JP2018081118A - Method for producing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing toner capable of stably and simply producing toner where an existence state of a mold release agent is controlled and low temperature fixability is excellent.SOLUTION: A method for producing toner having toner particles containing a binder resin and a mold release agent includes the following 3-1) and 3-2) steps or 4-1) and 4-2) steps, where the 3-1) step is a granulation step of forming a polymerizable monomer capable of forming the binder resin and particles of a polymerizable monomer composition containing the mold release agent in an aqueous medium, the 3-2) step is a reaction step of polymerizing the polymerizable monomer contained in the particles, in the 3-1) granulation step, the state is kept in which the mold release agent is dissolved in the polymerizable monomer, in the 3-2) reaction step, before the mold release agent is phase-separated from the polymerizable monomer, the mold release agent is crystallized, the 4-1) step is a granulation step of forming particles of a resin solution containing an organic solvent, the binder resin and the mold release agent in an aqueous medium, the 4-2) step is a solvent removing step of removing an organic solvent contained in the resin solution, in the 4-1) granulation step, the state is kept in which the mold release agent is dissolved in the resin solution, and in the 4-2) solvent removing step, before the mold release agent is phase-separated from the resin solution, the mold release agent is crystallized.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing toner used to form a toner image by developing an electrostatic latent image formed by a method such as electrophotography, electrostatic recording, or toner jet recording.

In recent years, energy saving of printers and copiers has been demanded. In order to cope with this, a toner having excellent low-temperature fixability is preferable. In order to obtain a toner excellent in low-temperature fixability, studies have been made to improve low-temperature fixability by using a release agent in the toner and efficiently obtaining a release effect.
The release agent is added in order to suppress the offset phenomenon at the time of fixing. Here, the offset phenomenon indicates an image detrimental effect in which a part of an image is brought to the fixing member due to adhesion between the toner and the fixing member. The offset phenomenon can be suppressed by using a release agent for the toner and eluting the release agent between the toner and the fixing member before the toner adheres to the fixing member.
Further, in order to improve the low-temperature fixability of the toner, it is necessary to lower the melt viscosity of the toner. However, when the melt viscosity of the toner is lowered, the adhesion to the fixing member is increased, so that an offset phenomenon is likely to occur. Therefore, in order to design a toner having excellent low-temperature fixability, it is more important to effectively use a release agent.
Patent Document 1 proposes a toner by a suspension polymerization method using hydrocarbon waxes having various melting points as a release agent.
In Patent Documents 2 and 3, in a method for producing a toner by a suspension polymerization method using a release agent, the toner is cooled at the time of production so that the release agent is crystallized and the release agent is dispersed. A method has been proposed.
Patent Document 4 proposes a toner manufacturing method in which a dispersion liquid in which a release agent is dispersed in the form of fine particles in advance is used for the toner so that the release agent is dispersed in the toner.

JP 2012-98714 A JP 63-173067 A JP-A-4-188156 JP 2005-338133 A

In the toner described in Patent Document 1, it is not disclosed that the effect of the release agent is further enhanced by controlling the presence state of the release agent in the toner.
Further, the toner production methods described in Patent Documents 2 and 3 do not disclose the point of controlling the crystallization of the release agent, and the crystallization of the release agent does not affect the production stability of the toner. The effect on developability has not been studied.
In Patent Document 4, there is a problem that a step of dispersing the release agent in the form of fine particles is required, and the toner manufacturing process becomes complicated.
The present invention provides a toner manufacturing method that solves the conventional problems. That is, the present invention provides a toner production method that can stably and easily produce a toner having excellent low-temperature fixability by controlling the presence of a release agent.

In order to achieve the above-mentioned object, the present invention provides a method for producing a toner having toner particles containing a binder resin and a release agent, the production method comprising the following 1-1) and 1-2): The present invention relates to a toner production method comprising the steps or steps 2-1) and 2-2).
1-1) A granulating step of forming particles of a polymerizable monomer composition containing the polymerizable monomer capable of forming the binder resin and the release agent in an aqueous medium,
1-2) a reaction step of polymerizing the polymerizable monomer contained in the particles,
The temperature of the aqueous medium in the granulation step of 1-1) is a temperature higher than Tc (0),
The temperature of the aqueous medium in the reaction step of 1-2) is higher than Tc (0) and equal to or lower than Tc (X).
(Tc (0) represents the crystallization temperature of the release agent in the polymerizable monomer composition in the granulation step,
Tc (X) represents the crystallization temperature of the release agent in the polymerizable monomer composition at the polymerization conversion rate X (%) of the polymerizable monomer.
However, the polymerization conversion rate X (%) is determined in the mixed solution of the polymerizable monomer, the polymer obtained by polymerizing the polymerizable monomer, and the release agent. This corresponds to the polymer concentration Y (%) when the phase is separated from the polymerizable monomer. )
2-1) a granulating step of forming particles of a resin solution containing an organic solvent, the binder resin, and the release agent in an aqueous medium;
2-2) a solvent removal step for removing the organic solvent contained in the resin solution,
The temperature of the aqueous medium in the granulation step of 2-1) is higher than Tc ′ (0),
The temperature of the aqueous medium in the solvent removal step 2-2) is higher than Tc ′ (0) and equal to or lower than Tc ′ (X ′).
(Tc ′ (0) represents the crystallization temperature of the release agent in the resin solution in the granulation step;
Tc ′ (X ′) represents the crystallization temperature of the release agent in the resin solution at a binder resin concentration X ′ (%).
However, the binder resin concentration X ′ (%) indicates the binder resin concentration (%) in the organic solvent when the release agent is phase-separated from the organic solvent. )
The present invention also relates to a method for producing a toner having toner particles containing a binder resin and a release agent, wherein the production method comprises the following steps 3-1) and 3-2), or 4-1: And 4-2). The present invention relates to a method for producing toner.
3-1) a granulating step of forming particles of a polymerizable monomer composition containing the polymerizable monomer capable of forming the binder resin and the release agent in an aqueous medium;
3-2) a reaction step of polymerizing the polymerizable monomer contained in the particles,
In the granulation step of 3-1), the release agent is in a state dissolved in the polymerizable monomer,
In the reaction step 3-2), the release agent is crystallized before the release agent phase-separates from the polymerizable monomer.
4-1) A granulating step of forming particles of a resin solution containing an organic solvent, the binder resin, and the release agent in an aqueous medium,
4-2) In the solvent removal step of removing the organic solvent contained in the resin solution, and in the granulation step of 4-1), the release agent is in a state dissolved in the resin solution,
In the solvent removal step 4-2), the release agent is crystallized before the release agent is phase-separated from the resin solution.

  According to the present invention, it is possible to provide a toner production method capable of stably and simply producing a toner excellent in low-temperature fixability by controlling the state of presence of a release agent.

It is a figure which shows the phase-separation pattern of a binder phase and a mold release agent. It is a figure which shows an example of the polymerization conversion rate X (%) which a mold release agent phase-separates. It is a figure which shows an example of Tc (0) and Tc (X). It is a schematic diagram which shows the evaluation criteria of the presence state of a mold release agent.

