material constituting the back surface layer is polyurethane obtained by polymerizing a polyester polyol having a weight average molecular weight of 100 or more and 2000 or less, an isocyanate compound, and a crosslinking agent. (((14))) The image forming apparatus according to (((13))), wherein the weight average molecular weight of the polyester polyol is 500 or more and 1,000 or less. (((15))) the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, The image forming apparatus according to any one of (((1))) to (((14))), wherein the material constituting the back layer is polyurethane obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and the proportion of the isocyanate compound in the material constituting the back layer is 5 mol % or more and 20 mol % or less. (((16))) The image forming apparatus according to (((15))), wherein the ratio of the isocyanate compound to the material constituting the back surface layer is 5 mol % or more and 15 mol % or less. (((17))) the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, The material constituting the back surface layer is a polymer of a polyol, an isocyanate compound, and a crosslinking agent, and has a crosslink density of 1.5×10 -3 mol / m 3 Over 2.5 x 10 -3 mol / m 3 The image forming apparatus according to any one of (((1))) to (((16))), wherein the polyurethane is: (((18))) The crosslink density is 1.8×10 -3 mol / m 3 Over 2.2 x 10 -3 mol / m 3 The image forming apparatus according to (((17))), (((19))) The image forming apparatus according to any one of (((1))) to (((18))), wherein the toner particles contain a binder resin including a crystalline resin and an amorphous resin, and the proportion of the crystalline resin in the binder resin is 3% by mass or more and 30% by mass or less. (((20))) The image forming apparatus according to (((19))), wherein the proportion of the crystalline resin in the binder resin is 5% by mass or more and 25% by mass or less. (((twenty one))) a charging step of charging the surface of the image carrier; an electrostatic charge forming step of forming an electrostatic image on the charged surface of the image carrier; an electrostatic image developing step of forming a toner image by developing the electrostatic image with an electrostatic image developing toner containing toner particles, the toner particles containing a metal pigment having an average equivalent circular diameter of 5 μm to 15 μm, an average value of b / a of a major axis diameter a to a minor axis diameter b in a cross section of the toner particles being 0.5 to 0.8, and an average value of an area occupied by the metal pigment in a projected image of the toner particles when viewed from the thickness direction of the toner particles being 0.5 to 0.7; a transfer step of transferring the toner image onto a recording medium; a cleaning step of bringing a cleaning blade into contact with the surface of the image carrier to clean the surface, the cleaning blade having a breaking energy of 5000 MPa·% or more and 15000 MPa·% or less and a 100% modulus of 10 MPa or more at the contact portion with the image carrier; An image forming method comprising:

