toner

Abstract

To provide a toner that can prevent a reduction in image density when a large number of images are formed.SOLUTION: A toner has toner particles containing a binder resin. The binder resin contains a polyester A containing a unit derived from isophthalic acid in an amount of 60 mol% or more as an acid component, in an amount of 50 mass% or more. The toner has aggregates containing silica and resin on the surface of the toner particles. When the number ratio of toner particles having the aggregates is defined as CI (number%), the CI is 1 number% or more and 15 number% or less. The number ratio of toner particles having the aggregates satisfies a predetermined criterion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to toners used in image forming processes such as electrophotography. [Background technology]

[0002] Methods of visualizing image information via electrostatic latent images, such as electrophotography, are used in copiers, multifunction machines, and printers. In recent years, as the applications of these machines have become more diverse, there has been a demand for even higher image quality and longer life for electrophotographic machines and toner cartridges. Furthermore, in order to maintain high image quality throughout its lifespan, it is effective to control the toner's surface properties so that they do not change throughout its lifespan. In a typical electrophotographic process, the toner's surface properties are controlled by disposing various organic or inorganic fine powders, commonly known as external additives, on the toner surface. Furthermore, to provide stable images throughout its lifespan in various regions around the world, it is necessary to maintain the toner's properties in various environments. External additives play an important role in such toner design. Generally, silica is used as an external additive, as it imparts fluidity to the toner and plays an important role in generating and maintaining charge through triboelectric charging. Patent Document 1 discloses a toner containing an amorphous composite resin having a polycondensation resin component obtained by polycondensing an alkylene oxide adduct of bisphenol A with an isophthalic acid compound and an aliphatic saturated carboxylic acid compound, and a styrene-based resin component, in order to obtain a toner with excellent low-temperature fixing properties. Compared to when a terephthalic acid compound or the like is used as a raw material, when an isophthalic acid compound is used as a raw material, the polymer chains are less entangled, forming flexible polymer chains and enabling a reduction in melt viscosity during fixing. Patent Document 2 discloses a toner that uses silica aggregates (silica agglomerates) as an external additive to achieve high image quality in high-temperature, high-humidity environments. The technology proposes a technique for suppressing fogging associated with charge leakage, which is caused by low-hydrophobicity areas on the surface of the silica agglomerates that are generated when the agglomerates are crushed, by setting the average primary particle size of the silica agglomerates to 50 nm or more and 500 nm or less. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-3851 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-65963 Summary of the Invention [Problem to be solved by the invention]

[0004] Although the toner of Patent Document 1 has excellent low-temperature fixing properties, the external stress on the toner increases with longer life, which can cause the external additives to become embedded in the toner particles, resulting in a decrease in image density in the latter half of the durability test. Furthermore, although the toner of Patent Document 2 can suppress fogging in high-temperature, high-humidity environments by using silica agglomerates, external stress on the toner due to its extended life can cause the silica agglomerates to break down, resulting in a decrease in image density in the latter half of the durability test. Therefore, there is a demand for a toner that can suppress a decrease in image density when forming images on a large number of sheets. The present disclosure aims to solve the above problems. [Means for solving the problem]

[0005] The present disclosure provides a toner having toner particles containing a binder resin, the binder resin contains 50% by mass or more of a polyester A containing 60% by mole or more of units derived from isophthalic acid as an acid component, The toner has aggregates containing silica and a resin on the surface of the toner particles, When the number ratio of toner particles having the agglomerates is defined as CI (number %), the CI of the toner is 1 number % or more and 15 number % or less, When the toner is treated under the ultrasonic condition A below, the number ratio of the toner particles containing the aggregates is Ca, When the toner is treated under the ultrasonic condition B below, the number ratio of the toner particles containing the aggregates is Cb, The toner is characterized in that the CI, Ca, and Cb satisfy the following formulas (1) and (2): Ultrasonic condition A: output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s Ultrasonic condition B: output frequency 30kHz, output capacity 25W, irradiation time 300s 0.90≦Ca / CI≦1.00 Formula (1) 0.10≦Cb / CI≦0.40 Formula (2) [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a toner that can suppress a decrease in image density when forming images on a large number of sheets. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a representative diagram of a toner having agglomerates. [Figure 2] This is an example of an image obtained by performing a predetermined process using ImageJ on an analysis image obtained in a method for confirming the dispersion state of a resin component contained in an aggregate. [Figure 3] This is an example of an image in which a total of 18 straight lines are drawn from one end of the image to the other at 10° intervals, passing through the midpoint of the image as a reference point. [Figure 4] FIG. 2 is a schematic diagram of a cross section of a toner having agglomerates. DETAILED DESCRIPTION OF THE INVENTION

[0008] In this disclosure, unless otherwise specified, the expressions "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined arbitrarily. Furthermore, a monomer unit refers to the reacted form of a monomer substance in a polymer. Furthermore, in the following description, toner particles before aggregates containing silica and resin are present on the toner particle surface may be referred to as "toner core particles."

[0009] [The process and significance of the present disclosure] There was a problem that image density was likely to decrease when forming multiple images (during durability testing). Through investigations by the present inventors, it was speculated that this problem was largely due to a decrease in toner fluidity, with the breakdown of agglomerates (agglomerates containing silica and resin) caused by mechanical stress when forming multiple images, and the embedding of external additives into the surfaces of toner particles.

[0010] As a result of investigating the disintegration of these silica agglomerates, it was found that by incorporating a resin into the silica agglomerates, the silica agglomerates can be gradually broken down in response to the mechanical stress that occurs when forming multiple images, thereby preventing the silica agglomerates from suddenly collapsing.

[0011] Furthermore, as a result of investigations focusing on the embedding of external additives, it was found that by incorporating isophthalic acid into the resin component of the toner, adhesion of external additives to the toner particle surface can be suppressed, and the embedding of external additives can be suppressed.

[0012] First, the inventors focused on isophthalic acid, a polyester monomer unit. Isophthalic acid has two carboxyl groups meta-positioned relative to the benzene ring. Therefore, it is more likely to form a zigzag polymer structure than terephthalic acid, which has two carboxyl groups para-positioned relative to the benzene ring, i.e., a linear structure. As a result, it is easier to form a flexible structure by suppressing interactions between polymer chains, and it is easier to maintain low-temperature fixability. Furthermore, isophthalic acid has a high-electron-density region (partial negative region) derived from the two carboxyl groups meta-positioned relative to the benzene ring. This partial negative region prevents external additives containing negatively charged silica and resin from embedding in the toner particle surface through electrostatic repulsion.

[0013] Furthermore, the inventors focused on the relationship between the partial negative areas on the toner particle surface and silica aggregates. The negatively charged silica particles contained in the aggregates electrostatically repel the partial negative areas on the toner particle surface. As the aggregates gradually break down, silica particles are generated, which then adhere to the toner particles and act as a fresh external additive to impart fluidity to the toner.

[0014] Furthermore, the inventors focused on agglomerates containing silica and resin. The agglomerates contain a resin that bonds the silica and toner particles. Therefore, unlike agglomerates containing only silica fine particles, the agglomerates do not disintegrate and gradually disintegrate depending on the energy applied. That is, agglomerates do not disintegrate from toner particles when low energy is applied. On the other hand, agglomerates disintegrate from toner particles when high energy is applied. That is, in the early stages of image formation, the agglomerates are not disintegrated because the energy applied to them by stirring and friction is low. After forming multiple images, the agglomerates are subjected to long periods of stirring and friction, and the energy applied increases, gradually disintegrating them. In addition, the silica fine particles generated by the disintegration of the agglomerates electrostatically repel the partial negative portions of the toner particles. The silica particles then detach from the toner particles and adhere to the surfaces of other toner particles as fresh external additives, imparting fluidity to the toner. Due to this effect, when forming multiple images, the agglomerates gradually supply external additives, thereby suppressing a decrease in image density.

[0015] In light of the above, the present inventors have conducted extensive research and found that a toner having the following main components can maintain fluidity and suppress a decrease in image density over a long period of use.

[0016] In a toner containing a binder resin and an external additive, 1) The binder resin contains 50% by mass or more of polyester A containing 60% by mole or more of units derived from isophthalic acid as an acid component, 2) the toner comprises at least toner particles; the toner has aggregates containing silica and resin on the surface of the toner particles; When the number ratio of toner particles having the agglomerates is defined as CI (number %), the CI of the toner is 1 number % or more and 15 number % or less, When the toner is treated under the ultrasonic condition A below, the number ratio of the toner particles containing the aggregates is Ca, When the toner is treated under the ultrasonic condition B below, the number ratio of the toner particles containing the aggregates is Cb, The Cl, Ca, and Cb satisfy the following formulas (1) and (2). Ultrasonic condition A: output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s Ultrasonic condition B: output frequency 30kHz, output capacity 25W, irradiation time 300s 0.90≦Ca / CI≦1.00 Formula (1) 0.10≦Cb / CI≦0.40 Formula (2)

[0017] As a result, it was found that the fluidity could be maintained throughout the image formation on a large number of sheets, and the decrease in image density could be significantly suppressed.

[0018] [Main configuration of the present invention] The following will describe in detail the preferred scope of the present disclosure based on the above mechanism.

[0019] The toner of the present disclosure has toner particles containing a binder resin.

[0020] The binder resin contains 50% by mass or more of polyester A, and polyester A contains a unit (U) derived from isophthalic acid based on the total units derived from the acid component. iso ) must be contained in an amount of 60 mol % or more (U iso (The total acid component x 100 is 60 mol % or more). This not only improves the low-temperature fixability, but also suppresses the embedding of the external additive into the toner particle surface by electrostatic repulsion, thereby suppressing the decrease in image density when forming multiple images. Preferably, U iso / Total acid components×100 is 90 mol % or more.

[0021] The toner of the present disclosure requires aggregates containing silica and resin on the surface of the toner particles. Figure 1 is a representative diagram of a toner having aggregates on the surface of the toner particles.

[0022] Examples of the silica and resin-containing aggregates include particles whose main component is silica and a resin capable of binding these particles together. Examples of silica-based particles include dry silica particles, known as dry process or fumed silica, which are produced by vapor phase oxidation of silicon halides, and wet silica particles, which are produced from water glass or the like. These particles may be subjected to hydrophobic treatment. Examples of the treatment agent used for hydrophobic treatment include silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, organic titanium compounds, and the like. These may be used alone or in combination.

[0023] The content of agglomerates in the toner, CI (number %), which is the percentage by number of toner particles containing agglomerates, must be 1.0 to 15.0% by number. If the CI is 1.0% by number or more, it is possible to suppress a decrease in image density due to insufficient supply of external additives when forming multiple images. Furthermore, if the CI is 15.0% by number or less, it is possible to effectively suppress a decrease in image density caused by contamination of conductive members (such as charging rollers) when forming multiple images, which is caused by excessive agglomerates.

[0024] In the toner of the present disclosure, when the number ratio of toner particles having agglomerates in the toner after treatment under ultrasonic condition A below is Ca (number %) and the number ratio of toner particles having agglomerates in the toner after treatment under ultrasonic condition B below is Cb (number %), it is necessary that the above CI, Ca, and Cb satisfy the relationship of formulas (1) and (2). Ultrasonic condition A: Output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s ·Ultrasonic condition B: Output frequency 30kHz, output capacity 25W, irradiation time 300s 0.90≦Ca / CI≦1.00 Formula (1) 0.10≦Cb / CI≦0.40 Formula (2)

[0025] If the Ca / CI range is 0.90 or more, it is possible to prevent agglomerates from breaking apart due to weak shear and stabilize the supply of external additives when forming images on multiple sheets, thereby suppressing a decrease in image density.

[0026] Furthermore, if the Cb / CI range is 0.40 or less, the agglomerates break apart when subjected to an appropriate shear force, which stabilizes the supply of external additives when forming multiple images, and suppresses a decrease in image density.

[0027] Polyester A is a polyester consisting of units (U) derived from an ethylene oxide adduct of bisphenol A. EO ) and units derived from propylene oxide adducts of bisphenol A (U PO ) and contains the unit U EO and unit U PO The total content of the ethylene oxide adduct of bisphenol A and the propylene oxide adduct of bisphenol A is preferably 90 mol % or more based on all units derived from the alcohol component. The ethylene oxide adduct of bisphenol A and the propylene oxide adduct of bisphenol A have a benzene ring in the main chain, which improves the durability of the toner and makes it possible to suppress a decrease in image density when forming multiple images.

[0028] Polyester A is a unit U EO Content ratio and unit U PO The unit U EO The content ratio of U EO / (U EO +U PO ) × 100 is preferably 15 mol % or more and 40 mol % or less. PO U EO Compared to U, it has a larger carbon number and is a bisphenol A unit to which propylene oxide with a branched structure has been added. EO / (U EO +U PO When the ratio of U to U is 15 mol % or more, the density of the benzene rings in the main chain increases, and the durability of the toner particles improves. EO / (U EO +U POWhen the ratio of U to U is 40 mol % or less, the hydrocarbon density in the main chain increases, and the durability of the toner particles improves, so that a decrease in image density when forming multiple images can be suppressed. EO / (U EO +U PO )×100 is preferably 15 mol % or more and 40 mol % or less.

