Toner

Abstract

To provide toner which is excellent in low-temperature fixability of a halftone image (scratch density reduction rate) and contamination resistance of a charging member under low-temperature low-humidity environment, still excellent in contamination resistance of the charging member for an image formation device employing one component development system and under low-temperature low-humidity environment, even if used for very frequently outputting a double-sided image, and further capable of outputting highly uniform halftone image.SOLUTION: The toner includes toner particles containing binder resin, and organic / inorganic composite fine particles. The binder resin contains polyester A of 50 mass% or more. The polyester A contains unit Uiso derived from isophthalic acid of 60 mol% or more with all unit derived from acid component as reference. The organic / inorganic composite fine particle includes a plurality of protrusions derived from the inorganic fine particle on the surface of the resin particle. The inorganic fine particle contains silica fine particles and the resin particle contains an ester group.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a toner used in an electrophotographic image forming apparatus.

Background Art

[0002] In electrophotographic image forming apparatuses, higher speed, smaller size, and longer life are required. Therefore, in order to enable these, further improvement in various performances of toner is required. For example, in order to contribute to the higher speed and smaller size of electrophotographic apparatuses, a toner having good low-temperature fixability (a property of being able to be fixed to paper with a small amount of heat) is required. This is because the process speed of fixing the toner to paper can be increased, which also contributes to the miniaturization of the fixing member. In addition, in order to contribute to the miniaturization, a one-component contact development system that does not contain carrier particles for charging the toner is preferably used from the viewpoint of reducing the number of parts. However, in this development system, since the toner and the photoreceptor continue to be in contact with each other for a long period of time, a toner with high durability that is less likely to cause toner deterioration and member contamination is required. Furthermore, recently, from the viewpoint of effective utilization of paper resources, in offices, printers are being used with double-sided printing set as the normal mode. When double-sided printing is set as the normal mode, since image formation is performed twice to obtain the same number of printed materials, the contact opportunity between the toner and other members increases, and the toner is used severely in terms of toner deterioration and member contamination. Therefore, the demand for a longer life of the image forming apparatus is increasing more and more. For these reasons, the demand for improving the low-temperature fixability and durability of toner has been increasing compared to the past. However, a toner with good low-temperature fixability tends to have poor durability of the toner, and there have been cases where the compatibility of these has been a problem. For example, in Patent Document 1, as a means for improving the low-temperature fixability of toner, it has been proposed that by using a toner containing a polyester resin having a unit derived from isophthalic acid as a binder resin, the reverse transfer property from a solid image to other images can be improved. On the one hand, for example, as in Patent Document 2, by using a toner containing organic-inorganic composite fine particles, when the toner is used for a long time, it is proposed to suppress the organic-inorganic composite fine particles from being buried or migrating from the surface of the toner, thereby enhancing the durability of the toner. Furthermore, as in Patent Document 3, it is proposed to have a polyester containing an isophthalic acid unit as a very small part of the binder resin of the toner and to contain organic-inorganic composite fine particles as an external additive.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a result of the inventors' study, for the toner described in Patent Document 1, by using a toner containing a polyester resin having a unit derived from isophthalic acid as a binder resin, a certain improvement effect was recognized for low-temperature fixing property. However, in an image forming apparatus employing a one-component development system, in a usage such as outputting double-sided images frequently in a low-temperature and low-humidity environment, during long-term use, the conductive member may be contaminated by the external additive of the toner, resulting in uneven halftone images. Also, although the toner described in Patent Document 2 certainly has the effect of improving the durability of the toner, in an image forming apparatus adopting a one-component development system where higher toner durability is required, in a usage such as frequently outputting double-sided images in a low-temperature and low-humidity environment, the organic-inorganic composite fine particles contaminate other members, so there is a limitation in achieving a long-life design. Also, there was room for improvement in the low-temperature fixability (abrasion density reduction rate) of halftone images in a low-temperature and low-humidity environment. Although the toner described in Patent Document 3 contains a polyester having a unit derived from isophthalic acid, the improvement in low-temperature fixability was insufficient. Also, in an image forming apparatus adopting a one-component development system, in a usage such as frequently outputting double-sided images in a low-temperature and low-humidity environment, the organic-inorganic composite fine particles contaminate the charging member, and unevenness in halftone images may occur during long-term use. Note that none of the above patent documents, including the examples, describe image formation in the double-sided printing mode, which is a mode that is strict about contamination. An object of the present disclosure is to provide a toner that solves the above drawbacks. Specifically, it is a toner having good low-temperature fixability of the toner and stain resistance of the charging member, and in an image forming apparatus adopting a one-component development system, even in a usage such as frequently outputting double-sided images in a low-temperature and low-humidity environment, the stain resistance of the charging member is also good due to the external additive of the toner, and an object is to provide a toner that can output a highly uniform halftone image.

Means for Solving the Problems

[0005] In order to solve the above problems, the present inventors intensively studied the low-temperature fixability of the toner and the stain resistance of the charging member. As a result, only when the toner particles contain a specific amount or more of polyester A containing units derived from a certain amount or more of isophthalic acid and the toner contains organic-inorganic composite fine particles having a specific shape and composition, it was found that both the low-temperature fixability (friction density reduction rate) of the halftone image in a low-temperature and low-humidity environment and the charge roller stain resistance (halftone density uniformity) after double-sided durability in a low-temperature and low-humidity environment can be achieved simultaneously. That is, the present disclosure relates to a toner having toner particles containing a binder resin and organic-inorganic composite fine particles, the binder resin contains 50% by mass or more of polyester A, and the polyester A has a unit U derived from isophthalic acid based on all units derived from acid components iso in a content ratio of 60 mol% or more, the organic-inorganic composite fine particles have a plurality of convex portions derived from inorganic fine particles on the surface of resin particles, the inorganic fine particles have silica fine particles, and the resin particles contain an ester group and is characterized by such a toner.

Advantages of the Invention

[0006] According to the present invention, both the low-temperature fixability of the toner and the stain resistance of the charging member can be achieved simultaneously. Therefore, even when used for a long time in a severe mode of toner deterioration and charging member contamination such as outputting double-sided images frequently in a low-temperature and low-humidity environment in an image forming apparatus employing a one-component contact development system, a toner can be provided in which the density uniformity of the halftone image is good and the low-temperature fixability (friction density reduction rate) of the halftone image is also good.

Modes for Carrying Out the Invention

[0007] In the present disclosure, the description of "XX or more and YY or less" or "XX to YY" representing a numerical range means a numerical range including the lower limit and the upper limit which are the endpoints, unless otherwise specified. When the numerical ranges are described stepwise, the upper and lower limits of each numerical range can be arbitrarily combined.

[0008] 〔Features of the Present Disclosure〕 As described above, as a means of improving the low-temperature fixability (print density reduction rate) of halftone images in a low-temperature and low-humidity environment, it is effective to include, as a main component of the binder resin, a polyester containing many units derived from isophthalic acid in toner particles. However, in an image forming apparatus employing a one-component contact development system, in a usage such as frequently outputting double-sided images in a low-temperature and low-humidity environment, it has been found that the external additive migrates from the surface of the toner particles to the photoreceptor, and the migrated external additive contaminates the charging member (charging roller).

[0009] As described above, in the one-component contact development system, since the toner and the photoreceptor are in contact for a long period of time, it is a strict system with respect to toner deterioration and the migration of the external additive to other members. Also, frequently outputting double-sided images is also a printing mode that is strict with respect to toner deterioration and the migration property of the external additive because the image formation time becomes long.

[0010] Furthermore, as a result of the study by the present inventors, it has been found that, particularly in a low-temperature and low-humidity environment, the external additive easily migrates from the toner particles to the photoreceptor due to an increase in the charge amount of the toner and an increase in the frictional force applied to the toner due to the hardening of the photoreceptor and the developing roller.

[0011] Therefore, in an image forming apparatus employing a one-component contact development system, in a usage such as frequently outputting double-sided images in a low-temperature and low-humidity environment, it has been found that the external additive accumulates on the charging member during long-term use, causing density unevenness in the halftone image.

[0012] Also, as a result of the detailed study by the present inventors, it has been found that when the toner particles contain a polyester having units derived from isophthalic acid as the binder resin, the silica fine particles easily migrate from the surface of the toner particles to the photoreceptor as compared with the case where the toner particles contain only a polyester having units derived from terephthalic acid.

[0013] Although the reason for this is not clear, the unit derived from isophthalic acid has a microscopically charged region (microscopic negative region) because the oxygen atoms of the carbonyl groups bonded to the benzene ring are likely to be oriented in the same direction, and it is presumed that the electrostatic repulsive force between this microscopic negative region and a negatively charged external additive such as silica makes it easier for the external additive to migrate to the photoreceptor.

[0014] Therefore, the present inventors earnestly studied means for suppressing the migration of the external additive to the photoreceptor in toner particles containing a polyester containing many units derived from infthalic acid as the main binder resin component. As a result, by incorporating specific organic-inorganic composite fine particles into the toner, it was found that it is possible to achieve both the low-temperature fixability (image density reduction rate) of halftone images in a low-temperature and low-humidity environment and the charge roller contamination resistance (halftone density uniformity) after double-sided durability in a low-temperature and low-humidity environment, and the present disclosure was completed.

[0015] That is, the present disclosure is a toner having toner particles containing a binder resin and organic-inorganic composite fine particles, the binder resin contains 50% by mass or more of polyester A, and the polyester A has a unit U derived from isophthalic acid, based on all units derived from the acid component, iso and the content ratio thereof is 60 mol% or more, the organic-inorganic composite fine particles have a plurality of convex portions derived from inorganic fine particles on the surface of the resin particles, the inorganic fine particles contain silica fine particles, and the resin particles contain an ester group. The content ratio of unit U, based on all units derived from the acid component, iso is a value calculated by the following formula. Unit U iso Content ratio (mol%) = (Number of units of unit U iso / Number of units of all acid components) × 100

[0016] By adopting the above configuration, it is considered that the stain resistance of the charging member can be improved by the following mechanism. The organic-inorganic composite fine particles contain silica fine particles forming convex portions and resin particles, and the resin particles have ester groups. The carbon atom located at the center of the COO bond of the ester group is less likely to attract charges compared to the surrounding oxygen atoms and the surrounding silica fine particles, and is considered to be a region with a small amount of charge (microscopic positive region) microscopically.

[0017] On the other hand, the toner particles contain a specific amount of polyester A containing a specific amount of units derived from isophthalic acid, so that they have a large number of microscopic negative regions formed by the units derived from isophthalic acid.

[0018] As a result, an electrostatic adhesion force is generated between the microscopic positive region of the organic-inorganic composite fine particles and the microscopic negative region of the toner particles. Therefore, even in long-term durable use, the organic-inorganic composite fine particles are less likely to transfer from the toner particles to the photoreceptor, and the stain resistance of the charging member is improved.

[0019] Hereinafter, each component of the present disclosure will be described in detail.

[0020] The toner of the present disclosure has toner particles containing a binder resin.

[0021] The binder resin contains 50% by mass or more of polyester A, and the polyester A has a unit U derived from isophthalic acid at a content ratio of 60 mol% or more based on all units derived from the acid component. iso This not only improves the low-temperature fixability (rubbing density reduction rate) of halftone images in a low-temperature and low-humidity environment, but also improves the stain resistance of the charging member and the density uniformity of halftone images even when a durability test is performed in a double-sided printing mode in a one-component contact development system.

[0022] The content ratio of unit U in polyester A based on all units derived from the acid component iso is preferably 90 mol% or more.

[0023] The organic-inorganic composite fine particles need to have a plurality of convex portions derived from inorganic fine particles on the surface of the resin particles. By the convex portions exerting an anchor effect, even in an environment where embedding of external additives is likely to occur, such as a high-temperature and high-humidity environment, the organic-inorganic composite fine particles are less likely to be embedded on the surface of the toner particles, and a toner with less fogging after double-sided durability in a high-temperature and high-humidity environment can be obtained.

[0024] The organic-inorganic composite fine particles need to contain silica fine particles as the inorganic fine particles. By containing the silica fine particles, the organic-inorganic composite fine particles become particles having negativity as a whole. Further, since the silica fine particles form the convex portions of the organic-inorganic composite fine particles, the convex portions are triboelectrically charged with a charge-imparting member such as a developing roller or a developing blade, and the organic-inorganic composite fine particles as a whole are likely to be negatively charged.

[0025] The resin particles of the organic-inorganic composite fine particles need to contain an ester group. Only when the resin particles contain an ester group, as described above, the resin particles have a region with few charges microscopically (a microscopic positive region). Thereby, an electrostatic adhesion force is generated between the microscopic positive region of the organic-inorganic composite fine particles and the microscopic negative region of the toner particles. Therefore, even when used for long-term durability in a low-temperature and low-humidity environment, the organic-inorganic composite fine particles are less likely to migrate from the toner particles to other members. Thus, the stain resistance of the charge-imparting member is improved, and the density uniformity of the halftone image after double-sided durability in a low-temperature and low-humidity environment is enhanced.

[0026] Polyester A contains a unit U derived from an ethylene oxide adduct of bisphenol A EO and a unit U derived from a propylene oxide adduct of bisphenol A PO and contains the unit U EO and the unit U POThe total content ratio is preferably 90 mol% or more based on all units derived from the alcohol component. Ethylene oxide adducts of bisphenol A and propylene oxide adducts of bisphenol A have the characteristic of being easily plasticized by waxes, crystalline polyesters, etc. contained in toner particles when heated and melted during fixing. Therefore, when the content is within the above range, when heated and melted during fixing, the binder resin is plasticized and easily penetrates into the fibers of the paper. As a result, the adhesiveness of the toner to the paper is further enhanced, and even at a lower fixing temperature, the resistance to bending of the image is good, which is preferable. Specifically, it is preferable because the bending resistance of line images in a low-temperature and low-humidity environment is good.

[0027] Also, for unit U EO the content ratio and unit U PO the content ratio of, the content ratio of unit U EO is preferably 15 mol% or more and 40 mol% or less. Here, the content ratio of unit U EO is a value calculated by the following formula. Unit U EO Content ratio (mol%) = Number of units of U EO / (Number of units of U EO + Number of units of U PO × 100

[0028] U PO is a bisphenol A unit to which propylene oxide having a larger number of carbon atoms and a branched structure is added compared to U EO . Therefore, unit U PO has a higher hydrophobicity and a lower intermolecular force compared to unit U EO . Conversely, unit U EO has a lower hydrophobicity and a higher intermolecular force compared to unit U PO .

[0029] Therefore, unit U EOSince the content ratio is 15 mol% or more, the intermolecular force of polyester A increases, so the deformation of polyester A tends to be suppressed in a high-temperature and high-humidity environment. On the other hand, unit U EO Since the content ratio is 40 mol% or less, the hydrophobicity of polyester A increases, so the moisture adsorption amount of polyester A does not become excessively high in a high-temperature and high-humidity environment. Due to these effects, unit U EO When the content ratio is 15 mol% or more and 40 mol% or less, the durability of the toner in a high-temperature and high-humidity environment is good, and fogging on the non-image area after double-sided durability in a high-temperature and high-humidity environment can be suppressed, which is preferable.

[0030] When measuring the number average molecular weight (Mn) and weight average molecular weight (Mw) of the tetrahydrofuran (THF) soluble component of polyester A using gel permeation chromatography (GPC), the number average molecular weight (Mn) is preferably 3000 or more and 10000 or less, and (Mw / Mn) is preferably 2.5 or more.

[0031] When the number average molecular weight (Mn) is 3,000 or more, the durability of the toner in a high-temperature and high-humidity environment is good, and fogging on the non-image area after double-sided durability in a high-temperature and high-humidity environment can be suppressed, which is preferable. On the other hand, when the number average molecular weight (Mn) is 10,000 or less, the melt fluidity of the binder resin at the time of fixing increases and it easily penetrates into the fibers of the paper, so the adhesiveness to the paper increases and the durability against bending of the image is good, which is preferable. More preferably, the number average molecular weight (Mn) is 4000 or more and 8000 or less.

[0032] Also, Mw / Mn being 2.5 or more means that the molecular weight distribution of polyester A is sufficiently wide, and sufficient entanglement occurs between the molecular chains of polyester A, so that the toner particles have sufficient hardness even in a high-temperature and high-humidity environment, the durability of the toner is good, and fogging on the non-image area can be suppressed, which is preferable. More preferably, it is 3.2 or more, and even more preferably 3.7 or more.

[0033] The binder resin preferably contains a crystalline polyester, as it can form a toner with good low-temperature fixing properties (scrub density reduction rate) of halftone images in a low-temperature and low-humidity environment. Preferred polyesters as the crystalline polyester will be described later.

