JP7293586B2 - image forming system - Google Patents

Description

TECHNICAL FIELD The present invention relates to an image forming system, and more particularly, a gloss system that achieves a wide range of glossiness from low glossiness to high glossiness while ensuring fixability and heat resistance of a toner for developing an electrostatic charge image. The present invention relates to an image forming system with a wider degree control range.

As user needs diversify, glossiness is one of the textures of images. As a system for changing the glossiness, in addition to the fixing temperature and adhesion amount of the toner for electrostatic image development (hereinafter also referred to as toner), for example, an image forming apparatus disclosed in Japanese Patent Laid-Open No. 2002-300001 can be used. can.

However, by simply using the image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 2002-200310, it is possible to expand the control range of glossiness with a single printing machine, and to increase the glossiness from low glossiness suitable for plain paper to high glossiness suitable for photographic images. Since it is not sufficient to achieve a wider range of glossiness up to glossiness, an image forming system capable of further expanding the control range of glossiness is desired.

JP 2014-240869 A

The present invention has been made in view of the above-mentioned problems and circumstances, and the problem to be solved is to achieve a wide range of toner from low glossiness to high glossiness while ensuring the fixability and heat resistance of the toner for electrostatic image development. To provide an image forming system which realizes a range of glossiness and widens the control range of glossiness.

In order to solve the above problems, in the process of studying the causes of the above problems, the present inventors have achieved fixability and heat resistance by combining a specific electrostatic image developing toner with a specific image forming apparatus. In addition, the present inventors have found that an image forming system can be obtained that achieves a wider range of glossiness from low glossiness to high glossiness and that has a wide glossiness control range.

That is, the above problems related to the present invention are solved by the following means.

1. An image forming system comprising at least an electrostatic charge image developing toner containing toner base particles containing a release agent and a binder resin, and an image forming apparatus,
the toner base particles have a domain-matrix structure and contain a first binder resin and a second binder resin as the binder resin;
the glass transition temperature (Tg) of the second binder resin is higher than the Tg of the first binder resin by 10° C. or more;
containing a vinyl resin as the first binder resin,
The second binder resin contains an amorphous polyester resin as a domain,
The amorphous polyester resin is a hybrid amorphous polyester resin formed by chemically bonding a vinyl-based polymer segment and a polyester-based polymer segment, and the image forming apparatus comprises at least
an image forming unit that forms a toner image on a transfer material using the electrostatic image developing toner;
a fixing driving unit that drives the fixing member to rotate;
a pressurizing drive unit that drives the pressurizing member to rotate;
a drive control unit that controls rotational driving of the fixing drive unit or the pressure drive unit; and
When the fixing member and the pressure member nip the transfer material and fix the toner image, the drive control unit rotates the fixing member and the pressure member by the following formula 1. An image forming system , wherein the ratio of the surface speed of the fixing member to the surface speed of the pressing member is adjusted to be within ±10%.
Formula 1 Ratio of the surface speed of the fixing member to the surface speed of the pressure member (%) = {(Surface speed of the fixing member (mm/sec) - Surface speed of the pressure member (mm/sec)) ÷ Speed of the pressure member Surface speed (mm/sec)}×100

2 . When the average maximum length of the cross section of the toner base particles is r, the second binder resin occupies 80% or more of the area of the cross section in the depth direction of r/4 from the surface. 2. The image forming system according to claim 1, wherein the image forming system comprises:

3 . 3. The image forming system according to item 1 or 2 , wherein the average diameter of the domains is in the range of 50 to 150 nm.

4 . 4. The image forming system according to any one of items 1 to 3 , wherein the release agent contains a hydrocarbon compound.

5 . 5. The image forming system according to any one of items 1 to 4 , wherein the toner base particles contain an average of 5 to 25% by mass of the second binder resin.

6 . 6. The image forming system according to any one of items 1 to 5 , wherein the toner base particles contain the release agent in an average of 5 to 15% by mass.

According to the above-described means of the present invention, the control range of glossiness is widened to achieve a wider range of glossiness from low glossiness to high glossiness while ensuring fixability and heat resistance of the toner for electrostatic image development. An image forming system can be provided.

Although the expression mechanism or action mechanism of the effects of the present invention has not been clarified, it is speculated as follows.

In toner particles for developing electrostatic images, conventional toner particles containing a binder resin of a single composition use a resin having a relatively high glass transition temperature (hereinafter also referred to as Tg) in order to ensure heat resistance. It was difficult to spread depending on the fixing member, and the glossiness control range was insufficient.

Glossiness is controlled by changing the surface velocities of the fixing member and the pressure member in the image forming apparatus, thereby generating a difference in deformation speed (also referred to as shear or shear stress) between the upper portion and the lower portion of the toner particles. This is done by spreading the toner particles due to shear stress. When the degree of spreading changes, the unevenness of the image surface changes, so the glossiness of the image changes.

Regarding the ease of spreading of the toner particles, when the toner particles constituting the toner for developing an electrostatic charge image are core-shell structure particles, the toner particles spread more easily, for example, to the core portion than the binder resin of a single composition. This is advantageous because the binder resin can be arranged. However, from the standpoint of heat-resistant storage stability of toner particles, since the shell is generally made of a binder resin having a high Tg (for example, the second binder resin in the present invention), extension due to shear stress is caused by the hardness of the shell. Ease of use is not enough.

On the other hand, when the toner for electrostatic charge image development is domain-matrix structure particles, the high Tg amorphous resin (for example, amorphous polyester) exists in a domain state without forming a film. The deformation due to the shear stress is dominated by the performance of the first binder resin forming the matrix, and the use of a binder resin having a relatively low Tg as the first binder resin makes it possible to sufficiently facilitate extension. Further, since the domains are present near the surface layer of the toner particles, there is an advantage that the heat-resistant storage stability can be maintained as compared with core-shell particles.

In addition, since a part of the binder resin exists as a domain on the surface of the toner as compared with the case where the toner is formed into a film by the shell, the releasing agent (wax) seeps out from the inside to the surface layer. , the release agent is more likely to ooze out from the domain-matrix structure particles than from the core-shell structure particles. After spreading the toner particles, if a releasing agent (wax) is present on the image surface, the image surface becomes smoother, resulting in higher glossiness.

Therefore, when the toner for developing an electrostatic charge image containing the domain-matrix structure particles according to the present invention is used by providing a difference in surface speed when the fixing member/pressure member of the image forming apparatus rotates, spreadability and separation can be achieved. It is presumed that the exuding effect of the stencil agent (wax) is increased, and the glossiness control range is further expanded.

Schematic diagram for explaining ease of spreading by a fixing member when various toner particles are used. FIG. 2 is a cross-sectional view showing an example of a fixing member and a pressure member, which are fixing devices; A diagram showing the internal configuration of the main body of the image forming apparatus.

An image forming system of the present invention comprises at least a toner for developing an electrostatic charge image containing toner base particles containing a release agent and a binder resin, and an image forming apparatus, wherein the toner is The base particles have a domain-matrix structure, contain a first binder resin and a second binder resin as the binder resin, and the glass transition temperature (Tg) of the second binder resin is 1 higher than the Tg of the binder resin by 10° C. or more, contains a vinyl resin as the first binder resin, contains an amorphous polyester resin as a domain as the second binder resin, and contains the amorphous polyester The resin is a hybrid amorphous polyester resin formed by chemically bonding a vinyl polymer segment and a polyester polymer segment, and the image forming apparatus uses at least the electrostatic image developing toner. an image forming section for forming a toner image on a transfer material by means of a toner image; a fixing driving section for rotationally driving a fixing member; a pressure driving section for rotationally driving a pressure member; and the fixing driving section or the pressure driving section. and a driving control unit for controlling the rotational drive of the fixing member and the pressure member, and the drive control unit controls the fixing member and the fixing member when fixing the toner image by sandwiching the transfer material between the fixing member and the pressure member. The ratio of the surface speed of the fixing member to the surface speed of the pressure member represented by the following formula 1 when the pressure member is rotationally driven is adjusted to be within ±10%. and
Formula 1 Ratio of the surface speed of the fixing member to the surface speed of the pressure member (%) = {(Surface speed of the fixing member (mm/sec) - Surface speed of the pressure member (mm/sec)) ÷ Speed of the pressure member Surface speed (mm/sec)}×100
This feature is a technical feature common to or corresponding to the following embodiments.

As an embodiment of the present invention, from the viewpoint of exhibiting the effect of the present invention, the toner base particles have a domain-matrix structure and the second binder resin is contained as domains, so that the toner particles have The spreadability due to the shear stress is dominated by the performance of the first binder resin that constitutes the matrix, so that the spreadability becomes easier, which is preferable. Furthermore, since the domains are present in the vicinity of the surface of the toner particles, the heat-resistant storage stability is also improved. In addition, since a part of the binder resin composition of the toner for electrostatic charge image development exists on the surface of the toner particles as a domain, there is a state where the release agent inside the toner particles seeps out. In the case of the domain-matrix structure, the release agent is more likely to seep out to the surface than in the case of the core-shell structure, and the glossiness can be controlled in a wider range.

When the average maximum length of the cross section of the toner base particles is r, the second binder resin occupies 80% or more of the area of the cross section in the depth direction of r/4 from the surface. From the viewpoint of enhancing the heat resistance, it is preferable that the

Here, the occupied area ratio of the domain near the surface of the toner base particle is the area from the surface to r/4 (r=average value of the maximum length of the cross section of the toner base particle) in the cross-sectional image of the toner base particle described later. is defined by the following formula, where a is a and b is the sum of the areas of the domains (parts observed by staining) existing in the area a.

Occupied area ratio (%) = (b/a) x 100
Further, the average diameter of the domains is preferably in the range of 50 to 150 nm. When the average diameter is 50 nm or more, the stability of the dispersion is good, and when the average diameter is 150 nm or less, the heat resistance is excellent.

Further, the toner base particles preferably contain a vinyl resin as the first binder resin, and more preferably, the vinyl resin is a styrene-acrylic resin. It is easy to enclose the release agent in the toner during manufacturing, and it is easy to control exudation of the release agent during fixing.

The toner base particles preferably contain an amorphous polyester as the second binder resin, and the amorphous polyester is formed by chemically bonding a vinyl-based polymer segment and a polyester-based polymer segment. The hybrid amorphous polyester resin is preferably a mixed amorphous polyester resin from the viewpoint of balancing fixability and heat resistance.

Further, the glass transition temperature (Tg) of the second binder resin is higher than the Tg of the first binder resin by 10° C. or more from the viewpoint of enhancing the spreadability of the toner particles and widening the control range of the glossiness. ,preferable.

When the fixing member and the pressure member are rotationally driven, the difference in their surface speeds is within ±10% of the surface speed of the pressure member, so that the spreadability of the toner particles is enhanced. , is a preferable range from the viewpoint of achieving compatibility between widening the control range of the glossiness and preventing the fixing member from being damaged or the like.

The release agent contains a hydrocarbon-based compound and is contained in the toner base particles in an average range of 5 to 15% by mass, thereby separating the solubility parameter (SP value) from the first binder resin. This is preferable because it is possible to increase the amount of oozing, so that the control range of the glossiness can be widened and the heat-resistant storage stability can be maintained.

When the base particles contain the second binder resin in an average range of 5 to 25% by mass, heat resistance and fixability are not deteriorated, and the control range of glossiness can be widened. ,preferable.

DETAILED DESCRIPTION OF THE INVENTION The present invention, its constituent elements, and embodiments and modes for carrying out the present invention will be described in detail below. In the present application, "-" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.

<<Outline of the image forming system of the present invention>>
An image forming system of the present invention comprises at least a toner for developing an electrostatic charge image containing toner base particles containing a release agent and a binder resin, and an image forming apparatus, wherein the toner is The base particles contain a first binder resin and a second binder resin as the binder resin, and the image forming apparatus uses at least the electrostatic image developing toner to transfer toner onto a transfer material. An image forming section for forming an image, a fixing driving section for rotationally driving a fixing member, a pressure driving section for rotationally driving a pressure member, and a drive for controlling rotational driving of the fixing driving section or the pressure driving section. and a control unit, wherein the drive control unit controls the surface speed of the fixing member and the pressure member when the toner image is fixed by sandwiching the transfer material between the fixing member and the pressure member. It is characterized by adjusting the difference from the surface speed of

Here, the toner for electrostatic charge image development in the present invention means an aggregate of toner particles. Further, toner particles refer to toner base particles to which an external additive is added. In the present invention, when there is no need to distinguish between the toner base particles and the toner particles, they may simply be referred to as toner particles.

