Toner, developer, toner storage unit, developer storage unit, image forming apparatus, and image forming method

Abstract

To provide a toner capable of achieving both low-temperature fixability and heat-resistant storage stability and suppressing contamination of a cleaning member and a photoreceptor while maintaining excellent cleaning properties.SOLUTION: Disclosed is a toner including a toner base particle containing a binder resin and a colorant, and an external additive, in which the circularity is 0.974 or more and 0.985 or less, a plurality of resin fine particles buried in the surface of the toner base particle is present, and when an increase rate of the surface on the average surface detected in an SPM analyzer is expressed as Sdr (%), the Sdr [%] satisfies the formula (1) [5<Sdr<50].SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a toner, a developer, a toner storage unit, a developer storage unit, an image forming apparatus, and an image forming method. [Background technology]

[0002] In recent years, toners have been required to have smaller particle size and high-temperature offset resistance for improving the quality of output images, low-temperature fixability for energy saving, and heat-resistant storage stability that can withstand high temperatures and humidity during storage and transportation after production. In particular, since the power consumption during fixation accounts for a large portion of the power consumption in the image formation process, improving low-temperature fixability is extremely important.

[0003] In order to improve the low-temperature fixability of a toner, it is necessary to use a material with a low melting point in the toner. However, a toner produced using a material with a low melting point has poor heat-resistant storage stability, and there is a trade-off between low-temperature fixability and heat-resistant storage stability.

[0004] Therefore, in order to achieve both low-temperature fixability and heat-resistant storage stability, a method for producing composite resin particles has been proposed, which includes a step of forming composite resin particles in which resin fine particles containing two types of resin as constituent components within the same particle are attached to the surface of the resin particle, and then removing part or all of the resin from the resin fine particles (see, for example, Patent Documents 1 to 3). Also, Patent Document 4 proposes having resin fine particles present on the surface of toner particles. Summary of the Invention [Problem to be solved by the invention]

[0005] Conventionally, there has been a demand for a technology that can simultaneously satisfy both low-temperature fixing properties and heat-resistant storage properties, good cleaning properties with respect to a photoreceptor (electrostatic latent image carrier), and suppression of contamination of a cleaning member and the photoreceptor. For example, an external additive such as inorganic fine particles is expected to act as a lubricant and contribute to an improvement in cleaning properties. On the other hand, there is a concern that such an external additive may cause contamination of a cleaning member such as a cleaning blade and the photoreceptor.

[0006] An object of the present invention is to provide a toner that can achieve both low-temperature fixing properties and heat-resistant storage properties, maintain good cleaning properties, and suppress contamination of a cleaning member and the photoreceptor.

Means for Solving the Problems

[0007] In order to solve the above problems, the present invention relates to a toner having a configuration as described in <1> below. <1>A toner containing toner base particles containing a binder resin and a colorant, and an external additive, having a circularity of 0.974 or more and 0.985 or less, wherein a plurality of resin fine particles buried in the surface of the toner base particles are present, when the increase rate of the surface in the average plane detected by an SPM analyzer is represented as Sdr [%], the toner is characterized in that the Sdr [%] satisfies the following formula (1). 5 < Sdr < 50 ··· Formula (1)

Effects of the Invention

[0008] According to the present invention, it is possible to provide a toner that can achieve both low-temperature fixing properties and heat-resistant storage properties, maintain good cleaning properties, and suppress contamination of a cleaning member and the photoreceptor.

Brief Description of the Drawings

[0009] [Figure 1] FIG. 1 is a schematic configuration diagram showing an example of an image forming apparatus of the present invention. [Figure 2]FIG. 2 is a schematic configuration diagram showing another example of the image forming apparatus of the present invention. [Figure 3] FIG. 3 is a schematic configuration diagram showing another example of the image forming apparatus of the present invention. [Figure 4] FIG. 4 is a partially enlarged view of FIG. 3. [Figure 5] FIG. 5 is a schematic configuration diagram showing an example of a process cartridge.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments for carrying out the present invention will be described. The following description is an example of embodiments of this invention and does not limit the scope of the present invention.

[0011] The toner of the present invention is a toner containing toner base particles containing a binder resin and a colorant, and an external additive, and has a circularity of 0.974 or more and 0.985 or less, and a plurality of resin fine particles buried in the surface of the toner base particles. When the rate of increase in the surface on the average plane detected by a SPM (Scanning Probe Microscope) analyzer is represented as Sdr [%], the toner is characterized in that the Sdr [%] satisfies the following formula (1). 5 < Sdr < 50 ··· Formula (1)

[0012] The toner of the present invention is characterized in that the circularity is 0.974 or more and 0.985 or less. By setting the circularity to 0.974 or more and 0.985 or less, the external additive coating efficiency is increased, and the heat-resistant storage property, durability, and cleaning property are improved. When the circularity is less than 0.974, the coating efficiency of the external additive decreases, and the spacer effect decreases, so the contact between toners and between the toner and the cleaning blade increases, and the cleaning property decreases. Also, when the circularity exceeds 0.985, the sphericity increases, and it slips through the slight gap formed between the cleaning blade and the image carrier, resulting in cleaning failure.

[0013] In the prior art, additives such as inorganic fine particles like silica and titanium oxide are added to the surface of general toner to impart fluidity and chargeability to the toner. In toner cleaning, it is known that toner is dammed up on a photoreceptor (also referred to as an image carrier or an electrostatic latent image carrier) by a cleaning blade which is an example of a cleaning member, and additives are released from the dammed-up toner. The released additives are supplied to the contact portion between the cleaning blade and the image carrier, and an accumulation layer due to the additives is formed. This acts as a lubricant between the cleaning blade and the image carrier, and thereby good cleaning performance of the toner can be obtained. However, when the amount of additives is large, the amount of additives released from the toner also increases accordingly, and the contamination of the cleaning blade and the photoreceptor progresses, and the wear of the cleaning blade and the deterioration of the photoreceptor become remarkable. Particularly when inorganic fine particles are used as an external additive, such problems become remarkable.

[0014] On the other hand, the toner of the present invention can suppress the contamination of the cleaning member and the photoreceptor while maintaining good cleaning performance. In the present invention, by covering the surface of toner base particles with resin fine particles, the resin fine particles do not inhibit fixing and can harden the toner, so the addition amount of inorganic fine particles can be reduced. Therefore, it is possible to suppress the contamination of the cleaning member and the photoreceptor while maintaining good cleaning performance. Further, in the present invention, it is characterized in that a plurality of resin fine particles are present on the surface of the toner base particles. The presence of a plurality of resin fine particles improves the spacer effect on the surface of the toner base particles, and the heat-resistant storage property, durability, and cleaning performance are improved. When there are no resin fine particles, the spacer effect on the base surface decreases, and the heat resistance, durability, and cleaning performance deteriorate.

[0015] Further, the toner of the present invention is characterized in that when the increase ratio of the surface in the average plane detected by an SPM analyzer is represented as Sdr [%], Sdr [%] satisfies the formula (1). 5 < Sdr < 50 ··· Formula (1) The surface increase rate Sdr [%] on the average surface of toner particles is a surface roughness parameter described in ISO25178. Sdr represents how much the developed area (surface area) of the defined area has increased with respect to the area of the defined area, and the Sdr [%] of a completely flat surface is 0%. Sdr [%] in the present invention is a parameter indicating how much the surface area has increased due to the unevenness of the toner surface with respect to the area of the surface roughness parameter calculation area, and is calculated by the following formula. Sdr [%] =(Increase in the area of the surface area in the defined area with respect to the area of the defined area / Area of the defined area) × 100 通常、トナー粒子の平均面粗さが大きい場合、外添剤の被覆効率が低下し、スペーサー効果が減少するため、トナー間、トナーとブレードとの間の接触が増え、クリーニング性が低下する。平均面における表面の増加割合Sdr[%]を5<Sdr<50とすることによって外添剤の被覆効率が向上し、外添剤がスペーサー効果を十分に発揮することで、耐熱保存性、耐久性、クリーニング性を向上させることができる。 Normally, when the average surface roughness of toner particles is large, the coating efficiency of the external additive decreases and the spacer effect decreases, so the contact between toners and between the toner and the blade increases, and the cleaning property deteriorates. By setting the surface increase rate Sdr [%] on the average surface to 5 < Sdr < 50, the coating efficiency of the external additive is improved, and the external additive sufficiently exhibits the spacer effect, thereby improving the heat-resistant storage stability, durability, and cleaning property.

[0016] When the surface increase rate Sdr [%] on the average surface is 5% or less, the sphericity increases, and it slips through the slight gap formed between the cleaning blade and the image carrier, resulting in cleaning failure. Also, when the surface increase rate Sdr [%] on the average surface is 50% or more, the coating efficiency of the external additive decreases and the spacer effect decreases, causing deterioration of heat-resistant storage stability, durability, and cleaning failure.

[0017] As a method for controlling the unevenness of the toner surface, there is no particular limitation, and it can be appropriately selected according to the purpose. For example, a method of unevenly distributing a deformant such as an inorganic filler (e.g., layered inorganic mineral) on the toner surface is known. The toner of the present invention controls the unevenness of the toner by controlling the arrangement of the inorganic filler on the toner surface.

[0018] The toner shape can also be controlled by the thixotropy of the toner droplets during polymerization. The toner of the present invention is characterized by containing a crystalline polyester resin. The crystalline polyester resin exists in the toner particles in a crystalline state, and by appropriately arranging the resin, it is possible to control the surface state of the toner.

[0019] The following describes the components constituting the toner, the carrier, the method for producing the toner, the image forming apparatus, the image forming method, and the like.

[0020] <Toner base particles> The toner base particles contain at least a binder resin and a colorant, and may further contain other components as required. The toner base particles are preferably obtained by dissolving or dispersing at least a binder resin and a colorant in an organic solvent, adding the resulting solution or dispersion to an aqueous phase, and removing the organic solvent from the resulting dispersion.More preferably, the toner base particles are obtained by dissolving or dispersing at least a binder resin precursor and a colorant in an organic solvent, adding the resulting solution or dispersion to an aqueous phase, causing a crosslinking or elongation reaction of the binder resin precursor, and removing the organic solvent.

[0021] <<Binder resin>> The toner generally contains a polyester resin as a binder resin, preferably a non-linear amorphous polyester resin, and more preferably a crystalline polyester resin. The component insoluble in THF preferably contains a non-linear amorphous polyester resin or a crystalline polyester resin.

[0022] -Amorphous polyester resin- The amorphous polyester resin is obtained by using a polyhydric alcohol component and a polycarboxylic acid component such as a polycarboxylic acid, a polycarboxylic acid anhydride, or a polycarboxylic acid ester. In the present invention, the amorphous polyester resin refers to a resin obtained by using a polyhydric alcohol component and a polycarboxylic acid component such as a polycarboxylic acid, a polycarboxylic acid anhydride, or a polycarboxylic acid ester, as described above. Modified polyester resins, such as prepolymers described below, and resins obtained by subjecting such prepolymers to a crosslinking and / or elongation reaction, do not fall under the category of amorphous polyester resins.

[0023] Examples of the polyhydric alcohol component include alkylene (carbon number 2 to 3) oxide (average number of added moles 1 to 10) adducts of bisphenol A such as polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane and polyoxyethylene(2.2)-2,2-bis(4-hydroxyphenyl)propane; ethylene glycol, propylene glycol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, hydrogenated bisphenol A, sorbitol, and alkylene (carbon number 2 to 3) oxide (average number of added moles 1 to 10) adducts thereof. These may be used alone or in combination of two or more.

[0024] Examples of the polycarboxylic acid component include dicarboxylic acids such as adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, and maleic acid; succinic acids substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, such as dodecenylsuccinic acid and octylsuccinic acid; trimellitic acid, pyromellitic acid; anhydrides of these acids, and alkyl (carbon number 1 to 8) esters of these acids. These may be used alone or in combination of two or more.

[0025] It is preferable that the amorphous polyester resin, the prepolymer described below, and the resin obtained by crosslinking and / or elongation reaction of this prepolymer are at least partially compatible with each other. This compatibility can improve low-temperature fixability and high-temperature offset resistance. Therefore, it is preferable that the polyhydric alcohol component and polycarboxylic acid component constituting the amorphous polyester resin and the polyhydric alcohol component and polycarboxylic acid component constituting the prepolymer described below have similar compositions.

[0026] The molecular weight of the amorphous polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but if the molecular weight is too low, the toner may have poor heat-resistant storage stability and poor durability against stress such as stirring in a developing device. Also, if the molecular weight is too high, the toner may have high viscoelasticity when melted, resulting in poor low-temperature fixability. For these reasons, the molecular weight of the amorphous polyester resin, as measured by GPC, is preferably a weight-average molecular weight (Mw) of 2,500 to 10,000, a number-average molecular weight (Mn) of 1,000 to 4,000, and an Mw / Mn ratio of 1.0 to 4.0.

[0027] The acid value of the amorphous polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 mgKOH / g to 50 mgKOH / g, and more preferably 5 mgKOH / g to 30 mgKOH / g. When the acid value is 1 mgKOH / g or more, the toner tends to be negatively charged, and further, when fixed to paper, the affinity between the paper and the toner is improved, thereby improving low-temperature fixability. When the acid value is 50 mgKOH / g or less, charging stability, particularly charging stability against environmental changes, is not reduced.

[0028] The hydroxyl value of the amorphous polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 mgKOH / g or more.

[0029] The glass transition temperature (Tg) of the amorphous polyester resin is not particularly limited and can be appropriately selected depending on the purpose. If the Tg is too low, the toner may have poor heat-resistant storage stability and poor durability against stress such as stirring in a developing device. If the Tg is too high, the toner may have high viscoelasticity when melted, resulting in poor low-temperature fixability. For these reasons, the Tg of the amorphous polyester resin is preferably 40°C to 70°C, more preferably 45°C to 60°C.

[0030] The content of the amorphous polyester resin is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 50 to 95 parts by weight, more preferably 60 to 90 parts by weight, per 100 parts by weight of the toner. If the content is less than 50 parts by weight, the dispersibility of the pigment and release agent in the toner may deteriorate, making the image more susceptible to fogging and distortion. If the content exceeds 95 parts by weight, the content of the crystalline polyester resin may be reduced, resulting in poor low-temperature fixability. If the content is within the above more preferred range, it is advantageous in that high image quality, high stability, and low-temperature fixability are all excellent.

[0031] The molecular structure of the amorphous polyester resin can be confirmed by NMR measurement of a solution or a solid, as well as by X-ray diffraction, GC / MS, LC / MS, IR measurement, etc. -1 and 990±10cm -1 One method is to detect amorphous polyester resins that do not have absorption due to olefin δCH (out-of-plane bending vibration).

[0032] -Crystalline polyester resin- The crystalline polyester resin has structural units derived from a saturated aliphatic diol. As the saturated aliphatic diol, it is preferable to use an alcohol component containing a straight-chain aliphatic diol having 2 to 8 carbon atoms. This allows the crystalline polyester resin to be uniformly and finely dispersed within the toner, preventing filming of the crystalline polyester resin, improving stress resistance, and achieving low-temperature fixability of the toner.

[0033] The crystalline polyester resin has high crystallinity and exhibits a thermal melting characteristic that causes a rapid decrease in viscosity near the fixing start temperature. By using the crystalline polyester resin with such characteristics in the toner, the toner has good heat-resistant storage stability due to its crystallinity up to just before the fixing start temperature, and then undergoes a rapid viscosity decrease (sharp melting property) at the fixing start temperature, resulting in a toner that combines good heat-resistant storage stability and low-temperature fixing ability. Furthermore, the toner also exhibits good results in terms of release width (the difference between the minimum fixing temperature and the temperature at which hot offset occurs).

[0034] The crystalline polyester resin is obtained by using a polyhydric alcohol component and a polycarboxylic acid component such as a polycarboxylic acid, a polycarboxylic acid anhydride, or a polycarboxylic acid ester. In the present invention, the crystalline polyester resin refers to a resin obtained by using a polyhydric alcohol component and a polycarboxylic acid component such as a polycarboxylic acid, a polycarboxylic acid anhydride, or a polycarboxylic acid ester, as described above. Modified crystalline polyester resins, such as the prepolymers described below, and resins obtained by subjecting the prepolymers to a crosslinking and / or elongation reaction, do not fall under the category of crystalline polyester resins.

[0035] --Polyhydric alcohol component-- The polyhydric alcohol component is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diols and trihydric or higher alcohols. Examples of the diol include saturated aliphatic diols. Examples of the saturated aliphatic diol include linear saturated aliphatic diols and branched saturated aliphatic diols. Among these, linear saturated aliphatic diols are preferred, and linear saturated aliphatic diols having 2 to 8 carbon atoms are more preferred. If the saturated aliphatic diol is branched, the crystallinity of the crystalline polyester resin may decrease, resulting in a lower melting point. Furthermore, if the carbon number in the main chain is less than 2, the melting temperature may increase when polycondensed with an aromatic dicarboxylic acid, making low-temperature fixation difficult. On the other hand, if the carbon number exceeds 8, it becomes difficult to obtain practical materials. It is more preferred that the carbon number be 8 or less.

[0036] Examples of the saturated aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosanedecanediol, etc. Among these, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol are preferred in terms of the high crystallinity and excellent sharp melt properties of the crystalline polyester resin. Examples of the trihydric or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These may be used alone or in combination of two or more.

[0037] --Polycarboxylic acid component-- As the polycarboxylic acid component, sebacic acid is used, but other dicarboxylic acids and tricarboxylic or higher carboxylic acids can be used in combination depending on the purpose. Examples of the dicarboxylic acid include saturated aliphatic dicarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, and 1,18-octadecanedicarboxylic acid; and aromatic dicarboxylic acids such as dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, and mesaconic acid; and further include anhydrides and lower alkyl esters of these.