[0034] The toner particles preferably have an average circularity of 0.950 or more and 0.980 or less, as this results in good transferability in a wide range of environments and enables the acquisition of good images even during long-term durable use. Specifically, when the average circularity is 0.950 or more, the non-electrostatic adhesion force between toner particles does not become excessively high even during long-term durable use in a high-temperature and high-humidity environment, so good transferability can be maintained, and the uniformity of solid images in a high-temperature and high-humidity environment is good, which is preferable.

[0035] On the other hand, when the average circularity is 0.980 or less, the toner particles have an appropriate non-electrostatic adhesion force even in a low-temperature and low-humidity environment where the non-electrostatic adhesion force between toner particles tends to be low. This can suppress the scattering of toner during the transfer process and improve the dot reproducibility of halftone images in a low-temperature and low-humidity environment, which is preferable. More preferably, the average circularity of the toner particles is 0.955 or more and 0.975 or less.

[0036] To adjust the average circularity of the toner to the preferred range in the present disclosure, as a toner manufacturing method, it is preferable to adopt a manufacturing method for chemical toners such as the emulsion aggregation method, suspension polymerization method, and suspension granulation method. When using the emulsion aggregation manufacturing method, in order to obtain the desired surface shape of the toner, it is preferable to provide a spheroidization process to adjust the circularity. When using the pulverization method, the circularity of the toner can also be adjusted by performing surface treatment with hot air through heat spheroidization treatment.

[0037] The organic-inorganic composite fine particles preferably have a number average particle diameter (D1) of 50 nm or more and 200 nm or less, and a shape factor SF-2 of 103 or more and 120 or less when measured at a magnification of 200,000 times. The shape factor SF-2 is an index of the degree of unevenness of the particles. When the value is 100, the particles become perfect circles, and the greater the numerical value, the greater the degree of unevenness. When D1 of the organic-inorganic composite fine particles is 200 nm or less and SF-2 is 103 or more, the organic-inorganic composite fine particles are likely to be fixed to the surface of the toner particles and less likely to migrate to other members, which is preferable.

[0038] As a result, even in a special image output mode such as continuously printing a high-quality printed image in a low-temperature and low-humidity environment, the occurrence of streak-like unevenness on the halftone image can be suppressed. This is preferable because it results in good suppression of streak on the halftone image after continuous durability of solid images in a low-temperature and low-humidity environment. Also, even when printing for a long time in a mode where the external additive is likely to contaminate the charging member in a streak pattern, it is preferable because contamination of the charging member can be reduced and the occurrence of streak-like unevenness on the halftone image can be suppressed. It is presumed that streak-like unevenness is likely to occur when continuously outputting a high-quality printed image because, compared to a normal printed image, the external additive migrates to the charging member in a short time, and thus the contamination state is likely to be biased during the accumulation process. More preferably, D1 is 185 nm or less, and more preferably, SF-2 is 105 or more.

[0039] On the other hand, when D1 is 50 nm or more and SF-2 is 120 or less, the organic-inorganic composite fine particles are less likely to be embedded in the surface of the toner particles even in a high-temperature and high-humidity environment, and it is preferable because fogging on the non-image area after double-sided durability in a high-temperature and high-humidity environment can be suppressed. More preferably, D1 is 53 nm or more, and more preferably, SF-2 is 117 or less.

[0040] The ratio P2 / P1, which is the ratio of the intensity P1 of the peak derived from Si-O to the intensity P2 of the peak derived from C=O obtained by ATR-IR measurement of the organic-inorganic composite fine particles, is 0.05 or more and 0.15 or less, which further improves the stain resistance of the charging member, and is preferable because a good halftone image can be obtained even when various images are output in a special output mode for a long time.

[0041] Since P1 is the peak intensity derived from Si-O, it serves as an index of the abundance of silica particles contained in the organic-inorganic composite fine particles. On the other hand, since P2 is the peak intensity derived from C=O, it serves as an index of the abundance of ester groups contained in the resin particles contained in the organic-inorganic composite fine particles. Therefore, P2 / P1 relatively indexes the abundance ratio of silica particles and ester groups in the resin particles in the organic-inorganic composite fine particles.

[0042] P2 / P1 can be controlled by controlling the type of monomer forming the resin particles, the mixing ratio of the monomers, and the mass ratio of the monomer forming the resin particles to the silica dispersion.

[0043] Organic-inorganic composite fine particles with P2 / P1 of 0.05 or more contain a sufficient amount of ester groups in the resin particles with respect to the negatively charged silica particles. Therefore, the electrostatic adhesion force between the microscopic positive regions of the ester groups and the microscopic negative regions of polyester A is strengthened, and even in a more severe usage environment, it is preferable because it is difficult for the organic-inorganic composite fine particles to migrate from the toner particles to the photoreceptor. Therefore, even in the case of long-term printing with a special image pattern where longitudinal unevenness is likely to occur in the stainability of the charging member, such as continuously outputting vertical stripe images, the density unevenness of the halftone image can be suppressed. Therefore, it is preferable because the halftone density uniformity after double-sided durability of vertical stripe images in a low-temperature and low-humidity environment is good.

[0044] On the other hand, when P2 / P1 is 0.15 or less, the organic-inorganic composite fine particles will have a sufficient amount of silica particles with respect to the amount of ester groups possessed by the resin particles, and will have high negativity as the organic-inorganic composite fine particles. Therefore, even in a low-temperature and low-humidity environment where the charging rise property of the toner is severe, the charging rise property will be good. Thus, even when a severe image pattern (ghost image having a halftone portion after a black background portion) that is likely to cause image unevenness due to poor charging rise property after double-sided durability in a low-temperature and low-humidity environment is output, it is preferable because the density uniformity of the halftone portion is good.

[0045] It is preferable that the organic-inorganic composite fine particles have a silica surface exposure rate B of 45% or more, more preferably 50% or more, as measured by X-ray photoelectron spectroscopy. By being within the above range, the negativity of the silica in the organic-inorganic composite fine particles becomes high, and after long-term use in a high-temperature and high-humidity environment, even when left for a long time and then used, it is preferable because fogging to the non-image portion can be suppressed.

[0046] The toner preferably has a value obtained by dividing P2 / P1 by the content ratio of U iso and multiplying by 100 that is 0.05 or more, based on all units derived from the acid component.

[0047] As described above, the P2 / P1 value relatively indexes the abundance ratio of silica particles and ester groups in the resin particles in the organic-inorganic composite fine particles. On the other hand, the content ratio of U iso represents the abundance ratio of units derived from isophthalic acid with respect to all acid components in polyester A.

[0048] In the toner of the present disclosure, the P2 / P1 value is U isoWhen the value obtained by multiplying by 100 and dividing by the total acid component × 100 value is 0.05 or more, the electrostatic adhesion force between the organic-inorganic composite fine particles and polyester A becomes even higher. Therefore, even when used for a long time in an extremely low temperature and low humidity environment, which is a more severe environment for the transfer of external additives to members, the charged member has excellent stain resistance, and the density uniformity of the halftone image after double-sided durability in the extremely low temperature and low humidity environment is good, which is preferable.

[0049] When the intensity P3 of the peak derived from the styrene unit and the intensity P2 of the peak derived from C=O are obtained by ATR-IR measurement of the organic-inorganic composite fine particles, the ratio (P2 / P3) is preferably 1.0 or more. As a result, in the resin particles contained in the organic-inorganic composite fine particles, the ester group unit exists in a specific amount or more with respect to the styrene unit. By containing the ester group in a specific amount or more, the resin particles can carry an appropriate amount of moisture even in a low temperature and low humidity environment, so that the charge externally applied to the organic-inorganic composite fine particles can be made uniform, and the charge distribution of the toner becomes good. Therefore, it is preferable because the line width uniformity after double-sided durability in a low temperature and low humidity environment is good. More preferably, P2 / P3 is 2.0 or more, and even more preferably 3.35 or more.

[0050] There is no particular limitation on the upper limit of P2 / P3, but it is preferably 10.0 or less because the chargeability of the toner in a high temperature and high humidity environment becomes good.

[0051] P2 / P3 can be controlled by the type of monomer forming the resin particles and the mixing ratio of the monomers.

[0052] The toner particles preferably contain 0.015 mass% or more and 0.150 mass% or less of aluminum element because the line width uniformity of the vertical thin line image in a low temperature and low humidity environment becomes good. The reason for obtaining this effect is not clear, but it is presumed that because the amount of aluminum element is in the above range, aluminum has a cross-linked structure in the toner particles and has appropriate elasticity even in a low temperature and low humidity environment, so that the toner can be uniformly loaded on the paper.

[0053] There is no limitation on the method of including an aluminum element in toner particles. In any step of the toner particle manufacturing process, a compound containing an aluminum element may be used so that the resulting toner particles contain the aluminum element.

[0054] For example, a method of adding a compound containing an aluminum element as a material constituting toner particles, or a method of including an aluminum element in the resulting toner particles by using a flocculant containing an aluminum element as the flocculant used in the flocculation step when manufacturing toner particles by the emulsion aggregation method. The content of the aluminum element in the toner particles can be calculated by the method of the examples.

[0055] It is preferable that the toner contains an alkylbenzenesulfonic acid and / or an alkylbenzenesulfonate because the line width uniformity of vertical thin line images in a high temperature and high humidity environment is improved.

[0056] The reason for obtaining this effect is not clear, but it is presumed that the uniformity of the charge on the toner surface is enhanced by the interaction between the alkylbenzenesulfonic acid and / or the alkylbenzenesulfonate and moisture in a high temperature and high humidity environment, so that even in the case of vertical thin line images, development and transfer can be performed faithfully to the latent image.

[0057] In terms of better line width uniformity of vertical thin line images in a higher temperature and high humidity environment, the alkyl group of the alkylbenzenesulfonic acid and / or the alkylbenzenesulfonate is preferably linear, and the carbon number of the alkyl group is more preferably 10 or more and 14 or less. Specifically, decylbenzenesulfonic acid and / or its salt (carbon number 10), undecylbenzenesulfonic acid and / or its salt (carbon number 11), dodecylbenzenesulfonic acid and / or its salt (carbon number 12), and tetradecylbenzenesulfonic acid and / or its salt (carbon number 14) are mentioned as preferred embodiments.

[0058] In addition, the metal constituting the alkylbenzene sulfonate may be a monovalent or divalent metal, and examples thereof include sodium, potassium, magnesium, calcium, and the like. From the viewpoint of achieving good line width uniformity of vertical thin line images in a higher temperature and humidity environment, a monovalent metal is preferable, and sodium is more preferable. Specifically, sodium decylbenzenesulfonate (carbon number 10), sodium undecylbenzenesulfonate (carbon number 11), sodium dodecylbenzenesulfonate (carbon number 12), and sodium tetradecylbenzenesulfonate (carbon number 14) are preferable, and sodium dodecylbenzenesulfonate is particularly preferable.

[0059] There is no limitation on the method of including alkylbenzene sulfonic acid and / or alkylbenzene sulfonate in the toner. In any step of the toner manufacturing process, a compound containing alkylbenzene sulfonic acid and / or alkylbenzene sulfonate may be used so that the resulting toner contains an alkylbenzene sulfonate.

[0060] For example, a method of adding a compound containing alkylbenzene sulfonic acid and / or alkylbenzene sulfonate as a material constituting the toner, or in the case of manufacturing a toner by an emulsion aggregation method, using alkylbenzene sulfonic acid and / or alkylbenzene sulfonate as a surfactant when preparing dispersions such as resin fine particle dispersions, colorant particle dispersions, and release agent particle dispersions to make the resulting toner contain an alkylbenzene sulfonate.

[0061] Regarding the determination of whether the toner contains alkylbenzene sulfonic acid and / or alkylbenzene sulfonate, it can be determined by the method of the examples. Further, the content (mass basis) of alkylbenzene sulfonic acid or alkylbenzene sulfonate is preferably 10 ppm or more and 1000 ppm or less with respect to the toner.

[0062] [Preferable embodiments of toner particles] Next, the preferred components and embodiments of the toner particles in the present disclosure will be described.

[0063] <Binder resin> The toner particles contain a binder resin. The content of the binder resin is preferably 50% by mass or more of the total amount of the resin components in the toner particles.

[0064] As described above, the binder resin needs to contain 50% by mass or more of polyester A, and 70% by mass or more is more preferable. This is because it further improves the charge roller contamination resistance (halftone density uniformity) after double-sided durability in a low-temperature and low-humidity environment, and also improves the low-temperature fixability (rubbing density reduction rate) of halftone images in a low-temperature and low-humidity environment.

[0065] In addition, the binder resin may contain polyesters other than polyester A. For example, it may contain styrene acrylic resins, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, mixed resins or composite resins thereof.

[0066] <Polyester A> As described above, for polyester A, the content ratio of unit U derived from isophthalic acid based on all units derived from acid components needs to be 60 mol% or more, and preferably 90 mol% or more. iso The polyester A used in the toner particles is preferably an amorphous polyester. It is sufficient to have a unit derived from isophthalic acid as an essential component, and examples include the following.

[0067] The polyester is obtained by selecting suitable ones from polyvalent carboxylic acids, polyols, hydroxycarboxylic acids, etc. and combining them, and synthesizing them using a known method such as the transesterification method or the polycondensation method. Preferably, the polyester contains a polycondensate of a dicarboxylic acid and a diol.

[0068] The polyester is obtained by selecting suitable ones from polyvalent carboxylic acids, polyols, hydroxycarboxylic acids, etc. and combining them, and synthesizing them using a known method such as the transesterification method or the polycondensation method. Preferably, the polyester contains a polycondensate of a dicarboxylic acid and a diol.

[0069] A polyvalent carboxylic acid is a compound containing two or more carboxy groups in one molecule. Among these, a dicarboxylic acid is a compound containing two carboxy groups in one molecule and is preferably used. For example, oxalic acid, succinic acid, glutaric acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, hexahydroterephthalic acid, malonic acid, pimelic acid, suberic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediacetic acid, o-phenylenediacetic acid, diphenylacetic acid, diphenyl-p,p'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracenedicarboxylic acid, cyclohexanedicarboxylic acid, etc. can be mentioned.

[0070] In addition, examples of polyvalent carboxylic acids other than the above dicarboxylic acids include trimellitic acid, trimesic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, pyrenetetracarboxylic acid, itaconic acid, glutaconic acid, n-dodecylsuccinic acid, n-dodecenylsuccinic acid, isododecylsuccinic acid, isododecenylsuccinic acid, n-octylsuccinic acid, n-octenylsuccinic acid, etc. These may be used alone or in combination of two or more.

[0071] A polyol is a compound containing two or more hydroxyl groups in one molecule. Among these, a diol is a compound containing two hydroxyl groups in one molecule and is preferably used. Specifically, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosanedecanediol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-butenediol, neopentyl glycol, polytetramethylene glycol, hydrogenated bisphenol A, bisphenol A, bisphenol F, bisphenol S, and alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts of the above bisphenols can be mentioned.

[0072] Among these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols. Particularly preferred are alkylene oxide adducts of bisphenols and a combination thereof with an alkylene glycol having 2 to 12 carbon atoms. Examples of the alkylene oxide adduct of bisphenol A include compounds represented by the following formula (A).

[0073] [Chemical formula] (In formula (A), each R is independently an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 0 or more and 10 or less.)

[0074] The alkylene oxide adduct of bisphenol A is preferably the propylene oxide adduct and / or ethylene oxide adduct of bisphenol A. More preferably, it is the propylene oxide adduct. Further, the average value of x + y is preferably 1 or more and 5 or less.

[0075] Examples of the alcohol having three or more valences include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, hexamethylolmelamine, hexaethylolemelamine, tetramethylolbenzoguanamine, tetraethylolebenzoguanamine, sorbitol, trisphenol PA, phenol novolak, cresol novolak, and alkylene oxide adducts of the polyphenols having three or more valences described above. These may be used alone or in combination of two or more.

[0076] The acid value of polyester A is preferably 4.0 mgKOH / g or more and 10.0 mgKOH / g or less.

[0077] <Release agent> In the present disclosure, known release agents can be contained in the toner.

[0078] Specifically, paraffin wax, microcrystalline wax, petroleum waxes represented by petrolatum and their derivatives, montan wax and its derivatives, hydrocarbon waxes obtained by the Fischer-Tropsch method and their derivatives, polyolefin waxes represented by polyethylene and their derivatives, carnauba wax, natural waxes represented by candelilla wax and their derivatives are included, and the derivatives include oxides, block copolymers with vinyl monomers, and graft-modified products.