[0337] According to the invention pertaining to (((1))), compared to an image forming apparatus using a cleaning blade that satisfies at least one of the conditions of a breaking energy exceeding 5000 MPa·% or less than 15000 MPa·% and a 100% modulus at the contact portion with the image carrier being less than 10 MPa, an image forming apparatus is provided in which the cleaning ability of toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images that contains toner particles that contain a metal pigment with an average equivalent circle diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction is 0.5 or more and 0.7 or less. According to the invention pertaining to (((2))), compared to an image forming apparatus using a cleaning blade that satisfies the condition of a breaking energy exceeding 7000 MPa·% or less than 12000 MPa·%, an image forming apparatus is provided in which the cleaning ability of the toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images that contains toner particles that contain a metal pigment with an average equivalent circle diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction is 0.5 or more and 0.7 or less. According to the invention related to (((3))), compared to an image forming apparatus using a cleaning blade that satisfies the condition that the 100% modulus at the contact portion with the image carrier is less than 12 MPa or more than 20 MPa, an image forming apparatus is provided in which the cleaning ability of the toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images that contains toner particles that contain a metal pigment with an average equivalent circle diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction is 0.5 or more and 0.7 or less. According to the inventions of (((4))) or (((5))), compared to an image forming apparatus using a cleaning blade in which the material constituting the contact portion with the image carrier is polyurethane obtained by polymerizing a polyester polyol having a weight-average molecular weight of less than 1,000 or more than 10,000, an isocyanate compound, and a crosslinking agent, an image forming apparatus is provided in which the removability of toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images containing toner particles that contain a metal pigment having an average equivalent circular diameter of 5 μm or more and 15 μm or less, the ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particle when viewed from the thickness direction is 0.5 or more and 0.7 or less. According to the inventions of (((6))) or (((7))), compared to an image forming apparatus using a cleaning blade in which the material constituting the contact portion with the image carrier is polyurethane obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and in which the proportion of the isocyanate compound in the material constituting the contact portion is less than 10 mol % or more than 40 mol %, an image forming apparatus is provided in which the cleaning ability of the toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images containing toner particles that contain a metal pigment having an average equivalent circle diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particle when viewed from the thickness direction is 0.5 or more and 0.7 or less. According to the invention of (((8))) or (((9))), the material constituting the contact portion with the image carrier is a polymer of a polyol, an isocyanate compound, and a crosslinking agent, and the crosslinking density is 0.90×10 -3 mol / m 3 Less than or 1.50 x 10 -3 mol / m 3 The present invention provides an image forming apparatus in which, compared to an image forming apparatus using a cleaning blade made of polyurethane having a thickness greater than 1000 nm, the cleaning ability of the toner particles by the cleaning blade is improved and the occurrence of toner filming by the cleaning blade is suppressed, even when using a toner for developing electrostatic images containing toner particles that contain a metal pigment having an average equivalent circular diameter of 5 μm to 15 μm, an average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 to 0.8, and an average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction being 0.5 to 0.7. According to the invention of (((10))), compared to an image forming apparatus using a cleaning blade having a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier from the surface layer, and having a back layer that satisfies at least one of the conditions of a 100% modulus of less than 3 MPa or more than 7 MPa and a permanent set elongation of 2.0% or more, there is provided an image forming apparatus in which the cleanability of toner particles is improved even when using a toner for developing electrostatic images that contains toner particles that contain a metal pigment having an average equivalent circle diameter of 5 μm to 15 μm, an average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section of 0.5 to 0.8, and an average area of ​​the metal pigment in a projected image of the toner particle when viewed from the thickness direction of 0.5 to 0.7. According to the invention of (((11))), compared to an image forming apparatus using a cleaning blade having a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier from the surface layer, and having a back layer that satisfies the condition that the 100% modulus is less than 4 MPa or more than 6 MPa, there is provided an image forming apparatus in which the cleanability of toner particles is improved even when using a toner for developing electrostatic images, the toner particles containing a metal pigment having an average equivalent circle diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction being 0.5 or more and 0.7 or less. According to the invention of (((12))), compared to an image forming apparatus using a cleaning blade having a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier from the surface layer, and having a back layer that satisfies the condition that the permanent set is greater than 1.0%, there is provided an image forming apparatus in which the cleanability of toner particles is improved even when using a toner for developing electrostatic images, the toner particles containing a metal pigment having an average equivalent circle diameter of 5 μm to 15 μm, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 to 0.8, and the average area of ​​the metal pigment in the projected image of the toner particles when viewed from the thickness direction being 0.5 to 0.7. According to the inventions of (((13))) or (((14))), compared to an image forming apparatus using a cleaning blade having a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier from the surface layer, wherein the material constituting the back layer is polyurethane obtained by polymerizing a polyester polyol having a weight-average molecular weight of 100 to 2000, an isocyanate compound, and a crosslinking agent, there is provided an image forming apparatus in which the cleanability of toner particles is improved even when using a toner for developing electrostatic images, the toner particles containing a metal pigment having an average circular equivalent diameter of 5 μm to 15 μm, an average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 to 0.8, and an average area occupied by the metal pigment in a projected image of the toner particle when viewed from the thickness direction being 0.5 to 0.7. According to the inventions of (((15))) or (((16))), compared to an image forming apparatus using a cleaning blade having a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier from the surface layer, wherein the material constituting the back layer is polyurethane obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and wherein the proportion of the isocyanate compound in the material constituting the back layer is 5 mol % or more and 20 mol % or less, an image forming apparatus is provided in which the cleanability of toner particles is improved even when using a toner for developing electrostatic images that contains toner particles that contain a metal pigment with an average equivalent circle diameter of 5 μm or more and 15 μm or less, and the ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area of ​​the metal pigment in a projected image of the toner particle when viewed from the thickness direction is 0.5 or more and 0.7 or less. According to the invention of (((17))) or (((18))), there is provided an image forming apparatus having a surface layer that contacts an image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, wherein the material constituting the back layer is a polymer of a polyol, an isocyanate compound, and a crosslinking agent, and the crosslinking density is 1.5×10 -3 mol / m 3 Over 2.5 x 10 -3 mol / m 3The present invention provides an image forming apparatus in which the cleaning ability of toner particles is improved compared to an image forming apparatus using a cleaning blade made of polyurethane having an average equivalent circle diameter of 5 μm to 15 μm, an average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section being 0.5 to 0.8, and an average area of ​​the metal pigment in the projected image of the toner particles when viewed from the thickness direction being 0.5 to 0.7. According to the invention of (((19))) or (((20))), there is provided an image forming apparatus which contains a binder resin including a crystalline resin and an amorphous resin, and in which the wear resistance of images is improved compared to an image forming apparatus which uses toner particles in which the proportion of the crystalline resin in the binder resin is less than 3 mass %. According to the invention of (((21))), compared to an image forming method using a cleaning blade that satisfies at least one of the conditions of a breaking energy of more than 5000 MPa·% or less than 15000 MPa·% and a 100% modulus of less than 10 MPa at the contact portion with the image carrier, the invention provides an image forming method in which the cleaning ability of toner particles by a cleaning blade is improved and the occurrence of toner filming by a cleaning blade is suppressed, even when using a toner for developing electrostatic images containing toner particles that contain a metal pigment having an average equivalent circle diameter of 5 μm or more and 15 μm or less, the average ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section is 0.5 or more and 0.8 or less, and the average area occupied by the metal pigment in the projected image of the toner particles when viewed from the thickness direction is 0.5 or more and 0.7 or less. [Explanation of symbols]

