Toner

Abstract

This invention relates to toners. A toner comprises toner particles and an external additive on the surface of the toner particles, wherein the external additive comprises an aggregate of fine silica particles surface-treated with silicone oil; when the number-average particle size of the aggregate of fine silica particles is defined as Rb, Rb is 12 to 80 nm. When the number-average particle size of the aggregate of fine silica particles is defined as Rb, Rb is 12 to 80 nm. 29 When the integral value of the Q unit in the CP / MAS measurement of Si-solid NMR is set to 100, the integral value of the D unit is defined as A, where A is 120 to 300, and the coefficient of variation of the particle size of the silica fine particle aggregates is 1.00 to 3.00 based on the number of silica fine particle aggregates.

Description

Technical Field

[0001] This disclosure relates to toners used in image forming methods such as electrophotography. Background Technology

[0002] In recent years, with the diversification of applications and operating environments, there has been a growing demand for image forming equipment such as copiers and printers to achieve higher speeds, higher image quality, and higher stability. Electrophotography involves a charging step, in which an electrostatic latent image carrier (hereinafter referred to as a photoreceptor) is charged; an exposure step, in which the charged electrostatic latent image carrier is exposed to form an electrostatic latent image; and a development step, in which the electrostatic latent image is developed with a toner to form a toner image. Next, the method further involves a transfer step, in which the toner image is transferred to a recording material, with or without an intermediate transfer member; and a fixing step, in which the toner image on the recording material is heated and pressure-fixed by passing the recording material through a roller gap formed by a pressure member and a rotatable image heating member; and finally, an output image.

[0003] In response to recent demands for increased speed, extended lifespan, and energy conservation, optimizing each step is crucial. In particular, for increasing speed and extending lifespan, and for ensuring adequate image fixing at low temperatures to conserve energy, it has traditionally been important to perform a developing step that uses toner to develop the electrostatic latent image to form a toner image.

[0004] As a means to improve durability, research has been conducted from the perspective of improving the external additives of the toner. Japanese Patent Application Publication No. 2016-142760 discloses a toner that has improved durability by improving the state of the external additives of the toner. Summary of the Invention

[0005] Through the inventors' research, the toner in Japanese Patent Application Publication No. 2016-142760 has excellent low-temperature fixing properties and durability. On the other hand, the inventors have recognized that there is room for improvement in extending the lifespan of image forming processes in recent years. Specifically, when the toner level is very low during durability testing, fogging occurs, resulting in a noticeably foggy image output as an irregular fogged image.

[0006] The present disclosure aims to provide a toner with excellent durability and the ability to suppress fogging even when the toner is applied in a high-speed electrophotographic image forming method.

[0007] This disclosure relates to a toner comprising:

[0008] Toner particles, and

[0009] External additives on the surface of colorant particles

[0010] in

[0011] The external additives consist of aggregates of fine silica particles surface-treated with silicone oil;

[0012] When the number-average particle size of aggregates of fine silica particles is defined as Rb, Rb is 12 to 80 nm.

[0013] When in fine silica particles 29 In Si-solid NMR CP / MAS measurements, when the integral value of the Q element is set to 100, the integral value of the D element is defined as A, where A ranges from 120 to 300.

[0014] The coefficient of variation for the particle size of silica fine particle aggregates ranges from 1.00 to 3.00, depending on the number of aggregates.

[0015] According to this disclosure, a toner with excellent durability and the ability to suppress fogging even when applied to a high-speed electrophotographic image forming method can be obtained.

[0016] Further features of the invention will become apparent from the following description of exemplary embodiments, with reference to the accompanying drawings. Attached Figure Description

[0017] Figure 1 A schematic diagram illustrating an example of the processing state of fine silica particles;

[0018] Figure 2 A schematic diagram illustrating an example of an aggregate of fine silica particles;

[0019] Figure 3 A schematic diagram illustrating an example of a hybrid processing device;

[0020] Figure 4 A schematic diagram illustrating an example of the structure of a stirring component;

[0021] Figure 5 A schematic diagram showing the measurement of fine silica particles; and

[0022] Figure 6 A diagram illustrating an example of an image forming apparatus. Detailed Implementation

[0023] In this disclosure, unless otherwise stated, the expression "from XX to YY" or "XX to YY" indicating a range of values ​​refers to a range of values ​​including the lower and upper limits as endpoints. Furthermore, when a range of values ​​is described in a segmented manner, the upper and lower limits of each range can be combined arbitrarily.

[0024] For example, to improve the durability of toners, there are methods for selecting external additives used in toners and controlling the state of these external additives in the toner. Specifically, using a large amount of small-diameter inorganic external additives tends to improve the flowability of the toner, which in turn tends to improve the durability of the toner.

[0025] However, problems arise from the perspective of changes in the state of external additives in the toner during durability testing. The toner on the developing roller is rubbed by the developing blade, causing the external additives in the toner to deaggregate if they are embedded or aggregated. In this document, this toner is referred to as "degraded toner." Compared to the toner before durability testing, the state of the external additives in the degraded toner changes, and therefore, its electrical properties tend to decrease.

[0026] When the degraded toner, due to changes in the state of external additives, is not developed, it remains on the developing roller. When this process is repeated, a significant amount of degraded toner remains on the developing roller. In the latter part of the durability test, a large amount of further degraded toner tends to be present on the developing roller, where the toner level decreases. At this point, a phenomenon occurs where the toner in the toner cartridge container does not mix with the toner on the developing roller.

[0027] In this situation, toners with normal charging properties and toners with abnormal charging properties coexist on the developing roller, leading to a problem of outputting significantly irregular, hazy images due to the toners with abnormal charging properties. This problem tends to occur when the toner level becomes very low during durability testing. In particular, this problem is frequently observed in toner cartridges that meet the requirements for extended lifespan and in toner cartridges that include miniaturized components.

[0028] Based on the state of the prior art described above, the inventors focused on and repeatedly studied the presence of external additives in toners during durability testing. As a result, the inventors discovered that by using external additives in an aggregated state and maintaining this aggregated state during durability testing, the aforementioned requirements could be well met. Specifically, the inventors discovered that by attaching silica fine particles with a relatively high parameter A (described later) to the surface of toner particles in aggregate form and by ensuring that the aggregate diameter is uniform, the aforementioned requirements could be well met. That is, this disclosure relates to the following toners.

[0029] This disclosure relates to a toner comprising:

[0030] Toner particles, and

[0031] External additives on the surface of colorant particles

[0032] in

[0033] The external additives consist of aggregates of fine silica particles surface-treated with silicone oil;

[0034] When the number-average particle size of aggregates of fine silica particles is defined as Rb, Rb is 12 to 80 nm.

[0035] When in fine silica particles 29 In Si-solid NMR CP / MAS measurements, when the integral value of the Q element is set to 100, the integral value of the D element is defined as A, where A ranges from 120 to 300.

[0036] The coefficient of variation for the particle size of silica fine particle aggregates ranges from 1.00 to 3.00, depending on the number of aggregates.

[0037] As a result of the inventors' research, by using the above-mentioned toner, it is possible to obtain a toner with excellent durability and the ability to reduce fogging in the final stage of durability.

[0038] The toner comprises toner particles and external additives on the surface of the toner particles. The external additives then consist of aggregates of fine silica particles surface-treated with silicone oil. This means that the fine silica particles present on the surface of the toner particles form aggregates. Figure 1 This is a schematic diagram illustrating primary particles of fine silica. 151 represents the processing agent for the fine silica particles, and 152 represents the fine silica particles. Figure 2 This is a schematic diagram illustrating aggregates of fine silica particles, with 153 representing aggregated fine silica particles. Aggregates can be identified by separating the fine silica particles contained in the toner using the method described later and by observing the separated fine silica particles.

[0039] When silica particles aggregate on the surface of toner particles, these aggregates contact the toner particle surface at multiple points, which disperses pressure when a force is applied along the embedding direction. Therefore, compared to the case where silica particles exist individually as primary particles on the toner particle surface, embedding of silica particles through friction with the developing blade can be suppressed.

[0040] The number average particle size (Rb) of aggregates of fine silica particles ranges from 12 to 80 nm. Rb refers to the number average particle size of aggregates of fine silica particles present on the surface of toner particles. The Rb of the fine silica particles contained in the toner can be calculated using the method described later. An Rb within this range provides toner with good flowability. Therefore, toner on the developing roller and in the toner cartridge container is more easily circulated, resulting in less likely accumulation of degraded toner on the developing roller.

[0041] The number average particle size Rb of the aggregates of fine silica particles is preferably 15 to 40 nm, more preferably 20 to 30 nm. The number average particle size Rb can be increased by increasing the amount of silicone oil (described later) in the fine silica particles or by using a modified silicone oil (described later). Furthermore, the number average particle size Rb can be reduced by decreasing the amount of silicone oil in the fine silica particles.

[0042] When fine silica particles 29 In Si-solid NMR CP / MAS measurements, when the integral value of the Q unit is set to 100, the integral value A (parameter A) of the D unit should be between 120 and 300.

[0043] The above parameter A and the following parameters B and A / B are obtained through 29 Calculated using Si-solid NMR. 29 In Si-solid NMR, four peaks can be observed for silicon atoms in a solid sample: M unit (Equation (4)), D unit (Equation (5)), T unit (Equation (6)) and Q unit (Equation (7)).

[0044] M-unit: (Ri)(Rj)(Rk)SiO 1 / 2 Equation (4)

[0045] D unit: (Rg)(Rh)Si(O) 1 / 2 Equation (5)

[0046] T-unit: RmSi(O) 1 / 2 Formula (6)

[0047] Q unit: Si(O) 1 / 2 Formula 4 (7)

[0048] In formulas (4), (5) and (6), Ri, Rj, Rk, Rg, Rh and Rm represent alkyl groups such as hydrocarbons with 1 to 6 carbon atoms, halogen atoms, hydroxyl groups, acetoxy groups, hydroxymethyl groups, epoxy groups, carboxyl groups, hydrogen atoms or alkoxy groups that are bonded to silicon.