[0079] Also, alcohols such as higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid or their acid amides, esters, ketones; hydrogenated castor oil and its derivatives, vegetable waxes, and animal waxes are included. These can be used alone or in combination.

[0080] Among these, when using polyolefin, hydrocarbon wax by Fischer-Tropsch method, or petroleum wax, the developability and transferability tend to improve, which is preferable. In addition, antioxidants may be added to these waxes as long as they do not affect the toner effect. Also, from the viewpoint of phase separation property with respect to the binder resin or crystallization temperature, higher fatty acid esters such as behenyl behenate and dibehenyl sebacate can be preferably exemplified.

[0081] In addition, the content of the release agent is preferably 1.0 part by mass or more and 30.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin.

[0082] The melting point of the release agent is preferably 30°C or higher and 120°C or lower, and more preferably 60°C or higher and 100°C or lower. By using a release agent having the above thermal properties, the release effect is efficiently exhibited and a wider fixing region is ensured.

[0083] <Plasticizer> The toner particles may contain a crystalline plasticizer to improve the sharp melt property. The plasticizer is not particularly limited, and known ones used for the following toners can be used.

[0084] Specifically, esters of monohydric alcohols and aliphatic carboxylic acids such as behenyl behenate, stearyl stearate, and palmitil palmitate, or esters of monohydric carboxylic acids and aliphatic alcohols; esters of dihydric alcohols and aliphatic carboxylic acids such as ethylene glycol distearate, dibehenyl sebacate, and diheheneate hexanediol, or esters of dihydric carboxylic acids and aliphatic alcohols; esters of trihydric alcohols and aliphatic carboxylic acids such as glycerin tribehenate, or esters of trihydric carboxylic acids and aliphatic alcohols; esters of tetrahydric alcohols and aliphatic carboxylic acids such as pentaerythritol tetrastearate and pentaerythritol tetrapalmitate, or esters of tetrahydric carboxylic acids and aliphatic alcohols; esters of hexahydric alcohols and aliphatic carboxylic acids such as dipentaerythritol hexastearate and dipentaerythritol hexapalmitate, or esters of hexahydric carboxylic acids and aliphatic alcohols; esters of polyhydric alcohols and aliphatic carboxylic acids such as polyglycerin behenate, or esters of polyhydric carboxylic acids and aliphatic alcohols; natural ester waxes such as carnauba wax and rice wax. These can be used alone or in combination.

[0085] <Crystalline polyester> The toner particles preferably contain a crystalline polyester. The crystalline polyester is preferably a polycondensate of monomers containing an aliphatic diol and / or an aliphatic dicarboxylic acid. The crystalline polyester refers to a polyester having a clear melting point as measured using a differential scanning calorimeter (DSC).

[0086] The crystalline polyester preferably contains monomer units derived from an aliphatic diol having 2 to 12 carbon atoms (more preferably 6 to 12 carbon atoms) and / or monomer units derived from an aliphatic dicarboxylic acid having 2 to 12 carbon atoms (more preferably 6 to 12 carbon atoms).

[0087] Such a crystalline polyester having such a structure enables good dispersibility of the crystalline polyester among toner particles and can suppress uneven wet spreading among toner particles during fixing. Therefore, it is preferable because it provides good low-temperature fixability for halftone images and line images.

[0088] Examples of the aliphatic diol having 2 to 12 carbon atoms include the following compounds: 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol.

[0089] Also, an aliphatic diol having a double bond can be used. Examples of the aliphatic diol having a double bond include the following compounds: 2-butene-1,4-diol, 3-hexene-1,6-diol, and 4-octene-1,8-diol.

[0090] Examples of the aliphatic dicarboxylic acid having 2 to 12 carbon atoms include the following compounds: oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid. Lower alkyl esters and acid anhydrides of these aliphatic dicarboxylic acids can also be used. Among these, sebacic acid, adipic acid, 1,10-decanedicarboxylic acid, and their lower alkyl esters and acid anhydrides are preferable. These can be used alone or in combination of two or more.

[0091] In addition, aromatic dicarboxylic acids can also be used. Examples of the aromatic dicarboxylic acids include the following compounds: terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4'-biphenyldicarboxylic acid. Among these, terephthalic acid is preferred in terms of easy availability and the tendency to form a polymer with a low melting point.

[0092] Moreover, dicarboxylic acids having a double bond can also be used. Dicarboxylic acids having a double bond can be suitably used for suppressing hot offset during fixing in that the entire resin can be crosslinked by utilizing the double bond. Examples of such dicarboxylic acids include fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid. Also included are their lower alkyl esters and acid anhydrides. Among these, fumaric acid and maleic acid are more preferred.

[0093] The method for producing the crystalline polyester is not particularly limited, and it can be produced by a general polyester polymerization method in which a dicarboxylic acid component and a diol component are reacted. For example, it can be produced by using either the direct polycondensation method or the transesterification method, depending on the type of monomer.

[0094] The peak temperature of the maximum endothermic peak measured using a differential scanning calorimeter (DSC) of the crystalline polyester is preferably 50.0 °C or higher and 100.0 °C or lower, and more preferably 60.0 °C or higher and 90.0 °C or lower from the viewpoint of low-temperature fixability.

[0095] The content of the crystalline polyester in the toner is preferably 3.0 mass% or more and 15.0 mass% or less from the viewpoint of the balance between low-temperature fixability and durability.

[0096] <Colorant> The toner particles may contain a colorant. As the colorant, known pigments and dyes can be used. From the viewpoint of excellent weather resistance, a pigment is preferable as the colorant. Examples of cyan-based colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds. Specifically, the following can be mentioned. C.I. Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66.

[0097] Examples of magenta-based colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, the following can be mentioned. C.I. Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254, and C.I. Pigment Violet 19.

[0098] Examples of yellow-based colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specifically, the following can be mentioned. C.I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185, 191, and 194.

[0099] Examples of black colorants include those toned to black using yellow-based colorants, magenta-based colorants, and cyan-based colorants, as well as carbon black and magnetic materials.

[0100] These colorants can be used alone, as a mixture, or even in a solid solution state. It is preferable to use the colorant in an amount of 1.0 part by mass or more and 20.0 parts by mass or less based on 100.0 parts by mass of the binder resin. When applying the manufacturing method in an aqueous medium described later using a magnetic material, a hydrophobic treatment can also be performed for the purpose of stably containing the magnetic material in the resin.

[0101] <Charge control agent, and charge control resin> The toner particles may contain a charge control agent or a charge control resin. As the charge control agent, known ones can be used, and in particular, a charge control agent with a fast triboelectric charging speed and capable of stably maintaining a certain triboelectric charge amount is preferable. Further, when the toner particles are produced by the suspension polymerization method, a charge control agent with low polymerization inhibitory properties and substantially no solubilized product in the aqueous medium is particularly preferable.

[0102] Examples of those for controlling the toner to be negatively charged include monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acid and dicarboxylic acid-based metal compounds, aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, phenol derivatives such as bisphenol, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthenic acid-based compounds, boron compounds, quaternary ammonium salts, calixarenes, and charge control resins.

[0103] Examples of the charge control resin include polymers or copolymers having a sulfonic acid group, a sulfonate group, or a sulfonic acid ester group. As the polymer having a sulfonic acid group, a sulfonate group, or a sulfonic acid ester group, a polymer containing 2% by mass or more of a sulfonic acid group-containing acrylamide-based monomer or a sulfonic acid group-containing methacrylamide-based monomer in the copolymerization ratio is particularly preferable, and a polymer containing 5% by mass or more is more preferable.

[0104] The charge control resin preferably has a glass transition temperature (Tg) of 35°C or higher and 90°C or lower, a peak molecular weight (Mp) of 10,000 or higher and 30,000 or lower, and a weight average molecular weight (Mw) of 25,000 or higher and 50,000 or lower. When this is used, favorable triboelectric charging characteristics can be imparted without affecting the thermal properties required for toner particles. Furthermore, when the charge control resin contains a sulfonic acid group, for example, the dispersibility of the charge control resin itself and the dispersibility of coloring agents and the like in the polymerizable monomer composition are improved, and the coloring power, transparency, and triboelectric charging characteristics can be further improved.

[0105] These charge control agents or charge control resins may be added alone or in combination of two or more. The addition amount of the charge control agent or charge control resin is preferably 0.01 parts by mass or more and 20.0 parts by mass or less, more preferably 0.5 parts by mass or more and 10.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin.

[0106] 〔Preferred embodiments of organic-inorganic composite fine particles〕 The organic-inorganic composite fine particles according to the present disclosure can be produced, for example, according to the description of the examples of WO2013 / 063291.

[0107] As the inorganic fine particles used in the organic-inorganic composite fine particles, in addition to silica fine particles, alumina fine particles, titania fine particles, zinc oxide fine particles, strontium titanate fine particles, cerium oxide fine particles, calcium carbonate fine particles, and the like can be used. Two or more selected in any combination from among these fine particle groups can also be used, but the organic-inorganic composite fine particles of the present disclosure need to contain silica fine particles. From the viewpoint of high negativity and difficulty in inhibiting the electrostatic adhesion force between polyester A and the resin particles, it is preferable to use silica fine particles.

[0108] As the resin particles contained in the organic-inorganic composite fine particles, conventionally known resin particles can be used, but from the viewpoints of the durability and charge uniformity of the toner, a vinyl-based resin is preferable.

[0109] Since the resin particles of the organic-inorganic composite fine particles have an ester group, a microscopic positive region can be formed due to the charge bias, and the electrostatic adhesion force between the organic-inorganic composite fine particles and the toner particle surface can be expressed by the interaction with the isophthalic acid unit of polyester A as described above.

[0110] In order to contain an ester group in the resin particles, it is preferable to use a vinyl monomer having an ester structure.

[0111] Also, by reacting the resin particles of the organic-inorganic composite fine particles with a part of the hydroxyl groups of the silica fine particles, the adhesion strength between the resin particles of the organic-inorganic composite fine particles and the silica fine particles increases, and the mechanical strength becomes strong, which is preferable. Therefore, as the monomer for forming the resin particles, the formula [R 3 3-x (OR 1 ) x SiR 2 Q is preferably possessed. x is 1, 2 or 3, R 1 is a methyl group or an ethyl group, R 2 is an alkyl bond group having the general formula C n H 2n where n is 1 or more and 10 or less, R 3 is a methyl group or an ethyl group, and Q is a substituted or unsubstituted vinyl group, acrylate ester group or methacrylate ester group. However, when Q is an unsubstituted or substituted vinyl, n is 2 or more and 10 or less.

[0112] For example, the following monomers can be exemplified.

[0113] (3-Acryloxypropyl)trimethoxysilane, (3-acryloxypropyl)triethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, methacryloxy methyltrimethoxysilane, methacryloxymethyltriethoxysilane, (3-acryloxypropyl)methyldimethoxysilane, methacryloxypropylmethyldimethoxysilane, methacryloxypropyldimethylethoxysilane, 3-butenyltrimethoxysilane, 3-butenyltriethoxysilane, 4-pentenyltriethoxysilane, 4-pentenyltrimethoxysilane, 5-hexenyltrimethoxysilane, 5-hexenylmethyldimethoxysilane, and methacryloxypropyldimethylmethoxysilane.

[0114] In addition, in order to adjust the amount of ester groups contained in the resin particles and the amount of C=O groups derived from the ester groups, styrene monomers and monomers having (meth)acrylate ester groups can also be used in combination as the monomers for forming the resin particles.

[0115] In addition, the organic-inorganic composite fine particles preferably have a hydrophobic surface by surface treatment in order to improve the chargeability in a high-temperature and high-humidity environment. Examples of the surface treatment include silane coupling treatment, oil treatment, surface treatment for forming an alumina film, etc., and they can be appropriately selected. It is also possible to select a plurality of types of surface treatment, and the order of these treatments is also arbitrary.

[0116] Examples of the silane coupling agent used for the silane coupling treatment include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilyl mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, 1-hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane having 2 to 12 siloxane units per molecule and hydroxyl groups bonded to Si per unit located at the terminals. These may be used alone or in combination of two or more. A preferred silane coupling agent is hexamethyldisilazane (HMDS).

[0117] Also, it may be treated with silicone oil or may be treated in combination with the above hydrophobic treatment.

[0118] The number average particle diameter (D1) and shape factor SF-2 of the primary particles of the organic-inorganic composite particles can be appropriately controlled by changing the particle diameter of the inorganic fine particles used in the production of the organic-inorganic composite particles and the amount ratio of the inorganic fine particles and the resin.

[0119] P2 / P1 and P2 / P3 of the organic-inorganic composite fine particles can be controlled by adjusting the monomer species forming the resin particles and the charging ratio of the monomer forming the resin particles and the silica fine particles.

[0120] [Method for producing toner] The method for manufacturing toner particles is not particularly limited, and known methods such as a grinding method, a suspension polymerization method, a dissolution suspension method, an emulsion aggregation method, and a dispersion polymerization method can be used. Here, the toner particles are preferably manufactured by the emulsion aggregation method. When manufactured by the emulsion aggregation method, polyester A contained as a binder resin is likely to be uniformly dispersed near the surface, and toner shape control is also possible. The details of the emulsion aggregation method will be described below.

[0121] <Emulsion Aggregation Method> The emulsion aggregation method is a method in which an aqueous dispersion of fine particles made of a constituent material of toner particles, which is sufficiently small with respect to the target particle diameter, is prepared in advance, and the fine particles are aggregated in an aqueous medium until they reach the particle diameter of the desired toner particles, and the resin is fused by heating or the like to manufacture toner particles.

[0122] That is, in the emulsion aggregation method, a "dispersion step" of preparing an aqueous dispersion of fine particles made of a constituent material of toner particles, an "aggregation step" of aggregating the fine particles made of a constituent material of toner particles and controlling the particle diameter until it reaches the particle diameter of the toner particles, a "fusion step" of fusing the resin contained in the obtained aggregated particles, a "spheroidization step" of further melting by heating or the like to control the surface shape of the toner particles, a subsequent "cooling step", an "annealing step" of heating and holding at a temperature equal to or higher than the crystallization temperature or the glass transition temperature of the binder resin, filtering and washing with ion-exchanged water or the like, and removing the moisture of the washed toner particles and drying them through a "post-treatment step", toner particles are manufactured. Next, each of these steps will be described.

[0123] [Step of Preparing an Aqueous Dispersion of Resin Fine Particles (Dispersion Step)] The aqueous dispersion of resin fine particles can be prepared by known methods, but is not limited to these techniques. Known methods include, for example, an emulsion polymerization method, a self-emulsification method, an inverse phase emulsification method in which an aqueous medium is added to a resin solution dissolved in an organic solvent to emulsify the resin, or a forced emulsification method in which the resin is forcibly emulsified by high-temperature treatment in an aqueous medium without using an organic solvent.

[0124] Specifically, a binder resin containing polyester A is dissolved in an organic solvent capable of dissolving these, and a surfactant and a basic compound are added. At this time, if the binder resin is a crystalline resin having a melting point, it may be heated to a temperature equal to or higher than the melting point and dissolved. Subsequently, while stirring with a homogenizer or the like, an aqueous medium is slowly added to precipitate resin fine particles. Thereafter, the solvent is removed by heating or reducing the pressure to prepare an aqueous dispersion of the resin fine particles. As the organic solvent used for dissolving the resin, any solvent capable of dissolving the resin can be used, but it is preferable to use an organic solvent that forms a homogeneous phase with water, such as toluene, from the viewpoint of suppressing the generation of coarse powder.

[0125] The surfactant used during the emulsification is not particularly limited. For example, anionic surfactants such as sulfate ester salts, sulfonate salts, carboxylate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols can be mentioned. The surfactant may be used alone or in combination of two or more.

[0126] Examples of the basic compound used during the dispersion step include inorganic bases such as sodium hydroxide and potassium hydroxide; and organic bases such as ammonia, triethylamine, trimethylamine, dimethylaminoethanol, and diethylaminoethanol. The basic compound may be used alone or in combination of two or more.

[0127] Also, the volume-based median diameter (D50) of the fine particles of the binder resin in the aqueous dispersion of the resin fine particles is preferably 0.05 μm or more and 1.0 μm or less, and more preferably 0.05 μm or more and 0.4 μm or less. By adjusting the volume-based median diameter (D50) within the above range, it becomes easy to obtain toner particles having a volume average diameter of 3 μm or more and 10 μm or less, which is an appropriate volume average diameter as toner particles.

[0128] For the measurement of the 50% particle size (D50) based on volume distribution, a dynamic light scattering particle size distribution analyzer NanoTrack UPA-EX150 (manufactured by Nikkiso Co., Ltd.) is used.