[0029] When the number average molecular weight (Mn) and weight average molecular weight (Mw) of the tetrahydrofuran (THF)-soluble component of polyester A are measured using gel permeation chromatography (GPC), the number average molecular weight (Mn) is preferably 3,000 to 10,000, and the (Mw / Mn) ratio is preferably 2.5 or greater. Having a number average molecular weight (Mn) of 3,000 or greater can prevent external additives from being embedded in the toner particles due to their excessively low strength, thereby preventing a decrease in image density when forming multiple images. Having a number average molecular weight (Mn) of 10,000 or less can prevent the collapse of aggregates due to their excessively high strength, thereby preventing a decrease in image density when forming multiple images. More preferably, the number average molecular weight (Mn) is 4,000 to 8,000. Having a (Mw / Mn) ratio of 2.5 or greater means that the molecular weight distribution of polyester A is sufficiently broad, resulting in high flexibility of the toner particles. As a result, it is possible to prevent the toner from deforming excessively when subjected to an impact, and it is also possible to prevent the toner from collapsing when subjected to an impact, thereby preventing a decrease in image density when forming multiple images.

[0030] The toner particles preferably contain 0.015% by mass or more and 0.150% by mass or less of aluminum element. When the amount of aluminum element is within the above range, aluminum forms a crosslinked structure in the toner particles. As a result, by imparting elasticity to the toner particles, plastic deformation of the toner particles is suppressed, and the disintegration of aggregates when forming multiple images can be stabilized, thereby suppressing a decrease in image density.

[0031] The binder resin preferably further contains a crystalline polyester. The use of a crystalline polyester improves fixability. The binder resin preferably contains 3.0% by mass or more and 30.0% by mass or less of the crystalline polyester. Preferred polyesters as the crystalline polyester will be described later.

[0032] The toner preferably has an average circularity of 0.950 or more and 0.980 or less. As a result, even if a strong impact is applied to the toner, pressure concentration is alleviated and agglomerates can be stably broken down, thereby suppressing a decrease in image density when forming multiple images. Furthermore, if the average circularity is 0.980 or less, the breaking up of agglomerates caused by excessively high toner fluidity is stabilized, thereby suppressing a decrease in image density when forming multiple images.

[0033] When the toner surface is observed under a scanning electron microscope, the area ratio of the resin component of the agglomerates is preferably 5% to 50% of the total agglomerates. As a result, when the agglomerates contain an appropriate amount of resin component, the disintegration of the agglomerates is appropriately controlled, and the effects of the present disclosure are achieved at a high level. If the resin component content is less than this range, the agglomerates are easily detached, making it difficult to achieve the effect of reducing image density when forming multiple images. If the resin component content is greater than this range, the agglomerates are difficult to detach, making it difficult to achieve the effect of reducing image density when forming multiple images. The area ratio of the resin component of the agglomerates can be controlled by adjusting the compounding ratio of the silica fine particles and the binder component, as well as manufacturing conditions such as stirring conditions.

[0034] The arithmetic mean Feret diameter Ag of the agglomerates is preferably 1000 nm or more and 8000 nm or less. If the agglomerates are in this range, the agglomerates are sufficiently large, so that the toner containing the agglomerates is stirred in the container for a longer period of time. As a result, the agglomerates have more opportunities to separate, and a decrease in image density when forming multiple images can be suppressed.

[0035] [Preferred components and embodiments of toner particles] Next, preferred components and embodiments of the toner particles will be described.

[0036] <Binder resin> The toner particles contain a binder resin. The content of the binder resin is preferably 50% by mass or more of the total amount of resin components in the toner particles. The binder resin may also contain polyesters other than Polyester A, such as styrene-acrylic resin, epoxy resin, polyester, polyurethane, polyamide, cellulose resin, polyether, or a mixed resin or composite resin thereof.

[0037] <Polyester A> As described above, polyester A has a ratio of unit U derived from isophthalic acid to the total units derived from the acid component. iso The polyester A used in the toner particles must contain 60 mol % or more, and preferably 90 mol % or more. The polyester A used in the toner particles is preferably an amorphous polyester.

[0038] It is sufficient if a unit derived from isophthalic acid is used as an essential component, and examples thereof include the following.

[0039] The polyester can be obtained by selecting and combining suitable polycarboxylic acids, polyols, hydroxycarboxylic acids, etc., and synthesizing them using a known method such as transesterification or polycondensation. Preferably, the polyester includes a condensation polymer of a dicarboxylic acid and a diol.

[0040] Polycarboxylic acids are compounds containing two or more carboxy groups in one molecule, and among these, dicarboxylic acids are compounds containing two carboxy groups in one molecule and are preferably used. Examples of the carboxylic acids include oxalic acid, succinic acid, glutaric acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-carboxylic acid, hexahydroterephthalic acid, malonic acid, pimelic acid, suberic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediacetic acid, o-phenylenediacetic acid, diphenylacetic acid, diphenyl-p,p'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracenedicarboxylic acid, and cyclohexanedicarboxylic acid.

[0041] Furthermore, examples of polycarboxylic acids other than dicarboxylic acids include trimellitic acid, trimesic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, pyrenetetracarboxylic acid, itaconic acid, glutaconic acid, n-dodecylsuccinic acid, n-dodecenylsuccinic acid, isododecylsuccinic acid, isododecenylsuccinic acid, n-octylsuccinic acid, n-octenylsuccinic acid, etc. These may be used alone or in combination of two or more.

[0042] Polyols are compounds containing two or more hydroxyl groups per molecule. Among them, diols are compounds containing two hydroxyl groups per molecule and are preferably used. Specifically, diols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,14-eicosanediol. Examples of suitable bisphenols include hexanediol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-butenediol, neopentyl glycol, polytetramethylene glycol, hydrogenated bisphenol A, bisphenol A, bisphenol F, bisphenol S, and alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts of the above bisphenols.

[0043] Among these, alkylene oxide adducts of bisphenols and alkylene glycols having from 2 to 12 carbon atoms are preferred, and alkylene oxide adducts of bisphenols and their combined use with alkylene glycols having from 2 to 12 carbon atoms are particularly preferred. Examples of alkylene oxide adducts of bisphenol A include compounds represented by the following formula (A):

[0044] [ka] (In formula (A), each R is independently an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x+y is 0 or more and 10 or less.)

[0045] The alkylene oxide adduct of bisphenol A is preferably a propylene oxide adduct and / or an ethylene oxide adduct of bisphenol A. It is more preferably a propylene oxide adduct. The average value of x+y is preferably 1 or more and 5 or less.

[0046] Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, hexamethylolmelamine, hexaethylolmelamine, tetramethylolbenzoguanamine, tetraethylolbenzoguanamine, sorbitol, trisphenol PA, phenol novolac, cresol novolac, alkylene oxide adducts of the above trihydric or higher polyphenols, etc. These may be used alone or in combination of two or more.

[0047] The acid value of the polyester A is preferably 4.0 mgKOH / g or more and 10.0 mgKOH / g or less.

[0048] <agglomerate> Specific examples of the aggregates containing silica and resin include particles containing silica as the main component and a resin component capable of binding these particles together.

[0049] Examples of silica-based particles that can be used include dry silica particles, known as dry process or fumed silica, produced by vapor-phase oxidation of silicon halides, and wet silica particles (hereinafter also referred to as colloidal silica) produced from water glass or the like. These particles may be subjected to a hydrophobic treatment. Examples of treatment agents used for the hydrophobic treatment include silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane compounds, silane coupling agents, and other treatment agents such as organosilicon compounds and organotitanium compounds. These may be used alone or in combination.

[0050] The number average particle size of the primary particles of the silica fine particles is preferably 10 nm or more and 200 nm or less (more preferably 15 nm or more and 150 nm or less). The number average particle size of the primary particles of the silica fine particles can be measured using a magnified photograph of the toner taken with a scanning electron microscope.

[0051] The resin component capable of binding silica microparticles must be able to bond the particles with an appropriate strength and must not be adversely affected by mechanical stress or environmental changes such as temperature and humidity during the development process. Examples of such materials include vinyl resins and polyesters, with vinyl resins being particularly preferred. These materials can maintain the silica microparticles with an appropriate bonding strength, allowing them to be continuously supplied to the development process as the toner is used. Furthermore, while the resin component itself is simultaneously supplied to the development process, appropriate selection of the resin component's hardness and responsiveness to environmental changes such as temperature and humidity can suppress component contamination and changes in development characteristics. Specific materials are described in the manufacturing method section below.

[0052] <Crystalline polyester> The toner particles preferably contain a crystalline polyester. The crystalline polyester is preferably a condensation polymer of a monomer containing an aliphatic diol and / or an aliphatic dicarboxylic acid. The crystalline polyester refers to a polyester that has a clear melting point as measured by a differential scanning calorimeter (DSC).

[0053] The crystalline polyester preferably contains a monomer unit derived from an aliphatic diol having 2 to 12 carbon atoms (more preferably 6 to 12 carbon atoms) and / or a monomer unit derived from an aliphatic dicarboxylic acid having 2 to 12 carbon atoms (more preferably 6 to 12 carbon atoms).

[0054] A crystalline polyester having such a structure is preferred because it improves the dispersibility of the crystalline polyester between toner particles, suppresses fusion of the toner particles, and thereby enables agglomerates to be broken down stably, thereby suppressing a decrease in image density when forming multiple images.

[0055] Examples of aliphatic diols having 2 to 12 carbon atoms include the following compounds: 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[0056] Aliphatic diols having a double bond can also be used, such as 2-butene-1,4-diol, 3-hexene-1,6-diol, and 4-octene-1,8-diol.

[0057] Examples of aliphatic dicarboxylic acids having 2 to 12 carbon atoms include the following compounds: oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, and 1,12-dodecanedicarboxylic acid. Lower alkyl esters and acid anhydrides of these aliphatic dicarboxylic acids can also be used. Of these, sebacic acid, adipic acid, and 1,10-decanedicarboxylic acid, as well as lower alkyl esters and acid anhydrides thereof, are preferred. These compounds may be used alone or in combination.

[0058] Aromatic dicarboxylic acids can also be used. Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4'-biphenyldicarboxylic acid. Among these, terephthalic acid is preferred because it is easily available and can easily form a polymer with a low melting point.

[0059] Furthermore, dicarboxylic acids having a double bond can also be used, which can be suitably used to suppress hot offset during fixing, since the double bond can be utilized to crosslink the entire resin.

[0060] Examples of such dicarboxylic acids include fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid. Also included are lower alkyl esters and acid anhydrides of these. Among these, fumaric acid and maleic acid are more preferred.

[0061] The method for producing the crystalline polyester is not particularly limited, and the crystalline polyester can be produced by a general polyester polymerization method in which a dicarboxylic acid component and a diol component are reacted. For example, the crystalline polyester can be produced by a direct polycondensation method or an ester exchange method, which are selected depending on the type of monomer.

[0062] The peak temperature of the maximum endothermic peak of the crystalline polyester measured using a differential scanning calorimeter (DSC) is preferably 50.0°C or higher and 100.0°C or lower, and from the viewpoint of low-temperature fixability, more preferably 60.0°C or higher and 90.0°C or lower.

[0063] <Release agent> A release agent may be blended into the toner as needed to prevent a decrease in image density when multiple images are formed. Any known release agent can be used. Specifically, petroleum waxes such as paraffin wax, microcrystalline wax, and petrolatum and their derivatives, montan wax and its derivatives, hydrocarbon waxes produced by the Fischer-Tropsch process and their derivatives, polyolefin waxes such as polyethylene and polypropylene and their derivatives, natural waxes such as carnauba wax and candelilla wax and their derivatives, and ester waxes can be used. Here, derivatives include oxides, block copolymers with vinyl monomers, and graft-modified products. Furthermore, ester waxes can be used, including monofunctional ester waxes, difunctional ester waxes, and multifunctional ester waxes such as tetrafunctional and hexafunctional ester waxes.

[0064] The melting point of the release agent is preferably 60° C. or higher and 140° C. or lower, more preferably 70° C. or higher and 130° C. or lower. When the melting point is 60° C. or higher and 140° C. or lower, the toner is easily plasticized during fixing, and a decrease in image density when forming multiple images is suppressed. In addition, the release agent is less likely to bleed out even when stored for a long period of time, which is preferable.

[0065] <Coloring agent> Examples of colorants include organic pigments, organic dyes, and inorganic pigments, but there are no particular limitations and any conventionally known colorant can be used.

[0066] Cyan colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds. Specific examples include CI Pigment Blue 1, CI Pigment Blue 7, CI Pigment Blue 15, CI Pigment Blue 15:1, CI Pigment Blue 15:2, CI Pigment Blue 15:3, CI Pigment Blue 15:4, CI Pigment Blue 60, CI Pigment Blue 62, and CI Pigment Blue 66.

[0067] Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds.