[0049] 29Two measurement methods are used for Si-solid-state NMR measurements: DD / MAS and CP / MAS. DD / MAS measurements provide information about the silicon atom content because all silicon atoms in the measured sample are observed. When measuring fine silica particles treated with silicone oil using DD / MAS, the Q unit represents the peak corresponding to the untreated substrate silica particles, and the D unit represents the peak corresponding to the silicone oil as the treatment agent. That is, when the integral value of the D unit obtained by setting the integral value of the Q unit to 100 in the DD / MAS measurement is taken as B (parameter B), parameter B represents the amount of silicone oil relative to the substrate silica particles. For example, the more silicone oil present on the surface of the substrate silica particles, the larger B becomes. B is preferably 20 to 60, more preferably 30 to 50.

[0050] Simultaneously, since CP / MAS measurements are performed while magnetizing silicon atoms via hydrogen atoms present in their vicinity, silicon atoms with hydrogen atoms in their vicinity can be observed with high sensitivity. The presence of hydrogen atoms near silicon atoms indicates low molecular mobility in the measured sample. That is, the lower the molecular mobility and the greater the quantity of the measured sample, the higher the sensitivity for observing silicon atoms. Specifically, when measuring fine silica particles surface-treated with silicone oil using CP / MAS measurements, parameter A contains not only information about the amount of silicone oil relative to the fine silica particles in the substrate but also information about the molecular mobility of the silicone oil. For example, the greater the amount of silicone oil with low molecular mobility present on the surface of the fine silica particles in the substrate, the larger the value of A.

[0051] The inventors conducted in-depth research and found that even when the aggregates are subjected to friction from a developing blade during durability testing, the silica fine particles exhibiting a high parameter A value easily maintain the shape of the silica fine particle aggregates.

[0052] The toner contains aggregates of fine silica particles surface-treated with silicone oil. Therefore, silicone oil is present within these aggregates of fine silica particles. Research conducted by the inventors revealed that when the silicone oil has a high degree of freedom, the aggregates of fine silica particles deaggregate when the toner is subjected to friction from a developing blade during durability testing. It is speculated that this is because the silicone oil, with its high degree of freedom, moves at the molecular level within the aggregates, making it easier for the fine silica particles to deaggregate.

[0053] The parameter A, representing the degree of freedom of silicone oil for fine silica particles, is between 120 and 300, indicating low degree of freedom in the silicone oil. A parameter A within this range allows the aggregates of fine silica particles to maintain their shape through durability testing, resulting in suppression of toner degradation. If parameter A is less than 120, the shape of the aggregates of fine silica particles tends to be difficult to maintain through durability testing, and toner degradation cannot be suppressed. If parameter A exceeds 300, the degree of freedom in the silicone oil is too low, making it difficult to control the coefficient of variation (described later) within a predetermined range.

[0054] Parameter A is preferably 140 to 200, and more preferably 150 to 170. Parameter A can be increased by increasing the amount of modified silicone oil used to treat fine silica particles and by using a low-viscosity silicone oil to shorten the molecular chain of the silicone oil. Furthermore, parameter A can be reduced by using a combination of modified silicone oil and silicone oil.

[0055] The coefficient of variation for particle size based on the number of aggregates of fine silica particles ranges from 1.00 to 3.00. This indicates that the aggregates of fine silica particles present on the surface of the toner particles are relatively uniform in size. The coefficient of variation can be calculated by separating the fine silica particles contained in the toner using the method described later.

[0056] Fine silica particles tend to aggregate, making it easy for these aggregates on the surface of toner particles to interlock. This phenomenon reduces the flowability of the toner, thus inhibiting the replacement of toner on the developing roller by the toner in the toner cartridge. In contrast, the inventors have discovered that uniformizing the size of the aggregates effectively maintains the flowability of the toner.

[0057] If the aggregates are not uniform in size, smaller aggregates may be trapped in the gaps between larger aggregates. Conversely, it is assumed that when the aggregates are uniform in size, this phenomenon hardly occurs and the flowability is good. The theoretical lower limit of the coefficient of variation is 1.00, which implies that the aggregates are perfectly uniform in size.

[0058] Meanwhile, a coefficient of variation below 3.00 suppresses the interlocking of aggregates on the surface of toner particles and maintains good toner flowability. Therefore, in the final stage of the durability test, toner on the developing roller is frequently replaced by toner in the toner cartridge. This suppresses the localization of degraded toner on the developing roller and inhibits irregular fogging in the final stage of the durability test.

[0059] The coefficient of variation is preferably 1.20 to 2.50, and more preferably 1.45 to 2.40.

[0060] Aggregates of fine silica particles with high parameter A exhibit minimal deaggregation during durability testing. Simultaneously, due to the formation of difficult-to-deaggregate aggregates from the fine silica particles, the size of the aggregates on the toner particle surface tends to be non-uniform. In this case, toner degradation on the developing roller may not be suppressed, as the degraded toner on the developing roller is unlikely to be replaced by the toner in the toner cartridge.

[0061] For example, in order to homogenize the size of aggregates on the surface of toner particles, methods for controlling the degrees of freedom of silicone oil, such as parameter A and parameter A / B (described later), can be mentioned, including production methods that include the step of deaggregating fine silica particles, and production methods that include the step of externally adding fine silica particles while dispersing them. Details will be described below.

[0062] The number average particle size Ra of the primary particles of the silica fine particles is preferably 5 to 30 nm, more preferably 5 to 15 nm, and even more preferably 6 to 10 nm. This means that the size of the primary particles of the silica fine particles is relatively small. When Ra meets this range, the toner on the developing roller is frequently replaced by the toner in the toner cartridge, thus suppressing the accumulation of degraded toner on the developing roller.

[0063] The number average particle size Ra of the primary particles of silica fine particles and the number average particle size Rb of the aggregates preferably satisfy the following formula (1) and more preferably satisfy the following formula (1′).

[0064] 2.5≤Rb / Ra≤5.0…(1)

[0065] 3.0≤Rb / Ra≤4.0…(1′)

[0066] This indicates the number of primary particles contained in the aggregates of silica fine particles. When Rb / Ra satisfies equation (1), the number of contact points between the aggregates of silica fine particles and the surface of the toner particles tends to be greater, and the embedding of the aggregates in the durability test can be more effectively suppressed.

[0067] The external additive further includes non-aggregates of silica fine particles surface-treated with silicone oil, and the proportion of aggregates of silica fine particles in the total number of aggregates and non-aggregates of silica fine particles is preferably 40% or more, more preferably 50% or more, and even more preferably 65% ​​or more. There is no particular limit to the upper limit, but the proportion is preferably 99% or less, more preferably 95% or less.

[0068] The number ratio indicates the proportion of non-aggregates and aggregates of silica fine particles present on the surface of the toner particles, and implies a relatively high proportion of aggregates. When this number ratio is above 40%, aggregate embedding can be more effectively suppressed in durability tests. The number ratio of aggregates in silica fine particles can be increased by using silica fine particles treated with modified silicone oil (described later), or further by using silica fine particles with high A values. Conversely, the number ratio of aggregates in silica fine particles can be decreased by extending the premixing time in external addition steps, etc.

[0069] When fine silica particles 29 When the integral value of the Q unit in the Si-solid NMR CP / MAS measurement is set to 100, the integral value of the D unit is taken as A. When the integral value of the Q unit in the DD / MAS measurement is set to 100, the value of the D unit is taken as B. A and B preferably satisfy the following formula (2), and more preferably satisfy the following formula (2').

[0070] 3.0≤A / B≤6.0…(2)

[0071] 3.5≤A / B≤5.0…(2')

[0072] As described above, parameter A represents the degree of mobility of the silicone oil, and parameter B represents the degree of silicone oil relative to the amount of silica fine particles in the substrate. Equation (2) represents the degree of mobility of the silicone oil contained in the silica fine particles relative to the amount of silicone oil. A ratio A / B that satisfies the above range helps to control the degree of deagglomeration of the silica fine particle aggregates within a suitable range. In addition, the shape of the silica fine particle aggregates is easily maintained during durability testing, and the coefficient of variation of the aggregate particle size can be easily controlled within a suitable range.

[0073] Adhesive resin

[0074] The toner particles preferably comprise a binder resin. Examples of binder resins include vinyl ester resins, polyester ester resins, epoxy resins, and polyurethane resins. These known resins can be used without particular limitation. From the viewpoint of balancing charge-carrying properties and fixing properties, the toner particles preferably comprise at least one selected from the group consisting of polyester resins and vinyl ester resins.

[0075] More preferably, the adhesive resin comprises a vinyl-based resin. Examples of polymerizable monomers (vinyl monomers) used to produce vinyl-based resins include the following.

[0076] It may include styrene and its derivatives, styrene unsaturated monoolefins, unsaturated polyenes, vinyl halides, vinyl esters, α-methylene aliphatic monocarboxylic acid esters, acrylates, vinyl ethers, vinyl ketones, N-vinyl compounds, and acrylic acid or methacrylic acid derivatives, etc.

[0077] In addition, monomers with carboxyl groups, such as unsaturated dicarboxylic acids, unsaturated dicarboxylic acid anhydrides, half esters of unsaturated dicarboxylic acids, unsaturated dicarboxylic acid esters, α,β-unsaturated acids, α,β-unsaturated acid anhydrides, α,β-unsaturated acids and anhydrides of lower fatty acids, alkenyl malonic acid, alkenyl glutaric acid, alkenyl adipic acid, their anhydrides and their monoesters, can be mentioned.

[0078] In addition, monomers with hydroxyl groups, such as acrylates and methacrylates, 4-(1-hydroxy-1-methylbutyl)styrene, and 4-(1-hydroxy-1-methylhexyl)styrene, can be mentioned.

[0079] Vinyl resins can have a crosslinking structure with a crosslinking agent having two or more vinyl groups. Examples of crosslinking agents include divinylbenzene.

[0080] Colorant

[0081] Toner particles may contain colorants. Examples of colorants include the following.

[0082] Examples of organic pigments or dyes that serve as cyan colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds.

[0083] Examples of organic pigments or dyes used as magenta colorants include the following: condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindole compounds, and perylene compounds.

[0084] Examples of organic pigments or dyes that serve as yellow colorants include compounds such as condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allyl amide compounds.

