JP6862149B2 - Toner manufacturing method - Google Patents

Description

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

In recent years, energy saving of printers and copiers has been required. In order to cope with this, a toner having excellent low temperature fixability is preferable. In order to obtain a toner having excellent low-temperature fixability, studies have been made to improve the low-temperature fixability by using a mold release agent for the toner and efficiently obtaining a mold release effect.
The release agent is added to suppress the offset phenomenon during fixing. Here, the offset phenomenon indicates an image adverse effect in which a part of the image is brought to the fixing member due to the adhesion between the toner and the fixing member. The offset phenomenon can be suppressed by using a mold release agent for the toner and eluting the mold 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 reduce the melt viscosity of the toner. However, if the melt viscosity of the toner is lowered, the adhesive force to the fixing member is increased, so that the offset phenomenon is likely to occur. Therefore, in order to design a toner having excellent low-temperature fixability, it is more important to effectively utilize the release agent.
Patent Document 1 proposes a toner obtained by a suspension polymerization method using a hydrocarbon wax having various melting points as a mold release agent.
In Patent Documents 2 and 3, in the method for producing toner by a suspension polymerization method using a release agent, the toner is cooled during production to crystallize the release agent and disperse the release agent. A method has been proposed.
Patent Document 4 proposes a method for producing a toner in which a release agent is dispersed in the toner in a dispersed state by using a dispersion liquid in which the release agent is dispersed in fine particles in advance.

Japanese Unexamined Patent Publication No. 2012-98714 Japanese Unexamined Patent Publication No. 63-173067 Japanese Unexamined Patent Publication No. 4-188156 Japanese Unexamined Patent Publication No. 2005-338133

The toner described in Patent Document 1 does not disclose 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 manufacturing methods described in Patent Documents 2 and 3 do not disclose that the crystallization of the release agent is controlled, and the crystallization of the release agent can be used for toner production stability. The effect on developability has not been investigated.
Further, Patent Document 4 requires a step of dispersing the release agent in the form of fine particles, which causes a problem that the toner manufacturing step becomes complicated.
The present invention provides a method for producing a toner that solves the conventional problems. That is, the present invention provides a method for producing a toner capable of stably and easily producing a toner having excellent low-temperature fixability by controlling the presence state of a release agent.

A method for producing a toner having toner particles containing a binder resin and a mold release agent in order to achieve the above-mentioned object.
The production method contains a polymerizable monomer capable of forming the binder resin and the release agent in the following steps (1-1) and (1-2) (1-1) aqueous medium. Granulation step, forming particles of polymerizable monomer composition,
(1-2) A reaction step of polymerizing the polymerizable monomer contained in the particles,
Have,
The polymerizable monomer is styrene and n-butyl acrylate.
The release agent is a hydrocarbon having a melting point of 60 ° C. or higher and 110 ° C. or lower.
The crystallization temperature of the mold release agent in the polymerizable monomer composition in the granulation step of (1-1) was set to Tc (0), and the polymerization conversion rate X (%) of the polymerizable monomer was set to Tc (0). ), The crystallization temperature of the release agent in the polymerizable monomer composition is Tc (X), and the polymerizable monomer and the polymer obtained by polymerizing the polymerizable monomer are polymerized. When the concentration Y (%) of the polymer when the release agent phase-separates from the polymerizable monomer is defined as the polymerization conversion rate X (%) in the mixed solution in which the release agent and the release agent are mixed.
The temperature of the aqueous medium in the granulation step of (1-1) is higher than Tc (0).
The temperature of the aqueous medium in the reaction step of (1-2) is higher than Tc (0) and lower than Tc (X).
The present invention relates to a method for producing a toner.

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

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

The present invention relates to a method for producing toner by a suspension polymerization method and a dissolution suspension method, but the mechanism based on the characteristics of both in the present invention is common, and the description thereof will be given below when the suspension polymerization method is used. ..

Normally, when toner is produced by the suspension polymerization method and the dissolution suspension method, the release agent tends to be unevenly distributed in one place of the toner, but the reason is not clear.

In the suspension polymerization method, a granulation step of forming particles of a polymerizable monomer composition containing a polymerizable monomer capable of forming a binder resin and a mold release agent in an aqueous medium, contained in the particles. Toner particles are produced through a reaction step of polymerizing the polymerizable monomer to be obtained. At this time, the release agent is uniformly dissolved in the polymerizable monomer, but after the polymerizable monomer forms a 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 the binder phase) and the release agent gradually form a phase-separated structure.

The present inventors considered that the position of the release agent can be controlled by examining the structure formation mechanism of the release agent in detail in the toner manufacturing process, and came to the present invention.

Specifically, it was 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 the release agent is not crystallized and remains melted when the binder phase and the release agent are phase-separated. In the present invention, it is referred to as a "phase separation preceding pattern". The second pattern is a pattern in which phase separation occurs by crystallizing the release agent before the binder phase and the release agent undergo phase separation. In the present invention, it is referred to as a "crystallization leading pattern" (Fig. 1).