  The present invention relates to a toner production method by suspension polymerization method and dissolution suspension method, but the mechanism based on both features in the present invention is common, and will be explained below using the suspension polymerization method. .

  Usually, when a toner is produced by a suspension polymerization method or a dissolution suspension method, the release agent tends to be unevenly distributed in one part of the toner, but the reason is not clear.

  In the suspension polymerization method, a granulation step for forming particles of a polymerizable monomer composition containing a polymerizable monomer capable of forming a binder resin and a release agent in an aqueous medium, contained in the particles The toner particles are manufactured through a reaction step of polymerizing the polymerizable monomer. At this time, the release agent is uniformly dissolved in the polymerizable monomer, but after the polymerizable monomer forms the binder resin through the reaction step, the binder resin and the release agent are phase separated. doing. That is, in the reaction step, it is considered that the binder resin, the polymerizable monomer (hereinafter also referred to as a binder phase) and the release agent gradually form a phase separation structure.

  The present inventors have considered that the position of the release agent can be controlled by examining in detail the structure forming mechanism of the release agent in the toner production process, and have reached the present invention.

  Specifically, it has been found that there are two possibilities for the phase separation pattern of the binder phase and the release agent. The first pattern is a pattern in which when the binder phase and the release agent are phase-separated, the release agent is not crystallized and remains melted. In the present invention, this is referred to as a “phase separation preceding pattern”. The second pattern is a pattern in which phase separation occurs due to crystallization of the release agent before the binder phase and the release agent are phase-separated. In the present invention, this is referred to as a “crystallization preceding pattern” (FIG. 1).

  Further, when the melting point of the release agent used in the prior art, the crystallization temperature of the release agent, and the polymerization reaction temperature were examined, it was found that all of them were phase separation preceding patterns. From these examination results, it was presumed that in the toner produced by the suspension polymerization method, the release agent tends to be unevenly distributed in one place due to the phase separation preceding pattern. In other words, when the binder phase and the release agent are phase-separated, the release agent is in a molten liquid state, so that it easily moves in the toner particles, and as a result, the release agent domains are aligned in one place. I guessed it would be.

  That is, the present inventors changed the release agent domain into a solid phase by using the second phase separation pattern as a crystallization preceding pattern, thereby suppressing the movement in the toner. Thought that it was possible to suppress the unity. As a result, there is provided a toner production method in which the release agent domain is not agglomerated in one place, the dispersion state of the release agent in the toner particles is controlled, and a toner excellent in low-temperature fixability can be easily produced. It came to invent.

  In the suspension polymerization method, the state in which the release agent is dissolved in the polymerizable monomer is maintained in the granulation step, and the release agent is crystallized before phase separation from the polymerizable monomer in the reaction step. In order to obtain a crystallization preceding pattern, the following conditions are required.

That is, it has the following steps 1-1) and 1-2),
1-1) A granulation step of forming particles of a polymerizable monomer composition containing a polymerizable monomer capable of forming a binder resin and a release agent in an aqueous medium,
1-2) A reaction step of polymerizing a polymerizable monomer contained in the particles,
The temperature of the aqueous medium in the granulation process of 1-1) is a temperature higher than Tc (0),
The temperature of the aqueous medium in the reaction step 1-2) is higher than Tc (0) and equal to or lower than Tc (X).
(Tc (0) represents the crystallization temperature of the release agent in the polymerizable monomer composition in the granulation step,
Tc (X) represents the crystallization temperature of the release agent in the polymerizable monomer composition at the polymerization conversion rate X (%) of the polymerizable monomer.
However, the polymerization conversion rate X (%) is determined in the mixed liquid in which the polymerizable monomer, the polymer obtained by polymerizing the polymerizable monomer, and the release agent are mixed. This corresponds to the polymer concentration Y (%) when phase-separating from the polymer. )

  When the temperature of the aqueous medium in the reaction step is Tc (X) or less, when the binder phase and the release agent are phase-separated, a state in which the release agent is crystallized can be obtained. As a result, it is possible to obtain a toner excellent in low-temperature fixability in which the release agent domains are not united in one place. In addition, since the temperature of the aqueous medium in the granulation step is higher than Tc (0), granulation can be performed in a state where the release agent is dissolved in the polymerizable monomer. It is possible to produce a toner with excellent properties. Furthermore, since the temperature of the aqueous medium in the reaction step is higher than Tc (0), rapid crystallization of the release agent in the reaction step can be suppressed, the production stability is excellent, and the release agent is a toner. It can be a method for producing a toner that is hardly exposed on the surface.

  A method for measuring the polymerization conversion rates X (%), Tc (0), and Tc (X) will be described later.

  In addition, in the case of the dissolution suspension method, the binder resin concentration X ′ (%) obtained in the same manner is used in place of the polymerization conversion rate X (%) quantified using the above-described method. Is possible.

  In the dissolution suspension method, the state in which the release agent is dissolved in the resin solution in the granulation step is maintained, and the release agent is crystallized before phase separation from the resin solution in the solvent removal step. In order to make a preceding pattern, the following conditions are required.

That is, it has the following steps 2-1) and 2-2),
2-1) a granulating step for forming particles of a resin solution containing an organic solvent, a binder resin and a release agent in an aqueous medium;
2-2) Solvent removal step for removing the organic solvent contained in the resin solution,
The temperature of the aqueous medium in the granulation step of 2-1) is higher than Tc ′ (0),
The temperature of the aqueous medium in the solvent removal step 2-2) is higher than Tc ′ (0) and equal to or lower than Tc ′ (X ′).
(Tc ′ (0) represents the crystallization temperature of the release agent in the resin solution in the granulation step,
Tc ′ (X ′) represents the crystallization temperature of the release agent in the resin solution at the binder resin concentration X ′ (%).
However, the binder resin concentration X ′ (%) indicates the binder resin concentration (%) in the organic solvent when the release agent undergoes phase separation from the organic solvent. )

  The temperature of the granulation step is preferably Tc (0) + 1 ° C. or higher, or Tc ′ (0) + 1 ° C. or higher, and Tc (0) + 2 ° C. or higher, or Tc ′ (0) + 2 ° C. or higher. It is more preferable.

  Further, in the dissolution suspension method, since the surface of the release agent due to solvent removal does not occur, it is easy to suppress the exposure to the toner surface while controlling the position of the release agent domain. As a result, a toner having better developability can be stably produced.

  A method for measuring the binder resin concentrations X ′ (%), Tc ′ (0), and Tc ′ (X ′) will be described later.

  Tc (0), Tc (X), Tc '(0) and Tc' (X ') can be controlled by the melting point of the release agent used, the crystallization temperature of the release agent, the amount added, and the type. In addition, the temperature of the aqueous medium in the manufacturing process can be controlled by setting the apparatus to be used.

