JP5920099B2 - Toner for developing electrostatic image and method for producing the same - Google Patents

Description

  The present invention relates to a toner for developing an electrostatic charge image (hereinafter also simply referred to as “toner”) used for electrophotographic image formation and a method for producing the same.

Currently, laws such as the “Procurement Law for the Procurement of Environmental Goods by the State (Green Purchasing Law)” have been enforced, and the government is moving away from petroleum-derived raw materials. Also in image formation, for example, use of a toner having a low environmental load such as a toner including a biomass plastic obtained from a raw material derived from an organic resource other than a fossil resource as a binder resin has been demanded.
Such raw materials derived from organic resources other than fossil resources are disclosed in, for example, Patent Document 1 and Patent Document 2.

JP 2009-57294 A JP 2010-043203 A

  The present invention has been made in consideration of the above-described circumstances, and an object thereof is to provide a toner for developing an electrostatic image having a low environmental load and a method for producing the same.

The electrostatic image developing toner of the present invention is an electrostatic image developing toner comprising toner particles containing a resin,
The resin contains a vinyl polymer having a structural unit represented by the following general formula (1).

[Wherein, R ¹ is a hydrogen atom or a methyl group, and R ² is —C (═O) O— (CH ₂ ) _n — (where n is an integer of 1 to 4) or a methylene group. R ³ is a furanyl group, a hydroxymethylfuranyl group, an optionally substituted benzyl group or an optionally substituted aryl group. ]

In the electrostatic image developing toner of the present invention, R ³ in the structural unit represented by the general formula (1) is a hydroxy group, a methoxy group, an ethoxy group, an isopropyl group, or —OC (═O) R ⁴ ( However, R ⁴ is preferably a phenyl group or a benzyl group substituted by any of an alkyl group having 1 to 4 carbon atoms.).

  In the electrostatic image developing toner of the present invention, the vinyl polymer is a structural unit represented by the general formula (1), a structural unit derived from a (meth) acrylic acid ester monomer, and a styrene-based polymer. A copolymer having a structural unit derived from a monomer is preferable.

  In the electrostatic image developing toner of the present invention, the content of the structural unit represented by the general formula (1) in the resin is preferably 35 to 70% by mass.

  In the toner for developing an electrostatic charge image of the present invention, the content of the structural unit represented by the general formula (1) in the toner particles is preferably 30 to 55% by mass.

The method for producing an electrostatic image developing toner of the present invention is a method for producing the above-described electrostatic image developing toner,
A step of producing a vinyl polymer having a structural unit represented by the above general formula (1) by using at least a polymerizable monomer represented by the following general formula (2) in an aqueous medium. It is characterized by including.

[Wherein, R ¹ is a hydrogen atom or a methyl group, and R ² is —C (═O) O— (CH ₂ ) _n — (where n is an integer of 1 to 4) or a methylene group. R ³ is a furanyl group, a hydroxymethylfuranyl group, an optionally substituted benzyl group or an optionally substituted aryl group. ]

  In the method for producing an electrostatic image developing toner of the present invention, it is preferable to form toner particles by aggregating resin fine particles made of the vinyl polymer in an aqueous medium.

  According to the toner for developing an electrostatic charge image of the present invention, the toner particles contain a vinyl polymer having a specific structural unit, and the vinyl polymer can be obtained from plant-derived raw materials. The load can be suppressed low.

  Further, according to the electrostatic image developing toner of the present invention, since the resin constituting the toner particles contains a specific structural unit, high charge stability is obtained, transferability is excellent, and a large amount of printing is performed. Excellent image stability.

  Hereinafter, the present invention will be specifically described.

〔toner〕
The toner of the present invention has a vinyl polymer having a structural unit represented by the above general formula (1) (hereinafter also referred to as “specific Schiff base-containing vinyl-based structural unit”) (hereinafter referred to as “specific vinyl-based”). The toner particles further include a colorant, a magnetic powder, a release agent, a charge control agent, and the like, if desired. Can be.

In the general formula (1) showing a specific Schiff base-containing vinyl-based structural unit, R ¹ is a hydrogen atom or a methyl group, and R ² is —C (═O) O— (CH ₂ ) _n — (wherein n is an integer of 1 to 4.) or a methylene group, and R ³ is a furanyl group, a hydroxymethylfuranyl group, an optionally substituted benzyl group or an optionally substituted aryl group. It is.

In the specific Schiff base-containing vinyl structural unit, R ³ is a hydroxy group, a methoxy group, an ethoxy group, an isopropyl group, and —OC (═O) R ⁴ (where R ⁴ is an alkyl group having 1 to 4 carbon atoms) Or a hydroxy group, a methoxy group, an ethoxy group, an isopropyl group, and —OC (═O) R ⁴ (wherein R ⁴ has 1 to 4 carbon atoms) It is preferably an alkyl group which is a benzyl group substituted by at least one of the following.

  Specific examples of the specific Schiff base-containing vinyl-based structural unit include those represented by the following formula (1-1) to the following formula (1-22).

  As will be described later, the specific Schiff base-containing vinyl-based structural unit is a polymerizable monomer represented by the general formula (2) (hereinafter also referred to as “specific Schiff base-containing vinyl-based monomer”). Is introduced into a specific vinyl polymer by performing a polymerization reaction, particularly a radical polymerization reaction.

This specific Schiff base-containing vinyl monomer is, for example, vanillin, homovanillin, ethyl vanillin, shilling aldehyde, anisaldehyde, verator obtained by decomposition of lignin contained in a large amount in wood, which is a non-edible plant. Aromatic aldehyde compounds such as aldehyde (3,4-dimethoxybenzaldehyde), cuminaldehyde, furfural and 5-hydroxymethylfurfural can be used as starting materials.
Specifically, (1) the Schiff base is formed with an aromatic aldehyde compound and allylamine or 2-methylallylamine, or (2) the Schiff is formed with an aromatic aldehyde compound and aminoalkyl (meth) acrylate. A Schiff base-containing vinyl derivative is synthesized by forming a base.