Furthermore, 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 speculated that the reason why the release agent tends to be unevenly distributed in one place in the toner produced by the suspension polymerization method is due to the phase separation preceding pattern. That is, 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 domain is integrated in one place. I guess I'll do it.

That is, the present inventors phase-separate the release agent as a solid by adopting the crystallization preceding pattern, which is the second phase separation pattern, and suppress the movement in the toner, thereby forming the release agent domain. I thought that it was possible to suppress the unification of. As a result, a method for producing a toner that can easily produce a toner having excellent low-temperature fixability by controlling the dispersion state of the release agent in the toner particles without aggregating the release agent domain in one place. I came to invent it.

In the suspension polymerization method, the release agent is kept dissolved in the polymerizable monomer in the granulation step, and the release agent is crystallized before the release agent is phase-separated from the polymerizable monomer in the reaction step. The following conditions are required in order to obtain a crystallization-preceding pattern to be polymerized.

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 and a mold release agent capable of forming a binder resin in an aqueous medium.
( 1-2) 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 higher than that of Tc (0).
The temperature of the aqueous medium in the reaction step of ( 1-2) is higher than Tc (0) and lower than Tc (X).
(Tc (0) indicates the crystallization temperature of the release agent in the polymerizable monomer composition in the granulation step.
Tc (X) indicates 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 such that in a mixed solution in which a polymerizable monomer, a polymer obtained by polymerizing the polymerizable monomer, and a release agent are mixed, the release agent is a polymerizable simple substance. It corresponds to the polymer concentration Y (%) at the time of phase separation from the polymer. )

When the temperature of the aqueous medium in the reaction step is Tc (X) or less, it is possible to obtain a state in which the release agent is crystallized when the binder phase and the release agent are phase-separated. As a result, it is possible to obtain a toner having excellent low temperature fixability in which the release agent domains are not integrated in one place. Further, since the temperature of the aqueous medium in the granulation step is higher than Tc (0), it is possible to granulate the mold release agent in a state of being dissolved in the polymerizable monomer, so that the production is stable. It can be a method for producing a toner having excellent properties. Further, 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 the toner. It can be a method for producing toner that is not easily exposed on the surface.

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

Further, in the case of the dissolution / suspension method, the same applies by using the binder resin concentration X'(%) obtained in the same manner instead of the polymerization conversion rate X (%) quantified by using the above method. Is possible.

In the dissolution / suspension method, the release agent is kept dissolved in the resin solution in the granulation step, and the release agent is crystallized before the release agent is phase-separated from the resin solution in the solvent removal step. The following conditions are required to make the preceding pattern.

That is, it has the following steps ( 2-1) and (2-2).
( 2-1) Granulation step of forming particles of a resin solution containing an organic solvent, a binder resin and a mold release agent in an aqueous medium.
( 2-2) Solvent removal step of 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 that of Tc'(0).
The temperature of the aqueous medium in the solvent removal step of ( 2-2) is higher than Tc'(0) and lower than Tc'(X').
(Tc'(0) indicates the crystallization temperature of the release agent in the resin solution in the granulation step.
Tc'(X') indicates the crystallization temperature of the release agent in the resin solution at the binding resin concentration X'(%).
However, the binding resin concentration X'(%) indicates the binding resin concentration (%) in the organic solvent when the release agent is phase-separated 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, Tc (0) + 2 ° C. or higher, or Tc'(0) + 2 ° C. or higher. Is more preferable.

Further, in the dissolution / suspension method, since the surface of the release agent is not exposed by removing the solvent, 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 more excellent developability can be stably produced.

The 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. Further, the temperature of the aqueous medium in the manufacturing process can be controlled by setting the apparatus to be used.

It is more preferable that 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 due to the stacking of release agent molecules. Therefore, the crystal growth of the release agent can be suppressed by adsorbing the release agent dispersant on the growth surface of the crystal. As a result, the size of the release agent domain can be controlled, and a toner having excellent low-temperature fixability can be obtained in which the release agent can be used more efficiently.

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 to the release agent domain, and more excellent release agent domain control is possible. Solubility is controlled by the type and molecular weight of the resin constituting the release agent dispersant, and the ratio of the structure having an affinity with the release agent constituting the release agent dispersant and the structure having an affinity with the binder. can do.

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

Further, the weight average molecular weight Mw of the release agent dispersant is preferably 3000 or more and 30,000 or less. Within the range, the effect of controlling the crystal growth of the release agent can be obtained 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 at the time of synthesizing the release agent dispersant and the initiator concentration. The 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. Within the range, the effect of controlling the crystal growth of the release agent and the elution of the release agent at the time of fixing can be compatible with each other.

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 the dissolution suspension method, a release agent is likely to be present in the vicinity of the toner surface layer. Therefore, the melting point of the release agent tends to have a large effect on the toner performance. When the melting point of the release agent is 60 ° C. or higher, it is possible to obtain a toner having excellent developability, which is less likely to cause coalescence of toners due to the release agent and contamination of members. Further, when the temperature is 110 ° C. or lower, the effect of the release agent can be sufficiently obtained even under the condition that the fixing temperature is low, and a toner having excellent 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.