[0068] Specific examples include CI Pigment Red 2, CI Pigment Red 3, CI Pigment Red 5, CI Pigment Red 6, CI Pigment Red 7, CI Pigment Violet 19, CI Pigment Red 23, CI Pigment Red 48:2, CI Pigment Red 48:3, CI Pigment Red 48:4, CI Pigment Red 57:1, CI Pigment Red 81:1, CI Pigment Red 122, CI Pigment Red 144, CI Pigment Red 146, CI Pigment Red 150, CI Pigment Red 166, CI Pigment Red 169, CI Pigment Red 177, CI Pigment Red 184, CI Pigment Red 185, CI Pigment Red 202, CI Pigment Red 206, CI Pigment Red 220, CI Pigment Red 221, and CI Pigment Red 254.

[0069] Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specific examples include the following: CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 15, CI Pigment Yellow 17, CI Pigment Yellow 62, CI Pigment Yellow 74, CI Pigment Yellow 83, CI Pigment Yellow 93, CI Pigment Yellow 94, CI Pigment Yellow 95, CI Pigment Yellow 97, CI Pigment Yellow 109, CI Pigment Yellow 110, CI Pigment Yellow 111, CI Pigment Yellow 120, CI Pigment Yellow 132, CI Pigment Yellow 133, CI Pigment Yellow 134, CI Pigment Yellow 135, CI Pigment Yellow 136, CI Pigment Yellow 137, CI Pigment Yellow 138, CI Pigment Yellow 139, CI Pigment Yellow 140, CI Pigment Yellow 141, CI Pigment Yellow 142, CI Pigment Yellow 143, CI Pigment Yellow 144, CI Pigment Yellow 145, CI Pigment Yellow 146, CI Pigment Yellow 147, CI Pigment Yellow 148, CI Pigment Yellow 149, CI Pigment Yellow 150, CI Pigment Yellow 151, CI Pigment Yellow 152, CI Pigment Yellow 153, CI Pigment Yellow 154, CI Pigment Yellow 155, CI Pigment Yellow 156, CI Pigment Yellow 157, CI Pigment Yellow 158, Yellow 127, CI Pigment Yellow 128, CI Pigment Yellow 129, CI Pigment Yellow 147, CI Pigment Yellow 151, CI Pigment Yellow 154, CI Pigment Yellow 155, CI Pigment Yellow 168, CI Pigment Yellow 174, CI Pigment Yellow 175, CI Pigment Yellow 176, CI Pigment Yellow 180, CI Pigment Yellow 181, CI Pigment Yellow 185, CI Pigment Yellow 191, and CI Pigment Yellow 194.

[0070] Examples of black colorants include carbon black, as well as the above-mentioned yellow colorants, magenta colorants, and cyan colorants, and those toned to black using magnetic materials.

[0071] These colorants may be used alone or in combination, or in the form of a solid solution. The colorant is selected in consideration of hue angle, chroma, brightness, lightfastness, transparency for overhead projectors, and dispersibility in toner particles.

[0072] When a magnetic material is used as a colorant, the magnetic material is composed mainly of magnetic iron oxide such as iron oxide or γ-iron oxide, and may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum, and silicon. These magnetic materials have a BET specific surface area of ​​2 m2 as measured by nitrogen adsorption. 2 / g or more 30m 2 / g or less, and 2 / g or more 28m 2 / g or less is more preferable. Also, a Mohs hardness of 5 or more and 7 or less is preferable. The shape of the magnetic material may be polyhedron, octahedron, hexahedron, sphere, needle-like, scale-like, etc., but those with little anisotropy such as polyhedron, octahedron, hexahedron, and sphere are preferred in terms of increasing image density.

[0073] The amount of colorant added is preferably 1 part by mass or more and 20 parts by mass or less relative to 100 parts by mass of the binder resin or the polymerizable monomer that constitutes the binder resin. When magnetic powder is used, the amount is preferably 20 parts by mass or more and 200 parts by mass or less, more preferably 40 parts by mass or more and 150 parts by mass or less relative to 100 parts by mass of the binder resin or the polymerizable monomer that constitutes the binder resin.

[0074] <External additives> The toner of the present disclosure may optionally contain inorganic external additives, etc., added to the toner particles, provided that the effects of the present disclosure are not impaired. From the viewpoint of durability when added to the toner particles, the inorganic external additives preferably have a particle size of 1 / 10 or less of the weight-average particle size of the toner particles. Examples of inorganic external additives include metal oxide fine particles (inorganic fine particles) such as silica, strontium titanate, fatty acid metal salts, alumina, titanium oxide, hydrotalcite compounds, zinc oxide fine particles, cerium oxide fine particles, and calcium carbonate fine particles. Furthermore, as the external additive, composite oxide fine particles using two or more metals can be used, or two or more types selected from these fine particle groups in any combination can be used (e.g., silica fine particles and strontium titanate particles). Furthermore, resin fine particles or organic-inorganic composite fine particles of resin fine particles and inorganic fine particles can also be used.

[0075] The external additive may be subjected to a hydrophobic treatment using a hydrophobic treatment agent, such as chlorosilanes such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, t-butyldimethylchlorosilane, and vinyltrichlorosilane; Tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane, n-butyltrimethoxysilane, i-butyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, i-butyl Alkoxysilanes such as ethyltriethoxysilane, decyltriethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, and γ-(2-aminoethyl)aminopropylmethyldimethoxysilane; silazanes such as hexaethyldisilazane, hexapropyldisilazane, hexabutyldisilazane, hexapentyldisilazane, hexahexyldisilazane, hexacyclohexyldisilazane, hexaphenyldisilazane, divinyltetramethyldisilazane, and dimethyltetravinyldisilazane; Silicone oils such as dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, alkyl-modified silicone oil, chloroalkyl-modified silicone oil, chlorophenyl-modified silicone oil, fatty acid-modified silicone oil, polyether-modified silicone oil, alkoxy-modified silicone oil, carbinol-modified silicone oil, amino-modified silicone oil, fluorine-modified silicone oil, and terminally reactive silicone oil; siloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethyldisiloxane, and octamethyltrisiloxane; Examples of fatty acids and metal salts thereof include long-chain fatty acids such as undecylic acid, lauric acid, tridecylic acid, dodecylic acid, myristic acid, palmitic acid, pentadecylic acid, stearic acid, heptadecylic acid, arachidic acid, montanic acid, oleic acid, linoleic acid, and arachidonic acid, and salts of the above fatty acids with metals such as zinc, iron, magnesium, aluminum, calcium, sodium, and lithium.

[0076] Among these, alkoxysilanes, silazanes, and silicone oils are preferably used because they are easy to hydrophobize. These hydrophobizing agents may be used alone or in combination of two or more.

[0077] The content of the external additive is preferably 0.05 parts by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the toner particles.

[0078] The weight average particle diameter (D4) of the toner is preferably 3.0 μm or more and 12.0 μm or less, more preferably 4.5 μm or more and 7.5 μm or less. When the weight average particle diameter (D4) is 3.0 μm or more and 12.0 μm or less, good fluidity is obtained, and the latent image can be developed faithfully.

[0079] [Toner Manufacturing Method] An example of a method for obtaining the toner particles will be described below, but the method is not limited to the following.

[0080] The method for producing toner particles is not particularly limited, and may be a suspension polymerization method, a solution suspension method, an emulsion aggregation method, a pulverization method, etc. As an example, a method for obtaining toner particles by an emulsion aggregation method will be described below.

[0081] <Method for producing toner particles (toner core particles) using emulsion aggregation method> (Resin particle dispersion liquid preparation process) The resin particle dispersion can be prepared by a known method, but is not limited to these methods, such as an emulsion polymerization method, a self-emulsification method, a phase inversion emulsification method in which a resin is emulsified by adding an aqueous medium to a resin solution dissolved in an organic solvent, or a forced emulsification method in which a resin is forcibly emulsified by high-temperature treatment in an aqueous medium without using an organic solvent.

[0082] As an example, a method for preparing a resin particle dispersion by phase inversion emulsification will be described below.

[0083] The resin components are dissolved in an organic solvent in which they are soluble, and a surfactant and a basic compound are added. If the resin component is a crystalline resin with a melting point, it can be dissolved by heating above the melting point. Next, an aqueous medium is slowly added while stirring using a homogenizer or the like to precipitate resin microparticles. Thereafter, the solvent is removed by heating or reducing the pressure to produce an aqueous dispersion of resin microparticles.

[0084] The organic solvent used to dissolve the resin component may be any solvent capable of dissolving the resin component, and specific examples include toluene and xylene.

[0085] Examples of surfactants used in the preparation process include anionic surfactants such as sulfate ester salts, sulfonate salts, carboxylate salts, phosphate esters, and soap-based surfactants; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols.

[0086] Examples of the basic compound used in the preparation step include inorganic bases such as sodium hydroxide and potassium hydroxide, and organic bases such as ammonia, triethylamine, trimethylamine, dimethylaminoethanol, and diethylaminoethanol. The basic compound may be used alone or in combination of two or more.

[0087] (Preparation of Colorant Dispersion) The colorant dispersion liquid can be prepared by any known dispersing method, and is not limited to any particular method, including, for example, a homogenizer, a ball mill, a colloid mill, an ultrasonic disperser, etc. Examples of surfactants used during dispersion include the surfactants described above.

[0088] (Preparation of Wax Dispersion) When preparing a wax dispersion, wax is dispersed in water together with a surfactant, a basic compound, and the like, and then the dispersion is heated to a temperature equal to or higher than the melting point of the wax and dispersed using a homogenizer or disperser that applies strong shear force. Through this process, a wax dispersion is obtained. Examples of surfactants used during dispersion include those described above. Examples of basic compounds used during dispersion include those described above.

[0089] The combination of colorant particles, binder resin particles, and wax particles is not particularly limited and can be freely selected as appropriate depending on the purpose. In addition to the above dispersion, other particle dispersions obtained by dispersing appropriately selected particles in a dispersion medium may be further mixed. The particles contained in the other particle dispersions are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include internal additive particles, charge control agent particles, inorganic particles, and abrasive particles. These particles may be dispersed in the binder resin particle dispersion or the colorant particle dispersion.

[0090] Examples of dispersants contained in binder resin particle dispersions, colorant particle dispersions, fine wax dispersions, and other particle dispersions include aqueous media containing polar surfactants. Examples of aqueous media include water such as distilled water and ion-exchanged water, and alcohols. These may be used alone or in combination of two or more. The content of the polar surfactant cannot be generally defined and can be appropriately selected depending on the purpose.

[0091] Examples of polar surfactants include anionic surfactants such as sulfate salts, sulfonates, phosphate esters, and soaps; and cationic surfactants such as amine salts and quaternary ammonium salts. Specific examples of anionic surfactants include sodium dodecylbenzenesulfonate, sodium tetradecylbenzenesulfonate, sodium dodecyl sulfate, sodium alkylnaphthalenesulfonate, and sodium dialkylsulfosuccinate. Specific examples of cationic surfactants include alkylbenzenedimethylammonium chloride, alkyltrimethylammonium chloride, and distearylammonium chloride. These surfactants may be used alone or in combination.

[0092] As the polar surfactant, sodium alkylbenzenesulfonate having an alkyl group with 12 to 14 carbon atoms is preferably used, since this can prevent voids in the transfer of vertical fine line images in a high-temperature, high-humidity environment. Sodium dodecylbenzenesulfonate is more preferably used.

[0093] These polar surfactants can also be used in combination with non-polar surfactants, such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, and polyhydric alcohol-based nonionic surfactants.

[0094] The content of the colorant particles is preferably 0.1 parts by mass or more and 30 parts by mass or less relative to 100 parts by mass of the binder resin in the aggregated particle dispersion when the aggregated particles are formed.

[0095] The content of wax particles is preferably 0.5 parts by mass or more and 25 parts by mass or less, and more preferably 5 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the binder resin in the aggregated particle dispersion when the aggregated particles are formed.

[0096] Furthermore, in order to more precisely control the chargeability of the resulting toner, charge control particles and binder resin particles may be added after the aggregated particles are formed.

[0097] The particle sizes of the binder resin particles, colorant particles, and other particles are measured using a laser diffraction / scattering particle size distribution measuring device LA-960V2 manufactured by Horiba, Ltd.

[0098] (Agglomerated particle formation process) In the aggregate particle forming step, first, a resin particle dispersion, a colorant dispersion, a wax dispersion, etc. are mixed to form a mixture, and then the mixture is heated at a temperature equal to or lower than the melting point of the resin particles to adjust the pH to acidity and cause aggregation, thereby forming aggregated particles containing resin particles, colorant particles, and release agent particles, thereby obtaining an aggregated particle dispersion.

[0099] (First fusion process) In the first fusion step, the pH of the aggregated particle dispersion is increased under stirring conditions similar to those in the aggregated particle formation step to stop the progression of aggregation, and the dispersion is then heated at a temperature equal to or higher than the melting point of the resin component to obtain a fused particle dispersion.