[0038] Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, anhydrides thereof, and lower alkyl esters thereof. The polycarboxylic acid component may contain a dicarboxylic acid component having a sulfonic acid group in addition to the saturated aliphatic dicarboxylic acid or aromatic dicarboxylic acid, or a dicarboxylic acid component having a double bond in addition to the saturated aliphatic dicarboxylic acid or aromatic dicarboxylic acid. These may be used alone or in combination of two or more.

[0039] The melting point of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 60° C. or higher and lower than 80° C. If the melting point is lower than 60° C., the crystalline polyester resin tends to melt at low temperatures, which may reduce the heat-resistant storage stability of the toner, whereas if the melting point is higher than 80° C., the amorphous polyester resin may not melt sufficiently due to heating during fixing, which may reduce the low-temperature fixability. The melting point can be measured by the endothermic peak value on a differential scanning calorimeter (DSC) chart.

[0040] The molecular weight of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint that a resin with a sharp molecular weight distribution and a low molecular weight has excellent low-temperature fixability, and that a large amount of low-molecular-weight components deteriorates heat-resistant storage stability, it is preferable that the ortho-dichlorobenzene-soluble portion of the crystalline polyester resin has a weight-average molecular weight (Mw) of 3,000 to 30,000, a number-average molecular weight (Mn) of 1,000 to 10,000, and an Mw / Mn of 1.0 to 10, as measured by GPC.

[0041] The acid value of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of affinity between paper and resin, in order to achieve the desired low-temperature fixability, the acid value is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, while in order to improve high-temperature offset resistance, the acid value is preferably 45 mgKOH / g or less.

[0042] The hydroxyl value of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose. In order to achieve desired temperature fixability and good charging characteristics, the hydroxyl value is preferably 0 mgKOH / g to 50 mgKOH / g, and more preferably 5 mgKOH / g to 50 mgKOH / g.

[0043] The molecular structure of the crystalline polyester resin can be confirmed by NMR measurement using a solution or solid, as well as X-ray diffraction, GC / MS, LC / MS, IR measurement, etc. A simple method is to detect a crystalline polyester resin by detecting an absorption at 965±10 cm-1 or 990±10 cm-1 in an infrared absorption spectrum based on δCH (out-of-plane bending vibration) of olefin.

[0044] The content of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 2 to 20 parts by weight, and more preferably 5 to 15 parts by weight, relative to 100 parts by weight of the toner. If the content is less than 2 parts by weight, the crystalline polyester resin may not provide sufficient sharp melting, resulting in poor low-temperature fixability. If the content exceeds 20 parts by weight, the heat-resistant storage stability may deteriorate and image fogging may occur easily. If the content is within the above more preferred range, it is advantageous in that high image quality, high stability, and low-temperature fixability are all excellent.

[0045] -Polymer having a site capable of reacting with an active hydrogen group-containing compound- The polymer having a site capable of reacting with an active hydrogen group-containing compound (hereinafter sometimes referred to as a "prepolymer") is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include polyol resins, polyacrylic resins, polyester resins, epoxy resins, derivatives thereof, etc. These may be used alone or in combination of two or more. Among these, polyester resins are preferred in terms of high fluidity and transparency when melted.

[0046] Examples of the site of the prepolymer that can react with the active hydrogen group-containing compound include an isocyanate group, an epoxy group, a carboxyl group, a functional group represented by -COCl, etc. These may be used alone or in combination of two or more. Of these, an isocyanate group is preferred.

[0047] The prepolymer is not particularly limited and can be appropriately selected depending on the purpose, but a polyester resin having an isocyanate group or the like capable of generating a urea bond is preferred, in that it allows for easy adjustment of the molecular weight of the polymer component, and ensures oil-less low-temperature fixing properties in dry toners, particularly good releasability and fixability even when there is no mechanism for applying release oil to the heating medium for fixing.

[0048] -Compounds containing active hydrogen groups- The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent, or the like when a polymer having a site capable of reacting with the active hydrogen group-containing compound undergoes an elongation reaction, a crosslinking reaction, or the like in an aqueous medium.

[0049] The active hydrogen group is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, etc. These may be used alone or in combination of two or more.

[0050] The active hydrogen group-containing compound is not particularly limited and can be appropriately selected depending on the purpose, but when the polymer having a site capable of reacting with the active hydrogen group-containing compound is a polyester resin containing an isocyanate group, amines are preferred because they can be polymerized by elongation reaction, crosslinking reaction, etc. with the polyester resin. The amines are not particularly limited and can be appropriately selected depending on the purpose, and examples include diamines, trivalent or higher amines, amino alcohols, amino mercaptans, amino acids, and compounds in which the amino group is blocked. These may be used alone or in combination of two or more. Among these, diamines and mixtures of diamines with small amounts of trivalent or higher amines are preferred.

[0051] The diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include aromatic diamines, alicyclic diamines, and aliphatic diamines. The aromatic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include phenylenediamine, diethyltoluenediamine, and 4,4'-diaminodiphenylmethane. The alicyclic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminocyclohexane, and isophoronediamine. The aliphatic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include ethylenediamine, tetramethylenediamine, and hexamethylenediamine.

[0052] The trivalent or higher amine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diethylenetriamine and triethylenetetramine.

[0053] The amino alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include ethanolamine and hydroxyethylaniline. The amino mercaptan is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aminoethyl mercaptan and aminopropyl mercaptan.

[0054] The amino acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aminopropionic acid and aminocaproic acid. The compound in which the amino group is blocked is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include ketimine compounds and oxazolizone compounds obtained by blocking the amino group with ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0055] -Polyester resin containing isocyanate groups- The polyester resin containing an isocyanate group (hereinafter, sometimes referred to as a "polyester prepolymer having an isocyanate group") is not particularly limited and can be appropriately selected depending on the purpose. For example, a reaction product of a polyester resin having an active hydrogen group obtained by polycondensation of a polyol and a polycarboxylic acid with a polyisocyanate can be mentioned.

[0056] --Polyol-- The polyol is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include diols, trihydric or higher alcohols, mixtures of diols and trihydric or higher alcohols, etc. These may be used alone or in combination of two or more. Among these, diols and mixtures of diols with small amounts of trihydric or higher alcohols are preferred.

[0057] The diol is not particularly limited and can be selected appropriately depending on the purpose, and examples thereof include alkylene glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol; diols having an oxyalkylene group such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; alicyclic diols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; alicyclic diols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added; bisphenols such as bisphenol A, bisphenol F, and bisphenol S; and alkylene oxide adducts of bisphenols, such as bisphenols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added. The number of carbon atoms in the alkylene glycol is not particularly limited and can be selected appropriately depending on the purpose, but a carbon number of 2 to 12 is preferred. Among these, alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols are preferred, and alkylene oxide adducts of bisphenols and mixtures of alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms are more preferred.

[0058] The trihydric or higher alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include trihydric or higher aliphatic alcohols, trihydric or higher polyphenols, and alkylene oxide adducts of trihydric or higher polyphenols. The trihydric or higher aliphatic alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol. The trivalent or higher polyphenols are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include trisphenol PA, phenol novolac, and cresol novolac. Examples of the alkylene oxide adducts of trivalent or higher polyphenols include those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to trivalent or higher polyphenols. When the diol and the trihydric or higher alcohol are used as a mixture, the mass ratio of the trihydric or higher alcohol to the diol is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01 mass % to 10 mass %, more preferably 0.01 mass % to 1 mass %.

[0059] --Polycarboxylic Acids-- The polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include dicarboxylic acids, trivalent or higher carboxylic acids, mixtures of dicarboxylic acids and trivalent or higher carboxylic acids, etc. These may be used alone or in combination of two or more. Among these, dicarboxylic acids and mixtures of dicarboxylic acids with a small amount of trivalent or higher polycarboxylic acids are preferred.

[0060] The dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include divalent alkanoic acids, divalent alkenoic acids, and aromatic dicarboxylic acids. The divalent alkanoic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include succinic acid, adipic acid, and sebacic acid. The divalent alkenoic acid is not particularly limited and can be appropriately selected depending on the purpose, but is preferably a divalent alkenoic acid having 4 to 20 carbon atoms. The divalent alkenoic acid having 4 to 20 carbon atoms is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include maleic acid and fumaric acid. The aromatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but is preferably an aromatic dicarboxylic acid having 8 to 20 carbon atoms. The aromatic dicarboxylic acid having 8 to 20 carbon atoms is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid.

[0061] The trivalent or higher carboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aromatic trivalent or higher carboxylic acids. The trivalent or higher aromatic carboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but is preferably a trivalent or higher aromatic carboxylic acid having 9 to 20 carbon atoms. The trivalent or higher aromatic carboxylic acid having 9 to 20 carbon atoms is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include trimellitic acid and pyromellitic acid.

[0062] As the polycarboxylic acid, an acid anhydride or a lower alkyl ester of any of a dicarboxylic acid, a trivalent or higher carboxylic acid, and a mixture of a dicarboxylic acid and a trivalent or higher carboxylic acid can also be used. The lower alkyl ester is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include methyl ester, ethyl ester, and isopropyl ester. When the dicarboxylic acid and the tri- or higher carboxylic acid are used in combination, the mass ratio of the tri- or higher carboxylic acid to the dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01% by mass to 10% by mass, and more preferably 0.01% by mass to 1% by mass.

[0063] When polyol and polycarboxylic acid are polycondensed, the equivalent ratio of hydroxyl groups of polyol to carboxyl groups of polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 to 2, more preferably 1 to 1.5, and particularly preferably 1.02 to 1.3.

[0064] The content of the polyol-derived structural units in the polyester prepolymer having an isocyanate group is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5% by mass to 40% by mass, more preferably 1% by mass to 30% by mass, and particularly preferably 2% by mass to 20% by mass. If the content is less than 0.5% by mass, the high-temperature offset resistance may decrease, making it difficult to achieve both the heat-resistant storage stability and low-temperature fixability of the toner, and if the content exceeds 40% by mass, the low-temperature fixability may decrease.

[0065] --Polyisocyanate-- The polyisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, araliphatic diisocyanates, isocyanurates, and those obtained by blocking these with phenol derivatives, oximes, caprolactam, etc.

[0066] The aliphatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include tetramethylene diisocyanate, hexamethylene diisocyanate, methyl 2,6-diisocyanatocaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, and tetramethylhexane diisocyanate.

[0067] The alicyclic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include isophorone diisocyanate and cyclohexylmethane diisocyanate.

[0068] The aromatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include tolylene diisocyanate, diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4′-diisocyanatodiphenyl, 4,4′-diisocyanato-3,3′-dimethyldiphenyl, 4,4′-diisocyanato-3-methyldiphenylmethane, and 4,4′-diisocyanato-diphenyl ether.

[0069] The aromatic aliphatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include α,α,α',α'-tetramethylxylylene diisocyanate. The isocyanurates are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include tris(isocyanatoalkyl)isocyanurate, tris(isocyanatocycloalkyl)isocyanurate, etc. These may be used alone or in combination of two or more.

[0070] When the polyisocyanate is reacted with a polyester resin having a hydroxyl group, the equivalent ratio of the isocyanate group of the polyisocyanate to the hydroxyl group of the polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 to 5, more preferably 1.2 to 4, and particularly preferably 1.5 to 3. If the equivalent ratio is less than 1, the offset resistance may decrease, and if it exceeds 5, the low-temperature fixability may decrease.

[0071] The content of the polyisocyanate-derived structural unit in the polyester prepolymer having an isocyanate group is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5% by mass to 40% by mass, more preferably 1% by mass to 30% by mass, and particularly preferably 2% by mass to 20% by mass. If the content is less than 0.5% by mass, high-temperature offset resistance may decrease, and if it exceeds 40% by mass, low-temperature fixability may decrease.

[0072] The average number of isocyanate groups contained in the polyester prepolymer having an isocyanate group per molecule is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 or more, more preferably 1.2 to 5, and particularly preferably 1.5 to 4. If the average number is less than 1, the molecular weight of the urea-modified polyester resin will be low, and high-temperature offset resistance may be reduced.

[0073] The mass ratio of the polyester prepolymer having an isocyanate group to the polyester resin containing 50 mol % or more of a propylene oxide adduct of a bisphenol in the polyhydric alcohol component and having a specific hydroxyl value and acid value is not particularly limited and can be appropriately selected depending on the purpose, but is preferably less than 5 / more than 95 to more than 25 / less than 75, and more preferably 10 / 90 to 25 / 75. If the mass ratio is less than 5 / 95, high-temperature offset resistance may decrease, and if it exceeds 25 / 75, low-temperature fixability and image gloss may decrease.

[0074] <Coloring agent> The colorant is not particularly limited and can be appropriately selected depending on the purpose. Examples of the colorant include carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, yellow ochre, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Balkan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, and anthrazan yellow BG. L, Isoindolinone Yellow, Bengala, Red Lead, Cinnabar, Cadmium Red, Cadmium Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Faise Red, Parachlor Orthonitroaniline Red, Lithol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Kanmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Lithol Rubin GX, Permanent Red F5R, Brilliant Cliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkali Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine, Prussian Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chromium Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake,Examples include malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc oxide, and lithopone. The content of the colorant is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 1 part by mass or more and 15 parts by mass or less, and more preferably 3 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the toner.

[0075] The colorant can also be used as a masterbatch combined with a resin. Examples of resins to be produced by the masterbatch or kneaded together with the masterbatch include, in addition to the hybrid resins, polymers of styrene or its substitution products such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, and styrene-α-chloromethyl methacrylate copolymer. styrene copolymers such as styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, and styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. These may be used alone or in combination of two or more.

[0076] The masterbatch can be obtained by mixing and kneading a resin and a colorant for the masterbatch under high shear force. An organic solvent can be used to enhance the interaction between the colorant and the resin. A method known as the flushing method, in which an aqueous paste containing the colorant in water is mixed and kneaded with a resin and an organic solvent to transfer the colorant to the resin and then remove the water and organic solvent components, is also preferred because it allows the colorant wet cake to be used as is, eliminating the need for drying. A high-shear dispersing device such as a three-roll mill is preferably used for mixing and kneading.

[0077] <Resin fine particles> In the present invention, the resin particles cover the surfaces of the toner base particles, and the resin particles covering the surfaces of the toner base particles have a core-shell structure consisting of a shell portion and a core portion. The coverage of the resin particles on the surface of the toner base particles is preferably 30% or more and 90% or less, and more preferably 30% or more and 70% or less. A coverage of 30% or more ensures the heat-resistant storage stability of the toner, while a coverage of 90% or less allows external additives to adhere easily and facilitates heat transfer during toner fixing, ensuring fixability. Furthermore, a coverage of 70% or less improves the above effects.

[0078] The coverage of the resin particles on the surface of the toner base particles is measured as follows. The resin fine particles on the surface of the toner base particle are observed with a scanning electron microscope (SEM) and images are taken. From the images, the ratio of the area of ​​the resin fine particles to the area of ​​the toner base particle is calculated using image processing software, and this is taken as the coverage rate.

[0079] The method for observing the resin particles will be described below: The external additives are removed as much as possible by ultrasonic wave-induced liberation treatment, and the resin particles are brought into a state close to that of toner base particles, and then observed.

[0080] -Method for separating external additives- [1] Add 50 ml of a 5% by weight aqueous solution containing a surfactant (product name: Noigen ET-165, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) to a 100 ml screw tube, add 3 g of toner to the mixture, and gently move it up and down and left and right. Then, mix it in a ball mill for 30 minutes to allow the toner to blend into the dispersion solution.

[0081] [2] Then, using an ultrasonic homogenizer (trade name homogenizer, model VCX750, CV33, manufactured by SONICS & MATERIALS LLC), set the output to 40 W and apply ultrasonic energy for 60 minutes.

[0082] [Ultrasonic conditions] Vibration time: 60 minutes continuous ·Amplitude: 40W ·Vibration start temperature: 23±1.5℃ ·Temperature during vibration: 23±1.5℃

[0083] [3] (1) The dispersion liquid is suction filtered using filter paper (product name: Qualitative Filter Paper (No. 2, 110 mm), manufactured by Advantec Toyo Co., Ltd.), washed twice with ion-exchanged water, filtered again, and the free additives are removed, after which the toner particles are dried. (2) The toner obtained in (1) above is observed with a scanning electron microscope (SEM). First, the external additives and fillers containing Si are detected by observing the backscattered electron image. (3) The image of (2) above is binarized using image processing software (ImageJ) to remove the external additives and fillers. Next, a secondary electron image is observed at the same position as in (2). Since resin fine particles cannot be observed in a backscattered electron image but can only be observed in a secondary electron image, the image is compared with the image obtained in (3), and the fine particles present in the areas other than the remaining external additives and filler (areas other than those excluded in (3)) are observed as resin fine particles.

[0084] [Photography conditions] Scanning electron microscope: SU-8230 (Hitachi High-Technologies Corporation) Magnification: 35,000x Image capture: SE (L): Secondary electrons, BSE (backscattered electrons) Acceleration voltage: 2.0 kV ·Acceleration current: 1.0μA Probe current: Normal Focus mode: UHR WD:8.0mm

[0085] The volume average primary particle diameter of the resin fine particles is preferably 5 nm to 100 nm, more preferably 10 nm to 100 nm, and even more preferably 10 nm to 50 nm. When the volume average primary particle diameter satisfies the range of 5 nm to 100 nm, low-temperature fixability is improved. The volume average primary particle size can be measured, for example, by observing images taken with a scanning electron microscope (SEM).