Further, it is preferable that the crystallization temperature of the release agent is 50 ° C. or higher and 100 ° C. or lower. The crystallization temperature of the release agent has a great influence on the Tc (0), Tc (X), Tc'(0) and Tc'(X'). Therefore, when the crystallization temperature is 50 ° C. or higher and 100 ° C. or lower, it is easy to design the method for producing the crystallization preceding pattern defined by the present invention, which is preferable. The method for measuring the melting point and the crystallization temperature will be described 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 the molecular weight distribution measured by gel permeation chromatography (GPC) of a 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 that the release agent domains are more likely to merge in one place. On the other hand, the smaller the molecular weight of the main peak, the lower the melt viscosity of the toner and the better the low temperature fixability. Therefore, by obtaining the toner having the main peak molecular weight in the above range by the production method specified in the present invention, a toner having more excellent low temperature fixability can be obtained. It is more preferable that the toner has a main peak in a region having a molecular weight of 8,000 or more and 30,000 or less. The molecular weight of the main peak of the toner can be controlled by the temperature at which the toner and the binder resin used for the toner are synthesized and the amount of the initiator. The method for measuring the molecular weight distribution of the toner will be described later.

An example of a material that can be used in the present invention is described below.

As the binder resin that can be used in the present invention, a conventionally known resin can be used. For example, polyester resin; styrene acrylic resin; polyamide resin; furan resin; epoxy resin; xylene resin; silicone resin and the like can be mentioned. Among these, styrene acrylic resin and polyester resin are preferable from the viewpoint of phase separation from the mold release agent and the production stability of the toner. Further, in the suspension polymerization method, it is a styrene acrylic resin from the viewpoint of a polymerizable monomer that can be used.

Examples of the polymerizable monomer that can be used are styrene-based monomers such as styrene, α-methylstyrene, and divinylbenzene; methyl acrylate, butyl acrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, and the like. 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 Anhydrous; nitrile-based vinyl monomer such as acrylonitrile; halogen-containing vinyl monomer such as vinyl chloride; nitro-based vinyl monomer such as nitrostyrene: and the like.

The polyester resin requires the following dibasic acids and derivatives thereof (carboxylic acid halides, esters, acid anhydrides) and dihydric alcohols as essential, and if necessary, trivalent or higher polybasic acids and derivatives thereof. A polyester resin prepared by a method of dehydrating and condensing (carboxylic acid halide, ester, acid anhydride), monobasic acid, trihydric or higher alcohol, monovalent alcohol and the like can be used.

Examples of the dibasic acid include maleic acid, phthalic acid, itaconic acid, phthalic acid, malonic acid, succinic acid, dodecylsuccinic acid, dodecenylsuccinic acid, adipic acid, azelaic acid, sebacic acid, decane-1,10-dicarboxylic acid and the like. Of aliphatic dibasic acids; phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, tetrabromphthalic acid, tetrachlorophthalic acid, het acid, hymic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, etc. Aromatic dibasic acids; and the like.

Examples of the derivative of the dibasic acid include carboxylic acid halides, esters and acid anhydrides of the above-mentioned aliphatic dibasic acid and aromatic dibasic acid.

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. , Dipropylene glycol, triethylene glycol, neopentyl glycol and other acyclic aliphatic diols; bisphenol A, bisphenol F and other bisphenols; bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, etc. Examples thereof include an alkylene oxide adduct of bisphenol A; aralkylene glycols such as xylylene diglycol; and the like.

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

As the release agent that can be used in the present invention, a general wax can be used. For example, monohydric alcohols such as behenyl behenate, stearyl stearate, palmityl palmitate and aliphatic monocarboxylic acid esters, or monohydric carboxylic acids and aliphatic monoalcohol esters; dibehenyl sebacate, hexanediol dibehenate, etc. Dihydric alcohol and aliphatic monocarboxylic acid ester, or dihydric carboxylic acid and aliphatic monoalcohol ester; trihydric alcohol such as glycerin tribehenate and aliphatic monocarboxylic acid ester, or trihydric carboxylic acid. And aliphatic monoalcohol esters; tetrahydric alcohols such as pentaerythritol tetrastearate, pentaerythritol tetrapalmitate and aliphatic monocarboxylic acid esters, or tetrahydric carboxylic acids and aliphatic monoalcohol esters; dipentaerythritol hexa. Hexalcohols and aliphatic monocarboxylic acid esters such as stearate and dipentaerythritol hexapalmitate, or esters of hexahydric carboxylic acids and aliphatic monoalcohols; polyhydric alcohols such as polyglycerin behenate and aliphatic monocarbonates. Carous acid ester or ester of polyhydric carboxylic acid and aliphatic monoalcohol; Natural ester wax such as carnauba wax and rice wax; Petroleum wax such as paraffin wax, microcrystallin wax and petrolatum and its derivatives; Carbide waxes and derivatives thereof; polyolefin waxes such as polyethylene wax and polypropylene wax and derivatives thereof; higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid; acid amide wax. Among these, a hydrocarbon wax having high phase separability with the binder resin, a tetrahydric or higher alcohol and an aliphatic monocarboxylic acid ester, or a tetravalent or higher carboxylic acid and an aliphatic monoalcohol ester wax is preferable. More preferably, it 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 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 the range, the release agent is rapidly eluted at the time of fixing, so that more excellent low temperature fixing property can be obtained. When toner is produced by the suspension polymerization method, the amount of the release agent added 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 resins having a structure having an affinity for the release agent and a structure having an 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. Can be mentioned. As a structure having an 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 a polymerizable monomer and an organic solvent, a styrene acrylic resin, Polyester resin is preferred. Further, 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 a styrene acrylic resin can be used.