  Specific examples of the Schiff base-containing vinyl derivative to be a specific Schiff base-containing vinyl-based structural unit include those represented by the following formula (2-1) to the following formula (2-22). be able to.

When the obtained Schiff base-containing vinyl derivative does not have a hydroxy group as a substituent, it can be used as a specific Schiff base-containing vinyl monomer as it is.
When the obtained Schiff base-containing vinyl derivative has a hydroxy group as a substituent, the hydroxy group is represented by (A) R ⁶ —COOH (R ⁶ is an alkyl group having 1 to 3 carbon atoms). -OCOR ⁶ by carrying out an esterification reaction with a carboxylic acid or carboxylic acid anhydride, and (B) a methoxy group by reacting in the presence of sulfuric acid and p-toluenesulfonic acid and methanol. It can be used as a specific Schiff base-containing vinyl monomer.
Further, when the obtained Schiff base-containing vinyl derivative has a C2-C4 alcohol group as a substituent, the alcohol group is converted to sulfuric acid, p-toluenesulfonic acid, and methanol in the same manner as in (B) above. It can be used as a specific Schiff base-containing vinyl-based monomer by reacting in the presence of a C2-C4 alkoxy group.

  The specific vinyl polymer may be a monopolymer having only a specific Schiff base-containing vinyl structural unit, or a structural unit derived from a specific Schiff base-containing vinyl structural unit and other polymerizable monomers. (Hereinafter, also referred to as “specific vinyl copolymer”), the specific vinyl polymer is preferably made of a specific vinyl copolymer.

  Examples of other polymerizable monomers that can form a specific vinyl copolymer include, for example, (meth) acrylic acid ester monomers, styrene monomers, and polymerizable monomers having an ionic dissociation group. Examples thereof include 4-mer, 4-acetoxystyrene, 3-methoxy-4-acetoxystyrene, methylisoeugenol, methyleugenol, 4-acetoxyisoeugenol, and 4-acetoxyeugenol.

  Specific examples of the (meth) acrylate monomer include methyl acrylate, ethyl acrylate, n-butyl acrylate, isopropyl acrylate, isobutyl acrylate, t-butyl acrylate, n-octyl acrylate, Acrylic acid ester derivatives such as 2-ethylhexyl acrylate, cyclohexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate; methyl methacrylate, ethyl methacrylate, n methacrylate -Butyl, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, stearyl methacrylate, meta Lauryl acrylic acid, phenyl methacrylate, dimethylaminoethyl methacrylate, and the like methacrylic acid ester derivatives such as diethylaminoethyl methacrylate is. Of these, n-butyl acrylate and 2-ethylhexyl acrylate are preferably used. These can be used individually by 1 type or in combination of 2 or more types.

  Specific examples of the styrene monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, Examples thereof include styrene and styrene derivatives such as p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, and pn-dodecylstyrene. . Of these, styrene is preferably used. These can be used individually by 1 type or in combination of 2 or more types.

  The ionic dissociation group refers to, for example, a substituent such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group. Specific examples of the polymerizable monomer having an ionic dissociation group include acrylic acid, methacrylic acid, and maleic acid. , Itaconic acid, fumaric acid, styrene sulfonic acid, acrylamidopropyl sulfonic acid and the like. Of these, acrylic acid and methacrylic acid are preferably used. These can be used individually by 1 type or in combination of 2 or more types.

The content (copolymerization ratio) of the specific Schiff base-containing vinyl-based structural unit in the specific vinyl-based copolymer is preferably 35 to 70% by mass.
Moreover, it is preferable that content (copolymerization ratio) of the structural unit derived from the polymerizable monomer which has an ionic dissociation group in this specific vinyl-type copolymer is 2-7 mass%.
When the content of the specific Schiff base-containing vinyl-based structural unit in the specific vinyl-based copolymer is too small, the initial image density may be lowered. Further, when the content of the specific Schiff base-containing vinyl structural unit in the specific vinyl copolymer is excessive, there is a possibility that the uniformity of the halftone image is lowered.

  The specific vinyl copolymer has, in particular, a specific Schiff base-containing vinyl structural unit, a structural unit derived from a (meth) acrylic acid ester monomer, and a structural unit derived from a styrene monomer. It is preferable to use a copolymer.

  The specific vinyl polymer constituting the toner of the present invention has a peak molecular weight of 3,500 to 20,000 obtained from a molecular weight distribution based on a styrene equivalent molecular weight measured by gel permeation chromatography (GPC). Preferably, it is 10,000 to 20,000. Here, the peak molecular weight refers to the molecular weight corresponding to the elution time of the peak top in the molecular weight distribution. When there are a plurality of peak tops in the molecular weight distribution, the molecular weight corresponds to the elution time of the peak top having the largest peak area ratio.

  The peak molecular weight of the specific vinyl polymer constituting the toner of the present invention is measured by gel permeation chromatography (GPC). Specifically, using an apparatus “HLC-8220” (manufactured by Tosoh Corporation) and a column “TSKguardcolumn + TSKgelSuperHZ-M3 series” (manufactured by Tosoh Corporation), while maintaining the column temperature at 40 ° C., tetrahydrofuran (THF) was used as a carrier solvent. Flow at a flow rate of 0.2 ml / min, and dissolve the measurement sample (specific vinyl polymer) in tetrahydrofuran to a concentration of 1 mg / ml under a dissolution condition in which treatment is performed for 5 minutes using an ultrasonic disperser at room temperature. Next, a sample solution is obtained by processing with a membrane filter having a pore size of 0.2 μm, and 10 μL of this sample solution is injected into the apparatus together with the above carrier solvent, and is detected using a refractive index detector (RI detector) and measured. Calibration by measuring the molecular weight distribution of a sample using monodisperse polystyrene standard particles Calculated using a line. Ten polystyrenes were used for calibration curve measurement.

