Toner

Abstract

To provide a toner which suppresses aggregation of a pigment and is excellent in coloring power.SOLUTION: A toner includes toner particles containing a binder resin, a pigment, and a pigment dispersant, wherein the pigment dispersant is a polymer containing a structure represented by formula (1) and a structure represented by formula (2).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to toners used to form toner images by developing electrostatic latent images formed by methods such as electrophotography, electrostatic recording, and toner jet recording. [Background technology]

[0002] As electrophotographic technology used in copiers, printers, facsimile receiving devices, etc. advances, the demands of users are becoming more stringent year by year. In recent years, there has been a strong demand for compact designs so that devices can be installed anywhere.

[0003] To meet the above demands, one method is to improve the coloring power of the toner and form an image using a smaller amount of toner, thereby reducing the size of the toner container.

[0004] In order to improve the coloring power of a toner, it is effective to finely disperse the pigment. As a means for improving pigment dispersibility, for example, Patent Document 1 proposes a toner containing a pigment dispersant having a portion that adsorbs to the pigment and a polymer portion that has good affinity with the pigment's dispersion medium, and a polar resin having an acid value in a specific range.

[0005] The above measures have made it possible to obtain a toner with high coloring power and excellent durability, and toner containers can be made smaller. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-049404 Summary of the Invention [Problem to be solved by the invention]

[0007] However, from the viewpoint of further miniaturization, there is a demand for image formation with a smaller amount of toner. The pigment dispersant disclosed in Patent Document 1 has a limited effect of suppressing pigment aggregation, and further improvement in coloring power cannot be expected. Therefore, there is still a demand for improving the coloring power of toner by improving pigment dispersibility.

[0008] The present disclosure provides a toner that suppresses pigment aggregation in the toner and has excellent coloring power. [Means for solving the problem]

[0009] The present disclosure provides a toner having toner particles containing a binder resin, a pigment, and a pigment dispersant, The toner is characterized in that the pigment dispersant is a polymer containing a structure represented by the following formula (1) and a structure represented by the following formula (2).

[0010] [ka]

[0011] (In formula (1), X, Y, and Z each independently represent -O-, a methylene group, or -NR5-; R5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; L1 represents an ester bond or an amide bond; R1 represents a hydrogen atom or a methyl group; R2 represents an alkylene group having 2 to 4 carbon atoms, R4 represents a substituted phenyl group, an unsubstituted phenyl group, a substituted polycyclic aromatic group, an unsubstituted polycyclic aromatic group, a substituted heterocyclic group, or an unsubstituted heterocyclic group; R3 represents a hydrogen atom, a substituted phenyl group, an unsubstituted phenyl group, an aralkyl group, a substituted alkyl group having from 1 to 18 carbon atoms, an unsubstituted alkyl group having from 1 to 18 carbon atoms, or a monovalent group in which a methylene group in an alkyl group having from 2 to 18 carbon atoms has been replaced with -O-, -COO-, or -CONH-.

[0012] [ka]

[0013] (In formula (2), At least two of R6 to R9 are -V-COOR 10 and the rest each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0014] V represents a single bond or an alkylene group having 1 to 2 carbon atoms; R 10 represents an alkyl group having 16 to 30 carbon atoms. [Effects of the Invention]

[0015] According to the present disclosure, a toner with excellent coloring power can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present disclosure will be described in detail below, but is not limited to these descriptions. In the present disclosure, the expressions "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined arbitrarily. Furthermore, a monomer unit refers to a structure formed by the reaction of a monomer in a polymer.

[0017] Each of the above requirements will be explained in detail below.

[0018] The toner of the present disclosure is A toner having toner particles containing a binder resin, a pigment, and a pigment dispersant, The pigment dispersant is a polymer containing a structure represented by the following formula (1) and a structure represented by the following formula (2).

[0019] [ka]

[0020] (In formula (1), X, Y, and Z each independently represent -O-, a methylene group, or -NR5-; R5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; L1 represents an ester bond or an amide bond; R1 represents a hydrogen atom or a methyl group; R2 represents an alkylene group having 2 to 4 carbon atoms, R4 represents a substituted phenyl group, an unsubstituted phenyl group, a substituted polycyclic aromatic group, an unsubstituted polycyclic aromatic group, a substituted heterocyclic group, or an unsubstituted heterocyclic group; R3 represents a hydrogen atom, a substituted phenyl group, an unsubstituted phenyl group, an aralkyl group, a substituted alkyl group having from 1 to 18 carbon atoms, an unsubstituted alkyl group having from 1 to 18 carbon atoms, or a monovalent group in which a methylene group in an alkyl group having from 2 to 18 carbon atoms has been replaced with -O-, -COO-, or -CONH-.

[0021] [ka]

[0022] (In formula (2), At least two of R6 to R9 are -V-COOR 10 and the rest each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0023] V represents a single bond or an alkylene group having 1 to 2 carbon atoms; R 10 represents an alkyl group having 16 to 30 carbon atoms. It has been found that a toner having excellent coloring power can be obtained by satisfying the above requirements. The present inventors consider the mechanism as follows.

[0024] The pigment dispersant of the present disclosure is a polymer containing a structure represented by formula (1) and a structure represented by formula (2).

[0025] The structure represented by formula (1) has a site that exhibits strong π-π interaction, and therefore easily interacts with the pigment, allowing the polymer containing the structure represented by formula (1) to exist in the vicinity of the pigment.

[0026] The structure represented by formula (2) has at least two long-chain alkyl groups, so the long-chain alkyl groups within the structure are close to each other. The action of these close long-chain alkyl groups tends to generate steric repulsion. Therefore, polymers containing the structure represented by formula (2) can improve the dispersion stability of pigments due to the exclusion effect of steric repulsion.

[0027] By using the pigment dispersant of the present disclosure, it is possible to suppress aggregation of pigment particles and stabilize the dispersed state of the pigment, thereby obtaining a toner with excellent coloring power.

[0028] <Pigment dispersant> The structure of the pigment dispersant represented by formula (1) and preferred embodiments thereof will be described in detail below.

[0029] The structure of the pigment dispersant containing formula (1) is a site that adsorbs to the pigment, also referred to as an adsorption site. R4 in formula (1) is a site responsible for π-π interaction with the pigment. Therefore, R4 must have a structure with π-planarity. Specifically, R4 can be a substituted phenyl group, an unsubstituted phenyl group, a substituted polycyclic aromatic group, an unsubstituted polycyclic aromatic group, a substituted heterocyclic group, or an unsubstituted heterocyclic group. Among these, a substituted polycyclic aromatic group, an unsubstituted polycyclic aromatic group, a substituted heterocyclic group, or an unsubstituted heterocyclic group is preferred because it exhibits stronger π-π interaction. More preferably, the structure of R4 is a benzimidazolinone structure. The benzimidazolinone structure has high structural planarity and strong hydrogen bonding properties, resulting in high adsorption to the pigment and improved coloring power of the toner. The substituent may be, for example, a halogen atom, a nitro group, an amino group, a hydroxy group, a cyano group, or a trifluoromethyl group.

[0030] R3 in formula (1) may incorporate a compound having π-planarity to enhance the pigment's adsorption to the pigment, or may incorporate a structure, such as an alkyl group, that adjusts the solubility in the dispersion medium. In this case, a structure that is not bulky is preferred so as not to inhibit adsorption to the pigment. Specifically, R3 represents a hydrogen atom, a substituted phenyl group, an unsubstituted phenyl group, an aralkyl group, a substituted alkyl group having from 1 to 18 carbon atoms, an unsubstituted alkyl group having from 1 to 18 carbon atoms, or a monovalent group in which a methylene group in an alkyl group having from 2 to 18 carbon atoms has been replaced with -O-, -COO-, or -CONH-. Examples of substituents that can be used include halogen atoms, nitro groups, amino groups, hydroxy groups, cyano groups, and trifluoromethyl groups. An alkyl group or a phenyl group having from 1 to 12 carbon atoms is preferred. An alkyl group having from 2 to 12 carbon atoms is more preferred, and an alkyl group having from 2 to 8 carbon atoms is even more preferred. When R3 has one of these structures, the pigment dispersant can maintain its adsorption to the pigment, making it easier to obtain good coloring power for the toner. The alkyl group may be linear, branched, or cyclic. If the alkyl group is substituted, the number of carbon atoms includes the number of carbon atoms of the substituent.

