toner

Abstract

To provide a toner that contains pigment dispersed in toner particles including a large amount of crystalline resin, that is, a toner excellent in low temperature fixability and tinting power.SOLUTION: A toner has toner particles containing a binder resin, pigment, and pigment dispersant. The binder resin contains a crystalline resin in an amount of 20.0 mass% or more and 100.0 mass% or less. The pigment dispersant is a polymer containing a specific structure interacting with the pigment, and a specific monomer unit interacting with the crystalline resin. The content of the specific structure interacting with the pigment in the pigment dispersant is 1.0 mass% or more and 15.0 mass% or less. The content of the specific monomer unit interacting with the crystalline resin in the pigment dispersant is 45.0 mass% or more and 80.0 mass% or less. The weight average molecular weight (Mw) of the pigment dispersant is 10000 or more and 50000 or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a toner used for forming a toner image by developing an electrostatic latent image formed by a method such as electrophotography, electrostatic recording, or toner jet recording. [Background technology]

[0002] Conventionally, energy saving has been considered as a major technical issue in electrophotographic devices, and a significant reduction in the amount of heat required for fixing devices has been considered. In particular, there is an increasing need for toners that can be fixed with less energy, that is, so-called "low-temperature fixing properties." As a method for enabling fixing at low temperatures, a method of using a crystalline resin as a binder resin has been considered. The molecular chains of a crystalline resin are regularly arranged, and the resin has the property of hardly softening at temperatures lower than the melting point. Furthermore, when the temperature of a crystalline resin exceeds the melting point, the crystals melt rapidly, and a rapid drop in viscosity occurs. For this reason, crystalline resins have been attracting attention as materials that have excellent sharp melting properties and low-temperature fixing properties. Patent Document 1 proposes a toner characterized in that a sea-island structure consisting of a sea part mainly made of a crystalline resin and an island part mainly made of an amorphous resin is observed in a cross-sectional observation of a toner particle. The toner described in Patent Document 1 can enable fixing with low energy. However, there is a problem in that the island part adversely affects the dispersion of a colorant such as a pigment, and the coloring power is likely to decrease. On the other hand, Patent Document 2 proposes a toner in which the structure of the adsorption site of the pigment dispersant and the relationship between the hydrophobicity parameters of the pigment dispersant and the fixing aid are specified in toner particles containing a binder resin, a pigment dispersant, and a fixing aid. The toner described in Patent Document 2 achieves both low-temperature fixing properties and coloring power. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-142632 A [Patent Document 2] JP 2017-049581 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a large amount of crystalline resin is introduced into the binder resin in order to further save energy, the effect is limited even if the pigment dispersant disclosed in Patent Document 2 is used. When a large amount of crystalline resin is introduced into the binder resin, the coloring power cannot be improved even if the pigment dispersion liquid disclosed in Patent Document 2 is used. Therefore, there is still a need to improve the low-temperature fixing property and coloring power of the toner. The present invention provides a toner in which a pigment is dispersed in toner particles containing a large amount of a crystalline resin, that is, a toner having excellent low-temperature fixing property and coloring power. [Means for solving the problem]

[0005] The present invention provides a toner having toner particles containing a binder resin, a pigment, and a pigment dispersant, The binder resin contains a crystalline resin in an amount of 20.0% by mass or more and 100.0% by mass or less, The pigment dispersant is a polymer containing a structure represented by the following formula (1) and a monomer unit represented by the following formula (2), The content of the structure represented by the following formula (1) in the pigment dispersant is 1.0 mass % or more and 15.0 mass % or less, The content of the monomer unit represented by the following formula (2) in the pigment dispersant is 45.0 mass % or more and 80.0 mass % or less, The toner is characterized in that the weight average molecular weight (Mw) of the pigment dispersant is 10,000 or more and 50,000 or less.

[0006] [ka] (In formula (1), X, Y, and Z each independently represent -O-, a methylene group, or -NR5-. R5 represents a hydrogen atom or a linear or branched 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 or unsubstituted phenyl group, a polycyclic aromatic group, or a heterocyclic group; R3 represents a hydrogen atom, a substituted or unsubstituted phenyl group, an aralkyl group, a linear, branched or cyclic alkyl group having from 1 to 18 carbon atoms, or a monovalent group derived by replacing at least one methylene group of an alkyl group having from 2 to 18 carbon atoms with an ether bond, an ester bond, or an amide bond.

[0007] [ka] (In formula (2), R6 represents a hydrogen atom or a methyl group; L1 represents an ester bond or an amide bond; m represents an integer between 20 and 30. Effect of the Invention

[0008] According to the present invention, a toner having excellent low-temperature fixing property and coloring power can be obtained. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The expressions "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the endpoints, that is, the lower limit and the upper limit, unless otherwise specified.

[0010] [Features of the present invention] The present invention provides a toner having toner particles containing a binder resin, a pigment, and a pigment dispersant, (i) the binder resin contains a crystalline resin in an amount of 20.0% by mass or more and 100.0% by mass or less; (ii) the pigment dispersant is a polymer containing a structure represented by the following formula (1) and a monomer unit represented by the following formula (2), the content of the structure represented by the following formula (1) in the pigment dispersant being 1.0 mass% or more and 15.0 mass% or less, and the content of the monomer unit represented by the following formula (2) being 45.0 mass% or more and 80.0 mass% or less,

[0011] [ka] (In formula (1), X, Y, and Z each independently represent -O-, a methylene group, or -NR5-. R5 represents a hydrogen atom or a linear or branched 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 or unsubstituted phenyl group, a polycyclic aromatic group, or a heterocyclic group; R3 represents a hydrogen atom, a substituted or unsubstituted phenyl group, an aralkyl group, a linear, branched or cyclic alkyl group having from 1 to 18 carbon atoms, or a monovalent group derived by replacing at least one methylene group of an alkyl group having from 2 to 18 carbon atoms with an ether bond, an ester bond, or an amide bond.

[0012] [ka] (In formula (2), R6 represents a hydrogen atom or a methyl group; L1 represents an ester bond or an amide bond; m represents an integer between 20 and 30.

[0013] (iii) Furthermore, the weight average molecular weight (Mw) of the pigment dispersant is 10,000 or more and 50,000 or less. The present invention is characterized by the following:

[0014] Each of the above requirements will be explained in detail below.

[0015] The toner of the present invention has toner particles containing a binder resin containing 20.0% by mass or more and 100.0% by mass or less of a crystalline resin, a pigment, and a pigment dispersant.

[0016] The pigment dispersant is a polymer containing the structure represented by the above formula (1) and the monomer unit represented by the above formula (2).

[0017] In addition, the content of the structure represented by the above formula (1) in the pigment dispersant is 1.0 mass % or more and 15.0 mass % or less, and the content of the monomer unit represented by the above formula (2) is 45.0 mass % or more and 80.0 mass % or less.

[0018] Furthermore, it is an essential requirement that the weight average molecular weight (Mw) of the pigment dispersant be 10,000 or more and 50,000 or less.

[0019] It has been found that by satisfying the above conditions, a toner having excellent low-temperature fixing ability and coloring power can be obtained. The present inventors consider the mechanism as follows.