  More preferably, the polymerizable monomer composition and the resin solution further contain a release agent dispersant having a structure having an affinity for the release agent and a structure having an affinity for the binder. By containing the release agent dispersant, the crystallization behavior of the release agent in the reaction step and the solvent removal step can be controlled. Specifically, the release agent crystals grow by stacking of release agent molecules. Therefore, the crystal growth of the release agent can be suppressed by adsorbing the release agent dispersant on the crystal growth surface. As a result, the size of the release agent domain can be controlled, and a toner having excellent low-temperature fixability that can more efficiently use the release agent can be obtained.

  Further, it is more preferable that the release agent dispersant is dissolved in the polymerizable monomer composition and the resin solution at the polymerization conversion rate X (%) and the binder resin concentration X ′ (%). Since the release agent dispersant is dissolved, it can be efficiently adsorbed on the release agent domain, and more excellent release agent domain control is possible. Solubility is controlled by the type of resin constituting the release agent dispersant, the molecular weight, and the ratio of the structure having affinity with the release agent constituting the release agent dispersant and the structure having affinity for the binder. can do.

  Specific compounds of the release agent dispersant that can be used in the present invention will be described later.

  The weight average molecular weight Mw of the release agent dispersant is preferably 3000 or more and 30000 or less. By being in the range, it is possible to obtain the effect of controlling the crystal growth of the release agent while designing the solubility in the polymerizable monomer and the organic solvent to be sufficient. The weight average molecular weight Mw of the release agent dispersant is more preferably 3000 or more and 20000 or less, and further preferably 3000 or more and 15000 or less. The weight average molecular weight Mw of the release agent dispersant can be controlled by the reaction conditions and initiator concentration during the synthesis of the release agent dispersant. A method for measuring the weight average molecular weight of the release agent dispersant will be described later.

  The content of the release agent dispersant is preferably 1.0 part by mass or more and 30.0 parts by mass or less, and 1.0 part by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the binder resin. More preferably. By being in the range, it is possible to achieve both the effect of controlling the crystal growth of the release agent and the elution of the release agent during fixing.

  The melting point of the release agent is preferably 60 ° C. or higher and 110 ° C. or lower. In the toner obtained by the present invention, unlike the toner obtained by the conventional suspension polymerization method and dissolution suspension method, the release agent tends to exist near the toner surface layer. For this reason, the influence of the melting point of the release agent on the toner performance tends to increase. When the melting point of the release agent is 60 ° C. or more, it is possible to obtain a toner having excellent developability that is less likely to cause toner coalescence and member contamination with the release agent. Further, when the temperature is 110 ° C. or lower, the effect of a release agent can be sufficiently obtained even under a condition where the fixing temperature is low, and a toner excellent in low-temperature fixability can be obtained. The melting point of the release agent is preferably 65 ° C. or higher and 95 ° C. or lower, and more preferably 70 ° C. or higher and 95 ° C. or lower.

  Moreover, it is preferable that the crystallization temperature of a mold release agent is 50 to 100 degreeC. The crystallization temperature of the release agent greatly affects the Tc (0), Tc (X), Tc ′ (0) and Tc ′ (X ′). Therefore, it is preferable that the crystallization temperature is 50 ° C. or more and 100 ° C. or less because it is easy to design the manufacturing method of the crystallization preceding pattern defined by the present invention. In addition, the measuring method of melting | fusing point and crystallization temperature is mentioned later.

  The toner of the present invention preferably has a main peak in a region having a molecular weight of 5000 or more and 35000 or less in a molecular weight distribution measured by gel permeation chromatography (GPC) soluble in tetrahydrofuran (THF). The lower the molecular weight of the main peak, the easier it is for the release agent to move in the toner, so the release agent domains are more likely to be united in one place. On the other hand, the lower the molecular weight of the main peak, the lower the melt viscosity of the toner and the better the low-temperature fixability. Therefore, a toner having a more excellent low-temperature fixability can be obtained by obtaining the toner having the main peak molecular weight in the above range by the production method defined in the present invention. More preferably, the toner has a main peak in a region having a molecular weight of 8000 or more and 30000 or less. The molecular weight of the main peak of the toner can be controlled by the temperature at the time of synthesizing the toner and the binder resin used for the toner and the amount of the initiator. A method for measuring the molecular weight distribution of the toner will be described later.

  Below, an example of the material which can be used for this invention is described.

  Conventionally known resins can be used as the binder resin that can be used in the present invention. For example, polyester resin; styrene acrylic resin; polyamide resin; furan resin; epoxy resin; xylene resin; Among these, styrene acrylic resins and polyester resins are preferable from the viewpoint of phase separation with a release agent and toner production stability. Moreover, in the suspension polymerization method, it is a styrene acrylic resin from a viewpoint of the polymerizable monomer which can be used.

  Examples of the polymerizable monomer that can be used include styrene monomers such as styrene, α-methylstyrene, and divinylbenzene; methyl acrylate, butyl acrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, Unsaturated carboxylic acid esters such as t-butyl methacrylate and 2-ethylhexyl methacrylate; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; unsaturated dicarboxylic acids such as maleic acid; unsaturated dicarboxylic acids such as maleic anhydride Examples thereof include anhydrides; nitrile vinyl monomers such as acrylonitrile; halogen-containing vinyl monomers such as vinyl chloride; nitro vinyl monomers such as nitrostyrene.

  As the polyester resin, the following dibasic acids and derivatives thereof (carboxylic acid halides, esters, acid anhydrides) and dihydric alcohols are essential, and tribasic or higher polybasic acids and derivatives thereof as necessary. A polyester resin prepared by a dehydration condensation method such as (carboxylic acid halide, ester, acid anhydride), monobasic acid, trihydric or higher alcohol, monohydric alcohol or the like can be used.

  Examples of the dibasic acid include maleic acid, fumaric acid, itaconic acid, succinic acid, malonic acid, succinic acid, dodecyl succinic acid, dodecenyl succinic acid, adipic acid, azelaic acid, sebacic acid, decane-1,10-dicarboxylic acid, etc. Aliphatic dibasic acids such as: phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, tetrabromophthalic acid, tetrachlorophthalic acid, het acid, hymic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, etc. Aromatic dibasic acid; and the like.

  Examples of the dibasic acid derivative include carboxylic acid halides, esterified products, and acid anhydrides of the above aliphatic dibasic acids and aromatic dibasic acids.

  On the other hand, examples of the divalent alcohol include ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and diethylene glycol. , Acyclic aliphatic diols such as dipropylene glycol, triethylene glycol and neopentyl glycol; bisphenols such as bisphenol A and bisphenol F; ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc. An alkylene oxide adduct of bisphenol A; aralkylene glycols such as xylylene glycol;

  Examples of the trivalent or higher polybasic acid and its anhydride include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, and the like.