[0031] R2 in formula (1) is a divalent functional group, which is an alkylene group having 2 to 4 carbon atoms. By using an alkylene group having 2 to 4 carbon atoms, the adsorption site exhibits good solubility, which makes it possible to suppress aggregation of the adsorption site, and the coloring power of the toner is likely to improve.

[0032] In formula (1), R1 represents a hydrogen atom or a methyl group.

[0033] In formula (1), X, Y, and Z each independently represent -O-, a methylene group, or -NR5-. R5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group may be linear, branched, or cyclic. It is preferable that two or more of X, Y, and Z are -NH-, as this improves the structural stability of the compound. It is particularly preferable that X and Z are -NH-. This is because when Z is -NH-, an amide bond is formed, which is advantageous for adsorption to the pigment. Furthermore, it is preferable that X is -NH- from the perspective of production. It is preferable that Y is -O- from the viewpoint of facilitating diversification of the structure of R3.

[0034] L1 in formula (1) is a linking moiety to the polymer moiety, and is an ester bond or an amide bond from the viewpoint of ease of production.

[0035] In view of the above, the adsorption site of the pigment dispersant of the present disclosure preferably has a structure represented by the following formula (3).

[0036] [ka]

[0037] (In formula (3), L1 represents an ester bond or an amide bond; R1 represents a hydrogen atom or a methyl group; R 11 represents an alkylene group having 2 to 4 carbon atoms, R 12 represents a hydrogen atom, a substituted phenyl group, an unsubstituted phenyl group, an aralkyl group, a substituted alkyl group having from 1 to 18 carbon atoms, an unsubstituted alkyl group having from 1 to 18 carbon atoms, or a monovalent group in which a methylene group in an alkyl group having from 2 to 18 carbon atoms has been replaced with -O-, -COO-, or -CONH-. When the pigment dispersant has the structure represented by formula (3) as the adsorption site, the pigment dispersion has improved adsorption to the pigment, which makes it easier to obtain a toner with good coloring power.

[0038] The content (mass %) of the structure represented by formula (1) in the pigment dispersant is preferably 1.0 mass % or more and 15.0 mass % or less. When the content of the structure represented by formula (1) is 1.0 mass % or more, the proportion of sites in the pigment dispersant that interact with the pigment increases, making it easier for the pigment dispersant to be present near the pigment. This makes it easier to obtain toner coloring power. When the content of the structure represented by formula (1) is 15.0 mass % or less, the length of the polymer chain (also called loop length) of the polymer site between the structures represented by formula (1) in the pigment dispersant becomes sufficient, making it easier to suppress aggregation of pigments due to steric hindrance. This makes it easier to obtain toner coloring power.

[0039] Next, the structure of the pigment dispersant represented by formula (2) will be described.

[0040] At least two of R6 to R9 in formula (2) are -V-COOR 10 (V represents a single bond or an alkylene group having 1 to 2 carbon atoms. R 10 represents an alkyl group having 16 to 30 carbon atoms. ) and the remaining groups are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. As mentioned above, the adjacent long-chain alkyl groups generate a steric repulsion force, which provides the exclusion effect necessary for pigment dispersion. R 10 When the carbon number of R is 16 or more, a steric repulsion sufficient for pigment dispersion is obtained, and a toner with excellent coloring power is obtained. In addition, the Tg of the pigment dispersant is increased, and the storage stability of the toner is improved. 10 When the carbon number of R is 30 or less, the interaction between the structure represented by formula (1) and the pigment is not inhibited, and the pigment dispersant can be present around the pigment, resulting in a toner with excellent coloring power. 10 The number of carbon atoms is more preferably 18 to 28, and even more preferably 20 to 24.

[0041] In order to incorporate the structure represented by formula (2) into a pigment dispersant, the following formula (2')

[0042] [ka]

[0043] (In formula (2'), R 6’ ~R 9’ At least two of these are -V-COOH, and the remaining groups each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0044] V represents a single bond or an alkylene group having 1 to 2 carbon atoms. and a long-chain alkyl monoalcohol having 16 to 30 carbon atoms (hereinafter referred to as the polymerizable ester of the present disclosure) is used as a polymerizable monomer.

[0045] Examples of polycarboxylic acids represented by formula (2') include maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, glutaconic acid, trans-aconitic acid, and cis-aconitic acid. Acid anhydrides and lower alkyl (having 1 to 4 carbon atoms) esters (e.g., methyl ester, ethyl ester, isopropyl ester, etc.) of these polycarboxylic acids may also be used. The polycarboxylic acids may be used alone or in combination of two or more. Of these, maleic acid, fumaric acid, itaconic acid, and their acid anhydrides are preferred to achieve the effects of the present disclosure.

[0046] Examples of the long-chain alkyl monoalcohol having 16 to 30 carbon atoms include cetanol, stearyl alcohol, 1-eicosanol, behenyl alcohol, 1-tetracosanol, and 1-triacontanol.

[0047] The method for producing the polymerizable ester is not particularly limited except for using a polycarboxylic acid represented by formula (2') and a monoalcohol having 16 to 30 carbon atoms. It is preferable to use an esterification catalyst and a stabilizer (polymerization inhibitor) to ensure that the condensation reaction is carried out and to suppress the reaction of carbon-carbon double bonds.

[0048] The content (mass %) of the structure represented by formula (2) in the pigment dispersant is preferably 5.0 mass % or more and 70.0 mass % or less. When the content of the structure represented by formula (2) is 5.0 mass % or more, an exclusion effect is obtained due to the steric repulsion of the adjacent long-chain alkyl groups, resulting in good toner coloring power and color unevenness (described later). When the content of the structure represented by formula (2) is 70.0 mass % or less, the interaction with the pigment is not inhibited, allowing the pigment dispersant to be present around the pigment, making it easier to obtain good toner coloring power. A more preferred content is 10.0 mass % or more and 60.0 mass % or less.

[0049] The pigment dispersant preferably contains, in addition to the structures represented by the above formulas (1) and (2), a monomer unit derived from the following monomer.

[0050] Monomers include styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, and styrene derivatives such as p-phenylstyrene; acrylic polymerizable monomers such as acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, n-lauryl acrylate, cyclohexyl acrylate, 2-methoxyethyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, and 2-benzoyloxyethyl acrylate; Methacrylic polymerizable monomers such as methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, 2-methoxyethyl methacrylate, diethyl phosphate ethyl methacrylate, and dibutyl phosphate ethyl methacrylate; acrylonitrile, and methacrylonitrile.

[0051] The weight average molecular weight (Mw) of the pigment dispersant is preferably 10,000 or more and 50,000 or less, and more preferably 15,000 or more and 40,000 or less.

[0052] <Manufacturing method of pigment dispersants> Next, a method for producing a pigment dispersant will be described. A pigment dispersant can be obtained by copolymerizing a compound having a polymerizable group introduced into the adsorption site with a polymerizable ester. Alternatively, the pigment dispersant can be obtained by adding an intermediate compound of the adsorption site to a resin containing a functional group capable of reacting with the intermediate compound of the adsorption site and a structure represented by formula (2). In either method, the pigment dispersant can be obtained by known synthesis and polymerization methods. For example, the pigment dispersant can be synthesized according to the scheme shown below.