The binder resin constituting the toner of the present invention may be composed of only a specific vinyl polymer, or may be a mixture of a specific vinyl polymer and another resin. It is preferable that content of the specific Schiff base containing vinyl-type structural unit in resin is 25-100 mass%, More preferably, it is 30-77 mass%.
When the content of the specific Schiff base-containing vinyl structural unit in the binder resin is too small, there is a possibility that the environmental load cannot be suppressed sufficiently low. Further, when the content of the specific Schiff base-containing vinyl structural unit in the binder resin is excessive, there is a possibility that the uniformity of the halftone image is lowered.
Control of the content of the specific Schiff base-containing vinyl structural unit in the binder resin is achieved by adjusting the content (copolymerization ratio) of the specific Schiff base-containing vinyl structural unit in the specific vinyl polymer. It can be carried out by adjusting the content of a specific vinyl polymer in the resin and by adjusting the combination thereof, but the specific Schiff base-containing vinyl structure in the specific vinyl polymer It is preferable to carry out by adjusting the unit content (copolymerization ratio).

  The content mass ratio of the specific vinyl polymer and other resin in the binder resin is preferably 77:23 to 30:70 with the specific vinyl polymer: other resin.

  The binder resin constituting the toner of the present invention preferably has a glass transition point of 35 to 70 ° C, more preferably 45 to 55 ° C. Moreover, it is preferable that a softening point is 80-110 degreeC, More preferably, it is 90-105 degreeC.

The glass transition point of the binder resin constituting the toner of the present invention can be determined using “Diamond DSC” (Perkin Elmer).
As a measurement procedure, 3.0 mg of binder resin is sealed in an aluminum pan and set in a holder. The reference used an empty aluminum pan. The measurement conditions were a measurement temperature of 0 ° C. to 200 ° C., a temperature increase rate of 10 ° C./min, a temperature decrease rate of 10 ° C./min, and heat-cool-heat temperature control. Analysis was performed based on the data in Heat. The glass transition temperature draws an extension of the baseline before the rise of the first endothermic peak and a tangent line indicating the maximum slope between the rise of the first peak and the peak apex, and the intersection is taken as the glass transition point. Show. 1st. The heat was raised at 200 ° C. for 5 minutes.

Further, the softening point of the binder resin constituting the toner of the present invention is measured as follows.
First, in an environment of 20 ° C. and 50% RH, 1.1 g of a binder resin was placed in a petri dish, leveled, and allowed to stand for 12 hours or more, and then 3820 kg / day using a molding machine “SSP-10A” (manufactured by Shimadzu Corporation). Pressurize with a force of cm ² for 30 seconds to prepare a cylindrical molded sample having a diameter of 1 cm. Then, this molded sample is subjected to a flow tester “CFT-500D” (Shimadzu Corporation) in an environment of 24 ° C. and 50% RH. Manufactured by using a piston with a diameter of 1 cm from a hole (1 mm diameter × 1 mm) of a cylindrical die under the conditions of a load of 196 N (20 kgf), a starting temperature of 60 ° C., a preheating time of 300 seconds, and a heating rate of 6 ° C./min. Then, the offset method temperature T _{offset, which} is extruded from the end of preheating and measured with the setting of the offset value of 5 mm by the melting temperature measurement method of the temperature rising method, is set as the softening point of the binder resin.

[Colorant]
When the toner particles according to the present invention are configured to contain a colorant, generally known dyes and pigments can be used as the colorant.
Examples of the colorant for obtaining a black toner include carbon black, magnetic material, and iron / titanium composite oxide black. Examples of the carbon black include channel black, furnace black, acetylene black, thermal black, and lamp black. Can be mentioned. Examples of the magnetic material include ferrite and magnetite.
Examples of the colorant for obtaining a yellow toner include C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, etc .; C.I. I. Pigment yellow 14, 17, 74, 93, 94, 138, 155, 180, 185, and the like.
Examples of the colorant for obtaining a magenta toner include C.I. I. Dyes such as Solvent Red 1, 49, 52, 58, 63, 111, 122; I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 122, 139, 144, 149, 166, 177, 178, 222, and the like.
Examples of the colorant for obtaining cyan toner include C.I. I. Dyes such as Solvent Blue 25, 36, 60, 70, 93, 95; I. Pigment Blue 1, 7, 15, 15, 60, 62, 66, 76, and the like.
The colorant for obtaining the toner of each color can be used alone or in combination of two or more for each color.

  The content ratio of the colorant is preferably 0.5 to 20% by mass in the toner particles, and more preferably 2 to 10% by mass.

[Magnetic powder]
In the case where the toner particles according to the present invention are configured to contain magnetic powder, for example, magnetite, γ-hematite, or various ferrites can be used as the magnetic powder.
The content ratio of the magnetic powder is preferably 10 to 500% by mass in the toner particles, and more preferably 20 to 200% by mass.

〔Release agent〕
In the case where the toner particles according to the present invention are configured to contain a release agent, the release agent is not particularly limited, and various known waxes can be used. Examples of the wax include low molecular weight polypropylene, polyethylene, or oxidized low molecular weight polypropylene, polyolefin such as polyethylene, paraffin, synthetic ester wax, and the like. In particular, a synthetic ester wax is used because of its low melting point and low viscosity. It is particularly preferable to use behenyl behenate, glycerine tribehenate, pentaerythritol tetrabehenate or the like as the synthetic ester wax.
The content of the releasing agent is preferably 1 to 30% by mass in the toner particles, and more preferably 3 to 15% by mass.

[Charge control agent]
In the case where the toner particles according to the present invention are configured to contain a charge control agent, the charge control agent is a substance that can be positively or negatively charged by frictional charging and is colorless. Any known positively chargeable charge control agent and negatively chargeable charge control agent can be used.
The content ratio of the charge control agent is preferably 0.01 to 30% by mass in the toner particles, and more preferably 0.1 to 10% by mass.