  As a release agent that can be used in the present invention, a general wax can be used. For example, monohydric alcohol and aliphatic monocarboxylic acid ester such as behenyl behenate, stearyl stearate, palmitic acid palmitate, etc., or ester of monohydric carboxylic acid and aliphatic monoalcohol; dibehenyl sebacate, hexanediol dibehenate, etc. A dihydric alcohol and an aliphatic monocarboxylic acid ester, or an ester of a divalent carboxylic acid and an aliphatic monoalcohol; a trihydric alcohol such as glycerol tribehenate and an aliphatic monocarboxylic acid ester, or a trivalent carboxylic acid And aliphatic monoalcohol esters; tetrahydric alcohols and aliphatic monocarboxylic acid esters such as pentaerythritol tetrastearate and pentaerythritol tetrapalmitate; or esters of tetravalent carboxylic acids and aliphatic monoalcohols; Hexavalent alcohols and aliphatic monocarboxylic acid esters such as pentaerythritol hexastearate and dipentaerythritol hexapalmitate, or esters of hexavalent carboxylic acids and aliphatic monoalcohols; and polyhydric alcohols such as polyglycerin behenate Aliphatic monocarboxylic acid esters or esters of polyhydric carboxylic acids and aliphatic monoalcohols; natural ester waxes such as carnauba wax and rice wax; petroleum waxes such as paraffin wax, microcrystalline wax, petrolatum and their derivatives; Hydrocarbon wax and its derivatives by Tropsch method; polyolefin wax and its derivatives such as polyethylene wax and polypropylene wax; higher aliphatic alcohol; stearic acid Fatty acids such as palmitic acid; acid amide waxes. Among these, hydrocarbon wax having high phase separation from the binder resin, tetravalent or higher alcohol and aliphatic monocarboxylic acid ester, or tetravalent or higher carboxylic acid and aliphatic monoalcohol ester wax are preferable. More preferred is a hydrocarbon wax.

  The content of the release agent is preferably 1.0 part by mass or more and 20.0 parts by mass or less, and is 2.0 parts by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the binder resin. Is more preferable. By being in this range, the release agent is quickly eluted at the time of fixing, so that a more excellent low-temperature fixing property can be obtained. When the toner is produced by the suspension polymerization method, the addition amount of the release agent is preferably 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. .

  Examples of the release agent dispersant that can be used in the present invention include a resin having a structure having affinity for the release agent and a structure having affinity for the binder as described above. Specifically, hydrocarbons such as polyethylene, polypropylene and polyolefin; long-chain alkyl acrylates such as polybehenyl acrylate, polystearyl acrylate and polylauryl acrylate; long-chain alkyl methacrylates such as polybehenyl methacrylate, polystearyl methacrylate and polylauryl methacrylate Is mentioned. As the structure having affinity for the binder, a conventionally known resin that can be used for the above-mentioned binder resin can be used, but from the viewpoint of solubility in the polymerizable monomer and the organic solvent, a styrene acrylic resin, Polyester resins are preferred. Furthermore, when the binder resin is a styrene acrylic resin, the styrene acrylic resin is more preferable as a structure having an affinity for the binder. The polymerizable monomer that can be used for the styrene acrylic resin can be used.

  The aqueous medium that can be used in the present invention is a medium mainly composed of water, and may contain a solvent miscible with water. The aqueous medium may contain a dispersion stabilizer. As the dispersion stabilizer added to the aqueous medium, known surfactants, organic dispersants, and inorganic dispersants can be used. Among these, inorganic dispersants can be suitably used because their production stability is not easily lost depending on the polymerization temperature and time. The following are mentioned as an inorganic dispersing agent. Multivalent metal phosphates such as tricalcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; inorganic salts such as calcium metasuccinate, calcium sulfate and barium sulfate; Inorganic oxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite and alumina.

  The organic solvent used for the resin solution in the dissolution suspension method is not particularly limited as long as it is compatible with the raw material of toner particles such as a binder resin and a release agent, but from the viewpoint of solvent removal. Those having a certain vapor pressure even below the boiling point of water are preferred. For example, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone and the like can be used.

  The toner production method of the present invention may further contain a polar resin. By containing the polar resin, the stability of the droplets in the aqueous medium is improved, so that more excellent production stability can be obtained. The polar resin is a resin having a functional group having a low acid dissociation constant such as a carboxy group or a sulfone group, or a resin having a functional group having a low base dissociation constant such as an amino group. Examples of the resin include known resins used in conventional toners, such as polyester resins and vinyl resins.

  The content of the polar resin is preferably 1.0 part by mass or more and 30.0 parts by mass or less with respect to 100 parts by mass of the binder resin.

  In the toner production method of the present invention, a charge control agent may be further used in the polymerizable monomer composition.

  Examples of the charge control agent for controlling the toner particles to be negatively charged include the following.

  Organometallic compound, chelate compound, monoazo metal compound, acetylacetone metal compound, urea derivative, metal-containing salicylic acid compound, metal-containing naphthoic acid compound, quaternary ammonium salt, calixarene, silicon compound, nonmetal carboxylic acid compound and derivatives thereof Is mentioned. A sulfonic acid resin having a sulfonic acid group, a sulfonic acid group, or a sulfonic acid ester group can be preferably used.

  As the charge control agent for controlling the toner particles to be positively charged, for example, the following charge control agents can be used.

  Modified products with nigrosine and fatty acid metal salts, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts which are analogs thereof And lake pigments thereof, triphenylmethane dyes and lake pigments thereof (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide) ), Metal salts of higher fatty acids; These can be used alone or in combination of two or more.

  The content of the charge control agent is preferably 0.01 parts by mass or more and 5.00 parts by mass or less with respect to 100 parts by mass of the binder resin.

  By adding a polar resin or a charge control agent to the polymerizable monomer composition, the interfacial tension of the polymerizable monomer composition and water is lowered, so the toner has a smaller particle size and a uniform particle size distribution. Particles are obtained.

  The toner production method of the present invention may further contain a colorant in the polymerizable monomer composition. Examples of the colorant include black colorants, yellow colorants, magenta colorants, and cyan colorants.

  Specific examples of the black colorant include carbon black.

  Specific examples of the colorant for yellow include the following monoazo compounds; disazo compounds; condensed azo compounds; isoindolinone compounds; isoindoline compounds; benzimidazolone compounds; anthraquinone compounds; azo metal complexes; Examples thereof include yellow pigments typified by compounds and the like. More specifically, the following C.I. I. Pigment yellow 74, 93, 95, 109, 111, 128, 155, 174, 180, 185 and the like.

  Specific examples of the magenta colorant include the following monoazo compounds; condensed azo compounds; diketopyrrolopyrrole compounds; anthraquinone compounds; quinacridone compounds; basic dye lake compounds; naphthol compounds: benzimidazolone compounds; Examples thereof include magenta pigments represented by compounds and the like. More specifically, the following C.I. I. Pigment Red 2,3,5,6,7,23,48: 2,48: 3,48: 4,57: 1,81: 1,122,144,146,150,166,169,177,184, 185, 202, 206, 220, 221, 238, 254, 269, C.I. I. And CI Pigment Bio Red 19.

  Specific examples of the colorant for cyan include cyan pigments represented by the following copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds; basic dye lake compounds, and the like. More specifically, the following C.I. I. Pigment blue 1,7,15,15: 1,15: 2,15: 3,15: 4,60,62,66.

  In addition to the pigments described above, various dyes conventionally known as colorants can also be used.

  The content of the colorant is preferably 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the binder resin.

  The toner of the present invention can be used as it is as a one-component developer or as a two-component developer by mixing with a magnetic carrier.

