Toner

Abstract

To provide a toner that can prevent density unevenness in a high temperature and high humidity environment, the occurrence of fogging, and fusion after long-term use, and can prevent the occurrence of ghost in a low temperature and low humidity environment.SOLUTION: A toner has a toner particle that contains a binder resin and an external additive. The toner particle further has a monovalent aliphatic alcohol. The monovalent aliphatic alcohol has 8-18 carbon atoms. The content ratio of the monovalent aliphatic alcohol extracted from the toner with ethanol is 30 mass ppm or more and 300 mass ppm or less in the toner. The external additive has at least one selected from the group consisting of hydrotalcite particles and alumina particles.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to toner used in electrophotography, electrostatic recording, and toner jet recording methods.

Background Art

[0002] In recent years, there has been a growing demand for higher performance in electrophotographic image forming apparatuses, and further improvement in various performances of toner has also been required. From the perspective of image quality, with the diversification of usage environments, it has become increasingly necessary to maintain a certain level of image quality for a long time in any usage environment (suppression of environmental dependence of image quality). For example, in a high-temperature and high-humidity environment, problems such as a decrease in chargeability due to moisture adsorption and fusion caused by bleeding of wax or oil are likely to occur. In a low-temperature and low-humidity environment, problems such as a decrease in fluidity due to toner charge-up and density unevenness of images due to non-uniform charging are likely to occur.

[0003] Conventionally, in order to improve chargeability in a high-temperature and high-humidity environment, charge aids such as microcarriers have been used as external additives. However, simply increasing the charge amount of toner was likely to cause various problems such as charge-up in a low-temperature and low-humidity environment. Therefore, the environmental dependence of image quality has been suppressed by controlling the characteristics of the toner matrix and external additives.

[0004] In Patent Document 1, it is proposed to suppress a decrease in charging in a high-temperature and high-humidity environment by adding hydrotalcite as an external additive. In Patent Document 2, the dielectric tangent is controlled by adding a magnetic substance into toner particles, and electrostatic offset in a low-temperature and low-humidity environment is suppressed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The toner described in Patent Document 1 suppresses fogging in a high-temperature and high-humidity environment. However, there are problems with the rise of charging, and the density at the leading edge of the image tends to decrease in a high-temperature and high-humidity environment. Also, in a low-temperature and low-humidity environment, it charges up and ghosting is likely to occur.

[0007] On the other hand, the toner described in Patent Document 2 suppresses fogging by suppressing excessive charging that tends to be a problem in a low-temperature and low-humidity environment. However, in a high-temperature and high-humidity environment, fogging is likely to occur due to insufficient charging, and there is room for improvement in the environmental dependence of image quality.

[0008] The present disclosure provides a toner that solves the above problems. Specifically, it provides a toner that can suppress density unevenness, fogging, and fusion during long-term use in a high-temperature and high-humidity environment, and suppress the occurrence of ghosting in a low-temperature and low-humidity environment.

Means for Solving the Problems

[0009] The present disclosure relates to a toner having toner particles containing a binder resin and an external additive, the toner particles further contain a monohydric aliphatic alcohol, the monohydric aliphatic alcohol has 8 to 18 carbon atoms, the content ratio of the monohydric aliphatic alcohol extracted from the toner with ethanol is 30 mass ppm or more and 300 mass ppm or less in the toner, the external additive relates to a toner having at least one selected from the group consisting of hydrotalcite particles and alumina particles.

Advantages of the Invention

[0010] According to the present disclosure, it is possible to provide a toner that can suppress density unevenness, fogging, and fusion during long-term use in a high-temperature and high-humidity environment, and suppress the occurrence of ghosting in a low-temperature and low-humidity environment.

Brief Description of the Drawings

[0011]

Figure 1

Embodiments for Carrying Out the Invention

[0012] In the present disclosure, descriptions such as "XX or more and YY or less" and "XX to YY" representing numerical ranges mean numerical ranges including the lower limit and the upper limit which are endpoints, unless otherwise specified. When numerical ranges are described stepwise, the upper limit and the lower limit of each numerical range can be arbitrarily combined.

[0013] Generally, hydrotalcite particles and alumina particles have a smaller work function than toner particles and impart electrons to the toner particles. Therefore, by adding hydrotalcite particles or alumina particles as external additives to negatively charged toner, these act as microcarriers and have the effect of improving the chargeability of the toner. The microcarriers give charge to the toner particles when leaving the toner particles to impart charging. Therefore, in order to sufficiently obtain the effect of improving chargeability, it is required to be in close contact with the toner particles before charging and to be rapidly dissociated from the toner particles when charging is necessary.

[0014] However, if the adhesion between the microcarrier and the toner particles is weakened to obtain the above effect, the charge imparting effect at the time of dissociation becomes small, so the chargeability at the initial stage of use is likely to decrease. Also, due to long-term use, the microcarrier detaches from the toner particles, and the chargeability of the toner is likely to change during use.

[0015] On the other hand, when the microcarrier is strongly adhered to the toner particles in order to improve the initial charge rise and the change in charge due to durable use, the microcarrier is difficult to dissociate from the toner particles when charging is necessary, and the chargeability is likely to decrease.

[0016] In addition, when the amount of microcarriers added is increased for further imparting chargeability, it exhibits a great effect in an environment where chargeability is likely to decrease, such as a high-temperature and high-humidity environment. On the other hand, in an environment where chargeability is likely to increase, such as a low-temperature and low-humidity environment, charging is likely to occur, and image defects such as ghosts are likely to occur. Therefore, it is a major issue to maintain good chargeability for a long period regardless of the usage environment.

[0017] As a result of repeated studies, the inventors of the present invention have found that the above problems can be solved by adding a monohydric aliphatic alcohol to the toner, controlling the addition amount and the number of carbon atoms of the monohydric aliphatic alcohol within a certain range, and externally adding hydrotalcite particles or alumina particles. Specifically, it has been found that the above problems can be solved by the following toner.

[0018] A toner having toner particles containing a binder resin and an external additive, wherein the toner particles further contain a monohydric aliphatic alcohol, the monohydric aliphatic alcohol has 8 to 18 carbon atoms, the content ratio of the monohydric aliphatic alcohol extracted from the toner with ethanol is 30 mass ppm or more and 300 mass ppm or less in the toner, and the external additive has at least one selected from the group consisting of hydrotalcite particles and alumina particles. A toner characterized by the above.

[0019] By adding a monohydric aliphatic alcohol to the toner, controlling the addition amount and the number of carbon atoms of the monohydric aliphatic alcohol within a certain range, and externally adding hydrotalcite particles or alumina particles, good chargeability can be maintained for a long time regardless of the usage environment. Specifically, due to the interaction between the alcohol and the hydrotalcite particles or alumina particles, the adhesion between the hydrotalcite particles or alumina particles and the toner particles can be moderately increased, and a large charge imparting effect can be obtained during dissociation. Also, the movement of charges on the toner surface becomes smooth due to the alcohol, and overcharging can be suppressed. Furthermore, by controlling the addition amount of the alcohol within a certain range, bleeding of the alcohol during durable use can be suppressed, and fusing can be suppressed.

[0020] The number of carbon atoms of the monohydric aliphatic alcohol is 8 to 18, preferably 10 to 16, and more preferably 12 to 14. When the number of carbon atoms is less than 8, the alcohol bleeds out on the surface of the toner particles, and fogging and density unevenness occur due to poor chargeability. Also, fusing to the sleeve or developing roller occurs during long-term use. When the number of carbon atoms is greater than 18, the dispersibility of the alcohol in the toner particles decreases, and the alcohol forms domains. As a result, the interaction between the hydrotalcite particles or alumina particles and the alcohol becomes non-uniform, the chargeability decreases, and the charge distribution becomes broad.

[0021] The content ratio of the monohydric aliphatic alcohol extracted from the toner with ethanol is 30 mass ppm or more and 300 mass ppm or less in the toner, preferably 70 mass ppm or more and 250 mass ppm or less, and more preferably 110 mass ppm or more and 200 mass ppm or less.

[0022] When the content ratio of the monohydric aliphatic alcohol is less than 30 mass ppm, the interaction with the hydrotalcite particles or alumina particles is weak, and the adhesion between the toner particles and the hydrotalcite particles or alumina particles becomes small. As a result, the charging rise of the toner becomes slow, and initial density unevenness and fogging occur in a high-temperature and high-humidity environment.

[0023] When the content ratio of the monohydric aliphatic alcohol is more than 300 ppm by mass, the monohydric aliphatic alcohol oozes out onto the surface of the toner particles, and fusion occurs due to long-term use. In addition, the interaction between the monohydric aliphatic alcohol and the hydrotalcite particles or alumina particles becomes stronger, and the adhesion between the toner particles and the hydrotalcite particles or alumina particles becomes too high. As a result, initial density unevenness and fogging occur in a high-temperature and high-humidity environment.

[0024] The external additive has at least one selected from the group consisting of hydrotalcite particles or alumina particles. The hydrotalcite particles or alumina particles have a small work function and a high positive chargeability. Therefore, by using them as an external additive, the negative chargeability of the toner can be increased. In addition, the hydrotalcite particles or alumina particles are likely to adsorb to the hydroxyl group of alcohol. As a result, it can interact with the alcohol in the toner particles to moderately increase the adhesion, and it is easy to control the chargeability.

[0025] The number average value of the major axis of at least one selected from the group consisting of hydrotalcite particles and alumina particles is preferably 60 nm or more and 820 nm or less, and more preferably 300 nm or more and 500 nm or less. When the number average value of the major axis is within the above range, the toner particles and the hydrotalcite particles or alumina particles adhere moderately, and it is easy to obtain the effect of improving the charge as a microcarrier. As a result, initial density unevenness and fogging can be more suppressed in a high-temperature and high-humidity environment. The number average value of the major axis of the hydrotalcite particles can be controlled by changing the ratio and type of the compound added during synthesis. In addition, the number average value of the major axis of the alumina particles can be controlled by changing the reaction temperature and reaction time.