[0085] Examples of black colorants include carbon black, and colorants that use the aforementioned yellow, magenta, and cyan colorants to achieve a black color.

[0086] When used, the colorant is preferably added and used in an amount of 1 to 20 parts by weight based on 100 parts by weight of polymerizable monomer or binder resin. The colorant particles may contain a magnetic material as a black colorant. Magnetic materials can also be used as colorants.

[0087] The magnetic material is mainly composed of iron(II,III) oxide or γ-iron oxide as the main components, and may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, and aluminum. The shapes of the magnetic material include polyhedra, octahedrons, hexahedrons, spheres, needles, and scales, with shapes exhibiting lower anisotropy, such as polyhedra, octahedrons, hexahedrons, and spheres, being preferred for improving image density. The magnetic material content is preferably 50 to 150 parts by weight per 100 parts by weight of polymerizable monomer or binder resin.

[0088] wax

[0089] The colorant particles preferably contain wax. The wax preferably includes hydrocarbon waxes. Examples of other waxes include amide waxes, higher fatty acids, long-chain alcohols, ketone waxes, ester waxes, and their derivatives such as grafted compounds and block compounds. Two or more waxes may be used in combination as needed.

[0090] Hydrocarbon waxes produced via the Fischer-Tropsch process can maintain good developing performance and heat-resistant staining properties over a long period. It should be noted that these hydrocarbon waxes can contain antioxidants without affecting the charge properties of the toner.

[0091] The wax content is 4.0 to 30.0 parts by weight, more preferably 4.0 to 28.0 parts by weight, per 100 parts by weight of adhesive resin.

[0092] Charge control agent

[0093] Toner particles may optionally contain charge control agents. Blending with charge control agents can stabilize charge properties and allow for optimal control of triboelectric charge based on the developing system.

[0094] As charge control agents, known charge control agents can be used, and those exhibiting high charging speed and the ability to stably maintain a certain charge are particularly preferred. Furthermore, when producing toner particles via direct polymerization, charge control agents exhibiting low polymerization inhibition performance and substantially free of substances soluble in aqueous media are particularly preferred.

[0095] The toner particles may contain a single charge control agent or a combination of two or more charge control agents. The blending amount of the charge control agent is preferably 0.3 to 10.0 parts by weight, more preferably 0.5 to 8.0 parts by weight, based on 100 parts by weight of polymerizable monomer or binder resin.

[0096] External additives

[0097] The toner contains external additives on the surface of the toner particles. These external additives include aggregates of fine silica particles surface-treated with silicone oil. By adding fine silica particles as external additives to the toner particles, improvements in charge stability, durable development performance, flowability, and durability can be achieved.

[0098] Further external additives may be added to the toner as needed. Examples of such external additives include fine resin particles and fine inorganic particles used as charging aids, conductivity imparting agents, flowability imparting agents, anti-caking agents, release agents during hot roller fixing, lubricants, and abrasives.

[0099] Examples of lubricants include polyvinyl fluoride powder, zinc stearate powder, and polyvinylidene fluoride powder. As abrasives, cerium oxide powder, silicon carbide powder, and strontium titanate powder may be mentioned, with strontium titanate powder being preferred.

[0100] Fine silica particles

[0101] The following describes fine silica particles. External additives include aggregates of fine silica particles surface-treated with silicone oil. Alternatively, external additives preferably include non-aggregates of fine silica particles surface-treated with silicone oil. Non-aggregates refer to fine silica particles existing in the form of primary particles.

[0102] Materials are known to be used as substrates for fine silica particles. Examples include silicon compounds, particularly silicon halides, typically silicon chloride, fumed silica typically produced by burning purified silicon tetrachloride in an oxyhydrogen flame, wet silica produced from water glass, sol-gel silica particles obtained by the wet process, gel silica particles, aqueous colloidal silica particles, alcohol silica particles, fused silica particles obtained by the fumed process, and deflagration silica particles.

[0103] A primary particle size of 5 to 30 nm for the silica fine particles before silicone oil surface treatment is preferred, as it sufficiently imparts high flowability and high charge-carrying properties to the toner. A number-average particle size greater than 5 nm more effectively inhibits the embedding of surface-treated silica fine particles into the toner particle surface and improves durability. A number-average particle size less than 30 nm provides good flowability.

[0104] Furthermore, modified silicone oil is preferably used as the surface treatment agent for silica fine particles. That is, the silicone oil preferably includes modified silicone oil. When modified silicone oil is used, it adheres strongly to the surface of the silica fine particles, thus reducing the molecular mobility of the modified silicone oil. Therefore, it is easier to control parameter A within a high range. As a result, it is easier to maintain the shape of the silica fine particle aggregates during durability testing, and because the generation of deteriorating toner can be suppressed, fogging irregularities in the final stage of durability testing can be more effectively suppressed.

[0105] The modified silicone oil is preferably a modified silicone oil having reactive groups at the ends of the silicone oil molecular chain, such as a compound represented by the following formula (B). Silicone oils with reactive groups at the ends of the molecular chain form chemical bonds with silanol groups on the surface of untreated silica fine particles at the molecular ends, thus reducing the mobility of the silicone oil. As a result, it is easier to maintain the shape of the silica fine particle aggregates during durability testing, and because the generation of deteriorating toners can be suppressed, fogging in the final stage of durability testing can be more effectively suppressed.

[0106]

[0107] In the formula, R 1 The symbol represents hydroxymethyl, hydroxyl, epoxy, carboxyl, alkyl (preferably alkyl with 1 to 6 carbons, more preferably alkyl with 1 to 3 carbons) or hydrogen atom, and R. 2 This indicates a hydroxymethyl, hydroxyl, epoxy, carboxyl, or hydrogen atom. Preferably, R 1 and R 2 Each can be independently replaced by a hydroxymethyl, hydroxyl, or hydrogen atom. In formula (B), the methyl groups in the side chains can be independently replaced by hydroxymethyl, hydroxyl, epoxy, carboxyl, or hydrogen atoms.

[0108] m represents the average number of repeating units, and is the kinematic viscosity of the modified silicone oil at 25°C that is between 20 and 1000 mm⁻¹. 2 / s (more preferably 25 to 200 mm) 2 / s, and more preferably 30 to 70 mm 2 The value of m ( / s). For example, m is 30 to 200 (preferably 40 to 100, more preferably 50 to 80).

[0109] More preferably, a modified silicone oil having hydroxyl groups at both ends, as shown in formula (D), is preferred. The hydroxyl groups present at the molecular ends form strong siloxane bonds with the silanol groups on the surface of the substrate silica fine particles. Therefore, the modified silicone oil, which is strongly attached to the surface of the substrate silica fine particles, has lower molecular mobility. As a result, it is easier to maintain the shape of the silica fine particle aggregates during durability testing, and because the generation of deteriorating toners can be suppressed, fogging in the final stage of durability testing can be more effectively suppressed.

[0110]

[0111] In equation (D), p represents the average number of repeating units, and is the kinematic viscosity of the modified silicone oil at 25°C that is between 20 and 1000 mm. 2 / s (more preferably 25 to 200 mm) 2 / s, and more preferably 30 to 70 mm 2 The value of p ( / s). For example, p is 30 to 200 (preferably 40 to 100, more preferably 50 to 80).

[0112] In addition, when modified silicone oil is used in combination with polydimethylsiloxane represented by formula (A), the silica fine particles are sufficiently hydrophobic, thereby further improving the charge-carrying properties.

[0113]

[0114] n represents the average number of repeating units, and is the kinematic viscosity of polydimethylsiloxane at 25°C that is between 20 and 1000 mm⁻¹. 2 / s (more preferably 25 to 200 mm) 2 / s, and more preferably 30 to 70 mm 2 The value of n ( / s). For example, n is 30 to 200 (preferably 40 to 100, more preferably 50 to 80).

[0115] Silicone fine particles can be treated with silicone oil using known wet or dry methods. Preferably, these methods are used to treat the silica fine particles in a dispersed state so that the silica fine particles have a suitable aggregate diameter mechanically.

[0116] The silicone oil represented by formula (A) or formula (B) is preferably a highly volatile silicone oil that can be effectively evaporated or removed in the surface treatment described later. Therefore, the silicone oil represented by formula (B) or formula (A) is preferably a silicone oil with a relatively small molecular weight. The molecular weight of the silicone oil is related to its kinematic viscosity; the lower the kinematic viscosity, the lower the molecular weight. Silicone oils with low kinematic viscosity have more reaction sites with fine silica particles, and the parameter A of the fine silica particles tends to be higher. The kinematic viscosity range at 25°C is preferably 20 to 1000 mm. 2 / s, more preferably 25 to 200 mm 2 / s, and even more preferably 30 to 70 mm 2 / s.

[0117] The amount of silicone oil used in the surface treatment of fine silica particles varies depending on the type of fine silica particles (specific surface area, etc.) or the type of silicone oil (molecular weight, etc.). This amount is based on 100 parts by weight of fine silica particles, preferably 1 to 40 parts by weight, more preferably 2 to 35 parts by weight, and even more preferably 5 to 30 parts by weight. Amounts within this range improve hydrophobicity and also make it easier to control the coefficient of variation within a specific range.

[0118] Surface treatment methods

[0119] The surface treatment method is preferably carried out in an inert gas atmosphere, such as nitrogen, to prevent hydrolysis and oxidation. Specifically, the method includes placing fine silica particles of the substrate into a container equipped with a mixing device such as a Henschel mixer, stirring the fine silica particles under nitrogen purging, spraying a diluted silicone oil solution, mixing the solution with the fine silica particles of the substrate, and heating the mixture to induce a reaction. Spraying can be performed before heating or simultaneously with heating below the treatment temperature.

[0120] Processing conditions

[0121] The surface treatment involves providing a given amount of the aforementioned silicone oil to fine silica particles in a substrate and heating the silicone oil while mixing, causing the silicone oil to react with the surface of the fine silica particles and fix the silicone oil onto the surface. Here, the silicone oil can be diluted with the various solvents described above and then provided to the fine silica particles in the substrate.