[0020] When dispersing a pigment in a binder resin containing 20.0% by mass or more of crystalline resin, it is necessary to design the binder resin and the pigment dispersant taking into consideration the interaction between them. Specifically, it is necessary to use a pigment dispersant that has a "site that interacts with the pigment" represented by formula (1) and a "site that interacts with the crystalline resin" that contains a monomer unit represented by formula (2).

[0021] Furthermore, the content of the structure represented by formula (1) in the pigment dispersant must be 1.0% by mass or more and 15.0% by mass or less, and the content of the monomer unit represented by formula (2) must be 45.0% by mass or more and 80.0% by mass or less. By setting the content within these ranges, a balance can be achieved between the interaction between the pigment and the pigment dispersant and the interaction between the pigment dispersant and the crystalline resin.

[0022] Here, the structure represented by formula (1) exhibits strong π-π interaction and has strong hydrogen bonding properties, and therefore easily interacts with the functional groups of the pigment. When a specified amount of formula (1) is contained, the pigment dispersant can be interposed near the pigment. On the other hand, when a specified amount of the monomer unit represented by formula (2) is contained, the affinity with the crystalline resin is increased, and even in a binder resin containing 20.0 mass% or more of crystalline resin, the polymer chain of the polymer moiety derived from formula (2) can spread in the binder resin. Then, the spread polymer chain exhibits steric hindrance and suppresses the aggregation of the pigments, thereby obtaining a toner with excellent low-temperature fixing property and coloring power, which is the effect of the present invention.

[0023] In the pigment dispersant, if the content of the structure represented by formula (1) is less than 1.0% by mass, the amount of interaction with the pigment is small, so that it cannot be present near the pigment, and the effect of the present invention cannot be obtained. In the pigment dispersant, if the content of the structure represented by formula (1) is more than 15.0% by mass, the proportion of the structure represented by formula (1) in the pigment dispersant becomes too large. Therefore, the polymer chain (also called loop length) of the polymer part between the structure represented by formula (1) and the structure represented by formula (1) is not sufficient, and steric hindrance for suppressing aggregation of pigments is not obtained in the pigment dispersant. Therefore, the coloring power of the toner is reduced.

[0024] In the pigment dispersant, if the content of the monomer unit represented by formula (2) is less than 45.0% by mass, the affinity to the binder resin containing 20.0% or more of crystalline resin is low. Therefore, the above-mentioned polymer portion shrinks, and steric hindrance to suppress the aggregation of pigments is not obtained. Therefore, the coloring power of the toner is reduced. In addition, the melting point of the pigment dispersant is reduced, and the heat-resistant storage stability is deteriorated. In the pigment dispersant, if the content of the monomer unit represented by formula (2) is more than 80.0% by mass, the affinity between the pigment dispersant and the crystalline resin becomes too high. Therefore, the pigment dispersant is taken up by the binder resin and cannot be interposed around the pigment. Therefore, the coloring power of the toner is reduced.

[0025] If the weight average molecular weight (Mw) of the pigment dispersant is less than 10,000, the steric hindrance in the pigment dispersant is not obtained. Therefore, the pigment dispersant cannot suppress the aggregation of the pigments. Therefore, the coloring power of the toner is reduced. In addition, the crystallinity derived from the side chain of the above-mentioned polymer portion is not obtained. Therefore, when the pigment dispersant is made into a toner, the pigment dispersant becomes a low melting point component, and the heat resistance and storage stability of the toner are poor. If the weight average molecular weight (Mw) of the pigment dispersant is more than 50,000, the intermolecular interaction between the side chain of the above-mentioned polymer portion and the crystalline resin in the binder resin increases. As a result, this intermolecular interaction becomes greater than the interaction between the structure represented by formula (1) of the pigment dispersant described above and the pigment. Then, the pigment dispersant is removed from the pigment and taken up by the crystalline resin in the binder resin. Therefore, the effect of the present invention is not obtained and the coloring power of the toner is reduced. In order for the pigment dispersant of the present invention to be effective in a binder resin containing a large amount of crystalline resin, the balance between the content of the structure represented by formula (1) and formula (2) in the pigment dispersant and its molecular weight is important.

[0026] [Components of toner] <The structure of pigment dispersant represented by formula (1)> The details and preferred embodiments of the structure represented by formula (1) in the pigment dispersant will be described below.

[0027] The structure of the pigment dispersant containing the formula (1) is a site that is adsorbed to the colorant, and is also called an adsorption site. R4 in the formula (1) is a site that mainly performs π-π interaction with the colorant. Therefore, R4 may be a compound having π-planarity. Among them, heterocyclic compounds and aromatic compounds substituted with polar groups are preferred because they have hydrogen bonding properties in addition to π-planarity. The optimal structure for R4 is a benzimidazolinone structure, which exhibits high adsorption to the colorant and further improves coloring power.

[0028] R3 may be a compound having π-planarity to compensate for the adsorption of the pigment dispersant to the colorant, or may be a structure such as an alkyl group that adjusts the solubility in the dispersion medium. In this case, it is preferable that the structure is not bulky so as not to inhibit the adsorption to the colorant. Specifically, R3 is preferably an alkyl group or a phenyl group having 1 to 12 carbon atoms, more preferably having 2 to 12 carbon atoms, and even more preferably having 2 to 8 carbon atoms. When R3 has these structures, the adsorption rate of the pigment dispersant to the colorant can be maintained, so that good coloring power of the toner is easily obtained. The alkyl group may be substituted or unsubstituted, and may be linear or branched. The phenyl group may be substituted or unsubstituted. In addition, when substituted, the carbon number includes the carbon number of the substituent.

[0029] R2 is a divalent functional group, an alkylene group having 2 to 4 carbon atoms. By making it an alkylene group having 2 to 4 carbon atoms, the adsorption site exhibits good solubility, so that aggregation of the adsorption site can be suppressed, and the coloring power of the toner is likely to be improved. The alkylene group may be substituted or unsubstituted, and may be linear or branched. In addition, when substituted, the number of carbon atoms includes the number of carbon atoms of the substituent.

[0030] X, Y, and Z are divalent linking groups, and it is preferable that at least two of X, Y, and Z are -NH-, since this improves the structural stability of the compound. In particular, it is 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 coloring material. In addition, it is preferable that X is -NH- from the viewpoint of production. In addition, when Y is -O-, there are many commercially available reagents for synthesis, which is advantageous for diversifying the structure of R3.

[0031] L1 is a linking moiety to the polymer moiety, and is an amide bond or an ester bond from the viewpoint of ease of production.

[0032] In view of the above, the adsorption site of the pigment dispersant of the present invention preferably has a structure represented by the following formula (3).

[0033] [ka] (In formula (3), L1 represents an ester bond or an amide bond; R1 represents a hydrogen atom or a methyl group; R8 represents an alkylene group having 2 to 4 carbon atoms; R7 represents a hydrogen atom, a substituted or unsubstituted phenyl group, an aralkyl group, a linear, branched or cyclic alkyl group having from 1 to 18 carbon atoms, or a monovalent group derived by replacing at least one methylene group of an alkyl group having from 2 to 18 carbon atoms with an ether bond, an ester bond, or an amide bond.

[0034] When the pigment dispersant has the structure of formula (3) as an adsorption site, the stability of the compound is improved for the above-mentioned reason. Therefore, the adsorption of the pigment dispersant to the coloring material is improved. As a result, it becomes easier to obtain a toner with good coloring power.