[0100] (Amorphous resin fine particle attachment process) In the amorphous resin particle adhesion step, an amorphous resin particle dispersion is added to a fused particle dispersion, and the pH is lowered to cause the amorphous resin particles to adhere to the surfaces of the fused particles, thereby obtaining a dispersion of resin-adhered particles. Here, this coating layer corresponds to the shell layer formed in the shell layer formation step described below. The amorphous resin particle dispersion can be produced in accordance with the aforementioned process for preparing the resin particle dispersion.

[0101] (Second fusion process) In the second fusion step, similar to the first fusion step, the pH of the resin-attached particle dispersion is increased to stop the progress of aggregation, and the resin-attached aggregated particles are fused by heating at a temperature equal to or higher than the melting point of the resin component, thereby obtaining a toner core particle dispersion in which toner core particles on which shell layers have been formed are dispersed.

[0102] <Method of manufacturing toner having agglomerates> In the method for producing toner particles having aggregates containing silica and a binder component, it is preferable to externally add the silica and the binder component to the toner core particles by a wet method, from the viewpoint of uniformly aggregating the silica and the binder component. When a toner having aggregates containing silica fine particles and a resin component is obtained by a wet method, (Step 1) obtaining a toner core particle dispersion in which toner core particles are dispersed in an aqueous medium; and (Step 2) A step of mixing silica and a polymerizable monomer (monomer) that becomes a resin component by polymerization into a toner core particle dispersion, and polymerizing the monomer in the toner core particle dispersion to form aggregates containing silica and resin on the toner core particles; It is preferred that the compound contains:

[0103] In step 1, the toner core particle dispersion may be obtained by using the toner core particle dispersion produced in the aqueous medium as is, or by adding dried toner core particles to the aqueous medium and mechanically dispersing them. When dispersing dried toner core particles in the aqueous medium, a dispersing aid may be used.

[0104] As the dispersing aid, known dispersion stabilizers and surfactants can be used.

[0105] Specifically, the following may be mentioned as dispersion stabilizers.

[0106] Inorganic dispersion stabilizers such as tricalcium phosphate, hydroxyapatite, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina; and organic dispersion stabilizers such as polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, and starch.

[0107] Examples of surfactants include anionic surfactants such as alkyl sulfate salts, alkylbenzene sulfonates, and fatty acid salts; nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxypropylene alkyl ethers; and cationic surfactants such as alkylamine salts and quaternary ammonium salts.

[0108] In step 1, the solid content of the toner core particle dispersion is preferably adjusted to 10% by mass or more and 50% by mass or less.

[0109] In step 2, the silica and the monomer serving as the resin component may be added directly to the toner core particle dispersion, or a dispersion in which the silica and the monomer are dispersed in advance may be added to the toner core particle dispersion. The dispersion aids exemplified in the section on step 1 can be used as a means for dispersing the silica and the monomer. Furthermore, when particles such as a fatty acid metal salt are mixed in addition to the silica, they are mixed together with the silica in step 2.

[0110] Examples of the resin component include polymers made of monofunctional polymerizable monomers or polyfunctional polymerizable monomers, copolymers obtained by combining two or more of these, and mixtures thereof.

[0111] Examples of the polymerizable monomer include the following.

[0112] Styrene; styrene derivatives such as α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, and p-phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, iso- Acrylic polymerizable monomers such as butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, and 2-benzoyloxyethyl acrylate; methyl methacrylate, ethyl methacrylate, and n-propyl methacrylate. methacrylic polymerizable monomers such as isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, and dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate, and other vinyl monomers; vinyl esters; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropyl ketone; trifunctional silane compounds having a methacryloxyalkyl group as a substituent, such as γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxyoctyltrimethoxysilane, γ-methacryloxypropyldiethoxymethoxysilane, and γ-methacryloxypropylethoxydimethoxysilane; Trifunctional silane compounds having an acryloxyalkyl group as a substituent, such as γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxyoctyltrimethoxysilane, γ-acryloxypropyldiethoxymethoxysilane, and γ-acryloxypropylethoxydimethoxysilane.

[0113] Among these, trifunctional silane compounds are preferably used because of their high affinity with silica. The following may also be used in combination with trifunctional silane compounds: organosilicon compounds having four reactive groups per molecule (tetrafunctional silanes), organosilicon compounds having two reactive groups per molecule (bifunctional silanes), or organosilicon compounds having one reactive group (monofunctional silanes). Examples include the following:

[0114] Trifunctional vinyl silanes such as dimethyldiethoxysilane, tetraethoxysilane, hexamethyldisilazane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, vinyltriisocyanatesilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldiethoxymethoxysilane, vinylethoxydimethoxysilane, vinylethoxydihydroxysilane, vinyldimethoxyhydroxysilane, vinylethoxymethoxyhydroxysilane, and vinyldiethoxyhydroxysilane.

[0115] In step 2, silica and a monomer serving as a resin component are added to and mixed with the toner core particle dispersion. At this time, it is preferable to adjust the temperature of the toner core particle dispersion to a temperature suitable for the polymerization reaction. Thereafter, a polymerization initiator is added while mixing the toner core particles, silica, and monomer, thereby polymerizing the added monomer. Agglomerates containing silica fine particles and a binder component are externally added to the toner core particles, thereby obtaining a toner particle dispersion.

[0116] As the polymerization initiator, any known polymerization initiator can be used without any particular limitation. Specific examples include the following:

[0117] Hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetic acid tert-hydroperoxide, tert-butyl performate, tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetic acid, tert-butyl permethoxyacetate, per-N-(3-toluyl)-tert-butyl palmitate benzoyl peroxide peroxide-based polymerization initiators typified by t-butyl peroxy 2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, etc.; azo- or diazo-based polymerization initiators typified by 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile, etc.; and the like.

[0118] (Step for obtaining the desired toner surface shape (spheronization step)) During or after the fusion step, it is preferable to carry out a spheronization step in which the temperature is further increased and maintained until the toner particles reach a desired circularity or surface shape. Specific temperatures for the spheronization step are, for example, 90° C. or higher, preferably 92° C. or higher, and preferably 95° C. or lower. The heating time for the spheronization step can be, for example, 3 hours or more, 5 hours or more, or 8 hours or more.

[0119] (filtration process, washing process, drying process, classification process, external addition process) Thereafter, a filtration process for filtering out the solid content of the toner particles, and optionally a washing process, a drying process, and a classification process for particle size adjustment are performed to obtain toner particles having aggregates containing silica and a resin component. The toner particles may be used as a toner as they are. If necessary, the toner particles and external additives such as inorganic fine powders may be mixed and adhered using a mixer to obtain a toner.

[0120] [Methods for measuring physical properties] The methods for measuring various physical properties will be explained below.

[0121] <Method for isolating toner particles> A dispersion medium is prepared by adding 0.50 g of Triton-X100 (manufactured by Kishida Chemical Co., Ltd.) to 100 g of ion-exchanged water. (1) 1.00 g of toner is accurately weighed into a vial, and the dispersion medium is added to make the total weight 10.00 g, and the solution is left to stand for 24 hours to prepare a sample liquid. (2) The sample liquid is subjected to an ultrasonic homogenizer treatment to liberate the external additives from the toner and disperse them in the dispersion medium. Ultrasonic treatment device: Ultrasonic homogenizer VP-050 (manufactured by Taitec Co., Ltd.) Microchip: Stepped microchip, tip diameter φ2mm Microchip tip position: Center of glass vial, 5 mm above the bottom of the vial Ultrasonic conditions: intensity 30%, 180 minutes. During this time, ultrasonic waves are applied while cooling the vial with ice water to prevent the dispersion from heating up. (3) The toner particles in the sample liquid are separated from the dispersion medium in which the external additives are dispersed by suction filtration (10 μm membrane filter) (filtrate). (4) The toner particles after filtration were recovered, and the dispersion medium was added again to make the total weight 10.00 g. The above steps (2) and (3) were then repeated a total of 10 times to recover the toner particles, which were then thoroughly dried at 45°C for 24 hours to isolate the toner particles.

[0122] <Method for separating binder resin from toner particles> 100 mg of toner particles were dissolved in 3 ml of chloroform. The insoluble matter was removed by filtration using a syringe equipped with a sample processing filter (pore size 0.2 μm to 0.5 μm, such as a Myshoridisk H-25-2 (Tosoh Corporation)). The soluble matter was then introduced into a preparative HPLC (apparatus: Japan Analytical Industry Co., Ltd. LC-9130 NEXT preparative column [60 cm], exclusion limits: 20,000 and 70,000, two columns connected), and chloroform eluent was pumped. Once a peak was confirmed in the resulting chromatogram, fractions with retention times corresponding to molecular weights of 2,000 or higher were collected using a monodisperse polystyrene standard sample. The solution of the obtained fraction is dried and solidified to separate it from the release agent and separate the binder resin.

[0123] <Composition analysis of binder resins consisting of multiple components> The chloroform-soluble portion of the separated binder resin is used as the sample. The sample is adjusted with chloroform so that the binder resin concentration is 0.1 mass %, and the solution is filtered through a 0.45 μm PTFE filter before being used for measurement. The gradient polymer LC measurement conditions are as follows: Equipment: UlTIMATE3000 (Thermo Fisher Scientific) Mobile phase: A chloroform (HPLC), B acetonitrile (HPLC) Gradient: 2 min (A / B = 0 / 100) → 25 min (A / B = 100 / 0) (The gradient of the mobile phase change was made linear.) Flow rate: 1.0mL / min Injection: 0.1% by mass x 20μL Column: Tosoh TSKgel ODS (4.6 mm diameter x 150 mm x 5 μm) Column temperature: 40℃ Detector: Corona Charged Aerosol Detector (Corona-CAD) (Thermo Fisher Scientific)

[0124] Fractionate polyester A at the time corresponding to polyester A. Also, fractionate the crystalline polyester at the time corresponding to the crystalline polyester. In the fractionation, take the necessary amounts of the respective chloroform / acetonitrile solutions, dry and concentrate them, and then use them as samples of polyester A (resin A) and crystalline polyester (resin B).

[0125] Using the samples of the resin A component and the resin B component, measure the composition ratio and mass ratio by nuclear magnetic resonance spectroscopy (NMR) as follows.

[0126] Add 1 mL of deuterated chloroform to 20 mg of the samples of the resin A component and the resin B component, dissolve them, and measure the proton NMR spectrum of the dissolved resin. From the obtained NMR spectrum, regarding the minimum unit sandwiched by ester bonds as the structure derived from the monomer, calculate the molar ratio and mass ratio of each monomer, and the content ratio of each monomer unit can be obtained. For example, in the case of a styrene-acrylic copolymer, the composition ratio and mass ratio can be calculated based on the peak around 6.5 ppm derived from the styrene monomer and the peak around 3.5 - 4.0 ppm derived from the acrylic monomer.

[0127] For nuclear magnetic resonance spectroscopy (NMR), the following apparatus and measurement conditions can be used. NMR apparatus: RESONANCE ECX500 manufactured by JEOL Ltd. Observed nucleus: proton Measurement mode: single pulse

[0128] <Quantification method of U in polyester A by NMR measurement iso , U EO , U PO > The component identification of polyester A and the measurement of the molar ratio and mass ratio by nuclear magnetic resonance spectroscopy (NMR) are as follows.

[0129] 1 mL of deuterated chloroform was added to 20 mg of the obtained polyester A, and the NMR spectrum of the protons of the dissolved polyester A was measured. From the obtained NMR spectrum, the smallest unit sandwiched between ester bonds was considered to be the structure derived from the monomer, and the molar ratio and mass ratio of each monomer were calculated.

[0130] For example, the composition ratio and mass ratio can be calculated based on the following peaks (chemical shift value, number of protons):

[0131] Isophthalic acid-derived units: 7.5 ppm (1), 8.2 ppm (2), 8.7 ppm (1) Terephthalic acid-derived units: 8.1 ppm (4) Units derived from ethylene oxide adducts of bisphenol A: 1.6 ppm (6), 4.3 ppm (4), 4.7 ppm (4), 6.8 ppm (4), 7.1 ppm (4) Units derived from propylene oxide adducts of bisphenol A: 1.5 ppm (6), 1.6 ppm (6), 4.1 ppm (4), 5.5 ppm (2), 6.8 ppm (4), 7.1 ppm (4) Ethylene glycol derived units: 4.3 ppm (4) NMR device: JEOL RESONANCE ECX500 Observation nucleus: Proton Measurement mode: Single pulse Base peak: TMS

[0132] NMR analysis revealed that the unit U derived from isophthalic acid was the basis for all units derived from the acid component. iso The content (mol%) of U was calculated based on the total units derived from the alcohol component. EO and U PO The total content (mol%) of U was calculated. EO The content ratio and U PO The ratio of U to the total content of EO The content (mol %) of was calculated.

[0133] <Method for measuring weight average molecular weight Mw and number average molecular weight Mn> The molecular weight of samples such as polyester A, crystalline polyester, and styrene-acrylic resin is measured by gel permeation chromatography (GPC) as follows.

