JP2019164278A - Method for manufacturing toner - Google Patents

Abstract

To provide a method for manufacturing a toner that prevents discoloration of an organic pigment and contamination in a mixer.SOLUTION: A method for manufacturing a toner includes a mixing step, a kneading step, and a pulverization step. In the mixing step, toner materials are mixed by using a mixer to obtain a mixture. In the kneading step, the mixture is kneaded while being fused to obtain a kneaded product. In the pulverization step, the kneaded product is pulverized to obtain a toner. The toner materials include at least one of an organic pigment having an azo group and an organic pigment having a quinacridone structure and a fine powdered binder resin. The maximum particle diameter of the fine powdered binder resin is 30 μm or less. The amount of added fine powdered binder resin is 70 mass% or more and less than 100 mass% based on the total mass of the toner materials.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a toner manufacturing method.

  For example, Patent Document 1 describes a toner production method including a step of obtaining a master batch containing a dye / pigment.

JP-A-3-72371

  In the toner production method described in Patent Document 1, the dye / pigment is heated in the step of obtaining a master batch. For this reason, when using an organic pigment with low heat resistance for formation of a masterbatch, it became clear by examination of this inventor that discoloration of an organic pigment is caused by heating.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a toner manufacturing method that suppresses discoloration of an organic pigment and contamination in a mixer.

  The toner manufacturing method according to the present invention includes a mixing step, a kneading step, and a pulverizing step. In the mixing step, the toner materials are mixed using a mixer to obtain a mixture. In the kneading step, the mixture is kneaded while melting to obtain a kneaded product. In the pulverization step, the kneaded product is pulverized to obtain a toner. The toner material contains at least one of an organic pigment having an azo group and an organic pigment having a quinacridone structure, and a fine powder binder resin. The maximum particle size of the finely powdered binder resin is 30 μm or less. The addition amount of the fine powdered binder resin is 70% by mass or more and less than 100% by mass with respect to the total mass of the toner material.

  The toner manufacturing method according to the present invention can suppress discoloration of the organic pigment and contamination in the mixer.

It is a figure which shows an example of the particle diameter distribution curve on the volume reference | standard of fine powder-like binder resin, This fine powder-like binder resin is used with the manufacturing method of the toner which concerns on embodiment of this invention. It is a figure which shows typically an example of the photograph which image | photographed the bottom face of the tank with which a mixer is equipped.

  First, the meaning of terms used in this specification and the measurement method will be described. The evaluation results (values indicating the shape or physical properties) of the powder (more specifically, toner, toner particles, external additives, mixture, kneaded product, pulverized product, etc.) It is the number average of the values measured for a considerable number of particles contained in the powder.

  Unless otherwise specified, the particle diameter of the powder and the number average primary particle diameter are equivalent to the circle equivalent diameter of the primary particles measured using a microscope (Haywood diameter: the same area as the projected area of the particles). Number average value).

Unless otherwise specified, the volume median diameter (D ₅₀ ) of the powder was measured based on the Coulter principle (pore electrical resistance method) using a “Coulter Counter Multisizer 3” manufactured by Beckman Coulter, Inc. Value. Hereinafter, the “volume median diameter” may be referred to as “D ₅₀ ”.

  A compound and its derivatives may be generically named by adding “system” after the compound name. When the name of a polymer is expressed by adding “system” after the compound name, it means that the repeating unit of the polymer is derived from the compound or a derivative thereof. Acrylic and methacrylic are sometimes collectively referred to as “(meth) acrylic”. The meanings of terms used in this specification and the measurement methods have been described above. Next, an embodiment of the present invention will be described.

[Toner Production Method]
Hereinafter, embodiments of the present invention will be described. The present embodiment relates to a toner manufacturing method. The toner manufacturing method of the present embodiment includes at least a mixing step, a kneading step, and a pulverizing step. The toner manufacturing method of the present embodiment preferably further includes a binder resin pulverization step. The toner manufacturing method of the present embodiment may further include a classification step as necessary. The toner production method is roughly classified into a pulverization method and a polymerization method. The toner manufacturing method of this embodiment belongs to a pulverization method. The toner manufactured by the manufacturing method of the present embodiment is a so-called pulverized toner.

<Mixing process>
In the mixing step, the toner materials are mixed using a mixer to obtain a mixture. The toner material contains at least one of an organic pigment having an azo group and an organic pigment having a quinacridone structure, and at least a fine powder binder resin. The maximum particle size of the fine powder binder resin is 30 μm or less. The addition amount of the fine powder binder resin is 70% by mass or more and less than 100% by mass with respect to the total mass of the toner material. Hereinafter, the “organic pigment having an azo group” may be referred to as an “azo pigment”, and the “organic pigment having a quinacridone structure” may be referred to as a “quinacridone pigment”. In addition, “fine powdered binder resin” may be referred to as “finely powdered first binder resin”, and “binder resin” used in fine powder form may be referred to as “first binder resin”.

  The toner manufacturing method of this embodiment can suppress discoloration of the organic pigment and contamination in the mixer. The reason is considered as follows. However, the following reason is a hypothesis, and the present invention is not limited by the following hypothesis.

  In the normal pulverization method, discoloration of the organic pigment and contamination in the mixer may be caused. First, contamination in the mixer will be described. In a normal pulverization method, in a mixing step, a pigment and a non-fine powdered binder resin are put into a container of a mixer and mixed. At this time, the pigment may adhere to the inner wall of the container of the mixer and the stirring blade due to the shearing force of the mixer, and may be fused. When the pigment is fused, the pigment remains in the mixer even after washing the mixer, causing contamination in the mixer.

  Next, the discoloration of the organic pigment will be described. In order to suppress contamination in the mixer, a master batch containing a binder resin and a high concentration of pigment may be used. However, the master batch is usually formed by kneading the binder resin and the pigment at a high temperature for a long time. For this reason, when an organic pigment with low heat resistance is used for formation of a masterbatch, discoloration of the organic pigment is caused by heating. In particular, the heat resistance of azo pigments and quinacridone pigments is low. For this reason, when an azo pigment and a quinacridone pigment are used as the organic pigment, discoloration of the azo pigment and the quinacridone pigment is likely to be caused by heating at the time of forming the master batch, and the discoloration of the organic pigment becomes remarkable.

  Here, in the toner manufacturing method of the present embodiment, using a mixer, at least one of the azo pigment and the quinacridone pigment and the fine powdered first binder resin are mixed to obtain a mixture. When the first binder resin is in the form of fine powder, the surface area of the first binder resin is increased. When the surface area of the first binder resin is large, the surface area of the surface of the organic pigment that is in contact with the first binder resin becomes large. Conversely, the surface area of the surface of the organic pigment that is not in contact with the toner material containing the first binder resin (hereinafter referred to as the non-contact area of the organic pigment) is reduced. When the non-contact area of the organic pigment is small, the surface free energy of the organic pigment can be lowered, and the organic pigment can be prevented from adhering to and fusing to the inner wall of the mixer and the stirring blade. As a result, contamination in the mixer can be suppressed.

  Further, since the first binder resin is in the form of fine powder, the toner material can be suitably mixed even when the shearing force of the mixer is small. As already described, the organic pigment tends to adhere to the inner wall of the mixer and the stirring blade due to the shearing force of the mixer. According to the toner manufacturing method of the present embodiment, the shearing force of the mixer can be reduced, and the organic pigment can be prevented from adhering to the inner wall of the mixer and the stirring blade to be fused. As a result, contamination in the mixer can be suppressed.

  In the toner manufacturing method of the present embodiment, at least one of the azo pigment and the quinacridone pigment is mixed with the fine powdered first binder resin. The azo pigment and the first binder resin exist independently and are not in a masterbatch form. In addition, the quinacridone pigment and the first binder resin exist independently and are not in a masterbatch form. That is, the azo pigment and the quinacridone pigment are not heated to form a master batch. For this reason, even if it is a case where at least one of an azo pigment and quinacridone pigment with low heat resistance is used, it can suppress that an organic pigment discolors by heating. As described above, the reason why the toner manufacturing method of the present embodiment can suppress discoloration of the organic pigment and contamination in the mixer has been described.

