JP2011047980A - Magnetic toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide magnetic toner exhibiting excellent durable developing property and high cleaning property, and at the same time, improving a start-up stripe defect. <P>SOLUTION: The magnetic toner comprises magnetic toner particles and a fatty acid metal salt, and is characterized in that: (1) the surface tension index I of the toner with respect to 45 vol% methanol aqueous solution, which is measured by a capillary suction time method and calculated according to formula (I):I=P<SB>α</SB>/(A×B×10<SP>6</SP>) is 5.0×10<SP>-3</SP>N/m or more and 1.0×10<SP>-1</SP>N/m or less, wherein I represents a surface tension index (N/m) of the magnetic toner, P<SB>α</SB>represents a capillary pressure (N/m<SP>2</SP>) of the magnetic toner with respect to a 45 vol% methanol aqueous solution, "A" represents a specific surface area (m<SP>2</SP>/g) of the magnetic toner, and "B" represents a true density (g/cm<SP>3</SP>) of the magnetic toner; (2) the fatty acid metal salt has a median diameter (D50) of 0.15 μm or more and 0.65 μm or less on a volume basis; and (3) the content of the fatty acid metal salt is 0.02 part by mass or more and 0.5 part by mass or less based on 100 parts by mass of the magnetic toner particles. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a magnetic toner used in electrophotography, electrostatic recording, magnetic recording, and the like.

  Magnetic toners have been widely put into practical use in monochrome copying machines and printers, and various studies are currently under way to further improve the image quality.

  In order to improve the image quality of the toner, there are methods such as reducing the particle size of the toner and increasing the circularity by hot air treatment (Patent Documents 1, 2, and 3). If the toner particle size is reduced, the resolution of the image is improved. Also, if the circularity of the toner increases and the toner surface becomes uniform and smooth, external additives that impart chargeability can also be uniformly present on the toner surface, and the transferability of the toner is improved because the charge distribution is sharp. To do. In addition, since the toner charge rises very quickly, deterioration of the durability developability is suppressed even under high temperature and high humidity conditions where the charge rise is generally poor and the distribution of the charge distribution is large. Can be achieved.

  However, the reduction in particle size and the increase in circularity tend to deteriorate the recoverability of the toner that remains without being transferred onto the electrostatic latent image carrier, so-called cleaning properties, and cause image defects called defective cleaning. It was in. As a countermeasure, a technique of externally adding a fatty acid metal salt to a toner is known. Fatty acid metal salts are known to function as cleaning aids, and it is possible to improve the cleaning properties of toner over a long period of time (Patent Document 4).

  In addition, there is a problem of starting streaks as an image defect different from cleaning failure. The starting stripe is a kind of image defect that causes a black stripe having a horizontal roller pitch on the image. As a generation mechanism, after the external additive released from the toner is accumulated at the tip of the cleaning blade, the electrostatic latent image carrier is agglomerated while it is stationary for a long time. Since the lump moves to the charging roller at the time of start-up and partially covers the surface thereof, a portion of the surface of the electrostatic latent image carrier is poorly charged and a start-up streak is generated.

  In order to improve the image quality, it is essential to take measures against starting stripes, and a technique for improving the cleaning property of magnetic toner and at the same time improving the starting stripes has been demanded.

Special registration 02563737 Special registration 03094676 JP 07-271090 A Special registration 03173321

  An object of the present invention is to provide a magnetic toner which has excellent durability developability, exhibits high cleaning properties, and at the same time has improved starting streaks.

The present invention relates to a magnetic toner having at least a magnetic toner particle containing at least a binder resin, a magnetic substance and a wax and a fatty acid metal salt.
(1) The surface tension index I of the magnetic toner with respect to a 45 volume% methanol aqueous solution measured by the capillary suction time method and calculated by the following formula (1) is 5.0 × 10 ⁻³ N / m or more. 0 × 10 ⁻¹ N / m or less,
(2) The fatty acid metal salt has a volume-based median diameter (D50) of 0.15 μm or more and 0.65 μm or less,
(3) The present invention relates to a magnetic toner, wherein the content of the fatty acid metal salt is 0.02 parts by mass or more and 0.5 parts by mass or less with respect to 100 parts by mass of the magnetic toner particles.

I = Pα / (A × B × 10 ⁶ ) Formula (1)
I: Surface tension index (N / m) of magnetic toner
Pα: Capillary pressure (N / m ² ) of magnetic toner with respect to 45% by volume methanol aqueous solution
A: Specific surface area of magnetic toner (m ² / g)
B: True density of magnetic toner (g / cm ³ )

  According to the present invention, it is also possible to provide a magnetic toner that is excellent in durable developability, exhibits high cleaning properties, and at the same time has improved startup streaks.

1 is a schematic cross-sectional view of a surface treatment apparatus of the present invention. FIG. 2 is a schematic cross-sectional view of a toner supply port and an airflow ejection member in the surface treatment apparatus of the present invention.

  The present invention relates to a magnetic toner, and an image forming method and a fixing method can be applied to a conventionally known electrophotographic process, and are not particularly limited.

The present invention relates to a magnetic toner having at least a magnetic toner particle containing at least a binder resin, a magnetic material, and a wax, and a fatty acid metal salt.
(1) The surface tension index I of the magnetic toner with respect to a 45 volume% methanol aqueous solution measured by the capillary suction time method and calculated by the following formula (1) is 5.0 × 10 ⁻³ N / m or more. 0 × 10 ⁻¹ N / m or less,
(2) The fatty acid metal salt has a volume-based median diameter (D50) of 0.15 μm or more and 0.65 μm or less,
(3) The present invention relates to a magnetic toner, wherein the content of the fatty acid metal salt is 0.02 parts by mass or more and 0.5 parts by mass or less with respect to 100 parts by mass of the magnetic toner particles.

I = Pα / (A × B × 10 ⁶ ) Formula (1)
I: Surface tension index (N / m) of magnetic toner
Pα: Capillary pressure (N / m ² ) of magnetic toner with respect to 45% by volume methanol aqueous solution
A: Specific surface area of magnetic toner (m ² / g)
B: True density of magnetic toner (g / cm ³ )

  In many image forming apparatuses, toner remaining on an electrostatic latent image carrier without being transferred to a recording medium (hereinafter referred to as transfer residual toner) is cleaned by various methods and stored as waste toner in a waste toner container. .

  Considering a general blade cleaning mechanism, the transfer residual toner is cleaned as the cleaning blade stably slides on the surface of the latent electrostatic image bearing member. However, when the adhesion between the transfer residual toner and the electrostatic latent image carrier is high, the cleaning blade vibrates irregularly and the transfer residual toner cannot be scraped stably. This causes a cleaning failure.

  Therefore, in order to suppress the occurrence of defective cleaning, it is considered important to reduce the adhesive force between the electrostatic latent image carrier and the transfer residual toner and to suppress the irregular vibration of the cleaning blade.

  Fatty acid metal salts are known to be effective as external additives for this purpose. Since the fatty acid metal salt acts as a lubricant between the toners, the aggregation of the transfer residual toner on the electrostatic latent image carrier is suppressed. Further, since it acts as a lubricant between the cleaning blade and the electrostatic latent image carrier, irregular vibration of the cleaning blade is suppressed.

Further, the surface tension index I of the toner with respect to a 45% by volume methanol aqueous solution, which is measured by the capillary suction time method and calculated by the following formula (1), is 5.0 × 10 ⁻³ N / m or more and 1.0 × 10 ⁻¹ N. / M or less, the median diameter (D50) on the volume basis of the fatty acid metal salt is within the above range, and the content of the fatty acid metal salt is 0.02 parts by mass with respect to 100 parts by mass of the magnetic toner particles. When the amount is 0.5 parts by mass or less, it has been clarified by the inventors that the starting stripe is improved.

I = Pα / (A × B × 10 ⁶ ) Formula (1)
I: Toner surface tension index (N / m)
Pα: Capillary pressure of toner with respect to 45% by volume methanol aqueous solution (N / m ² )
A: Specific surface area of the toner (m ² / g)
B: True density of toner (g / cm ³ )

  About the detailed reason, the present inventors guess as follows.

  The surface tension index is a numerical value calculated from a change in water pressure when a methanol aqueous solution is sucked by applying a certain pressure to the toner. Since the surface tension index is measured by pressurizing a methanol aqueous solution as compared with a value obtained from a normal wettability measurement, the influence of the fine structure of the surface of each toner is more reflected. Specifically, the fine structure of the surface of each toner is a state of adhesion of a hydrophobic external additive to each toner particle.

  When the surface tension index is within the above range, it indicates that the hydrophobic external additive containing the fatty acid metal salt is sufficiently uniformly distributed on the toner surface.

  The surface tension index can be controlled by a technique such as hot air treatment. For example, when control is performed by hot air treatment, first, if hot air treatment is performed on the toner particles themselves, the release agent is exposed from the inside of the toner, the toner surface is hydrophobized, unevenness is reduced, and the surface composition is uniform. Become. Therefore, when the external additive is externally added, the state of adhesion to the toner particles becomes more uniform as compared with the case where the hot air treatment is not performed. As a result, the surface tension index is improved.