[0129] [Coloring agent fine particle dispersion liquid] The coloring agent fine particle dispersion liquid may be used as necessary. The coloring agent fine particle dispersion liquid can be prepared by known methods listed below, but is not limited to these methods. It can be prepared by mixing a coloring agent, an aqueous medium, and a dispersant using a mixer such as a known stirrer, emulsifier, and disperser. As the dispersant used here, known ones such as surfactants and polymer dispersants can be used.

[0130] Both the surfactant and the polymer dispersant can be removed in the washing process described later, but a surfactant is preferred from the viewpoint of washing efficiency.

[0131] Examples of the surfactant include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, nonionic surfactants or anionic surfactants are preferred. Also, a nonionic surfactant and an anionic surfactant may be used in combination. The surfactant may be used alone or in combination of two or more. The concentration of the surfactant in the aqueous medium is preferably 0.5% by mass or more and 5% by mass or less.

[0132] The content of the coloring agent fine particles in the coloring agent fine particle dispersion liquid is not particularly limited, but is preferably 1% by mass or more and 30% by mass or less based on the total mass of the coloring agent fine particle dispersion liquid.

[0133] In addition, from the perspective of the dispersibility of the colorant in the finally obtained toner, the dispersed particle size of the colorant fine particles in the aqueous dispersion of the colorant preferably has a volume distribution-based 50% particle size (D50) of 0.5 μm or less. For the same reason, the volume distribution-based 90% particle size (D90) is preferably 2 μm or less. The dispersed particle size of the colorant fine particles dispersed in the aqueous medium is measured using a dynamic light scattering particle size distribution analyzer (NanoTrack UPA-EX150: manufactured by Nikkiso Co., Ltd.).

[0134] Examples of the mixer such as a known stirrer, emulsifier, and disperser used when dispersing the colorant in the aqueous medium include an ultrasonic homogenizer, a jet mill, a pressure homogenizer, a colloid mill, a ball mill, a sand mill, and a paint shaker. These may be used alone or in combination.

[0135] [Release agent (aliphatic hydrocarbon compound) fine particle dispersion] A release agent fine particle dispersion may be used as necessary. The release agent fine particle dispersion can be prepared by the known methods listed below, but is not limited to these methods.

[0136] The release agent fine particle dispersion is prepared by adding a release agent to an aqueous medium containing a surfactant, heating it to a temperature equal to or higher than the melting point of the release agent, and dispersing it into particles using a homogenizer having a strong shear imparting ability (for example, "ClearMix W Motion" manufactured by M-Technique Co., Ltd.) or a pressure discharge type disperser (for example, "Gorin Homogenizer" manufactured by Gorin Co., Ltd.), and then cooling it to a temperature lower than the melting point of the release agent.

[0137] The dispersed particle size of the release agent fine particle dispersion in the aqueous dispersion of the release agent preferably has a volume distribution-based 50% particle size (D50) of 0.03 μm or more and 1.0 μm or less, more preferably 0.1 μm or more and 0.5 μm or less. It is also preferable that there are no coarse particles of 1 μm or more.

[0138] When the dispersion particle size of the release agent fine particle dispersion liquid is within the above range, it becomes possible to finely disperse and present the release agent in the toner, maximizing the bleeding effect during fixing and obtaining good separability. The dispersion particle size of the release agent fine particle dispersion liquid dispersed in the aqueous medium can be measured with a dynamic light scattering particle size distribution meter (NanoTrac UPA-EX150: manufactured by Nikkiso Co., Ltd.).

[0139] [Mixing Step] In the mixing step, a mixed liquid is prepared by mixing at least one of a resin fine particle dispersion liquid, and, if necessary, a release agent fine particle dispersion liquid and a colorant fine particle dispersion liquid. It can be carried out using known mixing devices such as a homogenizer and a mixer.

[0140] [Step of Forming Aggregate Particles (Aggregation Step)] In the aggregation step, the fine particles contained in the mixed liquid prepared in the mixing step are aggregated to form aggregates with the target particle size. At this time, a flocculant is added and mixed, and, if necessary, at least one of heating and mechanical power is appropriately applied to form aggregates in which resin fine particles and, if necessary, at least one of release agent fine particles and colorant fine particles are aggregated.

[0141] Examples of the flocculant include cationic surfactants of quaternary salts, organic flocculants such as polyethyleneimine; inorganic metal salts such as sodium sulfate, sodium nitrate, sodium chloride, calcium chloride, calcium nitrate; inorganic ammonium salts such as ammonium sulfate, ammonium chloride, ammonium nitrate; and inorganic flocculants such as divalent or higher metal complexes. It is also possible to add an acid to lower the pH and cause soft aggregation, for example, sulfuric acid or nitric acid can be used.

[0142] The flocculant may be added in either the form of a dry powder or an aqueous solution dissolved in an aqueous medium. However, in order to cause uniform flocculation, it is preferably added in the form of an aqueous solution. Further, the addition and mixing of the flocculant are preferably carried out at a temperature equal to or lower than the glass transition temperature or melting point of the resin contained in the mixed solution. By carrying out the mixing under this temperature condition, flocculation proceeds relatively uniformly. The mixing of the flocculant into the mixed solution can be carried out using a known mixing device such as a homogenizer and a mixer. The flocculation step is a step of forming aggregates having a toner particle size in an aqueous medium. The volume average particle size of the aggregates produced in the flocculation step is preferably 3 μm or more and 10 μm or less. The volume average particle size can be measured with a particle size distribution analyzer (Coulter Multisizer III: manufactured by Coulter) by the Coulter method.

[0143] [Step of obtaining a dispersion liquid containing toner particles (fusion step)] In the fusion step, first, the flocculation is stopped under the same stirring as in the flocculation step in the dispersion liquid containing the aggregates obtained in the flocculation step. The stoppage of flocculation is carried out by adding a flocculation inhibitor such as a base capable of adjusting pH, a chelating compound, or an inorganic salt compound such as sodium chloride.

[0144] After the dispersion state of the aggregated particles in the dispersion liquid becomes stable due to the action of the flocculation inhibitor, it is heated to a temperature equal to or higher than the glass transition temperature or melting point of the binder resin to fuse the aggregated particles and adjust them to a desired particle size. Note that the volume-based 50% particle size (D50) of the toner particles is preferably 3 μm or more and 10 μm or less.

[0145] [Step of obtaining a desired surface shape of the toner (spheroidization step)] After or during the fusing process, it is preferable to further increase the temperature and conduct a spheroidization process in which the toner particles are held until they reach the desired roundness or surface shape. As the temperature of the specific spheroidization process, for example, it is 90°C or higher, preferably 92°C or higher, and preferably 95°C or lower. Examples of the heating time of the spheroidization process include a heating time of 3 hours or longer, 5 hours or longer, and 8 hours or longer. By this process, hydrogen bonds derived from boric acid are likely to be formed in the toner particles.

[0146] [Cooling Process] After the spheroidization process, it is preferable to conduct a cooling process in which the temperature of the dispersion liquid containing the obtained toner particles is cooled by controlling the cooling rate to a temperature lower than the crystallization temperature or glass transition temperature of the binder resin. By going through the cooling process, the formation of irregularities on the surface of the toner particles due to volume changes such as expansion or contraction of the materials in the toner particles can be suppressed. Therefore, it becomes easier to control the shape factor SF1 (cross-section) to be 105 or more and 125 or less, or to control the contact area ratio (D / S) of the toner to be 14% or less. Also, by increasing the cooling rate, the above volume change can be further suppressed, so the generation of dents on the surface of the toner particles can be suppressed, and the desired roundness or surface shape obtained in the spheroidization process can be maintained. The shape factor SF1 and the shape factor SF1 (cross-section) of the toner can be made 125 or less, and the contact area ratio (D / S) of the toner can be made 14% or less. The specific cooling rate is 0.1°C / second or higher, preferably 0.5°C / second or higher, more preferably 2°C / second or higher, and even more preferably 4°C / second or higher.

[0147] [Annealing Process] After the cooling step, it is preferable to perform an annealing step of heating and holding at a temperature equal to or higher than the crystallization temperature or the glass transition temperature of the adhesive resin, and when containing a release agent, at a temperature equal to or lower than the crystallization temperature of the release agent. By undergoing the annealing step, the above volume change can be further suppressed, so that the generation of dents on the surface of the toner particles can be suppressed. Therefore, the desired roundness or surface shape obtained through the cooling step can be maintained, the shape factor SF1 and the shape factor SF1 (cross-section) of the toner can be made 125 or less, and the contact area ratio (D / S) of the toner can be controlled to 14% or less. Specific annealing temperatures are 45°C or higher and 75°C or lower, preferably 50°C or higher and 70°C or lower, and more preferably 55°C or higher and 65°C or lower. The heat treatment time of the annealing step is, for example, within 5 hours, preferably 2 to 3 hours.

[0148] [Post-treatment step] In the method for manufacturing toner, further, post-treatment steps such as a cleaning step, a solid-liquid separation step, and a drying step may be performed, and by performing the post-treatment steps, toner particles in a dried state can be obtained.

[0149] <External addition treatment of organic-inorganic composite fine particles> The toner particles obtained as described above are externally added with organic-inorganic composite fine particles. Other conventionally known fine particles may be used in combination as necessary.

[0150] The addition amount of the organic-inorganic composite fine particles may be 0.1 part by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particles, but from the viewpoint of achieving both the durability and the member contamination resistance of the toner, it is preferably 0.1 part by mass or more and 3.0 parts by mass or less, and more preferably 0.2 part by mass or more and 2.0 parts by mass or less.

[0151] [Measurement methods for each physical property] Next, the measurement methods for each physical property according to the present disclosure will be described.

[0152] [Isolation method of toner particles and organic-inorganic composite fine particles, and measurement method of content of organic-inorganic composite fine particles in toner] Prepare a dispersion medium by adding 0.50 g of Triton-X100 (manufactured by Kishida Chemical Co., Ltd.) to 100 g of ion-exchanged water. (1) Weigh 1.00 g of toner precisely into a vial, add the above dispersion medium to make it 10.00 g, and then prepare a sample solution that is allowed to stand for 24 hours. (2) Subject the sample solution to ultrasonic homogenizer treatment to release the external additives from the toner and disperse them in the dispersion medium. Ultrasonic treatment device: Ultrasonic homogenizer VP-050 (manufactured by Taitec Corporation) Microchip: Step-type microchip, tip diameter φ2 mm Tip position of the microchip: Center of the glass vial and at a height of 5 mm from the bottom of the vial Ultrasonic conditions: Intensity 30%, 180 minutes. At this time, apply ultrasonic waves while cooling the vial with ice water so that the dispersion liquid does not heat up. (3) Separate the toner particles in the sample solution and the dispersion medium in which the external additives are dispersed (filtrate) by suction filtration (10 μm membrane filter). (4) Collect the toner particles after filtration, add the dispersion medium again to make it 10.00 g, and then repeat the above (2) and (3) 10 times in total to collect all the filtrates. (5) If other external additives are added, subject the collected filtrate to a centrifuge to separate it from other external additives and collect the organic-inorganic composite fine particles. (6) Dry the collected organic-inorganic composite fine particles sufficiently at 60 °C for 24 hours in a vacuum dryer to isolate the dried organic-inorganic composite fine particles.

[0153] By measuring the mass of the dried organic-inorganic composite fine particles, the mass of the organic-inorganic composite fine particles contained in 1.00 g of toner was determined. And 100 times that mass was taken as the content (mass%) of the organic-inorganic composite fine particles in the toner.

[0154] <Method for determining whether the resin particles of the organic-inorganic composite fine particles have an ester group> · Identification by pyrolysis GCMS The specific measurement conditions by pyrolysis GCMS are shown below. Mass spectrometer: Thermo Fisher Scientific ISQ GC device: Thermo Fisher Scientific Focus GC Ion source temperature: 250 °C Ionization method: EI Mass range: 50 - 1000 m / z Column: HP-5MS [30 m] Pyrolysis device: JPS-700 manufactured by Nippon Bunko Kogyo Co., Ltd. Add a small amount of organic-inorganic composite fine particles and 1 μL of tetramethylammonium hydroxide (TMAH) to a pyrolytic foil at 590 °C. Perform pyrolysis GC-MS measurement on the prepared sample under the above conditions to obtain peaks derived from the organic-inorganic composite fine particles. Due to the action of TMAH, which is a methylating agent, the compounds constituting the resin component are detected as methylated products. Analyze the obtained peaks. If the compounds constituting the resin component contain compounds having an ester group, it is determined that the resin particles of the organic-inorganic composite fine particles have an ester group.

[0155] <Method for measuring the number average particle diameter (D1) of organic-inorganic composite fine particles> The measurement of the number average particle diameter (D1) of the primary particles of the organic-inorganic composite fine particles was performed using a scanning electron microscope "S-4800" (trade name; manufactured by Hitachi, Ltd.).

[0156] Observe the toner to which the organic-inorganic composite fine particles are externally added, and measure the major axis of 100 primary particles of the organic-inorganic composite fine particles randomly in a field of view magnified up to 200,000 times to obtain the number average particle diameter (D1). The observation magnification was appropriately adjusted according to the size of the organic-inorganic composite fine particles.

[0157] <Method for measuring SF-2 of organic-inorganic composite fine particles> The measurement of the shape factor SF-2 of the organic-inorganic composite fine particles was performed using a scanning electron microscope "S-4800" (trade name; manufactured by Hitachi, Ltd.).

[0158] The measurement was carried out by observing the toner to which the organic-inorganic composite fine particles are externally added and calculating as follows.

[0159] The observation magnification was appropriately adjusted according to the size of the organic-inorganic composite fine particles. In the field of view magnified up to 200,000 times, using the image processing software "Image-Pro Plus 5.1J" (manufactured by Media Cybernetics), the perimeter and area of the primary particles of 100 random organic-inorganic composite fine particles were calculated.

[0160] SF-2 was calculated by the following formula, and its average value was taken as SF-2. SF-2 = (perimeter of the particle) 2 / area of the particle × 100 / 4π

[0161] <Method for measuring the content of silica fine particles in organic-inorganic composite fine particles> The measurement of the content of silica fine particles in the organic-inorganic composite fine particles was carried out using TGA Q5000IR (manufactured by TA Instruments). The measurement was performed according to the following procedure.

[0162] After weighing 10.0 mg of the sample into the sample pan, it was set on the main body.

[0163] Then, in an oxygen gas atmosphere, after holding at 50 °C for 1 minute, it was heated to 900 °C at a heating rate of 25 °C / min, and the weight change of the sample at this time was measured. Using the mass of the initial sample (W1) and the mass of the sample at 900 °C (W2), the content of the inorganic fine particles in the organic-inorganic composite fine particles B was determined by the following formula. Content of silica fine particles (mass %) = W2 / W1 × 100

[0164] When the externally added organic-inorganic composite fine particles were available, they were used as the sample. When they were not available, the organic-inorganic composite fine particles could be isolated from the toner for measurement.

[0165] <Method for measuring P2 / P1 and P2 / P3 of organic-inorganic composite fine particles> (Method for measuring P1, P2, and P3 by ATR-IR) The FT-IR spectrum is measured by the ATR method using a Fourier transform infrared spectrometer (Spectrum One: manufactured by PerkinElmer) equipped with a Universal ATR Sampling Accessory. The specific measurement procedure and the calculation methods for P1 and P2 are as follows.

[0166] As the ATR crystal, a Ge ATR crystal (refractive index = 4.0) is used. Other conditions are as follows. Range Start :4000cm -1 End :600cm -1 (Ge ATR crystal) Scan number :8 Resolution :4.00cm -1 Advanced :With CO2 / H2O correction

[0167] After attaching the Ge ATR crystal (refractive index = 4.0) to the apparatus and setting it to the absorbance measurement mode, first measure the background. Then, accurately weigh 0.01 g of the organic-inorganic composite fine particles onto the ATR crystal, pressurize the sample with the pressure arm (adjust the Force Gauge to 70 - 80), and then measure the FT-IR spectrum of the organic-inorganic composite fine particles.

[0168] By analyzing the obtained FT-IR spectrum, determine the peak heights of P1, P2, and P3.

[0169] (Calculation method for the peak height of P1) P1 is a peak derived from Si - O of the silica fine particles contained in the organic-inorganic composite fine particles, and has a peak top at 1100 cm -1 or higher and 1120 cm -1 or lower. For the obtained FT-IR spectrum, at 884 cm -1 or higher and 1347 cm -1The minimum values of the spectrum were connected within the following range to draw a baseline, and the peak height of P1 with respect to the baseline was determined.