The aqueous medium that can be used in the present invention is a medium containing water as a main component, and may contain a solvent that is miscible with water. Further, the aqueous medium may contain a dispersion stabilizer. As the dispersion stabilizer to be added to the aqueous medium, known surfactants, organic dispersants, and inorganic dispersants can be used. Among these, the inorganic dispersant does not easily lose its production stability even with the polymerization temperature and the passage of time, and can be preferably used. Examples of the inorganic dispersant include the following. Polyvalent metal phosphates such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate, inorganic salts such as calcium metasilicate, 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 the toner particles such as a binder resin and a mold release agent, but from the viewpoint of solvent removal. It is preferable that the solvent has a certain vapor pressure even below the boiling point of water. For example, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone and the like can be used.

The method for producing a toner 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 type of resin include known resins conventionally used for toner, and examples thereof include polyester-based resins and vinyl-based 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.

Further, in the method for producing a toner 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 load electrical include the following.

Organic metal compounds, chelate compounds, monoazo metal compounds, acetylacetone metal compounds, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthoic acid-based compounds, quaternary ammonium salts, calix arene, silicon compounds, non-metal carboxylic acid-based compounds and their derivatives. Can be mentioned. Further, a sulfonic acid resin having a sulfonic acid group, a sulfonic acid base, or a sulfonic acid ester group can be preferably used.

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

Modified products with niglosin and fatty acid metal salts, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salt which is an analog thereof. And these lake pigments, triphenylmethane dyes and these lake pigments (as lake agents, phosphotung acid, phosphomolybdic acid, phosphotungene molybdic acid, tannic acid, lauric acid, gallic acid, ferricianide, 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 between the polymerizable monomer composition and water is reduced, so that the toner has a smaller particle size and a uniform particle size distribution. Particles are obtained.

In the method for producing a toner of the present invention, a colorant may be further contained in the polymerizable monomer composition. Examples of the colorant include a black colorant, a yellow colorant, a magenta colorant, and a cyan colorant.

Specific examples of the black colorant include carbon black and the like.

Specific examples of the yellow colorant include the following monoazo compounds; disazo compounds; condensed azo compounds; isoindolinone compounds; isoindolin compounds; benzimidazolone compounds; anthracinone compounds; azometal complexes; methine compounds; allylamides. Examples thereof include yellow pigments typified by compounds. 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; thioindigo compounds; perylene. Examples thereof include magenta pigments typified by compounds. 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. Pigment Bio Red 19 and the like.

Specific examples of the cyan colorant include the following copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds; and cyan pigments typified by basic dye lake compounds. 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 above-mentioned pigments, 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 mixed with a magnetic carrier and used as a two-component developer.

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

When the toner particles are obtained by the suspension polymerization method, the polymerizable monomer that can form the binder resin, the release agent, and if necessary, the pigment, the polar resin, the charge control agent, and other materials are uniformly dissolved. Alternatively, it is dispersed to prepare a polymerizable monomer composition. Then, 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). Then, 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. After the polymerization is completed, the toner particles (before the addition of the external additive) are filtered, washed, and dried by a known method, and the external additive is mixed to obtain the toner of the present invention.

When obtaining toner particles by the dissolution / suspension method, first, a binder resin and a mold 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, the organic solvent contained in the granulated particles is removed to obtain toner particles through a solvent removal step of producing resin particles. After the solvent removal step is completed, the toner particles (before adding the external additive) are filtered, washed, and dried by a known method, and the external additive is mixed to obtain the toner of the present invention.

The method for measuring each physical characteristic value specified in the present invention will be described below.