In the image forming system of the present invention, by changing the surface speed of the fixing member and pressure member of the image forming apparatus, a deformation speed difference (=shearing or rubbing stress) is generated between the upper portion and the lower portion of the toner particles, and the toner particles are transferred. When the image is spread on the material and the degree of spreading changes, the unevenness of the image surface changes, so that the glossiness changes.

In terms of ease of spreading, the toner for developing an electrostatic charge image having a domain-matrix structure is more advantageous than the toner having a core-shell structure. Generally, when a binder resin having a high Tg is formed into a film as a shell, deformation due to shear stress is difficult to occur due to its hardness. , the deformation of the toner particles due to the shear stress is dominated by the performance of the low-Tg binder resin, which is the matrix, and thus tends to deform and spread easily.

In addition, in the domain-matrix structure, part of the binder resin is present as a domain on the toner surface, compared with the case where the release agent inside the toner particles is formed into a film as the shell of the core-shell structure. It is considered that the release agent tends to seep out when the toner particles spread or crack due to the fact that the mold agent seeps out from the inside to the surface layer. When the wax is present on the image surface, the image surface becomes smooth and thus has a higher gloss.

Therefore, the image forming apparatus according to the present invention, which is drive-controlled so as to have a difference in the surface speeds of the fixing member and the pressure member which are rotationally driven by the driving section, and the present invention, which includes the first binder resin and the second binder resin. By using the electrostatic image developing toner according to No. 2 in combination, the spreadability of the toner particles and the effect of wax exudation are significantly changed, and the control range of the glossiness can be further widened.

FIG. 1 is a schematic diagram illustrating how easily various toner particles are spread by a fixing member.

FIG. 1(a) shows a case where the toner particles are composed only of a single binder resin (here, referred to as a first binder resin). Therefore, since the toner particles are designed to have a relatively high Tg, there is a difference in surface speed between the fixing member and the pressure member, and even if shear stress occurs, the toner particles are not easily deformed, and the glossiness control range is small (Fig. 1(a) steps a to c).

FIG. 1B shows the case of toner particles having a core-shell structure, in which the toner particles are composed of a core portion containing the first binder resin and a shell portion containing the second binder resin. Since the Tg can be lowered, it is easier to spread than toner particles of a single composition due to shear stress. However, when a film is formed by shell particles that generally have a high Tg, deformation due to shear is less likely to occur due to the hardness of the shell particles, and the release agent (wax) is less likely to appear on the toner particle surface. is smaller than the required level (FIG. 1(b) steps d to f).

FIG. 1(c) shows the case where the toner particles have a domain-matrix structure consisting of a matrix containing the first binder resin and domains containing the second binder resin. In this case, due to the shear stress due to the surface velocity difference, the performance of the low-Tg first binder resin, which is the matrix, becomes dominant against deformation, so that the toner particles tend to spread and cracks easily occur in the toner particles. , the releasing agent inside the toner particles tends to seep out to the surface, so that the glossiness control range is widened (steps g to i in FIG. 1(c)). Further, since the domains are present in the vicinity of the surface layer, the heat-resistant storage stability of the toner particles themselves is improved.
[1] Toner for developing an electrostatic charge image The toner for developing an electrostatic charge image according to the present invention contains toner base particles containing at least a release agent and a binder resin, and the toner base particles contain the binder resin. and a first binder resin and a second binder resin.

[1] Toner base particles The structure of the toner base particles containing the first binder resin and the second binder resin is preferably a core-shell structure or a domain-matrix structure. It is more preferable to have

Here, the “domain matrix structure” is also called a “sea-island structure”, and has a closed interface (boundary between phases) in the continuous phase (matrix: corresponding to the sea) of the toner base particles. A structure in which island-like dispersed phases (domains) exist.

<<Toner base particles having a domain-matrix structure>>
In the toner base particles having a domain-matrix structure according to the present invention, it is preferable that the matrix contains the first binder resin and the domains contain the second binder resin.

The toner for electrostatic charge image development of the present invention preferably contains an amorphous resin as a binder resin. Among them, it is preferable to use a vinyl resin, which is an amorphous resin, as the first binder resin. Furthermore, it is preferable to use an amorphous polyester resin as the second binder resin, and the amorphous polyester is a hybrid amorphous polyester resin in which a vinyl-based polymer segment and a polyester-based polymer segment are chemically bonded. It is preferable to use

In addition, it is preferable that the glass transition temperature (Tg) of the second binder resin is 10° C. or more higher than the glass transition temperature (Tg) of the first binder resin. By adjusting the glass transition temperature (Tg) by selecting each material or the like, the spreadability of the toner particles can be changed, and the range of gloss control can be widened.

Further, the toner for electrostatic image development according to the present invention contains a release agent. Further, the toner for electrostatic charge image development can further contain a coloring agent and the like, and can also contain a charge control agent, an external additive, and the like, if necessary.

In the toner base particles having a domain-matrix structure according to the present invention, there is a portion in which the amorphous polyester resin or the hybrid amorphous polyester resin is incompatible with the amorphous resin. A domain may contain a lamellar crystal structure. In addition, this structure can be observed by the following. Further, it is preferable that wax or the like, which is a release agent, is added to the domain or matrix in addition to the resin.

Apparatus: Electron microscope "JSM-7401F" (manufactured by JEOL Ltd.)
Sample: section of toner particles stained with ruthenium tetroxide (RuO ₄ ) (section thickness: 60-100 nm)
Accelerating voltage: 30 kV
Magnification: 50,000 times Observation conditions: transmission electron detector, bright field image A method for preparing sections of the dyed toner particles is as follows.

1 to 2 mg of toner is put in a 10 mL sample bottle so as to be spread out, treated with ruthenium tetroxide (RuO ₄ ) under vapor dyeing conditions as shown below, and then photocurable resin "D-800" (manufactured by JEOL Ltd.). and photocured to form blocks. Ultrathin samples with a thickness of 60-100 nm were then cut from the blocks using a diamond-toothed microtome. Thereafter, the excised sample was treated again under the following treatment conditions and dyed.
- Ruthenium tetroxide treatment conditions The ruthenium tetroxide treatment is performed using a vacuum electron dyeing apparatus VSC1R1 (manufactured by Filgen Co., Ltd.). A sublimation chamber containing ruthenium tetroxide is installed in the staining apparatus according to the procedure of the apparatus, and after introducing the toner or ultra-thin section into the staining chamber, the conditions for staining with ruthenium tetroxide are room temperature (24-25°C), The treatment is performed under the conditions of concentration 3 (300 Pa) and time 10 minutes.

The sample obtained by the above treatment is observed as follows.
・Observation Observation is performed with an electron microscope “JSM-7401F” (manufactured by JEOL Ltd.) within 24 hours after staining.

As described above, when the toner for developing an electrostatic charge image according to the present invention has a domain-matrix structure, the average diameter of the domains is preferably in the range of 50 to 150 nm. The average diameter of the domains can be measured by observing and analyzing the domains stained by the above method with an electron microscope and an image processing analyzer (for example, "LUZEX (registered trademark) AP" manufactured by Nireco Co., Ltd.). can. The average diameter of the domain as used herein means the average value of the major diameter of the domain.

<Matrix>
The matrix constituting the toner base particles preferably contains a vinyl resin, which is an amorphous resin, as the first binder resin.

Here, exhibiting amorphousness means having a glass transition point (Tg) in an endothermic curve obtained by differential scanning calorimetry (DSC), but having a melting point, that is, a clear endothermic peak at elevated temperature. Say no. A clear endothermic peak means an endothermic peak having a half-value width of 15°C or less in an endothermic curve when the temperature is increased at a rate of temperature increase of 10°C/min.

(vinyl resin)
The vinyl resin is not particularly limited as long as it is obtained by polymerizing a vinyl compound, and examples thereof include acrylic acid ester resin, styrene-acrylic acid ester resin, ethylene-vinyl acetate resin and the like. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Among the above vinyl resins, styrene-acrylic acid ester resins (also referred to as styrene-acrylic resins) are preferred in consideration of plasticity during heat fixing. Therefore, styrene-acrylic resin as the amorphous resin will be described below.

A styrene-acrylic resin is formed by addition polymerization of at least a styrene monomer and a (meth)acrylate monomer. The styrene monomer referred to herein includes, in addition to styrene represented by the structural formula of CH ₂ ═CH—C ₆ H ₅ , those having a structure having known side chains and functional groups in the styrene structure. Further, the (meth)acrylic acid ester monomers referred to herein include, in addition to acrylic acid ester compounds and methacrylic acid ester compounds represented by CH ₂ =CHCOOR (R is an alkyl group), acrylic acid ester derivatives and methacrylic acid ester compounds. It includes an ester compound having a known side chain or functional group in its structure, such as an ester derivative.

Specific examples of styrene monomers and (meth)acrylic acid ester monomers capable of forming styrene-acrylic resins are shown below. Things are not limited to what is shown below.

First, specific examples of styrene monomers include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4- dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene and the like. These styrene monomers can be used alone or in combination of two or more.

Further, specific examples of (meth)acrylic ester monomers include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, and 2-ethylhexyl acrylate. , acrylic acid ester monomers such as stearyl acrylate, lauryl acrylate, phenyl acrylate; Methacrylic acid esters such as stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, and the like.

In the present specification, the term "(meth)acrylic acid ester monomer" is a generic term for "acrylic acid ester monomer" and "methacrylic acid ester monomer". "Methyl acrylate" is a general term for "methyl acrylate (methyl acrylate)" and "methyl methacrylate (methyl methacrylate)".

These acrylic acid ester monomers or methacrylic acid ester monomers can be used alone or in combination of two or more. That is, forming a copolymer using a styrene monomer and two or more acrylic acid ester monomers, or copolymerizing a styrene monomer and two or more methacrylic acid ester monomers. It is possible either to form a coalescence or to form a copolymer using a combination of styrene monomers and acrylate and methacrylate monomers.

The method of forming the styrene-acrylic resin is not particularly limited, and examples thereof include a method of polymerizing monomers using a known oil-soluble or water-soluble polymerization initiator. Specific examples of oil-soluble polymerization initiators include the following azo-based or diazo-based polymerization initiators and peroxide-based polymerization initiators.

Azo or diazo polymerization initiators include 2,2′-azobis-(2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis(cyclohexane-1 -carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and the like.

Peroxide polymerization initiators include benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, 2,4 -dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis-(4,4-t-butylperoxycyclohexyl)propane, tris-(t-butylperoxy)triazine and the like.

Moreover, when forming resin particles by an emulsion polymerization method, a water-soluble radical polymerization initiator can be used. Examples of water-soluble polymerization initiators include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetate, azobiscyanovaleric acid and its salts, and hydrogen peroxide.

The content of structural units derived from styrene monomers in the styrene-acrylic resin is preferably 60 to 85% by mass based on the total amount of the styrene-acrylic resin. Further, the content of structural units derived from (meth)acrylic acid ester monomers in the styrene-acrylic resin is preferably 10 to 35% by mass with respect to the total amount of the styrene-acrylic resin. By setting it as such a range, it becomes easy to control the plasticity of amorphous resin.

From the viewpoint of ensuring low temperature fixability, the weight average molecular weight (Mw) of the vinyl resin is preferably 10,000 to 100,000, more preferably 20,000 to 90,000.

The glass transition temperature (Tg) of the vinyl resin is preferably in the range of 30 to 75° C., more preferably in the range of 35 to 70° C., from the viewpoint of improving spreadability of the toner base particles during fixing. , 35 to 60°C.

Here, the glass transition point (Tg) can be measured using a differential scanning calorimeter such as Diamond DSC (manufactured by PerkinElmer). Specifically, 3.0 mg of the sample is enclosed in an aluminum pan and set in a holder. Set an empty aluminum pan as a reference. A first heating process in which the temperature is raised from 0 ° C. to 100 ° C. at a rate of 10 ° C./min and held at 100 ° C. for 1 minute, cooled from 100 ° C. to 0 ° C. at a cooling rate of 10 ° C./min, A cooling process in which the temperature is held for 1 minute, and a second heating process in which the temperature is raised from 0 ° C. to 100 ° C. at a rate of 10 ° C./min. Observe the baseline shift in the measured curve obtained at times, and take the glass transition point (Tg) as the intersection of the extension of the baseline before the shift and the tangent line showing the maximum slope of the shifted portion of the baseline.

Also, the weight average molecular weight (Mw) of the vinyl resin described above can be obtained from the molecular weight distribution measured by gel permeation chromatography (GPC) as follows.

