toner

Abstract

To provide a toner including a positive charge control resin, the toner attaining a charging property and a low-temperature fixation property under a high-temperature and high-moisture environment and a low-temperature and low-moisture environment.SOLUTION: The toner includes toner particles including a binder resin and an ester compound, the binder resin containing a resin A having a specific amount of a long-chain acrylate unit and a monomer unit of styrene and a resin B with a positive charge control property having a specific amount of a specific monomer unit, the ester compound having an alkyl chain with a specific length, the resin A being contained in the chloroform-soluble part of the toner particles A in a concentration of at least 60% by mass, and Spm is in the range from 18.00 to 19.00, both inclusive, when the SP value of the long-chain acrylate unit is SPm (J / cm3)1 / 2 and the SP value of the ester compound is SPw, and the SPm and the SPw satisfying the following expression (a) |SPm-SPw|≤1.50.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to toners used in recording methods that utilize electrophotography, electrostatic recording, and toner jet recording. [Background technology]

[0002] In recent years, the diversification of working styles has led to a diversification of the ways in which electrophotographic printers are used. In addition to traditional use in large offices with well-equipped operating environments, printers are increasingly being used in small offices and at home, creating a greater demand for smaller printers than ever before. Furthermore, with the trend toward globalization, printers must be designed for use in a wide range of regions, from developed to emerging countries, and printers that can output images of consistent quality in environments ranging from low temperature and low humidity to high temperature and high humidity are in demand.

[0003] There is a demand for printers that can output images of consistent quality on media that varies in type and smoothness, with different fillers contained in the paper. From the perspective of printer miniaturization, attention is being paid to electrophotographic printers that do not have cleaning systems, which can reduce the number of parts and waste toner.

[0004] However, if paper containing a large amount of talc (hereinafter referred to as talc paper) is used and the talc in the paper migrates to the photosensitive drum, the talc cannot be removed during the cleaning process. As a result, the talc can migrate into the charging member or the developing container, reducing the toner's triboelectric charging properties and resulting in poor image quality. Furthermore, from the perspectives of environmental friendliness and energy conservation, there is a demand for toner that can be fixed to paper at lower temperatures, and there is also a demand for improved toner melting properties.

[0005] In order to meet such demands and improve the charging characteristics and low-temperature fixing performance of the toner, Patent Document 1 describes a toner that contains a polyfunctional ester wax and a binder resin, and also contains a positive charge control resin that contains a unit derived from styrene and a unit derived from a quaternary ammonium base.

[0006] On the other hand, Patent Document 2 discloses a toner for developing electrostatic images, which contains, as a binder resin, a styrene-acrylic resin having a structural unit derived from a (meth)acrylic acid alkyl ester monomer having 8 to 22 carbon atoms in the alkyl group and a structural unit derived from a (meth)acrylic acid alkyl ester monomer having 1 to 7 carbon atoms in the alkyl group, and which is characterized by containing a crystalline ester compound. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-198569 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-035506 Summary of the Invention [Problem to be solved by the invention]

[0008] Indeed, Patent Document 1 describes that by including a positive charge control resin in the toner, the charging characteristics become good and the print durability in a 23°C / 50%RH environment becomes good. However, since the positive charge control resin containing a quaternary ammonium salt group is highly hygroscopic, the charging characteristics tend to decrease when left for a long period of time in a high-temperature, high-humidity environment. Therefore, when used in a harsh environment such as when using talc paper in a cleanerless system, there is room for improvement in image fogging. There is. Furthermore, when evaluating continuous durability printing in a low-temperature, low-humidity environment, the toner tends to charge up easily. Therefore, when used in harsh environments such as when using talc paper in a cleaner-less system, there is room for improvement in transfer residual fog.

[0009] On the other hand, in Patent Document 2, by using a styrene-acrylic resin, it is possible to control the affinity between a crystalline ester compound and a binder resin, and the melting characteristics of the toner can be improved, thereby improving low-temperature fixability. When such a toner is used as a two-component developer with abundant triboelectric charging opportunities, it can maintain a certain level of image quality even in a high-temperature, high-humidity environment. However, when a cleanerless system is adopted for one-component development with little opportunity for triboelectric charging, there is room for improvement in terms of maintaining stable image quality when durability printing is evaluated under high-temperature, high-humidity environments and low-temperature, low-humidity environments. Note that the toner in Patent Document 2 is a negatively charged toner, and there is no suggestion about a positive charge control resin.

[0010] As described above, there is still room for improvement in the technology for achieving high levels of both chargeability and low-temperature fixability in both high-temperature, high-humidity environments and low-temperature, low-humidity environments in order to accommodate cleanerless and energy-saving applications. The present disclosure provides a toner containing a positive charge control resin that exhibits both chargeability and low-temperature fixability in both high-temperature, high-humidity environments and low-temperature, low-humidity environments. [Means for solving the problem]

[0011] The present disclosure provides a toner having toner particles having a binder resin and an ester compound, The binder resin contains resin A and resin B, The resin A contains a monomer unit represented by the following formula (1) and a monomer unit represented by the following formula (2), In the following formula (1), R 1 represents a hydrogen atom or a methyl group, and R 2 represents a linear alkyl group having 10 to 14 carbon atoms, In the following formula (2), R 21 represents a hydrogen atom or a methyl group, The resin B contains a monomer unit represented by the following formula (3) and a monomer unit represented by the following formula (4), In the following formula (3), R 31 represents a hydrogen atom or a methyl group, and R 32represents a linear or branched alkylene group having 1 to 3 carbon atoms which may be substituted with halogen, and R 33 ~R 35 each independently represents a benzyl group, a phenethyl group, or a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; X represents a counter anion; In the following formula (4), R 22 represents a hydrogen atom or a methyl group, The ester compound is at least one ester compound selected from the group consisting of an ester compound represented by the following formula (5), an ester compound represented by the following formula (6), and an ester compound represented by the following formula (7), In the following formulas (5), (6) and (7), R 36 , R 41 represents an alkylene group having 2 to 8 carbon atoms, and R 37 , R 38 , R 42 , R 43 , R 51 and R 52 each independently represents a linear alkyl group having 14 to 24 carbon atoms, the content of the resin A in the chloroform-soluble matter of the toner particles is 60% by mass or more, the content of the monomer unit represented by formula (1) in the resin A is 1.0% by mass or more and 15.0% by mass or less, the content of the monomer unit represented by formula (2) in the resin A is 48.0% by mass or more, the content of the monomer unit represented by formula (4) in the resin B is 48.0% by mass or more, The SP value of the monomer unit represented by formula (1) is SPm (J / cm 3 ) 1 / 2 year, The SP value of the ester compound is SPw (J / cm 3 ) 1 / 2 When The SPm is 18.00 or more and 19.00 or less, The toner has SPm and SPw satisfying the following formula (a). |SPm-SPw|≦1.50 (a)

[0012] [ka] [ka] [Effects of the Invention]

[0013] According to the present disclosure, it is possible to provide a toner containing a positive charge control resin that exhibits both chargeability and low-temperature fixability in both high-temperature, high-humidity environments and low-temperature, low-humidity environments. DETAILED DESCRIPTION OF THE INVENTION

[0014] In the present disclosure, unless otherwise specified, the expressions "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined in any way.

[0015] The term "monomer unit" refers to the reacted form of a monomer substance in a polymer, and one unit is defined as one section of carbon-carbon bond in the main chain formed by polymerizing a vinyl monomer in a polymer. A vinyl monomer can be represented by the following formula (Z): [ka] [In formula (Z), Z1 represents a hydrogen atom or an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group), and Z2 represents an arbitrary substituent.]

[0016] The toner has positive charging properties because it contains resin B, which has positive charge control properties due to the monomer unit represented by formula (3). The above toner has positive charging properties and stable charging characteristics in high temperature and high humidity environments as well as low temperature and low humidity environments. Therefore, even when a durability test is conducted using talc paper with a large number of printed pages in a cleanerless system, the toner shows good quality in a wide range of usage environments. quality images can be obtained.

[0017] The inventors' investigations revealed that when a print durability test was conducted using talc paper, talc migrated to the photosensitive drum, contaminating the charging member and the toner charging member in the developing unit, reducing the toner's chargeability, and making the image more susceptible to fogging as the number of prints increased. Furthermore, because talc has a negative charge, it was found that electrophotographic systems using positively charged toner tend to be better able to suppress the migration of talc to the photosensitive drum than electrophotographic systems using negatively charged toner.

[0018] However, it has been found that a positively charged toner having a monomer unit represented by formula (3) has good chargeability in a normal temperature and normal humidity environment, but has concerns about environmental stability. As a result of investigations by the present inventors, it has been found that, because the monomer unit represented by formula (3) has high moisture absorption properties, when the toner is left for a long period of time in a high temperature and high humidity environment, for example, the chargeability tends to decrease and fogging tends to occur in non-image areas. On the other hand, when a durability test is conducted in a low-temperature, low-humidity environment with a large number of pages printed continuously, the toner charges up, reducing transfer efficiency. Therefore, when the toner is used in a cleaner-less system, it is easy to generate images where the non-image areas are stained with residual toner (transfer residual fog).

[0019] As a result of intensive research into the above-mentioned problems, the present inventors have found that it is important for the toner to contain Resin B, which is a positively chargeable resin having the above-mentioned specific structure, a specific Resin A, and a specific ester compound. They have also found that by controlling the ratio of the resin and the monomer unit in the chloroform-soluble matter of the toner particles, the charging stability in low-temperature, low-humidity environments and high-temperature, high-humidity environments can be improved, and the low-temperature fixability of the toner can also be improved.

[0020] The present disclosure provides a toner having toner particles having a binder resin and an ester compound, The binder resin contains resin A and resin B, The resin A contains a monomer unit represented by the following formula (1) and a monomer unit represented by the following formula (2), In the following formula (1), R 1 represents a hydrogen atom or a methyl group, and R 2 represents a linear alkyl group having 10 to 14 carbon atoms, In the following formula (2), R 21 represents a hydrogen atom or a methyl group, The resin B contains a monomer unit represented by the following formula (3) and a monomer unit represented by the following formula (4), In the following formula (3), R 31 represents a hydrogen atom or a methyl group, and R 32 represents a linear or branched alkylene group having 1 to 3 carbon atoms which may be substituted with halogen, and R 33 ~R 35 each independently represents a benzyl group, a phenethyl group, or a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; X represents a counter anion; In the following formula (4), R 22 represents a hydrogen atom or a methyl group, The ester compound is at least one ester compound selected from the group consisting of an ester compound represented by the following formula (5), an ester compound represented by the following formula (6), and an ester compound represented by the following formula (7), In the following formulas (5), (6) and (7), R 36 , R41 represents an alkylene group having 2 to 8 carbon atoms, and R 37 , R 38 , R 42 , R 43 , R 51 and R 52 each independently represents a linear alkyl group having 14 to 24 carbon atoms, the content of the resin A in the chloroform-soluble matter of the toner particles is 60% by mass or more, the content of the monomer unit represented by formula (1) in the resin A is 1.0% by mass or more and 15.0% by mass or less, the content of the monomer unit represented by formula (2) in the resin A is 48.0% by mass or more, the content of the monomer unit represented by formula (4) in the resin B is 48.0% by mass or more, The SP value of the monomer unit represented by formula (1) is SPm (J / cm 3 ) 1 / 2 The SP value of the ester compound is SPw (J / cm 3 ) 1 / 2 When The SPm is 18.00 or more and 19.00 or less, The toner has SPm and SPw satisfying the following formula (a). |SPm-SPw|≦1.50 (a)

[0021] [ka] [ka]

[0022] The toner particles contain a binder resin and an ester compound. The binder resin contains a resin A and a resin B. That is, the toner contains a resin A, a resin B, and an ester compound. First, we will explain how the toner particles containing these three materials can exhibit stable positive chargeability in environments ranging from low-temperature, low-humidity to high-temperature, high-humidity.

[0023] The monomer unit represented by formula (1) contained in resin A has a carbon number (R 2 ) is a monomer unit of acrylate or methacrylate having a linear alkyl group in which the number of carbon atoms is 10 or more and 14 or less. Hereinafter, this monomer unit will also be referred to as a "long-chain acrylate unit."

[0024] As a result of investigations by the present inventors, it was found that the long-chain acrylate unit of formula (1) in Resin A has a high affinity with the ester compound, and therefore when both of them coexist in a toner particle, a eutectic structure can be formed in which the ester compound is oriented in the vicinity of the long-chain acrylate unit. This eutectic structure is a highly hydrophobic and dense structure, and has the effect of suppressing moisture adsorption on the surface of the toner particle.