  Here, when the median diameter (D50) of the fatty acid metal salt is within the above range, the fatty acid metal salt has a strong adhesion to the toner particle surface and is uniformly distributed on the toner particle surface, so that it behaves together with the toner particle. It becomes easy to do. For this reason, the fluidity of the toner particles is sufficiently improved and maintained, so that it is difficult to form an aggregate of the external additive at the blade tip. Thereby, generation | occurrence | production of a starting stripe is suppressed.

  In addition, even if aggregates of external additives are formed, fatty acid metal salts with high releasability are contained, so aggregates are easily released from the electrostatic latent image carrier and collected on the blade. Generation of streaks is suppressed.

  Further, since the fatty acid metal salt is uniformly coated on the toner surface, there is little exposure of the toner particle surface, and the cleaning property is improved in order to suppress the formation of transfer residual toner aggregates. Further, since the fatty acid metal salt behaves together with the toner, it is uniformly coated on the electrostatic latent image carrier, and the cleaning property is improved.

When the surface tension index exceeds 1.0 × 10 ⁻¹ N / m, the external additive covers the toner particle surface excessively, so that the chargeability is lowered and the developability is deteriorated. In addition, when the surface tension index is less than 5.0 × 10 ⁻³ N / m, it indicates that the external additive is unevenly distributed on the toner surface, and thus a part of the external additive is released from the toner. This makes it easier to suppress the occurrence of startup stripes.

  Further, when the volume-based median diameter of the fatty acid metal salt exceeds 0.65 μm, it becomes difficult to uniformly distribute on the toner surface, and the adhesion to the toner particles becomes weak, so that aggregates are easily formed, This is not preferable because the starting stripe is difficult to be improved. If it is smaller than 0.15 μm, fatty acid metal salts are likely to adhere to each other, so that it is difficult to improve the starting stripe, which is not preferable.

  When the added amount of the fatty acid metal salt is less than 0.02 parts by mass, the amount of the fatty acid metal salt becomes too small to obtain a sufficient effect of improving the starting stripe, and the cleaning property is not improved. On the other hand, when the amount exceeds 0.50 parts by mass, the fatty acid metal salt amount becomes excessive and the chargeability of the toner is deteriorated, so that the developability is lowered.

  The fatty acid metal salt suitably used in the present invention is preferably a metal salt selected from zinc, calcium, magnesium, aluminum and lithium. Among these, fatty acid zinc or fatty acid calcium is particularly preferable, and when these are used, the effect of the present invention becomes more remarkable.

  Further, the fatty acid of the aliphatic metal salt is preferably a higher fatty acid having 12 to 22 carbon atoms. When fatty acids having 12 or more carbon atoms are used, it is easy to suppress the generation of free fatty acids. The amount of free fatty acid is preferably 0.20% by mass or less. When the number of carbon atoms of the fatty acid is 22 or less, the melting point of the fatty acid metal salt does not become too high, and good fixability is easily obtained. As the fatty acid, stearic acid is particularly preferable.

  As a result of the study by the present inventors, it has been clarified that the fatty acid metal salt exhibits the effect of improving the cleaning property most when the median diameter (D50) on a volume basis is 0.15 μm or more and 0.65 μm or less. About the detailed reason, the present inventors guess as follows.

  Since the fine fatty acid metal salt has a sufficiently small particle size, it can be present uniformly on the surface of the toner particles and effectively acts as a lubricant. Even when the same number of parts is added, the number of particles is increased as compared with a fatty acid metal salt having a large particle diameter, and the function as a lubricant can be effectively exhibited. Thus, the fine fatty acid metal salt can effectively reduce adhesion between the electrostatic latent image carrier and the transfer residual toner. Also, since the toner particles are uniformly present on the surface of each toner particle, the toner is charged uniformly and the generation of toner charged to a reverse polarity is reduced. For this reason, it is possible to suppress the occurrence of reverse polarity charged toner that has a strong adhesion to the electrostatic latent image carrier and causes cleaning failure. Since the reverse polarity charged toner also causes fogging, the reduction is also effective in improving the fogging.

  When the median diameter on the volume basis of the fatty acid metal salt is smaller than 0.15 μm, the fatty acid metal salt excessively coats the surface of the toner particles, so that the chargeability and developability deteriorate.

  If it exceeds 0.65 μm, the particle size is too large and the fatty acid metal salt is likely to be unevenly distributed on the surface of the toner particles, so that the charge distribution between the toner particles is widened and the toner of the opposite polarity is increased. The fog cannot be improved. Further, when the particle size is increased, the adhesion force of the fatty acid metal salt to the toner particle surface is lowered, and the release in the toner tends to occur easily. Therefore, it is not preferable to print a large number of sheets because the fatty acid metal salt is released from the toner and the effect is not exhibited.

  The fatty acid metal salt preferably has a span value B defined by the following formula (2) of 1.75 or less, more preferably 1.30 or less.

Span value B = (D95−D5) / D50 Formula (2)
D5: 5% cumulative diameter based on volume of fatty acid metal salt D50: 50% cumulative diameter based on volume of fatty acid metal salt D95: 95% cumulative diameter based on volume of fatty acid metal salt

  The span value B is an index indicating the particle size distribution of the fatty acid metal salt. When the span value B is 1.75 or less, the dispersion in the particle size of the fatty acid metal salt present in the toner is reduced, so that charging stability is further obtained and the toner charged to the opposite polarity tends to decrease. For this reason, the fog tends to be improved. More preferably, it is 1.30 or less, and when it is 1.30 or less, the fixing state of the fatty acid metal salt on the toner surface becomes uniform, and the proportion of the fatty acid metal salt that behaves together with the toner increases. Since it becomes difficult to form, the starting stripe tends to be improved.

  In the present invention, the liberation rate of the fatty acid metal salt of the toner is preferably 10.0% by mass or more and 40.0% by mass or less. When the liberation rate of the fatty acid metal salt is 10.0% by mass or more and 40.0% by mass or less, a certain amount of the fatty acid metal salt is present on the surface of the toner particles even after printing a large number of sheets. Since the effect of this invention is exhibited continuously, it is preferable.

  In addition to the particle size of the external additive, the liberation rate of the fatty acid metal salt is controlled by conditions such as the mixing time and the number of times of mixing of the toner and the external additive during external addition.

  The toner of the present invention is desirable when the average surface roughness (Ra) on the surface of the magnetic toner particles is 1.0 nm or more and 30.0 nm or less because transferability is excellent and consumption is reduced and durability development is excellent.

  The average surface roughness (Ra) of the toner particle surface in the above range means that the toner particle surface is smooth. Since the toner particle surface is smooth, the external additive can be present uniformly on the toner particle surface, the charge distribution becomes sharp, and the above-described effect is produced.

  The toner binder resin preferably contains a polymer having a structure in which a vinyl resin component and a hydrocarbon compound react together with the wax in the toner particles.

  The polymer having a structure in which a vinyl resin component and a hydrocarbon compound are reacted includes a graft having a structure in which a polyolefin is grafted on a vinyl resin component, or a vinyl resin component in which a vinyl monomer is graft-polymerized on a polyolefin. Polymers are particularly preferred.

  The polymer having a structure in which a vinyl resin component and a hydrocarbon compound react with each other functions as a surfactant for the binder resin and wax melted in a kneading step during toner production or a surface smoothing step by hot air treatment. . Accordingly, the polymer is preferable because it can control the primary average dispersed particle diameter of the wax in the toner particles and the transfer speed of the wax to the toner surface when the surface treatment is performed with hot air.

  Polyolefin is an unsaturated hydrocarbon monomer having one double bond with respect to a graft polymer having a vinyl resin component in which a polyolefin resin is grafted to the vinyl resin component, or a vinyl monomer is graft polymerized to a polyolefin. If it is a polymer or copolymer of this, it will not specifically limit, Various polyolefin can be used. In particular, polyethylene and polypropylene are preferably used.

  On the other hand, the following are mentioned as a vinyl-type monomer.

  Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethyl Styrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene Styrene monomers such as styrene and derivatives thereof.

  Amino group-containing α-methylene aliphatic monocarboxylic acid esters such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; vinyl monomers containing nitrogen atoms such as acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide.

  Unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; unsaturated such as maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride Dibasic acid anhydride: maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, alkenyl succinic acid Half-esters of unsaturated dibasic acids such as acid methyl half ester, fumaric acid methyl half ester and mesaconic acid methyl half ester; Unsaturated dibasic acid esters such as dimethylmaleic acid and dimethylfumaric acid; Acrylic acid, Methacrylic acid Α, β-unsaturated acids such as crotonic acid and cinnamic acid; α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic acid anhydride, and anhydrous α and β-unsaturated acids and lower fatty acids. A vinyl monomer containing a carboxyl group such as alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides thereof, and monoesters thereof.