The sample was added to tetrahydrofuran (THF) to a concentration of 1 mg/mL, dispersed for 5 minutes using an ultrasonic disperser at room temperature, and then treated with a membrane filter having a pore size of 0.2 μm to remove the sample solution. Prepare. Using a GPC apparatus HLC-8120GPC (manufactured by Tosoh Corporation) and columns TSKguardcolumn+TSKgelSuperHZM-M triplet (manufactured by Tosoh Corporation), tetrahydrofuran as a carrier solvent is flowed at a flow rate of 0.2 mL/min while maintaining the column temperature at 40°C. Inject 10 μL of the prepared sample solution into the GPC device together with the carrier solvent, detect the sample using a refractive index detector (RI detector), and use a calibration curve measured using monodisperse polystyrene standard particles. , to calculate the molecular weight distribution of the sample. The standard curve shows molecular weights of 6×10 ² , 2.1×10 ³ , 4×10 ³ , 1.75×10 ⁴ , 5.1×10 ⁴ , 1.1×10 ⁵ , 3.9×10, respectively. ⁵ , 8.6×10 ⁵ , 2×10 ⁶ , and 4.48×10 ⁶ , 10 polystyrene standard particles (manufactured by Pressure Chemical).

<domain>
As the domains constituting the toner base particles, it is preferable to use an amorphous polyester resin as the second binder resin. It is preferable to use a crystalline polyester resin.

(amorphous polyester resin)
It is preferable to use an amorphous polyester resin as the amorphous resin for the toner base particles according to the present invention. The amorphous resin may be used singly or in combination of two or more, and the molecular weight of the amorphous resin to be used is not particularly limited.

Amorphous polyester resins are polyester resins that do not have a melting point and have a relatively high glass transition temperature (Tg) when differential scanning calorimetry (DSC) is performed.

An amorphous polyester resin is obtained by a polycondensation reaction between a divalent or higher carboxylic acid (polycarboxylic acid) and a divalent or higher alcohol (polyhydric alcohol). A specific amorphous polyester resin is not particularly limited, and conventionally known amorphous polyester resins in this technical field can be used.

A specific method for producing the amorphous polyester resin is not particularly limited, and polycondensation (esterification) of a polyhydric carboxylic acid and a polyhydric alcohol using a known esterification catalyst is performed. Resin can be produced.

The catalyst, polycondensation (esterification) temperature, and polycondensation (esterification) time that can be used during production are not particularly limited, and are the same as those for the crystalline polyester resin.

Although the weight average molecular weight (Mw) of the amorphous polyester resin is not particularly limited, it is preferably in the range of 5,000 to 100,000, more preferably in the range of 5,000 to 50,000. When the weight-average molecular weight (Mw) is 5,000 or more, the heat-resistant storage stability of the toner can be improved, and when it is 100,000 or less, the low-temperature fixability can be further improved. The weight average molecular weight (Mw) can be measured by the method described above.

Examples of polyhydric carboxylic acids and polyhydric alcohols used in the preparation of amorphous polyester resins include, but are not particularly limited to, the following.

As polyvalent carboxylic acid, it is preferable to use unsaturated aliphatic polyvalent carboxylic acid, aromatic polyvalent carboxylic acid, and derivatives thereof. A saturated aliphatic polycarboxylic acid may be used in combination as long as an amorphous resin can be formed.

Examples of the unsaturated aliphatic polycarboxylic acids include methylenesuccinic acid, fumaric acid, maleic acid, 3-hexenedioic acid, 3-octenedioic acid, and alkenyl groups having 2 to 20 carbon atoms. Unsaturated aliphatic dicarboxylic acids such as succinic acid; 3-butene-1,2,3-tricarboxylic acid, 4-pentene-1,2,4-tricarboxylic acid, unsaturated aliphatic tricarboxylic acids such as aconitic acid; 4- Examples include unsaturated aliphatic tetracarboxylic acids such as pentene-1,2,3,4-tetracarboxylic acid. Lower alkyl esters and acid anhydrides of these can also be used.

Examples of the aromatic polycarboxylic acid include phthalic acid, terephthalic acid, isophthalic acid, t-butylisophthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-phenylene diacetic acid, and 2,6-naphthalene dicarboxylic acid. aromatic dicarboxylic acids such as acids, 4,4′-biphenyldicarboxylic acid, anthracenedicarboxylic acid; 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid (trimesic acid), aromatic tricarboxylic acids such as 1,2,4-naphthalenetricarboxylic acid and hemimellitic acid; aromatic tetracarboxylic acids such as pyromellitic acid and 1,2,3,4-butanetetracarboxylic acid; aromatics such as mellitic acid hexacarboxylic acid and the like. Lower alkyl esters and acid anhydrides of these can also be used.

The above polycarboxylic acids may be used alone, or two or more of them may be mixed and used.

As the polyhydric alcohol, it is preferable to use an unsaturated aliphatic polyhydric alcohol, an aromatic polyhydric alcohol, and derivatives thereof from the viewpoint of compatibility control with the crystalline polyester resin. A saturated aliphatic polyhydric alcohol may be used in combination if an amorphous resin can be obtained.

Examples of the unsaturated aliphatic polyhydric alcohol include 2-butene-1,4-diol, 3-butene-1,4-diol, 2-butyne-1,4-diol, 3-butyne-1,4 -diol, and unsaturated aliphatic diols such as 9-octadecene-7,12-diol. Moreover, these derivatives can also be used.

Examples of the aromatic polyhydric alcohol include bisphenols such as bisphenol A and bisphenol F, ethylene oxide adducts thereof, alkylene oxide adducts of bisphenols such as propylene oxide adducts, and 1,3,5-benzenetriol. , 1,2,4-benzenetriol, 1,3,5-trihydroxymethylbenzene and the like. Moreover, these derivatives can also be used. Among these, bisphenol A compounds such as ethylene oxide adducts and propylene oxide adducts of bisphenol A are preferably used from the viewpoint of facilitating the optimization of thermal properties.

Although the number of carbon atoms in the polyhydric alcohol having a valence of 3 or more is not particularly limited, it is preferably in the range of 3 to 20 carbon atoms because it facilitates optimization of thermal properties.

The above polyhydric alcohols may be used alone or in combination of two or more.

The glass transition temperature (Tg) of the amorphous polyester resin is preferably in the range of 45 to 75°C, more preferably in the range of 50 to 70°C, from the viewpoint of the heat-resistant storage stability of the toner particles. It is more preferably in the range of 55-65°C.

When the glass transition point of the amorphous resin is within the above range, both sufficient low-temperature fixability and heat-resistant storage stability can be obtained.

The acid value of the amorphous polyester resin can be measured according to the method (potentiometric titration method) described in JIS K0070-1992. In this measurement, the solvent used is a mixture of tetrahydrofuran and isopropyl alcohol at a volume ratio of 1:1.

(hybrid amorphous polyester resin)
The hybrid amorphous polyester resin contained in the domains in the binder resin according to the present invention is preferably a resin in which a vinyl-based polymer segment and a polyester-based polymer segment are chemically bonded. Hereinafter, "hybrid amorphous polyester resin" is also referred to as "hybrid resin".

It is preferable that the vinyl-based polymer segment and the polyester-based polymer segment are bonded via a bi-reactive monomer. The polyester-based polymerized segment refers to a portion derived from an amorphous polyester resin. That is, it refers to a molecular chain having the same chemical structure as that constituting the amorphous polyester resin.

A vinyl-based polymer segment constituting a hybrid resin refers to a portion derived from a vinyl resin. That is, it refers to a molecular chain with the same chemical structure as that which constitutes the vinyl resin. Here, as the vinyl monomer, those mentioned above as the monomers constituting the vinyl resin can be used in the same manner, so detailed description thereof will be omitted here. The content of the vinyl-based polymer segment in the hybrid resin is not particularly limited, but the hybridization rate of the hybrid resin is preferably in the range of 1 to 30% by mass, more preferably in the range of 10 to 20% by mass. is more preferable.

The polyester-based polymer segment constituting the hybrid resin is composed of an amorphous polyester resin produced by subjecting a polycarboxylic acid and a polyhydric alcohol to a polycondensation reaction in the presence of a catalyst. Here, the specific types of polyhydric carboxylic acid and polyhydric alcohol are as described above.

A bi-reactive monomer is a monomer that binds a polyester polymer segment and a vinyl polymer segment, and contains a hydroxy group, a carboxy group, an epoxy group, and a primary group that form the polyester polymer segment in the molecule. It is a monomer having both a group selected from an amino group and a secondary amino group and an ethylenically unsaturated group forming a vinyl polymer segment. Both reactive monomers are preferably monomers having a hydroxy or carboxy group and an ethylenically unsaturated group. More preferably, it is a monomer having a carboxy group and an ethylenically unsaturated group. That is, it is preferably a vinyl-based carboxylic acid.

Specific examples of the bi-reactive monomer include, for example, acrylic acid, methacrylic acid, fumaric acid, maleic acid and the like, and esters of these hydroxyalkyl (having 1 to 3 carbon atoms) Good, but acrylic acid, methacrylic acid, or fumaric acid is preferred from the viewpoint of reactivity. The polyester-based polymer segment and the vinyl-based polymer segment are bonded via this bi-reactive monomer.

From the viewpoint of improving the low-temperature fixability, high-temperature offset resistance, and durability of the toner, the amount of the both reactive monomers used is, for example, 100 parts by mass of the total amount of the vinyl monomers constituting the vinyl-based polymer segment. It is preferably in the range of 1 to 10 parts by mass, more preferably in the range of 4 to 8 parts by mass.

An existing general scheme can be used as a method for producing a hybrid resin. Typical methods include the following three methods.

<1> A polyester polymer segment is polymerized in advance, a bi-reactive monomer is reacted with the polyester polymer segment, and an aromatic vinyl monomer and ( A method of forming a hybrid resin by reacting a meth)acrylic acid ester-based monomer.

<2> A vinyl-based polymer segment is polymerized in advance, a bi-reactive monomer is reacted with the vinyl-based polymer segment, and a polyhydric carboxylic acid and a polyhydric alcohol are added to form a polyester-based polymer segment. A method of forming a polyester-based polymerized segment by reacting.

<3> A method in which a polyester-based polymer segment and a vinyl-based polymer segment are polymerized in advance, respectively, and then reacted with a bi-reactive monomer to bond the two.

In the present invention, any of the above production methods can be used, but the method of <2> is preferred. Specifically, a polyvalent carboxylic acid and a polyhydric alcohol forming a polyester polymer segment, and a vinyl monomer and a bi-reactive monomer forming a vinyl polymer segment are mixed, and a polymerization initiator is added. After addition polymerization of a vinyl monomer and a bi-reactive monomer to form a vinyl polymer segment, it is preferable to add an esterification catalyst to carry out a polycondensation reaction.

Here, various conventionally known catalysts can be used as the catalyst for synthesizing the polyester polymer segment. Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin (II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropylate bistriethanolamine. , for example, gallic acid (3,4,5-trihydroxybenzoic acid) and the like.

From the viewpoint of achieving both low-temperature fixability and heat-resistant storage stability, the weight average molecular weight (Mw) of the hybrid resin is preferably 10,000 to 100,000, more preferably 20,000 to 90,000.

The glass transition temperature (Tg) of the hybrid resin is preferably in the range of 45 to 75°C, more preferably in the range of 50 to 70°C, similarly to the amorphous polyester resin, and 55 to 65°C. is more preferably within the range of

(Content of amorphous resin and amorphous polyester resin or hybrid amorphous polyester resin in binder resin)
The content of the amorphous resin, which is the first binder resin, in the binder resin is preferably 50 to 97% by mass, more preferably 70 to 95% by mass, based on the total binder resin. . Within this range, a toner having good low-temperature fixability and improved charging uniformity, heat-resistant storage stability, and transferability under high-temperature and high-humidity conditions (also referred to as “HH transferability”) can be obtained. can get.

Furthermore, the content of the amorphous polyester resin or hybrid amorphous polyester resin as the second binder resin in the binder resin is preferably 3 to 50% by mass, more preferably 4 to 40% by mass, based on the total binder resin. is more preferred, and 5 to 25% by mass is even more preferred. Within this range, good low-temperature fixability can be obtained, heat-resistant storage stability can be improved, and the control range of glossiness can be widened.

<<Toner Base Particles Having a Core-Shell Structure>>
The toner for electrostatic image development according to the present invention may be toner base particles having a core-shell structure. Here, the core-shell structure refers to a form in which a resin forming a shell layer is agglomerated and fused on the surface of a core particle.

