阅读说明：本技术 调色剂 (Toner and image forming apparatus ) 是由 照井雄平 梅田宜良 松永智教 琴谷昇平 佐藤正道 于 2019-07-16 设计创作，主要内容包括：本发明涉及调色剂。一种调色剂,其包括调色剂颗粒,所述调色剂颗粒包含调色剂基础颗粒和在调色剂基础颗粒的表面上的有机硅聚合物,其中有机硅聚合物在调色剂基础颗粒的表面上形成具有规定结构的凸部,并且在调色剂截面中,当凸起宽度w为凸部和调色剂基础颗粒形成连续界面的部分的长度,凸起直径D为凸部的最大长度,和凸起高度H为从凸部的顶点至沿调色剂基础颗粒表面的圆周的线的长度,凸起直径D与凸起宽度w的比D/w为0.33至0.80的这些凸部的个数比例为70个数％以上。(The present invention relates to a toner. A toner includes toner particles containing toner base particles and a silicone polymer on the surface of the toner base particles, wherein the silicone polymer forms projections having a prescribed structure on the surface of the toner base particles, and in a toner cross section, when a projection width w is a length of a portion where the projections and the toner base particles form a continuous interface, a projection diameter D is a maximum length of the projections, and a projection height H is a length from an apex of the projections to a line along a circumference of the toner base particle surface, a ratio D/w of the projection diameter D to the projection width w is 0.33 to 0.80, and a proportion of the number of these projections is 70 number% or more.)

1. A toner, characterized by comprising:

toner particles comprising toner base particles and a silicone polymer present on the surface of the toner base particles, wherein

The silicone polymer has a structure given by the following formula (1);

the silicone polymer forms projections on the surface of the toner base particles; and

in a planar image obtained by observing a cross section of the toner with a Scanning Transmission Electron Microscope (STEM), drawing a line along a circumference of the surface of the toner base particle, and converting based on the line along the circumference, and

assuming that a length of a line along the circumference for a portion where the convex portion and the toner base particle form a continuous interface is taken as a convex width w, a maximum length of the convex portion in a normal direction of the convex width w is taken as a convex diameter D, and a length from a vertex of the convex portion to the line along the circumference in a line segment forming the convex diameter D is taken as a convex height H,

a ratio P (D/w) of the number of convex portions in which a ratio D/w of the protrusion diameter D to the protrusion width w is 0.33 to 0.80 is 70% by number or more among the convex portions having the protrusion height H of 40nm to 300nm,

R-SiO_3/2(1)

in the above formula, R represents an alkyl group having 1 to 6 carbons, or a phenyl group.

2. The toner according to claim 1, wherein when a cross section of the toner is observed using a scanning transmission electron microscope STEM, Σ w/L is 0.30 to 0.90 assuming that a width of the planar image is taken as a circumferential length L and a sum of protrusion widths w of the protrusions having a protrusion height H of 40nm to 300nm in the protrusions of the silicone polymer present in the planar image is taken as Σ w.

3. The toner according to claim 1 or 2, wherein a fixation ratio of the silicone polymer on the toner is 80% by mass or more.

4. The toner according to claim 1 or 2, wherein when a cumulative distribution of the projection heights H is configured for the projections having the projection heights H of 40nm to 300nm, H80 is a projection height corresponding to a cumulative of 80% by number of the projection heights H from a small side, and H80 is 65nm or more.

5. The toner according to claim 1 or 2, wherein R is an alkyl group having 1 to 6 carbons.

Technical Field

The present invention relates to a toner used for developing an electrostatic charge image for use in an image forming apparatus such as an electrophotographic apparatus, and an electrostatic printing apparatus.

Background

Laser printers and copiers are typical examples of electrophotographic system-based devices that use toner. In recent years, coloring has advanced in a dramatic manner, and a higher level of image quality is demanded for textures. The improvement in transferability is a problem with toner-based electrophotography. For example, when a toner image formed on a photosensitive member, i.e., an electrostatic image bearing member, is transferred to a transfer material during a transfer step, toner (untransferred toner) may remain on the photosensitive member.

For improving the transferability of the toner, it is generally known that it is effective to reduce the adhesion of the toner to the electrostatic image bearing member. The adhesion of the external additive to the surface of the toner particles is an example of a means for reducing the adhesion of the toner. In particular, in the known method for improving transfer efficiency, physical adhesion between the toner and the electrostatic image bearing member is reduced by a spacer effect due to the addition of the spherical external additive having a large particle diameter.

However, although this is effective as a method for improving transfer efficiency, the spherical large-particle-diameter external additive undergoes migration, detachment, and embedding (burial) due to long-term image output, and thus cannot be used as a spacer. As a result, it is difficult to stably obtain the intended effect of improving the transfer efficiency.

Therefore, a method of suppressing migration and detachment of an external additive by realizing semi-embedding (semi-embedding) of a large-particle-diameter external additive is proposed in japanese patent application laid-open No. 2009-36980.

On the other hand, japanese patent application laid-open No.2008-257217 proposes a method of suppressing detachment and entrapment by the use of a large-particle-diameter external additive having a hemispherical shape.

On the other hand, in order to achieve an improvement in transferability by a method other than external addition, a method in which the surface of toner particles is coated with an organosilicon compound has also been extensively studied.

