Toner, and image forming apparatus

Abstract

To provide a toner that can be charged to a predetermined charge amount and hardly adheres to a regulating member included in an image forming apparatus.SOLUTION: The toner includes toner particles. The toner particles each include a toner mother particle and an external additive attached to a surface of the toner mother particle. The external additive includes fluorine-containing lubricant particles. The surfaces of the toner mother particles have a ten point mean roughness of at least 30nm and no greater than 300nm. The average agglomerated particle size of the fluorine-containing lubricant particles is 200nm or more and 600nm or less. A ten point average roughness Rzt of the surface of the toner mother particle and an average aggregated particle diameter Dp of the fluorine-containing lubricating particles satisfy a formula (1) "1.5 ≤ Dp / Rzt ≤ 20.0".SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a toner and an image forming apparatus. [Background technology]

[0002] When forming an image using an image forming apparatus equipped with a developing unit having a toner carrier and a regulating member, toner may fuse to the regulating member. Toner fusion is particularly likely to occur when the image forming apparatus is used for a long period of time or in a high-temperature, high-humidity environment. The fusion of toner to the regulating member can reduce the toner's triboelectric charging property and cause fogging. To suppress such fogging, for example, in the preparation of toner particles contained in the toner described in Patent Document 1, resin particles are fused to the surface of colored particles containing a binder resin and a colorant by a salting-out / fusion method. The resin particles contain a polymer, and this polymer contains, for example, a polymerizable monomer A having a fluorine atom and a polymerizable monomer B having an acidic polar group as a polymerizable component A and a polymerizable monomer B having an acidic polar group as a polymerizable component B. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-328489 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when toner particles are produced by the method described in Patent Document 1, a polymer having a polymerization component A of a polymerizable monomer A having a fluorine atom is fused to the entire surface of the colored particle. Because fluorine atoms have a high negative charge, the toner described in Patent Document 1 is likely to be charged up to a negative charge due to the influence of the fluorine atoms of the polymer fused to the entire surface of the colored particle. For this reason, it is difficult to control the charge amount of the toner described in Patent Document 1 to a value within a desired range.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a toner that can be charged to a desired charge amount and that is less likely to adhere to a regulating member provided in an image forming apparatus. Another object of the present invention is to provide an image forming apparatus that can charge toner to a desired charge amount and that is less likely to adhere to a regulating member. [Means for solving the problem]

[0006] The toner according to the present invention includes toner particles. The toner particles include toner base particles and an external additive attached to the surface of the toner base particles. The external additive includes fluorine-containing lubricant particles. The ten-point mean roughness of the surface of the toner base particles is 30 nm or more and 300 nm or less. The mean agglomerated particle diameter of the fluorine-containing lubricant particles is 200 nm or more and 600 nm or less. The ten-point mean roughness Rzt of the surface of the toner base particles and the mean agglomerated particle diameter Dp of the fluorine-containing lubricant particles satisfy the following formula (1): 1.5≦Dp / Rzt≦20.0 (1)

[0007] The image forming apparatus according to the present invention includes a developing unit, a toner carrier that carries toner in the form of a toner layer, and a regulating member that contacts the toner layer on the toner carrier and regulates the thickness of the toner layer. [Effects of the Invention]

[0008] The toner according to the present invention can be charged to a desired charge amount and is less likely to adhere to a regulating member provided in an image forming apparatus. Also, the image forming apparatus according to the present invention can charge the toner to a desired charge amount and is less likely to cause the toner to adhere to a regulating member. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 10 is a diagram showing an image forming apparatus according to a second embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of the image carrier and the developing unit shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described. First, the terms used in this specification will be described. A toner is an aggregate (e.g., powder) of toner particles. An external additive is an aggregate (e.g., powder) of external additive particles. Unless otherwise specified, evaluation results (e.g., values ​​indicating shape and physical properties) of a powder (e.g., powder of toner particles and powder of external additive particles) are the number average of values ​​measured for each of a considerable number of particles selected from the powder. Unless otherwise specified, the softening point (Tm) is a value measured using a high-speed flow tester ("CFT-500D" manufactured by Shimadzu Corporation). In the S-shaped curve (horizontal axis: temperature, vertical axis: stroke) measured using the high-speed flow tester, the temperature at which "(baseline stroke value + maximum stroke value) / 2" occurs corresponds to the softening point. Volume median diameter (D 50 Unless otherwise specified, the mean diameter (average diameter) is the cumulative 50% value in the volumetric particle size distribution of the powder, measured using a laser diffraction / scattering particle size analyzer (HORIBA, Ltd., LA-950). Unless otherwise specified, the number-average primary particle diameter is the number average of the equivalent circle diameter (Heywood diameter: the diameter of a circle with the same area as the projected area of ​​a primary particle) of primary particles measured using a scanning electron microscope. Unless otherwise specified, the "major component" of a material refers to the component that is most abundant in the material by mass. Unless otherwise specified, the relative humidity is the value measured in accordance with JIS (Japanese Industrial Standards) Z8806:2001. Hereinafter, the compound name may be followed by "based" to refer to the compound and its derivatives collectively. When the compound name is followed by "based" to refer to a polymer, it means that the repeating unit of the polymer is derived from the compound or its derivative. Acrylic and methacrylic may be collectively referred to as "(meth)acrylic." Acrylonitrile and methacrylonitrile may be collectively referred to as "(meth)acrylonitrile." Each component described in this specification may be used alone or in combination of two or more. The terms used in this specification have been explained above.

[0011] [First embodiment: Toner] The first embodiment of the present invention relates to a toner. The toner of the present invention includes toner particles. The toner particles include toner base particles and an external additive attached to the surface of the toner base particles. The external additive includes fluorine-containing lubricant particles. The ten-point mean roughness of the surface of the toner base particles is 30 nm or more and 300 nm or less. The average agglomerated particle diameter of the fluorine-containing lubricant particles is 200 nm or more and 600 nm or less. The ten-point mean roughness (Rzt) of the surface of the toner base particles and the average agglomerated particle diameter (Dp) of the fluorine-containing lubricant particles satisfy the formula (1) "1.5≦Dp / Rzt≦20.0".

[0012] Hereinafter, the "ten-point average roughness of the surface of the toner base particle" may be referred to as the "toner base particle roughness Rzt." The "average agglomerated particle diameter of the fluorine-containing lubricant particles" may be referred to as the "fluorine-containing lubricant particle diameter Dp." "Dp / Rzt" in formula (1) may be referred to as the "ratio Dp / Rzt."

[0013] By virtue of the above-described configuration, the toner of the present invention can be charged to a desired charge amount and is less likely to adhere to a regulating member provided in an image forming apparatus. The reason for this is presumed to be as follows. Below, an example will be described in which the toner of this embodiment is used in an image forming apparatus equipped with a development unit that employs a non-magnetic one-component development method.