[0053] [ka]

[0054] In the above scheme, "-co-" means copolymerization.

[0055] The adsorption site having the polymerizable functional group introduced therein according to the above scheme can be polymerized with the polymerizable ester of the present disclosure by a conventionally known method such as radical polymerization, living radical polymerization, anionic polymerization, or cationic polymerization to form a pigment dispersant. In the pigment dispersant, the structure represented by formula (1) and the structure represented by formula (2) may be present in a random state or in a block state.

[0056] The reaction temperature and reaction time of each step, the type of solvent and catalyst used, and the purification method after synthesis can be selected appropriately according to the target product. The molecular structure of the synthesized adsorption site and the physical properties of the polymerized pigment dispersant can be identified using NMR (nuclear magnetic resonance), IR (infrared spectrophotometer), MS (mass spectrometer), GPC (gel permeation chromatography), etc.

[0057] On the other hand, when an intermediate of the adsorption site is added to a prepolymerized resin, it is necessary to make the resin before addition have a functional group capable of undergoing an addition reaction with the intermediate of the adsorption site. Known methods can be used for this purpose.

[0058] <Pigments> The pigment preferably includes a pigment selected from the following group:

[0059] Carbon black, CI Pigment Yellow 74, 93, 139, 155, 180, 185; CI Pigment Red 31, 122, 150, 170, 185, 258, 269; CI Pigment Blue 15:3, 15:4.

[0060] When the pigment is selected from the above group, adsorption due to π-π interactions and hydrogen bonding is stronger, so the pigment dispersant is more likely to be present near the pigment, and pigment dispersibility is more likely to be improved.

[0061] More preferred are carbon black, CI Pigment Yellow 74, 93, 155, 180, 185; CI Pigment Red 122, 150; and CI Pigment Blue 15:3.

[0062] The content (mass %) of the pigment dispersant in the toner particles is preferably 1.5% by mass to 30.0% by mass, more preferably 5.0% by mass to 25.0% by mass, and even more preferably 10.0% by mass to 20.0% by mass, based on the total mass of the pigment, from the viewpoint of the coloring power of the toner and color unevenness described below.

[0063] <Crystalline materials> From the viewpoint of low-temperature fixability, the toner of the present disclosure preferably contains a crystalline material, which is a material such as wax or crystalline resin that exhibits an endothermic peak in differential scanning calorimetry (DSC).

[0064] The content (mass %) of the crystalline material in the toner particles is preferably 20.0% by mass or more and 50.0% by mass or less from the viewpoint of low-temperature fixability. The crystalline material in the toner particles tends to crystallize and form domains when it melts during fixation and then cools and solidifies. If the content of the crystalline material in the toner particles is high, diffuse reflection occurs due to the domains of the crystalline material present in the toner layer after fixation, which tends to result in color unevenness in the image. When the above-mentioned pigment dispersant and crystalline material are incorporated into the toner, the long-chain alkyl group in the structure represented by formula (2) acts as a nucleating agent for the crystalline material. Because the pigment dispersant is finely dispersed in the toner particles, it can suppress the crystal growth of the crystalline material and the formation of domains. Therefore, diffuse reflection does not occur in the image, and color unevenness can be suppressed.

[0065] Specific examples of crystalline materials include waxes such as hydrocarbon waxes or ester waxes, and crystalline resins such as crystalline vinyl resins, crystalline polyesters, crystalline polyurethanes, and crystalline epoxy resins. Among these, crystalline vinyl resins or crystalline polyesters are preferred, and crystalline vinyl resins are more preferred.

[0066] When the crystalline resin is a crystalline vinyl resin, it preferably contains a structure represented by formula (4) or a structure represented by formula (5).

[0067] [ka]

[0068] (In formula (4), R 13 represents a hydrogen atom or a methyl group, L2 represents a single bond, -COO-, or -CONH-; n represents an integer between 15 and 30.

[0069] [ka]

[0070] (In formula (5), R 14 ~R 17 At least two of them are -W-COOR 18 and the remainder represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, W represents a single bond or an alkylene group having 1 to 2 carbon atoms; R 18 represents an alkyl group having 16 to 30 carbon atoms. When a crystalline vinyl resin has the above structure, it is easy to form a side chain crystalline structure, which results in sharp melting properties and improved low-temperature fixability. Furthermore, the side chain crystalline structure has a higher degree of crystallinity than a folded main chain crystalline structure, resulting in excellent durability and storage stability. n in formula (4) is preferably 17 or more and 29 or less, more preferably 19 or more and 23 or less. Furthermore, R in formula (5) 18 is preferably an alkyl group having 18 to 28 carbon atoms, more preferably an alkyl group having 20 to 24 carbon atoms.

[0071] In addition to the above structure, the crystalline vinyl resin may have a monomer unit derived from another polymerizable monomer.

[0072] Other polymerizable monomers include the following:

[0073] styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, and styrene derivatives such as p-phenylstyrene; acrylic polymerizable monomers such as acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, n-lauryl acrylate, cyclohexyl acrylate, 2-methoxyethyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, and 2-benzoyloxyethyl acrylate, and acrylonitrile; methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, 2-methoxyethyl methacrylate, diethyl phosphate ethyl methacrylate, and dibutyl phosphate ethyl methacrylate; and methacrylonitrile and other methacrylic polymerizable monomers.

[0074] Of these, styrene, methacrylic acid, acrylic acid, methyl (meth)acrylate, acrylonitrile, and methacrylonitrile are preferred.

[0075] The crystalline vinyl resin described here has a structure different from that of the pigment dispersant, and is a polymer that does not contain the structure represented by formula (1).

[0076] When wax is used as the crystalline material, the type of wax is not particularly limited, but hydrocarbon wax or ester wax is preferred.

[0077] Examples of hydrocarbon waxes include the following:

[0078] Low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight olefin copolymer, Fischer-Tropsch wax, paraffin wax, or waxes obtained by oxidizing or adding an acid thereto.

[0079] The ester wax may be any wax having at least one ester bond in one molecule, and either a natural ester wax or a synthetic ester wax may be used.

[0080] Examples of ester waxes include the following:

[0081] Esters of monohydric alcohols and monocarboxylic acids, such as behenyl behenate, stearyl stearate, and palmityl palmitate; Esters of dicarboxylic acids and monoalcohols, such as dibehenyl sebacate; Esters of dihydric alcohols and monocarboxylic acids, such as ethylene glycol distearate and hexanediol dibehenate; Esters of trihydric alcohols and monocarboxylic acids, such as glycerin tribehenate; Esters of tetrahydric alcohols and monocarboxylic acids, such as pentaerythritol tetrastearate and pentaerythritol tetrapalmitate; Esters of hexahydric alcohols and monocarboxylic acids, such as dipentaerythritol hexastearate, dipentaerythritol hexapalmitate, and dipentaerythritol hexabehenate; Esters of polyfunctional alcohols and monocarboxylic acids, such as polyglycerin behenate; natural ester waxes, such as carnauba wax and rice wax.

[0082] <Method of manufacturing toner particles> The manufacturing method for manufacturing the toner particles according to the present disclosure may be any manufacturing method, but it is preferable to obtain the toner particles by a manufacturing method in which the toner particles are granulated in an aqueous medium, such as a suspension polymerization method, an emulsion aggregation method, or a suspension granulation method.

[0083] Hereinafter, the suspension polymerization method that is most suitable for producing the toner particles used in the present disclosure will be described.

[0084] In addition to the pigment dispersant, pigment, crystalline material, and wax, the polymerizable monomer that forms the binder resin, and other additives as necessary, are uniformly dissolved or dispersed using a dispersing machine such as a homogenizer, ball mill, colloid mill, or ultrasonic disperser. A polymerization initiator is dissolved in the resulting solution to prepare a polymerizable monomer composition. Next, the polymerizable monomer composition is suspended in an aqueous medium containing a dispersion stabilizer, and the polymerizable monomer is polymerized to produce toner particles.

