Toner and image forming method

Abstract

To provide a toner that achieves both low-temperature fixation and storage stability in high-temperature environments. [Solution] A toner containing a graft polymer resin including a polyolefin resin and a styrene-based resin, a polyester resin, and a release agent, wherein when the toner heated to 50°C is measured by FTIR-ATR (total internal reflection absorption infrared spectroscopy), the peak intensity derived from the release agent is set to Wk-50 and the peak intensity derived from the polyester resin is set to RK-50; when the toner heated to 70°C is measured by FTIR-ATR, the peak intensity derived from the release agent is set to Wk-70 and the peak intensity derived from the polyester resin is set to RK-70; and when the toner heated to 90°C is measured by FTIR-ATR, the peak intensity derived from the release agent is set to Wk-90 and the peak intensity derived from the polyester resin is set to RK-90, the toner satisfies the following formulas (1) and (2). (Wk-70 / RK-70) / (Wk-50 / RK-50)≦1.1···(1) 1.5≦(Wk-90 / RK-90) / (Wk-50 / RK-50) (2)

Description

[Technical Field]

[0001] The present invention relates to toner and image forming method. [Background technology]

[0002] In electrophotographic devices, electrostatic recording devices, etc., electrical latent images or magnetic latent images are manifested by electrostatic latent image developing toner (also referred to as "toner" in this invention). For example, in electrophotography, an electrostatic latent image is formed on an electrostatic latent image carrier, and then the electrostatic latent image is developed using toner to form a toner image. When the toner image is transferred to a recording medium such as paper and fixed by methods such as heating, there is a problem that offset occurs, where the toner fuses to the heating roll, fixing belt, etc. Furthermore, although sea transport is the main means of transporting toner to users, the temperature during sea transport is rising year by year due to recent global warming. As a result, when toner is exposed to a high-temperature environment during transport, the wax in the toner may seep to the toner surface, and the toner may aggregate or solidify.

[0003] For example, Patent Document 1 discloses a pulverized toner containing a polyester resin and a styrene resin with high heat resistance and pulverability, with the aim of providing a pulverized toner that can achieve both low-temperature fixability and heat-resistant storage. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] One embodiment of the present invention aims to provide a toner that achieves both low-temperature fixability and storage stability in high-temperature environments. [Means for solving the problem]

[0005] To solve the above problems, one embodiment of the present invention is: A toner containing a graft polymer resin including a polyolefin resin and a styrene-based resin, a polyester resin, and a mold release agent, The peak intensity derived from the mold release agent is defined as Wk-50 and the peak intensity derived from the polyester resin is defined as RK-50, obtained by measuring the toner heated to 50°C using FTIR-ATR (Total Reflectance Absorption Infrared Spectroscopy). The peak intensity derived from the mold release agent, obtained by measuring the toner heated to 70°C using the FTIR-ATR method, is defined as Wk-70, and the peak intensity derived from the polyester resin is defined as RK-70. The toner is provided such that, when the toner heated to 90°C is measured by the FTIR-ATR method, the peak intensity derived from the mold release agent is denoted as Wk-90 and the peak intensity derived from the polyester resin is denoted as RK-90, the toner satisfies the following formulas (1) and (2). (Wk-70 / RK-70) / (Wk-50 / RK-50)≦1.1···(1) 1.5≦(Wk-90 / RK-90) / (Wk-50 / RK-50) (2) [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a toner that achieves both low-temperature fixability and storage stability in high-temperature environments. [Modes for carrying out the invention]

[0007] Embodiments of the present invention will be described in detail below. However, the embodiments are not limited to the following description and can be modified as appropriate without departing from the spirit of the invention. Furthermore, in this specification, "~" indicating a numerical range means that the numbers before and after it are included as the lower and upper limits, respectively, unless otherwise specified.

[0008] (toner) The toner of the present invention is A toner containing a graft polymer resin including a polyolefin resin and a styrene-based resin, a polyester resin, and a mold release agent, The peak intensity derived from the release agent obtained by measuring the toner heated to 50°C by the FTIR-ATR (Fourier Transform Infrared Spectroscopy with Attenuated Total Reflection) method is defined as Wk-50, and the peak intensity derived from the polyester resin is defined as RK-50. The peak intensity derived from the release agent obtained by measuring the toner heated to 70°C by the FTIR-ATR method is defined as Wk-70, and the peak intensity derived from the polyester resin is defined as RK-70. When the peak intensity derived from the release agent obtained by measuring the toner heated to 90°C by the FTIR-ATR method is defined as Wk-90, and the peak intensity derived from the polyester resin is defined as RK-90, the toner satisfies the following formulas (1) and (2). (Wk-70 / RK-70) / (Wk-50 / RK-50) ≤ 1.1 ··· (1) 1.5 ≤ (Wk-90 / RK-90) / (Wk-50 / RK-50) ··· (2)

[0009] In the toner of the present invention, most of the release agent is anchored to the resin of the graft polymer containing a polyolefin resin and a styrene resin at a temperature of 70°C or lower. Therefore, even when the toner of the present invention is stored at a high temperature, the release agent is less likely to bleed out onto the surface of the toner particles, and aggregation or solidification of the toner due to high-temperature storage is suppressed. On the other hand, in the fixing temperature range where the toner image is fixed onto the transfer medium, the bleeding effect due to the viscosity reduction of the release agent is greater than the anchoring effect of the release agent to the resin of the graft polymer containing a polyolefin resin and a styrene resin, so that the low-temperature fixing property of the toner can be ensured. Thus, the resin of the graft polymer containing a polyolefin resin and a styrene resin contributes to the compatibility of the low-temperature fixing property and the storage stability under high-temperature environments in the toner of the present invention.

[0010] The peak intensity derived from the release agent and the peak intensity derived from the polyester resin, which are obtained by measuring the toner by the FTIR-ATR (Fourier transform infrared reflection absorption spectroscopy) method, can be measured by an appropriately selected method. For example, as a method for measuring the peak intensity derived from the release agent and the peak intensity derived from the polyester resin of the toner heated to 50°C, it is as follows. For example, first, as a sample, a toner containing a resin of a graft polymer containing a polyolefin resin and a styrene resin, a polyester resin, and a release agent, heated to 50°C, was prepared. 3 g of the toner heated to 50°C was pressed with a 6 t load for 1 minute using an automatic pellet molding machine (Type M No.50 BRP-E; manufactured by MAEKAWA TESTING MACHINE CO.) to produce a pellet with a diameter of 40 mm (thickness of about 2 mm). The toner pellet was measured by the ATR method (total reflection method) using a Fourier transform infrared spectroscopic analyzer (for example, Avatar370 / ThermoElectron). This operation was repeated 4 times by changing the measurement location on the toner pellet. The average value of the peak intensity (height baseline 2830 cm -1 at 2850 cm -1 ~2870 cm -1 ) obtained each time was taken as the peak intensity Wk-50 derived from the release agent, and the average value of the peak intensity (height baseline 743 cm -1 at 828 cm -1 ~890 cm -1 ) was taken as the peak intensity RK-50 derived from the polyester resin. Here, the peak intensity at 2850 cm -1 where the height baseline is 2830~2870 cm -1 means that the peak in the range of 2830 cm -1 ~2870 cm -1 is taken as the peak intensity at 2850 cm -1 . Also, the peak intensity at 828 cm -1 where the height baseline is 743 cm -1 ~890 cm -1 means that the peak in the range of 743 cm -1 ~890 cm -1 is taken as the peak intensity at 828 cm -1 .