[0035] The structure represented by formula (1) may have the following tautomeric structures: These tautomers are also within the scope of the pigment dispersant used in the present invention.

[0036] [ka]

[0037] <Polymer moiety of pigment dispersant> Next, the polymer moiety will be described in detail. The polymer moiety (also called a dispersion moiety) refers to a structure between the structures represented by formula (1) and (1). The polymer portion contains a structure represented by formula (2). The structure represented by formula (2) can be obtained by polymerizing an ester compound of acrylic acid and a long-chain alkyl monoalcohol, for example, behenyl acrylate, as a monomer.

[0038] The polymer segment preferably contains a structure derived from the following monomer in addition to a predetermined amount of the monomer unit represented by the above formula (2).

[0039] 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, iso-propyl acrylate, n-butyl acrylate, iso-butyl 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, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl 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.

[0040] The polymer moiety can be produced by any of the polymerization methods of solution polymerization, suspension polymerization, emulsion polymerization, dispersion polymerization, precipitation polymerization, and bulk polymerization. Although not particularly limited, solution polymerization in a solvent capable of dissolving each component used during production is preferred. Specifically, the solvent can be a polar organic solvent such as alcohols such as methanol, ethanol, and 2-propanol, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and diethyl ether, ethylene glycol monoalkyl ethers or acetates thereof, propylene glycol monoalkyl ethers or acetates thereof, and diethylene glycol monoalkyl ethers, or a non-polar solvent such as toluene and xylene, either alone or in combination.

[0041] The pigment dispersant preferably has a melting point peak derived from the polymer portion containing the monomer unit at 50° C. to 70° C. in DSC measurement. By having a melting point of 50° C. to 70° C., the pigment dispersant has excellent resistance to deformation and good storage stability. The melting point can be adjusted by the content of the monomer unit represented by formula (2) and the type and content of other monomers.

[0042] <Manufacturing method of pigment dispersants> Next, a method for producing the pigment dispersant according to the present invention will be described. The pigment dispersant used in the present invention can be obtained by copolymerizing a compound having a polymerizable group introduced into the adsorption site with a monomer constituting the dispersion site, or by polymerizing a polymer site containing a functional group capable of reacting with an intermediate compound of the adsorption site in advance, and then adding the intermediate compound of the adsorption site. In either method, the pigment dispersant can be obtained by known synthesis methods and polymerization methods. For example, the pigment dispersant can be synthesized according to the scheme shown below.

[0043] [ka]

[0044] In the above scheme, "-co-" means copolymerization, and m and n each represent the repetition of a structural unit.

[0045] The adsorption site having the polymerizable functional group introduced therein in the above scheme can be polymerized with a dispersion site monomer by a conventionally known method such as radical polymerization, living radical polymerization, anionic polymerization, cationic polymerization, etc. In the dispersant, the adsorption site and the dispersion site may be present in a random state or in a block state.

[0046] The reaction temperature, reaction time, type of solvent and catalyst used, and purification method after synthesis may be appropriately selected according to the target product. The molecular structure of the synthesized adsorption site and the physical properties of the polymerized dispersant can be identified using NMR (nuclear magnetic resonance), IR (infrared spectrophotometer), MS (mass spectrometer), GPC (gel permeation chromatography), etc.

[0047] On the other hand, when the compound of the present invention is added to a polymer that has already been polymerized, it is necessary that the polymer before addition has a functional group capable of reacting with the compound. For this purpose, a known method can be used.

[0048] <Crystalline resin> Examples of the crystalline resin include vinyl resins, polyester resins, polyurethane resins, and epoxy resins having crystallinity. Among them, vinyl resins or polyester resins having crystallinity are preferred. Vinyl resins having crystallinity are more preferred.

[0049] When the crystalline resin is a vinyl resin having crystallinity, it preferably contains a unit represented by formula (4).

[0050] [ka] (In formula (4), R 21 represents a hydrogen atom or a methyl group, L2 represents a single bond, an ester bond, or an amide bond; n represents an integer between 15 and 30.

[0051] By containing the unit represented by formula (4), it becomes easy to form a side chain crystal structure, so that sharp melting property is obtained and low temperature fixability is further improved. n in formula (4) is preferably 17 or more and 29 or less, more preferably 19 or more and 23 or less.

[0052] In addition to the unit represented by formula (4), it is possible to have other monomer units. As a method for introducing other monomer units, there is a method of copolymerizing with other polymerizable monomers. The structure represented by formula (4) can be obtained, for example, by polymerizing behenyl acrylate as a monomer.

[0053] Other polymerizable monomers include the following:

[0054] 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, iso-propyl acrylate, n-butyl acrylate, iso-butyl 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 polymerizable monomers such as methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl 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.

[0055] Of these, it is preferable to use styrene, methacrylic acid, acrylic acid, methyl (meth)acrylate, acrylonitrile, and methacrylonitrile.

[0056] It is preferable that the polarity parameter P1 of the pigment dispersant and the polarity parameter P2 of the crystalline resin satisfy the following formula. │P1-P2│≦0.10 (P1 indicates the volume fraction of acetonitrile at the precipitation point of the pigment dispersant, which is determined by adding 0.10 parts by mass of acetonitrile to a solution consisting of 0.05 parts by mass of the pigment dispersant and 1.48 parts by mass of chloroform. P2 indicates the volume fraction of acetonitrile at the precipitation point of the crystalline resin when 0.10 parts by mass of acetonitrile is added to a solution consisting of 0.05 parts by mass of the crystalline resin and 1.48 parts by mass of chloroform.

[0057] The closer the polarity parameter values ​​of the pigment dispersant and the crystalline resin are, the higher the affinity is, which is preferable.

[0058] P1 can be controlled by changing the composition of the polymer portion of the pigment dispersant. P2 can be controlled by changing the composition of the crystalline resin. The method for measuring the polarity parameters will be described later in detail.

[0059] <Other resins> The binder resin preferably contains an amorphous resin as another resin. When the cross section of the toner particle is observed by a scanning transmission electron microscope, the cross section has a matrix-domain structure, the matrix preferably contains a crystalline resin as a main component, and the domain preferably contains an amorphous resin as a main component, and the toner particle has excellent durability and hot offset resistance. Examples of the amorphous resin include vinyl resin, polyester resin, polyurethane resin, and epoxy resin. Among them, vinyl resin is preferable.

[0060] Although the inclusion of a crystalline resin as the main component in the matrix provides the above-mentioned excellent properties, the crystalline resin in the matrix affects pigment dispersion, which tends to cause a decrease in the coloring power of the toner. However, by using the pigment dispersant of the present invention, it becomes possible to disperse the pigment without being affected by the crystalline resin in the matrix, and a toner with high coloring power can be obtained.

[0061] <Pigments> The pigment preferably contains any one selected from the following group:

[0062] Carbon black, CIPigment Yellow74, CIPigment Yellow93, CIPigment Yellow139, CIPigment Yellow155, CIPigment Yellow180, CIPigment Yellow185, CIPigment Red31, CIPigment Red122, CIPigment Red150, CIPigment Red170, CIPigment Red258, CIPigment Red269, CIPigment Blue15:3, and CIPigment Blue15:4.