[0085] Examples of monofunctional polymerizable monomers include styrene derivatives such as styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, and p-phenylstyrene; acrylic polymerizable monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, and 2-benzoyloxyethyl acrylate; Methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, and dibutyl phosphate ethyl methacrylate.

[0086] Further, examples of polyfunctional polymerizable monomers include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis(4-(acryloxydiethoxy)phenyl)propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis(4-(methacryloxydiethoxy)phenyl)propane, 2,2'-bis(4-(methacryloxypolyethoxy)phenyl)propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, and divinyl ether.

[0087] These polymerizable monomers can be used alone or in combination of two or more.

[0088] The polymerization initiator may be added simultaneously with the addition of other additives to the polymerizable monomer, or may be mixed immediately before suspending the polymerizable monomer in an aqueous medium. Alternatively, the polymerization initiator may be added in the form of a solution in the polymerizable monomer or a solvent immediately after granulation and before starting the polymerization reaction.

[0089] Examples of the polymerization initiator include organic peroxide initiators and azo polymerization initiators. Examples of organic peroxide initiators include benzoyl peroxide, lauroyl peroxide, di-α-cumyl peroxide, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, bis(4-t-butylcyclohexyl)peroxydicarbonate, 1,1-bis(t-butylperoxy)cyclododecane, t-butylperoxymaleic acid, bis(t-butylperoxy)isophthalate, methyl ethyl ketone peroxide, tert-butylperoxy-2-ethylhexanoate, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and tert-butylperoxypivalate.

[0090] Examples of the azo polymerization initiator include 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobismethylbutyronitrile.

[0091] Alternatively, a redox initiator, which combines an oxidizing substance and a reducing substance, can be used as the polymerization initiator. Examples of oxidizing substances include inorganic peroxides such as hydrogen peroxide, persulfates (sodium, potassium, and ammonium salts), and oxidizing metal salts such as tetravalent cerium salts. Examples of reducing substances include reducing metal salts (divalent iron salts, monovalent copper salts, and trivalent chromium salts), ammonia, lower amines (amines having approximately 1 to 6 carbon atoms, such as methylamine and ethylamine), amino compounds such as hydroxylamine, reducing sulfur compounds such as sodium thiosulfate, sodium hydrosulfite, sodium bisulfite, sodium sulfite, and sodium formaldehyde sulfoxylate, lower alcohols (having 1 to 6 carbon atoms), ascorbic acid or its salts, and lower aldehydes (having 1 to 6 carbon atoms).

[0092] The polymerization initiator is selected with reference to its 10-hour half-life temperature and is used alone or in combination. The amount of the polymerization initiator added varies depending on the desired degree of polymerization, but is generally 0.5 to 20.0 parts by mass per 100.0 parts by mass of the polymerizable monomer.

[0093] In addition, known chain transfer agents and polymerization inhibitors may be further added to control the degree of polymerization.

[0094] Various crosslinking agents can be used when polymerizing the polymerizable monomers, including polyfunctional compounds such as divinylbenzene, 4,4'-divinylbiphenyl, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, glycidyl acrylate, glycidyl methacrylate, trimethylolpropane triacrylate, and trimethylolpropane trimethacrylate.

[0095] The pigment is preferably used in an amount of 1.0 part by mass or more and 20.0 parts by mass or less per 100.0 parts by mass of the binder resin.

[0096] The dispersion stabilizer used in preparing the aqueous medium may be a known inorganic dispersion stabilizer or an organic dispersion stabilizer. Examples of inorganic dispersion stabilizers include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina. Examples of organic dispersion stabilizers include polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and its salts, and starch. The amount of these dispersion stabilizers used is preferably 0.2 to 20 parts by mass per 100 parts by mass of the polymerizable monomer.

[0097] When an inorganic dispersion stabilizer is used among these dispersion stabilizers, a commercially available one may be used as it is, but in order to obtain a dispersion stabilizer with a finer particle size, the inorganic compound may be produced in an aqueous medium. For example, tricalcium phosphate can be obtained by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high agitation.

[0098] In the present disclosure, the toner preferably has an external additive present on the surface of the toner particles in order to improve image quality. As the external additive, either an organic fine powder or an inorganic fine powder can be used, but inorganic fine powders such as silica fine powder, titanium oxide fine powder, or aluminum oxide fine powder are preferred.

[0099] These inorganic fine powders are preferably subjected to a hydrophobic treatment with a hydrophobizing agent such as a silane coupling agent, silicone oil, or a mixture thereof.

[0100] The amount of inorganic fine powder added is preferably 1.0 part by mass or more and 5.0 parts by mass or less with respect to 100.0 parts by mass of toner particles (base particles before adding external additives).

[0101] Hereinafter, methods for measuring various physical properties according to the present disclosure will be described.

[0102] <Composition analysis method> The structure determination of the pigment dispersant and crystalline material was carried out using the following equipment. 1 H NMR: JEOL Ltd. ECA-400 (solvent: deuterated chloroform) 13 C-NMR: Bruker Biospin FT-NMR AVANCE-600 (solvent: deuterated chloroform) In addition, 13 C-NMR was quantified by the inverse gated decoupling method using chromium(III) acetylacetonate as a relaxation reagent, and compositional analysis was performed.

[0103] The molar composition ratio of each monomer unit of the pigment dispersant and the crystalline material was calculated by the above measurement, and then the mass composition ratio was determined from the molecular weight of each monomer unit.

[0104] <Method for measuring molecular weight> The weight average molecular weight (Mw) of the toner and the pigment dispersant is measured using gel permeation chromatography (GPC) as follows.

[0105] The sample is dissolved in tetrahydrofuran (THF) at room temperature. The resulting solution is then filtered through a solvent-resistant membrane filter "Myshoridisc" (Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of components soluble in THF is 0.8 mass%. This sample solution is used for measurements under the following conditions. Equipment: High-speed GPC equipment "HLC-8220GPC" [manufactured by Tosoh Corporation] Column: LF-604 (two columns, manufactured by Showa Denko K.K.) Eluent:THF Flow rate: 0.6mL / min Oven temperature: 40°C Sample injection volume: 0.020 mL To calculate the molecular weight of a sample, a molecular weight calibration curve prepared using standard polystyrene resins (for example, trade names "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500", manufactured by Tosoh Corporation) is used.

[0106] <Method for measuring weight average particle diameter (D4) and number average particle diameter (D1) of toner particles> A precision particle size distribution analyzer using the pore electrical resistance method (product name: Coulter Counter Multisizer 3) and dedicated software (product name: Beckman Coulter Multisizer 3 Version 3.51, manufactured by Beckman Coulter, Inc.) are used. Measurements are performed with an aperture diameter of 100 μm and an effective number of measurement channels of 25,000. The measurement data are analyzed and calculated. The electrolyte solution used for the measurements is prepared by dissolving special-grade sodium chloride in ion-exchange water to a concentration of 1% by mass; for example, ISOTON II (product name) manufactured by Beckman Coulter, Inc. can be used. Before performing measurements and analysis, the dedicated software is configured as follows:

[0107] In the "Change Standard Measurement Method (SOM) screen" of the dedicated software, set the total count in control mode to 50,000 particles, the number of measurements to 1, and the Kd value obtained using standard particles (10.0 μm, manufactured by Beckman Coulter). Press the threshold / noise level measurement button to automatically set the threshold and noise level. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II (trade name), and check the option to flush the aperture tube after measurement.

[0108] In the dedicated software's "Pulse to particle size conversion setting screen," set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm or more and 60 μm or less.

[0109] The specific measurement method is as follows.

[0110] (1) Pour 200 mL of the electrolyte solution into a 250 mL round-bottom glass beaker made specifically for the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, use the "aperture flush" function of the analysis software to remove any dirt or air bubbles from inside the aperture tube.