[0014] First, to facilitate understanding, an overview of the developing unit 22 employing a non-magnetic single-component development method will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram illustrating an image forming apparatus 1 according to a second embodiment, which will be described later. FIG. 2 is an enlarged view of the image carrier 23 and developing unit 22 shown in FIG. 1. As shown in FIG. 1, the image forming apparatus 1 includes the developing unit 22 and the image carrier 23. As shown in FIG. 2, the developing unit 22 includes a storage frame 210, a supply roller 220, a toner carrier 230, and a regulating member 240. The storage frame 210 stores toner T therein. At a nip N1 between the supply roller 220 and the toner carrier 230, the supply roller 220 supplies the toner T stored in the storage frame 210 to the toner carrier 230. The toner carrier 230 carries the toner T supplied from the supply roller 220 on its surface (circumferential surface) 230a in the form of a toner layer (a so-called thin toner layer). If the toner layer is thick, only the surface of the toner layer is charged, making it difficult to uniformly charge the entire toner layer. To thin the toner layer, the regulating member 240 contacts the toner T carried on the surface 230a of the toner carrier 230 with a predetermined pressure at the nip N2 between the regulating member 240 and the toner carrier 230, thereby regulating the thickness of the toner layer. Regulating the thickness of the toner layer means adjusting the thickness of the toner layer to a predetermined uniform value. After the thickness is regulated, the toner T contained in the toner layer is supplied from the surface 230a of the toner carrier 230 to the electrostatic latent image formed on the surface (circumferential surface) 23a of the image carrier 23. The electrostatic latent image is then developed into a toner image. The development unit 22 employing the non-magnetic one-component development method has been outlined above with reference to FIGS.

[0015] When the non-magnetic one-component development method is adopted, strong mechanical stress is applied to the toner at the nip between the regulating member and the toner carrier. Furthermore, when the toner carrier is rotated, heat may be generated near the nip between the regulating member and the toner carrier. The mechanical stress and heat may cause the toner to adhere to the regulating member, resulting in the toner particles agglomerating and fusing together. The mechanical stress and heat are particularly likely to be generated when the toner base particles have a rough surface (for example, when the toner base particle roughness Rzt is 30 nm or more).

[0016] Therefore, in this embodiment, the external additive attached to the surface of the toner base particles contains fluorine-containing lubricant particles. The fluorine-containing lubricant particle diameter Dp is 200 nm or more. The toner base particle roughness Rzt is 300 nm or less. The ratio Dp / Rzt is 1.5 or more. By having these configurations, the fluorine-containing lubricant particles that have entered the recesses on the surface of the toner base particles sufficiently protrude relative to the protrusions on the surface of the toner base particles. The protruding fluorine-containing lubricant particles come into contact with the regulating member at the nip between the regulating member and the toner carrier. The contact of the fluorine-containing lubricant particles with the regulating member reduces mechanical stress in the nip and heat generation near the nip.

[0017] On the other hand, if the toner base particle roughness Rzt is less than 30 nm, many of the fluorine-containing lubricant particles will detach from the toner base particles before passing through the nip between the regulating member and the toner carrier. If the fluorine-containing lubricant particle diameter Dp is greater than 600 nm, many of the fluorine-containing lubricant particles will detach from the toner base particles before passing through the nip between the regulating member and the toner carrier. If the ratio Dp / Rzt is greater than 20.0, the fluorine-containing lubricant particles will excessively protrude from the convex portions on the surface of the toner base particles, causing many of the fluorine-containing lubricant particles to detach from the toner base particles before passing through the nip between the regulating member and the toner carrier. Therefore, in this embodiment, the toner base particle roughness Rzt is set to 30 nm or more, the fluorine-containing lubricant particle diameter Dp is set to 600 nm or less, and the ratio Dp / Rzt is set to 20.0 or less. As a result, many of the fluorine-containing lubricant particles reach the nip between the regulating member and the toner carrier while adhering to the toner base particles without detaching from them. This reduces mechanical stress at the nip and heat generation near the nip.

[0018] As described above, the toner of this embodiment can reduce the mechanical stress at the nip between the regulating member and the toner carrier, and the heat generation near the nip, thereby preventing the toner from adhering to the regulating member and preventing the toner particles from aggregating and fusing.

[0019] Here, the fluorine-containing lubricating particles have negative chargeability. If the ratio Dp / Rzt is less than 1.5, the negatively chargeable fluorine-containing lubricating particles remain in excess on the surface of the toner base particles even after passing through the nip between the regulating member and the toner carrier, reducing the chargeability (particularly, positive chargeability) of the toner. In this embodiment, by making the ratio Dp / Rzt 1.5 or more, the toner is charged to a desired charge amount (particularly, a desired positive charge amount). In addition, the occurrence of fog in the formed image can be suppressed.

[0020] The reasons why the toner of the present invention can be charged to a desired charge amount and is less likely to adhere to the regulating member provided in the image forming apparatus have been explained above.

[0021] The toner of the present embodiment is preferably used for developing electrostatic latent images, for example, as a positively charged non-magnetic one-component developing toner, and is preferably used in, for example, an image forming apparatus using a non-magnetic one-component developing method.

[0022] The toner of this embodiment may be a polymerized toner. However, the toner of this embodiment is preferably a pulverized toner. Pulverized toner includes toner particles having toner base particles formed by a pulverization method. On the other hand, polymerized toner includes toner particles having toner base particles formed by an aggregation method. The surfaces of toner base particles of pulverized toner are rougher than those of polymerized toner. For example, the toner base particle roughness Rzt of pulverized toner is likely to be 30 nm or more. Therefore, the mechanical stress and heat generation described above tend to be more pronounced when pulverized toner is used than when polymerized toner is used. However, the toner of this embodiment can reduce the mechanical stress at the nip between the regulating member and the toner carrier and the heat generation near the nip, thereby effectively suppressing toner adhesion to the regulating member, even when the toner is pulverized toner. Another advantage is that the manufacturing cost of pulverized toner is lower than that of polymerized toner. For example, using pulverized toner, which has a low manufacturing cost, in an image forming apparatus using a non-magnetic single-component development method, which has a relatively simple and inexpensive structure, can enhance cost advantages.

[0023] <Toner particles> The toner particles contained in the toner include toner base particles and an external additive. The external additive is attached to the surface of the toner base particles. The toner base particles are, for example, non-capsule toner particles that do not have a shell layer. However, the toner base particles may also be capsule toner particles that include a toner core and a shell layer that covers the toner core.

[0024] <External additives> The external additive contains at least fluorine-containing lubricant particles as external additive particles. The external additive preferably further contains resin particles as external additive particles. The external additive may further contain external additive particles other than the fluorine-containing lubricant particles and resin particles (hereinafter, sometimes referred to as other external additive particles).

[0025] (Fluorine-containing lubricant particles) As mentioned above, the fluorine-containing lubricant particle diameter Dp is 200 nm or more and 600 nm or less. In order to reduce the mechanical stress at the nip between the regulating member and the toner carrier, the fluorine-containing lubricant particle diameter Dp is preferably 250 nm or more, more preferably 450 nm or more, even more preferably more than 500 nm, and even more preferably 505 nm or more.

[0026] The toner is preferably a pulverized toner, and the fluorine-containing lubricant particle diameter Dp is preferably more than 500 nm and not more than 600 nm. As already mentioned, the surface of the toner base particles of pulverized toner is rougher than the surface of the toner base particles of polymerized toner. Therefore, even if the fluorine-containing lubricant particle diameter Dp is large, that is, more than 500 nm and not more than 600 nm, it is possible to suppress detachment from the toner base particles.

[0027] The fluorine-containing lubricant particle diameter Dp can be adjusted, for example, by changing one or both of the type of fluorine-containing lubricant particles and the external addition conditions (for example, the rotation speed and stirring time of the stirrer used for external addition). The fluorine-containing lubricant particle diameter Dp is measured, for example, using a scanning electron microscope photograph.

