Toner, resin particles, developer, toner storage unit, image forming apparatus, toner manufacturing method, and image forming method

Abstract

To provide a toner and a resin fine particle excellent in electrification characteristic, low-temperature fixability, high-temperature offset resistance, and blocking resistance after fixing.SOLUTION: A toner according to the present invention includes a cross-linking component. The cross-linking component includes a non-linear polymer branched into three or more and having a metal cross-linked terminal. The glass transition temperature Tg of the non-linear polymer is -60°C or more and less than 0°C.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Image forming devices such as multifunction peripherals (MFPs) and printers that use toner are widely used in various places such as offices. Toner is required to have high-temperature offset resistance and low-temperature fixing properties in order to improve the quality of output images and to save energy by reducing power consumption during fixing.

[0003] As a toner with improved high-temperature offset resistance and low-temperature fixability, for example, a toner containing toner particles obtained by mixing toner base particles containing a predetermined binder resin, wax, and colorant with predetermined boron nitride particles and then surface-treating the toner base particles with hot air has been proposed (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one aspect of the present invention is to provide a toner and resin particles that are excellent in chargeability, low-temperature fixability, high-temperature offset resistance, and blocking resistance after fixing. [Means for solving the problem]

[0005] One aspect of the toner according to the present invention is characterized in that it contains a crosslinking component, the crosslinking component containing a nonlinear polymer that is branched into three or more branches and has a metal-bridged end, and the glass transition temperature Tg of the nonlinear polymer measured by differential scanning calorimetry is -60°C or higher and lower than 0°C. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a toner and resin particles that are excellent in chargeability, low-temperature fixability, high-temperature offset resistance, and blocking resistance after fixing. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment. [Figure 2] FIG. 10 is a schematic configuration diagram illustrating another example of an image forming apparatus according to an embodiment. [Figure 3] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment. [Figure 4] FIG. 4 is a partial enlarged view of the image forming apparatus of FIG. 3. [Figure 5] FIG. 2 is a schematic diagram illustrating an example of a process cartridge according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described in detail. Note that the embodiments are not limited by the following description and can be modified as appropriate without departing from the spirit of the present invention. Furthermore, in this specification, a tilde "~" indicating a numerical range means that the numerical values ​​before and after it are included as the lower and upper limits, unless otherwise specified.

[0009] (toner) One embodiment of the toner according to the present invention comprises a crosslinking component, the crosslinking component comprising a non-linear polymer having three or more branches and having a metal-bridged end, and the glass transition temperature Tg of the non-linear polymer as measured by differential scanning calorimetry (DSC) is −60° C. or higher and lower than 0° C. One embodiment of the toner according to the present invention includes a crosslinking component, and the crosslinking component includes at least a THF (tetrahydrofuran) insoluble matter as a binder resin, and the THF insoluble matter includes a non-linear polymer branched to three or more branches and a metal ion, and the THF insoluble matter has a glass transition temperature Tg of −60° C. or higher and lower than 0° C. as measured by differential scanning calorimetry.

[0010] Improvements in chargeability and anti-blocking properties have not been considered for the toner of the prior art disclosed in Patent Document 1. Generally, when the chargeability of a toner is reduced, background scumming and toner scattering may occur, and in order to obtain excellent low-temperature fixability, it is necessary to reduce the thermal properties of the binder resin that constitutes the toner, so it is known that it is difficult to achieve both low-temperature fixability and anti-blocking properties.

[0011] The present inventors have conducted extensive research into toners containing binder resins and crosslinking components, and as a result have focused on the relationship between the branch structure, terminal structure, and glass transition temperature (Tg) of the crosslinking component and the properties of the crosslinking component. Therefore, the present inventors have investigated the relationship between the branch structure, terminal structure, and glass transition temperature (Tg) of the crosslinking component and the properties of the crosslinking component. Therefore, the present inventors have investigated the relationship between the branch structure, terminal structure, and glass transition temperature (Tg) of the crosslinking component, and the properties of the crosslinking component. 2nd By setting the temperature to be -60°C or higher and lower than 0°C, the crosslinking component can exhibit rubber-like properties, i.e., it deforms but does not flow at low temperatures. Therefore, it has been found that the toner of the present invention can improve the chargeability, high-temperature offset resistance, and blocking resistance after fixing while maintaining the low-temperature fixing property by including the crosslinking component having the above-mentioned structure in addition to the binder resin.

[0012] <Binder resin> In one embodiment of the toner according to the present invention, a binder resin includes an amorphous polyester resin, and may include a crystalline polyester resin as needed. The amorphous polyester resin is preferably linear. The amorphous polyester resin is preferably an unmodified polyester resin. One embodiment of the toner according to the present invention contains at least a THF (tetrahydrofuran) insoluble component as a binder resin, and may contain a crystalline resin as needed.

[0013] <<Unmodified polyester resin>> The unmodified polyester resin is a polyester resin obtained using a polyhydric alcohol and a polycarboxylic acid or a derivative thereof, such as a polycarboxylic acid, a polycarboxylic acid anhydride, or a polycarboxylic acid ester, and is not modified with an isocyanate compound or the like.

[0014] Examples of the polyhydric alcohol in the unmodified polyester resin include diols.

[0015] Examples of diols in the unmodified polyester resin include alkylene (carbon number 2 to 3) oxide (average number of added moles 1 to 10) adducts of bisphenol A such as polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane and polyoxyethylene(2.2)-2,2-bis(4-hydroxyphenyl)propane; ethylene glycol; propylene glycol; hydrogenated bisphenol A; and alkylene (carbon number 2 to 3) oxide (average number of added moles 1 to 10) adducts of hydrogenated bisphenol A. These may be used alone or in combination of two or more.

[0016] Examples of the polycarboxylic acid include dicarboxylic acids.

[0017] Examples of the dicarboxylic acid include adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, maleic acid, and succinic acids substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, such as dodecenylsuccinic acid and octylsuccinic acid. These may be used alone or in combination of two or more.

[0018] For the purpose of adjusting the acid value and hydroxyl value, the binder resin may contain at least one of a trivalent or higher carboxylic acid and a trivalent or higher alcohol at the end of the resin chain. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, and acid anhydrides thereof. Examples of the trihydric or higher alcohol include glycerin, pentaerythritol, and trimethylolpropane.

[0019] The acid value of the binder resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 mgKOH / g to 50 mgKOH / g, and more preferably 5 mgKOH / g to 30 mgKOH / g. When the acid value of the binder resin is 1 mgKOH / g or more, the toner is likely to be negatively charged, and further, when the toner is fixed to paper, the affinity between the paper and the toner is improved, and low-temperature fixability can be improved, which is preferable. If the acid value of the binder resin is 50 mgKOH / g or less, it is possible to suppress the charge stability, particularly the charge stability from being lowered due to environmental changes, which is preferable.

[0020] The hydroxyl value of the binder resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 mgKOH / g or more.

[0021] However, if the molecular weight of the binder resin is too low, the toner may have poor heat-resistant storage stability and poor durability against stress such as stirring in a developing machine, whereas if the molecular weight of the binder resin is too high, the toner may have high viscoelasticity when melted, resulting in poor low-temperature fixability.Therefore, the weight-average molecular weight Mw of the binder resin measured by gel permeation chromatography (GPC) is preferably 3,000 to 10,000, more preferably 4,000 to 7,000.The number-average molecular weight Mn of the binder resin is preferably 1,000 to 4,000, more preferably 1,500 to 3,000. The Mw / Mn ratio of the binder resin is preferably 1.0 to 4.0, and more preferably 1.0 to 3.5.

[0022] The glass transition temperature Tg of the binder resin is preferably 40°C to 70°C, more preferably 50°C to 60°C. If the binder resin has a glass transition temperature Tg of 40° C. or higher, the toner can maintain its heat-resistant storage stability, durability against stress such as stirring in a developing machine, and filming resistance, which is preferable. When the glass transition temperature Tg of the binder resin is 70° C. or less, deformation due to heat and pressure during toner fixing is sufficient, and sufficient low-temperature fixability can be obtained, which is preferable.

[0023] The molecular structure of the binder resin can be confirmed by NMR measurement using a solution or a solid, as well as by X-ray diffraction, GC / MS, LC / MS, IR measurement, etc. Conveniently, in the infrared absorption spectrum, ‐1 and 990±10cm ‐1 For example, a method is used to detect a binder resin that does not have absorption based on the δCH (out-of-plane bending vibration) of olefin.

[0024] The content of the binder resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50 to 90 parts by mass, more preferably 60 to 80 parts by mass, per 100 parts by mass of toner. If the content of the binder resin is 50 parts by mass or more, the dispersibility of the pigment and the release agent in the toner can be maintained, and fogging and distortion of the image are less likely to occur, which is preferable. When the content of the binder resin is 90 parts by mass or less, it is possible to suppress a decrease in the content of the non-linear polymer described below, and it is therefore possible to maintain low-temperature fixability, which is preferable. Furthermore, when the content of the binder resin is in the above more preferred range, it is preferable because both high image quality and low-temperature fixability are excellent.

[0025] <<Crystalline resin>> The crystalline resin is preferably one that melts at temperatures near the fixing temperature. By including such a crystalline resin in the toner, the crystalline resin melts and becomes compatible with the binder resin at the fixing temperature, improving the sharp melting properties of the toner and exhibiting excellent low-temperature fixing properties.

[0026] The melting point of the crystalline resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 60°C to 100°C. If the melting point of the crystalline resin is 60° C. or higher, the crystalline resin is unlikely to melt at low temperatures, and the heat-resistant storage stability of the toner can be maintained, which is preferable. If the melting point of the crystalline resin is 100° C. or less, the toner can exhibit sufficient low-temperature fixability, which is preferable.

[0027] The crystalline resin is not particularly limited as long as it has crystallinity and can be appropriately selected depending on the purpose, and examples thereof include polyester resins, polyurethane resins, polyurea resins, polyamide resins, polyether resins, vinyl resins, modified crystalline resins, etc. These may be used alone or in combination of two or more.

[0028] When the binder resin in the present invention contains a crystalline polyester resin as the crystalline resin, the content of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 parts by mass to 20 parts by mass, more preferably 5 parts by mass to 15 parts by mass, relative to 100 parts by mass of the toner. When the content of the crystalline polyester resin is 3 parts by mass or more, the crystalline polyester resin provides a sufficient sharp melt, and therefore, sufficient low-temperature fixability can be exhibited, which is preferable. When the content of the crystalline polyester resin is 20 parts by mass or less, heat-resistant storage stability can be maintained and image fogging is less likely to occur, which is preferable. Furthermore, when the content of the crystalline polyester resin is within the above-mentioned more preferable range, it is preferable because both high image quality and low-temperature fixability are excellent.

[0029] <Crosslinking component> One embodiment of the toner according to the present invention contains a crosslinking component, and the crosslinking component contains a non-linear polymer that is branched into three or more branches and has a metal-bridged end, and may contain other components as necessary. One embodiment of the toner according to the present invention contains a crosslinking component, and the crosslinking component contains at least a THF-insoluble component as a binder resin, and the THF-insoluble component contains a non-linear polymer branched to three or more atoms and a metal ion, and may contain other components as necessary.

[0030] <<Non-linear polymer>> The non-linear polymer in the present invention is obtained by reacting a non-linear reactive precursor with a metal ion. The metal crosslinks of the non-linear polymer are formed from metal ions of metal salts and do not contain urethane or urea groups, and therefore have excellent charging properties.

[0031] <<<Non-linear reactive precursors>>> The non-linear reactive precursor is not particularly limited as long as it is a polyester (hereinafter sometimes referred to as a prepolymer) having a group capable of reacting with a metal ion as described below, and can be appropriately selected depending on the purpose.

[0032] Examples of the group in the prepolymer that can react with a metal ion include carboxylic acid.

[0033] The prepolymer is non-linear. In this specification, "non-linear" means having a branched structure imparted by at least one of a trivalent or higher alcohol and a trivalent or higher carboxylic acid.

[0034] The trihydric or higher alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include trihydric or higher aliphatic alcohols, trihydric or higher polyphenols, and alkylene oxide adducts of trihydric or higher polyphenols.

[0035] The trihydric or higher aliphatic alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol.

[0036] The trivalent or higher polyphenols are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include trisphenol PA, phenol novolak, and cresol novolak.

[0037] The alkylene oxide adducts of the trivalent or higher polyphenols are not particularly limited and can be appropriately selected depending on the purpose. Examples include adducts of trivalent or higher polyphenols with alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide.

[0038] The trivalent or higher carboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include trivalent or higher aromatic carboxylic acids. Furthermore, anhydrides, lower (1 to 3 carbon atoms) alkyl esters, or halides of these may also be used.

[0039] The trivalent or higher aromatic carboxylic acid is preferably a trivalent or higher aromatic carboxylic acid having 9 to 20 carbon atoms. The trivalent or higher aromatic carboxylic acid having 9 to 20 carbon atoms is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include trimellitic acid and pyromellitic acid.

[0040] Specific examples of the prepolymer include polyester resins containing an isocyanate group.

[0041] <<<<<Polyester resin containing isocyanate groups>>>> The polyester resin containing an isocyanate group is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a reaction product of a polyester resin having an active hydrogen group with a polyisocyanate. The reaction product can be used in a reaction with a curing agent described later.

[0042] -Polyester resin with active hydrogen groups- The polyester resin having an active hydrogen group can be obtained, for example, by polycondensation of a diol, a dicarboxylic acid, and at least one of a trivalent or higher alcohol and a trivalent or higher carboxylic acid. The trivalent or higher alcohol and the trivalent or higher carboxylic acid impart a branched structure to the polyester resin containing an isocyanate group.

[0043] --Diol-- The diol in the polyester resin having an active hydrogen group is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aliphatic diols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol; diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol. Examples of suitable diols include diols having an oxyalkylene group such as 1,4-cyclohexanedimethanol and polytetramethylene glycol; alicyclic diols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; alicyclic diols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added; bisphenols such as bisphenol A, bisphenol F, and bisphenol S; and alkylene oxide adducts of bisphenols, such as bisphenols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added. Among these, aliphatic diols having 4 to 12 carbon atoms are preferred. These diols may be used alone or in combination of two or more.

[0044] --Dicarboxylic acid-- The dicarboxylic acid in the polyester resin having an active hydrogen group is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include aliphatic dicarboxylic acids, aromatic dicarboxylic acids, etc. Furthermore, anhydrides, lower (1 to 3 carbon atoms) alkyl esters, or halides of these may also be used.

[0045] The aliphatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include succinic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic acid, and fumaric acid.

[0046] The aromatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but aromatic dicarboxylic acids having 8 to 20 carbon atoms are preferred. The aromatic dicarboxylic acid having 8 to 20 carbon atoms is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid.

[0047] As the dicarboxylic acid in the polyester resin having an active hydrogen group, among aliphatic dicarboxylic acids, aromatic dicarboxylic acids, etc., aliphatic dicarboxylic acids having 4 to 12 carbon atoms are preferred. These dicarboxylic acids may be used alone or in combination of two or more.

[0048] --Trihydric or higher alcohols-- The trihydric or higher alcohol in the polyester resin having an active hydrogen group is the same as that in the prepolymer described above, and therefore details thereof are omitted.

[0049] --Trivalent or higher carboxylic acids-- The trivalent or higher carboxylic acid in the polyester resin having an active hydrogen group is the same as that in the prepolymer described above, and therefore details thereof are omitted.

[0050] -Polyisocyanate- The polyisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diisocyanates and tri- or higher valent isocyanates.

[0051] The diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, araliphatic diisocyanates, isocyanurates, and those obtained by blocking these with phenol derivatives, oximes, caprolactam, etc.

[0052] The aliphatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include tetramethylene diisocyanate, hexamethylene diisocyanate, methyl 2,6-diisocyanatocaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, and tetramethylhexane diisocyanate.

[0053] The alicyclic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include isophorone diisocyanate and cyclohexylmethane diisocyanate.

[0054] The aromatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include tolylene diisocyanate, diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4′-diisocyanatodiphenyl, 4,4′-diisocyanato-3,3′-dimethyldiphenyl, 4,4′-diisocyanato-3-methyldiphenylmethane, and 4,4′-diisocyanato-diphenyl ether.

[0055] The aromatic aliphatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include α,α,α',α'-tetramethylxylylene diisocyanate.

[0056] The isocyanurates are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include tris(isocyanatoalkyl)isocyanurate and tris(isocyanatocycloalkyl)isocyanurate.

[0057] These polyisocyanates may be used alone or in combination of two or more.

[0058] - Hardener - The curing agent is not particularly limited as long as it reacts with the prepolymer, and can be appropriately selected depending on the purpose. For example, an active hydrogen group-containing compound can be used.

[0059] --Compounds containing active hydrogen groups-- The active hydrogen group in the active hydrogen group-containing compound is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, etc. These may be used alone or in combination of two or more.

[0060] The active hydrogen group-containing compound is not particularly limited and can be appropriately selected depending on the purpose, but amines are preferred because they are capable of forming a urea bond.

[0061] The amines are not particularly limited and can be appropriately selected depending on the purpose. Examples include diamines, trivalent or higher amines, amino alcohols, amino mercaptans, amino acids, and compounds in which the amino groups of these compounds are blocked. These may be used alone or in combination of two or more. Among these, diamines and mixtures of diamines with a small amount of trivalent or higher amines are preferred.