[0086] The resin particles preferably consist of two types of resins. Hereinafter, resin particles consisting of one type of resin will be referred to as resin particles (A), and resin particles consisting of two types of resin will be referred to as resin particles (B). More preferably, the resin particles made of two types of resin have a core resin (core portion) and a shell resin (outer shell portion) that covers at least a part of the surface of the core resin. Hereinafter, the resin constituting the shell resin will be referred to as "resin (a1)," and the resin constituting the core resin will be referred to as "resin (a2)." Resin (a1) and resin (a2) are preferably polymers obtained by homopolymerizing or copolymerizing vinyl monomers.

[0087] The shell resin (hereinafter also referred to as "resin (a1)") and the core resin (hereinafter also referred to as "resin (a2)") are preferably polymers obtained by homopolymerizing or copolymerizing vinyl monomers.

[0088] Examples of the vinyl monomer include the following (1) to (10). (1) Vinyl hydrocarbons Examples of vinyl hydrocarbons include (1-1) aliphatic vinyl hydrocarbons, (1-2) alicyclic vinyl hydrocarbons, and (1-3) aromatic vinyl hydrocarbons. (1-1) Aliphatic vinyl hydrocarbons Examples of the aliphatic vinyl hydrocarbon include alkenes and alkadienes. Examples of the alkenes include ethylene, propylene, and α-olefins. Examples of the alkadienes include butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene, and 1,7-octadiene. (1-2) Alicyclic vinyl hydrocarbons Alicyclic vinyl hydrocarbons include mono- or di-cycloalkenes and alkadienes, and specific examples include (di)cyclopentadiene, terpene, and the like. (1-3) Aromatic vinyl hydrocarbons Examples of aromatic vinyl hydrocarbons include styrene and its hydrocarbyl (alkyl, cycloalkyl, aralkyl and / or alkenyl) substituted derivatives, and specific examples include α-methylstyrene, 2,4-dimethylstyrene and vinylnaphthalene.

[0089] (2) Carboxyl group-containing vinyl monomers and their salts Examples of the carboxyl group-containing vinyl monomer and its salt include unsaturated monocarboxylic acids (salts) having 3 to 30 carbon atoms, unsaturated dicarboxylic acids (salts), and anhydrides (salts) thereof, and monoalkyl (carbon number 1 to 24) esters thereof or salts thereof. Specific examples include carboxyl group-containing vinyl monomers such as (meth)acrylic acid, (anhydride) maleic acid, maleic acid monoalkyl esters, fumaric acid, fumaric acid monoalkyl esters, crotonic acid, itaconic acid, itaconic acid monoalkyl esters, itaconic acid glycol monoether, citraconic acid, citraconic acid monoalkyl esters, and cinnamic acid, and metal salts thereof.

[0090] In the present invention, the term "(salt)" means an acid or a salt thereof. For example, an unsaturated monocarboxylic acid (salt) having 3 to 30 carbon atoms means an unsaturated monocarboxylic acid or a salt thereof. In the present invention, "(meth)acrylic" means methacrylic acid or acrylic acid. In the present invention, "(meth)acryloyl" means methacryloyl or acryloyl. In the present invention, "(meth)acrylate" means methacrylate or acrylate.

[0091] (3) Sulfonic acid group-containing vinyl monomers, vinyl sulfate monoesters, and their salts Examples of the sulfonic acid group-containing vinyl monomer, vinyl sulfate monoester, and salts thereof include C2-C14 alkene sulfonic acids (salts), C2-C24 alkyl sulfonic acids (salts), sulfo(hydroxy)alkyl-(meth)acrylates (salts), (meth)acrylamides (salts), and alkylaryl sulfosuccinic acids (salts). Specifically, an example of an alkene sulfonic acid having 2 to 14 carbon atoms is vinyl sulfonic acid (salt), an example of an alkyl sulfonic acid (salt) having 2 to 24 carbon atoms is α-methylstyrene sulfonic acid (salt), and an example of a sulfo(hydroxy)alkyl-(meth)acrylate (salt) or (meth)acrylamide (salt) is sulfopropyl (meth)acrylate (salt), sulfuric acid ester (salt), or sulfonic acid group-containing vinyl monomer (salt).

[0092] (4) Phosphate-containing vinyl monomers and their salts Examples of the phosphoric acid group-containing vinyl monomer and its salt include (meth)acryloyloxyalkyl (C1-24) phosphate monoester (salt), (meth)acryloyloxyalkyl (C1-24) phosphonic acid (salt), and the like. Specific examples of the (meth)acryloyloxyalkyl (having 1 to 24 carbon atoms) phosphate monoester (salt) include 2-hydroxyethyl (meth)acryloylphosphate (salt), phenyl-2-acryloyloxyethyl phosphate (salt), and the like. Specific examples of the (meth)acryloyloxyalkyl (carbon number 1 to 24) phosphonic acid (salt) include 2-acryloyloxyethyl phosphonic acid (salt).

[0093] Examples of the salts of (2) to (4) above include alkali metal salts (sodium salts, potassium salts, etc.), alkaline earth metal salts (calcium salts, magnesium salts, etc.), ammonium salts, amine salts, and quaternary ammonium salts.

[0094] (5) Hydroxyl group-containing vinyl monomer Examples of the hydroxyl group-containing vinyl monomer include hydroxystyrene, N-methylol(meth)acrylamide, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, polyethylene glycol mono(meth)acrylate, (meth)allyl alcohol, crotyl alcohol, isocrotyl alcohol, 1-buten-3-ol, 2-buten-1-ol, 2-butene-1,4-diol, propargyl alcohol, 2-hydroxyethylpropenyl ether, and sucrose allyl ether.

[0095] (6) Nitrogen-containing vinyl monomers Examples of the nitrogen-containing vinyl monomer include (6-1) amino group-containing vinyl monomer, (6-2) amide group-containing vinyl monomer, (6-3) nitrile group-containing vinyl monomer, (6-4) quaternary ammonium cation group-containing vinyl monomer, and (6-5) nitro group-containing vinyl monomer. (6-1) Examples of amino group-containing vinyl monomers include aminoethyl (meth)acrylate. (6-2) Examples of amide group-containing vinyl monomers include (meth)acrylamide and N-methyl(meth)acrylamide. (6-3) Examples of nitrile group-containing vinyl monomers include (meth)acrylonitrile, cyanostyrene, and cyanoacrylate. (6-4) Examples of quaternary ammonium cation group-containing vinyl monomers include quaternized products of tertiary amine group-containing vinyl monomers such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, and diallylamine (which are quaternized using a quaternizing agent such as methyl chloride, dimethyl sulfate, benzyl chloride, or dimethyl carbonate). (6-5) Examples of nitro group-containing vinyl monomers include nitrostyrene.

[0096] (7) Epoxy group-containing vinyl monomer Examples of the epoxy group-containing vinyl monomer include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and p-vinylphenyl phenyl oxide.

[0097] (8) Halogen-containing vinyl monomers Examples of the halogen-containing vinyl monomer include vinyl chloride, vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluorostyrene, and chloroprene.

[0098] (9) Vinyl esters, vinyl (thio)ethers, vinyl ketones Examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl propionate, vinyl butyrate, diallyl phthalate, diallyl adipate, isopropenyl acetate, vinyl methacrylate, methyl 4-vinyl benzoate, cyclohexyl methacrylate, benzyl methacrylate, phenyl (meth)acrylate, vinyl methoxyacetate, vinyl benzoate, ethyl α-ethoxyacrylate, alkyl (meth)acrylates having an alkyl group of 1 to 50 carbon atoms [methyl (meth)acrylate], ) acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate, behenyl (meth)acrylate, etc.)], dialkyl fumarate (wherein the two alkyl groups are linear, branched, or alicyclic groups having 2 to 8 carbon atoms), dialkyl Examples of suitable poly(meth)acrylates include maleates (the two alkyl groups are straight-chain, branched-chain, or alicyclic groups having 2 to 8 carbon atoms), poly(meth)allyloxyalkanes (diallyloxyethane, triallyloxyethane, tetraallyloxyethane, tetraallyloxypropane, tetraallyloxybutane, tetramethallyloxyethane, etc.), vinyl monomers having polyalkylene glycol chains (polyethylene glycol (molecular weight 300) mono(meth)acrylate, polypropylene glycol (molecular weight 500) monoacrylate, methyl alcohol ethylene oxide 10 mole adduct (meth)acrylate, lauryl alcohol ethylene oxide 30 mole adduct (meth)acrylate, etc.), and poly(meth)acrylates (poly(meth)acrylates of polyhydric alcohols: ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, polyethylene glycol di(meth)acrylate, etc.). Examples of vinyl (thio)ethers include vinyl methyl ether. Examples of vinyl ketones include vinyl methyl ketone.

[0099] (10) Other vinyl monomers Other vinyl monomers include, for example, tetrafluoroethylene, fluoroacrylate, isocyanatoethyl (meth)acrylate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, and the like.

[0100] In synthesizing the resin (a1), the vinyl monomers (1) to (10) above may be used alone or in combination of two or more. As the resin (a1), from the viewpoint of low-temperature fixability, a styrene-(meth)acrylic acid ester copolymer and a (meth)acrylic acid ester copolymer are preferred, and a styrene-(meth)acrylic acid ester copolymer is more preferred. The resin (a1) containing a carboxylic acid imparts an acid value to the resin, and makes it easier to form toner particles in which the resin fine particles (B) adhere to the surface of the toner particles.

[0101] Examples of the vinyl monomer used in the resin (a2) include the same ones as those used in the resin (a1). In synthesizing the resin (a2), the vinyl monomers (1) to (10) listed for the resin (a1) may be used alone or in combination of two or more. As the resin (a2), from the viewpoint of low-temperature fixability, a styrene-(meth)acrylic acid ester copolymer and a (meth)acrylic acid ester copolymer are preferred, and a styrene-(meth)acrylic acid ester copolymer is more preferred.

[0102] In particular, it is preferable that the shell and core contain a styrene-acrylic resin. In this case, both heat-resistant storage stability and fixability can be achieved. Regarding the content of the resin in the shell and the content of the resin in the shell, it is preferable that the styrene-acrylic resin is contained in an amount of 50% by mass or more in each of the shell and core.

[0103] The loss modulus G" of the viscoelastic properties of the resin (a1) at a frequency of 1 Hz and 100°C is preferably 1.5 MPa to 100 MPa, more preferably 1.7 MPa to 30 MPa, and even more preferably 2.0 MPa to 10 MPa. The loss modulus G" of the viscoelastic properties of the resin (a2) at 100°C and a frequency of 1 Hz is preferably 0.01 MPa to 1.0 MPa, more preferably 0.02 MPa to 0.5 MPa, and even more preferably 0.05 MPa to 0.3 MPa. When the loss modulus G" of the viscoelastic properties is within this range, it is easy to form toner particles in which the resin fine particles (B) containing the resin (b1a1) and the resin (b2a2) as constituent components in the same particle adhere to the surface of the toner particle.

[0104] The loss modulus G″ of the viscoelastic properties of resin (a1) and resin (a2) at a frequency of 1 Hz and 100°C can be adjusted by changing the types and composition ratio of the constituent monomers or by adjusting the polymerization conditions (types and amounts of initiator and chain transfer agent, reaction temperature, etc.). Specifically, for example, by using the following composition, it is possible to adjust each G″ to fall within the above-mentioned range.

[0105] (1) Regarding the glass transition temperature (Tg1) calculated from the constituent monomers of resin (a1) and the glass transition temperature (Tg2) calculated from the constituent monomers of resin (a2), Tg1 is preferably 0°C to 150°C, more preferably 50°C to 100°C, and Tg2 is preferably -30°C to 100°C, more preferably 0°C to 80°C, and most preferably 30°C to 60°C.

[0106] The glass transition temperature (Tg) calculated from the constituent monomers is a value that can be calculated by the Fox method. Here, the Fox method [TGFox, Phys. Rev., 86, 652 (1952)] is a method for estimating the Tg of a copolymer from the Tg of each homopolymer, which is represented by the following formula: 1 / Tg=W1 / Tg1+W2 / Tg2++Wn / Tgn [In the formula, Tg is the glass transition temperature (expressed in absolute temperature) of the copolymer, Tg1, Tg2...Tgn are the glass transition temperatures (expressed in absolute temperature) of the homopolymers of each monomer component, and W1, W2...Wn are the weight fractions of each monomer component.]

[0107] As for the resin (a1), an example of a constituent monomer that satisfies the conditions (1) and (2) is a resin that contains, as a constituent monomer, preferably 10% by mass to 80% by mass, and more preferably 30% by mass to 60% by mass of styrene, and a total of preferably 10% by mass to 60% by mass, and more preferably 30% by mass to 50% by mass of methacrylic acid and / or acrylic acid, based on the total mass of the resin (a1).

[0108] Furthermore, examples of the resin (a2) include a resin that contains, as a constituent monomer, preferably 10% by mass to 100% by mass, more preferably 30% by mass to 90% by mass of styrene based on the total mass of the resin (a2), and preferably 0% by mass to 7.5% by mass in total, more preferably 0% by mass to 2.5% by mass of methacrylic acid and / or acrylic acid based on the total mass of the resin (a2).

[0109] (3) Polymerization conditions (types and amounts of initiator and chain transfer agent, reaction temperature, etc.) are adjusted. Specifically, with respect to the number average molecular weights (Mn1) and (Mn2) of resin (a1) and resin (a2), (Mn1) is preferably 2,000 to 2,000,000, more preferably 20,000 to 200,000. (Mn2) is preferably 1,000 to 1,000,000, more preferably 10,000 to 100,000.

[0110] The loss modulus G″ of the viscoelastic properties in the present invention is measured, for example, using the following viscoelasticity measuring device. Equipment: ARES-24A (Rheometrics) Jig: 25mm parallel plate Frequency: 1Hz Distortion rate: 10% Heating rate: 5℃ / min

[0111] The acid value (AVa1) of the resin (a1) is preferably from 75 mgKOH / g to 400 mgKOH / g, and more preferably from 150 mgKOH / g to 300 mgKOH / g. When the acid value is within the above range, the resin fine particles (B) containing vinyl units, which contain the resin (a1) and the resin (a2) as constituent components in the same particle, tend to form particles adhered to the surface of the toner. Resin (a1) having an acid value within the above range is a resin that contains methacrylic acid and / or acrylic acid in a total amount of preferably 10% to 60% by mass, more preferably 30% to 50% by mass, based on the total mass of resin (a1).

[0112] From the viewpoint of low-temperature fixability, the acid value (AVa2) of the resin (a2) is preferably from 0 mgKOH / g to 50 mgKOH / g, more preferably from 0 mgKOH / g to 20 mgKOH / g, and even more preferably 0 mgKOH / g. Resin (a2) having an acid value within this range is a resin that contains methacrylic acid and / or acrylic acid in a total amount of preferably 0% to 7.5% by mass, and more preferably 0% to 2.5% by mass, based on the total mass of resin (a2). The acid value can be measured, for example, by the method of JIS K0070:1992.

[0113] In the present invention, the glass transition temperature TgA of the shell portion (resin a1) is higher than the glass transition temperature TgB of the core portion (resin a2). By making the glass transition temperature TgA of the shell portion higher than the glass transition temperature TgB of the core portion, high heat-resistant storage stability can be ensured.

[0114] In this way, in order to make the glass transition temperature TgA of the shell portion of the resin microparticles higher than the glass transition temperature TgB of the core portion, for example, methods such as adjusting the type and ratio of monomers used when synthesizing the shell can be mentioned.

[0115] The glass transition temperature TgA of the shell portion of the resin fine particles and the glass transition temperature TgB of the core portion preferably satisfy TgA-TgB≧10° C., and more preferably TgA-TgB≧20° C. By making the difference between TgA and TgB 10° C. or more, an excellent balance is achieved between the ease of forming toner particles in which the resin fine particles (B) adhere to the toner surface and the low-temperature fixability of the toner particles of the present invention.

[0116] The difference in glass transition temperature can be adjusted to the above range, for example, by adjusting the type and ratio of monomers used when synthesizing the shell and core portions.

[0117] In the present invention, Tg is measured by the method (DSC) specified in ASTM D3418-82 using a "DSC60-A" (manufactured by Shimadzu Corporation). The glass transition temperature TgA of the shell portion and the glass transition temperature TgB of the core portion of the resin particles from the toner are measured as follows. In this embodiment, the resin microparticles having a core-shell structure are produced by forming the shell first and then the core, and therefore the Tg of the shell can be confirmed by sampling the shell after it is formed and measuring the Tg of the sample by DSC. The Tg of the core portion can be confirmed by isolating only the core portion by removing the shell portion of resin particles having a core-shell structure with an organic solvent or by heating, and then measuring the core portion by DSC.

[0118] The glass transition temperature TgA of the resin (a1) is preferably 0° C. to 150° C., and more preferably 50° C. to 100° C. If the glass transition temperature TgA is 0° C. or higher, the heat-resistant storage stability can be improved, and if it is 150° C. or lower, the inhibition of low-temperature fixability can be reduced.

[0119] The glass transition temperature TgB of the resin (a2) is preferably −30° C. to 100° C., more preferably 0° C. to 80° C., and even more preferably 30° C. to 60° C. If the glass transition temperature is −30° C. or higher, the heat-resistant storage stability can be improved, and if it is 100° C. or lower, the inhibition of low-temperature fixability can be reduced.

[0120] The glass transition temperature Tg of the resin microparticles is preferably 40° C. or higher and 70° C. or lower. In this case, high heat-resistant storage stability can be ensured without inhibiting fixation. To set the glass transition temperature Tg of the resin microparticles in the above range, for example, the glass transition temperatures of the shell and core portions can be appropriately adjusted.

[0121] The glass transition temperature Tg of the resin particles from the toner is measured as follows. The glass transition temperature Tg of the resin fine particles obtained by physically peeling the resin fine particles from the toner surface is measured by the above-mentioned measurement method, or the resin fine particles from the toner surface are separated using an organic solvent, the solvent is removed, and then the glass transition temperature Tg is measured by the above-mentioned measurement method.