In the toner as described above, the content of the specific Schiff base-containing vinyl structural unit in the toner particles is preferably 27 to 58% by mass, more preferably 30 to 55% by mass.
When the content of the specific Schiff base-containing vinyl-based structural unit in the toner particles is 27% by mass or more, the environmental load can be suppressed low.

[Average toner particle size]
The average particle size of the toner is preferably 4 to 10 μm, and more preferably 6 to 9 μm, for example, on a volume basis median diameter.
When the volume-based median diameter is in the above range, the transfer efficiency is increased, the image quality of halftone is improved, and the image quality of fine lines and dots is improved.

The volume-based median diameter of the toner is a computer system (manufactured by Beckman Coulter) equipped with data processing software “Software V3.51” connected to “Coulter Multisizer TA-III” (manufactured by Beckman Coulter). It is measured and calculated using a measuring device.
Specifically, 0.02 g of toner is added to 20 mL of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing toner particles). Then, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion, and this toner dispersion is placed in a beaker containing “ISOTON II” (manufactured by Beckman Coulter) in a sample stand. Pipet until the indicated concentration is 8%.
Here, a reproducible measurement value can be obtained by setting the concentration range. In the measuring apparatus, the measurement particle count is 25000, the aperture diameter is 50 μm, the frequency value is calculated by dividing the measurement range of 1 to 30 μm into 256, and the volume integrated fraction is 50 % Particle diameter is defined as the volume-based median diameter.

[Average circularity of toner]
The toner of the present invention preferably has an average circularity of 0.950 to 0.980 for the individual toner particles constituting the toner from the viewpoint of improving transfer efficiency.
The average circularity of the toner is a value measured using “FPIA-2100” (manufactured by Sysmex). Specifically, the toner is blended with an aqueous solution containing a surfactant, and subjected to ultrasonic dispersion treatment for 1 minute to disperse, and then measurement conditions HPF (high magnification imaging) are performed according to “FPIA-2100” (manufactured by Sysmex). ) Mode, photographing at an appropriate density of 3,000 to 10,000 HPF detections, calculating the circularity according to the following formula (T) for each toner particle, and adding the circularity of each toner particle , A value calculated by dividing by the total number of toner particles. If the number of HPF detections is in the above range, reproducibility can be obtained.
Formula (T): Circularity = (perimeter of a circle having the same projection area as the particle image) / (perimeter of the particle projection image)

  According to the toner as described above, a specific vinyl polymer is contained in the toner particles, and the specific vinyl polymer can be obtained from plant-derived raw materials. Can do.

In addition, according to the toner as described above, since the binder resin constituting the toner particles contains a specific Schiff base-containing vinyl-based structural unit, high charge stability is obtained, transferability is excellent, and a large amount of printing is performed. The image stability is excellent.
This is because, by including a specific Schiff base-containing vinyl-based structural unit in the binder resin that constitutes the toner particles, the toner charge rise time is shortened. It is presumed that this can be suppressed.

Further, according to the toner as described above, the binder resin constituting the toner particles contains a specific Schiff base-containing vinyl-based structural unit, and thus has excellent crease fixability.
This is because a toner using a conventional styrene-acrylic resin as a binder resin is mainly composed of styrene having a relatively strong hydrophobic property, and therefore has a structural unit derived from styrene in the resin and a hydrophilic group on the surface. Adhesive strength with the image support (paper) possessed cannot be sufficiently obtained, but in the toner using the binder resin containing the specific Schiff base-containing vinyl structural unit as described above, the specific Schiff base-containing vinyl system is used. High bond strength is obtained by the formation of hydrogen bonds between the ester bond or alkoxy group in the structural unit and the hydroxy group present on the surface of the image support (paper), resulting in excellent crease fixation. It is presumed that sex can be obtained.

[Toner Production Method]
The method for producing the toner of the present invention is not particularly limited, and examples thereof include a kneading / pulverization method, a suspension polymerization method, an emulsion aggregation method, an emulsion polymerization aggregation method, a miniemulsion polymerization aggregation method, and other known methods. In particular, from the viewpoint of reducing energy costs during production, by carrying out emulsion polymerization or miniemulsion polymerization using a specific Schiff base-containing vinyl monomer in an aqueous medium, a specific Schiff base-containing vinyl system can be obtained. Fine particles made of a binder resin containing a vinyl polymer having a structural unit (hereinafter, also referred to as “binder resin fine particles”) are prepared, and the binder resin fine particles are added to other toner particle constituents as necessary. It is preferable to use an emulsion polymerization aggregation method in which the fine particles are aggregated and fused together. Further, a method for producing a toner by a suspension polymerization method disclosed in JP 2010-191043 A can be preferably employed.

  In the emulsion polymerization aggregation method, the binder resin fine particles may be composed of two or more layers of binder resins having different compositions. In this case, the binder resin fine particles are prepared by an emulsion polymerization process (first-stage polymerization) according to a conventional method. A multi-stage polymerization method in which a polymerization initiator and a polymerizable monomer are added to the dispersion of the first resin fine particles and the system is polymerized (second-stage polymerization) can be employed.

Specifically showing an example of the production process when the toner of the present invention is obtained by an emulsion polymerization aggregation method,
(1A) a binder resin fine particle polymerization step for obtaining binder resin fine particles by allowing a radical polymerization initiator to act on a polymerizable monomer that should form a binder resin in an aqueous medium;
(1B) A colorant fine particle dispersion preparation step for preparing a dispersion of fine particles by colorant (hereinafter also referred to as “colorant fine particles”), if necessary,
(2) an associating step in which an aggregating agent is added to the aqueous medium in which the binder resin fine particles and the colorant fine particles are present, and salting-out proceeds, and at the same time, aggregation and fusion are performed to form associated particles;
(3) an aging step for forming toner by controlling the shape of the associated particles;
(4) A filtration and washing process for separating the toner particles from the aqueous medium and removing the surfactant from the toner particles.
(5) a drying step of drying the washed toner particles;
(6) An external additive adding step of adding an external additive to the dried toner particles.