[0062] The diamine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aromatic diamines, alicyclic diamines, and aliphatic diamines. The aromatic diamine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include phenylenediamine, diethyltoluenediamine, and 4,4'-diaminodiphenylmethane. The alicyclic diamine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminocyclohexane, and isophoronediamine. The aliphatic diamine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include ethylenediamine, tetramethylenediamine, and hexamethylenediamine.

[0063] The trivalent or higher amine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diethylenetriamine and triethylenetetramine.

[0064] The amino alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include ethanolamine and hydroxyethylaniline.

[0065] The amino mercaptan is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aminoethyl mercaptan and aminopropyl mercaptan.

[0066] The amino acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aminopropionic acid and aminocaproic acid.

[0067] The compound in which the amino group is blocked is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include ketimine compounds and oxazoline compounds obtained by blocking the amino group with ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0068] The molecular structure of the non-linear polymer such as the polyester resin containing an isocyanate group can be confirmed by NMR measurement of a solution or a solid, as well as X-ray diffraction, GC / MS, LC / MS, IR measurement, etc. Conveniently, in the infrared absorption spectrum, the peak at 965±10 cm -1 and 990±10cm -1 Examples of such a method include a method of detecting a polymer that does not have absorption due to δCH (out-of-plane bending vibration) of olefin as a non-linear polymer such as a polyester resin containing an isocyanate group.

[0069] The content of the non-linear polymer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50 to 90 parts by mass, more preferably 70 to 85 parts by mass, per 100 parts by mass of the toner. If the content of the non-linear polymer is 50 parts by mass or more, it is possible to maintain low-temperature fixability and high-temperature offset resistance, which is preferable. If the content of the non-linear polymer is 90 parts by mass or less, the heat-resistant storage stability and the glossiness and coloring degree of the image obtained after fixing can be maintained, which is preferable. If the content of the non-linear polymer is within the above-mentioned more preferred range, the toner is excellent in all of low-temperature fixability, high-temperature offset resistance, and heat-resistant storage stability, which is preferable.

[0070] <<Metal ions>> As described above, the metal ions function as a crosslinking agent that crosslinks the ends of the non-linear reactive precursor. In order to exhibit excellent fixability, it is preferable that the metal ions are of two or more types and are divalent or higher. The means for crosslinking the end of the reactive precursor with the metal ion is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a method of ionically crosslinking the end of the reactive precursor by adding a metal salt. The metal salt may be added and mixed into a solution in which the reactive precursor is dissolved, or an emulsion of a solution containing the reactive precursor dispersed in an aqueous medium may be prepared, and the metal salt may be added and mixed into the aqueous medium to crosslink the end.

[0071] The metal ions are not particularly limited and can be appropriately selected depending on the purpose. Examples include divalent metal ions, trivalent metal ions, and tetravalent metal ions.

[0072] The divalent metal ion is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include magnesium ion, calcium ion, strontium ion, etc. Among these, strontium ion is preferred.

[0073] The trivalent metal ion is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include aluminum ions, gallium ions, indium ions, thallium ions, etc. Among these, aluminum ions are preferred.

[0074] When two or more types of metal ions are contained, it is preferable that the metal ions have different valences in order to produce a difference in reaction rate.

[0075] When two or more types of metal ions are contained, the difference in the radii of the metal ions is preferably 50 pm or more, more preferably 55 pm to 120 pm, and even more preferably 60 pm to 65 pm. If the difference in ionic radius of the metal ions is 50 pm or more, the reactivity increases, enabling both hot offset and low-temperature fixation. That is, when the polyester resin containing the isocyanate group is crosslinked, the distance between the carboxyl groups (—COOH) that react with the metal ions increases. If a metal ion with a large ionic radius is present, the reaction becomes more likely, and crosslinking progresses more easily. On the other hand, as the reactant becomes larger due to crosslinking, steric hindrance also increases. However, if a metal ion with a small ionic radius is present, it can enter the steric gap, further facilitating the crosslinking reaction. Furthermore, increased reactivity also allows the reactant to react with amorphous resins. If the reactant reacts with the amorphous polyester resin, the hot offset and fixability of the toner according to one embodiment can be improved.

[0076] The metal ion species in the non-linear polymer of the present invention can be qualitatively identified by analyzing the THF-insoluble matter in the toner by X-ray fluorescence analysis. In the present invention, for example, the qualitative analysis of metal ions can be performed using an X-ray fluorescence spectrometer ZSX PrimusIV (manufactured by Rigaku Corporation). The form of the THF-insoluble sample to be measured is not particularly limited, but it is easier to handle if it is molded into pellets or sheets using a general pressure molding machine. For example, the sample is placed in a 15 mm diameter tableting die, and the die is placed in a high-temperature chamber maintained above the glass transition temperature for about an hour. Immediately after that, a load of 6 MPa is applied for one minute to obtain a pellet tablet of the THF-insoluble content, approximately 2 mm thick. This pellet tablet can then be placed in the sample holder of an X-ray fluorescence analyzer and subjected to qualitative analysis to detect the metal elements contained in the sample.

[0077] The non-linear polymer in the present invention has a DSC glass transition temperature Tg of −60° C. or higher and lower than 0° C. The DSC glass transition temperature Tg of the non-linear polymer is the glass transition temperature Tg at the second temperature rise in the DSC. 2nd It is preferable that: Since the non-linear polymer is an amorphous polyester, the glass transition temperature Tg1st and the glass transition temperature Tg at the second heating 2nd In either case, there is no significant change in the glass transition temperature Tg. However, since the glass transition temperature Tg of non-linear polymers is generally measured by heating them in a bulk state, the glass transition temperature Tg at the first temperature rise in DSC is 1st In this case, it is thought that the non-linear polymer contains air or other substances, resulting in increased noise. 2nd When the temperature is 100°C, the non-linear polymer contains almost no air or other substances, and the noise is small, allowing stable measurements.

[0078] The glass transition temperature Tg of the non-linear polymer at the second temperature rise in DSC 2nd As described above, the temperature is -60°C or higher and lower than 0°C, more preferably -50°C to -10°C, and even more preferably -40°C to -20°C. The DSC glass transition temperature Tg of the non-linear polymer 2nd However, if the temperature is -60°C or higher, the flow of the toner at low temperatures cannot be suppressed, and the problems of the deterioration of the heat-resistant storage stability and the deterioration of the filming resistance can be solved, which is preferable. The DSC glass transition temperature Tg of the non-linear polymer 2nd However, if the temperature is lower than 0° C., the toner cannot be sufficiently deformed by the heat and pressure applied during fixing, and the problem of insufficient low-temperature fixing property can be solved, which is preferable.

[0079] The crosslinked component in the toner of the present invention has a nonlinear polymer as described above, and the nonlinear polymer is metal-crosslinked by metal ions, and therefore is a gel polymer that is insoluble in THF (tetrahydrofuran). Therefore, the glass transition temperature of the nonlinear polymer of the present invention can be confirmed by measuring the glass transition temperature of the THF-insoluble component of the toner. The method for obtaining the THF-insoluble matter of the toner in the present invention is not particularly limited and can be appropriately selected depending on the purpose. For example, a method for obtaining an extraction residue using a dissolution filtration method or a Soxhlet extraction method can be mentioned.

[0080] In the present invention, the THF-insoluble matter can be obtained, for example, by the dissolution and filtration method described below. First, 1 g of toner was weighed and placed in 100 mL of THF. The mixture was stirred at 25°C for 6 hours using a stirrer to obtain a solution containing the toner solubles. The solution was then filtered through a 0.2 μm membrane filter, and the filtrate was again placed in 50 mL of THF and stirred for 10 minutes using a stirrer. This process was repeated two or three times, and the resulting filtrate was dried at 120°C and 10 kPa or less to obtain the THF-insolubles. When using the Soxhlet extraction method, it is desirable to reflux 1 part of toner with 100 parts of THF for 6 hours or more, and separate into THF-insoluble and soluble fractions.

[0081] The weight-average molecular weight of the non-linear polymer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 20,000 to 1,000,000 as measured by GPC. The weight-average molecular weight of the non-linear polymer is the molecular weight of a reaction product obtained by reacting a non-linear reactive precursor with a metal ion. If the weight average molecular weight of the non-linear polymer is 20,000 or more, the toner does not flow even at low temperatures, can maintain heat-resistant storage stability, can maintain viscosity when melted, and can maintain high-temperature offset resistance, which is preferable.

[0082] The molecular structure of the non-linear polymer can be confirmed by NMR measurement in a solution or solid, as well as by X-ray diffraction, GC / MS, LC / MS, IR measurement, etc. Conveniently, in the infrared absorption spectrum, -1 and 990±10cm -1 Examples include a method of detecting those that do not have absorption based on the δCH (out-of-plane bending vibration) of olefins as non-linear polymers.

[0083] <<Other Ingredients>> The other components are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a release agent, a colorant, a charge control agent, an external additive, a flowability improver, a cleaning property improver, and a magnetic material.

[0084] <<<Mold release agent>>> The release agent is not particularly limited and can be appropriately selected from known ones. Examples of wax and wax-based release agents include natural waxes such as vegetable waxes such as carnauba wax, cotton wax, Japan wax, and rice wax; animal waxes such as beeswax and lanolin; mineral waxes such as ozokerite and cerusine; and petroleum waxes such as paraffin, microcrystalline, and petrolatum.

[0085] In addition to these natural waxes, examples of the wax include Fischer-Tropsch wax, synthetic hydrocarbon waxes such as polyethylene and polypropylene; and synthetic waxes such as esters, ketones, and ethers.

[0086] Further, fatty acid amide compounds such as 12-hydroxystearic acid amide, stearic acid amide, phthalimide anhydride, and chlorinated hydrocarbons; low-molecular-weight crystalline polymer resins, such as homopolymers or copolymers of polyacrylates as poly-n-stearyl methacrylate and poly-n-lauryl methacrylate (for example, copolymers of n-stearyl acrylate and ethyl methacrylate); and crystalline polymers having long alkyl groups in their side chains may also be used.

[0087] Among the waxes exemplified above as the release agent, hydrocarbon waxes such as paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax, and polypropylene wax are preferred.

[0088] The melting point of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 60°C to 80°C. If the melting point of the release agent is 60° C. or higher, the release agent is unlikely to melt at low temperatures, and heat-resistant storage stability can be maintained, which is preferable. If the melting point of the release agent is 80°C or less, even when the resin melts and is in the fixing temperature range, the release agent will melt sufficiently, making it difficult for fixing offset to occur and image defects to occur, which is preferable.

[0089] The content of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 2 to 10 parts by mass, more preferably 3 to 8 parts by mass, per 100 parts by mass of the toner. If the content of the release agent is 2 parts by mass or more, high-temperature offset resistance during fixing and low-temperature fixability can be maintained, which is preferable. If the content of the release agent is 10 parts by mass or less, the heat-resistant storage stability is not reduced and image fogging and the like can be made less likely to occur, which is preferable. When the content of the release agent is within the above more preferred range, high image quality and fixing stability can be improved, which is preferable.

[0090] <<<Coloring agent>>> The colorant is not particularly limited and can be appropriately selected depending on the purpose. Examples of the colorant include carbon black, nigrosine dyes, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, yellow ochre, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Balkan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, and anthrazan yellow B. GL, Isoindolinone Yellow, Bengala, Red Lead, Cinnabar, Cadmium Red, Cadmium Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Faise Red, Parachlor Orthonitroaniline Red, Lithol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Lithol Rubin GX, Permanent Red F5R, Brilliant Antcarmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkali Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine, Prussian Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chromium Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake,Examples include malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc oxide, and lithopone.

[0091] The content of the colorant is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 to 15 parts by mass, more preferably 3 to 10 parts by mass, per 100 parts by mass of toner.

[0092] The colorant can also be used as a masterbatch composited with a resin. Examples of the resin used in the production of the masterbatch (masterbatch resin) or the resin kneaded with the masterbatch include, in addition to amorphous polyester resin, polymers of styrene or its substitution products such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloro ... Examples of suitable styrene copolymers include methyl acrylate copolymers, styrene-acrylonitrile copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, and styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resins, epoxy polyol resins, polyurethanes, polyamides, polyvinyl butyral, polyacrylic acid resins, rosin, modified rosin, terpene resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffin, and paraffin wax. These may be used alone or in combination of two or more.

[0093] The masterbatch can be obtained by mixing and kneading the masterbatch resin and colorant under high shear force. In this process, an organic solvent can be used to enhance the interaction between the colorant and the resin. A method known as the flushing method, in which an aqueous paste containing the colorant in water is mixed and kneaded with the resin and organic solvent to transfer the colorant to the resin and then remove the water and organic solvent components, is also preferred because it does not require drying since the wet cake of the colorant can be used as is. A high-shear dispersing device such as a three-roll mill is preferably used for mixing and kneading.

[0094] <<<Charge control agent>>> The charge control agent is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substance or compounds, tungsten simple substance or compounds, fluorine-based activators, metal salicylate, and metal salts of salicylic acid derivatives. Specific examples include the nigrosine dye Bontron 03, the quaternary ammonium salt Bontron P-51, the metal-containing azo dye Bontron S-34, the oxynaphthoic acid metal complex E-82, the salicylic acid metal complex E-84, and the phenol condensate E-89 (all manufactured by Orient Chemical Industry Co., Ltd.), the quaternary ammonium salt molybdenum complexes TP-302 and TP-415 (all manufactured by Hodogaya Chemical Co., Ltd.), LRA-901, and the boron complex LR-147 (all manufactured by Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone, azo pigments, and other polymeric compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.

[0095] The content of the charge control agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, relative to 100 parts by mass of toner. When the content of the charge control agent is 10 parts by mass or less, the chargeability of the toner does not become too high and the effect of the charge control agent can be maintained, so that the electrostatic attraction force with the developing roller does not increase too much, and a decrease in the fluidity of the developer and a decrease in image density can be suppressed, which is preferable. These charge control agents can be dissolved and dispersed after melt-kneading the master batch with a resin, or they can be added when directly dissolving and dispersing in an organic solvent, or they can be fixed on the surface of the toner after the toner particles are produced.

[0096] <<<External additives>>> The external additive is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include silica fine particles, hydrophobic silica, fatty acid metal salts (e.g., zinc stearate, aluminum stearate, etc.), metal oxides (e.g., titania, alumina, tin oxide, antimony oxide, etc.), fluoropolymers, etc. Among these, inorganic fine particles are preferred, and hydrophobically treated inorganic fine particles are more preferred.

[0097] Examples of the inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, etc. Among these, silica and titanium dioxide are preferred.

[0098] The average particle size of the primary particles of the inorganic fine particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 100 nm or less, and more preferably 3 nm or more and 70 nm or less. When the average particle size of the primary particles of the inorganic fine particles is within the above range, the inorganic fine particles are prevented from being embedded in the toner, the inorganic fine particles can effectively exhibit their functions, and uneven damage to the surface of the photoreceptor can be prevented.

[0099] The hydrophobic inorganic fine particles are not particularly limited and can be appropriately selected depending on the purpose. For example, hydrophobic treated silica fine particles, hydrophobic treated titania fine particles, hydrophobic treated titanium oxide fine particles, and hydrophobic treated alumina fine particles are preferred. These may be used alone or in combination of two or more.

[0100] Examples of the silica fine particles include R972, R974, RX200, RY200, R202, R805, and R812 (all manufactured by Nippon Aerosil Co., Ltd.). Examples of the titania microparticles include P-25 (manufactured by Nippon Aerosil Co., Ltd.), STT-30, STT-65C-S (all manufactured by Titanium Kogyo Co., Ltd.), TAF-140 (manufactured by Fuji Titanium Kogyo Co., Ltd.), MT-150W, MT-500B, MT-600B, MT-150A (all manufactured by Teika Corporation). Examples of the hydrophobized titanium oxide microparticles include T-805 (manufactured by Nippon Aerosil Co., Ltd.), STT-30A, STT-65S-S (all manufactured by Titanium Kogyo Co., Ltd.), TAF-500T, TAF-1500T (all manufactured by Fuji Titanium Kogyo Co., Ltd.), MT-100S, MT-100T (all manufactured by Teika Corporation), and IT-S (manufactured by Ishihara Sangyo Kaisha, Ltd.).

[0101] The hydrophobic treatment can be achieved, for example, by treating hydrophilic fine particles with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, or octyltrimethoxysilane.

[0102] Also suitable are silicone oil-treated oxide fine particles and silicone oil-treated inorganic fine particles, which are inorganic fine particles treated with silicone oil. When the silicone oil is used, it may be treated by applying heat if necessary.

[0103] The silicone oil is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methylhydrogen silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, phenol-modified silicone oil, carboxyl-modified silicone oil, mercapto-modified silicone oil, methacrylic-modified silicone oil, and α-methylstyrene-modified silicone oil.

[0104] The content of the external additive is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1 to 5 parts by mass, more preferably 0.3 to 3 parts by mass, relative to 100 parts by mass of the toner.

[0105] In addition to oxide fine particles, inorganic fine particles or hydrophobically treated inorganic fine particles can also be used as the external additive. Among the hydrophobized inorganic fine particles, the average particle size of the primary particles of the hydrophobized inorganic fine particles is preferably 1 nm to 100 nm, and more preferably 5 nm to 70 nm.

[0106] The external additive preferably contains at least one type of inorganic fine particles having an average primary particle size of 20 nm or less and at least one type of inorganic fine particles having an average primary particle size of 30 nm or more.

