JP6870322B2 - Toner for static charge image development - Google Patents

Description

The present invention relates to an electrostatic charge image developing toner having excellent low temperature fixability and blocking resistance.

Toner for static charge image development is used for image formation for visualizing static charge images in printers, copiers, facsimiles, and the like. Taking the formation of an image by the electrophotographic method as an example, an electrostatic latent image is first formed on a photoconductor drum, then developed with toner, transferred to a transfer paper or the like, and fixed by heat or the like. Image formation is performed.
As the toner for static charge image development, usually, a charge control agent, a mold release agent, a magnetic material, etc. are dry-mixed with a binder resin and a colorant, and then melt-kneaded with an extruder or the like, and then melt-kneaded. For the purpose of imparting various performances such as fluidity to toner particles obtained by the so-called melt-kneading pulverization method of pulverization and classification, for example, solid fine particles such as silica are attached to the surface as an external additive. The thing is used.

In recent years, high-definition image quality has been required for image formation in copiers and printers, and manufacturing methods such as suspension polymerization method, emulsion aggregation method, and dissolution suspension method, which make it easy to control the particle size and particle size distribution of toner particles, have been used. Proposed.
Furthermore, with the spread of copiers and printers in recent years, in addition to the demand for image quality, toners having particularly excellent high-speed printing and low-energy fixability have been desired, and the low-temperature fixability of toner has been improved. Although attempts have been made, the low temperature fixing property and the blocking resistance and the high temperature offset resistance are usually in a trade-off relationship, and it is desired to achieve both. Various studies have been made on these issues.

Patent Document 1 describes a toner containing a crystalline polyester resin and a mold release agent, and has a structure in which the crystalline polyester resin is in contact with the mold release agent on a ruthenium-dyed toner cross section. When the cross-sectional area of the body is A, the cross-sectional area of the release agent alone is B, and the cross-sectional area of the crystalline polyester resin alone is C, 40 ≦ 100 × A / (A + B + C) ≦ 70, 10 ≦ 100 × B / (A + B + C) ≦ 30, 20 ≦ 100 × C / (A + B + C) ≦ 30, a toner for static charge image development is disclosed.

Patent Document 2 contains a crystalline organic compound having a melting point of 50 to 150 ° C. as a fixing aid for the purpose of heat-resistant storage and low-temperature fixing, and the resin and the fixing aid are compatible with each other during heating. In the DSC measurement, the amount of heat absorption of the melting maximum value derived from the fixing aid at the second temperature rise is smaller than that at the first temperature rise, and the glass transition temperature of the toner is lower than the glass transition temperature of the resin, and the temperature rise 2 A toner for static charge image development has been proposed in which the glass transition temperature at the first time is lower than that at the first time.

Patent Document 3 has a core-shell structure having a toner mother particle and a shell layer, and the toner mother particle has a resin coating layer made of a water-soluble resin on the surface of the toner mother particle, and the resin coating layer. A toner for static charge image development having the shell layer is disclosed above.

Japanese Unexamined Patent Publication No. 2008-033057 Japanese Unexamined Patent Publication No. 2012-022331 Japanese Unexamined Patent Publication No. 2015-064573

An object to be solved by the present invention is to provide a toner for static charge image development that can achieve both low temperature fixability and blocking resistance.

The present inventor, as the most effective form for achieving both low temperature fixability and blocking resistance, is the difference between the second measurement value and the first measurement value of the temperature at which tan δ measured by the leometer reaches the maximum value. It was found that a form in which the ratio of the first measurement value of tan δ and the second measurement value of the tan δ maximum value to the first measurement value is adjusted to take a specific range is effective.

The present invention is based on the above findings, and the present invention is as follows.
<1>
The temperature at which tan δ is maximized at 40 ° C. or higher and 80 ° C. or lower in the first temperature rise measurement of the rheometer is defined as [T _1st ], and the temperature at which tan δ is maximized at 40 ° C. or higher and 80 ° C. or lower in the second temperature rise measurement is [T 1st]. when the _{T 2nd], [T 2nd]} - [T 1st] is at 1.0 ℃ more than 4.5 ℃ or less,
When the first measurement value observed at the maximum value of tanδ of 40 ° C. or higher and 80 ° C. or lower is [tanδ _1st ], [tanδ _1st ] is 1.15 or higher and 1.80 or lower.
When the second measured value observed at 40 ° C. or higher and 80 ° C. or lower is [tanδ _2nd ], the ratio [tanδ _2nd ] / [tanδ _1st ] is 1.50 or more and 2.20 or less. Toner for static charge image development.
<2>
The [T _2nd ]-[T _1st ] is 2.5 ° C. or higher and 4.5 ° C. or lower.
The [tan δ _1st ] is 1.15 or more and 1.80 or less.
The toner for developing an electrostatic charge image according to <1>, wherein the [tanδ _2nd ] / [tanδ _{1st] is 1.50 or more and 2.20 or less.}
<3>
The [T _2nd ]-[T _1st ] is 2.5 ° C. or higher and 4.5 ° C. or lower.
The [tan δ _1st ] is 1.15 or more and 1.80 or less.
The toner for developing an electrostatic charge image according to <1>, wherein the [tanδ _2nd ] / [tanδ _{1st] is 1.50 or more and 1.90 or less.}
<4>
The toner for static charge image development according to any one of <1> to <3>, which contains at least a binder resin and a colorant, and an external additive.
<5>
It contains at least an internal component containing a binder resin and a colorant, and an additional particle component existing around the internal component, and there is no shadow difference between the internal component and the additional particle component when measured with a transmission electron microscope. The toner for developing an electrostatic charge image according to <4>.
<6>
The toner for developing an electrostatic charge image according to any one of <1> to <5>, which has an average circularity of 0.95 to 0.99.
<7>
The toner for developing an electrostatic charge image according to any one of <1> to <6>, which has a volume average particle diameter of 5 to 8 μm.
<8>
The toner for developing an electrostatic charge image according to any one of <1> to <7>, which contains wax.

According to the present invention, it is possible to solve the above-mentioned problems and problems and provide a toner for static charge image development in which both low-temperature fixability and blocking resistance are compatible.

It is a schematic diagram of the graph of tan δ when the toner for developing an electrostatic charge image of this invention was measured with a rheometer. It is a schematic diagram of the cross section of the molded body when the toner for static charge image development of this invention is measured for the first time with a rheometer. It is an enlarged SEM image of one part of the static charge image developing toner produced in the examples of the present invention. The concave portion of the toner surface has few thinned additional particle components, and the convex portion has many of the components. It is a figure (photograph) which shows the present aspect.

1. 1. Measuring method and definition In the present invention, those before having an external additive are referred to as "toner mother particles". A toner having an external additive on the surface of the toner matrix particles is referred to as a "toner" or a "toner for developing an electrostatic charge image".

The toner of the present invention preferably contains "a toner matrix particle containing at least a binder resin and a colorant" and an "external additive", and further, "an internal component containing at least a binder resin and a colorant". It is particularly preferable that the component contains "component" and "additional particle component existing around the component".

In any of the methods for preparing toner matrix particles as described later, the additional particles (components) are those that are unevenly distributed on the surface of the toner matrix particles. The shape of the additional particles (components) when they become toner may be fine particles or thin films, and even if they continuously cover the internal components, they cover the internal components discontinuously. You may.

For example, FIG. 3 is an enlarged photograph of a part of one toner of the present invention. In the recess B on the surface of the toner mother particles, many black skins (the background of the internal component) are observed, and the toner mother particles Many thinned skins (additional particle components) without eaves are observed in the convex portion A on the surface.
The core-shell structure of the toner mother particles of the conventional toner is a structure in which the core is entirely covered by the shell or the core is partially covered by the shell regardless of the unevenness of the surface of the toner mother particles, and the shell is the core. It was a structure that covered the surface of the core as an independent skin (in which case the shell may look like a "scab").

When producing toner matrix particles in a wet medium (water-based and / or organic solvent is a continuous phase), additional particles are added almost at the same time as the internal component, and the interface between the internal component and the wet medium is controlled by polarity control or the like. There is a method of arranging the additional particles (components) in the above, and a method of adding the additional particles after the internal components and physically arranging the additional particles (components) on the surface of the internal components, and further, both of them. There is a method of arranging additional particles (components) by combining the methods.
When additional particles are added after the internal component, the shape, physical properties, compatibility, etc. of the internal component may change after the composition of the internal component is determined (subsequent heating, aging, stirring, etc.). , A method of adding additional particles can be mentioned.
The toner of the present invention has an aspect as produced by the above-mentioned production method.

Rheometer measurement of toner is performed according to the following procedure, and "rheometer measurement value" is defined as the measurement as follows. Further, the "first temperature rise" and the "second temperature rise" in the present invention are also defined as the temperature rise as follows.
The measurement is performed as follows using a rheometer ARES (measurement control software TA Orchestrator V7.2.0.2) manufactured by TA Instruments.

The toner for developing an electrostatic charge image of the present invention includes (shows) a toner having a numerical value (parameter) when measured by the measuring method described here with respect to the leometer measurement. "Toner pellet molding, temperature rise conditions, etc. during the first temperature rise measurement" that affect the result of the "second temperature rise measurement" are defined as follows in the first temperature rise measurement. ..
That is, the toner for developing an electrostatic charge image of the present invention is a toner having (showing) such a numerical value (parameter) when measured by the measuring method (device, setting, etc.) described in Examples and the like. is there.
That is, even when the numerical value (parameter) is measured by another device or other setting, the numerical value (parameter) is measured when the toner itself is measured by the measuring method described in the examples of the present specification. If it has (as shown), it is included in the present invention.

[Measurement of 8 mm cylindrical pellets]
Approximately 0.3 g of the sample was placed in a jig for 8 mm diameter and heated to 50 ° C. by a press machine (Kodaira Seisakusho 5 ton press PE-5Y) with a mold clamping force of 1.25 tons (gauge 25 kg / cm ² ). Pressurize for minutes and mold into pellets. In the present invention, this may be abbreviated as "molded body".
On the surface of the aluminum 8 mm disposable plate used for the measurement, 12 vertical and horizontal scratches are formed in a grid pattern, the width of the opening is 50 to 100 μm, and the depth is 1 to 10 μm (average 3 to 5 μm).

