Toner and toner manufacturing method

Abstract

To provide a toner that can have excellent low-temperature fixability, heat-resistant storage property, and mold releasability, and can have excellent durability.SOLUTION: A toner has a toner particle containing a resin component and wax. The resin component contains a vinyl polymer A having a monomer unit A represented by the formula (A). When a luminance histogram is obtained from STEM observation of a cross section of the toner particle, and when the total number of pixels from the luminance 0 to the luminance 9 is C and the total number of pixels from the luminance 0 to the luminance 245 is A, C and A satisfy the formula (1). When a luminance X is a luminance indicating the maximum value of the number of pixels P within a range from the luminance 10 to the luminance 245, a luminance M is a luminance when the number of pixels falls below 20% of P for the first time from the luminance X toward the luminance 245, and a luminance N is a luminance when the number of pixels falls below 20% of P for the first time from the luminance X toward the luminance 10, the value of the luminance M-the luminance N is 120-235.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In recent years, there has been an increasing demand for energy-saving measures for electrophotographic image forming apparatuses. As a countermeasure for energy saving, technology for fixing toner at a low temperature has been studied in order to reduce power consumption in the fixing process.

[0003] In order to improve the low-temperature fixability of a toner, a method of lowering the glass transition temperature of a resin component of the toner can be mentioned. However, lowering the glass transition temperature of a resin component leads to a deterioration in the heat-resistant storage stability of the toner, and therefore, it is difficult to achieve both low-temperature fixability and heat-resistant storage stability of the toner with this method.

[0004] Therefore, in order to achieve both low-temperature fixability and heat-resistant storage stability of toner, the use of crystalline resins in toner has been investigated. Amorphous resins, which are commonly used as resin components in toner, do not exhibit clear endothermic peaks in differential scanning calorimetry (DSC) measurements. On the other hand, crystalline resins exhibit endothermic peaks in DSC measurements. Crystalline resins exhibit a property of hardly softening up to their melting point due to the regular arrangement of alkyl groups between or within molecules. Due to this property, crystalline resins undergo a sharp melting of the crystals at the melting point, resulting in a rapid decrease in viscosity.

[0005] For this reason, crystalline resins have attracted attention as materials that have excellent sharp melting properties and that combine low-temperature fixability and heat-resistant storage stability of toner. Crystalline vinyl resins are known as one type of crystalline resin. Crystalline vinyl resins are vinyl polymers that have monomer units with long-chain alkyl groups. That is, crystalline vinyl resins have a main chain skeleton and long-chain alkyl groups as side chains. The long-chain alkyl groups in the side chains are regularly arranged and crystallized, resulting in the resin exhibiting crystallinity.

[0006] Patent Document 1 proposes a toner that uses a crystalline vinyl resin having a monomer unit with a long-chain alkyl group. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-130243 Summary of the Invention [Problem to be solved by the invention]

[0008] As a result of the inventors' investigation of the toner described in Patent Document 1, they recognized that further improvement in the durability of the toner is necessary. Specifically, they found that when a crystalline vinyl resin having a monomer unit with a long-chain alkyl group is used in combination with a wax, the toner may be prone to cracking and chipping.

[0009] One aspect of the present disclosure is to provide a toner that can have excellent low-temperature fixability, heat-resistant storage stability, and releasability, as well as excellent durability. [Means for solving the problem]

[0010] According to one aspect of the present disclosure, there is provided a toner having toner particles containing a resin component and a wax, The resin component is a vinyl polymer A having a monomer unit A represented by the following formula (A): Only , the wax is composed solely of esters of hexahydric alcohol and aliphatic monocarboxylic acid, The wax contained in the toner particles includes a wax that forms a eutectic structure with the resin component and a single wax that does not form a eutectic structure, In observing the cross section of the toner particle with a scanning transmission electron microscope, a backscattered electron image of the cross section of the toner particle is obtained, and the brightness of each pixel constituting the backscattered electron image is calculated. In the darkest part Brightness 0 to The brightest part When the brightness is divided into 256 levels of 255 and a brightness histogram is obtained with the horizontal axis representing brightness and the vertical axis representing the number of pixels, Let C be the total number of pixels with brightness 0 to 9, and A be the total number of pixels with brightness 0 to 245. The C and the A satisfy the following formula (1), 0.00 2 ≦C / A≦0.250 (1) The luminance X represents the maximum number of pixels P in the range of luminance 10 to luminance 245 of the histogram, The luminance when the number of pixels falls below 20% of P for the first time from the luminance X to the luminance 245 is defined as luminance M, When the luminance at which the number of pixels falls below 20% of P for the first time from the luminance X to the luminance 10 is luminance N, The value of luminance M-luminance N is 120 to 235 A toner characterized by the above-mentioned is provided.

[0011] [ka] (In formula (A), R 1 represents H or CH3, and R 2 represents an alkyl group having 18 to 36 carbon atoms. [Effects of the Invention]

[0012] According to one aspect of the present disclosure, it is possible to provide a toner that can have excellent low-temperature fixability, heat-resistant storage stability, and releasability, as well as excellent durability. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is an example of a 256-level brightness histogram obtained from a cross-sectional image of a toner particle of Toner 1 in an embodiment of the present disclosure. [Figure 2] 1 is an example of a 256-level brightness histogram obtained from a cross-sectional image of a toner particle of toner 35 in an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

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

[0015] (Meth)acrylate means acrylate and / or methacrylate, and (meth)acrylic acid means acrylic acid and / or methacrylic acid.

[0016] A monomer unit is a unit that constitutes a polymer, and refers to the reacted form of a monomer (polymerizable monomer). For example, one section of carbon-carbon bond in the main chain of a polymer formed by polymerizing a vinyl monomer is one monomer unit. A vinyl monomer can be represented by the following formula (Z), and a vinyl monomer unit is a structural unit of a polymer, and is the reacted form of a monomer represented by the following formula (Z). A monomer unit may also be simply referred to as a "unit."

[0017] [ka] (In formula (Z), R Z1 represents a hydrogen atom or an alkyl group, and R Z2 represents an optional substituent.

[0018] A crystalline resin refers to a resin that shows a clear endothermic peak in a differential scanning calorimeter (DSC) measurement using the resin, toner particles, or toner as a measurement sample (differential scanning calorimeter measurement is also referred to as DSC measurement).

[0019] The eutectic state means a state in which microcrystals of two or more substances are mixed and crystallized.

[0020] <Background to the invention and the presumed mechanism by which the effects of the present disclosure are realized> The present inventors believe that the reason why the durability of the toner disclosed in Patent Document 1 needs to be further improved is as follows.

[0021] Toners containing a polymer having a monomer unit with a long-chain alkyl group as a resin component of the toner tend to exhibit excellent low-temperature fixability and heat-resistant storage stability. The inventors believe that this is because the polymer has long-chain alkyl groups in its side chains, which lead to a regular arrangement of the long-chain alkyl groups in the side chains, which tends to increase crystallinity. This is an advantageous characteristic in terms of reducing the amount of heat required in the fixing step in the electrophotographic image formation process.

[0022] However, it has been discovered that when wax is added to the toner to improve release properties, the durability of the toner may become insufficient. Specifically, it has been discovered that the toner may be prone to cracking and chipping. One possible reason for this is that the resin component and wax in the toner particles may be prone to crystallization independently, which may lead to the formation of wax domains with clear boundaries relative to the resin component.

[0023] When the brightness histogram of the cross section of the toner particle was examined, a low brightness peak corresponding to the wax and a high brightness peak corresponding to the crystalline vinyl resin having a monomer unit with a long-chain alkyl group were observed independently. An example of the brightness histogram is shown in Figure 2. In other words, it was found that the resin component and the wax each have a clear boundary and are contained in the toner particle in an independent state.

[0024] Therefore, the present inventors came up with the idea of ​​forming a eutectic mixture of the wax with the resin component to make it difficult for the peak corresponding to the resin component and the peak corresponding to the wax to become independent, and controlling the peak of the resin component to become broad in the brightness histogram of the cross section of the toner particle. This makes it difficult for the resin component and the wax to have a clear boundary between them, without impairing the releasability exhibited by the wax, and the present inventors believed that this would make it easier to obtain a toner with excellent durability.

[0025] As a result of investigations conducted by the present inventors based on the above considerations, it has been found that a toner having the above-mentioned constituent requirements can have excellent low-temperature fixing property, heat-resistant storage stability, and releasability, and is likely to be a toner that can also have excellent durability. Each of the constituent requirements will be described in detail below.

[0026] <Brightness histogram of a toner particle cross section> When the brightness histogram according to the present disclosure was obtained by scanning transmission electron microscope observation, The brightness that indicates the maximum number of pixels P in the range of brightness 10 to brightness 245 of the histogram is defined as brightness X. The luminance when the number of pixels falls below 20% of P for the first time from the luminance X to the luminance 245 is defined as luminance M, When the luminance at which the number of pixels falls below 20% of P for the first time from the luminance X to the luminance 10 is luminance N, The value of luminance M-luminance N is 120 to 235 The toner is characterized by the above.

[0027] Under the conditions for obtaining a cross-sectional image of a toner particle, described below, the portions where wax is present are dark in a dark-field image of the cross section of the toner particle, while the portions where the resin component is present are relatively bright. The brightness of each pixel constituting the cross-sectional image of the toner particle is divided into 256 gradations, from brightness 0 to brightness 255, to obtain a brightness histogram with the brightness on the horizontal axis and the number of pixels on the vertical axis. With the darkest portion being 0 and the brightest portion being 255, the brightness X is the brightness showing the maximum number of pixels P within the brightness range of 10 to 245 in the brightness histogram. The brightness X showing the maximum number of pixels P within the above range is the brightness at which the number of pixels is greatest among the brightnesses corresponding to the portion of the toner primarily composed of the resin component. Furthermore, as described below, when obtaining the brightness histogram of the present disclosure, an image obtained by setting brightness X to 150 was used. That is, it is preferable to obtain the brightness histogram by setting the brightness at which the number of pixels is greatest among the brightnesses corresponding to the portion primarily composed of the resin component to 150. Which luminance in the luminance histogram corresponds to the portion mainly composed of the resin component can be determined by observing the luminance histogram in relation to the cross-sectional image of the toner particle, since the portion occupying the largest area in the cross-sectional image of the toner particle generally corresponds to the resin component.

[0028] In addition, pixels with a brightness of 246 or higher are excluded because they may contain noise such as overexposure.