[0338] 1 undercoat layer, 2 charge generation layer, 3 charge transport layer, 4 conductive substrate, 5 photosensitive layer, 7 electrophotographic photosensitive member, 8 charging device, 9 exposure device, 11 developing device, 13 cleaning device, 14 lubricant, 22 photoluminescent toner particles, 24 metal pigment, 40 transfer device, 50 intermediate transfer body, 100, 120 image forming apparatus, 131 cleaning blade, 132 fibrous member (roll-shaped), 133 fibrous member (flat brush-shaped), 300 process cartridge

Claims

1. an image carrier; a charging means for charging the surface of the image carrier; an electrostatic charge forming means for forming an electrostatic image on the charged surface of the image carrier; an electrostatic image developing means for developing the electrostatic image with the electrostatic image developing toner to form a toner image, the toner particles containing a metal pigment having an average equivalent circular diameter of 5 μm to 15 μm, the average value of the ratio b / a of the major axis diameter a to the minor axis diameter b in the cross section of the toner particles being 0.5 to 0.8, and the average value of the area occupied by the metal pigment in a projected image of the toner particles when viewed from the thickness direction of the toner particles being 0.5 to 0.7; a transfer means for transferring the toner image onto a recording medium; a cleaning means having a cleaning blade that comes into contact with the surface of the image carrier to clean the surface, the cleaning blade having a breaking energy of 5000 MPa % or more and 15000 MPa % or less and a 100% modulus of 10 MPa or more at the portion of contact with the image carrier; An image forming apparatus comprising:

2. 2. The image forming apparatus according to claim 1, wherein the cleaning blade has a breaking energy of 7000 MPa·% or more and 12000 MPa·% or less.

3. 2. The image forming apparatus according to claim 1, wherein the cleaning blade has a 100% modulus of 12 MPa or more and 20 MPa or less at the contact portion with the image carrier.

4. 2. The image forming apparatus according to claim 1, wherein the material constituting the contact portion of the cleaning blade with the image carrier is polyurethane obtained by polymerizing a polyester polyol having a weight average molecular weight of 1,000 to 10,000, an isocyanate compound, and a crosslinking agent.

5. 5. The image forming apparatus according to claim 4, wherein the weight average molecular weight of the polyester polyol is 2,000 or more and 8,000 or less.