1st temperature rise measurement: The pellet (molded body) is set in a measuring device equipped with a circular parallel plate with an upper and lower diameter of 8 mm, and the upper plate is lowered while the temperature is raised to 40 ° C. to adjust the force'Force'to 200 g. After that, measure under the following conditions.

Jig compliance'Fixture compliance' 0
Plate inertia'Tool inertia' 0
Measurement frequency'Frequency' 6.28 rad / sec
Initial temperature'Initial Temp.' 40.0 ℃
Final temperature'Final Temp.' 120.0 ℃
Heating rate'Ramp Rate' 4.0 ℃ / min
Retention time after temperature rise'Soak Time After Ramp' 20s (seconds)
Measurement cycle time'Time Per Measure' 10s (seconds)
Distortion'Strain' 0.025%

Option'Option'
Retention time before measurement after reaching the initial temperature'Delay Before Test'Non-set automatic tension adjustment'Auto Tension Adjustment'
Auto Tension Adjustment'Auto Tension Adjustment'Settings Auto Tension Direction'Auto Tension Direction'Compression
Initial Force'Initial Static Force' 204.0g
Auto Tension Sensitivity'Auto Tension Sensitivity' 2.0g
Automatic tension switching'Switch Auto Tension to Programmed Extension'
Sample elastic modulus setting'When Sample Modulus'<3.00e + 05Pa
Maximum Auto Tension Rate'Max Auto Tension Rate' 0.01mm / s (mm per second)
Auto Strain Adjustment'Auto Strain Adjustment'
Auto Strain Adjustment'Auto Strain'Setting Maximum Strain'Max Applied Strain' 40.0%
Maximum Allowed Torque'Max Allowed Torque' 100.0gf ・ cm
Minimum allowable torque'Min Allowed Torque' 0.2gf ・ cm
Strain Adjustment'Strain Adjustment' 20.0%

Setting at the end of measurement'End of Test'
Temperature control off'Turn OFF Temp Controller' No
Temperature setting after measurement'Set End of Test Temp'Yes
Temperature after measurement'Set End of Test Temp to' 40.0 ℃
Motor off'Turn OFF Motor' No
Hold'Turn Hold ON' Yes

Second temperature rise measurement: When the temperature drops to 40 ° C, the measurement at the second temperature rise is performed under the same conditions as the first. However, the settings at the end of measurement are as follows. When the first measurement is completed, the air is automatically cooled, and when the temperature reaches 40 ° C., the pellet (molded body) is not taken out, and the measurement at the time of the second temperature rise is immediately started.

Setting at the end of measurement'End of Test'
Temperature control off'Turn OFF Temp Controller' No
Temperature setting after measurement'Set End of Test Temp'Yes
Temperature after measurement'Set End of Test Temp to' 120.0 ℃
Motor off'Turn OFF Motor' No
Hold'Turn Hold ON'No

[T _2nd ]-[T _1st ] is calculated as follows.
Tanδ (= G "/ G') is obtained from the storage elastic modulus (G') and the loss elastic modulus (G") obtained in the first temperature rise measurement.
_{As shown in FIG. 1, the temperature [T 1st} ] at which the tan δ of the first temperature rise measurement reaches the maximum value is obtained. _{Similarly, the temperature [T 2nd} ] at which the tan δ of the second temperature rise measurement reaches the maximum value is obtained. Using them, [T _2nd ]-[T _1st ] is obtained.

[Tanδ _1st ] and [tanδ _2nd ] / [tanδ _1st ] are obtained as follows.
The tan δ is obtained from G'and G ″ obtained in the first temperature rise measurement, and the maximum value [tan δ _1st ] observed at 40 ° C. or higher and 80 ° C. or lower is obtained as shown in FIG. 1. Similarly, the second temperature rise is obtained. _{The maximum value [tanδ 2nd} ] observed at 40 ° C. or higher and 80 ° C. or lower in the measurement is obtained. Using them, [tanδ _2nd ] / [tanδ _1st ] is obtained.

2. Regulations for Toner for Electrostatic Image Development 2.1. [T _1st ], [T _2nd ], [T _2nd ]-[T _1st ]
In the toner for static charge image development of the present invention, [T _1st ] and [T _2nd ] do not have the same value. This is considered to indicate that the structure of the toner was changed by the heating at the time of the first measurement, and the scope of the invention is not limited below, but the reason is presumed as follows. ing.
Although details will be described later, the toner of the present invention comprises "an internal component containing at least a binder resin and a colorant", additional particles existing around the internal component, and an external additive.
Since the measurement sample is molded into pellets without heating the toner as much as possible, the internal components and the "additional particles and the external additive" are maintained in a separated state even after molding.

_{[T 1st} ] obtained by measuring this molded product is a value that reflects the properties of the internal components existing as a large domain.
On the other hand, [T _2nd ] is a value that reflects the average composition of the entire toner because the internal component, the additional particle component, and the external additive are melt-mixed by heating at the time of the first measurement.

When [T _2nd ]-[T _1st ] is large, the difference in thermal characteristics between the internal component and the additional particle component is large, or the thermal characteristics of the "additional particle component or external additive" with respect to the internal component are affected. It is presumed that the contribution ratio or mass ratio is high.
When [T _2nd ]-[T _1st ] is small, the difference in thermal characteristics between the internal component and the additional particle component is small, or it affects the thermal characteristics of the "additional particle component or external additive" with respect to the internal component. It is presumed that the contribution ratio or mass ratio is low.

[T _2nd ]-[T _1st ] is 1.0 ° C. or higher, preferably 1.1 ° C. or higher, more preferably 1.8 ° C. or higher, and particularly preferably 2.5 ° C. or higher. ..
Further, [T _2nd ]-[T _1st ] is 4.5 ° C. or lower, preferably 4.3 ° C. or lower, and particularly preferably 4.0 ° C. or lower.
Within this range, the toner has a good balance between blocking resistance and low temperature fixability.
If [T _2nd ]-[T _1st ] is too small, the blocking resistance tends to be insufficient, and if [T _2nd ]-[T _1st ] is too large, the low temperature fixability tends to be insufficient.

2.2. [Tanδ _1st ], [tanδ _2nd ]
In the toner for developing an electrostatic charge image of the present invention, [tanδ _1st ] and [tanδ _2nd ] do not have the same value. This is considered to indicate that the structure of the toner was changed by the heating at the time of the first measurement, and the reason is presumed as follows.
Since the measurement sample is produced by molding the toner into pellets without heating as much as possible, the difference in composition between the inside and the surface of the toner is maintained as it is even after molding, and as a result, the pellets are as shown in FIG. A structure composed of an additional particle component and an external additive is formed as a whole. Hereinafter, the “structure composed of the additional particle component and the external additive” may be simply abbreviated as “structure”.

In the first measurement, since the sample having this structure is measured, [tanδ _1st ] is a value that reflects the properties of the structure, and it is estimated that the physical properties and arrangement of the additional particle component and the external additive have an effect. Will be done.
On the other hand, in the second measurement, it is presumed that the internal component, the additional particle component, and the external additive are melt-mixed by the heating during the first measurement, and the sample in a state where the composition is averaged is measured. To.

When [tanδ _2nd ] / [tanδ _1st ] is large, there are many additional particles and external additives, but melt mixing by heating at the time of the first measurement is easy to proceed, and [tanδ _2nd ] / [tanδ _1st ] is small. In this case, it is estimated that there are few additional particles and external additives.
In order to balance the blocking resistance and the low temperature fixability, [tanδ _2nd ] / [tanδ _1st ] must be in an appropriate range, and this range is 1.50 or more and 2.20 or less. It is presumed that the toner in this range is in a state in which the additional particle component is thinly present in the vicinity of the surface of the toner mother particles and the external additive is externally added to the outside thereof.
Since the structure in the pellet (molded body) of the leometer measurement is formed by the additional particle component and the external additive, this measurement is not to measure the toner mother particle but to measure the toner. is important.

[Tanδ _1st ] is 1.15 or more, preferably 1.20 or more, and more preferably 1.30 or more. Further, [tan δ1st] is 1.80 or less, preferably 1.60 or less, and more preferably 1.40 or less.
If [tanδ _1st ] is too small, the low temperature fixability tends to be insufficient, and if [tanδ _1st ] is too large, the blocking resistance tends to be insufficient.

[Tanδ _2nd ] / [tanδ _1st ] is 1.50 or more, preferably 1.60 or more. Further, [tanδ _2nd ] / [tanδ _1st ] is 2.20 or less, preferably 2.00 or less, and more preferably 1.90 or less.
Within this range, the toner has an excellent balance between blocking resistance and low temperature fixability.
If [tanδ _2nd ] / [tanδ _1st ] is too small, the blocking resistance tends to be insufficient, and if [tanδ _2nd ] / [tanδ _1st ] is too large, the low temperature fixability tends to be insufficient.

For example, if the internal component and the additional particle component are completely different chemical components, or if the additional particle component is a component with extremely high Tg such as salt, the structure changes before and after the first measurement with the rheometer. [T _2nd ]-[T _1st ] approaches 0, and [tanδ _2nd ] / [tanδ _1st ] approaches 1.

The "heating and shear" at the time of the first measurement with the rheometer is heated under static conditions, and changes occur in a small part of the toner particle unit (for example, see the above description and FIG. 2). ing.

Further, from the viewpoint of increasing the adhesive strength and reducing the contamination of the members, it is particularly preferable that there is no shadow difference between the internal component and the added particle component when measured with a transmission electron microscope. The measurement conditions of the transmission electron microscope are measured as described in the examples, and the "shadow difference" is defined as the "shadow difference" when the photograph taken in such a measurement is viewed with the naked eye.
Here, "no shadow difference" means that there is no difference in the degree of dyeing (black and white degree) between the internal component and the additional particle component, and the edge of the additional particle component (that is, the boundary between the internal component and the additional particle component). Say you can't see. However, the above-mentioned "no shadow difference" does not exclude a mode in which the shadow difference is not clear and the shadow difference is hardly visible.