  In addition, when using a masterbatch, since the process of forming a masterbatch is further included, we are anxious also about manufacturing cost becoming high. However, since the toner manufacturing method of the present embodiment does not include a step of forming a master batch, the number of steps can be reduced and the manufacturing cost can be reduced.

(Organic pigment)
The toner material contains at least one of an azo pigment and a quinacridone pigment as an organic pigment. Pigments are roughly classified into organic pigments and inorganic pigments. Examples of organic pigments include azo pigments and quinacridone pigments. Examples of the inorganic pigment include carbon black. The heat resistance of organic pigments is low compared to the heat resistance of inorganic pigments. Furthermore, among organic pigments, azo pigments and quinacridone pigments have low heat resistance. Furthermore, the heat resistance of azo pigments is lower than the heat resistance of quinacridone pigments. This is because the azo group of the azo pigment tends to be hydrolyzed by heating. However, according to the toner manufacturing method of this embodiment, discoloration of the organic pigment can be suppressed even when at least one of an azo pigment and a quinacridone pigment having low heat resistance is used.

  Examples of azo pigments include monoazo pigments. A monoazo pigment is an organic pigment having one azo group. Examples of monoazo pigments include monoazo yellow pigments. A monoazo yellow pigment is a yellow organic pigment having one azo group.

Examples of azo pigments include insoluble azo pigments. Insoluble azo pigments are azo pigments that do not have hydrophilic groups (eg, —COOH groups and —SO ₃ H groups). The azo pigment is an insoluble azo pigment and may be a monoazo pigment.

Examples of azo pigments that are insoluble azo pigments and monoazo pigments include C.I. I. Pigment yellow (1, 2, 3, 4, 5, 6, 7, 9, and 73). Examples of the azo pigment include C.I. I. Pigment Yellow 73 may be used. These azo pigments have a relatively low molecular weight and do not have functional groups (for example, —COOH groups and —SO ₃ H groups that form hydrogen bonds) that strengthen the crystal structure. For this reason, these azo pigments have low heat resistance. However, according to the toner manufacturing method of the present embodiment, discoloration of the organic pigment can be suppressed even when such an azo pigment having low heat resistance is used.

  Examples of quinacridone pigments include C.I. I. Pigment violet 19, C.I. I. Pigment red (122, 202, and 209), and C.I. I. Pigment orange (48 and 49). Examples of quinacridone pigments include C.I. I. Pigment Red 122 may be used. According to the toner manufacturing method of the present embodiment, discoloration of the organic pigment can be suppressed even when these quinacridone pigments having low heat resistance are used.

  The toner material may contain only one azo pigment as a pigment or may contain two or more azo pigments. The toner material may contain only one kind of quinacridone pigment as a pigment, or may contain two or more kinds of quinacridone pigments. Further, the toner material may contain only one or both of an azo pigment and a quinacridone pigment as a pigment.

  In order to suppress contamination in the mixer, when one of an azo pigment and a quinacridone pigment is used, the amount of the azo pigment or the quinacridone pigment is greater than 0.0% by mass with respect to the mass of the binder resin. It is preferably 6.5% by mass or less, and more preferably greater than 0.0% by mass and 6.1% by mass or less. For the same reason, when both an azo pigment and a quinacridone pigment are used, the total amount of the azo pigment and the quinacridone pigment is larger than 0.0% by mass and 6.5% by mass with respect to the mass of the binder resin. It is preferable that it is below, and it is more preferable that it is larger than 0.0 mass% and below 6.1 mass%. In addition, when using 2 or more types of binder resin (for example, 1st binder resin and 2nd binder resin mentioned later), the mass of binder resin is the total mass of 2 or more types of binder resin. It is.

  In order to suppress contamination in the mixer, when one of an azo pigment and a quinacridone pigment is used, the amount of the azo pigment or the quinacridone pigment is greater than 0% by mass and 20% by mass with respect to the total mass of the toner material. % Or less, more preferably 0% by mass to 5% by mass or less. For the same reason, when both an azo pigment and a quinacridone pigment are used, the total amount of the azo pigment and the quinacridone pigment should be greater than 0% by mass and not greater than 20% by mass with respect to the total mass of the toner material. Is preferable, and it is more preferable that it is larger than 0 mass% and 5 mass% or less.

  As already described, neither the azo pigment nor the quinacridone pigment mixed in the mixing step is in the form of a masterbatch. The master batch contains an organic pigment and a binder resin. The master batch is an integrated product of an organic pigment and a binder resin. Organic pigments added in the mixing step (specifically, azo pigments and quinacridone pigments) do not contain a binder resin. Further, the binder resin added in the mixing step does not contain an azo pigment or a quinacridone pigment. When only the first binder resin is added as the binder resin in the mixing step, the binder resin added in the mixing step is the first binder resin. When the first binder resin and the second binder resin described later are added as the binder resin in the mixing step, the binder resin added in the mixing step is the first binder resin and the second binder resin. It is.

(Fine powder binder resin)
The toner material includes a fine powdery first binder resin as the binder resin. The addition amount of the fine powdered first binder resin is 70% by mass or more with respect to the total mass of the toner material. When the addition amount of the fine powdered first binder resin is 70% by mass or more with respect to the total mass of the toner material, contamination in the mixer can be suppressed. In order to suppress the contamination in the mixer, the amount of the fine powdered first binder resin added is preferably 80% by mass or more based on the total mass of the toner material. The addition amount of the fine powdered first binder resin is less than 100% by mass with respect to the total mass of the toner material. The upper limit of the addition amount of the fine powdered first binder resin is not particularly limited as long as it is less than 100% by mass, and can be, for example, 85% by mass or less based on the total mass of the toner material. The addition amount of the fine powdered first binder resin may be 70% by weight to less than 80% by weight, or 80% by weight to 85% by weight with respect to the total weight of the toner material.

The maximum particle size of the fine powdered first binder resin before being mixed in the mixing step is 30 μm or less. Hereinafter, the “maximum particle diameter” may be referred to as “D _MAX ”. When the D _MAX of the fine powdered first binder resin is 30 μm or less, contamination in the mixer can be suppressed. In order to suppress contamination in the mixer, the D _MAX of the finely powdered first binder resin is preferably 25 μm or less, and more preferably 15 μm or less. The lower limit of D _MAX of the finely powdered first binder resin is not particularly limited, but can be, for example, 1 μm or more. When the D _MAX of the fine powdered first binder resin is 1 μm or more, the surface free energy of the fine powdered first binder resin does not become too high, and the fine powdered first binder resin is the inner wall of the mixer. And it can suppress adhering to a stirring blade.

The 50% integrated diameter on a volume basis of the finely powdered binder resin before being mixed in the mixing step is preferably 9.3 μm or less. Hereinafter, “50% integrated diameter on a volume basis” may be referred to as “D ₅₀ ”. D ₅₀ is also called the median diameter or volume median diameter. When the D ₅₀ of the fine powdered first binder resin is 9.3 μm or less, contamination in the mixer can be suitably suppressed. In order to suitably suppress contamination in the mixer, the D ₅₀ of the fine powdered first binder resin is preferably 9.1 μm or less, and more preferably 7.0 μm or less. The lower limit of D ₅₀ of the fine powdered first binder resin is not particularly limited, but may be, for example, 0.1 μm or more.

The difference (D _MAX -D ₅₀ ) between D _MAX and D ₅₀ of the fine powdered first binder resin is preferably 20.0 μm or less, more preferably 16.0 μm or less, and 10.0 μm. The following is more preferable. The smaller the difference (D _MAX -D ₅₀ ), the sharper the particle size distribution of the fine powdered first binder resin. The smaller the difference (D _MAX -D ₅₀ ), the better the contamination in the mixer can be suppressed. The lower limit of the difference (D _MAX −D ₅₀ ) is not particularly limited, but can be, for example, 0.0 μm or more.

The 10% integrated diameter on a volume basis of the finely powdered binder resin before being mixed in the mixing step is preferably 6.1 μm or less. Hereinafter, “10% cumulative diameter on a volume basis” may be referred to as “D ₁₀ ”. When D ₁₀ of the fine powdered first binder resin is 6.1 μm or less, contamination in the mixer can be suitably suppressed. In order to suitably suppress contamination in the mixer, D ₁₀ of the fine powdered first binder resin is preferably 5.9 μm or less, and more preferably 4.5 μm or less. The lower limit of D ₁₀ of fine powder of the first binder resin is not particularly limited, for example, be a 0.0μm greater.