  The toner production method of the present invention is a suspension polymerization method or a dissolution suspension method.

  When toner particles are obtained by suspension polymerization, a polymerizable monomer that can form a binder resin, a release agent, and, if necessary, a pigment, a polar resin, a charge control agent, and other materials are uniformly dissolved. Alternatively, a polymerizable monomer composition is prepared by dispersing. Thereafter, this polymerizable monomer composition is dispersed in an aqueous medium using a stirrer to prepare a suspension (particles of the polymerizable monomer composition) (granulation step). Thereafter, the polymerizable monomer in the suspension (particles of the polymerizable monomer composition) is polymerized (reaction step) to obtain toner particles having a desired particle size. The toner particles (before the addition of the external additive) can be filtered, washed and dried by a known method after the polymerization is completed, and the external additive can be mixed to obtain the toner of the present invention.

  When obtaining toner particles by the dissolution suspension method, first, a binder resin and a release agent are dissolved in an organic solvent to prepare a resin solution (dissolution step). Next, the resin solution is dispersed in an aqueous medium to form particles of the resin solution (granulation step). Then, toner particles are obtained through a solvent removal step of removing the organic solvent contained in the granulated particles to produce resin particles. The toner particles (before the addition of the external additive) can be filtered, washed and dried by a known method after the solvent removal step, and the external additive can be mixed to obtain the toner of the present invention.

  Below, the measuring method of each physical property value prescribed | regulated by this invention is described.

<Numericalization of polymerization conversion rate X (%) at which phase separation occurs and binder resin concentration X ′ (%)>
(1) A polymerizable monomer and a polymer mixture obtained by polymerizing the polymerizable monomer are prepared. At this time, a mixed solution is prepared in which the polymer concentration Y (mass%) with respect to the total amount of the polymerizable monomer and the polymer is changed by 5% from 0% to 70%. The release agent is added to each liquid mixture at the same mass ratio as the toner production conditions.
(2) The mixed solution is heated to a predetermined temperature or higher to dissolve the polymer and the release agent. (The predetermined temperature is a temperature higher than the crystallization temperature of the release agent in the polymerizable monomer composition, and the measurement method will be described later.)
(3) About each liquid mixture after making it melt | dissolve, the transmittance | permeability is measured using the visible light transmittance meter (DST2500 Toago System Create company make), hold | maintaining above-mentioned temperature. And let the polymer concentration Y (mass%) in the liquid mixture by which the fall of the transmittance | permeability was confirmed be the polymerization conversion rate X (%) when phase separation occurs (FIG. 2).

Further, the binder resin concentration X ′ (%) is quantified as follows using the organic solvent and the binder resin.
(1) A mixed solution is prepared by mixing a binder resin and an organic solvent. At this time, a mixed solution is prepared in which the binder resin concentration Y (mass%) with respect to the mixed solution is changed by 5% from 0% to 70%. A release agent is added to each liquid mixture at the same mass ratio as the toner production conditions.
(2) The mixed solution is heated to a predetermined temperature or higher to dissolve the binder resin and the release agent. (The predetermined temperature is a temperature higher than the crystallization temperature of the release agent in the resin solution, and the measurement method will be described later.)
(3) About each liquid mixture after making it melt | dissolve, the transmittance | permeability is measured using a visible light transmittance meter (DST2500), hold | maintaining above-mentioned temperature. Then, the binder resin concentration Y (% by mass) in the mixed liquid in which the decrease in transmittance is confirmed is defined as the binder resin concentration X ′ (%) in the organic solvent when phase separation occurs.

<Measurement of crystallization temperature of release agent at each polymerization conversion rate, crystallization temperature of release agent at each binder resin concentration>
The crystallization temperature was measured as follows for each liquid mixture used for quantification of the polymerization conversion rate X (%) at which phase separation occurred.

  The crystallization temperature of the release agent at each polymerization conversion rate is measured using a differential scanning calorimeter “Q1000” (manufactured by TA Instruments). The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium. Specifically, the measurement sample is weighed in the range of 5 mg to 10 mg and placed in an aluminum pan. The pan is sealed using TzeroPan and TzeroHermetLid so that volatile components in the sample do not volatilize during the measurement. Using an empty pan as a reference, the temperature is raised at a rate of temperature rise of 10 ° C./min within a measurement range of 0 ° C. to 100 ° C. Hold at 100 ° C. for 1 minute, and then cool at a rate of temperature decrease of 10 ° C./min between 100 ° C. and 0 ° C. The peak temperature of the exothermic peak detected during this temperature lowering process is defined as the crystallization temperature. In addition, it measures in the temperature range which does not exceed the boiling point of the polymerizable monomer and organic solvent to be used.

  At this time, the polymer concentration Y in each mixed solution was set to a state of each polymerization conversion rate. Further, the crystallization temperature of the release agent at a polymerization conversion rate of 0% is Tc (0), and the crystallization temperature at the polymerization conversion rate X is Tc (X).

  FIG. 3 is a graph showing an example of the relationship between the crystallization temperature of the mold release agent obtained as described above and the polymerization conversion rate.

  Further, the crystallization temperature of the release agent at each binder resin concentration is measured in the same manner for each mixed solution used for quantification of the binder resin concentration X ′ (%) at which phase separation occurs. At this time, the crystallization temperature of the release agent at the binder resin concentration of 0% is Tc ′ (0), and the crystallization temperature at the binder resin concentration X ′ (%) is Tc ′ (X ′).

<Method for measuring molecular weight distribution of release agent dispersant, binder resin, toner and polar resin>
The molecular weight distribution of the release agent dispersant, binder resin, toner and polar resin is measured by gel permeation chromatography (GPC) as follows.

First, a sample is dissolved in tetrahydrofuran (THF) at room temperature over 24 hours. Then, the obtained solution is filtered through a solvent-resistant membrane filter “Mysholy disk” (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. In addition, a sample solution is prepared so that the density | concentration of the component soluble in THF may be 0.8 mass%. Using this sample solution, measurement is performed under the following conditions.
Apparatus: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)
Column: Seven series of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection volume: 0.10 ml

  In calculating the molecular weight of the sample, standard polystyrene resin (for example, trade name “TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F— 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500 ", manufactured by Tosoh Corporation) are used.

<Measuring method of melting point and crystallization temperature of release agent, measuring method of Tg of binder resin>
The melting point and crystallization temperature of the release agent are measured according to ASTM D3418-82 using a differential scanning calorimeter “Q1000”. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium. Specifically, 1 mg of a measurement sample is precisely weighed and placed in an aluminum pan, and an empty aluminum pan is used as a reference. The measurement range is 0 ° C. to 150 ° C., and the heating rate is 10 ° C. / The temperature is raised at a rate of minutes. Hold at 150 ° C. for 15 minutes, and then cool at a rate of temperature decrease of 10 ° C./min between 150 ° C. and 0 ° C. The peak temperature of the exothermic peak observed at this time is defined as the crystallization temperature of the release agent. Furthermore, it hold | maintains at 0 degreeC for 10 minutes, and measures at a rate of temperature increase of 10 degree-C / min between 0 degreeC and 150 degreeC after that. The peak temperature of the endothermic peak observed at this time is defined as the melting point of the release agent. The Tg of the binder resin is the midpoint of the baseline before and after the specific heat change of the specific heat change curve in the second temperature rising process when the sample is measured as described above. The intersection with the differential heat curve was defined as Tg (° C.) of the binder resin.