2.3. Composition of toner matrix particles 2.3.1. Internal component The toner mother particle is composed of an internal component containing at least a binder resin and a colorant, and additional particles existing around the internal component. The internal component and / or the additional particles may contain wax, a charge control agent, or the like, if necessary.
In the present invention, when the toner mother particles and the toner are formed, the "components caused by the additional particles" are used, including the case where the additional particles do not maintain the "initial particle shape at the time of the additional addition". It is called "additional particle component".
In addition, since the "additional particle component" in the toner mother particle or the toner has a form of particles, a thin film, a mixed state with other components, a compatible state, etc. It may be abbreviated as "additional particles".

The binder resin may be any resin that is generally used as a binder resin in the production of toner, and is not particularly limited. For example, a polystyrene resin, a poly (meth) acrylic resin, a polyolefin resin, or an epoxy resin is used. Examples thereof include resins, thermoplastic resins such as polyester resins, and mixtures of these resins.
As the monomer component used for producing the binder resin, a monomer generally used for producing the binder resin of toner can be appropriately used.
For example, a polymerizable monomer having an acidic group (hereinafter, may be simply referred to as an acidic monomer) and a polymerizable monomer having a basic group (hereinafter, may be simply referred to as a basic monomer). ), Any polymerizable monomer having neither an acidic group nor a basic group (hereinafter, may be referred to as another monomer) can be used.

When a polystyrene-based copolymer resin and a poly (meth) acrylic-based resin are used as the binder resin, the following monomers can be mentioned as examples. The "styrene-based or (meth) acrylic-based monomer" may be simply abbreviated as "monomer composition" below.

As the acidic monomer, a polymerizable monomer having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and silicic acid; a polymerizable monomer having a sulfonic acid group such as sulfonated styrene; Polymerizable monomers having a sulfonamide group such as vinylbenzene sulfonamide; and the like.

Examples of the basic monomer include aromatic vinyl compounds having an amino group such as aminostyrene; nitrogen-containing heterocyclic-containing polymerizable monomers such as vinylpyridine and vinylpyrrolidone; and amino such as dimethylaminoethyl acrylate and diethylaminoethyl methacrylate. (Meta) acrylic acid ester having a group; and the like.
These acidic monomers and basic monomers contribute to the dispersion stabilization of the toner matrix particles. It may be used alone, in combination of two or more, or may be present as a salt with a counterion.

Other monomers include styrenes such as styrene, methylstyrene, chlorostyrene, dichlorostyrene, pt-butylstyrene, pn-butylstyrene, pn-nonylstyrene; methyl acrylate, acrylic acid. Acrylic esters such as ethyl, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate , Isobutyl methacrylate, hydroxyethyl methacrylate, 2-ethylhexyl methacrylate and other methacrylate esters; acrylamide, N-propylacrylamide, N, N-dimethylacrylamide, N, N-dipropylacrylamide, N, N-dibutylacrylamide And acrylamides; etc. The "other monomers" may be used alone or in combination of two or more.

When the binder resin is a crosslinked resin, a polyfunctional monomer is used together with the above-mentioned polymerizable monomer. For example, divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and triethylene glycol are used. Examples thereof include dimethacrylate, tetraethylene glycol dimethacrylate, hexaethylene glycol dimethacrylate, nonaethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate and diallyl phthalate.
Of these, a bifunctional polymerizable monomer is preferable, and divinylbenzene, hexanediol diacrylate and the like are particularly preferable. These polyfunctional polymerizable monomers may be used alone or in combination of two or more.
It is also possible to use polymerizable monomers having a reactive group in the pendant group, for example, glycidyl methacrylate, methylolacrylamide, acrolein and the like.

If necessary, a known chain transfer agent can be used. Specific examples of the chain transfer agent include t-dodecyl mercaptan, dodecane thiol, diisopropyl xanthogen, carbon tetrachloride, trichlorobromomethane and the like. The chain transfer agent may be used alone or in combination of two or more, preferably 0 to 5% by mass with respect to the polymerizable monomer.

When the polystyrene-based copolymer resin and the poly (meth) acrylic-based resin are used as the binder resin, the number average molecular weight in gel permeation chromatography (hereinafter referred to as GPC) is preferably 5000 or more, more preferably 8000. As mentioned above, it is more preferably 10,000 or more, preferably 40,000 or less, more preferably 30,000 or less, and further preferably 20,000 or less. The weight average molecular weight is preferably 30,000 or more, more preferably 50,000 or more, preferably 300,000 or less, and more preferably 250,000 or less.

When a polyester resin is used as the binder resin, as the divalent alcohol, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, etc. Diols such as neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, bisphenol A, hydrogenated bisphenol A, polyoxyethylene bisphenol A, polyoxypropylene bisphenol A And the like; bisphenol A alkylene oxide adduct; etc.
Examples of the divalent acid include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebatic acid, azelaic acid and malon. Acids, anhydrides or lower alkyl esters of these acids; alkenyl succinic acids or alkyl succinic acids such as n-dodecenyl succinic acid, n-dodecyl succinic acid; and other divalent organic acids.

When the binder resin is a crosslinked resin, a polyfunctional monomer is used together with the above-mentioned polymerizable monomer. For example, as the trihydric or higher polyhydric alcohol, for example, sorbitol, 1, 2, 3, 6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butantriol, 1,2,5-pentanthriol, glycerol, 2-methylpropane Examples include triol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and others.
Examples of trivalent or higher valent acids include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid. 1,2,4-naphthalentricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7, Examples include 8-octanetetracarboxylic acids, these anhydrides, and others.

Further, regarding the acid value of the polyester resin, when it is manufactured by adhering the additional particles in water, the acid value of the additional particles is higher than that of the core (central) component (internal component) of the toner matrix particles. Specifically, it is preferable to adjust the acid value of the added particles to 1.1 times or more and 2.8 times or less the acid value of the internal component.
If this multiple is large, it is difficult for the added particles to be buried in the internal components, so that satisfactory blocking resistance can be obtained. If this multiple is small, the additional particles are added in water compared to the core component (internal component). The added particles do not become too stable, and the added particles tend to adhere to the internal components suitably.

These polyester resins can be synthesized by a usual method. Specifically, conditions such as reaction temperature (170 to 250 ° C.) and reaction pressure (5 mmHg to normal pressure) may be determined according to the reactivity of the monomer, and the reaction may be terminated when predetermined physical properties are obtained. ..
When a polyester resin is used as the binder resin, the number average molecular weight in GPC is preferably 2000 to 20000, more preferably 3000 to 12000.

Wax can be used as an offset inhibitor and for improving low temperature fixability, and it is preferable to use it.
As the wax used for the toner of the present invention, known waxes can be arbitrarily used. Specifically, olefin-based waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and copolymerized polyethylene; paraffin wax; bechenic acid. Ester-based waxes having long-chain aliphatic groups such as behenyl, montanic acid ester, stearyl stearate; plant-based waxes such as hydrogenated castor oil and carnauba wax; ketones having long-chain alkyl groups such as distearyl ketones; alkyl groups Silicone; higher fatty acids such as stearic acid; long-chain fatty acids (pentaerythritol, trimethylolpropane, glycerin, etc.) polyhydric alcohol esters or partial esters thereof; higher fatty acid amides such as oleic acid amide and stearic acid amide; etc. Illustrated.
Preferably, hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax; ester waxes; silicone waxes; and the like can be mentioned.

Among them, ester waxes are more preferable, and those mainly containing monoester waxes mainly containing C18 and / or C22 hydrocarbons are more preferable, and behenic acid behenic acid, stearyl behenate, behenic stearate, and mainly them. Those containing are most preferable. The wax may be used alone or in combination.

The melting point peak of the wax (the endothermic peak top at the time of the second temperature rise of the DSC of the toner) is preferably 90 ° C. or lower, more preferably 80 ° C. or lower, further preferably 75 ° C. or lower, more preferably 50 ° C. or higher, and more preferably 60 ° C. or higher. It is preferable, and 65 ° C. or higher is more preferable.
When the melting point peak of the wax is high, the blocking resistance tends to be improved, and when the melting point peak of the wax is low, the low temperature fixability tends to be improved.

The difference between the melting point peak of the wax and the onset temperature of the wax (the intersection temperature of the baseline before the endothermic peak at the second DSC of the toner and the tangent at the first inflection point appearing before the endothermic peak) is 10 ° C. or less. It is preferably 8 ° C. or lower, more preferably 4 ° C. or lower.
The onset temperature of the wax is preferably 86 ° C. or lower, more preferably 76 ° C. or lower, further preferably 71 ° C. or lower, further preferably 46 ° C. or higher, further preferably 56 ° C. or higher, further preferably 61 ° C. or higher. When the onset temperature is high, the blocking resistance tends to improve, and when the onset temperature is low, the low temperature fixability tends to improve.

The melting point of the wax is preferably 100 ° C. or lower, more preferably 90 ° C. or lower, further preferably 80 ° C. or lower, further preferably 40 ° C. or higher, still more preferably 50 ° C. or higher.

The amount of wax is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 5 parts by mass or more with respect to 100 parts by mass of toner. Further, it is preferably 35 parts by mass or less, more preferably 30 parts by mass or less, and further preferably 25 parts by mass or less.

As the colorant, a known colorant can be arbitrarily used. Specific examples of colorants include carbon black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine pigments, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallyl methane dyes, monoazo dyes, and so on. Any known dyeing pigment such as disazo-based dyeing pigment and condensed azo-based dyeing pigment can be used alone or in combination.
In the case of full-color toner, yellow is benzidine yellow, monoazo, condensed azo dye; magenta is quinacridone, monoazo dye; cyan is phthalocyanine dye; etc. Is preferable.

The colorant is preferably used in an amount of 3 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the toner.

Any known charge control agent can be used. Specific examples of charge control agents include niglosin dyes, amino group-containing vinyl copolymers, quaternary ammonium salt compounds, polyamine resins, etc. for positive chargeability, and chromium, zinc, iron, cobalt for negative chargeability. , Metal-containing azo dyes containing metals such as aluminum, salts of salicylic acid or alkyl salicylic acid with the above-mentioned metals, metal complexes and the like.
The amount of the charge control agent is preferably 0.1 to 25 parts by mass, more preferably 1 to 15 parts by mass with respect to 100 parts by mass of the toner.
The charge control agent may be mixed inside the toner mother particles, or may be used in a form of being adhered to the surface of the toner mother particles.