<Quantification of polymerization conversion rate X (%) at which phase separation occurs and the binder resin concentration X'(%)>
(1) Prepare a mixture of a polymerizable monomer and a polymer obtained by polymerizing the polymerizable monomer. 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 from 0% to 70% by 5%. The release agent is added to each mixed solution in 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) The transmittance of each dissolved solution is measured using a visible light transmittance meter (manufactured by DST2500 Toa System Create Co., Ltd.) while maintaining the above temperature. Then, the polymer concentration Y (mass%) in the mixed solution in which the decrease in transmittance is confirmed is defined as 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) Prepare a mixed solution by mixing the binder resin and the 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 from 0% to 70% by 5%. A mold release agent is added to each mixed solution in 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 mold 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) The transmittance of each dissolved solution is measured using a visible light transmittance meter (DST2500) while maintaining the above temperature. Then, the binder resin concentration Y (mass%) in the mixed solution 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 mold release agent crystallization temperature at each polymerization conversion rate and mold release agent crystallization temperature at each binder resin concentration>
The crystallization temperature of each mixed solution used for quantifying the polymerization conversion rate X (%) at which phase separation occurs was measured as follows.

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 melting points of indium and zinc are used for temperature correction of the device detector, and the heat of fusion of indium is used for the correction of calorific value. Specifically, the measurement sample is weighed in the range of 5 mg to 10 mg and placed in an aluminum pan. The bread is sealed using TzeroPan and TzeroHermeticLid so that the volatile components in the sample do not volatilize during the measurement. Using an empty pan as a reference, the temperature is raised between 0 ° C. and 100 ° C. at a heating rate of 10 ° C./min. Hold at 100 ° C. for 1 minute, then cool between 100 ° C. and 0 ° C. at a temperature lowering rate of 10 ° C./min. The peak temperature of the exothermic peak detected in this temperature lowering process is defined as the crystallization temperature. The measurement is performed in a temperature range that does not exceed the boiling points of the polymerizable monomer and the organic solvent used.

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

FIG. 3 shows a graph showing an example of the relationship between the crystallization temperature of the 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 quantifying the binder resin concentration X'(%) at which phase separation occurs. At this time, the crystallization temperature of the release agent at the binding resin concentration of 0% is Tc'(0), and the crystallization temperature at the binding resin concentration of X'(%) is Tc'(X').

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

First, the sample is dissolved in tetrahydrofuran (THF) over 24 hours at room temperature. Then, the obtained solution is filtered through a solvent-resistant membrane filter "Myshori Disc" (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. The sample solution is prepared so that the concentration of the component soluble in THF is 0.8% by mass. This sample solution is used for measurement under the following conditions.
Equipment: HLC8120 GPC (Detector: RI) (manufactured by Tosoh Corporation)
Column: 7 stations of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: tetrahydrofuran (THF)
Flow velocity: 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 Toso Co., Ltd.) is used.

<Measuring method of melting point and crystallization temperature of mold 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 melting points of indium and zinc are used for temperature correction of the device detector, and the heat of fusion of indium is used for the correction of calorific value. Specifically, 1 mg of the measurement sample is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference, and the temperature rise rate is 10 ° C./1 in the measurement range of 0 ° C. to 150 ° C. The temperature rises at the rate of minutes. Hold at 150 ° C. for 15 minutes, then cool between 150 ° C. and 0 ° C. at a cooling rate of 10 ° C./min. The peak temperature of the exothermic peak observed at this time is defined as the crystallization temperature of the release agent. Further, hold at 0 ° C. for 10 minutes, and then measure at a heating rate of 10 ° C./min between 0 ° C. and 150 ° C. The peak temperature of the endothermic peak observed at this time is defined as the melting point of the release agent. Further, the Tg of the binder resin is the line at the midpoint of the baseline before and after the specific heat change of the specific heat change curve in the second temperature rise process when the sample is measured in the same manner as above. The intersection with the differential heat curve was defined as Tg (° C.) of the binder resin.

<Measuring method of toner particle size distribution>
The weight average particle size (D4), the number average particle size (D1), and the particle size distribution (D4 / D1) of the toner are calculated as follows. As the measuring device, a precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark trade name, manufactured by Beckman Coulter Co., Ltd.) equipped with a 100 μm aperture tube by the pore electrical resistance method is used. For the setting of measurement conditions and the analysis of measurement data, the attached dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter) is used. The measurement is performed with 25,000 effective measurement channels.

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

Before performing measurement and analysis, set the above-mentioned dedicated software as follows.

On the "Change standard measurement method (SOM)" screen of the above-mentioned dedicated software, set the total count number of the control mode to 50,000 particles, measure once, and set the Kd value to "standard particle 10.0 μm" (Beckman Coulter). Set the value obtained using (manufactured by the company). By pressing the "threshold / noise level measurement button", the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, and the electrolyte to ISOTON II, and check “Flash of aperture tube after measurement”.

On the "Pulse to particle size conversion setting" screen of the dedicated software, the bin spacing is set to logarithmic particle size, the particle size bin is set to 256 particle size bins, and the particle size range is set from 2 μm to 60 μm.