[0025] The synergistic effect of this eutectic structure and the monomer unit represented by formula (3) of resin B, which has high charging ability, allows the toner to maintain an appropriate charge amount even when left for a long period of time in a high-temperature, high-humidity environment, thereby suppressing image fogging. Furthermore, since the toner has monomer units with the same structure or very similar structures in resin A (formula (2)) and resin B (formula (4)), the π-π interaction between the phenyl groups contained in formulas (2) and (4) allows the two to bond to each other. It is possible to form an oriented and packed state.

[0026] This packing structure promotes the exchange of charges between the molecular chains of resin A and resin B within the toner. As a result, even when a durability test is conducted in a low-temperature, low-humidity environment with a large number of printed pages, toner charge-up can be suppressed, high transfer efficiency can be maintained, and transfer residual fog can also be suppressed.

[0027] Next, the mechanism by which the low-temperature fixability of the toner is improved will be described. The toner has a eutectic structure formed by the long-chain acrylate unit and the ester compound and a packing structure due to the π-π interaction, so that the toner has good low-temperature fixability. The inventors believe that this is the case.

[0028] Specifically, when the toner is melted in the nip of the fixing unit, the long-chain acrylate unit of formula (1) has a high affinity with the ester compound, and when the ester compound melts, resin A is quickly plasticized via the long-chain acrylate unit of formula (1). Furthermore, because an interaction due to the packing structure is exerted between resin A and resin B, when resin A melts, resin B is also plasticized via the packing structure.

[0029] In this way, due to the effects of the eutectic structure and the packing structure, micro-melting chains occur within the toner particles in the fixing nip, and the entire toner particle is quickly plasticized, resulting in good low-temperature fixability.

[0030] The toner contains toner particles having an ester compound and a binder resin containing a resin A and a resin B. Each of the constituent elements will be described below. <Resin A> Resin A contains a monomer unit represented by the following formula (1) and a monomer unit represented by the following formula (2). [ka]

[0031] In formula (1), R 1 represents a hydrogen atom or a methyl group, and R 2 represents a linear alkyl group having 10 to 14 carbon atoms. 21 represents a hydrogen atom or a methyl group.

[0032] The long-chain acrylate unit represented by formula (1) has high molecular chain mobility. Therefore, resins containing long-chain acrylate units have a high degree of freedom when melted, making it easy to achieve low viscosity. As mentioned above, the inclusion of the monomer unit represented by formula (1) allows the formation of a eutectic structure with the ester compound, and through the above-mentioned mechanism, it is possible to achieve both charging stability and low-temperature fixability in both high-temperature, high-humidity environments and low-temperature, low-humidity environments.

[0033] Specifically, image fogging is suppressed even when a durability printing test is performed under a high-temperature, high-humidity environment, and transfer residual fogging is suppressed under a low-temperature, low-humidity environment, resulting in good low-temperature fixability. 2 is preferably a linear alkyl group having 11 to 13 carbon atoms, more preferably 12 carbon atoms. This can further improve the charging stability and low-temperature fixability in a high-temperature, high-humidity environment and a low-temperature, low-humidity environment. Specifically, the density stability of halftone images can be further improved even when a durability printing test is performed in a high-temperature, high-humidity environment, and the density stability of solid areas can be further improved when a durability printing test is performed in a low-temperature, low-humidity environment.

[0034] Formula (2) is a monomer unit of styrene or α-methylstyrene. The inclusion of the monomer unit represented by formula (2) improves the chargeability and durability of the toner. Furthermore, as described above, a packing structure can be formed between the monomer unit represented by formula (2) in resin A and the monomer unit represented by formula (4) in resin B. Therefore, the above-described mechanism makes it possible to achieve both charge stability and low-temperature fixability in both high-temperature, high-humidity environments and low-temperature, low-humidity environments. Specifically, image fogging can be suppressed even when a durability printing test is carried out in a high-temperature, high-humidity environment, and transfer residual fogging can be suppressed in a low-temperature, low-humidity environment, resulting in good low-temperature fixability.

[0035] Furthermore, the content of the monomer unit represented by formula (1) in resin A must be 1.0% by mass or more and 15.0% by mass or less. It is preferably 3.0% by mass or more and 15.0% by mass or less. A content of 1.0% by mass or more allows for the formation of a sufficient amount of eutectic structure. It is preferably 3.0% by mass or more, and more preferably 5.0% by mass or more. Meanwhile, since the monomer unit represented by formula (1) has a high concentration of alkyl chains, the absolute amount of charge tends not to be high. Therefore, from the viewpoint of controlling the charge amount of the toner, the content of formula (1) is 15.0% by mass or less. It is preferably 10.0% by mass or less, and more preferably 8.0% by mass or less.

[0036] The content of the monomer unit represented by formula (2) in resin A must be 48.0% by mass or more. When the content of the monomer unit represented by formula (2) is within the above range, the packing structure with the monomer unit represented by formula (4) in resin B is sufficient and uniformly dispersed. Therefore, charging can be stabilized in both high-temperature, high-humidity environments and low-temperature, low-humidity environments, and low-temperature fixability can also be achieved. The content of the monomer unit represented by formula (2) is preferably 51.0% by mass or more, more preferably 71.0% by mass or more, and even more preferably 75.0% by mass or more. There is no particular upper limit, but it is preferably 95.0% by mass or less, more preferably 90.0% by mass or less, and even more preferably 85.0% by mass or less.

[0037] The weight average molecular weight of Resin A is preferably 10,000 or more and 500,000 or less. The weight average molecular weight can be controlled by the reaction temperature, the amount of initiator, and the like when producing Resin A. The glass transition temperature of the resin A is preferably 40° C. or higher and 60° C. or lower. The glass transition temperature can be controlled by the type and amount of the units constituting the resin A.

[0038] As the resin A, known resins can be used simultaneously with the styrene-acrylic resin without any particular limitation, if necessary. Examples of resins that can be used simultaneously with the resin A include vinyl resins other than the styrene-acrylic resin, polyester resins, polyurethane resins, and polyamide resins.

[0039] Resin A may be obtained by polymerization. Examples of polymerizable monomers that form the monomer unit of Resin A represented by formula (1) include acrylic acid esters and methacrylic acid esters having a linear alkyl group having 10 to 14 carbon atoms, such as decyl acrylate, decyl methacrylate, lauryl acrylate, lauryl methacrylate, myristyl acrylate, and myristyl methacrylate. Of these, it is preferable to use lauryl acrylate or lauryl methacrylate.

[0040] The polymerizable monomer forming the monomer unit of resin A represented by formula (2) is styrene or α-methylstyrene, with styrene being particularly preferred.

[0041] Resin A may contain, in addition to the monomer unit represented by formula (1) and the monomer unit represented by formula (2), monomer units of other known polymerizable monomers without particular limitation. Other polymerizable monomers include monofunctional monomers having one polymerizable unsaturated bond in the molecule, such as acrylic acid esters such as methyl acrylate and n-butyl acrylate (n-butyl acrylate); methacrylic acid esters such as methyl methacrylate, 2-hydroxyethyl methacrylate, t-butyl methacrylate, and 2-ethylhexyl methacrylate; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; unsaturated dicarboxylic acids such as maleic acid; unsaturated dicarboxylic acid anhydrides such as maleic anhydride; nitrile-based vinyl monomers such as acrylonitrile; halogen-containing vinyl monomers such as vinyl chloride; and nitro-based vinyl monomers such as nitrostyrene; and polyfunctional monomers having multiple polymerizable unsaturated bonds in the molecule, such as divinylbenzene, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, and trimethylolpropane tri(meth)acrylate.

[0042] Among these, it is preferable to use alkyl acrylate or alkyl methacrylate (preferably having an alkyl group with 1 to 8 carbon atoms (more preferably 1 to 4 carbon atoms)), and it is even more preferable to use n-butyl acrylate. The content of monomer units of (meth)acrylic acid alkyl esters having an alkyl group with 1 to 8 carbon atoms (more preferably 1 to 4 carbon atoms) in Resin A is preferably 0.0 to 45.0 mass%, more preferably 5.0 to 35.0 mass%. The content of monomer units of n-butyl acrylate in Resin A is preferably 0.0 to 20.0 mass%. Furthermore, it is preferable that Resin A has a structure crosslinked with divinylbenzene. The content of the divinylbenzene component in Resin A is preferably 0.1 to 2.0 mass %, more preferably 0.5 to 1.5 mass %.

[0043] The content of the monomer unit represented by formula (3) in resin A is preferably less than 1.0% by mass, more preferably 0.5% by mass or less, even more preferably 0.1% by mass or less, and even more preferably 0.0% by mass. By making the content of the unit of formula (3) in resin A less than 1.0 mass %, it is possible to suppress aggregation between the monomer unit of formula (3) contained in resin A and the monomer unit of formula (3) contained in resin B, making it less likely that localized bias in charging will occur. As a result, it is possible to suppress uneven charging, particularly in low-temperature, low-humidity environments, and the density uniformity of solid images after durability printing tests is further improved.

[0044] <Resin B> The toner particles contain a resin B. The resin B contains a monomer unit represented by the following formula (3) and a monomer unit represented by the following formula (4). [ka]

[0045] In formula (3), R 31 represents a hydrogen atom or a methyl group, and R 32represents a linear or branched alkylene group having 1 to 3 carbon atoms (preferably 1 or 2 carbon atoms, more preferably 2 carbon atoms) which may be substituted with halogen, and R 33 ~R 35 are each independently a benzyl group, a phenethyl group, or a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms (preferably 1 to 3 carbon atoms, more preferably 1 or 2 carbon atoms, and even more preferably 1 carbon atom), and X is a counter anion. Examples of the counter ion include Cl. - , O.H. - Preferably, Cl - R 33 ~R 35 It is preferred that one of R is a benzyl group and the remaining two are a linear or branched alkyl group having 1 to 6 carbon atoms (preferably 1 to 3 carbon atoms, more preferably 1 or 2 carbon atoms, and even more preferably 1 carbon atom). 22 represents a hydrogen atom or a methyl group.

[0046] The monomer unit represented by formula (3) contains a quaternary ammonium salt group and is necessary for exhibiting positive charging properties. The toner has positive charging properties when Resin B contains the monomer unit represented by formula (3). The content of the monomer unit represented by formula (3) in Resin B is preferably 0.2 to 8.0 mass %, more preferably 0.5 to 6.0 mass %, and even more preferably 0.8 to 5.5 mass %.

[0047] The monomer unit represented by formula (4) is a monomer unit of styrene or α-methylstyrene. The eutectic structure formed by the long-chain acrylate unit of formula (1) and the ester compound, and the π-π interaction between formula (2) of resin A and formula (4) of resin B are formed. This results in a packing structure that stabilizes charging in both high-temperature, high-humidity environments and low-temperature, low-humidity environments, and achieves both low-temperature fixability. Specifically, image fogging can be suppressed even when a durability printing test is performed in a high-temperature, high-humidity environment, and transfer residual fogging can be suppressed in a low-temperature, low-humidity environment, resulting in good low-temperature fixability.

[0048] The content of the monomer unit represented by formula (4) in resin B must be 48.0% by mass or more. When the content of the monomer unit represented by formula (4) is within the above range, the packing structure with the formula (2) unit in resin A is in a sufficient amount and is uniformly dispersed. Therefore, charging can be stabilized in both high-temperature, high-humidity environments and low-temperature, low-humidity environments, and low-temperature fixability can also be achieved. The content of the monomer unit represented by formula (4) is preferably 51.0% by mass or more, more preferably is 71.0% by mass or more, and more preferably 75.0% by mass or more. There is no particular upper limit, but it is preferably 95.0% by mass or less, more preferably 90.0% by mass or less, and even more preferably 85.0% by mass or less.

[0049] In addition to the monomer unit represented by formula (3) and the monomer unit represented by formula (4), resin B may also contain a monomer unit of other polymerizable monomers known without particular limitation. As the other polymerizable monomer, the above-mentioned ones can be used. Among these, it is preferable to use alkyl acrylate or alkyl methacrylate (preferably having an alkyl group with 1 to 8 carbon atoms (more preferably 1 to 4 carbon atoms)), and it is even more preferable to use n-butyl acrylate. The content of monomer units of (meth)acrylic acid alkyl esters having an alkyl group with 1 to 8 carbon atoms (more preferably 1 to 4 carbon atoms) in Resin B is preferably 0.0 to 48.0 mass%, more preferably 5.0 to 30.0 mass%. The content of monomer units of n-butyl acrylate in Resin B is preferably 0.0 to 20.0 mass%.