[0122] The solubility parameter (hereinafter sometimes abbreviated as SP value) of the resin (a1) is set to 9 (cal / cm) from the viewpoint of ease of forming toner particles. 3 ) 1 / 2 ~13(cal / cm 3 ) 1 / 2 is preferable, and 9.5 (cal / cm 3)1 / 2 ~12.5(cal / cm 3 ) 1 / 2 More preferably, 10.5 (cal / cm 3 ) 1 / 2 ~11.5(cal / cm 3 ) 1 / 2 is more preferred. The SP value of the resin (a1) can be adjusted by changing the types and composition ratio of the constituent monomers.

[0123] The SP value of the resin (a2) is set to 8.5 (cal / cm 3 ) from the viewpoint of ease of forming toner particles.3 ) 1 / 2 ~12.5(cal / cm 3 ) 1 / 2 is preferable, and 9 (cal / cm 3 ) 1 / 2 ~12(cal / cm 3 ) 1 / 2 More preferably, 10 (cal / cm 3 ) 1 / 2 ~11(cal / cm 3 ) 1 / 2 is more preferred. The SP value of the resin (a2) can be adjusted by changing the types and composition ratio of the constituent monomers.

[0124] The SP value in the present invention is calculated by the method by Fedors [Polym. Eng. Sci. 14(2)152, (1974)].

[0125] From the viewpoint of the TgA of the resin (a1) and copolymerizability with other monomers, the resin (a1) preferably contains 10% by mass to 80% by mass, and more preferably 30% by mass to 60% by mass of styrene as a constituent monomer, based on the total mass of the resin (a1). From the viewpoint of TgB of resin (a2) and copolymerizability with other vinyl monomers, resin (a2) preferably contains 10% by mass to 100% by mass, and more preferably 30% by mass to 90% by mass of styrene as a constituent monomer, based on the total mass of resin (a2).

[0126] The number average molecular weight (Mn1) of the resin (a1) is preferably 2,000 to 2,000,000, and more preferably 20,000 to 200,000. When Mn1 is 2,000 or more, the heat-resistant storage stability of the toner is improved, and when it is 2,000,000 or less, the low-temperature fixability of the toner is less hindered.

[0127] The weight-average molecular weight (Mw1) of the resin (a1) is preferably larger than the weight-average molecular weight (Mw2) of the resin (a2), more preferably 1.5 times or more larger than Mw2, and even more preferably 2.0 times or more larger than Mw2. Within this range, an excellent balance between ease of toner particle formation and low-temperature fixability is achieved.

[0128] The weight average molecular weight (Mw1) of the resin (a1) is preferably 20,000 to 20,000,000, and more preferably 200,000 to 2,000,000. When Mw1 is 20,000 or more, the heat-resistant storage stability is improved, and when it is 20,000,000 or less, the low-temperature fixability is less hindered.

[0129] The number average molecular weight (Mn2) of the resin (a2) is preferably 1,000 to 1,000,000, and more preferably 10,000 to 100,000. When Mn2 is 1,000 or more, the heat-resistant storage stability of the toner is improved, and when it is 1,000,000 or less, the low-temperature fixability of the toner is less hindered.

[0130] The weight average molecular weight (Mw2) of the resin (a2) is preferably 10,000 to 10,000,000, and more preferably 100,000 to 1,000,000. When Mw2 is 10,000 or more, the heat-resistant storage stability of the toner is improved, and when it is 10,000,000 or less, the low-temperature fixability of the toner is less hindered.

[0131] Among these, it is preferable that Mw1 of resin (a1) is 200,000 to 2,000,000, Mw2 of resin (a2) is 100,000 to 500,000, and Mw1>Mw2.

[0132] In the present invention, Mn and Mw can be measured using gel permeation chromatography (GPC) under the following conditions. Equipment (example): "HLC-8120" [manufactured by Tosoh Corporation] Column (example): "TSK GEL GMH6" [manufactured by Tosoh Corporation] x 2 ·Measurement temperature: 40℃ Sample solution: 0.25% by weight tetrahydrofuran solution (insoluble matter filtered off with a glass filter) ·Solution injection volume: 100μl Detector: Refractive index detector Reference material: 12 standard polystyrene samples (TSK standard POLYSTYRENE) (molecular weights: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000, 355,000, 1,090,000, 2,890,000) [manufactured by Tosoh Corporation]

[0133] The mass ratio of resin (a1) to resin (a2) in the resin fine particles (B) is preferably 5 / 95 to 95 / 5, more preferably 25 / 75 to 75 / 25, and even more preferably 40 / 60 to 60 / 40. When the mass ratio of resin (a1) to resin (a2) is 5 / 95 or more, the toner has excellent heat-resistant storage stability, and when the mass ratio of resin (a1) to resin (a2) is 95 / 5 or less, toner particles in which resin fine particles (B) adhere to the surface of the toner particles are easily formed.

[0134] Methods for producing the resin fine particles (B) include known production methods, such as the following production methods (I) to (V). (I) A method of seed polymerization of constituent monomers of resin (a2) using fine particles of resin (a1) in an aqueous dispersion as seeds. (II) A method of seed polymerization of constituent monomers of resin (a1) using fine particles of resin (a2) in an aqueous dispersion as seeds. (III) A method in which a mixture of resin (a1) and resin (a2) is emulsified in an aqueous medium to obtain an aqueous dispersion of resin fine particles. (IV) A method in which a mixture of resin (a1) and constituent monomers of resin (a2) is emulsified in an aqueous medium, and then the constituent monomers of resin (a2) are polymerized to obtain an aqueous dispersion of resin fine particles. (V) A method in which a mixture of resin (a2) and the constituent monomers of resin (a1) is emulsified in an aqueous medium, and then the constituent monomers of resin (a1) are polymerized to obtain an aqueous dispersion of resin fine particles.

[0135] The fact that the resin microparticles (B) contain the shell resin (a1) and the core resin (a2) as constituent components within the same particle can be confirmed by observing an elemental mapping image of a cross section of the resin microparticles (B) using a known surface elemental analyzer (TOF-SIMSEDX-SEM, etc.), and by observing an electron microscope image of a cross section of the resin microparticles (B) stained with a stain corresponding to the functional groups contained in the resins (a1) and (a2).

[0136] Furthermore, the resin microparticles obtained by this method may be obtained as a mixture containing resin microparticles having only resin (a1) as a constituent resin component and resin microparticles having only resin (a2) as a constituent resin component, in addition to resin microparticles (B) containing resin (a1) and resin (a2) as constituent components within the same particle. In the composite process described below, the mixture may be used as is, or only the resin microparticles (B) may be isolated and used.

[0137] Specific examples of (I) include a method in which the constituent monomers of (a1) are polymerized dropwise to produce an aqueous dispersion of resin microparticles containing (a1), and then this is used as a seed to perform seed polymerization of the constituent monomers of (a2); and a method in which (a1), which has been produced in advance by solution polymerization or the like, is emulsified and dispersed in water, and then this is used as a seed to perform seed polymerization of the constituent monomers of (a2).

[0138] Specific examples of (II) include a method in which the constituent monomers of (a2) are polymerized dropwise to produce an aqueous dispersion of resin microparticles containing (a2), and then this is used as a seed to perform seed polymerization of the constituent monomers of (a1); and a method in which (a2), which has been produced in advance by solution polymerization or the like, is emulsified and dispersed in water, and then this is used as a seed to perform seed polymerization of the constituent monomers of (a1).

[0139] A specific example of (III) is a method in which solutions or melts of (a1) and (a2) previously prepared by solution polymerization or the like are mixed together, and the mixture is then emulsified and dispersed in an aqueous medium.

[0140] Specific examples of (IV) include a method in which (a1), which has been produced in advance by solution polymerization or the like, is mixed with the constituent monomers of (a2), the mixture is emulsified and dispersed in an aqueous medium, and then the constituent monomers of (a2) are polymerized; and a method in which (a1) is produced in the constituent monomers of (a2), the mixture is emulsified and dispersed in an aqueous medium, and then the constituent monomers of (a2) are polymerized.

[0141] Specific examples of (V) include a method in which (a2), which has been produced in advance by solution polymerization or the like, is mixed with the constituent monomers of (a1), the mixture is emulsified and dispersed in an aqueous medium, and then the constituent monomers of (a1) are polymerized; and a method in which (a2) is produced in the constituent monomers of (a1), the mixture is emulsified and dispersed in an aqueous medium, and then the constituent monomers of (a1) are polymerized.

[0142] In the present invention, any of the above production methods (I) to (V) is suitable.

[0143] The resin fine particles (B) are preferably used as an aqueous dispersion. The substance (aqueous medium) used in the aqueous dispersion is not particularly limited as long as it is soluble in water and can be appropriately selected depending on the purpose, and examples thereof include surfactants, buffers, protective colloids, etc. These may be used alone or in combination of two or more.

[0144] <External additives> In addition to oxide fine particles, inorganic fine particles or hydrophobized inorganic fine particles can be used as the external additive. The average particle size of the hydrophobized primary particles is preferably 1 nm to 200 nm, and more preferably 10 nm to 150 nm. It is also preferable to include at least one type of inorganic fine particles whose average particle size of the hydrophobized primary particles is 30 nm or less, and at least one type of inorganic fine particles whose average particle size is 50 nm or more. When the average particle size of the inorganic fine particles is 50 nm or more, they are easily blocked by the blade, improving filming and cleaning. The specific surface area according to the BET method is 20m 2 / g~500m 2 / g is preferred.

[0145] The external additive is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include silica fine particles, hydrophobic silica, fatty acid metal salts (e.g., zinc stearate, aluminum stearate, etc.), metal oxides (e.g., titania, alumina, tin oxide, antimony oxide, etc.), and fluoropolymers.

[0146] The content of the external additive is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5 parts by mass to 6.0 parts by mass, and more preferably 1.0 parts by mass to 4.0 parts by mass, relative to 100 parts by mass of the toner base particles.

[0147] <<Other external additives>> Other additives include titania, titanium oxide, and alumina fine particles. Examples of titania fine particles include P-25 (manufactured by Nippon Aerosil Co., Ltd.), STT-30, STT-65C-S (all manufactured by Titanium Kogyo Co., Ltd.), TAF-140 (manufactured by Fuji Titanium Kogyo Co., Ltd.), MT-150W, MT-500B, MT-600B, and MT-150A (all manufactured by Teika Corporation).

[0148] Examples of hydrophobized titanium oxide microparticles include T-805 (manufactured by Nippon Aerosil Co., Ltd.), STT-30A, STT-65S-S (all manufactured by Titanium Kogyo Co., Ltd.), TAF-500T, TAF-1500T (all manufactured by Fuji Titanium Kogyo Co., Ltd.), MT-100S, MT-100T (all manufactured by Teika Corporation), and IT-S (manufactured by Ishihara Sangyo Co., Ltd.).

[0149] To obtain hydrophobic treated oxide fine particles, hydrophobic treated silica fine particles, hydrophobic treated titania fine particles, or hydrophobic treated alumina fine particles, hydrophilic fine particles can be treated with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, or octyltrimethoxysilane.Also suitable are silicone oil-treated oxide fine particles and silicone oil-treated inorganic fine particles, which are obtained by treating inorganic fine particles with silicone oil, if necessary, by applying heat.

[0150] Examples of silicone oils that can be used include dimethylsilicone oil, methylphenylsilicone oil, chlorophenylsilicone oil, methylhydrogensilicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, phenol-modified silicone oil, carboxyl-modified silicone oil, mercapto-modified silicone oil, acrylic, methacrylic-modified silicone oil, and α-methylstyrene-modified silicone oil. Examples of inorganic fine particles that can be used include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pentagallo, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, silica and titanium dioxide are particularly preferred.

[0151] The content of the external additive is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1% by mass to 5% by mass, more preferably 0.3% by mass to 3% by mass, based on the toner. The average particle size of the primary particles of the inorganic fine particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 200 nm or less, and more preferably 10 nm to 100 nm. If it is smaller than 10 nm, the inorganic fine particles will be buried in the toner and will not effectively perform their function. If it exceeds 200 nm, it will undesirably damage the surface of the photoreceptor unevenly.

[0152] <Other ingredients> The other components are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include inorganic fillers, release agents, charge control agents, flowability improvers, cleaning improvers, and magnetic materials.

[0153] <<Inorganic filler>> The toner base particles of the present invention are produced by adding an inorganic filler to the above-described toner base particles. The inorganic filler is not particularly limited, but one or more types selected from calcium carbonate, kaolin clay, talc, barium sulfate, etc. can be added alone or in combination. These inorganic fillers may be surface-treated with a silane coupling agent, a surfactant, a metal soap, etc., and may be adjusted to a desired particle size distribution by classification, etc.

[0154] In addition to the above, the inorganic filler contained in the toner of the present invention is preferably a layered inorganic mineral, and more preferably a layered inorganic mineral modified with an organic ion. Layered inorganic minerals are inorganic minerals made up of layers several nanometers thick stacked on top of each other, and "modifying with organic ions" means introducing organic ions between the layers.

[0155] Known examples of layered inorganic minerals include smectites (e.g., montmorillonite and saponite), kaolins (e.g., kaolinite), magadiite, and kanemite. Synthetic minerals may also be used as layered inorganic minerals. Modified layered inorganic minerals have high hydrophilicity due to their modified layer structure. Therefore, if layered inorganic minerals are dispersed in an aqueous medium and used in a toner granulated without modification, the layered inorganic minerals migrate into the aqueous medium, preventing the toner from becoming irregularly shaped. However, modification increases hydrophilicity. Such modified layered inorganic minerals are pulverized and irregularly shaped during toner production, resulting in a particularly high concentration on the surface of toner particles. They can be uniformly dispersed throughout the toner base particles, thereby fulfilling charge control functions and contributing to low-temperature fixation. In this case, the content of the modified layered inorganic mineral in the toner material is preferably 0.2% by mass or more and 1.5% by mass or less.

[0156] The modified layered inorganic mineral used in the present invention is preferably one having a smectite-based basic crystal structure modified with an organic cation. Furthermore, metal anions can be introduced by substituting a portion of the divalent metal of the layered inorganic mineral with a trivalent metal. However, since the introduction of metal anions increases hydrophilicity, a layered inorganic compound in which at least a portion of the metal anions are modified with an organic anion is preferred.

[0157] The organic ion modifier for the layered inorganic mineral in which at least a portion of the ions of the layered inorganic mineral have been modified with organic ions includes quaternary alkyl ammonium salts, phosphonium salts, imidazolium salts, etc., with quaternary alkyl ammonium salts being preferred. Examples of the quaternary alkyl ammonium include trimethylstearyl ammonium, dimethylstearylbenzyl ammonium, dimethyloctadecyl ammonium, and oleylbis(2-hydroxyethyl)methyl ammonium.

[0158] The organic ion modifier further includes sulfates, sulfonates, carboxylates, or phosphates having branched, unbranched, or cyclic alkyl (C1 to C44), alkenyl (C1 to C22), alkoxy (C8 to C32), hydroxyalkyl (C2 to C22), ethylene oxide, propylene oxide, etc. Carboxylic acids having an ethylene oxide skeleton are preferred.

[0159] By modifying at least a portion of the layered inorganic mineral with an organic ion, the layered inorganic mineral has a suitable hydrophobicity, the oil phase containing the toner composition and / or the toner composition precursor has a non-Newtonian viscosity, and the toner can be deformed. In this case, the content of the layered inorganic mineral partially modified with an organic ion in the toner material is preferably 0.2% by mass or more and 1.5% by mass or less.

[0160] The layered inorganic mineral partially modified with organic ions can be appropriately selected, and examples thereof include montmorillonite, bentonite, hectorite, attapulgite, sepiolite, and mixtures thereof. Among these, montmorillonite or bentonite containing Al element is preferred because Al element is effective in improving charging ability.

[0161] Commercially available layered inorganic minerals partially modified with organic cations include quaternium-18 bentonites such as Bentone 3, Bentone 38, and Bentone 38V (manufactured by Rheox Corporation), Thixogel VP (manufactured by United Catalyst), Kraton 34, Kraton 40, and Kraton XL (manufactured by Southern Clay Corporation); stearalkonium bentonites such as Bentone 27 (manufactured by Rheox Corporation), Thixogel LG (manufactured by United Catalyst), Kraton AF, and Kraton APA (manufactured by Southern Clay Corporation); and quaternium-18 / benzalkonium bentonites such as Kraton HT and Kraton PS (manufactured by Southern Clay Corporation). Clayton AF and Kraton APA are particularly preferred. Furthermore, a particularly preferred layered inorganic mineral partially modified with organic anions is DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.) modified with an organic anion represented by the following general formula (1): An example of the following general formula (1) is Hitenol 330T (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). R1(OR2)nOSO3M ··· General formula (1) [In general formula (1), R1 represents an alkyl group having 13 carbon atoms, R2 represents an alkylene group having 2 to 6 carbon atoms, n represents an integer of 2 to 10, and M represents a monovalent metal element.]

[0162] <<Release Agent>> The release agent is not particularly limited and can be appropriately selected from known ones. Examples of waxes and wax release agents include natural waxes such as plant waxes such as carnauba wax, cotton wax, wood wax, and rice wax; animal waxes such as beeswax and lanolin; mineral waxes such as ozokerite and cerusine; and petroleum waxes such as paraffin, microcrystalline, and petrolatum.

[0163] In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax, polyethylene, and polypropylene; synthetic waxes such as esters, ketones, and ethers; and the like can also be used. Furthermore, fatty acid amide compounds such as 12-hydroxystearic acid amide, stearic acid amide, phthalimide anhydride, and chlorinated hydrocarbons; low-molecular-weight crystalline polymer resins, such as homopolymers or copolymers of polyacrylates as poly-n-stearyl methacrylate and poly-n-lauryl methacrylate (for example, copolymers of n-stearyl acrylate and ethyl methacrylate); and crystalline polymers having long alkyl groups in their side chains may also be used. Among these, hydrocarbon waxes such as paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax, and polypropylene wax are preferred.