<Measurement method of toner particle size distribution>
The weight average particle diameter (D4), number average particle diameter (D1) and particle size distribution (D4 / D1) of the toner are calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with an aperture tube of 100 μm is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. The measurement is performed with 25,000 effective measurement channels.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion exchange water so that the concentration becomes 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

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

  On the “Change Standard Measurement Method (SOM)” screen of the above-mentioned 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 Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.

  On the “pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) Put 200 mL of the above electrolytic solution into a glass 250 mL round-bottom beaker dedicated to Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 rpm. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) Put 30 mL of the aqueous electrolytic solution into a glass 100 mL flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. ) Is diluted 0.3 times with ion-exchanged water at a mass ratio of 0.3 mL.
(3) 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) having an electrical output of 120 W is prepared. Put 3.3 L of ion exchange water in the water tank of the ultrasonic disperser, and add 2 mL of Contaminone N into this water tank.
(4) The beaker of the above (2) is set in the beaker fixing hole of the ultrasonic disperser and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid surface of the electrolytic aqueous solution in the beaker is maximized.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, a toner or a dispersion of toner is added to the electrolytic aqueous solution little by little so that the toner becomes 10 mg, and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) Into the round bottom beaker (1) installed in the sample stand, the electrolyte aqueous solution (5) in which the toner is dispersed using a pipette is dropped to prepare a measurement concentration of 5%. . Measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated.

<Observation Method of Release Agent Domain in Toner>
As a method for observing the release agent domain in the toner, first, the toner is sufficiently dispersed in a photocurable epoxy resin, and then the epoxy resin is cured by irradiation with ultraviolet rays. The obtained cured product is cut using a microtome equipped with diamond teeth to produce a flaky sample. After the sample is dyed with ruthenium tetroxide, the tomographic morphology of the toner is observed under the condition of an acceleration voltage of 120 kV using a transmission electron microscope (TEM) (H7500 manufactured by HITACHI). In the above observation method, the amorphous part of the toner is strongly dyed with ruthenium tetroxide. As a result, the release agent domain can be observed as contrast. The observation magnification was 20000 times.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. All parts used in the examples indicate parts by mass. The method for producing toner particles 1 to 30 was used as an example, and the method for producing toner particles 31 to 45 was used as a comparative example.

<Manufacture of polar resin>
In a reaction vessel equipped with a stirrer, thermometer, nitrogen introduction tube, dehydration tube, and decompression device, terephthalic acid 25.0 mol%, isophthalic acid 25.0 mol%, bisphenol A propylene oxide 2 mol adduct 50.0 mol% The mixture was added to 100.0 parts of the mixture and heated to 130 ° C. with stirring. Thereafter, 0.52 part of di (2-ethylhexanoic acid) tin is added as an esterification catalyst, the temperature is raised to 200 ° C., and condensation polymerization is performed until the desired molecular weight is obtained, and 3.0 parts of trimellitic anhydride is further added. A polar resin was obtained. The polar resin measured according to the above method had a weight average molecular weight (Mw) of 12000, a glass transition temperature (Tg) of 70 ° C., and an acid value of 8.2 mgKOH / g.

<Manufacture of binder resin>
In a reaction vessel equipped with a reflux condenser, a stirrer, and a nitrogen introduction tube, 100.0 parts of toluene, 78.0 parts of styrene, 22.0 parts of n-butyl acrylate, 3.0 parts of t-butyl peroxypivalate The mixture was added, heated to 70 ° C. and stirred for 10 hours. Furthermore, it heated at 100 degreeC and the solvent was distilled off for 6 hours, and binder resin was obtained. The Tg of the binder resin measured according to the method described above was 58 ° C., and the weight average molecular weight Mw was 25000.

<Manufacture of release agent dispersant 1>
100.0 parts of behenyl acrylate, 64.0 parts of methyl ethyl ketone, 0.4 part of copper (I) bromide, 0.5 part of pentamethyldiethylenetriamine and 1.0 part of ethyl 2-bromoisobutyrate are placed in a flask for 1 hour at room temperature. Nitrogen substitution was performed under normal pressure. Then, it heated up at 65 degreeC and made it react until it became a desired molecular weight, and obtained polybehenyl acrylate.

  Next, after cooling to room temperature, 100.0 parts of the above polybehenyl acrylate was dissolved in 200.0 parts of chloroform, reprecipitated with 800.0 parts of ethanol, filtered and purified. The weight average molecular weight Mw of the polybehenyl acrylate measured according to the method described above was 3500, and the melting point (Tm) was 62 ° C.

  Next, 100.0 parts of purified polybehenyl acrylate, 100.0 parts of styrene, 1.1 parts of copper (I) bromide, and 1.3 parts of pentamethyldiethylenetriamine are placed in a flask and nitrogen is added at room temperature and normal pressure for 1 hour. Replacement was performed. Thereafter, the temperature was raised to 100 ° C., the reaction was stopped when the desired molecular weight was reached, and a polybehenyl acrylate-polystyrene block copolymer was obtained. After cooling to room temperature, 100.0 parts of the above polybehenyl acrylate-polystyrene block copolymer is dissolved in 200.0 parts of chloroform, reprecipitated with 800.0 parts of methanol, filtered and purified, and unreacted monomer The body, catalyst and solvent were removed. Then, it dried with the vacuum dryer set to 50 degreeC, and the mold release agent dispersing agent 1 was obtained. The weight average molecular weight Mw of the release agent dispersant 1 measured according to the above method was 8,000.

<Production of release agent dispersants 2 and 3>
The reaction time was adjusted in the same manner as in the method for producing the release agent dispersant 1, and release agent dispersants 2 and 3 were obtained. The weight average molecular weight Mw of the release agent dispersant 2 measured according to the above-described method was 20000, and the weight average molecular weight Mw of the release agent dispersant 3 was 30000.

  For the obtained release agent dispersants 1 to 3, the release agent dispersant is separated from the binder phase by using the same method as the method for measuring the polymerization conversion rate X (%) at which phase separation of the release agent occurs. The polymerization conversion rate for phase separation was quantified. The results are summarized in Table 1.

<Measurement of Melting Point Tm and Crystallization Temperature Tc of Release Agent>
About the mold release agent used for this invention, melting | fusing point Tm and crystallization temperature Tc were measured using the above-mentioned method. The results are summarized in Table 2.