  Acrylic acid or methacrylic acid ester such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1-hydroxy-1-methyl) (Hexyl) Vinyl monomers containing hydroxyl groups such as styrene.

  Methyl acrylate, ethyl acrylate, acrylate-n-butyl, acrylate isobutyl, propyl acrylate, acrylate-n-octyl, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, acrylate-2- An ester unit comprising an acrylic ester such as chloroethyl and acrylic ester such as phenyl acrylate.

  Methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylate-n-butyl, isobutyl methacrylate, methacrylate-n-octyl, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, methacryl Ester units composed of methacrylic acid esters such as α-methylene aliphatic monocarboxylic acid esters such as dimethylaminoethyl acid and diethylaminoethyl methacrylate.

  A polymer having a structure in which a vinyl resin component and a hydrocarbon compound are reacted is obtained by a known method such as a reaction between these monomers described above or a reaction between a monomer of one polymer and the other polymer. Can do.

  The constituent unit of the vinyl resin component preferably includes a styrene unit, and further acrylonitrile or methacrylonitrile.

  The mass ratio of the hydrocarbon compound and the vinyl resin component in the polymer is preferably 1/99 or more and 75/25 or less. It is preferable to use the hydrocarbon compound and the vinyl resin component in the above range in order to favorably disperse the wax in the toner particles.

  The content of the polymer having a structure in which the vinyl resin component and the hydrocarbon compound are reacted is preferably 0.2 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin. It is preferable to use the above polymer in the above range in order to favorably disperse the wax in the toner particles.

  The toner particles are preferably subjected to a surface treatment with heat. As such a surface treatment, it is particularly preferable to perform a surface treatment with hot air.

As a specific method for performing the surface treatment with hot air, there is a method in which the toner particles are instantaneously present in high-temperature hot air in a state where the toner particles are diffused in the air, and immediately thereafter are cooled with cold air. . The cold air is preferably dehumidified cold air, and specifically, it is preferably cold air having an absolute water content of 5 g / m ³ or less.

  The surface treatment of the toner particles by the above method can be performed uniformly without applying excessive heat to the toner particles. Further, it is possible to prevent the deterioration of the raw material components and to treat only the surface of the toner particles. Therefore, it is possible to prevent the excessive amount of wax from transferring to the toner particle surface and the uneven transfer of wax. Details of the surface treatment with hot air will be described later.

  As the binder resin used in the toner of the present invention, a known resin can be used. In particular, the resin preferably used as the binder resin is a resin having a styrene copolymer and / or a polyester unit.

  More preferably, the resin having a polyester unit contained in the total binder resin is 50% by mass or more, particularly preferably 70% by mass or more based on the total binder resin. When the resin having the polyester unit contained in the total binder resin is 50% by mass or more based on the total binder resin, it is preferable to obtain a toner having a surface tension index in the specific range.

  The “polyester unit” means a part derived from polyester, and examples of the resin having a polyester unit include polyester resins and hybrid resins. Specifically, the component constituting the polyester unit includes a divalent or higher valent alcohol monomer component, a divalent or higher carboxylic acid, a divalent or higher carboxylic acid anhydride, and a divalent or higher carboxylic acid ester. Ingredients.

  Examples of the wax used in the toner of the present invention include the following.

  Oxides of aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline wax, paraffin wax, Fischer-Tropsch wax, and aliphatic hydrocarbon waxes such as oxidized polyethylene wax, or Block copolymers of these: waxes based on fatty acid esters such as carnauba wax, behenyl behenate wax, montanate ester wax, and fatty acid esters such as deoxidized carnauba wax partially or fully deoxidized .

  Particularly preferred waxes include aliphatic hydrocarbon waxes and esters of fatty acids and alcohols. For example, low molecular weight alkylene polymer obtained by radical polymerization of alkylene under high pressure with Ziegler catalyst or metallocene catalyst under low pressure; alkylene polymer obtained by thermally decomposing high molecular weight alkylene polymer; synthesis containing carbon monoxide and hydrogen It is a synthetic hydrocarbon wax obtained from the distillation residue of hydrocarbons obtained by gas from the gas or by hydrogenation of these. Paraffin wax is also preferably used.

  The wax used in the toner of the present invention has a peak temperature of the maximum endothermic peak existing in the temperature range of 30 ° C. to 200 ° C. in the endothermic curve at the time of temperature rise measured by a differential scanning calorimetry (DSC) apparatus. Is preferably in the range of 45 ° C. or higher and 140 ° C. or lower. More preferably, it is the range of 65 to 120 degreeC, Most preferably, it is the range of 65 to 100 degreeC.

  When the peak temperature of the maximum endothermic peak of the wax is in the range of 45 ° C. or higher and 140 ° C. or lower, it is preferable for achieving good fixability.

  The content of the wax is preferably 3 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin. More preferably, they are 3 to 15 mass parts, More preferably, they are 3 to 10 mass parts.

  In the toner of the present invention, the molecular weight distribution measured by gel permeation chromatography (GPC) of the tetrahydrofuran (THF) soluble content of the toner preferably has a main peak molecular weight of 2000 to 15,000. In particular, the molecular weight is more preferably 2500 or more and 13,000 or less. The weight average molecular weight (Mw) / number average molecular weight (Mn) is preferably 3.0 or more and 15.0 or less, and more preferably 5.0 or more and 12.0 or less.

  When the above main peak and Mw / Mn satisfy the above range, it is preferable because the toner can achieve both good low-temperature fixability and high-temperature offset resistance. Further, when surface treatment is performed with hot air, it is possible to perform the treatment efficiently, and it is possible to satisfactorily prevent the toner from being coalesced, which is preferable.

  In the toner of the present invention, the glass transition temperature (Tg) of the toner is preferably 40 ° C. or higher and 90 ° C. or lower, and the softening temperature (Tm) is 80 ° C. or higher and 150 ° C. or lower. It is preferable for achieving both. In addition, when surface treatment with hot air is performed, it is preferable because the toner can be well prevented from being coalesced.

  The toner particles according to the present invention contain a magnetic material to form magnetic toner particles. In this case, the magnetic material can also serve as a colorant.

  Examples of the magnetic material include iron oxides such as magnetite, maghemite, and ferrite; magnetic metals such as iron, cobalt, and nickel, or these magnetic metals and aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, Examples thereof include alloys with bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, and mixtures thereof.

  The magnetic material has a number average particle size of 2.00 μm or less, preferably 0.05 μm or more and 0.50 μm or less. The amount to be contained in the toner is preferably 20 parts by mass or more and 200 parts by mass or less, and particularly preferably 40 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the binder resin.

  In the toner of the present invention, a known charge control agent can be used to stabilize the chargeability of the toner. The charge control agent varies depending on the type of charge control agent and the physical properties of other toner constituent materials, but is contained in an amount of 0.1 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the binder resin of the toner. It is preferable that 0.1 to 5.0 parts by mass is included. As such a charge control agent, there are known one that controls the toner to be negatively charged and one that controls the toner to be positively charged. One or two kinds of various kinds of charge control agents are used depending on the kind and use of the toner. The above can be used. The charge control agent may be added internally or externally to the toner.

  As the negatively chargeable charge control agent, for example, a polymer compound having an organometallic compound, a chelate compound, a sulfonic acid or a carboxylic acid in the side chain is effective. More specifically, there are a monoazo metal compound, an acetylacetone metal compound, an aromatic hydroxycarboxylic acid metal compound, an aromatic dicarboxylic acid metal compound, a polymer compound having a sulfonic acid or a carboxylic acid in the side chain, and the like. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and metal salts thereof, anhydrides, esters, and phenol derivatives such as bisphenol.

  In the toner of the present invention, an external additive is mixed with toner particles with a mixer such as a Henschel mixer for the purpose of improving the fluidity, transferability, and charging stability of the toner. Known external additives can be used, but it is particularly preferable to use a fatty acid metal salt.

  In addition to the above fatty acid metal salt, for example, fluorine resin powder such as vinylidene fluoride fine powder and polytetrafluoroethylene fine powder; titanium oxide fine powder; alumina fine powder; fine powder silica such as wet process silica and dry process silica; Fine powder obtained by subjecting them to surface treatment with a silane compound, an organosilicon compound, a titanium coupling agent, and silicone oil.

  As the titanium oxide fine powder, a titanium oxide fine powder obtained by low-temperature oxidation (thermal decomposition, hydrolysis) of a sulfuric acid method, a chlorine method, a volatile titanium compound such as titanium alkoxide, titanium halide, or titanium acetylacetonate is used. . As the crystal system, any of anatase type, rutile type, mixed crystal type thereof, and amorphous type can be used.

  The surface of the fine powder is preferably subjected to a hydrophobic treatment with a coupling agent, silicone oil, an organosilicon compound or the like. Examples of the method of hydrophobizing the surface of the fine powder include a method of chemically or physically treating with an organosilicon compound that reacts or physically adsorbs with the fine powder.