  Here, the “aqueous medium” refers to a medium composed of 50 to 100% by mass of water and 0 to 50% by mass of a water-soluble organic solvent. Examples of water-soluble organic solvents include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran, and alcohol-based organic solvents that do not dissolve the resulting resin such as methanol, ethanol, isopropanol, and butanol should be used. Is preferred.

As a method for incorporating a release agent in the toner particles, a method in which the binder resin fine particles are configured to contain a release agent, or in the association step for forming the toner particles, the fine particles of the release agent are contained in the aqueous medium. Examples thereof include a method in which a dispersion liquid obtained by dispersion is added and the binder resin fine particles, the colorant fine particles, and the release agent fine particles are salted out, aggregated, and fused, and these methods may be combined.
Examples of the method of incorporating the charge control agent in the toner particles include the same method as the method of incorporating the release agent described above.

(1A) Binder Resin Fine Particle Polymerization Step Specifically, the binder resin fine particle polymerization step includes, for example, a specific Schiff base-containing vinyl monomer in an aqueous medium and other desired polymerizability as required. The monomer is added and dispersed by applying mechanical energy to form oil droplets. In this state, the polymerizable monomer is subjected to radical polymerization reaction, so that the size is, for example, a volume-based median diameter. The binder resin fine particles made of a specific vinyl polymer having a thickness of about 50 to 300 nm are formed.

  The dispersing device for imparting mechanical energy for forming oil droplets is not particularly limited. For example, a commercially-available stirring device “CLEARMIX” (M (Technique, Inc.) is a typical example. In addition to the above-described stirring device provided with a rotor capable of rotating at high speed, devices such as an ultrasonic dispersion device, a mechanical homogenizer, a manton gourin, and a pressure homogenizer can be used.

  Although the temperature which concerns on radical polymerization reaction changes also with the kind of the polymerizable monomer and radical polymerization initiator to be used, it is preferable that it is 50-100 degreeC, for example, More preferably, it is 55-90 degreeC. The time required for the radical polymerization reaction varies depending on the kind of the polymerizable monomer used and the reaction rate of the radical from the radical polymerization initiator, but is preferably 2 to 12 hours, for example.

(Dispersion stabilizer)
In the binder resin fine particle polymerization step, an appropriate dispersion stabilizer can be added in order to stably disperse the fine particles in the aqueous medium.
Examples of the dispersion stabilizer include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, sulfuric acid. Examples include barium, bentonite, silica, and alumina. In addition, polyvinyl alcohol, gelatin, methylcellulose, sodium dodecylbenzenesulfonate, ethylene oxide adducts, higher alcohol sodium sulfate and the like which are generally used as surfactants can also be used as the dispersion stabilizer.
As such a surfactant, conventionally known various ionic surfactants, nonionic surfactants, and the like can be used.
Examples of ionic surfactants include sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6-sulfonate Sulfonates such as sodium ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sulfonate; There are sodium sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc., and fatty acid salts include sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, stearin And the like fatty acid salts; potassium, sulfuric acid ester salts such as calcium oleate.
Examples of nonionic surfactants include polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, esters of polyethylene glycol and higher fatty acids, alkylphenol polyethylene oxide, esters of higher fatty acids and polyethylene glycol, higher fatty acids and polypropylene. Examples include oxide esters and sorbitan esters.

(Polymerization initiator)
Examples of the polymerization initiator used in the polymerization relating to the specific Schiff base-containing vinyl monomer in the binder resin fine particle polymerization step include water-soluble polymerization initiators such as potassium persulfate, ammonium persulfate, and azobiscyanovaleric acid, Water-soluble redox polymerization initiators such as hydrogen oxide-ascorbic acid, and oil-soluble polymerization initiators such as azobisisobutyronitrile and azobisvaleronitrile can be used.

[Chain transfer agent]
In the binder resin fine particle polymerization step, a generally used chain transfer agent can be used for the purpose of adjusting the molecular weight of the specific vinyl polymer or binder resin. The chain transfer agent is not particularly limited, and examples thereof include n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, and tetrachloromethane.

(1B) Colorant fine particle dispersion preparation step This colorant fine particle dispersion preparation step is a step that is performed as necessary when toner particles containing a colorant are desired, and the colorant is contained in an aqueous medium. Is a step of preparing a dispersion liquid of colorant fine particles by dispersing in a fine particle form.

The colorant can be dispersed using mechanical energy.
The colorant fine particles preferably have a volume-based median diameter of 10 to 300 nm in a dispersed state, more preferably 100 to 200 nm, and particularly preferably 100 to 150 nm.
The volume-based median diameter of the colorant fine particles is measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.).

About (2) association process-(6) external additive addition process, it can carry out according to a conventionally well-known various method.

[Flocculant]
The flocculant used in the association step is not particularly limited, but one selected from metal salts is preferably used. Examples of the metal salt include monovalent metal salts such as alkali metal salts such as sodium, potassium and lithium; divalent metal salts such as calcium, magnesium, manganese and copper; and trivalent metal salts such as iron and aluminum. Etc. Specific metal salts can include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, and the like. It is particularly preferable to use a divalent metal salt. These can be used individually by 1 type or in combination of 2 or more types.

(External additive)
The above toner particles can constitute the toner of the present invention as they are, but in order to improve fluidity, chargeability, cleaning properties, etc., a fluidizing agent that is a so-called post-treatment agent is added to the toner particles. An external additive such as a cleaning aid may be added to constitute the toner of the present invention.