As an example of the technical idea of coating the surface of toner particles with a silicon compound, japanese patent application laid-open No.2001-75304 discloses a production method of a polymerized toner, which is characterized in that a silane coupling agent is added to the reaction system.

A method using a combination of a large-particle-diameter external additive and a silane coupling agent is proposed in japanese patent application laid-open No. 2017-138462. The method makes it possible to control the roughness of the toner particle surface while fixing the large-particle-diameter external additive on the toner particle surface with the silane coupling agent. As a result, migration, detachment, and entrapment of the large-particle-diameter external additive can be suppressed, and high transferability can be exhibited for a long period of time.

Disclosure of Invention

The invention in japanese patent application laid-open No.2009-36980 can suppress the migration and detachment of the large-particle-diameter external additive by realizing the half-embedding of the large-particle-diameter external additive, thereby providing a spacer effect that exhibits over a long period of time. However, it was found that as a result of the half embedding, embedding was accelerated in the latter half of the endurance test.

In addition, the use of the hemispherical-shaped large-particle-diameter external additive according to japanese patent application laid-open No.2008-257217 does suppress the migration and entrapment of the large-particle-diameter external additive, thus providing a spacer effect that exhibits over a long period of time. However, it was found that achieving uniform fixation of the large-particle-diameter external additive on the toner particle surface with this method is problematic, and therefore, maintenance of the transfer efficiency improving effect for accommodating further extension of the service life is problematic.

In the case of both japanese patent application laid-open nos. 2009-36980 and 2008-257217, it was also found that a problem of uniformity of fixation of the large-particle-diameter external additive occurs due to the use of dry external addition. Therefore, in the case of japanese patent application laid-open No.2009-36980, migration and detachment are not completely suppressed, and member contamination may occur by the detached large-particle-diameter external additive. Member contamination also occurs in the case of japanese patent application laid-open No.2008-257217 because the occurrence of migration and detachment is promoted when the hemispherical convex portions face the toner particle surface.

On the other hand, in the case of japanese patent application laid-open No.2001-75304, high transferability is not obtained due to insufficient coating by the silicon compound caused by insufficient deposition amount of the silicon compound on the toner particle surface.

In the case of japanese patent application laid-open No.2017-138462, it was found that since the large-particle-diameter external additive used is a sphere, the load in the normal direction received by the toner is finally concentrated at a single point on the large-particle-diameter external additive, and a problem arises with respect to the ability to resist embedment. As a result, this is not satisfactory in terms of obtaining further extension of the service life.

The present invention aims to solve these problems. That is, the present invention provides a toner that exhibits high transferability and is resistant to change even during long-term use, thereby maintaining high transferability.

As a result of intensive studies, the present inventors have found that a toner solving the above-described problems is obtained by forming projections on the surface of toner particles and by controlling the shape of these projections.

Accordingly, the present invention relates to a toner comprising toner particles comprising toner base particles and a silicone polymer on the surface of the toner base particles, wherein

The silicone polymer has a structure given by the following formula (1);

the silicone polymer forms projections on the surface of the toner base particles; and

in a plane image obtained by observing a toner cross section with a Scanning Transmission Electron Microscope (STEM), drawing a line along the circumference of the toner base particle surface, and converting based on the line along the circumference, and

assuming that the length of a line along the circumference for a portion where the convex portion and the toner base particle form a continuous interface is taken as a protrusion width w, the maximum length of the convex portion in the normal direction of the protrusion width w is taken as a protrusion diameter D, and the length of a line from the apex of the convex portion to the circumference in a line segment forming the protrusion diameter D is taken as a protrusion height H,

the ratio P (D/w) of the number of projections, in which the ratio D/w of the projection diameter D to the projection width w is 0.33 to 0.80, is 70% by number or more in projections having a projection height H of 40nm to 300 nm.

R-SiO_3/2(1)

In the formula, R represents an alkyl group having 1 to 6 carbons, or a phenyl group.

The present invention can thus provide a toner that exhibits high transferability and is resistant to change even during long-term use, thus maintaining high transferability.

Other features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic view of a cross section of a toner observed with STEM;

fig. 2 is a schematic view illustrating a method of measuring a convex shape on toner;

fig. 3 is a schematic view illustrating a method of measuring a convex shape on toner; and

fig. 4 is a schematic view illustrating a method of measuring a convex shape on toner.

Detailed Description

Embodiments of the present invention are described below, but the present invention is not limited to or by the following embodiments.

Unless specifically stated otherwise, the expressions "XX above and YY below" and "XX to YY" denoting a numerical range mean, in the present invention, a numerical range including the lower limit and the upper limit as endpoints.

The toner according to the present invention relates to a toner including toner particles containing toner base particles and a silicone polymer on the surface of the toner base particles, wherein

The silicone polymer has a structure given by the following formula (1);

the silicone polymer forms projections on the surface of the toner base particles; and

in a plane image obtained by observing a toner cross section with a Scanning Transmission Electron Microscope (STEM), drawing a line along the circumference of the toner base particle surface, and converting based on the line along the circumference, and

assuming that the length of a line along the circumference for a portion where the convex portion and the toner base particle form a continuous interface is taken as a protrusion width w, the maximum length of the convex portion in the normal direction of the protrusion width w is taken as a protrusion diameter D, and the length of a line from the apex of the convex portion to the circumference in a line segment forming the protrusion diameter D is taken as a protrusion height H,

the ratio P (D/w) of the number of projections, in which the ratio D/w of the projection diameter D to the projection width w is 0.33 to 0.80, is 70% by number or more in projections having a projection height H of 40nm to 300 nm.