  The amount of the external additive added is preferably 0.1 parts by mass or more and 8.0 parts by mass or less, and more preferably 0.1 parts by mass or more and 4.0 parts by mass or less with respect to 100 parts by mass of the toner particles.

  The number average particle diameter (D1) of the external additive is preferably 0.01 μm or more and 0.30 μm or less from the viewpoint of imparting fluidity.

  Hereinafter, although the manufacturing method of the toner of this invention is demonstrated, it is not limited to the following description.

  The toner of the present invention can be produced using a known method. For example, a binder resin and a wax, and an arbitrary material are mixed (raw material mixing step). The obtained mixture is melt-kneaded (melt-kneading step), cooled and pulverized (pulverization step). The obtained pulverized product is subjected to spheronization treatment, surface treatment with hot air, and classification treatment as necessary to obtain toner particles. Then, it can be produced by mixing an external additive with the obtained toner particles. The toner particles according to the present invention are more preferably obtained by performing a surface treatment with hot air.

  An example of a production example is shown below.

  First, in the raw material mixing step of mixing the raw materials to be supplied to the melt-kneading step, at least a binder resin and a wax are weighed and mixed, and mixed using a mixing device. Examples of the mixing apparatus include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, and a Nauter mixer.

  Further, the mixed toner raw materials are melt-kneaded to melt the resins and disperse wax and the like therein. In the melt-kneading step, for example, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. In recent years, single-screw or twin-screw extruders have become mainstream due to the advantage of being capable of continuous production. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by Kay C.K. The Further, the resin composition obtained by melt-kneading the toner raw material is melt-kneaded, rolled with two rolls or the like, and then cooled through a cooling step of cooling with water cooling or the like.

  The cooled resin composition obtained above is then pulverized to a desired particle size in the pulverization step. In the pulverization step, first, coarse pulverization is performed with a crusher, a hammer mill, a feather mill or the like, and further, pulverization is performed with a kryptron system manufactured by Kawasaki Heavy Industries, Ltd., a super rotor manufactured by Nissin Engineering Co., Ltd., or the like to obtain a pulverized product.

  After that, if necessary, classification is performed using a classifier such as an inertia class elbow jet (manufactured by Nippon Steel Mining Co., Ltd.) or a centrifugal classifier turboplex (manufactured by Hosokawa Micron Co., Ltd.) to obtain a classified product. .

  The toner particles used in the present invention are preferably obtained by obtaining the above pulverized product, then performing surface treatment with hot air, for example, using the surface treatment apparatus shown in FIG. . Alternatively, a method in which a pre-classified material is subjected to surface treatment with hot air using the surface device shown in FIG.

  As the surface treatment with hot air, a method of treating the surface of the toner by ejecting the toner by jetting from a high-pressure air supply nozzle and exposing the jetted toner to hot air is preferable. The temperature of the hot air is particularly preferably in the range of 100 ° C. or higher and 450 ° C. or lower.

  Here, an outline of the surface treatment apparatus used for producing the toner of the present invention will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view showing an example of a surface treatment apparatus according to the present invention, and FIG. 2 is a cross-sectional view showing an example of an airflow injection member.

  The toner particles 114 supplied from the toner supply port 100 are accelerated by the injection air injected from the high-pressure air supply nozzle 115 and travel toward the airflow injection member 102 below the injection air. As shown in FIG. 2, diffused air 110 is ejected from the airflow ejecting member 102, and the diffused air 110 diffuses the toner upward and outward. At this time, the toner diffusion state can be controlled by adjusting the flow rate of the injection air and the flow rate of the diffusion air.

  Further, a cooling jacket 106 is provided on the outer periphery of the toner supply port 100, the outer periphery of the surface treatment apparatus, and the outer periphery of the transfer pipe 116 for the purpose of preventing toner fusion. In addition, it is preferable to pass cooling water (preferably antifreeze such as ethylene glycol) through the cooling jacket.

  Further, the surface of the toner diffused by the diffusion air is treated with hot air supplied from the hot air supply port 101. At this time, the temperature C (° C.) of the hot air supply port is preferably 100 ° C. or higher and 450 ° C. or lower. More preferably, it is 100 degreeC or more and 400 degrees C or less. Within the above temperature range, the toner particle surface can be uniformly treated while suppressing coalescence of the toner particles.

  The toner whose surface has been treated with hot air is cooled by cold air supplied from a cold air supply port 103 provided on the outer periphery of the upper portion of the apparatus. At this time, cold air may be introduced from the second cold air supply port 104 provided on the side surface of the main body of the apparatus for the purpose of managing the temperature distribution in the apparatus and controlling the surface state of the toner. The outlet of the second cold air supply port 104 can use a slit shape, a louver shape, a perforated plate shape, a mesh shape, etc., and the introduction direction can be selected according to the purpose, horizontal to the center direction and along the device wall surface It is.

At this time, the temperature E (° C.) in the cold air supply port and the second cold air supply port is preferably −50 ° C. or more and 10 ° C. or less. More preferably, it is -40 degreeC or more and 8 degrees C or less. The cold air is preferably dehumidified cold air. Specifically, the absolute water content is preferably 5 g / m ³ or less. More preferably, it is 3 g / m ³ or less. By controlling the absolute moisture content of the cold air, it is possible to easily adjust the surface tension index of the toner surface.

  By setting the above temperature range, an appropriate treatment and prevention of fusion to the wall surface can be achieved with a good balance.

  Thereafter, the cooled toner is sucked by a blower and collected by a cyclone or the like through a transfer pipe 116.

  Next, the airflow injection unit provided in the surface treatment apparatus will be described with reference to FIG. FIG. 2 is a cross-sectional view showing an example of the airflow injection member.

  As shown in FIG. 2, the toner supplied from the upper part of the toner supply port 100 by the metering feeder is accelerated by the injection air in the same pipe toward the outlet, and by the diffusion air from the airflow injection member 102 installed in the apparatus. Spreads outward. Note that the lower end of the airflow ejecting member 102 is preferably disposed below the lower end of the toner supply port 100 within a range of 5 mm to 150 mm. When the lower end of the airflow injection member is connected to a position less than 5 mm from the outlet, if the amount of toner to be introduced into the apparatus is set large, clogging or processing failure may occur. On the other hand, if it exceeds 150 mm, the effect of the hot air for processing the toner diffused by the diffusion air may not be obtained uniformly, resulting in variations in the toner processing, and the toner transferability may be reduced. .

  Further, on the outer periphery of the toner supply port 100, an air flow supply port 111 for the purpose of preventing condensation may be provided between the toner supply port 100 and the cooling jacket 106. This air flow for preventing condensation may be introduced from diffused air or a supply device common to the cold air and the second cold air, or the outside air may be taken in with the intake port opened. It is also possible to operate the apparatus with the intake port closed as buffer air.

  Further, if necessary, surface modification and spheronization may be further performed using, for example, a hybridization system manufactured by Nara Machinery Co., Ltd. or a mechano-fusion system manufactured by Hosokawa Micron. In such a case, if necessary, a sieving machine such as a wind-type sieve high voltor (manufactured by Shin Tokyo Machine Co., Ltd.) may be used.

  On the other hand, as a method for externally treating the external additive, a high-speed stirrer that mixes a predetermined amount of classified toner particles and various known external additives and gives a shearing force to the powder of a Henschel mixer, a super mixer, etc. Can be used as an external adder and stirring and mixing.

  Next, it describes regarding the measuring method of each physical property which concerns on this invention.

<Method for Measuring Average Surface Roughness (Ra) of Toner Particle Surface>
The average surface roughness (Ra) of the toner particle surface was measured by the following measuring apparatus and measurement conditions. Scanning probe microscope: Probe station SPI3800N (manufactured by Seiko Instruments Inc.)
Measurement unit: SPA400
Measurement mode: DFM (resonance mode) shape image Cantilever: SI-DF40P
Resolution: X data number 256, Y data number 128
Measurement area: 1μm square

The toner in which the external additive is added to the toner particles needs to remove the external additive in advance, and the following method was used as a specific method.
(1) Put 45 mg of toner into a sample bottle and add 10 ml of methanol.
(2) Disperse the sample for 1 minute with an ultrasonic cleaner to separate the external additive.
(3) Separating toner particles and external additives by suction filtration (10 μm membrane filter). In the case of a toner containing a magnetic material, the toner particles may be fixed by applying a magnet to the bottom of the sample bottle to separate only the supernatant.
(4) The above (2) and (3) are performed three times in total, and the obtained toner particles are sufficiently dried at room temperature using a vacuum dryer.

  As another method of removing the external additive in place of the above (2) and (3), there is a method of dissolving the external additive with an alkali. As the alkali, an aqueous sodium hydroxide solution is preferred.