[0134] First, dissolve the sample in tetrahydrofuran (THF). In the case of polyester A or styrene acrylic resin, dissolve the sample in THF at room temperature for 24 hours. In the case of crystalline polyester, heat the THF to 40°C to dissolve the sample, then leave it for 24 hours.

[0135] The solution containing each sample was filtered through a solvent-resistant membrane filter "Myshoridisc" (Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. The sample solution was adjusted so that the concentration of components soluble in THF was 0.8% by mass. Measurements were performed using this sample solution under the following conditions. Apparatus: HLC8120GPC (detector: RI) (Tosoh Corporation) Column: Shodex KF-801, 802, 803, 804, 805, 806, 807 (7 columns, manufactured by Showa Denko Co., Ltd.) Eluent: tetrahydrofuran (THF) ·Flow rate: 1.0ml / min Oven temperature: 40.0℃ Sample injection volume: 0.10 ml

[0136] To calculate the molecular weight of a sample, a molecular weight calibration curve prepared using standard polystyrene resins (for example, trade names "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500", manufactured by Tosoh Corporation) is used.

[0137] <Method for quantifying aluminum element in toner particles> Measurement of the fluorescent X-ray of aluminum element conforms to JIS K 0119-1969, and specifically, is as follows.

[0138] The measurement equipment used was a wavelength dispersive X-ray fluorescence analyzer "Axios" (manufactured by PANalytical) and the accompanying dedicated software "SuperQ ver.4.0F" (manufactured by PANalytical) for setting measurement conditions and analyzing measurement data. Rh was used as the anode of the X-ray tube, the measurement atmosphere was vacuum, the measurement diameter (collimator mask diameter) was 27 mm, and the measurement time was 10 seconds. A proportional counter (PC) was used for detection.

[0139] The measurement sample was prepared by placing approximately 4 g of toner particles in a special aluminum ring for pressing, flattening it, and then pressing it at 20 MPa for 60 seconds using a tablet molding compressor "BRE-32" (manufactured by Maekawa Testing Machinery Manufacturing Co., Ltd.) to form a pellet with a thickness of approximately 2 mm and a diameter of approximately 39 mm.

[0140] Measurements are performed using an acceleration voltage and current of 24 kV and 160 mA for the X-ray generator, and elements are identified based on the peak positions of the obtained X-rays. Their concentrations are calculated from the counting rate (unit: cps), which is the number of X-ray photons per unit time.

[0141] <Measuring method for weight average particle size (D4) and number average particle size (D1)> The weight-average particle size (D4) and number-average particle size (D1) of the toner are calculated as follows. The measurement device used is a precision particle size distribution measurement device using the narrow-pore electrical resistance method, the Coulter Counter Multisizer 3 (registered trademark, manufactured by Beckman Coulter, Inc.), equipped with a 100 μm aperture tube. The measurement conditions are set and the measurement data is analyzed using the accompanying dedicated software, the Beckman Coulter Multisizer 3 Version 3.51 (manufactured by Beckman Coulter, Inc.). The measurement is performed using an effective number of measurement channels of 25,000.

[0142] The aqueous electrolyte solution used for the measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of approximately 1% by mass, such as "ISOTON II" (manufactured by Beckman Coulter).

[0143] Before carrying out the measurements and analyses, the dedicated software was set up as follows.

[0144] On the "Change Standard Measurement Method (SOMME)" screen of the dedicated software, set the total count in control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard Particles 10.0 μm" (Beckman Coulter). Press the "Threshold / Noise Level Measurement Button" to automatically set the threshold and noise level. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flush aperture tube after measurement."

[0145] On the "Pulse to particle size conversion setting" screen of the dedicated software, set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range from 2 μm to 60 μm.

[0146] The specific measurement method is as follows. (1) Pour approximately 200 mL of the electrolyte solution into a 250 mL round-bottom glass beaker made specifically for the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, use the "aperture flush" function of the dedicated software to remove any dirt and air bubbles from inside the aperture tube. (2) Approximately 30 mL of the above-mentioned aqueous electrolyte solution is placed in a 100 mL flat-bottom glass beaker, and approximately 0.3 mL of a solution prepared by diluting Contaminon N (a 10% aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) as a dispersant with ion-exchanged water by approximately three times its mass is added. (3) Prepare an ultrasonic disperser "Ultrasonic Dispension System Tetra150" (manufactured by Nikkaki Bios Co., Ltd.) with an electrical output of 120 W and two built-in oscillators with an oscillation frequency of 50 kHz and a phase difference of 180 degrees. Place approximately 3.3 L of ion-exchanged water in the ultrasonic disperser's water tank and add approximately 2 mL of Contaminon N to this water tank. (4) Set the beaker (2) in the beaker fixing hole of the ultrasonic disperser, operate the ultrasonic disperser, and adjust the height of the beaker so that the resonance state of the liquid surface of the electrolytic solution in the beaker is maximized. (5) While the electrolyte solution in the beaker in (4) is being irradiated with ultrasonic waves, approximately 10 mg of toner is added little by little to the electrolyte solution and dispersed. The ultrasonic dispersion process is then continued for another 60 seconds. During the ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be between 10°C and 40°C. (6) Using a pipette, add the electrolyte solution (5) containing the dispersed toner to the round-bottom beaker (1) placed in the sample stand, and adjust the measurement concentration to approximately 5%. Then, measure the particle count until it reaches 50,000 particles. (7) The measurement data is analyzed using the dedicated software provided with the device to calculate the weight-average particle size (D4) and number-average particle size (D1). Note that when the dedicated software is set to Graph / Volume %, the "Average diameter" on the "Analysis / Volume Statistics (Arithmetic Mean)" screen is the weight-average particle size (D4), and when the dedicated software is set to Graph / Number %, the "Average diameter" on the "Analysis / Number Statistics (Arithmetic Mean)" screen is the number-average particle size (D1).

[0147] <Method for obtaining a backscattered electron image of a toner surface> The toner base exposure rate is calculated using a backscattered electron image of the toner particle surface.

[0148] The backscattered electron image of the toner surface was obtained using a scanning electron microscope (SEM).

[0149] The backscattered electron image obtained from an SEM is also called a "composition image," and elements with smaller atomic numbers are detected as darker, while elements with larger atomic numbers are detected as brighter.

[0150] Toner particles are generally resin particles that mainly contain carbon-based compositions such as resin components and release agents. If silica or metal oxides are present on the surface of the toner particles, the silica or metal oxides will be observed as bright areas and the carbon-based resin parts will be observed as dark areas in the backscattered electron image obtained from the SEM.

[0151] The SEM equipment and observation conditions are as follows: Equipment used: ULTRA PLUS manufactured by Carl Zeiss Microscopy Co., Ltd. Accelerating voltage: 1.0 kV WD: 2.0 mm Aperture Size: 30.0 μm Detection signal: EsB (energy selective backscattered electrons) EsB Grid:800V Magnification: 50,000x Contrast: 63.0±5.0% (reference value) Brightness: 38.0±5.0% (reference value) Resolution: 1024 x 768 Pretreatment: Toner particles are scattered on carbon tape (no deposition is performed)

[0152] Contrast and brightness are set appropriately according to the state of the equipment being used. The accelerating voltage and EsB Grid are set to achieve the following: obtaining structural information on the outermost surface of the toner particles, preventing charging up of undeposited samples, and selectively detecting high-energy reflected electrons. The observation field is selected to be near the vertex where the curvature of the toner particles is smallest.

[0153] <How to confirm that the dark areas in a backscattered electron image are derived from carbon atoms> The fact that the dark areas in the observed backscattered electron image are derived from the resin can be confirmed by overlaying the backscattered electron image with an elemental mapping image obtained by energy dispersive X-ray analysis (EDS) using a scanning electron microscope (SEM).

[0154] The SEM / EDS equipment and observation conditions are as follows: Equipment used (SEM): ULTRA PLUS manufactured by Carl Zeiss Microscopy Co., Ltd. Equipment used (EDS): NORANSystem 7, Ultra Dry EDS Detector, manufactured by Thermo Fisher Scientific Co., Ltd. Accelerating voltage: 5.0 kV WD: 7.0 mm Aperture Size: 30.0 μm Detection signal: SE2 (secondary electrons) Magnification: 50,000x Mode: Spectral Imaging Pretreatment: Toner particles are scattered on carbon tape and platinum sputtered.

[0155] The element mapping image obtained by this method is superimposed on the backscattered electron image, and it is confirmed that the carbon atom parts in the mapping image match the dark parts in the backscattered electron image.

[0156] <Method for checking the dispersion state of resin components contained in agglomerates> The dispersion state of the resin component contained in the aggregates is calculated using a backscattered electron image of the aggregates on the toner surface, which is obtained in the same manner as the backscattered electron image of the toner surface.

[0157] The backscattered electron image obtained is used to calculate the dispersion state of the resin component contained in the aggregates using image processing software ImageJ (developed by Wayne Rasband). The procedure is as follows:

[0158] First, convert the backscattered electron image to be analyzed to 8-bit using Type in the Image menu. Next, set the Median diameter to 2.0 pixels using Filters in the Process menu to reduce image noise. After excluding the observation conditions display area at the bottom of the backscattered electron image, estimate the center of the image and use the Rectangle Tool on the toolbar to select a 1.5 μm square area from the center of the backscattered electron image.

[0159] Next, select Threshold from Adjust in the Image menu. Manually select all pixels that correspond to brightness B1 and click Apply to obtain a binarized image. This operation displays pixels that correspond to A1 in black (pixel group A1) and pixels that correspond to A2 in white (pixel group A2). Once again, estimate the center of the image after excluding the observation condition display area at the bottom of the backscattered electron image, and use the Rectangle Tool on the toolbar to select a 1.5 μm square area from the center of the backscattered electron image.

[0160] Next, use the straight line tool (Straight Line) on the toolbar to select the scale bar in the observation condition display area below the backscattered electron image. In this state, select Set Scale from the Analyze menu. A new window will open and the pixel distance of the selected straight line will be entered in the Distance in Pixels field. Enter the value of the scale bar (for example, 100) in the Known Distance field of the window, enter the unit of the scale bar (for example, nm) in the Unit of Measurement field, and click OK to complete the scale setting.

[0161] Next, select "Set Measurements" from the Analyze menu, check "Area" and "Feret's diameter", select "Analyze Particles" from the Analyze menu, check "Display Result", and click "OK" to perform domain analysis.

[0162] Next, the resulting analysis image is subjected to 10-pixel erode processing using ImageJ, and then a 10-pixel dilate processing is performed using ImageJ. Note that erode and dilate processing are performed using the Binary item in the Process menu. Figure 2 shows an example of an image obtained by performing the above processing.

[0163] Using the straight line tool (Straight Line) on the toolbar, draw a total of 18 straight lines from one end of the image to the other, passing through the midpoint of the analysis image as the reference point, at 10° intervals. Figure 3 shows an example of an image with lines drawn.

[0164] Next, the length L of the continuous bright line segments on the straight lines is measured, and the number of straight lines having a line segment with a length L of 100 nm or more is counted to confirm whether the number of straight lines in the agglomerate is 12 or more.

[0165] <Method for confirming the proportion of toner particles having agglomerates with 12 or more straight lines> For 30 toner particles having agglomerates contained in the toner to be evaluated, the above procedure is performed on the agglomerates, the number of toner particles having agglomerates with 12 or more straight lines is counted, and the proportion A of toner particles containing agglomerates with 12 or more straight lines is calculated using the following formula. A={(the number of toner particles containing aggregates having 12 or more straight lines) / 30}

[0166] <Method for confirming the area ratio of resin components contained in agglomerates> The area ratio of the resin component is calculated based on the domain D1 of the resin component and the domain D2 of the non-resin component using a backscattered electron image of the aggregates on the toner surface. The backscattered electron image of the aggregates on the toner surface is obtained in the same manner as the backscattered electron image of the toner surface.

[0167] The analysis of domains D1 and D2 is carried out by using the backscattered electron image of the outermost surface of the toner particle obtained by the above-mentioned method, using the image processing software ImageJ (developed by Wayne Rasband). The procedure is as follows.

[0168] First, convert the backscattered electron image to be analyzed to 8-bit using Type in the Image menu. Next, set the Median diameter to 2.0 pixels using Filters in the Process menu to reduce image noise. After excluding the observation conditions display area at the bottom of the backscattered electron image, estimate the center of the image and use the Rectangle Tool on the toolbar to select a 1.5 μm square area from the center of the backscattered electron image.

[0169] Next, use the Freehand selections function in the Image menu to select only the areas where the carbon atom parts of the mapping image and the dark areas of the backscattered electron image match, and paint them all black. Also, paint everything except the areas where the carbon atom parts of the mapping image and the dark areas of the backscattered electron image match with white. Next, select Threshold from Adjust. Manually, select 128 as the threshold, which is the middle gradation between black and white in an 8-bit image, and click Apply to obtain a binarized image.

[0170] By this operation, pixels corresponding to domain D1 (resin component) are displayed in black (pixel group A1), and pixels corresponding to domain D2 (non-resin component) are displayed in white (pixel group A2).