R-SiO_3/2(1)

In the formula, R represents an alkyl group having 1 to 6 carbons, or a phenyl group.

The above conditions and requirements are described in detail below.

The toner according to the present invention has projections containing a silicone polymer on the surface of toner particles. These projections are in surface contact with the surface of the toner base particles. This surface contact can be expected to provide a significant inhibiting effect on the migration, detachment, and entrapment of the projections. To show the degree of surface contact, STEM observation of the toner cross section was performed. Fig. 1-4 provide schematic illustrations of these protrusions on the toner particles.

Fig. 1 shows a STEM image 1. The image shows about one quarter of the toner particles, where 2 is the toner base particle, 3 is the surface of the toner base particle, and 4 is the convex portion. In fig. 2 to 4, 5 is the projection width w, 6 is the projection diameter D, and 7 is the projection height H.

An image of a toner cross section is observed, and a line is drawn along the circumference of the surface of the toner base particle. The conversion into a planar image is performed based on the line along the circumference. In the planar image, the projection width w is considered to be the length of a line along the circumference of a portion where the projection and the toner base particle form a continuous interface. The protrusion diameter D is considered as the maximum length of the protrusion in the normal direction of the protrusion width w, and the protrusion height H is considered as the length of a line from the apex of the protrusion to the circumference in the line segment forming the protrusion diameter D.

In fig. 2 and 4, the protrusion diameter D and the protrusion height H are the same, whereas in fig. 3 the protrusion diameter D is larger than the protrusion height H.

Fig. 4 schematically shows a fixed state of the pellet like a bowl pellet in which the central portion of the hemispherical pellet is depressed, obtained by crushing and dividing the hollow pellet. In fig. 4, the projection width w is the sum of the lengths of the organosilicon compounds in contact with the surfaces of the toner base particles. Therefore, the projection width W in fig. 4 is the sum of W1 and W2.

It was found that when the ratio D/w of the projection diameter D to the projection width w of the projection shape of the projections of the organosilicon compound is 0.33 to 0.80 based on the definition given above, the projections are resistant to migration, detachment, and embedding. That is, it was found that when the ratio P (D/w) of the number of convex portions having a ratio D/w of 0.33 to 0.80 is 70% by number or more with respect to convex portions having a protrusion height H of 40nm to 300nm, excellent transferability capable of withstanding extension of service life is exhibited.

It is considered that the transferability is improved by the generation of a spacer effect between the surface of the toner base particle and the transfer member due to the convex portion of at least 40 nm. On the other hand, it is considered that the convex portion of 300nm or less exhibits a significant effect of suppressing migration, detachment, and embedding during the evaluation of durability.

It was found that when the ratio of the number of the projections of 40nm to 300nm, P (D/w), is 70% by number or more, a high effect of suppressing the contamination of the member is exhibited while maintaining the transferability during the durability test. P (D/w) is preferably 75% by number or more and more preferably 80% by number or more. Although the upper limit is not particularly limited, it is preferably 99% by number or less and more preferably 98% by number or less.

In addition, when the toner cross section is observed using the scanning transmission electron microscope STEM, assuming that the width of the planar image (the length of a line along the circumference of the toner base particle surface) is taken as the circumferential length L, and the sum of the protrusion width w of the protrusion having the protrusion height H of 40nm to 300nm in the protrusion of the silicone polymer present in the planar image is taken as Σ w, Σ w/L is preferably 0.30 to 0.90.

When Σ w/L is 0.30 or more, good transferability and a good suppression effect on member contamination are provided, and when Σ w/L is 0.90 or less, excellent transferability is provided. More preferably, Σ w/L is 0.45 to 0.80.

The fixation ratio of the silicone polymer of the toner is preferably 80% by mass or more. The fixation rate of 80 mass% or more is advantageous for better maintenance of the transferability and the effect of suppressing the member contamination during long-term use. The fixation rate is more preferably 90% by mass or more and still more preferably 95% by mass or more. On the other hand, the upper limit is not particularly limited, but is preferably 99% by mass or less and more preferably 98% by mass or less. During the addition and polymerization of the organosilicon compound, the anchorage rate can be controlled by: the addition rate of the organosilicon compound, the reaction temperature, the reaction time, the pH during the reaction, and the timing of pH adjustment.

In addition, from the viewpoint of providing further improved transferability, among them, when the cumulative distribution of the projection heights H is constructed for the projections having the projection heights H of 40nm to 300nm, H80 is a projection height corresponding to a cumulative 80% by number of the projection heights H from the small side, and H80 is preferably 65nm or more. More preferably 75nm or more. The upper limit is not particularly limited, but is preferably 120nm or less and more preferably 100nm or less.

When the toner is observed with a scanning electron microscope SEM, the projection diameter R is the maximum diameter of the convex portion of the silicone polymer, and the number average diameter of the projection diameter R is preferably 20nm to 80 nm. 35nm to 60nm is more preferable. In this range, the occurrence of component contamination is hindered.

The toner contains a silicone polymer having a structure given by the following formula (1).

R-SiO_3/2(1)

(in the formula, R represents an alkyl group having 1 to 6 carbons, or a phenyl group.)