  As the toner particles, toner particles having a particle diameter equal to the weight average particle diameter (D4) measured by the Coulter counter method, which will be described later, were selected and measured. For the measured data, 10 or more different toner particles were measured, and the average value of the obtained data was calculated to obtain the average surface roughness (Ra) of the toner particles.

  The average surface roughness (Ra) is a three-dimensional extension of the centerline average roughness Ra defined in JIS B0601-1994 so that it can be applied to the measurement surface. It is a value obtained by averaging the absolute values of deviations from the reference surface to the designated surface, and is expressed by the following equation.

F (X, Y): surface S0 indicated by all measurement data: area Z0 when the designated surface is assumed to be ideally flat: average value of Z data (roughness data) in the designated surface (with the designated surface) Means a measurement area of 1 μm square in the present invention.)

<Method for Measuring Toner Weight Average Particle Size (D4)>
The weight average particle diameter (D4) of the toner is a precision particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) equipped with an aperture tube of 100 μm and a measurement condition setting. Using the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) for analyzing the measurement data, the measurement data is analyzed with 25,000 effective measurement channels. And calculated.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  In the “Standard Measurement Method (SOM) Change Screen” of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter, Inc.) The value obtained using the above was set. The threshold and noise level were automatically set by pressing the threshold / noise level measurement button. The current was set to 1600 μA, the gain was set to 2, the electrolyte was set to ISOTON II, and the aperture tube flash after the measurement was checked. In the “Pulse to Particle Size Conversion Setting Screen” of the dedicated software, the bin interval was set to logarithmic particle size, the particle size bin to 256 particle size bin, and the particle size range from 2 μm to 60 μm.

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic solution was placed in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod was stirred counterclockwise at 24 rpm. The dirt and bubbles in the aperture tube were removed by the “aperture flush” function of the analysis software.
(2) About 30 ml of the electrolytic aqueous solution is put in a glass 100 ml flat bottom beaker, and "Contaminone N" (nonionic surfactant, anionic surfactant, organic builder pH 7 precision measurement is used as a dispersant therein. About 0.3 ml of a diluted solution obtained by diluting a 10% by weight aqueous solution of a neutral detergent for washing a vessel (made by Wako Pure Chemical Industries, Ltd.) 3 times with ion-exchanged water was added.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated in a state where the phase is shifted by 180 degrees, and placed in a water tank of an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikkiki Bios Co., Ltd.) having an electrical output of 120 W. A predetermined amount of ion-exchanged water was added, and about 2 ml of the above-mentioned Contaminone N was added to this water tank.
(4) The beaker of (2) was set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser was operated. Then, the height position of the beaker was adjusted so that the resonance state of the liquid surface of the electrolytic aqueous solution in the beaker was maximized.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) was irradiated with ultrasonic waves, about 10 mg of toner was added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion treatment was further continued for 60 seconds. In the ultrasonic dispersion, the water temperature in the water tank was appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte aqueous solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . The measurement was performed until the number of measured particles reached 50,000.
(7) The measurement data was analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) was calculated. The “average diameter” on the analysis / volume statistics (arithmetic average) screen when the graph / volume% is set with the dedicated software is the weight average particle diameter (D4).

<Measurement method of surface tension index of toner>
The surface tension index of the toner was measured using the following method.

About 5.5 g of toner was gently put into a measurement cell, and tapping operation was performed for 1 minute at a tapping speed of 30 times / min using a tapping machine PTM-1 type (manufactured by Sankyo Piotech Co., Ltd.). This was set in a measuring device (manufactured by Sankyo Piotech Co., Ltd .: WTMY-232A wet tester) and measured. A capillary suction time method was used to measure the capillary pressure Pα (N / m ² ). The conditions for each measurement are as follows.
Solvent: 45% by volume methanol aqueous solution measurement mode: Constant flow method (A2 mode)
Liquid flow rate: 2.4 ml / min
Cell: Y-type measurement cell

The surface tension index I (N / m) of the toner is determined by the capillary pressure measured by the toner capillary suction time method as Pα (N / m ² ), the specific surface area of the toner as A (m ² / g), When the density was B (g / cm ³ ), it was calculated from the following formula (1). The specific surface area and true density of the toner were measured by the methods described later.

      I = Pα / (A × B × 106) Formula (1)

<Measurement method of specific surface area (BET method) of toner>
The specific surface area (BET method) of the toner was measured using a specific surface area measuring device Tristar 3000 (manufactured by Shimadzu Corporation).

  The specific surface area of the toner was calculated by adsorbing nitrogen gas on the sample surface according to the BET method and using the BET multipoint method. Before measuring the specific surface area, about 2 g of the sample is accurately weighed in a sample tube and evacuated at room temperature for 24 hours. After evacuation, the mass of the entire sample cell was measured, and the exact mass of the sample was calculated from the difference from the empty sample cell.

  Next, empty sample cells were set in the balance port and analysis port of the measurement apparatus. Next, a Dewar bottle containing liquid nitrogen was set at a predetermined position, and P0 was measured by a saturated vapor pressure (P0) measurement command. After the completion of the P0 measurement, the sample cell prepared in the analysis port was set, and after inputting the sample mass and P0, the measurement was started by the BET measurement command. After that, the BET specific surface area was automatically calculated.

<Measurement of true density of toner>
The true density of the toner was measured with a dry automatic densimeter autopycnometer (manufactured by Yuasa Ionics). The conditions are as follows.
Cell SM cell (10ml)
Sample amount 2.0g

  This measuring apparatus measures the true density of a solid / liquid based on a gas phase substitution method. Similar to the liquid phase replacement method, it is based on Archimedes' principle, but has high accuracy because a gas (argon gas) is used as a replacement medium.

<Measurement of median diameter and span value B of fatty acid metal salt>
The volume-based median diameter of the fatty acid metal salt used in the present invention is measured according to JIS Z8825-2 (2001), and is specifically as follows.

  As a measuring device, a laser diffraction / scattering particle size distribution measuring device “LA-920” (manufactured by Horiba, Ltd.) is used. The dedicated software “HORIBA LA-920 for Windows (registered trademark) WET (LA-920) Ver. 2.02” attached to LA-920 is used for setting measurement conditions and analyzing measurement data. As the measurement solvent, ion-exchanged water from which impure solids are removed in advance is used.

The measurement procedure is as follows.
(1) A batch type cell holder is attached to LA-920.
(2) A predetermined amount of ion-exchanged water is put into a batch type cell, and the batch type cell is set in a batch type cell holder.
(3) The inside of the batch cell is stirred using a dedicated stirrer chip.
(4) Press the “refractive index” button on the “display condition setting” screen and select the file “110A000I” (relative refractive index 1.10).
(5) In the “display condition setting” screen, the particle diameter reference is set as the volume reference.
(6) After performing warm-up operation for 1 hour or more, optical axis adjustment, optical axis fine adjustment, and blank measurement are performed.
(7) Put about 60 ml of ion-exchanged water in a glass 100 ml flat bottom beaker. Among them, as a dispersant, “Contaminone N” (a nonionic surfactant, an anionic surfactant, a 10% by weight aqueous solution of a neutral detergent for washing a pH 7 precision measuring instrument comprising an organic builder, Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting the product (manufactured) with ion exchange water about 3 times by mass is added.
(8) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dispersion System Tetora 150” (manufactured by Nikka Ki Bios) with an electrical output of 120 W is prepared. . About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
(9) The beaker of (7) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the aqueous solution in a beaker may become the maximum.
(10) In a state where the aqueous solution in the beaker of (9) is irradiated with ultrasonic waves, about 1 mg of a fatty acid metal salt is added to the aqueous solution in the beaker little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In this case, the fatty acid metal salt may become a lump and float on the liquid surface. In this case, the lump is submerged in water by shaking the beaker, and then ultrasonic dispersion is performed for 60 seconds. Moreover, in ultrasonic dispersion, it adjusts suitably so that the water temperature of a water tank may become 10 to 40 degreeC.
(11) The aqueous solution in which the fatty acid metal salt prepared in the above (10) is dispersed is immediately added little by little to a batch type cell, taking care not to introduce bubbles, and the transmittance of the tungsten lamp is 90% to 95%. Adjust so that Then, the particle size distribution is measured. Based on the obtained volume-based particle size distribution data, 5% integrated diameter, 50% integrated diameter, and 95% integrated diameter are calculated. The obtained values are D5, D50, and D95, and the span value B is obtained from these values.

<Rate of fatty acid metal salt>
The liberation rate of the fatty acid metal salt in the toner according to the present invention is determined using KM Shaker (manufactured by Iwaki Sangyo Co., Ltd.), X-ray fluorescence analyzer Axios (manufactured by PANalytical), and dedicated software for setting measurement conditions and analyzing measurement data Using “SuperQ ver. 4.0F” (manufactured by PANalytical), the liberation rate of the fatty acid metal salt is determined from the difference in the intensity of the fluorescent X-rays.