[0026] The total content of hydrotalcite particles and alumina particles is preferably 0.02 parts by mass or more, more preferably 0.03 parts by mass or more, still more preferably 0.05 parts by mass or more, and even more preferably 0.15 parts by mass or more with respect to 100 parts by mass of toner particles. When the addition amounts of the hydrotalcite particles and the alumina particles are within this range, the toner can obtain sufficiently large chargeability, and fogging and initial density unevenness in a high-temperature and high-humidity environment can be more suppressed.

[0027] The total content of hydrotalcite particles and alumina particles is preferably 1.00 parts by mass or less, more preferably 0.80 parts by mass or less, still more preferably 0.50 parts by mass or less, and even more preferably 0.30 parts by mass or less with respect to 100 parts by mass of toner particles. When the content of the hydrotalcite particles and the alumina particles is within this range, charge-up in a low-temperature and low-humidity environment can be suppressed, and ghosting can be further suppressed.

[0028] The binder resin preferably contains a styrene-acrylic resin. And the content ratio of the styrene-acrylic resin in the toner is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 75% by mass or more. The upper limit is not particularly limited, but is preferably 90% by mass or less, and more preferably 85% by mass or less. When the ratio of the styrene-acrylic resin is within the above range, it is easy to control the dispersibility of alcohol in the binder resin, and the interaction between the hydrotalcite particles or alumina particles and alcohol can be further enhanced.

[0029] When the work function of the toner particles is Wa and the work function of the hydrotalcite particles or alumina particles is Wb, it is preferable that Wa - Wb satisfies the relationship of the following formula (1). More preferably, it satisfies the relationship of formula (1´). 0.05 eV < Wa - Wb < 0.50 eV ···(1) 0.10 eV < Wa - Wb < 0.30 eV ···(1´)

[0030] Since Wa - Wb is greater than 0.05 eV, the chargeability is improved, and fogging in a high-temperature and high-humidity environment can be further suppressed. Also, since Wa - Wb is less than 0.50 eV, charge-up in a low-temperature and low-humidity environment can be suppressed, and ghosting can be further suppressed. The work function of the toner particles can be controlled by changing the types of charge control agents and pigments used. For example, the work function Wa of the toner particles is preferably 5.25 eV or more and 5.70 eV or less, and more preferably 5.40 eV or more and 5.60 eV or less.

[0031] The external additive contains an external additive C different from the hydrotalcite particles and alumina particles. When the work function of the external additive C is Wc, it is preferable that Wa, Wb, and Wc satisfy the relationship of the following formula (2). Wb < Wa < Wc ···(2) When Wa, Wb, and Wc satisfy the relationship of formula (2), the movement of charges on the toner surface becomes smooth, and ghosting in a low-temperature and low-humidity environment can be further suppressed. When the external additive C is, for example, silica, the work function of the external additive C can be controlled by changing the type of surface treatment agent.

[0032] At least one selected from the group consisting of hydrotalcite particles and alumina particles is preferably hydrotalcite particles. That is, it is preferable that the external additive contains hydrotalcite particles. The interaction with alcohol becomes larger due to the hydrotalcite particles, and the chargeability of the toner is more likely to be improved.

[0033] The average circularity of the toner is preferably 0.97 or more, and more preferably 0.98 or more. The upper limit is not particularly limited, but is preferably 1.00 or less, 0.99 or less. When the average circularity of the toner is within the above range, hydrotalcite particles or alumina particles are likely to adhere uniformly to the toner particle surface, and the charging of the toner is more likely to be uniform.

[0034] (Hydrotalcite particles) The hydrotalcite particles will be described in detail. The hydrotalcite particles are not particularly limited as long as they can achieve the properties. The hydrotalcite particles preferably contain Al and Mg. The hydrotalcite particles can preferably be represented by the following formula (A), and have a positively charged basic layer ([M 2+ 1-x M 3+ x (OH) - 2]) in formula (A) and a negatively charged intermediate layer ([x / nA n- ·mH2O), and are a layered inorganic compound. [M 2+ 1-x M 3+ x (OH) - 2][x / nA n- ·mH2O] (A)

[0035] In formula (A), as the divalent metal ion M 2+ , examples include Mg, Zn, Ca, Ba, Ni, Sr, Cu, Fe; as the trivalent metal ion M 3+ , examples include Al, B, Ga, Fe, Co, In. The divalent metal ion M 2+ and the trivalent metal ion M 3+ may be a solid solution containing a plurality of different elements, and may contain a trace amount of a monovalent metal ion in addition to these metal ions. A n- represents an n-valent anion such as CO3 2- , OH - , Cl - , I - , F - , Br - , SO4 2- , HCO3 2- , CH3COO - , NO3 - , etc., and these may be single or in plurality. m≧0.

[0036] Examples of the compound contained in formula (A) include [Mg 2+ 0.750 Al 3+ 0.250 (OH)- 2.000 [0.125CO3 2- ·0.500H2O] can be mentioned.

[0037] From the viewpoint of the ability to impart charge, the hydrotalcite particles are divalent metal ions M 2+ Preferably include Mg as 2+ and trivalent metal ions M 3+ Preferably include Al as 3+ In addition, as the n-valent anion, from the viewpoint of imparting chargeability to the toner particles, CO3 2- , Cl - are preferred.

[0038] The hydrotalcite particles may be treated with a surface treatment agent for the purpose of imparting hydrophobicity or controlling chargeability, but from the viewpoint of maintaining the strong positive polarity responsible for the high charge imparting effect of the hydrotalcite particles, it is preferably used untreated. When using a surface treatment agent, higher fatty acids, coupling agents, esters, oils such as silicone oil can be used.

[0039] As a method for surface-treating hydrotalcite particles with a surface treatment agent, known methods can be used. For example, there are methods of dissolving and mixing the surface treatment agent in a solvent, or heating and dissolving it to make it liquid and then wet-mixing it with untreated hydrotalcite particles. In addition, there is a method of mechanically dry-mixing the surface treatment agent in fine powder form and hydrotalcite particles. After surface treatment, means such as washing, dehydration, drying, pulverization, and classification can be appropriately selected as necessary to obtain surface-treated hydrotalcite particles.

[0040] The work function of the hydrotalcite particles is preferably 4.95 eV or more and 5.40 eV or less, and more preferably 5.10 eV or more and 5.30 eV or less. When the work function of the hydrotalcite particles is within the above range, it becomes easier to obtain the effect as a charge assistant for negatively charged toner. The work function of the hydrotalcite particles depends on the type and amount of the surface treatment agent, M in the hydrotalcite particles 2+ and M3+ It can be controlled by changing the type and ratio and the type of the n-valent anion.

[0041] (Alumina particles) Subsequently, the alumina particles will be described in detail. The alumina particles are not particularly limited as long as they can achieve the above characteristics. As a method for producing the alumina particles, known methods can be adopted. For example, the Bayer process, the underwater spark discharge method, the aluminum alum thermal decomposition method, the ammonium aluminum carbonate thermal decomposition method, the method of firing the alumina hydrate obtained by hydrolyzing aluminum alkoxide, the Chemical Vapor Deposition method, etc. can be mentioned. Among these, the alumina particles produced by the Chemical Vapor Deposition method are preferable because they have a polyhedral shape and the particle size distribution is likely to be uniform.

[0042] The alumina particles may be treated with a surface treatment agent for the purpose of imparting hydrophobicity or controlling the chargeability, but it is preferable to use them untreated from the viewpoint of maintaining the strong positive polarity responsible for the high charge imparting effect of the alumina particles. When using a surface treatment agent, oils with a hydrophobizing action, coupling agents, and resins with a hydrophobizing action are preferable. Among these, silicone-based oils and coupling agents, organic acid-based resins, etc. are preferably used. As an example of the oils that can be used, there are silicone oils such as dimethylpolysiloxane and methylhydrogenpolysiloxane, paraffin, mineral oil, etc. The surface treatment method of the alumina particles with these hydrophobizing treatment agents can be carried out by known methods.

[0043] The work function of the alumina particles is preferably 4.95 eV or more and 5.40 eV or less, and more preferably 5.10 eV or more and 5.30 eV or less. When the work function of the alumina particles is within the above range, it becomes easier to obtain the effect as a charge assistant for the negatively charged toner. The work function of the alumina particles can be controlled by changing the type and amount of the surface treatment agent and the crystal structure of the alumina particles.

[0044] The raw materials used for toner particles will be described. The toner particles contain a binder resin. As the binder resin used for the toner particles, the following polymers and the like can be used. Homopolymers of styrene and its substituents such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; Styrenic copolymers such as styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic ester copolymer, and styrene-methacrylic ester copolymer; Polyvinyl chloride, phenol resin, natural resin-modified phenol resin, natural resin-modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane resin, polyamide resin, furan resin, epoxy resin, xylene resin, polyethylene resin, polypropylene resin, and the like.

[0045] From the viewpoints of developability, fixability, and compatibility with monohydric aliphatic alcohols, it is preferable that the main component of the binder resin is a styrenic copolymer which is a copolymer of styrene and other vinyl monomers. More preferably, it is a styrene-acrylic resin.

[0046] The toner particles contain a monohydric aliphatic alcohol. The monohydric aliphatic alcohol includes any of linear or branched aliphatic Family alcohols, and the monohydric aliphatic alcohol may be used alone or in combination of a plurality. Examples of the monohydric aliphatic alcohol having 8 to 18 carbon atoms include octyl alcohol, decyl alcohol, dodecyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, and stearyl alcohol. Among them, linear aliphatic alcohols are preferable.