[0011] Regarding the toner heated to 70°C and the toner heated to 90°C, similar to the toner heated to 50°C described above, the peak intensity derived from the release agent and the peak intensity derived from the polyester resin can be measured by the FTIR-ATR (Fourier Transform Infrared Reflection Absorption Spectroscopy) method. The "toner heated to 70°C" used in this measurement is a toner containing a resin of a graft polymer containing a polyolefin resin and a styrene resin, a polyester resin, and a release agent, heated to 70°C. Let the peak intensity derived from the release agent obtained by measuring the toner heated to 70°C by the above method or the like be Wk-70, and the peak intensity derived from the polyester resin be RK-70. Also, the "toner heated to 90°C" used in this measurement is a toner containing a resin of a graft polymer containing a polyolefin resin and a styrene resin, a polyester resin, and a release agent, heated to 90°C. Let the peak intensity derived from the release agent obtained by measuring the toner heated to 90°C by the above method or the like be Wk-90, and the peak intensity derived from the polyester resin be RK-90.

[0012] Note that the peak intensity derived from the release agent can be set by extracting characteristic peaks from the overall spectrum of the FTIR-ATR method of the release agent alone. The peak intensity derived from the polyester resin can be set by extracting characteristic peaks from the overall spectrum of the FTIR-ATR method of the polyester resin alone.

[0013] In the toner of the present invention, Wk-50, Wk-70, Wk-90 and RK-50, RK-70, RK-90 satisfy the following formulas (1) and (2). (Wk-70 / RK-70) / (Wk-50 / RK-50) ≦ 1.1 ··· (1) 1.5 ≦ (Wk-90 / RK-90) / (Wk-50 / RK-50) ··· (2) Here, the ratio of the peak intensity derived from the release agent to the peak intensity derived from the polyester resin in the toner at a certain temperature represents the amount of release agent on the toner surface at that temperature. Therefore, (Wk-50 / RK-50) represents the amount of release agent on the toner surface at 50°C, (Wk-70 / RK-70) represents the amount of release agent on the toner surface at 70°C, and (Wk-90 / RK-90) represents the amount of release agent on the toner surface at 90°C.

[0014] In equation (1), if (Wk-70 / RK-70) / (Wk-50 / RK-50) > 1.1, the amount of release agent on the toner surface at 70°C becomes significantly greater than the amount at 50°C. This leads to increased release agent seepage during storage in high-temperature environments, making the toner more prone to agglomeration or solidification. Furthermore, in equation (2), if 1.5 > (Wk-90 / RK-90) / (Wk-50 / RK-50), the amount of release agent on the toner surface at 90°C becomes less than the amount at 50°C. This results in less release agent seepage during toner image fixation, leading to poor low-temperature fixation.

[0015] <Graft polymer resin containing polyolefin resin and styrene-based resin> The toner of the present invention contains a graft polymer resin comprising a polyolefin resin and a styrene-based resin. In the toner of the present invention, the graft polymer resin comprising the polyolefin resin and the styrene-based resin acts as a dispersant for the release agent, and at temperatures below 70°C, most of the release agent remains anchored to the graft polymer resin comprising the polyolefin resin and the styrene-based resin.

[0016] There are no particular restrictions on the content of the graft polymer containing polyolefin resin and styrene resin, and it can be appropriately selected depending on the purpose. However, in toner, it is preferably 0.5% by mass or more and 25% by mass or less, more preferably 1% by mass or more and 10% by mass or less, and even more preferably 2% by mass or more and 5% by mass or less. If the content of the graft polymer containing polyolefin resin and styrene resin in the toner is 0.5% by mass or more, the release agent can be prevented from seeping out during high-temperature storage due to the anchoring effect of the release agent, and if it is 25% by mass or less, there is no problem with the release agent seeping out during fixing.

[0017] Polyolefin resins and styrene-based resins are not particularly limited as long as they can form graft polymers, and can be appropriately selected according to the purpose.

[0018] -Polyolefin resin- Polyolefin resin is a resin composed solely of carbon and hydrogen. Preferred polyolefin resins for use in the toner of the present invention include, for example, polyethylene and polypropylene.

[0019] -Styrene resin- Styrene-based resins are resins having a styrene backbone, and are homopolymers or copolymers containing styrene or styrene-substituted compounds. There are no particular restrictions on the styrene-based resin, and it can be appropriately selected depending on the purpose. Examples include polymers of styrene and its substituted products such as polystyrene, poly-p-styrene, and polyvinyltoluene; styrene-α-methylstyrene copolymer; styrene-p-chlorostyrene copolymer; styrene-vinyltoluene copolymer; styrene-α-methyl methacrylate copolymer; styrene-acrylonitrile copolymer; styrene-vinyl methyl ether copolymer; styrene-vinyl methyl ketone copolymer; styrene-butadiene copolymer; styrene-isoprene copolymer; styrene-maleic acid ester copolymer; chloropolystyrene; poly-α-methylstyrene; styrene / chlorostyrene copolymer; and styrene / vinyl chloride copolymer. A composition of the following is preferred: styrene / vinyl acetate copolymer, styrene / maleic acid copolymer, styrene / acrylic acid ester copolymer (styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer, styrene / phenyl acrylate copolymer, etc.), styrene / methacrylic acid ester copolymer (styrene / methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene / phenyl methacrylate copolymer, etc.), styrene / α-methyl chloroacrylate copolymer, styrene / acrylonitrile / acrylic acid ester copolymer, styrene-αmethylstyrene copolymer, etc. These may be used individually or in combination of two or more.

[0020] <Polyester resin> The toner of the present invention contains a polyester resin. As the polyester resin, one obtained by a polycondensation reaction between a commonly known alcohol and a carboxylic acid can be used.

[0021] Examples of alcohols include diols, etherified bisphenols, divalent alcohol monomers obtained by substituting these with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms, and trivalent or higher alcohol monomers.

[0022] Examples of diols include ethylene glycol, polyethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-propylene glycol, neopentyl glycol, and 1,4-butenediol.

[0023] Examples of etherified bisphenols include 1,4-bis(hydroxymethyl)cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylene-modified bisphenol A, polyoxypropylene-modified bisphenol A, bisphenol A propylene oxide, and bisphenol A ethylene oxide.

[0024] Examples of trivalent or higher high-alcohol monomers include sorbitol, 1,2,3,6-hexanetetrol, 1,4-salbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene.

[0025] These can be used individually or in combination of two or more.

[0026] Examples of carboxylic acids include monocarboxylic acids, divalent organic acid monomers, anhydrides of these acids, dimers of lower alkyl esters and linolenic acid, and trivalent or higher polyvalent carboxylic acid monomers.

[0027] Examples of monocarboxylic acids include palmitic acid, stearic acid, and oleic acid.