Specific measurement methods are as follows.
(1) About 1 g of toner is placed on a PVC ring having a ring diameter of 22 mm × 16 mm × 5 mm, and compressed by 100 kgf with a press machine to prepare a sample. The obtained sample is measured with a fluorescent X-ray analyzer (Axios) to obtain the net strength derived from the metal element of the fatty acid metal salt contained in the toner.
(2) The toner particles are also measured with a fluorescent X-ray analyzer (Axios) in the same manner as in (1), and the net intensity derived only from the toner particles is obtained for the metal element contained in the fatty acid metal salt.
(3) Precisely evaluate 1 g of toner and add 16 g of methanol to a 30 cc vial. The toner is put into the vial, and after standing for 30 seconds, it is shaken under the following conditions to separate the toner and methanol. At this time, for example, a toner containing a magnetic material is preferably separated by a magnetic force.

[Shaking device / conditions]
Device: KM Shaker (Iwaki Sangyo Co., Ltd.)
model: V. SX
Shake condition: Set speed to 50 and shake for 10 seconds

  The separated toner is dried overnight in a vacuum dryer, and about 1 g of the obtained sample is placed on a vinyl ring similar to (1), and compressed by 100 kgf in a press machine to prepare a sample. The obtained sample is measured with a fluorescent X-ray analyzer (Axios), and the net intensity derived from the fatty acid metal salt contained in the sample after shaking in methanol is obtained.

  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 300 seconds. Further, when measuring a light element, it is detected by a proportional counter (PC), and when measuring a heavy element, it is detected by a scintillation counter (SC).

  The liberation rate of the fatty acid metal salt is determined from the following formula by measuring the Kα-ray net intensity (KCPS) of the metal element of the fatty acid metal salt before and after shaking with methanol.

Fatty acid metal salt liberation rate (%) = {(BT)-(AT)} / (BT) × 100
A: Net strength of metal element of fatty acid metal salt in toner after shaking with methanol
B: Net strength of metal element of fatty acid metal salt in toner before methanol shaking T: Net strength of toner particles

<Measurement method of peak temperature of maximum endothermic peak of wax or resin>
The peak temperature of the maximum endothermic peak was measured according to ASTM D3417-99 using a differential scanning calorimeter “Q1000” (manufactured by TA Instruments).
For the temperature correction of the device detection unit, the melting points of indium and zinc were used, and for the correction of the heat amount, the heat of fusion of indium was used.

  Specifically, about 10 mg of a sample is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference. The measurement was performed at ° C / min. In the measurement, the temperature was once raised to 200 ° C., subsequently lowered to 30 ° C., and then the temperature was raised again. The peak temperature of the maximum endothermic peak was determined using a DSC curve in the temperature range of 30 to 200 ° C. in the second temperature raising process.

<Measurement Method of Glass Transition Temperature (Tg) of Resin or Toner>
The glass transition temperature (Tg) was measured in accordance with ASTM D3418-99 using a differential scanning calorimeter “Q1000” (manufactured by TA Instruments).
For the temperature correction of the device detection unit, the melting points of indium and zinc were used, and for the correction of the heat amount, the heat of fusion of indium was used.

  Specifically, about 10 mg of a sample is precisely weighed, put into an aluminum pan, an empty aluminum pan is used as a reference, and a temperature rising rate is 10 ° C./min between a measurement range of 30 to 200 ° C. The measurement was performed. During this temperature raising process, a specific heat change was obtained in the temperature range of 40 ° C to 100 ° C. At this time, the glass transition temperature Tg was defined as the intersection of the midpoint line of the baseline before and after the change in specific heat and the differential heat curve.

  Hereinafter, the present invention will be described more specifically with reference to production examples and examples, but these do not limit the present invention in any way. “Part” is based on mass unless otherwise specified.

<Examples of magnetic iron oxide production>
20.5 liters of 3.0 mol / l sodium hydroxide aqueous solution is put in a reaction vessel, and 22.2 liters of ferrous sulfate aqueous solution containing 1.55 mol / l Fe ²⁺ is added thereto, and the reaction temperature is increased. A ferrous salt suspension containing ferrous hydroxide colloid was produced at 92 ° C.

  Thereafter, the reaction was started by aeration of air at 90 l / min, and at the same time, 0.28 liter of sodium silicate aqueous solution having 29 g of Si was added over 50 minutes. Thereafter, stirring was continued for 30 minutes to advance the oxidation reaction, thereby obtaining a ferrous suspension containing magnetite nuclei particles.

  Furthermore, 0.3 liter of 8.0 mol / l sodium hydroxide aqueous solution was added to the suspension to adjust the pH to 9.3. The reaction was continued for 30 minutes at a reaction temperature of 92 ° C. while aeration of 95 l / min of air was performed to generate magnetite particles.

  Further, 150 ml of 0.55 mol / l aluminum sulfate aqueous solution was added and stirred sufficiently, and then filtered, washed with water, dried and crushed to obtain magnetic iron oxide 1.

<Manufacture of binder resin>
As polyester unit components, 71.0 parts of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 28.0 parts of terephthalic acid, 1.0 part of trimellitic anhydride and titanium tetrabutoxide 0.5 part was put into a 4-liter four-necked flask made of glass, and a thermometer, a stirring rod, a condenser and a nitrogen introducing tube were attached and placed in a mantle heater. Next, after the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and the mixture was reacted at 200 ° C. for 4 hours to obtain a resin 1-1 having a polyester unit. Resin 1-1 having this polyester unit had a weight average molecular weight (Mw) of 80000, a number average molecular weight (Mn) of 3500, and a peak molecular weight (Mp) of 5700.

  In addition, as a polyester unit component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 70.0 parts, terephthalic acid 20.0 parts, isophthalic acid 3.0 parts, trimellitic anhydride 7.0 parts of acid and 0.5 part of titanium tetrabutoxide were placed in a 4-liter 4-neck flask made of glass, and a thermometer, a stir bar, a condenser and a nitrogen inlet tube were attached and placed in a mantle heater. Next, after the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and the mixture was reacted at a temperature of 220 ° C. for 6 hours to obtain a resin 1-2 having a polyester unit. Resin 1-2 having this polyester unit had a weight average molecular weight (Mw) of 120,000, a number average molecular weight (Mn) of 4000, and a peak molecular weight (Mp) of 7800.

The polyester resin 1-1: 50 parts and the polyester resin 1-2: 50 parts are premixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.), and the rotational speed is 3 with a melt kneader PCM30 (Ikegai Iron Works Co., Ltd.). .3 s ⁻¹ , kneaded resin temperature was 100 ° C. and melt blended to obtain binder resin 1.

<Production of fatty acid metal salt 1>
A receiving container with a stirrer was prepared, and the stirrer was rotated at 350 rpm. 500 parts of 0.5 mass% sodium stearate aqueous solution was put into this receiving container, and the liquid temperature was adjusted to 85 ° C. Next, 525 parts of 0.2 mass% zinc sulfate aqueous solution was dripped at this receptacle over 15 minutes. After the completion of charging the whole amount, the reaction was terminated by aging for 10 minutes at the temperature during the reaction.

Next, the fatty acid metal salt slurry thus obtained was washed by filtration. The obtained washed fatty acid metal salt cake was roughly crushed and then dried at 105 ° C. using a continuous instantaneous air dryer. Then, after pulverizing with a nano grinding mill [NJ-300] (manufactured by Sanrex) under conditions of an air volume of 6.0 m ³ / min and a processing speed of 80 kg / h, reslurry and fine particles using a wet centrifugal classifier The coarse particles were removed. Then, it dried at 80 degreeC using the continuous instantaneous airflow dryer, and obtained the fatty-acid metal salt fine particle 1. The obtained fatty acid metal salt fine particles 1 had a volume-based median diameter (D50s) of 0.45 μm and a span value B of 0.92.

<Production of fatty acid metal salt 2>
In the production of fatty acid metal salt 1, the conditions of the wet centrifugal classifier were changed to obtain fatty acid metal salt 2 having a median diameter (D50s) on the volume basis of 0.45 μm and a span value B of 1.3.

<Production of fatty acid metal salt 3>
In the production of fatty acid metal salt 1, the conditions of the wet centrifugal classifier were changed to obtain fatty acid metal salt 3 having a median diameter (D50s) of 0.45 μm and a span value B of 1.75 on a volume basis.

<Production of fatty acid metal salt 4>
In the production of fatty acid metal salt 1, the conditions of the wet centrifugal classifier were changed to obtain fatty acid metal salt 4 having a median diameter (D50s) of 0.45 μm and a span value B of 1.9 on a volume basis.

<Production of fatty acid metal salt 5>
In the production of the fatty acid metal salt 1, the 0.5 mass% sodium stearate aqueous solution was changed to a 0.25 mass% sodium stearate aqueous solution, and the 0.2 mass% zinc sulfate aqueous solution was changed to a 0.15 mass% zinc sulfate aqueous solution. Further, the pulverization condition was changed to 10.0 m ³ / min, and the pulverization process was further changed three times. The obtained fatty acid metal salt 5 had a volume-based median diameter (D50s) of 0.15 μm and a span value B of 1.94.