[0171] Again, estimate the center of the image after excluding the observation condition display area at the bottom of the backscattered electron image, and use the Rectangle Tool on the toolbar to select a 1.5 μm square area from the center of the backscattered electron image.

[0172] Next, use the straight line tool (Straight Line) on the toolbar to select the scale bar in the observation condition display area below the backscattered electron image. In this state, select Set Scale from the Analyze menu. A new window will open and the pixel distance of the selected straight line will be entered in the Distance in Pixels field.

[0173] Enter the value of the scale bar (for example, 100) in the Known Distance field of the window, enter the unit of the scale bar (for example, nm) in the Unit of Measurement field, and click OK to complete the scale setting.

[0174] Next, select "Set Measurements" from the Analyze menu, check "Area" and "Feret's diameter", select "Analyze Particles" from the Analyze menu, check "Display Result", and click "OK" to perform domain analysis.

[0175] From the newly opened Results window, the area (Area) of each domain corresponding to domain D1 formed by pixel group A1 and domain D2 formed by pixel group A2 is obtained.

[0176] The total area of ​​the resulting resin component domains D1 was defined as S1 (μm 2 ), and the total area of ​​the domains D2 other than the resin component is S2 (μm 2 ) The resin component area ratio S is calculated from the obtained S1 and S2 using the following formula. S(area%)={S1 / (S1+S2)}×100

[0177] The above procedure is carried out for 10 visual fields for the toner particles to be evaluated, and the arithmetic mean value is used as the resin component area ratio.

[0178] <Method for observing toner and calculating the number of toner particles> The toner is observed using a scanning electron microscope (SEM). The SEM equipment and observation conditions are as follows: Equipment used: Carl Zeiss ULTRA PLUS Microscope Accelerating voltage: 1.0 kV WD: 2.0 mm Aperture Size: 30.0 μm Detection signal: SE2 (secondary electrons) Observation magnification: 2,000x Contrast: 45.0±5.0% (reference value) Brightness: 38.0±5.0% (reference value) Resolution: 1024 x 768 Pretreatment: Toner particles are scattered on carbon tape (no deposition is performed)

[0179] The contrast and brightness are set appropriately according to the state of the device being used, and the acceleration voltage is set to achieve the objectives of obtaining structural information on the outermost surface of the toner particles and preventing charge-up of undeposited samples.

[0180] The number of observation fields is determined by counting the number of toner particles, Tall (pieces), whose entire particles are contained within the observation field in the obtained secondary electron image, and observing until the number of observation fields reaches 300 or more.

[0181] <Calculation method for the number ratio CI of toner particles having agglomerates> In the secondary electron images obtained in all the fields of view in the above observation, the number of toner particles that have agglomerates among the toner particles that are entirely within the observation field of view is counted and taken as Tagg (pieces). For toner that has agglomerates, the number of toner particles as shown in Figure 1 is counted.

[0182] From the obtained Tall (pieces) and Tagg (pieces), CI (number %) is calculated using the following formula. CI (number%) = Tag / Tall × 100

[0183] <Method for measuring the size of agglomerates and method for counting toner containing agglomerates> In the aforementioned scanning electron microscope observation, the entire toner is photographed at an appropriate magnification (5k to 10k) and saved. The image resolution is 1024 x 768 pixels.

[0184] From the obtained SEM image, areas judged to be aggregates are selected on the image using image analysis software Image J (developed by Wayne Rasband). The size of the aggregate is defined as the maximum Feret's diameter of this selected area. The calculation procedure is shown below. (1) Set the scale by selecting [Analyze]-[Set Scale]. (2) Check [Analyze]-[Set Measurements]-[Feret's diameter]. (3) Select [Freehand Selections] and hand-select the aggregates on the image. (4) Select [Analyze]-[Measure] to obtain the maximum Feret diameter of the selected area. (5) If multiple agglomerates are present on the image, steps (3) and (4) are repeated. (6) The remaining images observed for toner having agglomerates with a maximum Feret diameter of 500 nm or more and 8000 nm or less are subjected to the same analysis. (7) The maximum value of the Feret diameter obtained from the analysis results is taken as the maximum Feret diameter.

[0185] The aggregates are those having a maximum Feret's diameter of 500 nm or more and 8000 nm or less.

[0186] A random sample of toner is observed under a scanning electron microscope, and the arithmetic mean value of the maximum Feret diameter of a total of 100 agglomerates is defined as Ag. Furthermore, the percentage of toner particles having agglomerates among the randomly observed toner particles is defined as CI.

[0187] <Method for evaluating whether silica fine particles and resin components are contained in agglomerates> The presence of silica particles and resin components in the aggregates is confirmed using STEM-EDX and a scanning electron microscope.

[0188] First, the cross-sectional structure and composition of the aggregates are evaluated using STEM-EDX for toner particles having aggregates.

[0189] Using an osmium plasma coater (Filgen, OPC80T), a protective Os film (5 nm) and a naphthalene film (20 nm) are applied to the toner particles, which are then embedded in a photocurable resin D800 (JEOL). A 100 nm thick cross section of the toner particles is then prepared using an ultrasonic ultramicrotome (Leica, UC7) at a cutting speed of 1 mm / s. It is recommended to process multiple toner particles at once to obtain cross sections of 300–500 toner particles. Figure 4 shows a schematic diagram of the cross section of a toner particle with agglomerates. In Figure 4, 100 represents the agglomerates, 101 represents the external additive, and 102 represents the toner particles (toner mother particles).

[0190] The obtained cross section is observed by STEM-EDX using the STEM function of a TEM-EDX (TEM: JEOL, JEM2800 (200 keV), EDX detector: JEOL, Dry SD 100 GV, EDX system: Thermo Fisher, NORAN SYSTEM 7). The STEM probe size is 1.0 nm, the observation magnification is 50 to 300 k, the EDX image size is 256 x 256 pixels, and the storage rate is adjusted to 10,000 cps, and 50 frames are acquired by accumulating them. The field of view is set so that the agglomerates present on the periphery of the toner particles are included in the observation location.

[0191] The presence of silica-based particles and resin components in the agglomerates can be determined by confirming that there are separate areas in the same location where silicon and oxygen are abundant and areas where elements derived from the resin component are abundant. When resin is used as the resin component, carbon is abundant.

[0192] Next, a backscattered electron image of the toner having the aggregates is observed using a scanning electron microscope under the following image capturing conditions.

[0193] (1) Sample preparation Carbon tape is attached to a sample stage (aluminum sample stage 12.5 mm diameter x 6 mm thickness) and the toner is placed on top of it. Excess sample is then removed from the sample stage using air blowing. The sample stage is then placed in the sample holder and placed in a scanning electron microscope (Zeiss UltraPlus).

[0194] (2) Setting electron microscope observation conditions The presence of aggregates containing silica particles and resin components is confirmed using images obtained by backscattered electron imaging with Ultra Plus. Because the image contrast in backscattered electron images changes depending on the elemental composition, the presence of silica and binding components in the aggregates can be determined. The accelerating voltage is 0.7 kV, the ECB grid is 500 V, and the WD is 3.0 mm.

[0195] (3) Focus adjustment Set the observation magnification to 30,000 (30k) and adjust the alignment and stigma. Next, adjust the field of view at the appropriate observation magnification to an area that appears to have the morphology of an aggregate. The backscattered electron image obtained shows two contrasts: one that appears to correspond to silica, and one that appears to be a binding component, and it can be determined that this is the same aggregate as the one whose composition was observed using STEM-EDX.

[0196] <Method for calculating the number proportions Ca and Cb of toner particles having agglomerates when ultrasonic treatment is performed> Approximately 10 ml of ion-exchanged water, from which impurities such as solids have been removed, is placed in a glass container.

[0197] Approximately 0.5 ml of a diluted solution of "Contaminon N" (a 10% aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) diluted approximately three times by mass with ion-exchanged water was added to the mixture. Approximately 0.02 g of the measurement sample was then added, and while stirring, the following dispersion process was carried out using an ultrasonic disperser to obtain the dispersion for measurement. The dispersion was then cooled appropriately so that its temperature was between 10°C and 40°C. An ultrasonic homogenizer ("VP-050" manufactured by TAITEC Co., Ltd.) with an oscillation frequency of 30 kHz was used as the ultrasonic disperser, with the vibrating part inserted 1.0 cm into the dispersion and vibrated under ultrasonic condition A or ultrasonic condition B below. Ultrasonic condition A: Output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s ·Ultrasonic condition B: Output frequency 30kHz, output capacity 25W, irradiation time 300s The dispersion obtained by the above procedure is filtered using Kiriyama filter paper (No. 5C: pore size 1 μm) to separate the particles from the filtrate, and the obtained particles are further washed with 100 parts by mass of ion-exchanged water and vacuum-dried at 25°C for 24 hours to obtain a powder for measuring the number proportions Ca and Cb of toner particles containing aggregates.

[0198] For the obtained powder, Ca and Cb are calculated using the same procedure as in the "method for calculating the number ratio CI of toner particles having agglomerates," and it is confirmed whether the relationships of the following formulas (1) and (2) are satisfied. 0.90≦Ca / CI≦1.00 Formula (1) 0.10≦Cb / CI≦0.40 Formula (2)

[0199] <Method for isolating binder resin from toner particles> -Method for separating binder resin from toner particles 100 mg of toner particles were dissolved in 3 ml of chloroform. Next, insoluble matter was removed by suction filtration using a syringe equipped with a sample processing filter (pore size 0.2 μm to 0.5 μm, such as a Myshoridisk H-25-2 (Tosoh Corporation)). The soluble matter was introduced into a preparative HPLC (apparatus: Japan Analytical Industry Co., Ltd. LC-9130 NEXT preparative column [60 cm], exclusion limits: 20,000 and 70,000, two columns connected), and chloroform eluent was pumped. Once a peak was confirmed in the resulting chromatographic display, fractions with retention times corresponding to molecular weights of 2,000 or higher were collected using a monodisperse polystyrene standard sample. The solution of the obtained fraction is dried and solidified to separate it from the release agent and separate the binder resin.

[0200] <Composition analysis of polyester A and crystalline polyester> The chloroform-soluble portion of the separated binder resin is used as the sample. The sample is adjusted with chloroform so that the binder resin concentration is 0.1 mass %, and the solution is filtered through a 0.45 μm PTFE filter before being used for measurement. The gradient polymer LC measurement conditions are as follows: Equipment: UlTIMATE3000 (Thermo Fisher Scientific) Mobile phase: A chloroform (HPLC), B acetonitrile (HPLC) Gradient: 2 min (A / B = 0 / 100) → 25 min (A / B = 100 / 0) (The gradient of the mobile phase change was made linear.) Flow rate: 1.0mL / min Injection: 0.1% by mass x 20μL Column: Tosoh TSKgel ODS (4.6 mm diameter x 150 mm x 5 μm) Column temperature: 40°C Detector: Corona Charged Aerosol Detector (Corona-CAD) (Thermo Fisher Scientific)

[0201] Collect polyester A within the time range corresponding to polyester A (7 to 9 minutes). Also, collect the crystalline polyester within the time range corresponding to the crystalline polyester (13 to 15 minutes). For the collection, take the required amount of each chloroform / acetonitrile solution, perform drying and concentration, and then use them as samples of polyester A and crystalline polyester.

[0202] Using the samples of the polyester A component and the crystalline polyester component, measure the composition ratio and mass ratio by nuclear magnetic resonance spectroscopy (NMR) as follows.

[0203] Add 1 mL of deuterated chloroform to 20 mg of the samples of the polyester A component and the crystalline polyester component, dissolve them, and measure the proton NMR spectrum of the dissolved resin. From the obtained NMR spectrum, regarding the smallest unit sandwiched by ester bonds as the structure derived from the monomer, calculate the molar ratio and mass ratio of each monomer, and determine the content ratio of each monomer unit.

[0204] For nuclear magnetic resonance spectroscopy (NMR), the following devices and measurement conditions can be used. NMR device: RESONANCE ECX500 manufactured by JEOL Ltd. Observed nucleus: Proton Measurement mode: Single pulse

[0205] <Quantification method of U, U, and U in polyester A by NMR measurement iso , U EO , U PO > · Identification of components of polyester A and measurement of molar ratio and mass ratio by nuclear magnetic resonance spectroscopy (NMR) Add 1 mL of deuterated chloroform to 20 mg of the obtained polyester A, dissolve it, and measure the proton NMR spectrum of the dissolved polyester A. From the obtained NMR spectrum, regarding the smallest unit sandwiched by ester bonds as the structure derived from the monomer, calculate the molar ratio and mass ratio of each monomer.