[0164] The melting point of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 60°C or higher and lower than 95°C. The release agent is more preferably a hydrocarbon wax having a melting point of 60° C. or more and less than 95° C. Such a release agent can effectively act as a release agent between the fixing roller and the toner interface, and therefore can improve high-temperature offset resistance without applying a release agent such as oil to the fixing roller.

[0165] In particular, hydrocarbon waxes are preferred because they have almost no compatibility with the amorphous polyester resin and can function independently of each other, and therefore do not impair the softening effect of the crystalline polyester resin as a binder resin or the offset property of the release agent. When the melting point of the release agent is 60° C. or higher, the release agent does not melt at low temperatures, improving the heat-resistant storage stability of the toner. When the melting point of the release agent is lower than 95° C., the release agent melts sufficiently by heating during fixing, resulting in sufficient offset properties.

[0166] The content of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 2 to 10 parts by mass, and more preferably 3 to 8 parts by mass, relative to 100 parts by mass of the toner. When the content is 2 parts by mass or more, high-temperature offset resistance during fixing and low-temperature fixability are improved, and when it is 10 parts by mass or less, heat-resistant storage stability is not deteriorated and image fogging is not likely to occur. When the content is within the above more preferred range, it is advantageous in terms of improving image quality and fixing stability.

[0167] <<Charge control agent>> The charge control agent is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdic acid chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substance or compounds, tungsten simple substance or compounds, fluorine-based activators, metal salicylate salts, and metal salts of salicylic acid derivatives. Specific examples include the nigrosine dye Bontron 03, the quaternary ammonium salt Bontron P-51, the metal-containing azo dye Bontron S-34, the oxynaphthoic acid metal complex E-82, the salicylic acid metal complex E-84, and the phenol condensate E-89 (all manufactured by Orient Chemical Industry Co., Ltd.), the quaternary ammonium salt molybdenum complexes TP-302 and TP-415 (both manufactured by Hodogaya Chemical Co., Ltd.), LRA-901, the boron complex LR-147 (manufactured by Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone, azo pigments, and other polymeric compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.

[0168] The content of the charge control agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, relative to 100 parts by weight of the toner. If the content exceeds 10 parts by weight, the toner becomes too electrostatically charged, reducing the effect of the main charge control agent and increasing the electrostatic attraction force with the developing roller, which may result in a decrease in the fluidity of the developer and a decrease in image density. These charge control agents can be melt-kneaded with a master batch and a resin and then dissolved and dispersed, or they can be added when directly dissolved and dispersed in an organic solvent, or they can be fixed on the surface of the toner after toner particle production.

[0169] The acid value of the toner is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5 mgKOH / g to 40 mgKOH / g from the viewpoint of controlling low-temperature fixability (lower limit fixation temperature), hot offset temperature, etc. If the acid value is less than 0.5 mgKOH / g, the effect of improving dispersion stability by the base during production may not be obtained, or when the prepolymer is used, the elongation reaction and / or crosslinking reaction may be more likely to proceed, resulting in reduced production stability. If the acid value exceeds 40 mgKOH / g, when the prepolymer is used, the elongation reaction and / or crosslinking reaction may be insufficient, resulting in reduced high-temperature offset resistance.

[0170] <<Flow improver>> The flowability improver is not particularly limited and can be appropriately selected depending on the purpose as long as it can perform a surface treatment to increase hydrophobicity and prevent deterioration of flow properties and charging properties even under high humidity, and examples thereof include silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils, etc. It is particularly preferable that the silica and titanium oxide are surface-treated with such a flowability improver and used as hydrophobic silica and hydrophobic titanium oxide.

[0171] <<Cleaning improver>> The cleaning property improver is not particularly limited as long as it is added to the toner to remove the developer remaining on the photoreceptor or primary transfer medium after transfer, and can be appropriately selected depending on the purpose, and examples thereof include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles, etc. The polymer fine particles preferably have a relatively narrow particle size distribution, and are suitably those with a volume average particle size of 0.01 μm to 1 μm.

[0172] <<Magnetic materials>> The magnetic material is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include iron powder, magnetite, ferrite, etc. Among these, white materials are preferred in terms of color tone.

[0173] The acid value of the toner is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5 mgKOH / g to 40 mgKOH / g from the viewpoint of controlling low-temperature fixability (lower limit fixation temperature), hot offset temperature, etc. If the acid value is less than 0.5 mgKOH / g, the effect of improving dispersion stability by the base during production may not be obtained, or when the prepolymer is used, the elongation reaction and / or crosslinking reaction may be more likely to proceed, resulting in reduced production stability. If the acid value exceeds 40 mgKOH / g, when the prepolymer is used, the elongation reaction and / or crosslinking reaction may be insufficient, resulting in reduced high-temperature offset resistance.

[0174] <Toner properties> <<Glass transition temperature>> The glass transition temperature (Tg) of the toner is not particularly limited and can be appropriately selected depending on the purpose, but the glass transition temperature (Tg1st) calculated at the first temperature rise in DSC measurement is preferably 45°C or higher and lower than 65°C, and more preferably 50°C or higher and 60°C or lower. This allows low-temperature fixability, heat-resistant storage stability, and high durability to be obtained. If the Tg1st is lower than 45°C, blocking may occur in the developing machine or filming may occur on the photoreceptor, and if it is 65°C or higher, the low-temperature fixability may be reduced. Furthermore, the glass transition temperature (Tg2nd) calculated at the second temperature rise in DSC measurement of the toner is preferably 20° C. or higher and lower than 40° C. If the Tg2nd is lower than 20° C., blocking may occur in the developing machine or filming may occur on the photoreceptor, and if it is 40° C. or higher, low-temperature fixability may decrease.

[0175] <<Volume average particle size>> The volume average particle diameter of the toner is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 μm to 7 μm. The ratio of the volume average particle diameter to the number average particle diameter is preferably 1.2 or less. It is also preferable that the toner contains 1% to 10% by number of components having a volume average particle diameter of 2 μm or less.

[0176] <<Measuring method for acid value and hydroxyl value>> The hydroxyl value can be measured using a method in accordance with JIS K0070-1966. Specifically, 0.5 g of sample is weighed into a 100 mL volumetric flask and 5 mL of acetylation reagent is added. Next, the flask is heated in a hot bath at 100 ± 5°C for 1 to 2 hours, after which it is removed from the bath and allowed to cool. Water is then added and the flask is shaken to decompose the acetic anhydride. Next, to completely decompose the acetic anhydride, the flask is again heated in the hot bath for at least 10 minutes, allowed to cool, and then the walls of the flask are thoroughly washed with an organic solvent. Furthermore, the hydroxyl value was measured at 23 °C using a potentiometric automatic titrator DL-53 Titrator (Mettler-Toledo) and an electrode DG113-SC (Mettler-Toledo), and the results were analyzed using the analytical software LabX Light Version 1.00.000. A mixed solvent of 120 mL of toluene and 30 mL of ethanol was used to calibrate the apparatus. At this time, the measurement conditions are as follows:

[0177] [Measurement conditions] Stir Speed[%] 25 Time[s] 15 EQP titration Titrant / Sensor Titrant CH3ONa Concentration [mol / L] 0.1 Sensor DG115 Unit of measurement mV Predispensing to volume Volume [mL] 1.0 Wait time[s] 0 Titrant addition Dynamic dE(set)[mV] 8.0 dV(min)[mL] 0.03 dV(max)[mL] 0.5 Measure mode Equilibrium controlled dE[mV] 0.5 dt[s] 1.0 t(min)[s] 2.0 t(max)[s] 20.0 Recognition Threshold 100.0 Steepest jump only No Range No Tendency None Termination at maximum volume [mL] 10.0 at potential No at slope No after number EQPs Yes n=1 comb.termination conditions No Evaluation Procedure Standard Potential 1 No. Potential2 No Stop for reevaluation No

[0178] The acid value can be measured using a method in accordance with JIS K0070-1992. Specifically, 0.5 g of sample (0.3 g of ethyl acetate-soluble fraction) was first added to 120 mL of toluene and stirred at 23 °C for approximately 10 hours to dissolve the sample. Next, 30 mL of ethanol was added to obtain the sample solution. If the sample does not dissolve, solvents such as dioxane or tetrahydrofuran were used. Furthermore, the acid value was measured at 23 °C using a potentiometric automatic titrator DL-53 Titrator (Mettler-Toledo) and a DG113-SC electrode (Mettler-Toledo), and the results were analyzed using the analysis software LabX Light Version 1.00.000. A mixed solvent of 120 mL of toluene and 30 mL of ethanol was used to calibrate the instrument. In this case, the measurement conditions are the same as those for the hydroxyl value described above.

[0179] The acid value can be measured as described above, but specifically, it is titrated with a pre-standardized 0.1 N potassium hydroxide / alcohol solution, and the acid value is calculated from the titer using the formula: acid value [mgKOH / g] = titer [mL] × N × 56.1 [mg / mL] / sample mass [g] (where N is the factor of the 0.1 N potassium hydroxide / alcohol solution).

[0180] The acid value of the toner is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5 mgKOH / g to 40 mgKOH / g from the viewpoint of controlling low-temperature fixability (lower limit fixation temperature), hot offset temperature, etc. If the acid value is less than 0.5 mgKOH / g, the effect of improving dispersion stability by the base during production may not be obtained, or when the prepolymer is used, the elongation reaction and / or crosslinking reaction may be more likely to proceed, resulting in reduced production stability. If the acid value exceeds 40 mgKOH / g, when the prepolymer is used, the elongation reaction and / or crosslinking reaction may be insufficient, resulting in reduced high-temperature offset resistance.

[0181] <<Method for measuring melting point and glass transition temperature (Tg)>> The melting point and glass transition temperature (Tg) in the present invention can be measured, for example, using a DSC system (differential scanning calorimeter) ("DSC-60", manufactured by Shimadzu Corporation). Specifically, the melting point and glass transition temperature of the sample can be measured by the following procedure. First, approximately 5.0 mg of the target sample is placed in an aluminum sample container, which is then placed on a holder unit and set in an electric furnace. Next, the sample is heated from 0°C to 150°C at a heating rate of 10°C / min under a nitrogen atmosphere. The sample is then cooled from 150°C to 0°C at a cooling rate of 10°C / min, and further heated to 150°C at a heating rate of 10°C / min. A DSC curve is then measured using a differential scanning calorimeter (DSC-60, Shimadzu Corporation). From the DSC curves obtained, the DSC curve during the first heating run can be selected using the "Endothermic Shoulder Temperature" analysis program in the DSC-60 system, and the glass transition temperature of the target sample during the first heating run can be determined. Also, the DSC curve during the second heating run can be selected using the "Endothermic Shoulder Temperature" program, and the glass transition temperature of the target sample during the second heating run can be determined. Furthermore, the DSC curve obtained during the first heating run can be selected using the "Endothermic Peak Temperature" analysis program in the DSC-60 system, and the melting point of the target sample during the first heating run can be determined. Also, the "Endothermic Peak Temperature" can be used to select the DSC curve during the second heating run, and the melting point of the target sample during the second heating run can be determined.

[0182] In the present invention, when a toner is used as a target sample, the glass transition temperature during the first temperature rise is designated as Tg1st, and the glass transition temperature during the second temperature rise is designated as Tg2nd. In the present invention, the melting point, Tg, of each constituent component during the second temperature rise is taken as the melting point, Tg, of each sample.

[0183] <<Method for measuring particle size distribution>> The volume average particle diameter (D4), number average particle diameter (Dn), and the ratio (D4 / Dn) of the toner can be measured using, for example, a Coulter Counter TA-II or a Coulter Multisizer II (both manufactured by Coulter). In the present invention, a Coulter Multisizer II was used. The measurement method is described below. First, 0.1 mL to 5 mL of a surfactant (preferably polyoxyethylene alkyl ether (nonionic surfactant)) is added as a dispersant to 100 mL to 150 mL of electrolytic solution. Here, the electrolytic solution is a 1% by mass NaCl aqueous solution prepared using primary sodium chloride, such as ISOTON-II (manufactured by Coulter). 2 mg to 20 mg of a measurement sample is then added. The electrolytic solution with the suspended sample is subjected to a dispersion treatment using an ultrasonic disperser for approximately 1 to 3 minutes, and the volume and number of toner particles or toner particles are measured using a 100 μm aperture in the measuring device, and the volume distribution and number distribution are calculated. The volume average particle size (D4) and number average particle size (Dn) of the toner can be determined from the obtained distribution. Thirteen channels are used: 2.00 μm or more and less than 2.52 μm; 2.52 μm or more and less than 3.17 μm; 3.17 μm or more and less than 4.00 μm; 4.00 μm or more and less than 5.04 μm; 5.04 μm or more and less than 6.35 μm; 6.35 μm or more and less than 8.00 μm; 8.00 μm or more and less than 10.08 μm; 10.08 μm or more and less than 12.70 μm; 12.70 μm or more and less than 16.00 μm; 16.00 μm or more and less than 20.20 μm; 20.20 μm or more and less than 25.40 μm; 25.40 μm or more and less than 32.00 μm; and 32.00 μm or more and less than 40.30 μm, and the target particles are 2.00 μm or more and less than 40.30 μm in size.

[0184] <Toner manufacturing method> The method for producing the toner is not particularly limited and can be appropriately selected depending on the purpose. However, it is preferable that the toner is granulated by dispersing an oil phase containing at least the amorphous polyester resin, the crystalline polyester resin, the release agent, and the colorant in an aqueous medium. An example of a method for producing such a toner is a known dissolution suspension method. As another example of the toner manufacturing method, a method of forming toner base particles while producing a material (hereinafter sometimes referred to as an "adhesive substrate") produced by an elongation reaction and / or crosslinking reaction between the active hydrogen group-containing compound and a polymer having a site capable of reacting with the active hydrogen group-containing compound is described below. In such a method, steps such as preparation of an aqueous medium, preparation of an oil phase containing toner materials, emulsification or dispersion of the toner materials, and removal of the organic solvent are carried out.

[0185] -Preparation of aqueous medium (aqueous phase)- The aqueous medium can be prepared, for example, by dispersing resin particles in the aqueous medium. The amount of resin particles added to the aqueous medium is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 0.5% by mass to 10% by mass. The resin particles are not particularly limited and can be selected appropriately depending on the purpose, and examples include surfactants, poorly water-soluble inorganic compound dispersants, and polymeric protective colloids. These may be used alone or in combination of two or more types. Among these, surfactants are preferred.

[0186] The aqueous medium is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include water, a solvent miscible with water, a mixture thereof, etc. These may be used alone or in combination of two or more. Of these, water is preferred. The water-miscible solvent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include alcohol, dimethylformamide, tetrahydrofuran, cellosolves, lower ketones, etc. The alcohol is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include methanol, isopropanol, ethylene glycol, etc. The lower ketone is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include acetone, methyl ethyl ketone, etc.

[0187] -Preparation of oil phase- The oil phase containing the toner materials can be prepared by dissolving or dispersing the toner materials, including the active hydrogen group-containing compound, the polymer having a site capable of reacting with the active hydrogen group-containing compound, the crystalline polyester resin, the amorphous polyester resin, the release agent, the hybrid resin, and the colorant, in an organic solvent.

[0188] The organic solvent is not particularly limited and can be appropriately selected depending on the purpose, but an organic solvent having a boiling point of less than 150° C. is preferred in terms of ease of removal. The organic solvent having a boiling point of less than 150° C. is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, etc. These may be used alone or in combination of two or more. Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride, etc. are preferred, and ethyl acetate is more preferred.

[0189] -Emulsification or dispersion- The toner materials can be emulsified or dispersed by dispersing an oil phase containing the toner materials in the aqueous medium. When the toner materials are emulsified or dispersed, an active hydrogen group-containing compound and a polymer having a site capable of reacting with the active hydrogen group-containing compound undergo an elongation reaction and / or crosslinking reaction, thereby producing an adhesive substrate.

[0190] The adhesive substrate may be produced, for example, by emulsifying or dispersing an oil phase containing a polymer reactive with active hydrogen groups, such as a polyester prepolymer having an isocyanate group, in an aqueous medium together with a compound containing active hydrogen groups, such as an amine, and then subjecting the two to an elongation reaction and / or crosslinking reaction in the aqueous medium; by emulsifying or dispersing an oil phase containing toner materials in an aqueous medium to which a compound containing active hydrogen groups has been added in advance, and then subjecting the two to an elongation reaction and / or crosslinking reaction in the aqueous medium; or by emulsifying or dispersing an oil phase containing toner materials in an aqueous medium, and then adding a compound containing active hydrogen groups, and subjecting the two to an elongation reaction and / or crosslinking reaction from the particle interface in the aqueous medium. Note that when the two are subject to an elongation reaction and / or crosslinking reaction from the particle interface, the urea-modified polyester resin is preferentially formed on the surface of the resulting toner, and a concentration gradient of the urea-modified polyester resin can be formed in the toner.

[0191] The reaction conditions (reaction time, reaction temperature) for producing the adhesive base material are not particularly limited and can be appropriately selected depending on the combination of the active hydrogen group-containing compound and the polymer having a site capable of reacting with the active hydrogen group-containing compound. The reaction time is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 minutes to 40 hours, more preferably 2 hours to 24 hours. The reaction temperature is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0°C to 150°C, more preferably 40°C to 98°C.

[0192] The method for stably forming a dispersion liquid containing a polymer having a site capable of reacting with an active hydrogen group-containing compound, such as a polyester prepolymer having an isocyanate group, in the aqueous medium is not particularly limited and can be appropriately selected depending on the purpose. For example, there is a method in which an oil phase prepared by dissolving or dispersing toner materials in a solvent is added to an aqueous medium phase, and the mixture is dispersed by shear force.