In the silicone polymer having a structure represented by formula (1), one of the four valencies of the Si atom is bonded to R, and the remaining three are bonded to O atoms. The O atom is in a state where its two valences are each bonded to Si, thereby providing a siloxane bond (Si-O-Si). The Si and O atoms are considered at the level of the silicone polymer, since there are two Si atomsAt three O atoms, so that they consist of-SiO_3/2And (4) showing. It is believed that the-SiO of the organosilicon polymer_3/2The structure has a structure of silicon dioxide (SiO) composed of a large number of siloxane bonds₂) Similar properties.

R in the partial structure given by formula (1) is preferably an alkyl group having 1 to 6 carbons, and more preferably an alkyl group having 1 to 3 carbons.

Preferred examples of the alkyl group having 1 to 3 carbons are methyl, ethyl, and propyl. More preferably, R is methyl.

The silicone polymer is preferably a polycondensate of silicone compounds having a structure given by the following formula (Z).

(in the formula (Z), R₁Represents a hydrocarbon group (preferably an alkyl group) having 1 to 6 carbons, and R₂、R₃And R₄Each independently represents a halogen atom, a hydroxyl group, an acetoxy group, or an alkoxy group. )

R₁Preferred is an aliphatic hydrocarbon group having 1 to 3 carbons, and more preferred is a methyl group.

R₂、R₃And R₄Each independently represents a halogen atom, a hydroxyl group, an acetoxy group, or an alkoxy group (hereinafter also referred to as a reactive group). These reactive groups undergo hydrolysis, addition polymerization, and polycondensation, thereby forming a crosslinked structure.

The hydrolysis proceeds smoothly at room temperature, and from the viewpoint of the deposition behavior on the surface of the toner base particle, an alkoxy group having 1 to 3 carbons is preferable, and a methoxy group and an ethoxy group are more preferable.

R can be controlled using reaction temperature, reaction time, reaction solvent, and pH₂、R₃And R₄Hydrolysis, addition polymerization, and polycondensation. To obtain the silicone polymer for use in the present invention, it is possible to use R other than in the formula (Z) given above₁In addition to three reactive groups (R) in a single molecule₂、R₃And R₄) Or a combination of a plurality of such organosilicon compounds (hereinafter also referred to as trifunctional silanes).

The following are examples of compounds having formula (Z):

trifunctional methylsilanes such as methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, methylethoxydimethoxysilane, methyltrichlorosilane, methylmethoxydichlorosilane, methylethoxydichlorosilane, methyldimethoxysilane, methylmethoxyethoxysilane, methyldiethoxychlorosilane, methyltriacetoxysilane, methyldiacetoxysilane, methyldiacetoxyloxyethoxysilane, methylacethoxydiethoxysilane, methyltrimethoxysilane, methylmethoxydihydroxysilane, methylethoxydihydroxysilane, methyldimethoxysilane, methyldimethoxyhydroxysilane, methylethoxymethoxyhydroxysilane and methyldiethoxyhydroxysilane;

trifunctional silanes, such as ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, ethyltrisoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, propyltriacetoxysilane, propyltrisoxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltrisiloxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane, hexyltriacetoxysilane, and hexyltrisiloxanes; and

trifunctional phenylsilanes, for example phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane and phenyltrihydroxysilane.

To the extent that the effects of the present invention are not impaired, a silicone polymer obtained by using a combination of the following compound and an organosilicon compound having a structure given by the formula (Z) can be used: an organosilicon compound having four reactive groups in each molecule (tetrafunctional silane), an organosilicon compound having two reactive groups in each molecule (bifunctional silane), or an organosilicon compound having one reactive group (monofunctional silane). Examples are as follows:

dimethyldiethoxysilane, tetraethoxysilane, hexamethyldisilazane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane and 3- (2-aminoethyl) aminopropyltriethoxysilane, and trifunctional vinylsilanes such as vinyltriisocyanate silane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldiethoxymethoxysilane, vinylethoxydimethoxysilane, vinylethoxydihydroxysilane, vinyldimethoxyhydroxysilane, vinylethoxymethoxyhydroxysilane and vinyldiethoxymethylhydroxysilane.

The content of the silicone polymer in the toner particles is preferably 1.0% by mass to 10.0% by mass.

The following are examples of preferred methods for forming the convex shape as specified above on the toner particle surface: the toner base particles are dispersed in an aqueous medium to obtain a toner base particle dispersion, and then an organic silicon compound is added and the formation of a convex shape is caused to produce a toner particle dispersion.

The solid content concentration in the toner base particle dispersion liquid is preferably adjusted to 25 to 50 mass%. It is preferable to adjust the temperature of the toner base particle dispersion liquid to 35 ℃ or higher in advance. In addition, the pH of the toner base particle dispersion is preferably adjusted to a pH that inhibits the progress of condensation of the organosilicon compound. Since the pH that hinders the progress of condensation of the organosilicon compound varies depending on the particular substance, it is preferable to be within ± 0.5 centered on the pH at which the reaction is most hindered.

It is preferable to use an organosilicon compound subjected to hydrolysis treatment. For example, as the pretreatment of the organosilicon compound, the hydrolysis may be carried out in advance in a separate vessel. The supply concentration (charge concentration) of the hydrolysis is preferably 40 to 500 parts by mass, more preferably 100 to 400 parts by mass of water from which an ionic component has been removed, for example, deionized water or RO water, for 100 parts by mass of the amount of the organosilicon compound used. The conditions during hydrolysis are preferably pH 2 to 7, temperature 15 ℃ to 80 ℃, and time 30 to 600 minutes.