[0206] For example, the composition ratio and mass ratio can be calculated based on the following peaks (chemical shift value, number of protons): Isophthalic acid-derived units: 7.5 ppm (1), 8.2 ppm (2), 8.7 ppm (1) Terephthalic acid-derived units: 8.1 ppm (4) Units derived from ethylene oxide adducts of bisphenol A: 1.6 ppm (6), 4.3 ppm (4), 4.7 ppm (4), 6.8 ppm (4), 7.1 ppm (4) Units derived from propylene oxide adducts of bisphenol A: 1.5 ppm (6), 1.6 ppm (6), 4.1 ppm (4), 5.5 ppm (2), 6.8 ppm (4), 7.1 ppm (4) Ethylene glycol derived units: 4.3 ppm (4) NMR device: JEOL RESONANCE ECX500 Observation nucleus: Proton Measurement mode: Single pulse Base peak: TMS

[0207] NMR analysis revealed that the unit U derived from isophthalic acid was the basis for all units derived from the acid component. iso The content (mol%) of U was calculated based on the total units derived from the alcohol component. EO and U PO The total content (mol%) of U was calculated. EO The content ratio and U PO U EO The content (mol %) of was calculated.

[0208] <Method for measuring the average circularity of toner particles> The average circularity of the toner or toner particles is measured using a flow particle image analyzer, "FPIA-3000" (manufactured by Sysmex Corporation), under the measurement and analysis conditions used during calibration work.

[0209] To 20 mL of ion-exchanged water, an appropriate amount of surfactant and alkylbenzene sulfonate was added as a dispersant, and then 0.02 g of the measurement sample was added and dispersed for 2 minutes using a tabletop ultrasonic cleaner disperser (product name: VS-150, manufactured by Vervoclear Co., Ltd.) with an oscillation frequency of 50 kHz and an electrical output of 150 watts to obtain a dispersion for measurement. At this time, the dispersion was appropriately cooled so that the temperature was between 10°C and 40°C.

[0210] For the measurement, the flow particle image analyzer equipped with a standard objective lens (10x) is used, and the particle sheath "PSE-900A" (manufactured by Sysmex Corporation) is used as the sheath liquid. The dispersion liquid prepared according to the above procedure is introduced into the flow particle image analyzer, and 3,000 toner particles (particles) are measured in HPF measurement mode and total count mode. The binarization threshold for particle analysis is set to 85%, and the analyzed particle diameter is limited to a circle-equivalent diameter of 1.98 μm or more and 19.92 μm or less, and the average circularity of the toner particles (particles) is determined.

[0211] Before starting the measurement, automatic focus adjustment is performed using standard latex particles (for example, 5100A (trade name) manufactured by Duke Scientific diluted with ion-exchanged water). After that, it is preferable to perform focus adjustment every two hours from the start of the measurement.

[0212] <Determining the presence of dodecylbenzenesulfonic acid or dodecylbenzenesulfonate salts in toner> The presence or absence of dodecylbenzenesulfonic acid or dodecylbenzenesulfonate salts is determined by performing analysis using the MS / MS (mass-mass spectrometry) method with a tandem mass spectrometer directly connected to a liquid chromatograph ESI / MS analyzer.

[0213] The MS / MS method is a mass spectrometry technique that allows for the detection of fragments with even smaller molecular weights by measuring fragments extracted in a first analytical system in a second analytical system, thereby facilitating structural analysis of a sample.

[0214] Dissolution condition A: At 25° C., 10 times the mass of methanol (JIS K8891 equivalent) is used relative to the toner, and the toner is stirred for 10 hours at a rotor speed of 200 rpm using a stirring device. Centrifugation condition A: Rotation is carried out at 25°C, a rotation radius of 10.1 cm, and a rotation speed of 3500 rpm for 30 minutes. The sample is prepared using toner under the above-mentioned elution condition A, and then separated into a solid content and a supernatant liquid under the above-mentioned centrifugation condition A.

[0215] The supernatant obtained by the above adjustment is supplied to the measuring device described below, and liquid chromatograph ESI / MS analysis is performed under the following analytical condition B. A mass spectrum of the anion is obtained, and it is confirmed that a peak is detected at m / z = 325. In addition, the ion detected as a peak at m / z = 325 is supplied as a precursor ion to a tandem mass spectrometer, and an MS / MS spectrum is obtained under analytical condition B. Measurement device: Ultimate3000 (Thermo Fisher Scientific) Mass spectrometer: LCQ Fleet (manufactured by Thermo Fisher Scientific) Analysis condition B: Under the following conditions, the ionized material is detected as an anion under the conditions of capillary voltage: -35 V, tube lens voltage: -110 V, and the ion detected at m / z = 325 is selected as the precursor ion, and the ion is detected by collision-induced dissociation in an inert gas: He with a collision energy of 35 eV. Ionization method: Electrospray Ionization (ESI) Sheath Gas: 10 (arb. unit.) Aux Gas: 5 (arb. unit.) Spray voltage: 5kV Capillary temperature: 275℃ Mobile phase: Methanol (JISK8891 standard equivalent) Column: Not used (no stationary phase) Flow rate: 1ml / min Injection volume: 10μl Chromatogram detector: UV detector MS acquisition time: 5min MS measurement range: 50-1500 m / z Collision inert gas: He (helium) Collision energy: 35 eV

[0216] <Quantitative Determination of Dodecylbenzenesulfonic Acid or Dodecylbenzenesulfonate in Toner> The amount of dodecylbenzenesulfonic acid or dodecylbenzenesulfonate in the toner is determined by subjecting the methanol extract of the toner to LC / MS measurement. A calibration curve is created using sodium dodecylbenzenesulfonate as a standard, and then quantification is performed.

[0217] (LC / MS analysis conditions) Model: Agilent 6130 Quadropore LC / MS (Agilent Technologies) Eluent: methanol Column: ZORBAX Eclipse Plus C18 (1.8 μm, 100 × 4.6 mm I.D.) (Agilent Technologies) Flow rate: 1.0 mL / min Column temperature: 30℃

[0218] [Configurations included in the embodiments of the present invention] The disclosure of this embodiment includes the following configuration. (Configuration 1) A toner having toner particles containing a binder resin, the binder resin contains 50% by mass or more of a polyester A containing 60% by mole or more of units derived from isophthalic acid as an acid component, The toner has aggregates containing silica and a resin on the surface of the toner particles, When the number ratio of toner particles having the agglomerates is defined as CI (number %), the CI of the toner is 1 number % or more and 15 number % or less, When the toner is treated under the ultrasonic condition A below, the number ratio of the toner particles containing the aggregates is Ca, When the toner is treated under the ultrasonic condition B below, the number ratio of the toner particles containing the aggregates is Cb, The toner is characterized in that the CI, the Ca, and the Cb satisfy the following formulas (1) and (2): Ultrasonic condition A: output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s Ultrasonic condition B: output frequency 30kHz, output capacity 25W, irradiation time 300s 0.90≦Ca / CI≦1.00 Formula (1) 0.10≦Cb / CI≦0.40 Formula (2) (Configuration 2) The toner according to Configuration 1, wherein the polyester A contains 90 mol % or more of units derived from isophthalic acid as the acid component. (Configuration 3) The polyester A contains a unit (U) derived from an ethylene oxide adduct of bisphenol A. EO ) and units derived from propylene oxide adducts of bisphenol A (U PO ), and the unit U EO and the unit U PO 3. The toner according to claim 1, wherein the total content of the units derived from the alcohol component is 90 mol % or more based on all units derived from the alcohol component. (Configuration 4) The unit U EO The content ratio of the unit U PO The content ratio of the unit U EO The content ratio of U EO / (U EO +U PO 4. The toner according to configuration 3, wherein 15 mol % or more and 40 mol % or less of the total amount of the toner particles is 100 mol % or less. (Configuration 5) The toner according to any one of Configurations 1 to 4, wherein the number average molecular weight (Mn) of the tetrahydrofuran (THF) soluble portion of the polyester A measured using gel permeation chromatography (GPC) is 3,000 or more and 10,000 or less, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2.5 or more. (Configuration 6) The toner according to any one of Configurations 1 to 5, wherein the toner particles contain 0.015% by mass or more and 0.150% by mass or less of aluminum element. (Configuration 7) The toner according to any one of Configurations 1 to 6, wherein the binder resin contains a crystalline polyester. (Configuration 8) The toner according to any one of Configurations 1 to 7, wherein the toner has an average circularity of 0.950 or more and 0.980 or less. (Configuration 9) The toner according to any one of Configurations 1 to 8, wherein, when the toner having the agglomerates is observed under a scanning electron microscope, the area ratio of the resin component of the agglomerates to the area of ​​the entire agglomerates is 5% to 50%. (Configuration 10) The toner according to any one of Configurations 1 to 9, wherein the arithmetic mean value Ag of the Feret's diameter of the aggregates is 1000 nm or more and 8000 nm or less. [Example]

[0219] Hereinafter, the present disclosure will be described in more detail with reference to Production Examples and Examples, but these are not intended to limit the present disclosure in any way. In the formulations below, "parts" always refer to parts by mass.

[0220] <Production Example 1 of Polyester A> Bisphenol A ethylene oxide 2 mole adduct (BPA-EO) 25 mole parts Bisphenol A propylene oxide 2 mole adduct (BPA-PO) 75 mole parts Isophthalic acid 100 mol parts The above monomers were charged into a flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, and distillation column, and the temperature was raised to 190°C over 1 hour. It was confirmed that the reaction system was uniformly stirred. 1.0 part of tin distearate was added to 100 parts of these monomers. The temperature was then raised from 190°C to 250°C over 5 hours while distilling off the generated water, and the dehydration condensation reaction was carried out at 250°C for an additional 2 hours.

[0221] As a result, polyester A-1 having Mn of 8000 and Mw / Mn of 3.5 was obtained.

[0222] <Production Examples 2 to 6 of Polyester A> Polyesters A-2 to A-6 were obtained in the same manner as in Production Example 1 of Polyester A, except that the monomers used in Production Example 1 of Polyester A were changed as shown in Table 1, and the reaction temperature and dehydration condensation time were changed so that the Mn and Mw / Mn of the resulting Polyester A would be the desired values. The results are shown in Table 1.

[0223] [Table 1]

[0224] <Crystalline Polyester Production Example 1> 1,10-Decanedicarboxylic acid 100 mol parts 1,9-nonanediol 100 mol parts 0.8 parts of tin dioctylate as a catalyst for 100 parts of the total mass of the acid alcohol The above materials were placed in a heated and dried two-necked flask, and nitrogen gas was introduced into the vessel to maintain an inert atmosphere while stirring. The mixture was then heated to 170°C for 6 hours with stirring. The mixture was then gradually heated to 230°C under reduced pressure with continued stirring and maintained at this temperature for an additional 3 hours. When the mixture reached a viscous state, it was air-cooled to terminate the reaction, producing Crystalline Polyester 1. The resulting physical properties are shown in Table 2.

[0225] <Crystalline Polyester Production Examples 2 and 3> Crystalline polyesters 2 and 3 were obtained in the same manner as in Crystalline Polyester Production Example 1, except that the alcohol monomers and acid monomers used were changed as shown in Table 2. The physical properties of Crystalline Polyesters 2 and 3 are shown in Table 2.

[0226] [Table 2]

[0227] <Preparation of Resin Particle Dispersion of Polyester A-1> Polyester A-1 100 parts 50 parts methyl ethyl ketone 20 parts isopropyl alcohol The above-mentioned methyl ethyl ketone and isopropyl alcohol were added to a container. Then, the above-mentioned polyester A-1 was gradually added and stirred until completely dissolved, yielding a polyester A-1 solution. The container containing this polyester A-1 solution was set to 65°C, and while stirring, a 10% aqueous ammonia solution was gradually added dropwise to a total of 5 parts, followed by 230 parts of ion-exchanged water at a rate of 10 ml / min to induce phase inversion emulsification. The pressure was then reduced in an evaporator to remove the solvent, yielding a resin particle dispersion of polyester A-1. The volume average particle size of the resin particles contained in this resin particle dispersion was 130 nm. The resin particle solid content was adjusted to 20% with ion-exchanged water.

[0228] <Preparation of Resin Particle Dispersion of Crystalline Polyester 1> 100 parts crystalline polyester 50 parts methyl ethyl ketone 20 parts isopropyl alcohol The methyl ethyl ketone and isopropyl alcohol were added to a container. The crystalline polyester 1 was then gradually added and stirred until completely dissolved, yielding a crystalline polyester 1 solution. The container containing the crystalline polyester 1 solution was set to 40°C, and while stirring, a 10% aqueous ammonia solution was gradually added dropwise to a total of 3.5 parts, followed by 230 parts of ion-exchanged water at a rate of 10 ml / min to induce phase inversion emulsification. The pressure was then reduced to remove the solvent, yielding a resin particle dispersion of crystalline polyester 1. The volume average particle size of the resin particles in this resin particle dispersion was 150 nm. The resin particle solid content was adjusted to 20% with ion-exchanged water.

[0229] <Preparation of Colorant Particle Dispersion> Copper phthalocyanine (pigment blue 15:3) 45 parts 5 parts of ionic surfactant Neogen RK (sodium dodecylbenzenesulfonate, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 190 parts ion-exchanged water The above components were mixed and dispersed for 10 minutes using a homogenizer (Ultra Turrax manufactured by IKA), and then dispersed for 20 minutes using an Ultimizer (opposed collision type wet grinder: manufactured by Sugino Machine Co., Ltd.) at a pressure of 250 MPa, to obtain a colorant particle dispersion liquid having a volume average particle size of 120 nm and a solid content of 20%.