[0028] The number average primary particle diameter of the fluorine-containing lubricating particles is preferably 100 nm or more and 400 nm or less, and more preferably 200 nm or more and 300 nm or less.

[0029] The fluorine-containing lubricant particles have fluorine atoms. Examples of the fluorine-containing lubricant particles include fluororesin particles. The fluororesin particles contain a fluororesin. The fluororesin content in the fluororesin particles is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 100% by mass.

[0030] Examples of fluororesins include polytetrafluoroethylene (PTFE), perfluoroalkoxy fluororesins, polychlorotrifluoroethylene, polyvinylidene fluoride, polydichlorodifluoroethylene, tetrafluoroethylene-n-perfluoroalkyl vinyl ether copolymers, tetrafluoroethylene-hexafluoropropylene copolymers, tetrafluoroethylene-ethylene copolymers, tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymers, and tetrafluoroethylene-perfluoroalkoxy ethylene copolymers. PTFE is preferred as the fluororesin. Fluorine-containing lubricating particles are preferably fluororesin particles, and PTFE particles are more preferred.

[0031] When the fluorine-containing lubricant particles are fluororesin particles, emulsion polymerization is a preferred method for preparing the fluororesin particles. The fluororesin particles obtained by emulsion polymerization are nearly spherical, making them suitable as external additives for toner. Commercially available fluororesin particles may also be used. Examples of such commercially available products include KTL-500F (manufactured by Kitamura Co., Ltd., number average primary particle diameter 300 nm), Lubron (registered trademark) L2 (manufactured by Daikin Industries, Ltd., number average primary particle diameter 300 nm), Lubron (registered trademark) L5 (manufactured by Daikin Industries, Ltd., number average primary particle diameter 200 nm), Fluon Lubricant L170J (manufactured by Asahi ICI Fluoropolymers Co., Ltd., number average primary particle diameter 100 nm), and Fluon Lube Examples of such polymers include Lycant L172J (manufactured by Asahi ICI Fluoropolymers Co., Ltd., number average primary particle diameter 0.1 μm), MP-1100 (manufactured by Mitsui-Chemours Fluoroproducts Co., Ltd., number average primary particle diameter 200 nm), MP-1200 (manufactured by Mitsui-Chemours Fluoroproducts Co., Ltd., number average primary particle diameter 300 nm), and TLP-10F-1 (manufactured by Mitsui-Chemours Fluoroproducts Co., Ltd., number average primary particle diameter 200 nm).

[0032] The content of the fluorine-containing lubricating particles is preferably 0.1 to 5.0 parts by mass, more preferably 0.2 to 3.0 parts by mass, and even more preferably 0.5 to 1.5 parts by mass, relative to 100.0 parts by mass of the toner base particles. The content of the fluorine-containing lubricating particles in the external additive is preferably 40 to 80% by mass, and more preferably 50 to 70% by mass.

[0033] (resin particles) The resin particles contain a resin. The resin content in the resin particles is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 100% by mass.

[0034] Examples of resins contained in the resin particles include styrene resins, acrylic resins (more specifically, acrylic acid ester polymers and methacrylic acid ester polymers, etc.), polyolefins (more specifically, polyethylene and polypropylene, etc.), vinyl chloride resins, polyvinyl alcohol, vinyl ether resins, N-vinyl resins, polyester resins, polyamide resins, and urethane resins. Copolymers of these resins, i.e., copolymers in which any repeating unit is introduced into the resin (more specifically, styrene-acrylic resins, styrene-butadiene resins, etc.), may also be used. The resin contained in the resin particles does not need to have fluorine atoms.

[0035] The resin contained in the resin particles is preferably a styrene-acrylic resin, which is a polymer of one or more styrene-based monomers and one or more acrylic acid-based monomers.

[0036] When the resin particles contain a styrene-acrylic resin, the styrene-acrylic resin is preferably a cross-linked styrene-acrylic resin. The cross-linked styrene-acrylic resin has a cross-linked structure derived from a cross-linking agent. The cross-linked styrene-acrylic resin is a polymer of one or more styrene-based monomers, one or more acrylic acid-based monomers, and a cross-linking agent.

[0037] Suitable examples of styrene-based monomers include styrene, alkylstyrene, and hydroxystyrene. Examples of alkylstyrenes include α-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, and 4-t-butylstyrene. Examples of hydroxystyrenes include p-hydroxystyrene and m-hydroxystyrene. Styrene is preferred as the styrene-based monomer. The content of repeating units derived from styrene-based monomers in a styrene-acrylic resin (e.g., a crosslinked styrene-acrylic resin) is preferably 5% by mass or more and 15% by mass or less.

[0038] Suitable examples of acrylic acid monomers include (meth)acrylic acid, (meth)acrylonitrile, (meth)acrylic acid alkyl esters, and (meth)acrylic acid hydroxyalkyl esters. Suitable examples of (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate (more specifically, n-propyl (meth)acrylate and iso-propyl (meth)acrylate), butyl (meth)acrylate (more specifically, n-butyl (meth)acrylate and iso-butyl (meth)acrylate), and 2-ethylhexyl (meth)acrylate. Suitable examples of (meth)acrylic acid hydroxyalkyl esters include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. The acrylic acid monomer is preferably a (meth)acrylic acid alkyl ester, more preferably butyl (meth)acrylate, further preferably n-butyl (meth)acrylate, and particularly preferably n-butyl methacrylate. The content of repeating units derived from acrylic acid monomers in the styrene-acrylic resin (e.g., crosslinked styrene-acrylic resin) is preferably 50% by mass or more and 60% by mass or less.

[0039] The crosslinking agent has two or more unsaturated bonds (e.g., carbon-carbon double bonds). Suitable examples of the crosslinking agent include N,N'-methylenebisacrylamide, divinylbenzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, 1,4-butanediol dimethacrylate, and 1,6-hexanediol dimethacrylate. Divinylbenzene is preferred as the crosslinking agent. The content of repeating units derived from the crosslinking agent having two or more unsaturated bonds in the crosslinked styrene-acrylic resin is preferably 30% by mass or more and 40% by mass or less.

[0040] The resin particles are preferably styrene-acrylic resin particles, more preferably cross-linked styrene-acrylic resin particles, and have a number average primary particle diameter of preferably 40 nm to 100 nm, more preferably 45 nm to 90 nm.

[0041] The content of the resin particles is preferably 0.1 to 5.0 parts by mass, more preferably 0.5 to 3.0 parts by mass, and even more preferably 0.7 to 1.4 parts by mass, relative to 100.0 parts by mass of the toner base particles. The content of the resin particles in the external additive is preferably 20 to 60% by mass, and more preferably 30 to 50% by mass.

[0042] (Other external additive particles) Examples of other external additive particles include silica particles, particles of metal oxides (specifically, magnesium oxide, zinc oxide, etc.), and particles of organic acid compounds such as fatty acid metal salts (specifically, zinc stearate, etc.). The content of other external additive particles is, for example, 0.1 parts by mass or more and 5.0 parts by mass or less relative to 100.0 parts by mass of the toner base particles.