[0028] Examples of divalent organic acid monomers include maleic acid, fumaric acid, mesaconic acid, citraconic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, malonic acid, and those obtained by substituting these with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms.

[0029] Examples of polyvalent carboxylic acid monomers with three or more valent carboxylic acids include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalentricarboxylic acid, 1,2,4-naphthalentricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra(methylenecarboxyl)methane, 1,2,7,8-octanetetracarboxylic acid embol trimeric acid, and anhydrides of these acids.

[0030] These can be used individually or in combination of two or more.

[0031] The molecular weight of the polyester resin is preferably 3,500 to 5,500, and more preferably 4,000 to 4,500.

[0032] The molecular weight of polyester resins can be determined from the molecular weight distribution of THF-soluble components obtained by GPC (gel permeation chromatography). Calibration curves can be created using standard polystyrene samples.

[0033] There are no particular restrictions on the polyester resin content, and it can be appropriately selected depending on the purpose. However, in the toner matrix particles, it is preferably 70% to 90% by mass, and more preferably 75% to 85% by mass.

[0034] <Release agent> The release agent contained in the toner of the present invention is not particularly limited as long as it is used in ordinary toners, and can be appropriately selected according to the purpose, but it is preferable that it has a melting point of 70°C or higher and 100°C or lower. A release agent with a melting point of 70°C or higher is suitable for improving storage in high-temperature environments, and a release agent with a melting point of 100°C or lower makes it easier to ensure low-temperature fixation.

[0035] One method for measuring the melting point of the release agent in toner is differential scanning calorimetry (DSC). For example, it can be measured using a DSC system (differential scanning calorimeter) (DSC-60, manufactured by Shimadzu Corporation) by the following method.

[0036] As a sample, approximately 5.0 mg of toner is placed in an aluminum sample container, the sample container is placed on a holder unit, and then set in an electric furnace. Next, under a nitrogen atmosphere, it is heated from 20°C to 150°C at a heating rate of 10°C / min, and the DSC curve is measured using a differential scanning calorimeter (DSC-60, manufactured by Shimadzu Corporation). From the obtained DSC curve, the melting point of the release agent can be determined by reading the bottom value of the melting peak originating from the release agent using the analysis program in the DSC-60 system. Since the release agent is generally a crystalline component, almost the same DSC profile is obtained for the first heating and the second heating. Therefore, the melting point of the release agent may be determined from the melting peak of the release agent in the first heating, or from the melting peak of the release agent in the second heating, but from the viewpoint of simplicity, it is preferable to determine it from the melting peak of the release agent in the first heating.

[0037] Furthermore, in the toner of the present invention, the endothermic amount of the endothermic peak originating from the mold release agent in differential scanning calorimetry (DSC) is preferably 2.0 mJ / mg or more and 3.5 mJ / mg or less. An endothermic amount of 2.0 mJ / mg or more is suitable for improving the low-temperature fixability of the toner, and an endothermic amount of 3.5 mJ / mg or less is suitable for improving storage performance in high-temperature environments. The endothermic amount of the endothermic peak originating from the mold release agent can be determined, for example, by calculating the peak area of ​​the measured endothermic peak from the DSC curve obtained by measurement using a differential scanning calorimeter (DSC-60, manufactured by Shimadzu Corporation) using an analysis program in the DSC-60 system. This endothermic amount may be calibrated, for example, by measuring a standard sample of indium. In the present invention, the endothermic amount of the endothermic peak originating from the mold release agent is expressed as ΔH, and its unit is mJ / mg.

[0038] The release agent contained in the toner of the present invention is not particularly limited and can be appropriately selected depending on the purpose. Examples include synthetic hydrocarbon waxes such as Fischer-Tropsch wax, polyethylene, and polypropylene; synthetic waxes such as esters, ketones, and ethers. Natural waxes include plant-based waxes such as carnauba wax, cotton wax, and wood wax and rice wax; animal-based waxes such as beeswax and lanolin; mineral waxes such as ozokerite and cerucine; and petroleum waxes such as paraffin, microcrystalline, and petrolatum. Furthermore, examples include fatty acid amide compounds such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride, and chlorinated hydrocarbons; homopolymers or copolymers of polyacrylates such as poly-n-stearyl methacrylate and poly-n-lauryl methacrylate, which are low molecular weight crystalline polymer resins (for example, copolymers of n-stearyl acrylate and ethyl methacrylate); and crystalline polymers having long alkyl groups in the side chains. These may be used individually or in combination of two or more.

[0039] Among these, hydrocarbon waxes such as paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax, and polypropylene wax are preferred, with Fischer-Tropsch wax being particularly preferred.

[0040] There are no particular restrictions on the content of the release agent, and it can be appropriately selected according to the purpose, but it is preferably 0.5% by mass or more and 10% by mass or less in the toner matrix particles, more preferably 1% by mass or more and 7% by mass or less, and even more preferably 2% by mass or more and 4% by mass or less. If the content of the release agent in the toner matrix particles is 0.5% by mass or more, a release effect can be exerted when fixing, and if it is 10% by mass or less, the seepage of the release agent during storage can be suppressed.

[0041] <Other ingredients> The toner of the present invention may contain other components besides those mentioned above. Examples of other components include colorants, external additives, charge control agents, fluidity enhancers, cleaning properties enhancers, and magnetic materials.

[0042] -Colorants- There are no particular restrictions on the aforementioned colorants, and they can be appropriately selected according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, yellow ochre, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, anthrazane yellow BG L, Isoindolinone Yellow, Bengara, Red Lead, Red Lead, Cadmium Red, Cadmium Mercury Red, Antimony Red, Permanent Red 4R, Para Red, Faise Red, Parachloro-orthonitroaniline Red, Risol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risol Rubin GX, Permanent Red F5R, Brilli Antcarmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinon Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkali Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine, Navy Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chromium Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake,Examples include malachite green lake, phthalocyanine green, anthraquinone green, titanium dioxide, zinc oxide, and lithobone. These may be used individually or in combination of two or more.

[0043] There are no particular restrictions on the colorant content, and it can be appropriately selected depending on the purpose, but in the toner matrix particles, it is preferably 1% by mass or more and 15% by mass or less, and more preferably 3% by mass or more and 12% by mass or less.

[0044] -External additives- Examples of external additives include metal oxides, silicon compounds, and other fine particles.

[0045] Examples of metal oxides include aluminum oxide, zinc oxide, cerium oxide, and zirconium oxide. These may be used individually or in combination of two or more.

[0046] Examples of silicon compounds include silicon oxide (silica), silicon carbide, silicon nitride, and silicon tetrachloride. These may be used individually or in combination of two or more. Among these, silicon oxide (silica) is preferred.

[0047] Other examples of fine particles include fatty acid metal salts (e.g., zinc stearate, aluminum stearate, etc.) and fluoropolymers.