[0063] When the pigment is any one selected from the above group, adsorption due to π-π interactions or hydrogen bonding is stronger, so that the pigment dispersant is more likely to be present near the pigment, and pigment dispersibility is more likely to be improved.

[0064] More preferably, the pigments are carbon black; CI Pigment Yellow 155, 180, 185; CI Pigment Red 122, 150; CI Pigment Blue 15:3.

[0065] The content of the pigment dispersant relative to the pigment is preferably 1.0 parts by mass or more and 20 parts by mass or less, and more preferably 3.0 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the pigment.

[0066] <Wax> The toner particles according to the present invention may have a wax. As the wax, it is preferable to use a wax having a number average molecular weight (Mn) of 300 or more and 3000 or less, since this makes it easier to ensure releasability. There is no particular limitation on the type of wax, but it is preferable to use a hydrocarbon wax or an ester wax.

[0067] Examples of hydrocarbon waxes include the following:

[0068] Aliphatic hydrocarbon waxes: low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight olefin copolymer, Fischer-Tropsch wax, or waxes obtained by oxidizing or adding an acid to these.

[0069] The ester wax may be any wax having at least one ester bond in one molecule, and may be either a natural ester wax or a synthetic ester wax.

[0070] The ester wax is not particularly limited, but is preferably an ester of a tetravalent or more and an octavalent alcohol and an aliphatic monocarboxylic acid, or an ester of a tetravalent or more and an octavalent carboxylic acid and an aliphatic monoalcohol. Examples of the ester wax include the following. Esters of monohydric alcohols and monocarboxylic acids, such as behenyl behenate, stearyl stearate, and palmityl palmitate; Esters of divalent carboxylic 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; Among these, esters of hexahydric alcohols and monocarboxylic acids such as dipentaerythritol hexastearate, dipentaerythritol hexapalmitate, dipentaerythritol hexabehenate, etc. are preferred. They interact with the pigment dispersant of the present invention, reducing the domain size of the wax, eliminating the uneven distribution of the pigment in the toner particles, and further improving the coloring power and color gamut.

[0071] <Method of manufacturing toner particles> The toner particles according to the present invention may be produced by any method, but it is preferable to produce the toner particles by a method for producing toner particles in which a polymerizable monomer composition is granulated in an aqueous medium, such as a suspension polymerization method, an emulsion polymerization method, or a suspension granulation method.

[0072] A method for producing toner particles will be described below using the suspension polymerization method, which is the most suitable method for producing toner particles used in the present invention.

[0073] The above-mentioned pigment dispersant, pigment, crystalline resin, wax, polymerizable monomers for forming other resins of the binder resin, and other additives as necessary are uniformly dissolved or dispersed by a dispersing machine such as a homogenizer, a ball mill, a colloid mill, or an ultrasonic dispersing machine, and a polymerization initiator is dissolved therein to prepare a polymerizable composition. The polymerizable composition is then suspended in an aqueous medium containing a dispersion stabilizer and polymerized to produce toner particles.

[0074] The polymerizable monomer may be, as a monofunctional polymerizable monomer, 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, iso-propyl acrylate, n-butyl acrylate, iso-butyl 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, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl 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.

[0075] Examples of the polyfunctional polymerizable monomer 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 dimeth ... Examples of suitable vinyl ethers include 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.

[0076] Monofunctional polymerizable monomers can be used alone or in combination of two or more kinds, monofunctional polymerizable monomers can be used in combination with polyfunctional polymerizable monomers, or polyfunctional polymerizable monomers can be used alone or in combination of two or more kinds.

[0077] The polymerization initiator may be added simultaneously with the addition of other additives to the polymerizable monomer, or may be mixed immediately before suspending in an aqueous medium. Also, 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.

[0078] 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 including the crystalline resin.

[0079] The polymerization initiator may be an organic peroxide initiator or an azo polymerization initiator. The organic peroxide initiator may be the following: 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.

[0080] 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.

[0081] Also, a redox initiator combining an oxidizing substance and a reducing substance can be used as the polymerization initiator. Examples of the oxidizing substance include hydrogen peroxide, inorganic peroxides such as persulfates (sodium salts, potassium salts, and ammonium salts), and oxidizing metal salts such as tetravalent cerium salts. Examples of the reducing substance include reducing metal salts (divalent iron salts, monovalent copper salts, and trivalent chromium salts), ammonia, lower amines (amines having about 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 hydrogensulfite, 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).

[0082] 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 to be added varies depending on the desired degree of polymerization, but is generally 0.5 parts by mass or more and 20.0 parts by mass or less per 100.0 parts by mass of the polymerizable monomer.

[0083] In order to control the degree of polymerization, a known chain transfer agent and a polymerization inhibitor may be further added.

[0084] When polymerizing the polymerizable monomer, various crosslinking agents can be used, such as polyfunctional compounds including 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.

[0085] The dispersion stabilizer used when 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. On the other hand, 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 parts by mass or more and 20.0 parts by mass or less relative to 100.0 parts by mass of the polymerizable monomer.

[0086] Among these dispersion stabilizers, when a dispersion stabilizer of an inorganic compound is used, 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, in the case of tricalcium phosphate, it can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high agitation.

[0087] In the present invention, in order to improve image quality, it is preferable that an external additive is added to the toner particles. As the external additive, inorganic fine powder such as silica fine powder, titanium oxide fine powder, or aluminum oxide fine powder is preferably used.

[0088] These inorganic fine powders are preferably subjected to a hydrophobizing treatment with a hydrophobizing agent such as a silane coupling agent, silicone oil or a mixture thereof.

[0089] Furthermore, in the toner of the present invention, external additives other than those mentioned above may be mixed into the toner particles, if necessary.

[0090] The total 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 (toner particles before addition of external additives).

[0091] [Methods for measuring various physical properties] The methods for measuring various physical properties according to the present invention will be described below.

[0092] <Composition analysis method> The structure of the pigment dispersant and the crystalline resin were determined using the following equipment. 13 C-NMR: FT-NMR AVANCE-600 manufactured by Bruker Biospin (solvent used: deuterated chloroform) In addition, 13 C-NMR was quantified and compositional analysis was performed using the inverse gated decoupling method with chromium(III) acetylacetonate as a relaxation reagent.

[0093] The molar composition ratios of each monomer unit of the pigment dispersant and the crystalline resin were calculated by the above measurements, and then the mass composition ratios were calculated from the molecular weights of each monomer unit.

[0094] <Method of measuring molecular weight> The weight average molecular weight (Mw) of the toner and the pigment dispersant is measured by gel permeation chromatography (GPC) as follows.

[0095] A sample is dissolved in tetrahydrofuran (THF) at room temperature. The resulting solution is then filtered through a solvent-resistant membrane filter "Myshoridisc" (manufactured by 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 to perform measurements under the following conditions. Equipment: High-speed GPC equipment "HLC-8220GPC" [Tosoh Corporation] Column: 2 columns of LF-604 [Showa Denko Co., Ltd.] Eluent:THF Flow rate: 0.6mL / min Oven temperature: 40℃ Sample injection volume: 0.020mL In calculating the molecular weight of a sample, a molecular weight calibration curve prepared using standard polystyrene resins (e.g., 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.

[0096] <Measuring method for polarity parameters P1 and P2> The polarity parameter P1 in the present invention was measured by the following method.