It is a particle in which the amorphous resin is used as a core particle, and the amorphous polyester resin or the hybrid amorphous polyester resin in which the vinyl-based polymer segment and the polyester-based polymer segment are bonded as a shell layer is arranged on the core particle. is preferred.

The shell layer may not cover the entire surface of the core particles, and the core particles may be partially exposed. The cross section of the core-shell structure can be confirmed by a known observation means such as a transmission electron microscope (TEM) or a scanning probe microscope (SPM).

In the case of the core-shell structure, the core particles and the shell layer can have different characteristics such as glass transition point, melting point, hardness, etc., and the toner particles can be designed according to the purpose. For example, a resin having a relatively high glass transition point (Tg) is aggregated and fused to the surface of a core particle containing a binder resin, a coloring agent, a releasing agent, etc. and having a relatively low glass transition point (Tg). to form the shell layer.

Japanese Patent Application Laid-Open No. 2016-161780 can be referred to for a method for producing toner particles having a core-shell structure. In order to obtain toner particles having a core-shell structure by an emulsion aggregation method, first, fine binder resin particles for core particles and a colorant are aggregated (fused) to prepare core particles, and then core particles are prepared. By adding fine binder resin particles for the shell portion to the dispersion liquid of (1), the fine binder resin particles for the shell portion are aggregated and fused to the surface of the core particles to form the shell portion covering the surface of the core particles. Obtainable.

[2] Release Agent The release agent is not particularly limited, and various known waxes can be used. Examples of release agents that can be used include polyolefin waxes such as polyethylene wax and polypropylene wax, branched hydrocarbon waxes such as microcrystalline wax, long-chain hydrocarbon waxes such as paraffin wax and sazol wax, and distearyl wax. dialkyl ketone waxes such as ketones, carnauba wax, montan wax, behenic acid behenate, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18 - Ester waxes such as octadecanediol distearate, tristearyl trimellitate and distearyl maleate, and amide waxes such as ethylenediamine behenylamide and tristearylamide trimellitate.

The melting point of the releasing agent is preferably in the range of 60-90°C. This makes it easier for the release agent to maintain a dispersed state within the toner particles during the production of the toner, thereby suppressing the release agent from being exposed on the surface of the toner particles.

A preferred release agent contains a hydrocarbon compound, and the content thereof is in the range of 1 to 20% by mass on average with respect to 100% by mass of the toner base particles. By separating the SP value from , bleeding increases, so that the control range of glossiness can be widened and heat-resistant storage stability can be maintained.

More preferably, the content of the release agent is in the range of 5 to 15 mass % on average.

[3] Colorant In the present invention, the toner particles can be used as a colorant by combining dyes and pigments generally known as colorants. In addition, by using a yellow pigment as the colorant, a yellow toner having excellent low-temperature fixability and less scattering can be suitably produced.

As a coloring agent for a yellow toner, C.I. I. Pigment Yellow 74 is preferably used. As a result, it is possible to reduce the content of the colorant, so it is thought that the incorporation of the colorant into the toner is improved, which suppresses toner scattering, and suppresses the filler effect, resulting in excellent low-temperature fixability. be done.

From the viewpoint of obtaining a desired color tone or higher coloring power as a colorant for yellow toner, C.I. I. Pigment Yellow 74 and C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 185, C.I. I. Solvent Yellow 93 and C.I. I. At least one of Solvent Yellow 163 is preferably contained. The content of these pigments that can be used in combination is preferably in the range of 1 to 10% by mass with respect to 100% by mass of the toner base particles, from the viewpoint of obtaining high coloring power and preventing deterioration of chargeability. It is preferably within the range of 3 to 8% by mass.

In addition to the above yellow pigments, generally known dyes and organic pigments can be combined and used as colorants in accordance with the desired color. Examples of organic pigments include C.I. I. Pigment Red 5, 48:1, 53:1, 57:1, 81:4, 122, 139, 144, 149, 166, 177, 178, 222, 238, 269, C.I. I. Pigment Yellow 14, 17, 94, 138, C.I. I. Pigment Orage 31, 43, C.I. I. Pigment Blue 15:3, Pigment Blue 60, Pigment Blue 76, etc. Examples of dyes include C.I. I. Solvent Red 1, 49, 52, 58, 68, 11, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 69, 70, 93, 95 and the like can be mentioned.

The content of the colorant is preferably in the range of 1 to 20 parts by mass, more preferably in the range of 2 to 15 parts by mass, based on 100 parts by mass of the toner base particles.

[4] Charge Control Agents, External Additives In addition to the above-described essential components, the toner particles according to the present invention may optionally contain internal additives such as charge control agents; inorganic fine particles, organic fine particles, lubricants, and the like. An external additive may be contained.

(Charge control agent)
As the charge control agent, various known compounds such as nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, and metal salicylates can be used. .

The charge control agent is added in an amount of generally 0.1 to 10% by mass, preferably 0.5 to 5% by mass, based on 100% by mass of the finally obtained toner base particles.

As for the size of the charge control agent particles, the number average primary particle diameter is preferably 10 to 1000 nm, preferably 50 to 500 nm, and particularly preferably 80 to 300 nm.

(external additive)
The toner particles can be used as a toner as they are, but may be treated with an external additive such as a fluidizing agent or a cleaning aid in order to improve fluidity, chargeability, cleanability, and the like.

Examples of external additives include inorganic oxide fine particles such as silica fine particles, alumina fine particles and titanium oxide fine particles, inorganic stearic acid compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, strontium titanate, zinc titanate and the like. Inorganic titanate compound fine particles and the like can be mentioned. These can be used individually by 1 type or in combination of 2 or more types.

From the viewpoint of improving heat-resistant storage stability and environmental stability, these inorganic particles are preferably subjected to gloss treatment with a silane coupling agent, a titanium coupling agent, a higher fatty acid, a silicone oil, or the like.

The amount of the external additive added (the total amount added when a plurality of external additives are used) is preferably in the range of 0.05 to 5 parts by mass with respect to 100 parts by mass of the toner base particles. .1 to 3 parts by mass is more preferable.

[5] Method for producing a toner for developing an electrostatic charge image Examples of the method for producing a toner for developing an electrostatic charge image according to the present invention include a kneading pulverization method, a suspension polymerization method, an emulsion aggregation method, a dissolution suspension method, and a polyester elongation method. , a dispersion polymerization method, other known methods, and the like. Among these methods, it is preferable to employ the emulsion aggregation method from the viewpoint of uniformity of particle size, controllability of shape, and ease of forming a domain matrix structure. The emulsion aggregation method will be described below.

The method for producing toner particles according to the present invention by an emulsion aggregation method comprises an aqueous dispersion of amorphous vinyl resin particles, an aqueous dispersion of amorphous polyester resin particles or hybrid amorphous polyester resin particles, and colorant particles. and a water-based dispersion, and aggregate the amorphous resin particles, the amorphous polyester resin particles or the hybrid amorphous polyester resin particles, and the colorant particles to form toner particles.

(Emulsion aggregation method)
In the emulsion aggregation method, a dispersion of fine resin particles (hereinafter also referred to as "fine resin particles") dispersed with a surfactant or dispersion stabilizer is mixed with a dispersion of toner particle constituents such as colorant fine particles. 2) A method of forming toner particles by adding an aggregating agent to agglomerate to a desired toner particle size, then, or simultaneously with the agglomeration, fusing resin fine particles, and controlling the shape to form toner particles. .

Here, the fine resin particles may be toner particles having a core-shell structure made of resins having different compositions, or composite particles having a domain-matrix structure and having a plurality of layers.

Resin fine particles can be produced, for example, by an emulsion polymerization method, a mini-emulsion polymerization method, a phase inversion emulsification method, or a combination of several production methods. When resin fine particles contain a release agent, it is preferable to use a mini-emulsion polymerization method.

When the release agent is contained in the toner particles, the resin fine particles may contain the release agent. The template agent fine particles may be aggregated together with the resin fine particles.

Toner particles having a domain-matrix structure can also be obtained by an emulsion aggregation method. While the matrix particles are produced by fusing, the fine binder resin particles for the domains are added to the dispersion liquid of the matrix particles, and the fine binder resin particles for the domains are aggregated from the inside to the surface of the matrix particles. , can be obtained by fusing to form domains in matrix particles.

An example of steps of a method for producing a toner by an emulsion aggregation method will be described below.

(Step (1))
In step (1), an aqueous dispersion of amorphous vinyl resin particles is prepared as an amorphous resin dispersion. At this stage, it is preferable to incorporate a release agent into the amorphous vinyl resin particles.

Specifically, an amorphous vinyl resin is synthesized, dissolved or dispersed in an organic solvent to prepare an oil phase liquid, and this oil phase liquid is phase-inverted emulsified to form amorphous vinyl resin particles in an aqueous medium. disperse After controlling the particle size of the oil droplets to a desired particle size, the organic solvent is removed to obtain an aqueous dispersion of the amorphous vinyl resin.

The organic solvent used for the oil phase liquid preferably has a low boiling point and a low solubility in water from the viewpoint of facilitating the removal treatment after the formation of oil droplets. Specific examples include methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, and xylene. These may be used individually by 1 type, and may be used in combination of 2 or more type.

The amount of the organic solvent to be used is usually within the range of 1 to 300 parts by weight per 100 parts by weight of the amorphous vinyl resin.

Emulsification and dispersion of the oil phase liquid can be performed using mechanical energy.

(Step (2))
In step (2), an aqueous dispersion of amorphous polyester resin particles or hybrid amorphous polyester resin is prepared.

An aqueous dispersion of amorphous polyester resin particles or hybrid amorphous polyester resin particles can be prepared in the same manner as described above.

The average particle diameter of the amorphous polyester resin particles or the hybrid amorphous polyester resin particles is preferably in the range of 30 to 400 nm in volume-based median diameter (d ₅₀ ). The volume-based median diameter (d ₅₀ ) of the amorphous polyester resin particles can be measured using Microtrac UPA-150 (manufactured by Nikkiso Co., Ltd.).

(Step (3))
In step (3), the colorant is dispersed in the form of fine particles in an aqueous medium to prepare an aqueous dispersion of colorant particles.

An aqueous dispersion of colorant particles can be obtained by dispersing a colorant in an aqueous medium to which a surfactant is added at a critical micelle concentration (CMC) or higher.

Dispersion of the colorant can be carried out using mechanical energy, and the disperser used is not particularly limited, but preferably an ultrasonic disperser, a mechanical homogenizer, a Manton Gaulin or a pressure homogenizer. Media-type dispersers such as pressure dispersers, sand grinders, Getzmann mills and diamond fine mills can be used.

The volume-based median diameter (d ₅₀ ) of the colorant particles in the aqueous dispersion is preferably in the range of 10 to 300 nm, more preferably in the range of 100 to 200 nm, and more preferably in the range of 100 to 150 nm. It is particularly preferred to be within

The volume-based median diameter (d ₅₀ ) of the colorant particles can be measured using Microtrac UPA-150 (manufactured by Nikkiso Co., Ltd.).

(Step (4))
In step (4), toner particles are formed by aggregating amorphous vinyl resin particles, amorphous polyester resin particles, colorant particles and other toner constituent particles.

Specifically, a flocculant having a critical flocculation concentration or higher is added to a system in which an aqueous medium and an aqueous dispersion of each particle are mixed, and the temperature is raised to a temperature higher than the glass transition temperature (Tg) of the amorphous resin particles. agglomerate.

(coagulant)
Although the flocculant is not particularly limited, one selected from metal salts such as alkali metal salts and alkaline earth metal salts is preferably used. Examples of metal salts include salts of monovalent metals such as sodium, potassium and lithium; salts of divalent metals such as calcium, magnesium, manganese and copper; and salts of trivalent metals such as iron and aluminum. Specific metal salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, and the like. It is particularly preferred to use a divalent metal salt because it can promote

These may be used individually by 1 type, and may be used in combination of 2 or more type.

(Step (5))
In step (5), the toner particles formed in step (4) are subjected to aging treatment to control the shape to a desired shape. Step (5) can be performed as necessary.

Specifically, the toner particle dispersion liquid obtained in step (4) is heated and stirred, and the heating temperature, stirring speed, heating time, and the like are adjusted so that the toner particles have a desired degree of circularity.

(Step (4B))
In step (4B), the toner particles obtained in step (4) or (5) are used as matrix particles, and domains are formed at least partially from the inside to the surface of the matrix particles. Step (4B) may be performed when toner particles having a domain-matrix structure are formed.

In the case of forming toner particles having a domain-matrix structure, a resin constituting the domains is dispersed in an aqueous medium to prepare a dispersion liquid of the resin particles of the domains, and the resin particles of the domains are aggregated from the inside to the surface of the matrix particles. , to fuse. Thereby, a dispersion liquid of toner particles having a domain-matrix structure can be obtained.