[0043] <Toner base particles> As mentioned above, the toner base particle roughness Rzt is 30 nm or more and 300 nm or less. To balance the reduction of mechanical stress at the nip between the regulating member and the toner carrier and the prevention of detachment of fluorine-containing lubricant particles from the toner base particles, the toner base particle roughness Rzt is preferably 50 nm or more and 250 nm or less. The toner base particle roughness Rzt can be adjusted, for example, by changing the pulverization conditions when forming the toner base particles (e.g., the number of pulverizations, material input rate, and rotation speed of the pulverizer). The toner base particle roughness Rzt can also be adjusted by thermal shape control, such as with Meteoraidbo. The toner base particle roughness Rzt can also be adjusted, for example, by shape control, such as by heating the pulverized toner in water. The toner base particle roughness Rzt is measured, for example, using a scanning probe microscope according to the method described in JIS (Japanese Industrial Standards) B0601:2013 or a method equivalent thereto.

[0044] As already mentioned, the toner base particle roughness Rzt and the fluorine-containing lubricant particle diameter Dp satisfy the formula (1) "1.5≦Dp / Rzt≦20.0". That is, the ratio Dp / Rzt is 1.5 or more and 20.0 or less. In order to balance the reduction of mechanical stress at the nip between the regulating member and the toner carrier and the suppression of detachment of the fluorine-containing lubricant particles from the toner base particles, the ratio Dp / Rzt is preferably 2.0 or more and 15.0 or less, and more preferably 3.0 or more and 10.0 or less.

[0045] To ensure sufficient toner chargeability (especially positive chargeability) while reducing mechanical stress at the nip between the regulating member and the toner carrier, the area ratio of the surface area of ​​the toner base particles covered with fluorine-containing lubricating particles is preferably 0.2% to 2.0%, more preferably 0.5% to 1.5%. Hereinafter, the "area ratio of the surface area of ​​the toner base particles covered with fluorine-containing lubricating particles" may be referred to as the "predetermined coverage." The area covered with fluorine-containing lubricating particles is, in other words, the area to which the fluorine-containing lubricating particles adhere. The predetermined coverage can be adjusted, for example, by changing the amount of fluorine-containing lubricating particles added relative to the mass of the toner base particles and / or the external addition conditions (e.g., the rotation speed and stirring time of the agitator used for external addition). The predetermined coverage can be measured, for example, by capturing a backscattered electron image of the toner particles using a scanning electron microscope and analyzing the backscattered electron image.

[0046] The toner base particles contain, for example, a binder resin as a main component, and may further contain an internal additive (for example, at least one of a colorant, a release agent, a charge control agent, and other additives) as needed.

[0047] (binder resin) The content of the binder resin in the toner base particles is preferably 60% by mass or more and 95% by mass or less, and more preferably 75% by mass or more and 90% by mass or less. From the viewpoint of improving the low-temperature fixability of the toner, the softening point of the binder resin is preferably 100°C or more and 150°C or less.

[0048] From the viewpoint of improving the low-temperature fixability of the toner, the toner base particles preferably contain a thermoplastic resin as a binder resin, and more preferably contain the thermoplastic resin in a proportion of 85% by mass or more of the total binder resin. Examples of thermoplastic resins include styrene resins, acrylic resins, polyolefins (e.g., polyethylene and polypropylene), vinyl resins (e.g., vinyl chloride resins, polyvinyl alcohol, vinyl ether resins, and N-vinyl resins), polyesters, polyamides, and urethane resins. Copolymers of these resins, i.e., copolymers in which any repeating unit is introduced into the above resins (e.g., styrene-acrylic resins and styrene-butadiene resins), can also be used as binder resins.

[0049] From the viewpoint of improving the low-temperature fixability of the toner, polyester resins are preferred as binder resins. Polyester resins are obtained by polycondensation of one or more polyhydric alcohols and one or more polycarboxylic acids. Examples of polyhydric alcohols used to synthesize polyester resins include dihydric alcohols (e.g., diol compounds and bisphenol compounds) and trihydric or higher alcohols. Examples of polycarboxylic acids used to synthesize polyester resins include dicarboxylic acids and tricarboxylic or higher carboxylic acids. Note that instead of polycarboxylic acids, polycarboxylic acid derivatives capable of forming ester bonds by polycondensation (e.g., polycarboxylic acid anhydrides and polycarboxylic acid halides) may be used.

[0050] Examples of diol compounds include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 2-butene-1,4-diol, 1,5-pentanediol, 2-pentene-1,5-diol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, 1,4-benzenediol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

[0051] Examples of bisphenol compounds include bisphenol A, hydrogenated bisphenol A, ethylene oxide adducts of bisphenol A (for example, polyoxyethylene(2.2)-2,2-bis(4-hydroxyphenyl)propane), and propylene oxide adducts of bisphenol A.

[0052] Examples of trihydric or higher alcohols include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, diglycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene.

[0053] Examples of divalent carboxylic acids include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, terephthalic acid, isophthalic acid, cyclohexanedicarboxylic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, succinic acid, alkylsuccinic acids (more specifically, n-butylsuccinic acid, isobutylsuccinic acid, n-octylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid), and alkenylsuccinic acids (more specifically, n-butenylsuccinic acid, isobutenylsuccinic acid, n-octenylsuccinic acid, n-dodecenylsuccinic acid, isododecenylsuccinic acid).

[0054] Examples of trivalent or higher carboxylic acids include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxylpropane, 1,2,4-cyclohexanetricarboxylic acid, tetra(methylenecarboxyl)methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, and empol trimer acid.

[0055] The polyester resin is preferably a condensation polymer of bisphenol A ethylene oxide adduct, terephthalic acid, and trimellitic acid, and more preferably a condensation polymer of polyoxyethylene(2,2)-2,2-bis(4-hydroxyphenyl)propane, terephthalic acid, and trimellitic acid.

[0056] (coloring agent) As the colorant, a known pigment or dye can be used in accordance with the color of the toner. From the viewpoint of forming a high-quality image using the toner, the content of the colorant is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

[0057] The toner base particles may contain a black colorant. Examples of black colorants include carbon black. The black colorant may also be a colorant toned to black using a yellow colorant, a magenta colorant, and a cyan colorant.

[0058] The toner base particles may contain color colorants, such as yellow colorants, magenta colorants, and cyan colorants.

[0059] The yellow colorant may be, for example, one or more compounds selected from the group consisting of condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and arylamide compounds. Examples of the yellow colorant include CI Pigment Yellow (3, 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 191, and 194), Naphthol Yellow S, Hansa Yellow G, and CI Vat Yellow.

[0060] Examples of magenta colorants that can be used include one or more compounds selected from the group consisting of condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Examples of magenta colorants include CI Pigment Red (2, 3, 5, 6, 7, 19, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254).

[0061] The cyan colorant may be, for example, one or more compounds selected from the group consisting of copper phthalocyanine compounds, anthraquinone compounds, and basic dye lake compounds, including, for example, CI Pigment Blue (1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66), phthalocyanine blue, CI Vat Blue, and CI Acid Blue.

[0062] (mold release agent) The release agent is used, for example, for the purpose of imparting offset resistance to the toner. From the viewpoint of imparting sufficient offset resistance to the toner, the content of the release agent is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

[0063] Examples of release agents include aliphatic hydrocarbon waxes, oxidized aliphatic hydrocarbon waxes, vegetable waxes, animal waxes, mineral waxes, ester waxes primarily composed of fatty acid esters, and waxes in which fatty acid esters have been partially or completely deoxidized. Examples of aliphatic hydrocarbon waxes include low-molecular-weight polyethylene, low-molecular-weight polypropylene, polyolefin copolymers, polyolefin waxes, microcrystalline waxes, paraffin waxes, and Fischer-Tropsch waxes. Examples of oxidized aliphatic hydrocarbon waxes include oxidized polyethylene waxes and block copolymers of oxidized polyethylene waxes. Examples of vegetable waxes include candelilla wax, carnauba wax, Japan wax, jojoba wax, and rice wax. Examples of animal waxes include beeswax, lanolin, and spermaceti. Examples of mineral waxes include ozokerite, ceresin, and petrolatum. Examples of ester waxes primarily composed of fatty acid esters include Montan acid ester wax and castor wax. Examples of waxes in which fatty acid esters have been partially or completely deoxidized include deoxidized carnauba wax. As the release agent, carnauba wax is preferred.