The specific measurement method is as follows.
(1) Put 200 mL of the above-mentioned electrolytic aqueous solution in a glass 250 mL round bottom beaker dedicated to Multisizer 3, set it on a sample stand, and stir the stirrer rod counterclockwise at 24 rpm. Then, the dirt and air bubbles in the aperture tube are removed by the "aperture flash" function of the dedicated software.
(2) Put 30 mL of the above-mentioned electrolytic aqueous solution in a 100 mL flat-bottomed beaker made of glass. Among them, as a dispersant, "Contaminone N" (a 10% by mass aqueous solution of a neutral detergent for cleaning a precision measuring instrument with a pH of 7 consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd. ) Is diluted 3 times by mass with ion-exchanged water, and 0.3 mL of the diluted solution is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are built in with their phases shifted by 180 degrees, and an ultrasonic disperser "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios Co., Ltd.) having an electrical output of 120 W is prepared. Put 3.3 L of ion-exchanged water in the water tank of the ultrasonic disperser, and add 2 mL of contaminantin N to this water tank.
(4) The beaker of the above-mentioned (2) is set in the beaker fixing hole of the above-mentioned 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 level of the electrolytic aqueous solution in the beaker is maximized.
(5) In a state where the electrolytic aqueous solution in the beaker of the above-mentioned (4) is irradiated with ultrasonic waves, toner or a dispersion of toner is added little by little to the electrolytic aqueous solution so that the amount of toner becomes 10 mg, and the toner is dispersed. Then, the ultrasonic dispersion processing is continued for another 60 seconds. In ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be 10 ° C. or higher and 40 ° C. or lower.
(6) Using a pipette, the above-mentioned electrolyte aqueous solution (5) in which toner is dispersed is dropped onto the above-mentioned round bottom beaker installed in the sample stand, and the measured concentration is adjusted to 5%. .. Then, the measurement is performed until the number of measurement particles reaches 50,000.
(7) The measurement data is analyzed by the above-mentioned 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 of 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 irradiating with ultraviolet rays. The obtained cured product is cut using a microtome equipped with diamond teeth to prepare a flaky sample. After dyeing the sample 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, Ltd.). In the above observation method, the amorphous part of the toner is strongly stained with ruthenium tetroxide. As a result, the release agent domain can be observed as contrast. The observation magnification was 20000 times.

Hereinafter, the present invention will be specifically described 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.

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

<Manufacturing of binding 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, and 3.0 parts of t-butylperoxypivalate were placed. It was added, heated to 70 ° C. and stirred for 10 hours. Further, the mixture was heated to 100 ° C. and the solvent was distilled off for 6 hours to obtain a binder resin. The Tg of the binder resin measured according to the above method was 58 ° C., and the weight average molecular weight Mw was 25,000.

<Manufacturing 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, 1.0 part of ethyl 2-bromoisobutyrate were placed in a flask and kept at room temperature for 1 hour. Nitrogen substitution was performed under normal pressure. Then, the temperature was raised to 65 ° C. and reacted until the desired molecular weight was obtained to obtain polybehenyl acrylate.

Then, after cooling to room temperature, 100.0 parts of the polybehenyl acrylate was dissolved in 200.0 parts of chloroform, and reprecipitation, filtration and purification were carried out with 800.0 parts of ethanol. The weight average molecular weight Mw of the polybehenyl acrylate measured according to the above method 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 were placed in a flask, and nitrogen was added for 1 hour at normal temperature and pressure. Substitution was performed. Then, the temperature was raised to 100 ° C., and the reaction was stopped when the desired molecular weight was reached to obtain a polybehenyl acrylate-polystyrene block copolymer. 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, purified, and unreacted single amount. The body, catalyst and solvent were removed. Then, it was dried in a vacuum dryer set at 50 ° C. to obtain a release agent dispersant 1. The weight average molecular weight Mw of the release agent dispersant 1 measured according to the above method was 8000.

<Manufacturing 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, to obtain the release agent dispersants 2 and 3. The weight average molecular weight Mw of the release agent dispersant 2 measured according to the above method was 20000, and the weight average molecular weight Mw of the release agent dispersant 3 was 30,000.

With respect to the obtained release agent dispersants 1 to 3, the release agent dispersant is transferred 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 mold release agent>
For the release agent used in the present invention, the melting point Tm and the crystallization temperature Tc were measured by using the above-mentioned method. The results are summarized in Table 2.

<Measurement of polymerization conversion rate X (%), Tc (0), Tc (X) in which the release agent is phase-separated in toners 1 to 27 and 31 to 42>
In the production of toners 1 to 27 and 31 to 42 shown below (manufacturing of toner by the suspension polymerization method), the polymerization conversion rate X (%) and Tc (0) at which the release agent is phase-separated by using the above-mentioned method. ), Tc (X) was measured. At this time, a mixture of styrene and n-butyl acrylate at a mass ratio of 78:22 was used as the polymerizable monomer, and the polymer obtained by polymerizing the polymerizable monomer was styrene and n-. A resin (Tg55 ° C., weight average molecular weight Mw30000) obtained by copolymerizing butyl acrylate with a mass ratio of 78:22 was used. The results are summarized in Table 3.