The difference (D _MAX −D ₁₀ ) between D _MAX and D ₁₀ of the fine powdered first binder resin is preferably 30.0 μm or less, more preferably 20.0 μm or less, and 15.0 μm. The following is more preferable. The smaller the difference (D _MAX -D ₁₀ ), the sharper the particle size distribution of the fine powdered first binder resin. The smaller the difference (D _MAX −D ₁₀ ), the better the contamination in the mixer can be suppressed. The lower limit of the difference (D _MAX −D ₁₀ ) is not particularly limited, but can be, for example, 0.0 μm or more.

D _MAX , D ₅₀ , and D ₁₀ of the fine powdered first binder resin can be measured using a particle size distribution measuring apparatus using the Coulter principle. Details of the measurement method of D _MAX , D ₅₀ , and D ₁₀ of the fine powdered first binder resin will be described later in Examples. The D _MAX , D ₅₀ , and D ₁₀ of the fine powdered first binder resin can be adjusted, for example, by changing the pulverization conditions of the first binder resin. In addition, about the grinding | pulverization conditions (specifically processing amount, rotation speed, etc.) of 1st binder resin, it mentions later by a binder resin pulverization process.

  As the first binder resin added in fine powder form, a thermoplastic resin is preferable. Examples of the thermoplastic resin include polyester resin, styrene resin, acrylic acid resin, olefin resin, vinyl resin, polyamide resin, and urethane resin. Only 1 type may be sufficient as 1st binder resin added by fine powder form, and 2 or more types may be sufficient as it. A polyester resin is preferable as the first binder resin added in fine powder form.

  The polyester resin is obtained by polycondensing an alcohol monomer and a carboxylic acid monomer. The polyester resin is a polymer of an alcohol monomer and a carboxylic acid monomer.

  Examples of alcohol monomers include diol monomers, bisphenol monomers, and trihydric or higher alcohol monomers.

  Examples of diol monomers include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 2-butene-1,4-diol. 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

  Examples of bisphenol monomers include bisphenol A, hydrogenated bisphenol A, bisphenol A ethylene oxide adduct, and bisphenol A propylene oxide adduct (eg, propylene oxide 2 mol adduct of bisphenol A).

  Examples of trihydric or higher alcohol monomers include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. 1,2,5-pentanetriol, glycerol, diglycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-triol Hydroxymethylbenzene is mentioned.

  Examples of the carboxylic acid monomer include a divalent carboxylic acid monomer and a trivalent or higher carboxylic acid monomer.

  Examples of divalent carboxylic acid monomers include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, 5-sulfoisophthalic acid, sodium 5-sulfoisophthalate, cyclohexanedicarboxylic acid , Adipic acid, sebacic acid, azelaic acid, malonic acid, succinic acid, alkyl succinic acid, and alkenyl succinic acid. Examples of alkyl succinic acids include n-butyl succinic acid, isobutyl succinic acid, n-octyl succinic acid, n-dodecyl succinic acid, and isododecyl succinic acid. Examples of alkenyl succinic acids include n-butenyl succinic acid, isobutenyl succinic acid, n-octenyl succinic acid, n-dodecenyl succinic acid, and isododecenyl succinic acid.

  Examples of trivalent or higher carboxylic acid monomers include 1,2,4-benzenetricarboxylic acid (trimellitic 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 (methylenecarboxyl) methane 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, and empole trimer acid.

  For the synthesis of the polyester resin, only one alcohol monomer may be used, or two or more alcohol monomers may be used. In the synthesis of the polyester resin, only one carboxylic acid monomer may be used, or two or more carboxylic acid monomers may be used. Further, the carboxylic acid monomer may be used after being derivatized into an ester-forming derivative. Examples of ester-forming derivatives include acid halides, acid anhydrides, and alkyl (eg, alkyl having 1 to 6 carbon atoms) esters. In order to obtain a toner suitable for image formation, the amount of the binder resin is preferably 50% by mass or more and 99% by mass or less, and 75% by mass or more and 90% by mass or less with respect to the total mass of the toner material. It is more preferable that

  As an example of a mixer used in the mixing step, a mixer having a stirring blade can be mentioned. The mixer includes, for example, a container (for example, a tank) into which the toner material is charged and a stirring blade that stirs the toner material in the container. The number of stirring blades is preferably four (two upper blades and two lower blades). An FM mixer is an example of a mixer that includes a stirring blade.

  In order to suitably suppress contamination in the mixer, the rotation speed of the stirring blade of the mixer is preferably 100 rpm to 2000 rpm, more preferably 100 rpm to 1000 rpm, and more preferably 100 rpm to 750 rpm. Further preferred. In order to suitably suppress contamination in the mixer, the mixing time is preferably 5 seconds or more and 600 seconds or less, and more preferably 60 seconds or more and 180 seconds or less. The temperature inside the container of the mixer is preferably 0 ° C. or higher and 50 ° C. or lower, and more preferably 0 ° C. or higher and 30 ° C. or lower.

  In order to improve workability, it is preferable not to use a solvent in the mixing step. In order to suppress discoloration of the organic pigment, it is preferable not to heat the toner material in the mixing step. The toner material preferably does not contain a dye. In order to improve workability, it is preferable to use the mixture in powder form in the kneading step without solidifying the mixture obtained in the mixing step to obtain an integrated product.

  A commercially available product may be used as the finely powdered first binder resin added in the mixing step. Or you may obtain 1st binder resin of fine powder form by performing the binder resin micronization process shown next.

<Binder resin pulverization process>
The binder resin fine particle forming step is performed before the mixing step. In the binder resin pulverization step, the first binder resin is pulverized until D _MAX becomes 30 μm or less to obtain a finely powdered first binder resin. In the binder resin pulverization step, it is preferable to pulverize the first binder resin until D ₅₀ falls within the preferred range already described. In the binder resin pulverization step, it is preferable to pulverize the first binder resin until D ₁₀ falls within the preferred range already described. The D _MAX of the finely powdered first binder resin obtained in the binder resin micronization step is 30 μm or less. The fine powdery first binder resin obtained in the binder resin micronization step can be used in the mixing step.

  For example, the first binder resin is pulverized by using a pulverizer. Examples of the pulverizer include a turbo mill and a jet mill. As an example of a turbo mill, there is a turbo mill that crushes a raw material by high-speed overflow generated on the back surface of a minute wave groove on a rotor surface that rotates at high speed and pressure vibration. When a turbo mill is used as the pulverizer, the throughput of the turbo mill is preferably 10 kg / hour or more and 100 kg / hour or less, and more preferably 30 kg / hour or more and 40 kg / hour or less. When a turbo mill is used as a pulverizer, the rotational speed of the turbo mill is preferably 5700 rpm or more and 7000 rpm or less, and more preferably 5800 rpm or more and 6800 rpm or less. As an example of a jet mill, there is a jet mill that pulverizes an object to be crushed by colliding with a collision plate.

<Kneading process>
In the kneading step, the mixture obtained in the mixing step is kneaded while melting to obtain a kneaded product. For example, the mixture is kneaded by using a melt kneader (for example, a single-screw or twin-screw extruder). The charging speed of the mixture into the melt kneader is preferably 0.1 kg / hour or more and 10 kg / hour. The shaft rotation speed of the melt-kneading apparatus is preferably 50 rpm or more and 500 rpm or less, and more preferably 100 rpm or more and 200 rpm or less. In order to suppress discoloration of the organic pigment, the kneading temperature is preferably lower than the temperature at which the azo pigment and the quinacridone pigment discolor. For the same reason, the kneading temperature is preferably 50 ° C. or higher and 100 ° C. or lower.