[0122] The heating temperature in this surface treatment varies depending on the reactivity of the silicone oil used, and is preferably from 150°C to 350°C, more preferably from 250°C to 320°C. The treatment time varies depending on the heating temperature and the reactivity of the silicone oil used, and is preferably from 5 to 300 minutes, more preferably from 30 to 200 minutes, and even more preferably from 60 to 150 minutes. These ranges allow for a sufficient reaction between the silicone oil and the fine silica particles in the substrate.

[0123] From the viewpoint of improving fluidity and electrical properties, the total content of aggregates and non-aggregates of silica fine particles is preferably 0.10 to 4.00 parts by mass, more preferably 0.20 to 3.50 parts by mass, even more preferably 0.20 to 1.00 parts by mass, and even more preferably 0.30 to 0.50 parts by mass per 100 parts by mass of toner particles.

[0124] In addition to the silica particles mentioned above, other inorganic fine particles may be present on the surface of the toner. Examples of inorganic particles include titanium dioxide particles, aluminum oxide particles, and their composite oxide particles.

[0125] Production method of colorant

[0126] There are no particular limitations on the manufacturing method of the toner particles; any known method can be used. From the viewpoint of obtaining good flowability of the toner, the toner particles are preferably manufactured in an aqueous medium, for example, by dispersion polymerization, associative aggregation, dissolution-suspension polymerization, and suspension polymerization, with suspension polymerization being particularly preferred.

[0127] The method for manufacturing toner particles by suspension polymerization includes the steps of dispersing a polymerizable monomer composition comprising a polymerizable monomer capable of producing a binder resin and optional additives such as colorants in an aqueous medium and granulating the particles, and then polymerizing the polymerizable monomer contained in the granulated particles to obtain toner particles. The aforementioned polymerizable monomer, which is used as a binder resin material, can be used as a polymerizable monomer. From the viewpoint of developing and fixing performance, the weight-average particle size (D4) of the toner is preferably 5.0 to 10.0 μm, more preferably 6.0 to 9.0 μm.

[0128] For example, when manufacturing toner granules by pulverization, the binder resin and optional additives such as colorants and release agents are thoroughly mixed using a mixer such as a Henschel mixer or a ball mill. Subsequently, the mixture is melt-kneaded using a thermal kneader such as a heated roller, kneader, or extruder to disperse or dissolve the toner material. The toner material is then cooled, cured, pulverized, graded, and optionally surface-treated to obtain toner granules. Grading or surface treatment can be performed first. For production efficiency, a multi-stage grading machine is preferred for the grading step.

[0129] Pulverization can be carried out using known pulverizing methods such as mechanical impact pulverizers or jet pulverizers.

[0130] Examples of methods for applying mechanical impact force include the use of mechanical impact pulverizers such as the Cryptoron system manufactured by Kawasaki Heavy Industries, Ltd., or the Turbo Mill manufactured by FREUND-TURBO Corporation. Other methods involve applying mechanical impact force to toner particles using compression and friction, such as the Mechano Fusion system manufactured by Hosokawa Micron Corporation and the Hybridization system manufactured by Nara Machinery Co., Ltd.

[0131] For example, in suspension polymerization, polymerizable monomers and colorants (and, if necessary, further polymerization initiators, crosslinking agents, charge control agents, and other additives) are uniformly dissolved or dispersed to obtain a polymerizable monomer composition. The polymerizable monomer is then dispersed using a suitable stirrer in a continuous phase (e.g., an aqueous phase) containing a dispersion stabilizer, while a polymerization reaction is carried out to obtain colorant particles with the desired particle size.

[0132] In addition to the monomers described above, which are examples of vinyl monomers, known polymerizable monomers can also be used as polymerizable monomers constituting the polymerizable monomer composition. Among these, considering the developing properties and durability of the toner, it is preferable to use styrene or styrene derivatives alone or in combination with other polymerizable monomers.

[0133] The preferred polymerization initiator used in suspension polymerization has a half-life of 0.5 to 30.0 hours during the polymerization reaction. Furthermore, the amount of polymerization initiator added is preferably 0.5 to 20.0 parts by mass per 100 parts by mass of polymerizable monomer. Specific examples of preferred polymerization initiators include the above-described polymerization initiators, azo-based or diazo-based polymerization initiators, and peroxide-based polymerization initiators.

[0134] In suspension polymerization, the aforementioned crosslinking agent can be added during the polymerization reaction. The amount added is based on 100 parts by weight of polymerizable monomer, preferably 0.1 to 10.0 parts by weight.

[0135] Here, the preferred crosslinking agent is a compound having two or more polymerizable double bonds. For example, as mentioned above, aromatic divinyl compounds, carboxylic acid esters having two double bonds, divinyl compounds, and compounds having three or more vinyl groups are preferred. These can be used alone or in combination of two or more.

[0136] The following describes, but is not limited to, the manufacture of toner particles by suspension polymerization. First, a polymerizable monomer composition, obtained by appropriately adding the aforementioned polymerizable monomers and colorants, and uniformly dissolving or dispersing the contents using a homogenizer, ball mill, or ultrasonic disperser, is suspended in an aqueous medium containing a dispersion stabilizer for granulation. Since the resulting toner particles have a narrow particle size, it is preferable to use a disperser such as a high-speed mixer or ultrasonic disperser to achieve the desired toner particle size in one step. The polymerization initiator can be added simultaneously with other additives to the polymerizable monomers, or it can be added immediately before suspension in the aqueous medium. Alternatively, the polymerization initiator dissolved in the polymerizable monomers or solvent can be added immediately after granulation or before the polymerization reaction begins.

[0137] After granulation, use a regular mixer to thoroughly stir until the granules are maintained in their state and to prevent them from suspending or settling.

[0138] Surfactants, organic dispersants, and inorganic dispersants are known to be used as dispersion stabilizers. Among these, inorganic dispersants are preferred because they are less likely to generate harmful ultrafine particles, impart dispersion stability due to steric hindrance, and are less prone to loss of stability even with changes in reaction temperature. They are also easy to wash out. Examples of such inorganic dispersants include polyvalent metal salts of phosphates such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, and hydroxyapatite; carbonates such as calcium carbonate and magnesium carbonate; inorganic salts such as calcium metasilicate, calcium sulfate, and barium sulfate; and inorganic compounds such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide.

[0139] These inorganic dispersants are preferably used in amounts of 0.20 to 20.00 parts by weight of polymerizable monomers per 100 parts by weight. Dispersion stabilizers can be used alone or in combination of several. In addition, surfactants can be used in combination in amounts of 0.0001 to 0.1000 parts by weight of polymerizable monomers per 100 parts by weight.

[0140] The polymerization temperature of the polymerizable monomers is typically set above 40°C, preferably between 50°C and 90°C. After polymerization of the polymerizable monomers is complete, the resulting polymer particles are filtered, washed, and dried to obtain toner particles.

[0141] During the drying step, the drying temperature and drying time can be determined while checking the moisture content of the toner particles. From the viewpoint of toner flowability, the moisture content in the toner is preferably 1.00% by mass or less, more preferably 0.40% by mass or less, even more preferably 0.30% by mass or less, and even more preferably 0.20% by mass or less. There is no particular limitation on the lower limit, but the numerical proportion is preferably 0.01% by mass or more, more preferably 0.05% by mass or more.

[0142] Fine silica particles are externally added to and mixed with the resulting toner particles to adhere to the surface of the toner particles, thereby obtaining a toner. Additionally, a grading step may be included in the manufacturing process (before mixing the fine silica particles) to remove coarse and fine particles contained within the toner particles.

[0143] External addition steps

[0144] As a mixing process device for externally adding and mixing fine silica particles, known mixing process devices can be used, but Figure 3 The device shown is preferred because it allows for easy control of the coefficient of variation of the aggregate particle size. Figure 3 This is a schematic diagram illustrating an example of a mixing processing apparatus that can be used when fine silica particles are externally added and mixed.

[0145] The mixing equipment has a structure that applies proportions of toner particles and fine silica particles within a narrow gap. This allows the fine silica particles to adhere to the surface of the toner particles while simultaneously ensuring that the aggregates of fine silica particles are of uniform size. Therefore, it is easier to control the coefficient of variation of the aggregate particle size within the aforementioned range.

[0146] Furthermore, as described later, since the toner particles and silica fine particles readily circulate in the axial direction of the rotating component and readily and evenly mix before curing, the coefficient of variation can be easily controlled within a preferred range.

[0147] Mixing equipment (such as Henschel mixers) can be used to mix toner particles and fine silica particles. Figure 3 The device shown is preferred because it allows for easy control of externally added states. That is, as... Figure 3 The device shown has a construction that facilitates the application of toner in appropriate proportions, and the coefficient of variation can be easily controlled during short-time processing. Meanwhile, Figure 4 This is a schematic diagram illustrating an example of the configuration of a stirring component used in a mixing processing apparatus. Referring hereafter... Figures 3 to 4 Explain the steps of external addition and mixing of fine silica particles.

[0148] A mixing device for adding and mixing fine silica particles externally has a rotating member 2 with at least a plurality of stirring members 3 arranged on its surface, a driver 8 (7 indicating a central shaft) that rotatably drives the rotating member, and a main body housing 1 spaced apart from the stirring members 3.

[0149] The gap between the inner circumference of the main body shell 1 and the stirring member 3 is preferably kept constant and very small so as to uniformly apply the toner particles and make the silica fine particle aggregates uniform in size, while making the aggregates more easily adhere to the surface of the toner particles.

[0150] The inner diameter of the main casing 1 of the device is less than twice the outer diameter of the rotating component 2. Figure 3 An example is shown in which the inner circumferential diameter of the main body shell 1 is 1.7 times the outer circumferential diameter of the rotating member 2 (the diameter of the main body portion of the stirring member 3 excluding the rotating member 2). When the inner circumferential diameter of the main body shell 1 is less than twice the outer circumferential diameter of the rotating member 2, the processing space for applying force to the toner particles is appropriately limited, and sufficient impact force is applied to the silica fine particles that form secondary particles.

[0151] Preferably, the gap is adjusted according to the size of the main body shell. Sufficient proportion of silica particles can be applied by setting the gap to approximately 1% to 5% of the inner circumferential diameter of the main body shell 1. Specifically, when the inner circumferential diameter of the main body shell 1 is approximately 130 mm, the gap should be approximately 2 to 5 mm, and when the inner circumferential diameter of the main body shell 1 is approximately 800 mm, the gap should be approximately 10 to 30 mm.