[0107] The specific surface area of ​​the external additive by the BET method is 20 m 2 / g~500m 2 / g is preferred.

[0108] <<<Flow improver>>> The flowability improver is not particularly limited as long as it is capable of performing a surface treatment to increase hydrophobicity and prevent deterioration of flowability and charging properties even under high humidity conditions, and can be appropriately selected depending on the purpose. Examples of the flowability improver include silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils. It is particularly preferable that the silica and titanium oxide are surface-treated with such a flowability improver and used as hydrophobic silica and hydrophobic titanium oxide.

[0109] <<<Cleaning improver>>> The cleaning property improver is not particularly limited as long as it is added to the toner in order to remove the developer remaining on the photosensitive member or the primary transfer medium after transfer, and can be appropriately selected depending on the purpose. Examples of the cleaning property improver include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, and polymer fine particles produced by soap-free emulsion polymerization, such as polymethyl methacrylate fine particles and polystyrene fine particles.

[0110] The polymer particles preferably have a relatively narrow particle size distribution, and the volume average particle size is preferably 0.01 μm to 1 μm.

[0111] <<<Magnetic materials>>> The magnetic material is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include iron powder, magnetite, ferrite, etc. Among these, white materials are preferred in terms of color tone.

[0112] The glass transition temperature Tg of the toner according to this embodiment at the first temperature rise in DSC 1stThe temperature may be 20°C to 40°C. Conventional toners generally have a relatively high glass transition temperature Tg exceeding 40°C. Therefore, for example, if the glass transition temperature Tg is 50°C or lower, the toner is likely to aggregate due to temperature changes during transportation and storage in high-temperature environments such as summer or tropical regions. As a result, solidification in the toner bottle and toner adhesion in the developing machine are likely to occur. Furthermore, toner clogging in the toner bottle can lead to poor replenishment, and toner adhesion in the developing machine can lead to image abnormalities. The toner according to this embodiment has a glass transition temperature Tg 1st Even if the temperature is lower than the glass transition temperature (Tg) of conventional toner, the polymer contained in the toner is non-linear, so the glass transition temperature (Tg) 1st It is possible to maintain heat-resistant storage stability while having the function of reducing the temperature. In the toner according to this embodiment, the glass transition temperature Tg 1st If the temperature is 20° C. or higher, the heat-resistant storage stability of the toner can be maintained, and blocking in the developing machine and filming on the photoreceptor can be suppressed, which is preferable. In the toner according to this embodiment, the glass transition temperature Tg 1st If the temperature is 40° C. or less, the toner can exhibit low-temperature fixability, which is preferable.

[0113] The glass transition temperature Tg 1st and the glass transition temperature Tg 2nd Difference from (Tg 1st -Tg 2nd The difference (Tg) is not particularly limited and can be selected appropriately depending on the purpose, but it is preferably 10°C or more. 1st -Tg 2nd ) is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50°C or less. The difference (Tg 1st -Tg 2nd If the difference (Tg ) is 10° C. or more, the low-temperature fixability is excellent, which is preferable. 1st -Tg 2nd) being 10°C or higher means that the crystalline polyester resin and the amorphous polyester resin, which were in an incompatible state before heating (before the first temperature increase), become compatible after heating (after the first temperature increase). Note that the compatibility after heating does not need to be a complete compatibility state.

[0114] The melting point of the toner according to this embodiment is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 60°C to 80°C.

[0115] The content of the tetrahydrofuran (THF) insoluble matter in the toner according to this embodiment is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 15% by mass to 35% by mass, more preferably 20% by mass to 30% by mass. If the content of the THF-insoluble matter is 15% by mass or more, the constant temperature fixability can be maintained, and if it is 35% by mass or less, the heat-resistant storage stability can be maintained, which are both suitable. The content of the THF insoluble matter in the toner in the present invention can be measured by weighing the amount of the THF insoluble matter obtained by the Soxhlet extraction method of the toner using an electronic balance, and can be calculated by the following equation (1). (THF insoluble matter (g) / toner amount before extraction (g)) × 100 (1)

[0116] The THF-insoluble component corresponds to a non-linear amorphous polyester resin. The toner according to the present embodiment has a lower glass transition temperature Tg than conventional toners, but by including a specific amount of the THF-insoluble component, the toner can maintain sufficient heat-resistant storage stability.

[0117] The volume average particle size of the toner of the present invention is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 μm to 7 μm.

[0118] The ratio of the volume average particle diameter to the number average particle diameter in the toner of the present invention is preferably 1.2 or less.

[0119] The toner of the present invention preferably contains components having a volume average particle size of 2 μm or less in an amount of 1% by number to 10% by number.

[0120] <Methods for calculating and analyzing various properties of toner and toner components> The glass transition temperature Tg, acid value, hydroxyl value, molecular weight, and melting point of the amorphous polyester resin, the crystalline polyester resin, and the release agent may be measured for each of them, or may be separated from the toner by GPC or the like, and the constituent monomer ratio, melting point, and glass transition temperature Tg of each separated component may be calculated using the analytical methods described below.

[0121] Separation of each component by GPC can be carried out, for example, by the following method. (1) In GPC measurement using tetrahydrofuran (THF) as the mobile phase, the eluate is fractionated using a fraction collector or the like, and fractions corresponding to the desired molecular weight portion of the full integral of the elution curve are collected. (2) The combined eluate is concentrated and dried using an evaporator or the like, and the solid content is then dissolved in a heavy solvent such as deuterated chloroform or deuterated THF, 1 H-NMR measurement is performed, and the ratio of constituent monomers of the resin in the eluted components is calculated from the integral ratio of each element. (3) Another method is to concentrate the eluate, then hydrolyze it with sodium hydroxide or the like, and calculate the ratio of constituent monomers by qualitative and quantitative analysis of the decomposition products using high performance liquid chromatography (HPLC) or the like.

[0122] <<Method for separating toner components>> An example of a method for separating each component when analyzing the toner according to an embodiment will be described in detail. First, 1 g of toner is placed in 100 mL of THF and stirred at 25°C for 30 minutes to obtain a solution in which the THF-soluble components are dissolved. The solution is then filtered through a membrane filter with a mesh size of 0.2 μm to obtain the THF-soluble components in the toner. This is then dissolved in THF to prepare a sample for GPC measurement, which is then injected into the GPC used to measure the molecular weight of each resin described above. Meanwhile, a fraction collector is placed at the eluate outlet of the GPC, and the eluate is fractionated at predetermined counts, and the eluate is obtained at 5% area ratios from the start of elution (the rise of the curve) of the elution curve. Next, for each elution fraction, 30 mg of sample was dissolved in 1 mL of deuterated chloroform, and 0.05% by volume of tetramethylsilane (TMS) was added as a reference substance. The solution was filled into a 5 mm diameter glass tube for NMR measurement, and a nuclear magnetic resonance spectrometer (JNM-AL400, manufactured by JEOL Ltd.) was used at a temperature of 23°C to 25°C, and 128 measurements were performed to obtain a spectrum. The monomer composition and composition ratio of the amorphous polyester resin, crystalline polyester resin, etc. contained in the toner were determined from the peak integral ratio of the obtained spectrum. For example, the peaks were assigned as follows, and the component ratios of the constituent monomers were determined from their respective integral ratios. -Peak assignment- Around 8.25 ppm: Derived from the benzene ring of trimellitic acid (one hydrogen) Around 8.07 ppm to 8.10 ppm: From the benzene ring of terephthalic acid (4 hydrogen atoms) Around 7.1 ppm to 7.25 ppm: Derived from the benzene ring of bisphenol A (4 hydrogen atoms) Around 6.8 ppm: from the benzene ring of bisphenol A (4 hydrogen atoms) and from the double bond of fumaric acid (2 hydrogen atoms) Around 5.2 ppm to 5.4 ppm: derived from methine of bisphenol A propylene oxide adduct (one hydrogen) Around 3.7 ppm to 4.7 ppm: Methylene-derived compounds of bisphenol A propylene oxide adducts (2 hydrogen atoms) and methylene-derived compounds of bisphenol A ethylene oxide adducts (4 hydrogen atoms) Around 1.6 ppm: derived from the methyl group of bisphenol A (6 hydrogen atoms)

[0123] From these results, for example, the extract recovered in the fraction containing 90% or more of amorphous polyester resin can be treated as an amorphous polyester resin, and similarly, the extract recovered in the fraction containing 90% or more of crystalline polyester resin can be treated as a crystalline polyester resin.

[0124] <<Measuring method for melting point and glass transition temperature Tg>> The melting point and glass transition temperature Tg of each separated component can be measured using, for example, a DSC system (differential scanning calorimeter) ("Q-200", manufactured by TA Instruments). Specifically, the melting point and glass transition temperature of the sample can be measured by the following procedure. First, approximately 5.0 mg of the target sample was placed in an aluminum sample container, which was then placed on a holder unit and placed in an electric furnace. Next, under a nitrogen atmosphere, the sample was heated from -80°C to 150°C at a heating rate of 10°C / min (first heating). The sample was then cooled from 150°C to -80°C at a cooling rate of 10°C / min, and further heated to 150°C at a heating rate of 10°C / min (second heating). During both the first and second heating, DSC curves were measured using a differential scanning calorimeter (TA Instruments, model Q-200). From the DSC curves obtained, the DSC curve at the first temperature rise was selected using the analysis program in the Q-200 system, and the glass transition temperature Tg of the target sample at the first temperature rise was calculated. 1st Similarly, select the DSC curve during the second heating and calculate the glass transition temperature Tg 2nd Ask for. From the DSC curves obtained, the analysis program in the Q-200 system can be used to select the DSC curve during the first heating run and determine the endothermic peak top temperature during the first heating run of the target sample as the melting point. Similarly, the DSC curve during the second heating run can be selected and the endothermic peak top temperature during the second heating run of the target sample as the melting point.

[0125] In this specification, when toner is used as a target sample, the glass transition temperature at the first temperature rise is referred to as the glass transition temperature Tg 1st The glass transition temperature during the second temperature rise is the glass transition temperature Tg 2nd Let's say.

[0126] In this specification, unless otherwise specified, the melting points and glass transition temperatures Tg of other components such as non-linear polymers, binder resins, crystalline polyester resins, and release agents refer to the endothermic peak top temperatures and glass transition temperatures Tg during the second temperature rise. 2nd are the melting points and glass transition temperatures Tg of the respective target samples.

[0127] Thus, one embodiment of the toner according to the present invention contains a crosslinking component, which includes a non-linear polymer branched into three or more branches and having a metal-bridged end, and the glass transition temperature Tg of the non-linear polymer is −60° C. or higher and lower than 0° C. Also, one embodiment of the toner according to the present invention contains a crosslinking component, which includes at least a THF (tetrahydrofuran) insoluble component as a binder resin, which THF insoluble component includes a non-linear polymer branched into three or more branches and a metal ion, and the glass transition temperature Tg of the non-linear polymer measured by differential scanning calorimetry is −60° C. or higher and lower than 0° C. The nonlinear polymer of the present invention has a very low glass transition temperature Tg and therefore has the property of deforming at low temperatures. Therefore, the nonlinear polymer easily deforms under heat and pressure during fixation, making it easier to contact a recording medium such as paper at lower temperatures. Furthermore, the nonlinear polymer is formed from a nonlinear reactive precursor, has a branched structure in the molecular skeleton, and the molecular chain has a three-dimensional network structure. Therefore, the nonlinear polymer has rubber-like properties that do not flow even when deformed at low temperatures, and can increase the amount of charge. Furthermore, the crosslinking component in the present invention can maintain fixability by forming a metal bridge with a metal ion at the end. Furthermore, the toner according to this embodiment can reduce adhesion to recording media such as paper and components within a developing machine by increasing the charge amount. Therefore, when the toner is fixed on the paper surface and stacked in a paper output tray, blocking, in which the toner adheres to the recording medium due to pressure from the weight of the recording medium and residual heat generated during fixing, can be prevented. Furthermore, the toner can be easily removed using a cleaning blade. Therefore, the toner according to the present embodiment has excellent chargeability, reduces adhesive force, and can achieve both low-temperature fixability and hot offset resistance. Therefore, the toner according to the present embodiment has excellent chargeability, low-temperature fixability, high-temperature offset resistance, and blocking resistance after fixing.

[0128] The toner according to this embodiment can contain two types of divalent or higher metal ions in the metal bridge of the non-linear polymer, which allows the crosslinking component to more easily come into contact with the recording medium, thereby enabling the toner according to this embodiment to have improved fixability.

[0129] In the toner according to this embodiment, two types of divalent or higher metal ions contained in the metal bridge of the non-linear polymer can have different valences, which increases the charge capacity of the metal ions forming metal bridges at the ends of the crosslinking components, allowing the toner according to this embodiment to exhibit better chargeability.

[0130] In the toner according to this embodiment, the difference in ionic radius between the two types of divalent or higher metal ions contained in the metal bridge of the nonlinear polymer can be 50 pm or more. By increasing the difference in size between the two types of metal ions that form metal bridges at the ends of the crosslinking components, it becomes easier to form a more complex three-dimensional network structure of the crosslinking components. As a result, the toner according to this embodiment can have better charging properties, low-temperature fixing properties, high-temperature offset resistance, and blocking resistance.

[0131] (Resin fine particles) The resin microparticles of the present invention contain a crosslinking component, and the crosslinking component contains at least a THF (tetrahydrofuran) insoluble matter as a binder resin, and the THF insoluble matter contains a non-linear polymer branched to three or more branches and a metal ion, and the glass transition temperature Tg of the THF insoluble matter measured by differential scanning calorimetry is -60°C or higher and lower than 0°C. The components and measuring methods of the resin particles are the same as those of the toner described above, and therefore descriptions thereof will be omitted.

[0132] (Toner manufacturing method) The toner manufacturing method according to one embodiment preferably includes a granulation step of forming toner base particles by dispersing an oil phase containing a non-linear polymer and a crystalline polyester resin, and further containing a release agent, a colorant, etc., in an aqueous medium and granulating the resulting mixture.

[0133] In a toner manufacturing method according to an embodiment, in the granulation step, a prepolymer, which is a nonlinear reactive precursor, may be used instead of the nonlinear polymer, and an oil phase containing a curing agent, etc. The oil phase containing the prepolymer is mixed with an aqueous medium, and a nonlinear polymer is generated by at least one of an elongation reaction and a crosslinking reaction between the prepolymer and the curing agent, thereby forming toner base particles and an amorphous polyester resin.

[0134] In addition, in the toner manufacturing method according to one embodiment, in the granulation step, a prepolymer, which is a nonlinear reactive precursor, may be used instead of the nonlinear polymer, and an oil phase containing an active hydrogen group-containing compound, a curing agent, etc. The prepolymer, which is a nonlinear reactive precursor, the oil phase containing the active hydrogen group-containing compound, and an aqueous medium are mixed, and toner base particles are formed while the nonlinear polymer is generated by at least one of an elongation reaction and a crosslinking reaction between the prepolymer and the curing agent.

[0135] Furthermore, in the toner manufacturing method according to one embodiment, in the granulation step, a prepolymer, which is a nonlinear reactive precursor, may be used instead of the nonlinear polymer, and an oil phase obtained by dissolving or dispersing the polyester resin and the prepolymer in an organic solvent may be subjected to phase inversion emulsification. After the oil phase is subjected to phase inversion emulsification and the organic solvent is removed, a dispersion liquid containing a crystalline polyester resin is mixed to prepare a mixed liquid, and the crystalline polyester resin in the mixed liquid is aggregated to form toner base particles.

[0136] The toner can be produced by, for example, a solution suspension method, an emulsion aggregation method, or the like. Examples of the method for producing a toner using the solution suspension method include a method for producing toner base particles while elongating a non-linear polymer through at least one of an elongation reaction and a crosslinking reaction between a prepolymer, which is a non-linear reactive precursor, and a metal ion.

[0137] The method for producing toner base particles using the solution suspension method includes a step of preparing an aqueous dispersion of a crystalline polyester resin (crystalline polyester resin dispersion) (crystalline polyester resin dispersion preparation step), a step of preparing an aqueous medium (aqueous medium preparation step), a step of preparing an oil phase containing toner materials (oil phase preparation step), a step of emulsifying or dispersing the toner materials (emulsification or dispersion step), and a step of removing the organic solvent (organic solvent removal step), and may include other steps as necessary.

[0138] <Preparation process of crystalline polyester resin dispersion> The crystalline polyester resin dispersion is preferably prepared by a phase inversion emulsification method. The phase inversion emulsification method is a method in which an organic solvent, a neutralizing agent, and a surfactant are added to a resin as needed, and an aqueous medium is added dropwise under stirring to obtain emulsified particles, and then the organic solvent in the resin dispersion is removed to obtain an emulsion. Heating may also be performed as needed.

[0139] The organic solvent used in the phase inversion emulsification method is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include methanol, ethanol, propanol, IPA, butanol, ethyl acetate, MEK, and combinations thereof. Among these, organic solvents having a boiling point of less than 150° C. are preferred because they are easily removed.

[0140] The neutralizing agent is not particularly limited and can be appropriately selected depending on the purpose. For example, common acids and alkalis such as nitric acid, hydrochloric acid, sodium hydroxide, and ammonia can be used.