<Crushing process>
In the pulverization step, the kneaded product obtained in the kneading step is pulverized to obtain a toner. The pulverization step preferably includes a primary pulverization step and a secondary pulverization step. In the primary pulverization step, the kneaded product obtained in the kneading step is primarily pulverized to obtain a primary pulverized product. For the primary pulverization, for example, a pulverizer (specifically, a mill or the like) can be used. D ₅₀ of the primary ground material is smaller than the D ₅₀ of the kneaded product. In the secondary pulverization step, the primary pulverized product is subjected to secondary pulverization to obtain a secondary pulverized product. For the secondary pulverization, for example, a pulverizer (specifically, a jet mill or the like) can be used. The D ₅₀ of the secondary pulverized product is smaller than the D _{50 of the} primary pulverized product. The secondary pulverized product may be used as a toner. Or you may perform the classification process shown next to a secondary ground material. In order to suppress discoloration of the organic pigment, the pulverization step is preferably performed without heating.

<Classification process>
The secondary pulverized product obtained in the secondary pulverization step is classified. Thereby, a toner having a desired particle diameter is obtained. For classification, for example, a classifier (specifically, an air classifier or the like) can be used. In order to suppress discoloration of the organic pigment, the classification step is preferably performed without heating. The toner manufacturing method of the present embodiment has been described above.

[toner]
Next, the toner manufactured by the manufacturing method of this embodiment will be described. The toner includes toner particles. The toner is an aggregate (powder) of toner particles.

  The toner material mixed in the mixing step includes at least one of an azo pigment and a quinacridone pigment and at least a fine powdered first binder resin. The toner material includes at least one of a non-fine powdered binder resin, a charge control agent, and a release agent in addition to at least one of the azo pigment and the quinacridone pigment and the fine powdered first binder resin. May further be included.

(Non-fine powder binder resin)
The toner material mixed in the mixing step may further contain a non-fine powder binder resin. Hereinafter, the “non-fine binder resin” may be referred to as a “second binder resin”. The D _MAX of the second binder resin is preferably 1000 μm or more and 3000 μm or less. D ₅₀ of the second binder resin is preferably 700 μm or more and 1000 μm or less. D ₁₀ of the second binder resin is preferably 300 μm or more and 700 μm or less. D _MAX , D ₅₀ , and D ₁₀ of the second binder resin can be measured using a particle size distribution measuring apparatus using the Coulter principle. Details of the measurement method of D _MAX , D ₅₀ , and D ₁₀ of the second binder resin will be described later in Examples.

  The amount of the second binder resin added is preferably 0% by mass to 12% by mass with respect to the total mass of the toner material. The addition amount of the second binder resin may be 0 mass with respect to the total mass of the toner material. That is, the second binder resin may not be added. The toner material may contain only the fine powdered first binder resin as the binder resin.

  The amount of the second binder resin added is preferably 0% by mass to 15% by mass with respect to the total mass of the binder resin. The addition amount of the first binder resin is preferably 85% by mass or more and 100% by mass or less with respect to the total mass of the binder resin. The addition amount of the second binder resin is preferably 0% by mass or more and 17% by mass or less with respect to the addition amount of the first binder resin.

Suitable examples of the second binder resin added in a non-fine powder form are those of the first binder resin added in a fine powder form except that the particle diameters (for example, D _MAX , D ₅₀ , and D ₁₀ ) are different. Same as the preferred example. Only 1 type may be sufficient as 2nd binder resin added by non-fine powder form, and 2 or more types may be sufficient as it. As the second binder resin added in a non-fine powder state, a polyester resin is preferable.

(Release agent)
The toner material mixed in the mixing step may further contain a release agent. Examples of the release agent include aliphatic hydrocarbon wax (specifically, low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, Fischer-Tropsch wax, etc.), fat Group hydrocarbon wax oxides (specifically, oxidized polyethylene wax and block copolymers thereof), vegetable waxes (specifically, candelilla wax, carnauba wax, wood wax, jojoba wax, and rice) Waxes), animal waxes (specifically, beeswax, lanolin, and whale wax), mineral waxes (specifically, ozokerite, ceresin, petrolatum, etc.), waxes based on fatty acid esters ( Specifically, the montanic acid ester Scan, and castor wax, etc.), and the wax (specifically a part or all is de-oxidation of fatty acids esters, deoxidized carnauba wax, etc.). As a mold release agent, carnauba wax is preferable.

  The addition amount of the release agent is preferably 15% by mass or less, and more preferably 10% by mass or less with respect to the total mass of the toner material. The toner material may contain only one type of release agent or two or more types of release agents.

(Charge control agent)
The toner material mixed in the mixing step may further contain a charge control agent. The toner material contains a positively chargeable charge control agent (specifically, pyridine, nigrosine, a quaternary ammonium salt, a polymer containing a repeating unit derived from a quaternary ammonium salt, etc.), thereby enhancing the cationicity of the toner. be able to. Since the toner material contains a negatively chargeable charge control agent (specifically, an organometallic complex, a chelate compound, etc.), the anionicity of the toner can be enhanced. However, when sufficient chargeability is ensured in the toner, the toner material does not need to contain a charge control agent.

  In order to suppress toner discoloration and contamination in the mixer, the charge control agent is preferably not a dye (specifically, nigrosine or the like). For the same reason, the charge control agent is preferably a polymer containing a repeating unit derived from a quaternary ammonium salt, and more preferably a styrene-acrylic acid resin containing a repeating unit derived from a quaternary ammonium salt. The styrene-acrylic acid resin is a polymer of a styrene monomer and an acrylic acid monomer. The styrene monomer is styrene or a derivative thereof. The acrylic acid monomer is (meth) acrylic acid or a derivative thereof.

  The addition amount of the charge control agent is preferably 5% by mass or less, and more preferably 3% by mass or less, based on the total mass of the toner material. The toner material may contain only one type of charge control agent or may contain two or more types of charge control agents.

(External additive)
An external additive (specifically, a powder that is an aggregate of external additive particles) may be adhered to the surface of the toner particles. Unlike the internal additive, the external additive is not present inside the toner particles but is selectively present only on the surface of the toner particles. For example, the toner particles (powder) and the external additive (powder) are stirred together, whereby the external additive particles can be attached to the surface of the toner particles.

  In order to fully exert the function of the external additive while suppressing the detachment of the external additive particles from the toner particles, the amount of the external additive (when two or more types of external additive particles are used, The total amount of these external additive particles) is preferably 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the toner particles. The number average primary particle diameter of the external additive particles is preferably 5 nm or more and 50 nm or less, and more preferably 10 nm or more and 35 nm or less.

  As the external additive particles, inorganic particles are preferable, and particles of silica particles or metal oxides (specifically, alumina, titanium oxide, magnesium oxide, zinc oxide, strontium titanate, barium titanate, etc.) are particularly preferable. preferable. However, as external additive particles, organic acid compound particles such as fatty acid metal salts (specifically, zinc stearate, etc.) or resin particles may be used. The external additive particles may be surface-treated external additive particles, more specifically, external additive particles (for example, positively-charged silica particles) imparted with positive charge by the surface treatment. Only one external additive particle may be provided on the surface of the toner particle, or two or more external additive particles may be provided.

In the toner manufactured by the manufacturing method of the present embodiment, the D ₅₀ of the toner particles is preferably 4 μm or more and 9 μm or less. The toner manufactured by the manufacturing method of the present embodiment may be a non-capsule toner without a shell layer or a capsule toner with a shell layer. The toner manufactured by the manufacturing method of the present embodiment can be used for developing an electrostatic latent image, for example, as a positively chargeable toner or a negatively chargeable toner. Toner may be used as a one-component developer. Further, the toner and the carrier may be mixed to use the toner as a two-component developer. When the toner is a one-component developer, the toner is positively or negatively charged by friction with a developing sleeve or a toner charging member (for example, a doctor blade) in the developing unit. In the case of a two-component developer containing toner and carrier, the toner is positively or negatively charged by being rubbed with the carrier in the developing portion.

The present invention will be described more specifically with reference to examples. The present invention is not limited to the scope of the examples. In the following description, L value, a value, and b value mean L ^* value, a ^* value, and b ^* value in the CIE 1976 (L ^* , a ^* , b ^* ) color space, respectively.