[0047] The toner particles may contain a colorant. Examples of the colorant include the following. Examples of the black colorant include carbon black; those obtained by toning to black using a yellow colorant, a magenta colorant, and a cyan colorant. As the colorant, a pigment may be used alone.

[0048] Examples of pigments for magenta toners include the following: C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57:1, 58, 60, 63, 64, 68, 81:1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269, 282; C.I. Pigment Violet 19; C.I. Vat Red 1, 2, 10, 13, 15, 23, 29, 35. Examples of dyes for magenta toners include the following: C.I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121; C.I. Disperse Red 9; C.I. Solvent Violet 8, 13, 14, 21, 27; oil-soluble dyes such as C.I. Disperse Violet 1; basic dyes such as C.I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; C.I. Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28.

[0049] Examples of pigments for cyan toners include the following: C.I. Pigment Blue 2, 3, 15:2, 15:3, 15:4, 16, 17; C.I. Vat Blue 6; C.I. Acid Blue 45, and copper phthalocyanine pigments in which 1 to 5 phthalimidomethyl groups are substituted on the phthalocyanine skeleton. Examples of dyes for cyan toners include C.I. Solvent Blue 70. Examples of pigments for yellow toners include the following: C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185; C.I. Vat Yellow 1, 3, 20. Examples of dyes for yellow toners include C.I. Solvent Yellow 162.

[0050] These colorants can be used alone, mixed, or even in a solid solution state. The colorant preferably contains at least one selected from the group consisting of C.I. Pigment Violet 19, C.I. Pigment Red 122, C.I. Pigment Red 202, and C.I. Pigment Red 209. Due to the quinacridone skeleton contained in these colorants, the charge is delocalized, and fogging is more easily suppressed. The content of the colorant is preferably 0.1 part by mass or more and 30.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin. When the content of the colorant is within the above range, it is easy to achieve a balance in terms of hue angle, chroma, lightness, lightfastness, OHP transparency, and dispersibility in the toner.

[0051] It is also possible to make magnetic toner particles by incorporating a magnetic material as a colorant into the toner particles. Examples of magnetic materials include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; or alloys and mixtures of these metals with metals such as aluminum, copper, magnesium, tin, zinc, beryllium, calcium, manganese, selenium, titanium, tungsten, and vanadium. The above magnetic material is preferably a magnetic material with a modified surface.

[0052] When preparing magnetic toner by the polymerization method, it is preferable to use a surface modifier that is a polymerization-inhibitor-free substance and has been subjected to a hydrophobization treatment. Examples of such surface modifiers include silane coupling agents and titanium coupling agents. The number average particle diameter of these magnetic materials is preferably 2.0 μm or less, and more preferably 0.1 μm or more and 0.5 μm or less. The content of the magnetic material is preferably 20 parts by mass or more and 200 parts by mass or less, and more preferably 40 parts by mass or more and 150 parts by mass or less, based on 100 parts by mass of the binder resin.

[0053] The toner particles preferably contain a release agent. Examples of the release agent include waxes mainly composed of fatty acid esters such as carnauba wax and montanic acid ester wax; those obtained by removing part or all of the acid components from fatty acid esters such as deacidified carnauba wax; methyl ester compounds having a hydroxy group obtained by hydrogenating vegetable oils; saturated fatty acid monoesters such as stearyl stearate and behenyl behenate; diester compounds of saturated aliphatic dicarboxylic acids and saturated aliphatic alcohols such as dibehenyl sebacate, distearyl dodecanedioate, and distearyl octadecanedioate; diester compounds of saturated aliphatic diols and saturated fatty acids such as nonanediol dibehenate and dodecanediol distearate; aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax or block copolymers thereof; waxes grafted with vinyl monomers such as styrene and acrylic acid onto aliphatic hydrocarbon waxes; saturated straight-chain fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassidic acid, eleostearic acid, and parinaric acid; saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubyl alcohol, ceryl alcohol, and melissyl alcohol; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide, oleic acid amide, and lauric acid amide; saturated fatty acid bisamides such as methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, and hexamethylene bisstearic acid amide; unsaturated fatty acid amides such as ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipic acid amide, and N,N'-dioleyl sebacic acid amide; aromatic bisamides such as m-xylene bisstearic acid amide and N,N'-distearyl isophthalic acid amide; fatty acid metal salts (commonly referred to as metal soaps) such as calcium stearate, calcium laurate, zinc stearate, and magnesium stearate;Examples thereof include long-chain alkyl alcohols or long-chain alkyl carboxylic acids having 12 or more carbon atoms; etc.

[0054] The content of the release agent in the toner particles is preferably 1.0 mass% to 30.0 mass%, more preferably 2.0 mass% to 25.0 mass%.

[0055] The toner particles may contain a charge control agent. Examples of the charge control agent for controlling the toner to be negatively charged include the following. As organometallic compounds and chelate compounds, monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids, and metal compounds of dicarboxylic acid systems. Others include aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, or esters, phenol derivatives such as bisphenol, etc. Further, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthenic acid-based compounds, boron compounds, quaternary ammonium salts, and calixarenes are included.

[0056] On the other hand, examples of the charge control agent for controlling the toner to be positively charged include the following. Nigrosine and nigrosine modified products with fatty acid metal salts; guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthalenesulfonate, tetrabutylammonium tetrafluoroborate, (3-acrylamidopropyl)trimethylammonium chloride, and onium salts such as phosphonium salts which are analogs thereof and lake pigments thereof; triphenylmethane dyes and lake pigments thereof (as the lake-forming agent, phosphotungstic acid, phosphomolybdic acid, phosphotungstomolybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide Substances, ferrocyanides, etc.); metal salts of higher fatty acids; resin-based charge control agents. These charge control agents can be contained alone or in combination of two or more. As the addition amount of these charge control agents, it is preferably 0.01 part by mass to 10.00 parts by mass with respect to 100.0 parts by mass of the binder resin or the polymerizable monomer that forms the binder resin.

[0057] The method for manufacturing toner particles will be described. Known means can be used for the method for manufacturing toner particles, and wet manufacturing methods such as suspension polymerization method, emulsion polymerization aggregation method, emulsion aggregation method, etc. can be used, or kneading and pulverization method can be used. The toner particles are preferably toner particles obtained by a wet manufacturing method, and more preferably toner particles obtained by a suspension polymerization method.

[0058] In the suspension polymerization method, a polymerizable monomer composition containing a polymerizable monomer capable of forming a binder resin, a monohydric aliphatic alcohol, and additives such as a colorant and wax as required is dispersed in an aqueous medium to form droplet particles of the polymerizable monomer composition, and toner particles are manufactured by passing through a granulation step and a polymerization step of polymerizing the polymerizable monomer in the droplet particles. Preferred examples of the polymerizable monomer include vinyl-based polymerizable monomers. Specifically, the following can be exemplified.

[0059] For example, styrene; styrene derivatives such as α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene; acrylic polymerizable monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate; methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, vinyl formate.

[0060] The binder resin is preferably a styrene acrylic resin. That is, the binder resin is preferably at least one selected from the group consisting of acrylic polymerizable monomers and methacrylic polymerizable monomers, and a polymer of styrene.

[0061] The emulsion aggregation method is a method for producing toner in which an aqueous dispersion of fine particles made of a constituent material of toner particles, which is sufficiently small with respect to the target particle size, is prepared in advance, and the fine particles are aggregated in an aqueous medium until they reach the particle size of the toner, and the resin is fused by heating.

[0062] Preferably, the emulsion aggregation method includes a dispersion step of preparing each fine particle dispersion liquid containing the constituent material of the toner particles, an aggregation step of aggregating the fine particles containing the constituent material of the toner particles and controlling the particle size until it reaches the particle size of the toner particles to obtain aggregated particles, and a fusion step of fusing the resin contained in the obtained aggregated particles. Further, if necessary, subsequent cooling steps, a filtration / washing step of filtering the obtained toner particles and washing them with ion-exchanged water or the like, and a step of removing the moisture of the washed toner particles and drying them are performed.

[0063] An example of a manufacturing method for producing toner particles by the kneading and pulverizing method will be described below. In the raw material mixing step, as materials constituting the toner particles, a binder resin, a monohydric aliphatic alcohol, and other additives such as a colorant and wax as required are weighed in predetermined amounts, blended, and mixed. Examples of mixing devices include a double cone mixer, a V-type mixer, a drum-type mixer, a super mixer, an FM mixer, a Nauta mixer, and a mechano hybrid (manufactured by Nippon Coke Industry Co., Ltd.).

[0064] Next, the mixed materials are melt-kneaded to disperse a colorant, wax, etc. in the binder resin. In the melt-kneading step, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. Due to the advantage of continuous production, single-screw or twin-screw extruders are the mainstream. For example, KTK type twin-screw extruder (manufactured by Kobe Steel, Ltd.), TEM type twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), PCM kneader (manufactured by Ikegai Corporation), twin-screw extruder (manufactured by K.C.K. Co., Ltd.), co-kneader (manufactured by Buss Co., Ltd.), and Neidex (manufactured by Nippon Coke Industry Co., Ltd.) can be mentioned. Further, the resin composition obtained by melt-kneading may be rolled with a two-roll, etc. and cooled with water, etc. in the cooling step.

[0065] Then, the cooled product of the obtained resin composition is pulverized to a desired particle size in the pulverizing step. In the pulverizing step, for example, it is roughly pulverized with a pulverizer such as a crusher, a hammer mill, or a feather mill. Then, further, for example, it may be finely pulverized with a fine pulverizer using a cryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), a super rotor (manufactured by Nisshin Engineering Co., Ltd.), a turbo mill (manufactured by Freund Turbo Co., Ltd.), or an air jet method.