[0141] The surfactant used in the preparation of the crystalline polyester resin dispersion is not particularly limited and can be appropriately selected depending on the purpose. For example, it may be selected from ionic surfactants and nonionic surfactants. The ionic surfactants include anionic surfactants and cationic surfactants. These surfactants may be used alone or in combination of two or more.

[0142] The method for removing the organic solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples include a method in which the temperature of the entire reaction system is gradually increased to evaporate the organic solvent in the oil droplets, and a method in which the dispersion is sprayed into a dry atmosphere to remove the organic solvent in the oil droplets.

[0143] <Aqueous medium preparation process> The aqueous medium (aqueous phase) can be prepared, for example, by dispersing resin particles in the aqueous medium. The amount of the resin particles added to the aqueous medium is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5 to 10 parts by mass per 100 parts by mass of the aqueous medium. The aqueous medium is not particularly limited and can be appropriately selected depending on the purpose. Examples include water, a solvent miscible with water, and a mixture thereof. These may be used alone or in combination of two or more. Among these, water is preferred.

[0144] The water-miscible solvent can be appropriately selected depending on the purpose, and examples thereof include alcohols, lower ketones, dimethylformamide, tetrahydrofuran, and cellosolves. The alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include methanol, isopropanol, and ethylene glycol. The lower ketones are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include acetone and methyl ethyl ketone.

[0145] <Oil phase preparation step> The oil phase containing the toner materials includes at least a non-linear reactive precursor, an amorphous polyester resin, and a crystalline polyester resin, and can be prepared by dissolving or dispersing the toner materials, which further include a curing agent, a releasing agent, a colorant, etc., as necessary, in an organic solvent.

[0146] The organic solvent used in the step of preparing the oil phase is not particularly limited and can be appropriately selected depending on the purpose, but organic solvents with a boiling point of less than 150° C. are preferred because they are easily removed.

[0147] The organic solvent having a boiling point of less than 150° C. is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, etc. These may be used alone or in combination of two or more. Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferred, and ethyl acetate is more preferred.

[0148] <Emulsification or dispersion process> The toner materials can be emulsified or dispersed by dispersing the oil phase containing the toner materials in an aqueous medium. When the toner materials are emulsified or dispersed, at least one of an elongation reaction and a crosslinking reaction is carried out between metal ions and a non-linear reactive precursor, thereby producing a non-linear polymer.

[0149] The non-linear polymer can be produced, for example, by the following methods (1) and (2). (1) An oil phase containing a nonlinear reactive precursor and a metal ion is emulsified or dispersed in an aqueous medium, and the metal ion and the nonlinear reactive precursor are subjected to an elongation reaction and / or a crosslinking reaction in the aqueous medium to produce a nonlinear polymer. (2) An oil phase containing a non-linear reactive precursor is emulsified or dispersed in an aqueous medium to which metal ions have been added in advance, and a non-linear polymer is produced by reacting the curing agent with the non-linear reactive precursor in the aqueous medium through either an elongation reaction or a crosslinking reaction. The reaction time for producing the non-linear polymer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 minutes to 40 hours, more preferably 2 hours to 24 hours. The reaction temperature for producing the non-linear polymer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0°C to 150°C, more preferably 40°C to 98°C.

[0150] The method for stably forming a dispersion liquid containing a non-linear reactive precursor in the aqueous medium is not particularly limited and can be appropriately selected depending on the purpose. For example, there is a method in which an oil phase prepared by dissolving or dispersing toner materials in a solvent is added to an aqueous medium, and the oil phase is dispersed by shear force.

[0151] The dispersing machine for the dispersion is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a low-speed shear dispersing machine, a high-speed shear dispersing machine, a friction dispersing machine, a high-pressure jet dispersing machine, and an ultrasonic dispersing machine. Among these, a high-speed shear type disperser is preferred because it can control the particle size of the dispersion (oil droplets) to 2 μm to 20 μm.

[0152] When the high-speed shear disperser is used, conditions such as the rotation speed, dispersing time, and dispersing temperature can be appropriately selected depending on the purpose. The rotation speed of the high-speed shear disperser is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1,000 rpm to 30,000 rpm, and more preferably 5,000 rpm to 20,000 rpm. The dispersion time in the high-speed shear disperser is not particularly limited and can be appropriately selected depending on the purpose, but in the case of a batch system, it is preferably 0.1 to 5 minutes. The dispersion temperature in the high-speed shear disperser is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0° C. to 150° C., more preferably 40° C. to 98° C. under pressure. Generally, the higher the dispersion temperature, the easier the dispersion.

[0153] The amount of the aqueous medium used when emulsifying or dispersing the toner materials is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50 parts by mass to 2000 parts by mass, and more preferably 100 parts by mass to 1000 parts by mass, relative to 100 parts by mass of the toner materials. If the amount of the aqueous medium used is 50 parts by mass or more, the toner materials can be stably dispersed, and toner base particles having a predetermined particle size can be obtained, which is preferable. If the amount of the aqueous medium used is 2000 parts by mass or less, production costs can be reduced, which is preferable.

[0154] When emulsifying or dispersing the oil phase containing the toner materials, it is preferable to use a dispersant from the viewpoint of stabilizing the dispersion of oil droplets and the like, forming them into a desired shape, and sharpening the particle size distribution.

[0155] The dispersant is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include surfactants, poorly water-soluble inorganic compound dispersants, and polymeric protective colloids. These may be used alone or in combination of two or more. Among these, surfactants are preferred.

[0156] The surfactant in the dispersant is not particularly limited and can be appropriately selected depending on the purpose. For example, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, etc. can be used.

[0157] The anionic surfactant is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, etc. Among these, those having a fluoroalkyl group are preferred.

[0158] <Organic solvent removal process> Toner base particles can be obtained by removing the organic solvent from the dispersion liquid such as the emulsified slurry. The method for removing the organic solvent from the dispersion is not particularly limited and can be appropriately selected depending on the purpose. Examples include a method in which the temperature of the entire reaction system is gradually increased to evaporate the organic solvent in the oil droplets, and a method in which the dispersion is sprayed into a dry atmosphere to remove the organic solvent in the oil droplets.

[0159] Once the organic solvent is removed, toner base particles are formed. The toner base particles can be washed, dried, and further classified. The classification may be carried out by removing fine particles in the liquid using a cyclone, decanter, centrifugal separation or the like, or the classification operation may be carried out after drying.

[0160] <External addition process> The obtained toner base particles may be mixed with external additives, charge control agents, etc. At this time, by applying a mechanical impact force, it is possible to prevent particles of the external additives, etc. from being detached from the surface of the toner base particles. Next, the mixture is passed through a sieve of 250 mesh or more to remove coarse particles and aggregated particles, thereby obtaining the toner according to one embodiment.

[0161] The method for applying the mechanical impact force can be appropriately selected depending on the purpose, and examples thereof include a method of applying an impact force to the mixture using blades rotating at high speed, and a method of introducing the mixture into a high-speed airflow to accelerate it and causing particles to collide with each other or with an appropriate collision plate.

[0162] The device used in the method of applying the mechanical impact force is not particularly limited and can be appropriately selected depending on the purpose. Examples include an Ang Mill (manufactured by Hosokawa Micron Corporation), a device obtained by modifying an I-type Mill (manufactured by Nippon Pneumatic Co., Ltd.) to reduce the grinding air pressure, a Hybridization System (manufactured by Nara Machinery Works), a Kryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), and an automatic mortar.

[0163] (developer) The developer according to an embodiment includes the toner according to an embodiment, and may include other appropriately selected components such as a carrier, if necessary. As a result, the developer according to an embodiment can form an image that is excellent in chargeability, low-temperature fixability, high-temperature offset resistance, and blocking resistance after fixing.

[0164] The developer may be a one-component developer or a two-component developer, but when used in a high-speed printer or the like that corresponds to the recent improvement in information processing speed, a two-component developer is preferable from the viewpoint of improving the developer life.

[0165] When the toner according to one embodiment is used in a one-component developer, even if the toner is balanced, there is little fluctuation in the particle size of the toner, there is little toner filming on the developing roller, and there is little toner fusion to components such as blades that thin the toner layer, and good and stable developability and images can be obtained even with long-term stirring in the developing device.

[0166] When the toner according to an embodiment is used in a two-component developer, it can be mixed with a carrier and used as a developer. When the developer is used as a two-component developer, fluctuations in the particle size of the toner are small even when the toner is balanced over a long period of time, and good and stable developability and images can be obtained even when the developer is stirred for a long period of time in a developing device.

[0167] The content of the carrier in the two-component developer can be appropriately selected depending on the purpose, but is preferably 90 parts by mass to 98 parts by mass, and more preferably 93 parts by mass to 97 parts by mass, relative to 100 parts by mass of the two-component developer.

[0168] The developer according to one embodiment can be suitably used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, and a two-component development method.

[0169] <Career> The carrier is not particularly limited and can be appropriately selected depending on the purpose, but it is preferable that the carrier has a core material and a resin layer (coating layer) that coats the core material.

[0170] <<Core material>> The material for the core material is not particularly limited and can be selected appropriately depending on the purpose. Examples include manganese-strontium-based materials with a density of 50 emu / g to 90 emu / g and manganese-magnesium-based materials with a density of 50 emu / g to 90 emu / g. To ensure image density, it is preferable to use high-magnetization materials such as iron powder with a density of 100 emu / g or more, or magnetite with a density of 75 emu / g to 120 emu / g. It is also preferable to use low-magnetization materials such as copper-zinc-based materials with a density of 30 emu / g to 80 emu / g, as this can reduce the impact of the developer in a standing state on the photoreceptor and is advantageous for achieving high image quality. These materials may be used alone or in combination of two or more.

[0171] The volume average particle size of the core material is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 μm to 150 μm, more preferably 40 μm to 100 μm. If the volume average particle diameter of the core material is 10 μm or more, the amount of fine powder in the carrier increases, which is preferable because it can effectively prevent the problem of carrier scattering due to a decrease in magnetization per particle. On the other hand, if the volume average particle diameter of the core material is 150 μm or less, the specific surface area decreases, which can cause toner scattering, and in the case of full color toners with many solid areas, this can effectively prevent the problem of poor reproduction of the solid areas in particular, which is preferable.

[0172] <<Resin layer>> The resin layer contains a resin and may contain other components as required. The resin used in the resin layer may be a known material capable of imparting the necessary electrostatic property, and specifically, a silicone resin, an acrylic resin, or a combination thereof is preferably used. In addition, the composition for forming the resin layer preferably contains a silane coupling agent.

[0173] The average thickness of the resin layer is preferably 0.05 μm to 0.50 μm.

[0174] (Toner storage unit) The toner storage unit according to an embodiment can store the toner according to an embodiment. The toner storage unit according to an embodiment refers to a unit that stores toner in a unit having a function of storing toner. Here, examples of the toner storage unit include a toner storage container, a developing unit, and a process cartridge.

[0175] The toner storage container refers to a container that stores toner. The developing device has a means for storing toner and developing the toner. The process cartridge is a cartridge that integrates at least an electrostatic latent image carrier (also called an image carrier) and a developing means, contains toner, and is detachably mountable to an image forming apparatus. The process cartridge may further include at least one selected from a charging means, an exposure means, a cleaning means, etc.

[0176] The toner storage unit according to an embodiment stores the toner according to an embodiment. By mounting the toner storage unit according to an embodiment on an image forming apparatus and forming an image using the toner according to an embodiment, the toner storage unit according to an embodiment can form an image that is excellent in chargeability, low-temperature fixability, high-temperature offset resistance, and blocking resistance after fixing.

[0177] (Image forming device) An image forming apparatus according to one embodiment includes an electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and a developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a visible image, and may include other units as necessary.

[0178] More preferably, the image forming apparatus according to one embodiment includes, in addition to the electrostatic latent image carrier, electrostatic latent image forming unit, and developing unit, a transfer unit that transfers the visible image onto a recording medium, and a fixing unit that fixes the transferred image onto the surface of the recording medium.

[0179] In the developing section, a toner according to an embodiment is used. Preferably, a developer containing the toner according to an embodiment and, if necessary, other components such as a carrier may be used to form a toner image.

[0180] <Electrostatic latent image carrier> The structure, size, etc. of the electrostatic latent image carrier (sometimes referred to as an "electrophotographic photoreceptor" or "photoreceptor") are not particularly limited, and can be appropriately selected from known ones. The material of the electrostatic latent image carrier is not particularly limited and can be appropriately selected from known materials, and examples thereof include inorganic photoconductors such as amorphous silicon and selenium, and organic photoconductors (OPC) such as polysilane and phthalopolymethine, etc. Among these, amorphous silicon is preferred in terms of long life.

[0181] As an amorphous silicon photoreceptor, for example, a photoreceptor having a photoconductive layer made of a-Si formed on a support by heating the support to 50°C to 400°C and forming a film on the support by a film formation method such as vacuum deposition, sputtering, ion plating, thermal CVD (chemical vapor deposition), photo-CVD, plasma CVD, etc. Among these, plasma CVD, that is, a method in which a raw material gas is decomposed by direct current, high frequency, or microwave glow discharge to form an a-Si deposited film on the support, is preferred.

[0182] The shape of the electrostatic latent image carrier is not particularly limited and can be appropriately selected depending on the purpose, but a cylindrical shape is preferred.The outer diameter of the cylindrical electrostatic latent image carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 mm to 100 mm, more preferably 5 mm to 50 mm, and particularly preferably 10 mm to 30 mm.

[0183] <Electrostatic latent image formation unit> The electrostatic latent image forming unit is not particularly limited as long as it is a means for forming an electrostatic latent image on an electrostatic latent image bearing member, and can be appropriately selected depending on the purpose. The electrostatic latent image forming unit includes, for example, a charging member (charger) that uniformly charges the surface of the electrostatic latent image carrier, and an exposure member (exposure device) that imagewise exposes the surface of the electrostatic latent image carrier.

[0184] The charger is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a contact charger equipped with a conductive or semiconductive roll, brush, film, rubber blade, etc., and a non-contact charger utilizing corona discharge such as a corotron or scorotron.

[0185] The shape of the charger may be any shape such as a roller, a magnetic brush, a fur brush, etc., and can be selected according to the specifications and shape of the image forming apparatus.

[0186] The charger is preferably one that is arranged in contact or non-contact with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by applying a superimposed DC and AC voltage to it, or one that is a charging roller that is arranged in close proximity to the electrostatic latent image carrier but not in contact with it via a gap tape and charges the surface of the electrostatic latent image carrier by applying a superimposed DC and AC voltage to the charging roller.

[0187] The charger is not limited to a contact type charger, but it is preferable to use a contact type charging member in order to obtain an image forming apparatus in which ozone generated from the charger is reduced.

[0188] The exposing device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger in the form of an image to be formed, and can be appropriately selected depending on the purpose. Examples of the exposing device include various exposing devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.

[0189] The light source used in the exposure device is not particularly limited and can be appropriately selected depending on the purpose. Examples include general light-emitting materials such as fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light-emitting diodes (LEDs), semiconductor lasers (LDs), and electroluminescence (EL). In addition, in the light source used in the exposure device, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used in order to irradiate only light in a desired wavelength range.

[0190] It is also possible to employ a backlight system in which exposure is performed imagewise from the back side of the electrostatic latent image carrier.

[0191] <Developing section> The developing unit is not particularly limited as long as it can develop the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image, and can be appropriately selected depending on the purpose. The developing unit may suitably be, for example, one that contains toner and includes a developing unit that can apply the toner to the electrostatic latent image in a contact or non-contact manner, and a developing unit that includes a toner container is preferred.

[0192] The developing unit may be a single color developing unit or a multi-color developing unit. As the developing device, for example, a developing device having an agitator that charges the toner by friction agitation, a magnetic field generating unit fixed inside, and a rotatable developer carrier that carries developer containing toner on its surface is preferred.

[0193] <Transfer section> The transfer section preferably has a first transfer section that transfers a visible image onto an intermediate transfer member to form a composite transfer image, and a second transfer section that transfers the composite transfer image onto a recording medium. The intermediate transfer member is not particularly limited and can be appropriately selected from known transfer members depending on the purpose, and a suitable example thereof is a transfer belt.

[0194] The transfer section (primary transfer means and secondary transfer section) preferably has at least a transfer device that peels and charges a visible image formed on an electrostatic latent image carrier (photosensitive member) onto a recording medium. The number of transfer sections may be one or more.

[0195] Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device. The recording medium is typically plain paper, but is not particularly limited as long as it can be used to transfer the unfixed image after development, and can be selected appropriately depending on the purpose. PET base for overhead projectors can also be used.

[0196] <Fixing section> The fixing section is not particularly limited and can be appropriately selected depending on the purpose, but a known heating and pressurizing section is suitable. The heating and pressurizing unit may be a combination of a heating roller and a pressure roller, or a combination of a heating roller, a pressure roller and an endless belt.

[0197] The fixing section is preferably a heating and pressurizing section that has a heating element having a heat generating element, a film in contact with the heating element, and a pressure member that is in pressure contact with the heating element via the film, and that can heat and fix a recording medium on which an unfixed image has been formed by passing it between the film and the pressure member.

[0198] The heating temperature in the heating and pressurizing section is usually preferably 80°C to 200°C. The surface pressure in the heating and pressing section is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 N / cm 2 ~80N / cm 2 It is preferable that:

[0199] In this embodiment, depending on the purpose, for example, a known optical fixing device may be used together with or instead of the fixing unit.