[0064] (charge control agent) Charge control agents are used, for example, for the purpose of providing a toner having excellent charge stability or excellent charge rise characteristics. The charge rise characteristics of a toner are an index of whether the toner can be charged to a predetermined charge level in a short period of time. By incorporating a positively chargeable charge control agent into the toner base particles, the cationic nature of the toner base particles can be strengthened.

[0065] From the viewpoint of obtaining a toner having excellent charge stability, the content of the charge control agent is preferably 0.1 to 30 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of the binder resin.

[0066] Examples of positively chargeable charge control agents include azine compounds, direct dyes, acid dyes, alkoxylated amines, alkylamides, quaternary ammonium salt compounds, and resins containing quaternary ammonium cation groups. Quaternary ammonium salt compounds are preferred as charge control agents.

[0067] (Other additives) Examples of other additives that may be contained in the toner base particles include a compatibilizer, a pH adjuster, and other known additives.

[0068] <Toner manufacturing method> The toner of the present embodiment can be produced, for example, by carrying out a toner base particle forming step and an external addition step.

[0069] (Toner base particle formation process) In the toner base particle forming step, the toner base particles are formed by, for example, an aggregation method or a pulverization method.

[0070] The aggregation method includes, for example, an aggregation step and a coalescence step. In the aggregation step, fine particles containing components constituting the toner base particles are aggregated in an aqueous medium to form aggregated particles. In the coalescence step, components contained in the aggregated particles are coalesced in the aqueous medium to form toner base particles.

[0071] In order to adjust the toner base particle roughness Rzt to a value within a desired range, it is preferable to form the toner base particles by a pulverization method. Furthermore, the pulverization method allows toner base particles to be formed relatively easily and also enables reduction in production costs. When the toner base particles are formed by the pulverization method, the toner base particle formation process includes, for example, a kneading process and a pulverization process. The toner base particle formation process may further include a mixing process before the kneading process. Furthermore, the toner base particle formation process may further include at least one of a fine pulverization process and a classification process after the pulverization process.

[0072] In the mixing step, a binder resin and an internal additive, which is added as needed, are mixed to obtain a mixture. In the kneading step, the toner materials (for example, the mixture obtained in the mixing step) are melted and kneaded to obtain a kneaded product. In the pulverizing step, the obtained kneaded product is cooled, for example, to room temperature (25°C), and then pulverized to obtain a pulverized product. If it is necessary to reduce the diameter of the pulverized product obtained in the pulverizing step, a fine pulverizing step may be carried out to further pulverize the pulverized product. Furthermore, if the particle size of the pulverized product is to be uniform, a classification step may be carried out to classify the pulverized product. Through the above steps, toner base particles, which are the pulverized product, are obtained.

[0073] (External addition process) In the external addition step, an external additive (more specifically, an external additive containing fluorine-containing lubricant particles) is attached to the surface of the toner base particles to obtain a toner containing toner particles. In the external addition step, the toner base particles and the external additive are stirred, for example, with a stirrer, to cause the external additive to be attached to the surface of the toner base particles. When the external additive is attached by stirring, the toner base particles and the external additive particles are physically fixed to each other, not chemically (i.e., without chemical reaction).

[0074] [Second embodiment: image forming apparatus] The second embodiment of the present invention relates to an image forming apparatus. Hereinafter, an image forming apparatus 1, which is an example of the image forming apparatus of the present invention, will be described with reference to FIGS. 1 and 2 again. Note that the same reference symbols in the drawings represent the same or corresponding parts. Dimensional relationships such as length, width, thickness, and depth have been changed as appropriate for clarity and simplification of the drawings, and do not represent actual dimensional relationships.

[0075] As shown in FIG. 1, the image forming apparatus 1 includes a paper feed section 10, a conveyance section 11, an image forming section 12, a fixing section 13, a discharge section 14, and a control section 15.

[0076] The paper feed unit 10 includes a paper feed cassette 30 and a paper feed roller group 31. The paper feed cassette 30 can accommodate multiple recording media P. The paper feed roller group 31 feeds the recording media P accommodated in the paper feed cassette 30 one by one to the conveyance unit 11. The recording media P are made of, for example, paper or synthetic resin.

[0077] The conveying section 11 extends from the paper feeding section 10 to the discharge section 14. The conveying section 11 conveys the recording medium P from the paper feeding section 10 to the discharge section 14, passing through the image forming section 12 and the fixing section 13.

[0078] The image forming unit 12 includes an exposure unit 20, a charging unit 21, a developing unit 22, toner T (see FIG. 2), an image carrier 23, a cleaning unit 24, and a transfer unit 25. The charging unit 21, the developing unit 22, the transfer unit 25, and the cleaning unit 24 are arranged along the circumferential surface of the image carrier 23 in the order listed from the upstream side in the rotation direction R of the image carrier 23 (clockwise direction in FIG. 1).

[0079] The charging unit 21 uniformly charges the image carrier 23 to a preset polarity.

[0080] The exposure unit 20 irradiates (exposes) light onto the surface 23a (see FIG. 2) of the charged image carrier 23. The exposure unit 20 exposes the surface 23a of the image carrier 23 based on image data input to the image forming apparatus 1. As a result, an electrostatic latent image is formed on the surface 23a of the image carrier 23.

[0081] The developing unit 22 contains toner T. The developing unit 22 supplies the toner T to the electrostatic latent image formed on the surface 23a of the image carrier 23, and develops the electrostatic latent image into a toner image. Details of the developing unit 22 will be described later.

[0082] The toner T is the toner described in the first embodiment. Therefore, for the same reasons as those described in the first embodiment, the image forming apparatus 1 including the toner T can charge the toner T to a desired charge amount, and the toner T is less likely to adhere to the regulating member 240 (see FIG. 2).

[0083] The image carrier 23 carries a toner image on its surface 23a. The image carrier 23 is, for example, a photosensitive drum.

[0084] The transfer unit 25 is disposed opposite the image carrier 23 and transfers the toner image on the image carrier 23 onto the recording medium P.

[0085] The cleaning unit 24 collects the toner T remaining on the surface 23a of the image carrier 23 after transfer from the surface 23a of the image carrier 23.

[0086] The fixing unit 13 includes a heating unit 40 and a pressure unit 41. The heating unit 40 and the pressure unit 41 are arranged opposite each other. The pressure unit 41 presses the heating unit 40 to form a fixing nip. The recording medium P onto which the toner image has been transferred passes through the fixing nip and is heated and pressurized. As a result, the toner T is fixed to the recording medium P. The recording medium P is transported from the fixing unit 13 to the discharge unit 14 by the transport unit 11.

[0087] The discharge section 14 includes a discharge roller pair 60 and a discharge tray 61. The discharge roller pair 60 discharges the recording medium P onto the discharge tray 61.