[0048] -Static control agent- There are no particular restrictions on the charge control agent, and it can be appropriately selected depending on the purpose. Examples include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, elemental or compound phosphorus, elemental or compound tungsten, fluorine-based surfactants, metal salicylic acid salts, and metal salts of salicylic acid derivatives. Specifically, examples include the nigrosine-based dye Bontron 03, the quaternary ammonium salt Bontron P-51, the metal-containing azo dye Bontron S-34, the oxynaphthoic acid-based metal complex E-82, the salicylic acid-based metal complex E-84, the phenolic condensate E-89 (all manufactured by Orient Chemical Industry Co., Ltd.), the quaternary ammonium salt molybdenum complexes TP-302 and TP-415 (both manufactured by Hodogaya Chemical Co., Ltd.), LRA-901, the boron complex LR-147 (manufactured by Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone, azo pigments, and other polymer compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.

[0049] There are no particular restrictions on the content of the charge control agent, and it can be appropriately selected depending on the purpose, but in the toner matrix particles, it is preferably 0.1% by mass or more and 10% by mass or less, and more preferably 0.2% by mass or more and 5% by mass or less.

[0050] - Fluidity improver - The fluidity improver is not particularly limited as long as it can increase hydrophobicity through surface treatment and prevent deterioration of fluidity and electrostatic properties even under high humidity conditions, and can be appropriately selected according to the purpose. Examples include silane coupling agents, silylation agents, silane coupling agents having alkyl fluoride compounds, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils. It is particularly preferable to surface treat silica and titanium dioxide with such fluidity improvers and use them as hydrophobic silica and hydrophobic titanium dioxide.

[0051] -Cleaning performance enhancer- The cleaning agent is not particularly limited as long as it is added to the toner to remove residual developer after transfer from the electrostatic latent image carrier, primary transfer medium, etc., and can be appropriately selected according to the purpose. Examples include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, polymer microparticles produced by soap-free emulsion polymerization such as polymethyl methacrylate microparticles and polystyrene microparticles. The polymer microparticles are preferably those with a relatively narrow particle size distribution, and those with a volume average particle size of 0.01 μm to 1 μm are preferred.

[0052] -Magnetic materials- There are no particular restrictions on the magnetic material, and it can be appropriately selected depending on the purpose. Examples include iron powder, magnetite, and ferrite. Among these, white materials are preferred in terms of color.

[0053] <Toner manufacturing method> The toner of the present invention may be manufactured by mixing, kneading, grinding, and classifying the above components to obtain toner particles having a desired particle size. Alternatively, the toner of the present invention may be manufactured by mixing these toner particles, which are used as toner matrix particles, with an external additive such as inorganic fine particles.

[0054] Specifically, for example, after pre-mixing each of the above components using a mixer such as a Henschel mixer, the constituent materials are thoroughly kneaded using a twin-screw extruder, such as a KTK twin-screw extruder manufactured by Kobe Steel, Ltd., a TEM twin-screw extruder manufactured by Toshiba Machine Co., Ltd., a PCM twin-screw extruder manufactured by Ikegai Co., Ltd., or a KEX twin-screw extruder manufactured by Kurimoto Iron Works Co., Ltd., or a continuous single-screw kneader, such as a KCK kneader. At this time, methods to increase the specific energy include reducing the amount of material being kneaded or lowering the kneader's set temperature to knead the mixture in a high-viscosity state.

[0055] Next, after the kneaded material is cooled, it is coarsely ground using a hammer mill or the like, then finely ground using a jet-stream pulverizer or a mechanical pulverizer, and finally classified to a predetermined particle size using a swirling airflow classifier or a classifier using the Coanda effect.

[0056] Classification can be carried out by removing particulate matter, for example, using a cyclone, decanter, or centrifuge.

[0057] After the grinding and classification are completed, the ground material is separated into airflow using centrifugal force or other means to produce toner particles of a predetermined size.

[0058] The weight-average particle size of the resulting toner particles is preferably 4 μm to 10 μm, and more preferably 5 μm to 8 μm. The weight-average particle size can be measured, for example, using a device that measures the particle size distribution of toner particles using the Coulter counter method. Examples of such devices include the Coulter Multisizer 4e (manufactured by Beckman Coulter).

[0059] (Developer) The developer using the toner of the present invention may be either a one-component developer or a two-component developer. For example, a two-component developer comprises the toner of the present invention and a carrier. There are no particular restrictions on the carrier, and it can be appropriately selected according to the purpose, but one having a core material and a resin layer covering the core material is preferred.

[0060] There are no particular restrictions on the core material, and it can be appropriately selected according to the purpose. For example, manganese-strontium (Mn-Sr) materials and manganese-magnesium (Mn-Mg) materials with a magnetization of 50 emu / g to 90 emu / g are preferred. In terms of ensuring image density, highly magnetized materials such as iron powder (100 emu / g or more) and magnetite (75 emu / g to 120 emu / g) are preferred. Furthermore, weakly magnetized materials such as copper-zinc (Cu-Zn) materials (30 emu / g to 80 emu / g) are preferred because they can reduce the contact of the toner with the electrostatic latent image support, which is advantageous for improving image quality. These may be used individually or in combination of two or more types.

[0061] The volume-average particle size of the core material is preferably 25 μm or more and 200 μm or less.

[0062] There are no particular restrictions on the material of the resin layer, and it can be appropriately selected according to the purpose. Examples include amino resins, polyvinyl resins, polystyrene resins, halogenated olefin resins, polyester resins, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoropropylene resins, copolymers of vinylidene fluoride and acrylic monomers, copolymers of vinylidene fluoride and vinyl fluoride, fluoropolymers such as terpolymers of tetrafluoroethylene, vinylidene fluoride and non-fluorinated monomers, and silicone resins. These may be used individually or in combination of two or more.

[0063] In a two-component developer, the mixing ratio of toner to carrier is preferably 2.0% by mass or more and 12.0% by mass or less, and more preferably 2.5% by mass or more and 10.0% by mass or less.

[0064] (Toner storage unit) In this invention, a toner storage unit refers to a unit having the function of storing toner, in which the toner of this invention is stored. Here, examples of the toner storage unit include a toner storage container, a developer, a process cartridge, and the like. A toner container refers to a container that holds toner. A developing unit refers to a device that has the means to store toner and develop it. A process cartridge is defined as a device that integrates at least an image carrier and a developing means, contains toner, and is detachable from an image forming apparatus. The process cartridge may further include at least one selected from a charging means, an exposure means, and a cleaning means. The toner storage unit in the present invention contains the toner of the present invention, and the aggregation or solidification of the toner is suppressed, making it easier for the toner to be supplied from the toner storage unit to the image forming apparatus.

[0065] <Processing Cartridge> The process cartridge according to the present invention comprises an electrostatic latent image carrier that carries an electrostatic latent image, and a developing means that develops the electrostatic latent image carried on the electrostatic latent image carrier using toner to form a visible image, and may further include other means such as a charging means, an exposure means, a developing means, a transfer means, a cleaning means, and a static elimination means as needed. The developing means includes a developer container for containing the toner or developer of the present invention, and a developer carrier for carrying and transporting the toner or developer contained in the developer container. It may also include a layer thickness regulating member for regulating the thickness of the toner layer to be carried. The process cartridge according to the present invention can be detachably mounted on various electrophotographic devices, facsimile machines, and printers, and is preferably detachably mounted on the image forming apparatus of the present invention, which will be described later.