2.3.2. Additional particles (ingredients)
The toner mother particles are composed of the internal components and additional particles existing around the internal components. If necessary, the internal component and / or the additional particles may contain wax, a charge control agent, or the like.
Examples of the type of "additional particle component" which is a component of the additional particle include the resin used as a binder resin in producing toner.
The type of resin is not particularly limited, and examples thereof include thermoplastic resins such as polystyrene-based resins, poly (meth) acrylic-based resins, polyolefin-based resins, epoxy-based resins, and polyester-based resins, and mixtures of these resins. ..

3. 3. Preparation of Toner for Electrostatic Image Development The toner of the present invention may be produced by any known method, and is not particularly limited.

3.1. Method for producing toner matrix particles 3.1.1. A method for producing toner matrix particles by aggregating particles smaller than the toner matrix particles A method can be used in which each raw material is prepared as particles smaller than the toner matrix particle size, and these are mixed and aggregated to obtain toner matrix particles. ..

3.1.1.1. A method of preparing an emulsion polymerization binder resin as "polymer primary particles" smaller than the toner matrix particle size and obtaining a dispersion liquid of the polymer primary particles will be described below.
Further, the same method can be used for producing the additional particles.

The polymer primary particles having a styrene-based or (meth) acrylic-based monomer (monomer composition) as a constituent element are prepared by using the above-mentioned monomer composition, a chain transfer agent as necessary, and an emulsifier. Obtained by emulsion polymerization.

Known emulsifiers can be used, but one or more emulsifiers selected from cationic surfactants, anionic surfactants, and nonionic surfactants can be used in combination.

Examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide and the like.
Examples of the anionic surfactant include fatty acid soaps such as sodium stearate and sodium dodecylate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate and the like.
Examples of the nonionic surfactant include polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose and the like. Can be mentioned.

The amount of the emulsifier used is preferably 0.1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. When the amount of the emulsifier used is large, the particle size of the obtained polymer primary particles becomes small, and when the amount used is small, the particle size of the obtained polymer primary particles becomes large. Further, for these emulsifiers, for example, one or more kinds of polyvinyl alcohols such as partially or completely saponified polyvinyl alcohol and cellulose derivatives such as hydroxyethyl cellulose can be used in combination as a protective colloid.

Further, if necessary, one or a combination of two or more known polymerization initiators can be used. For example, a redox initiator, hydrogen peroxide, 4, 4 which is a combination of persulfates such as potassium persulfate, sodium persulfate, ammonium persulfate, and a reducing agent such as acidic sodium sulfite containing these persulfates as one component. A water-soluble polymerization initiator such as'-azobiscyanovaleric acid, t-butyl hydroperoxide, cumene hydroperoxide, etc., and a redox in which these water-soluble polymerization initiators are combined with a reducing agent such as ferrous salt as one component. Initiators, benzoyl peroxide, 2,2'-azobis-isobutyronitrile, etc. are used. These polymerization initiators may be added to the polymerization system before, at the same time as, or after the addition of the polymerizable monomer, and these addition methods may be combined as necessary.

In order to disperse the wax in the toner with a suitable dispersion particle size, it is preferable to carry out so-called seed polymerization in which the wax is added as a seed during emulsion polymerization. By adding the wax as a seed, the wax is finely and uniformly dispersed in the toner, so that deterioration of the chargeability and heat resistance of the toner can be suppressed.
Further, a wax / long-chain polymerizable monomer dispersion obtained by pre-dispersing the wax with a long-chain polymerizable monomer such as stearyl acrylate in an aqueous dispersion medium is prepared, and the wax / long-chain polymerizable monomer is prepared. It is also possible to polymerize the polymerizable monomer in the presence of.

It is possible to carry out emulsion polymerization using a colorant as a seed, but when a polymerizable monomer is polymerized in the presence of a colorant, the metal in the colorant affects radical polymerization, making it difficult to control the molecular weight and rheology of the resin, which is desirable. Since there is a possibility that the physical properties of the above can not be obtained, it is preferable to add the colorant dispersion liquid in the next step without adding the colorant at the time of emulsion polymerization.

3.1.1.2. Method of emulsifying resin After obtaining resin by bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc., it is mixed with an aqueous medium and heated to a temperature higher than the melting point of the resin or the glass transition temperature. By lowering the viscosity of the resin and applying shearing force to emulsify the resin, primary polymer particles can be obtained.

Examples of the emulsifying machine for applying the shearing force include a homogenizer, a homomixer, a pressurized kneader, an extruder, a media disperser and the like.
If the viscosity of the resin at the time of emulsification is high and the particle size does not decrease to the desired particle size, the desired particles are emulsified by raising the temperature using an emulsifying device capable of pressurizing above atmospheric pressure and lowering the resin viscosity. Polymer primary particles having a diameter can be obtained.
As another method, a method of mixing an organic solvent with the resin in advance to reduce the viscosity of the resin may be used. The organic solvent used is not particularly limited as long as it dissolves the resin, but is a ketone solvent such as tetrahydrofuran (THF), methyl acetate, ethyl acetate and methyl ethyl ketone, and a benzene solvent such as benzene, toluene and xylene. Etc. can be used. Further, an alcohol solvent such as ethanol or isopropyl alcohol may be added to the water or resin for the purpose of improving the affinity with the aqueous medium and controlling the particle size distribution. When an organic solvent is added, it is necessary to remove the organic solvent from the emulsified solution after the emulsification is completed. As a method for removing the organic solvent, there is a method of volatilizing the organic solvent while reducing the pressure at room temperature or under heating.

Further, for the purpose of controlling the particle size distribution, salts such as sodium chloride and potassium chloride, ammonia and the like may be added.

An emulsifier or dispersant may be added for the purpose of controlling the particle size distribution. For example, water-soluble polymers such as polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose and sodium polyacrylate; the above-mentioned emulsifiers; inorganic compounds such as tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate and barium carbonate Can be mentioned. The amount used is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the resin.

When a resin containing an acidic group or a basic group is used, the amount of the emulsifier or dispersant added can be reduced, but the hygroscopicity of the resin may be increased and the chargeability may be deteriorated.

Moreover, the phase inversion emulsification method may be used. In the phase inversion emulsification method, an organic solvent, a neutralizing agent, or a dispersion stabilizer is added to the resin as necessary, and an aqueous medium is added dropwise to the resin under stirring to obtain emulsified particles, and then the resin dispersion liquid is obtained. This is a method of obtaining an emulsion by removing the organic solvent inside. As the organic solvent, the same organic solvent as described above can be used. As the neutralizing agent, general acids such as nitric acid, hydrochloric acid, sodium hydroxide and ammonia, and alkalis can be used.

3.1.1.3. Formation of Toner Mother Particles by Aggregation and Aging The volume average particle size of the obtained polymer primary particles is usually 0.02 μm or more, preferably 0.05 μm in any of the above preparation methods of emulsion polymerization and resin emulsification. The above is particularly preferably 0.1 μm or more, usually 3 μm or less, preferably 2 μm or less, and particularly preferably 1 μm or less.
When the volume average particle size of the polymer primary particles is smaller than the above range, it may be difficult to control the aggregation rate in the aggregation step. On the other hand, when it is larger than the above range, the particle size of the toner mother particles obtained by aggregation tends to be large, and it may be difficult to obtain the toner mother particles having a target particle size.

In the agglomeration step, the compounding components such as the polymer primary particles, the colorant particles, and if necessary, the charge control agent and the wax are mixed simultaneously or sequentially. A dispersion liquid of each component, that is, a polymer primary particle dispersion liquid, a colorant particle dispersion liquid, a charge control agent dispersion liquid, and a wax fine particle dispersion liquid are prepared in advance, and these are mixed and mixed dispersion liquid. Is preferable from the viewpoint of composition uniformity and particle size uniformity.

The colorant is preferably used in a state of being dispersed in water in the presence of an emulsifier, and the volume average particle size of the colorant particles is preferably 0.01 μm or more, particularly preferably 0.05 μm or more, and preferably 3 μm. Hereinafter, it is particularly preferably 1 μm.

In the coagulation step, coagulation is usually performed in a tank equipped with a stirrer, but there are a method of heating, a method of adding an electrolyte, and a method of combining these.
When the primary particles of the polymer are agglomerated under stirring to obtain a particle agglomerate of a desired size, the particle size of the particle agglomerates is controlled from the balance between the cohesive force of the particles and the shearing force of the agitation. However, the cohesive force can be increased by heating or adding an electrolyte.

When an electrolyte is added to perform aggregation, the electrolyte may be an acid, an alkali, or a salt, and may be an organic type or an inorganic type. Specifically, the acid is hydrochloric acid, nitrate, sulfuric acid, or citrate. acid, and the like; alkali, sodium hydroxide, potassium hydroxide, aqueous ammonia or the like; as a _{salt, NaCl, KCl, LiCl, Na} 2 SO 4, K 2 SO 4, Li 2 SO 4, MgCl 2, CaCl 2, MgSO 4 , CaSO ₄ , ZnSO ₄ , Al ₂ (SO ₄ ) ₃ , Fe ₂ (SO ₄ ) ₃ , CH ₃ COONa, C ₆ H ₅ SO ₃ Na and the like.
Of these, an inorganic salt having a divalent or higher polyvalent metal cation is preferable.

The amount of the electrolyte added varies depending on the type of electrolyte, the target particle size, etc., but is preferably 0.02 parts by mass or more, more preferably 0.05 parts by mass or more, based on 100 parts by mass of the solid component of the mixed dispersion. preferable. Further, 25 parts by mass or less is preferable, and further, 15 parts by mass or less, particularly 10 parts by mass or less is preferable.
If the amount added is too small, the progress of agglomeration will be slowed down and fine powder of 1 μm or less will remain after agglomeration, or the average particle size of the obtained particle agglomerates will not reach the target particle size. On the other hand, if the amount is too large, rapid agglomeration tends to occur and it becomes difficult to control the particle size, which may cause problems such as coarse powder or amorphous particles being contained in the obtained agglomerated particles.
The agglomeration temperature when the electrolyte is added to perform agglomeration is preferably 20 ° C. or higher, particularly preferably 30 ° C. or higher, preferably 70 ° C. or lower, and particularly preferably 60 ° C. or lower.