[0029] In the brightness histogram above, lower brightness is darker and higher brightness is brighter, so pixels with brightness 0 to 9 correspond to the single wax. Also, pixels with brightness 10 to 245 correspond to the resin component and the eutectic structure of the wax and the resin component. In the present disclosure, the single wax means a wax that has a clear boundary with the resin component.

[0030] Also, the luminance when the number of pixels falls below 20% of P for the first time from luminance X to luminance 245 is defined as luminance M. When the number of pixels falls below 20% of P for the first time from brightness X to brightness 10, the brightness is N. The value of luminance M-luminance N is 120-235.

[0031] The value of brightness M - brightness N indicates how broad the peak is, with the maximum value being the number of pixels P at brightness X, and it is believed that the larger this value, the more the eutectic structure of wax and resin component is contained in the toner particles. By containing this eutectic structure in the toner particles, it is believed that the resin component and wax do not have a clear boundary with each other without impairing the releasability of the toner, and it is believed that it becomes easier to obtain a toner with excellent durability.

[0032] That is, when the value of brightness M - brightness N is 120 or more, a toner having excellent releasability and durability is easily obtained. Therefore, it is 120 or more, and preferably 150 or more. There is no particular upper limit, but it is 235 or less, more preferably 200 or less, and even more preferably 180 or less.

[0033] If the value of luminance M - luminance N is 119 or less, the releasability or durability may be insufficient. Here, the reason why the value of luminance M - luminance N is small is thought to be the following (1) and / or (2). (1) In the toner particles, the wax is completely compatible with the resin component. (2) In the toner particles, the wax is contained in the resin component with a clear boundary.

[0034] In the above (1), a sharp peak corresponding to the state in which the wax and the resin component are compatible is observed in the brightness histogram. Because the wax and the resin component are compatible, there are fewer starting points for cracking and chipping of the toner, which is thought to be advantageous for durability. However, because the wax is compatible with the resin component, it is thought that the wax does not easily bleed onto the toner surface during fixing, which may lead to a decrease in releasability.

[0035] In the case of (2), as mentioned above, cracks and chips tend to occur in the toner, and the durability of the toner tends to decrease.

[0036] Methods for controlling the value of luminance M-luminance N within the above range include controlling the type and amount of wax added, and performing heat treatment to cause the wax and resin component to form a eutectic.

[0037] The heat treatment may involve first raising the temperature to a temperature at which both the wax and resin component are in a molten state, and then maintaining the temperature at which the wax preferentially crystallizes. That is, the temperature is maintained at a temperature lower than the melting point of the wax but higher than the melting point of the resin component. This allows the wax and resin component to crystallize under conditions favorable to the wax from a mixed state, which is thought to make it easier for the eutectic structure to be incorporated into the toner particles.

[0038] Furthermore, it was found that even without the above-mentioned heat treatment, the value of luminance M - luminance N may fall within a preferable range when a large amount of an ester wax having multiple long-chain alkyl groups and a branched structure, such as dipentaerythritol hexabehenate, is used.

[0039] In the above brightness histogram, when the total number of pixels in the brightness range of 0 to 9 is C and the total number of pixels in the brightness range of 0 to 245 is A, C and A satisfy the following formula (1). 0.000≦C / A≦0.250 (1)

[0040] As described above, in the brightness histogram, the total number of pixels with brightness levels of 0 to 9 corresponds to the single wax. Satisfying the above formula (1), i.e., the smaller the amount of single wax in the toner particles, the fewer the starting points for cracking and chipping of the toner, making it easier to obtain a toner with excellent durability. Preferably, the following formula (2) is satisfied, more preferably the following formula (3) is satisfied, and even more preferably the following formula (4) is satisfied. 0.000≦C / A≦0.100 (2) 0.000≦C / A≦0.080 (3) 0.000≦C / A≦0.040 (4)

[0041] <Resin component> The resin component is preferably a binder resin. That is, the toner has toner particles containing a binder resin and a wax, and the binder resin preferably contains a vinyl polymer A having a monomer unit A represented by the above formula (A).

[0042] <Vinyl Polymer A and Monomer Unit A> The vinyl polymer A has a monomer unit A represented by the following formula (A).

[0043] [ka] (In formula (A), R 1 represents H or CH3, and R 2 represents an alkyl group having 18 to 36 carbon atoms.

[0044] The vinyl polymer A has a monomer unit A having a long-chain alkyl group (an alkyl group having 18 to 36 carbon atoms) as a side chain of the vinyl polymer A, which tends to increase the crystallinity of the vinyl polymer A and makes it easier to obtain a toner having excellent low-temperature fixability and heat-resistant storage stability. Furthermore, the vinyl polymer A is preferably a crystalline resin that exhibits a clear endothermic peak in DSC measurement.

[0045] The monomer unit A can be incorporated as a monomer unit of the vinyl polymer A by vinyl polymerization of a (meth)acrylic acid ester having an alkyl group with 18 to 36 carbon atoms as a polymerizable monomer.

[0046] Examples of (meth)acrylic acid esters having an alkyl group having 18 to 36 carbon atoms include (meth)acrylic acid esters having a linear alkyl group having 18 to 36 carbon atoms [stearyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, heneicosanyl (meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate, ceryl (meth)acrylate, octacosyl (meth)acrylate, myricyl (meth)acrylate, doriaconta (meth)acrylate, etc.] and (meth)acrylic acid esters having a branched alkyl group having 18 to 36 carbon atoms [2-decyltetradecyl (meth)acrylate, etc.].

[0047] Among these, from the viewpoint of low-temperature fixability and heat-resistant storage stability of the toner, preferred are (meth)acrylic acid esters having a linear alkyl group with 18 to 36 carbon atoms, more preferred are (meth)acrylic acid esters having a linear alkyl group with 18 to 30 carbon atoms, and even more preferred are linear stearyl (meth)acrylate and behenyl (meth)acrylate. 2 is a linear alkyl group having 18 to 36 carbon atoms, more preferably a linear alkyl group having 18 to 30 carbon atoms, and even more preferably an alkyl group having 18 or 22 carbon atoms. 1 is preferably hydrogen.

[0048] The polymerizable monomer (hereinafter also referred to as monomer (a)) forming the monomer unit A and the monomer unit A may be used alone or in combination of two or more kinds.

[0049] Furthermore, the content of the monomer unit A in the vinyl polymer A is preferably 20.0 to 80.0% by mass. If the content is 20.0% by mass or more, a toner having excellent low-temperature fixability and heat-resistant storage stability is likely to be obtained. Therefore, it is preferably 20.0% by mass or more, more preferably 40.0% by mass or more, and more preferably 45.0% by mass or more. If the content is 80.0% by mass or less, a toner having appropriate elasticity is likely to be obtained. Therefore, it is preferably 80.0% by mass or less, more preferably 75.0% by mass or less, and even more preferably 60.0% by mass or less.

[0050] The content of the monomer unit A is the sum of the content of all the monomer units represented by the above formula (A). The same applies when a plurality of monomers (a) are present.

[0051] Furthermore, the content of vinyl polymer A in the resin component is preferably 30.0% by mass or more. When the content is 30.0% by mass or more, a toner having excellent low-temperature fixability and heat-resistant storage stability is easily obtained. Therefore, the content is preferably 30.0% by mass or more, more preferably 40.0% by mass or more, more preferably 60.0% by mass or more, and even more preferably 80.0% by mass or more. Even more preferably, the content is 100.0% by mass, i.e., the resin component is composed solely of vinyl polymer A. There is no particular upper limit, but it is 100.0% by mass.

[0052] The weight average molecular weight (Mw) of the vinyl polymer A is preferably 10,000 to 200,000. The Mw is more preferably 20,000 to 150,000, and even more preferably 40,000 to 70,000. Having the Mw within the above range is preferable because it makes it easier to appropriately control the elasticity of the toner.

[0053] From the viewpoint of low-temperature fixability, the melting point of the vinyl polymer A is preferably 50 to 80°C.

[0054] <Other monomer units> From the viewpoint of appropriately controlling the physical properties of the toner, the vinyl polymer A preferably has a monomer unit other than the monomer unit A described above.

[0055] The vinyl polymer A having other monomer units can be incorporated as monomer units of the vinyl polymer A by vinyl polymerization of the corresponding polymerizable monomer (hereinafter also referred to as other monomer).

[0056] Examples of the other monomers include the following monomers, and one type may be used alone, or two or more types may be used in combination. Monomers containing nitrile groups, such as acrylonitrile and methacrylonitrile. Monomers having a hydroxy group; for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, etc. Monomers having an amide group; for example, acrylamide, a monomer obtained by reacting an amine having 1 to 30 carbon atoms with a carboxylic acid having 2 to 30 carbon atoms and an ethylenically unsaturated bond (acrylic acid, methacrylic acid, etc.). Monomers having a urethane group: For example, alcohols having 2 to 22 carbon atoms with an ethylenically unsaturated bond (e.g., 2-hydroxyethyl methacrylate, vinyl alcohol, etc.) and isocyanates having 1 to 30 carbon atoms [monoisocyanate compounds (e.g., benzenesulfonyl isocyanate, tosyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, butyl isocyanate, hexyl isocyanate, t-butyl isocyanate, cyclohexyl isocyanate, isocyanate, octyl isocyanate, 2-ethylhexyl isocyanate, dodecyl isocyanate, adamantyl isocyanate, 2,6-dimethylphenyl isocyanate, 3,5-dimethylphenyl isocyanate, and 2,6-dipropylphenyl isocyanate, etc.), aliphatic diisocyanate compounds (trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propyl Diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate, etc.), alicyclic diisocyanate compounds (1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated trimethylsilane diisocyanate, diisocyanate and hydrogenated tetramethylxylylene diisocyanate, etc.), and aromatic diisocyanate compounds (phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, etc.), and alcohols having 1 to 26 carbon atoms (methanol, ethanol, propanol, isopropyl alcohol, butanol, t-butyl alcohol, pentanol, heptanol, octanol, 2-ethylhexanol, nonanol, decanol, undecyl alcohol, lauryl alcohol, dodecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetanol, heptadecanol, stearyl alcohol, isostearyl alcohol, elaidyl alcohol, oleic acid, and monomers obtained by reacting an isocyanate having 2 to 30 carbon atoms and an ethylenically unsaturated bond (e.g., 2-isocyanatoethyl (meth)acrylate, 2-(0-[1'-methylpropylideneamino]carboxyamino)ethyl (meth)acrylate, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl (meth)acrylate, and 1,1-(bis(meth)acryloyloxymethyl)ethyl isocyanate, etc.). Monomers having a urea group: for example, monomers obtained by reacting an amine having 3 to 22 carbon atoms [primary amines (normal butylamine, t-butylamine, propylamine, isopropylamine, etc.), secondary amines (di-normal ethylamine, di-normal propylamine, di-normal butylamine, etc.), aniline, cycloxylamine, etc.] with an isocyanate having 2 to 30 carbon atoms and an ethylenically unsaturated bond. Vinyl esters: for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl pivalate, vinyl octylate Monomers containing a carboxy group; for example, methacrylic acid, acrylic acid, 2-carboxyethyl (meth)acrylate. (Meth)acrylic acid esters: methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc. Styrene-based monomers: styrene, α-methylstyrene, etc.