[0152] In the external addition and mixing step of silica fine particles, a mixing processing device is used, and the rotating member 2 is rotated by the driver 8 to stir and mix the toner particles and silica fine particles placed in the mixing processing device, so as to externally add and mix the silica fine particles on the surface of the toner particles.

[0153] like Figure 4 As shown, at least a portion of the plurality of stirring members 3 is formed as a supply stirring member 3a that supplies toner particles and silica fine particles in one axial direction of the rotating member 2 as the rotating member 2 rotates. In addition, at least a portion of the plurality of stirring members 3 is formed as a return stirring member 3b that returns the toner particles and silica fine particles in another axial direction of the rotating member as the rotating member 2 rotates.

[0154] Here, as Figure 3 As shown, when the main body shell 1 is provided with a raw material supply port 5 and a product discharge port 6 at both ends, the direction from the raw material supply port 5 to the product discharge port 6 ( Figure 3 The direction from the center to the right is called the "supply direction".

[0155] That is, such as Figure 4As shown, the plate surface of the stirring member 3a is inclined so as to supply toner particles in the supply direction (13). At the same time, the plate surface of the stirring member 3b is inclined so as to supply toner particles and silica fine particles in the return direction (12).

[0156] While the process involves repeated feeding in the "supply direction 13" and "return direction 12", fine silica particles are added and mixed onto the surface of the toner particles.

[0157] The stirring components 3a and 3b comprise a group of multiple components arranged circumferentially spaced along the rotating component 2. The stirring components 3a and 3b in... Figure 4 The example shown includes a group of two components separated from each other at 180° intervals on rotating component 2. However, multiple components can be arranged as a group, such as a group of four components arranged at 120° or 90° intervals.

[0158] exist Figure 4 In the example shown, a total of 12 stirring components 3a and 3b are formed at equal intervals.

[0159] In addition, Figure 4 In this context, D represents the width of the stirring member, and d represents the spacing of the overlapping portions of the stirring members. From the viewpoint of effectively supplying toner particles and silica fine particles in both the supply and return directions, D is preferably relative to... Figure 4 The length of the rotating component 2 is 20% to 30% of its width. Figure 4 This indicates an example where D is 23%. When an extension line is drawn vertically from the edge position of the stirring member 3a, the stirring members 3a and 3b preferably have a certain degree of overlap d between them. This allows for the effective application of a share to the silica fine particles as secondary particles. To apply the share, d is preferably 10% to 30% relative to D.

[0160] In addition to Figure 4 Besides the shape shown, blades of any shape that can supply toner particles in both the supply and return directions while maintaining a gap are also acceptable. Specifically, blade structures with curved surfaces and blade tips engaged with the rotating member 2 via rod-shaped arms are also acceptable.

[0161] The following will be based on Figure 3 and Figure 4 The schematic diagram of the device shown is described in detail. Figure 3The device shown has a rotating member 2 on which at least a plurality of stirring elements 3 are disposed on its surface, a driver 8 for rotatably driving the rotating member 2, and a main body housing 1 disposed at intervals from the stirring members 3. The device further has a jacket 4 disposed inside the main body housing 1 and on the edge side surface 10 of the rotating member, through which cooling and heating media can flow.

[0162] also, Figure 3 The device shown has a raw material supply port 5 formed on the upper part of the main body shell 1 to introduce toner particles and fine silica particles. In addition, the device has a product discharge port 6 formed on the lower part of the main body shell 1 to discharge the toner that has undergone external addition and mixing treatment to the outside of the main body shell 1.

[0163] also, Figure 3 The device shown has a raw material supply port internal component 16 inserted into the raw material supply port 5 and a product discharge port internal component 17 inserted into the product discharge port 6.

[0164] First, the inner component 16 for the raw material supply port is removed from the raw material supply port 5, and toner particles are supplied to the processing space 9 from the raw material supply port 5. Next, fine silica particles are introduced into the processing space 9 from the raw material supply port 5 and inserted into the inner component 16 for the raw material supply port. Then, the rotating member 2 is rotated by the driver 8 (11 indicates the direction of rotation), and the material to be processed as described above is externally added and mixed while being stirred and mixed by a plurality of stirring members 3 provided on the surface of the rotating member 2.

[0165] It should be noted that the external addition and mixing treatment is preferably performed under multiple conditions to control the size of the silica fine particle aggregates and the coefficient of variation representing uniformity. Specifically, with the aim of deagglomerating the silica fine particles, the external addition and mixing treatment is performed under conditions where the silica fine particles are not fixed to the toner particles, and then under conditions where the deagglomerated silica fine particles are fixed to the toner particles. In the first external addition and mixing treatment, when the treatment conditions are too strong, the deagglomerated silica fine particles further deagglomerate, and the proportion of primary silica fine particles adhering to the surface of the toner particles tends to increase.

[0166] More specifically, it is preferable to control the power of the driver 8 at 0.2 to 0.3 W / g as the condition for the first external addition and mixing treatment, and to control the power of the driver 8 at 0.2 to 0.5 W / g as the condition for the second external addition and mixing treatment.

[0167] When the power in the first treatment is above 0.2 W / g, the aggregates of fine silica particles can be appropriately deaggregated, and the coefficient of variation tends to be easily controlled to be low. When the power in the first treatment is below 0.3 W / g, the deaggregation of fine silica particles can be sufficiently promoted while the embedding of fine silica particles into the surface of toner particles can be suppressed, and the coefficient of variation tends to be easily controlled to be low.

[0168] When the power in the second treatment is above 0.2 W / g, the fine silica particles easily adhere to the surface of the toner particles, and good charging properties and flowability can be easily obtained. When the power in the second treatment is below 0.5 W / g, the fine silica particles moderately deaggregate, and the aggregates of fine silica particles easily adhere to the surface of the toner particles.

[0169] The preferred processing time for the first external addition and mixing treatment is 1 to 10 minutes. Within this range, the silica fine particles deagglomerate well. The preferred processing time for the second external addition and mixing treatment is 4 to 20 minutes. By satisfying the above range, the aggregates of silica fine particles can be fully adhered to the surface of the toner particles.

[0170] After the external addition and mixing process is completed, the internal component 17 for the product discharge port 6 is removed, and the rotating member 2 is rotated by the drive 8, causing the toner to be discharged from the product discharge port 6. Optionally, coarse particles or the like are separated from the obtained toner using a screening machine such as a circular vibrating screen to obtain the toner.

[0171] Image forming equipment

[0172] Next, along Figure 6 Describe examples of image forming devices in which toners can be appropriately used. Figure 6In this diagram, 100 represents a photosensitive drum. Surrounding the photosensitive drum are arranged a primary charging roller 117, a developing sleeve 102, a developing apparatus 140 having a developing scraper 103 and a stirring member 141, a transfer charging roller 114, a cleaner 116, and a positioning roller 124. The photosensitive drum 100 is charged to, for example, -600V via the primary charging roller 117 (the applied voltage is, for example, AC voltage: 1.85kVpp, DC voltage: -620Vdc). Then, the photosensitive material 100 is irradiated with a laser beam 123 from a laser generator 121 used for exposure, thereby forming an electrostatic latent image corresponding to the target image. The electrostatic latent image on the photosensitive drum 100 is developed by the developing apparatus 140 using a single-component toner to form a toner image. The toner image is transferred onto a transfer material via a transfer roller 114, which connects the photosensitive material to the transfer material. The transfer material carrying the toner image is conveyed to the fixing unit 126 via the transfer belt 125 and fixed onto the transfer material. Some toner remaining on the photoreceptor is cleaned by the cleaner 116.

[0173] It should be noted that this description refers to an image forming apparatus for a magnetic single-component skip development system, but the same image forming apparatus can be used for skip development or contact development.

[0174] Method for measuring the weight-average particle size (Dv) of toners

[0175] The weight-average particle size (Dv) of the toner was calculated as follows. Measurements were performed using a precision particle size distribution measuring device with a 100 μm inlet tube (Coulter CounterMultisizer 3 (registered trademark), manufactured by Beckman Coulter, Inc.), based on pore resistance measurement, and dedicated software for setting measurement conditions and analyzing measurement data (Beckman CoulterMultisizer 3 Version 3.51, manufactured by Beckman Coulter, Inc.). Measurements were performed using 25,000 effective measurement channels, and the measurement data were then analyzed and calculated.

[0176] As the electrolyte aqueous solution used in the measurement, a solution of high-grade sodium chloride dissolved in ion-exchange water at a concentration of about 1% by mass, such as "ISOTON II" (manufactured by Beckman Coulter), can be used.

[0177] Before performing measurements and analysis, set up the dedicated software as follows.

[0178] On the "Standard Operating Method (SOM) Change" screen of the dedicated software, set the total count for the control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard Particle 10.0 μm" (Beckman Coulter). The threshold and noise level are automatically set by pressing the "Threshold / Noise Level Measurement Button". Additionally, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check the "Rinse Port after Measurement" option. On the "Pulse to Particle Size Conversion Settings" screen of the dedicated software, set the element spacing to logarithmic particle size, the number of particle size elements to 256, and the particle size range to 2 μm to 60 μm. The specific measurement method is as follows.

[0179] 1. Place 200 mL of electrolyte solution into a dedicated Multisizer 3 250 mL glass round-bottom beaker. Place the beaker on the sample stage and rotate the stir bar counterclockwise at 24 rpm. Use the "Venere rinse" function in the dedicated software to remove contaminants and air bubbles from the vise.

[0180] 2. Place approximately 30 mL of the electrolyte solution into a 100 mL glass beaker. Add approximately 0.3 mL of the diluted solution obtained by diluting “Contaminon N” (a 10% by mass aqueous solution of a pH 7 neutral detergent for washing precision measuring instruments, which includes nonionic surfactants, anionic surfactants and organic builders, available from Wako Pure Chemical Industries, Ltd.) by approximately 3 times by mass with deionized water as a dispersant to the beaker.