<Production of fatty acid metal salt 6>
In the production of the fatty acid metal salt 1, the 0.5 mass% sodium stearate aqueous solution was changed to a 0.20 mass% sodium stearate aqueous solution, and the 0.2 mass% zinc sulfate aqueous solution was changed to a 0.10 mass% zinc sulfate aqueous solution. Further, the pulverization condition was changed to 12.0 m ³ / min, and the pulverization process was further changed to 3 times. The obtained fatty acid metal salt 6 had a volume-based median diameter (D50s) of 0.10 μm and a span value B of 1.94.

<Production of fatty acid metal salt 7>
In the production of fatty acid metal salt 1, 0.5% by mass sodium stearate aqueous solution was changed to 0.7% by mass sodium stearate aqueous solution, and 0.2% by mass zinc sulfate aqueous solution was changed to 0.3% by mass zinc sulfate aqueous solution. did. The pulverization conditions were an air volume of 4.0 m ³ / min and a processing speed of 50 kg / h. Other processes were the same as the production of fatty acid metal salt 1 to obtain fatty acid metal salt 7. The obtained fatty acid metal salt 7 had a volume-based median diameter (D50s) of 0.65 μm and a span value B of 1.9.

<Production of fatty acid metal salt 8>
In the production of fatty acid metal salt 1, 0.5% by mass sodium stearate aqueous solution was changed to 1.0% by mass sodium stearate aqueous solution, and 0.2% by mass zinc sulfate aqueous solution was changed to 0.4% by mass zinc sulfate aqueous solution. did. Further, the reaction was terminated by aging for 15 minutes. Further, the pulverization condition was changed to 4.0 m ³ / min. Other steps were carried out in the same manner as the production of fatty acid metal salt 1 to obtain fatty acid metal salt 8. The volume-based median diameter (D50s) of the obtained fatty acid metal salt 8 was 0.70 μm, and the span value B was 1.96.

<Production of fatty acid metal salt 9>
In the production of fatty acid metal salt 1, 0.5% by mass sodium stearate aqueous solution was changed to 1.2% by mass sodium stearate aqueous solution, and 0.2% by mass zinc sulfate aqueous solution was changed to 0.5% by mass zinc sulfate aqueous solution. did. Further, the reaction was terminated by aging for 15 minutes. Further, the pulverization condition was changed to 4.0 m ³ / min. Other steps were carried out in the same manner as in the production of fatty acid metal salt 1 to obtain fatty acid metal salt 9. The obtained fatty acid metal salt 9 had a volume-based median diameter (D50s) of 0.80 μm and a span value B of 1.96.

<Manufacture of toner 1>
Styrene 64 parts, n-butyl acrylate 13.5 parts, acrylonitrile 2.5 parts were charged in an autoclave, and the system was replaced with N ₂ and kept at 180 ° C. while stirring at elevated temperature. A polymer in which 50 parts of a 2% by mass t-butyl hydroperoxide xylene solution was continuously dropped into the system for 5 hours, and after cooling, the solvent was separated and removed, and the vinyl resin component reacted with the low-density polyethylene. A was obtained. When the molecular weight of the polymer A was measured, it was weight average molecular weight (Mw) 7000 and number average molecular weight (Mn) 3000.

・ Binder resin 1 100 parts ・ Polymer A 2 parts ・ Fischer-Tropsch wax (peak temperature of maximum endothermic peak 105 ° C.) 4 parts ・ Magnetic substance 95 parts ・ Monoazo iron compound (T-77, manufactured by Hodogaya Chemical Co., Ltd.) 2 parts The above formulation was mixed with a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.), and then a twin-screw kneader set at a temperature of 130 ° C. (PCM-30 type, manufactured by Ikekai Tekko Co., Ltd.) Kneaded. The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized material. The obtained coarsely crushed material was pulverized with a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.). Furthermore, classification was performed by a multi-division classifier using the Coanda effect to obtain magnetic substance-containing resin particles. The obtained magnetic substance-containing resin particles have a weight average particle diameter (D4) of 6.3 μm, 25.6% by number of particles having a particle diameter of 4.0 μm or less, and particles having a particle diameter of 10.1 μm or more. The ratio was 2.6% by volume.

  The magnetic substance-containing resin particles were subjected to a surface treatment using the surface smoothing apparatus shown in FIG. The lower end of the airflow ejecting member 102 is disposed 100 mm below the lower end of the toner supply port 100.

The operating conditions are: feed amount = 5 kg / hr, hot air temperature C = 250 ° C., hot air flow rate = 6 m ³ / min, cold air temperature E = 5 ° C., cold air flow rate = 4 m ³ / min, cold air absolute moisture content = 3 g / m ³ , Blower air volume = 20 m ³ / min, injection air flow rate = 1 m ³ / min, diffusion air = 0.3 m ³ / min.

  By the surface treatment under the above conditions, 18.6% by number of particles having a weight average particle diameter (D4) of 6.7 μm, a particle diameter of 4.0 μm or less, and 3.1% by volume of particles having a particle diameter of 10.1 μm or more. Some toner particles 1 were obtained. The average surface roughness (Ra) measured with a scanning probe microscope on the surface of the obtained toner particles 1 was 15 nm.

  To 100 parts of the obtained toner particles, 0.10 parts of fatty acid metal salt 1 and 1.5 parts of hydrophobic silica fine powder surface-treated with hexamethyldisilazane (number average primary particle diameter: 10 nm) were added, Mixing is performed for 240 seconds at a peripheral speed of 40 m / S using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) (mixing step 1). Then, it rests for 60 seconds. Further, a mixing process for 240 seconds was performed (mixing process 2). The toner thus obtained is referred to as Toner 1.

The obtained toner had a surface tension index of 6.3 × 10 ⁻³ N / m. Table 1 shows the physical properties of Toner 1 thus obtained.

<Manufacture of toners 2 to 17>
In the production of the toner 1, as shown in Table 1, the type, content, number of release agent parts, mixing time of external addition conditions, rest time, number of mixing steps, and peripheral speed are changed as shown in Table 1, 17 was obtained. Table 1 shows the physical properties of Toners 2 to 17.

<Manufacture of Toner 18>
Binder resin (styrene / butyl acrylate / methacrylic acid / acrylic acid having an alkyl group having 18 carbon atoms = 78/20/1/1 Mw: 266000 Mw / Mn:
30.2) 62.5 parts, 35 parts of magnetic material, 1.5 parts of biscol 550P (manufactured by Sanyo Chemical) 1.5 parts or more were mixed with a Henschel mixer FM20B (manufactured by Mitsui Miike). The mixture was heated and kneaded with a twin-screw kneading extruder PCM30 (manufactured by Ikegai Iron Works Co., Ltd.), finely pulverized with a jet mill pulverizer IDS2 (manufactured by Nippon Pneumatic Industry Co., Ltd.), and airflow classifier DS2 Fine powder was cut using a material manufactured by Matik Kogyo Co., Ltd., and particles having an average particle diameter of 8 μm were obtained.

  The magnetic material-containing resin particles were treated at a heater temperature of 350 ° C. using the surface smoothing apparatus shown in FIG. Thereafter, the toner base and the hydrophobic silica fine powder prepared as described above were mixed as an external addition treatment with a Henschel mixer FM20B (manufactured by Mitsui Miike Co., Ltd.) and externally added. In the present invention, hydrophobic silica is used for the inorganic fine powder subjected to the hydrophobic treatment. Finally, agglomerates were extracted with a vibration sieve to obtain toner 18. Table 1 shows the physical properties of Toner 18.

<Manufacture of Toner 19>
Styrene butyl acrylate resin 100 parts Magnetite 60 parts Charge control agent (Orient Chemical Co., Ltd. N-01) 2 parts The above is uniformly dispersed by a mixer equipped with stirring blades. Magnetic toner powder having an average particle size of 10 μm, kneaded with PCM30 manufactured by Ikekai Tekko Co., Ltd. Got.

This magnetic toner was introduced into a hot air stream at 350 ° C. to melt the toner surface resin and suppress the exposure of the magnetic material. The processing time in the hot air (the time for the toner to pass through the hot air) is about 0.1 to 4 seconds, the supply rate is 1 kg / h, and the air flow to generate the hot air is 0.35 m at a wind pressure of 3 kg / cm ² G. ³ / min.

  After this surface modification treatment, 1.5 parts of hydrophobic silica as an external additive and 0.10 parts of fatty acid metal salt 9 were externally added to obtain a magnetic toner 19. Table 1 shows the physical properties of Toner 19.

<Manufacture of toner 20>
Styrene butyl acrylate copolymer resin (monomer ratio 82/18) 62.5 parts Magnetic iron oxide 35 parts Polypropylene 1.5 parts The above is uniformly dispersed by a mixer equipped with stirring blades. The resulting lump was kneaded with a cutter mill or the like, then finely pulverized with a jet mill pulverizer, and further classified with an airflow classifier to obtain a magnetic toner powder.