[0170] (Calculation method of peak height of P2) P2 is a peak derived from C=O of the resin particles of the organic-inorganic composite particles, and has a peak top at 1715 cm -1 or more and 1735 cm -1 or less.

[0171] Regarding the obtained FT-IR spectrum, the minimum values of the spectrum were connected within the range of 1660 cm -1 or more and 1805 cm -1 or less to draw a baseline, and the peak height of P2 with respect to the baseline was determined.

[0172] (Calculation method of peak height of P3) P3 is a peak derived from the out-of-plane bending vibration of the benzene ring of styrene of the resin particles of the organic-inorganic composite particles, and has a peak top at 680 cm -1 or more and 710 cm -1 or less.

[0173] Regarding the obtained FT-IR spectrum, the minimum values of the spectrum were connected within the range of 650 cm -1 or more and 730 cm -1 or less to draw a baseline, and the peak height of P3 with respect to the baseline was determined.

[0174] (Calculation method of P2 / P1) P2 / P1 was calculated by dividing the peak height of P2 by the peak height of P1.

[0175] (Calculation method of P2 / P3) P2 / P3 was calculated by dividing the peak height of P2 by the peak height of P3.

[0176] (Measurement method of surface exposure rate B of silica of organic-inorganic composite particles) When the inorganic fine particles present on the surface of the organic-inorganic composite particles are silica fine particles, the surface exposure rate B of silica can be measured by the following method.

[0177] The surface exposure rate B of silica in the organic-inorganic composite particles is measured by ESCA (X-ray photoelectron spectroscopy).

[0178] It is calculated from the atomic weight of silicon derived from silica (hereinafter abbreviated as Si). ESCA is an analytical method for detecting atoms in a region of several nanometers or less in the depth direction of the sample surface. Therefore, it is possible to detect the atoms on the surface of the organic-inorganic composite particles.

[0179] As the sample holder, a 75 mm square platen (equipped with a screw hole of about 1 mm diameter for fixing the sample) attached to the apparatus was used. Since the screw hole of the platen penetrates, the hole was plugged with resin or the like to create a recess for powder measurement with a depth of about 0.5 mm. The measurement sample was packed into the recess with a spatula or the like and polished to prepare a sample.

[0180] The apparatus and measurement conditions of ESCA are as follows. Apparatus used: Quantum 2000 manufactured by ULVAC-PHI, Inc. Analysis method: Narrow analysis Measurement conditions: X-ray source: Al-Kα X-ray conditions: 100 μ25W15 kV Photoelectron capture angle: 45° PassEnergy: 58.70 eV Measurement range: φ100 μm

[0181] Measurement was performed under the above conditions.

[0182] First, the organic-inorganic composite particles were measured. For calculating the quantitative value of Si atoms, the peaks of C1c (B.E. 280 to 295 eV), O1s (B.E. 525 to 540 eV), and Si2p (B.E. 95 to 113 eV) were used. Let the quantitative value of the Si element obtained here be X1.

[0183] Next, in the same manner, elemental analysis of the silica fine particles alone is performed, and the quantitative value of the Si element obtained here is defined as X2.

[0184] In the present disclosure, the surface exposure rate B of silica was determined as follows using the above X1 and X2. Surface exposure rate B (%) of silica = X1 / X2 × 100

[0185] Also, as the silica fine particles alone, calculations were performed using silica fine particles 4 (number average particle diameter 110 nm) obtained by the sol-gel method described in the production examples in the examples described later. When the external additive is silica alone, the surface silica abundance ratio is 100%, and particularly when there is no surface treatment, the surface silica abundance ratio of the resin particles is 0%.

[0186] <Method for isolating toner particles> In (4) of the method for isolating organic-inorganic composite fine particles and the method for measuring the content of organic-inorganic composite fine particles in toner, the toner particles obtained by repeating filtration 10 times in total were collected and dried sufficiently at 45 °C for 24 hours to isolate the toner particles.

[0187] <Method for isolating binder resin from toner particles> Dissolve 100 mg of toner particles in 3 ml of chloroform. Next, insoluble components are removed by suction filtration with a syringe equipped with a sample treatment filter (pore size 0.2 μm or more and 0.5 μm or less, for example, Micron Disc H-25-2 (manufactured by Tosoh Corporation) etc.). The soluble components are introduced into preparative HPLC (apparatus: LC-9130 NEXT preparative column [60 cm] manufactured by Japan Analytical Industry Co., Ltd., exclusion limit: 20000, two connected with 70000) and the chloroform eluent is fed. When a peak can be confirmed in the display of the obtained chromatograph, the retention time with a molecular weight of 2000 or more is fractionated using a monodisperse polystyrene standard sample. The solution of the obtained fraction is dried and solidified to separate the release agent and fractionate the binder resin.

[0188] <Composition analysis of binder resin composed of multiple components> Use the chloroform-soluble component of the separated binder resin as a sample. The sample is adjusted with chloroform so that the toner particle concentration is 0.1% by mass, and the solution is filtered through a 0.45 μm PTFE filter and used for measurement. The gradient polymer LC measurement conditions are shown below.

[0189] Apparatus: UlTIMATE3000 (manufactured by Thermo Fisher Scientific) Mobile phase: A Chloroform (HPLC), B Acetonitrile (HPLC) Gradient: 2 min (A / B = 0 / 100) → 25 min (A / B = 100 / 0) (Note that the gradient of the change in the mobile phase was made linear.) Flow rate: 1.0 mL / min Injection: 0.1% by mass × 20 μL Column: Tosoh TSKgel ODS (4.6 mmφ × 150 mm × 5 μm) Column temperature: 40 °C Detector: Corona charged particle detector (Corona-CAD) (manufactured by Thermo Fisher Scientific)

[0190] Collect polyester A at the time corresponding to polyester A (7 minutes to 9 minutes). Also, collect the crystalline polyester at the time corresponding to the crystalline polyester (13 minutes to 15 minutes). In the collection, collect the required amount of each chloroform / acetonitrile solution, dry and concentrate it, and then use it as a sample of polyester A (resin A) and crystalline polyester (resin B).

[0191] Using the samples of the resin A component and the resin B component, measure the composition ratio and mass ratio by nuclear magnetic resonance spectroscopy (NMR) as follows.

[0192] Add 1 mL of deuterated chloroform to 20 mg of the resin A component and the resin B component sample, and measure the proton NMR spectrum of the dissolved resin. From the obtained NMR spectrum, the molar ratio and mass ratio of each monomer can be calculated, and the content ratio of each monomer unit can be determined. For example, in the case of a styrene-acrylic copolymer, the composition ratio and mass ratio can be calculated based on the peak near 6.5 ppm derived from the styrene monomer and the peak near 3.5 ppm to 4.0 ppm derived from the acrylic monomer.

[0193] For nuclear magnetic resonance spectroscopy (NMR), the following apparatus and measurement conditions can be used. NMR apparatus: RESONANCE ECX500 manufactured by JEOL Ltd. Observed nucleus: proton Measurement mode: single pulse

[0194] <Quantification method of U, U, U in polyester A by NMR measurement iso , U EO , U PO > The component identification, molar ratio, and mass ratio of polyester A by nuclear magnetic resonance spectroscopy (NMR) are as follows.

[0195] Add 1 mL of deuterated chloroform to 20 mg of the obtained polyester A, and measure the proton NMR spectrum of the dissolved polyester A. From the obtained NMR spectrum, regarding the smallest unit sandwiched by ester bonds as the structure derived from the monomer, the molar ratio and mass ratio of each monomer were calculated.

[0196] For example, the composition ratio and mass ratio can be calculated based on the following peaks (chemical shift value, number of protons).

[0197] Unit derived from isophthalic acid: 7.5 ppm (1), 8.2 ppm (2), 8.7 ppm (1) Unit derived from terephthalic acid: 8.1 ppm (4) Units derived from ethylene oxide adduct of bisphenol A: 1.6 ppm (6), 4.3 ppm (4), 4.7 ppm (4), 6.8 ppm (4), 7.1 ppm (4) Units derived from propylene oxide adduct of bisphenol A: 1.5 ppm (6), 1.6 ppm (6), 4.1 ppm (4), 5.5 ppm (2), 6.8 ppm (4), 7.1 ppm (4) Units derived from ethylene glycol: 4.3 ppm (4) NMR apparatus: JEOL RESONANCE ECX500 Observed nucleus: Proton, Measurement mode: Single pulse, Reference peak: TMS By the NMR analysis, the content (mol%) of unit U derived from isophthalic acid was determined based on all units derived from the acid component. Also, the total content ratio (mol%) of U iso and U EO was determined based on all units derived from the alcohol component. And the content ratio (mol%) of U PO in the total of the content ratio of U EO and the content ratio of U PO was determined. EO

[0198] <Method for measuring weight average molecular weight Mw and number average molecular weight Mn> The molecular weights of samples such as polyester A, crystalline polyester, and styrene acrylic are measured as follows by gel permeation chromatography (GPC).

[0199] First, dissolve the sample in tetrahydrofuran (THF). In the case of polyester A and styrene acrylic, dissolve it in THF at room temperature over 24 hours. In the case of crystalline polyester, heat THF to 40 °C to dissolve it and then leave it for 24 hours.

[0200] ​For the solution in which each sample is dissolved, filter it through a solvent-resistant membrane filter "Microsyringe Disk" with a pore size of 0.2 μm (manufactured by Tosoh Corporation) to obtain a sample solution. Note that the sample solution is adjusted so that the concentration of the components soluble in THF is 0.8% by mass. Using this sample solution, measurements are carried out under the following conditions. Apparatus: HLC8120GPC (Detector: RI) (manufactured by Tosoh Corporation) · Column: Seven columns of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko K.K.) Eluent: Tetrahydrofuran (THF) · Flow rate: 1.0 ml / min · Oven temperature: 40.0 °C · Sample injection volume: 0.10 ml When calculating the molecular weight of the sample, a molecular weight calibration curve prepared using a standard polystyrene resin (for example, trade names "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500", manufactured by Tosoh Corporation) is used.

[0201] <Measurement method of melting point> The melting points of crystalline polyester, mold release agent, plasticizer, etc. are measured under the following conditions using a differential scanning calorimeter (DSC) Q2000 (manufactured by TA Instruments). Heating rate: 10 °C / min Measurement start temperature: 20 °C Measurement end temperature: 180 °C For the temperature correction of the apparatus detection part, the melting points of indium and zinc are used, and for the heat quantity correction, the heat of fusion of indium is used. Specifically, accurately weigh about 5 mg of the sample, put it into an aluminum pan, and perform one measurement. As a reference, an empty aluminum pan is used. The peak temperature of the maximum endothermic peak at that time is taken as the melting point.

[0202] <Measurement of glass transition temperature Tg> The glass transition temperature Tg is measured in accordance with ASTM D3418-82 using a differential scanning calorimeter "Q2000" (manufactured by TA Instruments). For the temperature correction of the apparatus detection part, the melting points of indium and zinc are used, and for the correction of the heat quantity, the heat of fusion of indium is used. Specifically, approximately 2 mg of the sample is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference. The measurement is carried out at a heating rate of 10 °C / min within the measurement temperature range of -10 to 200 °C. In the measurement, the temperature is first raised to 200 °C, then cooled to -10 °C, and then heated again. The specific heat change can be obtained in the temperature range of 30 °C to 100 °C during the second heating process. The intersection point of the line at the midpoint between the baseline before and after the specific heat change occurs and the differential thermal curve is defined as the glass transition temperature Tg.

[0203] <Measurement of acid value> The acid value is the number of milligrams of potassium hydroxide required to neutralize the acid contained in 1 g of the sample. In the present disclosure, the acid value is measured in accordance with JIS K 0070-1992. Specifically, the measurement is carried out according to the following procedure.

[0204] Titration is performed using a 0.1 mol / l potassium hydroxide ethyl alcohol solution (manufactured by Kishida Chemical Co., Ltd.). The factor of the above potassium hydroxide ethyl alcohol solution can be determined using a potentiometric titrator (Potentiometric Titration Measuring Device AT-510 manufactured by Kyoto Electronics Industry Co., Ltd.). Take 100 ml of 0.100 mol / l hydrochloric acid into a 250 ml tall beaker and titrate it with the above potassium hydroxide ethyl alcohol solution, and determine it from the amount of the above potassium hydroxide ethyl alcohol solution required for neutralization. The above 0.100 mol / l hydrochloric acid is prepared in accordance with JIS K 8001-1998.

[0205] The measurement conditions for acid value measurement are shown below. Titrator: Potentiometric Titrator AT-510 (manufactured by Kyoto Electronics Industry Co., Ltd.) Electrode: Composite glass electrode double junction type (manufactured by Kyoto Electronics Industry Co., Ltd.) Control Software for Titration Device: AT-WIN Titration Analysis Software: Tview During titration, the titration parameters and control parameters are set as follows. Titration Parameters Titration Mode: Blank Titration Titration Style: Total Volume Titration Maximum Titration Volume: 20 ml Waiting Time before Titration: 30 seconds Titration Direction: Automatic Control Parameters Endpoint Judgment Potential: 30 dE Endpoint Judgment Potential Value: 50 dE / dmL Endpoint Detection Judgment: Not Set Control Speed Mode: Standard Gain: 1 Data Acquisition Potential: 4 mV Data Acquisition Titration Volume: 0.1 ml In this test, 0.100 g of the measurement sample is accurately weighed into a 250 ml beaker, 150 ml of a mixed solution of toluene / ethanol (3:1) is added, and it is dissolved over 1 hour. Using the above potentiometric titration device, titration is performed using the above potassium hydroxide ethyl alcohol solution. In the blank test, titration is performed in the same manner as the above operation, except that no sample is used (i.e., only the mixed solution of toluene / ethanol (3:1)). The obtained result is substituted into the following formula to calculate the acid value. A = [(C - B) × f × 5.611] / S (In the formula, A: acid value (mgKOH / g), B: added amount of potassium hydroxide ethyl alcohol solution in the blank test (ml), C: added amount of potassium hydroxide ethyl alcohol solution in this test (ml), f: factor of potassium hydroxide solution, S: sample (g).)

[0206] <Method for Measuring Average Circularity of Toner (Particles)> For measuring the average circularity of toner or toner particles, the "FPIA-3000 type" (manufactured by Sysmex Corporation), a flow-type particle image analyzer, is used, and measurement is performed under the measurement and analysis conditions during calibration work.

[0207] To 20 mL of ion-exchanged water, an appropriate amount of a surfactant, alkylbenzene sulfonate, as a dispersant was added, and then 0.02 g of a measurement sample was added. Using a tabletop ultrasonic cleaner disperser (product name: VS-150, manufactured by Ver-Voclea Co., Ltd.) with an oscillation frequency of 50 kHz and an electrical output of 150 watts, a dispersion treatment was performed for 2 minutes to obtain a dispersion for measurement. At that time, it was appropriately cooled so that the temperature of the dispersion was 10°C or higher and 40°C or lower.

[0208] For measurement, the flow-type particle image analyzer equipped with a standard objective lens (10 times) was used, and for the sheath fluid, Particle Sheath "PSE-900A" (manufactured by Sysmex Corporation) was used. The dispersion adjusted according to the above procedure was introduced into the flow-type particle image analyzer, and in the HPF measurement mode, 3000 toner (particles) were measured in the total count mode. The binarization threshold value at the time of particle analysis was set to 85%, the analysis particle diameter was limited to a circle equivalent diameter of 1.98 μm or more and 19.92 μm or less, and the average circularity of the toner (particles) was determined.

[0209] At the time of measurement, before the start of measurement, automatic focus adjustment was performed using standard latex particles (for example, 5100A (product name) manufactured by Duke Scientific diluted with ion-exchanged water). Thereafter, it is preferable to perform focus adjustment every 2 hours from the start of measurement.

[0210] <Method for Measuring Weight Average Particle Diameter (D4) of Toner> The weight average particle diameter (D4) and number average particle diameter (D1) of the toner were measured and calculated using a precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, Inc.) equipped with a 100 μm aperture tube and the dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.) for setting measurement conditions and analyzing measurement data at an effective measurement channel number of 25,000 channels.

[0211] The electrolytic aqueous solution used for measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of about 1% by mass. For example, "ISOTON II" (manufactured by Beckman Coulter) can be used.

[0212] Before measurement and analysis, the settings of the dedicated software were made as follows.

[0213] On the "Change Screen of Standard Measurement Method (SOM)" of the dedicated software, set the total count number in the control mode to 50,000 particles, the number of measurements to 1 time, and set the Kd value to the value obtained using "Standard Particle 10.0 μm" (manufactured by Beckman Coulter). By pressing the measurement button for the threshold value / noise level, the threshold value and the noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check the flash of the aperture tube after measurement.