[0066] Thereafter, if necessary, it is classified using a classifier or a sieve such as an elbow jet (manufactured by Nippon Steel Mining Co., Ltd.) of the inertial classification method, a turbo plex (manufactured by Hosokawa Micron Corporation), a TSP separator (manufactured by Hosokawa Micron Corporation), or a faculty (manufactured by Hosokawa Micron Corporation) of the centrifugal classification method to obtain toner particles.

[0067] Also, the toner particles may be spheroidized. For example, after pulverization, spheroidization may be performed using a hybridization system (manufactured by Nara Machinery Co., Ltd.), a mechanofusion system (manufactured by Hosokawa Micron Corporation), a facultative (manufactured by Hosokawa Micron Corporation), or a Meteor Rainbow MR Type (manufactured by Nippon Pneumatic Mfg. Co., Ltd.). From the viewpoint of low-temperature fixability, the glass transition temperature (Tg) of the toner particles is preferably 40°C or higher and 60°C or lower.

[0068] At least one selected from the group consisting of hydrotalcite particles and alumina particles, and optionally an external additive C can be externally added and mixed to the obtained toner particles to obtain toner. The external addition and mixing may be performed by known means using a Henschel mixer or the like.

[0069] The toner particles preferably have a core-shell structure having a core particle and a shell on the surface of the core particle. By the toner particles having a core-shell structure, the durability and chargeability of the toner can be improved. The shell does not necessarily need to cover the entire core particle, and there may be a portion where the core particle is exposed.

[0070] The resin for forming the shell of the toner particles preferably mainly contains resins such as polyester resins and styrene-acrylic resins, and more preferably mainly contains polyester resins. Since polyester resins are easily compatible with alcohols, when the shell has a polyester resin, monohydric aliphatic alcohols efficiently gather near the surface of the toner particles, and the effect can be easily obtained with a small amount of alcohol addition.

[0071] In the cross-sectional observation of the toner by a transmission electron microscope, it is preferable that a shell exists inside the contour of the cross-section of the toner particles and the shell contains a polyester resin. And the thickness of the shell is preferably 0.8 nm to 100 nm, and more preferably 1 nm to 30 nm.

[0072] When the thickness of the shell is 0.8 nm or more, the durability is likely to be improved. Also, with the polyester resin, the monohydric aliphatic alcohol tends to gather near the surface of the toner particles. When the thickness of the shell is 100 nm or less, the fixing property becomes better. Also, the alcohol gathers moderately near the surface of the toner particles, and it becomes easier to suppress fusion during long-term use. The measurement method of the shell thickness will be described later. The method for measuring the thickness will be described later.

[0073] As the monomers used for the polyester resin, polyhydric alcohols (di- or tri- or higher-valent alcohols), polyvalent carboxylic acids (di- or tri- or higher-valent carboxylic acids), their acid anhydrides or their lower alkyl esters are used.

[0074] As the polyhydric alcohol monomers used for the polyester resin, the following polyhydric alcohol monomers can be used. As the dihydric alcohol component, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, and bisphenols represented by the formula (A) and their derivatives; diols represented by the formula (B) can be mentioned.

Chemical formula

[0075] (In the formula (A), R represents an ethylene group or a propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 0 or more and 10 or less.)

Chemical formula

[0076] (In formula (B), R’ represents -CH2CH2-, -CH2CH(CH3)-, or -CH2C(CH3)2-, x and y are each an integer of 0 or more, and the average value of x + y is 0 or more and 10 or less.) Examples of the alcohol component having a valency of 3 or more include sorbitol, 1,2,3,6 - hexanetetrol, 1,4 - sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4 - butanetriol, 1,2,5 - pentanetriol, glycerol, 2 - methylpropanetriol, 2 - methyl - 1,2,4 - butanetriol, trimethylolethane, trimethylolpropane, 1,3,5 - trihydroxymethylbenzene. Among these, preferably, glycerol, trimethylolpropane, and pentaerythritol are used. These divalent alcohols and alcohols having a valency of 3 or more can be used alone or in combination of two or more.

[0077] As the polyvalent carboxylic acid monomer used in the polyester resin, the following polyvalent carboxylic acid monomers can be used. Examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n - dodecenyl succinic acid, isododecenyl succinic acid, n - dodecyl succinic acid, isododecyl succinic acid, n - octenyl succinic acid, n - octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, anhydrides of these acids and lower alkyl esters thereof. Among these, maleic acid, fumaric acid, terephthalic acid, and n - dodecenyl succinic acid are preferably used.

[0078] Examples of the carboxylic acid, acid anhydride or lower alkyl ester thereof having a valency of 3 or more include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra(methylene carboxyl)methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, Empol trimer acid, acid anhydrides thereof or lower alkyl esters thereof. Among these, 1,2,4-benzenetricarboxylic acid, that is, trimellitic acid or a derivative thereof is preferably used because it is inexpensive and the reaction control is easy. These divalent carboxylic acids, etc. and carboxylic acids having a valency of 3 or more can be used alone or in combination of two or more.

[0079] The method for producing the polyester resin is not particularly limited, and a known method can be used. For example, the above-mentioned alcohol monomer and carboxylic acid monomer are charged simultaneously, and polymerized through an esterification reaction or transesterification reaction, and a condensation reaction to produce a polyester resin.

[0080] As the styrene acrylic resin used for the shell, the above-mentioned vinyl polymerizable monomers can be used. In addition, it is preferable to use monomers having a polar group such as acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. The styrene acrylic resin used for the shell is preferably a polymer of at least one selected from the group consisting of acrylic polymerizable monomers and methacrylic polymerizable monomers, at least one selected from the group consisting of monomers having a polar group, and styrene.

[0081] In order to improve the performance of the toner, the external additive preferably contains an external additive C different from the hydrotalcite particles and alumina particles.

[0082] External additive C includes, for example, fluororesin particles such as vinylidene fluoride fine particles and polytetrafluoroethylene fine powder; silica fine particles such as wet-process silica or dry-process silica, titanium oxide fine particles, alumina fine particles; hydrophobized fine particles obtained by surface-treating them with a hydrophobizing agent such as a silane compound, a titanium coupling agent, or silicone oil; oxides such as zinc oxide and tin oxide; complex oxides such as strontium titanate, barium titanate, calcium titanate, strontium zirconate, and calcium zirconate; carbonate compounds such as calcium carbonate and magnesium carbonate, and the like.

[0083] External additive C is preferably silica fine particles, and dry-process silica fine particles, so-called dry-process silica or fumed silica, which are fine particles produced by vapor-phase oxidation of a silicon halogen compound, are preferred. The dry process uses, for example, the thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame, and the basic reaction formula is as follows. SiCl4 + 2H2 + O2 → SiO2 + 4HCl In this manufacturing process, it is also possible to obtain composite fine particles of silica and other metal oxides by using another metal halogen compound such as aluminum chloride or titanium chloride together with the silicon halogen compound, and these are also included as the silica fine particles.

[0084] External additive C is preferably used because it can impart high chargeability and fluidity when the number-average particle diameter of the primary particles is 3 nm or more and 200 nm or less. The number-average particle diameter of the primary particles of external additive C is more preferably 5 nm or more and 20 nm or less. The content of external additive C is preferably 0.01 part by mass or more and 3.0 parts by mass or less, more preferably 0.5 part by mass or more and 2.0 parts by mass or less, based on 100 parts by mass of toner particles. When the content of external additive C is within the above range, good fluidity can be achieved while improving the fixing property. Furthermore, it is preferable that external additive C is surface-treated with a hydrophobizing agent. Surface treatment of external additive C makes it easier to obtain good images regardless of the use environment.

[0085] The measurement methods of various physical properties will be described below. <Identification and Quantification of Monohydric Aliphatic Alcohols in Toner> (Preparation of Extraction Sample) Add 2 g of toner and 18 g of ethanol, homogenize by hand shaking, and then irradiate with ultrasonic waves for 5 min. Thereafter, leave it to stand in a constant temperature bath at 60 °C for one day and night, and further leave it to stand at room temperature for 3 days. Collect the supernatant of the sample after standing and filter it through a PTFE syringe filter (pore diameter 250 nm), and use the filtrate as the extraction sample.

[0086] (GC / MS Analysis) The GC / MS apparatus is GC TRACE-1310 (manufactured by Thermo Scientifi c), the detector is a single quadrupole analyzer MS ISQ LT (manufactured by Thermo Scientific), and the autosampler is TRIPLUS RSH (Thermo Scientific). The measurement is carried out under the conditions shown below. Sample amount: 1 μL (liquid injection) Column: HP5-MS (manufactured by Agilent Technologies) Length: 30 m, inner diameter 0.25 mm, film thickness 0.25 μm Split ratio: 10 Split flow: 15 mL / min Inlet temperature: 250 °C Flow rate of helium gas in the column: 1.5 mL / min MS ionization: EI Column temperature condition: Hold at 40 °C for 3 min, then increase to 300 °C at 10 °C / min and hold for 10 min. Ion source temperature: 250 °C Mass Range: m / z 45 - 1000 Carrier line temperature: 250 °C

[0087] (Calibration curve preparation) Prepare calibration curve samples such that the concentration (mass basis) of monohydric aliphatic alcohols in the ethanol solution is 10 ppm, 50 ppm, 100 ppm, and 250 ppm. Measure these samples under the above conditions and prepare a calibration curve from the peak area values of the monohydric aliphatic alcohols. Use the obtained calibration curve to analyze the above extraction sample and calculate the content ratio of monohydric aliphatic alcohols in the toner extracted with ethanol.