[0066] (Image forming apparatus) The image forming apparatus of the present invention includes an electrostatic latent image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, a developing means for developing the electrostatic latent image formed on the electrostatic latent image carrier using the toner of the present invention to form a toner image, a transfer means for transferring the toner image to a transfer target, and a fixing means for fixing the transferred image to the surface of the transfer target, and may further include other configurations as necessary.

[0067] In addition to the electrostatic latent image carrier, electrostatic latent image forming means, developing means, transfer means, and fixing means described above, the image forming apparatus of the present invention may also include other means such as static elimination means, cleaning means, recycling means, and control means.

[0068] In the developing means, a toner image may be formed by using a developer containing the toner of the present invention, and optionally containing other components.

[0069] <Electrostatic latent image carrier> The material, shape, structure, size, etc. of the electrostatic latent image carrier are not particularly limited and can be appropriately selected from known materials. Examples of materials for the electrostatic latent image carrier include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors (OPC) such as polysilane and phthalopolymethine.

[0070] There are no particular restrictions on the shape of the electrostatic latent image carrier, and it can be appropriately selected depending on the purpose, but a cylindrical shape is preferred. There are no particular restrictions on the outer diameter of the cylindrical electrostatic latent image carrier, and it can be appropriately selected depending on the purpose, but 3 mm to 100 mm is preferred, 5 mm to 50 mm is more preferred, and 10 mm to 30 mm is particularly preferred.

[0071] <Electrostatic latent image forming means> The electrostatic latent image forming unit is not particularly limited as long as it is a means for forming an electrostatic latent image on an electrostatic latent image carrier, and can be appropriately selected according to the purpose. The electrostatic latent image forming means may include, for example, a charger, which is a charging member that uniformly charges the surface of the electrostatic latent image carrier, and an exposure member, which is an exposure member that exposes the surface of the electrostatic latent image carrier in an image-like manner.

[0072] The charger is not particularly limited and can be appropriately selected according to the purpose, but examples include contact chargers equipped with conductive or semiconductive rolls, brushes, films, rubber blades, etc., and non-contact chargers that utilize corona discharge such as Corotron and Scorotron.

[0073] The shape of the charger can be anything other than a roller, such as a magnetic brush or a fur brush, and can be selected according to the specifications and configuration of the image forming apparatus.

[0074] Preferably, the charger is positioned in contact with or without contact with the electrostatic latent image carrier, and charges the surface of the electrostatic latent image carrier by superimposing DC and AC voltages. Alternatively, it is preferable that the charger is a charging roller positioned in close proximity to the electrostatic latent image carrier via a gap tape, and charges the surface of the electrostatic latent image carrier by superimposing DC and AC voltages on the charging roller.

[0075] While the charger is not limited to a contact-type charger, it is preferable to use a contact-type charging element because it allows for the creation of an image forming apparatus with reduced ozone generation from the charger.

[0076] The exposure device is not particularly limited as long as it can expose the surface of an electrostatic latent image carrier charged by a charger in the manner of the image to be formed, and can be appropriately selected according to the purpose. Examples of exposure devices include copying optical systems, rod lens array systems, laser optical systems, and liquid crystal shutter optical systems.

[0077] There are no particular restrictions on the light source used in an exposure unit, and it can be appropriately selected according to the purpose. Examples include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light-emitting diodes (LEDs), semiconductor lasers (LDs), electroluminescent devices (ELs), and other types of light-emitting materials.

[0078] Furthermore, various filters such as sharp-cut filters, band-pass filters, near-infrared cut filters, dichroic filters, interference filters, and color temperature conversion filters can be used to illuminate only the desired wavelength range.

[0079] Furthermore, the exposure unit may employ a back-facing method that exposes the electrostatic latent image carrier in an image-like manner from the back side.

[0080] <Developing method> The developing means is not particularly limited as long as it can develop the electrostatic latent image formed on the electrostatic latent image carrier to form a toner image, and can be appropriately selected according to the purpose. The developing means can preferably be one that includes a developer that contains toner and can apply toner to the electrostatic latent image by contact or non-contact, and a developer equipped with a toner container is preferred.

[0081] The developing unit may be a single-color developing unit or a multi-color developing unit. Suitable developing devices include, for example, a developing apparatus that has an agitator that frictionally agitates and charges the toner, a magnetic field generating unit fixed inside, and a developer carrier such as a magnetic roller that carries the developer containing the toner on its surface and is rotatable.

[0082] <Transfer method> The transfer means preferably comprises a primary transfer means for transferring a toner image onto an intermediate transfer body to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a transfer target. The intermediate transfer body is not particularly limited and can be appropriately selected from known transfer bodies depending on the purpose; for example, a transfer belt is a suitable example.

[0083] The transfer means (primary transfer means and secondary transfer means) preferably includes at least a transfer device that exfoliates and charges the toner image formed on the electrostatic latent image carrier toward the transfer target. There may be one transfer means or two or more.

[0084] Examples of transfer devices include corona discharge transfer devices, transfer belts, transfer rollers, pressure transfer rollers, and adhesive transfer devices.

[0085] While plain paper is typically used as the transfer medium, there are no particular restrictions as long as it can transfer the unfixed image after development. It can be appropriately selected from known transfer mediums such as recording paper depending on the purpose, and PET bases for OHPs can also be used.

[0086] <Method of fixing> The fixing means is not particularly limited and can be appropriately selected according to the purpose, but a known heating and pressing section is preferred. Examples of heating and pressing sections include a combination of a heating roller and a pressing roller, and a combination of a heating roller, a pressing roller and an endless belt.

[0087] The fixing means preferably comprises a heating element equipped with a heating element, a film in contact with the heating element, and a pressing member that presses against the heating element via the film, and is a heating and pressing unit that can heat and fix a transfer object on which an unfixed image has been formed between the film and the pressing member.

[0088] The heating temperature in the heating and pressurizing section is usually preferably between 80°C and 200°C.

[0089] There are no particular restrictions on the surface pressure in the heating and pressurizing section, and it can be appropriately selected according to the purpose, but 10 N / cm is recommended. 2 ~80 N / cm 2 It is preferable that this be the case.

[0090] In this embodiment, depending on the purpose, a known optical fuser may be used together with or in place of the fuser unit.

[0091] <Other means> The image forming apparatus of the present invention may also include other means, such as static elimination means, cleaning means, recycling means, control means, etc.

[0092] <<Static elimination means>> The means for static elimination is not particularly limited, and it is sufficient if a static elimination bias can be applied to the electrostatic latent image carrier. A known static eliminator can be appropriately selected, for example, a static elimination lamp is a suitable example.

[0093] <<Cleaning Methods>> The cleaning means only needs to be able to remove toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Examples of cleaning means include magnetic brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

[0094] The image forming apparatus of the present invention can improve cleaning performance by having a cleaning means. Specifically, by controlling the adhesion force between toners, the fluidity of the toner can be controlled, thereby improving cleaning performance. Furthermore, by controlling the characteristics of the toner after degradation, excellent cleaning quality can be maintained even under harsh conditions such as extended lifespan and high temperature and humidity. In addition, since the external additive can be sufficiently released from the toner on the electrostatic latent image carrier, a deposit layer (dam layer) of the external additive can be formed in the cleaning blade nip section, thereby achieving high cleaning performance.