The time required for agglomeration is optimized by the shape of the device and the processing scale, but in order for the particle size of the toner matrix particles to reach the target particle size, the toner must be held at the predetermined temperature for at least 30 minutes or more. Is preferable. The temperature rise until the temperature reaches a predetermined temperature may be raised at a constant rate, or may be raised stepwise.

Examples of the composition and preparation method of the additional particles include those described above. The addition may be once or may be multiple times. The first additional particles and the subsequent additional particles may be different or may be any combination.

The timing of adding the additional particles may be any timing, and may be charged at the same time as the raw material of the internal component (for example, polymer primary particles, pigment, wax, etc.), or a part or all of the raw material of the internal component. May be added after agglomeration.

When the internal component and the additional particles are charged at the same time, if the polarity of the additional particles is designed so that the polarity is between the internal component and the medium (for example, water), the additional particles will spontaneously form around the internal component. It becomes attached.
When the additional particles are attached in a wet medium such as in water and / or in an organic solvent, including the production method described later, the additional particles may be added after the composition of the raw material of the internal component is determined. , It is preferable from the viewpoint that the additional particles can be arranged on the surface of the internal component.
Further, in the case of the above method of producing toner mother particles by aggregating particles smaller than the toner mother particles, it is possible to add additional particles after agglomerating a part or all of the internal components. It is preferable from the viewpoint that additional particles can be arranged on the surface of.

In order to increase the stability of the particle agglomerates obtained in the agglomeration step, it is preferable to carry out fusion within the agglomerated particles in the aging step after the agglomeration step.
The temperature of the aging step is preferably Tg or more of the polymer primary particles, more preferably 5 ° C. or higher than the Tg of the polymer primary particles, and preferably Tg or less of the additional particles, more preferably additional addition. The temperature is 5 ° C. lower than the Tg of the particles.
The time required for the aging step varies depending on the shape of the target toner matrix particles, but is preferably 0.1 to 10 hours, particularly preferably 0.5 to 5 hours after reaching Tg or more of the polymer primary particles. It is desirable to hold the time.

After the aggregation step, preferably before the aging step or at the stage during the aging step, it is preferable to add a surfactant, adjust the pH, or use both in combination.
As the surfactant used here, one or more kinds of emulsifiers that can be used when producing the polymer primary particles can be selected and used, and particularly used when the polymer primary particles are produced. It is preferable to use the same emulsifier.
When the surfactant is added, the amount added is not limited, but is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, and preferably 0.3 parts by mass or more with respect to 100 parts by mass of the solid component of the mixed dispersion liquid. Is 20 parts by mass or less, more preferably 15 parts by mass or less, still more preferably 10 parts by mass or less.
By adding a surfactant or adjusting the pH after the agglomeration step and before the completion of the aging step, it is possible to suppress the agglomeration of the particle agglomerates obtained in the agglomeration step, and after the aging step. In some cases, the formation of coarse particles can be suppressed.

By controlling the time of the aging process, toner of various shapes such as grape type in which the polymer primary particles are kept in agglomerated shape, potato type in which fusion is advanced, spherical shape in which fusion is further advanced, etc. Mother particles can be produced.

3.1.2. Method for Producing Particles of Toner Mother Particle Size A method of obtaining toner mother particles by mixing each raw material, atomizing the mixture to the size of the toner mother particles, atomizing the mixture, and then attaching additional particles. Can be used.

3.1.2.1. Method for Producing by Suspension Polymerization In the same "styrene-based or (meth) acrylic-based monomer" (monomer composition) as the above-mentioned monomer composition, a colorant, a polymerization initiator, and if necessary Then, additives such as wax, polar resin, charge control agent, and cross-linking agent are added to prepare a uniformly dissolved or dispersed monomer composition.
This monomer composition is dispersed in an aqueous medium containing a suspension stabilizer or the like, if necessary. The stirring speed and time are adjusted so that the droplets of the monomer composition have the desired size of the toner matrix particles, and the particles are granulated. After that, the toner mother particles can be obtained by carrying out polymerization by stirring to the extent that the particle state is maintained and the precipitation of the particles is prevented by the action of the dispersion stabilizer.

Specific examples of the suspension stabilizer include calcium phosphate, magnesium phosphate, calcium hydroxide, magnesium hydroxide and the like. These may be used alone or in combination of two or more, and are preferably 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. The suspension stabilizer may be added to the polymerization system at any time before, at the same time as, or after the addition of the polymerizable monomer, and these addition methods may be combined as necessary.

When the monomer composition contains a polar resin, the polar resin easily moves to the vicinity of the surface of the droplet after the monomer composition is dispersed in an aqueous medium to form droplets. By carrying out polymerization in this state, toner mother particles having different compositions inside and on the surface can be obtained. For example, if a polar resin having a higher Tg than the Tg after polymerization of the monomer is selected, a structure in which the Tg is low inside the toner matrix particles and the resin having a high Tg is present on the surface in a high ratio can be obtained. ..

The timing of adding the additional particles is not particularly limited, but it is preferable to add the additional particles after 90% of the polymerization time. Examples of the composition and preparation method of the additional particles include those described above. The addition may be once or may be multiple times. The first additional particles and the subsequent additional particles may be different or may be any combination.

In addition, a pH adjuster, a degree of polymerization adjuster, an antifoaming agent and the like can be appropriately added to the reaction system.

3.1.2.2. Method for producing by dissolution suspension An oil-based dispersion in which at least a binder resin and a colorant, and if necessary, a wax, a charge control agent, etc. are dissolved or dispersed in an organic solvent is prepared, and this is dispersed in an aqueous medium.
The timing of adding the additional particles is not particularly limited, but it is preferable to add the additional particles after dispersing the oil-based dispersion in the aqueous medium. After that, the organic solvent can be removed from the dispersion liquid to obtain toner matrix particles.
Examples of the composition and preparation method of the additional particles include those described above. The additional particles may be added once or multiple times. The first additional particles and the subsequent additional particles may be different or may be any combination.

As the water-based medium, water alone may be used, but a solvent miscible with water may be used in combination.
If necessary, a dispersant can be used. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion becomes stable. As the dispersant, the same emulsifier as that used for the emulsion polymerization described above can be used. In addition, various hydrophilic polymer substances that form a polymer-based protective colloid can be present in an aqueous medium.

Further, as the dispersant, inorganic fine particles and / or polymer fine particles can be used.
As the inorganic fine particles, various conventionally known inorganic compounds that are insoluble or sparingly soluble in water are used. Such examples include tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite and the like.
The polymer fine particles used as the dispersant may also have the properties of the additional particles. That is, the polymer fine particles as the dispersant may be used as the additional particles.

When the oil-based dispersion liquid is dispersed in an aqueous medium, a known disperser such as a low-speed shearing type, a high-speed shearing type, a friction type, a high-pressure jet type, or an ultrasonic wave can be applied as a dispersing device.

An oily dispersion may be prepared using a prepolymer having a reactive group instead of the binder resin, dispersed in an aqueous medium, and then reacted with the reactive group to extend the resin. In this method, since the prepolymer has a relatively low molecular weight, the viscosity of the oil-based dispersion is unlikely to increase, and dispersion in an aqueous medium is facilitated.

In order to facilitate uniform dispersion of the colorant in the oil-based dispersion, the colorant may be prepared in advance as a masterbatch compounded with a resin and dispersed in an organic solvent.

As a method for removing the organic solvent, there is a method of volatilizing the organic solvent while reducing the pressure at room temperature or under heating.

When a highly polar resin and a low polar resin are used in combination as the binder resin, the monomer composition is dispersed in an aqueous medium to form droplets, and then the highly polar resin is placed near the surface of the droplets. The resin with low polarity moves to the vicinity of the center of the droplet. After that, by removing the organic solvent, toner mother particles having different compositions inside and on the surface can be obtained.
When an oil-based dispersion is prepared using a prepolymer capable of reacting with an active hydrogen group-containing compound, the oil-based dispersion is dispersed in an aqueous medium, and then an active hydrogen group-containing compound is added in the aqueous medium. By causing both to be elongated or crosslinked from the surface of the droplet, the elongated or crosslinked resin is preferentially generated on the surface of the droplet. After that, by removing the organic solvent, toner mother particles having different compositions inside and on the surface can be obtained.

By selecting the raw material in consideration of Tg by these methods, a structure in which the ratio of the resin having a high Tg is higher on the surface than on the inside of the toner matrix particles can be obtained.
Further, the polymer fine particles used as the dispersant are regarded as the additional particles, and the physical properties of the additional particles are adjusted to create a structure in which the additional particles (polymer fine particles) are present on the surface of the toner matrix particles. May be good.

3.1.3. Method for producing toner matrix particles by melt-kneading and crushing method The melt-kneading and crushing method is an extruder after dry-mixing a binder resin and a colorant with a charge control agent, a mold release agent, a magnetic material, etc., if necessary. The toner is melt-kneaded with or the like, then pulverized and classified to obtain toner matrix particles, and then an external additive is added to obtain toner.
After obtaining the toner mother particles, additional particles may be added and adhered to the surface of the internal component. Although not limited, it is preferable to add an external additive after adding the additional particles.

3.2. Cleaning and drying of toner matrix particles The above-mentioned "method of aggregating particles smaller than toner matrix particles to produce toner matrix particles", "method of producing particles of the size of toner matrix particles by suspension polymerization", "dissolution suspension" The toner matrix particles produced by the method of producing particles of the size of the toner matrix particles by turbidity are separated from the aqueous solvent, washed, dried, and externally treated to be used as the toner for static charge image development. Will be done.

Water is used as the liquid used for cleaning, but it can also be washed with an aqueous solution of acid or alkali. Further, it can be washed with hot water or hot water, and these methods can be used in combination. By going through such a washing step, suspension stabilizers, emulsifiers, unreacted monomers and the like can be reduced and removed.
In the cleaning step, for example, the toner matrix particles are formed into a concentrated slurry or wet cake by filtering, decantation, etc., and a new cleaning liquid is added thereto to disperse the toner matrix particles. preferable. It is preferable to collect the toner matrix particles after washing in the form of a wet cake in terms of handling in the subsequent drying step.