[0193] The dispersing machine for the dispersion is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a low-speed shear dispersing machine, a high-speed shear dispersing machine, a friction dispersing machine, a high-pressure jet dispersing machine, and an ultrasonic dispersing machine. Among these, a high-speed shear type disperser is preferred because it can control the particle size of the dispersion (oil droplets) to 2 μm to 20 μm. When the high-speed shear disperser is used, conditions such as the rotation speed, dispersing time, and dispersing temperature can be appropriately selected depending on the purpose. The rotation speed is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1,000 rpm to 30,000 rpm, and more preferably 5,000 rpm to 20,000 rpm. The dispersion time is not particularly limited and can be appropriately selected depending on the purpose, but in the case of a batch method, it is preferably 0.1 to 5 minutes. The dispersion temperature is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0° C. to 150° C. under pressure, and more preferably 40° C. to 98° C. Generally, the higher the dispersion temperature, the easier the dispersion.

[0194] The amount of the aqueous medium used when emulsifying or dispersing the toner materials is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50 parts by mass to 2,000 parts by mass, and more preferably 100 parts by mass to 1,000 parts by mass, relative to 100 parts by mass of the toner materials. If the amount of the aqueous medium used is less than 50 parts by mass, the dispersion state of the toner materials may be poor, and toner base particles having the desired particle size may not be obtained, whereas if the amount of the aqueous medium used is more than 2,000 parts by mass, the production cost may become high.

[0195] When the oil phase containing the toner materials is emulsified or dispersed, it is preferable to use a dispersant from the viewpoint of stabilizing the dispersion of oil droplets and the like, forming a desired shape, and sharpening the particle size distribution. The dispersant is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include surfactants, poorly water-soluble inorganic compound dispersants, and polymeric protective colloids. These may be used alone or in combination of two or more. Among these, surfactants are preferred.

[0196] The surfactant is not particularly limited and can be appropriately selected depending on the purpose. For example, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, etc. can be used. The anionic surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include alkylbenzene sulfonates, α-olefin sulfonates, and phosphate esters. Among these, those having a fluoroalkyl group are preferred.

[0197] A catalyst can be used in the elongation reaction and / or crosslinking reaction when producing the adhesive substrate. The catalyst is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include dibutyltin laurate and dioctyltin laurate.

[0198] -Removal of organic solvents- The method for removing the organic solvent from the dispersion liquid such as the emulsified slurry is not particularly limited and can be appropriately selected depending on the purpose. Examples of the method include a method in which the temperature of the entire reaction system is gradually increased to evaporate the organic solvent in the oil droplets, and a method in which the dispersion liquid is sprayed into a dry atmosphere to remove the organic solvent in the oil droplets. When the organic solvent is removed, toner base particles are formed. The toner base particles can be washed, dried, and further classified. The classification can be performed by removing fine particles in a liquid using a cyclone, decanter, centrifugal separation, or the like, or the classification operation can be performed after drying.

[0199] The obtained toner base particles may be mixed with particles of the external additive, the charge control agent, etc. At this time, by applying a mechanical impact force, it is possible to prevent the particles of the external additive, etc. from being detached from the surface of the toner base particles. The method for applying the mechanical impact force is not particularly limited and can be appropriately selected depending on the purpose. Examples include a method of applying an impact force to the mixture using blades rotating at high speed, and a method of introducing the mixture into a high-speed airflow and accelerating it to cause particles to collide with each other or with an appropriate collision plate. The apparatus used in the above method is not particularly limited and can be appropriately selected depending on the purpose. Examples include an Ang Mill (manufactured by Hosokawa Micron Corporation), an apparatus obtained by modifying an I-type Mill (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) to reduce the grinding air pressure, a Hybridization System (manufactured by Nara Machinery Works), a Cryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), and an automatic mortar.

[0200] <Developer> The developer of the present invention contains at least the toner, and optionally contains other components such as a carrier that are appropriately selected. Therefore, it is possible to stably form high-quality images with excellent transferability, charging property, etc. The developer may be a one-component developer or a two-component developer, but when used in a high-speed printer or the like that corresponds to the recent improvement in information processing speed, a two-component developer is preferred because of its improved lifespan. When the developer is used as a one-component developer, even if the toner is balanced, there is little fluctuation in the particle size of the toner, there is little toner filming on the developing roller, and there is little toner fusion to components such as blades that thin the toner layer, and good and stable developability and images can be obtained even with long-term stirring in the developing device. When the developer is used as a two-component developer, fluctuations in the particle size of the toner are small even when the toner is balanced over a long period of time, and good and stable developability and images can be obtained even when the developer is stirred for a long period of time in a developing device. When the toner is used in a two-component developer, it may be mixed with the carrier. The content of the carrier in the two-component developer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 90% by mass to 98% by mass, more preferably 93% by mass to 97% by mass.

[0201] <Career> The carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably one having a core material and a resin layer covering the core material.

[0202] -Core material- The material for the core is not particularly limited and can be appropriately selected depending on the purpose. Examples include manganese-strontium-based materials and manganese-magnesium-based materials with a density of 50 emu / g to 90 emu / g. To ensure image density, it is preferable to use high-magnetization materials such as iron powder with a density of 100 emu / g or more, or magnetite with a density of 75 emu / g to 120 emu / g. It is also preferable to use low-magnetization materials such as copper-zinc-based materials with a density of 30 emu / g to 80 emu / g, as this can reduce the impact of the developer in a standing state on the photoreceptor and is advantageous for achieving high image quality. These may be used alone or in combination of two or more.

[0203] The volume average particle size of the core material is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 μm to 150 μm, more preferably 40 μm to 100 μm. If the volume average particle diameter is less than 10 μm, the amount of fine powder in the carrier increases, which may reduce the magnetization per particle and cause the carrier to scatter. If the volume average particle diameter exceeds 150 μm, the specific surface area decreases, which may cause the toner to scatter, and in full color toners that have many solid areas, the reproduction of the solid areas may be particularly poor.

[0204] -Resin layer- The material for the resin layer is not particularly limited and can be appropriately selected from known resins depending on the purpose. Examples thereof include amino resins, polyvinyl resins, polystyrene resins, polyhalogenated olefins, polyester resins, polycarbonate resins, polyethylene, polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, fluoro terpolymers such as copolymers of vinylidene fluoride and an acrylic monomer, copolymers of vinylidene fluoride and vinyl fluoride, copolymers of tetrafluoroethylene, vinylidene fluoride and a monomer not having a fluoro group, and silicone resins. These may be used alone or in combination of two or more.

[0205] The amino resin is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. The polyvinyl resin is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include acrylic resin, polymethyl methacrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, and polyvinyl butyral. The polystyrene resin is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include polystyrene and styrene-acrylic copolymers. The polyhalogenated olefin is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include polyvinyl chloride. The polyester resin is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include polyethylene terephthalate and polybutylene terephthalate.

[0206] The resin layer may contain conductive powder, etc., as needed. The conductive powder is not particularly limited and can be appropriately selected depending on the purpose. Examples include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. The conductive powder preferably has an average particle size of 1 μm or less. If the average particle size exceeds 1 μm, it may be difficult to control the electrical resistance.

[0207] The resin layer can be formed by dissolving a silicone resin or the like in a solvent to prepare a coating solution, applying the coating solution to the surface of the core material using a known coating method, drying the coating solution, and then baking the coating solution. The coating method is not particularly limited and can be appropriately selected depending on the purpose. For example, a dip coating method, a spray method, a brush coating method, etc. can be used. The solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the solvent include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, and butyl cellosolve acetate. The baking may be performed by an external heating method or an internal heating method, and examples thereof include a method using a fixed electric furnace, a fluidized electric furnace, a rotary electric furnace, a burner furnace, or the like, and a method using microwaves.

[0208] The content of the resin layer in the carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01% by mass to 5.0% by mass. If the content is less than 0.01% by mass, a uniform resin layer may not be formed on the surface of the core material, and if it exceeds 5.0% by mass, the resin layer may be too thick, causing fusion of carrier particles, resulting in a decrease in carrier uniformity.

[0209] (Toner storage unit) The toner storage unit according to the present invention refers to a unit having a function of storing toner and storing the toner. Examples of the toner storage unit include a toner storage container, a developing unit, and a process cartridge. The toner container refers to a container that stores toner. The developing device is a device that contains toner and has means for developing.

[0210] <Process cartridge> The process cartridge, which is an embodiment of the toner storage unit of the present invention, is formed so as to be detachably mountable to various image forming apparatuses, and has at least a photosensitive member that carries an electrostatic latent image, and a developing means that develops the electrostatic latent image carried on the photosensitive member with the developer of the present invention to form a toner image. The process cartridge may further have other means as necessary. The developing means includes at least a developer container that contains the developer of the present invention and a developer carrier that carries and transports the developer contained in the developer container. The developing means may further include a regulating member or the like for regulating the thickness of the developer carried.

[0211] By mounting the toner storage unit on an image forming apparatus and forming an image, it is possible to take advantage of the characteristics of the toner, which has excellent offset resistance, charging stability, stress resistance, and background scumming properties, and can provide high-definition, high-quality images over a long period of time, thereby forming high-quality, high-definition images with long-term image stability.

[0212] (Developer storage unit) The developer containing unit according to the present invention refers to a unit that contains a developer having toner and carrier.

[0213] (Image forming apparatus and image forming method) The image forming apparatus of the present invention has at least an electrostatic latent image carrier, an electrostatic latent image forming means, and a developing means, and may further have other means as required. The image forming method according to the present invention includes at least an electrostatic latent image forming step and a development step, and may further include other steps as required. The image forming method can be suitably performed by the image forming apparatus, the electrostatic latent image forming step can be suitably performed by the electrostatic latent image forming means, the developing step can be suitably performed by the developing means, and the other steps can be suitably performed by the other means.

[0214] More preferably, the image forming apparatus of the present invention includes an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, developing means provided with toner for developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image, transfer means for transferring the toner image formed on the electrostatic latent image carrier to the surface of a recording medium, and fixing means for fixing the toner image transferred to the surface of the recording medium. Furthermore, the image forming method of the present invention more preferably includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, a developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image, a transfer step of transferring the toner image formed on the electrostatic latent image carrier to the surface of a recording medium, and a fixing step of fixing the toner image transferred to the surface of the recording medium.

[0215] The toner is used in the developing means. Preferably, the toner image is formed by using a developer containing the toner and, if necessary, other components such as a carrier.

[0216] <Electrostatic latent image carrier> The material, structure, and size of the electrostatic latent image carrier (hereinafter also referred to as "photoreceptor") are not particularly limited and can be appropriately selected from known materials. Examples of the material include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors such as polysilane and phthalopolymethine.

[0217] <Electrostatic latent image forming means> The electrostatic latent image forming means is not particularly limited as long as it is a means for forming an electrostatic latent image on the electrostatic latent image carrier, and can be appropriately selected depending on the purpose. For example, it may be a means having at least a charging member that charges the surface of the electrostatic latent image carrier, and an exposure member that exposes the surface of the electrostatic latent image carrier to light in an imagewise manner.

[0218] <Developing method> The developing unit is not particularly limited as long as it is a developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image and is equipped with toner, and can be appropriately selected depending on the purpose.

[0219] <Cleaning Method> The image forming apparatus of the present invention preferably has a cleaning means. As described above, the toner of the present invention has excellent cleaning properties. Therefore, by applying the toner to the image forming apparatus having a cleaning unit, the cleaning properties are improved in the following respects. By improving the spacer effect of the toner base particles, the fluidity of the toner is maintained even under stress, improving cleaning performance. When the amount A (mass %) of the external additive (silica) released satisfies the above-mentioned formula (3), the external additive is sufficiently released from the toner on the photoreceptor, and a deposition layer (dam layer) of the external additive is formed in the cleaning blade nip, thereby achieving high cleaning performance.

[0220] The cleaning means is not particularly limited as long as it can remove the toner remaining on the photosensitive member, and can be appropriately selected depending on the purpose. Examples of the cleaning means include a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.

[0221] <Other methods> Examples of the other means include a transfer means, a fixing means, a discharging means, a recycling means, and a control means.

[0222] Next, one embodiment of the method for forming an image using the image forming apparatus of the present invention will be described with reference to FIG.

[0223] An example of an image forming apparatus of the present invention is shown in Figure 1. The color image forming apparatus 100A shown in Figure 1 includes a photosensitive drum 10 (hereinafter sometimes referred to as "photosensitive member 10") as the electrostatic latent image carrier, a charging roller 20 as the charging means, an exposure device 30 as the exposure means, a developing unit 40 as the developing means, an intermediate transfer body 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a discharging lamp 70 as the discharging means.

[0224] The intermediate transfer body 50 is an endless belt that is designed to move in the direction of the arrow by three rollers 51 arranged inside and tensioning it. Some of the three rollers 51 also function as transfer bias rollers that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer body 50. A cleaning device 90 having a cleaning blade is arranged near the intermediate transfer body 50. Also, a transfer roller 80 serving as the transfer means that can apply a transfer bias for transferring (secondary transfer) the developed image (toner image) to transfer paper 95 as a recording medium is arranged near the intermediate transfer body 50, facing the intermediate transfer body 50. A corona charger 58 for applying an electric charge to the toner image on the intermediate transfer body 50 is arranged around the intermediate transfer body 50, between the contact point between the photoreceptor 10 and the intermediate transfer body 50 and the contact point between the intermediate transfer body 50 and the transfer paper 95, in the direction of rotation of the intermediate transfer body 50.

[0225] A black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C are arranged directly opposite each other around the photosensitive drum 10. The black developing unit 45K includes a developer container 42K, a developer supply roller 43K, and a developing roller 44K. The yellow developing unit 45Y includes a developer container 42Y, a developer supply roller 43Y, and a developing roller 44Y. The magenta developing unit 45M includes a developer container 42M, a developer supply roller 43M, and a developing roller 44M. The cyan developing unit 45C includes a developer container 42C, a developer supply roller 43C, and a developing roller 44C. The developing belt 41 is an endless belt that is rotatably stretched around multiple belt rollers, and a portion of the belt 41 contacts the electrostatic latent image carrier 10.

[0226] In the color image forming apparatus 100A shown in FIG. 1, for example, a charging roller 20 uniformly charges the photosensitive drum 10. An exposure device 30 exposes the photosensitive drum 10 to light in an imagewise manner to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 10 is developed by supplying toner from a developing device 40 to form a toner image. The toner image is transferred (primary transfer) onto an intermediate transfer body 50 by a voltage applied from a roller 51, and is further transferred (secondary transfer) onto a transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. Any remaining toner on the photosensitive drum 10 is removed by a cleaning device 60, and the charge on the photosensitive drum 10 is temporarily removed by a discharging lamp 70.

[0227] Another example of the image forming apparatus of the present invention is shown in Figure 2. Image forming apparatus 100B has the same configuration as image forming apparatus 100A shown in Figure 1, except that it does not have developing belt 41 and has black developing unit 45K, yellow developing unit 45Y, magenta developing unit 45M, and cyan developing unit 45C arranged directly opposite each other around photosensitive drum 10.

[0228] Another example of the image forming apparatus of the present invention is shown in Fig. 3. The image forming apparatus 100C shown in Fig. 3 includes a copying machine main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400. An endless belt-like intermediate transfer body 50 is provided in the center of the copying machine main body 150. The intermediate transfer body 50 is stretched around support rollers 14, 15, and 16 and is rotatable clockwise in FIG. 3. An intermediate transfer body cleaning device 17 for removing residual toner from the intermediate transfer body 50 is located near the support roller 15. A tandem developing device 120 is located around the intermediate transfer body 50, stretched around the support rollers 14 and 15, along the transport direction of the intermediate transfer body 50. The tandem developing device 120 includes four image forming means 120 for yellow, cyan, magenta, and black, which are arranged side by side and face each other. An exposure device 21, which is the exposure member, is located near the tandem developing device 120. A secondary transfer device 22 is located on the side of the intermediate transfer body 50 opposite the side where the tandem developing device 120 is located. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched over a pair of rollers 23, and the transfer paper 95 and the intermediate transfer body 50 transported on the secondary transfer belt 24 can come into contact with each other. A fixing device 25, which is the fixing means, is disposed near the secondary transfer device 22. The fixing device 25 includes a fixing belt 26, which is an endless belt, and a pressure roller 27 disposed so as to be pressed against the fixing belt 26. In the tandem image forming apparatus, a sheet inverting device 28 is disposed near the secondary transfer device 22 and the fixing device 25 to invert the transfer paper 95 in order to form images on both sides of the transfer paper 95.

[0229] Next, we will explain how to form a full-color image (color copy) using the tandem developing device 120. That is, first, an original is set on the platen 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and the original is set on the contact glass 32 of the scanner 300, and then the automatic document feeder 400 is closed.

[0230] When the start switch is pressed, the scanner 300 is driven after the document is transported and moved onto the contact glass 32 when the document is set on the automatic document feeder 400, or immediately when the document is set on the contact glass 32. Then, the first travelling body 33 and the second travelling body 34 travel. At this time, light from a light source is irradiated by the first travelling body 33, and the light reflected from the document surface is reflected by a mirror on the second travelling body 34 and received by the reading sensor 36 through the imaging lens 35, and the color document (color image) is read, and image information of black, yellow, magenta, and cyan is generated.