The resulting hydrolyzed solution is mixed with the toner base particle dispersion liquid, and is adjusted to a pH suitable for condensation (preferably 6 to 12 or 1 to 3, and more preferably 8 to 12). Formation of a convex shape is promoted by adjusting the amount of the hydrolysis solution to 5.0 parts by mass to 30.0 parts by mass of the organosilicon compound with respect to 100 parts by mass of the toner base particles. The condensation temperature and time during formation of the convex shape are preferably maintained at 35 ℃ to 99 ℃ for 60 minutes to 72 hours.

In view of the control of the convex shape on the surface of the toner particles, the adjustment of pH is preferably performed in two stages. The convex shape on the toner particle surface can be controlled by performing condensation of the organosilicon compound with appropriately adjusting the holding time before adjustment of pH and the holding time before adjustment of pH in the second stage. For example, it is preferable to perform the holding at a pH of 4.0 to 6.0 for 0.5 hours to 1.5 hours, and then at a pH of 8.0 to 11.0 for 3.0 hours to 5.0 hours. The bump shape can also be controlled by adjusting the condensation temperature of the organosilicon compound in the range of 35 ℃ to 80 ℃.

For example, the projection width w may be controlled using, for example, the addition amount of the organosilicon compound, the reaction temperature, the reaction pH of the first stage, and the reaction time. For example, as the reaction time of the first stage is prolonged, the projection width tends to increase.

The bump diameter D and the bump height H can be controlled by, for example, the addition amount of the silicone polymer, the reaction temperature, and the second-stage pH. For example, as the reaction pH in the second stage increases, the bump diameter D and the bump height H tend to increase.

Specific toner production methods are described below, but are not intended to be limiting or restricted to these.

Preferably, the toner base particles are produced in an aqueous medium, and projections of the silicone-containing polymer are formed on the surface of the toner base particles.

The suspension polymerization method, the dissolution suspension method, and the emulsion aggregation method are preferred production methods of the toner base particles, with the suspension polymerization method being more preferred. The suspension polymerization method facilitates uniform deposition of the silicone polymer on the surface of the toner base particle, supports excellent adhesion of the silicone polymer, and provides excellent environmental stability, excellent inhibiting effect of the charge reversal component, and excellent durability duration during long-term use. The suspension polymerization process is described further below.

The toner base particles are obtained in a suspension polymerization method by granulating a polymerizable monomer composition containing a polymerizable monomer that can produce a binder resin, and optionally an additive such as a colorant, in an aqueous medium, and then polymerizing the polymerizable monomer present in the polymerizable monomer composition.

The polymerizable monomer composition may also optionally contain a release agent as well as other resins. After the polymerization step is complete, the produced particles can be washed using known methods and recovered by filtration. The temperature may be increased in the latter half of the polymerization step. In order to remove the unreacted polymerizable monomer and by-products, a part of the dispersion medium may be distilled off from the reaction system in the latter half of the polymerization step or after completion of the polymerization step.

Preferably, the projections of the silicone polymer are formed using the above-described method and the toner base particles thus obtained.

A release agent may be used in the toner. The release agent may be exemplified as follows:

petroleum-based waxes such as paraffin, microcrystalline wax and vaseline, and derivatives thereof; montan wax and derivatives thereof; hydrocarbon waxes produced by the fischer-tropsch process, and derivatives thereof; polyolefin waxes such as polyethylene and polypropylene, and derivatives thereof; natural waxes such as carnauba wax and candelilla wax, and derivatives thereof; a higher aliphatic alcohol; fatty acids such as stearic acid and palmitic acid, and their amides, esters, and ketones; hydrogenated castor oil and derivatives thereof; and vegetable wax, animal wax and silicone resin.

The derivatives include oxides, and block copolymers and graft-modified products with vinyl monomers. A single mold release agent may be used, or a mixture of a plurality of mold release agents may be used.

The content of the release agent is preferably 2.0 parts by mass to 30.0 parts by mass with respect to 100 parts by mass of the binder resin or the polymerizable monomer for producing the binder resin.

For example, the following resins may be used as the other resins:

homopolymers of styrene or its derivatives, such as polystyrene and polyvinyltoluene; styrenic copolymers, such as styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-vinyl acetate copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-vinyl acetate copolymer, styrene-, Styrene-isoprene copolymers, styrene-maleic acid copolymers, and styrene-maleic acid ester copolymers; and polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic hydrocarbon resin, alicyclic hydrocarbon resin, and aromatic petroleum resin. One of these may be used, or a mixture of a plurality of them may be used.

The following vinyl-based polymerizable monomers are advantageous examples of the polymerizable monomers:

styrene; styrene derivatives such as α -methylstyrene, β -methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2, 4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, and p-phenylstyrene; acrylic polymerizable monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate (dimethyl phosphate ethyl acrylate), diethyl phosphate ethyl acrylate), dibutyl phosphate ethyl acrylate, and 2-benzoyloxyethyl acrylate; methacrylic-based polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, and dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, and vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; and vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropyl ketone.