[0181] 3. Prepare an ultrasonic disperser (Ultrasonic Dispersion System Tetra 150 manufactured by Nikkaki Bios Co., Ltd.) with a 120W power output and two built-in oscillators with 180° phase offset and a 50kHz oscillation frequency. Place approximately 3.3L of ion-exchanged water in the water bath of the ultrasonic dispersion system and add approximately 2mL of Contaminon N to the water bath.

[0182] 4. Place the beaker from step (2) into the beaker fixing hole of the ultrasonic disperser and start the ultrasonic disperser. Adjust the height of the beaker to maximize the resonance state of the electrolyte aqueous solution surface inside the beaker.

[0183] 5. While irradiating the electrolyte solution in the beaker mentioned in (4) with ultrasound, add approximately 10 mg of toner to the electrolyte solution in small amounts each time and disperse it therein. Continue the ultrasonic dispersion treatment for another 60 seconds. When performing ultrasonic dispersion, adjust the temperature of the water bath appropriately to a temperature between 10°C and 40°C.

[0184] 6. Add the electrolyte aqueous solution containing the colorant mentioned in (5) above dropwise to the round-bottom beaker set on the sample stage mentioned in (1) above using a pipette, and adjust the measurement concentration to about 5%. Perform the measurement until the number of particles measured reaches 50,000.

[0185] 7. Calculate the weight-average particle size (Dv) by analyzing the measurement data using the accompanying dedicated software. When the dedicated software is set to Graphics / Volume %, the "Average Diameter" on the "Analysis / Volume Statistics (Arithmetic Mean)" screen is the weight-average particle size (Dv).

[0186] Through fine silica particles 29 Calculation methods for A and A / B in Si-solid NMR measurements

[0187] Parameters A, B, and A / B use fine silica particles separated from the toner surface via... 29 The calculation is performed using Si-solid-state NMR measurements. The following describes a method for separating fine silica particles from the surface of a toner. 29 Si solid-state NMR measurement method.

[0188] Methods for separating fine silica particles from the surface of toners

[0189] When fine silica particles separated from the surface of a toner are used as a measurement sample, the separation of fine silica particles from the toner is performed according to the following steps.

[0190] A total of 160 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) was added to 100 mL of ion-exchanged water and dissolved in a water bath to prepare a sucrose concentrate. A dispersion was prepared by placing a total of 31 g of the sucrose concentrate and 6 mL of Contaminone N (a 10% by mass aqueous solution of a pH 7 neutral detergent for washing precision measuring instruments, comprising nonionic surfactants, anionic surfactants, and organic builders, available from Wako Pure Chemical Industries, Ltd.) in a centrifuge tube. 1 g of toner was added to the dispersion, and the toner clumps were broken up using a spatula or similar tool.

[0191] The centrifuge tubes were placed in a KM Shaker (model: V.SX, manufactured by Iwaki Sangyo Co., Ltd.) and shaken for 20 minutes at 350 reciprocating motions per minute. After shaking, the solution was transferred to a 50 mL glass tube for centrifugation at 3500 rpm for 30 min.

[0192] After centrifugation, the toner is present in the uppermost layer of the glass tube, while the fine silica particles are present in the lower aqueous solution. A sample of the lower aqueous solution is taken and centrifuged repeatedly as needed to ensure thorough separation. The dispersion is then dried, and the fine silica particles are sampled.

[0193] Next, the fine silica particles recovered from the toner... 29 Si-solid NMR measurements were performed under the following conditions.

[0194] 29 Measurement conditions for Si-solid NMR

[0195] Equipment: AVANCE III 500, manufactured by BRUKER

[0196] Probe: 4mm MAS BB / 1H

[0197] Temperature measured: room temperature

[0198] Sample rotation number: 6kHz

[0199] Sample: Fine silica particles, 150 mg

[0200] Measured nuclear frequency: 99.36MHz

[0201] Reference material: DSS (external standard: 1.534 ppm)

[0202] Observation width: 29.76kHz

[0203] Measurement methods: DD / MAS, CP / MAS

[0204] 90° pulse width: 4.00μs, -1dB

[0205] Contact time: 1.75 to 10 ms

[0206] Repetition time: 30s (DD / MASS), 10s (CP / MAS)

[0207] Total number of times: 2048

[0208] LB value: 50Hz

[0209] After measurement, various silane components with different substituents and bonding groups were separated into the following M units, D units, T units and Q units by curve fitting.

[0210] M-unit structure: (Ri)(Rj)(Rk)SiO 1 / 2 Equation (4)

[0211] D-unit structure: (Rg)(Rh)Si(O) 1 / 2 Equation (5)

[0212] T-unit structure: RmSi(O) 1 / 2 Formula (6)

[0213] Q-unit structure: Si(O) 1 / 2 Formula 4 (7)

[0214] In formulas (4), (5), and (6), Ri, Rj, Rk, Rg, Rh, and Rm represent alkyl groups such as hydrocarbons with 1 to 6 carbon atoms, halogen atoms, hydroxyl groups, acetoxy groups, hydroxymethyl groups, epoxy groups, carboxyl groups, hydrogen atoms, or alkoxy groups that are bonded to silicon.

[0215] After peak separation, the values ​​of parameters A, B, and A / B are calculated. It is assumed that the integral value of the D unit obtained when the integral value of the Q unit in the CP / MAS measurement is set to 100 is taken as A, and the integral value of the D unit obtained when the integral value of the Q unit in the DD / MAS measurement is set to 100 is taken as B. Here, the measurement method for parameters A, B, and A / B of the silica fine particles contained in the toner is described, but the raw material containing the silica fine particles can also be measured.

[0216] Determining whether fine silica particles have been surface-treated with silicone oil

[0217] As an analytical method to confirm the use of silicone oil for surface treatment of fine silica particles, a thermal decomposition apparatus (Japan Analytical Industry Co., Ltd., JPS-330) was used. MS spectra derived from silicone oil were obtained by heating a 0.1 mg sample from 20°C to 500°C. For comparison, MS spectra of silicone oil were similarly measured. The two spectra were compared, and if the percentage of match between the MS spectra derived from silicone oil was high, the fine silica particles could be identified as having been surface-treated with silicone oil.

[0218] The number-average particle size Rb of aggregates of fine silica particles, the number-average particle size Ra of primary particles, Rb / Ra, and variation coefficient. Number calculation

[0219] For the sampled silica fine particles attached to the surface of the toner particles, various physical properties were measured, such as the number-average particle size Rb of the silica fine particle aggregates, the number-average particle size Ra of the primary particles, Rb / Ra, and the coefficient of variation. When multiple silica fine particles were included, the silica fine particles with a primary particle size of less than 50 nm were analyzed as the target among all silica fine particles attached to the surface of the toner particles.

[0220] Fine silica particles were sampled from the toner.

[0221] (1) Sample fine silica particles

[0222] Place 0.1g of toner, 20ml of deionized water, and 0.1ml of Contaminon N (a 10% by mass aqueous solution of a pH 7 neutral detergent for washing precision measuring instruments, comprising nonionic surfactants, anionic surfactants, and organic builders, available from Wako Pure Chemical Industries, Ltd.) into a 30ml glass vial.

[0223] The ultrasonic transducer UH-50 (manufactured by SMT Co., Ltd., with a tip diameter of [missing information]) was used. The tip of a titanium alloy chip is placed in the center of the vial, 5 mm above the bottom, and the silica particles are separated from the toner particles by ultrasonic dispersion. It should be noted that the ultrasonic dispersion output is set to 30 W to ensure that the shape of the silica particle aggregates on the toner particle surface does not change. After 10 minutes of ultrasonic treatment, the vial is allowed to stand for 30 minutes, and the supernatant is sampled and dropped onto a glass slide. The vial is then dried overnight. During this time, the vial is vacuum-dried below 30°C without heating to obtain the silica particle sample for measurement.

[0224] Measurement of fine silica particles

[0225] (2) SEM observation

[0226] Fine silica particles were measured using images obtained by observing backscattered electron images from a field emission scanning electron microscope (S-4800, Hitachi High-Technologies Corporation). Since backscattered electron images provide higher contrast than secondary electron images, high-precision measurements of fine silica particles are possible. The observation conditions are listed below.

[0227] Accelerating voltage: 0.8kV

[0228] Transmit current: 20μA

[0229] Detector: [SE (U)], [+BSE (LA100)]

[0230] Probe current: [Normal]

[0231] Focus Mode: [UHR]

[0232] WD: [3.0mm]

[0233] (3) Focus adjustment

[0234] Drag the magnification display on the control panel and set the magnification to 100000 (100k). Rotate the focus knob [COARSE] on the operation panel to adjust the aperture alignment when the image is focused to a certain extent. Click [Align] on the control panel to display the alignment dialog box and select [Beam]. Rotate the STIGMA / ALIGNMENT knobs (X, Y) on the operation panel to move the displayed beam of light to the center of the concentric circles. Next, select [Aperture], and then turn the STIGMA / ALIGNMENT knobs (X, Y) little by little to stop or minimize the image movement. Close the aperture dialog box and use autofocus to focus the image. Repeat this process twice more to focus the image.

[0235] Figure 5 This is an example of a schematic diagram of observed fine silica particles. 154 represents an aggregate of fine silica particles, 155 represents the maximum Feret diameter, and 156 represents the minimum Feret diameter. 157 represents the particle size of the primary particles of the fine silica particles. At least 300 fine silica particles were then measured. The number-average particle size of the aggregate of fine silica particles with the maximum Feret diameter was selected as the number-average particle size Rb of the aggregate. The number-average particle size of the primary particles was selected as the number-average particle size Ra of the primary particles of the fine silica particles. Rb / Ra can be obtained using Rb and Ra calculated as above.

[0236] The coefficient of variation (standard deviation / arithmetic mean) calculated using all data from Rb is taken as the coefficient of variation of particle size based on the number of aggregates of fine silica particles. Furthermore, the number of aggregates relative to the number of aggregates and the number of non-aggregate forms (the ratio of aggregates) can be obtained from the number of aggregates relative to the sum of the number of aggregates and the number of fine silica particles existing as primary particles.

[0237] It should be noted that when the fine silica particles observed in the above SEM observations are not considered as primary particles, it is judged that an aggregate has formed.