[0111] (2) 30 mL of the aqueous electrolyte solution is placed in a 100 mL flat-bottom glass beaker, and 0.3 mL of a diluted solution prepared by diluting Contaminon N (trade name) (a 10% aqueous solution of a neutral detergent for cleaning precision measuring instruments, manufactured by Wako Pure Chemical Industries, Ltd.) three times by mass with ion-exchanged water is added thereto.

[0112] (3) A predetermined amount of ion-exchanged water and 2 mL of Contaminon N (trade name) are added to the water tank of an ultrasonic disperser (trade name: Ultrasonic Dispersion System Tetora150, manufactured by Nikkaki Bios Co., Ltd.) that has two oscillators with an oscillation frequency of 50 kHz built in with a phase shift of 180 degrees and an electrical output of 120 W.

[0113] (4) The beaker (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height of the beaker is adjusted so that the resonance state of the liquid surface of the electrolytic solution in the beaker is maximized.

[0114] (5) While the electrolyte solution in the beaker in (4) is being irradiated with ultrasonic waves, 10 mg of toner (particles) is added little by little to the electrolyte solution and dispersed. The ultrasonic dispersion process is then continued for another 60 seconds. During the ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to 10°C to 40°C.

[0115] (6) Using a pipette, the electrolytic solution (5) containing dispersed toner particles is dropped into the round-bottom beaker (1) placed in the sample stand, and the measurement concentration is adjusted to 5%. Then, measurements are continued until the number of particles measured reaches 50,000.

[0116] (7) The measurement data is analyzed using the dedicated software provided with the device to calculate the weight average particle size (D4). When the dedicated software is set to Graph / Volume %, the "Average diameter" on the Analysis / Volume Statistics (Arithmetic Mean) screen is the weight average particle size (D4). When the dedicated software is set to Graph / Number %, the "Average diameter" on the Analysis / Number Statistics (Arithmetic Mean) screen is the number average particle size (D1).

[0117] <Method for measuring the endothermic peak temperature of toner> The peak temperature of the maximum endothermic peak of the toner is measured using a differential scanning calorimeter "Q1000" (manufactured by TA Instruments) in accordance with ASTM D3418-82. The melting points of indium and zinc are used to correct the temperature of the detector, and the heat of fusion of indium is used to correct the amount of heat.

[0118] Specifically, approximately 10 mg of toner is weighed out and placed in an aluminum pan. An empty aluminum pan is used as a reference, and measurements are performed at a temperature rise rate of 10°C / min within a measurement temperature range of 30 to 200°C. In the measurement, the temperature is raised to 200°C once, then lowered to 30°C, and then raised again. The maximum endothermic peak of the DSC curve in the temperature range of 30 to 200°C during this second temperature rise is taken as the maximum endothermic peak of the endothermic curve in the DSC measurement of the toner of the present disclosure. [Example]

[0119] The present disclosure will be specifically explained by the following Production Examples and Examples. However, these do not limit the present disclosure in any way. In the Production Examples and Examples, "parts" and "%" are all by mass unless otherwise specified.

[0120] [Synthesis of polymerizable compound A] <Polymerizable compound A1> Polymerizable compound A1 was synthesized according to the synthesis scheme shown below.

[0121] [ka]

[0122] Synthesis of intermediate (1): 20.6 parts of diethyl malonate, 19.8 parts of 2-methacryloyloxyethyl isocyanate (trade name "Karends MOI", manufactured by Showa Denko KK), and 0.284 parts of 2,6-di-tert-butyl-p-cresol were dissolved in 100 parts of xylene and heated to 60°C. 0.214 parts of sodium methoxide was added and the reaction was carried out for 8 hours, after which 200 parts of water was added to stop the reaction. The organic layer was extracted and concentrated with toluene, and the resulting residue was crystallized from toluene to obtain intermediate (1) represented by the above formula.

[0123] Synthesis of polymerizable compound A1: Next, 19.8 parts of intermediate (1), 11.4 parts of 5-amino-2-benzimidazolinone, and 0.138 parts of 2,6-di-tert-butyl-p-cresol were dissolved in 140 parts of N,N-dimethylformamide, and the mixture was heated and stirred at 80°C for 6 hours to react. After the reaction, the N,N-dimethylformamide was distilled off under reduced pressure, and 300 parts of water was added to the resulting residue. The precipitate was filtered to obtain a polymerizable compound A1 represented by the above formula.

[0124] <Polymerizable compound A2> Polymerizable compound A2 was synthesized according to the following scheme.

[0125] [ka]

[0126] Polymerizable compound A2 represented by the above formula was synthesized in the same manner as in the synthesis of polymerizable compound A1, except that in the synthesis of polymerizable compound A1, 5-amino-2-benzimidazolinone was changed to 3-aminophenylureide.

[0127] <Polymerizable compound A3> Polymerizable compound A3 was synthesized according to the following scheme.

[0128] Synthesis of intermediate (2): To 11.0 parts of 4-aminophenol, 140 parts of dilute hydrochloric acid was added and cooled to below 5°C. 37.0 parts of 19.0% aqueous sodium nitrite solution was added dropwise to this solution while cooling with ice to prepare a diazonium salt solution. Next, 237 parts of ethanol and 126.0 parts of 36.5% aqueous sodium acetate solution were added to 10.0 parts of acetylacetone, stirred, and cooled to below 5°C. The previously prepared diazonium salt solution was slowly added dropwise to this solution, and the mixture was stirred under ice cooling for 30 minutes and then at room temperature for 1 hour. The resulting precipitate was then collected by filtration, washed with water, and dried to obtain intermediate (2).

[0129] Synthesis of intermediate (3): 15.6 parts of the intermediate (2) obtained above was dissolved in 80.6 parts of methanol, and 86.0 parts of a 2 mol / L aqueous sodium hydroxide solution was added. The mixture was cooled to 5°C or below. A mixture of 30.5 parts of benzaldehyde and 20.5 parts of ethanol was added dropwise to the solution, and the mixture was allowed to react under ice cooling for 3 hours, and then allowed to stand overnight in a refrigerator. After standing, the reaction solution was poured into 500 parts of cold water and neutralized with acetic acid. The resulting precipitate was separated and purified using silica gel column chromatography to obtain intermediate (3).

[0130] Synthesis of polymerizable compound A3: 14.4 parts of the intermediate (3) obtained above was dissolved in 170 parts of pyridine and then cooled to below 5°C. A solution of 4.21 parts of methacryloyl chloride in 30.0 parts of pyridine was added dropwise to this solution and stirred for 1 hour. Thereafter, 200 parts of water was added to terminate the reaction, and the mixture was extracted with chloroform, washed with water, and concentrated to obtain a polymerizable compound A3 having the following structure.

[0131] [ka]

[0132] [Synthesis of polymerizable ester compound] <Polymerizable ester compound 1> A pressure reactor equipped with a stirrer, temperature controller, thermometer, air inlet tube, pressure reducer, and water reducer was charged with 980.0 parts of behenyl alcohol, 175.0 parts of fumaric acid, 2.5 parts of dibutyltin oxide, and 1.0 part of 2,6-di-tert-butyl-p-cresol, and the mixture was stirred at 120°C to homogenize. The mixture was then heated to 165°C and esterified at 21 kPa for 3 hours while removing distilled water, followed by esterification at 3 kPa or less for 12 hours while removing distilled water. The mixture was discharged to obtain polymerizable ester compound 1.

[0133] <Synthesis of polymerizable ester compounds 2 to 4> Polymerizable ester compounds 2 to 4 were synthesized in the same manner as in the synthesis of polymerizable ester compound 1, except that the unsaturated polycarboxylic acid and long-chain alkyl alcohol used in the synthesis of polymerizable ester compound 1 were changed as shown in Table 1. The obtained polymerizable ester compounds had the structure of the following formula (2').