[0057] Among the above, monomers having a nitrile group are preferred. By using these, the melting point can be easily controlled without excessively lowering the crystallinity of the vinyl polymer A, and a toner having excellent low-temperature fixability and heat-resistant storage stability can be easily obtained. In addition, the use of ethyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, or styrene is preferred because it makes it easy to appropriately control the elasticity of the toner.

[0058] <Resins other than vinyl polymer A> In addition to the vinyl polymer A, materials that can be used as the resin component of the toner include vinyl resins, polyesters, polyurethanes, epoxy resins, etc. that do not fall under the category of the vinyl polymer A. Among these, vinyl resins, polyesters, and polyurethanes that do not fall under the category of the vinyl polymer A are preferred from the viewpoint of electrophotographic properties.

[0059] Examples of the monomer constituting the vinyl resin that does not fall under the category of vinyl polymer A include the above-mentioned monomers other than monomer (a). Two or more types may be used in combination, if necessary.

[0060] Polyesters can be obtained by a polycondensation reaction between a divalent or higher polycarboxylic acid and a polyhydric alcohol.

[0061] Examples of polycarboxylic acids include the following compounds:

[0062] Dibasic acids such as succinic acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, malonic acid, and dodecenylsuccinic acid, and their anhydrides or lower alkyl esters, and aliphatic unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, and citraconic acid. 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, and their anhydrides or lower alkyl esters. These may be used alone or in combination of two or more.

[0063] Examples of polyhydric alcohols include the following compounds:

[0064] Alkylene glycols (ethylene glycol, 1,2-propylene glycol, and 1,3-propylene glycol); alkylene ether glycols (polyethylene glycol and polypropylene glycol); alicyclic diols (1,4-cyclohexanedimethanol); bisphenols (bisphenol A); and alkylene oxide (ethylene oxide and propylene oxide) adducts of alicyclic diols. The alkyl moieties of the alkylene glycols and alkylene ether glycols may be linear or branched. In the present disclosure, branched alkylene glycols are also preferably used. Further examples include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These may be used alone or in combination of two or more.

[0065] For the purpose of adjusting the acid value or hydroxyl value, monovalent acids such as acetic acid and benzoic acid, and monovalent alcohols such as cyclohexanol and benzyl alcohol can also be used as needed.

[0066] The method for producing the polyester is not particularly limited, but examples thereof include transesterification and direct polycondensation.

[0067] Polyurethane is obtained by the reaction of a diol component and a diisocyanate component.

[0068] Examples of diisocyanate components include the following: aromatic diisocyanates having 6 to 20 carbon atoms (excluding carbon atoms in NCO groups, the same applies below), aliphatic diisocyanates having 2 to 18 carbon atoms, alicyclic diisocyanates having 4 to 15 carbon atoms, modified products of these diisocyanates (modified products containing a urethane group, a carbodiimide group, an allophanate group, a urea group, a biuret group, a uretdione group, a uretoimine group, an isocyanurate group, or an oxazolidone group; hereinafter, also referred to as "modified diisocyanates"), and mixtures of two or more of these.

[0069] Aromatic diisocyanates include m- and / or p-xylylene diisocyanate (XDI) and α,α,α',α'-tetramethylxylylene diisocyanate.

[0070] Additionally, examples of aliphatic diisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), and dodecamethylene diisocyanate.

[0071] Examples of alicyclic diisocyanates include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate, cyclohexylene diisocyanate, and methylcyclohexylene diisocyanate.

[0072] Among these, aromatic diisocyanates having 6 to 15 carbon atoms, aliphatic diisocyanates having 4 to 12 carbon atoms, and alicyclic diisocyanates having 4 to 15 carbon atoms are preferred, and XDI, IPDI, and HDI are particularly preferred.

[0073] In addition to the diisocyanate component, a tri- or higher isocyanate compound can also be used.

[0074] As the diol component that can be used in the polyurethane, the same dihydric alcohols that can be used in the polyester described above can be used.

[0075] <Wax> The wax contained in the toner particles is preferably an ester wax, and one type of ester wax may be used alone, or two or more types may be used in combination.

[0076] The ester wax in the present disclosure 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.

[0077] The ester wax is not particularly limited, but examples thereof include the following:

[0078] 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; The ester wax is preferably an ester of an alcohol and an aliphatic monocarboxylic acid. 2is the number of carbon atoms in the linear alkyl group represented by the formula (1) and Wc is the average number of carbon atoms in the linear alkyl groups contained in the ester wax, it is preferable that the following formula (5) is satisfied. |Ac-Wc|≦6.0 (5) In the present disclosure, straight chain alkyl groups do not include alkylene or branched alkyl groups.

[0079] By satisfying the above formula (5), it is believed that the ester wax and the vinyl polymer A are likely to form a eutectic, making it easier to obtain a toner with excellent releasability and durability. The reason why the ester wax and the vinyl polymer A are likely to form a eutectic is that the lengths of the linear alkyl chains of the vinyl polymer A and the wax are similar, making it easy to form a stable crystal structure not only when they are completely separated and crystallized independently, but also when they are entangled. The present inventors believe that this makes it easier for the ester wax and the vinyl polymer A to form a eutectic. More preferably, |Ac-Wc|≦4.0, and even more preferably, |Ac-Wc|≦2.0.

[0080] R in monomer unit A 2 When there are multiple types of linear alkyl groups represented by the formula: 2 is the number of carbon atoms, n a (Meth)acrylic acid ester having a straight chain alkyl group of X a Mass% and carbon number m a (Meth)acrylic acid ester, which is an alkyl group of Y a When contained in mass %, the above Ac is calculated by the following formula (6). Ac=(n a X a +m a Y a ) / 100 (6)

[0081] When multiple types of ester waxes are present, the value of |Ac-Wc| is calculated using the calculated Ac and the Wc of each ester wax, and it is determined for each ester wax whether the value of |Ac-Wc| is within the above range. That is, it is preferable to contain an ester wax whose value of |Ac-Wc| is within the above range. Alternatively, an ester wax whose value of |Ac-Wc| is not within the above range may be contained.

[0082] In the present disclosure, the ester wax is preferably an ester of a trivalent or higher alcohol and an aliphatic monocarboxylic acid, more preferably an ester of a tetravalent or higher alcohol and an aliphatic monocarboxylic acid, and even more preferably an ester of a hexavalent or higher alcohol and an aliphatic monocarboxylic acid.

[0083] The valence of the trihydric or higher alcohol corresponds to the number of branched structures of the ester wax. By using a wax with a branched structure, the vinyl polymer A and the wax tend to form a eutectic, which tends to improve durability and releasability. The reason for this tendency is that the wax is branched, and the R 1 possessed by the monomer unit A in the vinyl polymer A is easily dispersed in the gaps between the wax crystals. 2 It is thought that this makes it easier for R 2 It is thought that when the wax penetrates into the gaps between the wax, the wax in the toner particles tends to form a mesh-like structure, making the boundary between the wax and the resin component less clear and less likely to become a starting point for cracking and chipping of the toner.

[0084] The wax contained in the toner particles preferably further contains a hydrocarbon wax. The hydrocarbon wax may be used alone or in combination of two or more kinds.

[0085] The hydrocarbon wax is not particularly limited, but examples thereof include the following:

[0086] 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.

[0087] The ratio of the mass of wax to the mass of the resin component is preferably 1.0 to 25.0% by mass. When the ratio is 1.0% by mass or more, a toner with excellent releasability is easily obtained. Therefore, it is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, and even more preferably 5.0% by mass or more. Furthermore, when the ratio is 25.0% by mass or less, the amount of a single wax in the toner particles is unlikely to become excessive, and cracking and chipping of the toner are unlikely to occur. Therefore, it is preferably 25.0% by mass or less, more preferably 20.0% by mass or less, and even more preferably 15.0% by mass or less. When multiple types of wax are contained in the toner particles, the total mass of those waxes is used for calculation.

[0088] The molecular weight of the wax is preferably 1000 to 3000. If the molecular weight of the wax is 1000 or more, it is thought that the compatibility between the vinyl polymer A and the wax becomes poor, and a toner having excellent low-temperature fixability, heat-resistant storage stability, and releasability is easily obtained. Therefore, the molecular weight is preferably 1000 or more, and more preferably 1500 or more. Furthermore, if the molecular weight is 3000 or less, the releasability of the toner is easily maintained appropriately. Therefore, the molecular weight is preferably 3000 or less, and more preferably 2500 or less.

[0089] The melting point of the wax is preferably higher than the melting point of the vinyl polymer A contained in the toner. This is preferable because controlling the melting point as described above and carrying out the heat treatment described later in the toner production process makes it easier to obtain a toner that satisfies the above-mentioned range of values ​​of luminance M - luminance N.

[0090] The melting point of the wax is more preferably 60 to 120° C. It is believed that when the wax has a melting point in this range, it melts and easily seeps out onto the toner particle surface during fixing. A melting point of 70 to 100° C. is more preferable.

[0091] <Core-shell structure> The toner of the present disclosure may have a core having a resin component and a wax, and a shell phase that covers the core.

[0092] The resin that forms the shell phase can be any of the resins described above as resins that can be used as the resin component other than the vinyl polymer A. Among these, vinyl resins and polyesters are preferred from the viewpoint of charging stability.

[0093] <Various additives> If necessary, the toner may contain one or more additives selected from colorants, magnetic materials, charge control agents, fluidizing agents, etc. Various additives used in the toner will be specifically described below.