  In the reference examples, examples, and comparative examples, the following pigments were used. As an azo pigment, C.I. I. Pigment Yellow 73 (“Hansa Brilliant Yellow 4GX” manufactured by Clariant) was used. As quinacridone pigments, C.I. I. Pigment Red 122 (“Pigment Red 3090” manufactured by Sanyo Dyeing Co., Ltd.) was used. Carbon black (“REGAL (registered trademark) 330R” manufactured by Cabot Corporation) was used as the inorganic pigment.

[Comparison of heat resistance of pigments (reference example)]
First, as a reference example for helping understanding, a comparison result between the heat resistance of an organic pigment and the heat resistance of an inorganic pigment is shown. The comparison method between the heat resistance of the organic pigment and the heat resistance of the inorganic pigment was as follows.

  First, the L value, a value, and b value of each pigment were measured using a reflection densitometer (“SpectroEye (registered trademark)” manufactured by X-Rite). The measured L value, a value, and b value were designated as “L value, a value, and b value of the pigment before heating”, respectively. Subsequently, 5 g of the pigment was heated in an oven at 110 ° C. for 45 minutes. After heating, the L value, a value, and b value of each pigment were measured again using a reflection densitometer (“SpectroEye” manufactured by X-Rite). The measured L value, a value, and b value were defined as “the L value, a value, and b value of the pigment after heating”, respectively. And the difference of L value before a heating, a value, and b value was calculated | required. Specifically, the difference between the L values before and after heating was determined from the calculation formula “difference in L value = L value of the pigment after heating−L value of the pigment before heating”. From the calculation formula “difference in a value = a value of pigment after heating−a value of pigment before heating”, the difference in a value before and after heating was determined. The difference between the b values before and after heating was determined from the calculation formula “difference in b value = b value of pigment after heating−b value of pigment before heating”.

  Table 1 shows the L value, a value, and b value of the pigment before heating, and the L value, a value, and b value of the pigment after heating. Table 1 shows the difference in L value before and after heating, the difference in a value, and the difference in b value. A pigment having at least one of the absolute value of the difference in L value before and after heating, the absolute value of the difference in a value, and the absolute value of the difference in b value as 1 or more was evaluated as having poor heat resistance.

  “Red 122” and “Yellow 73” in Table 1 indicate “CI Pigment Red 122” and “CI Pigment Yellow 73”, respectively. “L value”, “a value”, and “b value” in the “Before heating” column in Table 1 indicate the L value, a value, and b value of the pigment before heating, respectively. “L value”, “a value”, and “b value” in the “After heating” column of Table 1 indicate the L value, a value, and b value of the pigment after heating, respectively. “L value”, “a value”, and “b value” in the “Difference (before heating−after heating)” column in Table 1 are the difference in L value before and after heating, the difference in a value, and b, respectively. Indicates the difference in values.

  As is clear from Reference Example 3 in Table 1, carbon black, which is an inorganic pigment, was excellent in heat resistance. For this reason, even when a masterbatch containing carbon black and a binder resin is formed by kneading for a long time at a high temperature, it is considered that discoloration of the carbon black in the masterbatch is hardly caused.

  On the other hand, as is clear from Reference Example 1 in Table 1, C.I. I. Pigment Red 122 was inferior in heat resistance. As is clear from Reference Example 2 in Table 1, the azo pigment C.I. I. Pigment Yellow 73 was inferior in heat resistance. For this reason, when a masterbatch containing such an organic pigment and a binder resin is formed by kneading at a high temperature for a long time, discoloration of the organic pigment in the masterbatch is likely to be caused. The toner production method according to the present invention is considered to be particularly effective for such an organic pigment having low heat resistance.

  Next, production methods, measurement methods, evaluation methods, and evaluation results of toners A-1 to A-3, B-1 to B-5, C-1 to C-3, and D-1 to D-5 ,explain. The configuration of each toner is shown in Table 3 and Table 4 described later. In the evaluation in which an error occurs, a considerable number of measurement values with sufficiently small errors are obtained, and the number average of the obtained measurement values is used as the evaluation value.

[Toner Production Method]
<Preparation of Toner A-2>
(Binder resin pulverization process)
Turbo mill ("Multi Cooling System Turbo Mill T400 (RS type)" manufactured by Freund Turbo Inc., grinding method: Method of grinding raw materials by high-speed overflow generated on the back of minute wave grooves on the surface of a rotor rotating at high speed, and pressure vibration ), The polyester resin (“CBC500” manufactured by Kao Corporation, D _MAX : 2000 μm, D ₅₀ : 900 μm, D ₁₀ : 500 μm) as a first binder resin was pulverized. The grinding conditions were a throughput of 30 kg / hour and a rotation speed of 6000 rpm. Thereby, a fine powdery first binder resin was obtained. D _MAX of the obtained finely powdered first binder resin was 25 μm, D ₅₀ was 9.1 μm, and D ₁₀ was 5.9 μm.

(Mixing process)
As a toner material, 70 parts by mass of a finely powdered first binder resin obtained in the binder resin pulverization step, 12 parts by mass of a second binder resin, and 5 parts by mass of a pigment (quinacridone pigment, specifically C Pigment Red 122), 10 parts by weight of a release agent (Carnauba wax, “Carnauba Wax No. 1” manufactured by Kato Yoko Co., Ltd.), and 3 parts by weight of a charge control agent (polymer type positively chargeable charge control). Agent, “Acrybase (registered trademark) FCA-201-PS” manufactured by Fujikura Kasei Co., Ltd., component: styrene-acrylic acid resin containing a repeating unit derived from a quaternary ammonium salt) was used. The second binder resin was an unpulverized polyester resin (“CBC500” manufactured by Kao Corporation, D _MAX : 2000 μm, D ₅₀ : 900 μm, D ₁₀ : 500 μm). The total mass of the toner material is 100 parts by mass (that is, 70 parts by mass of the first binder resin + 12 parts by mass of the second binder resin + 5 parts by mass of the pigment + 10 parts by mass of the release agent + 3 parts by mass of the charge control agent). )Met. The addition amount of the fine powdered first binder resin with respect to the total mass of the toner material was 70 mass% (that is, 100 × 70 mass parts of the first binder resin / 100 mass parts of the total mass of the toner material). .

  As a mixer, an FM mixer (“FM-20B” manufactured by Nippon Coke Industries, Ltd.) was used. This FM mixer was provided with a tank for charging the toner material and a stirring blade for stirring the toner material in the tank. The capacity of the tank was 20L. There were 4 stirring blades (2 upper blades and 2 lower blades). Four stirring blades were provided on one shaft.

  The toner material was charged into the FM mixer tank. Using an FM mixer, the toner materials were mixed for 120 seconds under the conditions of a temperature in the tank of 24 ° C. and a rotating speed of the stirring blade of 740 rpm. This gave a mixture. The mixture was removed from the tank. The tank after taking out the mixture was used for evaluation of the contamination in the mixer described later.

(Kneading process)
Using a twin-screw extruder, the mixture obtained in the mixing step was kneaded while melting under the conditions of a material charging speed of 5 kg / hour, a shaft rotation speed of 160 rpm, and a set temperature of 100 ° C. This obtained the kneaded material. The kneaded product was cooled.

(Crushing process)
The cooled kneaded material was first pulverized using a pulverizer (“Rotoplex 16/8 type” manufactured by Toa Machinery Co., Ltd.) to obtain a primary pulverized material. The primary pulverized product was subjected to secondary pulverization using a jet mill (“Ultrasonic Jet Mill I Type” manufactured by Nippon Pneumatic Industry Co., Ltd.) to obtain a secondary pulverized product.

(Classification process)
Using a classifier (a wind classifier using the Coanda effect, “Elbow Jet EJ-LABO type” manufactured by Nittetsu Mining Co., Ltd.), the secondary pulverized product was classified to obtain toner A-2.

<Preparation of Toner A-1>
In the production of the toner A-1, 70 parts by mass of the fine powdered first binder resin and 12 parts by mass of the second binder resin, 82 parts by mass of the finely powdered first binder resin and 0 parts by mass of the first binder resin. Changed to 2 binder resin. In the production of the toner A-1, the second binder resin was not used. Thereby, the addition amount of the fine powdered first binder resin with respect to the total mass of the toner material was changed from 70% by mass to the value shown in Table 3. Except for these changes, Toner A-1 was prepared by the same method as that for Toner A-2.