A heat treatment step can be carried out in order to more strongly agglomerate and fuse the resin particles of the domains to the matrix particles. The heat treatment may be performed until toner particles having the desired degree of circularity are obtained.

(Step (6))
In step (6), the dispersion of toner particles is cooled. As for the cooling treatment conditions, it is preferable to cool at a cooling rate of 1 to 20° C./min. A specific method for the cooling treatment is not particularly limited, and examples include a method of introducing a refrigerant from the outside of the reaction vessel for cooling, a method of directly introducing cold water into the reaction system for cooling, and the like. can be done.

(Step (7))
In step (7), the toner particles are subjected to solid-liquid separation from the cooled dispersion liquid of the toner particles, and the toner cake obtained by the solid-liquid separation (toner particles in a cake-like wet state) is treated with a surfactant. Remove and wash the attached substances such as coagulants.

Solid-liquid separation is not particularly limited, and a centrifugal method, a vacuum filtration method using a Nutsche or the like, a filtration method using a filter press or the like, and the like can be used. In washing, it is preferable to wash with water until the electrical conductivity of the slurry reaches 10 μS/cm.

(Step (8))
In step (8), the washed toner cake is dried.

For drying the toner cake, spray dryers, vacuum freeze dryers, vacuum dryers, etc. can be mentioned, and static shelf dryers, moving shelf dryers, fluidized bed dryers, rotary dryers, agitating dryers, etc. can be used. It is preferable to use a machine or the like.

The moisture content of the toner particles after drying is preferably 5% by mass or less, more preferably 2% by mass or less.

In addition, when toner particles after drying are agglomerated due to a weak attractive force between particles, the agglomerates may be crushed. Mechanical crushers such as jet mills, Henschel mixers, coffee mills, and food processors can be used as crushers.

(Step (9))
In step (9), an external additive is added to the toner particles. Step (9) can be performed as necessary.

A mechanical mixer such as a Henschel mixer or coffee mill can be used to add the external additive.

[6] Physical Properties of Toner for Electrostatic Charge Image <Particle Size of Toner Particles>
As for the average particle diameter of the toner particles, the volume-based median diameter (d ₅₀ ) is preferably in the range of 3 to 15 μm, more preferably in the range of 4 to 8 μm.

Within the above range, high reproducibility can be obtained even for extremely minute dot images of the 1200 dpi level.

The average particle size of the toner particles can be controlled by adjusting the concentration of the aggregating agent used during production, the amount of the organic solvent added, the fusion bonding time, the composition of the binder resin, and the like.

For the measurement of the volume-based median diameter (d ₅₀ ) of the toner particles, a measuring device comprising Multisizer 3 (manufactured by Beckman Coulter, Inc.) connected to a computer system equipped with data processing software Software V3.51 is used. can be done.

Specifically, a measurement sample (toner) is added to a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing toner particles). Then, ultrasonic dispersion is performed to prepare a toner particle dispersion. This toner particle dispersion is pipetted into a beaker containing ISOTON II (manufactured by Beckman Coulter, Inc.) in a sample stand until the concentration indicated by the measuring device reaches 8%. Here, by using this concentration, reproducible measured values can be obtained. Then, in the measuring device, the measured particle count number is 25000, the aperture diameter is 100 μm, and the frequency value is calculated by dividing the measurement range of 2 to 60 μm into 256, and 50 from the larger volume integrated fraction. % particle size is given as volume-based median diameter (d ₅₀ ).

<Average Circularity of Toner Particles>
Toner particles preferably have an average circularity in the range of 0.930 to 1.000, more preferably in the range of 0.950 to 0.995, from the viewpoint of enhancing the stability of charging characteristics and low-temperature fixability. is more preferable.

When the average circularity is within the above range, individual toner particles are less likely to be crushed. As a result, it is possible to suppress the contamination of the triboelectrification imparting member, stabilize the chargeability of the toner, and improve the image quality of the formed image.

The average circularity of toner particles can be measured using FPIA-3000 (manufactured by Sysmex).

Specifically, the sample to be measured (toner) is soaked in an aqueous solution containing a surfactant, and ultrasonically dispersed for 1 minute to disperse the sample. After that, FPIA-3000 (manufactured by Sysmex) is used to perform imaging at an appropriate density of 3,000 to 10,000 HPF detections under the measurement conditions of HPF (high magnification imaging) mode. If the HPF detection number is within the above range, reproducible measured values can be obtained. From the photographed particle image, the circularity of each toner particle is calculated according to the following formula (I), and the circularity of each toner particle is added and divided by the total number of toner particles to obtain the average circularity.

Formula (I): Circularity of toner particles=(perimeter of circle having the same projected area as particle image)/(perimeter of projected particle image)
[7] Developer The electrostatic charge image developing toner according to the present invention can be used as a magnetic or non-magnetic one-component developer, but may be mixed with a carrier and used as a two-component developer. When the toner is used as a two-component developer, magnetic particles made of conventionally known materials such as metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead are used as the carrier. Ferrite particles are particularly preferred.

As the carrier, a coated carrier in which the surface of magnetic particles is coated with a coating agent such as a resin, or a dispersion type carrier in which magnetic fine powder is dispersed in a binder resin may be used.

The volume-based median diameter (d ₅₀ ) of the carrier is preferably in the range of 20 to 100 μm, more preferably in the range of 25 to 80 μm.

The volume-based median diameter (d ₅₀ ) of the carrier can be measured, for example, with a laser diffraction particle size distribution analyzer HELOS (manufactured by SYMPATEC) equipped with a wet disperser.

[2] Image Forming Apparatus The image forming apparatus according to the present invention comprises an image forming section for forming a toner image on a transfer material using the electrostatic charge image developing toner according to the present invention, a fixing member, and the fixing member. a fixing drive unit that rotates, a pressure member, a pressure drive unit that drives the pressure member to rotate, and a drive control unit that controls rotation of the fixing drive unit or the pressure drive unit; wherein the drive control unit changes a difference between a surface speed of the fixing member and a surface speed of the pressure member when the image is fixed by sandwiching the transfer material between the fixing member and the pressure member. Characterized by

The difference between the surface speed of the fixing member when rotationally driven by the fixing driving section and the surface speed of the pressing member when rotationally driven by the pressure driving section is within a range of ±10%. Controlling is a preferable range from the viewpoint of widening the control range of the glossiness and from the viewpoint of preventing the fixing member from being damaged.

For example, when the fixing member and the pressure member are rollers, the surface speed of the fixing member and the surface speed of the pressure member are determined by marking an arbitrary position on the outer periphery and rotating the roller at a predetermined number of rotations. The movement distance (circumferential length) of the marked portion when the movement is performed can be obtained by measuring and analyzing using a moving image capturing device or the like. The unit of surface velocity is (mm/sec).

Also, the relationship between the surface speed of the rotationally driven fixing member and the surface speed of the pressure member can be obtained by the following equation (1).

Formula 1 Ratio of the surface speed of the fixing member to the surface speed of the pressure member (%) = {(Surface speed of the fixing member (mm/sec) - Surface speed of the pressure member (mm/sec)) ÷ Speed of the pressure member Surface speed (mm/sec)}×100
[1] Fixing Member As the fixing member, a system using a fixing roller or a fixing belt is known, but both of them can be preferably used without any particular limitation.

The fixing roller is preferably a rubber roller that fixes the toner particles to the transfer material in the image forming apparatus. It is a thing. Similarly, the fixing belt is preferably a resin belt that fixes the toner particles to the transfer material. In general, the outer layer of the resin belt such as polyamide is coated with a rubber member molded using, for example, the following silicone rubber composition. It is what you do.

The fixing roller has a three-layer structure consisting of a metal core, a solid rubber layer covering the outer peripheral surface of the metal core, and a sponge rubber layer covering the outer peripheral surface of the solid rubber layer. However, it is not limited to these. Here, the solid rubber layer and the sponge rubber layer are each preferably made of silicone rubber.

In the fixing roller, the metal core is preferably made of a metal material such as aluminum, iron, and SUS.

The thickness of the cored bar 2 is about 0.1 to 5 mm, and more preferably about 0.1 to 1.5 mm in consideration of weight reduction and warm-up time. The diameter of the cored bar 2 is preferably about 10 to 50 mm.

It is preferable that the silicone rubber has heat resistance to the above-mentioned fixing temperature and elasticity for securing the dimension of the area (the length of the nip portion) where the transfer material is pressed.

The solid rubber layer is a solid hard layer. The thickness of the solid rubber layer is preferably in the range of 5-10 mm, more preferably in the range of 7-8 mm.

On the other hand, the sponge rubber layer is a sponge-like soft layer containing countless microballoons. The thickness of the sponge rubber layer 4 is preferably in the range of 5-100 μm, more preferably in the range of 80-90 μm.

FIG. 2 is a schematic diagram showing an example of a fixing device used in the present invention.

For example, the fixing device may be a biaxial belt type fixing device as shown in FIG. 2, or may be a uniaxial belt type fixing device shown by a heating roller 132 and a pressure roller 131 in FIG. 3 which will be described later. .

In the biaxial belt type fixing device shown in FIG. 2, the fixing device 10 is pressed against a heating roller 12 and a pressure roller 13, each of which has a rotation axis perpendicular to the paper surface. A fixing roller 14 as a fixing member is arranged, and the transfer material P is conveyed between them. At least a portion of the heating roller 12 is hollow, and a heat source (not shown) such as a heater is arranged in the hollow portion. This internal heat generation heats the fixing belt 11 .

Further, a fixing drive unit (not shown) that rotationally drives the fixing roller 14 that is the fixing member, a pressure driving unit (not shown) that rotationally drives the pressure roller 13 that is the pressure member, and the fixing drive unit and a drive control section (control section 200 described later) that controls the rotational drive of the pressing drive section. The drive control section controls the surface speeds of the fixing roller and the pressure roller.

In the above configuration, when the pressure roller 14 is rotated counterclockwise by a driving means (not shown), the fixing belt 11, the heating roller 12, and the fixing roller 14 are rotated clockwise. The fixing belt 11 is heated by the heating roller 12 in contact therewith, and the fixing roller 14 is also heated. Then, the transfer material on which the toner image is formed is heated and pressurized by passing through the nip portion, and the toner image transferred onto the transfer material is fused and fixed.

Here, the transfer material P is not particularly limited, and includes plain paper from thin paper to thick paper, high-quality paper, coated printing paper such as art paper or coated paper, commercially available Japanese paper and postcard paper, and OHP paper. Various types such as plastic films and cloth can be mentioned.

A method for producing a fixing member includes steps of adding a high-molecular-weight silicon compound having a weight-average molecular weight within the range of 900 to 1700 to a silicone rubber raw material to prepare a silicone mixture, and a silicone rubber precursor comprising the silicone mixture. It is preferable to have a step of heating. Thus, by adding a high molecular weight silicon compound to a silicone rubber raw material to prepare a silicone mixture, it is possible to obtain a silicone rubber composition containing a large amount of high molecular weight components and having excellent durability. By heating the mixture of silicone rubber precursors, it is possible to obtain a silicone rubber composition with excellent durability and a low content of low-molecular-weight components.

(Step of preparing silicone mixture)
The step of preparing a silicone mixture is a step of adding a polymeric silicon compound having a weight average molecular weight within the range of 900 to 1,700 to a silicone rubber raw material to prepare a silicone mixture. A specific example of a method for forming a precursor of silicone rubber, which will be a rubber member of the fixing member, will be described below with respect to the heating roller shown in FIG. 3, which is an example of the fixing member.

First, silicone rubber raw materials to be molded with low-molecular-weight monomers, etc. are added, for example, high-molecular-weight silicon compounds having a weight-average molecular weight within the range of 900 to 1,700 and a curing agent (e.g., CAT-1602, Shin-Etsu Chemical Co., Ltd.). ) and mixed well with a stirrer to obtain a silicone mixture. Thermally expandable microcapsules and other additives may be added as necessary. For example, to this silicone mixture, expanded heat-expandable microcapsules (for example, Expancel 461, a microballoon manufactured by Akzo Nobel) are added and mixed with a stirrer to form a silicone containing heat-expandable microcapsules. A mixture can be obtained.

For example, an aluminum core and a paper tube thicker than the core are covered so that the core is at the center, and a silicone mixture that does not contain thermally expandable microcapsules is placed between the paper tube and the core. is poured in and heated to complete curing, the paper tube is removed to form a solid rubber layer.