[0088] The control unit 15 controls the operation of each unit included in the image forming apparatus 1. The control unit 15 is, for example, a processor such as a CPU (Central Processing Unit). The control unit 15 comprehensively controls the operation of the image forming apparatus 1 to realize various functions.

[0089] Next, the details of the developing unit 22 will be described with reference to Figure 2. The developing unit 22 employs a non-magnetic single-component development method. As already mentioned, the developing unit 22 includes a storage frame 210, a supply roller 220, a toner carrier 230, and a regulating member 240. The lengths of the supply roller 220 and the toner carrier 230 in the axial direction (the direction perpendicular to the paper surface of Figure 2) are approximately the same as the length of the image carrier 23.

[0090] The storage frame 210 stores toner T therein. The storage frame 210 includes a supply roller 220, a toner carrier 230, and a regulating member 240 therein. The storage frame 210 has an opening 211, which is disposed opposite the image carrier 23. The opening 211 exposes a portion of the toner carrier 230 to the outside of the storage frame 210.

[0091] Supply roller 220 is supported so as to be rotatable in the direction of the arrow in FIG. 2 (counterclockwise in FIG. 2). Supply roller 220 carries toner T contained inside storage frame 210 on its surface (circumferential surface). A nip N1 is provided between toner carrier 230 and supply roller 220. In nip N1, supply roller 220 supplies toner T carried on its surface to toner carrier 230. In addition, in nip N1, toner T on supply roller 220 comes into contact with toner carrier 230, thereby causing toner T to be frictionally charged.

[0092] The toner carrier 230 is supported so as to be rotatable in the direction of the arrow in FIG. 2 (counterclockwise in FIG. 2). The toner carrier 230 is disposed opposite the supply roller 220. The toner carrier 230 is also disposed opposite the image carrier 23 through the opening 211 of the storage frame 210. The toner carrier 230 carries the toner T supplied from the supply roller 220 on its surface (circumferential surface) 230a in the form of a toner layer. The toner T is carried on the surface 230a of the toner carrier 230 due to the image force acting between the toner carrier 230 and the toner T. The toner carrier 230 is, for example, a development roller.

[0093] The toner carrier 230 includes a conductive support 231, an elastic layer 232, and a coating layer 233. The elastic layer 232 is provided on the conductive support 231 (specifically, on the outer peripheral surface of the conductive support 231). The elastic layer 232 is made of, for example, silicone rubber. The coating layer 233 is provided on the elastic layer 232 (specifically, on the outer peripheral surface of the elastic layer 232). The coating layer 233 is made of, for example, urethane.

[0094] The regulating member 240 is plate-shaped. One end 241 of the regulating member 240 is fixed to the storage frame 210, and the other end 242 is a free end. The regulating member 240 is bent toward the opposite side to the toner carrier 230 near the outer edge of the other end 242 (free end). The regulating member 240 is made of, for example, stainless steel (SUS). The regulating member 240 is, for example, a regulating blade.

[0095] The regulating member 240 is flexible and deformable so that the other end 242 approaches the toner carrier 230. The toner carrier 230 has one or more magnet portions (not shown) therein. The regulating member 240 is magnetic. The other end 242 of the magnetic regulating member 240 is urged toward the toner carrier 230 by the magnetic force generated by the magnet portion of the toner carrier 230. In this way, a nip N2 is formed between the regulating member 240 and the surface 230a of the toner carrier 230. In the nip N2, the regulating member 240 comes into contact with the toner layer on the toner carrier 230 (specifically, the toner layer formed on the surface 230a of the toner carrier 230) with a predetermined pressure to regulate the thickness of the toner layer. In order to regulate the thickness of the toner layer within a desired range, the contact line pressure of the regulating member 240 with respect to the toner layer on the toner carrier is preferably 15 N / m or more and 60 N / m or less, and more preferably 30 N / m or more and 60 N / m or less. Furthermore, at the nip N2, the toner T on the toner carrier 230 comes into contact with the regulating member 240, thereby further triboelectrically charging the toner T.

[0096] When a development bias is applied to the toner carrier 230, the toner T contained in the toner layer is supplied from the toner carrier 230 to the electrostatic latent image formed on the surface 23a of the image carrier 23 through the opening 211. The details of the developing unit 22 have been described above with reference to FIG.

[0097] 1 has been described as an example of the image forming apparatus of the second embodiment. However, the image forming apparatus of the second embodiment is not limited to the image forming apparatus 1 described above, and can be modified in the following ways, for example.

[0098] For example, in the second embodiment, the image forming apparatus 1 is an apparatus that records an image using a single color toner T, but this is not limiting. The image forming apparatus 1 may also be an apparatus that records a color image using multiple color toners T.

[0099] For example, in the second embodiment, the regulating member 240 is plate-shaped, but this is not limiting. The regulating member 240 may be roller-shaped. When the regulating member 240 is roller-shaped, the peripheral surface of the roller-shaped regulating member 240 comes into contact with the toner layer on the toner carrier 230 (specifically, the toner layer formed on the surface 230a of the toner carrier 230) with a predetermined pressure, thereby regulating the thickness of the toner layer. [Example]

[0100] Examples of the present invention will be described below, but the present invention is not limited to the scope of the examples. First, a method for measuring the number average primary particle diameter will be described.

[0101] [Number average primary particle size] The number-average primary particle diameter of external additive particles (for example, styrene acrylic resin particles) was determined from particle projection images taken using a scanning electron microscope ("JSM-7600F" manufactured by JEOL Ltd.) Specifically, the external additive particles were observed using the scanning electron microscope, and the number-average primary particle diameter was determined as the number-average circle-equivalent diameter (Heywood diameter: diameter of a circle having the same area as the projected area of ​​a primary particle) of 100 external additive particles.

[0102] [Fluorine-containing lubricant particles] The following commercially available products were used as fluorine-containing lubricating particles used as external additives. Fluorine-containing lubricant particles (F1): PTFE particles (Kitamura Co., Ltd. "KTL-500F") Fluorine-containing lubricating particles (F2): PTFE particles ("Lubron (registered trademark) L-5" manufactured by Daikin Industries, Ltd.) Fluorine-containing lubricating particles (F3): PTFE particles ("Lubron (registered trademark) L-2" manufactured by Daikin Industries, Ltd.)

[0103] [Styrene acrylic resin particles] Styrene acrylic resin particles to be used as an external additive were prepared by the following method.

[0104] <Preparation of styrene acrylic resin particles (RA)> A four-neck flask equipped with a stirrer, condenser, thermometer, and nitrogen inlet tube was charged with 600 g of ion-exchanged water, 6 g of emulsifier sodium dodecylbenzenesulfonate, 100 g of n-butyl methacrylate, 20 g of styrene, 15 g of initiator benzoyl peroxide, and 70 g of crosslinker divinylbenzene. Nitrogen gas was then introduced into the flask while stirring the contents, creating a nitrogen atmosphere inside the flask. The temperature of the flask contents was then raised to 90°C under a nitrogen atmosphere while stirring the contents. The contents were then subjected to a polymerization reaction for 200 minutes (hereinafter referred to as polymerization time Z) under the conditions of a nitrogen atmosphere and a temperature of 90°C. This resulted in an emulsion containing the reaction product. The resulting emulsion was cooled, washed, and dehydrated to obtain styrene-acrylic resin particles (RA). The styrene-acrylic resin particles (RA) were a polymer of n-butyl methacrylate, styrene, and divinylbenzene, and had a crosslinked structure derived from divinylbenzene. The number average primary particle diameter of the styrene acrylic resin particles (RA) was 90.0 nm.