<Preparation of Toner A-3>
In the production of the toner A-3, the pulverization condition in the binder resin pulverization step was changed to 6800 rpm. As a result, D _MAX , D ₅₀ , and D ₁₀ of the obtained finely powdered first binder resin were changed to the values shown in Table 3. Except for these changes, Toner A-3 was prepared by the same method as that for Toner A-2.

<Preparation of Toner B-1>
In the preparation of the toner B-1, 70 parts by mass of the finely powdered first binder resin and 12 parts by mass of the second binder resin, 60 parts by mass of the finely powdered first binder resin and 22 parts by mass of the first binder resin. Changed to 2 binder resin. Thereby, the addition amount of the fine powdered first binder resin with respect to the total mass of the toner material was changed from 70% by mass to the value shown in Table 3. Except for these changes, Toner B-1 was prepared by the same method as that for Toner A-2.

<Preparation of Toner B-2>
In the preparation of the toner B-2, 70 parts by mass of the fine powdered first binder resin and 12 parts by mass of the second binder resin, 50 parts by mass of the finely powdered first binder resin, and 32 parts by mass of the first binder resin. Changed to 2 binder resin. Thereby, the addition amount of the fine powdered first binder resin with respect to the total mass of the toner material was changed from 70% by mass to the value shown in Table 3. Except for these changes, Toner B-2 was prepared in the same manner as Toner A-2.

<Preparation of Toner B-3>
In the production of the toner B-3, 70 parts by mass of the fine powdered first binder resin and 12 parts by mass of the second binder resin, 0 part by mass of the finely powdered first binder resin and 82 parts by mass of the first binder resin. Changed to 2 binder resin. In the production of the toner B-3, the fine powdered first binder resin was not used. Except for these changes, Toner B-3 was prepared in the same manner as Toner A-2.

<Preparation of Toner B-4>
In the production of the toner B-4, the pulverization condition in the binder resin pulverization step was changed to 5600 rpm. As a result, D _MAX , D ₅₀ , and D ₁₀ of the obtained finely powdered first binder resin were changed to the values shown in Table 3. Except for these changes, Toner B-4 was prepared in the same manner as Toner A-2.

<Preparation of Toner B-5>
(Master batch formation process)
Using an FM mixer (“FM-20B” manufactured by Nippon Coke Industries, Ltd.), 50 parts by mass of a binder resin and 50 parts by mass of a pigment (quinacridone pigment, specifically CI Pigment Red 122) were mixed. To obtain a mixture. The binder resin was an unpulverized polyester resin (“CBC500” manufactured by Kao Corporation, D _MAX : 2000 μm, D ₅₀ : 900 μm, D ₁₀ : 500 μm). Subsequently, the mixture was kneaded for 45 minutes using a kneading machine (open roll continuous kneading granulator, “Neekex MOS-160” manufactured by Nippon Coke Co., Ltd.) to obtain a kneaded product. This kneader was equipped with two rolls. The surface temperature of the roll was set to 110 ° C. Subsequently, the obtained kneaded material was pulverized using a pulverizer (“Rotoplex 16/8 type” manufactured by Toa Machinery Co., Ltd.) to obtain a pulverized product. The grinding conditions were a charging speed of 3.6 kg / hour, a frequency of 50 Hz, and a rotation speed of 960 rpm. Subsequently, the pulverized product was sieved using a sieve having an opening of 2500 μm. As a result, a master batch containing the pigment and the binder resin was obtained. D _MAX , D ₅₀ , and D ₁₀ of the obtained master batch were values shown in Table 3, respectively.

(Mixing process)
As a toner material, 10 parts by mass of a master batch (a master batch containing 5 parts by mass of a pigment and 5 parts by mass of a binder resin), 77 parts by mass of a second binder resin, and 10 parts by mass of a release agent. Molding agent (Carnauba wax, “Carnauba wax No. 1” manufactured by Kato Yoko Co., Ltd.) and 3 parts by mass of charge control agent (Polymer type positively chargeable charge control agent, “Acrybase” (registered trademark) manufactured by Fujikura Kasei Co., Ltd. ) FCA-201-PS ", component: a styrene-acrylic acid resin containing a repeating unit derived from a quaternary ammonium salt. The second binder resin was an unpulverized polyester resin (“CBC500” manufactured by Kao Corporation, D _MAX : 2000 μm, D ₅₀ : 900 μm, D ₁₀ : 500 μm). The total mass of the toner material was 100 parts by mass (that is, 10 parts by mass master batch + 77 parts by mass of the second binder resin + 10 parts by mass of the release agent + 3 parts by mass of the charge control agent). In the production of the toner B-5, the pulverized fine powdery first binder resin was not used.

  As the mixer, the FM mixer used in the production of the toner A-2 was used. The toner material was charged into the FM mixer tank. Using an FM mixer, the toner material was mixed for 120 seconds under the conditions of a temperature in the dunk of 24 ° C. and a rotating speed of the stirring blade of 740 rpm. This gave a mixture. The mixture was removed from the tank. The tank after taking out the mixture was used for evaluation of the contamination in the mixer described later.

(Kneading process, crushing process, and classification process)
Toner B-5 was kneaded, pulverized, and classified in the same manner as toner A-2, kneaded, pulverized, and classified. As a result, Toner B-5 was obtained.

<Preparation of Toner C-2>
A toner C-2 was produced in the same manner as in the production of the toner A-2 except that the following points were changed. In the binder resin pulverization step, the pulverization conditions were changed to a throughput of 40 kg / hour and a rotation speed of 5800 rpm. As a result, the D _MAX of the obtained finely powdered first binder resin was changed to the values shown in Table 4. In the mixing step, the pigment is mixed with C.I. I. Pigment Red 122, C.I. I. Pigment Yellow 73

<Preparation of Toner C-1>
A toner C-1 was produced in the same manner as in the production of the toner A-1, except that the following points were changed. In the binder resin pulverization step, the pulverization conditions were changed to a throughput of 40 kg / hour and a rotation speed of 5800 rpm. As a result, the D _MAX of the obtained finely powdered first binder resin was changed to the values shown in Table 4. In the mixing step, the pigment is mixed with C.I. I. Pigment Red 122, C.I. I. Pigment Yellow 73

<Preparation of Toner C-3>
A toner C-3 was produced in the same manner as in the production of the toner A-3 except that the following points were changed. In the mixing step, the pigment is mixed with C.I. I. Pigment Red 122, C.I. I. Pigment Yellow 73

<Preparation of Toner D-1>
A toner D-1 was produced in the same manner as the production of the toner B-1, except that the following points were changed. In the binder resin pulverization step, the pulverization conditions were changed to a throughput of 40 kg / hour and a rotation speed of 5800 rpm. As a result, the D _MAX of the obtained finely powdered first binder resin was changed to the values shown in Table 4. In the mixing step, the pigment is mixed with C.I. I. Pigment Red 122, C.I. I. Pigment Yellow 73

<Preparation of Toner D-2>
A toner D-2 was produced in the same manner as in the production of the toner B-2 except that the following points were changed. In the binder resin pulverization step, the pulverization conditions were changed to a throughput of 40 kg / hour and a rotation speed of 5800 rpm. As a result, the D _MAX of the obtained finely powdered first binder resin was changed to the values shown in Table 4. In the mixing step, the pigment is mixed with C.I. I. Pigment Red 122, C.I. I. Pigment Yellow 73

<Preparation of Toner D-3>
Toner D-3 was prepared in the same manner as toner B-3 except that the following points were changed. In the mixing step, the pigment is mixed with C.I. I. Pigment Red 122, C.I. I. Pigment Yellow 73

<Preparation of Toner D-4>
A toner D-4 was produced in the same manner as in the production of the toner B-4 except that the following points were changed. In the mixing step, the pigment is mixed with C.I. I. Pigment Red 122, C.I. I. Pigment Yellow 73

<Preparation of Toner D-5>
A toner D-5 was produced in the same manner as in the production of the toner B-5 except that the following points were changed. In the master batch forming step, the pulverization condition was changed to a rotation speed of 800 rpm. The pulverization conditions other than the rotational speed were the same as those for the production of the toner B-5. Thus, the D _MAX of the resulting master batch was changed to the values shown in Table 4. In the mixing step, the pigment is mixed with C.I. I. Pigment Red 122, C.I. I. Pigment Yellow 73