<Manufacturing of toner 1>
-Styrene: 60.0 parts-C. I. Pigment Blue 15: 3 (manufactured by Dainichiseika Co., Ltd.): 6.0 parts The above material was put into an attritor (manufactured by Mitsui Miike Machinery Co., Ltd.), and zirconia particles with a diameter of 1.7 mm were used for 5 hours at 220 rpm. The mixture was dispersed to obtain a pigment dispersion liquid.

In the above 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 above material was kept warm at 70 ° C., and T.I. K. A polymerizable monomer composition was prepared by uniformly dissolving and dispersing at 500 rpm using a homomixer (manufactured by Tokushu Kagaku Kogyo Co., Ltd.).

On the other hand, the addition of 0.1mol / L-Na ₃ PO ₄ aqueous solution 850.0 parts of 10% hydrochloric acid 8.0 parts in a container equipped with a high speed stirrer CLEARMIX (manufactured by M Technique Co., Ltd.), the rotational speed It was adjusted to 15000 rpm and heated to 70 ° C. 68.0 parts of a 1.0 mol / L-CaCl ₂ aqueous solution was added thereto to prepare an aqueous medium containing a calcium phosphate compound.

The polymerizable monomer composition was put into the aqueous medium, and 7.0 parts of t-butylperoxypivalate as a polymerization initiator was added. Granulation was carried out for 10 minutes while maintaining 15,000 rpm with the stirring device as it was (granulation step). After that, the stirrer was changed from a high-speed stirrer to a propeller stirring blade, and the reaction was carried out at 70 ° C. for 10 hours while refluxing (reaction step).

After completion of the polymerization step, the slurry was cooled, a part thereof was extracted, and the particle size distribution was measured using the above-mentioned method. Further, 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. Then, it was washed with three times the amount of water of the slurry, filtered and dried, and then the particle size was adjusted by classification to obtain toner particles.

Then, 100.0 parts of the toner particles are treated with dimethyl silicone oil (20% by mass) as a fluidity improver, and the hydrophobic treated silica fine powder is triboelectrically charged with the same polarity (negative value) as the toner particles. Add 2.0 parts of the body (number average particle size of primary particles: 10 nm, BET specific surface area: 170 m ^{2 /} g) and mix at 3000 rpm for 15 minutes using a Mitsui Henchel mixer (manufactured by Mitsui Miike Kakoki Co., Ltd.). Toner 1 was obtained.

<Manufacturing of toners 2-27 and 31-42>
As shown in Table 4, the toner except for changing the type and amount of mold release agent, the type and amount of mold release agent dispersant, the type and amount of initiator, the temperature of the granulation process, and the temperature of the reaction process. Toners 2-27 and 31-42 were obtained in the same manner as in the production of 1.

The initiator 1 in Table 4 is t-butylperoxypivalate (half-life temperature 58 ° C.), and the initiator 2 is 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate (half-life). The temperature is 37 ° C.).

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

<Manufacturing of toner 28>
-Bundling resin: 100.0 parts-C. I. Pigment Blue 15: 3 (manufactured by Dainichiseika Co., Ltd.): 6.0 parts, polar resin: 5.0 parts, release agent dispersant 1: 5.0 parts, toluene: 200.0 parts The mixture was mixed and dispersed for 10 hours to obtain a resin solution. On the other hand, the addition of 0.1mol / L-Na ₃ PO ₄ aqueous solution 850.0 parts of 10% hydrochloric acid 8.0 parts in a container equipped with a high speed stirrer CLEARMIX (manufactured by M Technique Co., Ltd.), the rotational speed It was adjusted to 15000 rpm and heated to 70 ° C. 68.0 parts of a 1.0 mol / L-CaCl ₂ aqueous solution was added thereto to prepare an aqueous medium containing a calcium phosphate compound. After heating the resin solution to 70 ° C., 1: 10.0 parts of the release agent is dissolved, the resin solution is put into the aqueous medium, and the stirring device is used as it is while maintaining 15,000 rpm. Granulation was performed for 10 minutes (granulation step). After that, the stirrer was changed from a high-speed stirrer to a propeller stirrer, and the solvent was removed at 70 ° C. under reduced pressure to 20 kPa (solvent removal step).

After the solvent removal step was completed, the slurry was cooled, a part thereof was extracted, and the particle size distribution was measured using the above-mentioned method. Further, the toner 28 was obtained by washing, filtering, drying, classifying, and externally adding the toner 1 in the same manner as in the method for producing the toner 1.

<Manufacturing of toners 29-30 and 43-45>
As shown in Table 4, the same as 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 process, and the temperature of the solvent removal process are changed. 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. The relationship between (or the solvent removal step temperature) and Tc (0), Tc (X) (or Tc'(0), Tc'(X')) is summarized in Table 5.

[Examples 1 to 30, Comparative Examples 1 to 15]
The performance of each of the obtained toners was evaluated according to the following method.