[0200] <Other Divisions> The other units are not particularly limited and can be appropriately selected depending on the purpose. For example, a static eliminator, a recycle unit, a control unit, etc. can be provided.

[0201] <<Static electricity removal unit>> The charge removing unit is not particularly limited as long as it can apply a charge removing bias to the electrostatic latent image bearing member, and can be appropriately selected from known charge removers, and a suitable example is a charge removing lamp.

[0202] <<Cleaning section>> The cleaning unit may be any type that can remove toner remaining on the electrostatic latent image carrier, and may be appropriately selected from among known cleaners. Examples of the cleaning unit include a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.

[0203] The image forming apparatus according to the first embodiment has a cleaning unit, which improves cleaning performance. Specifically, by controlling the inter-toner adhesion, the fluidity of the toner is controlled, improving cleaning performance. Furthermore, by controlling the properties of the deteriorated toner, excellent cleaning quality can be maintained even under harsh conditions such as extended life and high temperature and humidity. Furthermore, since the external additives can be sufficiently liberated from the toner on the photoreceptor, a deposition layer (dam layer) of the external additives can be formed in the cleaning blade nip, thereby achieving high cleaning performance.

[0204] <<Recycling Department>> The recycling section is not particularly limited, and examples thereof include known conveying means.

[0205] <<Control Unit>> The control unit can control the operation of each of the above units. The control unit is not particularly limited as long as it can control the movements of the above-mentioned units, and can be appropriately selected depending on the purpose. Examples of the control unit include control devices such as a sequencer and a computer.

[0206] The image forming apparatus according to one embodiment can form images using the toner according to one embodiment, and can therefore provide images that are excellent in chargeability, low-temperature fixability, high-temperature offset resistance, and blocking resistance after fixing.

[0207] (Image forming method) An image forming method according to one embodiment includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and a developing step of developing the electrostatic latent image with toner to form a visible image, and may further include other steps as necessary. The image forming method can be suitably performed by the image forming apparatus, the electrostatic latent image forming process can be suitably performed by the electrostatic latent image forming unit, the developing process can be suitably performed by the developing unit, and the other processes can be suitably performed by the other units.

[0208] Furthermore, the image forming method according to one embodiment more preferably includes, in addition to the electrostatic latent image forming step and the developing step, a transfer step of transferring the visible image onto a recording medium, and a fixing step of fixing the transferred image onto the surface of the recording medium.

[0209] <Electrostatic latent image formation process> The electrostatic latent image forming process is a process of forming an electrostatic latent image on an electrostatic latent image carrier, and includes a charging process of charging the surface of the electrostatic latent image carrier, and an exposure process of exposing the charged surface of the electrostatic latent image carrier to light to form an electrostatic latent image. The charging can be carried out, for example, by applying a voltage to the surface of the electrostatic latent image bearing member using a charger. The exposure can be carried out, for example, by exposing the surface of the electrostatic latent image bearing member to light in an imagewise manner using the exposure unit. The formation of an electrostatic latent image can be carried out, for example, by uniformly charging the surface of the electrostatic latent image bearing member and then exposing it to light in an imagewise manner, and can be carried out by an electrostatic latent image forming unit.

[0210] <Developing process> The developing step is a step of sequentially developing the electrostatic latent image with toners of multiple colors to form a visible image. The visible image can be formed, for example, by developing the electrostatic latent image with the toners, using the developing device. In the developing step, a toner according to an embodiment is used. Preferably, a toner image may be formed by using a developer containing the toner according to an embodiment and, if necessary, other components such as a carrier.

[0211] In the developing device, for example, toner and carrier are mixed and stirred, and the toner becomes charged by friction during this process and is held in a standing state on the surface of the rotating magnet roller, forming a magnetic brush. Because the magnet roller is located near an electrostatic latent image carrier (photosensitive member), some of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the electrostatic latent image carrier (photosensitive member) by electrical attraction. As a result, the electrostatic latent image is developed with toner, and a visible toner image is formed on the surface of the electrostatic latent image carrier (photosensitive member).

[0212] <Transfer process> The transfer step is a step of transferring a visible image onto a recording medium. The transfer step preferably uses an intermediate transfer member, and after the visible image is primarily transferred onto the intermediate transfer member, the visible image is secondarily transferred onto the recording medium. It is more preferable that the transfer step includes a first transfer step in which a visible image is transferred onto an intermediate transfer body using toner of two or more colors, preferably full-color toner, to form a composite transfer image, and a second transfer step in which the composite transfer image is transferred onto a recording medium. The transfer can be performed, for example, by charging the visible image onto an electrostatic latent image carrier (photosensitive member) using a transfer charger, and can be performed in the transfer section.

[0213] <Fixing process> The fixing step is a step of fixing the visible image transferred onto the recording medium using a fixing device, and may be performed for each color developer each time it is transferred onto the recording medium, or may be performed simultaneously for each color developer in a stacked state.

[0214] <Other processes> The image forming method according to the first embodiment may include other steps appropriately selected as necessary. The other steps are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a static elimination step, a cleaning step, and a recycling step.

[0215] <<Static elimination process>> The charge removal step is a step of removing electricity by applying a charge removal bias to the electrostatic latent image bearing member, and can be suitably performed by the charge removal unit.

[0216] <<Cleaning process>> The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier, and can be suitably performed by the cleaning unit.

[0217] <<Recycling process>> The recycling step is a step of recycling the toner removed in the cleaning step into the developing unit, and can be suitably carried out by the recycling unit.

[0218] The image forming method according to an embodiment can form an image using the toner according to an embodiment, and therefore can provide an image that is excellent in chargeability, low-temperature fixability, high-temperature offset resistance, and blocking resistance after fixing.

[0219] [One embodiment of the image forming apparatus] Next, one aspect of an image forming apparatus according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing an example of an image forming apparatus according to an embodiment. As shown in Fig. 1, the image forming apparatus 1A includes a photosensitive drum 10 serving as an electrostatic latent image carrier, a charging roller 20 serving as a charging unit, an exposure device 30 serving as an exposure unit, a developing device 40 serving as a developing unit, an intermediate transfer body (intermediate transfer belt) 50, a cleaning device 60 serving as a cleaning unit, a transfer roller 70 serving as a transfer unit, a static elimination lamp 80 serving as a static elimination unit, and an intermediate transfer body cleaning device 90.

[0220] The intermediate transfer body 50 is an endless belt stretched by three rollers 51 arranged inside and designed to be movable in the direction of the arrow by the three rollers 51. Some of the three rollers 51 also function as transfer bias rollers that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer body 50. An intermediate transfer body cleaning device 90 is arranged near the intermediate transfer body 50. Furthermore, a transfer roller 70 is arranged near the intermediate transfer body 50 facing the intermediate transfer body 50, and can apply a transfer bias (secondary transfer bias) for transferring (secondary transfer) the developed image (toner image) to transfer paper P as a recording medium. Corona chargers 52 for applying electric charge to the toner image on the intermediate transfer body 50 are arranged around the intermediate transfer body 50, between the contact point between the photosensitive drum 10 and the intermediate transfer body 50 and the contact point between the intermediate transfer body 50 and the transfer paper P, relative to the rotational direction of the intermediate transfer body 50.

[0221] The developing device 40 is composed of a developing belt 41, which is a developer carrier, and a black (Bk) developing unit 42K, a yellow (Y) developing unit 42Y, a magenta (M) developing unit 42M, and a cyan (C) developing unit 42C, which are arranged around the developing belt 41.

[0222] The developing belt 41 is an endless belt stretched around a plurality of belt rollers and can move in the direction of the arrow in the drawing. Furthermore, a part of the developing belt 41 is in contact with the photosensitive drum 10.

[0223] The black developing unit 42K includes a developer container 421K, a developer supply roller 422K, and a developing roller (developer carrier) 423K. The yellow developing unit 42Y includes a developer container 421Y, a developer supply roller 422Y, and a developing roller 423Y. The magenta developing unit 42M includes a developer container 421M, a developer supply roller 422M, and a developing roller 423M. The cyan developing unit 42C includes a developer container 421C, a developer supply roller 422C, and a developing roller 423C.

[0224] Next, a method for forming an image using the image forming apparatus 1A will be described. First, the surface of the photosensitive drum 10 is uniformly charged using the charging roller 20. Then, the photosensitive drum 10 is exposed to exposure light L using the exposure device 30 to form an electrostatic latent image. Next, the electrostatic latent image formed on the photosensitive drum 10 is developed with toner supplied from the developing device 40 to form a toner image. The toner image formed on the photosensitive drum 10 is then transferred (primary transfer) onto the intermediate transfer body 50 by a transfer bias applied from the roller 51, and then transferred (secondary transfer) onto the transfer paper P fed by a paper feed unit (not shown) by a transfer bias applied from the transfer roller 70. Meanwhile, after the toner image has been transferred onto the intermediate transfer body 50, residual toner on the surface of the photosensitive drum 10 is removed by the cleaning device 60, and then the photosensitive drum 10 is discharged by the discharge lamp 80. After the image transfer, residual toner on the intermediate transfer body 50 is removed by the intermediate transfer body cleaning device 90. After the transfer process is completed, the transfer paper P is transported to a fixing unit, where the transferred toner image is fixed to the transfer paper P.

[0225] Fig. 2 is a schematic diagram showing another example of an image forming apparatus according to an embodiment. As shown in Fig. 2, image forming apparatus 1B has the same configuration as image forming apparatus 1A shown in Fig. 1, except that image forming apparatus 1A does not have developing belt 41 and instead has black developing unit 42K, yellow developing unit 42Y, magenta developing unit 42M, and cyan developing unit 42C arranged directly opposite each other around photosensitive drum 10.

[0226] 3 is a schematic diagram showing another example of an image forming apparatus according to an embodiment. As shown in FIG. 3, image forming apparatus 1C is a tandem color image forming apparatus, and includes copying machine main body 110, paper feed table 120, scanner 130, automatic document feeder (ADF) 140, secondary transfer device 150, fixing device 160 as a fixing unit, and sheet inverting device 170.

[0227] An endless belt-like intermediate transfer body 50 is provided in the center of the copying machine main body 110. The intermediate transfer body 50 is an endless belt stretched over three rollers 53A, 53B, and 53C, and can move in the direction of the arrow in FIG. 3. An intermediate transfer body cleaning device 90 is disposed near roller 53B to remove toner remaining on the intermediate transfer body 50 after the toner image has been transferred to the recording paper. Opposite the intermediate transfer body 50 stretched over rollers 53A and 53B and along the transport direction, image forming units (yellow (Y) development unit 42Y, cyan (C) development unit 42C, magenta (M) development unit 42M, and black (Bk) development unit 42K) are disposed.

[0228] An exposure device 30 is also disposed near the image forming units. A secondary transfer device 150 is disposed on the side of the intermediate transfer body 50 opposite to the side on which the image forming units are disposed. The secondary transfer device 150 includes a secondary transfer belt 151. The secondary transfer belt 151 is an endless belt stretched over a pair of rollers 152, and the recording paper transported on the secondary transfer belt 151 and the intermediate transfer body 50 can come into contact between roller 53C and roller 152.

[0229] In addition, a fixing device 160 is disposed near the secondary transfer belt 151. The fixing device 160 includes a fixing belt 161, which is an endless belt stretched over a pair of rollers, and a pressure roller 162 that is disposed so as to be pressed against the fixing belt 161.

[0230] Further, near the secondary transfer belt 151 and the fixing device 160, a sheet reversing device 170 is disposed for reversing the recording paper when forming images on both sides of the recording paper.

[0231] Next, a method for forming a full-color image using the image forming apparatus 1C will be described. First, a color original is placed on the platen 141 of the automatic document feeder (ADF) 140, or the automatic document feeder 140 is opened and the color original is placed on the contact glass 131 of the scanner 130, and then the automatic document feeder 140 is closed.

[0232] When a start switch (not shown) is pressed and a color original is set on the automatic document feeder 140, the color original is conveyed and moved onto the contact glass 131, and then the scanner 130 is driven, and the first and second traveling bodies 132 and 133 equipped with light sources start to move. On the other hand, when an original is set on the contact glass 131, the scanner 130 is immediately driven, and the first and second traveling bodies 132 and 133 equipped with light sources start to move. At this time, light irradiated from the first traveling body 132 is reflected from the surface of the original by a mirror on the second traveling body 133, and then received by a reading sensor 136 through an imaging lens 135, thereby reading the color original (color image), and image information of black, yellow, magenta, and cyan is obtained.

[0233] The image information for each color is transmitted to the developing units for each color (yellow developing unit 42Y, cyan developing unit 42C, magenta developing unit 42M, and black developing unit 42K), respectively, and a toner image of each color is formed.

[0234] Fig. 4 is a partial enlarged view of the image forming apparatus of Fig. 3. As shown in Fig. 4, each development unit (yellow development unit 42Y, cyan development unit 42C, magenta development unit 42M, and black development unit 42K) includes a photosensitive drum 10 (black photosensitive drum 10K, yellow photosensitive drum 10Y, magenta photosensitive drum 10M, and cyan photosensitive drum 10C), a charging roller 20 serving as a charging unit that uniformly charges the photosensitive drum 10, an exposure device 30 (not shown) that exposes the photosensitive drum 10 to exposure light L based on image information for each color and forms an electrostatic latent image of each color on the photosensitive drum 10, a development device 40 serving as a development unit that develops the electrostatic latent image with a developer of each color to form a toner image of each color, a transfer charger 62 (not shown) for transferring the toner image onto an intermediate transfer body 50, a cleaning device 60, and a discharging lamp 80.

[0235] 3, the toner images of each color formed by the developing units of each color (yellow developing unit 42Y, cyan developing unit 42C, magenta developing unit 42M, and black developing unit 42K) are sequentially transferred (primary transfer) onto intermediate transfer body 50, which moves while being stretched over rollers 53A, 53B, and 53C. Then, the toner images of each color are superimposed on intermediate transfer body 50 to form a composite toner image.

[0236] On the other hand, in the paper feed table 120, one of the paper feed rollers 121 is selectively rotated to feed recording paper from one of the paper feed cassettes 123 provided in multiple stages in a paper bank 122. The recording paper is separated one by one by separation roller 124, sent to paper feed path 125, transported by transport roller 126, guided to paper feed path 111 inside copying machine main body 110, and stopped by striking registration roller 112. Alternatively, manual feed roller 113 is rotated to feed out recording paper on manual feed tray 114, and manual feed roller 113 separates the recording paper one by one, guides it to manual feed path 115, and stops by striking registration roller 112.

[0237] The registration roller 112 is generally grounded when used, but may be used with a bias applied to it in order to remove paper dust from the recording paper.

[0238] Next, the registration roller 112 is rotated in synchronization with the composite toner image formed on the intermediate transfer body 50, and a recording paper is sent between the intermediate transfer body 50 and the secondary transfer belt 151, and the composite toner image is transferred (secondary transfer) onto the recording paper. Any toner remaining on the intermediate transfer body 50 after the composite toner image has been transferred is removed by the intermediate transfer body cleaning device 90.

[0239] The recording paper onto which the composite toner image has been transferred is transported by a secondary transfer belt 151, and then the composite toner image is fixed onto the recording paper by a fixing device 160.

[0240] Thereafter, the conveying path of the recording paper is switched by the switching claw 116, and the recording paper is discharged onto the paper discharge tray 118 by the discharge rollers 117. Alternatively, the conveying path of the recording paper is switched by the switching claw 116, the recording paper is inverted by the sheet inverting device 170, and is again guided to the secondary transfer belt 151, and after an image is formed on the back side in the same manner, the recording paper is discharged onto the paper discharge tray 118 by the discharge rollers 117.

[0241] <Process cartridge> The process cartridge according to one embodiment is molded so as to be detachably attachable to various image forming devices, and has an electrostatic latent image carrier that carries an electrostatic latent image, and a developing unit that develops the electrostatic latent image carried on the electrostatic latent image carrier with the developer according to the above-described one embodiment to form a toner image, and may have other configurations as necessary.

[0242] The electrostatic latent image carrier is the same as the electrostatic latent image carrier of the image forming apparatus described above, and therefore details thereof will be omitted.

[0243] The developing unit includes a developer container that contains the developer according to an embodiment, and a developer carrier that carries and transports the developer contained in the developer container. The developing unit may further include a regulating member or the like to regulate the thickness of the developer carried.

[0244] An example of a process cartridge according to one embodiment is shown in Fig. 5. As shown in Fig. 5, the image forming apparatus process cartridge 200 includes a photosensitive drum 10, a corona charger 22 as a charging unit, a developing device 40, a cleaning device 60, and a transfer roller 70 (not shown). [Example]

[0245] Hereinafter, the embodiment will be described in more detail with reference to examples and comparative examples, but the embodiment is not limited to these examples and comparative examples.