[0050] The content of the monomer unit represented by formula (1) in resin B is preferably less than 1.0% by mass, more preferably 0.5% by mass or less, even more preferably 0.1% by mass or less, and even more preferably 0.0% by mass. By setting the content of the monomer unit represented by formula (1) within the above range, the eutectic structure formed by the monomer unit represented by formula (1) and the ester compound in resin A can be stably present in the vicinity of the monomer unit represented by formula (3) in resin B. This enhances the effect of suppressing moisture adsorption by the eutectic structure, improving the density uniformity of halftone images after a durability printing test under a high-temperature, high-humidity environment.

[0051] <Ester compounds> The toner particles contain at least one ester compound selected from the group consisting of an ester compound represented by the following formula (5), an ester compound represented by the following formula (6), and an ester compound represented by the following formula (7). [ka]

[0052] In formula (5), formula (6) and formula (7), R 36 , R 41 represents an alkylene group having 2 to 8 carbon atoms, and R 37 , R 38 , R 42 , R 43 , R 51 and R 52 each independently represents a linear alkyl group having 14 to 24 carbon atoms (preferably 16 to 24, more preferably 17 to 22). The ester compounds of formulas (5) to (7) have high affinity with the monomer unit of formula (1) of resin A, and therefore easily increase compatibility when melted, enabling good low-temperature fixability to be achieved.

[0053] Furthermore, the ester compound selected from formulas (5) to (7) has a high structural similarity with the long-chain acrylate unit of formula (1), allowing the formation of the aforementioned eutectic structure. Furthermore, the presence of a packing structure between the aforementioned formula (2) of resin A and formula (4) of resin B enhances charging stability in both high-temperature, high-humidity and low-temperature, low-humidity environments. Specifically, image fogging can be suppressed even when a durability printing test is performed in a high-temperature, high-humidity environment, and transfer residual fogging can be suppressed in a low-temperature, low-humidity environment, resulting in good low-temperature fixability.

[0054] Examples of the compound represented by formula (5) include ethylene glycol dipalmitate, ethylene glycol distearate, ethylene glycol dieicosanate, ethylene glycol dibehenate, ethylene glycol ditetracosanate, butanediol distearate, butanediol dibehenate, hexanediol distearate, hexanediol dibehenate, octanediol distearate, and octanediol dibehenate.

[0055] Examples of the compound represented by formula (6) include distearyl succinate, dibehenyl succinate, distearyl adipate, dibehenyl adipate, distearyl suberate, dibehenyl suberate, distearyl sebacate, and dibehenyl sebacate.

[0056] Examples of the compound represented by formula (7) include palmityl palmitate, stearyl palmitate, behenyl palmitate, palmityl stearate, stearyl stearate, behenyl stearate, palmityl behenate, stearyl behenate, and behenyl behenate.

[0057] Among the above ester compounds, at least one selected from the group consisting of ethylene glycol distearate, ethylene glycol dibehenate, dibehenyl sebacate, stearyl behenate, behenyl behenate, and behenyl stearate is preferred, as the ester compound, since it has a melting point and molecular weight within preferred ranges as described below and is likely to form a eutectic structure with the unit of formula (1).

[0058] The melting point of the ester compound is preferably 60° C. or more and 90° C. or less, more preferably 65° C. or more and 85° C. or less. The molecular weight of the ester compound is preferably 500 or more and 900 or less, more preferably 550 or more and 850 or less.

[0059] The content of the ester compound is preferably 1.0 parts by mass or more and 40.0 parts by mass or less, more preferably 3.0 parts by mass or more and 30.0 parts by mass or less, and even more preferably 5.0 parts by mass or more and 25.0 parts by mass or less, relative to 100.0 parts by mass of the binder resin.

[0060] <Content of Resin A in chloroform solubles> The toner exhibits good charge stability in both high-temperature and high-humidity environments and low-temperature and low-humidity environments due to the above-mentioned eutectic structure and the packing structure resulting from π-π interactions, and can also achieve low-temperature fixability. Therefore, the content of the monomer units of formulas (1) and (2) in resin A in the chloroform soluble matter, the content of the monomer units of formulas (1) and (2) in resin A, and the content of the monomer unit of formula (4) in resin B are The content of is controlled.

[0061] Specifically, the content of resin A in the chloroform-soluble matter of the toner particles must be 60% by mass or more. A content of resin A of 60% by mass or more ensures that the eutectic structure composed of the monomer unit of formula (1) and the ester compound is present in a sufficient amount in the toner and is uniformly dispersed. This allows for stable charging in both high-temperature, high-humidity environments and low-temperature, low-humidity environments, while also achieving low-temperature fixability. The content of resin A in the chloroform-soluble matter of the toner particles is more preferably 70% by mass or more. While there is no particular upper limit, it is preferably 100% by mass or less, more preferably 99% by mass or less, and even more preferably 98% by mass or less.

[0062] To control the content ratio of Resin A in the chloroform-soluble portion of toner particles, it is preferable to control the blending amounts of Resin A and Resin B in the toner manufacturing process. Further, regarding the content ratio (by mass) of Resin A and Resin B in the chloroform-soluble portion, it is preferable that Resin A:Resin B = 60:40 to 99.9:0.1 from the viewpoint of achieving both charging stability and low-temperature fixing performance under high-temperature and high-humidity environments and low-temperature and low-humidity environments. More preferably, Resin A:Resin B = 80:20 to 99.7:0.3, and even more preferably, Resin A:Resin B = 90:10 to 99.5:0.5.

[0063] The content ratio of Resin A in the binder resin is preferably 60.0 to 99.5% by mass, more preferably 80.0 to 99.0% by mass, and even more preferably 90.0 to 98.0% by mass. The content ratio of Resin B in the binder resin is preferably 0.5 to 40.0% by mass, more preferably 1.0 to 30.0% by mass, and even more preferably 1.5 to 10.0% by mass.

[0064] <SP value> Let the SP value of the monomer unit represented by formula (1) be SPm (J / cm 3 ) 1 / 2 and let the SP value of the ester compound be SPw (J / cm 3 ) 1 / 2 At this time, it is necessary that SPm is 18.00 or more and 19.00 or less, and SPm and SPw satisfy the following formula (a). │SPm - SPw│≦1.50 ···(a)

[0065] Since SPm is 18.00 or more, the polarity of the monomer unit becomes moderately high, so the charging property under high-temperature and high-humidity environments is maintained high, and the occurrence of durable standing fogging can be suppressed. Since SPm is 19.00 or less, the polarity of the monomer unit is not excessively high, so charge-up under low-temperature and low-humidity environments is suppressed, and transfer residual fogging can be suppressed. SPm is preferably 18.50 to 18.90. Furthermore, SPw is preferably from 17.00 to 18.50, and more preferably from 17.40 to 18.20.

[0066] By satisfying |SPm-SPw|≦1.50, the affinity between the monomer unit of formula (1) and the ester compound is high, allowing the monomer unit of formula (1) and the ester compound to form a eutectic structure. This results in good charge stability in high-temperature, high-humidity environments, and good low-temperature fixability. |SPm-SPw| is preferably 1.30 or less, and more preferably 1.20 or less. While there is no particular lower limit, it is preferably 0.00 or more, 0.30 or more, or 0.50 or more.

[0067] SPw, the SP value of the ester compound, is calculated according to Fedors. SPm, the SP value of the monomer unit, is calculated according to the calculation method proposed by Fedors. , is calculated as follows: Here, the monomer unit constituting resin A means, when resin A is a vinyl resin (when a polymer constituting the resin is produced by a polymerization reaction of a vinyl monomer), a molecular structure in which the double bond of the vinyl monomer is cleaved by polymerization.

[0068] For example, the SP value (SPm) of a monomer unit (J / cm 3 ) 1 / 2 When calculating the evaporation energy (Δei) (J / mol) and molar volume (Δvi) (cm) for the atom or atomic group in the molecular structure of the monomer unit, refer to the table in "Polym. Eng. Sci., 14(2), 147-154 (1974)". 3 / mol) and calculate using the following formula: SPm=(ΣΔei / ΣΔvi) 1 / 2 The unit of SP value is (J / cm 3 ) 1 / 2 However, 1 (cal / cm 3 ) 1 / 2 =2.046×10 -3 (J / cm 3 )1 / 2 by (cal / cm 3 ) 1 / 2 can be converted into units of

[0069] <Sulfide group> Resin A preferably has at least one selected from the group consisting of a sulfide group and a disulfide group. The structure of a sulfide group is represented by RS-R', and is a structure in which the oxygen of an ether is replaced with sulfur. Sulfide groups and disulfide groups have unpaired electrons, and therefore have good charge transfer properties. When Resin A has a sulfide group or a disulfide group, the charge transfer properties within Resin A and the charge transfer properties between Resin A and Resin B can be further promoted, and the charge uniformity of the toner can be further improved.

[0070] This effect can further suppress charge-up in low-temperature, low-humidity environments, and can further suppress residual transfer fog and density fluctuations in solid images after durable printing. Furthermore, the toner is more uniformly charged when transferred onto paper, allowing it to pass through the fixing nip with a high electrostatic adhesion to the paper, further improving the low-temperature fixability of the toner. This is particularly preferred because it can further improve the adhesion of the toner to talc paper.

[0071] As a means for introducing sulfide groups into Resin A, for example, the following compounds are preferably added: mercaptans such as t-dodecyl mercaptan, n-dodecyl mercaptan, and n-octyl mercaptan; and disulfides such as tetraethylthiuranium disulfide. Resin A preferably has a sulfide group or disulfide group formed by at least one selected from the group consisting of the above-mentioned mercaptans and disulfides. Resin A more preferably has a disulfide group formed by tetraethylthiuranium disulfide. Resin A preferably contains 0.2 to 2.6% by mass, more preferably 0.4 to 1.6% by mass, of the components of the above-mentioned mercaptans and disulfides.

[0072] <Monomer unit of formula (8)> Resin A preferably further contains a monomer unit represented by the following formula (8). [ka]

[0073] When Resin A contains the monomer unit of formula (8), the positive chargeability of the toner is further enhanced. As a result, image fogging in a high-temperature, high-humidity environment and residual fogging after transfer in a low-temperature, low-humidity environment can be further suppressed. Although not particularly limited, it is preferable that the monomer unit of formula (8) be more likely to be present near the surface of the toner particles, as this is advantageous for charge buildup. Therefore, it is also preferable that the monomer that forms the monomer unit of formula (8) be added in the latter half of the toner production process. The content of the monomer unit represented by formula (8) in the resin A is preferably 0.0 to 35.0 mass %, more preferably 0.2 to 5.0 mass %, and even more preferably 0.5 to 2.0 mass %.

[0074] <Loss modulus G"> In the dynamic viscoelasticity measurement of the toner, the loss modulus G" of the toner at 100°C was 3.0 x 10 5 (dyn / cm 2 ) or less, more preferably 7.0 × 10 4 (dyn / cm 2 ) or less. Within the above range, the low-temperature fixability is further improved. Furthermore, when the loss modulus at 100°C is within the above range, the fluidity of the molten toner increases in the fixing nip, and the toner deforms and fixes in accordance with the unevenness of the paper, which is preferable because it further improves the adhesion to the paper. There is no particular lower limit for the loss modulus, but it is preferably 2.0 x 10 4 (dyn / cm 2 ) or more, more preferably 4.0 × 10 4 (dyn / cm 2 )That's all. Control of the loss modulus G" of toner at 100°C can be roughly divided into control of the binder resin and control of the ester compound. With regard to the binder resin, the loss modulus G" can be controlled by adjusting the molecular weight, the content of the molecular weight modifier, the type and content of the monomer in formula (1), the amounts of resin A and resin B, and changing the material type of the monomer that makes up the binder resin. The loss modulus G" can be controlled by the content of the ester compound in the toner and the type of ester compound.

[0075] <Average circularity of toner> The average circularity of the toner is preferably 0.94 or more and 0.99 or less, and more preferably 0.97 or more and 0.99 or less, from the viewpoint of further improving transferability.