[0095] <<Recycling Methods>> There are no particular restrictions on recycling methods, and examples include well-known transportation methods.

[0096] <<Control means>> The control means can control the movement of each of the above-mentioned parts. The control means is not particularly limited as long as it can control the movement of each of the above-mentioned means, and can be appropriately selected according to the purpose. Examples include control devices such as sequencers and computers.

[0097] (Image forming method) The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, a developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with the toner of the present invention to form a toner image, a transfer step of transferring the toner image onto a transfer target, and a fixing step of fixing the toner image transferred onto the transfer target.

[0098] Furthermore, the image forming method of the present invention may further include, as necessary, other steps such as a static elimination step, a cleaning step, a recycling step, a control step, etc.

[0099] <Electrostatic latent image formation process> The electrostatic latent image formation process is a process of forming an electrostatic latent image on an electrostatic latent image carrier, and may include a charging step of charging the surface of the electrostatic latent image carrier and an exposure step of exposing the charged surface of the electrostatic latent image carrier to form an electrostatic latent image. Charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using a charger. Exposure can be performed, for example, by exposing the surface of the electrostatic latent image carrier in an image-like manner using the exposure device, and specifically, by exposing it in an image-like manner based on image data. Formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then exposing it in an image-like manner, and can be performed by an electrostatic latent image formation means.

[0100] <Developing process> The development process involves developing an electrostatic latent image with toner to form a toner image. The toner image can be formed, for example, by developing the electrostatic latent image using the toner of the present invention, and this can be done using a developing unit. Multiple toner colors may also be used for development.

[0101] Inside the developing unit, for example, toner is agitated, and the friction caused by this agitation causes the toner to become charged. This charge is then held in a pile-like state on the surface of the rotating magnetic roller, forming a magnetic brush. Since the magnetic roller is positioned near the electrostatic latent image carrier, some of the toner that makes up the magnetic brush formed on the surface of the magnetic roller is moved to the surface of the electrostatic latent image carrier by electrical attraction. As a result, the electrostatic latent image is developed by the toner, and a toner image is formed on the surface of the electrostatic latent image carrier.

[0102] <Transfer process> The transfer process is a process of transferring a toner image to a transfer target. Preferably, the transfer process uses an intermediate transfer body, first transferring the toner image onto the intermediate transfer body, and then secondarily transferring the toner image onto the transfer target. More preferably, the transfer process uses two or more toners, preferably full-color toners, and includes a first transfer process of transferring the toner image onto an intermediate transfer body to form a composite transfer image, and a second transfer process of transferring the composite transfer image onto the transfer target. The transfer can be performed, for example, by charging an electrostatic latent image carrier with a transfer charger, and can be suitably carried out by the transfer means described above.

[0103] <Fixing process> The fixing process is the process of fixing the toner image transferred to the transfer target using a fixing device. This process may be performed for each color developer after the transfer to the transfer target, or it may be performed simultaneously for each color developer in a stacked state.

[0104] <Other processes> The image forming method of the present invention may further include other steps as appropriate, such as a static elimination step, a cleaning step, a recycling step, a control step, and so on.

[0105] <<Static elimination process>> The static elimination process involves applying a static elimination bias to the electrostatic latent image carrier to remove static electricity, and this process can be more effectively performed by the static elimination unit.

[0106] <<Cleaning Process>> The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier, and can be suitably carried out by the cleaning means.

[0107] <<Recycling Process>> The recycling process involves recycling the toner removed in the cleaning process to a developing means, and this process can be suitably carried out by the recycling means.

[0108] <<Control Process>> The control step is a step of controlling the movement of each of the above-mentioned means, and can be suitably carried out by the control means. [Examples]

[0109] The embodiments will be described in more detail below with reference to examples and comparative examples, but the embodiments of the present invention are not limited to these examples and comparative examples.

[0110] <Synthesis of resin A> In an autoclave reaction vessel equipped with a stirring rod, nitrogen inlet tube, and thermometer, 368 parts by mass of xylene and 158 parts by mass of ethylene-propylene copolymer (softening point 74°C) were charged and the temperature was raised to 165°C. Then, a mixture consisting of 846 parts by mass of styrene, 32 parts by mass of 2-ethylhexyl acrylate, and 15 parts by mass of maleic anhydride, in which 55 parts by mass of t-butyl peroxybenzoate was dissolved as a polymerization initiator, was added dropwise to the mixture in the autoclave reaction vessel over 5 hours and stirred. After that, the mixture was stirred for a further 1 hour. Next, the solvent was removed to obtain resin A.

[0111] <Synthesis of resin B> As raw material monomers for the polyester resin, a monomer mixture consisting of 45 mol% polyoxypropylene (2,2)-2,2-bis(4-hydroxyphenyl)propane (hereinafter abbreviated as "BPA-PO") and 30 mol% sebacic acid was placed in a 5-liter autoclave reaction vessel equipped with a distillation column to a total volume of 4000 g. 5 g of dibutyltin oxide was then charged as an esterification catalyst. These were subjected to a condensation polymerization reaction at 230°C for 6 hours under a nitrogen atmosphere, and then cooled to 160°C. Subsequently, a mixture containing 15 mol% styrene, 10 mol% acrylic acid, and 25 g of di-tert-butylperoxide as a polymerization initiator was added dropwise to the reaction product in the autoclave reaction vessel over 1 hour while stirring at 160°C. Subsequently, the mixture was kept at the same temperature for another hour to allow it to undergo addition polymerization, and then the temperature was raised to 200°C to allow it to undergo condensation polymerization to obtain resin B.

[0112] <Synthesis of polyester resin C> In a reaction vessel equipped with a condenser, a stirrer, and nitrogen inlet, the monomer species shown in Table 1 below and tetrabutoxytitanate as a condensation catalyst were placed and reacted at 230°C for 6 hours under a nitrogen stream, while distilling off the water produced. Next, the reaction was carried out under reduced pressure of 5 mmHg to 20 mmHg for 1 hour to obtain polyester resin C. In Table 1, "25 mol%" for bisphenol A(2,2) propylene oxide (25 mol%) and bisphenol A(2,2) ethylene oxide (25 mol%) refers to the proportion of the alcohol component when the acid component and alcohol component are both 50 mol%.

[0113] [Table 1]

[0114] (Example 1) —Preparation of toner matrix particles— Polyester resin C: 84 parts by mass Fischer-Tropsch wax (release agent) (FNP-0090 Nippon Seiro Co., Ltd.): 2.0 parts by mass Resin A (dispersant for mold release): 2.0 parts by mass Carbon black (coloring agent) (#44, manufactured by Mitsubishi Chemical Corporation): 11 parts by mass Azo iron compound (charge control agent) (T-77, manufactured by Hodogaya Chemical Co., Ltd.): 1 part by mass

[0115] The raw materials for the toner matrix particles described above were pre-mixed using a Henschel mixer (FM20B, manufactured by Mitsui Miike Chemical Machinery Co., Ltd.), and then melted and kneaded at 120°C in a twin-screw kneader (PCM-30, manufactured by Ikegai Co., Ltd.). The resulting kneaded material was rolled to a thickness of 2.7 mm using rollers, cooled to room temperature using a belt cooler, and then coarsely ground to 200 μm to 300 μm using a hammer mill.