[0246] <Production Example A-1: ​​Synthesis of Prepolymer A-1> 3-methyl-1,5-pentanediol, isophthalic acid, and adipic acid were added to a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, along with titanium tetraisopropoxide (1000 ppm relative to the resin component). The OH / COOH molar ratio of hydroxyl groups to carboxyl groups was 1.1, the diol component was 110 mol% 3-methyl-1,5-pentanediol, and the dicarboxylic acid component was 40 mol% isophthalic acid and 60 mol% adipic acid. The temperature was then raised to 200°C over approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The reaction was then continued for another 5 hours under reduced pressure of 10 to 15 mmHg, yielding intermediate polyester A-1. Next, in a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, intermediate polyester A-1 and hexamethylene isocyanate derivative (HDI isocyanurate) were placed so that the molar ratio (NCO / OH) of the isocyanate groups of HDI isocyanurate to the hydroxyl groups of intermediate polyester A-1 was 2.0, and ethyl acetate was added to dissolve to form a 50% ethyl acetate solution. The mixture was then heated to 80°C under a nitrogen stream and reacted for 5 hours to obtain an ethyl acetate solution of a prepolymer (OH group-terminated prepolymer A-1) having hydroxyl groups at its termini. The pressure was then reduced until the amount of residual ethyl acetate in the ethyl acetate solution of OH group-terminated prepolymer A-1 was 100 ppm or less. Next, OH-terminated prepolymer A-1 and monomethyl ester succinic acid were placed in a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube so that the molar ratio (CH3 / OH) of the methyl groups of monomethyl ester succinic acid to the hydroxyl groups of OH-terminated prepolymer A-1 was 2.0, and the mixture was reacted at 150°C for 6 hours. This produced a carboxylic acid-terminated prepolymer (prepolymer A-1), which is a non-linear polymer.

[0247] <Production Example A-2: Synthesis of Prepolymer A-2> 3-methyl-1,5-pentanediol, isophthalic acid, adipic acid, and trimellitic anhydride were added to a reaction vessel equipped with a heater, condenser, stirrer, and nitrogen inlet tube, along with titanium tetraisopropoxide (1,000 ppm relative to the resin component). The OH / COOH molar ratio of hydroxyl groups to carboxyl groups was 1.1, the diol component was 110 mol% 3-methyl-1,5-pentanediol, the dicarboxylic acid component was 40 mol% isophthalic acid and 60 mol% adipic acid, and the amount of trimellitic anhydride in the total monomers was 1 mol%. The temperature was then raised to 200°C over approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The reaction was then continued for another 5 hours under reduced pressure of 10 to 15 mmHg, yielding intermediate polyester A-2. Next, in a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, intermediate polyester A-2 and a hexamethylene isocyanate derivative (HDI isocyanurate) were placed so that the molar ratio (NCO / OH) of the isocyanate groups of HDI isocyanurate to the hydroxyl groups of intermediate polyester A-2 was 2.0, and ethyl acetate was added to dissolve the mixture to form a 50% ethyl acetate solution. The mixture was then heated to 80°C under a nitrogen stream and reacted for 5 hours to obtain an ethyl acetate solution of a hydroxyl-terminated prepolymer (OH-terminated prepolymer A-2). The pressure was then reduced until the amount of residual ethyl acetate in the ethyl acetate solution of OH-terminated prepolymer A-2 was 100 ppm or less. Next, into a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, OH-terminated prepolymer A-2 and monomethyl ester succinic acid were placed in amounts such that the molar ratio (CH3 / OH) of the hydroxyl groups of OH-terminated prepolymer A-2 to the methyl groups of monomethyl ester succinic acid was 2.0, and the mixture was reacted for 6 hours at 150°C. This produced a carboxylic acid-terminated prepolymer (prepolymer A-2), a non-linear polymer.

[0248] <Production Example A-3: Synthesis of Prepolymer A-3> 3-methyl-1,5-pentanediol, adipic acid, and titanium tetraisopropoxide (1,000 ppm relative to the resin component) were added to a reaction vessel equipped with a heater, condenser, stirrer, and nitrogen inlet. The OH / COOH molar ratio of hydroxyl groups to carboxyl groups was 1.1, the diol component was 110 mol% 3-methyl-1,5-pentanediol, and the dicarboxylic acid component was 100 mol% adipic acid. The temperature was then raised to 200°C over approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The reaction was then continued for another 5 hours under reduced pressure of 10 to 15 mmHg, yielding intermediate polyester A-3. Next, in a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, intermediate polyester A-3 and a hexamethylene isocyanate derivative (HDI isocyanurate) were placed so that the molar ratio (NCO / OH) of the isocyanate groups of HDI isocyanurate to the hydroxyl groups of intermediate polyester A-3 was 2.0, and ethyl acetate was added to dissolve the mixture to form a 50% ethyl acetate solution. The mixture was then heated to 80°C under a nitrogen stream and reacted for 5 hours to obtain an ethyl acetate solution of a hydroxyl-terminated prepolymer (OH-terminated prepolymer A-3). The pressure was then reduced until the amount of residual ethyl acetate in the ethyl acetate solution of OH-terminated prepolymer A-3 was 100 ppm or less. Next, OH-terminated prepolymer A-3 and monomethyl ester succinic acid were placed in a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, in amounts such that the molar ratio (CH3 / OH) of the hydroxyl groups of the OH-terminated prepolymer A-3 to the methyl groups of the monomethyl ester succinic acid was 2.0, and the mixture was reacted for 6 hours at 150°C. This produced a carboxylic acid-terminated prepolymer (prepolymer A-3), a non-linear polymer.

[0249] <Production Example A-4: Synthesis of Prepolymer A-4> 3-Methyl-1,5-pentanediol and isophthalic acid were added to a reaction vessel equipped with a heater, condenser, stirrer, and nitrogen inlet tube, along with titanium tetraisopropoxide (1,000 ppm relative to the resin component). The OH / COOH molar ratio of hydroxyl groups to carboxyl groups was 1.1, the diol component was 110 mol% 3-methyl-1,5-pentanediol, and the dicarboxylic acid component was 100 mol% isophthalic acid. The temperature was then raised to 200°C over approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The reaction was then continued for another 5 hours under reduced pressure of 10 to 15 mmHg, yielding intermediate polyester A-4. Next, intermediate polyester A-4 and hexamethylene isocyanate derivative (HDI isocyanurate) were placed in a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, so that the molar ratio (NCO / OH) of the isocyanate groups of HDI isocyanurate to the hydroxyl groups of intermediate polyester A-4 was 2.0, and ethyl acetate was added to dissolve the mixture to form a 50% ethyl acetate solution. The mixture was then heated to 80°C under a nitrogen stream and reacted for 5 hours to obtain an ethyl acetate solution of hydroxyl-terminated prepolymer (OH-terminated prepolymer A-4). The pressure was then reduced until the amount of residual ethyl acetate in the ethyl acetate solution of OH-terminated prepolymer A-4 was 100 ppm or less. Next, OH-terminated prepolymer A-4 and monomethyl ester succinic acid were placed in a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, in amounts such that the molar ratio (CH3 / OH) of the hydroxyl groups of OH-terminated prepolymer A-4 to the methyl groups of monomethyl ester succinic acid was 2.0, and the mixture was reacted at 150°C for 6 hours, thereby obtaining a carboxylic acid-terminated prepolymer (prepolymer A-4), which is a non-linear polymer.

[0250] <Production Example a-1: Synthesis of Prepolymer a-1> 3-methyl-1,5-pentanediol, isophthalic acid, adipic acid, and trimellitic anhydride were added to a reaction vessel equipped with a heater, condenser, stirrer, and nitrogen inlet tube, along with titanium tetraisopropoxide (1,000 ppm relative to the resin component). The OH / COOH molar ratio of hydroxyl groups to carboxyl groups was 1.1, the diol component was 110 mol% 3-methyl-1,5-pentanediol, the dicarboxylic acid component was 40 mol% isophthalic acid and 60 mol% adipic acid, and the amount of trimellitic anhydride in the total monomers was 1 mol%. The temperature was then raised to 200°C over approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The reaction was then continued for another 5 hours under reduced pressure of 10 to 15 mmHg, yielding intermediate polyester a-1. Next, intermediate polyester a-1 and isophorone diisocyanate (IPDI) were added to a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube so that the molar ratio (NCO / OH) of the hydroxyl groups of intermediate polyester a-1 to the isocyanate groups of IPDI was 2.0, and the mixture was diluted with ethyl acetate to form a 50% ethyl acetate solution, followed by reaction for 5 hours at 100° C. This produced prepolymer a-1, a nonlinear polymer.

[0251] <Production Example a-2: Synthesis of Prepolymer a-2> 3-Methyl-1,5-pentanediol, isophthalic acid, and adipic acid were added to a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, along with titanium tetraisopropoxide (1,000 ppm relative to the resin component). The OH / COOH molar ratio (hydroxyl to carboxyl group) was 1.1, the diol component was 100 mol% 3-methyl-1,5-pentanediol, and the dicarboxylic acid component was 50 mol% isophthalic acid and 60 mol% adipic acid. The temperature was then raised to 200°C over approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The reaction was then continued for another 5 hours under reduced pressure of 10 to 15 mmHg, yielding a linear prepolymer (prepolymer a-2).

[0252] <Production Example a-3: Synthesis of Prepolymer a-3> 3-methyl-1,5-pentanediol, 2-mol ethylene oxide adduct of bisphenol A, and isophthalic acid were added to a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, along with titanium tetraisopropoxide (1,000 ppm relative to the resin component). The OH / COOH molar ratio of hydroxyl groups to carboxyl groups was 1.1, the diol component consisted of 80 mol% 3-methyl-1,5-pentanediol and 30 mol% 2-mol ethylene oxide adduct of bisphenol A, and the dicarboxylic acid component consisted of 100 mol% isophthalic acid. The temperature was then raised to 200°C over approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The reaction was then continued for another 5 hours under reduced pressure of 10 to 15 mmHg, yielding intermediate polyester a-3. Next, intermediate polyester a-3 and hexamethylene isocyanate derivative (HDI isocyanurate) were placed in a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, so that the molar ratio (NCO / OH) of the isocyanate groups of HDI isocyanurate to the hydroxyl groups of intermediate polyester a-3 was 2.0, and ethyl acetate was added to dissolve the mixture to form a 50% ethyl acetate solution. The mixture was then heated to 80°C under a nitrogen stream and reacted for 5 hours to obtain an ethyl acetate solution of a hydroxyl-terminated prepolymer (OH-terminated prepolymer a-3). The pressure was then reduced until the amount of residual ethyl acetate in the ethyl acetate solution of OH-terminated prepolymer a-3 was 100 ppm or less. Next, into a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, OH-terminated prepolymer a-3 and monomethyl ester succinic acid were placed in amounts such that the molar ratio (CH3 / OH) of the hydroxyl groups of the OH-terminated prepolymer a-3 to the methyl groups of the monomethyl ester succinic acid was 2.0, and the mixture was reacted at 150°C for 6 hours. This produced a carboxylic acid-terminated prepolymer (prepolymer a-3), which is a non-linear polymer.

[0253] <Production Example a-4: Synthesis of Prepolymer a-4> 3-methyl-1,5-pentanediol, 1,10-dodecanedioic acid, and titanium tetraisopropoxide (1,000 ppm relative to the resin component) were added to a reaction vessel equipped with a heater, condenser, stirrer, and nitrogen inlet. The OH / COOH molar ratio of hydroxyl groups to carboxyl groups was 1.1, the diol component was 110 mol% 3-methyl-1,5-pentanediol, and the dicarboxylic acid component was 100 mol% 1,10-dodecanedioic acid. The temperature was then raised to 200°C over approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The reaction was then continued for another 5 hours under reduced pressure of 10 to 15 mmHg, yielding intermediate polyester a-4. Next, intermediate polyester a-4 and a hexamethylene isocyanate derivative (HDI isocyanurate) were placed in a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, so that the molar ratio (NCO / OH) of the isocyanate groups of HDI isocyanurate to the hydroxyl groups of intermediate polyester a-4 was 2.0, and ethyl acetate was added to dissolve the mixture to form a 50% ethyl acetate solution. The mixture was then heated to 80°C under a nitrogen stream and reacted for 5 hours to obtain an ethyl acetate solution of a hydroxyl-terminated prepolymer (OH-terminated prepolymer a-4). The pressure was then reduced until the amount of residual ethyl acetate in the ethyl acetate solution of OH-terminated prepolymer a-4 was 100 ppm or less. Next, OH-terminated prepolymer a-4 and monomethyl ester succinic acid were placed in a reaction vessel equipped with a heater, a condenser, a stirrer, and a nitrogen inlet tube, in amounts such that the molar ratio (CH3 / OH) of the hydroxyl groups of the OH-terminated prepolymer a-4 to the methyl groups of the monomethyl ester succinic acid was 2.0, and the mixture was reacted at 150°C for 6 hours. This produced a carboxylic acid-terminated prepolymer (prepolymer a-4), which is a non-linear polymer.

[0254] <Production Example B: Synthesis of Amorphous Polyester Resin B> A four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was charged with bisphenol A 2-mol ethylene oxide adduct, bisphenol A 3-mol propylene oxide adduct, isophthalic acid, and adipic acid such that the molar ratio of the 2-mol ethylene oxide adduct of bisphenol A to the 3-mol propylene oxide adduct (bisphenol A 2-mol ethylene oxide adduct / bisphenol A 3-mol propylene oxide adduct) was 85 / 15, the molar ratio of isophthalic acid to adipic acid (isophthalic acid / adipic acid) was 80 / 20, and the molar ratio of hydroxyl groups to carboxyl groups, OH / COOH, was 1.3. This mixture was then reacted with titanium tetraisopropoxide (500 ppm relative to the resin components) at 230°C under normal pressure for 8 hours, and then further reacted at a reduced pressure of 10 to 15 mmHg for 4 hours. After that, trimellitic anhydride was added to the reaction vessel so that the amount was 1 mol% relative to the total resin components. The reaction was then continued at 180°C under normal pressure for 3 hours. This yielded amorphous polyester resin B.

[0255] <Production Example C-1: Synthesis of Crystalline Polyester Resin C-1> Dodecanedioic acid and 1,6-hexanediol were charged into a 5L four-neck flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple so that the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 0.9. This mixture was then reacted with titanium tetraisopropoxide (500 ppm relative to the resin components) at 180°C for 10 hours, then heated to 200°C and reacted for 3 hours, and then reacted at a pressure of 8.3 kPa for an additional 2 hours. This yielded crystalline polyester resin C-1.

[0256] <Production Example C-2: Synthesis of Crystalline Polyester Resin C-2> A 5L four-neck flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was charged with 1,6-hexanediol and sebacic acid so that the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 1.1. This mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin components) while draining water. The temperature was raised to 235°C and the reaction was continued for 1 hour. The reaction was then continued for 6 hours under a reduced pressure of 10 mmHg or less. The temperature was then raised to 185°C, and trimellitic anhydride was added so that the molar ratio to COOH groups was 0.053. The reaction was continued for 2 hours with stirring. This yielded crystalline polyester resin C-2.

[0257] <Toner Production> [Example 1] In this example, the toner was prepared by a solution suspension method.

[0258] (Masterbatch (MB) synthesis) 1,200 parts by mass of water, 500 parts by mass of carbon black (Printex 35, manufactured by Dexa, DBP oil absorption = 42 mL / 100 mg, pH = 9.5), and 500 parts by mass of amorphous polyester resin B were added to a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) and mixed. The mixture was kneaded using two rolls at 150°C for 30 minutes, then rolled and cooled, and pulverized in a pulperizer. Masterbatch 1 was thus obtained.

[0259] (Preparation of wax dispersion) A container equipped with a stirring rod and thermometer was charged with 50 parts by mass of paraffin wax (HNP-9, manufactured by Nippon Seiro Co., Ltd., hydrocarbon wax, melting point 75°C, SP value 8.8) as a release agent 1 and 450 parts of ethyl acetate. The mixture was heated to 80°C with stirring and maintained at 80°C for 5 hours. The mixture was then cooled to 30°C over 1 hour and dispersed using a bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.) at a liquid feed rate of 1 kg / hour, a disk peripheral speed of 6 m / sec, and 80% by volume of 0.5 mm zirconia beads, with three passes. Wax dispersion 1 was thus obtained.

[0260] (Preparation of crystalline polyester resin dispersion) 50 parts by mass of crystalline polyester resin C-1 and 450 parts by mass of ethyl acetate were placed in a container equipped with a stirring rod and a thermometer, and the mixture was heated to 80°C while stirring and maintained at 80°C for 5 hours. The mixture was then cooled to 30°C over 1 hour and dispersed using a bead mill (Ultraviscomill, manufactured by Imex) at a liquid feed rate of 1 kg / hour, a disk peripheral speed of 6 m / sec, and 80% by volume of 0.5 mm zirconia beads, with three passes. This resulted in crystalline polyester resin dispersion 1.

[0261] (Preparation of oil phase) 500 parts by mass of wax dispersion 1, 300 parts by mass of prepolymer A-1, 500 parts by mass of crystalline polyester resin dispersion 1, 650 parts by mass of amorphous polyester resin B, and 100 parts by mass of masterbatch 1 were placed in a container and mixed at 5000 rpm for 60 minutes using a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) to obtain oil phase 1.

[0262] (Synthesis of organic fine particle emulsion (fine particle dispersion)) A reaction vessel equipped with a stirrer and thermometer was charged with 683 parts by weight of water, 11 parts by weight of sodium salt of methacrylic acid ethylene oxide adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries, Ltd.), 138 parts by weight of styrene, 138 parts by weight of methacrylic acid, and 1 part by weight of ammonium persulfate. This mixture was stirred at 400 rpm for 15 minutes, resulting in a white emulsion. The emulsion was heated to an internal temperature of 75°C and allowed to react for 5 hours. 30 parts by weight of a 1% aqueous ammonium persulfate solution was then added, and the mixture was aged at 75°C for 5 hours to obtain an aqueous dispersion of a vinyl resin (a copolymer of styrene, methacrylic acid, and sodium salt of methacrylic acid ethylene oxide adduct sulfate) (microparticle dispersion 1). The volume-average particle size of the microparticles contained in the resulting microparticle dispersion 1 was measured using an LA-920 (manufactured by HORIBA). The volume-average particle size was 0.14 μm.