[0134] [ka]

[0135] [Table 1]

[0136] [Synthesis of pigment dispersant] <Pigment dispersant (Sy-1)> In a nitrogen-substituted eggplant-shaped flask, Behenyl acrylate 35.0 parts Styrene 14.0 parts Polymerizable compound A1 7.0 parts Polymerizable ester compound 1 30.0 parts Azobisisobutyronitrile 1.5 parts The mixture was stirred at 80° C. Polymerization was allowed to proceed while monitoring the molecular weight by GPC, and when the molecular weight reached the desired value, the mixture was cooled with ice water to terminate the reaction, thereby obtaining a pigment dispersant (Sy-1).

[0137] <Pigment dispersants (Sy-2 to Sy-15)> Pigment dispersants Sy-2 to Sy-15 were obtained in the same manner as in the production example of pigment dispersant Sy-1, except that the compositions were changed to those shown in Table 2.

[0138] [Table 2]

[0139] The terms in the table have the following meanings: MAN: methacrylonitrile BEA: Behenyl acrylate [Synthesis of crystalline resin] <Crystalline resin C1> The following materials were placed in a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube under a nitrogen atmosphere. Toluene 100.0 parts Behenyl acrylate 80.0 parts Styrene 20.0 parts Polymerization initiator: 0.5 parts t-butyl peroxypivalate (NOF Corporation: Perbutyl PV) The reaction vessel was heated to 70°C while stirring at 200 rpm, and the polymerization reaction was carried out for 12 hours, resulting in a solution in which the polymer of the monomer composition was dissolved in toluene. Toluene and residual monomers were then removed by distillation at 160°C and 1 hPa to obtain crystalline resin C1. The weight average molecular weight (Mw) of the obtained crystalline resin C1 was 30,000, and the melting point (Tm) was 60°C.

[0140] <Crystalline resin C2> 118.0 parts of sebacic acid and 69.0 parts of 1,6-hexanediol were added to a reaction vessel equipped with a stirrer, thermometer, nitrogen inlet tube, dehydration tube, and pressure reducing device, and the mixture was heated to 130°C with stirring. After adding 0.7 parts of titanium (IV) isopropoxide as an esterification catalyst, the mixture was heated to 160°C and subjected to condensation polymerization over 5 hours. The mixture was then heated to 180°C and reacted under reduced pressure until the desired molecular weight was reached, yielding crystalline resin C2. The resulting crystalline resin C2 had a weight average molecular weight (Mw) of 28,000 and a melting point (Tm) of 69°C.

[0141] <Crystalline resin C3> The following materials were placed in a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube under a nitrogen atmosphere. Toluene 100.0 parts Polymerizable ester compound 1 50.0 parts Styrene 50.0 parts Polymerization initiator: 0.5 parts t-butyl peroxypivalate (NOF Corporation: Perbutyl PV) The reaction vessel was heated to 70°C while stirring at 200 rpm, and the polymerization reaction was carried out for 12 hours, resulting in a solution in which the polymer of the monomer composition was dissolved in toluene. Toluene and residual monomers were then removed by distillation at 160°C and 1 hPa to obtain crystalline resin C3. The weight average molecular weight (Mw) of the obtained crystalline resin C3 was 32,000, and the melting point (Tm) was 65°C.

[0142] <Production example of black toner 1> [Preparation step of colorant dispersion 1] Styrene monomer 100.0 parts Carbon black (CB) 20.0 parts (Nipex35: Orion Engineered Carbons) Pigment dispersant Sy-1 2.0 parts The above materials were introduced into an attritor (manufactured by Mitsui Mining Co., Ltd.) and stirred at 200 rpm at 25° C. for 180 minutes using zirconia beads (200 parts) with a radius of 2.5 mm to prepare colorant dispersion liquid 1.

[0143] [Preparation of toner composition solution] Colorant dispersion 1 41.8 parts Styrene 8.6 parts n-Butyl acrylate (BA) 14.6 parts ·Crystalline resin C1 27.4 parts Dipentaerythritol hexastearate 7.7 parts The above materials were mixed and heated to 65° C., and dissolved and dispersed for 60 minutes at 5,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain toner composition solution 1.

[0144] [Preparation process of dispersion liquid (aqueous medium)] In a 2-liter four-neck flask equipped with a high-speed stirring device TK-Homomixer, 710 parts of ion-exchanged water was charged with 450 parts of a 0.1 mol / L NaPO aqueous solution and heated to 60° C. Then, 67.7 parts of a 1.0 mol / L CaCl aqueous solution was gradually added to obtain an aqueous medium 1 containing a calcium phosphate compound.

[0145] [Granulation process] While maintaining the temperature of the aqueous medium 1 at 60°C and the rotation speed of the stirrer at 12,500 rpm, the toner composition solution 1 was poured into the aqueous medium 1, and 3.5 parts of t-butyl peroxypivalate as a polymerization initiator was added. Granulation was continued for 10 minutes while maintaining the stirring speed at 12,500 rpm.

[0146] [Polymerization process] The high-speed stirrer was changed to a stirrer equipped with a propeller stirring blade, and polymerization was carried out for 5.0 hours while stirring at 200 rpm and maintaining the temperature at 70°C. Thereafter, the temperature was raised to 98°C and heated for 3.0 hours to remove residual monomers, yielding black toner particle dispersion 1 in which black toner particles were dispersed.

[0147] Hydrochloric acid was added to the obtained black toner particle dispersion 1 to adjust the pH to 1.4, and the mixture was stirred for 1 hour to dissolve the calcium phosphate salt. This was subjected to solid-liquid separation in a pressure filter at a pressure of 0.4 MPa, yielding toner cake 1. Next, ion-exchanged water was added to the pressure filter until it was filled with water, and toner cake 1 was washed at a pressure of 0.4 MPa. This washing procedure was repeated three times, and then the mixture was dried to yield black toner particles 1.

[0148] To 100.0 parts of the obtained black toner particles 1, 1.5 parts of hydrophobic silica fine powder (number average particle diameter of primary particles: 10 nm) that had been surface-treated with hexamethyldisilazane was added, and the mixture was mixed for 300 seconds in a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) to obtain black toner 1. The composition and physical properties of black toner 1 are shown in Table 3.

[0149] <Production example of black toner 2 to 28> Black toners 2 to 28 were obtained in the same manner as in the production example of black toner 1, except that the composition of black toner particles 1 was changed as shown in Table 3. The compositions and physical properties of black toners 2 to 28 are shown in Table 3.

[0150] [Table 3-1]

[0151] [Table 3-2]

[0152] <Production example of magenta toner 1> [Preparation step of colorant dispersion 2] Styrene monomer 100.0 parts Pigment Red 122 (PR-122) 12.5 parts (Toner Magenta E [Clariant]) Pigment Red 150 (PR-150) 7.5 parts (Fuji Fast Carmine 522 [manufactured by Fuji Pigment Co., Ltd.]) Pigment dispersant (Sy-1) 2.0 parts The above materials were introduced into an attritor (manufactured by Mitsui Mining Co., Ltd.) and stirred at 200 rpm at 25° C. for 180 minutes using zirconia beads (200 parts) with a radius of 2.5 mm to prepare colorant dispersion liquid 2.

[0153] Thereafter, magenta toner 1 was obtained in the same manner as in the production example of black toner 1, except for using colorant dispersion liquid 2. The composition and physical properties of magenta toner 1 obtained are shown in Table 4.

[0154] <Production Example of Magenta Toners 2 and 3> Magenta toners 2 and 3 were obtained in the same manner as in the production example of magenta toner 1, except that the composition was changed as shown in Table 4. The compositions and physical properties of magenta toners 2 and 3 are shown in Table 4.