[0076] In particular, when rough paper with large irregularities is used, uneven toner transfer occurs in the convex and concave parts of the paper, and the toner cannot be sufficiently transferred to the concave parts of the paper, resulting in uneven density in the solid image. By making the average circularity of the toner 0.97 or more, transferability can be further improved, and more uniform solid images can be obtained even in the latter half of the durability printing test.

[0077] On the other hand, the average circularity is 0.99 or less, which prevents the dot image from scattering when transferred. The method for measuring the average circularity of the toner will be described later.

[0078] <Average major axis of domain r1> When a cross section of the toner is observed using a scanning transmission electron microscope, it is preferable that domains of the ester compound are present in the cross section of the toner, the average number of the domains in the cross section of the toner is 100 or more, and when the average major axis of the domains is r1 (μm), r1 is 1.00 μm or less. The average number of domains is more preferably 130 or more, even more preferably 150 or more, particularly preferably 200 or more, and best still 250 or more. On the other hand, there is no particular upper limit, but it is preferably 10,000 or less, more preferably 5,000 or less, even more preferably 1,000 or less, and even more preferably 600 or less. The average major axis r1 is more preferably 0.50 μm or less, even more preferably 0.3 μm or less, particularly preferably 0.20 μm or less, and best 0.10 μm or less. On the other hand, there is no particular lower limit, but it is preferably 0.001 μm or more.

[0079] An r1 of 1.00 μm or less means that the ester compound is finely divided in the toner particles, and the eutectic structure formed by the monomer unit of formula (1) and the ester compound is more easily dispersed uniformly within the toner particles. This increases the charging uniformity within the toner particles, further improving the toner transferability, especially when using rough paper with large irregularities, and making it easier to obtain more uniform solid images even in the latter half of the durability printing test.

[0080] In order to set r1 within the above range, it is preferable to set the type and content of the monomer of formula (1) in resin A and the content of the ester compound within appropriate ranges, and to set the quenching rate and annealing conditions in the toner production method within appropriate ranges.

[0081] <Surface nitrogen index> When the toner is measured by X-ray photoelectron spectroscopy (ESCA), the surface nitrogen content index, which is the amount of N (nitrogen atoms) present relative to the total of C (carbon atoms), N (nitrogen atoms), O (oxygen atoms), and Si (silicon atoms), is preferably 0.2 atomic % to 5.0 atomic %, more preferably 0.4 atomic % to 2.0 atomic %, and even more preferably 0.6 atomic % to 1.5 atomic %. A surface nitrogen content index of 0.2 atomic% or more stabilizes the toner charge amount in a high-temperature, high-humidity environment, resulting in better density stability of halftone images even in print durability tests. On the other hand, a surface nitrogen content index of 5.0 atomic% or less stabilizes the toner charge amount in a low-temperature, low-humidity environment, making it easier to obtain more uniform solid images even in durability print tests.

[0082] The surface nitrogen index can be controlled as follows. The surface nitrogen index can be increased by increasing the amount of the monomer unit of formula (3) contained in resin B near the toner surface. Because the monomer unit of formula (3) is a highly polar unit, the surface nitrogen index can be easily increased by using a suspension polymerization method to produce toner in an aqueous medium. This can also be adjusted by adjusting the content of resin B within a preferred range. Furthermore, when suspension polymerization is used, the amount of surface nitrogen can be controlled by controlling the interaction between resin A and resin B. Specifically, the type and content of the monomer unit represented by formula (1) in the resin A are adjusted to a preferred range, and the resin A has at least one selected from the group consisting of a sulfide group and a disulfide group. Both resins have a suitable degree of hydrophobicity, and the monomer unit of formula (3) contained in resin B tends to be oriented near the toner surface, which tends to increase the amount of surface nitrogen.

[0083] <Release agent> The toner particles may contain a known wax as a release agent in addition to the above specific ester compound. Examples of release agents include petroleum waxes and derivatives thereof, such as paraffin wax, microcrystalline wax, and petrolatum, montan wax and derivatives thereof, hydrocarbon waxes and derivatives thereof produced by the Fischer-Tropsch process, polyolefin waxes and derivatives thereof, such as polyethylene, and natural waxes and derivatives thereof, such as carnauba wax and candelilla wax. The derivatives also include oxides, block copolymers with vinyl monomers, and graft-modified products. These may be used alone or in combination. The content of the release agent other than the ester compound is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the binder resin.

[0084] <Coloring agent> The toner particles may contain a colorant, which may be any of known pigments and dyes of black, yellow, magenta, cyan, and other colors, magnetic materials, and the like, without any particular limitation. Examples of black colorants include black pigments such as carbon black. Examples of yellow colorants include yellow pigments and yellow dyes such as monoazo compounds, disazo compounds, condensed azo compounds, isoindolinone compounds, benzimidazolone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specific examples include CI Pigment Yellow 74, 93, 95, 109, 111, 128, 155, 174, 180, and 185, and CI Solvent Yellow 162.

[0085] Examples of magenta colorants include magenta pigments and magenta dyes such as monoazo compounds, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specific examples include CI 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, 238, 254, 269, and CI Pigment Violet 19.

[0086] Examples of cyan colorants include cyan pigments and cyan dyes such as copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds. Specific examples include CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66. The content of the colorant is preferably 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin or polymerizable monomer.

[0087] The toner may also contain a magnetic material to form a magnetic toner, in which case the magnetic material may also serve as a colorant. Magnetic materials include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel, or combinations of these metals with aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, and cadmium. Examples of the alloy include alloys with metals such as aluminum, calcium, manganese, selenium, titanium, tungsten, and vanadium, and mixtures thereof. When a magnetic material is used as the colorant, the content of the magnetic material is preferably 30.0 parts by mass or more and 100.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin.

[0088] <Other charge control agents> The toner contains resin B as a positive charge control agent. The toner may contain other charge control agents within the range that does not impair the above-mentioned effects. There are no particular restrictions on the other charge control agents that can be contained, and known ones can be used. For example, negative charge control agents include metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, and dicarboxylic acids, or polymers or copolymers having metal compounds of the aromatic carboxylic acids; polymers or copolymers having sulfonic acid groups, sulfonate salt groups, or sulfonate ester groups; metal salts or metal complexes of azo dyes or azo pigments; boron compounds, silicon compounds, and calixarenes.

[0089] On the other hand, examples of the positive charge control agent include quaternary ammonium salts, polymeric compounds having quaternary ammonium salts in the side chains, guanidine compounds, nigrosine compounds, imidazole compounds, etc. As the polymer or copolymer having a sulfonate group or a sulfonate ester group, a homopolymer of a sulfonate group-containing vinyl monomer such as styrene sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, vinyl sulfonic acid, or methacrylic sulfonic acid, or a copolymer of a vinyl monomer and a sulfonate group-containing vinyl monomer as shown in the binder resin section, etc., can be used. The content of the other charge control agent is preferably 0.01 parts by mass or more and 5.0 parts by mass or less relative to 100.0 parts by mass of the resin A.

[0090] <External additives> The toner may also contain external additives. As the external additive, any known external additive can be used without any particular limitation. Examples of external additives include raw silica microparticles such as wet-process silica and dry-process silica, or surface-treated silica microparticles obtained by surface-treating such raw silica microparticles with a treating agent such as a silane coupling agent, a titanium coupling agent, or silicone oil; metal oxide microparticles such as titanium oxide microparticles, aluminum oxide microparticles, zinc oxide microparticles, and tin oxide microparticles, or metal oxide microparticles obtained by hydrophobizing metal oxides; fatty acid metal salts such as zinc stearate, calcium stearate, and zinc stearate; metal complexes of aromatic carboxylic acids such as salicylic acid, alkyl salicylic acid, dialkyl salicylic acid, naphthoic acid, and dicarboxylic acid; clay minerals such as hydrotalcite; fluorine-based resin microparticles such as vinylidene fluoride microparticles and polytetrafluoroethylene microparticles; inorganic microparticles such as calcium carbonate, calcium phosphate, and cerium oxide; and organic microparticles such as polymethyl methacrylate resin, silicone resin, and melamine resin. From the viewpoint of fluidity and charging stability, it is preferable to use silica fine particles obtained by treating the original silica fine particles with silicone oil. The content of the external additive in the toner is preferably 0.1 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particles.

[0091] <Production of toner particles> Known methods can be used to produce toner particles, and kneading and grinding methods and wet production methods can be used. From the viewpoint of uniform particle size and shape controllability, wet production methods are preferably used. Further, wet production methods include suspension polymerization, dissolution suspension, and emulsion aggregation methods, and these methods are suitable for forming a eutectic structure between the monomer unit of formula (1) and the ester compound. From this viewpoint, it is preferable to use the suspension polymerization method.

[0092] The suspension polymerization method will be described below. In the suspension polymerization method, a polymerizable monomer composition is obtained by uniformly dissolving or dispersing a polymerizable monomer that forms resin A, resin B, and an ester compound (and, if necessary, a colorant, polymerization initiator, crosslinking agent, charge control agent, and other additives). This polymerizable monomer composition is then dispersed in a continuous layer (e.g., an aqueous phase) containing a dispersant using an appropriate stirrer, and a polymerization reaction is simultaneously carried out to obtain toner particles having a desired particle size. The toner particles obtained by this suspension polymerization method (hereinafter also referred to as "polymerized toner particles") have an approximately spherical shape, and therefore a relatively uniform charge distribution, which is expected to improve image quality.

[0093] In the production of polymerized toner particles, examples of the polymerizable monomer that constitutes the polymerizable monomer composition include the following. It is preferable to use a monovinyl monomer as the polymerizable monomer. Examples of the monovinyl monomer include styrene, styrene derivatives such as vinyltoluene and α-methylstyrene, acrylic acid and methacrylic acid, acrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and dimethylaminoethyl acrylate, methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, and dimethylaminoethyl methacrylate, nitrile compounds such as acrylonitrile and methacrylonitrile, amide compounds such as acrylamide and methacrylamide, and olefins such as ethylene, propylene, and butylene.

[0094] Among these, it is preferable that the monovinyl monomer contains at least one selected from the group consisting of styrene, a styrene derivative, an acrylic acid ester, and a methacrylic acid ester, and more preferably contains at least one selected from the group consisting of styrene and a styrene derivative, and at least one selected from the group consisting of an acrylic acid ester and a methacrylic acid ester, as the monovinyl monomer. These monovinyl monomers can be used either alone or in combination of two or more.

[0095] The polymerizable monomer preferably contains a monovinyl monomer as a main component. Specifically, the content of the monovinyl monomer in the polymerizable monomer is preferably 50% by mass to 100% by mass.

[0096] Examples of polymerization initiators used in the polymerization production of toner particles include persulfates such as potassium persulfate and ammonium persulfate; azo compounds such as 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobisisobutyronitrile; and organic peroxides such as di-t-butyl peroxide, benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, t-butylperoxydiethylacetate, t-hexylperoxy-2-ethylbutanoate, diisopropyl peroxydicarbonate, di-t-butylperoxyisophthalate, and t-butylperoxyisobutyrate. These can be used alone or in combination of two or more. Among these, it is preferable to use organic peroxides, since they can reduce the amount of residual polymerizable monomers and provide excellent print durability.

[0097] Among organic peroxides, it has good initiator efficiency and can reduce residual polymerizable monomers. Peroxyesters are preferred because they can be used in combination with other peroxyesters, and non-aromatic peroxyesters, i.e., peroxyesters without an aromatic ring, are more preferred. As described above, the polymerization initiator may be added after the polymerizable monomer composition is dispersed in an aqueous medium and before droplets are formed, or may be added to the polymerizable monomer composition before it is dispersed in an aqueous medium.

[0098] The amount of the polymerization initiator used for polymerizing the polymerizable monomer composition is preferably 0.1 to 20 parts by mass, more preferably 0.3 to 15 parts by mass, and particularly preferably 1 to 10 parts by mass, relative to 100 parts by mass of the polymerizable monomer.

[0099] When the toner particles are produced by a polymerization method, a crosslinking agent may be added. The amount of the crosslinking agent added is preferably 0.001 to 15 parts by mass per 100 parts by mass of the polymerizable monomer.

[0100] As the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used. Specific examples include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof; ester compounds in which two or more carboxylic acids having carbon-carbon double bonds are ester-bonded to alcohols having two or more hydroxyl groups, such as ethylene glycol dimethacrylate and diethylene glycol dimethacrylate; other divinyl compounds such as N,N-divinylaniline and divinyl ether; and compounds having three or more vinyl groups. These crosslinking agents can be used either alone or in combination of two or more.