[0116] Next, the coarsely ground mixture was finely ground using a supersonic jet pulverizer, LabJet (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), and then classified using an airflow classifier (MDS-I, manufactured by Nippon Pneumatic Mfg. Co., Ltd.), adjusting the louver opening as needed to ensure that the weight-average particle size was in the range of 5.8 ± 0.2 μm, thereby obtaining toner matrix particles.

[0117] —Toner production— To 100 parts by mass of the obtained toner matrix particles, 1.0 part by mass of silica (HDK-2000, manufactured by Clariant Co., Ltd.) and 1.0 part by mass of silica (H05TD, manufactured by Clariant Co., Ltd.) were added as external additives, and the mixture was stirred and mixed in a Henschel mixer to produce toner.

[0118] Except for changing the contents and amounts of the release agent and dispersant as shown in Table 2, the toners for Examples 2-10 and Comparative Examples 1-3 were prepared in the same manner as in Example 1. In Examples 1-10 and Comparative Examples 1-3, one of the following was used as the release agent: four types of Fischer-Tropsch wax (FNP-0090 Nippon Seiro Co., Ltd., FT-115H Nippon Seiro Co., Ltd., SX-105 Nippon Seiro Co., Ltd., or FT-165 Nippon Seiro Co., Ltd.), paraffin wax (HNP-9 Nippon Seiro Co., Ltd.), and carnauba wax.

[0119] [Table 2]

[0120] <Measuring the melting point of the release agent and the endothermic amount of the endothermic peak derived from the release agent> The melting point of the release agent used in the toner of Example 1 was measured using a DSC system (Differential Scanning Calorimeter) (DSC-60, manufactured by Shimadzu Corporation) by the following method.

[0121] Approximately 5.0 mg of the toner from Example 1 was placed in an aluminum sample container, which was then placed on a holder unit and set in an electric furnace. Next, under a nitrogen atmosphere, the furnace was heated from 20°C to 150°C at a heating rate of 10°C / min, and the DSC curve was measured using a differential scanning calorimeter (DSC-60, manufactured by Shimadzu Corporation). From the obtained DSC curve, the melting point of the release agent was determined by reading the bottom value of the melting peak originating from the release agent using the analysis program in the DSC-60 system. Furthermore, the endothermic amount ΔH (mJ / mg) of the endothermic peak originating from the release agent was determined by calculating the peak area of ​​the endothermic peak originating from the release agent in the DSC curve obtained by differential scanning calorimeter (DSC) using the analysis program in the DSC-60 system.

[0122] In the same manner as in Example 1, the melting points of the release agents used in the toners of Examples 2-10 and Comparative Examples 1-3, and the endothermic amount of the endothermic peak originating from the release agent in differential scanning calorimetry (DSC) were measured. The endothermic amount of the endothermic peak originating from the release agent was determined, for example, by calculating the peak area of ​​the measured endothermic peak from the DSC curve obtained by measurement using a differential scanning calorimeter (DSC-60, manufactured by Shimadzu Corporation) and an analysis program in the DSC-60 system. This endothermic amount was determined by calibration by measuring a standard sample of indium. The endothermic amount of the endothermic peak originating from the release agent was defined as ΔH (mJ / mg). The results are shown in Table 3.

[0123] <Measurement by FTIR-ATR (Fourier Transform Infrared Reflection-Absorption Spectroscopy) Method> - Toner heated to -50°C Regarding the toner of Example 1 heated to 50°C, the peak intensity derived from the release agent and the peak intensity derived from the polyester resin were measured by the FTIR-ATR (Fourier Transform Infrared Reflection-Absorption Spectroscopy) method as follows. First, as a sample, a toner containing a resin of a graft polymer containing a polyolefin resin and a styrene-based resin, a polyester resin, and a release agent, heated to 50°C, was prepared. 3 g of the toner heated to 50°C was pressed with a 6 t load for 1 minute using an automatic pellet molding machine (Type M No.50 BRP-E; manufactured by MAEKAWA TESTING MACHINE CO.) to produce a 40 mmφ (thickness: about 2 mm) pellet. The toner pellet was measured by the ATR method (total reflection method) using a Fourier transform infrared spectroscopic analyzer (Avatar370 / ThermoElectron). The peak intensity at 2850 cm -1 (baseline of height 2830 cm -1 ~ 2870 cm -1 ) was taken as the peak intensity derived from the release agent, and the peak intensity at 828 cm -1 (baseline of height 743 cm -1 ~ 890 cm -1 ) was taken as the peak intensity derived from the polyester resin. For each peak intensity, the average value after measuring 4 times by changing the measurement location on the toner pellet was taken as the peak intensity Wk-50 derived from the release agent and the peak intensity RK-50 derived from the polyester resin. Here, the peak intensity at 2850 cm -1 where the baseline of height is 2830~2870 cm -1 means that the peak within the range of 2830 cm -1 ~ 2870 cm -1 is taken as the peak intensity at 2850 cm -1 . Also, the peak intensity at 828 cm -1 where the baseline of height is 743 cm -1 means that the peak within the range of 743 cm -1 ~ 890 cm -1 is taken as the peak intensity at 828 cm -1This means that the peak intensity is set to [value].

[0124] The peak intensity derived from the release agent was determined by extracting characteristic peaks from the full spectrum of the FTIR-ATR method for the release agent alone. The peak intensity derived from the polyester resin was determined from the peaks derived from the benzene rings of the polyester resin.

[0125] -Toner heated to 70℃- For the toner from Example 1, which was heated to 70°C, the peak intensity derived from the release agent and the peak intensity derived from the polyester resin were measured using the FTIR-ATR method, in the same manner as for the toner heated to 50°C. For each peak intensity, the average value after four measurements at different locations on the toner pellet was defined as the peak intensity derived from the release agent (Wk-70) and the peak intensity derived from the polyester resin (RK-70).

[0126] -Toner heated to 90℃- For the toner from Example 1, which was heated to 90°C, the peak intensity derived from the release agent and the peak intensity derived from the polyester resin were measured using the FTIR-ATR method, in the same manner as for the toner heated to 50°C. For each peak intensity, the average value after four measurements at different locations on the toner pellet was defined as the peak intensity derived from the release agent (Wk-90) and the peak intensity derived from the polyester resin (RK-90).

[0127] The peak intensities Wk-50, Wk-70, and Wk-90 derived from the release agent and the peak intensities RK-50, RK-70, and RK-90 derived from the polyester resin of the toner of Example 1, obtained by the above measurements, were substituted into the following equations (1) and (2) to obtain the values ​​of equation (1) and equation (2). (Wk-70 / RK-70) / (Wk-50 / RK-50)...(1) (Wk-90 / RK-90) / (Wk-50 / RK-50)...(2)

[0128] For the toners of Examples 2-10 and Comparative Examples 1-3, the peak intensities Wk-50, Wk-70, and Wk-90 derived from the mold release agent and the peak intensities RK-50, RK-70, and RK-90 derived from the polyester resin were determined in the same manner as in Example 1. These values ​​were then substituted into equations (1) and (2) to obtain the values ​​of equation (1) and equation (2). The results are shown in Table 3.