[0238] Measurement of the moisture content of toner

[0239] The moisture content of the toner was measured using a moisture meter (mark3 HP moisture analyzer, manufactured by Sartorius AG). Specifically, the moisture content was determined by weighing 10g of toner into an aluminum pan and heating the moisture meter to 120°C.

[0240] Example

[0241] The invention will now be described in more detail with reference to embodiments and comparative examples, but the invention is not limited thereto. Unless otherwise stated, the quantities used in the examples are based on mass.

[0242] Production example of fine silica particles 1

[0243] 100 parts of fumed silica (substrate silica; spherical, BET specific surface area: 300 m²) were used. 2 / g) is placed in a reaction vessel, and then, under nitrogen purging and stirring, 20 parts of R in formula (B) diluted with 100 parts hexane are added. 1 and R 2 Polydimethylsiloxane with hydroxyl groups and unsubstituted side chains (kinematic viscosity at 25°C: 50 mm) 2 A solution containing silica particles ( / s) was first reacted at 300°C with continuous stirring. Then, the resulting silica particles were deagglomerated using a needle-type deagglomerator to obtain silica particles 1. The number average particle size of the primary particles of the obtained silica particles 1 was 7 nm.

[0244] The physical properties of the silica fine particles 1 are listed in Table 1.

[0245] [Table 1]

[0246]

[0247] Production examples of silica fine particles 2 to 14

[0248] In addition to changing the processing conditions 1 (R in polydimethylsiloxane) in the production example of silica fine particles 1 as shown in Table 1, 1 and R 2 Except for the type and amount of polydimethylsiloxane added and processing conditions 2 (type and amount of polydimethylsiloxane added), silica fine particles 2 to 14 are produced in the same manner as the production method of silica fine particles 1. The physical properties of silica fine particles 2 to 14 are listed in Table 1. Here, processing condition 2 refers to the process carried out after processing condition 1, in which R in the polydimethylsiloxane of formula (B) is used. 1 and R 2The conditions for processing polydimethylsiloxane of methyl group, i.e., polydimethylsiloxane of formula (A), and changing the amount of polydimethylsiloxane added.

[0249] Production example of silica fine particles 15

[0250] Untreated dry silica (average primary particle size = 9 nm) was placed in an autoclave equipped with a stirrer and heated at 200°C in a fluidized state with stirring. The reactor was purged with nitrogen, sealed, and 25 parts of hexamethyldisilazane were sprayed inside every 100 parts of dry silica to treat the silane compounds in a fluidized state. The reaction was continued for 60 minutes and then terminated. After the reaction was complete, the autoclave was depressurized and washed with a nitrogen stream to remove excess hexamethyldisilazane and byproducts from the hydrophobic silica.

[0251] Furthermore, while stirring inside the reaction tank, 10 parts of dimethyl silicone oil (viscosity = 100 mm) were added. 2 Spray the mixture onto 100 parts of dry silica and continue stirring for 30 minutes. Then, while stirring, raise the temperature to 300°C. Stir the mixture for another 2 hours, then remove it and perform depolymerization treatment to obtain fine silica particles 15. The physical properties of the fine silica particles 15 are listed in Table 1.

[0252] Production example of silica fine particles 16

[0253] Oxygen is supplied to the burner to ignite it, and then hydrogen is supplied to the burner to form a flame. Silicon tetrachloride is then supplied to the burner to vaporize, thereby obtaining fine silicon dioxide particles. The disclosures in Japanese Patent Application Publication No. 2002-003213 and Japanese Patent No. 6478664 are referred to as specific production methods.

[0254] Specifically, oxygen is supplied to the burner through the combustion-supporting gas supply pipe to ignite the ignition burner, and hydrogen is supplied to the burner through the combustible gas supply pipe to form a flame. Silicon tetrachloride is vaporized in an evaporator and supplied thereto for a flame hydrolysis reaction. The resulting fine silica powder is recovered through a bag filter in a recovery unit to produce fine silica particles. The specific blowing conditions for each gas are as follows: silicon tetrachloride blowing rate: 200 kg / hr, hydrogen blowing rate: 60 Nm. 3 / hr, oxygen blowing rate: 60Nm 3 / hr. The number average particle size of the obtained silica fine particles is 30 nm, and the BET specific surface area is 50 m². 2 / g.

[0255] Ten parts of hexamethyldisilazane were added to 100 parts of the obtained silica fine particles as a surface treatment agent for hydrophobic treatment to obtain silica fine particles 16. The physical properties of the obtained silica fine particles 16 are listed in Table 1.

[0256] Production example of fine silica particles 17

[0257] 100 parts of fumed silica (the number average particle size of the primary silica substrate is 14 nm) were placed in a reaction vessel. Then, under nitrogen purging and stirring, 20 parts of methylhydrogen polysiloxane (kinematic viscosity at 25°C: 20 mmHg) diluted with 100 parts of hexane were added. 2 The solution was prepared by continuous stirring. The resulting silica particles were then deagglomerated using a needle-type deagglomerator to obtain silica fine particles 17. The number average particle size of the primary particles of the obtained silica fine particles 17 was 14 nm. The physical properties of the silica fine particles 17 are listed in Table 1.

[0258] Production examples of magnetic materials

[0259] Magnetic body 1

[0260] An aqueous solution containing ferrous hydroxide is prepared by mixing 1.00 to 1.10 equivalents of caustic soda solution relative to iron, 0.12% by mass of P₂O₅ relative to iron (based on phosphorus), and 0.60% by mass of SiO₂ relative to iron in an aqueous solution of ferrous sulfate. An oxidation reaction is then carried out at 85°C and pH 8.0 of the aqueous solution while air is blown in, to prepare a slurry solution containing seed crystals.

[0261] Next, ferrous sulfate solution was added to the slurry, making its initial amount relative to the alkali (sodium component in caustic soda) 0.90 to 1.20 equivalents. The slurry solution was then maintained at pH 7.6 to promote the oxidation reaction while air was blown into the slurry solution, thereby obtaining a slurry containing magnetic iron oxides. After filtration and washing, the aqueous slurry was removed all at once. At this point, a small sample of the aqueous content was taken, and the water content was measured.

[0262] Next, the aqueous sample was added to another aqueous medium without drying, and redispersed in a needle mill while stirring and circulating the slurry, adjusting the pH of the redispersed solution to approximately 4.8. Then, while stirring, 1.7 parts of n-hexyltrimethoxysilane coupling agent (the amount of magnetic iron oxide was calculated by subtracting the water content from the aqueous sample) were added for hydrolysis. Afterwards, the dispersion was surface-treated by thorough stirring while adjusting the pH to 8.6. The resulting hydrophobic magnetic material was filtered through a filter press, washed with plenty of water, and dried at 100°C for 15 minutes, followed by drying at 90°C for 30 minutes. The resulting particles were then deaggregated to obtain magnetic material 1 with a volume average particle size of 0.23 μm.

[0263] Production Example of Non-crystalline Polyester Resin 1

[0264] The molar ratio of polyester monomers is set as follows.

[0265] BPA-PO / BPA-EO / TPA / TMA=50 / 50 / 70 / 12

[0266] Here, the abbreviations represent the following: BPA-PO: 2.2 mol adduct of bisphenol A propylene oxide; BPA-EO: 2.2 mol adduct of bisphenol A ethylene oxide; TPA: terephthalic acid; and TMA: trimellitic anhydride.

[0267] The monomers other than TMA listed above, along with 0.1% by mass of tetrabutyl titanate as a catalyst, were placed in a flask equipped with a dehydration tube, stirring blades, and a nitrogen inlet tube, and subjected to a polycondensation reaction at 220°C for 10 hours. Subsequently, TMA was further added, and the reaction continued at 210°C until the desired acid value was achieved, thus obtaining amorphous polyester resin 1 (glass transition temperature Tg of 64°C, acid value of 17 mg KOH / g, and peak molecular weight of 6300).

[0268] Example 1 of the production of colorant granules

[0269] 720 parts of ion-exchanged water were supplied with 450 parts of 0.1M Na3PO4 aqueous solution, and the mixture was heated at 60°C. Then, 67.7 parts of 1.0M CaCl2 aqueous solution were added to obtain an aqueous medium containing a dispersant stabilizer.

[0270] Styrene: 78.0 parts

[0271] • n-Butyl acrylate: 22.0 parts

[0272] • Divinylbenzene: 0.6 parts

[0273] • Iron complex of monoazo dyes (T-77: Hodogaya Chemical Co., Ltd.): 2.0 parts

[0274] ·Magnetic material 1: 90.0 parts

[0275] • Non-crystalline polyester resin 1:3.0 parts

[0276] The above formulation was uniformly dispersed and mixed using a mill (Mitsui Miike Kakoki Kk) to obtain a polymerizable monomer composition. The obtained polymerizable monomer composition was heated at 60°C, and 15.0 parts of Fischer-Tropsch wax (melting point: 74°C, number average molecular weight Mn: 500) were added and mixed. After the wax dissolved, 7.0 parts of dilauryl peroxide as a polymerization initiator were dissolved to obtain a colorant composition.

[0277] The colorant composition was placed in an aqueous medium and granulated by stirring at 12,500 rpm at 60°C under a nitrogen atmosphere for 12 minutes using a TK type homogenizer (TokusyukiKakogyou KK). Afterwards, the reaction was continued at 74°C for 6 hours while stirring with a paddle stirrer.

[0278] After the reaction was complete, the suspension was cooled, hydrochloric acid was added, and the suspension was washed and filtered. The filtrate was then dried at 40°C for 66 hours to obtain toner particles 1. The weight-average particle size (Dv) of the obtained toner particles 1 was 7.2 μm. The moisture content of toner particles 1 was 0.15% by mass.

[0279] Production Example of Toner Granules 2

[0280] Except for changing the drying conditions to 40°C for 40 hours, toner particles 2 were obtained in the same manner as in the production example of toner particles 1. The weight-average particle size Dv of the obtained toner particles 2 was 7.2 μm. The moisture content of toner particles 2 was 0.40% by mass.