Examples of the external additive include inorganic oxide fine particles composed of silica fine particles, alumina fine particles, titanium oxide fine particles, inorganic stearate compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, strontium titanate, titanium, and the like. Inorganic titanic acid compound fine particles such as zinc acid are listed. These can be used individually by 1 type or in combination of 2 or more types.
These inorganic fine particles are preferably subjected to surface treatment with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil or the like in order to improve heat-resistant storage stability and environmental stability.
The total amount of these various external additives added is 0.05 to 5 parts by mass, preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the toner. In addition, various external additives may be used in combination.

(Developer)
The toner of the present invention can be used as a magnetic or non-magnetic one-component developer, but may be mixed with a carrier and used as a two-component developer.
When toner is used as a two-component developer, the mixing amount of the toner with respect to the carrier is preferably 2 to 10% by mass.
A mixing device for mixing the toner and the carrier is not particularly limited, and examples thereof include a Nauter mixer, a W cone, and a V-type mixer.
As the carrier, magnetic particles made of conventionally known materials such as metals such as iron, ferrite and magnetite and alloys of these metals with metals such as aluminum and lead can be used, and ferrite particles are particularly preferable.
Further, as the carrier, a coat carrier in which the surface of magnetic particles is coated with a coating agent such as a resin, a binder type carrier in which magnetic fine powder is dispersed in a binder resin, or the like may be used.
The coating resin constituting the coat carrier is not particularly limited, and examples thereof include olefin resins, styrene resins, styrene-acrylic resins, silicone resins, ester resins, and fluorine resins. Moreover, it does not specifically limit as resin which comprises a resin dispersion type carrier, A well-known thing can be used, For example, a styrene-acrylic-type resin, a polyester resin, a fluororesin, a phenol resin etc. can be used.

  The volume-based median diameter of the carrier is preferably 20 to 100 μm, and more preferably 20 to 60 μm. The volume-based median diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

(Image forming method)
The toner of the present invention can be suitably used in an image forming method including a fixing step by a heat and pressure fixing method capable of applying pressure and heating. Particularly, it is suitable for an image forming method in which fixing is performed at a relatively low fixing temperature in which the fixing temperature in the fixing step is 80 to 110 ° C., preferably 80 to 95 ° C. at the surface temperature of the heating member in the fixing nip portion. Can be used for
Furthermore, it can be suitably used for a high-speed fixing image forming method in which the fixing linear speed is 200 to 600 mm / sec.
In this image forming method, specifically, the toner as described above is used, for example, an electrostatic latent image formed on a photoreceptor is developed to obtain a toner image, and this toner image is used as an image support. Then, the toner image transferred onto the image support is fixed by a fixing process using a thermal pressure fixing method, whereby a printed matter on which a visible image is formed is obtained.

(Image support)
Specific examples of the image support used in the image forming method using the toner of the present invention include, for example, coated paper such as plain paper, fine paper, art paper or coated paper from thin paper to thick paper. Various types of printing paper such as commercially available Japanese paper and postcard paper can be used, but the invention is not limited to these.

  As mentioned above, although embodiment of this invention was described concretely, embodiment of this invention is not limited to said example, A various change can be added.

  Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto.

<Synthesis example 1 of Schiff base-containing vinyl monomer>
In a four-headed flask equipped with a condenser, a stirrer, a thermometer and a dropping funnel, 600 mL of ethanol, aldehyde raw material: 152.15 g (1.0 mol) of vanillin and 1.90 g (0.01 mol) of p-toluenesulfonic acid are placed. While stirring at room temperature, 74.68 g (1.05 mol) of amine raw material: 2-methylallylamine was added dropwise over 30 minutes. After further stirring for 6 hours, the inside of the flask was heated to 50 ° C. and reacted for 3 hours. Thereafter, ethanol was removed using an evaporator, and further distillation under reduced pressure was performed to obtain a Schiff base-containing vinyl monomer [1] composed of the compound represented by the above formula (2-1).

<Synthetic Examples 2 to 9 of Schiff Base-Containing Vinyl Monomer>
In Synthesis Example 1, 1.05 mol described in Table 1 was used as an amine raw material, and 1.0 mol described in Table 1 was used instead of vanillin as an aldehyde raw material. The Schiff base-containing vinyl monomers [2] to [9] comprising the compounds represented by the above formulas (2-2) to (2-9) were obtained.

<Synthesis example 10 of Schiff base-containing vinyl monomer>
In a four-headed flask equipped with a condenser, a stirrer, a thermometer and a dropping funnel, 600 mL of toluene, aldehyde raw material: 96.09 g (1.0 mol) of 5-hydroxymethylfurfural and 1.90 g of p-toluenesulfonic acid (0.8. 01 mol) was added, and 74.68 g (1.05 mol) of amine raw material: 2-methylallylamine was added dropwise over 30 minutes while stirring at 60 ° C. After further stirring for 6 hours, the inside of the flask was heated to 80 ° C. and reacted for 3 hours. Thereafter, 94.53 mL (1.0 mol) of acetic anhydride and 14.17 g (0.14 mol) of triethylamine were added, the internal temperature was set to 110 ° C., and the mixture was heated and stirred for 3 hours. Thereafter, the toluene was removed using an evaporator. Further, by performing distillation under reduced pressure, a Schiff base-containing vinyl monomer [10] composed of the compound represented by the above formula (2-10) was obtained.

<Synthesis example 11 of Schiff base-containing vinyl monomer>
In a four-head flask equipped with a condenser, a stirrer, a thermometer and a dropping funnel, ethanol 600 mL, aldehyde raw material: 152.15 g (1.0 mol) aldehyde raw material: amine raw material: 120.90 g (1.05 mol) aminomethyl methacrylate, and After adding 0.95 g (0.005 mol) of p-toluenesulfonic acid and stirring at room temperature for 6 hours, the flask was heated to 50 ° C. and reacted for 3 hours. Thereafter, ethanol was removed using an evaporator and further distilled under reduced pressure to obtain a Schiff base-containing vinyl monomer [11] composed of the compound represented by the above formula (2-11).