After externally adding 1.0 part of hydrophobic silica and 0.2 part of polytetrafluoroethylene using Henschel mixer FM-20B (manufactured by Mitsui Miike Chemical Co., Ltd.), hot air temperature is 250 ° C., supply rate is 1 kg / h, compression Surface modification treatment was performed with an air pressure of 0.5 kg / cm ² and a hot air volume of 0.3 m ³ to obtain a magnetic toner 20. Table 1 shows the physical properties of Toner 20.

<Manufacture of toner 21>
Styrene acrylic resin (Sanyo Kasei Co., Ltd. UNI3000) 100 parts magnetite (Toda Kogyo Co., Ltd. MAT305) 70 parts Charge control agent (Orient Chemical Co., Ltd. N-01) 4 parts The above materials are mixed in powder form. Then, the magnetite and the charge control agent are dispersed in the resin while heating with a kneading extruder. After the heat-kneaded material is cooled, it is coarsely pulverized and finely pulverized to form fine particles on the order of several μm. Further, it was classified with an air classifier to obtain powder toner particles having a particle diameter of 3 to 20 μm.

Hydrophobic silica fine powder (particle diameter 10 to 20 nm) 1 part (Nippon Aerosil Co., Ltd. HVK2150) with respect to 100 parts of the toner particles
Silicon carbide fine powder (specific gravity 5 g / cm ³ ) 0.5 part (Fujimi Polishing Co., Ltd. WA # 4000)
Zinc stearate fine powder 0.3 parts (Sakai Chemical Industry Co., Ltd. SZ-DFF)
Were mixed and stirred with a Henschel mixer to obtain toner 21. Table 1 shows the physical properties of Toner 21.

<Example 1>
1. Evaluation of Cleaning Property In the evaluation of the magnetic toner of the present invention, a test under a low temperature and low humidity environment (0 ° C./about 15% RH) was conducted as a stricter evaluation. In a low temperature environment, the cleaning blade becomes hard, and the surface of the electrostatic latent image carrier is not easily scraped. In particular, when the image is printed in the intermittent mode after the cleaning blade is sufficiently cooled, a large torque is applied to the blade, which is the most severe. In the evaluation of the magnetic toner of the present invention, an evaluation test was conducted in consideration of this point.

The magnetic toner 1 was left in a low-temperature and low-humidity environment for 24 hours, and P1006 (manufactured by HP) was used to perform a printing test of 1500 sheets in a 2-sheet intermittent mode with a printing rate of 4% and 7 seconds / sheet. . As the recording medium, A4 75 g / m ² paper was used. The cartridge used was a modified P1006 cartridge and the linear pressure of the cleaning blade was adjusted from 2.5 kgf / m to 8.0 kgf / m. If the linear pressure is high, the cleaning blade tends to vibrate irregularly, so that it is a strict evaluation for cleaning.

  The obtained horizontal line image was visually evaluated, and the cleaning property was judged according to the following criteria. In addition, since there is toner that slips through when cleaning failure occurs, the electrostatic latent image carrier cannot be charged at that portion, and black streaks are observed.

Specific evaluation criteria were as follows.
A: Black streaks are not seen.
B: 10 or less black streaks are observed on the image.
C: 11 or more small black streaks are observed on the image.
D: Slight black stripes and dark black stripes are observed on the image.

  The evaluation results are shown in Table 2.

2. Starting streak evaluation Magnetic toner 1 is allowed to stand in a normal temperature and humidity environment (23 ° C./60% RH) for 24 hours. A 1000-sheet printing test was conducted in the intermittent mode. As the recording medium, A4 75 g / m ² paper was used. The cartridge used was a modified P1006 cartridge and the linear pressure of the cleaning blade was adjusted from 2.5 kgf / m to 8.0 kgf / m. When the linear pressure is high, the external additive staying between the electrostatic latent image carrier and the cleaning blade is more strongly pressed against the electrostatic latent image carrier and promotes aggregation. Become.

  After passing 1000 sheets, it was left overnight and a halftone image for evaluation was output the next day. Further, the same paper passing was repeated up to the 1500th sheet, and then a halftone image was output for final evaluation. Further, after the end of the durability of 1500 sheets, a halftone image for evaluation was output in the morning the next day. In the obtained halftone image, it was visually confirmed whether or not a start stripe was generated.

Specifically, the starting stripe appears as a black stripe having a roller pitch in the horizontal direction on the image. The evaluation criteria were as follows.
A: Not allowed.
B: Although it is recognized, it is very slight and disappears after outputting several images. It is within the allowable range.
C: Recognized. A large number of image outputs are required until disappearance.
D: Obviously recognized.

  The evaluation results are shown in Table 2.

3. Durability developability Magnetic toner 1 is left in a normal temperature and humidity environment (23 ° C./60% RH) for 24 hours, and P1006 (manufactured by HP) is used. A 1500-sheet printing test was performed in the intermittent mode. As the recording medium, A4 75 g / m ² paper was used.

  Before and after passing the paper, a chart with a solid image formed on the entire surface of the printing paper is output one sheet at a time, and this solid image is measured with a Macbeth densitometer (Macbeth Co., Ltd.) using an SPI filter and a reflection densitometer. Went. The original used a chart with an image ratio of 5%, and the image density after durability and the image density at the beginning of durability were also evaluated.

○ Evaluation standard for endurance density Rank A: Reflection density before endurance is 1.55 or more Rank B: Reflection density before endurance is 1.50 or more and less than 1.55 Rank C: Reflection density before endurance is 1.40 or more Less than 1.50 Rank D: Reflection density before durability is less than 1.40

  The evaluation results are shown in Table 2.

○ Evaluation standard of density after durability Rank A: Reflection density after durability is 1.40 or more Rank B: Reflection density after durability is 1.35 or more and less than 1.40 Rank C: Reflection density after durability is 1.30 or more Less than 1.35 rank D: reflection density after durability is 1.20 or more and less than 1.30

  The evaluation results are shown in Table 2.

In addition, three white images were output before and after paper passing durability, and the reflectance was measured using a REFECTMETER MODEL TC-6DS manufactured by Tokyo Denshoku. On the other hand, the reflectance of the transfer paper (standard paper) before white image formation was measured in the same manner. The filter used was a green filter, and fog was calculated according to the following formula.
Fog (reflectance) (%) = reflectance of standard paper (%)-reflectance of white image sample (%)

  The fog was evaluated according to the following criteria using the maximum fog value obtained.

○ Evaluation standard rank A of fog under normal temperature and humidity environment: Very good (less than 0.2%)
Rank B: Practical level (0.2% to less than 0.5%)
Rank C: Practical level (0.5% or more and less than 1.5%)
Rank D: Practically unfavorable level (1.5% or more)

  The evaluation results are shown in Table 2.

<Examples 2 to 11>
An image output test was performed in the same manner as in Example 1 except that toners 2 to 11 were used as toners. The evaluation results are shown in Table 2.

<Comparative Examples 1 to 10>
An image output test was performed in the same manner as in Example 1 except that toners 12 to 21 were used as the toner. The evaluation results are shown in Table 3.

100: Toner supply port 101: Hot air supply port 102: Airflow injection member 103: Cold air supply port 104: Second cold air supply port 106: Cooling jacket 110: Diffusion air 111: Airflow supply port 112 for the purpose of preventing condensation Diffusing member 114 having a hole: toner 115: high-pressure air supply nozzle 116: transfer pipe

Claims (3)

In a magnetic toner having at least a magnetic toner particle containing at least a binder resin, a magnetic substance and a wax and a fatty acid metal salt,
(1) The surface tension index I of the magnetic toner with respect to a 45 volume% methanol aqueous solution measured by the capillary suction time method and calculated by the following formula (1) is 5.0 × 10 ⁻³ N / m or more. 0 × 10 ⁻¹ N / m or less,
(2) The fatty acid metal salt has a volume-based median diameter (D50) of 0.15 μm or more and 0.65 μm or less,
(3) The magnetic toner, wherein the content of the fatty acid metal salt is 0.02 parts by mass or more and 0.5 parts by mass or less with respect to 100 parts by mass of the magnetic toner particles.
I = Pα / (A × B × 10 ⁶ ) Formula (1)
I: Surface tension index (N / m) of magnetic toner
Pα: Capillary pressure (N / m ² ) of magnetic toner with respect to 45% by volume methanol aqueous solution
A: Specific surface area of magnetic toner (m ² / g)
B: True density of magnetic toner (g / cm ³ )   The magnetic toner according to claim 1, wherein the magnetic toner has a liberation rate of the fatty acid metal salt from toner particles of 10.0% by mass or more and 40.0% by mass or less.   3. The magnetic toner according to claim 1, wherein an average surface roughness (Ra) of the surface of the magnetic toner particles measured with a scanning probe microscope is 1.0 nm or more and 30.0 nm or less.

Images