[0263] (Preparation of aqueous phase) 690 parts by mass of water, 83 parts by mass of microparticle dispersion 1, 37 parts by mass of a 48.5% aqueous solution of sodium dodecyldiphenyletherdisulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.), 90 parts by mass of ethyl acetate, 150 parts by mass of a 5% magnesium chloride solution, and 150 parts by mass of a 5% calcium chloride solution were mixed and stirred to obtain a milky white liquid. This was designated as aqueous phase 1. In this example, a magnesium chloride solution and a 5% calcium chloride solution were used as aqueous solutions of metal salts, and the magnesium ions (Mg 2+ ) and calcium ions (Ca ) contained in 5% calcium chloride solution. 2+ ) functions as a cross-linking agent.

[0264] (Emulsification and desolvation) To a vessel containing 800 parts by mass of oil phase 1, 1200 parts by mass of aqueous phase 1 was added and mixed for 20 minutes at 13,000 rpm using a TK homomixer to obtain emulsified slurry 1. The obtained emulsified slurry 1 was placed in a vessel equipped with a stirrer and thermometer, and the solvent was removed at 30°C for 8 hours, followed by aging at 45°C for 4 hours to obtain dispersion slurry 1. In this example, magnesium ions and calcium ions were metal-bridged to the ends of prepolymer A-1 in dispersion slurry 1, producing a nonlinear polymer as a crosslinked component.

[0265] (Washing and drying) 1100 parts by mass of the dispersed slurry was filtered under reduced pressure, and then the following operations (1) to (4) were carried out twice to obtain a filter cake 1. (1) 100 parts of ion-exchanged water was added to the filter cake, and the mixture was mixed with a TK homomixer (at 12,000 rpm for 10 minutes), followed by filtration. (2): 100 parts by mass of a 10% aqueous sodium hydroxide solution was added to the filter cake of (1), and the mixture was mixed with a TK homomixer (at 12,000 rpm for 30 minutes), followed by filtration under reduced pressure. (3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), and the mixture was mixed with a TK homomixer (at 12,000 rpm for 10 minutes), followed by filtration. (4): 300 parts by mass of ion-exchanged water was added to the filter cake of (3), and the mixture was mixed with a TK homomixer (at a rotation speed of 12,000 rpm for 10 minutes), followed by filtration. The obtained filter cake 1 was dried in a circulating air dryer at 45° C. for 48 hours and sieved through a mesh with an opening of 75 μm to obtain a toner base 1.

[0266] (External addition treatment) Toner base 1, 0.6 parts by mass of hydrophobic silica having an average particle size of 100 nm, 1.0 part by mass of titanium oxide having an average particle size of 20 nm, and 0.8 parts by mass of hydrophobic silica fine powder having an average particle size of 15 nm were added to 100 parts by mass of toner base 1, and mixed in a Henschel mixer to obtain toner 1.

[0267] (Number of branches of cross-linking component) Since prepolymer A-1 is obtained by reacting the hydroxyl group of intermediate polyester A-1 with the isocyanate group of HDI isocyanurate, it is believed that the number of branches of the crosslinking component contained in the obtained toner 1 is three or more.

[0268] (DSC glass transition temperature Tg of prepolymer) The glass transition temperature Tg of the prepolymer A-1 contained in the obtained toner 1 was -35.4°C. The glass transition temperature Tg of Toner 1 was measured as follows. Prepolymer A-1 was separated using the Soxhlet extraction method. 5.0 mg of the target sample, prepolymer A-1, was placed in an aluminum sample container. The sample container was then placed on a holder unit and set in an electric furnace. Next, under a nitrogen atmosphere, the sample was heated from -80°C to 150°C at a heating rate of 10°C / min (first heating). It was then cooled from 150°C to -80°C at a cooling rate of 10°C / min. The prepolymer A-1 was further heated under the same conditions as the first heating (second heating). During this second heating, a DSC curve was measured using a differential scanning calorimeter ("Q-200," manufactured by TA Instruments). From the obtained DSC curves, the DSC curve during the second heating was selected using the analysis program in the Q-200 system, and the glass transition temperature (Tg) of prepolymer A-1 during the second heating was determined. 2nd was determined as the DSC Tg of the prepolymer.

[0269] (THF insoluble matter content) The content of the THF insoluble matter in the obtained toner 1 was 13.8% by mass. The method for measuring the content of the THF insoluble matter in Toner 1 is as follows. 1 g of Toner 1 was weighed out and placed in 100 mL of THF. The mixture was stirred for 6 hours at 25°C using a stirrer to obtain a solution in which the soluble content of Toner 1 was dissolved. The solution was then filtered through a 0.2 μm membrane filter, and the filtrate was again placed in 50 mL of THF and stirred for 10 minutes using a stirrer. This process was repeated two or three times, and the resulting filtrate was dried at 120°C and 10 kPa or less to obtain a THF-insoluble content. The resulting THF-insoluble content was weighed using an electronic balance, and the content of the THF-insoluble content in Toner 1 was calculated using the following equation (2): (THF insoluble matter (g) / toner amount before extraction (g)) × 100 (2)

[0270] [Example 2] Toner 2 was obtained in the same manner as in Example 1, except that the 5% calcium chloride solution used in (preparation of aqueous phase) in Example 1 was changed to a 5% aluminum chloride solution. The number of branches of the crosslinking component contained in the obtained toner 2 is considered to be 3 or more, similar to that in Example 1. The glass transition temperature Tg of the prepolymer A-1 contained in the obtained toner 2 was -37.6°C. The content of the THF insoluble matter in the obtained toner 2 was 13.9% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0271] [Example 3] Toner 3 was obtained in the same manner as in Example 2, except that the 5% magnesium chloride solution used in (preparation of aqueous phase) in Example 2 was changed to a 5% gallium chloride solution. The number of branches of the crosslinking component contained in the obtained toner 3 is considered to be 3 or more, similar to that in Example 1. The glass transition temperature Tg of the prepolymer A-1 contained in the obtained toner 3 was -37.9°C. The content of the THF insoluble matter in the obtained toner 3 was 14.2% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0272] [Example 4] Toner 4 was obtained in the same manner as in Example 2, except that the 5% magnesium chloride solution used in (preparation of aqueous phase) in Example 2 was changed to a 5% strontium hydroxide solution. The number of branches of the crosslinking component contained in the obtained toner 4 is considered to be 3 or more, similar to that in Example 1. The glass transition temperature Tg of the prepolymer A-1 contained in the obtained toner 4 was -37.5°C. The content of the THF insoluble matter in the obtained toner 4 was 14.0% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0273] [Example 5] Toner 5 was obtained in the same manner as in Example 1, except that the prepolymer A-1 used in (preparation of oil phase) in Example 1 was changed to prepolymer A-2. Prepolymer A-2 is obtained by reacting the hydroxyl groups of intermediate polyester A-2 with the isocyanate groups of HDI isocyanurate, and then adding trimellitic anhydride. Therefore, the number of branches of the crosslinking component contained in the obtained toner 5 is thought to be three or more. The glass transition temperature Tg of the prepolymer A-2 contained in the obtained toner 5 was -37.7°C. The content of the THF insoluble matter in the obtained toner 5 was 14.1% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0274] [Example 6] Toner 6 was obtained in the same manner as in Example 4, except that the prepolymer A-1 used in (preparation of oil phase) in Example 4 was changed to prepolymer A-2. The number of branches of the crosslinking component contained in the obtained toner 6 is considered to be 3 or more, similar to that in Example 5. The glass transition temperature Tg of the prepolymer A-2 contained in the obtained toner 6 was -37.6°C. The content of the THF insoluble matter in the obtained toner 6 was 14.2% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0275] [Example 7] In this example, the toner was prepared using an emulsion aggregation method.

[0276] (Production of wax emulsion 1) To 100 parts by mass of ion-exchanged water, 28 parts by mass of wax (HNP-9, manufactured by Nippon Seiro) and Sanisol B50 as a surfactant were added. This was dispersed using a homogenizer while heated to 90°C, yielding Wax Emulsion 1. The solid content was 30%.

[0277] [Preparation of crystalline polyester resin dispersion 2] A four-neck flask was charged with crystalline polyester resin C-2 (55 parts by mass), methyl ethyl ketone (35 parts by mass), and 2-propyl alcohol (10 parts by mass). The mixture was then heated and stirred at the melting point of crystalline polyester resin C-2 to dissolve the crystalline polyester resin C-2. A 28% by mass aqueous ammonia solution was then added to achieve a neutralization rate of 200%. The neutralization rate was calculated from the acid value of the crystalline polyester resin. 130 parts by mass of ion-exchanged water was then gradually added to perform phase inversion emulsification, followed by solvent removal. Ion-exchanged water was then added to adjust the solids concentration (crystalline polyester resin concentration) to 25% by mass, yielding crystalline polyester resin dispersion 2, a binder resin dispersion for toner. The particle size of the crystalline polyester resin in crystalline polyester resin dispersion 2 was 250 nm.

[0278] (Preparation of oil phase) A four-neck flask was charged with 71 parts by mass of amorphous polyester resin B, 30 parts by mass of prepolymer A-2, and 5 parts by mass of carbon black, followed by the addition of 100 parts by mass of ethyl acetate. The mixture was stirred to dissolve and disperse. Five parts by mass of a 28% by mass aqueous ammonia solution was then added to achieve a neutralization rate of 400%. This produced oil phase 7.

[0279] (Emulsification and desolvation) 300 parts by mass of a 2% aqueous solution of sodium dodecyl sulfate was gradually added to the oil phase 7 to carry out phase inversion emulsification. The solvent was then removed to obtain emulsified slurry 7. The particle size of emulsified slurry 7 was measured to be 0.50 μm. The solid content was also measured to be 23.0%.

[0280] (Agglomeration and fusion process) 117.5 parts by weight of emulsified slurry 7, 6.0 parts by weight of crystalline polyester resin dispersion 2, 5.0 parts by weight of wax emulsion 1, and 300 parts by weight of ion-exchanged water were placed in a container and stirred for 1 minute. Next, 100 parts by weight of 5% magnesium chloride solution and 50 parts by weight of 5% calcium chloride solution were added dropwise to the mixture, and after stirring for another 5 minutes, the temperature was raised to 60 ° C. Then, when the particle size reached 5.0 μm, 50 parts by weight of sodium chloride was added to terminate the aggregation process, and aggregated slurry 7 was obtained. The aggregated slurry 7 was heated to 70 ° C while stirring, and when the desired circularity of 0.960 was reached, it was cooled to obtain dispersion slurry 7.

[0281] (annealing, washing and drying) Dispersion Slurry 7 was stored at 45°C for 10 hours, filtered under reduced pressure, and then washed and dried as follows. This procedure was repeated until the electrical conductivity of the reslurry liquid became 10 μC / cm or less, and then filtered to obtain Filter Cake 7. (1) 100 parts by mass of ion-exchanged water was added to the filter cake, and the mixture was mixed with a TK homomixer (rotation speed: 12,000 rpm, mixing time: 10 minutes), and then filtered. (2): 900 parts by mass of ion-exchanged water was added to the filter cake of (1), and the mixture was mixed in a TK homomixer while applying ultrasonic vibration (at a rotation speed of 12,000 rpm for 30 minutes), followed by filtration under reduced pressure. The filtered cake 7 was dried in a circulating air dryer at 45° C. for 48 hours and sieved through a 75 μm mesh to obtain a toner base 7.

[0282] (External addition treatment) Toner base 7 was mixed with 100 parts by mass of toner base 7, 0.6 parts by mass of hydrophobic silica having an average particle size of 100 nm, 1.0 part by mass of titanium oxide having an average particle size of 20 nm, and 0.8 parts by mass of hydrophobic silica fine powder having an average particle size of 15 nm, using a Henschel mixer, to obtain toner 7.

[0283] The number of branches of the cross-linking component contained in the obtained toner 7 is considered to be 3 or more, similar to that in Example 5. The glass transition temperature Tg of the prepolymer A-2 contained in the obtained toner 7 was -36.8°C. The content of the THF insoluble matter in the obtained toner 7 was 14.1% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0284] [Example 8] Toner 8 was obtained in the same manner as in Example 7, except that the 5% calcium chloride solution used in the aggregation and fusion step in Example 7 was changed to a 5% aluminum chloride solution and a 5% strontium hydroxide solution. The number of branches of the crosslinking component contained in the obtained toner 8 is considered to be 3 or more, similar to that in Example 5. The glass transition temperature Tg of the prepolymer A-2 contained in the obtained toner 8 was -38.2°C. The content of the THF insoluble matter in the obtained toner 8 was 14.3% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0285] [Example 9] Toner 11 was obtained in the same manner as in Example 1, except that the 5% calcium chloride solution and 5% magnesium chloride solution used in (preparation of aqueous phase) in Example 1 were changed to only 5% calcium chloride solution. The number of branches of the crosslinking component contained in the obtained toner 11 is considered to be 3 or more, similar to Example 1. The glass transition temperature Tg of the prepolymer A-1 contained in the obtained toner 11 was -37.2°C. The content of THF insoluble matter in the obtained toner 11 was 13.6% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0286] [Example 10] Toner 12 was obtained in the same manner as in Example 1, except that the 5% calcium chloride solution and 5% magnesium chloride solution used in (preparation of aqueous phase) in Example 1 were changed to only a 5% aluminum chloride solution. The number of branches of the crosslinking component contained in the obtained toner 12 is considered to be 3 or more, similar to that in Example 1. The glass transition temperature Tg of the prepolymer A-1 contained in the obtained toner 12 was -36.9°C. The content of the THF insoluble matter in the obtained toner 12 was 14.0% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0287] [Example 11] Toner 13 was obtained in the same manner as in Example 1, except that in (preparation of oil phase) in Example 1, 340 parts by mass of prepolymer A-1 was used instead of 300 parts by mass, and 630 parts by mass of amorphous polyester resin B was used instead of 650 parts by mass. The number of branches of the cross-linking component contained in the obtained toner 13 is considered to be 3 or more, similar to that in Example 1. The glass transition temperature Tg of the prepolymer A-1 contained in the obtained toner 13 was -35.4°C. The content of the THF insoluble matter in the obtained toner 13 was 15.0% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0288] [Example 12] Toner 14 was obtained in the same manner as in Example 1, except that in the preparation of the oil phase in Example 1, 740 parts by mass of prepolymer A-1 was used instead of 300 parts by mass, and 430 parts by mass of amorphous polyester resin B was used instead of 650 parts by mass. The number of branches of the crosslinking component contained in the obtained toner 14 is thought to be 3 or more, similar to Example 1. The glass transition temperature Tg of the prepolymer A-1 contained in the obtained toner 14 was -35.2°C. The content of the THF insoluble matter in the obtained toner 14 was 34.8% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0289] [Example 13] Toner 15 was obtained in the same manner as in Example 1, except that prepolymer A-3 was used instead of prepolymer A-1. The number of branches of the crosslinking component contained in the obtained toner 15 is considered to be 3 or more, similar to that in Example 1. The glass transition temperature Tg of the prepolymer A-3 contained in the obtained toner 15 was -60.0°C. The content of the THF insoluble matter in the obtained toner 15 was 13.6% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0290] [Example 14] Toner 16 was obtained in the same manner as in Example 1, except that prepolymer A-4 was used instead of prepolymer A-1. The number of branches of the cross-linking component contained in the obtained toner 16 is considered to be 3 or more, similar to that in Example 1. The glass transition temperature Tg of the prepolymer A-4 contained in the obtained toner 16 was -0.1°C. The content of the THF insoluble matter in the obtained toner 16 was 13.6% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0291] [Example 15] Toner 19 was obtained in the same manner as in Example 1, except that in (preparation of oil phase) in Example 1, 560 parts by mass of prepolymer A-1 was used instead of 300 parts by mass, and 240 parts by mass of amorphous polyester resin B was used instead of 650 parts by mass. The number of branches of the crosslinking component contained in the obtained toner 19 is considered to be 3 or more, similar to that in Example 1. The glass transition temperature Tg of the prepolymer A-1 contained in the obtained toner 19 was -35.4°C. The content of the THF insoluble matter in the obtained toner 19 was 24.9% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0292] [Example 16] Toner 20 was obtained in the same manner as in Example 1, except that in (preparation of oil phase) in Example 1, 560 parts by mass of prepolymer A-1 was used instead of 300 parts by mass, and 240 parts by mass of amorphous polyester resin B was used instead of 650 parts by mass, and the 5% calcium chloride solution used in (preparation of aqueous phase) was changed to 5% aluminum chloride solution, and the 5% magnesium chloride solution was changed to 5% strontium hydroxide solution. The number of branches of the cross-linking component contained in the obtained toner 20 is considered to be 3 or more, similar to Example 1. The glass transition temperature Tg of the prepolymer A-1 contained in the obtained toner 20 was -34.8°C. The content of THF insoluble matter in the obtained toner 20 was 25.3% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0293] [Comparative Example 1] Toner 9 was obtained in the same manner as in Example 1, except that (preparation of oil phase) and (preparation of water phase) in Example 1 were changed as follows. (Preparation of oil phase) 500 parts by mass of wax dispersion 1, 300 parts by mass of prepolymer a-1, 500 parts by mass of crystalline polyester resin dispersion 1, 700 parts by mass of amorphous polyester resin B, 100 parts by mass of masterbatch 1, and 2 parts by mass of a 20% solution of IPDA in ethyl acetate were placed in a container. The mixture was then mixed at 5,000 rpm for 60 minutes using a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) to obtain oil phase 9. (Preparation of aqueous phase) 990 parts by mass of water, 83 parts by mass of microparticle dispersion 1, 37 parts by mass of a 48.5% aqueous solution of sodium dodecyldiphenyletherdisulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.), and 90 parts by mass of ethyl acetate were mixed and stirred to obtain a milky white liquid. This was designated as aqueous phase 9. The number of branches of the crosslinking component contained in the obtained toner 9 is considered to be 3 or more, similar to that in Example 1. The glass transition temperature Tg of the prepolymer a-1 contained in the obtained toner 9 was -38.5°C. The content of the THF insoluble matter in the obtained toner 9 was 14.6% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0294] Comparative Example 2 Toner 10 was obtained in the same manner as in Example 1, except that prepolymer A-1 was changed to prepolymer a-2. Since the prepolymer a-2 is a linear polymer, the number of branches of the crosslinking component contained in the obtained toner 10 is two or less. The glass transition temperature Tg of the prepolymer a-2 contained in the obtained toner 10 was -38.8°C. The content of THF insoluble matter in the obtained toner 10 was 8.5% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0295] Comparative Example 3 Toner 17 was obtained in the same manner as in Example 1, except that prepolymer a-3 was used instead of prepolymer A-1. The number of branches of the cross-linking component contained in the obtained toner 17 is considered to be 3 or more, similar to that in Example 1. The glass transition temperature Tg of the prepolymer a-3 contained in the obtained toner 17 was 5.2°C. The content of the THF insoluble matter in the obtained toner was 13.8% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0296] Comparative Example 4 Toner 18 was obtained in the same manner as in Example 1, except that prepolymer a-4 was used instead of prepolymer A-1. The number of branches of the cross-linking component contained in the obtained toner 18 is considered to be 3 or more, similar to that in Example 1. The glass transition temperature Tg of the prepolymer a-4 contained in the obtained toner 18 was -67.6°C. The content of the THF insoluble matter in the obtained toner 18 was 13.9% by mass. The glass transition temperature Tg and the content of THF insoluble matter were measured in the same manner as in Example 1.