[0101] As other additives, it is preferable to use a molecular weight modifier when polymerizing the polymerizable monomer that becomes the binder resin after polymerization. The molecular weight modifier is not particularly limited as long as it is one generally used as a molecular weight modifier for toners, but a molecular weight modifier having a sulfide group and / or a disulfide group is preferred. Examples include mercaptans such as t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, and 2,2,4,6,6-pentamethylheptane-4-thiol; and thiuram disulfides such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, N,N'-dimethyl-N,N'-diphenylthiuram disulfide, and N,N'-dioctadecyl-N,N'-diisopropylthiuram disulfide. These molecular weight modifiers may be used alone or in combination of two or more. The molecular weight modifier is used in an amount of preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the polymerizable monomer.

[0102] In a method for producing toner particles by polymerization, the above-mentioned raw materials for the toner particles are generally added appropriately, and the polymerizable monomer composition is uniformly dissolved or dispersed using a dispersing machine such as a homogenizer, a ball mill, or an ultrasonic dispersing machine, and then suspended in an aqueous medium containing a dispersing agent. At this time, if a high-speed dispersing machine such as a high-speed stirrer or an ultrasonic dispersing machine is used to quickly obtain the desired toner particle size, the particle size of the obtained toner particles will become sharper.

[0103] The polymerization initiator may be added simultaneously with the addition of other additives to the polymerizable monomer, or may be mixed immediately before suspending the polymerizable monomer in an aqueous medium. Alternatively, the polymerization initiator dissolved in the polymerizable monomer or solvent may be added immediately after granulation and before starting the polymerization reaction. After granulation, a conventional stirrer may be used to stir the mixture to such an extent that the particle state is maintained and the particles are prevented from floating or settling.

[0104] When producing toner particles, known surfactants, organic dispersants, and inorganic dispersants can be used as dispersants. In particular, inorganic dispersants are preferred because they provide dispersion stability through their steric hindrance, which means they are resistant to changes in reaction temperature and are easy to wash away, without adversely affecting the toner. Examples of such inorganic dispersants include sulfates such as barium sulfate and calcium sulfate; carbonates such as barium carbonate, calcium carbonate, and magnesium carbonate; phosphates such as calcium phosphate; metal oxides such as aluminum oxide and titanium oxide; and metal hydroxides such as aluminum hydroxide, magnesium hydroxide, sodium hydroxide, and ferric hydroxide.

[0105] These inorganic dispersants are preferably used in an amount of 0.2 to 20 parts by mass per 100 parts by mass of the polymerizable monomer. The dispersants may be used alone or in combination. Furthermore, a surfactant may be used in an amount of 0.001 to 0.1 parts by mass.

[0106] In the step of polymerizing the polymerizable monomer, the polymerization temperature is preferably 50° C. or higher, more preferably 60 to 95° C. The polymerization reaction time is preferably 1 to 20 hours, more preferably 2 to 15 hours.

[0107] The toner particles are preferably core-shell type (also called "capsule type") toner particles having a core particle containing a binder resin and a shell (preferably different from the core particle) on the surface of the core particle. The core-shell type toner particles can achieve a balance between lowering the fixing temperature and preventing aggregation during storage by coating the core particle made of a material having a low softening point with a material having a higher softening point. The shell does not need to cover the entire core particle, and the core particle may be exposed on the surface of the toner particle.

[0108] The method for producing the core-shell type toner particles using the above-mentioned polymer particles is not particularly limited, and they can be produced by a conventionally known method. Among them, an in situ polymerization method or a phase separation method is preferred from the viewpoint of production efficiency.

[0109] A method for producing core-shell type toner particles by in situ polymerization will be described below. Core-shell type polymer particles can be obtained by adding a polymerizable monomer for forming a shell (polymerizable monomer for shell) and a polymerization initiator to an aqueous medium in which core particles are dispersed, and polymerizing them.

[0110] As the polymerizable monomer for the shell, the same polymerizable monomers as those described above can be used. Among them, it is preferable to use monomers that can give polymers with a glass transition temperature (Tg) exceeding 80°C, such as styrene, acrylonitrile, and methyl methacrylate, either alone or in combination. Of these, it is preferable to use at least methyl methacrylate as the polymerizable monomer for the shell.

[0111] The shell preferably contains a polymer of a (meth)acrylic acid alkyl ester. The (meth)acrylic acid alkyl ester is preferably at least one (meth)acrylic acid alkyl ester selected from the group consisting of (meth)acrylic acid alkyl esters having an alkyl group of 1 to 4 carbon atoms (more preferably 1 or 2). The (meth)acrylic acid alkyl ester having an alkyl group of 1 to 4 carbon atoms refers to an ester of (meth)acrylic acid and an alcohol having 1 to 4 carbon atoms. The shell more preferably contains a methyl methacrylate polymer. That is, the shell more preferably has a monomer unit represented by the formula (8). The content ratio of the shell in the toner particles is 0.1 to 2.0. The content is preferably 0.5 to 1.5 mass %, more preferably 0.5 to 1.5 mass %.

[0112] Examples of polymerization initiators used in the polymerization of the shell polymerizable monomer include water-soluble polymerization initiators such as metal persulfates, such as potassium persulfate and ammonium persulfate; and azo initiators, such as 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2'-azobis-(2-methyl-N-(1,1-bis(hydroxymethyl)2-hydroxyethyl)propionamide), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine], and hydrates thereof. These can be used alone or in combination of two or more. The amount of polymerization initiator is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the shell polymerizable monomer.

[0113] When the phase separation method is used, it is preferable to add a polymer obtained by prepolymerizing a substance that forms the shell to the polymerizable monomer that forms the core. When a prepolymerized polymer is used, it is more preferable that the prepolymer is a reactive polymer having an unsaturated bond.

[0114] The polymerization temperature for the shell is preferably 50° C. or higher, more preferably 60 to 95° C. The polymerization reaction time is preferably 1 to 20 hours, more preferably 2 to 15 hours.

[0115] The resulting polymer particles can be filtered, washed, and dried as needed by known methods to obtain toner particles. If necessary, a classification step can be performed to remove coarse particles and fine particles contained in the toner particles.

[0116] The obtained toner particles can be used as they are. Alternatively, the toner can be obtained by mixing an external additive (external additive) with the toner particles as needed and attaching it to the surface of the toner particles. The external additives can be those mentioned above.

[0117] The agitator used for the mixing treatment is not particularly limited as long as it is an agitator that can adhere the external additive to the surface of the toner particles. For example, the external addition treatment can be performed using an agitator capable of mixing and stirring, such as FM Mixer (trade name, manufactured by Nippon Coke and Engineering Co., Ltd.), Super Mixer (trade name, manufactured by Kawada Manufacturing Co., Ltd.), Q Mixer (trade name, manufactured by Nippon Coke and Engineering Co., Ltd.), Mechanofusion System (trade name, manufactured by Hosokawa Micron Corporation), and Mechano Mill (trade name, manufactured by Okada Seiko Co., Ltd.).

[0118] The volume average particle diameter (Dv) of the toner is preferably 3.00 μm to 9.00 μm, and more preferably 5.00 μm to 8.00 μm. By setting the volume average particle diameter (Dv) of the toner in the above range, the toner can be easily handled while fully satisfying dot reproducibility. The ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of the toner is preferably 1.25 or less, and more preferably less than 1.25. The Dv and Dv / Dn of the toner can be controlled by the amount of dispersant, the type of agitator, the rotation speed, etc.

[0119] The weight-average molecular weight (Mw) of the binder resin is preferably 10,000 to 300,000, more preferably 15,000 to 260,000, and even more preferably 20,000 to 230,000. When the weight-average molecular weight of the binder resin is 300,000 or less, low-temperature fixability tends to be improved. When the weight-average molecular weight of the binder resin is 10,000 or more, heat-resistant storage stability tends to be improved.

[0120] The molecular weight distribution (Mw / Mn) of the binder resin is preferably 2 to 40, more preferably 3 to 35, and even more preferably 3 to 23. When the molecular weight distribution is 40 or less, low-temperature fixability and storage stability tend to be improved. When the molecular weight distribution is 2 or more, hot offset resistance tends to be improved.

[0121] The methods for measuring the various physical properties according to the present disclosure are described below. <Measurement of the content of Resin A in the chloroform soluble matter of toner particles by gradient polymer elution chromatography (GPEC)> The chloroform-soluble portion of the toner particles is used as the 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 before measurement. The gradient polymer LC measurement conditions are as follows: Equipment: UlTIMATE3000 (Thermo Fisher Scientific) Mobile phase: A chloroform (HPLC), B acetonitrile (HPLC) Gradient: 2 min (A / B = 0 / 100) → 25 min (A / B = 100 / 0) (The gradient of the mobile phase change was made linear.) Flow rate: 1.0mL / min Injection: 0.1% by mass x 20μL Column: Tosoh TSKgel ODS (4.6 mm diameter x 150 mm x 5 μm) Column temperature: 40℃ Detector: Corona Charged Aerosol Detector (Corona-CAD) (Therm Fisher Scientific)

[0122] In the chromatograph (time-intensity) of this measurement, a peak signal appears at a time (chloroform / acetonitrile concentration) that depends on the polarity of the material. For the chromatograph (time-intensity) obtained in the measurement, the following Sa and Sb values are calculated, and the content of resin A in the binder resin is calculated from Sa / (Sa+Sb) x 100(%). Sa value: integral value of the peak corresponding to resin A (time 10 to 13 minutes) Sb value: Integrated value of the peak corresponding to Resin B (time 4 minutes to 9.9 minutes)

[0123] (Separation of toner particles from toner) If necessary, the measurement can be carried out using toner particles from which external additives have been removed by the following method. Add 160 g of sucrose (Kishida Chemical) to 100 mL of ion-exchanged water and dissolve in a hot water bath to prepare a sucrose concentrate. Add 31 g of the sucrose concentrate and 6 mL of Contaminon N (a 10% by weight aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of nonionic surfactants, anionic surfactants, and organic builders, manufactured by Wako Pure Chemical Industries, Ltd.) to a centrifuge tube (50 mL). Add 1.0 g of toner and break up any clumps with a spatula. Shake the centrifuge tube at 300 strokes per minute (spm) for 20 minutes using a shaker (AS-1N, AS ONE Corporation). After shaking, transfer the solution to a 50 mL glass tube for a swing-out rotor and separate it in a centrifuge (H-9R, Kokusan Corporation) at 3500 rpm for 30 minutes. This operation separates the toner particles from the external additives. Visually confirm that the toner particles and aqueous solution have been sufficiently separated, and collect the toner particles that have separated to the top layer with a spatula or similar. The collected toner particles are filtered through a vacuum filter and then dried in a dryer for at least one hour to obtain a sample for measurement. This operation is repeated multiple times to ensure the required amount.

[0124] <Composition analysis of Resin A and Resin B> The chloroform-soluble portion of the toner particles is used as the 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 before measurement. The gradient polymer LC measurement conditions are as follows: Equipment: UlTIMATE3000 (Thermo Fisher Scientific) Mobile phase: A chloroform (HPLC), B acetonitrile (HPLC) Gradient: 2 min (A / B = 0 / 100) → 25 min (A / B = 100 / 0) (The gradient of the mobile phase change was made linear.) Flow rate: 1.0mL / min Injection: 0.1% by mass x 20μL Column: Tosoh TSKgel ODS (4.6 mm diameter x 150 mm x 5 μm) Column temperature: 40℃ Detector: Corona Charged Aerosol Detector (Corona-CAD) (Therm Fisher Scientific)

[0125] Resin A is separated at a time corresponding to Resin A (10 to 13 minutes). Resin B is separated at a time corresponding to Resin B (4 to 9.9 minutes). For separation, the required amount of each chloroform / acetonitrile solution is collected, dried, and concentrated to obtain samples of Resin A and Resin B components. Using samples of resin component A and resin component B, the composition ratio and mass ratio are measured by nuclear magnetic resonance spectroscopy (NMR) as follows.