[Dispersed state of mold release agent]
The cross-sectional structure of the obtained toner was observed using the above-mentioned method, and the toner was evaluated according to the following criteria. It is preferable that the release agent is dispersed in the toner rather than being united in one place because the release agent is quickly eluted at the time of fixing.
A: It is dispersed as fine linear crystals.
B: Dispersed as thick linear crystals.
C: It is united in about 1 or 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) from which the fixing unit was removed was prepared, toner was taken out from the cyan cartridge, and toner to be evaluated was filled instead. ^{Next, an unfixed toner image (0.7 mg / cm 2} ) of 2.0 cm in length and 15.0 cm in width is passed through the image receiving paper (Canon office planner 64 g / m ^{2) using the filled toner.} It was formed at a portion 1.0 cm from the upper end in the direction. Next, the removed fixing unit was modified so that the fixing temperature and process speed could be adjusted, and the fixing test of the unfixed image was performed using this.

First, under a normal temperature and humidity environment (23 ° C., 60% RH), the process speed is set to 230 mm / s, the initial temperature is 140 ° C., and the set temperature is gradually raised by 5 ° C. The image was fixed.

The 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 5 times at a speed of 0.2 m / sec with Sylbon paper (Dusper K-3) loaded with a load ^{of 4.9 kPa (50 g / cm 2).} , The minimum temperature at which image peeling of 150 μm or more in diameter is within 3 pieces. If the 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: The fixing start point on the low temperature side is 160 ° C or 165 ° C.
D: The fixing start point on the low temperature side is 170 ° C or 175 ° C.
E: The fixing start point on the low temperature side is 180 ° C or higher.

[Developability]
A commercially available color laser printer (HP Color LaserJet 3525dn, manufactured by HP) was modified and evaluated so that it could be operated even with only one color process cartridge installed. The toner contained in the cyan cartridge mounted on this color laser printer was extracted, the inside was cleaned by an air blow, and then the toner (200 g) to be evaluated was filled instead. ^{A Canon office planner (64 g / m 2} ) was used as an image receiving paper under normal temperature and humidity (23 ° C., 60% RH), and 1000 1% print rate charts were continuously printed. After the image was drawn, a halftone image was further output, 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: Vertical streaks in the paper ejection direction, which are seen as development streaks, are not seen on the developing roller and the image of the halftone portion.
B: Although there are 1 to 3 fine streaks on the developing roller, vertical streaks in the paper ejection direction, which are seen as development streaks, are not seen on the image of the halftone portion.
C: Although there are 4 to 6 fine streaks on the developing roller, vertical streaks in the paper ejection direction, which are seen as development streaks, are not seen on the image of the halftone portion.
D: There are 7 to 9 fine streaks on the developing roller, and visible developing streaks can be seen on the image of the halftone portion.
E: Ten or more streaks are seen on the developing roller, and visible developing streaks are also seen on the image of the halftone portion.

[Manufacturing stability]
In the particle size distribution of the suspension after the reaction step or the solvent removal step in the toner manufacturing step, the ratio D4 / D1 of the weight average particle size D4 (μm) and the number average particle size D1 (μm) is as follows. It was evaluated according to the criteria of. The closer the value of the ratio D4 / D1 is to 1, the sharper the particle size distribution is, which means that the production stability is excellent.
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 1. Less than 35 E: D4 / D1 is 1.35 or more

The results are shown in Table 6.

Claims (3)

A method for producing a toner having toner particles containing a binder resin and a mold release agent.
The production method contains a polymerizable monomer capable of forming the binder resin and the release agent in the following steps (1-1) and (1-2) (1-1) aqueous medium. Granulation step, forming particles of polymerizable monomer composition,
(1-2) A reaction step of polymerizing the polymerizable monomer contained in the particles,
Have,
The polymerizable monomer is styrene and n-butyl acrylate.
The release agent is a hydrocarbon having a melting point of 60 ° C. or higher and 110 ° C. or lower.
The crystallization temperature of the mold release agent in the polymerizable monomer composition in the granulation step of (1-1) was set to Tc (0), and the polymerization conversion rate X (%) of the polymerizable monomer was set to Tc (0). ), The crystallization temperature of the release agent in the polymerizable monomer composition is Tc (X), and the polymerizable monomer and the polymer obtained by polymerizing the polymerizable monomer are polymerized. When the concentration Y (%) of the polymer when the release agent phase-separates from the polymerizable monomer is defined as the polymerization conversion rate X (%) in the mixed solution in which the release agent and the release agent are mixed.
The temperature of the aqueous medium in the granulation step of (1-1) is higher than Tc (0).
The temperature of the aqueous medium in the reaction step of (1-2) is higher than Tc (0) and lower than Tc (X).
A method for producing toner, which is characterized by the fact that. The method for producing a toner according to claim 1, wherein the polymerizable monomer composition further contains a release agent dispersant. The method for producing a toner according to claim 2, wherein the release agent dispersant is dissolved in the polymerizable monomer composition at the polymerization conversion rate X (%).

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