[0214] On the "Conversion Setting Screen from Pulse to Particle Size" of the dedicated software, set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm to 60 μm.

[0215] The specific measurement method is as follows. 1. Pour about 200 ml of the electrolytic aqueous solution into a 250 ml round-bottom glass beaker dedicated to Multisizer 3, set it on the sample stand, and stir with a stirrer rod counterclockwise at 24 revolutions per second. Then, use the "Flash of Aperture" function of the analysis software to remove dirt and bubbles in the aperture tube. 2. Pour about 30 ml of the electrolytic aqueous solution into a 100 ml flat-bottom glass beaker, and add about 0.3 ml of a dilution obtained by diluting "Contaminon N" (a 10% by mass aqueous solution of a neutral detergent for precision measuring instruments with pH 7 composed of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) as a dispersant 3 times by mass with ion-exchanged water. 3. Incorporate two oscillators with an oscillation frequency of 50 kHz with a 180-degree phase shift, put a predetermined amount of ion-exchanged water into the water tank of the ultrasonic disperser "Ultrasonic Dispersion System Tetora150" (manufactured by Nikkaki Bios Co., Ltd.) with an electrical output of 120 W, and add approximately 2 ml of the contaminon N into this water tank. 4. Set the beaker in step 2 into the beaker fixing hole of the ultrasonic disperser and operate the ultrasonic disperser. Then, adjust the height position of the beaker so that the resonance state of the liquid level of the electrolytic aqueous solution in the beaker is maximized. 5. While irradiating the electrolytic aqueous solution in the beaker in step 4 with ultrasonic waves, add approximately 10 mg of toner little by little to the electrolytic aqueous solution and disperse it. Then, continue the ultrasonic dispersion treatment for another 60 seconds. In ultrasonic dispersion, appropriately adjust so that the water temperature of the water tank is 10°C or higher and 40°C or lower. 6. Drop the electrolytic aqueous solution in step 5 in which the toner is dispersed into the round-bottom beaker in step 1 installed in the sample stand using a pipette, and adjust so that the measured concentration becomes approximately 5%. And perform the measurement until the measured number of particles reaches 50,000. 7. Analyze the measurement data using the dedicated software attached to the device, and calculate the weight average particle diameter (D4) and the number average particle diameter (D1). When graph / number% and graph / volume% are respectively set in the dedicated software, the "arithmetic diameter" on the analysis / number statistical value (arithmetic mean) and analysis / volume statistical value (arithmetic mean) screens are the number average particle diameter (D1) and the weight average particle diameter (D4), respectively.

[0216] [Configuration included in the embodiment of the present disclosure] The disclosure of this embodiment includes the following configurations. (Configuration 1) A toner having toner particles containing a binder resin and organic-inorganic composite fine particles, The binder resin contains 50% by mass or more of polyester A, The polyester A is the unit U derived from isophthalic acid based on all units derived from the acid component iso and the content ratio thereof is 60 mol% or more, The organic-inorganic composite fine particles have a plurality of convex portions derived from inorganic fine particles on the surface of the resin particles, the inorganic fine particles include silica fine particles, the resin particles contain an ester group, and the toner is characterized by this. (Constitution 2) The unit U of the polyester A iso The toner according to Constitution 1, wherein the content ratio is 90 mol% or more. (Constitution 3) The polyester A contains a unit U derived from an ethylene oxide adduct of bisphenol A EO and a unit U derived from a propylene oxide adduct of bisphenol A PO , and the total content ratio of the unit U EO and the unit U PO is 90 mol% or more based on all units derived from the alcohol component. The toner according to Constitution 1 or 2. (Constitution 4) The content ratio of the unit U EO and the content ratio of the unit U PO The content ratio of the unit U EO is 15 mol% or more and 40 mol% or less with respect to the total of the content ratio of the unit U (Constitution 5) When the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the tetrahydrofuran (THF) soluble component of the polyester A are measured using gel permeation chromatography (GPC), the number average molecular weight (Mn) is 3000 or more and 10000 or less, and the ratio (Mw / Mn) is 2.5 or more. The toner according to any one of Constitutions 1 to 4. (Constitution 6) The toner according to any one of Constitutions 1 to 5, wherein the binder resin contains a crystalline polyester. (Constitution 7) The toner according to any one of Constitutions 1 to 6, wherein the average circularity of the toner is 0.950 or more and 0.980 or less. (Constitution 8) The number average particle diameter (D1) of the organic-inorganic composite fine particles is 50 nm or more and 200 nm or less, and the shape factor SF-2 of the organic-inorganic composite fine particles when measured at a magnification of 200,000 times is 103 or more and 120 or less. The toner according to any one of Constitutions 1 to 7. (Configuration 9) The toner according to any one of Configurations 1 to 8, wherein P2 / P1, which is the ratio of the intensity P1 of the peak derived from Si-O to the intensity P2 of the peak derived from C=O obtained by ATR-IR of the organic-inorganic composite fine particles, is 0.05 or more and 0.15 or less. (Configuration 10) The toner according to Configuration 9, wherein the value obtained by dividing P2 / P1 by the content ratio of the unit U iso and multiplying by 100 is 0.05 or more. (Configuration 11) The toner according to any one of Configurations 1 to 10, wherein the surface exposure rate B of silica in the organic-inorganic composite fine particles measured by X-ray photoelectron spectroscopy is 45% or more. (Configuration 12) The toner according to any one of Configurations 1 to 11, wherein when the intensity P3 of the peak derived from the styrene unit and the intensity P2 of the peak derived from C=O are obtained by ATR-IR measurement of the organic-inorganic composite fine particles, the ratio (P2 / P3) is 1.0 or more. (Configuration 13) The toner according to any one of Configurations 1 to 12, wherein the toner particles contain 0.015% by mass or more and 0.150% by mass or less of an aluminum element. (Configuration 14) The toner according to any one of Configurations 1 to 13, wherein the toner contains at least one compound selected from the group consisting of alkylbenzenesulfonic acid and alkylbenzenesulfonate.

Examples

[0217] The present disclosure will be described in more detail below with reference to Examples and Comparative Examples, but the present disclosure is not limited thereto. Parts used in the examples are on a mass basis unless otherwise specified.

[0218] <Production Example 1 of Polyester A> · 27 mol parts of bisphenol A ethylene oxide 2 mol adduct (BPA-EO) · 73 mol parts of bisphenol A propylene oxide 2 mol adduct (BPA-PO) · 100 mol parts of isophthalic acid The above monomers were charged into a flask equipped with a stirring device, a nitrogen inlet tube, a temperature sensor, and a rectification column. The temperature was raised to 190°C in 1 hour, and it was confirmed that the reaction system was uniformly stirred. 1.0 part of tin distearate was added to 100 parts of these monomers. Further, while distilling off the generated water, the temperature was raised from 190°C to 245°C over 5 hours, and a dehydration condensation reaction was carried out at 245°C for another 2 hours.

[0219] As a result, polyester A-1 with a glass transition temperature of 60.1°C, an acid value of 10 mgKOH / g, a hydroxyl value of 25 mgKOH / g, Mn of 4800, and Mw / Mn of 6.7 was obtained.

[0220] <Production Examples 2 to 12 of Polyester A> In Production Example 1 of polyester A, except that the monomers used were changed as described in Table 1 and the reaction temperature and dehydration condensation time were changed so that Mn and Mw / Mn of the resulting polyester A would be the desired values, polyester A-2 to A-12 were obtained in the same manner as in Production Example 1 of polyester A. The results are shown in Table 1.

[0221]

Table 1

[0222] <Production Example of Styrene-Acrylic Resin> · Styrene 77 parts · Butyl acrylate 23 parts · Di-t-butyl peroxide 1.0 part After raising the temperature of 200 parts of xylene to 200°C, the above components were added dropwise into xylene over 4 hours, and then held for 1 hour under reflux of xylene to complete the polymerization. The physical properties of the obtained styrene-acrylic resin are shown in Table 2.

[0223]

Table 2

[0224] <Production Example 1 of Crystalline Polyester> Into a reaction vessel equipped with a nitrogen inlet tube, a dehydrating tube, a stirrer, and a thermocouple, · 100 mol parts of 1,10-decanedicarboxylic acid · 100 mol parts of 1,9-nonanediol · 0.8 part of tin dioctylate as a catalyst based on the total mass of the acid and alcohol The above materials were placed in a two-necked flask that had been heated and dried, nitrogen gas was introduced into the vessel to maintain an inert atmosphere, and the temperature was raised while stirring. Then, stirring was carried out at 170 °C for 6 hours. Thereafter, while continuing stirring, the temperature was gradually raised to 230 °C under reduced pressure and held for an additional 3 hours. When it became viscous, it was air-cooled and the reaction was stopped to produce crystalline polyester 1. The physical properties obtained are shown in Table 3.

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

[0226]

Table 3

[0227] <Production Examples 1 to 16 of Organic-Inorganic Composite Fine Particles> Organic-inorganic composite fine particles 1 to 16 were produced according to Example 1 of WO2013 / 063291. At this time, methacryloxypropyltrimethoxysilane (hereinafter abbreviated as MPS) and styrene were used in combination as monomers for forming the resin, and the mixing ratio of MPS and styrene was adjusted so that P2 / P3 was the value shown in Table 4. Also, the mass ratio of the monomer for forming the resin to the silica dispersion, the silica exposure rate, and the content of inorganic fine particles (silica fine particles 1 to 3) were adjusted to desired values. The physical properties of organic-inorganic composite fine particles 1 to 16 are shown in Table 4.

[0228]

Table 4

[0229] <Production Example of Silica Fine Particles 4> In the presence of methanol, water, and aqueous ammonia, while heating and stirring, tetramethoxysilane was added dropwise to obtain a suspension of silica fine particles. The heating temperature, stirring speed, and dropping time were adjusted so that the particle size of the obtained silica fine particles would be the values shown in Table 8 below. To the dispersion obtained by solvent replacement, hexamethyldisilazane was added as a hydrophobizing agent at room temperature in an amount of 10 parts per 100 parts of the obtained silica fine particles. Thereafter, the mixture was heated to 120 °C and reacted to perform hydrophobization treatment on the surface of the silica fine particles.

[0230] After passing through a wet sieve to remove coarse particles, the solvent was removed and dried to obtain silica fine particles 4 (sol-gel silica) having a number average particle size of 110 nm and an SF-2 value of 1.00.

[0231] <Preparation of Resin Particle Dispersion of Polyester A-1> · 100 parts of Polyester A-1 · 50 parts of Methyl Ethyl Ketone · 20 parts of Isopropyl Alcohol Methyl ethyl ketone and isopropyl alcohol were charged into a container. Thereafter, the above polyester A-1 was gradually charged and stirred to be completely dissolved to obtain a polyester A-1 solution. The container containing this polyester A-1 solution was set to 65 °C, and while stirring, a total of 5 parts of 10% aqueous ammonia solution was gradually added dropwise, and further 230 parts of ion-exchanged water was gradually added dropwise at a rate of 10 ml / min to cause phase inversion emulsification. Further, the solvent was removed under reduced pressure using an evaporator to obtain a resin particle dispersion of polyester A-1. The volume average particle size of the resin particles contained in this resin particle dispersion was 130 nm. Also, the resin particle solid content was adjusted to 20% with ion-exchanged water.

[0232] <Preparation of Resin Particle Dispersion of Crystalline Polyester 1> · 100 parts of Crystalline Polyester 1 · 50 parts of methyl ethyl ketone · 20 parts of isopropyl alcohol The above-mentioned methyl ethyl ketone and isopropyl alcohol were put into a container. Then, the above-mentioned crystalline polyester 1 was gradually added, followed by stirring to completely dissolve it and obtain a solution of crystalline polyester 1. The container containing the solution of crystalline polyester 1 was set at 40°C, and while stirring, a total of 3.5 parts of 10% aqueous ammonia solution was gradually added dropwise. Further, 230 parts of ion-exchanged water was gradually added dropwise at a rate of 10 ml / min to perform phase inversion emulsification. Further, the solvent was removed under reduced pressure to obtain a resin particle dispersion of crystalline polyester 1. The volume average particle diameter of the resin particles in this resin particle dispersion was 150 nm. Also, the resin particle solid content was adjusted to 20% with ion-exchanged water.

[0233] <Preparation of Colorant Particle Dispersion> · 45 parts of copper phthalocyanine (Pigment Blue 15:3) · 5 parts of sodium dodecylbenzenesulfonate · 190 parts of ion-exchanged water The above components were mixed and dispersed for 10 minutes by a homogenizer (Ultra Turrax manufactured by IKA). Then, using an Altimizer (counter-collision type wet grinder: manufactured by Sugino Machine Co., Ltd.), a dispersion treatment was performed at a pressure of 250 MPa for 20 minutes to obtain a colorant particle dispersion with a volume average particle diameter of 120 nm and a solid content of 20%.

[0234] <Preparation of Release Agent Particle Dispersion> · 15 parts of release agent (hydrocarbon wax, melting point: 79°C) · 2 parts of sodium dodecylbenzenesulfonate · 240 parts of ion-exchanged water The above was heated to 100°C and sufficiently dispersed with Ultra Turrax T50 manufactured by IKA. Then, using a pressure discharge type Gorin homogenizer, it was heated to 115°C and subjected to a dispersion treatment for 1 hour to obtain a release agent particle dispersion with a volume average particle diameter of 160 nm and a solid content of 20%.

[0235] <Manufacture of Toner Particles 1> · 900 parts of the resin particle dispersion of polyester A-1 · 100 parts of the resin particle dispersion of crystalline polyester 1 · 50 parts of the colorant particle dispersion · 80 parts of the release agent particle dispersion First, each of the above materials was put into a round stainless steel flask and mixed. Subsequently, it was dispersed at 5000 r / min for 10 minutes using a homogenizer Ultra Turrax T50 (manufactured by IKA). After adding a 1.0% nitric acid aqueous solution and adjusting the pH to 3.0, an aqueous solution prepared by dissolving 0.50 part of aluminum chloride (coagulant) in 20 parts of ion-exchanged water was added under stirring at 30°C so that the content of aluminum element in the resulting toner particles became the desired amount. Then, using a stirring blade in a water bath for heating, it was heated to 58°C while appropriately adjusting the rotation speed such that the mixed solution was stirred.

[0236] The volume average particle diameter of the formed aggregated particles was appropriately confirmed using a Coulter Multisizer III. When aggregated particles with a volume average particle diameter of 6.0 μm were formed, the aggregation process was terminated.

[0237] Subsequently, as a spheroidization process, the pH was adjusted to 9.0 using a 5% sodium hydroxide aqueous solution, and it was heated to 92°C while continuing stirring.

[0238] When the desired surface shape was obtained, heating was stopped. As a cooling process, ice was quickly added so that the cooling rate became 10°C / second or more, and it was cooled to 40°C. Further, as an annealing process, an annealing treatment was performed at 55°C for 3 hours.

[0239] Thereafter, it was cooled to 25°C, filtered and solid-liquid separated, and then washed with ion-exchanged water. After the washing was completed, it was dried using a vacuum dryer to obtain toner particles 1 with a weight average particle diameter (D4) of 7.1 μm. The physical properties of toner particles 1 are shown in Tables 5 and 9.

[0240] <Manufacturing Examples of Toner Particles 2 to 10, 12 to 36, 38> The materials were used in such a way that the formulations and physical properties shown in Tables 5 to 9 were obtained. The toner particles 2 to 10, 12 to 36, and 38 were obtained in the same manner as in the production example of toner particle 1, except that the type and blending amount of the alkylbenzene sulfonate added to the colorant particle dispersion and / or the mold release agent particle dispersion were adjusted. The physical properties of the obtained toner particles 2 to 10, 12 to 36, and 38 are shown in Tables 5 to 9.

[0241] <Production Example of Toner Particle 11> (Production of Toner Particles by Grinding Method) The following materials were thoroughly mixed with an FM mixer (manufactured by Nippon Coke Industry Co., Ltd.), and then melt-kneaded with a twin-screw kneader (manufactured by Ikegai Iron Works Co., Ltd.) set at a temperature of 100°C. · 90.0 parts of Polyester A-1 · 10.0 parts of Crystalline Polyester 1 · Hydrocarbon wax (melting point: 79°C) 8.0 parts · 5.0 parts of C.I.Pigment Blue15:3

[0242] The obtained kneaded product was cooled and coarsely ground to 1 mm or less with a hammer mill to obtain a coarsely ground product.