[0088] The structure of the monohydric aliphatic alcohol is determined by analyzing the above extraction sample using an FT NMR apparatus JNM - EX400 (manufactured by JEOL Ltd.) 1 H - NMR 400 MHz, CDCl3, room temperature (25 °C)]( 13 C - NMR, etc. are also used in combination) for structure determination.

[0089] (Measurement of work function of toner particles and external additives) The work function of toner particles and external additives is measured by the following measurement method. The work function is quantified as the energy (eV) required to extract electrons from the substance. The work function is measured using a surface analyzer (AC - 2 manufactured by Riken Keiki Co., Ltd.). In the said apparatus, a deuterium lamp is used and measurement is performed under the following conditions. Irradiation light quantity: 800 nW Spectrometer: Monochromatic light Spot size: 4 [mm] × 4 [mm] Energy scanning range: 3.6 - 6.2 [eV] Anode voltage: 2910 V Measurement time: 30 [sec / 1 point]

[0090] Then, the photoelectrons emitted from the sample surface are detected and processed through calculation using the work function calculation software incorporated in the surface analyzer. Regarding the work function, it is measured with a repetitive accuracy (standard deviation) of 0.02 [eV]. When measuring powder, a cell for powder measurement is used.

[0091] In the above surface analysis, when the excitation energy of monochromatic light is scanned from low to high at intervals of 0.05 eV, photoquantum emission starts from a certain energy value [eV], and this energy threshold is taken as the work function [eV].

[0092] An example of the measurement curve of the work function obtained by measurement under the above conditions is shown in FIG. 1. In FIG. 1, the horizontal axis represents the excitation energy [eV], and the vertical axis represents the value of the square root of the number of emitted photoelectrons (normalized photoquantum yield) Y. Generally, when the excitation energy value exceeds a certain threshold, the emission of photoelectrons, that is, the normalized photoquantum yield increases rapidly, and the work function measurement curve rises rapidly. The rising point is defined as the photoelectric work function value [Wf]. This photoelectric work function value [Wf] is taken as the work function of the sample. In the measurement of the work function, as the sample, toner particles, hydrotalcite particles, alumina particles or external additive C is used. Regarding the toner particles, toner particles from which the external additive has been removed by the following method may be used as the sample.

[0093] 160 g of sucrose (manufactured by Kishida Chemical) is added to 100 mL of ion-exchanged water, and while stirring with hot water, it is dissolved to prepare a thick sucrose solution. 31 g of the thick sucrose solution and 6 mL of contaminon N are placed in a centrifuge tube to prepare a dispersion. 1 g of toner is added to this dispersion, and the toner lumps are loosened with a spatula or the like.

[0094] The centrifuge tube is shaken for 20 minutes at 350 reciprocations per minute using the "KM Shaker" (model: V.SX) manufactured by Iwaki Sangyo Co., Ltd. After shaking, the solution is transferred to a glass tube (50 mL) for a swinging rotor and centrifuged at 3500 rpm for 30 minutes using a centrifuge. In the glass tube after centrifugation, toner particles are present in the uppermost layer, and external additives are present on the aqueous solution side in the lower layer. The toner particles in the uppermost layer are separated. If necessary, shaking and centrifugation may be repeated to ensure sufficient separation.

[0095] Regarding hydrotalcite particles or alumina particles, and external additive C, when they can be obtained individually, hydrotalcite particles or alumina particles, and external additive C can be measured individually. When they cannot be obtained individually, the toner is dispersed in a solvent such as chloroform, and then hydrotalcite particles, alumina particles, and external additive C are separated by the difference in specific gravity using centrifugation or the like. The method is as follows.

[0096] First, 1 g of toner is added to 31 g of chloroform in a vial and dispersed to separate hydrotalcite particles, alumina particles, and external additive C from the toner. For dispersion, an ultrasonic homogenizer is used to treat for 30 minutes to prepare a dispersion. The treatment conditions are as follows. as follows. Ultrasonic treatment device: Ultrasonic homogenizer VP-050 (manufactured by Taitec Corporation) Microchip: Step-type microchip, tip diameter φ2 mm Tip position of the microchip: Center of the glass vial and 5 mm height from the bottom of the vial Ultrasonic conditions: Intensity 30%, 30 minutes. At this time, apply ultrasonic waves while cooling the vial with ice water so that the dispersion does not heat up.

[0097] The dispersion is transferred to a glass tube (50 mL) for a swinging rotor and centrifuged using a centrifuge (H-9R; manufactured by Kokusan Co., Ltd.) at 58.33S -1Centrifugation is carried out under conditions of 100°C for 30 minutes. After centrifugation, the fractions mainly containing hydrotalcite particles or alumina particles and external additive C can be separated from the glass tube due to their specific gravity. If separation is not successful, adjust the rotation speed and time of the centrifugation. The fraction obtained is dried under vacuum conditions (40°C / 24 hours) to obtain a sample.

[0098] <Method of measuring weight average particle size (D4) of toner> The weight-average particle size (D4) of the toner particles was measured using a precision particle size distribution measuring device called the Coulter Counter Multisiz er 3" (registered trademark, manufactured by Beckman Coulter, Inc.) and the measurement conditions and data The accompanying dedicated software for data analysis, "Beckman Coulter Multisize The electrolyte used for the measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of approximately 1% by mass, for example, "ISOTON II" (Beckman Coulter, Inc.). Cut.

[0099] Before carrying out measurements and analysis, the dedicated software is set up as follows. In the "Change Standard Measurement Method (SOM) Screen" of the dedicated software, the total count number in control mode is set to 50,000 particles, the number of measurements is set to 1, and the Kd value is set to the value obtained using "Standard Particle 10.0 μm" (Beckman Coulter, Inc.). The threshold and noise level are automatically set by pressing the threshold / noise level measurement button. In addition, the current is set to 1,600 μA, the gain to 2, and the electrolyte to ISOTON II. After measurement, Check the flash of the aperture tube. In the "Conversion Setting Screen from Pulse to Particle Size" of the dedicated software, set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm or more and 60 μm or less. The specific measurement method is as follows.

[0100] (1) Pour about 200 mL of the electrolytic aqueous solution into a 250 mL round-bottom glass beaker dedicated to Multisizer 3, set it on the sample stand, and stir with a stirrer rod counterclockwise at 24 revolutions per second. Then, use the "Flash of Aperture Tube" function of the dedicated software to remove dirt and bubbles in the aperture tube. (2) Pour about 30 mL of the electrolytic aqueous solution into a 100 mL flat-bottom glass beaker, and add about 0.3 mL of the following dilution as a dispersant. · Dilution: A dilution obtained by diluting "Contaminon N" (a neutral detergent for precision measuring instruments with a pH of 7 composed of a nonionic surfactant, an anionic surfactant, and an organic builder, 10% by mass aqueous solution, manufactured by Wako Pure Chemical Industries, Ltd.) 3-fold by mass with ion-exchanged water (3) Put a predetermined amount of ion-exchanged water into the water tank of the following ultrasonic disperser with two oscillators with an oscillation frequency of 50 kHz built in with a 180-degree phase shift and an electrical output of 120 W, and add about 2 mL of the Contaminon N to this water tank. · Ultrasonic disperser: "Ultrasonic Dispersion System Tetora150" (manufactured by Nikkaki Bios Co., Ltd.) (4) Set the beaker in (2) in the beaker fixing hole of the ultrasonic disperser and operate the ultrasonic disperser. Then, adjust the height position of the beaker so that the resonance state of the liquid surface of the electrolytic aqueous solution in the beaker is maximized. (5) While irradiating the electrolytic aqueous solution in the beaker in (4) with ultrasonic waves, add about 10 mg of toner little by little to the electrolytic aqueous solution and disperse it. Then, continue the ultrasonic dispersion treatment for another 60 seconds. Note that during ultrasonic dispersion, adjust the water temperature in the water tank to be 15°C or more and 40°C or less as appropriate. (6) After the ultrasonic dispersion treatment, take out about 10 mL of the electrolytic aqueous solution from the beaker in (4) and put it into a 250 mL round-bottom glass beaker dedicated to Multisizer 3. (7) Set the beaker on the sample stand of Multisizer 3, and measure the particle size distribution of the toner in the electrolytic aqueous solution using Multisizer 3. (6) Using a pipette, drop the electrolytic aqueous solution of (5) in which toner is dispersed into the round-bottomed beaker of (1) installed in the sample stand, and adjust it so that the measurement concentration becomes about 5%. Then, perform the measurement until the number of measured particles reaches 50,000. (7) Analyze the measurement data using the dedicated software attached to the device to calculate the weight average particle size (D4). When set to graph / volume% in the dedicated software, the "average diameter" on the analysis / volume statistical value (arithmetic mean) screen is the weight average particle size (D4).