[0094] <Coloring agent> The coloring agents include the following:

[0095] Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.Specifically, CI Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 155, 168, and 180 are preferably used.

[0096] Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds.Specific examples of suitable magenta colorants include CI Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254.

[0097] Examples of cyan colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds. Specifically, CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66 are preferably used.

[0098] The colorant used in the toner of the present disclosure is selected in consideration of hue angle, chroma, brightness, lightfastness, OHP transparency, and dispersibility in toner particles.

[0099] When the colorant is not magnetic particles, the colorant is preferably contained in an amount of 1.0 to 20.0 parts by mass relative to 100.0 parts by mass of the resin component. When magnetic particles are used as the colorant, the amount added is preferably 40.0 parts by mass or more and 150.0 parts by mass or less relative to 100.0 parts by mass of the resin component.

[0100] <Charge control agent> The charge control agent can be used without any particular limitation.

[0101] Examples of negative charge control agents include the following:

[0102] Monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acid and dicarboxylic acid based metal compounds.

[0103] Examples of the positive charge control agent include quaternary ammonium salts, polymeric compounds having quaternary ammonium salts in the side chains; guanidine compounds; pyridine compounds; nigrosine compounds; and imidazole compounds.

[0104] The charge control agent is preferably contained in an amount of 0.01 to 20.0 parts by mass, more preferably 0.5 to 10.0 parts by mass, relative to 100.0 parts by mass of toner particles.

[0105] <External additives> Examples of external additives include the following:

[0106] Inorganic fine particles selected from the group consisting of silica fine particles, alumina fine particles, and titania fine particles, or composite oxides thereof, etc. Examples of composite oxides include silica aluminum fine particles and strontium titanate fine particles.

[0107] The amount of the external additive contained is preferably 0.01 to 8.0 parts by mass, and more preferably 0.1 to 4.0 parts by mass, relative to 100 parts by mass of the toner particles.

[0108] <Toner manufacturing method> The toner and toner particles may be produced by any method, including, but not limited to, a pulverization method, a suspension polymerization method, an emulsion aggregation method, a solution suspension method, etc. Among the above, the suspension polymerization method is preferred.

[0109] In order to satisfy the above-mentioned range of the brightness M-brightness N value, it is preferable to control the contents of the vinyl polymer A and the wax and heat-treat the toner particles for 30 minutes or more at a temperature between the melting points of the vinyl polymer A and the wax.

[0110] That is, the method for producing a toner according to the present disclosure is A step of obtaining toner base particles containing wax and a resin component; and When the melting point of the wax is TmW and the melting point of the vinyl-based polymer A is TmA, a step of obtaining toner particles by performing heat treatment on the toner mother particles for 30 minutes or more in the temperature range of TmA to TmW. It is preferable that it is a method for producing a toner characterized by having this.

[0111] In order to easily satisfy the above range of the value of luminance M - luminance N, the content ratio of the vinyl-based polymer A in the resin component is preferably 30.0% by mass or more, and the content ratio of the wax with respect to the mass of the resin component is preferably 1.0 to 25.0% by mass.

[0112] Also, since it is considered that the wax crystallizes preferentially rather than the vinyl-based polymer A when the temperature for performing the heat treatment is in the range of TmA to TmW, the eutectic structure of the wax and the vinyl-based polymer A is likely to be contained in the toner particles, and the value of luminance M - luminance N is likely to increase, which is preferable. Also, it is preferable that TmA < TmW.

[0113] Also, it is preferable to set the temperature of the toner particles to TmW or more before the above heat treatment step. Thereby, the vinyl-based polymer A and the wax contained in the toner particles are likely to be in a molten state, and by performing the above heat treatment step thereafter, crystallization proceeds under favorable conditions for the wax from the state where both are mixed, and it is considered that an eutectic structure is likely to be formed.

[0114] Also, when the time for performing the above heat treatment is 30 minutes or more, it is considered that the wax contained in the toner particles is likely to be preferentially and sufficiently crystallized. Therefore, it is preferably 30 minutes or more, more preferably 1 hour or more, and even more preferably 2.5 hours or more. The upper limit is not particularly limited, but it is preferably 5 hours or less.

[0115] <Step of obtaining toner particles> The step of obtaining the toner particles is preferably a step of obtaining toner particles by a suspension polymerization method. In producing toner particles by the suspension polymerization method, a polymerizable monomer composition containing a polymerizable monomer, a wax, and optionally a colorant, etc. is added to an aqueous medium, and the polymerizable monomer composition is granulated in the aqueous medium to form particles of the polymerizable monomer composition. Then, the polymerizable monomer contained in the particles of the polymerizable monomer composition is polymerized to produce a resin component, thereby obtaining toner particles.

[0116] The step of obtaining the toner particles may also be a step of obtaining toner particles by a pulverization method. In producing toner particles by the pulverization method, first, toner components such as a resin material containing vinyl polymer A, wax, and, if necessary, a colorant, are mixed. These are thoroughly mixed using a mixer such as a Henschel mixer or a ball mill. Next, the mixture is melted using a thermal mixer such as a roll, kneader, or extruder. The mixture is further kneaded and mixed to make the resin and other components compatible with each other, and various materials are dispersed in the mixture. After cooling and solidifying, the mixture is pulverized and classified to obtain toner particles.

[0117] The above-mentioned process for obtaining toner particles may be a process for obtaining toner particles by emulsion aggregation. In the production of toner particles by emulsion aggregation, an aqueous dispersion of a resin material containing vinyl polymer A, a wax, and, if necessary, a colorant, etc. is prepared (aqueous dispersion process), and after mixing, the mixture is aggregated to a desired particle size using a metal salt or the like (aggregation process). The obtained aggregates are heated to fuse (heat fusion process), and then cooled and washed and dried to obtain toner particles.

[0118] The step of obtaining the toner particles may be a step of obtaining toner particles by a solution suspension method. In preparing toner particles by the solution suspension method, first, a resin material containing vinyl polymer A, wax, and, if necessary, a colorant, etc., are dissolved or dispersed in an organic solvent (resin dissolution step). The resulting solution or dispersion is then dispersed in a poor solvent such as water to obtain granules (droplets) of approximately the size of the toner particles (granulation step). The organic solvent contained in the obtained granules is removed by distillation (solvent removal step), followed by washing and drying (washing and drying step), thereby obtaining toner particles.

[0119] <Various measurement methods, etc.> Various measurement methods will be described below.

[0120] <Acquisition of cross-sectional images of toner particles using a scanning transmission electron microscope (STEM)> The state of wax in the toner particles is confirmed by observing the cross section of the toner particles using a scanning transmission electron microscope. The cross section of the toner particles is observed after ruthenium staining. That is, the cross section image of the toner particles according to the present disclosure is preferably a cross section image of the toner particles stained with ruthenium.

[0121] The procedure for observing the cross section of the toner is as follows.

[0122] The toner is dispersed as much as possible, and the sample is embedded in a visible light curable resin (D-800, manufactured by Nissin EM Co., Ltd.), and cut to a thickness of 100 nm using an ultrasonic ultramicrotome (UC7, manufactured by Leica).

[0123] The obtained thin section sample was stained for 15 minutes in a 500 Pa RuO4 gas atmosphere using a vacuum staining apparatus (VSC4R1H, Filgen), and STEM images were acquired using a scanning transmission electron microscope (JEM2800, JEOL). Under the above staining conditions, differences in the degree of staining occur between the crystallized wax and the resin, allowing the presence of the wax to be confirmed by the contrast difference. Observation conditions were set to an acceleration voltage of 200 kV, a STEM probe size of 1 nm, an image size of 1024 × 1024 pixels, and a magnification of 30,000, and dark-field (STEM-DF) images were acquired. Contrast and brightness were adjusted so that the brightness of the area containing the resin component, which has the maximum number of pixels, was 150 in the brightness histogram shown below by IMAGE J. Furthermore, the brightness of the wax in the cross section of the toner particle was adjusted to 0.

[0124] In this case, when selecting toner particles for which a cross-sectional image is to be obtained, the weight-average particle diameter (D4) of the toner is measured by the measurement method described later, and then 10 toner particles having a major axis diameter 0.8 to 1.1 times the D4 are arbitrarily selected. In addition, the image is obtained so that two or more toner particles do not fit within the field of view of one image.

[0125] <Brightness histogram and physical properties calculated from the histogram> The brightness histogram is obtained by analyzing the STEM image of the toner particle cross section obtained by the above method using image processing software Image J (developed by Wayne Rashand). That is, the brightness histogram is preferably a brightness histogram obtained when a 256-level brightness spectrum is measured for the image obtained by image analysis of the toner particle cross section. The specific procedure is shown below.

[0126] First, convert the backscattered electron image to be analyzed to 8-bit using Type in the Image menu.

[0127] Next, the analysis range is specified to be only the area inside the toner outline. Here, the boundary of the toner outline is the interface between the visible light curable resin and the toner cross section. Clear the area outside the analysis range by selecting Clear Outside from the Edit menu.

[0128] From the Filters menu in the Process menu, set the Median diameter to 2.0 pixels to reduce image noise.

[0129] Next, select Histogram from the Analyze menu to display the brightness histogram in a new window. Also, obtain the brightness histogram values ​​from the List in that window. Using the obtained values, calculate the following values: - The range of brightness values ​​with a number of pixels that is 20% or more of the number of pixels at brightness P, between brightness 10 and 245 The total number of pixels C with brightness 0-9, and the total number of pixels A with brightness 0-245 If the brightness X, where the maximum number of pixels P in the brightness range of 10 to 245 is between 140 and 160 in the acquired histogram, is between 140 and 160, you can adjust the brightness of the STEM image using the video editing software Microsoft Photo (Microsoft Corporation). In this case, first erase the STEM image except for the analysis range using IMAGE J, then open it in the video editing software Microsoft Photo. Select Edit from the Edit and Create menu, and move the light cursor on the adjustment screen to adjust the brightness so that brightness X is 150.

[0130] After adjusting the brightness, open the STEM image again in IMAGE J, select the area inside the toner outline as the analysis range, and obtain a brightness histogram. Obtain the brightness histogram values ​​from the list of the obtained brightness histogram.

[0131] If the brightness P is not within the range of 140 or more and less than 160, it is necessary to acquire a STEM image again so that the brightness P becomes 150.