[Measuring method]
(Measurement of D _MAX , D ₅₀ , and D ₁₀ )
D of the fine powdered first binder resin used for the production of each of toners A-1 to A-3, B-1 to B-5, C-1 to C-3, and D-1 to D-5. _MAX , D ₅₀ , and D ₁₀ were measured by the following method. First, 0.1 g of a measurement target (a fine powdered first binder resin) was dispersed in 30 mL of an electrolytic solution (“Brand name Coulter II-pc” manufactured by Beckman Coulter, Inc.) to obtain a dispersion. . The obtained dispersion was set in a precision particle size distribution measuring device (“Coulter Counter Multisizer 3” manufactured by Beckman Coulter, Inc.). This particle size distribution measuring apparatus measures using the Coulter principle. The current flowing through the aperture (pore) provided in the measuring device was set to 5 mA. Using the measuring device, the particle diameter of the measurement target (fine powdered first binder resin) in the dispersion was measured to obtain a particle size distribution curve based on the volume of the measurement target. D _MAX , D ₅₀ , and D ₁₀ were determined from the obtained particle size distribution curve. Tables 3 and 4 show the determined D _MAX , D ₅₀ , and D ₁₀ .

As a representative example, FIG. 1 shows a particle size distribution curve on a volume basis of the finely powdered first binder resin (measurement target) used for the production of the toner A-2. The horizontal axis in FIG. 1 indicates the particle diameter (unit: μm) of the measurement object measured on a volume basis. The vertical axis | shaft in FIG. 1 shows the abundance ratio (unit:%) of the measuring object which has each particle diameter measured on the volume basis. In the particle size distribution curve shown in FIG. 1, the particle size at which the abundance ratio accumulated from the small particle size side (0 μm side) becomes 10% is defined as D ₁₀ . In the particle size distribution curve shown in FIG. 1, the particle size at which the abundance ratio integrated from the small particle size side (0 μm side) is 50% is defined as D ₅₀ . In the particle size distribution curve shown in FIG. 1, the maximum value of the particle size that is confirmed to be present is defined as D _MAX . Incidentally, D _MAX of the second binder resin, D _50, and D ₁₀ may, D _MAX pulverulent first binder resin was measured at D _50, and D ₁₀ in the same way.

[Evaluation method and evaluation results]
For each sample (Toners A-1 to A-3, B-1 to B-5, C-1 to C-3, and D-1 to D-5), evaluation of contamination in the mixer, and pigment Discoloration was evaluated.

<Evaluation of contamination in the mixer>
Hereinafter, with reference to FIG. 2, the evaluation method of the contamination in the mixer will be described. FIG. 2 schematically shows a photograph 10 taken of a bottom surface 12 of a tank provided in an FM mixer that is a mixer. The photograph 10 shown in FIG. 2 shows the bottom surface 12 of the tank of the FM mixer, the wall surface 14 of the tank, the shaft 16, and the white paper 18. The FM mixer tank is cylindrical. The tank has a circular bottom surface 12 and a wall surface 14 provided vertically along the outer periphery of the bottom surface 12. A toner material is charged into the tank. A shaft 16 having four stirring blades (not shown) is provided in the center of the bottom surface 12 of the tank. As the shaft 16 rotates, the stirring blades rotate. By rotating the stirring blade, the toner material in the tank is mixed. A blank paper 18 for adjusting the luminance of the digital camera is placed in one area of the bottom surface 12 of the tank.

  First, a digital camera was fixed in an unused tank of the FM mixer so that a photograph 10 having a composition as shown in FIG. 2 could be taken. The brightness of the digital camera was adjusted using the blank paper 18. Using a digital camera, the bottom surface 12 of the unused tank of the FM mixer was photographed to obtain a first photograph. The first photo was printed on glossy photographic paper using a color printer. Of the bottom surface 12 of the tank shown in the printed first photo, five locations (location A, location B, location C, location D, and location E in FIG. 2) in the area where the white paper 18 is not placed. Each L value was measured. For measurement of the L value, a reflection densitometer (“SpectroEye” manufactured by X-Rite) was used. The number average value of the five L values measured was defined as “the L value of the bottom surface of the tank before the mixing step”. Table 2 shows L values and number average values (that is, “L values of the bottom surface of the tank before the mixing step”) measured at five locations. “The tank bottom L value before mixing” in Table 2 indicates “the tank bottom L value before the mixing step”.

  Next, the mixture is mixed in the mixing step of the manufacturing method of each sample (Toners A-1 to A-3, B-1 to B-5, C-1 to C-3, and D-1 to D-5). The following operation was performed on the tank after removal. Toner material remaining slightly in the tank after removal of the mixture was removed using a dust collector. Next, a digital camera was fixed in the tank so that a photograph 10 having a composition as shown in FIG. 2 could be taken. A blank paper 18 was placed in the tank. The brightness of the digital camera was adjusted using the blank paper 18. Using a digital camera, the bottom surface 12 of the FM mixer tank after the mixing process was photographed to obtain a second photograph. A second photo was printed on glossy photographic paper using a color printer. Of the bottom surface 12 of the tank shown in the printed second photo, five locations (location A, location B, location C, location D, and location E in FIG. 2) in the area where the white paper 18 is not placed. Each L value was measured. For measurement of the L value, a reflection densitometer (“SpectroEye” manufactured by X-Rite) was used. The number average value of the five L values measured was defined as “the L value of the bottom surface of the tank after the mixing step”. The “L value of the bottom surface of the tank after the mixing step” of each sample is shown in Tables 3 and 4. From the “L value of the bottom surface of the tank after the mixing step”, contamination in the mixer was evaluated according to the following criteria. In addition, the value of the “L value of the bottom surface of the tank after the mixing process” is larger, and the closer the value is to the L value of the bottom surface of the tank before the mixing process (ie, 94.3), It is difficult to fuse and indicates that the inside of the mixer is not contaminated by the pigment.

(Evaluation criteria for contamination in mixers)
Good (contamination suppression): The L value of the bottom surface of the tank after the mixing step is 80 or more.
Poor (contamination generation): The L value of the bottom surface of the tank after the mixing step is less than 80.

<Evaluation of discoloration of pigment>
Mixture obtained in the mixing step of the manufacturing method of each sample (each of toners A-1 to A-3, B-1 to B-5, C-1 to C-3, and D-1 to D-5) On the other hand, L value, a value, and b value were measured. A reflection densitometer (“SpectroEye” manufactured by X-Rite) was used to measure the L value, the a value, and the b value. The L value, a value, and b value of the measured mixture were defined as “L value, a value, and b value of the mixture after the mixing step”, respectively.

  C. I. For the toners A-1 to A-3 and B-1 to B-5 using Pigment Red 122, the degree of color change was determined by the following method. The color change degree of the L value was determined from the calculation formula “L value color change = (L value of the mixture after the mixing step) − (L value of the pigment before heating)”. The discoloration degree of the a value was determined from the calculation formula “a discoloration degree of the a value = (a value of the mixture after the mixing step) − (a value of the pigment before heating)”. The b value discoloration degree was determined from the calculation formula “b value discoloration degree = (b value of the mixture after the mixing step) − (b value of the pigment before heating)”. The L value of the pigment before heating, the a value of the pigment before heating, and the b value of the pigment before heating in the calculation formula are respectively the pigment before heating (CI Pigment Red shown in Reference Example 1 above). The L value of 122) (ie 61), the a value of the pigment before heating (ie 78), and the b value of the pigment before heating (ie -4.8) were substituted.

  C. I. With respect to toners C-1 to C-3 and D-1 to D-5 using Pigment Yellow 73, the degree of color change was determined by the following method. The color change degree of the L value was determined from the calculation formula “L value color change = (L value of the mixture after the mixing step) − (L value of the pigment before heating)”. The discoloration degree of the a value was determined from the calculation formula “a discoloration degree of the a value = (a value of the mixture after the mixing step) − (a value of the pigment before heating)”. The b value discoloration degree was determined from the calculation formula “b value discoloration degree = (b value of the mixture after the mixing step) − (b value of the pigment before heating)”. In the calculation formula, the L value of the pigment before heating, the a value of the pigment before heating, and the b value of the pigment before heating are the pigment before heating (CI Pigment Yellow shown in Reference Example 2), respectively. 73) L value (ie 81), pigment a value before heating (ie -7.2) and pigment b value before heating (ie 94).