[0101] <Measurement of the average circularity of toner> The average circularity of the toner is measured using a flow-type particle image measuring device "FPIA-3000" (manufactured by Sysmex Corporation) under the measurement and analysis conditions during the calibration operation. The specific measurement method is as follows. First, put about 20 ml of ion-exchanged water from which impurities and solids have been removed in advance into a glass container. Add about 0.2 ml of a dilution obtained by diluting "Contaminon N" (a 10% by mass aqueous solution of a neutral detergent for precision measuring instruments with pH 7 composed of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) about 3 times by mass with ion-exchanged water as a dispersant. Further, add about 0.02 g of the measurement sample and perform a dispersion treatment for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. At that time, appropriately cool so that the temperature of the dispersion is 10°C or higher and 40°C or lower. As the ultrasonic disperser, use a tabletop ultrasonic cleaner disperser with an oscillation frequency of 50 kHz and an electrical output of 150 W (for example, "VS-150" (manufactured by Vervo Clear)), put a predetermined amount of ion-exchanged water in the water tank, and add about 2 ml of the Contaminon N to this water tank. For the measurement, use the flow-type particle image analyzer equipped with "UPlanApro" (magnification 10 times, numerical aperture 0.40) as the objective lens, and use "Particle Sheath PSE-900A" (manufactured by Sysmex Corporation) as the sheath fluid. Introduce the dispersion adjusted according to the above procedure into the flow-type particle image analyzer, and measure 3000 toner particles in the total count mode in the HPF measurement mode. Then, set the binarization threshold during particle analysis to 85%, limit the analysis particle diameter to be not less than 1.985 μm and less than 39.69 μm in terms of equivalent circle diameter, and obtain the average circularity. Before starting the measurement, perform automatic focus adjustment using standard latex particles (for example, "RESEARCH AND TEST PARTICLES Latex Microsph ere Suspensions 5200A" manufactured by Duke Scientific Corporation diluted with ion-exchanged water). Thereafter, it is preferable to perform focus adjustment every 2 hours from the start of the measurement. RESEARCH AND TEST PARTICLES Latex Microsph ere Suspensions 5200A" diluted with ion-exchanged water). Thereafter, it is preferable to perform focus adjustment every 2 hours from the start of the measurement. In the examples of the present application, a flow-type particle image analyzer that has received a calibration certificate issued by Sysmex Corporation was used. The measurement was performed under the measurement and analysis conditions at the time of receiving the calibration certificate, except that the analysis particle diameter was limited to be not less than 1.985 μm and less than 39.69 μm in terms of equivalent circle diameter.

[0102] <Measurement of the proportion of styrene-acrylic resin in toner> For the analysis of the content ratio of the resin, pyrolysis gas chromatography-mass spectrometry (hereinafter, pyrolysis GC / MS) and NMR are used. In the present disclosure, components having a molecular weight of 1500 or more are the measurement targets. This is because the region with a molecular weight of less than 1500 has a high proportion of wax and is considered to be a region where the resin is hardly contained. In pyrolysis GC / MS, the constituent monomers of the total amount of resin in the toner can be determined, and the peak area of each monomer can be obtained. However, for quantification, normalization of the peak intensity using a sample with a known concentration as a reference is required. On the other hand, in NMR, it is possible to determine and quantify the constituent monomers without using a sample with a known concentration. Therefore, depending on the situation, the determination of the constituent monomers is performed while comparing the spectra of both NMR and pyrolysis GC / MS. In pyrolysis GC / MS, the constituent monomers of the total amount of resin in the toner can be determined, and the peak area of each monomer can be obtained. However, for quantification, normalization of the peak intensity using a sample with a known concentration as a reference is required. On the other hand, in NMR, it is possible to determine and quantify the constituent monomers without using a sample with a known concentration. Therefore, depending on the situation, the determination of the constituent monomers is performed while comparing the spectra of both NMR and pyrolysis GC / MS.

[0103] Specifically, when the resin component that is insoluble in deuterated chloroform, which is the extraction solvent during NMR measurement, is less than 5.0% by mass, quantification is performed by NMR measurement. On the other hand, when the resin component that is insoluble in deuterated chloroform is 5.0% by mass or more, both NMR and pyrolysis GC / MS measurements are performed on the deuterated chloroform-soluble component, and pyrolysis GC / MS measurement is performed on the deuterated chloroform-insoluble component. In this case, first, NMR measurement of the deuterated chloroform-soluble component is performed to determine and quantify the constituent monomers (quantification result 1). Next, pyrolysis GC / MS measurement is performed on the deuterated chloroform-soluble component to obtain the peak areas of the peaks attributed to each constituent monomer. Using the quantification result 1 obtained from the NMR measurement, the relationship between the amount of each constituent monomer and the peak area of pyrolysis GC / MS is determined. Next, pyrolysis GC / MS measurement of the deuterated chloroform-insoluble component is performed to obtain the peak areas of the peaks attributed to each constituent monomer. Based on the relationship between the amount of each constituent monomer and the peak area of pyrolysis GC / MS obtained from the measurement of the deuterated chloroform-soluble component, quantification of the constituent monomers in the deuterated chloroform-insoluble component is performed (quantification result 2). Then, combining quantification result 1 and quantification result 2 gives the final quantification result of each constituent monomer.

[0104] Specifically, the following operations are performed. (1) Weigh 500 mg of toner precisely into a 30 mL glass sample bottle, add 10 mL of deuterated chloroform, then cover it and disperse and dissolve it for 1 hour using an ultrasonic disperser. Next, filter it through a 0.4 μm diameter membrane filter and collect the filtrate. At this time, the deuterated chloroform-insoluble component remains on the membrane filter. (2) For 3 mL of the filtrate, use preparative high-performance liquid chromatography (HPLC) to remove components with a molecular weight less than 1500 using a fraction collector, and collect the resin solution. Remove chloroform from the collected solution using a rotary evaporator to obtain the resin. For components with a molecular weight less than 1500, measure a polystyrene resin with a known molecular weight in advance to determine and obtain the elution time. (3) Dissolve 20 mg of the obtained resin in 1 mL of deuterated chloroform, 1 Perform 1H-NMR measurement, assign the spectra for each constituent monomer used in the styrene acrylic resin, and determine the quantitative values. (4) If analysis of the deuterated chloroform-insoluble fraction is required, perform the analysis by pyrolysis GC / MS. If necessary, perform derivatization treatment such as methylation.

[0105] (NMR measurement conditions) Apparatus: FT NMR apparatus JNM-EX400 (manufactured by JEOL Ltd.) Measurement frequency: 400 MHz Pulse condition: 5.0 μs Frequency range: 10500 Hz Number of integrations: 1024 times Measurement temperature: 25 °C Sample: Put 50 mg of the measurement sample into a sample tube with an inner diameter of 5 mm, add deuterated chloroform (CDCl3) as a solvent, and dissolve it in a constant temperature bath at 40 °C for preparation. Prepare by adding deuterated chloroform (CDCl3) as a solvent and dissolving it in a constant temperature bath at 40 °C. Determine the mol ratio of each monomer component from the integration value of the obtained spectrum, and calculate the composition ratio (mass %) based on this.

[0106] (Pyrolysis GC / MS measurement conditions) Pyrolysis apparatus: JPS-700 (manufactured by JEOL Ltd.) Decomposition temperature: 590 °C GC / MS apparatus: Focus GC / ISQ (Thermo Fisher) Column: HP-5MS, length 60 m, inner diameter 0.25 mm, film thickness 0.25 μm Inlet temperature: 200 °C Flow pressure: 100 kPa Split: 50 mL / min MS ionization: EI Ion source temperature: 200 °C Mass Range: 45 - 650

[0107] <Identification of the resin species of the shell of toner particles> The resin type of the shell of toner particles is analyzed using time-of-flight secondary ion mass spectrometry (TOF-SIMS). For measuring the amount of polyester on the surface of toner particles, for example, when the polyester resin has a structure derived from phthalic acid, isophthalic acid, or terephthalic acid, TRIFT-IV manufactured by ULVAC-PHI, Inc. can be used. The analysis conditions were as follows.

[0108] Sample preparation: Attach the toner to an indium sheet. Note that toner particles obtained by separating the external additive from the toner may be used as the sample. Sample pretreatment: None Primary ion: Au + Acceleration voltage: 30 kV Charge neutralization mode: On Measurement mode: Positive Raster: 100 μm Calculation of peak intensity (EI) of phthalic acid, isophthalic acid, or terephthalic acid containing an ester group: According to the standard software of ULVAC-PHI, Inc. (Win Cadense), mass number 14 The total number of counted peaks from 148 to 150 is taken as the peak intensity (EI). Calculation of peak intensity from other resins: According to the standard software of ULVAC-PHI, Inc. (Win Cad ense), the total number of counted peaks from mass number 90 to 105 is taken as the peak intensity from other resins.

[0109] The sum of this peak intensity and the peak intensity (EI) of phthalic acid, isophthalic acid, or terephthalic acid containing the above ester group is taken as the peak intensity (ZI) from the resin on the surface of the toner particles. EI / ZI is calculated from the above peak intensities. For example, when EI / ZI ≥ 0.5, it is determined that a polyester resin is present on the surface of the toner particles. The mass number in the measurement of the peak intensity (EI) can be changed according to the constituent monomers of the polyester resin used.

[0110] <Measurement of shell thickness> The thickness of the shell is measured by a transmission electron microscope. The cross-section of the toner observed by the transmission electron microscope is prepared as follows. First, toner is scattered in a single layer on a cover glass (Matsunami Glass Ind., Ltd., square cover glass; square No. 1), and an Os film (5 nm) and a naphthalene film (20 nm) are applied to the toner as a protective film using an osmium plasma coater (Filgen, Inc., OPC80T). Next, a PTFE tube (inner diameter Φ1.5 mm × outer diameter Φ3 mm × 3 mm) is filled with a photocurable resin D800 (JEOL Ltd.), and the cover glass is gently placed on the tube in such a direction that the toner is in contact with the photocurable resin D800. After irradiating light in this state to cure the resin, the cover glass and the tube are removed to form a cylindrical resin in which the toner is embedded on the outermost surface.

[0111] Using an ultrasonic ultramicrotome (Leica Microsystems, UC7), at a cutting speed of 0.6 mm / s, cut from the outermost surface of the cylindrical resin by a length equal to the radius of the toner (for example, 4.0 μm when the weight average particle size (D4) is 8.0 μm) to expose the cross-section of the center part of the toner. Next, cut to a film thickness of 100 nm to prepare a thin sample of the cross-section of the toner. By cutting in such a manner, the cross-section of the center part of the toner can be obtained. Using a transmission electron microscope (TEM) (JEOL JEM2800), a TEM image of the toner is prepared under the condition of an acceleration voltage of 200 k V. The probe size of the TEM is 1 nm, and the image is acquired at an image size of 1024 × 1024 pixels. In the obtained TEM image, the binder resin and the shell contained in the core particles are observed as different contrasts. Although the difference in light and dark varies depending on the material, in the present disclosure, the portion observed as a part with a contrast different from that of the binder resin contained in the core particles is defined as the shell. Ten toners within ±1.0 μm from the weight average particle size (D4) are selected for imaging. The observation magnification is 20,000 times.