In the drying step, a vibration type fluid drying method, a circulation type fluid drying method or the like, a flow drying method, an air flow drying method, a vacuum drying method, a freeze drying method, a spray drying method, a flash jet method and the like are used. The operating conditions such as temperature, air volume, and decompression degree in the drying step are appropriately optimized based on the Tg of the colored particles, the shape, mechanism, size, and the like of the apparatus used.

3.3. Timing of addition of additional particles When preparing toner matrix particles in a wet medium (in water and / or in an organic solvent), additional particles (or a simple resin that is a raw material thereof) are added (dissolved / dispersed) at the same time as the internal components. (It may be in any state of suspension), and thermodynamically, the additional particles may be arranged on the surface of the internal component and the wet medium, and the composition and / or shape of the internal component is determined. The additional particles may be added later to physically cover the surface of the internal component with the additional particles continuously and / or discontinuously.

Furthermore, when the toner matrix particles are produced in a wet medium (in water and / or in an organic solvent), additional particles may be added before or after the washing step or before and after the drying step. Further, the additional particles may be added in the external addition step described later, and when the additional particles are attached in the external addition step, it is preferable to add the additional particles and fix them, and then add the external additive. ..

4. In order for the composition of the toner matrix particles [T _2nd ]-[T _1st ] to satisfy 1.0 ° C. or higher and 4.5 ° C. or lower, "at least an internal component containing a binder resin and a colorant" and additional particles are required. Since it is not completely melt-mixed, it is necessary to adjust the balance between the particle size and the content of the added particles and adjust the content of each component such as wax and colorant.
The particle size of the added particles is preferably 50 nm or more, more preferably 70 nm or more, preferably 300 nm or less, and more preferably 250 nm or less. As the particle size of the additional particles increases, it is preferable to reduce the amount of the additional particles added to achieve a balance.

When determining the amount of additional particles to be added, the coverage can be used. The coverage can be calculated from the ratio of the surface area obtained from the target particle size when the toner mother particles are assumed to be spheres and the projected area obtained from the average particle size when the additional particles are assumed to be spheres.
When the particle size of the added particles is 100 nm or more and 150 nm or less, the coverage is preferably 40% or more and 90% or less. When the particle size of the added particles is 150 nm or more, the coverage is preferably 20% or more and 80% or less. When the particle size of the added particles is smaller than 100 nm, the coverage is preferably 60% or more.
By setting the "additional amount of additional particles" and "coverage" as described above, the present invention [T _2nd ]-[T _1st ], [tanδ _1st ] and [tanδ _2nd ] / It can be in the value range of [tan δ _1st].

In order for [tanδ _2nd ] / [tanδ _1st ] to satisfy 1.50 or more and 2.20 or less, in addition to the balance between the particle size and the amount of the additional particles, when the particle size of the additional particles is 100 nm or more, , It is preferable to spread the added particles by impact by an external addition operation.
On the other hand, when the particle size of the additional particles is smaller than 100 nm, it tends to be difficult for the additional particles to be expanded by the external addition operation, so it is preferable to increase the addition amount.

In order for [tan δ _1st ] to satisfy 1.15 or more and 1.80 or less, the particle size of the added particles is preferably 50 nm or more, more preferably 70 nm or more, preferably 300 nm or less, and more preferably 250 nm or less. It is preferable to balance by reducing the addition amount as the particle size of the additional particles increases.

When the particle size of the added particles is 100 nm or more and 150 nm or less, the coverage is preferably 40% or more and 90% or less. When the particle size of the added particles is 150 nm or more, the coverage is preferably 20% or more and 80% or less. When the particle size of the added particles is smaller than 100 nm, the coverage is preferably 60% or more. When the particle size of the added particles is larger than 200 nm, the coverage is preferably 45% or less.
Including the above-mentioned "impact of external addition operation", "particle size of additional particles", "coverage", etc., [T _2nd ]-[T _1st ], [tan δ _{1st] of the present invention.} ] And [tanδ _2nd ] / [tanδ _1st ].

To adjust so that [T _2nd ]-[T _1st ] is 1.0 ° C. or higher and 4.5 ° C. or lower, and [tanδ _2nd ] / [tanδ _1st ] is 1.50 or higher and 2.20 or lower. It is desirable to combine the compositions so that the binder resin and the additional particles have an appropriate affinity.
In the first measurement, the measurement is started in a state where the binder resin and the additional particles are not melt-mixed. When the first measurement is completed, the binder resin and the additional particles are melt-mixed with each other by heating during that period. In the second measurement, the measurement is started from a state in which they are melt-mixed with each other. This difference appears in [T _2nd ]-[T _1st ] and [tanδ _2nd ] / [tanδ _1st ].

Therefore, it is desirable to adjust the affinity by selecting the type of resin contained in the additional particles according to the type of binder resin. Although not limited to the following specific values, for example, if the binder resin is a styrene acrylic resin, the resin contained in the additional particles is also a styrene acrylic resin, and the ratio of the styrene monomer to the acrylic monomer is bonded. When the resin is 70:30, the resin contained in the additional particles is 95: 5, or when the number of parts of the hydrophilic monomer is 1 part with respect to 100 parts by mass of the other monomer. The composition of the additional resin is different by 1.5 parts of the resin and a hybrid resin of styrene acrylic resin and polyester as either the binder resin or the additional particles. Be done.

Since appropriate compatibility between the internal component and the additional particle component can be obtained, the difference between the SP value of the binder resin and the SP value of the additional particle component is preferably 0.5 to 1.0, and 0. It is more preferably 6 to 0.8.

If the binding resin is polyester, the resin contained in the additional particles is also polyester, and the acid value is determined. If the binding resin is 3 mgKOH / g or less, the resin contained in the additional particles is 4 mgKOH / g or more and 20 mgKOH / g or less. The binding resin does not have a hydroxyl value, and the resin contained in the additional particles has a hydroxyl value.

If the binding resin and the resin contained in the additional particles are the same or similar, or if the resin physical characteristics are the same or similar, there is no difference between _{[T 1st} ] and [T _2nd]. Further, since the binder resin and the additional particles are melt-mixed during the production of the toner mother particles, the _{values of [tanδ 1st} ] and [tanδ _2nd ] are almost the same.
The additional particles contain a resin, but preferably contain a wax. When the internal component also contains wax, the wax contained in the internal component and the wax contained in the additional particles may be of the same type, but it is preferable to use different types. In addition, a charge control agent or the like may be contained.

By setting the above-mentioned "difference in type or physical properties between the" binding resin "and the" resin contained in the additional particles "" and the like, the present invention [T _2nd ]-[ It can be in the value range of _{[T 1st} ], [tanδ _1st ] and [tanδ _2nd ] / [tanδ _1st].

The number average molecular weight of the added particles in GPC is preferably 8,000 or more, more preferably 10,000 or more, still more preferably 13,000 or more, preferably 50,000 or less, more preferably 40,000 or less, still more preferably. It is desirable that it is 35,000 or less. The weight average molecular weight is preferably 20,000 or more, more preferably 30,000 or more, preferably 300,000 or less, and more preferably 200,000 or less.
The Tg of the additional particles is preferably 65 ° C. or higher, more preferably 70 ° C. or higher, preferably 95 ° C. or lower, and more preferably 90 ° C. or lower. Further, it is necessary to be higher than Tg of the binder resin, more preferably 20 ° C. or higher, and further preferably 25 ° C. or higher. Further, it is preferable that the temperature is not higher than Tg of the binder resin by 50 ° C. or more.

In order for [tanδ _1st ] to satisfy 1.15 or more and 1.80 or less and [tanδ _2nd ] / [tanδ _1st ] to satisfy 1.50 or more and 2.20 or less, the additional particles should be placed near the surface of the toner matrix particles. It needs to be located. An effective composition of the additional particles for that purpose is that when the toner matrix particles are produced in an aqueous medium, the composition is more compatible with the aqueous medium than the binder resin (composition having affinity). For example, an ionic polymerization initiator having a higher ratio of acidic monomer or basic monomer than the binder resin and 1.0 part by mass or more with respect to 100 parts by mass of other monomers. Use, combine these, etc.

As an example shown in FIG. 3, when the additional particles are attached to the particles having an uneven shape to obtain the toner mother particles, many of the additional particles tend to adhere to the convex portion A. In the conventional toner, the additional particles do not stay near the surface after adhesion, but are deeply embedded inside.
On the other hand, in the toner of the present invention, the additional particles stay near the surface. As a result, the obtained toner matrix particles have a biased distribution in which the additional particles are located on the surface of the toner matrix particles and are not uniformly distributed over the entire surface.

"Molecular weight of additional particles", "Relationship between Tg of additional particles and Tg of binding resin", "Affinity of additional particles for aqueous medium", "Particles before attachment of additional particles" It can be in the value range _{of [T 2nd} ]-[T _1st ], [tanδ _1st ] and [tanδ _2nd ] / [tanδ _1st ] of the present invention, including setting to "shape of".

5. Attachment 5.1. External Additive In the present invention, an external additive is added in order to obtain the physical characteristics of the toner of the present invention, and to improve the fluidity and charge controllability of the toner. Since the external additive adheres to the entire surface of the toner matrix particles, it is preferable that the portion where the additional particles do not exist is also covered with the external additive. As the external additive, it can be appropriately selected and used from various inorganic or organic fine particles. Further, two or more kinds of external additives may be used in combination.

Inorganic fine particles include various carbides such as silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobide carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide, boron nitride, titanium nitride. , Various nitrides such as zirconium nitride, various carbides such as zirconium boride, various oxides such as titanium oxide, calcium oxide, magnesium oxide, zinc oxide, copper oxide, aluminum oxide, cerium oxide, silica, colloidal silica, titanium Various titanic acid compounds such as calcium acid, magnesium titanate, strontium titanate, phosphoric acid compounds such as calcium phosphate, sulfides such as molybdenum disulfide, fluorides such as magnesium fluoride and carbon fluoride, aluminum stearate, calcium stearate. , Various metal soaps such as zinc stearate and magnesium stearate, talc, bentonite, various carbon blacks, conductive carbon blacks, magnetites, ferrites and the like can be used.

As the organic fine particles, fine particles such as a styrene resin, an acrylic resin, an epoxy resin, and a melamine resin can be used. Further, the charge stability can be improved by using fine particles containing a fluorine atom.