[0105] <Preparation of styrene acrylic resin particles (RB)> Styrene-acrylic resin particles (RB) were prepared in the same manner as styrene-acrylic resin particles (RA), except that the polymerization time Z was changed to 90 minutes. The styrene-acrylic resin particles (RB) were a polymer of n-butyl methacrylate, styrene, and divinylbenzene, and had a crosslinked structure derived from divinylbenzene. The number-average primary particle diameter of the styrene-acrylic resin particles (RB) was 45.0 nm.

[0106] [Binder resin] A polyester resin (PE) used as a binder resin for toner base particles was prepared by the following method. 1.0 mol of polyoxyethylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, 4.5 mol of terephthalic acid, 0.5 mol of trimellitic anhydride, and 4 g of dibutyltin oxide were placed in a reaction vessel. The contents of the reaction vessel were reacted at 230°C for 8 hours under a nitrogen atmosphere. Next, unreacted raw materials in the reaction vessel were distilled off under reduced pressure at 8.3 kPa. The resulting reaction product was washed and then dried. This yielded a polyester resin (PE) with a softening point of 120°C.

[0107] [Toner production] Toners (T-A1) to (T-A5) according to the present invention and toners (T-B1) to (T-B10) according to the comparative examples were prepared by the following method. The preparation conditions for each toner are shown in Tables 1 and 2 below.

[0108] [Table 1]

[0109] [Table 2]

[0110] The abbreviations used in Tables 1 and 2 are as follows: -: No relevant fine grinding has been carried out Amount: Amount added per 100.0 parts by mass of toner base particles Part: Part by weight Diameter: Number average primary particle diameter Lubricating particles: Fluorine-containing lubricating particles Resin particles: styrene acrylic resin particles

[0111] <Preparation of Toner (T-A1)> (Formation of toner base particles) 100 parts by weight of the polyester resin (PE) as a binder resin, 5 parts by weight of carbon black (REGAL® 330R, manufactured by Cabot Specialty Chemicals) as a colorant, 10 parts by weight of carnauba wax (Carnauba No. 1, manufactured by Kato Yoko Co., Ltd.) as a mold release agent, and 3 parts by weight of a quaternary ammonium salt compound (FCA210PS, manufactured by Fujikura Kasei Co., Ltd.) as a charge control agent were mixed using an FM mixer (FM20B, manufactured by Nippon Coke & Engineering Co., Ltd.). The resulting mixture was melted and kneaded at 150°C using a twin-screw extruder (TEM45, manufactured by Toshiba Machine Co., Ltd.). The resulting kneaded mixture was cooled. The cooled kneaded mixture was coarsely pulverized using an impact screen-type fine pulverizer (Feathermill® FM-2S 350 x 600, manufactured by Hosokawa Micron Corporation).

[0112] The obtained coarsely pulverized material was finely pulverized three times (hereinafter referred to as "fine pulverization times A") using a mechanical pulverizer. A turbo mill (Freund Turbo Corporation, model: RSS type) was used as the mechanical pulverizer. The first fine pulverization was carried out under the conditions of a raw material input rate (hereinafter referred to as "input rate B") of 15 kg / h and a rotor rotation speed (hereinafter referred to as "rotation speed C") in the pulverizer of 9000 rpm. The second and third fine pulverizations were carried out under the conditions of an input rate B of 7 kg / h and a rotor rotation speed C of 7000 rpm.

[0113] The resulting finely pulverized material was classified using a classifier (Nitetsu Mining Co., Ltd., "Elbow Jet EJ-LABO type") to obtain toner base particles. 50 ) was 8 μm.

[0114] (external attachment) Using an FM mixer ("FM-10B" manufactured by Nippon Coke & Engineering Co., Ltd.), 100.0 parts by mass of toner base particles, 1.0 parts by mass of fluorine-containing lubricant particles (F1), 0.6 parts by mass of styrene-acrylic resin particles (RB), and 1.4 parts by mass of positively charged silica particles ("REA90" manufactured by Nippon Aerosil Co., Ltd.) were stirred at a rotation speed (hereinafter referred to as "rotation speed D") of 3500 rpm for 10 minutes (hereinafter referred to as "stirring time E"). By stirring, the external additives, fluorine-containing lubricant particles (F1), styrene-acrylic resin particles (RB), and positively charged silica particles, adhered to the surface of the toner base particles, resulting in toner particles. In this way, a toner (T-A1) containing toner particles was obtained.

[0115] <Preparation of Toners (T-A2) to (T-A5) and (T-B1) to (T-B10)> Toners (T-A2) to (T-A5) and (T-B1) to (T-B10) were produced in the same manner as toner (T-A1), except that in the formation of the toner base particles, the number of times of pulverization A, the input speed B, and the rotation speed C were as shown in Table 1, and in the external addition, the type and amount of fluorine-containing lubricant particles, the type and amount of styrene acrylic resin particles, the rotation speed D, and the stirring time E were as shown in Table 2.

[0116] In the formation of the toner base particles, the toner base particle roughness Rzt was adjusted to a desired value by changing the number of times of fine pulverization A, the feeding speed B, and the rotation speed C. In the external addition, the rotation speed D and the stirring time E were changed to adjust the fluorine-containing lubricant particle diameter Dp to a desired value.

[0117] [measurement] The toner base particle roughness Rzt, fluorine-containing lubricant particle diameter Dp, ratio Dp / Rzt, and predetermined coverage were measured by the following methods. The measurement results are shown in Table 3 below.

[0118] <Toner particle roughness Rzt> The toner base particle roughness Rzt was measured using a scanning probe microscope (SPM, "Multifunctional Unit AFM5200S" manufactured by Hitachi High-Tech Science Corporation) under the following measurement conditions.

[0119] (Measurement conditions) Measurement mode: DFM (resonance mode) shape image Cantilever: SI-DF3-R Resolution (X data / Y data): 256 / 256 Measurement area: 1 μm square area at the center of the surface of a toner base particle observed using a scanning probe microscope

[0120] <Fluorine-containing lubricant particle diameter Dp> The fluorine-containing lubricant particle diameter Dp was measured using a scanning electron microscope (field emission scanning electron microscope, "JSM-7600F" manufactured by JEOL Ltd.) The aggregate particle diameters of 100 fluorine-containing lubricant particles were measured, and the number average value was taken as the fluorine-containing lubricant particle diameter Dp.

[0121] <Ratio Dp / Rzt> The ratio Dp / Rzt was calculated from the formula "Ratio Dp / Rzt=Fluorine-containing lubricant particle diameter Dp / Toner base particle roughness Rzt".

[0122] <Prescribed coverage rate> The toner particles contained in the toner were observed using a field emission scanning electron microscope (FE-SEM) (JEOL Ltd., "JSM-7600F"), and a backscattered electron image (surface image) of the toner particles was obtained. The surface image was analyzed using image analysis software (Mitani Shoji Co., Ltd., "WinROOF") to determine the predetermined coverage. The predetermined coverage corresponds to the area ratio of the surface area of ​​the toner base particle that is covered with fluorine-containing lubricant particles.

[0123] In addition, with respect to a portion on the surface of a toner base particle where multiple types of external additive particles overlap, it was determined that the outermost external additive particle (more specifically, the external additive particle located farthest from the surface of the toner base particle) covers that portion. For example, on the surface of a toner base particle, a portion where styrene acrylic resin particles and fluorine-containing lubricating particles overlap in this order was determined to be covered by the outermost fluorine-containing lubricating particle.