<Synthesis examples 12 to 19 of Schiff base-containing vinyl monomers>
In Synthesis Example 1, 1.05 mol described in Table 1 was used as an amine raw material, and 1.0 mol described in Table 1 was used instead of vanillin as an aldehyde raw material. The Schiff base-containing vinyl monomers [12] to [19] comprising the compounds represented by the above formulas (2-12) to (2-19) were obtained.

<Synthesis example 20 of Schiff base-containing vinyl monomer>
In a four-headed flask equipped with a condenser, a stirrer, a thermometer and a dropping funnel, 600 mL of toluene, aldehyde raw material: 96.09 g (1.0 mol) of 5-hydroxymethylfurfural, amine raw material: 74.68 g of aminoethyl methacrylate (1 0.05 mol) and 0.95 g (0.005 mol) of p-toluenesulfonic acid were added dropwise with stirring at 60 ° C. over 30 minutes. After further stirring for 6 hours, the inside of the flask was heated to 80 ° C. and reacted for 3 hours. Thereafter, 94.53 mL (1.0 mol) of acetic anhydride and 14.17 g (0.14 mol) of triethylamine were added, the internal temperature was set to 110 ° C., and the mixture was heated and stirred for 3 hours. Thereafter, the toluene was removed using an evaporator. Furthermore, by performing distillation under reduced pressure, a Schiff base-containing vinyl monomer [20] composed of the compound represented by the above formula (2-20) was obtained.

<Synthesis example 21 of Schiff base-containing vinyl monomer>
The above Schiff base-containing vinyl monomer [1] is reacted with an equimolar amount of acetic anhydride in xylene at 130 ° C. for 3 hours to contain a Schiff base comprising the compound represented by the above formula (2-21). A vinyl monomer [21] was obtained.

<Synthesis example 22 of Schiff base-containing vinyl monomer>
The above Schiff base-containing vinyl monomer [11] is reacted with an equimolar amount of acetic anhydride in xylene at 130 ° C. for 3 hours to contain a Schiff base comprising the compound represented by the above formula (2-22). A vinyl monomer [22] was obtained.

<Polymerization Example 1 of Vinyl Polymer>
To the above Schiff base-containing vinyl monomer [1] 724.71 g, n-butyl acrylate (BA) 295.87 g and methacrylic acid (MAA) 38.66 g, behenyl behenate 115.85 g was added and dissolved by heating. As a result, a monomer solution was obtained. Further, an aqueous solution in which 1.93 g of sodium dodecyl sulfate was dissolved in 3336.8 g of pure water was heated to 80 ° C., the above monomer solution was added, and a monomer emulsion was prepared by performing high-speed stirring.
The above monomer emulsion was added to a polymerization tank equipped with a stirrer, a cooling pipe, a nitrogen introduction pipe, and a thermometer, and nitrogen was allowed to flow while stirring to maintain the internal temperature of the polymerization tank at 80 ° C. In this state, a polymerization initiator solution in which 9.92 g of potassium persulfate was dissolved in 188.5 g of pure water was added, and 8.84 g of n-octyl mercaptan was divided into 10 portions while stirring under a nitrogen stream, and divided over 1 hour. Added. The polymerization reaction was carried out at 80 ° C. for 6 hours as it was, followed by cooling to room temperature and filtering the contents to obtain latex [1] in which binder resin fine particles were dispersed.
The binder resin fine particles in the latex [1] contained a structural unit represented by the above formula (1-1).

<Polymerization Examples 2-22 of Vinyl Polymer>
In Polymerization Example 1 of the vinyl polymer, the Schiff base-containing vinyl monomer shown in Table 1 was used in place of the Schiff base-containing vinyl monomer [1], and the copolymerization monomer was used according to the formulation in Table 1. Latex [2] to [22] were obtained in the same manner except that it was used.
The binder resin fine particles in the latexes [2] to [22] contained structural units represented by the above formulas (1-2) to (2-22), respectively.

[Example 1: Toner Production Example 1]
First, a cyan pigment (Pigment Blue 15: 3) was stirred while stirring a solution obtained by dissolving 1.65 g of a surfactant “Dowfax (registered trademark) 2A-1” (manufactured by Dow Chemical Co., Ltd.) in 31.25 g of pure water. A colorant fine particle dispersion [Cy] was prepared by gradually adding 4.7 g.
Next, latex [1] 316.48 g (solid content (binder resin fine particle content) 79.1 g), colorant fine particle dispersion [Cy] 37.60 g, surfactant “Emar E-27C (active ingredient 27%) After mixing 0.24 g (manufactured by Kao) of surfactant solution in 4.9 g of pure water and 120.41 g of pure water, and adjusting pH to 10 with 0.5N aqueous sodium hydroxide solution. Then, the mixture was put into a reaction vessel equipped with a stirrer, a thermometer, and a cooling tube and stirred. Further, a magnesium chloride aqueous solution in which 20.9 g of magnesium chloride hexahydrate was dissolved in 13.64 g of pure water was slowly added dropwise with stirring. The internal temperature of the reaction vessel was raised to 85 ° C. while stirring as it was.
The temperature was kept at 85 ° C., the internal solution was sampled while stirring, the particle size was measured using “Coulter Multisizer 3”, and when the volume-based median diameter reached 6.50 μm, A sodium chloride aqueous solution in which 64.25 g of sodium chloride was dissolved in 256.99 g of pure water was added, and the mixture was further maintained at 85 ° C. with stirring. Particle size measurement and flow type particle image analyzer “FIPA-2100” (manufactured by Sysmex Corporation) The particle shape factor is measured while confirming that there is no fluctuation in the particle size, and when the shape factor reaches 0.965, it is cooled to room temperature, and the reaction solution is filtered and washed. After repeating, drying was performed to prepare toner particles [1X].
To the toner particles [1X], 1% by mass of hydrophobic silica (number average primary particle size = 12 nm) and 0.3% by mass of hydrophobic titania (number average primary particle size = 20 nm) are added and mixed by a Henschel mixer. By performing the external addition treatment, the toner [1] of the present invention was obtained.