[0132] The same image analysis is performed on 10 STEM images of each toner, and the above values ​​are calculated. The average of the obtained values ​​for the 10 images is taken as the physical property value of each toner.

[0133] <Method for measuring the content of various monomer units in a resin> The content ratio of various monomer units in the resin is measured as follows: 1 H-NMR was performed under the following conditions. Measuring device: FT NMR device JNM-EX400 (manufactured by JEOL Ltd.) Measurement frequency: 400MHz Pulse condition: 5.0 μs Frequency range: 10500Hz Accumulation count: 64 times Measurement temperature: 30℃ Sample: 50 mg of the measurement sample is placed in a sample tube with an inner diameter of 5 mm, deuterated chloroform (CDCl3) is added as a solvent, and the sample is dissolved in a thermostatic bath at 40°C.

[0134] obtained 1 The H-NMR chart is analyzed to identify the structure of each monomer unit. Here, as an example, the measurement of the content ratio of monomer unit A in vinyl polymer A is described. 1 In the H-NMR chart, a peak that is independent of the peaks attributable to the constituent elements of the monomer unit A is selected from the peaks attributable to the constituent elements of the other monomer units, and the integral value S1 of this peak is calculated. The integral values ​​of the other monomer units contained in the vinyl polymer A are also calculated in the same manner.

[0135] When the monomer units constituting the vinyl polymer A are the monomer unit A and one other monomer unit, the content of the monomer unit A is determined as follows using the above-mentioned integral value S1 and the integral value S2 of the peak of the other monomer unit: where n1 and n2 are the numbers of hydrogen atoms in the constituent elements to which the peak of interest for each site belongs.

[0136] Content of monomer unit A (mol%)= {(S1 / n1) / ((S1 / n1)+(S2 / n2))}×100 Even when two or more other monomer units are present, the content of the monomer unit A can be calculated in the same manner.

[0137] In addition, when a polymerizable monomer that does not contain a hydrogen atom in any component other than the vinyl group is used, 13 Measured nuclei using C-NMR 13 C, and measurements were taken in single pulse mode. 1 Calculate in the same manner by H-NMR.

[0138] The proportion (mol %) of each unit calculated by the above method is multiplied by the molecular weight of each unit to convert the content of each unit into mass %.

[0139] Furthermore, when NMR is measured using a toner sample, the peaks of wax and resins other than vinyl polymer A may overlap, making it impossible to observe independent peaks. This may make it impossible to calculate the content of each unit in vinyl polymer A. In such cases, vinyl polymer A' can be produced by carrying out the same production process without using wax or other resins, and this can be analyzed as vinyl polymer A.

[0140] <Method for measuring the weight average molecular weight (Mw) of a resin> The weight average molecular weight (Mw) of the resin is measured by gel permeation chromatography (GPC) as follows.

[0141] First, the sample is dissolved in tetrahydrofuran (THF) at room temperature for 24 hours. 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 for measurements under the following conditions. Apparatus: HLC8120 GPC (detector: RI) (Tosoh Corporation) Column: Shodex KF-801, 802, 803, 804, 805, 806, 807 (7 columns, manufactured by Showa Denko Co., Ltd.) Eluent: tetrahydrofuran (THF) Flow rate: 1.0mL / min Oven temperature: 40.0℃ Sample injection volume: 0.10 mL

[0142] 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.

[0143] <Wax molecular weight measurement> The molecular weight of the release agent is measured by gel permeation chromatography (GPC) as follows: Special grade 2,6-di-t-butyl-4-methylphenol (BHT) is added to o-dichlorobenzene for gel chromatography to a concentration of 0.10 mass / volume % and dissolved at room temperature.

[0144] The release agent and the o-dichlorobenzene with added BHT are placed in a sample bottle and heated on a hot plate set to 150°C to dissolve the release agent. Once the release agent has dissolved, it is placed in a preheated filter unit and installed in the main unit. The sample that passes through the filter unit is used as the GPC sample. The sample solution is adjusted to a concentration of 0.15% by mass. This sample solution is used for measurement under the following conditions. Equipment: HLC-8121GPC / HT (Tosoh Corporation) Detector: High temperature RI Column: TSKgel GMHHR-H HT 2-series (Tosoh Corporation) ·Temperature: 135.0℃ Solvent: o-dichlorobenzene for gel chromatography (with 0.10% BHT by mass / volume added) ·Flow rate: 1.0mL / min ·Injection volume: 0.4mL

[0145] In calculating the molecular weight of the release agent, 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.

[0146] <Method for measuring melting point> The melting point is measured using a DSC Q1000 (manufactured by TA Instruments) under the following conditions.

[0147] Heating rate: 10°C / min Measurement start temperature: 20℃ Measurement end temperature: 180℃ 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.

[0148] Specifically, 5 mg of sample is precisely weighed and placed in an aluminum pan for differential scanning calorimetry, with an empty silver pan used as a reference.

[0149] The peak temperature of the maximum endothermic peak in the first heating process is taken as the melting point.

[0150] The maximum endothermic peak is the peak with the largest amount of endothermic heat when there are multiple peaks.

[0151] <Measurement of weight average particle size (D4) of toner> The weight-average particle size (D4) of the toner is calculated as follows. The measurement device used is a precision particle size distribution measurement device using the narrow-pore electrical resistance method, the Coulter Counter Multisizer 3 (registered trademark, manufactured by Beckman Coulter, Inc.), equipped with a 100 μm aperture tube. The measurement conditions are set and the measurement data is analyzed using the accompanying dedicated software, the Beckman Coulter Multisizer 3 Version 3.51 (manufactured by Beckman Coulter, Inc.). The measurement is performed using an effective number of measurement channels of 25,000.

[0152] The aqueous electrolyte solution used for the measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of 1.0%, for example, "ISOTON II" (manufactured by Beckman Coulter, Inc.).

[0153] Before performing measurements and analysis, the dedicated software is set up as follows.

[0154] On the "Change Standard Measurement Method (SOMME)" 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 to the value obtained using "Standard Particles 10.0 μm" (Beckman Coulter, Inc.). Press the "Threshold / Noise Level Measurement Button" to automatically set the threshold and noise level. Also, set the current to 1,600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flush aperture tube after measurement."

[0155] On 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 from 2 μm to 60 μm.

[0156] The specific measurement method is as follows. (1) Pour 200.0 mL of 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 Tube Flush" function of the dedicated software to remove any dirt and air bubbles from inside the aperture tube. (2) 30.0 mL of the electrolyte solution is placed in a 100 mL flat-bottom glass beaker. 0.3 mL of a diluted solution of "Contaminon N" (a 10% aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) diluted three times by mass with ion-exchanged water is added as a dispersant. (3) Prepare an ultrasonic disperser "Ultrasonic Dispersion System Tetra150" (manufactured by Nikkaki Bios Co., Ltd.) with an electrical output of 120 W and two built-in oscillators with an oscillation frequency of 50 kHz and a phase shift of 180 degrees. Place 3.3 L of ion-exchanged water in the ultrasonic disperser's water tank and add 2.0 mL of Contaminon N to this water tank. (4) Set the beaker (2) in the beaker fixing hole of the ultrasonic disperser, operate the ultrasonic disperser, and adjust the height of the beaker so that the resonance state of the liquid surface of the electrolytic solution in the beaker is maximized. (5) While the electrolyte solution in the beaker in (4) is being irradiated with ultrasonic waves, 10 mg of toner particles are 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 process, the water temperature in the water tank is appropriately adjusted to be between 10°C and 40°C. (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. (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). [Example]

[0157] The present disclosure will be specifically described below with reference to examples, but these examples are not intended to limit the present disclosure in any way. In the following formulations, parts are by mass unless otherwise specified. Moreover, Examples 7 to 9 and 24 to 30 are reference examples.

[0158] The respective measurement results in the examples were measured by the measurement methods described above. The 50% particle size (D50) based on the volume distribution of the dispersion was measured using a dynamic light scattering particle size distribution analyzer Nanotrac UPA-EX150 (manufactured by Nikkiso).

[0159] <Shell resin manufacturing example> The following materials were placed in an autoclave equipped with a pressure reducing device, a water separating device, a nitrogen gas introducing device, a temperature measuring device, and a stirring device. Terephthalic acid 32.3 parts by mass (50.0 mol%) Bisphenol A-propylene oxide 2 mole adduct 67.7 parts by mass (50.0 mole%) Potassium titanium oxalate 0.02 parts A reaction was carried out under a nitrogen atmosphere at normal pressure at 220°C for 8 hours to obtain a shell resin, which was an amorphous polyester. The weight average molecular weight (hereinafter also referred to as Mw) and glass transition temperature (Tg) of the obtained shell resin were measured, and Mw was 20,000 and Tg was 70°C.

[0160] <Wax used in toner production> Table 1 shows the types and properties of the waxes used in the production of the toner.

[0161] [Table 1]

[0162] <Toner 1 manufacturing example> [Toner production by suspension polymerization method] (Preparation of Toner Particles 1) The following materials were charged into an attritor (manufactured by Nippon Coke Company). Methacrylonitrile (monomer (b)) 25.0 parts Styrene (monomer (c)) 10.0 parts Ethyl methacrylate (monomer (d)) 15.0 parts Colorant: Pigment Blue 15:3 6.5 parts The raw material dispersion was obtained by dispersing the mixture using zirconia beads having a diameter of 5 mm at 200 rpm for 2 hours.

[0163] Separately, 735.0 parts of ion-exchanged water and 16.0 parts of trisodium phosphate dodecahydrate were placed in a vessel equipped with a high-speed homogenizer (Primix Corporation) and a thermometer, and the mixture was heated to 60°C while stirring at 12,000 rpm. Next, an aqueous calcium chloride solution prepared by dissolving 9.0 parts of calcium chloride dihydrate in 65.0 parts of ion-exchanged water was placed in the vessel, and the mixture was stirred at 12,000 rpm for 30 minutes while maintaining the temperature at 60°C. 10% hydrochloric acid was added to the mixture to adjust the pH to 6.0, yielding an aqueous medium in which a dispersion stabilizer containing hydroxyapatite was dispersed in water.