[0129] [Table 3]

[0130] The toners of Examples 1-10 and Comparative Examples 1-3 were evaluated for their low-temperature fixability and storage performance under high-temperature conditions using the evaluation methods described below.

[0131] <Evaluation of low-temperature fixation> The toners from Examples 1-10 and Comparative Examples 1-3 were placed in the toner container of a Ricoh Co., Ltd. copier (RICOH MPC 6003), and after going through an electrostatic latent image formation process including an exposure process and a development process, the toner was deposited onto paper (Ricoh Co., Ltd. Type 6200) at a concentration of 0.4 mg / cm². 2 A solid image was transferred (transfer step), and the solid image was fixed (fixing step) to form an image on paper. The linear velocity for fixing the toner image was set to 256 mm / second. The fixing temperature in the fixing step was changed in 5°C increments to form an image on paper, and the lower limit temperature at which cold offset did not occur (fixing lower limit temperature) was measured. Low-temperature fixing performance was evaluated according to the evaluation criteria below. The results are shown in Table 4. The NIP width in the fixing means was 11 mm.

[0132] -Evaluation Criteria for Low-Temperature Fixation- A: Below 125℃ B: 125℃ or higher and less than 135℃ C: 135℃ or higher

[0133] <Evaluation of storage performance under high-temperature conditions> The toners of Examples 1-10 and Comparative Examples 1-3 were left to stand at 50°C for 6 hours, and their penetration depth was measured according to JIS K2235 (25°C). The storage performance under high-temperature conditions was evaluated according to the evaluation criteria below. The results are shown in Table 4. A VR-5610 penetration meter (Shimadzu Corporation) was used to measure the penetration depth.

[0134] -Evaluation criteria for storage performance in high-temperature environments- A:22mm or more B: 20mm or more and less than 22mm C: Less than 20mm

[0135] [Table 4]

[0136] We determined that a toner that has a low-temperature fixation rating of "A" or "B" and a storage rating of "A" or "B" in a high-temperature environment is suitable for implementation under the present invention.

[0137] In Examples 1 to 10, the low-temperature fixability was evaluated as "A" or "B," and the storage performance under high-temperature conditions was also evaluated as "A" or "B."

[0138] In Comparative Example 1, the value of equation (2) was less than 1.5, resulting in less release agent seepage when fixing the toner image, and the low-temperature fixing performance was evaluated as "C".

[0139] In Comparative Example 2, the value of equation (1) was greater than 1.1, resulting in excessive release agent leakage under high-temperature conditions, and thus the storage performance under high-temperature conditions was rated as "C".

[0140] In Comparative Example 3, since the toner did not contain a graft polymer resin including polyolefin resin and styrene-based resin, it was possible to suppress the leaching of the release agent in high-temperature environments. However, the amount of release agent leaching when fixing the toner image was reduced, resulting in a low-temperature fixing performance evaluation of "C," and it was not possible to achieve both low-temperature fixing and storage performance in high-temperature environments.

[0141] From the above, it has been shown that a toner satisfying the configuration of the present invention can achieve both low-temperature fixation and storage in high-temperature environments.

[0142] Examples of the present invention are as follows: <1> A toner containing a graft polymer resin including a polyolefin resin and a styrene-based resin, a polyester resin, and a mold release agent, The peak intensity derived from the mold release agent is defined as Wk-50 and the peak intensity derived from the polyester resin is defined as RK-50, obtained by measuring the toner heated to 50°C using FTIR-ATR (Total Reflectance Absorption Infrared Spectroscopy). The peak intensity derived from the mold release agent, obtained by measuring the toner heated to 70°C using the FTIR-ATR method, is defined as Wk-70, and the peak intensity derived from the polyester resin is defined as RK-70. A toner that satisfies the following equations (1) and (2), obtained by measuring toner heated to 90°C using the FTIR-ATR method, where the peak intensity originating from the release agent is denoted as Wk-90 and the peak intensity originating from the polyester resin is denoted as RK-90. (Wk-70 / RK-70) / (Wk-50 / RK-50)≦1.1···(1) 1.5≦(Wk-90 / RK-90) / (Wk-50 / RK-50) (2) <2> The release agent has a melting point of 70°C or higher and 100°C or lower. In differential scanning calorimetry (DSC), the endothermic amount of the endothermic peak originating from the mold release agent is 2.0 mJ / mg or more and 3.5 mJ / mg or less. <1> The toner listed. <3> The above release agent is a hydrocarbon wax. <1> or <2> The toner listed. <4> The hydrocarbon wax is Fischer-Tropsch wax, <1> , <2> or <3> The toner listed. <5> An electrostatic latent image formation process for forming an electrostatic latent image on an electrostatic latent image carrier, The electrostatic latent image formed on the electrostatic latent image carrier is <1> , <2> , <3> or <4> A developing process in which a toner image is formed by developing with the toner described above, A transfer step of transferring the toner image onto a transfer target, A fixing step for fixing the toner image transferred onto the transfer target, An image forming method, including the method described above.

[0143] the above <1> from <4> One of the toners, the above <5> This image formation method solves the problems of the conventional method and achieves the objectives of the present invention. [Prior art documents] [Patent Documents]

[0144] [Patent Document 1] Japanese Patent Publication No. 2021-144186

Claims

1. A toner containing a graft polymer resin including a polyolefin resin and a styrene-based resin, a polyester resin, and a mold release agent, The peak intensity derived from the mold release agent is defined as Wk-50 and the peak intensity derived from the polyester resin is defined as RK-50, obtained by measuring the toner heated to 50°C using FTIR-ATR (Total Reflectance Absorption Infrared Spectroscopy). The peak intensity derived from the mold release agent, obtained by measuring the toner heated to 70°C using the FTIR-ATR method, is defined as Wk-70, and the peak intensity derived from the polyester resin is defined as RK-70. A toner that satisfies the following formulas (1) and (2), when the peak intensity derived from the mold release agent is determined by measuring the toner heated to 90°C using the FTIR-ATR method, and the peak intensity derived from the polyester resin is determined as Wk-90. (Wk-70 / RK-70) / (Wk-50 / RK-50)≦1.1...(1) 1.5≦(Wk-90 / RK-90) / (Wk-50 / RK-50)...(2)

2. The release agent has a melting point of 70°C or higher and 100°C or lower. The toner according to claim 1, wherein the endothermic amount of the endothermic peak originating from the mold release agent in differential scanning calorimetry (DSC) is 2.0 mJ / mg or more and 3.5 mJ / mg or less.

3. The toner according to claim 1, wherein the mold release agent is a hydrocarbon wax.

4. The toner according to claim 3, wherein the hydrocarbon wax is Fischer-Tropsch wax.

5. An electrostatic latent image formation process for forming an electrostatic latent image on an electrostatic latent image carrier, A developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with the toner described in any one of claims 1 to 4 to form a toner image, A transfer step of transferring the toner image onto a transfer target, A fixing step for fixing the toner image transferred onto the transfer target, An image forming method, including the method described above.

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