[0155] [Table 4]

[0156] <Production example of yellow toner 1> [Preparation step of colorant dispersion 3] Styrene monomer 100.0 parts Pigment Yellow 155 (PY-155) 20.0 parts (Paliotol Yellow D1155 [BASF]) Pigment dispersant (Sy-1) 2.0 parts The above materials were introduced into an attritor (manufactured by Mitsui Mining Co., Ltd.) and stirred at 200 rpm at 25° C. for 180 minutes using zirconia beads (200 parts) with a radius of 2.5 mm to prepare colorant dispersion 3.

[0157] Thereafter, yellow toner 1 was obtained in the same manner as in the production example for black toner 1, except that colorant dispersion liquid 3 was used. The composition and physical properties of yellow toner 1 obtained are shown in Table 5.

[0158] <Production example of yellow toners 2 to 7> Yellow toners 2 to 7 were obtained in the same manner as in the production example of yellow toner 1, except that the composition was changed as shown in Table 5. Table 5 shows the composition and physical properties of yellow toners 2 to 7.

[0159] [Table 5]

[0160] <Production example of cyan toner 1> [Preparation step of colorant dispersion 4] Styrene monomer 100.0 parts Pigment Blue 15:3 20.0 parts (ECB-308 [manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.]) Pigment dispersant (Sy-1) 2.0 parts The above materials were introduced into an attritor (manufactured by Mitsui Mining Co., Ltd.) and stirred at 200 rpm at 25° C. for 180 minutes using zirconia beads (200 parts) with a radius of 2.5 mm to prepare colorant dispersion liquid 4.

[0161] Thereafter, cyan toner 1 was obtained in the same manner as in the production example of black toner 1, except that colorant dispersion liquid 4 was used. The composition and physical properties of the obtained cyan toner 1 are shown in Table 6.

[0162] <Production Example of Cyan Toners 2 and 3> Cyan toners 2 and 3 were obtained in the same manner as in the production example of cyan toner 1, except that the composition was changed as shown in Table 6. The compositions and physical properties of cyan toners 2 and 3 are shown in Table 6.

[0163] [Table 6]

[0164] <Evaluation> A commercially available color laser printer (HP LaserJet Enterprise Color M555dn) was partially modified for evaluation. The printer was modified so that it could operate with only one color process cartridge installed. The printer was also modified so that the fixing unit temperature could be adjusted as desired.

[0165] All process cartridges installed in the printer were removed and replaced. The toner inside the black toner process cartridge was removed and the interior was cleaned with an air blower, after which the toner (250 g) to be evaluated was introduced into the process cartridge. Only the refilled black toner process cartridge was installed in the printer, and the following evaluations were carried out. The specific evaluation methods are as follows:

[0166] <Coloring strength evaluation method> A rectangular solid image of 6.5 cm x 14.0 cm (toner amount: 0.45 mg / cm) was printed in the center of the transfer material. 2 ) was output and used as an evaluation image. The image density in the evaluation image was measured to evaluate coloring power. The image density was measured using an X-Rite color reflection densitometer (X-Rite 404A). The density was measured at five points in the solid image area: the top right, top left, center, bottom right, and bottom left, and the average value was used to evaluate the image density. Letter-size glossy paper (HP Brochure Paper 150g, Glossy) was used as the transfer material.

[0167] (Evaluation criteria) A: Image density is 1.70 or more B: Image density is 1.65 or more and less than 1.70 C: Image density is 1.60 or more and less than 1.65 D: Image density is less than 1.60 <Color unevenness evaluation method> Solid image on transfer material (toner amount: 0.45 mg / cm 2) was fixed at a fixing temperature of 200°C to obtain a print image. After leaving the print image in a high-temperature, high-humidity environment (temperature 32°C / humidity 85% RH) for one month, the solid image was divided into 15 sections (5 sections lengthwise and 3 sections widthwise), and the gloss value of the center of each section was measured using a PG-3D (manufactured by Nippon Denshoku Industries Co., Ltd.). The maximum, minimum, and average gloss values ​​of the 15 sections were used to calculate the difference between the average and maximum values, and the difference between the average and minimum values. The larger absolute value of the calculated difference was used to calculate the percentage of the difference relative to the average value, and color unevenness was evaluated according to the following criteria. Letter-size glossy paper (HP Brochure Paper 150g, Glossy) was used as the transfer material.

[0168] (Evaluation criteria) A: 3.0% or less B: 3.1% or more and 5.0% or less C: 5.1% or more and 10.0% or less D: 10.1% or more <Low temperature fixability evaluation method> Solid image on transfer material (toner amount: 0.45 mg / cm 2 The fixing temperature was changed from 115°C in 5°C increments to carry out a fixing test. The density of the resulting fixed image was measured, and a 50 g / cm 2 After applying a load of 1000 kJ / cm2 and rubbing five times with Silbon paper (Lenz Cleaning Paper "dasper(R)" (Ozu Paper Co. Ltd.), the image density was measured again. The temperature at which the density reduction rate before and after rubbing was 10% or less was taken as the fixing start temperature. The fixing temperature was measured on the surface of the fixing roller using a non-contact thermometer. The transfer material was LETTER size plain paper (Vitality, manufactured by XEROX, 75 g / m2) 2 ) was used.

[0169] (Evaluation criteria) A: Fixing start temperature is 115℃ B: Fixing start temperature is 120℃ to 130℃ C: Fixing start temperature is 135℃ to 145℃ D: Fixing start temperature is 150°C or higher <Streak (developability) evaluation method> After printing 30,000 sheets of horizontal line images with a 1% print ratio in a high temperature and humidity environment (temperature 32°C / humidity 85%RH), the print quality was measured on letter-size plain paper (Vitality, manufactured by XEROX, 75g / m 2 ) and halftone (toner amount: 0.25 mg / cm 2 The halftone image was observed for the presence or absence of vertical streaks in the paper ejection direction, and the developability was evaluated as follows.

[0170] (Evaluation criteria) A: Not occurred B: Vertical streaks occur in 1 to 3 places C: Vertical streaks occur in 4 to 6 places D: Vertical lines appear in 7 or more places, or vertical lines with a width of 0.5 mm or more appear. <Evaluation method for storage stability (heat resistance)> 5 g of each toner was placed in a 50 mL resin cup and left to stand for 3 days at a temperature of 60° C. and a humidity of 10% RH, and the occurrence of agglomerates was checked and evaluated according to the following criteria.

[0171] (Evaluation criteria) A: No clumps formed. B: Slight clumps formed, but crumbled when lightly pressed with a finger. C: Agglomerates form that do not crumble even when lightly pressed with a finger. D: Cohesion and does not crumble.

[0172] Examples 1 to 24 In Examples 1 to 24, the above evaluations were carried out using black toners 1 to 24, respectively. The evaluation results are shown in Table 7.

[0173] Comparative Examples 1 to 4 In Comparative Examples 1 to 4, the above evaluations were carried out using black toners 25 to 28, respectively. The evaluation results are shown in Table 7.

[0174] [Table 7]

[0175] Examples 25 to 37 In Examples 25 to 27, the above evaluation was performed using magenta toners 1 to 3, respectively. In Examples 28 to 34, the above evaluation was performed using yellow toners 1 to 7, respectively. In Examples 35 to 37, the above evaluation was performed using cyan toners 1 to 3, respectively. The evaluation results are shown in Table 8.

[0176] [Table 8]

[0177] The present disclosure relates to the following configurations.