[0243] Next, the obtained coarsely ground product was finely ground to about 6.5 μm using a turbo mill manufactured by Turbo Industry Co., Ltd., and then the fine coarse powder was cut using a multi-division classifier utilizing the Coandă effect to obtain toner particle 11.

[0244] The weight average particle diameter (D4) of toner particle 11 was 7.1 μm, the Tg was 58.4°C, and the average circularity was 0.94. The physical properties are shown in Tables 5 and 9.

[0245] <Production Example of Toner Particle 37> (Production of Toner Particles by Suspension Polymerization Method) [Colorant Dispersion Preparation Step] · 68 parts of Styrene · 19 parts of n-Butyl Acrylate · 5.0 parts of C.I.Pigment Blue15:3 · Loading charge control agent (aluminum compound of dialkyl salicylic acid) 1 part The above components were dispersed using a media agitation mill with zirconia beads to prepare a colorant dispersion liquid.

[0246] [Polymerizable monomer composition preparation step] · Colorant dispersion liquid 93.0 parts · Polyester A-1 3.0 parts · Crystalline polyester 1 10.0 parts · Hydrocarbon wax (melting point: 79 °C) 8.0 parts · Loading charge control agent (aluminum compound of dialkyl salicylic acid) 1 part The above components were put into a temperature-adjustable stirring tank, heated to 63 °C while stirring, and stirring was continued for another 45 minutes to obtain a polymerizable monomer composition.

[0247] [Aqueous medium preparation step] · Water 97.8 parts · Na3PO4 1.2 parts · 10% hydrochloric acid aqueous solution 0.3 part The above components were put into another temperature-adjustable stirring tank, and stirred until Na3PO4 was completely dissolved while heating to 60 °C.

[0248] To this, a solution prepared by dissolving 0.7 part of CaCl2 in 5 parts of water was added, and stirring was carried out for 30 minutes while maintaining the temperature at 60 °C at a rotation speed of 50 s -1 using "Clear Mix" (manufactured by M Technique Co., Ltd.) to obtain an aqueous medium which is a water suspension of fine particles of Ca3(PO4)2.

[0249] [Granulation step] The obtained aqueous medium was stirred at 60 °C using "Clear Mix" (manufactured by M Technique Co., Ltd.) at a rotation speed of 50 s -1 while adding the above-mentioned polymerizable monomer composition thereto, and stirring was continued for 3 minutes. Thereafter, 7.0 parts of t-butyl peroxy pivalate, which is a polymerization initiator, was added to 100 parts of the polymerizable monomer, and stirring was further carried out for 7 minutes to obtain a polymerizable monomer composition dispersion liquid.

[0250] [Polymerization step] The polymerizable monomer composition dispersion obtained by the above process was introduced into a temperature-controlled stirring tank, the liquid temperature was raised to 67 °C, and polymerization was carried out for 5 hours while stirring. Then, the temperature was raised to 80 °C and polymerization was continued for 4 hours to obtain a polymer particle dispersion.

[0251] [Volatile component removal step and cooling step] The polymer particle dispersion obtained in the polymerization step was introduced into a stirring tank capable of being heated by steam, steam was blown in from the steam inlet to raise the liquid temperature to 100 °C, and the volatile component removal step was carried out by stirring for 5 hours.

[0252] [Solid-liquid separation step, washing step and drying step] Hydrochloric acid was added to the polymer particle dispersion and stirred to dissolve the Ca3(PO4)2 particles covering the polymer particles. The solution was de-liquored with a pressure filter, water was added to make it a dispersion again, and then it was de-liquored again with a pressure filter for solid-liquid separation. This operation was repeated until Ca3(PO4)2 was sufficiently removed for washing. After washing, the polymer particles finally obtained by solid-liquid separation were sufficiently dried by known drying means to obtain toner particles 37.

[0253] When the particle size of the obtained toner particles 37 was measured, the weight average particle diameter (D4) was 7.1 μm, and the glass transition temperature Tg of the toner particles 37 was 59 °C. The physical properties are shown in Tables 8 and 9.

[0254] [Production example of toner 1] External addition was performed on the above toner particles 1. Using an FM mixer (FM10 manufactured by Nippon Coke & Engineering Co., Ltd.), 20.0 g of the organic-inorganic composite fine particles 1 was added to 2.0 kg of the toner particles 1, and then external addition was carried out by mixing at 3000 rpm for 5 minutes. At this time, by diverting the cold water flowing through the cooling jacket and controlling the temperature, the temperature in the tank after 5 minutes of mixing was adjusted to 35 °C.

[0255] Thereafter, the mixture of the toner particles and the organic-inorganic composite fine particles was sieved with a mesh having an opening of 75 μm to obtain Toner 1. The physical properties of Toner 1 are shown in Tables 5 and 9.

[0256] <Production Examples of Toners 2 to 38> In the production example of Toner 1, except that the types of the toner particles and the types of the organic-inorganic composite fine particles were changed, Toners 2 to 38 were obtained in the same manner as in the production example of Toner 1. The physical properties of the obtained Toners 2 to 38 are shown in Tables 5 to 9. Note that Toners 35 and 38 are examples in which silica fine particles were added instead of the organic-inorganic composite fine particles as an external additive.

[0257]

Table 5

[0258]

Table 6

[0259]

Table 7

[0260]

Table 8

[0261]

Table 9-1

[0262]

Table 9-2

[0263]

Table 9-3

[0264]

Table 9-4

[0265] 〔Example 1〕 An HP LaserJet Enterprise Color M555dn, a color laser printer equipped with a one-component toner contact developing blade cleaning system, and an HP212X black toner cartridge (W2120X) CRG, its consumable cartridge, were modified and used.

[0266] The main body was modified so that the process speed would be 150% and printing tests could be performed with only the black station. Also, the cartridge was modified by increasing the volume of the toner container so that the following toner filling amounts would be included, and evaluations were carried out. By doing so, more durable evaluations with a longer lifespan can be performed on a main body that is faster than before.

[0267] <Evaluation 1. Low-temperature fixability (scrub density reduction rate) of halftone images in a low-temperature and low-humidity (L / L) environment> The evaluation of low-temperature fixability was carried out in a low-temperature and low-humidity environment (temperature 15°C, relative humidity 10%), which is a severe environment for evaluating low-temperature fixability. The printer main body and a toner cartridge filled with 550 g of the toner (Toner 1) according to Example 1 were left in an environment of 15°C and 10% RH for 24 hours for the purpose of temperature and humidity adjustment in the evaluation environment. As the evaluation paper, COTTON BOND LIGHT COCKLE (basis weight 90 g / m 2 ) was used, which is a rough paper and is likely to be disadvantaged in low-temperature fixability due to the unevenness of the paper.

[0268] The evaluation procedure was as follows: From the state where the entire fuser was at room temperature, the density of the halftone image (measured using a portable spectrocolorimeter Exact Advance (manufactured by X-Rite)) was adjusted so that the image density would be 0.75 to 0.80 at a set temperature of 170°C, and 10 sheets were printed.

[0269] Thereafter, printing was performed at a set temperature of 150°C, and the fixed image was rubbed 10 times with a sylvon paper with a load of 5.4 kPa. From the image density before and after rubbing, the density reduction rate at 150°C was calculated using the following formula. Density reduction rate (%) = (Image density before rubbing - Image density after rubbing) / Image density before rubbing × 100

[0270] Similarly, the fixing temperature was increased by 5°C each time, and the density reduction rate was calculated up to 200°C.

[0271] From the evaluation results of the fixing temperature and the density reduction rate obtained by a series of operations, a quadratic polynomial approximation was performed to obtain a relational expression between the fixing temperature and the density reduction rate. Using this relational expression, the temperature at which the density reduction rate becomes 15% was calculated, and this temperature was set as the fixing temperature indicating the threshold value with good low-temperature fixability.

[0272] The lower the fixing temperature, the better the low-temperature fixability. In this disclosure, C or higher is the acceptable level. The evaluation results are shown in Table 10. (Evaluation criteria) A: The fixing temperature is less than 180°C. B: The fixing temperature is 180°C or higher and less than 190°C. C: The fixing temperature is 190°C or higher and less than 200°C. D: The fixing temperature is 200°C or higher.

[0273] <Evaluation 2. Anti-charging roller contamination property (halftone density uniformity) after double-sided durability in a low-temperature and low-humidity environment> The printer main body and the toner cartridge filled with 550 g of the toner (toner 1) according to Example 1 were left in a low-temperature and low-humidity environment of 15°C and 10% RH for 24 hours for the purpose of temperature and humidity adjustment in the evaluation environment. After leaving, in the same low-temperature and low-humidity environment, using the vitality manufactured by Xerox of LETTER size (LTR basis weight 75 g / m 2 )), a durability evaluation was carried out with a double-sided printing setting, taking two double-sided sheets as one job, and outputting 30,000 sheets (60,000 images) of a horizontal line image with a printing rate of 1.0% and a margin of 5 mm.

[0274] After that, it was changed to single-sided printing mode, and as the 30,001st sheet (60,001st image), a halftone image with a printing rate of 23% and a margin of 5 mm was output (halftone image 1).

[0275] After that, after replacing the charging roller with a new one, as the 30,002nd sheet (60,002nd image), one halftone image with a printing rate of 23% was output (halftone image 2).

[0276] Using a portable spectrocolorimeter, Exact Advance (manufactured by X-Rite), for the halftone images 1 and 2, for three columns: the central column, the column 20 mm from the left end, and the column 20 mm from the right end, in the vertical direction from the front end to the rear end of the paper, at 50 mm intervals from the front end of the paper, the image density at 5 points was measured, and a total of 15 points were measured for each.

[0277] For the halftone images 1 and 2, after obtaining the density difference (the difference between the maximum value and the minimum value of the 15-point measurement) respectively, the difference between the density difference of the halftone image 1 and the density difference of the halftone image 2 was calculated to obtain the halftone density difference due to the contamination of the charging roller after the durability evaluation.

[0278] The less the toner contaminates the charging roller, the more it can output a halftone image with a density difference equivalent to that of a new charging roller. Therefore, the halftone density difference due to the contamination of the charging roller after the durability evaluation becomes smaller. Therefore, the evaluation was carried out according to the following criteria. The evaluation results are shown in Table 10. (Evaluation Criteria) A: The halftone density difference due to the contamination of the charging roller after the durability evaluation is less than 0.05. B: The halftone density difference due to the contamination of the charging roller after the durability evaluation is 0.05 or more and less than 0.10. C: The halftone density difference due to the contamination of the charging roller after the durability evaluation is 0.10 or more and less than 0.15. D: The halftone density difference due to the contamination of the charging roller after the durability evaluation is 0.15 or more.

[0279] <Evaluation 3. Fogging after double-sided durability in a high-temperature and high-humidity (H / H) environment> The printer main body and the toner cartridge filled with 550 g of the toner (toner 1) according to Example 1 were left for 24 hours in a high-temperature and high-humidity environment (32.5°C, 85% RH) for the purpose of temperature and humidity control in the evaluation environment. After leaving, in the same high-temperature and high-humidity environment, using the vitality manufactured by Xerox in LETTER size (LTR basis weight 75 g / m 2 ), a durability evaluation was carried out with a double-sided printing setting, where two double-sided sheets were considered as one job, an image density of 1.0%, a 5-mm margin, and a horizontal line image was output 30,000 times (60,000 images).

[0280] After that, a sheet of paper with a 5 cm × 5 cm sticker attached to the center of the printed surface of the paper was set in the cassette, then the mode was changed to single-sided printing, and a full-white image was output as the 30,001st (60,001st image) (full-white image 1).

[0281] After peeling off the sticker of the full-white image 1, using a white colorimeter TC-6DX (manufactured by Tokyo Denshoku Co., Ltd.), the reflectance (%) of the part where the sticker was attached and the reflectance (%) of the part where the sticker was not attached were measured, and the difference between the two was measured and calculated as fogging (%) and evaluated according to the following criteria. The evaluation results are shown in Table 10. (Evaluation Criteria) A: The fogging after the durability evaluation in a high-temperature and high-humidity environment is less than 0.5. B: The fogging after the durability evaluation in a high-temperature and high-humidity environment is 0.5 or more and less than 1.0. C: The fogging after the durability evaluation in a high-temperature and high-humidity environment is 1.0 or more and less than 1.5. D: The fogging after the durability evaluation in a high-temperature and high-humidity environment is 1.5 or more.

[0282] <Evaluation 4. Bend resistance of line images in a low-temperature and low-humidity environment> The evaluation was carried out in a low-temperature and low-humidity environment (temperature 15°C, relative humidity 10%), which is a severe environment for evaluating low-temperature fixing properties. The printer main body and the toner cartridge filled with 550 g of the toner (toner 1) according to Example 1 were left in the same low-temperature and low-humidity environment for 24 hours for the purpose of temperature and humidity adjustment in the evaluation environment. As the evaluation paper, vitality (LTR basis weight 75 g / m 2 ) manufactured by Xerox in LETTER size was used.

[0283] The evaluation procedure was as follows: From the state where the entire fixing device was at room temperature, at a set temperature of 170°C, 10 images each having 5 horizontal lines with a line width of 180 μm and a leading margin of 5 mm at 5 mm intervals were output.

[0284] After that, drawing was performed at a set temperature of 150°C. Along the paper feeding method, the central part was folded so that the image forming surface was on the inside. Then, a 100 g weight was placed on the back surface of the folded part and rubbed 10 times.

[0285] After that, after unfolding the folded paper again, the fixed image was rubbed 10 times with a silicone paper with a load of 5.4 kPa on the folded part. The line width before rubbing and the line width of the rubbed part after rubbing were observed with a magnifying glass. The fixing temperature at which, on average, 70% or more of the line width was maintained compared to before rubbing was determined to be the fixing temperature with folding resistance.

[0286] Then, the fixing temperature was increased by 5°C from 150°C to 200°C, and the evaluation was carried out according to the following criteria. In the present disclosure, C or more can be tolerated. The evaluation results are shown in Table 10. (Evaluation Criteria) A: The fixing temperature is less than 180°C. B: The fixing temperature is 180°C or more and less than 190°C. C: The fixing temperature is 190°C or more and less than 200°C. D: The fixing temperature is 200°C or more.

[0287] <Evaluation 5. Uniformity of solid images in a high-temperature and high-humidity environment> The printer main body and the toner cartridge filled with 550 g of the toner (toner 1) according to Example 1 were left for 24 hours in a high-temperature and high-humidity environment (32.5 °C, 85% RH) for the purpose of temperature and humidity control in the evaluation environment. After leaving, in the same high-temperature and high-humidity environment, using XEROX's vitality of LETTER size (LTR basis weight 75 g / m 2 ), as a double-sided printing setting, an image with a full-white image on the first side and a solid image with a 5-mm margin on the second side was output as 1,000 sheets (2,000 images) in a job of two double-sided sheets to conduct a durability evaluation.

[0288] Since the transferability of the double-sided image requires transferability to the heated and thickened paper, it is a strict evaluation as the evaluation of transferability.

[0289] Then, for the solid image on the second side of the 1,000th sheet, using a portable spectrophotometer X-Rite Advance (manufactured by X-Rite), for three columns of the central column, the column 20 mm from the left end, and the column 20 mm from the right end, in the vertical direction from the tip to the rear end of the paper, at 50-mm intervals from the paper tip, five-point image densities were measured, and a total of 15 points were measured for each. Then, from the difference between the maximum value and the minimum value of the image density, the density uniformity of the solid image was determined. The evaluation results are shown in Table 10. (Evaluation criteria) A: The density difference of the solid image is less than 0.05. B: The density difference of the solid image is 0.05 or more and less than 0.10. C: The density difference of the solid image is 0.10 or more and less than 0.15. D: The density difference of the solid image is 0.15 or more.

[0290] <Evaluation 6. Dot reproducibility of halftone images in a low-temperature and low-humidity environment> The printer main body and the toner cartridge filled with 550 g of the toner (toner 1) according to Example 1 were left for 24 hours in a low-temperature and low-humidity environment of 15 °C and 10% RH for the purpose of temperature and humidity control in the evaluation environment. As the evaluation paper, XEROX's vitality of LETTER size (LTR basis weight 75 g / m 2 ) was used.

[0291] As a double-sided printing setting, an endurance evaluation was carried out to output 1,000 sheets (2,000 images) in two-sided two-sheet as one job, with a full-white image on the first side and a halftone image with a printing rate of 23% and a margin of 5 mm on the second side.

[0292] After that, after leaving it in the same environment for 24 hours, two-sided two-sheet as one job, 1,001 sheets, a full-white image on the first side, and a halftone image with a printing rate of 23% and a margin of 5 mm on the second side were output.