[0230] <Preparation of Release Agent Particle Dispersion> Release agent (hydrocarbon wax, melting point: 79°C) 15 parts 2 parts of ionic surfactant Neogen RK (Dai-ichi Kogyo Seiyaku Co., Ltd.) 240 parts ion-exchanged water The above mixture was heated to 100°C and thoroughly dispersed using an IKA Ultra Turrax T50. After that, the mixture was heated to 115°C using a pressure discharge Gaulin homogenizer and dispersed for 1 hour, to obtain a release agent particle dispersion liquid with a volume average particle size of 160 nm and a solid content of 20%.

[0231] <Production of Toner Core Particle Dispersion 1> Polyester A-1 resin particle dispersion 90.0 parts 10.0 parts of crystalline polyester 1 resin particle dispersion Colorant particle dispersion 5.0 parts Release agent particle dispersion 8.0 parts First, the above materials were placed in a round stainless steel flask and mixed. Then, the mixture was dispersed for 10 minutes at 5000 rpm using an Ultra Turrax T50 homogenizer (manufactured by IKA). After adjusting the pH to 8.0 with a 1 mol / L aqueous solution of sodium hydroxide, an aqueous solution of 0.50 parts of aluminum chloride dissolved in 20 parts of ion-exchanged water was added as a flocculant at 30°C over 10 minutes with stirring. After leaving the mixture for 3 minutes, the temperature was raised to 50°C to generate core particles.

[0232] The volume average particle size of the formed aggregated particles was appropriately confirmed using a Coulter Multisizer III, and the aggregation step was terminated when aggregated particles having a size of 6.0 μm were formed.

[0233] Thereafter, as a spheronization step, a 1 mol / L aqueous solution of sodium hydroxide was added to adjust the pH to 9.0, and the mixture was heated to 92°C while continuing to stir.

[0234] When the desired surface shape was obtained, heating was stopped and the mixture was cooled to room temperature, thereby obtaining toner core particle dispersion 1.

[0235] <Preparation Example of Monomer Dispersion Liquid 1 Having Silica Fine Particles and Resin Component> Styrene: 100 parts Methacryloxypropyltrimethoxysilane: 20 parts Colloidal silica: 70 parts The mixture was dispersed using a homogenizer (IKA Ultra Turrax T50), the temperature inside the container was adjusted to 25°C, and the mixture was stirred for 1 hour to obtain a monomer dispersion 1 for agglomerates containing silica microparticles and a resin component.

[0236] <Preparation Examples of Monomer Dispersions 2 to 9 Containing Silica Fine Particles and Resin Component> Monomer dispersions 2 to 9 for agglomerates containing silica and a resin component were obtained in the same manner as in the preparation of monomer dispersion 1 containing silica and a resin component, except that the number of parts and material types were changed as shown in Table 3.

[0237] [Table 3]

[0238] Next, an example of toner production will be described.

[0239] <Toner 1 manufacturing example> Toner core particle dispersion 1 in an amount such that the amount of toner core particles was 100 parts, 2.75 parts of the monomer dispersion 1 obtained by the above method and 0.005 parts of potassium persulfate were added, the temperature inside the container was adjusted to 90°C, and the mixture was stirred for 2 hours using a full-zone stirring blade to obtain toner particle dispersion 1.

[0240] Hydrochloric acid was added to the resulting toner particle dispersion 1 to adjust the pH to 1.5 or less, and the mixture was stirred and left for 1 hour. The mixture was then subjected to solid-liquid separation using a pressure filter to obtain a toner cake. This was then reslurried with ion-exchanged water to form a dispersion again, and then subjected to solid-liquid separation using the aforementioned filter. The reslurrying and solid-liquid separation were repeated until the electrical conductivity of the filtrate reached 5.0 μS / cm or less, after which solid-liquid separation was finally performed to obtain a toner cake. The resulting toner cake was dried and further classified using a classifier to obtain toner particles 1 having agglomerates on the toner particle surface. The weight-average particle size of toner particles 1 was 6.9 μm.

[0241] External addition was performed on the above toner particles 1. Using an FM mixer (FM10 manufactured by Nippon Coke & Engineering Co., Ltd.), 20.0 g of hydrophobic silica fine particles (number average particle diameter of primary particles: 7 nm) surface-treated with dimethyl silicone oil was added to 2.0 kg of toner particles 1, and then the mixture was mixed at 3000 rpm for 5 minutes. During this process, the temperature inside the tank was adjusted to 35°C after 5 minutes of mixing by controlling the flow and temperature of cold water flowing through the cooling jacket.

[0242] Thereafter, the toner was sieved through a mesh with 75 μm openings to obtain Toner 1. The physical properties of Toner 1 are shown in Table 4-3.

[0243] <Production example of toners 2 to 28> Toner particles 2 to 28 and toners 2 to 28 were obtained in the same manner as in the production example of toner 1, except that the number of parts, material types, and production conditions were changed as shown in Tables 4-1 and 4-2. The physical properties of the obtained toners 2 to 28 are shown in Table 4-3.

[0244] [Table 4-1]

[0245] The "number of parts (parts)" in Table 4-1 indicates the amount of resin particle dispersion used in preparing the toner core particle dispersion.

[0246] [Table 4-2]

[0247] In Table 4-2, "parts (parts)" indicates the amount added to the toner core particle dispersion liquid so that the amount of toner core particles becomes 100 parts.

[0248] [Table 4-3]

[0249] Example 1 As the image forming apparatus for evaluating the performance of the toner, a color laser printer, HP LaserJet Enterprise Color M555dn, equipped with a one-component toner contact development blade cleaning system, and its consumable cartridge, a modified HP212X black toner cartridge (W2120X) CRG, were used.

[0250] The main body was modified so that the process speed was 150% and printing tests could be performed using only the black station. The cartridge was also modified to increase the volume of the toner container so that the following toner loading amount could be accommodated, and the following evaluations 1 to 4 were carried out. By doing this, a configuration was achieved that allowed for the formation of more images on a faster main body than before. The evaluation results are shown in Table 5.

[0251] <Evaluation 1. Density reduction when printing multiple images under high temperature and humidity conditions> To evaluate image density, the image density was evaluated after forming a large number of images in a high-temperature, high-humidity environment (temperature 30°C, relative humidity 80%). The printer body and a toner cartridge filled with 550 g of Toner 1 were left in a 30°C, 80% RH environment for one day in order to control the temperature and humidity in the evaluation environment. After that, the image density was evaluated on a letter-size XEROX 4200 paper (manufactured by XEROX, 75 g / m) in the same environment. 2 ) to a solid black image (toner loading amount: 0.6 mg / cm 2) was output on one sheet. This solid black image was designated the initial solid black image. Subsequently, an image with a printing ratio of 1.0% was output on 20,000 sheets under the same environment, and then a solid black image was output. This solid black image was designated the solid black image after multiple image formation. The densities of these initial and multiple image formation solid black images were measured using a Macbeth reflection densitometer (manufactured by Macbeth). At this time, it was determined that the smaller the difference between the reflection density of the initial solid black image and the reflection density of the solid black image after 20,000 image formations, the more successfully the image density reduction was suppressed. A: Excellent (difference less than 0.06) B: Excellent (difference is 0.06 or more and less than 0.12) C: Good (difference is 0.12 or more and less than 0.18) D: Poor (difference is 0.18 or more)

[0252] <Evaluation 2. Density reduction when printing multiple images under normal temperature and humidity conditions> Image density was evaluated by image density evaluation during multiple image formation in a normal temperature and humidity environment (temperature 25°C, relative humidity 55%). The printer body and a toner cartridge filled with 550 g of Toner 1 were left in a 25°C, 55% RH environment for one day to control the temperature and humidity in the evaluation environment. A solid black image was then printed under the same environment. This solid black image was designated the initial solid black image. Next, an image with a 1.0% printing ratio was printed under the same environment, and 20,000 images with a 1.0% printing ratio were printed, after which a solid black image was printed. This solid black image was designated the solid black image after multiple image formation. The densities of these initial and multiple image formation solid black images were measured using a Macbeth reflection densitometer (manufactured by Macbeth). The smaller the difference between the reflection density of the initial solid black image and the reflection density of the solid black image after 20,000 image formations, the more successfully image density reduction was suppressed. A: Excellent (difference less than 0.06) B: Excellent (difference is 0.06 or more and less than 0.12) C: Good (difference is 0.12 or more and less than 0.18) D: Poor (difference is 0.18 or more)

[0253] <Evaluation 3: Vertical streaks when printing multiple images under high temperature and humidity conditions> To evaluate image density, vertical streaks were evaluated when printing multiple images in a high-temperature, high-humidity environment (temperature 30°C, relative humidity 80%). The printer body and a toner cartridge filled with 550g of Toner 1 were left in a 30°C, 80% RH environment for one day in order to control the temperature and humidity in the evaluation environment.

[0254] Next, under the same environment, 20,000 images with a printing ratio of 1.0% were printed, and then a halftone image (HT image) was printed and the number of vertical streaks on the image was measured. A: Excellent (0 streaks) B: Excellent (1 minor streak) C: Good (one clearly visible streak) D: Poor (two or more clearly visible lines)

[0255] <Evaluation 4. Density unevenness when printing multiple images under high temperature and humidity conditions> To evaluate image density, we evaluated density unevenness when printing multiple images in a high-temperature, high-humidity environment (temperature 30°C, relative humidity 80%). The printer body and a toner cartridge filled with 550g of Toner 1 were left in a 30°C, 80% RH environment for one day to regulate the temperature and humidity in the evaluation environment. Next, under the same environment, 20,000 images with a printing ratio of 1.0% were printed, and then a solid black image was printed. The density of the resulting solid black image was measured at 20 random points, and the difference between the maximum and minimum measured densities was used for evaluation. A: Excellent (density difference less than 0.10) B: Excellent (density difference is 0.10 or more and less than 0.20) C: Good (density difference is 0.20 or more and less than 0.30) D: Poor (density difference is 0.30 or more)

[0256] [Examples 2 to 21, Comparative Examples 1 to 7] Except for replacing Toner 1 with Toners 2 to 28, evaluation was carried out in the same manner as in Example 1. The evaluation results are shown in Table 5.

[0257] [Table 5]

Claims

1. In a toner having toner particles containing a binder resin, the binder resin contains 50% by mass or more of a polyester A containing 60% by mole or more of units derived from isophthalic acid as an acid component, The toner has aggregates containing silica and a resin on the surface of the toner particles, the toner has a CI (number %) of 1 to 15% by number, where CI is the number ratio of toner particles having the agglomerates; When the toner is treated under the ultrasonic condition A below, the number ratio of the toner particles containing the aggregates is Ca, When the toner is treated under the ultrasonic condition B below, the number ratio of the toner particles containing the aggregates is represented by Cb, The toner is characterized in that the CI, the Ca, and the Cb satisfy the following formulas (1) and (2): Ultrasonic condition A: output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s Ultrasonic condition B: output frequency 30kHz, output capacity 25W, irradiation time 300s 0.90≦Ca / CI≦1.00 Formula (1) 0.10≦Cb / CI≦0.40 Formula (2)

2. 2. The toner according to claim 1, wherein the polyester A contains 90 mol % or more of units derived from isophthalic acid as an acid component.

3. The polyester A contains a unit (U EO ) and units derived from a propylene oxide adduct of bisphenol A (U PO ) and the unit U EO and the unit U PO 3. The toner according to claim 1, wherein the total content of the units derived from the alcohol component is 90 mol % or more based on all units derived from the alcohol component.

4. The unit U EO The content ratio of the unit U PO The content ratio of the unit U EO The content ratio of U EO / (U EO +U PO 4. The toner according to claim 3, wherein the value of (x, y)×100 is 15 mol % or more and 40 mol % or less.

5. 3. The toner according to claim 1, wherein the number average molecular weight (Mn) of the polyester A, measured by gel permeation chromatography (GPC) of a tetrahydrofuran (THF)-soluble component, is 3,000 or more and 10,000 or less, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2.5 or more.

6. 3. The toner according to claim 1, wherein the toner particles contain aluminum in an amount of 0.015% by mass or more and 0.150% by mass or less.

7. 3. The toner according to claim 1, wherein the binder resin contains a crystalline polyester.

8. 3. The toner according to claim 1, wherein the average circularity of the toner is 0.950 or more and 0.980 or less.

9. 3. The toner according to claim 1, wherein, when the toner having the agglomerates is observed under a scanning electron microscope, the area ratio of the resin component of the agglomerates to the area of ​​the entire agglomerates is 5% or more and 50% or less.

10. 3. The toner according to claim 1, wherein the arithmetic mean value Ag of the Feret's diameter of the aggregates is 1,000 nm or more and 8,000 nm or less.

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