[0164] Subsequently, the raw material dispersion liquid was transferred to a container equipped with a stirrer and a thermometer, and the temperature was raised to 60° C. while stirring at 100 rpm. The following materials were then added thereto. Behenyl acrylate (monomer (a)) 50.0 parts Shell resin 4.0 parts 9.0 parts wax After stirring at 100 rpm for 30 minutes while maintaining the temperature at 60°C, 5.0 parts of t-butyl peroxypivalate (Perbutyl PV, manufactured by NOF Corporation) was added as a polymerization initiator and stirred for another minute, and then the mixture was poured into the aqueous medium being stirred at 12,000 rpm with the high-speed stirrer described above. Stirring was continued at 12,000 rpm with the high-speed stirrer described above for 20 minutes while maintaining the temperature at 60°C, to obtain a granulation liquid.

[0165] The granulation liquid was transferred to a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube, and heated to 70° C. while stirring at 150 rpm under a nitrogen atmosphere. A polymerization reaction was carried out at 150 rpm for 12 hours while maintaining the temperature at 70° C., thereby obtaining a toner particle dispersion.

[0166] The resulting toner particle dispersion was heated to 95°C and stirred at 150 rpm for 1 hour while maintaining the temperature at 95°C. Then, the mixture was cooled to 70°C while stirring, and heat-treated for 3 hours while maintaining the temperature at 70°C. After the heat treatment, the mixture was cooled to 30°C, and diluted hydrochloric acid was added while maintaining the stirring until the pH reached 1.5, dissolving the dispersion stabilizer. The solids were then filtered, thoroughly washed with ion-exchanged water, and vacuum-dried at 30°C for 24 hours to obtain toner particles 1 containing polymer A1.

[0167] To 100.0 parts of toner particles 1, 2.0 parts of silica fine particles (hydrophobized with hexamethyldisilazane, number-average particle size of primary particles: 10 nm) were added as an external additive, and mixed for 15 minutes at 3000 rpm using an FM mixer (manufactured by Nippon Coke & Engineering Co., Ltd.) to obtain toner 1. Figure 1 shows one of ten 256-level brightness histograms obtained from STEM images of the cross section of the obtained toner 1. In Figure 1, the brightness X was 150, P was 7336, brightness M was 215, and brightness N was 30. The physical properties of toner 1 are also shown in Tables 5 and 6.

[0168] <Production examples of toners 2-20, 27-38> Toners 2 to 20 and 27 to 38 were obtained by carrying out the same operations as in the production example of Toner 1, except that the type and amount of monomer used were changed as shown in Table 2, and the type and amount of wax added, and the temperature and time of heat treatment were changed as shown in Table 3. The physical properties of Toners 2 to 20 and 27 to 38 are shown in Tables 5 and 6.

[0169] Furthermore, one of ten 256-level brightness histograms obtained from STEM images of the cross section of the obtained toner 35 is shown in Figure 2. In Figure 2, the brightness X was 150, P was 15,709 particles, brightness M was 179, and brightness N was 120.

[0170] [Table 2]

[0171] The abbreviations in Table 2 are as follows: BEA: Behenyl acrylate STA: stearyl acrylate OCA: Octacosa acrylate MYA: Myristyl acrylate CEA: Cetyl acrylate MN: methacrylonitrile VA: vinyl acetate St: styrene VBA: vinyl benzoate ME: Ethyl methacrylate AB: butyl acrylate

[0172] [Table 3]

[0173] In Table 3, Toner 14 and Toner 38 were not heat treated.

[0174] <Toner 21 manufacturing example> (Production Example of Polymer A2) 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 by mass Monomer composition 100.0 parts by mass (The monomer composition was a mixture of behenyl acrylate, methacrylonitrile, ethyl methacrylate, and styrene in the ratios shown below. Behenyl acrylate (monomer (a)) 50.0 parts by mass Methacrylonitrile 25.0 parts by mass Ethyl methacrylate 15.0 parts by mass Styrene 10.0 parts by mass t-Butyl peroxypivalate (NOF Corporation: Perbutyl PV) 0.5 parts

[0175] The reactor was heated to 70°C while stirring at 200 rpm, and the polymerization reaction was carried out for 12 hours, obtaining a solution in which a polymer of the monomer composition was dissolved in toluene. The obtained solution was cooled to 25°C, and then poured into 1000.0 parts of methanol while stirring, to precipitate the methanol-insoluble matter. The obtained methanol-insoluble matter was filtered, washed with methanol, and then vacuum-dried at 40°C for 24 hours to obtain Polymer A2.

[0176] [Toner manufacturing by pulverization method] ·Polymer A2 100.0 parts by mass Colorant: Pigment Blue 15:3 (Dainichi Seika Chemicals) 6.5 parts by weight Wax 1 9.0 parts by weight Charge control agent (LR147: manufactured by Nippon Carlit Co., Ltd.) 2.0 parts by weight

[0177] The above materials were premixed in an FM mixer (manufactured by Nippon Coke & Engineering Co., Ltd.), and then melt-kneaded at a discharge temperature of 135°C in a twin-screw kneading extruder (PCM-30 model manufactured by Ikegai Iron Works Co., Ltd.) set at a temperature of 120°C to obtain a kneaded product.

[0178] During the cooling process, the resulting kneaded product was held at 95°C for 1 hour, and then held at 70°C for 3 hours for heat treatment. The heat-treated kneaded product was coarsely pulverized using a hammer mill and then pulverized using a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.) to obtain finely pulverized powder. The obtained finely pulverized powder was classified using a multi-division classifier utilizing the Coanda effect to obtain toner particles 21 having a weight average particle size (D4) of 7.0 μm.

[0179] To 100.0 parts of toner particles 21, 2.0 parts of silica fine particles (hydrophobized with hexamethyldisilazane, number average particle size of primary particles: 10 nm) were added as an external additive, and the mixture was mixed at 3000 rpm for 15 minutes using an FM mixer (manufactured by Nippon Coke & Engineering Co., Ltd.) to obtain toner 21. The physical properties of toner 21 are shown in Tables 5 and 6.

[0180] <Production Example of Toner 22> [Toner production by emulsion aggregation method] (Preparation of Polymer A2 Dispersion) Toluene 300.0 parts by mass ·Polymer A2 100.0 parts by mass The above materials were weighed and mixed, and polymer A2 was dissolved at 90° C. to obtain a toluene solution.

[0181] Separately, 5.0 parts by mass of sodium dodecylbenzenesulfonate and 10.0 parts by mass of sodium laurate were added to 700.0 parts by mass of ion-exchanged water and dissolved by heating at 90°C to obtain an aqueous solution. Next, the toluene solution and the aqueous solution were mixed and stirred at 7000 rpm using an ultra-high speed stirring device TK Robomix (manufactured by Primix). Further, the mixture was emulsified at a pressure of 200 MPa using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo). Thereafter, the toluene was removed using an evaporator, and the concentration was adjusted with ion-exchanged water to obtain a polymer A2 dispersion containing 20% ​​by mass of polymer A2 microparticles.

[0182] The 50% particle size (D50) based on volume distribution of the polymer A2 dispersion was measured and found to be 0.40 μm.

[0183] (Preparation of Wax Dispersion 1) Wax 1 100.0 parts by mass Anionic surfactant Neogen RK (Dai-ichi Kogyo Seiyaku) 5.0 parts by weight Ion-exchanged water 395.0 parts by mass

[0184] The above materials were placed in a mixing vessel equipped with a stirrer and heated to 90°C. They were then circulated through a Clearmix W Motion (manufactured by M Technique) and dispersed for 60 minutes under the following conditions: Rotor outer diameter: 3cm Clearance: 0.3mm Rotor speed: 19,000 rpm Screen rotation speed: 19000 rpm

[0185] After the dispersion process, the mixture was cooled to 40°C under cooling conditions of a rotor rotation speed of 1000 rpm, a screen rotation speed of 0 rpm, and a cooling rate of 10°C / min, thereby obtaining wax dispersion 1 containing 20% ​​by mass of wax 1 microparticles.

[0186] The 50% particle size (D50) of the volume distribution of the fine particles of Wax 1 was measured and found to be 0.15 μm.

[0187] (Preparation of Colorant Dispersion 1) Colorant (Pigment Blue 15:3) 50.0 parts by weight 7.5 parts by weight of anionic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku) Ion-exchanged water 442.5 parts by mass The above materials were weighed, mixed, dissolved, and dispersed for 1 hour using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.) to obtain colorant dispersion 1 containing 10% by mass of colorant fine particles.

[0188] The 50% particle size (D50) of the colorant particles based on volume distribution was measured and found to be 0.20 μm.

[0189] (Preparation of Toner 22) The following materials were placed in a round stainless steel flask and mixed. ·Polymer A2 dispersion liquid 500.0 parts by mass Wax dispersion 1 45.0 parts by mass Colorant dispersion 1 80.0 parts by mass Ion-exchanged water 160.0 parts by mass

[0190] After mixing, the mixture was dispersed at 5,000 rpm for 10 minutes using an Ultra Turrax T50 homogenizer (manufactured by IKA). A 1.0% aqueous nitric acid solution was added to adjust the pH to 3.0, and the mixture was then heated to 58°C in a heating water bath using a stirring blade while appropriately adjusting the rotation speed so that the mixture was stirred. The formed aggregated particles were appropriately checked, and when aggregated particles with a weight-average particle size (D4) of 6.0 μm were formed, a 5% aqueous sodium hydroxide solution was added to adjust the pH to 9.0. The mixture was then heated to 75°C while continuing to stir. The aggregated particles were fused by holding at 75°C for 1 hour.

[0191] Next, the temperature was raised to 90°C, and then the temperature was maintained at 90°C for 1 hour, and then the temperature was maintained at 70°C for 3 hours, thereby carrying out a heat treatment.

[0192] After the heat treatment, the mixture was cooled to 30°C, filtered, solid-liquid separated, and then washed with ion-exchanged water. After washing, the mixture was dried using a vacuum dryer to obtain toner particles 22 having a weight average particle size (D4) of 6.1 μm.

[0193] To 100.0 parts of toner particles 22, 2.0 parts of silica fine particles (hydrophobized with hexamethyldisilazane, number average particle size of primary particles: 10 nm) were added as an external additive, and the mixture was mixed at 3000 rpm for 15 minutes using an FM mixer (manufactured by Nippon Coke & Engineering Co., Ltd.) to obtain toner 22. The physical properties of toner 22 are shown in Tables 5 and 6.