  Tables 3 and 4 show the L value, a value, and b value of the mixture after the mixing step. Further, Table 3 and Table 4 show the obtained color change degrees of the L value, the a value, and the b value. Note that C.I. I. In the mixture obtained in the mixing step of toners A-1 to A-3 and B-1 to B-5 using Pigment Red 122, the type and amount of pigment, the type and amount of release agent, and charge control The type and amount of agent is the same. The amount of the binder resin (the total amount of the first binder resin and the second binder resin) is the same. The binder resin (first binder resin and second binder resin) is the same because “CBC500” manufactured by Kao Corporation is used. From these facts, although the object to be measured is different between the mixture and the pigment, it is considered that the degree of color change substantially indicates the color change of the pigment. This is because C.I. I. The same applies to the toners C-1 to C-3 and D-1 to D-5 using the pigment yellow 73. From the above, it was judged that the color change of the pigment was suppressed as the absolute value of the color change degree was smaller.

In Tables 3 and 4, “Red 122”, “Yellow 73”, “fine powder binder resin”, “D _MAX ”, “D ₅₀ ”, and “D ₁₀ ” are respectively “CI Pigment Red”. 122 ”,“ CI Pigment Yellow 73 ”,“ finely powdered first binder resin ”,“ maximum particle diameter of finely powdered first binder resin ”,“ volume of finely powdered first binder resin ” “50% cumulative diameter on the basis” and “10% cumulative diameter on the volume basis of the finely powdered first binder resin” are shown. However, “D _MAX ”, “D ₅₀ ”, and “D ₁₀ ” of toners B-5 and D-5 represent the maximum particle diameter of the master batch containing the pigment and the binder resin, and 50% integration on a volume basis. The diameter and the 10% integrated diameter on a volume basis are shown.

  “Amount” in Tables 3 and 4 indicates “amount of added fine powdered first binder resin (unit: mass%) relative to the total mass of the toner material”. “L value”, “a value”, and “b value” in the “Mixed mixture” column in Table 3 and Table 4 indicate the L value, a value, and b value of the mixture after the mixing step, respectively. . “L value”, “a value”, and “b value” in the “Discoloration degree” column in Table 3 and Table 4 are the L value discoloration degree, the a value discoloration degree, and the b value discoloration degree, respectively. Indicates. “After-mixing tank bottom L value” in Tables 3 and 4 indicates “L-value of tank bottom after mixing process”. In “Toner B-5” in Table 3 and “Toner D-5” in Table 4, “(master batch)” indicates that the organic pigment was in the form of a master batch. Note that toners other than toners B-5 and D-5 (specifically, toners A-1 to A-3, B-1 to B-4, C-1 to C-3, and D-1 to D-4). None of the organic pigments used in) was in the form of a masterbatch.

  Toners A-1 to A-3 and C-1 to C-3 were manufactured by the following manufacturing method. Specifically, these toner manufacturing methods include a mixing step of mixing toner materials using a mixer to obtain a mixture, a kneading step of kneading the mixture while melting to obtain a kneaded product, and pulverizing the kneaded product And a pulverizing step for obtaining a toner. The toner material includes at least one of an azo pigment and a quinacridone pigment (specifically, CI Pigment Red 122 or CI Pigment Yellow 73) and a finely powdered binder resin (specifically, a finely powdered first resin). 1 binder resin). The maximum particle size of the fine powdered first binder resin was 30 μm or less. The addition amount of the fine powdered first binder resin was 70% by mass or more and less than 100% by mass with respect to the total mass of the toner material. For this reason, as shown in Tables 3 and 4, in the production of the toners A-1 to A-3 and C-1 to C-3, the absolute value of the degree of color change is small, and the color change of the organic pigment is suppressed. It was. Further, in the production of the toners A-1 to A-3 and C-1 to C-3, the L value on the tank bottom after the mixing step was 80 or more, and contamination in the mixer was suppressed.

  On the other hand, in the production methods of the toners B-1 to B-2 and D-1 to D-2, the addition amount of the fine powdered first binder resin is less than 70% by mass with respect to the total mass of the toner material. there were. In the production methods of the toners B-3 and D-3, the toner material did not contain the fine powdered first binder resin. That is, in the manufacturing method of the toners B-3 and D-3, the fine powdery first binder resin was not added. In the production methods of the toners B-4 and D-4, the maximum particle size of the fine powdered first binder resin was more than 30 μm. For this reason, as shown in Tables 3 and 4, in the production of the toners B-1 to B-4 and D-1 to D-4, the L value on the bottom surface of the tank after the mixing step is less than 80, and the mixing is performed. Inflight contamination could not be suppressed.

  In the production methods of the toners B-5 and D-5, the toner material did not contain the fine powdered first binder resin. In the production methods of the toners B-5 and D-5, an organic pigment in the form of a master batch was used. Therefore, as shown in Table 3, in the production of the toner B-5, the absolute value of the L value discoloration is 14.0, and the absolute value of the L value discoloration of the toners A-1 to A-3 is as follows. It was large compared with the value (1.0 or more and 4.0 or less). In the production of the toner B-5, the absolute value of the color change of the value a is 26.0, and the absolute value of the color change of the value a of the toners A-1 to A-3 (15.0 to 17.0). ) Was larger than In the production of the toner B-5, the absolute value of the b value change degree is 2.5, and the absolute value of the b value change degree of the toners A-1 to A-3 (1.5 to 1.8). ) Was larger than Further, as shown in Table 4, in the production of the toner D-5, the absolute value of the L value discoloration degree is 12, and the absolute value of the L value discoloration degree of the toners C-1 to C-3 (1 More than 5 or less). In the production of the toner D-5, the absolute value of the a-value discoloration is 1.7, and the absolute value of the a-value discoloration of the toners C-1 to C-3 (0.7 to 0.9). ) Was larger than In the production of the toner D-5, the absolute value of the b value discoloration is 19, which is larger than the absolute value of the b value discoloration (from 6 to 11) of the toners C-1 to C-3. It was. For these reasons, discoloration of the organic pigment was not suppressed in the production methods of the toners B-5 and D-5.

  From the above, according to the toner production method according to the present invention including the production methods of toners A-1 to A-3 and C-1 to C-3, the discoloration of the organic pigment and the contamination in the mixer are caused. It was shown that it can be suppressed.

  The toner manufactured by the manufacturing method according to the present invention can be used for forming an image in, for example, a copying machine, a printer, or a multifunction machine.

10: Photo 12: Bottom surface 14: Wall surface 16: Shaft 18: Blank paper

Claims (6)

A mixing step of mixing toner materials using a mixer to obtain a mixture;
Kneading while melting the mixture to obtain a kneaded product; and
Pulverizing the kneaded product to obtain toner,
The toner material includes at least one of an organic pigment having an azo group and an organic pigment having a quinacridone structure, and a fine powder binder resin,
The fine particle-like binder resin has a maximum particle size of 30 μm or less,
A method for producing a toner, wherein the addition amount of the fine powdered binder resin is 70% by mass or more and less than 100% by mass with respect to the total mass of the toner material.   The toner manufacturing method according to claim 1, further comprising a binder resin pulverization step of pulverizing the binder resin to obtain the finely powdered binder resin having a maximum particle size of 30 μm or less.   The toner production method according to claim 1, wherein a 50% integrated diameter of the fine powdered binder resin on a volume basis is 9.3 μm or less.   The toner production method according to claim 1, wherein a 10% integrated diameter of the fine powdered binder resin on a volume basis is 6.1 μm or less.   The organic pigment having an azo group is C.I. I. Pigment Yellow 73 and the organic pigment having the quinacridone structure is C.I. I. The toner production method according to claim 1, comprising Pigment Red 122.   The method for producing a toner according to claim 1, wherein the organic pigment having an azo group and the organic pigment having a quinacridone structure are not in a master batch shape.

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