[0124] In the measurement procedure, first, the predetermined coverage F1 was measured in 10 visual fields (dimensions of one visual field: 2 μm × 2 μm) for each toner particle. The arithmetic mean of the 10 predetermined coverage F1 values ​​obtained in each visual field was taken as the predetermined coverage F2 of that toner particle. Furthermore, the predetermined coverage F2 was measured for each of the 10 toner particles contained in the toner. The arithmetic mean of the predetermined coverage F2 values ​​obtained for the 10 toner particles was taken as the predetermined coverage of the toner.

[0125] [Table 3]

[0126] [evaluation] The charge amount of the toner on the developing roller and the adhesion of the toner to the regulating blade were evaluated for each toner by the following methods. The evaluation results are shown in Table 4 below.

[0127] <Amount of charge> A monochrome printer ("PA2000" manufactured by Kyocera Document Solutions Inc.) was used as the evaluation machine. This evaluation machine was equipped with a development unit including a development roller and a regulating blade. The contact line pressure of the regulating blade was set to 40 N / m. Toner was set in the evaluation machine. Images were printed on 500 sheets of paper using the evaluation machine under the condition of two-sheet intermittent printing in an environment of 23°C temperature and 50% relative humidity (NN environment). After printing 500 sheets, the toner on the development roller of the evaluation machine was sucked using a Q / m meter ("MODEL 210HS-1" manufactured by Trek) and its charge amount (unit: +μC / g) was measured. The charge amount of the toner on the development roller was evaluated according to the following criteria.

[0128] (Standard for charge amount) A (good): The toner charge amount is +15 μC / g or more. B (bad): The toner charge amount is less than +15 μC / g.

[0129] <Toner adhesion> After printing the above 500 sheets, the regulating blade of the evaluation machine was visually observed to check whether or not toner was adhering to the regulating blade. Toner adhesion was judged according to the following criteria.

[0130] (Toner adhesion standard) A (Good): No toner is adhering to the regulating blade. B (Fail): Toner is attached to the regulation blade.

[0131] In addition to the above evaluation, the presence or absence of fog was checked for the image printed on the 500th sheet. If fog was found, this was noted in the "Remarks" column of Table 4.

[0132] [Table 4]

[0133] The toner (T-B1) had a toner base particle roughness Rzt of less than 30 nm. The evaluation of toner adhesion of the toner (T-B1) was poor.

[0134] In the toner (T-B2), the toner base particle roughness Rzt was less than 30 nm, and the ratio Dp / Rzt was more than 20.0 The evaluation of toner adhesion of the toner (T-B2) was poor.

[0135] In the toner (T-B3), the fluorine-containing lubricant particle diameter Dp was greater than 600 nm, and the ratio Dp / Rzt was greater than 20.0 The evaluation of toner adhesion of the toner (T-B3) was poor.

[0136] In the toner (T-B4), the fluorine-containing lubricant particle diameter Dp was less than 200 nm, and the ratio Dp / Rzt was less than 1.5. The evaluation of toner adhesion of the toner (T-B4) was poor.

[0137] The ratio Dp / Rzt of the toner (T-B5) was less than 1.5. The evaluation of the charge amount of the toner (T-B5) was poor. In addition, fog also occurred in the formed image.

[0138] In the toner (T-B6), the fluorine-containing lubricant particle diameter Dp was more than 600 nm. The evaluation of the toner adhesion of the toner (T-B6) was poor.

[0139] In the toner (T-B7), the toner base particle roughness Rzt was more than 300 nm, and the fluorine-containing lubricant particle diameter Dp was more than 600 nm. The evaluation of toner adhesion and the evaluation of charge amount of the toner (T-B7) were poor.

[0140] In the toner (T-B8), the toner base particle roughness Rzt was more than 300 nm, and the fluorine-containing lubricant particle diameter Dp was more than 600 nm. The evaluation of toner adhesion of the toner (T-B8) was poor.

[0141] In the toner (T-B9), the toner base particle roughness Rzt was more than 300 nm, and the ratio Dp / Rzt was less than 1.5. The evaluation of the toner adhesion of the toner (T-B9) was poor.

[0142] In the toner (T-B10), the fluorine-containing lubricant particle diameter Dp was less than 200 nm, and the ratio Dp / Rzt was less than 1.5. The evaluation of toner adhesion of the toner (T-B10) was poor.

[0143] On the other hand, in toners (T-A1) to (T-A5), the toner base particle roughness Rzt was 30 nm or more and 300 nm or less, the fluorine-containing lubricant particle diameter Dp was 200 nm or more and 600 nm or less, and the ratio Dp / Rzt was 1.5 or more and 20.0 or less. The evaluation of toner adhesion and the evaluation of charge amount of toners (T-A1) to (T-A5) were both good.

[0144] From the above, it is judged that the toners of the present invention, including toners (T-A1) to (T-A5), can be charged to a desired charge amount and are unlikely to adhere to a regulating member provided in an image forming apparatus.Furthermore, it is judged that an image forming apparatus equipped with the toner of the present invention can also charge toner to a desired charge amount and is unlikely to cause the toner to adhere to a regulating member. [Industrial Applicability]

[0145] The toner of the present invention can be used to form an image using a multifunction machine or a printer. The image forming apparatus of the present invention can be used, for example, as a multifunction machine or a printer to form an image. [Explanation of symbols]

[0146] 1: Image forming device 22: Development unit 23: Image carrier 230: Toner carrier 240: Regulating member T: Toner

Claims

1. A toner comprising toner particles, The toner particles include toner base particles and an external additive attached to the surface of the toner base particles, The external additive contains fluorine-containing lubricant particles, the ten-point average roughness of the surface of the toner base particle is 30 nm or more and 300 nm or less; The fluorine-containing lubricating particles have an average agglomerated particle size of 200 nm or more and 600 nm or less, The toner, wherein the ten-point height of the surface of the toner base particles Rzt and the average agglomerated particle diameter Dp of the fluorine-containing lubricant particles satisfy the following formula (1): 1.5≦Dp / Rzt≦20.0 (1)

2. 2. The toner according to claim 1, wherein the area ratio of the surface area of ​​the toner base particle covered with the fluorine-containing lubricant particles is 0.2% or more and 2.0% or less.

3. 3. The toner according to claim 1, wherein the fluorine-containing lubricating particles are polytetrafluoroethylene particles.

4. The external additive further contains cross-linked styrene acrylic resin particles, 3. The toner according to claim 1, wherein the number average primary particle diameter of the cross-linked styrene acrylic resin particles is 40 nm or more and 100 nm or less.

5. the toner is a pulverized toner, 3. The toner according to claim 1, wherein the fluorine-containing lubricating particles have an average agglomerated particle size of more than 500 nm and not more than 600 nm.

6. 3. The toner according to claim 1, wherein the toner is a positively charged non-magnetic one-component toner for development.

7. An image forming apparatus including a developing unit, The developing unit a toner carrier that carries toner in the form of a toner layer; a regulating member that comes into contact with the toner layer on the toner carrier and regulates the thickness of the toner layer; Equipped with 3. An image forming apparatus, wherein the toner is the toner according to claim 1.

8. 8. The image forming apparatus according to claim 7, wherein the contact line pressure of the regulating member against the toner layer on the toner carrier is 30 N / m or more and 60 N / m or less.

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