[0194] <Toner 23 manufacturing example> [Toner production by solution suspension method] (Preparation of Colorant Dispersion 2) The following materials were placed in a heat-resistant glass container. Colorant (Pigment Blue 15:3) 100.0 parts by mass Ethyl acetate 150.0 parts by mass Glass beads (1 mm) 200.0 parts by mass

[0195] After dispersing for 5 hours using a paint shaker, the glass beads were removed using a nylon mesh to obtain colorant dispersion 2. The 50% particle size (D50) based on volume distribution of colorant dispersion 2 was measured and found to be 0.20 μm.

[0196] (Preparation of Wax Dispersion 2) Wax 1 20.0 parts by mass Ethyl acetate 80.0 parts by mass The above materials were placed in a sealable reaction vessel and heated with stirring at 80° C. Subsequently, the system was cooled to 25° C. over 3 hours while gently stirring at 50 rpm, yielding a milky white liquid.

[0197] This solution was placed in a heat-resistant container together with 30.0 parts by mass of glass beads with a diameter of 1 mm, and dispersed for 3 hours using a paint shaker (manufactured by Toyo Seiki Seisaku-sho), after which the glass beads were removed using a nylon mesh to obtain Wax Dispersion 2. When the 50% particle size (D50) based on volume distribution of Wax Dispersion 2 was measured, it was found to be 0.23 μm.

[0198] (Preparation of oil phase) The following materials were placed in a beaker and stirred at 3000 rpm for 1 minute using a Disper (manufactured by Tokushu Kika Co., Ltd.). ·100.0 parts by mass of the above polymer A2 Ethyl acetate 85.0 parts by mass Furthermore, the following materials were added to the beaker and stirred at 6000 rpm for 3 minutes using a Disper (manufactured by Tokushu Kika Co., Ltd.) to prepare an oil phase. Wax dispersion 2 (solid content 20% by mass) 45.0 parts by mass Colorant dispersion 2 (solid content 40% by mass) 12.5 parts by mass Ethyl acetate 5.0 parts by mass

[0199] (Preparation of aqueous phase) 100.0 parts by mass of sodium dodecyl diphenyl ether disulfonate aqueous solution (Eleminol MON7, manufactured by Sanyo Chemical Industries, Ltd.) Ion-exchanged water 900.0 parts by mass The above materials were placed in a beaker and stirred at 3000 rpm for 3 minutes using a Disper (manufactured by Tokushu Kika Co., Ltd.) to prepare an aqueous phase.

[0200] (Preparation of Toner 23) The oil phase was added to the aqueous phase and dispersed at 10,000 rpm for 10 minutes using a TK homomixer (manufactured by Tokushu Kika Co., Ltd.). The solvent was then removed for 30 minutes at 30°C under a reduced pressure of 50 mmHg. The resulting slurry was heated and stirred for 1 hour while maintaining the temperature at 90°C. It was then cooled to 70°C and heat-treated for 3 hours while maintaining the temperature at 70°C. The mixture was then filtered, and the surfactant was removed by repeating the filtration and re-dispersion into ion-exchanged water five times to obtain a filter cake.

[0201] The filter cake was dried under vacuum and then subjected to air classification to obtain toner particles 23.

[0202] The same external additions as in Toner 1 were made to Toner Particles 23 to obtain Toner 23. The physical properties of Toner 23 are shown in Tables 5 and 6.

[0203] <Production example of toners 24 to 26> (Preparation of amorphous resin 1) The following materials were placed in a heated and dried two-necked flask while introducing nitrogen. Polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane 30.0 parts by mass Polyoxyethylene (2.2)-2,2-bis(4-hydroxyphenyl)propane 33.0 parts by mass Terephthalic acid 21.0 parts by mass Dodecenyl succinic acid 15.0 parts by mass Dibutyltin oxide 0.1 parts by mass

[0204] After replacing the atmosphere in the system with nitrogen, the mixture was stirred at 215°C for 5 hours. Then, while continuing to stir, the temperature was gradually increased to 230°C under reduced pressure and maintained at that temperature for an additional 2 hours. The mixture was then air-cooled to terminate the reaction, yielding amorphous resin 1, an amorphous polyester. The weight-average molecular weight (Mw) and glass transition temperature (Tg) of amorphous resin 1 were measured, revealing that Mw was 23,500 and Tg was 55°C.

[0205] (Preparation of amorphous resin dispersion 1) The following materials were mixed and dissolved at 90°C. Toluene 300.0 parts by mass ·Amorphous resin 1 100.0 parts by mass Separately, the following materials were mixed and dissolved at 90°C. Ion-exchanged water 700.0 parts by mass Sodium dodecylbenzenesulfonate 5.0 parts by mass Sodium laurate 10.0 parts by mass

[0206] The resulting aqueous solution and the toluene solution were mixed and stirred at 7000 rpm using an ultra-high speed stirrer TK Robomix (manufactured by Primix). The mixture was then emulsified at a pressure of 200 MPa using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo). The toluene was then removed using an evaporator, and the concentration was adjusted with ion-exchanged water to obtain an amorphous resin 1 dispersion containing 20% ​​by mass of amorphous resin 1 microparticles.

[0207] The 50% particle size (D50) of the amorphous resin fine particles based on volume distribution was measured and found to be 0.38 μm.

[0208] [Toner production by emulsion aggregation method] Toners 24 to 26 were obtained in the same manner as in the production example of Toner 22, except that the amounts of Polymer A2 dispersion and Amorphous Resin Dispersion 1 added were changed as shown in Table 4. The physical properties of Toners 24 to 26 are shown in Tables 5 and 6.

[0209] [Table 4]

[0210] <Toner 39 manufacturing example> (Preparation of Polymer A3) 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 Dodecanethiol Monomer composition (The monomer composition is a mixture of behenyl acrylate and acrylic acid in the ratio shown below. Behenyl acrylate (monomer (a)) 91.5 parts by mass Acrylic acid 8.5 parts by mass Azoisobutyronitrile (AIBN) 0.75 parts by mass

[0211] The reactor was heated to 70°C while stirring at 200 rpm, and the polymerization reaction was carried out for 16 hours, obtaining a solution in which the polymer of the monomer composition was dissolved in toluene. After the temperature of the obtained solution was lowered to 25°C, the solution was poured into 1000.0 parts of methanol while stirring, and the methanol-insoluble matter was precipitated. The obtained methanol-insoluble matter was filtered, washed with methanol, and then vacuum-dried at 40°C for 24 hours to obtain Polymer A3.

[0212] (Preparation of Polymer A3 Dispersion) ·Polymer A3 30 parts by mass Sodium dodecylbenzenesulfonate 1.5 parts by mass Ion-exchanged water 150 parts by weight

[0213] The above materials were weighed, mixed, heated to 90°C, and stirred at 8000 rpm using an emulsifier (Ultra Turrax T-50, manufactured by IKA) to prepare a polymer A3 dispersion. The 50% particle size (D50) based on volume distribution of the polymer A3 dispersion was measured and found to be 0.30 μm.

[0214] <Preparation of amorphous resin 2> The following materials were placed in a heated and dried two-necked flask while introducing nitrogen. Polyoxyethylene (2,0)-2,2-bis(4-hydroxyphenyl)propane 19.0 parts by mass Polyoxypropylene (2,2)-2,2-bis(4-hydroxyphenyl)propane 51.0 parts by mass Terephthalic acid 23.0 parts by mass n-Dodecenyl succinic acid 4.5 parts by mass Isophthalic acid 3.0 parts by mass Dibutyltin oxide 0.02 parts by mass

[0215] After replacing the atmosphere in the system with nitrogen, the temperature was raised and the reaction was carried out at 150 to 230°C for about 12 hours. Thereafter, the pressure was gradually reduced to 210 to 250°C, and amorphous resin 2 was obtained. The weight average molecular weight (Mw) and glass transition temperature (Tg) of the obtained amorphous resin 2 were measured, and the Mw was 15,400 and the Tg was 65°C.

[0216] (Preparation of Amorphous Resin 2 Dispersion) ·Amorphous resin 2 30 parts by mass Ethyl acetate 100 parts by mass The above materials were weighed and mixed to dissolve the amorphous resin 2. Furthermore, the following materials were added. Sodium dodecylbenzenesulfonate 1.5 parts by mass 150g of ion-exchanged water

[0217] The mixture was heated to 60°C and stirred at 8000 rpm using an emulsifier (Ultra Turrax T-50, manufactured by IKA), and then the ethyl acetate was evaporated to prepare a dispersion of amorphous resin 2. The 50% particle size (D50) based on volume distribution of the amorphous resin 2 dispersion was measured and found to be 0.18 μm.

[0218] (Preparation of Colorant Dispersion 3) Colorant (Pigment Blue 15:3) 50 parts by weight Anionic surfactant Neogen SC (Dai-ichi Kogyo Seiyaku) 5.0 parts by mass Ion-exchanged water 200.0 parts by mass

[0219] The above materials were mixed and dissolved, and dispersed for 10 minutes using a homogenizer (Ultra Turrax manufactured by IKA), to obtain a colorant dispersion 3 having a median particle size of 175 nm and a solid content of 22.5 parts by mass.

[0220] (Preparation of Wax Dispersion 3) Wax 7 25.0 parts by mass Anionic surfactant Neogen SC (Dai-ichi Kogyo Seiyaku) 5.0 parts by mass Ion-exchanged water 200.0 parts by mass

[0221] The above materials were mixed and heated to 97°C, then dispersed using a homogenizer (Ultra Turrax T50, manufactured by IKA), and then homogenized at 105°C and 550 kg / cm using a Gaulin homogenizer (manufactured by Meiwa Shoji). 2 Dispersion treatment was carried out 20 times under the above conditions to obtain Wax Dispersion 3. When the 50% particle size (D50) based on volume distribution of Wax Dispersion 3 was measured, it was 0.20 μm.

[0222] (Preparation of Toner 39) ·Amorphous resin 2 dispersion liquid 400.0 parts by mass ·Polymer A3 dispersion liquid 100.0 parts by mass Colorant dispersion 3 20.0 parts by mass Wax dispersion 3 70.0 parts by mass 1.5 parts by weight of 10% polyaluminum chloride aqueous solution (manufactured by Asada Chemical Co., Ltd.)

[0223] The above materials were mixed and dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50, manufactured by IKA), and the contents of the flask were heated to 45°C while stirring, and maintained at 45°C for 30 minutes.

[0224] Thereafter, the temperature of the obtained content was gradually raised to 55°C, and an aqueous sodium hydroxide solution was added to adjust the pH to 8. Thereafter, the temperature was raised to 90°C, and the aggregates were allowed to coalesce over 1 hour. Thereafter, the content was cooled and filtered, washed with ion-exchanged water, and then dried to obtain toner particles 39.