Among these vinyl monomers, styrene derivatives, acrylic polymerizable monomers, and methacrylic polymerizable monomers are preferable.

A polymerization initiator may be added to polymerize the polymerizable monomer. The following are examples of polymerization initiators:

azo and diazo-based polymerization initiators such as 2,2 '-azobis (2, 4-dipivalonitrile), 2' -azobisisobutyronitrile, 1 '-azobis (cyclohexane-1-carbonitrile), 2' -azobis-4-methoxy-2, 4-dimethylvaleronitrile, and azobisisobutyronitrile; and peroxide-based polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl carbonate peroxide, cumene hydroperoxide, 2, 4-dichlorobenzoyl peroxide, and lauroyl peroxide.

These polymerization initiators are preferably added in an amount of 0.5 to 30.0 parts by mass relative to 100 parts by mass of the polymerizable monomer, and a single polymerization initiator may be used or a plurality of polymerization initiators may be used in combination.

In order to control the molecular weight of the binder resin constituting the toner base particles, a chain transfer agent may be added at the time of polymerization of the polymerizable monomer. The preferable addition amount is 0.001 to 15.000 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

In order to control the molecular weight of the binder resin constituting the toner base particles, a crosslinking agent may be added at the time of polymerization of the polymerizable monomer. The following are examples:

divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1, 3-butanediol diacrylate, 1, 4-butanediol diacrylate, 1, 5-pentanediol diacrylate, 1, 6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, the diacrylates of polyethylene glycol #200, #400 and #600, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester-type diacrylates (MANDA, Nippon Kayaku Co., Ltd.), and crosslinking agents obtained by changing the aforementioned acrylates to methacrylates.

The polyfunctional crosslinking monomer may be exemplified by: pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylates and methacrylates thereof, 2-bis (4-methacryloxypolyethoxyphenyl) propane, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, and diallyl chlorendate.

The preferable addition amount is 0.001 to 15.000 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

When the medium used for the suspension polymerization is an aqueous medium, the following may be used as a dispersion stabilizer for the particles of the polymerizable monomer composition:

tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina.

The following are examples of organic dispersants: polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, the sodium salt of carboxymethyl cellulose, and starch.

Commercially available nonionic, anionic, or cationic surfactants may also be used. Examples of such surfactants are as follows: sodium lauryl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, and potassium stearate.

A colorant may be used in the toner; the colorant is not particularly limited, and known colorants can be used.

The content of the colorant is preferably 3.0 parts by mass to 15.0 parts by mass with respect to 100 parts by mass of the binder resin or the polymerizable monomer that can produce the binder resin.

A charge control agent may be used during toner production, and a known charge control agent may be used. The amount of the charge control agent added is preferably 0.01 to 10.00 parts by mass with respect to 100 parts by mass of the binder resin or the polymerizable monomer.

The toner particles themselves may be used as a toner, or any of various organic or inorganic fine powders may be externally added to the toner particles. In view of durability when added to toner particles, a particle diameter of one tenth or less of the weight average particle diameter of toner particles is preferable for the organic or inorganic fine powder.

For example, the following substances are used for organic or inorganic fine powders.

(1) Fluidity imparting agent: silica, alumina, titania, carbon black, and fluorinated carbon.

(2) Grinding agent: metal oxides (e.g., strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide), nitrides (e.g., silicon nitride), carbides (e.g., silicon carbide), metal salts (e.g., calcium sulfate, barium sulfate, calcium carbonate).

(3) Lubricant: fluorine resin powder (e.g., vinylidene fluoride and polytetrafluoroethylene), and metal salt of fatty acid (e.g., zinc stearate and calcium stearate).

(4) Charge controlling particles: metal oxides (e.g., tin oxide, titanium oxide, zinc oxide, silica, alumina), carbon black.

Organic or inorganic fine powders may be surface treated to improve the fluidity of the toner and to provide more uniform toner charging. The treating agent for hydrophobizing the organic or inorganic fine powder may be exemplified by unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oils, various modified silicone oils, silane compounds, silane coupling agents, organic silicon compounds other than the foregoing, and organic titanium compounds. These treating agents may be used alone, or a plurality of them may be used in combination.

The measurement method according to the present invention is described below.

Method for observing toner cross section by Scanning Transmission Electron Microscope (STEM)

A cross section of the toner observed with a Scanning Transmission Electron Microscope (STEM) was prepared as follows.

The method of preparing the toner section is described below.

The toner was first spread as a single layer on a cover Glass (Square cover Glass, Square No.1, Matsunami Glass ind., Ltd.), and an Os film (5nm) and a naphthalene film (20nm) were applied thereon as protective films using an Osmium Plasma Coater (OPC80T, Filgen, Inc.).

Then, D800 photocurable resin (A)JEOL Ltd.) filled into PTFE tubing

And the above cover glass was gently placed on the tube with the toner facing the tube to contact the D800 photocurable resin. The assembly was exposed to light and the resin was cured, and then the cover glass and the tube were removed to produce a cylindrical resin in which toner was embedded on the outermost surface side.

Using an ultrasonic microtome (UC7, Leica), a cross section of the center portion of the toner was produced by cutting at a cutting speed of 0.6mm/s from the outermost surface side of the cylindrical resin at a length just equal to the radius of the toner (e.g., 4.0 μm when the weight average particle diameter (D4) was 8.0 μm).