[0097] Put 50 mg (0.05 g) of pigment dispersant into an 8 ml sample bottle, dissolve it in 1.48 g of chloroform, and measure the initial mass (W1). Place a stir bar in the sample bottle, and while stirring with a magnetic stirrer, (a) drop 100 mg (0.1 g) of acetonitrile and continue stirring for 20 seconds. (b) Visually check to see if it has become cloudy. If it has not become cloudy, repeat steps (a) and (b). Stop the operation at the point where cloudiness is confirmed (precipitation point) and measure the mass (W2). All measurements are performed at 25°C and normal pressure.

[0098] Calculate P1 according to the following formula: Initial mass before adding acetonitrile W1(g) Mass W2 (g) at the cloudy point after adding acetonitrile Polarity Parameter = {(W2-W1) / 0.78} / {((W2-W1) / 0.78)+1}

[0099] P2 is also measured in the same manner as above, except that the pigment dispersant is replaced with a crystalline resin.

[0100] <Melt point measurement method> The melting points of the pigment dispersant and the like are measured using a differential scanning calorimeter "Q1000" (manufactured by TA Instruments) in accordance with ASTM D3418-82.

[0101] The melting points of indium and zinc are used for temperature correction of the device detection section, and the heat of fusion of indium is used for heat correction.

[0102] Specifically, 5 mg of sample is weighed out and placed in an aluminum pan, and an empty aluminum pan is used as a reference. Measurements are performed at a temperature range of 0°C to 150°C at a heating rate of 10°C / min. In the measurement, the temperature is raised to 150°C once, then lowered to 0°C, and then raised again. The peak temperature of the maximum endothermic peak on the DSC curve in the temperature range of 0°C to 150°C during this second heating process is taken as the melting point.

[0103] <Observation of matrix domain structure in toner cross section> The state of the matrix domain structure (sea-island structure) in the cross section of the toner is confirmed by observing the cross section of the toner using a scanning transmission electron microscope. The cross section of the toner is observed after ruthenium staining. That is, the cross section image of the toner is a cross section image of a toner stained with ruthenium, and the observation procedure for the cross section of the toner is as follows.

[0104] The toner is embedded in a visible light curable resin (D-800, manufactured by Nissin EM Co., Ltd.) so as to be as dispersed as possible, and cut to a thickness of 100 nm using an ultrasonic ultramicrotome (UC7, manufactured by Leica Co., Ltd.).

[0105] The obtained thin sample is stained for 15 minutes in a 500 Pa RuO4 gas atmosphere using a vacuum staining device (VSC4R1H, Filgen), and a STEM image is obtained using a scanning transmission electron microscope (JEM2800, JEOL). Under the above staining conditions, there is a difference in the degree of staining between the crystalline resin and the amorphous resin, so the presence of the matrix domain structure can be confirmed by the contrast difference.

[0106] The observation conditions are set as follows: acceleration voltage is 200 kV, STEM probe size is 1 nm, image size is 1024×1024 pixels, and magnification is 30000, and a dark field (STEM-DF) image is acquired.

[0107] Contrast and Brightness are adjusted so that the brightness when the maximum number of pixels is present in the part mainly composed of resin components becomes 150 in the brightness histogram by IMAGE J shown below.

[0108] If the brightness is between 140 and 160, you can adjust the brightness using Microsoft Photos.

[0109] <Method of measuring weight-average particle size (D4) and number-average particle size (D1) of toner particles> A precision particle size distribution measuring device 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. The aperture diameter is 100 μm, and measurements are performed with an effective number of measurement channels of 25,000, and the measurement data is analyzed and calculated. The electrolyte solution used for the measurement is one in which special grade sodium chloride is dissolved in ion-exchanged water to a concentration of 1 mass%, for example, ISOTON II (product name) manufactured by Beckman Coulter, Inc. can be used. Note that before performing the measurement and analysis, the dedicated software is set up as follows.

[0110] In the "Change Standard Measurement Method (SOM) screen" of the dedicated software, set the total count number in the control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using (standard particle 10.0 μm, manufactured by Beckman Coulter). Press the threshold / noise level measurement button to automatically set the threshold and noise level. In addition, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II (trade name), and check the aperture tube flush after measurement.

[0111] In the "Pulse to particle size conversion setting screen" of the dedicated software, set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm to 60 μm.

[0112] The specific measurement method is as follows. (1) Pour 200 mL of the electrolyte solution into a 250 mL round-bottom glass beaker made exclusively 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 dirt and air bubbles from inside the aperture tube. (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 of Contaminon N (trade name) (a 10% aqueous solution of a neutral detergent for cleaning precision measuring instruments, manufactured by Wako Pure Chemical Industries, Ltd.) diluted 3 times by mass with ion-exchanged water is added thereto. (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 (product name: Ultrasonic Dispersion System Tetora150, manufactured by Nikkaki Bios Co., Ltd.) that has two built-in oscillators with an oscillation frequency of 50 kHz and a phase shift of 180 degrees and an electrical output of 120 W. (4) The beaker (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid surface of the electrolyte solution in the beaker is maximized. (5) While the electrolyte solution in the beaker in (4) is irradiated with ultrasonic waves, 10 mg of toner (particles) is added little by little to the electrolyte solution and dispersed. Then, ultrasonic dispersion treatment is continued for another 60 seconds. During ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to 10°C to 40°C. (6) Using a pipette, the electrolyte solution (5) in which the toner (particles) is dispersed is dropped into the round-bottom beaker (1) placed in the sample stand, and the measurement concentration is adjusted to 5%. Then, the measurement is continued until the number of particles measured reaches 50,000. (7) The measurement data is analyzed using the dedicated software that comes with the device, and the weight average particle size (D4) is calculated. Note that 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).