[0231] Then, the image information for black, yellow, magenta, and cyan is transmitted to the image forming means 120 (image forming means for black, image forming means for yellow, image forming means for magenta, and image forming means for cyan) in the tandem developing device 120, respectively. Then, in each image forming means, a toner image for black, yellow, magenta, and cyan is formed. That is, as shown in FIG. 4, each image forming means 120 (image forming means for black, image forming means for yellow, image forming means for magenta, and image forming means for cyan) in the tandem developing device 120 comprises an electrostatic latent image carrier 10 (electrostatic latent image carrier 10K for black, electrostatic latent image carrier 10Y for yellow, electrostatic latent image carrier 10M for magenta, and electrostatic latent image carrier 10C for cyan), a charging device 20 which is the charging means for uniformly charging the electrostatic latent image carrier 10, and a charging device 21 which charges the electrostatic latent image carrier 10 based on each color image information. The image forming device 120 includes an exposure device that exposes the electrostatic latent image carrier to light (L in FIG. 4) in the form of an image corresponding to each color image to form an electrostatic latent image corresponding to each color image on the electrostatic latent image carrier, a developing device 61 that is the developing means that develops the electrostatic latent image with each color toner (black toner, yellow toner, magenta toner, and cyan toner) to form a toner image with each color toner, a transfer charger 62 that transfers the toner image onto the intermediate transfer body 50, a cleaning device 63, and a static eliminator 64. Each image forming means 120 is capable of forming a single color image (black image, yellow image, magenta image, and cyan image) based on image information for the corresponding color. The black image formed on the black electrostatic latent image carrier 10K, the yellow image formed on the yellow electrostatic latent image carrier 10Y, the magenta image formed on the magenta electrostatic latent image carrier 10M, and the cyan image formed on the cyan electrostatic latent image carrier 10C are sequentially transferred (primary transfer) onto the intermediate transfer body 50 which is rotated by support rollers 14, 15, and 16. Then, the black image, the yellow image, the magenta image, and the cyan image formed on the cyan electrostatic latent image carrier 10C are superimposed on the intermediate transfer body 50 to form a composite color image (color transfer image).

[0232] Meanwhile, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in a paper bank 143. The sheets are separated one by one by a separation roller 145 and sent out to a paper feed path 146, then transported by a transport roller 147 and guided to a paper feed path 148 inside the copier main body 150, where they are stopped by striking against a registration roller 49. Alternatively, the paper feed roller 142 is rotated to feed out sheets (recording paper) from a manual feed tray 54, and the sheets are separated one by one by a separation roller 52 and placed in a manual feed path 53, where they are also stopped by striking against a registration roller 49. Note that the registration roller 49 is generally grounded when used, but may be used with a bias applied to remove paper dust from the sheets. Then, the registration rollers 49 are rotated in time with the composite color image (color transfer image) formed on the intermediate transfer body 50, and a sheet (recording paper) is sent between the intermediate transfer body 50 and the secondary transfer device 22, and the composite color image (color transfer image) is transferred (secondary transfer) onto the sheet (recording paper) by the secondary transfer device 22. In this way, a color image is transferred and formed on the sheet (recording paper). After the image transfer, any remaining toner on the intermediate transfer body 50 is cleaned by the intermediate transfer body cleaning device 17.

[0233] The sheet (recording paper) onto which the color image has been transferred is transported by secondary transfer device 22 and sent to fixing device 25, where the composite color image (color transfer image) is fixed onto the sheet (recording paper) by heat and pressure. Thereafter, the sheet (recording paper) is switched by switching claw 55, discharged by discharge rollers 56, and stacked on paper output tray 57. Alternatively, the sheet can be switched by switching claw 55, inverted by sheet inverting device 28, and guided to the transfer position again, where an image is also recorded on the back side, and then discharged by discharge rollers 56 and stacked on paper output tray 57.

[0234] 5 shows an example of a process cartridge according to the present invention. The process cartridge 110 includes the photosensitive drum 10, a corona charger 58, a developing device 40, a transfer roller 80, and a cleaning device 90. [Example]

[0235] Examples of the present invention will be described below, but the present invention is not limited to the following examples. In the following description, "parts" and "%" represent "parts by mass" and "%", respectively.

[0236] - Toner manufacturing - (Production Example 1) <Synthesis of crystalline polyester resin 1> Sebacic acid and 1,6-hexanediol were charged into a reaction vessel equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple. The molar ratio of hydroxyl groups to carboxyl groups was 0.9, and 500 ppm of titanium tetraisopropoxide was added relative to the total monomer content. The mixture was then reacted at 180°C for 10 hours, then heated to 200°C and reacted for 3 hours. The mixture was then reacted for another 2 hours under a reduced pressure of 8.3 kPa to obtain [Crystalline Polyester Resin 1]. [Crystalline Polyester Resin 1] had a melting point of 67°C and a weight-average molecular weight of 25,000.

[0237] (Production Example 2) <Synthesis of amorphous polyester resin 1> A 5 L four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was charged with 1,427.5 g of bisphenol A propylene oxide side 2 mole adduct, 20.2 g of trimethylolpropane, 512.7 g of terephthalic acid, and 119.9 g of adipic acid, and the mixture was reacted at 230°C under normal pressure for 10 hours, and then at a reduced pressure of 10 to 15 mmHg for 5 hours. After that, 41.0 g of trimellitic anhydride was charged into the reaction vessel, and the mixture was reacted at 180°C and normal pressure for 3 hours to obtain [Amorphous Polyester Resin 1]. [Amorphous polyester resin 1] had a weight average molecular weight of 10,000, a number average molecular weight of 2,900, a Tg of 57.5°C, and an acid value of 20 mgKOH / g.

[0238] (Production Example 3) (Synthesis of Prepolymer 1) Into a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide adduct (2 moles), 81 parts of bisphenol A propylene oxide adduct (2 moles), 283 parts of terephthalic acid, 22 parts of trimellitic anhydride, and 2 parts of dibutyltin oxide were added. The reaction was carried out at 230 °C for 8 hours under normal pressure, and then at a reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, a Tg of 55 °C, an acid value of 0.5 mg KOH / g, and a hydroxyl value of 51 mg KOH / g. Next, into a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, 410 parts of [Intermediate Polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate were added and reacted at 100 °C for 5 hours to obtain [Prepolymer 1]. The free isocyanate content of [Prepolymer 1] was 1.53%.

[0239] (Production Example 4) (Synthesis of Ketimine Compound 1) Into a reaction vessel equipped with a stirrer bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 °C for 5 hours to obtain [Ketimine Compound 1]. The amine value of [Ketimine Compound 1] was 418 mg KOH / g.

[0240] (Production Example 5) (Preparation of Masterbatch 1) 1,200 parts of water, 540 parts of carbon black (Printex 35 manufactured by Degussa) [DBP oil absorption = 42 mL / 100 mg, pH = 9.5], and 1,200 parts of amorphous polyester resin 1 were added and mixed with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). The mixture was kneaded at 150 °C for 30 minutes using two rolls, then rolled and cooled and pulverized with a pelletizer to obtain [Masterbatch 1].

[0241] (Production Example 6) (Preparation of WAX Dispersion 1) A container equipped with a stirring rod and a thermometer was charged with 50 parts of paraffin wax (HNP-9, hydrocarbon wax, melting point 75°C, SP value 8.8, manufactured by Nippon Seiro Co., Ltd.) as a release agent 1 and 450 parts of ethyl acetate. The mixture was heated to 80°C with stirring and maintained at 80°C for 5 hours. After that, the mixture was cooled to 30°C over 1 hour. A bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.) was used to disperse the mixture at a feed rate of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 80% volumetric filling with 0.5 mm diameter zirconia beads, with 3 passes to obtain [WAX Dispersion 1].

[0242] (Production Example 7) <Preparation of Crystalline Polyester Resin Dispersion 1> 100 parts of crystalline polyester resin 1 and 200 parts of ethyl acetate were placed in a 2 L metal container, heated to 75°C and dissolved, and then rapidly cooled in an ice-water bath at a rate of 27°C / min. 500 mL of glass beads (3 mm diameter) were added, and the mixture was pulverized for 10 hours using a batch sand mill (manufactured by Kampe Hapio Co., Ltd.) to obtain [Crystalline polyester resin dispersion 1].

[0243] (Production Example 8) <Production of aqueous dispersion (W0-1) of resin fine particles (A)> A reaction vessel equipped with a stirrer, a heating / cooling device, and a thermometer was charged with 3710 parts of water and 200 parts of polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ester ammonium (Aqualon KH-1025, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and the mixture was homogenized by stirring at 200 rpm. The homogenized mixture was heated to raise the system temperature to 75°C, after which 90 parts of a 10% aqueous ammonium persulfate solution was added, followed by the dropwise addition of a mixture of 450 parts of styrene, 250 parts of butyl acrylate, and 300 parts of methacrylic acid over 4 hours. After the dropwise addition, the mixture was aged at 75°C for 4 hours to obtain an aqueous dispersion (W0-1) containing a resin (a1-1), which is a polymer in which the monomer and polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ester ammonium are copolymerized. The volume average particle size of the fine particles in the aqueous dispersion (W0-1) was measured by dynamic light scattering (light scattering electrophoresis apparatus: ELS-8000 manufactured by Otsuka Electronics Co., Ltd.) and was found to be 15 nm. A portion of the aqueous dispersion (W0-1) was dried to isolate resin (a1-1), which had a glass transition temperature (TgA) of 75°C and an acid value of 195 mgKOH / g.

[0244] (Production Example 9) <Production of Aqueous Dispersion (W-1) of Resin Fine Particles (B)> Next, 667 parts of the aqueous dispersion (W0-1) of resin microparticles (A) and 248 parts of water were charged into a reaction vessel equipped with a stirrer, a heating / cooling device, and a thermometer, and 0.267 parts of tertiary butyl hydroperoxide (Perbutyl H, manufactured by NOF Corporation) was added. The system was then heated to raise the temperature inside the system to 70°C, after which 43.3 parts of styrene, 23.3 parts of butyl acrylate, and 18.0 parts of a 1% aqueous ascorbic acid solution were added dropwise over 2 hours. After the dropwise addition, the mixture was aged at 70°C for 4 hours to obtain an aqueous dispersion (W-1) of resin microparticles (B) containing resin (a2-1), a polymer copolymerized from the monomers described above, and resin (a1-1) as constituent components within the same particle, using resin microparticles (A) in the aqueous dispersion (W0-1) as seeds. The volume average particle size of the resin fine particles (B) was measured in the same manner as above and was found to be 17.3 nm. The aqueous dispersion (W-1) of resin fine particles (B) was neutralized with 10% aqueous ammonia to a pH of 9.0, and the precipitate was centrifuged and dried to isolate resin (a2-1). The glass transition temperature (Tg) of the resin was 61°C.

[0245] It was confirmed as follows that the aqueous dispersion (W-1) of resin fine particles (B) contained resin fine particles (B) containing resin (a1-1) and resin (a2-1) as constituent components in the same particle. Specifically, 2 parts of gelatin (Cook Gelatin, manufactured by Morinaga Milk Industry Co., Ltd.) was dissolved in 15 parts of water heated to 95-100°C, and the solution was air-cooled to 40°C. An aqueous dispersion (W-1) of resin microparticles (A-1) was mixed with the gelatin solution in a 1:1 mass ratio, stirred well, and then cooled to 10°C for 1 hour to produce a hardened gel. This gel was sliced ​​into 80 nm thick sections using an ultramicrotome (Ultramicrotome UC7, FC7, manufactured by Leica Microsystems) while maintaining the temperature at -80°C. The sections were then vapor-stained with a 2% aqueous solution of ruthenium tetroxide for 5 minutes, and then observed under a transmission electron microscope (Hitachi Technologies, H-7100) for confirmation.

[0246] (Production Example 10) <Production of Resin Particle Dispersion 1> A reaction vessel equipped with a stirrer and thermometer was charged with 683 parts of water, 11 parts of sodium salt of methacrylic acid ethylene oxide adduct sulfate (trade name: Eleminol RS-30, manufactured by Sanyo Chemical Industries, Ltd.), 138 parts of styrene, 138 parts of methacrylic acid, and 1 part of ammonium persulfate. The mixture was stirred at 400 rpm for 15 minutes, yielding a white emulsion. The mixture was heated to a system temperature of 75°C and allowed to react for 5 hours. 30 parts of a 1% aqueous ammonium persulfate solution was then added, and the mixture was aged at 75°C for 5 hours to obtain an aqueous dispersion of a vinyl resin (a copolymer of styrene, methacrylic acid, and sodium salt of methacrylic acid ethylene oxide adduct sulfate) [Resin Particle Dispersion 1]. Measurement of [Resin Particle Dispersion 1] using an LA-920 (manufactured by HORIBA) revealed a volume average particle size of 0.14 μm. A portion of [Particle Dispersion 1] was dried to isolate the resin.

[0247] The products of Production Examples 1 to 10 are shown in Table 1 below. [Table 1]

[0248] Example 1 <Toner Preparation> -Preparation of oil phase 1- 500 parts of [WAX dispersion 1], 200 parts of [Prepolymer 1], 500 parts of [Crystalline polyester resin dispersion 1], 750 parts of [Amorphous polyester resin 1], 100 parts of [Masterbatch 1], 8 parts of [Inorganic filler 1 (trimethylstearylammonium modified montmorillonite)], and 2 parts of [Ketimine compound 1] as a curing agent were placed in a container and mixed at 5,000 rpm for 60 minutes using a TK Homomixer (manufactured by Primix Corporation) to obtain [Oil phase 1].

[0249] - Preparation of aqueous phase 1 - Into a beaker were charged 990 parts of ion-exchanged water, a mixed liquid of 33 parts of aqueous dispersion (W-1) and 60 parts of aqueous dispersion (W0-1), 6 parts of sodium carboxymethyl cellulose, 37 parts of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.), and 90 parts of ethyl acetate, to obtain [Aqueous Phase 1].

[0250] -Emulsification and desolvation- To the vessel containing the oil phase 1, 1,200 parts of water phase 1 was added, and the mixture was mixed for 20 minutes at 13,000 rpm using a TK homomixer to obtain emulsified slurry 1. [Emulsified slurry 1] was placed in a container equipped with a stirrer and a thermometer, and the solvent was removed at 30°C for 8 hours, followed by aging at 45°C for 4 hours to obtain [Dispersed slurry 1].

[0251] -Washing, heating treatment, drying- After 100 parts of [Dispersion Slurry 1] was filtered under reduced pressure, (1) 100 parts of ion-exchanged water was added to the filter cake, and the mixture was mixed with a TK homomixer (at 12,000 rpm for 10 minutes) and then filtered. (2): 100 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of (1), and the mixture was mixed in a TK homomixer (at 12,000 rpm for 30 minutes), followed by filtration under reduced pressure. (3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), and the mixture was mixed in a TK homomixer (at 12,000 rpm for 10 minutes) and then filtered. (4): 300 parts of ion-exchanged water is added to the filter cake of (3), mixed with a TK homomixer (at 12,000 rpm for 10 minutes), and then filtered. The above steps (1) to (4) were performed twice. (5): 100 parts of ion-exchanged water was added to the filter cake of (4), and the mixture was mixed at 12,000 rpm for 10 minutes using a TK homomixer, and then heated at 50°C for 4 hours and filtered to obtain [Filter Cake 1]. (6): [Filter cake 1] was dried in a circulating air dryer at 45° C. for 48 hours, and sieved through a 75 μm mesh to obtain [toner base particles 1].

[0252] Using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), 100 parts of toner base particles, 2.8 parts of hydrophobic silica particles with an average particle size of 50 nm, and 1.0 part of hydrophobic titanium oxide with an average particle size of 20 nm were mixed with [Toner 1] at a peripheral speed of 40 m for a mixing time of 3 minutes to obtain [Toner 1]. [Toner 1] had a volume average particle size of 5.5 μm, a ratio of volume average particle size to number average particle size of 1.1, and 4% by number of components with a volume average particle size of 2 μm or less.

[0253] Example 2 In Example 1, [Toner 2] was obtained by changing the amount of [Crystalline Polyester Resin Dispersion 1] to 550 parts, the amount of [Amorphous Polyester Resin 1] to 700 parts, the amount of [Inorganic Filler 1] to 10 parts, and the stirring time during mixing using the Henschel mixer to 16 minutes.

[0254] Example 3 In Example 1, [Toner 3] was obtained by changing the amount of [Crystalline Polyester Resin Dispersion 1] to 520 parts, the amount of [Amorphous Polyester Resin 1] to 730 parts, the amount of [Inorganic Filler 1] to 9 parts, and the stirring time during mixing using the Henschel mixer to 9 minutes.

[0255] Example 4 In Example 1, [Toner 4] was obtained by changing the amount of [Crystalline Polyester Resin Dispersion 1] to 560 parts, the amount of [Amorphous Polyester Resin 1] to 690 parts, the amount of [Inorganic Filler 1] to 11 parts, and the stirring time during mixing using the Henschel mixer to 9 minutes.

[0256] Example 5 In Example 1, [Toner 5] was obtained by changing the amount of [Crystalline Polyester Resin Dispersion 1] to 530 parts, the amount of [Amorphous Polyester Resin 1] to 720 parts, the amount of [Inorganic Filler 1] to 9 parts, and the stirring time during mixing using the Henschel mixer to 9 minutes.

[0257] Example 6 In Example 1, the amount of [Inorganic Filler 1] was changed to 10 parts, and the stirring time during mixing using the Henschel mixer was changed to 6 minutes, thereby obtaining [Toner 6].

[0258] Example 7 In Example 1, [Toner 7] was obtained by changing the amount of [Crystalline Polyester Resin Dispersion 1] to 520 parts, the amount of [Amorphous Polyester Resin 1] to 730 parts, the amount of [Inorganic Filler 1] to 9 parts, the heat treatment time to 6 hours, and the stirring time during mixing using a Henschel mixer to 6 minutes.

[0259] Example 8 In Example 1, [Toner 8] was obtained by changing the amount of [Crystalline Polyester Resin Dispersion 1] to 525 parts, the amount of [Amorphous Polyester Resin 1] to 725 parts, the amount of [Inorganic Filler 1] to 10 parts, and the stirring time during mixing using the Henschel mixer to 6 minutes.