[0281] Production Example of Toner Granules 3

[0282] Except for changing the drying conditions to 40°C for 30 hours, toner particles 3 were obtained in the same manner as in the production example of toner particles 1. The weight-average particle size Dv of the obtained toner particles 3 was 7.2 μm. The moisture content of the toner particles 3 was 0.50% by mass.

[0283] Example 1 of the production of toner

[0284] use Figure 3The equipment shown performs external addition and mixing treatment on the toner particles 1 obtained in the toner particle production example 1.

[0285] In this implementation scheme, the following is used Figure 3 The main body shell 1 shown has an inner circumferential diameter of 130 mm and a processing space 9 with a capacity of 2.0 × 10⁻⁶ mm. -3 m 3 The device, drive 8, is rated for 5.5kW and uses a device with the following characteristics: Figure 4 The stirring component 3 is shown in the figure. Figure 4 The overlap width d between the stirring components 3a and 3b is set to 0.25D relative to the maximum width D of the stirring component 3, and the gap between the stirring component 3 and the inner circumference of the main body shell 1 is 3.0mm.

[0286] Using the aforementioned equipment, 100 parts of toner granules 1 and 0.40 parts of silica fine granules 1 are placed into... Figure 3 In the apparatus shown, after the toner particles and silica fine particles are supplied, premixing is performed to uniformly mix the toner particles and silica fine particles. The premixing conditions are set as follows: the power of driver 8 is 0.25 W / g, and the processing time is 3 minutes.

[0287] After premixing, external addition and mixing are performed. For external addition and mixing conditions, the circumferential speed of the outermost end of the stirring component 3 is adjusted so that the power of the driver 8 is kept constant at 0.40 W / g, and the processing time is set to 5 minutes.

[0288] After external addition and mixing, coarse particles were removed using a circular vibrating screen with a diameter of 500 mm and an opening of 75 μm to obtain toner 1. Analysis of toner 1 showed that parameter A was 158, Rb was 25 nm, and the coefficient of variation was 2.25. The moisture content of toner 1 was 0.15% by mass. The external addition conditions and physical properties of toner 1 are listed in Tables 2-1 and 2-2.

[0289] Production Examples 2 to 17 of Toners and Production Examples 2 to 4 and 8 of Comparative Toners

[0290] Toners 2 to 17 and comparative toners 2 to 4 and 8 were obtained by changing the toner particles, silica fine particles, and external addition conditions in the production example of toner 1 as listed in Table 3. The physical properties of the obtained toners are listed in Table 2-2.

[0291] Comparative example of toner production 1

[0292] To 100 parts of toner granules 3, 0.5 parts of silica fine particles 8 were dry-mixed with FM 10C (manufactured by Nippon Coke & Engineering Co., Ltd.) at 3400 rpm for 10 minutes to obtain comparative toner 1. The physical properties of the obtained comparative toner 1 are shown in Table 2-2.

[0293] Production examples of colorant 5

[0294] use Figure 3 The device shown performs external addition and mixing of toner particles 3.

[0295] Specifically, 100 parts of toner granules 3 and 0.40 parts of silica fine particles 15 are placed in... Figure 3 In the device shown, premixing is then performed. The premixing conditions are set to a power of 0.10 W / g for driver 8 and a processing time of 1 minute. After premixing, external addition and mixing are performed. The external addition and mixing conditions are adjusted to a power of 0.60 W / g for driver 8 and a processing time of 3 minutes.

[0296] Next, 0.10 parts (0.50 parts in total relative to 100 parts of toner particles) of fine silica particles 15 were added, the power of the drive 8 was adjusted to be constant at 0.60 W / g, and the process was performed for an additional two minutes. After the external addition and mixing process, coarse particles were removed using a circular vibrating screen with a 500 mm diameter sieve and a 75 μm opening to obtain comparative toner 5. The physical properties of comparative toner 5 are listed in Table 2-2.

[0297] Comparative examples of the production of colorant 6

[0298] To 100 parts of toner particles 3, 0.5 parts of fine silica particles 16 and 1.0 parts of hydrophobic silica particles RY 300 (manufactured by Nippon Coke & Engineering Co., Ltd., with a primary particle size of 8 nm treated with dimethyl silicone oil) were dry-mixed for 10 minutes using FM 10C (manufactured by Nippon Coke & Engineering Co., Ltd.) at 3400 rpm to obtain comparative toner 6. The physical properties of the obtained comparative toner 6 are shown in Table 2-2.

[0299] Production examples of comparative toner 7

[0300] To 100 parts of toner particles 3, 2.0 parts of fine silica particles 17 and 1.0 part of NX90 (manufactured by Nippon Aerosil Co., Ltd., primary particle number average size: 12 nm; treatment agent: hexamethyldisilazane) were added. This treatment was carried out in a 20-liter external addition treatment unit FM 20C (Nippon Coke & Engineering Co., Ltd.) at 30°C, with the stirring blade circumferential speed set to 50 m / sec and the treatment time set to 10 minutes. After this treatment, coarse particles were removed using a 45 μm opening screen to obtain comparative toner 7.

[0301] The physical properties of the obtained comparative toner 7 are listed in Tables 2-1 and 2-2.

[0302] [Table 2-1]

[0303]

[0304] [Table 2-2]

[0305]

[0306] In the table, A represents parameter A, and B represents parameter B. The coefficient of variation refers to the coefficient of variation of particle size based on the number of aggregates.

[0307] Example 1

[0308] Durability evaluation

[0309] The following evaluation was conducted using toner 1. The evaluation was performed at 32.5°C and 80% RH. For the fixing medium, A4-sized OceRedLabel paper sheets (basis weight: 80 g / m²) manufactured by Canon Inc. were used. 2 The commercially available LBP-3100 (manufactured by Canon Inc.) was used as the image forming device, and a modified version of the machine was used, which increased the printing speed from 16 pages / minute to 40 pages / minute.

[0310] 8,000 horizontal lines were printed in intermittent mode, each representing 1.5% of the print volume. After printing another 8,000 sheets, the toner cartridge was removed, vibrated 30 times, and the images were output again. Vibration of the toner cartridge mixes the degraded toner on the developing roller with the relatively undegraded toner in the toner cartridge container, resulting in a broadening of the toner's charge characteristics on the developing roller. Therefore, the evaluation of fogging and fogging irregularities is very stringent. The following evaluation was conducted, and good results were obtained. Table 3 shows the obtained evaluation results.

[0311] Image density

[0312] Image density is measured by forming solid black image portions, and the density of the solid black image is measured using a Macbeth transmission-reflectance density meter (manufactured by Macbeth Corporation). It should be noted that higher image density is better.

[0313] Fog

[0314] A solid white image was output, and its reflectance was measured using a REFLECTMETERMODEL TC-6DS manufactured by Tokyo Denshoku Co., Ltd. Simultaneously, the reflectance of the transfer paper (standard paper) before the solid white image was formed was also measured. A green color filter was used as the filter. The fogging effect was calculated using the following formula based on the reflectance before and after the solid white image output.

[0315] Fogging (reflectance) (%) = Reflectance of standard paper (%) - Reflectance of white solid image sample (%)

[0316] It should be noted that lower fogging (reflectivity) is better. The average fogging value is taken as the average value of the fogging values ​​evaluated at 10 points on a single evaluation image, and the maximum value is taken as the maximum fogging value. Because the irregular charge properties of the toner cause fogging in the output as an irregular image, the maximum fogging value is particularly large.

[0317] Examples 2 to 17

[0318] The toners 2 to 17 were evaluated in the same manner as in Example 1, and good results were obtained.

[0319] Table 3 shows the evaluation results.

[0320] [Table 3]

[0321]

[0322] In the table, solid lines represent the image density of solid black images.

[0323] Comparative Examples 1 to 8

[0324] Comparative toners 1 to 8 were tested in the same manner as in Example 1. Table 4 shows the evaluation results.

[0325] [Table 4]

[0326]

[0327] While the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims is to be interpreted in the broadest sense to cover all such modifications and equivalent structures and functions.

Claims

1. A toner comprising: Toner particles, and External additives on the surface of the colorant particles Its features are, The external additive comprises an aggregate of fine silica particles surface-treated with silicone oil; When the number-average particle size of the aggregates of the silica fine particles is defined as Rb, Rb is 12 to 80 nm; When the fine silica particles 29 In Si-solid NMR CP / MAS measurements, when the integral value of the Q cell is set to 100, the integral value of the D cell is defined as A, where A ranges from 120 to 300. Based on the number of aggregates of the silica fine particles, the coefficient of variation of the particle size of the aggregates of silica fine particles is between 1.00 and 3.

00. The external additive further comprises non-aggregates of fine silica particles surface-treated with silicone oil. Based on the total number of aggregates and non-aggregates of the silica fine particles, the proportion of aggregates of the silica fine particles is more than 40%. The silicone oil comprises a modified silicone oil, which is a compound represented by the following formula (B): In equation (B), R 1 Represents hydroxymethyl, hydroxyl, epoxy, carboxyl, alkyl, or hydrogen atom, and R 2 The radical represents hydroxymethyl, hydroxyl, epoxy, or carboxyl; and m represents the average number of repeating units, where m is the kinematic viscosity of the modified silicone oil represented by formula (B) at a temperature of 25°C, which is between 20 and 1000 mm. 2 The value of / s.

2. The toner according to claim 1, wherein, When the number-average particle size of the primary particles of the silica fine particles is defined as Ra, Ra is 5 to 30 nm.

3. The toner according to claim 1 or 2, wherein, When the number-average particle size of the primary particles of the silica fine particles is defined as Ra, Ra and Rb satisfy the following equation (1): 2.5 ≤ Rb / Ra ≤ 5.0 … (1).

4. The toner according to claim 1 or 2, wherein, The total content of the aggregates and non-aggregates of the silica fine particles is 0.10 to 4.00 parts by weight per 100 parts by weight of the toner particles.

5. The toner according to claim 1 or 2, wherein, When the fine silica particles are... 29 When the integral value of the D cell obtained in the DD / MAS measurement of Si-solid NMR is set to 100 and defined as B, A and B satisfy the following equation (2): 3.0 ≤ A / B ≤ 6.0 … (2).

6. The toner according to claim 1 or 2, wherein, The moisture content of the toner is less than 0.40% by mass.

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