[0113] [Configuration included in the embodiment of the present invention] The disclosure of this embodiment includes the following configuration. (Configuration 1) A toner having toner particles containing a binder resin, a pigment, and a pigment dispersant, The binder resin contains a crystalline resin in an amount of 20.0% by mass or more and 100.0% by mass or less, The pigment dispersant is a polymer containing a structure represented by the above formula (1) and a monomer unit represented by the above formula (2), the content 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, the content of the monomer unit represented by the formula (2) in the pigment dispersant is 45.0% by mass or more and 80.0% by mass or less, The toner is characterized in that the weight average molecular weight (Mw) of the pigment dispersant is 10,000 or more and 50,000 or less. (Configuration 2) The toner according to configuration 1, wherein the structure represented by formula (1) is a structure represented by formula (3). (Configuration 3) The toner according to configuration 1 or 2, wherein the pigment dispersant has a melting point peak at 50° C. or higher and 70° C. or lower, which is derived from a polymer moiety containing the monomer unit, as measured by DSC. (Configuration 4) The binder resin contains an amorphous resin, The toner according to any one of Configurations 1 to 3, wherein when a cross section of the toner particle is observed with a scanning transmission electron microscope, a matrix domain structure is observed on the cross section, the crystalline resin is contained as a main component in the matrix, and the amorphous resin is contained as a main component in the domain. (Configuration 5) The toner according to any one of configurations 1 to 4, wherein the crystalline resin contains a structure represented by the above formula (4). (Configuration 6) The toner according to any one of Configurations 1 to 5, wherein a polarity parameter P1 of the pigment dispersant and a polarity parameter P2 of the crystalline resin satisfy the following formula: │P1-P2│≦0.10 (P1 indicates the volume fraction of acetonitrile at the precipitation point of the pigment dispersant, which is determined by adding 0.10 parts by mass of acetonitrile to a solution consisting of 0.05 parts by mass of the pigment dispersant and 1.48 parts by mass of chloroform. P2 indicates the volume fraction of acetonitrile at the precipitation point of the crystalline resin when 0.10 parts by mass of acetonitrile is added to a solution consisting of 0.05 parts by mass of the crystalline resin and 1.48 parts by mass of chloroform. (Configuration 7) The toner according to any one of Configurations 1 to 6, wherein the toner particles contain a wax, and the number average molecular weight (Mn) of the wax is 300 or more and 3,000 or less. (Configuration 8) The toner according to configuration 7, wherein the wax is an ester wax. (Configuration 9) The toner according to configuration 8, wherein the wax is an ester of a tetrahydric or more and an octahydric or less alcohol and an aliphatic monocarboxylic acid, or an ester of a tetrahydric or more and an octahydric or less carboxylic acid and an aliphatic monoalcohol. (Configuration 10) The pigment is 10. The toner according to any one of claims 1 to 9, comprising any one selected from the group consisting of carbon black, CI Pigment Yellow 74, CI Pigment Yellow 93, CI Pigment Yellow 139, CI Pigment Yellow 155, CI Pigment Yellow 180, CI Pigment Yellow 185, CI Pigment Red 31, CI Pigment Red 122, CI Pigment Red 150, CI Pigment Red 170, CI Pigment Red 258, CI Pigment Red 269, CI Pigment Blue 15:3, and CI Pigment Blue 15:4. EXAMPLES

[0114] The present invention will be specifically described with reference to the following Production Examples and Examples. However, these do not limit the present invention in any way. In the Production Examples and Examples, "parts" and "%" are all by mass unless otherwise specified.

[0115] <Synthesis of compound (A1)> Compound (A1) was synthesized according to the synthesis scheme shown below.

[0116] [ka]

[0117] Synthesis of intermediate (1): First, intermediate (1) was synthesized by referring to the description of Synthesis Example 1 in JP-A-10-316643. Diethyl malonate 20.6 parts (0.129 moles) 2-Methacryloyloxyethyl isocyanate (product name "Karends MOI", manufactured by Showa Denko) 19.8 parts (0.128 moles) 0.284 parts (1.29 mmol) of 2,6-di-tert-butyl-p-cresol The above was dissolved in 100 parts (0.942 moles) of xylene and heated to 60°C. 0.214 parts (3.96 millimoles) of sodium methoxide was added and reacted for 8 hours, after which 200 parts (11.1 moles) of water was added to terminate 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.

[0118] Synthesis of compound (A1): next, Intermediate (1) 19.8 parts (62.8 mmol) 5-Amino-2-benzimidazolinone 11.4 parts (76.4 mmol) 0.138 parts (0.626 mmol) of 2,6-di-tert-butyl-p-cresol The above was dissolved in 141 parts (1.93 moles) of N,N-dimethylformamide, and the mixture was heated and stirred at 80° C. for 6 hours to cause a reaction. After the reaction, the N,N-dimethylformamide was distilled off under reduced pressure, and 300 parts (16.7 moles) of water was added to the resulting residue. The precipitate was filtered to obtain the compound (A1) represented by the above formula.

[0119] <Synthesis of compound (A2)> Compound (A2) was synthesized according to the following scheme.

[0120] [ka]

[0121] Compound (A2) represented by the above formula was synthesized in the same manner as in the synthesis of compound (A1) described above, except that in the synthesis of compound (A1), 5-amino-2-benzimidazolinone was changed to 3-aminophenylureido.

[0122] <Synthesis of compound (A3)> Compound (A3) was synthesized according to the following scheme.

[0123] [ka]

[0124] Synthesis of intermediate (2): 14.5 parts (62.4 mmol) of triethyl carboxymalonate 3-Aminophenylureide 11.5 parts (76.1 mmol) 0.138 parts (0.626 mmol) of 2,6-di-tert-butyl-p-cresol The above was dissolved in 141 parts (1.93 moles) of N,N-dimethylformamide, and the mixture was reacted by heating and stirring at 80° C. for 6 hours. After the reaction, the N,N-dimethylformamide was distilled off under reduced pressure, and 300 parts (16.7 moles) of water was added to the resulting residue. The precipitate was filtered to obtain intermediate (2) represented by the above formula.

[0125] Synthesis of compound (A3): Intermediate (2) 18.9 parts (56.0 mmol) N,N-Dimethylformamide 50.0 parts (0.684 moles) 0.124 parts (0.563 mmol) of 2,6-di-tert-butyl-p-cresol Ethylenediamine 5.05 parts (84.0 mmol) The mixture was mixed and reacted at 80° C. for 6 hours with stirring. After the reaction, N,N-dimethylformamide was distilled off under reduced pressure, and 300 parts (16.7 moles) of water was added to the resulting residue. The precipitate was filtered to obtain the compound (A3) represented by the above formula.

[0126] <Synthesis of pigment dispersant> Next, the pigment dispersants (Sy-1) to (Sy-12) and (Sy-19) used in the present invention, and the pigment dispersants (Sy-13) to (Sy-18) used in the comparative examples were synthesized using the synthesized compounds (A1) to (A3).

[0127] (Synthesis of pigment dispersant (Sy-1)) Into a nitrogen-substituted eggplant flask, 64.3 parts of behenyl acrylate, 27.8 parts of styrene, 7.8 parts of compound (A1), and 1.5 parts of azobisisobutyronitrile were placed and 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 reaction was stopped by cooling with ice water to obtain a pigment dispersant (SY-1).

[0128] The resulting pigment dispersant (Sy-1) was purified by solid-liquid separation in methanol, a poor solvent, and then the weight average molecular weight was measured using GPC. The weight average molecular weight (Mw) of the resulting pigment dispersant (Sy-1) is shown in Table 1. Table 1 also shows the melting point (Tm) and the polarity parameter P1.

[0129] (Synthesis of pigment dispersants (Sy-2 to Sy-19)) Pigment dispersants Sy-2 to Sy-18 and Sy-19 were obtained in the same manner as in the production example of pigment dispersant Sy-1, except that the composition was changed to that shown in Table 1. The compositions and physical properties of pigment dispersants Sy2 to Sy-19 are shown in Table 1.

[0130] [Table 1] The terms in the table have the following meanings: BEA: Behenyl acrylate St: styrene MA: Methyl acrylate LMA: Lauryl methacrylate 2-MTA: 2-Methoxyethyl acrylate MAN: Methacrylonitrile

[0131] <Production Example of Crystalline Resin C-1> 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 Corp.: Perbutyl PV)

[0132] The inside of the reaction vessel was heated to 70°C while stirring at 200 rpm to carry out a polymerization reaction for 12 hours, and a solution in which the polymer of the monomer composition was dissolved in toluene was obtained. Toluene and residual monomers were then distilled off at 160°C and 1 hPa to obtain crystalline resin C-1.

[0133] <Production Example of Crystalline Resin C-2> Crystalline resins C-2 and C-5 were obtained in the same manner as for preparing crystalline resin C-1, except that the raw materials were changed as shown in Table 2 in the preparation of crystalline resin C-1.