[0112] For the measurement of thickness, commercially available image analysis software, WinROOF (manufactured by Mitani Corporation), is used. In the TEM images of 10 toner particles randomly selected according to the above criteria, for each toner, the thickness of the shell is measured at 4 points. Specifically, two straight lines perpendicular to each other are drawn at approximately the center of the toner cross-section, and the thickness of the shell is measured at the 4 points where the two straight lines intersect the shell. The thickness of the shell is defined as the distance from the contour of the cross-section of the toner particle to the interface between the binder resin and the shell. The arithmetic mean value of all the measured values is taken as the thickness of the shell of the toner particle.

[0113] <Method for Measuring the Number Average Value of the Major Axis of Hydrotalcite Particles or Alumina Particles and the Number Average Particle Size of the Primary Particles of Exterior Additive C> The locations of the hydrotalcite particles, alumina particles, and exterior additive C such as silica particles present on the toner surface can be identified by observation with a super-high-resolution field emission scanning electron microscope S-4800 (Hitachi High-Technologies Corporation) (SEM-EDX) and elemental analysis. For example, observation and elemental mapping are performed in a continuous field of view at a magnification of 20,000 times. When the presence of both elements, Mg and Al, can be confirmed for the observed particles, these can be judged as hydrotalcite particles. Similarly, when the presence of Al can be confirmed for the observed particles, these can be judged as alumina particles, and when the presence of Si can be confirmed, these can be judged as silica particles.

[0114] The method for measuring the number average value of the major axis of hydrotalcite particles is described below. The major axis is measured for at least 300 hydrotalcite particles on the toner surface and the average is obtained. Some of the hydrotalcite particles exist as aggregated particles, but such aggregated particles are not the object of particle size measurement. Also, the maximum diameter of the particle is treated as the major axis. Also, the average of the major axis of the alumina particles is measured and calculated in the same manner as the average of the major axis of the hydrotalcite particles. Also, when the exterior additive C is silica particles, if the shape is spherical, the absolute maximum length is counted as the particle size, and if it has a major axis and a minor axis, the major axis is counted as the particle size, and the number average particle size of the primary particles is calculated.

[0115] <Method for Measuring Contents of Hydrotalcite Particles, Alumina Particles, and Excipient C> The contents of the hydrotalcite particles, alumina particles, and excipient C are determined by calculation from the intensities of the elements derived from the hydrotalcite particles, alumina particles, and excipient C in the toner measured by a wavelength-dispersive X-ray fluorescence analyzer (XRF). For example, using the calibration curve method, the content of the hydrotalcite particles can be analyzed and calculated from the intensities of the Al and Mg elements. Also, the content of the alumina particles can be analyzed and calculated from the intensity of the Al element. Further, when excipient C is silica particles, the content can be analyzed and calculated from the intensity of the Si element.

[0116] As the measuring device, a wavelength-dispersive X-ray fluorescence analyzer "Axios" (manufactured by PANalytical) and dedicated software "SuperQ ver.4.0F" (manufactured by PANalytical) attached for setting measurement conditions and analyzing measurement data are used. Note that Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, the measurement diameter (collimator mask diameter) is 10 mm, and the measurement time is 10 seconds. Also, when measuring light elements, a proportional counter (PC) is used for detection, and when measuring heavy elements, a scintillation counter (SC) is used for detection. Measurement is performed under the above conditions, the elements are identified based on the obtained X-ray peak positions, and the concentration is calculated from the counting rate (unit: cps), which is the number of X-ray photons per unit time. Note that as the measurement sample, about 1 g of toner is placed in a dedicated pressing aluminum ring and flattened, and a pellet molded to a thickness of about 2 mm by pressurizing at 20 MPa for 60 seconds using a tablet molding compression machine "BRE-32" (manufactured by Maehara Testing Machine Co., Ltd.) is used. Based on a calibration curve prepared in advance from a sample with a known content, the content is calculated from the obtained peak intensity.

Examples

[0117] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto in any way. Parts used in the examples are on a mass basis unless otherwise specified.

[0118] <Production Example of Excipient B1> 203.3 g of magnesium chloride hexahydrate and 96.6 g of aluminum chloride hexahydrate were dissolved in 1 L of deionized water. While maintaining this solution at 25°C, the pH was adjusted to 10.5 with a solution prepared by dissolving 60 g of sodium hydroxide in 1 L of deionized water. Then, it was aged at 98°C for 24 hours. After cooling, the precipitate was washed with deionized water until the conductivity of the filtrate became 100 μS / cm or less, and a slurry with a concentration of 5 mass% was obtained. While stirring this slurry, Excipient B1 was obtained by spray drying with a spray dryer (DL-41, manufactured by Yamato Scientific Co., Ltd.) at a drying temperature of 180°C, a spray pressure of 0.16 MPa, and a spray rate of approximately 150 mL / min. The physical properties are shown in Table 1.

[0119]

Table 1

[0120] <Production Examples of Excipients B2 to B10> In the production of Excipient B1, Excipients B2 to B10 were obtained in the same manner except that the addition amounts of magnesium chloride hexahydrate and aluminum chloride hexahydrate, and the spray pressure and spray rate of the spray dryer were adjusted. The physical properties are shown in Table 1.

[0121] <Production Example of Excipient B11> Using aluminum hydroxide as the alumina raw material, 0.02 parts of α-alumina was added as a seed crystal (the addition amount is based on 100 parts of the alumina amount obtained from the alumina raw material, the same applies hereinafter), and hydrogen chloride gas was introduced into a tubular furnace as the atmosphere gas for experiments. The introduction temperature of the atmosphere gas was 900°C, the holding temperature (firing temperature) was 1200°C, and the holding time (firing time) was 30 minutes. The physical properties of Excipient B11 are shown in Table 1.

[0122] <Production Example of Excipient B12> Fumed silica (trade name AEROSIL 380S, specific surface area by BET method 380 m 2 / g, number average primary particle diameter 7 nm, manufactured by Nippon Aerosil Co., Ltd.) 100 parts, 10.0 parts of polydimethylsiloxane was sprayed, and stirring was continued for 30 minutes. Then, while stirring, the temperature was raised to 300 °C and stirring was continued for another 2 hours to prepare an external additive B12. The physical properties are shown in Table 1.

[0123] <Production Example of External Additive B13> An external additive B13 was produced in the same manner as external additive B12, except that polydimethylsiloxane was changed to amino-modified silicone oil. The physical properties are shown in Table 1.

[0124] <Production Example of External Additive B14> Anatase-type titanium oxide was treated with 12% by mass of isobutyltrimethoxysilane to obtain an external additive B14. The physical properties are shown in Table 1.

[0125] <Production Example of Shell Resin 1> In a reaction vessel equipped with a nitrogen inlet tube, a dehydrating tube, a stirrer, and a thermocouple, 40 mol% of terephthalic acid, 10 mol% of trimellitic acid, and 50 mol% of bisphenol A-propylene oxide (PO) 2 mol adduct were placed, and 1.5 parts of dibutyltin oxide was added as a catalyst per 100 parts of the total amount of monomers. Then, the temperature was quickly raised to 180 °C at normal pressure under a nitrogen atmosphere, and then water was distilled off while heating from 180 °C to 210 °C at a rate of 10 °C / hour to perform polycondensation. After reaching 210 °C, the pressure inside the reaction vessel was reduced to 5 kPa or less, and polycondensation was performed under the conditions of 210 °C and 5 kPa or less to obtain shell resin 1. At that time, the polymerization time was adjusted so that the softening point of the obtained shell resin 1 was 120 °C.

[0126] <Production Example of Shell Resin 2> 300 parts of xylene (boiling point 144 °C) was charged into a flask capable of pressurization and depressurization, and after sufficiently replacing the inside of the container with nitrogen while stirring, the temperature was raised to reflux. A mixed solution of the following raw materials was added. · Styrene 91.7 parts · 2.50 parts of methyl methacrylate · 3.30 parts of methacrylic acid · 2.50 parts of 2-hydroxyethyl methacrylate · 2.00 parts of di-tert-butyl peroxide Polymerization was carried out at a polymerization temperature of 175 °C and a reaction pressure of 0.125 MPa for 5 hours. Then, a solvent removal step was carried out under reduced pressure for 3 hours to remove xylene, and the resulting product was pulverized to obtain shell resin 2 (acid value = 10.9, molecular weight (Mp) = 14,500).

[0127] <Production Example of Toner Particle A1> 390.0 parts of ion-exchanged water and 14.0 parts of sodium phosphate (dodecahydrate) [manufactured by Rasa Industries Co., Ltd.] were charged into a reaction vessel, and the mixture was kept at 65 °C for 1.0 hour while purging with nitrogen. Next, while stirring at 12,000 rpm using a T.K. homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), an aqueous calcium chloride solution in which 9.2 parts of calcium chloride (dihydrate) was dissolved in 10.0 parts of ion-exchanged water was added all at once to prepare an aqueous medium containing a dispersion stabilizer. Further, hydrochloric acid was added to the aqueous medium to adjust the pH to 6.0, and aqueous medium 1 was obtained.