Examples 2 to 22: Toner production examples 2 to 22
Toner [2] to [22] were obtained in the same manner as in Toner Production Example 1 except that latex [2] to [22] were used instead of latex [1], respectively.

[Developer Production Examples 1 to 22]
100 parts by mass of ferrite particles (volume-based median diameter: 50 μm (manufactured by Powdertech)) and 4 parts by mass of methyl methacrylate-cyclohexyl methacrylate copolymer resin (volume-based median diameter of primary particles: 85 nm) Put in a stirring blade type high speed stirring device, mix for 15 minutes under the conditions of peripheral speed of stirring blade: 8 m / s, temperature: 30 ° C., then raise the temperature to 120 ° C. and continue stirring for 4 hours, then cool, A resin-coated carrier was prepared by removing fragments of methyl methacrylate-cyclohexyl methacrylate copolymer resin using a 200-mesh sieve.
Developers [1] to [22] were prepared by mixing the resin-coated carrier with each of the toners [1] to [22] so that the toner concentration was 7% by mass.

The following evaluation was performed using the developer [1] to [22] sequentially loaded in the cyan developing device of a commercially available color multifunction peripheral “bizhub PRO C6500” (manufactured by Konica Minolta Business Technologies). It was. As the image support (evaluation paper), “CF paper (A4, 80 g / m ² )” (manufactured by Konica Minolta Business Solutions, Inc.) was used.

(1) Uniformity of halftone images In a high-temperature and high-humidity environment (temperature of 30 ° C. and humidity of 80% RH), 10,000 halftone images consisting of cyan dots on the entire surface are continuously printed in the printer mode. With respect to the halftone images obtained on the first and 10,000th sheets, the fineness was visually evaluated according to the following evaluation criteria. 〜 To △ are acceptable levels. The results are shown in Table 2.
-Evaluation criteria-
A: A fine and uniform halftone image is reproduced.
○: Although almost indistinguishable with the naked eye, the edges of the dots are slightly rough when observed with a magnifying glass.
(Triangle | delta): Although very slight nonuniformity with the naked eye, ie, image roughening has arisen, it is an acceptable range.
X: Roughness is felt with the naked eye and non-uniformity is visually recognized.

(2) Image density In a normal temperature and low humidity (temperature 20 ° C., humidity 20% RH) environment, continuously output 10,000 sheets of 5 cm square solid images adjusted so that the toner adhesion amount is constant. With respect to the solid image obtained on the 10,000th sheet, the image density was measured using a transmission densitometer “TD904” (manufactured by Macbeth), and this image density was evaluated. A case where the image density is 1.20 or more is regarded as a pass level. The results are shown in Table 2.

  In Table 1, the copolymerization ratio of the SV monomer is {(mass of specific Schiff base-containing vinyl monomer (SV monomer)) / (formation of specific vinyl polymer). The total amount of monomers used in the toner)} × 100, and the content of the SV structural unit in the toner is {(mass of specific Schiff base-containing vinyl monomer) / (condensation). It is calculated by the following equation: mass of resin to be deposited + mass of release agent (behenyl behenate) + mass of colorant)} × 100.

As is apparent from Tables 1 and 2, the toner of the present invention contains a binder resin having a specific Schiff base-containing vinyl-based structural unit, but it was confirmed that the toner can be used for image formation as a toner. In addition, it was confirmed that the toner of the present invention can obtain high image stability.

Claims (7)

An electrostatic image developing toner comprising toner particles containing a resin,
The toner for developing an electrostatic charge image, wherein the resin contains a vinyl polymer having a structural unit represented by the following general formula (1).

[Wherein, R ¹ is a hydrogen atom or a methyl group, and R ² is —C (═O) O— (CH ₂ ) _n — (where n is an integer of 1 to 4) or a methylene group. R ³ is a furanyl group, a hydroxymethylfuranyl group, an optionally substituted benzyl group or an optionally substituted aryl group. ] R ³ in the structural unit represented by the general formula (1) is a hydroxy group, a methoxy group, an ethoxy group, an isopropyl group, and —OC (═O) R ⁴ (wherein R ⁴ has 1 to 4 carbon atoms) 2. The toner for developing an electrostatic charge image according to claim 1, wherein the toner is a phenyl group or a benzyl group substituted by any one of an alkyl group.   Copolymer in which the vinyl polymer has a structural unit represented by the general formula (1), a structural unit derived from a (meth) acrylic acid ester monomer, and a structural unit derived from a styrene monomer. The electrostatic image developing toner according to claim 1, wherein the toner is a combined toner.   4. The electrostatic charge image developing according to claim 1, wherein the content of the structural unit represented by the general formula (1) in the resin is 35 to 70% by mass. 5. toner.   5. The electrostatic charge image development according to claim 1, wherein the content of the structural unit represented by the general formula (1) in the toner particles is 30 to 55% by mass. Toner. A method for producing the electrostatic image developing toner according to any one of claims 1 to 5,
A vinyl polymer having a structural unit represented by the general formula (1) according to claim 1 is obtained by using at least a polymerizable monomer represented by the following general formula (2) in an aqueous medium. A method for producing a toner for developing an electrostatic image, comprising a step of generating the toner.

[Wherein, R ¹ is a hydrogen atom or a methyl group, and R ² is —C (═O) O— (CH ₂ ) _n — (where n is an integer of 1 to 4) or a methylene group. R ³ is a furanyl group, a hydroxymethylfuranyl group, an optionally substituted benzyl group or an optionally substituted aryl group. ] 7. The method for producing a toner for developing an electrostatic image according to claim 6, wherein toner particles are formed by agglomerating resin fine particles made of the vinyl polymer in an aqueous medium.