Among these external additives, silica, titanium oxide, alumina, zinc oxide, various carbon blacks, conductive carbon blacks and the like are preferably used. The external additive is a silane coupling agent such as hexamethyldisilazane (HMDS) or dimethyldichlorosilane (DMDS), a titanate-based coupling agent, silicone oil, or dimethyl silicone oil on the surface of the inorganic or organic fine particles. Hydrophobic with treatment agents such as silicone oil treatment agents such as modified silicone oil and amino-modified silicone oil, silicone varnish, fluorine-based silane coupling agents, fluorine-based silicone oils, and coupling agents having amino groups and quaternary ammonium bases. It is also possible to use one that has been subjected to surface treatment such as siliconization. Two or more kinds of the treatment agent can be used in combination.

The amount of the external additive added is preferably 1.0 part by mass or more, particularly preferably 1.5 parts by mass or more, preferably 6.5 parts by mass or less, and 5.5 parts by mass with respect to 100 parts by mass of the toner mother particles. Part or less is particularly preferable.

In the toner of the present invention, conductive fine particles may be used as an external additive from the viewpoint of charge control. Examples of the conductive fine particles include metal oxides such as conductive titanium oxide, silica, and magnetite, or those doped with a conductive substance, and conjugated double bonds such as polyacetylene, polyphenylacetylene, and poly-p-phenylene. Examples thereof include organic fine particles obtained by doping a polymer having a conductive substance such as a metal with a conductive substance such as metal, and carbon typified by carbon black or graphite. From the viewpoint of imparting conductivity without impairing the fluidity of the toner, conductive oxidation More preferably, it is doped with titanium or a conductive substance thereof.

The lower limit of the content of the conductive fine particles is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and 0.2 parts by mass or more with respect to 100 parts by mass of the toner mother particles. It is particularly preferable to have.
On the other hand, the upper limit of the content of the conductive fine particles is preferably 3 parts by mass or less, more preferably 2 parts by mass or less, and particularly preferably 1 part by mass or less.

5.2. External Addition Method The external addition method includes a method using a high-speed stirrer such as a Henschel mixer and a method using a device capable of applying compressive shear stress.
The toner can be produced by a one-step external addition method in which all the external additives are added to the toner matrix particles at the same time and externally added, but it can also be produced by a piecewise external addition method in which each external additive is externally added.
In order to prevent the temperature from rising during the external addition, a cooling device may be installed in the container, or a piecewise external attachment may be used.

6. Others The volume average particle size of the toner of the present invention is preferably 3 μm or more, more preferably 5 μm or more. Further, 15 μm or less is preferable, 10 μm or less is more preferable, and 8 μm or less is particularly preferable.
As for the shape, the average circularity measured by using the flow type particle image analyzer FPIA-3000 is preferably 0.90 or more, more preferably 0.92 or more, still more preferably 0.94 or more, and particularly preferably 0.94 or more. It is 0.95 or more, preferably 0.99 or less. If the average circularity is too small, the image density may decrease due to poor adhesion of the external additive to the toner matrix particles, which may cause a decrease in image density. If the average circularity is too large, cleaning defects due to the shape may occur.

The toner for static charge image development of the present invention may be used in any form of a two-component developer that uses the toner together with a carrier, or a magnetic or non-magnetic one-component developer that does not use a carrier.
When used as a two-component developer, as the carrier, a magnetic substance such as iron powder, magnetite powder, or ferrite powder, a substance having a resin coating on the surface thereof, or a known carrier such as a magnetic carrier can be used. As the coating resin of the resin coating carrier, generally known styrene resin, acrylic resin, styrene acrylic copolymer resin, silicone resin, modified silicone resin, fluororesin, or a mixture thereof can be used.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded. In the following examples, the terms "parts" and "%" simply mean "parts by mass" and "% by mass" when it comes to mass.

The particle size, average circularity, weight average molecular weight, emulsion solid content concentration, etc. of each particle were measured as follows.
<Measurement of median diameter (D50)>
The medium diameter (D50) of particles having a medium diameter (D50) of less than 1 micron is manufactured by Nikkiso Co., Ltd., model Microtrac Nanotrac150 (hereinafter abbreviated as nanotrack) and its analysis software, MicrotracParticle Analyzer Ver10.1.2-. Described in the instruction manual under the measurement conditions of 019EE, ion-exchanged water having an electrical conductivity of 0.5 μS / cm as a solvent, solvent refractive index: 1.333, measurement time: 120 seconds, and number of measurements: 5 times. The average value was calculated by the above-mentioned method.
Other setting conditions were particle refractive index: 1.59, transparency: transmission, shape: true sphere, and density: 1.04.

<Measurement of volume median particle size (Dv50)>
For the volume median particle diameter (Dv50) of the particles having a volume median particle diameter (Dv50) of 1 micron or more, Beckman Coulter's Multisizer III (aperture diameter 100 μm: hereinafter abbreviated as multisizer) is used. Using Isoton II of the same company as a dispersion medium, the particles were dispersed and measured so that the dispersoid concentration was 0.03%.

<Measurement of average circularity>
For the average circularity, the dispersoid was dispersed in a dispersion medium (Cell sheath: manufactured by Sysmex Corporation) so as to be 5720 to 7140 pieces / μL, and HPF analysis was performed using a flow-type particle analyzer (FPIA3000: manufactured by Sysmex Corporation). The measurement was performed in the HPF mode under the conditions of an amount of 0.35 μL and an HPF detection amount of 2000 to 2500 pieces.

<Weight average molecular weight (Mw)>
After the polymer primary particle dispersion and the additional particle dispersion were freeze-dried to remove water, the THF-soluble component was measured by gel permeation chromatography (GPC) under the following conditions.
Equipment: GPC equipment HLC-8320 manufactured by Tosoh Corporation, column: TOSOH TSKgel SuperHM-H (diameter 6 mm x length 150 mm x 2), solvent: THF, column temperature: 40 ° C., flow rate: 0.5 mL / min, sample concentration: 0 .1% by mass, calibration curve: standard polystyrene used

<Emulsion solid content concentration>
The emulsion solid content concentration was determined by heating a 2 g sample at 195 ° C. for 90 minutes to evaporate the water content using an infrared moisture meter FD-610 manufactured by Kett Science Laboratory Co., Ltd.

<Measurement method with transmission electron microscope, measurement method of shading difference>
After the toner was embedded in an epoxy resin and cured, it was exposed to gas with ruthenium tetroxide for 5 minutes to distinguish and dye the components (shell) and internal components (core) of the added particles. Next, a cross section was cut out with a knife, and an ultrathin section of toner having a thickness of 200 nm was prepared using an ultramicrotome. Further, using a TEM (transmission electron microscope) H7500 (manufactured by Hitachi High-Tech), an ultrathin section of the toner was observed at an acceleration voltage of 100 kV, and the shadow difference was confirmed with the naked eye.

Example 1
<Preparation of wax dispersion liquid A1>
As wax, ester wax 1 (manufactured by Nichiyu Co., Ltd., product name: WEP-3, catalog melting point 73 ° C., catalog acid value 0.1 mgKOH / g, catalog hydroxyl value 3 mgKOH / g or less) 30.00 parts (1440 g), decaglycerin Decavehenate (manufactured by Mitsubishi Chemical Foods Co., Ltd., product name: B100D, hydroxyl value 27, melting point 70 ° C) 0.24 part, 20% sodium dodecylbenzenesulfonate aqueous solution (hereinafter abbreviated as "20% DBS aqueous solution") 1 .93 parts and 67.83 parts of desalted water were heated to 90 ° C. and mixed in a CSTR type stirring layer equipped with a 45 ° C. inclined 3-stage paddle blade for 20 minutes.
Next, while the dispersion was heated to 90 ° C., circulation emulsification was started using a valve homogenizer (manufactured by Gorin, 15-M-8PA type) under a pressure condition of 25 MPa, and the particle size was measured with nanotrack. The wax dispersion liquid A1 (emulsion solid content concentration = 31.2%) was prepared by dispersing until the medium diameter (D50) became 245 nm.

<Preparation of wax dispersion liquid A2>
22.50 parts of the above ester wax 1, ester wax 2 (manufactured by Nichiyu Co., Ltd., product name: WEP-5, catalog melting point 82 ° C, catalog acid value 0.1 mgKOH / g, catalog hydroxyl value 3 mgKOH / g or less) 7.50 Wax dispersion in the same manner as wax dispersion A1, except that parts (1080 g), 0.24 parts of decaglycerin decabehenate, 1.93 parts of 20% DBS aqueous solution, and 67.83 parts of desalted water were used. A2 (aqueous solid content concentration = 31.1%) was prepared.

<Preparation of polymer primary particle dispersion liquid B1>
34.7 parts of wax dispersion A1, 252 parts of desalinated water, 0.5% iron sulfate (II) in a reactor equipped with a stirrer, a heating / cooling device, a concentrator, and a device for charging each raw material / auxiliary agent. 0.02 part of a heptahydrate aqueous solution was charged, and the temperature was raised to 90 ° C. under a nitrogen stream while stirring.
Then, the mixture of the following monomer / emulsifier solution was added over 240 minutes while continuing stirring.
The time at which the addition of the mixture of the monomer and the emulsifier aqueous solution was started was defined as the start of polymerization, and the following initiator aqueous solution was added over 0 to 480 minutes from the start of polymerization. The following iron sulfate aqueous solution was added 240 minutes after the start of polymerization. The temperature was raised to 95 ° C. 300 minutes after the start of polymerization. Heating and stirring were continued until 540 minutes after the start of polymerization.

[Monomers]
Styrene 70.9 parts Butyl acrylate 29.1 parts Acrylic acid 0.85 parts Trichlorobromomethane 1.0 part Hexanediol diacrylate 0.95 parts

[Aqueous solution of emulsifier]
20% DBS aqueous solution 1.0 part Demineralized water 66.9 parts

[Initiator aqueous solution]
8% hydrogen peroxide aqueous solution 28.0 parts 8% L- (+) ascorbic acid aqueous solution 28.0 parts

[Iron sulfate aqueous solution]
0.5% iron (II) sulfate heptahydrate aqueous solution 0.08 part

After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle dispersion liquid B1. The median diameter (D50) measured using Nanotrack was 239 nm. The weight average molecular weight (Mw) was 67,000.