[0126] 1 mL of deuterated chloroform is added to 20 mg samples of resin component A and resin component B, and the proton NMR spectrum of the dissolved resin is measured. The molar and mass ratios of each monomer are calculated from the obtained NMR spectrum, and the content 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 at around 6.5 ppm derived from the styrene monomer and the peak at around 3.5-4.0 ppm derived from the acrylic monomer. The following equipment and measurement conditions can be used for nuclear magnetic resonance spectroscopy (NMR). NMR device: JEOL RESONANCE ECX500 Observed nucleus: proton Measurement mode: Single pulse

[0127] <Molecular weight measurement of ester compounds by mass spectrometry> Separation of ester compounds from toner The molecular weight of the ester compound in the toner can be determined by measuring the toner, but it is more preferable to measure it after carrying out a separation operation. The toner is dispersed in ethanol, a poor solvent for the toner, and the temperature is raised to a temperature above the melting point of the ester compound. Pressure may be applied at this time if necessary. By this operation, the ester compound exceeds its melting point and is melted and extracted into the ethanol. If pressure is applied in addition to heating, the ester compound can be separated from the toner by performing solid-liquid separation while still under pressure. The extract is then dried and solidified to obtain the ester compound. The ester compound can be identified and its molecular weight measured by pyrolysis GCMS using the following equipment and measurement conditions. Mass spectrometer: ISQ manufactured by ThermoFisher Scientific GC equipment: ThermoFisher Scientific FocusGC Ion source temperature: 250℃ Ionization method: EI Mass range: 50-1000m / z Column: HP-5MS [30 m] Pyrolysis equipment: Japan Analytical Industry Co., Ltd. JPS-700

[0128] A small amount of the ester compound separated by extraction and 1 μL of tetramethylammonium hydroxide (TMAH) are added to a pyrofoil at 590°C. The resulting sample is subjected to pyrolysis GCMS measurement under the above conditions, and peaks are obtained for the alcohol and carboxylic acid components derived from the ester compound. The alcohol and carboxylic acid components are detected as methylated products due to the action of the methylating agent TMAH. The molecular weight of the ester compound can be determined by analyzing the peaks obtained and identifying the structure of the ester compound. When the ester compound is identified and its molecular weight is measured by the direct introduction method, the following apparatus and measurement conditions can be used. Mass spectrometer: ISQ manufactured by ThermoFisher Scientific Ion source temperature: 250°C Electron energy: 70 eV Mass range: 50-1000 m / z (CI) Reagent Gas: Methane (Cl) Ionization method: ThermoFisher Scientific Direct Exposure Probe (DEP), 0mA (10sec) - 10mA / sec - 1000mA (10sec) The ester compounds separated by extraction are placed directly on the filament of the DEP unit and measured. The molecular ions in the mass spectrum of the main component peak between 0.5 and 1 minute of the resulting chromatogram are confirmed to identify the ester compounds and determine their molecular weights.

[0129] <Method for measuring the content of ester compounds in toner> The content of the ester compound in the toner can be measured using a thermal analyzer (trade name: DSC Q2000, manufactured by TA Instruments Japan, Inc.). 5.0 mg of toner was placed in a sample container in an aluminum pan (KIT No. 0219-0041), the sample container was placed on a holder unit, and set in an electric furnace. Under a nitrogen atmosphere, the sample was heated from 30°C to 200°C at a temperature increase rate of 10°C / min, and a differential scanning calorimeter (DSC) was used to measure the DSC curve, and the endothermic heat of the ester compound in the toner was calculated. The endothermic heat of the ester compound in the toner was also calculated in the same manner using a 5.0 mg sample of the ester compound alone. The endothermic heat of the ester compound obtained in each measurement was then used to calculate the wax content using the following formula: Content of ester compound in toner (mass%) = (endothermic heat amount of ester compound in toner sample (J / g)) / (endothermic heat amount of ester compound alone (J / g)) × 100

[0130] <Volume Average Particle Size Dv and Particle Size Distribution Dv / Dn of Toner> The volume average particle diameter Dv, number average particle diameter Dn, and particle size distribution Dv / Dn of the toner are measured using a particle size analyzer (manufactured by Beckman Coulter, Inc., trade name: Multisizer). Measurements using this Multisizer are performed under the following conditions: aperture diameter: 100 μm, dispersion medium: Isoton II (trade name), concentration: 10%, number of particles measured: 100,000. Specifically, 0.2 g of toner is placed in a beaker, and an alkylbenzene sulfonic acid aqueous solution (manufactured by Fujifilm Corporation, product name: Drywell) is added as a dispersant. 2 mL of dispersion medium is then added to moisten the toner, after which 10 mL of dispersion medium is added, and the toner is dispersed in an ultrasonic disperser for 1 minute before measurement using the particle size measuring instrument described above.

[0131] <Method for measuring the melting point of ester compounds> Weigh 6 mg to 8 mg of the ester compound into a sample holder and measure it with a differential scanning calorimeter (DSC). Using a Co-Instruments Inc. (trade name: RDC-220), measurements are performed under conditions of heating from -20°C to 100°C at a rate of 10°C / min to obtain a DSC curve. The peak temperature of the endothermic peak in the DSC curve is taken as the melting point.

[0132] <Method for measuring the glass transition temperature of toner> The glass transition temperature of the toner is measured in accordance with ASTM D3418-97. Specifically, 10 mg of the dried toner was weighed out and placed in an aluminum pan. An empty aluminum pan was used as a reference. The glass transition temperature of the weighed toner was measured using a differential scanning calorimeter (manufactured by SII NanoTechnology, Inc., product name: DSC6220) in accordance with ASTM D 3418-97 at a temperature range of 0°C to 150°C and a heating rate of 10°C / min.

[0133] <Method for measuring weight average molecular weight (Mw) and peak molecular weight (Mp) of resins, etc.> The weight average molecular weight (Mw) and peak molecular weight (Mp) of a resin are measured using gel permeation chromatography (GPC) as follows. (1) Preparation of measurement samples The sample and tetrahydrofuran (THF) are mixed at a concentration of 5.0 mg / mL, left at room temperature for 5 to 6 hours, and then shaken thoroughly to thoroughly mix the THF and sample until the sample no longer combines. The mixture is then left at room temperature for at least 12 hours. The time from the start of mixing the sample and THF to the end of the standing period is set at at least 72 hours, and the tetrahydrofuran (THF)-soluble portion of the sample is obtained. Thereafter, the solution is filtered through a solvent-resistant membrane filter (pore size 0.45 μm to 0.50 μm, Myshoridisc H-25-2 [manufactured by Tosoh Corporation]) to obtain a sample solution.

[0134] (2) Measurement of the sample Using the obtained sample solution, measurements are carried out under the following conditions. Apparatus: High-speed GPC apparatus LC-GPC 150C (Waters) Column: Shodex GPC KF-801, 802, 803, 804, 805, 806, 807 (Showa Denko Co., Ltd.) in 7-unit series Mobile phase: THF Flow rate: 1.0mL / min Column temperature: 40℃ Sample injection volume: 100 μL Detector: RI (refractive index) detector

[0135] When measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithm of the calibration curve prepared using several monodisperse polystyrene standard samples and the count number. The standard polystyrene samples used to create the calibration curve were those manufactured by Pressure Chemical Co. or Toyo Soda Kogyo Co., Ltd., with a molecular weight of 6.0 × 10 2 , 2.1×10 3 , 4.0×10 3 , 1.75×10 4 , 5.1×10 4 , 1.1×10 5 , 3.9 × 10 5 , 8.6×10 5 , 2.0×10 6 , 4.48×10 6 Use the following.

[0136] <Method for measuring the area occupied by wax domains in a toner cross section using a transmission electron microscope> Cross-sectional observation of the toner using a transmission electron microscope (TEM) and evaluation of the wax domains are carried out as follows. By staining the toner cross section with ruthenium, the crystalline material is obtained as a clear contrast. The crystalline material is stained more weakly than the amorphous material. This is thought to be because the dye material penetrates less deeply into the crystalline material than into the amorphous material due to differences in density, etc. The amount of ruthenium atoms varies depending on the intensity of the staining, so the areas that are stained strongly contain ruthenium. Areas with a high concentration of ruthenium atoms have a low penetration rate for the electron beam, making them appear black in the image. On the other hand, areas with a low concentration of ruthenium atoms have a high penetration rate for the electron beam, making them appear white in the image.

[0137] Using an osmium plasma coater (Filgen, OPC80T), a protective film of osmium (5 nm) and a naphthalene film (20 nm) were applied to the toner, which was then embedded in photocurable resin D800 (JEOL). A toner cross section with a thickness of 60 nm was then prepared using an ultrasonic ultramicrotome (Leica, UC7) at a cutting speed of 1 mm / s. The cross section was stained for 15 minutes in a 500 Pa atmosphere of RuO gas using a vacuum electron staining device (Filgen, VSC4R1H) and then observed using the STEM mode of a TEM (JEOL, JEM2800). The STEM probe size was 1 nm, and the image size was 1024 pixels x 1024 pixels. The obtained images are binarized (threshold 120 / 255 levels) using the image processing software "Image-Pro Plus (Media Cybernetics)". By binarizing, the crystalline domains can be extracted.

[0138] <Method for calculating the average number of domains of ester compounds and the average major axis r1 (μm) of the domains of ester compounds> Using the toner cross-section observation method described above, 50 toner particles within ±2.0 μm of the volume average particle size were randomly selected and photographed to obtain cross-sectional images. Compared to amorphous resins and magnetic materials, crystalline materials are less susceptible to Ru staining, and appear white to gray in the cross-sectional images. The average number of domains of the ester compound is determined by counting the number of domains with a major axis of 20 nm or more in the above-mentioned 50 toner cross-sectional images, and the average value among the 50 toner particles is taken as the average number of domains of the ester compound. Furthermore, the average major axis r1 (μm) of the ester compound domains is measured by randomly selecting 10 cross sections from the above-mentioned toner cross-sectional image, then randomly selecting 100 domains of the ester compound from the 10 cross sections, and measuring the major axis. The average value of these is taken as the average major axis r1 (μm) of the ester compound domains in the toner cross section.

[0139] <Method for measuring average circularity of toner> The average circularity of the toner is measured using a flow particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) under the measurement and analysis conditions used during the calibration process. The specific measurement method is as follows. First, 20 mL of ion-exchanged water from which impurities such as solids have been removed is placed in a glass container, and 0.2 mL of a solution prepared by diluting "Contaminon N" (a 10% aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) three times by mass with ion-exchanged water is added as a dispersant. 0.02 g of the sample to be measured was then added, and the mixture was dispersed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. The dispersion was then cooled appropriately so that the temperature was between 10°C and 40°C. A tabletop ultrasonic cleaner disperser "VS-150" (manufactured by Vervoclear) with an oscillation frequency of 50 kHz and an electrical output of 150 W was used as the ultrasonic disperser. A predetermined amount of ion-exchanged water was placed in the water tank, and 2 mL of the Contaminon N was added to the water tank.

[0140] For the measurement, the flow particle image analyzer described above equipped with the "LUCPLFLN" objective lens (magnification 20x, numerical aperture 0.40) was used, and the particle sheath "PSE-900A" (manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion prepared according to the above procedure was introduced into the flow particle image analyzer, and 2,000 magnetic toner particles were counted in HPF measurement mode and total count mode. The average circularity of the toner was calculated from the results.

[0141] <Measurement of dynamic viscoelasticity of toner> The measuring device was a rotating plate type rheometer "ARES" (TA INSTRUMEN A toner tablet press (manufactured by TS Co., Ltd.) is used as the measurement sample. The toner is pressure-molded into a disk shape with a diameter of 7.9 mm and a thickness of 2.0±0.3 mm using a tablet press at 25°C. The sample is attached to a parallel plate, and the temperature is raised from room temperature (25°C) to the viscoelasticity measurement starting temperature (50°C), and measurement is started under the following conditions. The measurement conditions are as follows: (1) Set the sample so that the initial normal force is 0. (2) Use parallel plates with a diameter of 7.9 mm. (3) The frequency is 1.0 Hz. (4) The initial applied strain (Strain) is set to 0.1%. (5) Between 50°C and 160°C, the temperature rise rate is 2.0°C / min. Measurements are taken at a sampling frequency of 1 time / °C.

[0142] The measurement is performed under the following automatic adjustment mode setting conditions: Measurement is performed in automatic strain adjustment mode (Auto Strain). (6) Set the maximum applied strain to 20.0%. (7) Set the maximum torque (Max Allowed Torque) to 200.0 g·cm and the minimum torque (Min Allowed Torque) to 0.2 g·cm. (8) Strain Adjustment to 20.0% of Curvature In the measurement, the automatic tension adjustment mode (Auto Tension) is adopted. (9) Set Auto Tension Direction to Compression. (10) Set the initial static force to 10.0 g and the auto tension sensitivity to 40.0 g. (11) The operating conditions of the auto tension are as follows: Sample Modulus is 1.0×10 3 (Pa) or more. From the loss modulus G" value at 100°C in this measurement, the loss modulus G" (dyn / cm) of the toner at 100°C in the dynamic viscoelasticity measurement was calculated. 2 ) is found.