Thin flake samples of the toner cross-section were then prepared by cutting at a film thickness of 100 nm. The cross section of the center portion of the toner can be obtained by cutting according to this step.

Images were acquired using a STEM probe size of 1nm and an image size of 1024 × 1024 pixels. The Image is acquired by adjusting Contrast (Contrast) to 1425 and Brightness (Brightness) to 3750 on a Detector Control (Detector Control) panel of the bright field Image, and adjusting Contrast to 0.0, Brightness to 0.5, and Gamma to 1.00 on an Image Control (Image Control) panel. As shown in fig. 1, the image magnification is 100,000 times, and image acquisition is performed to match about one-fourth to one-half of the circumference of the cross section of one toner particle.

By using Image processing software (Image J (from)https://imagej.nih.gov/ij/Available)) image processing the obtained image to measure the convex portion of the silicone-containing polymer. The 30 STEM images were subjected to image processing.

First, a line is drawn along the circumference of the toner base particle using a line drawing tool (selected segment line on the Straight tab). In the region where the silicone polymer projections are embedded in the toner base particles, the lines are smoothly connected as if this embedding had not occurred.

Conversion into a flat image is performed based on the line (Selection) is selected on an Edit (Edit) tab and the line width is converted into 500 pixels using an attribute, and then Selection (Selection) is selected on the Edit (Edit) tab and a streamer is performed). Using the above method, the protrusion width w, protrusion diameter D, and protrusion height H were measured at each individual position of the convex portion of the silicone-containing polymer in the planar image. P (D/w) was calculated from the measurement results of 30 STEM images. A cumulative distribution of protrusion heights H is also generated and H80 is calculated.

In addition, Σ w is used for the sum of the protrusion widths w of the convex portions having the protrusion height H of 40nm to 300nm existing in the planar image for image analysis, and the circumferential length L is used for the width of the planar image for image processing. The width of the plane image corresponds to the length of the surface of the toner base particle in the STEM image. Calculate the single image Σ w/L and use the arithmetic mean of 30 STEM images.

Details of the measurement of the convex portion are as described above and shown in fig. 2 to 4.

The Scale on the image is overlapped with a Straight Line (Straight Line) in the Straight tab in ImageJ and the length of the Scale on the image is Set using Set Scale in the Analyze tab and then measured. Line segments corresponding to the bump width w and bump height H are drawn with Straight lines in the bump tab (bump Line) and can be measured using Measure in the Analyze tab.

Method for calculating average particle diameter of protrusions using Scanning Electron Microscope (SEM)

The SEM observation method was as follows. This method was performed using an image taken with an S-4800Hitachi ultra High resolution field emission scanning electron microscope (Hitachi High-Technologies Corporation). The image acquisition conditions using S-4800 are as follows.

(1) Sample preparation

A conductive paste (product No.16053, PELCO Colloidal Graphite, isoproapanol Base, TED PELLA, Inc.) was thinly coated on a sample stage (15mm × 6mm aluminum sample stage), and a toner was sprayed thereon. After removing the excess toner from the sample stage using an air blower, platinum vapor deposition was performed at 15mA for 15 seconds. The sample stage was placed in the sample holder, and the height of the sample stage was adjusted to 30mm using a sample height gauge.

(2) Conditions for S-4800 Observation were set

Liquid nitrogen was introduced to the edge of the anti-contamination container attached to the S-4800 enclosure and allowed to stand for 30 minutes. "PC-SEM" for S-4800 was started and flash (FE tip to be electron source cleaned) was performed. Click the acceleration voltage display area in the control panel on the screen and press the [ flash ] button to open the flash execution dialog. Confirm that the flash intensity is 2 and perform. The emission current caused by the flash was confirmed to be 20 to 40 μ a. The sample holder was inserted into the sample chamber of the S-4800 enclosure. Press [ home ] on the control panel to transfer the sample holder to the viewing position.

The acceleration voltage display area is clicked to open the HV setting dialog, and the acceleration voltage is set to [2.0kV ], and the emission current is set to [10 μ a ]. In the [ base ] tab of the operation panel, the signal selection is set to [ SE ]; select [ lower (L) ]forthe SE detector; and the instrument is placed in a backscattered electron image viewing mode. Similarly, in the [ base ] tab of the operator panel, the probe current of the electron optics condition block is set to [ Normal ]; setting the focus mode to [ UHR ]; and WD was set to [8.0mm ]. An ON button in an acceleration voltage display area of the control panel is pressed to apply the acceleration voltage.

(3) Focus adjustment

The magnification is set to 5,000(5k) times by dragging within the enlarged display area of the control panel. The [ COARSE ] focus knob on the operation panel is rotated to adjust the aperture alignment with a certain degree of focus. Click [ Align ] in the control panel and display the alignment dialog and select [ beam (beam) ]. The displayed beam is moved to the center of the concentric circles by rotating the STIGMA/align knob (X, Y) on the operating panel.

Then [ aperture ] is selected and the STIGMA/align knob (X, Y) is rotated once and adjusted to stop or minimize the motion of the image. The iris dialog is closed and focusing is performed in the case of autofocus. Focusing is performed by repeating this operation another two times. In the case of adjusting the center of the maximum diameter of the observed particle to the center of the measurement screen, the magnification is set to 10,000X (10k) by dragging within the enlarged display area of the control panel. The [ COARSE ] focus knob on the operation panel is rotated to adjust the aperture alignment with a certain degree of focus. Click [ Align ] in the control panel and display the alignment dialog and select [ beam ]. The displayed beam is moved to the center of the concentric circles by rotating the STIGMA/align knob (X, Y) on the operating panel.