<Measurement of Polymerization Conversion Ratios X (%), Tc (0), and Tc (X) in Toners 1 to 27 and 31 to 42 at which the release agent undergoes phase separation>
In the production of toners 1-27 and 31-42 shown below (manufacture of toner by suspension polymerization method), polymerization conversion rate X (%), Tc (0 ) And Tc (X) were measured. At this time, as a polymerizable monomer, a polymer obtained by polymerizing a polymerizable monomer using a mixture of styrene and n-butyl acrylate at a mass ratio of 78:22 is used. A resin (Tg 55 ° C., weight average molecular weight Mw 30000) obtained by copolymerizing butyl acrylate at a mass ratio of 78:22 was used. The results are summarized in Table 3.

<Manufacture of toner 1>
Styrene: 60.0 parts C.I. I. Pigment Blue 15: 3 (manufactured by Dainichi Seika Co., Ltd.): 6.0 parts The above materials are put into an attritor (manufactured by Mitsui Miike Chemical Co., Ltd.), and zirconia particles having a diameter of 1.7 mm are used, and at 220 rpm for 5 hours. Dispersion was performed to obtain a pigment dispersion.

In the pigment dispersion,
-Styrene: 18.0 parts-n-butyl acrylate: 22.0 parts-Polar resin: 5.0 parts-Release agent 1: 10.0 parts-Release agent dispersant 1: 5.0 parts . The material was kept at 70 ° C. K. Using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), a polymerizable monomer composition was prepared by uniformly dissolving and dispersing at 500 rpm.

Meanwhile, 850.0 parts of a 0.1 mol / L-Na ₃ PO ₄ aqueous solution and 8.0 parts of 10% hydrochloric acid were added to a container equipped with a high-speed agitator CLEARMIX (M Technique Co., Ltd.), and the number of revolutions was adjusted. It adjusted to 15000 rpm and heated to 70 degreeC. Here was added 1.0mol / L-CaCl ₂ aqueous solution 68.0 parts, to prepare an aqueous medium containing a calcium phosphate compound.

  The polymerizable monomer composition was charged into the aqueous medium, and 7.0 parts of t-butyl peroxypivalate as a polymerization initiator was added. The mixture was granulated for 10 minutes while maintaining 15000 rpm with the stirring device (granulation step). Thereafter, the stirrer was changed from a high-speed stirrer to a propeller stirring blade, and the mixture was reacted at 70 ° C. for 10 hours while refluxing (reaction process).

  After completion of the polymerization step, the slurry was cooled, a part was extracted, and the particle size distribution was measured using the method described above. Furthermore, hydrochloric acid was added to the slurry to adjust the pH to 1.4, and the mixture was stirred for 1 hour to dissolve the calcium phosphate salt. Thereafter, the slurry was washed with a water amount three times that of the slurry, filtered and dried, and then the particle diameter was adjusted by classification to obtain toner particles.

Thereafter, 100.0 parts of the toner particles are treated with dimethyl silicone oil (20% by mass) as a fluidity improver, and hydrophobized silica fine powder that is triboelectrically charged to the same polarity (negative polarity) as the toner particles. (Part number average particle diameter of primary particles: 10 nm, BET specific surface area: 170 m ^{2 /} g) is added and mixed for 15 minutes at 3000 rpm using a Mitsui Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Thus, toner 1 was obtained.

<Manufacture of toners 2-27 and 31-42>
As shown in Table 4, the toner except for changing the type and amount of the release agent, the type and amount of the release agent dispersant, the type and amount of the initiator, the temperature of the granulation process, and the temperature of the reaction process In the same manner as in the production of No. 1, toners 2 to 27 and 31 to 42 were obtained.

  In Table 4, initiator 1 is t-butyl peroxypivalate (half-life temperature 58 ° C.), and initiator 2 is 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate (half-life). Temperature 37 ° C.).

<Measurement of Binder Resin Concentration X ′ (%), Tc ′ (0), Tc ′ (X ′) at which Toner 28-30 and 43-45 phase separate the release agent>
In the production of the toners 28 to 30 and 43 to 45 shown below (manufacturing of the toner by the dissolution suspension method), the binder resin concentration X ′ (%) and Tc at which the release agent is phase-separated using the above-described method '(0), Tc' (X ') was measured. At this time, toluene was used as the organic solvent, and as the binder resin, a resin (Tg 58 ° C., weight) obtained by copolymerizing styrene and n-butyl acrylate at 78:22, which was produced by the above-described binder resin production method. Average molecular weight Mw25000) was used. The results are summarized in Table 3.

<Manufacture of Toner 28>
Binder resin: 100.0 parts C.I. I. Pigment Blue 15: 3 (manufactured by Dainichi Seika Co., Ltd.): 6.0 parts Polar resin: 5.0 parts Release agent dispersant 1: 5.0 parts Toluene: 200.0 parts The mixture was dispersed for 10 hours to obtain a resin solution. Meanwhile, 850.0 parts of a 0.1 mol / L-Na ₃ PO ₄ aqueous solution and 8.0 parts of 10% hydrochloric acid were added to a container equipped with a high-speed agitator CLEARMIX (M Technique Co., Ltd.), and the number of revolutions was adjusted. It adjusted to 15000 rpm and heated to 70 degreeC. Here was added 1.0mol / L-CaCl ₂ aqueous solution 68.0 parts, to prepare an aqueous medium containing a calcium phosphate compound. After the resin solution is heated to 70 ° C., the release agent (10.0 parts) is dissolved, and the resin solution is put into the aqueous medium, and is maintained at 15000 rpm with the stirring device. Granulated for 10 minutes (granulation step). Then, the stirrer was changed from a high-speed stirrer to a propeller stirring blade, and the solvent was removed at 70 ° C. under reduced pressure up to 20 kPa (solvent removal step).

  After completion of the solvent removal step, the slurry was cooled, a part was extracted, and the particle size distribution was measured using the method described above. Further, washing, filtration, drying, classification, and external addition were performed in the same manner as in the production method of the toner 1 to obtain the toner 28.

<Manufacture of toners 29 to 30 and 43 to 45>
As shown in Table 4, similar to the production of the toner 28 except that the type and amount of the release agent, the type and amount of the release agent dispersant, the temperature of the granulation step, and the temperature of the solvent removal step are changed. Thus, toners 29 to 30 and 43 to 45 were obtained.

  For all toners, the relationship between the polymerization conversion rate (or binder resin concentration) when the release agent and the release agent dispersant are phase-separated from the binder phase, and the granulation process temperature and reaction process temperature during toner production. Table 5 summarizes the relationship between (or solvent removal process temperature) and Tc (0), Tc (X) (or Tc ′ (0), Tc ′ (X ′)).

[Examples 1-30, Comparative Examples 1-15]
Each toner obtained was evaluated for performance according to the following method.

[Dispersed state of release agent]
About the obtained toner, the cross-sectional structure was observed using the method described above and evaluated according to the following criteria. In addition, it is preferable that the release agent is dispersed rather than being united in one place in the toner because the release agent is quickly eluted during fixing.
A: Dispersed as fine linear crystals.
B: Dispersed as thick linear crystals.
C: It is united in about 1 to 2 places.

  A schematic diagram of typical structures of A, B, and C is shown in FIG.