[0143] <Measurement of Toner Surface Nitrogen Index> The surface nitrogen index of the toner is determined by X-ray photoelectron spectroscopy (ESCA) as follows. The target elements are C (carbon atom), N (nitrogen atom), O (oxygen atom), and Si (silicon atom). The ESCA equipment and measurement conditions are as follows: Equipment used: PHI 1600S X-ray photoelectron spectrometer Measurement conditions: X-ray source MgKα (400W) Spectral range: 800μmφ The surface atomic concentration is calculated from the measured peak intensity of each element using the relative sensitivity factor provided by PHI. The peak top range of each element is as follows: C1s: 279-297 eV N1s: 392-410 eV O1s: 524-542 eV Si2p: 95-113 eV The abundance of nitrogen atoms (atomic %) obtained from the peak top range of each element by normalizing so that the sum of the atomic % of each atom of C, N, O, and Si is 100 atomic % is defined as the surface nitrogen content index. [Example]

[0144] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to these examples. Note that the number of parts in the examples is based on mass unless otherwise specified.

[0145] <Method of producing ester compound 1> Into a reaction vessel equipped with a thermometer, a nitrogen inlet tube, a stirrer, a Dean-Stark trap, and a Dimroth condenser, 100 parts of behenyl alcohol as an alcohol monomer and 80 parts of stearic acid as a carboxylic acid monomer were added, and an esterification reaction was carried out at 200°C for 15 hours. To the resulting ester compound, 20 parts of toluene and 25 parts of isopropanol were added, and 190 parts of a 10% aqueous potassium hydroxide solution, in an amount equivalent to 1.5 times the acid value of the ester compound, was added, followed by stirring at 70°C for 4 hours. The water tank was then removed. 20 parts of ion-exchanged water was then added, followed by stirring at 70°C for 1 hour, after which the water tank was removed and washed. The above washing process was repeated until the pH of the removed water tank became neutral. The solvent was then removed under reduced pressure at 200°C and 1 kPa to obtain the final product, behenyl stearate (ester compound 1), an ester compound of behenyl alcohol and stearic acid. The physical properties of the obtained ester compound 1 are shown in Table 1.

[0146] <Method of producing ester compounds 2 to 5> Ester compounds 2 to 5 were obtained in the same manner as in the production method of ester compound 1, except that the monomers were changed so as to obtain the compounds shown in Table 1. The physical properties of the obtained ester compounds 2 to 5 are shown in Table 1. [Table 1]

[0147] <Resin B1 manufacturing example> A 2L flask equipped with a stirrer, condenser, thermometer, and nitrogen inlet tube was charged with 100 parts of a monomer mixture consisting of 81 parts of styrene, 16 parts of n-butyl acrylate, and 3 parts of dimethylaminoethyl methacrylate benzyl chloride, in 900 parts of toluene. The mixture was polymerized at 75°C for 8 hours in the presence of 4 parts of azobisdimethylvaleronitrile. After polymerization, the toluene was distilled off, the mixture was dried under reduced pressure at 40°C, and then crushed in a hammer mill. The crushed material was further dried under reduced pressure at 40°C for 48 hours to obtain Resin B1. The physical properties of the resulting Resin B1 were Mw = 21,000 and Tg = 60°C.

[0148] <Production Examples of Resins B2 to B7> Resins B2 to B7 were obtained in the same manner as in the production example for Resin B1, except that the blending amounts in the production method for Resin B1 were changed as shown in Table 2. In the table, the numbers indicate the number of parts of each monomer. [Table 2]

[0149] <Method of Manufacturing Toner Particle 1> Styrene: 81 parts n-Butyl acrylate: 11 parts Lauryl acrylate: 6 parts Divinylbenzene: 1 part ·Resin B: 2.06 parts Colorant: Carbon black (Mitsubishi Chemical, product name: #25B) 7 parts Molecular weight regulator: 1 part tetraethyl thiuram disulfide The above materials were stirred and mixed using a conventional stirring device, and then uniformly dispersed using a media-type disperser and heated to 63° C. 20 parts of ester compound 1 were added thereto, and 5 parts of Fischer-Trops wax (HNP51, manufactured by Nippon Seiro Co., Ltd.) as a release agent were mixed and dissolved to obtain a polymerizable monomer composition. On the other hand, in a stirring tank at room temperature, an aqueous solution prepared by dissolving 7.4 parts of magnesium chloride in 250 parts of ion-exchanged water was gradually added with stirring to prepare a magnesium hydroxide colloidal dispersion (3.0 parts of magnesium hydroxide).

[0150] The polymerizable monomer composition was added to the magnesium hydroxide colloidal dispersion obtained above at room temperature, the temperature was raised to 60°C, and the mixture was stirred until the droplets were stabilized. Five parts of t-butylperoxy-2-ethylhexanoate (manufactured by NOF Corporation, trade name: Perbutyl O) was added as a polymerization initiator, and then the mixture was stirred at a high shear rate of 15,000 rpm using an in-line emulsifying disperser (manufactured by Pacific Machinery Works, trade name: Milder) to form droplets of the polymerizable monomer composition.

[0151] The magnesium hydroxide colloidal dispersion containing droplets of the polymerizable monomer composition was placed in a reactor equipped with a stirring blade. The temperature was raised to 89°C and maintained constant, allowing for polymerization. Next, when the polymerization conversion reached 98%, the system temperature was cooled to 75°C. 15 minutes after reaching 75°C, 1 part of methyl methacrylate and 0.36 parts of 2,2'-azobis[2-methyl-N-(1,1-bis(hydroxymethyl)2-hydroxyethyl)propionamide] tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd., trade name: VA086) dissolved in 10 parts of ion-exchanged water were added as shell polymerizable monomers. After continuing the polymerization for another 3 hours, the reaction was stopped, yielding an aqueous dispersion of colored resin particles with a pH of 9.5.

[0152] After this, the aqueous dispersion of colored resin particles was heated to 90°C and passed through a nitrogen gas flow rate of 0.6 m 3 The stripping treatment was carried out for 5 hours at 1000 kJ / (hr·kg). After that, the suspension was cooled by adding water at 0°C. The suspension was cooled from 98.0°C to 30°C at a rate of 3.0°C / sec, then heated to 48°C and maintained at that temperature for 6 hours. Thereafter, the suspension was allowed to cool naturally to 25°C at room temperature. The cooling rate was 1°C / min.

[0153] Next, while stirring the obtained aqueous dispersion, the pH of the system was adjusted to 6.5 or less with sulfuric acid and acid washing was performed, and after separating the water by filtration, 500 parts of ion-exchanged water was added to re-slurry the mixture and water washing was performed. Thereafter, dehydration and water washing were repeated several times, and the solid content was separated by filtration, placed in a dryer, and dried at a temperature of 40°C for 12 hours to obtain toner particles 1.

[0154] To the toner particles 1 (100 parts) obtained above, 0.7 parts of hydrophobicized silica fine particles having a number average primary particle size of 7 nm and 1 part of hydrophobicized silica fine particles having a number average primary particle size of 50 nm were added and mixed using a high-speed mixer (manufactured by Nippon Coke & Engineering Co., Ltd., product name: FM Mixer) to produce toner 1. The physical properties of the obtained toner 1 are shown in Table 3-2.

[0155] <Production of Toners 2 to 32> Toner particles 2 to 32 were obtained in the same manner as toner particle 1, except that the formulation and the quenching rate in the cooling step were changed as shown in Tables 3-1, 3-3, and 3-5. Furthermore, the obtained toner particles were externally added in the same manner as toner 1, to obtain toner particles 2 to 32. The toner physical properties are shown in Tables 3-2, 3-4, and 3-6. [Table 3-1] In Tables 3-1, 3-3, and 3-5, the numerical values for each material indicate the number of parts, and the numerical values for resin ratios indicate mass %.

[0156] [Table 3-2] In Tables 3-2, 3-4, and 3-6, the proportion of resin A and the content of each monomer unit are in mass%. The unit of the SP value is (J / cm 3 ) 1 / 2 The unit of r1 is μm. The notation 6.2×10^4 is 6.2×10 4 The surface nitrogen index is expressed in atomic percent. Regarding "presence or absence of sulfide group in resin A," if resin A has at least one selected from the group consisting of sulfide group and disulfide group, mark it as ◯, and if not, mark it as ×. Regarding "presence or absence of formula (8) in resin A," if resin A has a monomer unit of formula (8), mark it as ◯, and if not, mark it as ×.

[0157] [Table 3-3]

[0158] [Table 3-4]

[0159] [Table 3-5]

[0160] [Table 3-6]

[0161] Table 4 shows the correspondence between the toner and the toner particles in each of the examples and comparative examples. [Table 4]

[0162] <Examples 1 to 22 and Comparative Examples 1 to 10> Toners 1 to 32 were used to carry out the following evaluations. The evaluation results are shown in Tables 5-1 to 5-3.

[0163] [Table 5-1]

[0164] [Table 5-2]

[0165] [Table 5-3]

[0166] <Evaluation 1: Evaluation of durability and fogging under high temperature and humidity conditions> The evaluation procedure used a Brother Industries monochrome laser printer (HL-5470DW) with a cleanerless system and a cartridge with the paper dust collection roller removed. The toner was left in a high-temperature, high-humidity environment (temperature 32.5°C, humidity 80% RH) together with the image forming device for one day, and then 15,000 sheets of horizontal line images with a printing rate of 1% were printed in intermittent mode under the above environment, followed by three solid images. After leaving the printer for 30 days, the fogging during storage was evaluated. When left in a high-temperature, high-humidity environment for a long period of time, the toner's chargeability is more likely to decrease and image fogging is more likely to occur than in evaluations under normal high-temperature, high-humidity environments. Furthermore, by leaving the power on without removing or inserting the process cartridge during the storage period, the pre-printing rotation time required for charging the toner is shortened, resulting in a more stringent evaluation of the toner's charge retention. The evaluation paper used was A4-size Century Star paper (manufactured by Century Textiles & Industries), a talc paper.

[0167] For the evaluation of fogging, after printing three solid images after 15,000 sheets, a completely white image was printed using a paper with a sticky note attached to part of the printed surface of the image as a mask (white image 1). Furthermore, the process cartridge was left in the main unit and the main unit was left in a high-temperature, high-humidity environment for 30 days without being turned off, and then an all-white image was printed using paper with sticky notes attached to mask part of the printed surface of the image (white image 2). For White Image 2, after removing the sticky note, the reflectance (%) was measured at five points on both the sticky note and non-sticky note areas, and the average value was calculated. The difference between the average values was then calculated and this was taken as the fogging after long-term storage. The reflectance was measured using a digital white light meter (TC-6D model, manufactured by Tokyo Denshoku Co., Ltd., using a green filter). The lower the fog, the better the result, and the evaluation was based on the following criteria. A grade of C or above was considered good. [Evaluation criteria] A. Foaming after leaving is less than 0.5% B. Foaming after leaving is 0.5% or more but less than 1.0% C. Foaming after leaving is 1.0% or more but less than 2.0% D. Foaming after leaving is 2.0% or more

[0168] <Evaluation 2: Evaluation of transfer residual fog durability under low temperature and low humidity environment> The evaluation procedure used a Brother Industries monochrome laser printer (HL-5470DW) with a cleanerless system and a cartridge with the paper dust collection roller removed. The toner was left in a low-temperature, low-humidity environment (temperature 15°C, humidity 5% RH) together with the image forming device for one day, and then 15,000 sheets of horizontal line images with a printing rate of 1% were printed in intermittent mode under the above environment, and three solid images were also printed. The residual transfer fogging after the durability test was then evaluated using the following procedure: A sheet of paper was prepared with a sticky note affixed to the position on the photosensitive drum where the image from the second week would be output (photosensitive drum pitch: approximately 94.2 mm). Specifically, a sheet of paper was prepared with a sticky note affixed to the center, 99 mm to 124 mm from the leading edge, and an image with a 20 mm wide solid black band was output, leaving a 5 mm margin at the leading edge (solid band image 1). Transfer residual fog occurs at a position 104 to 124 mm from the leading edge of the paper of solid band image 1. After removing the sticky notes from the area 104 mm to 124 mm from the leading edge of the paper of solid band image 1, the reflectance (%) was measured at five points for the part with the sticky note and the part without the sticky note, and the average value was calculated. The difference between the average values was then calculated and this was taken as transfer residual fog, and evaluation was performed according to the following criteria. [Evaluation criteria] A. Transfer residual fog is less than 0.5% B. Transfer residual fog is 0.5% or more and less than 1.0% C. Transfer residual fog is 1.0% or more and less than 2.0% D. Transfer residual fog is 2.0% or more

[0169] <Evaluation 3: Evaluation of low-temperature fixability> The evaluation of low-temperature fixability was carried out in a low-temperature, low-humidity environment (temperature 15°C, humidity 5% RH) using an HL-5470DW (monochrome laser printer manufactured by Brother Industries) and a cartridge with the paper dust collection roller removed. The image forming apparatus was modified so that the fixing temperature of the fixing unit could be set as desired. Using this device, the fixing temperature of the fixing unit was adjusted in 5°C increments within a range of 180°C to 230°C, and an all-solid black image with a 100% print ratio and a 5mm margin was output (solid black image 1) on A4-size Century Star paper (Century Textiles & Industries), a talc paper, as the evaluation paper. At this time, the presence or absence of white spots in the solid image portion of solid black image 1 was visually evaluated, and the lowest temperature at which white spots did not appear was determined to be the minimum fixing temperature, and this minimum fixing temperature was used to evaluate low-temperature fixability. [Evaluation criteria] A: The minimum fixing temperature is less than 200°C. B: The minimum fixing temperature is 200°C or higher and lower than 210°C. C: The minimum fixing temperature is 210°C or higher and lower than 220°C. D: The minimum fixing temperature is 220°C or higher.