6. 2. The image forming apparatus according to claim 1, wherein the material constituting the contact portion of the cleaning blade with the image carrier is polyurethane obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and the proportion of the isocyanate compound in the material constituting the contact portion is 10 mol % or more and 40 mol % or less.

7. 7. The image forming apparatus according to claim 6, wherein the ratio of the isocyanate compound to the material constituting the contact portion is 15 mol % or more and 30 mol % or less.

8. The cleaning blade is made of a material constituting a contact portion with the image carrier, which is obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and has a crosslinking density of 0.90×10 －３ mol / m ３ Above 1.50 x 10 －３ mol / m ３ 2. The image forming apparatus according to claim 1, wherein the polyurethane is:

9. The crosslink density is 1.00×10 －３ mol / m ３ The above is 1.30 x 10 －３ mol / m ３ 9. The image forming apparatus according to claim 8, wherein:

10. the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, 2. The image forming apparatus according to claim 1, wherein the back surface layer has a 100% modulus of 3 MPa or more and 7 MPa or less, and a permanent set of less than 2.0%.

11. The image forming apparatus according to claim 10 , wherein the back surface layer has a 100% modulus of 4 MPa or more and 6 MPa or less.

12. The image forming apparatus according to claim 10, wherein the back layer has a permanent set of 1.0% or less.

13. the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, 2. The image forming apparatus according to claim 1, wherein the material constituting the back surface layer is polyurethane obtained by polymerizing polyester polyol having a weight average molecular weight of 100 to 2000, an isocyanate compound, and a crosslinking agent.

14. 14. The image forming apparatus according to claim 13, wherein the weight average molecular weight of the polyester polyol is 500 or more and 1,000 or less.

15. the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, 2. The image forming apparatus according to claim 1, wherein the material constituting the back layer is polyurethane obtained by polymerizing a polyol, an isocyanate compound, and a crosslinking agent, and the proportion of the isocyanate compound in the material constituting the back layer is 5 mol % or more and 20 mol % or less.

16. 16. The image forming apparatus according to claim 15, wherein the ratio of the isocyanate compound to the material constituting the back surface layer is 5 mol % or more and 15 mol % or less.

17. the cleaning blade has a surface layer that contacts the image carrier and a back layer that is disposed on the opposite side of the image carrier with respect to the surface layer, The material constituting the back surface layer is a polymer of a polyol, an isocyanate compound, and a crosslinking agent, and has a crosslinking density of 1.5×10 －３ mol / m ３ 2.5 x 10 or more －３ mol / m ３ 2. The image forming apparatus according to claim 1, wherein the polyurethane is:

18. The crosslink density is 1.8×10 －３ mol / m ３ The above is 2.2 x 10 －３ mol / m ３ 18. The image forming apparatus according to claim 17,

19. 2. The image forming apparatus according to claim 1, wherein the toner particles contain a binder resin including a crystalline resin and an amorphous resin, and the proportion of the crystalline resin in the binder resin is 3% by mass or more and 30% by mass or less.

20. 20. The image forming apparatus according to claim 19, wherein the proportion of the crystalline resin in the binder resin is 5% by mass or more and 25% by mass or less.

21. a charging step of charging the surface of the image carrier; an electrostatic charge forming step of forming an electrostatic image on the charged surface of the image carrier; an electrostatic image developing step of forming a toner image by developing the electrostatic image with an electrostatic image developing toner containing toner particles, the toner particles containing a metal pigment having an average equivalent circular diameter of 5 μm to 15 μm, an average value of the ratio b / a of the major axis diameter a to the minor axis diameter b in a cross section of the toner particles being 0.5 to 0.8, and an average value of the area occupied by the metal pigment in a projected image of the toner particles when viewed from the thickness direction of the toner particles being 0.5 to 0.7; a transfer step of transferring the toner image onto a recording medium; a cleaning step of bringing a cleaning blade into contact with the surface of the image carrier to clean the surface, the cleaning blade having a breaking energy of 5000 MPa % or more and 15000 MPa % or less and a 100% modulus of 10 MPa or more at the contact portion with the image carrier; An image forming method comprising:

Images