[Low temperature fixability]
A color laser printer (HP Color LaserJet 3525dn, manufactured by HP) with the fixing unit removed was prepared, and the toner was taken out from the cyan cartridge and filled with the toner to be evaluated instead. Next, an unfixed toner image (0.7 mg / cm ² ) having a length of 2.0 cm and a width of 15.0 cm is passed on the image receiving paper (Canon office planner 64 g / m ² ) using the filled toner. It formed in the part of 1.0 cm from the upper end part with respect to the direction. Next, the removed fixing unit was remodeled so that the fixing temperature and the process speed could be adjusted, and a fixing test of an unfixed image was performed using this.

  First, in a normal temperature and normal humidity environment (23 ° C., 60% RH), the process speed is set to 230 mm / s, the initial temperature is set to 140 ° C., and the set temperature is sequentially increased by 5 ° C., and the above unfixed at each temperature. The image was fixed.

Evaluation criteria for low-temperature fixability are as follows. The low temperature side fixing start point is when the surface of the image is rubbed five times at a speed of 0.2 m / sec with Sylbon paper (Dasper K-3) applied with a load of 4.9 kPa (50 g / cm ² ). This is the lowest temperature at which image peeling with a diameter of 150 μm or more is within 3 pieces. When fixing is not performed firmly, the image peeling tends to increase.

(Evaluation criteria)
A: Low temperature side fixing start point is 145 ° C. or less B: Low temperature side fixing start point is 150 ° C. or 155 ° C.
C: Low temperature side fixing start point is 160 ° C. or 165 ° C.
D: Low temperature side fixing start point is 170 ° C. or 175 ° C.
E: Low temperature side fixing start point is 180 ° C or higher

[Developability]
A commercially available color laser printer (HP Color LaserJet 3525dn, manufactured by HP) was modified and evaluated so as to operate even when only one color process cartridge was installed. The toner contained in the cyan cartridge mounted on the color laser printer was taken out, the interior was cleaned by air blow, and the toner to be evaluated (200 g) was filled instead. Under normal temperature and humidity (23 ° C., 60% RH), Canon office planner (64 g / m ² ) was used as the image receiving paper, and 1000 sheets of a 1% printing rate chart were continuously drawn. After the image was printed, a halftone image was further output, and the presence or absence of image streaks in the developing roller and the halftone image was observed, and the developability was evaluated as follows.

(Evaluation criteria)
A: A vertical streak in the paper discharge direction that appears as a development streak is not seen on the image on the developing roller and the halftone portion.
B: Although there are 1 to 3 fine streaks on the developing roller, no vertical streak in the paper discharge direction seen as a developing streak is observed on the halftone image.
C: Although there are 4 to 6 fine streaks on the developing roller, no vertical streak in the paper discharge direction, which is seen as a developing streak, is seen on the halftone image.
D: There are 7 to 9 fine streaks on the developing roller, and visible development streaks can be seen on the halftone image.
E: Ten or more streaks are seen on the developing roller, and visible development streaks are also seen on the halftone image.

[Manufacturing stability]
The ratio D4 / D1 between the weight average particle diameter D4 (μm) and the number average particle diameter D1 (μm) in the particle size distribution of the suspension after the reaction process or after the solvent removal process in the toner production process is as follows. Evaluation was performed according to the criteria. The closer the value of the ratio D4 / D1 is to 1, the sharper the particle size distribution and the better the production stability.
A: D4 / D1 is less than 1.20 B: D4 / D1 is 1.20 or more and less than 1.25 C: D4 / D1 is 1.25 or more and less than 1.30 D: D4 / D1 is 1.30 or more and 1. Less than 35 E: D4 / D1 is 1.35 or more

  The results are shown in Table 6.

Claims (6)

A method for producing a toner having toner particles containing a binder resin and a release agent, the production method comprising the following steps 1-1) and 1-2), or 2-1) and 2-2): A method for producing toner, comprising the steps of:
1-1) A granulating step of forming particles of a polymerizable monomer composition containing the polymerizable monomer capable of forming the binder resin and the release agent in an aqueous medium,
1-2) a reaction step of polymerizing the polymerizable monomer contained in the particles,
The temperature of the aqueous medium in the granulation step of 1-1) is a temperature higher than Tc (0),
The temperature of the aqueous medium in the reaction step of 1-2) is higher than Tc (0) and equal to or lower than Tc (X).
(Tc (0) represents the crystallization temperature of the release agent in the polymerizable monomer composition in the granulation step,
Tc (X) represents the crystallization temperature of the release agent in the polymerizable monomer composition at the polymerization conversion rate X (%) of the polymerizable monomer.
However, the polymerization conversion rate X (%) is determined in the mixed solution of the polymerizable monomer, the polymer obtained by polymerizing the polymerizable monomer, and the release agent. This corresponds to the polymer concentration Y (%) when the phase is separated from the polymerizable monomer. )
2-1) a granulating step of forming particles of a resin solution containing an organic solvent, the binder resin, and the release agent in an aqueous medium;
2-2) a solvent removal step for removing the organic solvent contained in the resin solution,
The temperature of the aqueous medium in the granulation step of 2-1) is higher than Tc ′ (0),
The temperature of the aqueous medium in the solvent removal step 2-2) is higher than Tc ′ (0) and equal to or lower than Tc ′ (X ′).
(Tc ′ (0) represents the crystallization temperature of the release agent in the resin solution in the granulation step;
Tc ′ (X ′) represents the crystallization temperature of the release agent in the resin solution at a binder resin concentration X ′ (%).
However, the binder resin concentration X ′ (%) indicates the binder resin concentration Y (%) in the organic solvent when the release agent is phase-separated from the organic solvent. )   The method for producing a toner according to claim 1, wherein the polymerizable monomer composition and the resin solution further contain a release agent dispersant.   3. The release agent dispersant is dissolved in the polymerizable monomer composition and the resin solution at the polymerization conversion rate X (%) and the binder resin concentration X ′ (%). Toner production method.   The method for producing a toner according to claim 1, wherein the release agent has a melting point of 60 ° C. or higher and 110 ° C. or lower.   The method for producing a toner according to claim 1, wherein the release agent has a crystallization temperature of 50 ° C. or more and 100 ° C. or less. A method for producing a toner having toner particles containing a binder resin and a release agent, the production method comprising the following steps 3-1) and 3-2), or 4-1) and 4-2): A method for producing toner, comprising the steps of:
3-1) a granulating step of forming particles of a polymerizable monomer composition containing the polymerizable monomer capable of forming the binder resin and the release agent in an aqueous medium;
3-2) a reaction step of polymerizing the polymerizable monomer contained in the particles,
In the granulation step of 3-1), the release agent is in a state dissolved in the polymerizable monomer,
In the reaction step 3-2), the release agent is crystallized before the release agent phase-separates from the polymerizable monomer.
4-1) A granulating step of forming particles of a resin solution containing an organic solvent, the binder resin, and the release agent in an aqueous medium,
4-2) In the solvent removal step of removing the organic solvent contained in the resin solution, and in the granulation step of 4-1), the release agent is in a state dissolved in the resin solution,
In the solvent removal step 4-2), the release agent is crystallized before the release agent is phase-separated from the resin solution.

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