[0134] <Production Example of Crystalline Resin C-3> In a reaction vessel equipped with a stirrer, a thermometer, a nitrogen inlet tube, a dehydration tube, and a pressure reducing device, 118.0 parts of sebacic acid and 69.0 parts of 1,6-hexanediol were added and heated to a temperature of 130°C while stirring. After adding 0.7 parts of titanium (IV) isopropoxide as an esterification catalyst, the temperature was raised to 160°C and polycondensed for 5 hours. Thereafter, the temperature was raised to 180°C and the reaction was continued while reducing the pressure until the desired molecular weight was obtained, to obtain crystalline resin C-3.

[0135] <Production Example of Crystalline Resin C-4> In a reaction vessel equipped with a stirrer, a thermometer, a nitrogen inlet tube, a dehydration tube, and a pressure reducing device, 118.0 parts of sebacic acid and 69.0 parts of 1,6-hexanediol were added and heated to a temperature of 130°C while stirring. After adding 0.7 parts of titanium (IV) isopropoxide, the temperature was raised to 160°C and polycondensed over 5 hours. Then, 7.0 parts of acrylic acid and 50.0 parts of styrene were dropped over 1 hour. After continuing stirring for 1 hour while maintaining the temperature at 160°C, the monomer of the styrene resin component was removed at 8.3 kPa for 1 hour. After that, the temperature was raised to 210°C and reacted until the desired molecular weight was reached to obtain crystalline resin C-4.

[0136] Table 2 shows the compositions and physical properties of crystalline resins C-1 to C-5.

[0137] [Table 2]

[0138] <Production example of black toner 1> [Preparation process of pigment dispersion 1] Styrene monomer 100.0 parts Carbon black (CB) 20.0 parts (Nipex35: manufactured by Oorion 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) having a radius of 2.5 mm to prepare pigment dispersion 1.

[0139] [Preparation of toner composition solution] Pigment dispersion 1 48.8 parts Styrene 4.0 parts n-Butyl acrylate (BA) 19.0 parts ·Crystalline resin C-1 35.0 parts Dipentaerythritol hexastearate 10.0 parts The above materials were mixed and heated to 65° C., and then uniformly 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.

[0140] [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 were charged with 450 parts of 0.1M-Na3PO4 aqueous solution and heated to 60°C. Then, 67.7 parts of 1.0M-CaCl2 aqueous solution were gradually added to obtain an aqueous medium 1 containing a calcium phosphate compound.

[0141] [Granulation process] While maintaining the temperature of the aqueous medium 1 at 60° C. and the rotation speed of the stirring device at 12,500 rpm, the toner composition solution 1 was poured into the aqueous medium 1, and 9.0 parts of t-butyl peroxypivalate as a polymerization initiator was added. Granulation was continued for 10 minutes while maintaining the stirring device at 12,500 rpm.

[0142] [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, thereby obtaining a black toner particle dispersion in which black toner particles are dispersed.

[0143] Hydrochloric acid was added to the obtained black toner particle dispersion 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 under a pressure of 0.4 MPa to obtain a toner cake. Next, ion-exchanged water was added to the pressure filter until it was filled with water, and the mixture was washed under a pressure of 0.4 MPa. This washing operation was repeated three times, and then the mixture was dried to obtain black toner particles 1. The weight average particle size (D4) of the obtained black toner particles 1 was 6.9 μm.

[0144] To 100.0 parts of the obtained black toner particles 1, 1.5 parts (number average primary particle diameter: 10 nm) of hydrophobic silica fine powder surface-treated with hexamethyldisilazane was added, and a mixing process was carried out 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.

[0145] <Production examples of black toner 2-29> Black toners 2 to 29 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. Black toners 2 to 29 are shown in Table 3.

[0146] [Table 3-1]

[0147] [Table 3-2]

[0148] <Production example of magenta toner 1> [Preparation process of pigment 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) having a radius of 2.5 mm to prepare pigment dispersion 2.

[0149] Thereafter, magenta toner 1 was obtained in the same manner as for black toner 1. The composition and physical properties of magenta toner 1 obtained are shown in Table 4.

[0150] <Production example of magenta toners 2 to 5> Magenta toners 2 to 5 were obtained in the same manner as in the production example of magenta toner 1, except that the pigment dispersant of magenta toner 1 was changed as shown in Table 4. Magenta toners 2 to 5 are shown in Table 4.

[0151] [Table 4]

[0152] <Production Example of Yellow Toner 1> [Preparation process of pigment dispersion 2] 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) having a radius of 2.5 mm to prepare pigment dispersion 2.

[0153] Thereafter, yellow toner 1 was obtained in the same manner as black toner 1. The composition and physical properties of yellow toner 1 thus obtained are shown in Table 5.

[0154] <Production Examples of Yellow Toners 2 to 5> Yellow toners 2 to 5 were obtained in the same manner as in the production example of yellow toner 1, except that the pigment of yellow toner 1 was changed as shown in Table 5. Yellow toners 2 to 5 are shown in Table 5.

[0155] [Table 5]

[0156] <Production example of cyan toner 1> [Preparation process of pigment dispersion 2] Styrene monomer 100.0 parts Pigment Blue 15:3 20.0 parts (ECB-308 [manufactured by Dainichi Seika Chemicals 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) having a radius of 2.5 mm to prepare pigment dispersion 2.

[0157] Thereafter, cyan toner 1 was obtained in the same manner as black toner 1. The composition and physical properties of the obtained cyan toner 1 are shown in Table 6.

[0158] <Production Example of Cyan Toner 2 to 5> Cyan toners 2 to 5 were obtained in the same manner as in the production example of cyan toner 1, except that the pigment dispersant of cyan toner 1 was changed as shown in Table 6. Cyan toners 2 to 5 are shown in Table 6.

[0159] [Table 6]

[0160] <Image evaluation> The image evaluation was performed using a commercially available color laser printer [HP LaserJet Enterprise Color M555dn] that was partially 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 changed to any desired value.

[0161] The toner was removed from the black toner process cartridge installed in this color laser printer, the inside was cleaned with an air blower, and then each toner (250 g) was introduced into the process cartridge, and the process cartridge refilled with toner was installed in the color laser printer, and the following image evaluation was performed. The specific image evaluation items are as follows.