[0297] <Evaluation> The resulting toners of each of the examples and comparative examples were evaluated for charging property, low-temperature fixability, hot offset property, and blocking resistance.

[0298] [Chargeability] The toner chargeability was evaluated by calculating the toner charge amount. 0.35 g of toner and 5 g of carrier were placed in a stainless steel cylindrical container (inner diameter 25 mm, height 30 mm) at 23°C and 53±3% humidity. After 12 hours of conditioning, the container was sealed and rotated at 300 rpm for 5 minutes. A sample of the toner and carrier mixture was taken from the container, placed in a 400-mesh blow-off gauge, and subjected to air blowing at 5 kPa for 3 minutes. The charge was then measured using a Q / M meter (manufactured by EPPING). The Q / M meter settings were a 400-mesh stainless steel mesh, a soft blow pressure of 1050 V, and a suction time of 90 seconds. The charge amount was calculated using the following formula (3). A charge amount of 26 μC / g or greater was considered to be good for the toner chargeability. Charge amount (μC / g) = total charge after 90 seconds (μC) / amount of toner absorbed (g) Equation (3)

[0299] [Low temperature fixability] The low-temperature fixability of the toner was evaluated by measuring the minimum fixing temperature of the toner. Using a device with a modified fixing section of the imageo MP C5002 (manufactured by Ricoh Co., Ltd.), a copying test was carried out on Type 6200 paper (manufactured by Ricoh Co., Ltd.). Specifically, the fixing temperature was changed to measure the temperature at which cold offset occurred (minimum fixing temperature). The evaluation conditions for the minimum fixing temperature were a paper feed linear speed of 200 mm / s and a surface pressure of 1.0 kgf / cm. 2 The nip width was set to 7 mm. If the lower limit fixing temperature was less than 140° C., the toner obtained in this embodiment was evaluated as having sufficient low-temperature fixing property. (Evaluation criteria) ◎: Less than 120℃ ○: 120℃ or higher and lower than 130℃ △: 130℃ or higher but lower than 140℃ ×: 140℃ or higher

[0300] [Hot offset resistance] The hot offset property of the toner was evaluated by measuring the maximum fixing temperature of the toner. Using a device with a modified fixing section of an imageo MP C5002 (manufactured by Ricoh Co., Ltd.), a copying test was carried out on Type 6200 paper (manufactured by Ricoh Co., Ltd.). Specifically, the fixing temperature was changed to measure the temperature at which hot offset occurred (maximum fixing temperature). The evaluation conditions for the maximum fixing temperature were a paper feed linear speed of 100 mm / s and a surface pressure of 1.0 kgf / cm. 2 The nip width was set to 7 mm. If the upper limit fixing temperature was 170° C. or higher, the toner obtained in this embodiment was evaluated as having sufficient hot offset properties.

[0301] [Blocking resistance] Print a 3cm x 15cm rectangular solid image on PPC paper type 6000<70W>A4 T-line (manufactured by Ricoh Co., Ltd.) with a toner adhesion of 0.85mg / cm 2The image was formed so that the image was as follows: and 200 sheets were output continuously on one side. The fixing temperature was controlled so that it was mainly the cold offset temperature + 20°C. The 200 output images were left stacked for 1 hour, and then the adhesion of the images to each other was evaluated based on the following evaluation criteria. If the blocking resistance was rated as "◎" or "◯", the toner obtained in this embodiment was evaluated to have sufficient blocking resistance. (Evaluation criteria) ◎: No sticking of sheets of paper at all ○: There is some sticking between the sheets of paper, but there is no problem with the image when the sheets are separated. △: There is some sticking of the sheets together, and the gloss of the image changes when the sheets are separated. ×: The sheets stick together, and the image or paper is damaged when the sheets are separated.

[0302] [comprehensive evaluation] The overall evaluation was made according to the following evaluation criteria. A toner that was rated as "◯" or "◎" for all evaluation items, had a charge amount of 30 μC / g or more, and had an upper limit fixing temperature of 180° C. or more was rated as "◎". A toner that was rated "◯" or "◎" for all evaluation items, had a charge amount of 26 μC / g or more, and had an upper limit fixing temperature of 170° C. or more was rated "◯". When all evaluation items were "○" or "◎", the charge amount was 20 μC / g or more and 26 μC / g or less, and the upper limit fixing temperature was 160°C or more and less than 170°C, the evaluation was "△". If all evaluation items had one or more "△" or "×", if the charge amount was less than 20 μC / g, or if the upper limit fixing temperature was less than 160° C., it was judged as "×". (Evaluation criteria) ◎:Excellent ○:Excellent △: Somewhat excellent ×: Same as before or not suitable for practical use

[0303] Table 2 shows the evaluation results of the charge resistance, minimum fixing temperature, maximum fixing temperature, and blocking resistance of the obtained toners of each Example and Comparative Example. The ionic radius (pm) of the metal ions was calculated as follows: Calcium chloride divalent calcium ion; 100 pm · Magnesium chloride divalent magnesium ion; 72pm Aluminum chloride (trivalent aluminum ion); 54pm · Trivalent gallium ion of gallium chloride; 47pm · Strontium hydroxide trivalent strontium ion; 118pm

[0304] [Table 1]

[0305] [Table 2]

[0306] From Tables 1 and 2, it was confirmed that the toners of Examples 1 to 16 satisfied the requirements for use in terms of chargeability, low-temperature fixability, hot offset, and blocking resistance. In contrast, it was confirmed that the toners obtained in Comparative Examples 1 to 4 did not satisfy the requirements for use in terms of at least one of chargeability, low-temperature fixability, hot offset, and blocking resistance, and therefore had practical problems.

[0307] Therefore, unlike the toners of Comparative Examples 1 to 4, the toners of Examples 1 to 16 contain a crosslinking component, which is a three-branched nonlinear polymer with metal crosslinking at the ends, and by setting the glass transition temperature Tg of the nonlinear polymer to be −60°C or higher and lower than 0°C, the toners are excellent in chargeability, low-temperature fixing property, hot offset, and anti-blocking after fixing, and can be said to be high-quality toners.

[0308] Although the embodiments have been described above, they are presented as examples and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as set forth in the claims.

[0309] The present invention includes, for example, the following aspects. <1> The toner comprises a crosslinking component, the crosslinking component comprising a non-linear polymer that is branched into three or more branches and has a metal-bridged end, and the glass transition temperature Tg of the non-linear polymer measured by differential scanning calorimetry is -60°C or higher and lower than 0°C. <2> The toner comprises a crosslinking component, the crosslinking component containing at least a THF (tetrahydrofuran) insoluble matter as a binder resin, the THF insoluble matter containing a non-linear polymer branched to three or more branches and a metal ion, and the THF insoluble matter has a glass transition temperature Tg of -60°C or higher and lower than 0°C as measured by differential scanning calorimetry. <3> The content of the THF-insoluble matter is 15 to 35 mass %. <2> The toner is as described in <4> The metal bridge of the non-linear polymer contains two kinds of divalent or higher metal ions. <1> From the above <3> The toner according to any one of the above items. <5> The two types of divalent or higher valent metal ions have different valences. <4> The toner is as described in <6> The difference in ionic radius between the two types of divalent or higher metal ions is 50 pm or more. <4> From the above <5> The toner according to any one of the above items. <7> The aforementioned <1> From the above <6> 10. A developer comprising the toner according to any one of claims 1 to 9. <8> The aforementioned <1> From the above <6> 1. A toner storage unit characterized by storing the toner according to any one of the above items. <9> an oil phase containing a prepolymer, which is a non-linear reactive precursor, is mixed with an aqueous medium, and a non-linear polymer is generated by at least one of an elongation reaction and a crosslinking reaction between the prepolymer and a curing agent, thereby forming toner base particles; <1> From the above <6> 10. A method for producing a toner, comprising the steps of: <10> a prepolymer, which is a non-linear reactive precursor, an oil phase containing an active hydrogen group-containing compound, and an aqueous medium are mixed together, and toner base particles are formed while a non-linear polymer is generated by at least one of an elongation reaction and a crosslinking reaction between the prepolymer and a curing agent; <1> From the above <6> 10. A method for producing a toner, comprising the steps of: <11> An oil phase in which a polyester resin and a prepolymer, which is a non-linear reactive precursor, are dissolved or dispersed in an organic solvent is subjected to phase inversion emulsification, the organic solvent is removed, and then a dispersion containing a crystalline polyester resin is mixed to prepare a mixed liquid, the crystalline polyester resin in the mixed liquid is aggregated to form toner base particles, and <1> From the above <6> 10. A method for producing a toner, comprising the steps of: <12> a developing unit that develops the electrostatic latent image using toner to form a visible image; a transfer unit that transfers the visible image to a recording medium; and a fixing unit that fixes the transferred image to the recording medium, wherein the toner is <1> From the above <6> 10. An image forming apparatus comprising the toner according to any one of claims 1 to 9. <13> An electrostatic latent image is formed on an electrostatic latent image carrier, the electrostatic latent image is developed with toner to form a visible image, the visible image is transferred to a recording medium, and the transferred image is fixed on the recording medium, and the toner is <1> From the above <6> 2. An image forming method, characterized in that the toner is the toner described in any one of 1. to 1. <14> The resin microparticles contain a crosslinking component, which contains at least a THF (tetrahydrofuran) insoluble component as a binder resin, and the THF insoluble component contains a non-linear polymer branched into three or more branches and a metal ion, and the glass transition temperature Tg of the THF insoluble component measured by differential scanning calorimetry is -60°C or higher and lower than 0°C.

[0310] The aforementioned <1> From the above <6> the toner of <7> the developer, <8> the toner storage unit, <9> From the above <11> The method for producing the toner <12> The image forming apparatus <13> The image forming method of <14> The resin particles described above can solve the various problems encountered in the past and achieve the object of the present invention. [Explanation of symbols]

[0311] 1A Image forming device 1B Image forming device 1C Image forming device 10 Electrostatic latent image carrier (photosensitive drum) 10K Black (Bk) Photoconductor Drum 10Y Yellow (Y) photoconductor drum 10M Magenta (M) photoconductor drum 10C Cyan (C) photoconductor drum 20 Charging roller (charging part) 30 Exposure device (exposure section) 40 Developing device (developing section) 41 Developing belt 42K Black (Bk) Development Unit 421K Developer compartment 422K Developer supply roller 423K Developing roller (developer carrier) 42Y Yellow (Y) Development Unit 421Y Developer storage unit 422Y Developer supply roller 423Y Developing roller (developer carrier) 42M Magenta (M) Development Unit 421M Developer compartment 422M Developer supply roller 423M Developing roller (developer carrier) 42C Cyan (C) Development Unit 421C Developer storage unit 422C Developer supply roller 423C Developing roller (developer carrier) 50 Intermediate transfer body (intermediate transfer belt) 51 Laura 52 Corona charger 53A Roller 53B Lola 53C Lola 60 Cleaning device (cleaning section) 62 Transfer charger 70 Transfer roller (transfer section) 80 Static elimination lamp (static elimination part) 90 Intermediate transfer cleaning device 95 Transfer paper 110 Copying device body 111 Paper feed path 112 Registration roller 113 Manual feed roller 114 Tray 115 Manual feed path 116 Switching claw 117 Discharge roller 118 Paper output tray 120 Paper feed table 121 Paper feed roller 122 Paper Bank 123 Paper cassette 124 Separation roller 125 Paper feed path 126 Conveyor roller 130 Scanner 131 Contact Glass 132 First Running Body 133 Second Running Body 135 Imaging Lens 136 Reading sensor 140 Automatic Document Feeder (ADF) 141 manuscript table 150 Secondary transfer device 151 Secondary transfer belt 152 Laura 160 Fixing device 161 Fixing belt 162 Pressure roller 170 Sheet inverting device 200 Image forming device process cartridge L exposure light P Transfer paper [Prior art documents] [Patent documents]

[0312] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-125413

Claims

1. Contains a cross-linking component, the cross-linking component includes a non-linear polymer that is branched into three or more branches and has a metal-bridged end; The toner is characterized in that the glass transition temperature Tg of the non-linear polymer measured by differential scanning calorimetry is -60°C or higher and lower than 0°C.

2. Contains a cross-linking component, The crosslinking component contains at least a THF (tetrahydrofuran) insoluble component as a binder resin, the THF-insoluble matter contains a non-linear polymer branched to three or more branches and a metal ion; The toner is characterized in that the THF-insoluble matter has a glass transition temperature Tg measured by differential scanning calorimetry of -60°C or higher and lower than 0°C.

3. 3. The toner according to claim 2, wherein the content of the THF-insoluble matter is 15 to 35% by mass.

4. 4. The toner according to claim 1, wherein the metal bridge of the non-linear polymer contains two kinds of divalent or higher metal ions.

5. The toner according to claim 4 , wherein the two types of divalent or higher valent metal ions have different valences.

6. 6. The toner according to claim 4, wherein the difference in ionic radius between the two types of divalent or higher valent metal ions is 50 pm or more.

7. A developer comprising the toner according to any one of claims 1 to 6.

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

9. 7. A method for producing a toner according to claim 1, comprising: mixing an oil phase containing a prepolymer, which is a non-linear reactive precursor, with an aqueous medium; and forming toner base particles while generating a non-linear polymer through at least one of an elongation reaction and a crosslinking reaction between the prepolymer and a curing agent.

10. 7. A method for producing a toner according to claim 1, comprising: mixing a prepolymer, which is a non-linear reactive precursor, an oil phase containing an active hydrogen group-containing compound, and an aqueous medium; and forming toner base particles while generating a non-linear polymer through at least one of an elongation reaction and a crosslinking reaction between the prepolymer and a curing agent.

11. 7. A method for producing a toner, comprising: subjecting a polyester resin and a prepolymer, which is a non-linear reactive precursor, to a phase inversion emulsification to form an oil phase dissolved or dispersed in an organic solvent; removing the organic solvent; and then mixing the resulting mixture with a dispersion containing a crystalline polyester resin to prepare a mixed liquid; and aggregating the crystalline polyester resin in the mixed liquid to form toner base particles, thereby producing the toner according to claim 1.

12. an electrostatic latent image carrier; an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier; a developing unit that develops the electrostatic latent image with toner to form a visible image; a transfer unit that transfers the visible image onto a recording medium; a fixing unit that fixes the transferred image onto the recording medium, 7. An image forming apparatus, wherein the toner is the toner according to claim 1.

13. forming an electrostatic latent image on an electrostatic latent image carrier, developing the electrostatic latent image with toner to form a visible image, transferring the visible image to a recording medium, and fixing the transferred image on the recording medium; 7. An image forming method, wherein the toner is the toner according to claim 1.

14. Contains a cross-linking component, The crosslinking component contains at least a THF (tetrahydrofuran) insoluble component as a binder resin, the THF-insoluble matter contains a non-linear polymer branched to three or more branches and a metal ion; The resin particles are characterized in that the THF-insoluble portion has a glass transition temperature Tg measured by differential scanning calorimetry of -60°C or higher and lower than 0°C.

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