[0170] <Evaluation 4: Adhesion of fixed image to paper> The adhesion of the fixed image to the paper was evaluated in a low-temperature, low-humidity environment (temperature 15°C, humidity 5% RH) using an HL-5470DW (monochrome laser printer manufactured by Brother Industries) and a cartridge with the paper dust collection roller removed. The image forming apparatus was modified so that the fixing temperature of the fixing unit could be set as desired. The fixing temperature was set to the minimum fixing temperature obtained in evaluation 3, and the paper was fixed at three locations (left, right, and center) with 5 mm margins at the leading edge, left and right margins, and three locations at 30 mm intervals in the longitudinal direction, for a total of nine locations (5 mm x 5 mm). Three copies of halftone image 1 having the halftone patch portion of the above were printed, and the adhesion to the paper was evaluated by evaluating the halftone density maintenance rate before and after rubbing using the second copy of the image. Halftone images were used because they have many areas where the toner is formed as isolated dots, and when the image is rubbed, the toner easily comes off the paper, making for a more rigorous evaluation. Furthermore, the evaluation paper used was A4-size Century Star paper (manufactured by Century Textiles & Industries), which is a talc paper. Compared to regular paper, talc paper is prone to poor adhesion between the paper and toner due to the filler, making for a more rigorous evaluation.

[0171] The densities of the nine halftone patch areas were measured using a Macbeth reflection densitometer (manufactured by Macbeth Co.), and the density of the image forming device was adjusted so that the average value of the densities of the halftone patch areas was 0.70 or more and 0.80 or less. Specifically, in the image before rubbing, the densities of the nine halftone patch areas were measured using a Macbeth reflection densitometer (manufactured by Macbeth Co.), and the average value was calculated (initial density). Then, each of the nine halftone patch areas of the image was painted with 55 g / cm 2 After rubbing the halftone patch 10 times with Silbon paper under a weight of 0.05g, the density of each halftone patch was measured with a Macbeth reflection densitometer (manufactured by Macbeth Co.) and the average value was calculated (density after rubbing). The density after rubbing was divided by the initial density and then multiplied by 100 to determine the density maintenance rate after rubbing, and the result was evaluated according to the following criteria. [Evaluation criteria] A. Maintains 90% or more of the concentration after rubbing B. The retention rate of concentration after rubbing is 80% or more but less than 90% C. The retention rate of concentration after rubbing is 75% or more but less than 80% D. The density retention rate after rubbing is less than 75%.

[0172] <Evaluation 5: Halftone density uniformity after durability test in a high temperature and humidity environment> The evaluation procedure used a Brother Industries HL-5470DW monochrome laser printer with a cleanerless system and a cartridge with the paper dust collection roller removed. The toner was left in a high-temperature, high-humidity environment (temperature 32.5°C, humidity 80% RH) together with the image forming device for one day, and then 15,000 sheets of horizontal line images with a 1% coverage were printed in intermittent mode under the same conditions. The evaluation paper used was A4-size Century Star paper (Century Textiles & Industries), a talc paper. After that, 20mm x 20mm solid black patches and 20mm x 20mm solid white patches were arranged alternately with a 5mm margin at the tip, and then halftone image 2 was output with a halftone image arranged over the entire surface.

[0173] The halftone densities of the above image at the position where the image of the second week of the photosensitive drum for the solid black patch and solid white patch is output (photosensitive drum pitch: approximately 94.2 mm) were taken as the halftone density after solid black and the halftone density after solid white, respectively, and the halftone density uniformity after durability was calculated from the difference between the two. In this evaluation, there is a tendency for differences in toner chargeability to occur between solid white and solid black, and halftone image density is easily affected by chargeability, so it is a strict evaluation. Specifically, for halftone image 2, the density of the halftone image after solid black was measured at 10 points between 99 mm and 119 mm from the leading edge of the paper, and the average value was calculated to be the halftone density after solid black.Similarly, the density of the halftone image after solid white was measured at 10 points, and the average value was calculated to be the halftone density after solid white. [Evaluation criteria] A. The halftone density difference after durability is less than 0.05. B. The halftone density difference after durability testing is 0.05 or more and less than 0.10. C. The halftone density difference after durability test is 0.10 or more and less than 0.15. D. The halftone density difference after durability is 0.15 or more.

[0174] <Evaluation 6: Solid density uniformity after durability in a low temperature and low humidity environment> The evaluation procedure used a Brother Industries, Ltd. monochrome laser printer (HL-5470DW) with a cleanerless system and a cartridge with the paper dust collection roller removed. The toner was left in an image-forming device in a low-temperature, low-humidity environment (temperature 15°C, humidity 5% RH) for one day. Then, under the same conditions, 15,000 sheets of horizontal line images with a 1% coverage were printed in intermittent mode. Three solid images were also printed, and the solid density uniformity was evaluated using the second image. Specifically, the density of the solid images was measured at 100 points, and the difference between the maximum and minimum values was calculated. The evaluation paper used was A4-size Century Star paper (Century Textiles & Industries, Inc.), a talc paper. [Evaluation criteria] A. The difference in solid density after durability is less than 0.05. B. The difference in solid density after durability is 0.05 or more and less than 0.10. C. The difference in solid density after durability is 0.10 or more and less than 0.15. D. The difference in solid density after durability is 0.15 or more.

[0175] <Evaluation 7: Uniformity of solid density after durability test on rough paper> The evaluation procedure used a Brother Industries HL-5470DW monochrome laser printer with a cleanerless system and a cartridge with the paper dust collection roller removed. The toner was left in an image forming device in a low-temperature, low-humidity environment (temperature 15°C, humidity 5% RH) for one day, and then 15,000 sheets of horizontal line images with a 1% coverage were printed in intermittent mode under the above environment. Three solid images were also printed, and the solid density uniformity was evaluated using the second image. Specifically, the density of the solid images was measured at 100 points, and the difference between the maximum and minimum values was calculated. The evaluation paper used was a rough COTTON BOND LIGHT COCKLE paper (basis weight 75g LTR, length 279mm, width 216mm). Rough paper has large unevenness and is prone to in-plane unevenness in the transfer bias, so it is a strict evaluation of transferability. [Evaluation criteria] A. The difference in solid density after durability is less than 0.05. B. The difference in solid density after durability is 0.05 or more and less than 0.10. C. The difference in solid density after durability is 0.10 or more and less than 0.15. D. The difference in solid density after durability is 0.15 or more.

Claims

1. A toner having toner particles having a binder resin and an ester compound, The binder resin contains resin A and resin B, The resin A contains a monomer unit represented by the following formula (1) and a monomer unit represented by the following formula (2), In the formula (1), R １ represents a hydrogen atom or a methyl group, and R ２ represents a linear alkyl group having 10 to 14 carbon atoms, In the formula (2), R ２１ represents a hydrogen atom or a methyl group, The resin B contains a monomer unit represented by the following formula (3) and a monomer unit represented by the following formula (4), In the formula (3), R ３１ represents a hydrogen atom or a methyl group, and R ３２ represents a linear or branched alkylene group having 1 to 3 carbon atoms which may be substituted with halogen; R ３３ ~R ３５ each independently represents a benzyl group, a phenethyl group, or a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms; X represents a counter anion; In the formula (4), R ２２ represents a hydrogen atom or a methyl group, The ester compound is at least one ester compound selected from the group consisting of an ester compound represented by the following formula (5), an ester compound represented by the following formula (6), and an ester compound represented by the following formula (7), In the formula (5), the formula (6) and the formula (7), R ３６ , R ４１ represents an alkylene group having 2 to 8 carbon atoms, and R ３７ , R ３８ , R ４２ , R ４３ , R ５１ and R ５２ each independently represents a linear alkyl group having 14 to 24 carbon atoms, the content of the resin A in the chloroform-soluble matter of the toner particles is 60% by mass or more, the content of the monomer unit represented by formula (1) in the resin A is 1.0% by mass or more and 15.0% by mass or less, the content of the monomer unit represented by formula (2) in the resin A is 48.0% by mass or more, the content of the monomer unit represented by formula (4) in the resin B is 48.0 mass% or more, The SP value of the monomer unit represented by formula (1) is SPm (J / cm ３ ) １／２ The SP value of the ester compound is SPw (J / cm ３ ) １／２ When The SPm is 18.00 or more and 19.00 or less, The SPm and the SPw satisfy the following formula (a): A toner characterized by: |SPm-SPw|≦1.50...(a)

2. 2. The toner according to claim 1, wherein the resin A has at least one selected from the group consisting of a sulfide group and a disulfide group.

3. 3. The toner according to claim 1, wherein the content of the monomer unit represented by formula (1) in the resin A is 3.0% by mass or more and 15.0% by mass or less.

4. In the formula (1), the R ２ 4. The toner according to claim 1, wherein R represents a linear alkyl group having 12 carbon atoms.

5. 5. The resin A according to claim 1, wherein the resin A has a monomer unit represented by the following formula (8):

1. The toner according to claim 1.

6. In the dynamic viscoelasticity measurement of the toner, the loss modulus G″ of the toner at 100° C. is 3.0×10 ５ (dyn / cm ２ 6. The toner according to claim 1, wherein the toner has a particle size of 1000 nm or less.

7. 7. The toner according to claim 1, wherein the average circularity of the toner is 0.97 or more and 0.99 or less.

8. When a cross section of the toner is observed using a scanning transmission electron microscope, a domain of the ester compound is present in the cross section of the toner, the average number of the domains in the cross section of the toner is 100 or more; When the average major axis of the domain is r1 (μm), r1 is 1.00 μm or less. The toner according to any one of claims 1 to 7.

9. 9. The toner according to claim 1, wherein a surface nitrogen content index, which is the amount of N (nitrogen atoms) present relative to the total of C (carbon atoms), N (nitrogen atoms), O (oxygen atoms), and Si (silicon atoms), when the toner is measured by X-ray photoelectron spectroscopy, is 0.2 atomic % or more and 5.0 atomic % or less.

10. the content of the monomer unit represented by formula (3) in the resin A is less than 1.0 mass %, The content of the monomer unit represented by the formula (1) in the resin B is less than 1.0 mass %. The toner according to any one of claims 1 to 9.

11. the toner particles are core-shell type toner particles having a core particle containing the binder resin and a shell on the surface of the core particle, the shell comprises a polymer of a (meth)acrylic acid alkyl ester; The (meth)acrylic acid alkyl ester is at least one (meth)acrylic acid alkyl ester selected from the group consisting of (meth)acrylic acid alkyl esters having an alkyl group having 1 to 4 carbon atoms. The toner according to any one of claims 1 to 10.

Images