[0225] To 100.0 parts of toner particles 39, 2.0 parts of silica fine particles (hydrophobized with hexamethyldisilazane, number average particle size of primary particles: 10 nm) were added as an external additive, and the mixture was mixed at 3000 rpm for 15 minutes using an FM mixer (manufactured by Nippon Coke & Engineering Co., Ltd.) to obtain toner 39. The physical properties of toner 39 are shown in Tables 5 and 6.

[0226] [Table 5]

[0227] *Toner 27: 7.0 parts Wax 1 and 2.0 parts Wax 9 Toner 28: 2.0 parts Wax 1 and 7.0 parts Wax 9 Toner 29: 5.0 parts Wax 1 and 4.0 parts Wax 9 Toner 30: 4.0 parts Wax 1 and 5.0 parts Wax 9 In Table 5, Wc of the ester wax means the average number of carbon atoms in the linear alkyl groups contained in the ester wax.

[0228] The melting point and Mw of polymer A in Table 5 are the melting point and Mw of a polymer obtained by performing the same operations as in the corresponding toner production examples, except that the shell resin, wax, and colorant were not added and the step of mixing using silica fine particles was not performed.

[0229] The polymers obtained in this manner were produced in the same manner as the resins contained in the corresponding toners, and therefore were determined to have physical properties equivalent to those of the respective polymers A contained in the toners.

[0230] [Table 6]

[0231] Example 1 Toner 1 was evaluated as follows, and the evaluation results are shown in Table 7.

[0232] <Evaluation of low-temperature fixability of toner> To evaluate the low-temperature fixability of the toner, a modified laser beam printer (product name: LBP-7700C, manufactured by Canon Inc.) was used as the image forming apparatus. The modifications to the modified machine were that it could operate even when the fixing unit was removed, and that the fixing temperature could be freely set. The paper used to output the image was white paper (product name: Fox River Bond (90 g / m 2 ), FOX RIVER Co., Ltd.

[0233] First, the toner was removed from the cartridge and cleaned with an air blower, and then 300 g of Toner 1 was filled into the cartridge. The cartridge was then left for 48 hours in an environment of 25°C temperature and 40% RH humidity, and then installed in the cyan station of the printer under the same environment, with dummy cartridges installed in the other stations. Evaluations were then conducted under the same environment as above.

[0234] Next, using the image forming apparatus described above with the fixing unit removed, an unfixed image of an image pattern was printed in which a 10 mm x 10 mm square image was transferred to 9 points, which were the intersections of the lines dividing the long and short sides of the paper into four equal parts. The toner amount on the paper was 0.80 mg / cm. 2 It was decided.

[0235] Using the removed fixing unit, the process speed was set to 250 mm / s, and the initial temperature was 90°C. The set temperature was gradually increased by 5°C increments, and the unfixed image was fixed at each temperature, to obtain fixed images at each temperature. 2A load of 1000 kJ / cm was applied, and the toner was rubbed with Silbon paper (Lenz Cleaning Paper "dasper(R)" (Ozu Paper Co. Ltd.). The image density was measured before and after the rubbing, and the temperature at which the decrease in image density after rubbing relative to the image density before rubbing was 20% or less was taken as the fixing start temperature, and this value was used to evaluate the low-temperature fixability of the toner. Toners with a fixing start temperature of 120°C or less were determined to have the effects of the present disclosure. The evaluation results are shown in Table 7.

[0236] <Evaluation of Toner Durability> The toner release properties were evaluated using the modified image forming device and paper used in the above evaluation of low-temperature fixability in a room temperature and humidity environment of 25°C and 40%RH. The durability of the toner was evaluated using the contamination concentration of non-image areas caused by fine powder generated by cracks and chips in the toner as an evaluation index.

[0237] First, an all-white image was printed at a process speed of 120 mm / sec onto an evaluation sheet with a sticky note attached near the bottom center. The reflectance D1 (%) of the portion of the evaluation sheet that was hidden by the sticky note and the reflectance D2 (%) of the portion that was not hidden were measured, and the difference was taken as the contamination density value Di (%) of the non-image area before durability testing (Di = D2 - D1 (%)). The reflectance was measured using a REFLECTOMETER MODEL TC-6DS (manufactured by Tokyo Denshoku Co., Ltd.) with an amber filter attached.

[0238] Next, a horizontal line pattern with a print rate of 1% was printed on two sheets per job, with the machine pausing between jobs before the next job began. A total of 15,000 images were output in this mode, and the evaluation machine was then turned off and left for 72 hours immediately after image output was completed. After leaving the machine, the evaluation machine was turned on again, and an all-white image was output on evaluation paper with a sticky note attached near the bottom center, in the same manner as above, and the contamination density value (Dr (%)) of the non-image area after durability testing was calculated.

[0239] The (Dr-Di) was calculated from the two obtained values, and this value was used to evaluate the durability of the toner. The evaluation results are shown in Table 7. A (Dr-Di) value of less than 4.0% was determined to be one in which the effects of the present disclosure were obtained.

[0240] <Evaluation of toner releasability> The toner release property was evaluated using a modified image forming apparatus used in the evaluation of low-temperature fixability, and white paper (product name: GF-500 (A4, basis weight 64.0 g / m)) was used as the paper. 2 (Canon Marketing Japan Inc.) was used. In addition, the same procedure as above was carried out after filling 300 g of Toner 1 into the cartridge.

[0241] Using the modified machine with the fixing unit removed, an unfixed image was printed 1 mm from the leading edge of the evaluation paper, 100 mm wide in the paper feed direction and 200 mm wide in the direction perpendicular to the paper feed direction. The paper feed direction was portrait, and the toner amount of the unfixed image was 0.8 mg / cm. 2 It was decided.

[0242] Then, using the removed fixing unit, the temperature was increased by 6 points in 10°C increments from the fixing start temperature in the evaluation of low-temperature fixability described above, and the number of temperatures at which the fixed image did not wrap around the fixing roller was measured, and the toner releasability was evaluated based on this number. The evaluation results are shown in Table 7. When there was one or more temperatures at which the fixed image did not wrap around the fixing roller, it was determined that the effects of the present disclosure were achieved.

[0243] <Evaluation of heat-resistant storage stability of toner> 6 g of Toner 1 was placed in a 100 mL plastic cup and left to stand for 10 days in an environment of a temperature of 50° C. and a humidity of 20% RH, and then the degree of cohesion of the left Toner 1 was measured as follows.

[0244] The measurement device used was a "Powder Tester" (Hosokawa Micron Corporation) with a digital display vibrometer "Digivro MODEL 1332A" (Showa Sokki Co., Ltd.) connected to the side of the vibration table. A sieve with a mesh size of 38 μm (400 mesh), a sieve with a mesh size of 75 μm (200 mesh), and a sieve with a mesh size of 150 μm (100 mesh) were placed on top of each other on the vibration table of the powder tester from the bottom up. Measurements were carried out in an environment of 23°C and 60% RH according to the following procedure. (1) The vibration amplitude of the vibration table was adjusted in advance so that the displacement value on the digital display vibrometer would be 0.60 mm (peak-to-peak). (2) The toner that had been left for 10 days as described above was then left for 24 hours in an environment of 23°C and 60% RH, and 5 g of the toner was precisely weighed out and gently placed on the top sieve with 150 μm openings. (3) After vibrating the sieves for 15 seconds, the mass of the toner remaining on each sieve was measured, and the degree of cohesion (%) was calculated using the following formula. The evaluation results are shown in Table 7. A degree of cohesion of 30% or less was determined to be one in which the effects of the present disclosure were achieved. Cohesion degree (%) = {(mass of sample on 150 μm mesh sieve (g)) / 5 (g)} × 100 + {(Sample mass (g) on ​​75 μm mesh sieve) / 5 (g)} x 100 x 0.6 + {(Sample mass (g) on ​​38 μm mesh sieve) / 5 (g)} x 100 x 0.2

[0245] [Table 7]

Claims

1. A toner having toner particles containing a resin component and a wax, the resin component is a vinyl polymer A having a monomer unit A represented by the following formula (A), the wax is composed solely of esters of hexahydric alcohol and aliphatic monocarboxylic acid, The wax contained in the toner particles includes a wax that forms a eutectic structure with the resin component and a single wax that does not form a eutectic structure, When a backscattered electron image of the cross section of the toner particle is obtained by observing the cross section of the toner particle with a scanning transmission electron microscope, and the brightness of each pixel constituting the backscattered electron image is divided into 256 gradations from a brightness of 0 at the darkest part to a brightness of 255 at the brightest part, a brightness histogram is obtained in which the horizontal axis is brightness and the vertical axis is the number of pixels. When the total number of pixels with brightness 0 to 9 is C and the total number of pixels with brightness 0 to 245 is A, The C and the A satisfy the following formula (1), 0.002≦C / A≦0.250 (1) The luminance indicating the maximum number P of pixels in the range of luminance 10 to luminance 245 of the histogram is defined as luminance X, The luminance at which the number of pixels falls below 20% of P for the first time from the luminance X toward the luminance 245 is defined as luminance M, When the number of pixels falls below 20% of P for the first time from the brightness X to the brightness 10, the brightness is defined as N. The value of luminance M-luminance N is 120 to 235 A toner characterized by: 【Chemistry 1】 (In formula (A), R １ is H or CH ３ indicates R ２ represents an alkyl group having 18 to 36 carbon atoms.)

2. The C and the A satisfy the following formula (2): 0.002≦C / A≦0.100 (2) The toner according to claim 1 .

3. 3. The toner according to claim 1, wherein the content of the monomer unit A in the vinyl polymer A is 20.0 to 80.0% by mass.

4. 4. The toner according to claim 1, wherein the ratio of the mass of the wax to the mass of the resin component is 1.0 to 25.0% by mass.

5. 5. The toner according to claim 1, wherein the wax has a molecular weight of 1,000 to 3,000.

6. A method for producing the toner according to any one of claims 1 to 5, The manufacturing method comprises: obtaining toner base particles containing the wax and the resin component; and When the melting point of the wax is TmW and the melting point of the vinyl polymer A is TmA, a step of subjecting the toner base particles to a heat treatment in a temperature range of TmA to TmW for 30 minutes or more to obtain toner particles; A toner manufacturing method comprising:

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