[0293] Regarding the scattering property of toner on the image, in a low-temperature and low-humidity environment, when the image is output from the state where the main body is cooled, other members in contact with the toner are hard and easy to jump, so it is a strict evaluation.

[0294] Then, regarding the halftone image on the second side of the 1,001st sheet, it was confirmed with a magnifying glass, the degree of scattered toner particles was judged, and the dot reproducibility was evaluated. The evaluation results are shown in Table 10. (Evaluation criteria) A: The dots with scattering are less than 5%. B: The dots with scattering are 5% or more and less than 10%. C: The dots with scattering are 10% or more and less than 15%. D: The dots with scattering are 15% or more.

[0295] <Evaluation 7. Streaks of halftone image after continuous durability of solid image in low-temperature and low-humidity environment> The printer main body and the toner cartridge filled with 550 g of the toner (toner 1) according to Example 1 were left in a low-temperature and low-humidity environment of 15°C and 10% RH for 24 hours for the purpose of temperature and humidity control in the evaluation environment. After leaving, in the same low-temperature and low-humidity environment, vitality manufactured by Xerox in LETTER size (LTR basis weight 75 g / m 2Using [[ID=]], a durability evaluation was conducted for double-sided printing settings. With two double-sided sheets per job, for both the first and second sides, 500 sheets (1000 images) of solid black images with a 100% printing rate and 5 mm margins were output.

[0296] After that, the printing mode was changed to single-sided printing, and as the 501st sheet, one halftone image with a 23% printing rate was output.

[0297] After that, after replacing the charging roller with a new one, as the 502nd sheet, one halftone image with a 23% printing rate was output.

[0298] Then, the vertical streaks in the halftone image of the 501st sheet were compared with the vertical streaks in the halftone image of the 502nd sheet. The number of streaks determined to be due to charging roller contamination was counted, and evaluation was performed according to the following criteria. The evaluation results are shown in Table 11. (Evaluation Criteria) A: No vertical streaks due to charging roller contamination have occurred. B: Vertical streaks due to charging roller contamination have occurred, but less than 3. C: Vertical streaks due to charging roller contamination have occurred, but 3 or more and less than 6. D: Vertical streaks due to charging roller contamination have occurred, but 6 or more.

[0299] <Evaluation 8. Halftone Density Uniformity after Double-Sided Durability of Vertical Band Images in a Low Temperature and Low Humidity Environment> The printer main body and the toner cartridge filled with 550 g of the toner according to Example 1 (Toner 1) were left in a low temperature and low humidity environment of 15°C and 10% RH for 24 hours for the purpose of temperature and humidity control in the evaluation environment. After leaving, in the same low temperature and low humidity environment, using 2 a durability evaluation was conducted for double-sided printing settings. With two double-sided sheets per job, for both the first and second sides, 500 sheets (1000 images) of vertical band images with a 50% printing rate (the left side of the image is all black and the right side is all white) and 5 mm margins were output.

[0300] After that, the printing mode was changed to single-sided printing mode, and as the 501st sheet, one halftone image with a printing rate of 23% was output.

[0301] After that, after replacing the charging roller with a new one, as the 502nd sheet, one halftone image with a printing rate of 23% was output.

[0302] Then, using the portable spectrocolorimeter X-Rite Advance (manufactured by X-Rite), for the 501st halftone image and the 502nd halftone image, for three columns: the central column, the column 20 mm from the left end, and the column 20 mm from the right end, in the vertical direction from the front end to the rear end of the paper, at intervals of 50 mm from the front end of the paper, the image density at 5 points was measured, and a total of 15 points were measured for each.

[0303] Then, for the 501st halftone image and the 502nd halftone image, after obtaining the density difference (the difference between the maximum value and the minimum value of the 15-point measurement), the difference between the two was obtained.

[0304] For toners with less contamination of the charging roller due to the double-sided durability of the vertical stripe image, it is possible to output a halftone image with a density difference equivalent to that of a new charging roller. Therefore, the larger the difference, the greater the halftone density difference due to charging roller contamination was determined. In the present disclosure, C or more is allowed. The evaluation results are shown in Table 11. (Evaluation Criteria) A: The halftone density difference due to charging roller contamination is less than 0.05. B: The halftone density difference due to charging roller contamination after durability evaluation is 0.05 or more and less than 0.10. C: The halftone density difference due to charging roller contamination after durability evaluation is 0.10 or more and less than 0.15. D: The halftone density difference due to charging roller contamination after durability evaluation is 0.15 or more.

[0305] <Evaluation 9. Density difference of the halftone part of the ghost image after double-sided durability in a low-temperature and low-humidity environment> In the same manner as in Evaluation 2, in a low-temperature and low-humidity environment, with double-sided printing settings, taking two double-sided sheets as one job, a durability evaluation was carried out to output 30,000 sheets (60,000 images) of a horizontal line image with a printing rate of 1.0% and a margin of 5 mm.

[0306] After that, after replacing the charging roller with a new one, as the 30,001st sheet (the 60,001st image), after a leading margin of 5 mm, a solid black patch of 10 mm × 10 mm was provided, and then a halftone image with a printing rate of 23% was output for 1 sheet (ghost evaluation image).

[0307] Using a portable spectrophotometer, X-Rite Advance (manufactured by X-Rite), the density of the halftone part of the ghost evaluation image was measured, the difference between the maximum value and the minimum value was obtained, and the density difference of the halftone part of the ghost image was obtained.

[0308] When the charging property of the toner is good, for the halftone part corresponding to the cycle of the photoreceptor of the solid black patch, it is difficult for a density difference to occur with other regions, so the density difference of the halftone part of the ghost image becomes good. Evaluation was carried out according to the following criteria. The evaluation results are shown in Table 11. (Evaluation Criteria) A: The density difference of the halftone part of the ghost image is less than 0.05. B: The density difference of the halftone part of the ghost image is 0.05 or more and less than 0.10. C: The density difference of the halftone part of the ghost image is 0.10 or more and less than 0.15. D: The density difference of the halftone part of the ghost image is 0.15 or more.

[0309] <Evaluation 10. Fogging after durability in a high-temperature and high-humidity environment> The printer main body and a toner cartridge filled with 550 g of the toner (Toner 1) according to Example 1 were left for 24 hours in a high-temperature and high-humidity environment (32.5°C 85% RH) for the purpose of temperature and humidity control in the evaluation environment. After leaving, in the same high-temperature and high-humidity environment, a vitality manufactured by Xerox in LETTER size (LTR basis weight 75 g / m 2Using [[]], a durability evaluation was carried out with double-sided printing settings, where two double-sided sheets were considered as one job, and a horizontal line image with a printing rate of 2.0% and a margin of 5 mm was output 5,000 sheets (10,000 images).

[0310] After leaving it for 7 days, a sheet of paper with a 5 cm × 5 cm sticker attached to the center of the printed surface of the paper was set in the cassette, then changed to single-sided printing mode, and a full-white image was output as the 5,001st sheet (10,001st image) (Full-white image 1).

[0311] After peeling off the sticker of the full-white image 1, using a white colorimeter TC-6DX (manufactured by Tokyo Denshoku Co., Ltd.), the reflectance (%) of the part where the sticker was attached and the reflectance (%) of the part where the sticker was not attached were measured, and the difference between the two was measured and calculated as the ghosting (%) and evaluated according to the following criteria. The evaluation results are shown in Table 11. (Evaluation criteria) A: The ghosting after durability evaluation under high-temperature and high-humidity environment is less than 0.5. B: The ghosting after durability evaluation under high-temperature and high-humidity environment is 0.5 or more and less than 1.0. C: The ghosting after durability evaluation under high-temperature and high-humidity environment is 1.0 or more and less than 1.5. D: The ghosting after durability evaluation under high-temperature and high-humidity environment is 1.5 or more.

[0312] <Evaluation 11. Halftone density uniformity after double-sided durability under extremely low temperature and low humidity environment> The printer main body and the toner cartridge filled with 550 g of the toner (Toner 1) according to Example 1 were left in an extremely low temperature and low humidity environment of 5°C and 10% RH for 24 hours for the purpose of temperature and humidity control in the evaluation environment. After leaving, in the same extremely low temperature and low humidity environment, using the vitality of Xerox (LTR basis weight 75 g / m 2 ) with double-sided printing settings, where two double-sided sheets were considered as one job, and a durability evaluation was carried out to output a horizontal line image with a printing rate of 1% for both the first side and the second side 10,000 sheets (20,000 images).

[0313] After that, it was changed to single-sided printing mode, and as the 10,001st sheet, one halftone image with a printing rate of 23% was output.

[0314] After that, after replacing the charging roller with a new one, as the 10,002nd sheet, one halftone image with a printing rate of 23% was output.

[0315] Then, using the portable spectrocolorimeter X-Rite Advance (manufactured by X-Rite), for the 10,001st halftone image and the 10,002nd halftone image, for three columns: the central column, the column 20 mm from the left end, and the column 20 mm from the right end, in the vertical direction from the front end to the rear end of the paper, at intervals of 50 mm from the front end of the paper, the image density at 5 points was measured, and a total of 15 points were measured for each.

[0316] Then, for the 10,001st halftone image and the 10,002nd halftone image, after obtaining the density difference (the difference between the maximum value and the minimum value of the 15-point measurement), the difference between the two was obtained.

[0317] The less the toner that causes less contamination of the charging roller due to double-sided durability in an extremely low temperature and low humidity environment, the more it can output a halftone image with a density difference equivalent to that of a new charging roller. Therefore, the larger the difference, the greater the halftone density difference due to charging roller contamination was determined. In the present disclosure, C or more is allowed. The evaluation results are shown in Table 11. (Evaluation Criteria) A: The halftone density difference due to charging roller contamination in an extremely low temperature and low humidity environment is less than 0.05. B: The halftone density difference due to charging roller contamination in an extremely low temperature and low humidity environment is 0.05 or more and less than 0.10. C: The halftone density difference due to charging roller contamination in an extremely low temperature and low humidity environment is 0.10 or more and less than 0.15. D: The halftone density difference due to charging roller contamination in an extremely low temperature and low humidity environment is 0.15 or more.

[0318] <Evaluation 12. Line Width Uniformity after Double-Sided Durability in a Low Temperature and Low Humidity Environment> In the same manner as in Evaluation 2, a durability evaluation was carried out in a low-temperature and low-humidity environment under double-sided printing settings. With two double-sided sheets as one job, a horizontal line image with a printing rate of 1.0% and a margin of 5 mm was output 30,000 times (60,000 images).

[0319] After that, after replacing the charging roller with a new one, as the 30,001st sheet (60,001st image), a horizontal line image with 10 horizontal lines spaced 5 mm apart and a leading margin of 5 mm, each line being 4 dots wide, was output once.

[0320] For this horizontal line image, the line width was measured using a magnifying glass, and the difference between the maximum value and the minimum value was obtained. The smaller the difference in line width, the better the line width stability. The evaluation results are shown in Table 11. (Evaluation Criteria) A: The difference in line width is less than 5 μm. B: The difference in line width is 5 μm or more and less than 10 μm. C: The difference in line width is 10 μm or more and less than 15 μm. D: The difference in line width is 15 μm or more.

[0321] <Evaluation 13. Line Width Uniformity of Vertical Thin Line Images in Low-Temperature and Low-Humidity Environments> In the same manner as in Evaluation 2, in a low-temperature and low-humidity environment of 15°C and 10% RH, under double-sided printing settings, a durability evaluation was carried out with two double-sided sheets as one job, outputting 30,000 horizontal line images (60,000 images) with a printing rate of 1.0% and a margin of 5 mm.

[0322] After that, after replacing the charging roller with a new one, as the 30,001st sheet (60,001st image), a vertical line image with 10 vertical lines spaced 5 mm apart and a leading margin of 5 mm, each line being 4 dots wide, was output once.

[0323] For this vertical line image, the line width was measured using a magnifying glass, and the difference between the maximum value and the minimum value was obtained. The smaller the difference in line width, the better the line width stability. The evaluation results are shown in Table 12. (Evaluation Criteria) A: The difference in line width is less than 5 μm. B: The difference in line width is 5 μm or more and less than 10 μm. C: The difference in line width is 10 μm or more and less than 15 μm. D: The difference in line width is 15 μm or more.

[0324] <Evaluation 14. Line Width Uniformity of Vertical Thin Line Images in High Temperature and High Humidity Environment> In the same manner as in Evaluation 3, in a high temperature and high humidity environment of 32.5°C and 85% RH, with double-sided printing settings, two double-sided sheets were considered as one job, and a durability evaluation was carried out to output 30,000 sheets (60,000 images) of horizontal line images with a printing rate of 1.0% and a margin of 5 mm.

[0325] After that, after replacing the charging roller with a new one, as the 30,001st sheet (60,001st image), a vertical line image with 10 vertical lines spaced 5 mm apart and a leading margin of 5 mm was output with 4 dots.

[0326] For this vertical line image, the line width was measured using a loupe, and the difference between the maximum value and the minimum value was obtained. The smaller the difference in line width, the better the line width stability. The evaluation results are shown in Table 12. (Evaluation Criteria) A: The difference in line width is less than 5 μm. B: The difference in line width is 5 μm or more and less than 10 μm. C: The difference in line width is 10 μm or more and less than 15 μm. D: The difference in line width is 15 μm or more.

[0327] [Examples 2 to 33, Comparative Examples 1 to 5] The evaluation toner was set as toner 2 to 33, 34 to 38, and the evaluation was carried out in the same manner as in Example 1. The evaluation results of Examples 2 to 33 and Comparative Examples 1 to 5 are shown in Tables 10 to 12, respectively.

[0328]

Table 10

[0329]

Table 11

[0330]

Table 12

Claims

1. A toner comprising toner particles containing a binder resin and organic-inorganic composite fine particles, wherein the binder resin contains 50% by mass or more of polyester A, The polyester A has a content ratio of unit U derived from isophthalic acid of 60 mol% or more based on all units derived from acid components. iso and the organic-inorganic composite fine particles have a plurality of convex portions derived from inorganic fine particles on the surface of resin particles, the inorganic fine particles have silica fine particles, the resin particles contain an ester group, and the toner is characterized in that.

2. The unit U of the polyester A iso The toner according to claim 1, wherein the content ratio is 90 mol% or more.

3. The polyester A contains a unit U derived from an ethylene oxide adduct of bisphenol A EO and a unit U derived from a propylene oxide adduct of bisphenol A PO and the total content ratio of the unit U EO and the unit U PO is 90 mol% or more based on all units derived from the alcohol component. The toner according to claim 1 or 2

4. the unit U EO content ratio and the unit U PO content ratio, the content ratio of the unit U EO is 15 mol% or more and 40 mol% or less, the toner according to claim 3.

5. When the tetrahydrofuran (THF) soluble content of the polyester A is measured for the number average molecular weight (Mn) and the weight average molecular weight (Mw) using gel permeation chromatography (GPC), the number average molecular weight (Mn) is 3000 or more and 10000 or less, and the ratio (Mw / Mn) is 2.5 or more. The toner according to claim 1 or 2.

6. The toner according to claim 1 or 2, wherein the binder resin contains a crystalline polyester.

7. The toner according to claim 1 or 2, wherein the average circularity of the toner is 0.950 or more and 0.980 or less.

8. The number average particle diameter (D1) of the organic-inorganic composite fine particles is 50 nm or more and 200 nm or less, and the shape factor SF-2 of the organic-inorganic composite fine particles when measured at a magnification of 200,000 times is 103 or more and 120 or less. The toner according to claim 1 or 2.

9. P2 / P1, which is the ratio of the intensity P1 of the peak derived from Si-O and the intensity P2 of the peak derived from C=O obtained by ATR-IR of the organic-inorganic composite fine particles, is 0.05 or more and 0.15 or less. The toner according to claim 1 or 2.

10. Dividing the P2 / P1 by the content ratio of the unit U iso and multiplying the result by 100, the toner according to claim 9, wherein the value is 0.05 or more.

11. The surface exposure rate B of silica of the organic-inorganic composite fine particles measured by X-ray photoelectron spectroscopy is 45% or more. The toner according to claim 1 or 2.

12. When the intensity P3 of the peak derived from the styrene unit and the intensity P2 of the peak derived from C=O are obtained by ATR-IR measurement of the organic-inorganic composite fine particles, the ratio (P2 / P3) is 1.0 or more. The toner according to claim 1 or 2.

13. The toner particles contain 0.015% by mass or more and 0.150% by mass or less of aluminum element. The toner according to claim 1 or 2.

14. The toner according to claim 1 or 2, which contains at least one compound selected from the group consisting of alkylbenzene sulfonic acid and alkylbenzene sulfonate.

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