Thereafter, a silicone mixture containing thermally expandable microcapsules is applied to this solid rubber layer to obtain a silicone rubber precursor.

Next, the precursor of this silicone rubber can be converted into the silicone rubber constituting the rubber member of the fixing member through a heating step.

The method for forming the precursor of the silicone rubber is not limited to the above. For example, a silicone mixture containing a rubber raw material may be applied directly onto the metal core to form the precursor of the silicone rubber.

The step of heating the precursor is the above-described step of heating the silicone precursor composed of the silicone mixture. Heating may be performed during heating when the rubber member constituting the fixing member is molded or vulcanized, or may be performed during heating by providing a separate heating step after molding or vulcanization. The temperature in the heating step is preferably in the range of 160-280°C. Also, the heating time is preferably in the range of 30 to 300 minutes, more preferably in the range of 35 to 60 minutes. Thus, by adding a high-molecular-weight silicon compound to a silicone rubber raw material, it is possible to obtain a silicone rubber composition containing a large amount of high-molecular-weight components and having excellent durability. As a body, by heat-treating within the above temperature range, it is possible to obtain a fixing member having excellent durability and a small amount of low-molecular-weight components.

A heating method is not particularly limited, and a known method can be applied. Typically, the chamber is externally heated to heat the silicone rubber precursor contained within the chamber. A heating method may be a batch type or a continuous type. For example, in the case of a batch method, the precursor of the silicone rubber may be left standing in the chamber and taken out after being heated for a predetermined period of time. In the case of a continuous method, a cylindrical heating chamber may be used, and heating may be performed for a predetermined time while moving the precursor of the silicone rubber inside the heating chamber.

[2] Image Forming Apparatus An example of the schematic configuration of a color tandem type image forming apparatus 100 having a fixing member and a pressure member according to the present invention will be described with reference to FIG. This image forming apparatus is a multifunction machine having functions such as a scanner, a copier, and a printer, and is called an MFP (Multi Function Peripheral or Multi Function Printer).

As shown in FIG. 3, the image forming apparatus 100 includes an annular intermediate transfer belt 108 that is wound around two rollers 102 and 106 and that moves in the circumferential direction.

Of the two rollers 102, 106, one roller 102 is arranged on the left side in the figure and the other roller 106 is arranged on the right side in the figure. The intermediate transfer belt 108 is supported by these rollers 102 and 106 and driven to rotate in the arrow X direction.

Below the intermediate transfer belt 108, image forming segments 110Y, 110M, 110C, and 110K corresponding to yellow (Y), magenta (M), cyan (C), and black (K) toners are arranged in order from the left in the drawing. are arranged side by side.

Each of the image forming segments 110Y, 110M, 110C, and 110K are configured similarly to each other except for the toner colors they handle.

For example, the yellow image forming segment 110Y is configured by integrating a photosensitive drum 190, a charging device 191, an exposure device 192, a developing device 193 that develops using toner, and a cleaner device 195. .

A primary transfer roller 194 is provided at a position facing the photosensitive drum 190 with the intermediate transfer belt 108 interposed therebetween.

At the time of image formation, the surface of the photoreceptor drum 190 is first uniformly charged by the charging device 191, and then the surface of the photoreceptor drum 190 is exposed by the exposure device 192 to form a latent image thereon. Next, the developing device 193 develops the latent image on the surface of the photosensitive drum 190 into a toner image. This toner image is transferred to intermediate transfer belt 108 by voltage application between photoreceptor drum 190 and primary transfer roller 194 . A cleaning device 195 cleans the transfer residual toner on the surface of the photosensitive drum 190 .

As the intermediate transfer belt 108 moves in the direction of the arrow X, four-color toner images are superimposed and formed on the intermediate transfer belt 108 as an output image by the image forming segments 110Y, 110M, 110C, and 110K.

On the left side of 108, a cleaning device 125 for removing residual toner from the surface of the intermediate transfer belt 108 and a toner collection box 126 for collecting the toner removed by the cleaning device 125 are provided.

A secondary transfer roller 112 is provided on the right side of the intermediate transfer belt 108 across a conveying path 124 for the transfer material. A transport roller 120 is provided at a position corresponding to the upstream side of the secondary transfer roller 112 in the transport path 124 . An optical density sensor 115 is provided for detecting the toner pattern on the intermediate transfer belt 108 .

A fixing device 130 for fixing toner onto a transfer material is provided in the upper right portion of the main body casing 101 .

In the present invention, the fixing device 130 includes a fixing member, a fixing driving section that rotationally drives the fixing member, a pressure member, a pressure driving section that rotationally drives the pressure member, the fixing driving section or the fixing driving section. a drive control unit for controlling rotational driving of the pressure drive unit, the drive control unit controlling the surface of the fixing member when the transfer material is nipped between the fixing member and the pressure member to fix the image; It is characterized by varying the difference between the speed and the surface speed of the pressure member.

The fixing device 130 includes a pair of a fixing roller, which is a fixing member according to the present invention, and a pressure roller, which is a pressure member, extending perpendicularly to the paper surface in FIG. In FIG. 3, there is a heating roller 132 as a fixing roller, and the other is a pressure roller 131 .

The heating roller 132 and the pressure roller 131 each have a drive section (not shown) and a drive control section (the control section 200 in FIG. 3), and control the surface speed of the rotationally driven heating roller 132 and the pressure roller 131. .

Heating roller 132 is heated to a predetermined target temperature (for example, a fixing temperature within the range of 180 to 200° C.) by heater 133 . The pressure roller 131 is biased toward the heating roller 132 by a spring (not shown). Thus, the pressure roller 131 and the heating roller 132 form a nip portion for fixing.

The toner image is fixed on the transfer material 90 by passing the transfer material 90 onto which the toner image has been transferred through the nip portion. The temperatures of pressure roller 131 and heat roller 132 are detected by temperature sensors 135 and 136, respectively.

At the bottom of the main body casing 101, two stages of paper feed cassettes 116A and 116B for containing the transfer material 90 are provided. FIG. 3 shows a state in which the transfer material 90 is accommodated only in the paper feed cassette 116A.

Each of the paper feed cassettes 116A and 116B is provided with a paper feed roller 118 for feeding the transfer material and a paper feed sensor 117 for detecting the fed transfer material.

A control unit 200 comprising a CPU (Central Processing Unit) for controlling the operation of the entire image forming apparatus is provided in the main body casing 101 . The control unit 200 also has a function of controlling the rotational driving of the fixing driving unit or the pressure driving unit, and determines the surface speed of the fixing member when the image is fixed by being sandwiched between the fixing member and the pressure member. and the surface speed of the pressure member are changed by inputting conditions in advance.

During image formation, the control unit 200 controls the transfer material 90 to feed the transfer material 90 one by one from the paper feed cassette 116A to the transport path 124 by the paper feed roller 118 . The transfer material 90 sent to the transport path 124 is sent to a toner transfer position between the intermediate transfer belt 108 and the secondary transfer roller 112 by the transport roller 120 at the timing of the registration sensor 114 .

On the other hand, as described above, four-color toner images are superimposed on the intermediate transfer belt 108 by the image forming segments 110Y, 110M, 110C, and 110K. A four-color toner image on the intermediate transfer belt 108 is transferred by the secondary transfer roller 112 .

The transfer material 90 to which the toner image has been transferred is conveyed through a nip formed by a pressure roller 131 and a heating roller 132 of the fixing device 130 and is heated and pressed. As a result, the toner image is fixed on the transfer material 90 .

Finally, the transfer material 90 on which the toner image is fixed is discharged by the paper discharge roller 121 through the paper discharge path 127 to the paper discharge tray section 122 provided on the upper surface of the main body casing 101 .

Note that the image forming apparatus 100 is provided with a switchback transport path 128 for feeding the transfer material 90 again to the toner transfer position in the case of double-sided printing.

As described above, pressure roller 131 constitutes one of the fixing rollers, and here a silicone rubber roller is used.

It should be noted that the embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be changed as appropriate without departing from the gist of the present invention.

In the above description, the heating roller is used as the fixing member, and the pressure roller is used as the pressure member. However, the fixing belt system shown in FIG. Further, the fixing belt referred to in this specification is a fixing belt made of silicone rubber used when fixing toner onto a transfer material in an image forming apparatus. Specifically, it refers to known fixing belts used in fixing devices, such as those described in JP-A-2017-194550, JP-A-2017-173445, and JP-A-2017-97187.

Each step in image formation using the image forming apparatus of the present invention will be described below.

The steps in the image formation are preferably carried out by steps used in a general electrophotographic image forming method, such as a charging step, an electrostatic latent image forming step, a developing step, a fixing step, and a cleaning step. .

(Electrifying process)
In this step, the electrophotographic photosensitive member is charged. The charging method is not particularly limited, and for example, a known method such as a charging roller method in which the electrophotographic photosensitive member is charged by a charging roller may be used.

(Step of forming electrostatic latent image)
In this step, an electrostatic latent image is formed on an electrophotographic photosensitive member (electrostatic latent image carrier).

The electrophotographic photoreceptor is not particularly limited, and examples thereof include a drum-shaped one made of an organic photoreceptor such as polysilane or phthalopolymethine.

The electrostatic latent image is formed, for example, by uniformly charging the surface of the electrophotographic photosensitive member by charging means and exposing the surface of the electrophotographic photosensitive member imagewise by exposing means. The electrostatic latent image is an image formed on the surface of the electrophotographic photosensitive member by such charging means.

Charging means and exposure means are not particularly limited, and those commonly used in electrophotography can be used.

(Process of developing)
The developing step is a step of developing the electrostatic latent image with toner (generally, a dry developer containing toner) to form a toner image.

The formation of the toner image is performed, for example, by using a dry developer containing toner and using a developing means comprising a stirrer that frictionally stirs and charges the toner, and a rotatable magnet roller.

Specifically, in the developing means, for example, toner and carrier are mixed and agitated, and the toner is charged by friction at that time, held on the surface of a rotating magnet roller, and a magnetic brush is formed. Since the magnet roller is arranged in the vicinity of the electrophotographic photosensitive member, part of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the electrophotographic photosensitive member due to the electric attraction force. . As a result, the electrostatic latent image is developed with toner to form a toner image on the surface of the electrophotographic photosensitive member.

(Step of transferring)
In this step, the toner image is transferred onto the recording medium.

Transfer of the toner image onto the transfer material is performed by charging the toner image onto the transfer material.

As a transfer means, for example, a corona transfer device using corona discharge, a transfer belt, a transfer roller, or the like can be used.

In the transferring step, for example, an intermediate transfer member is used, and after the toner image is primarily transferred onto the intermediate transfer member, the toner image is secondarily transferred onto the transfer material. It is also possible to transfer the formed toner image directly onto the transfer material.

(Fixation process)
In the fixing process according to the present invention, a transfer material, on which an unfixed image (toner image) formed using toner is transferred, is transferred between a heated fixing belt or fixing roller and a pressure roller as a pressure member. It has a step of fixing the unfixed image on the transfer material by passing through the gap.

In the fixing process, as described above, a fixing belt or a fixing roller as a fixing rotating body and a pressure member provided in a state of being pressed against the fixing belt or the fixing roller so as to form a fixing nip portion. and a pressure roller of the belt fixing method or the roller fixing method.

(Cleaning process)
In this step, developer that has not been used for image formation or that has not been transferred is removed from the developer carrier such as a photoreceptor or an intermediate transfer member.

The cleaning method is not particularly limited, but it is preferable to use a blade that scrapes the surface of the photoreceptor and whose tip is in contact with the object to be cleaned, such as the photoreceptor.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these. In the examples, "parts" or "%" are used, but "mass parts" or "mass%" are indicated unless otherwise specified.

<Preparation of Resin Fine Particle Dispersion Liquid for Toner>
<Preparation of Fine Particle Dispersion (A ₁ ) of Styrene-Acrylic Resin (1)>
1. First-stage polymerization (preparation of "resin fine particles (a ₁ )" dispersion)
An anion prepared by dissolving 2.0 parts by mass of an anionic surfactant "sodium lauryl sulfate" in 2900 parts by mass of deionized water in advance in a reaction vessel equipped with a stirring device, temperature sensor, temperature control device, cooling pipe, and nitrogen introducing device. A surfactant solution was charged, and the internal temperature was raised to 80° C. while stirring at a stirring speed of 230 rpm under nitrogen flow.