[0162] [Evaluation method for coloring strength] A rectangular solid image of 6.5 cm x 14.0 cm is printed in the center of the transfer material (toner load: 0.45 mg / cm 2 ) was output as an evaluation image. The image density in the evaluation image was measured to evaluate the coloring power. The image density was measured using an X-Rite color reflection densitometer (X-Rite404A). The density was measured at five points in the solid image area: the upper right, upper left, center, lower right, and lower 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. (Evaluation Criteria) A: Image density is 1.60 or more B: Image density is 1.50 or more and less than 1.60 C: Image density is 1.40 or more and less than 1.50 D: Image density is less than 1.40

[0163] [Evaluation method for low-temperature fixability] Solid image on transfer material (toner load: 0.45 mg / cm 2 The fixing temperature was measured by a non-contact thermometer on the surface of the fixing roller. The transfer material was LETTER size plain paper (Vitality, XEROX, 75 g / m 2 ) was used. (Evaluation Criteria) A: Low temperature fixing start temperature is 115℃ or less B: Low-temperature fixing start temperature is 120°C or higher and 130°C or lower C: Low temperature fixing start temperature is 135℃ or higher and 145℃ or lower D: Low temperature fixing start temperature is 150℃ or higher

[0164] [Method for evaluating hot offset resistance] A fixed image was prepared in the same manner as in the above evaluation method, and the maximum fixing temperature was evaluated. The maximum fixing temperature is defined as the highest temperature at which offset does not occur. (Evaluation Criteria) A: Maximum fixing temperature is 205℃ or higher B: Maximum fixing temperature is 195℃ or 200℃ C: Maximum fixing temperature is 185℃ or 190℃ D: Maximum fixing temperature is 180℃ or less

[0165] <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 presence or absence of aggregates was examined and evaluated according to the following criteria. (Evaluation Criteria) A: No clumps formed B: Slight clumps formed, crumbles when lightly pressed with fingers C: Agglomerates form, but do not crumble even when lightly pressed with fingers D: Completely aggregated

[0166] <Evaluation method for streaks (developability)> After completing a test of printing out 30,000 sheets of an image with a horizontal line coverage rate of 1% in a high temperature and high humidity environment (temperature 32°C / humidity 85% RH), the image was printed on LETTER size plain paper (Vitality, XEROX, 75g / m 2 ) and halftone (toner load: 0.25mg / 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. (Evaluation Criteria) A: Not occurred B: Vertical stripes in the paper ejection direction appear in 1 to 3 places on the halftone image. C: Four to six vertical streaks in the paper ejection direction appear on the halftone image. D: Seven or more vertical lines appear in the paper ejection direction on the halftone image, or vertical lines with a width of 0.5 mm or more appear.

[0167] [Examples 1 to 22] The above evaluations were performed using black toners 1 to 20, respectively, in Examples 1 to 20, black toner 28 in Example 21, and black toner 29 in Example 22. The evaluation results are shown in Table 7.

[0168] [Comparative Examples 1 to 7] In Comparative Examples 1 to 7, the above evaluations were carried out using black toners 21 to 27, respectively. The evaluation results are shown in Table 7. In addition, in Comparative Example 4, the toner completely aggregated in the evaluation of heat resistance, so that evaluations of low temperature fixability, hot offset resistance, and developability were not carried out.

[0169] [Table 7]

[0170] [Examples 22 to 36] In Examples 22 to 26, the above evaluation was performed using magenta toners 1 to 5, respectively. In Examples 27 to 31, the above evaluation was performed using yellow toners 1 to 5, respectively. In Examples 32 to 36, the above evaluation was performed using cyan toners 1 to 5, respectively. The evaluation results are shown in Table 8.

[0171] [Table 8]

Claims

1. A toner having toner particles containing a binder resin, a pigment, and a pigment dispersant, The binder resin contains a crystalline resin in an amount of 20.0% by mass or more and 100.0% by mass or less, The pigment dispersant is a polymer containing a structure represented by the following formula (1) and a monomer unit represented by the following formula (2), The content of the structure represented by the following formula (1) in the pigment dispersant is 1.0 mass % or more and 15.0 mass % or less: The content of the monomer unit represented by the following formula (2) in the pigment dispersant is 45.0 mass % or more and 80.0 mass % or less: The toner is characterized in that the weight average molecular weight (Mw) of the pigment dispersant is 10,000 or more and 50,000 or less. 【Chemistry 1】 (In formula (1), X, Y, and Z each independently represent -O-, a methylene group, or -NR 5 - or 5 represents a hydrogen atom or a linear or branched 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 or unsubstituted phenyl group, polycyclic aromatic group, or heterocyclic group, R 3 represents a hydrogen atom, a substituted or unsubstituted phenyl group, an aralkyl group, a linear, branched or cyclic alkyl group having from 1 to 18 carbon atoms, or a monovalent group derived by replacing at least any methylene group of an alkyl group having from 2 to 18 carbon atoms with an ether bond, an ester bond, or an amide bond. 【Chemistry 2】 (In formula (2), R 6 represents a hydrogen atom or a methyl group, L 1 represents an ester bond or an amide bond, m represents an integer of 20 or more and 30 or less.

2. The toner according to claim 1 , wherein the structure represented by the formula (1) is a structure represented by the following formula (3): 【Chemistry 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 8 represents an alkylene group having 2 to 4 carbon atoms, R 7 represents a hydrogen atom, a substituted or unsubstituted phenyl group, an aralkyl group, a linear, branched or cyclic alkyl group having from 1 to 18 carbon atoms, or a monovalent group derived by replacing at least any methylene group of an alkyl group having from 2 to 18 carbon atoms with an ether bond, an ester bond, or an amide bond.

3. 3. The toner according to claim 1, wherein the pigment dispersant has a melting point peak at 50° C. or higher and 70° C. or lower, which is derived from a polymer moiety containing the monomer unit, as measured by DSC.

4. The binder resin contains an amorphous resin, 3. The toner according to claim 1, wherein when a cross-section of the toner particle is observed with a scanning transmission electron microscope, a matrix domain structure is observed on the cross-section, the crystalline resin is contained as a main component in the matrix, and the amorphous resin is contained as a main component in the domain.

5. The toner according to claim 1 , wherein the crystalline resin contains a structure represented by the following formula (4): 【Chemistry 4】 (In formula (4), R 21 represents a hydrogen atom or a methyl group, L 2 represents a single bond, an ester bond, or an amide bond; n represents an integer of 15 or more and 30 or less.

6. 3. The toner according to claim 1, wherein a polarity parameter P1 of the pigment dispersant and a polarity parameter P2 of the crystalline resin satisfy the following formula: |P1-P2|≦0.10 (P1 indicates the volume fraction of acetonitrile at the precipitation point of the pigment dispersant, which is determined by adding 0.10 parts by mass of acetonitrile to a solution consisting of 0.05 parts by mass of the pigment dispersant and 1.48 parts by mass of chloroform. P2 indicates the volume fraction of acetonitrile at the precipitation point of the crystalline resin when 0.10 parts by mass of acetonitrile is added to a solution consisting of 0.05 parts by mass of the crystalline resin and 1.48 parts by mass of chloroform.

7. 3. The toner according to claim 1, wherein the toner particles contain a wax, and the wax has a number average molecular weight (Mn) of 300 or more and 3,000 or less.

8. 8. The toner according to claim 7, wherein the wax is an ester wax.

9. 9. The toner according to claim 8, wherein the wax is an ester of a tetravalent or more and an octavalent or less alcohol and an aliphatic monocarboxylic acid, or an ester of a tetravalent or more and an octavalent or less carboxylic acid and an aliphatic monoalcohol.

10. The pigment is carbon black, C. I. Pigment Yellow74, C. I. Pigment Yellow93, C. I. Pigment Yellow139, C. I. Pigment Yellow155, C. I. Pigment Yellow180, C. I. Pigment Yellow185, C. I. Pigment Red31, C. I. Pigment Red122, C. I. Pigment Red150, C. I. Pigment Red170, C. I. Pigment Red258, C. I.

3. The toner according to claim 1, comprising any one selected from the group consisting of C. I. Pigment Red 269, C. I. Pigment Blue 15:3, and C. I. Pigment Blue 15:4.

Images