[0178] (Configuration 1) A toner having toner particles containing a binder resin, a pigment, and a pigment dispersant, The toner is characterized in that the pigment dispersant is a polymer containing a structure represented by the following formula (1) and a structure represented by the following formula (2):

[0179] [ka]

[0180] (In formula (1), X, Y, and Z each independently represent -O-, a methylene group, or -NR5-; R5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; L1 represents an ester bond or an amide bond; R1 represents a hydrogen atom or a methyl group; R2 represents an alkylene group having 2 to 4 carbon atoms, R4 represents a substituted phenyl group, an unsubstituted phenyl group, a substituted polycyclic aromatic group, an unsubstituted polycyclic aromatic group, a substituted heterocyclic group, or an unsubstituted heterocyclic group; R3 represents a hydrogen atom, a substituted phenyl group, an unsubstituted phenyl group, an aralkyl group, a substituted alkyl group having from 1 to 18 carbon atoms, an unsubstituted alkyl group having from 1 to 18 carbon atoms, or a monovalent group in which a methylene group in an alkyl group having from 2 to 18 carbon atoms has been replaced with -O-, -COO-, or -CONH-.

[0181] [ka]

[0182] (In formula (2), At least two of R6 to R9 are -V-COOR 10 and the rest each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0183] V represents a single bond or an alkylene group having 1 to 2 carbon atoms; R 10 represents an alkyl group having 16 to 30 carbon atoms. (Configuration 2) 2. The toner according to configuration 1, wherein the content (% by mass) of the structure represented by formula (1) in the pigment dispersant is 1.0% by mass or more and 15.0% by mass or less.

[0184] (Configuration 3) 3. The toner according to configuration 1 or 2, wherein the content (mass %) of the structure represented by formula (2) in the pigment dispersant is 5.0 mass % or more and 70.0 mass % or less.

[0185] (Configuration 4) 4. The toner according to any one of configurations 1 to 3, wherein the structure represented by formula (1) is a structure represented by formula (3):

[0186] [ka]

[0187] (In formula (3), L1 represents an ester bond or an amide bond; R1 represents a hydrogen atom or a methyl group; R 11 represents an alkylene group having 2 to 4 carbon atoms, R 12 represents a hydrogen atom, a substituted phenyl group, an unsubstituted phenyl group, an aralkyl group, a substituted alkyl group having from 1 to 18 carbon atoms, an unsubstituted alkyl group having from 1 to 18 carbon atoms, or a monovalent group in which a methylene group in an alkyl group having from 2 to 18 carbon atoms has been replaced with -O-, -COO-, or -CONH-. (Configuration 5) 5. The toner according to any one of configurations 1 to 4, wherein the content (mass %) of the pigment dispersant in the toner particles is 1.5 mass % or more and 30.0 mass % or less with respect to the total mass of the pigment.

[0188] (Configuration 6) The pigment is 6. The toner according to any one of configurations 1 to 5, wherein the pigment is at least one pigment selected from the group consisting of carbon black, CI Pigment Yellow 74, 93, 139, 155, 180, and 185, CI Pigment Red 31, 122, 150, 170, 258, and 269, and CI Pigment Blue 15:3 and 15:4.

[0189] (Configuration 7) 7. The toner according to any one of configurations 1 to 6, wherein the toner particles contain a crystalline material.

[0190] (Configuration 8) 8. The toner according to configuration 7, wherein the content (mass %) of the crystalline material in the toner particles is 20.0 mass % or more and 50.0 mass % or less based on the toner particles.

[0191] (Configuration 9) 9. The toner according to configuration 7 or 8, wherein the crystalline material is a crystalline resin.

[0192] (Configuration 10) 10. The toner according to configuration 9, wherein the crystalline resin is a crystalline vinyl resin having a structure represented by the following formula (4) or a crystalline vinyl resin having a structure represented by the following formula (5):

[0193] [ka]

[0194] (In formula (4), R 13 represents a hydrogen atom or a methyl group, L2 represents a single bond, -COO-, or -CONH-; n represents an integer between 15 and 30.

[0195] [ka]

[0196] (In formula (5), R 14 ~R 17 At least two of them are -W-COOR 18 and the remainder represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, W represents a single bond or an alkylene group having 1 to 2 carbon atoms; R 18 represents an alkyl group having 16 to 30 carbon atoms.

Claims

1. A toner having toner particles containing a binder resin, a pigment, and a pigment dispersant, The toner is characterized in that the pigment dispersant is a polymer containing a structure represented by the following formula (1) and a structure represented by the following formula (2): 【Chemistry 1】 (In formula (1), X, Y, and Z each independently represent —O—, a methylene group, or —NR ５ represents -, R ５ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, L １ represents an ester bond or an amide bond, R １ represents a hydrogen atom or a methyl group, R ２ represents an alkylene group having 2 to 4 carbon atoms, R ４ represents a substituted phenyl group, an unsubstituted phenyl group, a substituted polycyclic aromatic group, an unsubstituted polycyclic aromatic group, a substituted heterocyclic group, or an unsubstituted heterocyclic group, R ３ represents a hydrogen atom, a substituted phenyl group, an unsubstituted phenyl group, an aralkyl group, a substituted alkyl group having from 1 to 18 carbon atoms, an unsubstituted alkyl group having from 1 to 18 carbon atoms, or a monovalent group in which a methylene group in an alkyl group having from 2 to 18 carbon atoms has been replaced with -O-, -COO-, or -CONH-. 【Chemistry 2】 (In formula (2), R ６ ~R ９ At least two of the groups are -V-COOR １０ and the rest each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. V represents a single bond or an alkylene group having 1 to 2 carbon atoms; R １０ represents an alkyl group having 16 to 30 carbon atoms.

2. 2. The toner according to claim 1, wherein the content (% by mass) of the structure represented by formula (1) in the pigment dispersant is 1.0% by mass or more and 15.0% by mass or less.

3. 3. The toner according to claim 1, wherein the content (% by mass) of the structure represented by formula (2) in the pigment dispersant is 5.0% by mass or more and 70.0% by mass or less.

4. 3. The toner according to claim 1, wherein the structure represented by formula (1) is a structure represented by formula (3): 【Transformation 3】 (In formula (3), L １ represents an ester bond or an amide bond, R １ represents a hydrogen atom or a methyl group, R １１ represents an alkylene group having 2 to 4 carbon atoms, R １２ represents a hydrogen atom, a substituted phenyl group, an unsubstituted phenyl group, an aralkyl group, a substituted alkyl group having from 1 to 18 carbon atoms, an unsubstituted alkyl group having from 1 to 18 carbon atoms, or a monovalent group in which a methylene group in an alkyl group having from 2 to 18 carbon atoms has been replaced with -O-, -COO-, or -CONH-.

5. 3. The toner according to claim 1, wherein the content (mass %) of the pigment dispersant in the toner particles is 1.5 mass % or more and 30.0 mass % or less with respect to the total mass of the pigment.

6. The pigment is 3. The toner according to claim 1, wherein the toner is at least one pigment selected from the group consisting of carbon black, C. I. Pigment Yellow 74, 93, 139, 155, 180, and 185, C. I. Pigment Red 31, 122, 150, 170, 258, and 269, and C. I. Pigment Blue 15:3 and 15:

4.

7. 3. The toner according to claim 1, wherein the toner particles contain a crystalline material.

8. 8. The toner according to claim 7, wherein the content (% by mass) of the crystalline material in the toner particles is 20.0% by mass or more and 50.0% by mass or less based on the toner particles.

9. 9. The toner according to claim 7, wherein the crystalline material is a crystalline resin.

10. 10. The toner according to claim 9, wherein the crystalline resin is a crystalline vinyl resin having a structure represented by the following formula (4) or a crystalline vinyl resin having a structure represented by the following formula (5): 【Chemistry 4】 (In formula (4), R １３ represents a hydrogen atom or a methyl group, L ２ represents a single bond, —COO—, or —CONH—; n represents an integer of 15 or more and 30 or less. 【Transformation 5】 (In formula (5), R １４ ~R １７ At least two of the above are -W-COOR １８ and the remainder represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, W represents a single bond or an alkylene group having 1 to 2 carbon atoms; R １８ represents an alkyl group having 16 to 30 carbon atoms.

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