[0128] On the other hand, the following materials were charged into an attritor (manufactured by Nippon Coke & Engineering Co., Ltd.), and further zirconia particles with a diameter of 1.7 mm were charged. After dispersing at 220 rpm for 5.0 hours, the zirconia particles were removed to prepare dispersion liquid 1 in which a colorant was dispersed. · 60.0 parts of styrene · 6.5 parts of colorant (Pigment Red 122)

[0129] Next, the following materials were added to the prepared dispersion liquid 1. · 15.0 parts of styrene · 25.0 parts of n-butyl acrylate · 4.0 parts of shell resin 1 · 0.7 part of charge control agent (aluminum di-tert-butyl salicylate) · 9.0 parts of hydrocarbon wax (HNP-51, manufactured by Nippon Seiro Co., Ltd.) ​· 0.5 part of dodecyl alcohol

[0130] After that, the mixture was heated to a temperature of 60°C and then stirred at 9000 r / min with a TK type homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) for dissolution and dispersion. 10.0 parts of a polymerization initiator 2,2'-azobis(2,4-dimethylvaleronitrile) was dissolved therein to prepare a monomer composition. The monomer composition was introduced into the above aqueous medium, and granulation was carried out at a temperature of 60°C for 15 minutes while rotating a Clear mixer at 15000 rpm. Then, it was transferred to a propeller type stirrer and reacted at a temperature of 70°C for 5 hours while stirring at 100 r / min. After that, the temperature was raised to 80°C and the reaction was further carried out for 5 hours to produce toner particles. After completion of the polymerization reaction, the slurry containing the particles was cooled, hydrochloric acid was added, the pH was adjusted to 1.4 or less, and it was stirred and left for 1 hour, followed by solid-liquid separation with a pressure filter to obtain a toner cake. This was reslurried with ion-exchanged water to form a dispersion again, and then solid-liquid separation was carried out with the above-mentioned filter. Reslurrying and solid-liquid separation were repeated until the electric conductivity of the filtrate became 5.0 μS / cm or less, and finally solid-liquid separation was carried out to obtain a toner cake. The obtained toner cake was dried with an air current dryer flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.). The drying conditions were an injection temperature of 90°C, a dryer outlet temperature of 40°C, and the supply rate of the toner cake was adjusted to a rate at which the outlet temperature did not deviate from 40°C according to the water content of the toner cake. Further, using a multi-stage classifier utilizing the Coanda effect, fine and coarse powder was cut to obtain toner particles A1 having a weight average particle diameter (D4) of 6.8 μm. The physical properties are shown in Table 2.

[0131]

Table 2

[0132] <Production Example of Toner 1> To 100 parts of the obtained toner particles 1, external additives of the types and amounts shown in Table 3 were externally added and mixed with FM10C (manufactured by Nippon Coke & Engineering Co., Ltd.). The external addition conditions were: toner particle charge amount: 1.8 kg, rotation speed: 60 s -1, External addition was carried out in 15 minutes. Then, it was sieved with a mesh having an opening of 200 μm to obtain Toner 1. The physical properties are shown in Table 3.

[0133]

Table 3

[0134] <Production Examples of Toner Particles A2 to A20> As shown in Table 2, Toner Particles A2 to A20 were obtained in the same manner as Toner Particles 1 except that the type and amount of alcohol, the amount and type of shell resin, and the type of pigment were changed. The physical properties are shown in Table 2.

[0135] <Production Examples of Toners 2 to 27> As shown in Table 3, Toners 2 to 27 were obtained in the same manner as Toner 1 except that the type and amount of external additives were changed. The physical properties are shown in Table 3. Also, when the content of the external additives in the obtained toners was measured, it was confirmed that each external additive was contained in the amounts described in Table 3.

[0136] <Example 1> The following evaluations were performed on Toner 1. A cartridge filled with Toner 1 obtained above was attached to a Canon laser beam printer LBP652C, and the following evaluations were carried out. As the transfer material, A4 CS-680 (basis weight 68 g / cm 2 ) was used. Also, the evaluations were carried out after leaving the machine standing in each evaluation environment for 3 days.

[0137] <1>Evaluation of Tip Concentration The evaluation was carried out in a high temperature and high humidity (H / H) environment (32.5 °C, 80% RH). A solid image was output, and the image density for one rotation of the developing roller from the top of the solid image and the image density after the second rotation and subsequent rotations were measured with a color reflection densitometer (X-Rite 404A). Based on the difference in these image densities, the evaluation was carried out as follows and the evaluation results are shown in Table 4. A: The image density difference is 0.05 or less B: The image density difference is greater than 0.05 and less than or equal to 0.10 C: The image density difference is greater than 0.10 and less than or equal to 0.15 D: The image density difference is greater than 0.15

[0138] <2> Evaluation of fogging The evaluation was carried out in a high temperature and high humidity (H / H) environment (32.5 °C, 80% RH). In the H / H environment, after continuously outputting 1000 sheets of 1% printed images, one sheet of solid white image with 0% printing was output, and its reflectance (%) was measured with a "REFLECTOMETER MODEL TC-6DS" (manufactured by Tokyo Denshoku Co., Ltd.). The obtained reflectance was evaluated using the value (fogging value) (%) obtained by subtracting the reflectance (%) of the unused printout paper (standard paper) measured in the same way. The smaller the value, the more the image fogging is suppressed. The evaluation results are shown in Table 4 (Evaluation criteria) A: The fogging value is less than 1.0% B: The fogging value is 1.0% or more and less than 3.0% C: The fogging value is 3.0% or more and less than 5.0% D: The fogging value is 5.0% or more

[0139] <3> Evaluation of ghosting The evaluation was carried out in a low temperature and low humidity (L / L) environment (15.0 °C, 10% RH). After continuously outputting 1000 sheets of solid white images with a single-color 0% printing rate, a single-color ghost determination image was output. The ghost determination image is a halftone image with a toner loading amount of 0.20 mg / cm 2 formed by arranging 7 solid images of 15 mm × 15 mm in a horizontal row at 15 mm intervals at a position 5 mm from the upper end of the transfer paper. The density difference caused by the 15 mm × 15 mm solid images in the halftone part of the image was visually determined. The evaluation results are shown in Table 4 (Evaluation criteria) A: No density difference is observed B: A very slight density difference is observed C: A slight density difference is observed D: A distinct density difference is observed

[0140] <4>Evaluation of Fixing The evaluation was carried out in a high-temperature and high-humidity (H / H) environment (32.5°C, 80% RH). After continuously outputting 7,000 sheets of 1% printed images, the developing container was disassembled, and the surface and ends of the toner carrier were visually inspected for evaluation. The evaluation results are shown in Table 4. (Evaluation Criteria) A: There are no streaks in the circumferential direction on the surface or ends of the toner carrier due to toner breakage or fixing, or foreign matter being trapped between the toner regulating member and the toner carrier. B: Slight foreign matter trapping between the toner carrier and the toner end seal can be observed. C: 1 to 4 streaks in the circumferential direction can be observed at the ends. D: 5 or more streaks in the circumferential direction can be observed throughout the area.

[0141] <Examples 2 to 21> For Toners 2 to 21, the same evaluation as in Example 1 was carried out. The results are shown in Table 4.

[0142] <Comparative Examples 1 to 6> For Toners 22 to 27, the same evaluation as in Example 1 was carried out. The results are shown in Table 4.

[0143]

Table 4

Claims

1. A toner having toner particles containing a binder resin and an external additive, wherein the toner particles further contain a monohydric aliphatic alcohol, the monohydric aliphatic alcohol has 8 to 18 carbon atoms, the content ratio of the monohydric aliphatic alcohol extracted from the toner with ethanol is 30 ppm by mass or more and 300 ppm by mass or less in the toner, and the external additive has at least one selected from the group consisting of hydrotalcite particles and alumina particles.

2. The toner according to claim 1, wherein the number average value of the major axis of at least one selected from the group consisting of the hydrotalcite particles and the alumina particles is 60 nm or more and 820 nm or less.

3. The toner according to claim 1 or 2, wherein the total content of the hydrotalcite particles and the alumina particles is 0.02 part by mass or more and 1.00 part by mass or less with respect to 100 parts by mass of the toner particles.

4. The toner according to any one of claims 1 to 3, wherein the total content of the hydrotalcite particles and the alumina particles is 0.05 part by mass or more and 0.50 part by mass or less with respect to 100 parts by mass of the toner particles.

5. wherein the binder resin contains a styrene acrylic resin, and the content ratio of the styrene acrylic resin in the toner is 50% by mass or more.

6. The toner according to any one of claims 1 to 5, wherein when the work function of the toner particles is Wa and the work function of the hydrotalcite particles or the alumina particles is Wb, Wa - Wb satisfies the following formula (1). 0.05 eV < Wa - Wb < 0.50 eV... (1)

7. wherein the toner particles contain a colorant, and the colorant contains at least one selected from the group consisting of C.I. Pigment Violet 19, C.I. Pigment Red 122, C.I. Pigment Red 202, and C.I. Pigment Red 209.

8. wherein the external additive contains an external additive C different from the hydrotalcite particles and the alumina particles, and when the work function of the external additive C is Wc, Wa, Wb, and Wc satisfy the following formula (2). Wb < Wa < Wc... (2)

9. The toner according to any one of claims 1 to 8, wherein at least one selected from the group consisting of the hydrotalcite particles and alumina particles is hydrotalcite particles.

10. The toner particles have a core-shell structure having a core particle and a shell on the surface of the core particle, In the cross-sectional observation of the toner by a transmission electron microscope, the shell is present inside the contour of the cross-section of the toner particle, the shell contains a polyester resin, The toner according to any one of claims 1 to 9, wherein the thickness of the shell is 0.8 nm to 100 nm.

11. The toner according to any one of claims 1 to 10, wherein the average circularity of the toner is 0.97 or more.

Images