[0260] (Comparative Example 1) [Toner 9] was obtained in the same manner as in Example 6, except that in Example 6, a mixture of 33 parts of aqueous dispersion (W-1) and 60 parts of aqueous dispersion (W0-1) was replaced with 83 parts of [Resin Microparticle Dispersion 1].

[0261] (Comparative Example 2) In Example 1, [Toner 10] was obtained by changing the amount of [Crystalline Polyester Resin Dispersion 1] to 300 parts, the amount of [Amorphous Polyester Resin 1] to 950 parts, the heat treatment time to 6 hours, and the stirring time during mixing using a Henschel mixer to 6 minutes.

[0262] (Comparative Example 3) In Example 1, [Toner 11] was obtained by changing the amount of [Crystalline Polyester Resin Dispersion 1] to 560 parts, the amount of [Amorphous Polyester Resin 1] to 690 parts, the amount of [Inorganic Filler 1] to 12 parts, and the stirring time during mixing using the Henschel mixer to 13 minutes.

[0263] Comparative Example 4 In Example 1, [Toner 12] was obtained by changing the amount of [Crystalline Polyester Resin Dispersion 1] to 570 parts, the amount of [Amorphous Polyester Resin 1] to 680 parts, the amount of [Inorganic Filler 1] to 12 parts, the heat treatment time to 6 hours, and the stirring time during mixing using a Henschel mixer to 20 minutes.

[0264] (Comparative Example 5) In Comparative Example 1, [Toner 13] was obtained by changing the amount of [Crystalline Polyester Resin Dispersion 1] to 0 parts, the amount of [Amorphous Polyester Resin 1] to 1250 parts, the amount of [Inorganic Filler 1] to 12 parts, and the stirring time during mixing using the Henschel mixer to 4 minutes.

[0265] (evaluation) The above-obtained [Toner 1] to [Toner 13] were evaluated according to the following evaluation items and evaluation methods. The evaluation results are shown in Table 2.

[0266] <Increase in surface area of ​​average toner surface> The SPM (Scanning Probe Microscope) method used in this invention is a method for measuring the surface shape of a sample by scanning with a probe with a tip diameter of approximately 10 nm, sensing the atomic force acting between the probe and atoms on the sample surface. It has extremely high resolution and can measure the uneven shape in the Z direction relative to the scanning direction (X direction) of the probe. In this invention, the surface of a toner particle was scanned with the SPM probe to measure the shape of the toner particle surface.

[0267] When measuring a toner surface using an SPM, the tip is scanned along the surface of a toner particle in an area approximately 1 μm square. The vertical displacement at this time is used as information in the Z-axis direction. This measurement is performed 3 to 10 times, changing the measurement location and the toner particle sample, to understand the overall state of the particle. It is practical to first evaluate the surface condition using an SPM image, confirm the surface to which additives are attached, and then perform a quantitative roughness analysis. Furthermore, the roughness (amplitude) defined in this invention is the difference between the concave and convex portions in the Z direction of the small-cycle roughness and large-cycle roughness of the profile obtained by SPM measurement.

[0268] The conditions for the SPM measurement device are as follows: measuring equipment; Atomic force microscope system Bruker AXS Dimension Icon Measurement mode; PeakForceQNM OMCL-AC240TS Material: Si Resonance frequency 70[Hz] Spring constant 2 [N / m] cantilever

[0269] Sdr can be calculated by analyzing the 3D data obtained by surface measurement using an atomic force microscope using the analysis software NanoScope Analysis (Bruker). Specifically, first, the tilt of the 3D data is corrected using the PlaneFit function, which uses a linear equation. Next, the PlaneFit function, which uses a quadratic equation, removes the toner particle shape information. Then, the Roughness function is used to calculate Sdr. The analysis region for calculating Sdr is adjusted as appropriate so that it does not include areas other than toner particles.

[0270] <Average circularity> The average circularity of the toner was measured using a wet flow particle size and shape analyzer FPIA-2100 and analysis software FPIA-2100 Data Processing Program for FPIA version 00-10 (Sysmex Corporation). Specifically, 0.1-0.5 mL of a 10% aqueous solution of alkylbenzene sulfonate salt Neogen SC-A (Dai-ichi Kogyo Seiyaku Co., Ltd.) and 0.1-0.5 g of toner were added to a 100 mL glass beaker, stirred with a microspatula, and 80 mL of ion-exchanged water was added. The mixture was then dispersed for 1 minute using an ultrasonic disperser UH-50 (SMT Corporation) at 20 kHz and 50 W / 10 cm³, followed by a total of 5 minutes of dispersion to obtain a measurement sample. The average circularity of particles with an equivalent circle diameter of 0.60 μm or greater but less than 159.21 μm was measured using a measurement sample with a particle concentration of 4000-8000 particles / 10 cm³.

[0271] <Amount of silica released by ultrasonic vibration method> In the present invention, the amount of liberated external additive is defined as a value obtained according to the measurement method described below. The amount A (mass %) of silica liberated from the toner was measured by the following procedure. 10 g of polyoxyalkylene alkyl ether (Noigen ET-165, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 300 mL of pure water were placed in a 500 mL beaker and dispersed by ultrasonication for 1 hour to obtain dispersion A. Dispersion A was then transferred to a 2 L measuring flask, made up to the volume, and dissolved by ultrasonication for 1 hour to obtain dispersion B containing 0.5% polyoxyalkylene alkyl ether. 50 mL of dispersion B was poured into a 110 mL screw tube, and 3.75 g of the sample toner was added. The screw tube was stirred for 30 to 90 minutes until dispersion B was absorbed into the tube, yielding liquid C. The rotation speed was kept as low as possible to prevent bubbles from forming. After the toner was sufficiently dispersed, an ultrasonic homogenizer (VCX750, manufactured by SONICS & Materials, Inc., 20 kHz, 750 watts) was used, with the vibration head inserted 2.5 cm into liquid C. Ultrasonic vibrations were applied for 1 minute at 40% output energy to produce liquid D.

[0272] Liquid D was placed in a 50 mL centrifuge tube and centrifuged at 2,000 rpm for 2 minutes to obtain a supernatant and a precipitate. The precipitate was poured into a separatory funnel while being washed with 60 mL of pure water, and the washing water was removed by suction filtration. The filtered precipitate was placed back into the mini-cup, and 60 mL of pure water was poured into the mini-cup. The mixture was then stirred five times with the handle of a spatula. The washing water was removed again by suction filtration, and the toner remaining on the filter paper was collected and dried in a 40°C thermostatic chamber for 8 hours. After drying, 3 g of the resulting toner was molded into pellets with a diameter of 3 mm and a thickness of 2 mm using an automatic pressure molding machine (T-BRB-32, manufactured by Maekawa Corporation; load 6.0 t, pressure time 60 seconds). This was used as the post-treatment sample toner. The initial sample toner that had not been subjected to the above treatment was similarly molded into pellets having a diameter of 3 mm and a thickness of 2 mm to prepare a pre-treatment sample toner.

[0273] The silica content of the pelletized sample toner was measured by quantitative analysis using a fluorescent X-ray analyzer (ZSX-100e, manufactured by Rigaku Corporation). The calibration curve used was prepared in advance using sample toners with silica contents of 0.1, 1, and 1.8 parts per 100 parts of toner.

[0274] The amount of liberated silica A (mass %) was calculated by the following formula. Silica release amount A (mass%) = [silica content (parts) of sample toner before treatment - silica content (parts) of sample toner after treatment] / sample toner before treatment (parts) × 100

[0275] In addition, the content B (mass%) of the external additive of the present invention was calculated by quantitative analysis using a fluorescent X-ray analyzer (ZSX-100e, manufactured by Rigaku Corporation) and measuring the amount of silica in a pellet-molded sample of the above-mentioned untreated sample toner.

[0276] Next, the "heat-resistant storage stability," "durability," and "cleaning ability" were evaluated for each of the developers containing the toners of Examples 1 to 8 and Comparative Examples 1 to 5. The results are shown in Tables 1 and 2 below.

[0277] <Heat-resistant storage stability> A 50 mL glass container was filled with 10 g of toner, tapped thoroughly until the apparent density of the resulting toner powder remained constant, and then the container was capped. After being left in a thermostatic chamber at 50°C for 24 hours, the container was cooled to 24°C, and the penetration was measured using a penetration test (JIS K2235-1991). The "heat-resistant storage stability" was evaluated based on the following evaluation criteria. A larger penetration indicates better heat-resistant storage stability. Penetrations of less than 15 mm are likely to cause problems in use. -Evaluation criteria- ◎: Penetration is 25mm or more ○: Penetration is 20mm or more and less than 25mm △: Penetration is 15mm or more and less than 20mm ×: Penetration less than 15 mm

[0278] <Durability> Each developer containing toner was filled into a digital full-color multifunction printer (device name: Imagio MP C5000, manufactured by Ricoh Co., Ltd.) in a low-temperature, low-humidity environment (10°C, 15% RH) and a high-temperature, high-humidity environment (27°C, 80% RH), and then 500,000 images with an image area ratio of 5% were copied. Next, after printing a full solid image, the image was visually observed and evaluated for "durability" based on the following evaluation criteria. -Evaluation criteria- ◎: No streaky color loss occurs ○: A slight streak of color loss occurs (less than 5% of the solid image area) △: Thin streaky color loss occurs (5% to less than 10% of the solid image area) ×: A large amount of thin streaks of color loss (10% or more of the solid image area) or a large amount of thick streaks of color loss occurs

[0279] <Cleaning ability> After filling each developer containing toner into a digital full-color multifunction printer (device name: Imagio MP C5000, manufactured by Ricoh Co., Ltd.), A4 size, toner adhesion amount: 1.0 mg / cm 2 A solid image of 1000 sheets was copied. The initial state was defined as the time when 100,000 sheets were copied, and the time when 100,000 sheets were copied was defined as the time elapsed. Next, in each case, the toner remaining on the photoreceptor that had passed through the cleaning process was transferred to white paper using Scotch tape (manufactured by Sumitomo 3M Limited), and then the reflection density was measured using a reflection densitometer (device name: RD514, manufactured by Gretag Macbeth) and the "cleanability" was evaluated based on the following evaluation criteria. -Evaluation criteria- ◎: The difference in reflection density between the initial and aged state is less than 0.01 ○: The difference in reflection density between the initial state and the aged state is 0.01 or more and less than 0.025 △: The difference in reflection density between the initial state and the aged state is 0.025 or more and less than 0.05 ×: The difference in reflection density between the initial state and the aged state is 0.05 or more.

[0280] [Table 2]

[0281] As described above, in Examples 1 to 8, excellent results in heat storage stability, durability, and cleaning property were obtained. Also, in the toner, by controlling the shape, resin fine particles on the surface of the toner base particles, and toner surface roughness, the heat storage stability, durability, and cleaning property were improved.

[0282] On the other hand, in Comparative Example 1, since there are no resin fine particles on the surface of the toner base particles and the spacer effect decreases, the heat storage stability and durability deteriorate. In Comparative Example 2, since the roundness is high, it is spherical, and the unevenness on the surface of the toner base particles is small, the external additive is easily peeled off from the base surface, and the durability and cleaning property deteriorate. In Comparative Example 3, since the roundness is small, the coating efficiency of the external additive decreases, and the heat storage stability, durability, and cleaning property deteriorate. In Comparative Example 4, since the roundness is small and the unevenness on the surface of the toner is large, the coating efficiency of the external additive decreases, and the heat storage stability, durability, and cleaning property deteriorate. In Comparative Example 5, since the roundness is small, the unevenness on the surface of the toner is large, there are no resin fine particles on the surface of the toner base particles, and the amount of free external additive is also large, the coating efficiency of the external additive and the spacer effect of the toner base particles decrease, and the heat storage stability, durability, and cleaning property deteriorate.

[0283] The present invention relates to the toner described in <1> below, and includes <2> to <9> below as embodiments. <1>A toner containing toner base particles containing a binder resin and a colorant, and an external additive, having a roundness of 0.974 or more and 0.985 or less, wherein a plurality of resin fine particles buried in the toner base surface are present, When the increase ratio of the surface in the average plane detected by the SPM analyzer is represented as Sdr [%], the toner is characterized in that the Sdr [%] satisfies the following formula (1). 5 < Sdr < 50 ··· Formula (1) <2>The toner according to <1> above, wherein the Sdr [%] satisfies the following formula (2). 10 < Sdr < 40 ··· Formula (2) <3>The toner according to <1> or <2> above, wherein the amount A [% by mass] of the externally added agent released from the toner satisfies the following formula (3). 0.3 < A < 2.0 ··· Formula (3) <4>The toner according to any one of <1> to <3> above, wherein the content B [% by mass] of the externally added agent of the toner satisfies the following formula (4). 0.5 ≤ B ≤ 6.0 ··· Formula (4) <5>A toner container unit characterized by containing the toner according to any one of <1> to <4> above. <6>A developer characterized by having the toner according to any one of <1> to <4> above and a carrier. <7>A developer container unit characterized by containing the developer according to <6> above. <8>An electrostatic latent image carrier, An electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, Developing means for developing the electrostatic latent image to form a visible image using the toner according to any one of <1> to <4> above or the developer according to <6> above, Transfer means for transferring the visible image onto a recording medium, Fixing means for fixing the transferred image on the recording medium, An image forming apparatus characterized by having these. <9>An electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, A developing step of developing the electrostatic latent image to form a visible image using the toner according to any one of <1> to <4> above or the developer according to <6> above, A transfer step of transferring the visible image onto a recording medium, A fixing step of fixing the transferred image on the recording medium, An image forming method characterized by having these.

Explanation of Signs

[0284] 10 Electrostatic latent image carrier, photosensitive drum 10K black electrostatic latent image carrier 10Y Yellow electrostatic latent image carrier 10M Magenta electrostatic latent image carrier 10C Cyan electrostatic latent image carrier 14 Support roller 15 Support roller 16 Support roller 17 Cleaning device 18 Image forming means 20 Charging roller, charging device 21 Exposure equipment 22 Secondary transfer device 23 Laura 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet inverting device 30 Exposure equipment 32 Contact Glass 33 First running body 34 Second running body 35 Imaging lens 36 reading sensor 40 Developer 41 Developing belt 42K Developer compartment 42Y Developer storage unit 42M Developer compartment 42C Developer storage unit 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K developing roller 44Y developing roller 44M developing roller 44C Developing roller 45K Black Development Unit 45Y Yellow Development Unit 45M Magenta Development Unit 45C Cyan Development Unit 49 Registration roller 50 Intermediate transfer body 51 Laura 52 Separation roller 53 Manual feed path 54 Manual feed tray 55 Switching claw 56 Discharge roller 57 Output tray 58 Corona charger 60 Cleaning Device 61 Developing device 62 Transfer charger 63 Cleaning device 64 Static elimination lamp 70 Static elimination lamp 80 Transfer roller 90 Cleaning Device 95 Transfer paper 100A, 100B, 100C image forming device 110 Process cartridge 120 Tandem developing unit 130 manuscript table 142 Paper feed roller 143 Paper Bank 144 Paper cassette 145 Separation roller 146 Paper feed path 147 Conveyor roller 148 Paper feed path 150 Copying device body 200 Paper feed table 300 scanner 400 Automatic Document Feeder (ADF) L exposure [Prior art documents] [Patent documents]

[0285] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-284881 [Patent Document 2] Japanese Patent Application Publication No. 2019-099809 [Patent Document 3] Japanese Patent Application Publication No. 2019-143128 [Patent Document 4] Japanese Patent Application Laid-Open No. 2007-233030

Claims

1. A toner comprising toner base particles containing a binder resin and a colorant, and an external additive, The circularity is 0.974 or more and 0.985 or less, The surface of the toner base particles is covered with resin particles. the resin fine particles have a volume average primary particle diameter of 5 nm or more and 100 nm or less, and have a core-shell structure consisting of a shell portion and a core portion; the shell portion and the core portion of the resin microparticles contain a styrene-acrylic resin; a plurality of the resin fine particles are present embedded in the surface of the toner base particle, A toner characterized in that, when the surface increase rate in an average surface detected by an SPM analyzer is expressed as Sdr [%], the Sdr [%] satisfies the following formula (1): 5<Sdr<50... Formula (1)

2. The toner according to claim 1 , wherein the Sdr [%] satisfies the following formula (2): 10<Sdr<40... Formula (2)

3. The toner according to claim 1 or 2, wherein an amount A [mass %] of the external additive liberated from the toner satisfies the following formula (3): 0.3<A<2.0... Formula (3)

4. The toner according to claim 1 , wherein a content B [mass %] of the external additive in the toner satisfies the following formula (4): 0.5≦B≦6.0... Formula (4)

5. 5. The toner according to claim 1, wherein the toner has a volume average particle size of 3 [mu]m or more and 7 [mu]m or less, and a ratio of the volume average particle size to the number average particle size is 1.2 or less.

6. A toner storage unit containing the toner according to any one of claims 1 to 5.

7. A developer comprising the toner according to claim 1 and a carrier.

8. A developer containing unit containing the developer according to claim 7.

9. an electrostatic latent image carrier; an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier; a developing unit that develops the electrostatic latent image to form a visible image using the toner according to any one of claims 1 to 5 or the developer according to claim 7; a transfer means for transferring the visible image onto a recording medium; a fixing means for fixing the transferred image on the recording medium; An image forming apparatus comprising:

10. an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier; a developing step of developing the electrostatic latent image to form a visible image using the toner according to any one of claims 1 to 5 or the developer according to claim 7; a transfer step of transferring the visible image onto a recording medium; a fixing step of fixing the transferred image on the recording medium; An image forming method comprising the steps of:

Images