After adding 9.0 parts by mass of a polymerization initiator "potassium persulfate (KPS)" to this surfactant solution and adjusting the internal temperature to 78 ° C.,
A monomer solution (1) consisting of styrene 540 parts by mass, n-butyl acrylate 270 parts by mass, methacrylic acid 65 parts by mass, and n-octyl mercaptan 17 parts by mass was added dropwise over 3 hours. Polymerization (first-stage polymerization) was performed by heating and stirring to prepare a dispersion liquid of "resin fine particles (a ₁ )".

2. Second-stage polymerization: formation of intermediate layer (preparation of dispersion liquid of "resin fine particles (a ₁₁ )")
In a flask equipped with a stirrer,
Styrene 94 parts by mass n-butyl acrylate 60 parts by mass Methacrylic acid 11 parts by mass n-octyl mercaptan 5 parts by mass HNP-51 (melting point: 77 ° C.) was added to the monomer solution (2) as a hydrocarbon release agent. 57 parts by mass was added and heated to 85° C. for dissolution to prepare a monomer solution (2).

On the other hand, a surfactant solution obtained by dissolving 2 parts by mass of an anionic surfactant "sodium lauryl sulfate" in 1100 parts by mass of ion-exchanged water was heated to 90 ° C., and this surfactant solution was added to "resin fine particles (a ₁ )” was added to 28 parts by mass in terms of the solid content of “resin fine particles (a ₁ )”, and then the unit The polymer solution (2) was mixed and dispersed for 4 hours to prepare a dispersion containing emulsified particles with a dispersed particle diameter of 350 nm. An aqueous initiator solution dissolved in parts by mass is added, and the system is heated and stirred at 90° C. for 2 hours to carry out polymerization (second-stage polymerization) to obtain a dispersion of "resin fine particles (a ₁₁ )". prepared.

3. Third-stage polymerization: Preparation of outer layer (“fine particle dispersion (A ₁ ) of styrene-acrylic resin ( ₁ )”) A polymerization initiator “KPS ” 2.5 parts by mass was dissolved in 110 parts by mass of ion-exchanged water to add an aqueous initiator solution, and under a temperature condition of 80 ° C.,
A monomer solution (3) consisting of 200 parts by mass of styrene, 130 parts by mass of n-butyl acrylate, and 5.2 parts by mass of n-octyl mercaptan was added dropwise over 1 hour. After completion of dropping, polymerization (third-stage polymerization) was performed by heating and stirring for 3 hours. Thereafter, the mixture was cooled to 28° C. to prepare a “fine particle dispersion (A ₁ ) of styrene/acrylic resin (1)” in which fine particles of styrene/acrylic resin (1) were dispersed in the anionic surfactant solution. . The glass transition point of this styrene-acrylic resin (1) was 35°C.

<Preparation of Aqueous Dispersion (B ₁ ) of Hybrid Amorphous Polyester Resin b ₁ Fine Particles>
A raw material monomer for the following addition polymerizable resin (styrene-acrylic resin: StAc) segment, a bi-reactive monomer, and a radical polymerization initiator were placed in a dropping funnel.

Styrene 80 parts by mass n-Butyl acrylate 20 parts by mass Acrylic acid 10 parts by mass Polymerization initiator (di-t-butyl peroxide) 16 parts by mass.

In addition, the following raw material monomers for the polycondensation resin (amorphous polyester resin: APEs) segment are placed in a four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple, heated to 170 ° C., Dissolved.

Bisphenol A propylene oxide 2 mol adduct 285.7 parts by mass Terephthalic acid 66.9 parts by mass Fumaric acid 47.4 parts by mass

Next, the raw material monomer for the addition polymerization resin was added dropwise over 90 minutes while stirring, and after aging for 60 minutes, the unreacted addition polymerization monomer was removed under reduced pressure (8 kPa). After that, 0.4 parts by mass of Ti(OBu) ₄ was added as an esterification catalyst, the temperature was raised to 250° C., and the reaction was continued under normal pressure (101.3 kPa) for 5 hours and then under reduced pressure (8 kPa) for 1 hour. gone. After cooling to 200° C., the reaction was carried out under reduced pressure (20 kPa). Then, the solvent was removed to obtain a hybrid amorphous polyester resin _b1 . The resulting hybrid amorphous polyester resin _b1 had a glass transition temperature (Tg) of 58°C and a weight average molecular weight (Mw) of 53,000.

100 parts by mass of the obtained hybrid amorphous polyester resin b ₁ was dissolved in 400 parts by mass of ethyl acetate (manufactured by Kanto Kagaku Co., Ltd.) to prepare 638 parts by mass of a 0.26% by mass sodium lauryl sulfate solution. and ultrasonically dispersed for 60 minutes at V-LEVEL 300 μA with an ultrasonic homogenizer “US-150T” (manufactured by Nippon Seiki Seisakusho Co., Ltd.) while stirring. After that, while heating to 40° C., a diaphragm vacuum pump “V-700” (manufactured by BUCHI) was used to completely remove ethyl acetate while stirring under reduced pressure for 3 hours to obtain a solid content of 13.5. An aqueous dispersion (B ₁ ) of fine particles of hybrid amorphous polyester resin b ₁ in wt. % was prepared. At this time, the volume-based median diameter of the fine particles of the hybrid amorphous polyester resin b ₁ contained in the dispersion (B ₁ ) was 100 nm.

(Preparation of aqueous dispersion of colorant particles (Cy ₁ ))
90 parts by mass of sodium n-dodecylsulfate was added to 1600 parts by mass of deionized water. While stirring this solution, 420 parts by mass of copper phthalocyanine (CI Pigment Blue 15:3) was gradually added, and then a stirring device "CLEARMIX (registered trademark)" (manufactured by M Technic Co., Ltd.) was added. An aqueous dispersion of colorant particles (Cy ₁ ) was prepared by performing a dispersion treatment using In the resulting aqueous dispersion of colorant particles (Cy ₁ ), the volume-based median diameter of the colorant particles was 110 nm.

<Preparation of fine resin particles for styrene/acrylic shell>
An anion prepared by dissolving 2.0 parts by mass of an anionic surfactant "sodium lauryl sulfate" in 2900 parts by mass of deionized water in advance in a reaction vessel equipped with a stirring device, temperature sensor, temperature control device, cooling pipe, and nitrogen introducing device. A surfactant was charged, and the internal temperature was raised to 80° C. while stirring at a stirring speed of 230 rpm in a nitrogen stream. After adding 10.0 parts by mass of a polymerization initiator "potassium persulfate (KPS)" to this surfactant solution and raising the internal temperature to 78 ° C.,
A monomer solution (4) consisting of styrene 502.8 parts by mass, n-butyl acrylate 185.2 parts by mass, methacrylic acid 112 parts by mass, and n-octyl mercaptan 14 parts by mass was added dropwise over 3 hours. A dispersion liquid of "resin fine particles for styrene/acrylic shell (sh ₁ )" was prepared by heating and stirring for 1 hour at . Tg was 58°C.

<Preparation of Toner 1>
(aggregation/fusion process)
Into a reaction vessel equipped with a stirrer, a temperature sensor, and a cooling pipe, 444 parts by mass of "styrene/acrylic resin fine particle dispersion (A1)" as a matrix resin fine particle dispersion (in terms of solid content) and 1600 mass of ion-exchanged water were added. After adding the part, a 5 mol/liter sodium hydroxide aqueous solution was added to adjust the pH to 10 and the liquid temperature to 20°C.

After that, 40 parts by mass of "colorant fine particle dispersion (Cy ₁ )" in terms of solid content was added. Then, an aqueous solution prepared by dissolving 75 parts by mass of magnesium chloride in 75 parts by mass of ion-exchanged water was added with stirring at 30° C. over 10 minutes. Thereafter, the system was allowed to stand for 3 minutes before starting to heat up, and the system was heated to 80°C over 60 minutes, and the particle growth reaction was continued while maintaining the temperature at 80°C. In this state, the particle size of the associated particles was measured using "Multisizer 3" (manufactured by Beckman Coulter, Inc.). stopped growing. After that, 54 parts by mass of the hybrid amorphous polyester resin fine particle dispersion (B ₁ ) was added, and when the supernatant became transparent, an aqueous solution prepared by dissolving 125 parts by mass of sodium chloride in 500 parts by mass of ion-exchanged water was added. Grain growth was stopped. Furthermore, the temperature is raised and the particles are heated and stirred at 90° C. to promote fusion of the particles. 4000 particles) When the average circularity reached 0.960, the particles were cooled to 30° C. to obtain a “dispersion liquid of toner base particles [1]”.

(Washing/drying process)
The "dispersion liquid of toner base particles [1]" prepared in the aggregation/fusion step was solid-liquid separated by a centrifugal separator to remove coarse particles and fine particles, thereby forming a wet cake of toner base particles. The wet cake was washed with ion-exchanged water at 35°C until the electric conductivity of the slurry with 10 times the amount of ion-exchanged water reached 5 µS/cm, and then transferred to "Flash Jet Dryer" (manufactured by Seishin Enterprise Co., Ltd.). , and dried until the water content reached 0.5% by mass to prepare "toner base particles [1]".

(External additive treatment step)
2.5% by mass of hydrophobic silica (number average primary particle size = 120 nm), 1.0% by mass of hydrophobic silica (number average primary particle size = 12 nm), and 0.6% by mass of hydrophobic titania (number average primary particle diameter=20 nm) was added and mixed by a Henschel mixer to prepare "toner 1".

"Preparation of Toner 2"
Toner 2 was obtained in the same manner as in the preparation of Toner 1, except that in the step of preparing the hybrid amorphous polyester resin fine particle dispersion (B ₁ ), ultrasonic dispersion was performed for 30 minutes to obtain particles of 160 nm.

"Preparation of Toner 3"
Toner 3 was obtained in the same manner as in Toner 1 except for the following.
The following raw material monomers for the polycondensation resin (amorphous polyester resin: APEs) segment are placed in a four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple, heated to 170 ° C. and dissolved. rice field.

Bisphenol A propylene oxide 2 mol adduct 285.7 parts by mass Terephthalic acid 75.1 parts by mass Fumaric acid 42.0 parts by mass Next, the raw material monomers for the addition polymerization resin were added dropwise over 90 minutes while stirring, followed by aging for 60 minutes. After that, unreacted addition-polymerized monomers were removed under reduced pressure (8 kPa). After that, 0.4 parts by mass of Ti(OBu) ₄ was added as an esterification catalyst, the temperature was raised to 250° C., and the reaction was continued under normal pressure (101.3 kPa) for 5 hours and then under reduced pressure (8 kPa) for 1 hour. gone. After cooling to 200° C., the reaction was carried out under reduced pressure (20 kPa). Then, the solvent was removed to obtain a non-hybrid amorphous polyester resin _b2 as a second binder resin. The resulting non-hybrid amorphous polyester resin _b2 had a glass transition temperature (Tg) of 58°C and a weight average molecular weight (Mw) of 33,000.

100 parts by mass of the obtained non-hybrid amorphous polyester resin b ₂ was dissolved in 400 parts by mass of ethyl acetate (manufactured by Kanto Kagaku Co., Ltd.) to prepare 638 parts by mass of a 0.26% by mass sodium lauryl sulfate solution. While stirring, ultrasonically dispersed at V-LEVEL 300 μA for 60 minutes with an ultrasonic homogenizer “US-150T” (manufactured by Nippon Seiki Seisakusho Co., Ltd.). After that, while heating to 40° C., a diaphragm vacuum pump “V-700” (manufactured by BUCHI) was used to completely remove ethyl acetate while stirring under reduced pressure for 3 hours to obtain a solid content of 14.5. An aqueous dispersion (B ₂ ) of fine particles of non-hybrid amorphous polyester resin b ₂ was prepared. At this time, the volume-based median diameter of the fine particles of the non-hybrid amorphous polyester resin b ₂ contained in the dispersion (B ₂ ) was 100 nm.

"Preparation of Toner 4"
Toner 4 was prepared in the same manner as in Toner 1, except that behenyl behenate (melting point: 73° C.), which is an ester release agent, was used as the release agent.

"Preparation of Toner 5"
In the production of Toner 1, in the aggregation and fusion process, the stirring rate was increased when the particle size reached 5.5 μm, and when the supernatant became transparent, the stirring rate was decreased again. Toner 5 was produced in the same manner except that the thickness was 2 μm, the temperature was further increased to 90° C., and the temperature was lowered to 30° C. when the circularity reached 0.960.

"Preparation of Toner 6"
Toner 6 was obtained in the same manner as in Toner 1, except that 27 parts by mass of HNP-51 was added as a releasing agent in the second stage polymerization.

"Preparation of Toner 7"
Toner 7 was obtained in the same manner as in Toner 1, except that 128 parts by mass of HNP-51 was added as a releasing agent in the second stage polymerization.