<Preparation of additional particle dispersion liquid B2>
50.7 parts of wax dispersion A2, 3.50 parts of 20% DBS aqueous solution, and 349 parts of desalinated water are charged into a reactor equipped with a stirrer, a heating / cooling device, a concentrator, and a device for charging each raw material / auxiliary agent. The temperature was raised to 75 ° C. under a nitrogen stream with stirring.
After 5 minutes of adding the following initiator aqueous solution 1, a mixture of the following monomer / emulsifier solution was added over 180 minutes while continuing stirring. The time when the addition of the mixture of the monomer and the emulsifier aqueous solution was started was defined as the start of polymerization, and the following iron sulfate aqueous solution was added 180 minutes after the start of polymerization. The temperature was raised to 93 ° C. 180 minutes after the start of polymerization. The following initiator aqueous solution 2 was added over 240 to 60 minutes from the start of polymerization. The following initiator aqueous solution 3 was added over 240 to 120 minutes from the start of polymerization. Heating and stirring were continued until 480 minutes after the start of polymerization.

[Monomers]
Styrene 97.9 parts Butyl acrylate 2.1 parts Acrylic acid 1.5 parts 1-dodecanethiol 1.0 part

[Aqueous solution of emulsifier]
20% DBS aqueous solution 1.0 part Demineralized water 66.7 parts

[Initiator aqueous solution 1]
20% Ammonium Persulfate Aqueous Solution 6.0 Parts [Initiator Aqueous Solution 2]
8% hydrogen peroxide aqueous solution 14.2 parts [Initiator aqueous solution 3]
8% L- (+) ascorbic acid aqueous solution 21.3 parts

[Iron sulfate aqueous solution]
0.5% iron (II) sulfate heptahydrate aqueous solution 0.05 part

After completion of the polymerization reaction, the mixture was cooled to obtain a milky white additional particle dispersion liquid B2. The median diameter (D50) measured using Nanotrack was 112 nm. The weight average molecular weight (Mw) was 41000.

<Preparation of toner mother particle C1>
89 parts (solid content) of the polymer primary particle dispersion liquid B1 and 0.27 parts (solid content) of the 20% DBS aqueous solution were removed from the mixer equipped with a stirrer, a heating / cooling device, and a device for charging each raw material / auxiliary agent. 33 parts of ionized water, 0.52 parts (solid content) of 5% iron (II) sulfate heptahydrate aqueous solution, 18 parts of cyan colorant EP-700 (manufactured by Dainichi Seika Co., Ltd.), 41 parts of deionized water. The mixture was added in order with stirring.
The temperature was raised to 45 ° C. over 260 minutes. Here, when the volume median particle diameter (Dv50) was measured using a multisizer, it was 5.2 μm. 9.8 parts (solid content) of the polymer primary particle dispersion liquid B1 was added.

After 30 minutes, 4.0 parts (solid content) of the additional particle dispersion liquid B2 was added. After 90 minutes, 4.1 parts (solid content) of a 20% DBS aqueous solution and 23 parts of deionized water were added, and then the temperature was raised to 69 ° C. over 60 minutes and maintained for 45 minutes. Then it was cooled to 30 ° C.

The obtained dispersion liquid was extracted and suction-filtered with an ejector using a filter paper of type 5 C (manufactured by Toyo Filter Paper Co., Ltd., No. 5C). The cake remaining on the filter paper was transferred to a stainless steel container equipped with a stirrer (propeller blade), ion-exchanged water having an electric conductivity of 1 μS / cm was added and stirred to uniformly disperse the cake, and then the cake was stirred for 30 minutes. This step was repeated until the electrical conductivity of the filtrate became 2 μS / cm, and then the obtained cake was dried in a blower dryer set at 40 ° C. for 48 hours to obtain toner mother particles C1.

<Manufacturing of toner D1>
Polymer / silica composite particles (ATLAS100: manufactured by Cabot: silica / polymer ratio = 70/30, true specific gravity = 1.7 g / cm ³ , containing octahydropentalene) are added to the toner mother particle C1 (100 parts). Add 4 parts, 0.5 parts of titania and silica composite oxide particles (STX501: manufactured by Nippon Aerosil Co., Ltd.), 0.4 parts of small particle size silica (RY200L: manufactured by Nippon Aerosil Co., Ltd.), and use a toner mixer. Toner D1 was obtained by stirring, mixing and sieving at 3000 rpm for 15 minutes.

Examples 2-8, Comparative Examples 1-3
In Example 1, except that the number of copies of the 20% DBS aqueous solution charged into the reactor at the time of preparing the additional particles, the particle size of the obtained additional particles, and the coverage were changed to the compositions shown in Table 1. Each toner was produced in the same manner as in 1.

Comparative Example 4
The toner of Comparative Example 4 was produced in the same manner as in Example 1 of JP-A-2006-145888.

Comparative Example 5
The toner of Comparative Example 5 was produced in the same manner as in Example 4 of JP-A-2014-081614.

Table 1 shows various physical characteristics of the obtained toner.

The toners obtained in Examples 1 to 8 and Comparative Examples 1 to 5 were used for evaluation and determination by the following method. The measured toner (sample) was immediately after production, that is, immediately after external addition, but the measured values are almost the same regardless of whether the toner (sample) is aged or already contained in a developing layer or the like. That is common technical knowledge. In addition, an appropriate value may not be obtained for the toner after external addition placed in an environment of 50 ° C. or higher.

[Measuring method of blocking resistance]
10 g of toner is placed in a cylindrical container with an inner diameter of 3 cm and a height of 6 cm, a load of 20 g is applied, and the mixture is left in an environment of a temperature of 50 ° C. and a humidity of 55% for 48 hours. The degree of aggregation was confirmed by applying.

[Criteria for blocking resistance]
⊚: Collapses with a load of 150 g or less ○: Collapses with a load of more than 150 g and 300 g or less Δ: Collapses with a load of more than 300 g and 900 g or less ×: Does not collapse unless a load of more than 900 g is applied

[Measurement method of fixability]
A recording paper (basis weight 80 g / m ² paper) carrying an unfixed toner image was prepared and tested as follows using a thermal roll fixing type fixing machine.

The roller diameter is 27 mm, the nip width is 9 mm, the fixing speed is 229 mm / sec, the upper roller has a heater, the roller surface is composed of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), and the silicone oil is Not applied.

The surface temperature of the roller was raised in increments of 5 ° C. from 135 ° C., ^{and a recording paper carrying an unfixed toner image having an adhesion amount of about 0.5 mg / cm 2} was conveyed to the fixing nip portion to obtain a fixed image.
A mending tape was attached to the fixed image, and a 2 kg weight was passed over the mending tape to bring the tape and the fixed image into close contact with each other. The mending tape was peeled off, and the degree to which the fixed image was transferred to the tape was visually determined. The following judgment was made based on the average value of the three tests.

[Criteria for fixability]
⊚: Fixes at 145 ° C or lower ◯: Fixes above 145 ° C and below 150 ° C ×: Fixes above 150 ° C

<Result>
As can be seen from Table 1, the toners of Examples 1 to 8 achieved both fixability and blocking resistance, but the toners of Comparative Examples 1 to 5 achieved both fixability and blocking resistance. However, either the fixing property or the blocking resistance was inferior.

The toner for static charge image development having the "measured value with a leometer" of the present invention can achieve both low temperature fixability and blocking resistance, so that it can be used for image formation that visualizes static charge images in printers, copiers, facsimiles, etc. It is widely used in the field.

1 Graph of tan δ obtained by the first measurement of the leometer 2 Graph of tan δ obtained by the second measurement of the leometer 3 Structure consisting of additional particles and an additive 4 At least the binder resin and the colorant Internal components contained A Convex part of toner surface with many thinned additional particle components B Concave part of toner surface with few thinned additional particle components

Claims (8)

The temperature at which tan δ becomes maximum in the first temperature rise measurement observed in the process of raising the temperature from 40 ° C to 120 ° C of the _{leometer is set to [T 1st} ], and then cooled to 40 ° C. When the temperature of 40 ° C. or higher and 80 ° C. or lower, which maximizes tan δ in the second temperature rise measurement observed in the temperature rise process from 40 ° C to 120 ° C _{, is set to [T 2nd} ], [T _2nd ]-[T _1st ] is 1.0 ° C or higher and 4.5 ° C or lower.
When the first measurement value observed at the maximum value of tanδ of 40 ° C. or higher and 80 ° C. or lower is [tanδ _1st ], [tanδ _1st ] is 1.15 or higher and 1.80 or lower.
When the second measured value observed at 40 ° C. or higher and 80 ° C. or lower is [tanδ _2nd ], the ratio [tanδ _2nd ] / [tanδ _1st ] is 1.50 or more and 2.20 or less. Toner for static charge image development. The [T _2nd ]-[T _1st ] is 2.5 ° C. or higher and 4.5 ° C. or lower.
The [tan δ _1st ] is 1.15 or more and 1.80 or less.
The toner for developing an electrostatic charge image according to claim 1, wherein the [tanδ _2nd ] / [tanδ _{1st] is 1.50 or more and 2.20 or less.} The [T _2nd ]-[T _1st ] is 2.5 ° C. or higher and 4.5 ° C. or lower.
The [tan δ _1st ] is 1.15 or more and 1.80 or less.
The toner for developing an electrostatic charge image according to claim 1, wherein the [tanδ _2nd ] / [tanδ _{1st] is 1.50 or more and 1.90 or less.} The toner for static charge image development according to any one of claims 1 to 3, which contains at least a toner mother particle containing a binder resin and a colorant, and an external additive. The toner mother particles contain at least an internal component containing a binder resin and a colorant, and an additional particle component existing around the internal component, and when the toner for electrostatic charge image development is measured with a transmission electron microscope. The toner for static charge image development according to claim 4, wherein there is no shadow difference between the internal component and the additional particle component. The toner for developing an electrostatic charge image according to any one of claims 1 to 5, which has an average circularity of 0.95 to 0.99. The toner for developing an electrostatic charge image according to any one of claims 1 to 6, wherein the volume average particle diameter is 5 to 8 μm. The toner for developing an electrostatic charge image according to any one of claims 1 to 7, which contains wax.

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