Then [ iris ] is selected and the STIGMA/align knob (X, Y) is rotated once and adjusted to stop or minimize the motion of the image. The iris dialog is closed and focusing is performed in the case of autofocus. Then the magnification was set to 50,000(50k) times; focus adjustment is performed as above using the focus knob and the STIGMA/align knob; and refocusing using autofocus. This operation is repeated to achieve focusing.

(4) Image storage

Brightness adjustment is performed using the ABC mode, and a photograph of 640 × 480 pixels in size is taken and saved.

Using the obtained SEM images, the number average diameter of 20nm or more convex portions present at 500 positions on the toner particle surface was calculated using image processing software (ImageJ) (D1). The measurement method is as follows.

Measurement of number average diameter of projections of Silicone Polymer

The convex portions in the image and the toner base particles are binarized and color-distinguished by particle analysis. Then, the maximum diameter of the selected shape is selected from the measurement instruction, and the protrusion diameter R (maximum diameter) of the convex portion at one position is measured. This operation is performed a plurality of times, and the number average diameter of the projection diameter R is calculated by determining the arithmetic average of 500 positions.

Method for measuring fixation rate of organic silicon polymer

A sucrose concentrate was prepared by adding 160g of sucrose (Kishida Chemical co., Ltd.) to 100mL of deionized water and dissolving while heating on a water bath. 31g of this sucrose concentrate and 6mL of Contaminon N (a 10 mass% aqueous solution of a precision measuring instrument cleaning neutral pH7 detergent, which includes a nonionic surfactant, an anionic surfactant, and an organic auxiliary agent, Wako Pure Chemical Industries, Ltd.) were introduced into a centrifugal separation tube (50mL volume) to prepare a dispersion. 1.0g of toner was added to the dispersion, and the toner lumps were broken up using, for example, a doctor blade.

The centrifuge tube was shaken for 20 minutes with a shaker at 350 strokes per minute (spm). After shaking, the solution was transferred to a glass tube (50mL volume) to rotate a rotor, and separation was performed using a centrifugal separator (H-9R, Kokusan co., Ltd.) at 3,500rpm for 30 minutes. Satisfactory separation of the toner from the aqueous solution was visually checked, and the toner separated into the uppermost layer was recovered with, for example, a blade. The aqueous solution containing the recovered toner was filtered on a vacuum filter and then dried in a dryer for 1 hour or more. The dried product was crushed with a spatula and the amount of silicon was measured by X-ray fluorescence. The fixation ratio (%) was calculated from the ratio of the amounts of the measuring elements between the toner after water washing and the starting toner.

The measurement of the X-ray fluorescence of the specific element is based on JIS K0119-.

An "Axios" wavelength dispersive X-ray fluorescence analyzer (PANalytical b.v.) was used as a measuring instrument, and "SuperQ ver.4.0 f" (PANalytical b.v.) software attached to the instrument was used to set measurement conditions and analyze measurement data. Rh for X-ray tube anodes; vacuum was used for the measuring atmosphere; the measurement diameter (collimator mask diameter) was 10 mm; and a measurement time of 10 seconds. In the case of measuring light elements, detection is performed with a Proportional Counter (PC), and in the case of measuring heavy elements, detection is performed with a flicker counter (SC).

About 1g of the starting toner or the water-washed toner was introduced into a special aluminum compacting ring having a diameter of 10mm and smoothed, and pellets were produced by forming into a thickness of about 2mm by compression at 20MPa for 60 seconds using a "BRE-32" tablet forming Machine (Maekawa Testing Machine mfg.co., Ltd.) and used as a sample for measurement.

Performing measurements using the above conditions and identifying elements based on the positions of the resulting X-ray peaks; their concentration is calculated from the count rate (units: cps), i.e. the number of X-ray photons per unit time.

For example, in order to quantify the amount of silicon in the toner, for example, 0.5 parts by mass of Silica (SiO) is added₂) The fine powder was added to 100 parts by mass of the toner particles, and sufficient mixing was performed using a coffee mill. 2.0 parts by mass and 5.0 parts by mass of each of the fine silica powders were similarly mixed with the toner particles, and they were used as samples for calibration curve construction.

For each of these samples, pellets of the sample for calibration curve construction were produced as described above using a tablet press-forming machine, and the count rate (unit: cps) of Si — K α line observed at a diffraction angle (2 θ) ═ 109.08 ° was measured using PET for spectroscopic crystals. In this case, the acceleration voltage and current values of the X-ray generator are 24kV and 100mA, respectively. By placing the obtained X-ray count rates on the vertical axis and applying each calibration curve to the SiO in the sample₂The addition was placed on the horizontal axis to obtain a calibration curve in the form of a linear function.

The toner to be analyzed was then made into pellets as described above using a tablet forming machine, and measurement of the Si — ka line count rate thereof was performed. The silicone polymer content in the toner is determined from the above calibration curve. The ratio of the amount of the element in the toner after water washing calculated by this method to the amount of the element in the starting toner was determined and used as the fixation ratio (%).