"Preparation of Toner 8"
In the production of Toner 1, 53 parts by mass of HNP-51 was added as a releasing agent in the second stage polymerization to obtain a styrene-acrylic resin. Toner was prepared in the same manner except that 476.5 parts by mass of the styrene/acrylic resin and 21.5 parts by mass of the hybrid amorphous polyester resin fine particle dispersion (B ₁ ) were used in the aggregation/fusion process. 8 was produced.

"Preparation of Toner 9"
In the production of Toner 1, 73 parts by mass of HNP-51 was added as a releasing agent in the second stage polymerization to obtain a styrene-acrylic resin. Toner 8 was prepared in the same manner as above, except that 358 parts by mass of the styrene-acrylic resin and 140 parts by mass of the hybrid amorphous polyester resin fine particle dispersion (B ₁ ) were used in the aggregation/fusion process. .

"Preparation of Toner 10"
In the production of Toner 1, a dispersion liquid (A ₂ ) of styrene-acrylic resin particles was obtained by changing the third-stage polymerization as follows.

Styrene 240 parts by mass n-Butyl acrylate 90 parts by mass The Tg of the obtained resin was 45°C.
Also, in the production of the hybrid amorphous polyester resin, the following changes were made.

Bisphenol A propylene oxide 2 mol adduct 285.7 parts by mass Terephthalic acid 55 parts by mass Fumaric acid 56 parts by mass

The resulting resin had a molecular weight of 30,000 and a Tg of 44°C.

Toner 10 was obtained in the same manner as in the preparation of Toner 1, except that the aggregation/fusion process was changed as described above.

"Preparation of Toner 11"
Toner 11 was obtained in the same manner as in Toner 1, except that the resin for styrene-acrylic shell (sh1) was used instead of the hybrid amorphous polyester resin. When the cross section of the toner was observed, it was confirmed that the shell was formed into a film.

"Preparation of Toner 12"
In the production of Toner 1, 50.5 parts by mass of HNP-51 was added as a releasing agent in the second stage polymerization.

After adding 498 parts by mass of the resin particle liquid in terms of solid content and 1600 parts by mass of ion-exchanged water to a reactor equipped with a stirrer, a temperature sensor, and a cooling pipe, a 5 mol/liter sodium hydroxide aqueous solution was added. The pH was adjusted to 10, and the liquid temperature was adjusted to 20°C.

After that, 40 parts by mass of "colorant fine particle dispersion (Cy ₁ )" in terms of solid content was added. Then, an aqueous solution prepared by dissolving 75 parts by mass of magnesium chloride in 75 parts by mass of ion-exchanged water was added with stirring at 30° C. over 10 minutes. Thereafter, the system was allowed to stand for 3 minutes before starting to heat up, and the system was heated to 80°C over 60 minutes, and the particle growth reaction was continued while maintaining the temperature at 80°C. In this state, the particle diameter of the associated particles was measured using "Multisizer 3" (manufactured by Beckman _Coulter , Inc.). An aqueous solution dissolved in 500 parts by mass of ion-exchanged water was added to stop grain growth. Furthermore, the temperature is raised and the particles are heated and stirred at 90° C. to promote fusion of the particles. 4000 particles) When the average circularity reached 0.960, the particles were cooled to 30° C. to obtain a “dispersion liquid of toner base particles [12]”.

Toner 12 was obtained using only the first binder resin in the same manner as in the production of Toner 1 except for the above change.

<Production of developer>
For toners 1 to 12 prepared as described above, a ferrite carrier coated with a copolymer resin of cyclohexyl methacrylate and methyl methacrylate (monomer mass ratio=1:1) and having a volume average diameter of 40 μm was used, and the toner concentration was 6. Developers 1 to 12 were prepared by mixing so as to make the mass %, and the following evaluations were performed. The mixer was mixed for 30 minutes using a V-type mixer.

≪Evaluation method≫
Toners 1 to 12 produced were evaluated as follows.

(Glossiness)
As an image forming apparatus, a commercially available full-color multifunction machine "bizhub PRO C6500" (manufactured by Konica Minolta) ^was modified, and a toner adhesion amount of 8 g/ A solid image patch (2.5 cm×4 cm) of m ² was formed at three locations in the longitudinal direction of the paper and in the center in the lateral direction to form an unfixed image patch.

As a single driving machine, a prototype machine was produced in which the fixing driving section was the upper roller (denoted as upper R), the pressure roller was the lower roller, and the drive control section was also added. "No speed difference" refers to a state in which the upper roller follows when the surface speed on the pressure side is set to 315 mm/s and pressure bonding is performed. On the other hand, the surface speed difference of -5% refers to a state in which the drive control unit is adjusted so that the upper roller is 299.3 mm/s (5% slower than 315 mm/s) when pressed. The speed was adjusted accordingly to fuse the previously unfused image patch.

The obtained image was measured with a gloss meter (manufactured by 75° Gardner Co.), the average value of three points was obtained, and the difference between the average values without speed difference and with speed difference was obtained.

(Heat resistant storage stability)
0.5 g of toner is placed in a 10 mL glass bottle with an inner diameter of 21 mm, the lid is closed, and after shaking 600 times at room temperature using a shaker "Tap Denser KYT-2000" (manufactured by Seishin Enterprise Co., Ltd.), the lid is removed. was left for 2 hours in an environment of a temperature of 55° C. and a humidity of 35% RH. Next, the toner is placed on a 48-mesh (350 μm mesh) sieve while being careful not to break up toner aggregates, and is set in a “powder tester” (manufactured by Hosokawa Micron Corporation). After fixing and adjusting the vibration intensity to a feeding width of 1 mm and applying vibration for 10 seconds, the ratio (% by mass) of the amount of toner remaining on the sieve was measured, and the toner agglomeration rate was calculated by the following formula. This test was repeated while maintaining the humidity at 35% RH and increasing the test temperature by 0.1° C. until the toner aggregation rate exceeded 50 mass %. The maximum test temperature (maximum heat-resistant storage temperature) at which the toner aggregation rate does not exceed 50% by mass was used as an index of heat-resistant storage stability.

In the present invention, the case where the limit heat resistant storage temperature is 56.0°C or higher is regarded as acceptable. Results are shown in Table I.

Toner aggregation rate (% by mass)=Residual toner mass on sieve (g)/0.5 (g)×100
(Fixability (under-offset (UO) temperature))
As an image forming apparatus, a commercially available full-color multifunction machine "bizhub PRO C6500" (manufactured by Konica Minolta) was modified so that the surface temperature of the fixing upper belt and the fixing lower roller can be changed. /m ² " (manufactured by Nippon Paper Industries), a solid image with a toner adhesion amount of 11.3 g/m ² was output at a fixing temperature of 200°C and a fixing speed of 315 mm/sec. was repeated until cold offset occurred, and the lowest surface temperature of the fixing upper belt at which cold offset did not occur was investigated. In each test, the fixing temperature means the surface temperature of the upper fixing belt, and the surface temperature of the lower fixing roller was set at 70°C. The lower the minimum fixation temperature, the better the low-temperature fixability. In this evaluation, the case where the temperature was 125°C or less was regarded as a pass.

(Observation of domain structure)
Using a scanning transmission electron microscope "JSM-7401F" (manufactured by JEOL Ltd.) as an evaluation device, a bright-field image of a RuO _4- stained toner base particle section with a thickness of 100 to 200 nm at an acceleration voltage of 30 kV and a magnification of 10000 times. observed.

RuO ₄ stained toner sections were prepared as follows.

After dispersing the toner base particles in a photocurable resin "D-800" (manufactured by JEOL Ltd.), photocuring is performed to form a block, and a microtome with diamond teeth is used to measure the thickness from the block. Flake-like samples of 100-200 nm were cut and mounted on grids with supporting membranes for transmission electron microscopy. A filter paper was placed on a 5 cmφ plastic petri dish with the toner base particle pieces thus prepared, and a grid with the pieces was placed thereon with the surface on which the pieces were placed facing up. Next, 2 to 3 drops of 0.5% RuO ₄ staining solution are dropped at two points in the petri dish, and the lid is closed. used for The dyeing conditions (time, temperature, concentration and amount of staining agent) were adjusted so that each resin could be distinguished when observed with a transmission electron microscope.

(Identification method)
The resin component in the toner base particles was identified according to the following criteria.

Observed dark: Styrene-acrylic resin (1)
Observed Bright: Amorphous Polyester Resin or Hybrid Amorphous Resin (2)
Observed bright and interface dark: release agent (measurement of domain diameter, domain area and domain volume)
As an evaluation apparatus, a transmission electron microscope (same as the observation of the domain structure) and an image processing analysis apparatus "LUZEX (registered trademark) AP" (manufactured by Nireco Corporation) were used.

A toner image for measurement was obtained in the same manner as in "observation of domain structure".

(Evaluation method of occupied area ratio)
The toner base particle images for measurement are selected from 25 or more fields of view in which the maximum length of the cross section of the toner base particles is ±10% of the volume average particle size (median diameter d50 ₎ of the toner base particles . board.

The occupied area ratio of the domains in the vicinity of the surface is defined as the area of the domain, where r is the average value of the maximum length of the cross section of the toner base particles, and a is the area of the cross section in the depth direction from the surface to r/4. It is defined by the following formula, where b is the total area obtained by binarizing the amorphous polyester resin or hybrid amorphous polyester resin observed in dyeing in the a portion.

Occupied area ratio (%) = (b/a) x 100
The above measurements were performed on 10 toner particles, and the average value was used.

From Table I, it can be seen that by combining the image forming apparatus of the present invention with the toner particles 1 to 11 of the present invention, the fixability and heat resistance of the toner particles can be secured, and a wide range of glossiness from low gloss to high gloss can be achieved. It was possible to realize a range of glossiness, and to provide an image forming system with a wide glossiness control range.

In particular, it has been found that the use of toner particles having a domain-matrix structure broadens the controllability of glossiness.

P Transfer material 1 Toner for electrostatic charge image development 2 First binding resin 3 Second binding resin 4 Release agent 5 Fixing roller 10 Fixing device 11 Fixing belt 12 Heating roller 13 Pressure roller 14 Fixing roller 100 Image forming apparatus 108 Intermediate Transfer Belt 110Y, 110M, 110C, 110K Image Forming Unit 130 Fixing Device 131 Pressure Roller 132 Heating Roller 190 Photosensitive Drum 191 Charging Device 192 Exposure Device 193 Developing Device 195 Cleaner Device

Claims (6)

An image forming system comprising at least an electrostatic charge image developing toner containing toner base particles containing a release agent and a binder resin, and an image forming apparatus,
the toner base particles have a domain-matrix structure and contain a first binder resin and a second binder resin as the binder resin;
the glass transition temperature (Tg) of the second binder resin is higher than the Tg of the first binder resin by 10° C. or more;
containing a vinyl resin as the first binder resin,
The second binder resin contains an amorphous polyester resin as a domain,
The amorphous polyester resin is a hybrid amorphous polyester resin formed by chemically bonding a vinyl-based polymer segment and a polyester-based polymer segment, and the image forming apparatus comprises at least
an image forming unit that forms a toner image on a transfer material using the electrostatic charge image developing toner;
a fixing driving unit that drives the fixing member to rotate;
a pressurizing drive unit that rotationally drives the pressurizing member;
a drive control unit that controls rotational driving of the fixing drive unit or the pressure drive unit; and
When the fixing member and the pressure member nip the transfer material and fix the toner image, the drive control unit rotates the fixing member and the pressure member according to the following formula 1. An image forming system , wherein the ratio of the surface speed of the fixing member to the surface speed of the pressing member is adjusted to be within ±10%.
Formula 1 Ratio of the surface speed of the fixing member to the surface speed of the pressure member (%) = {(surface speed of the fixing member (mm/sec) - surface speed of the pressure member (mm/sec)) / pressure member Surface speed (mm/sec)}×100 When the average maximum length of the cross section of the toner base particles is r, the second binder resin occupies 80% or more of the area of the cross section in the depth direction of r/4 from the surface. 2. The image forming system of claim 1, wherein the image forming system comprises: 3. The image forming system according to claim 1, wherein the average diameter of the domains is in the range of 50-150 nm. 4. The image forming system according to any one of claims 1 to 3, wherein the release agent contains a hydrocarbon compound. 5. The image forming system according to any one of claims 1 to 4, wherein the toner base particles contain the second binder resin in an average of 5 to 25% by mass. 6. The image forming system according to any one of claims 1 to 5, wherein the toner base particles contain the release agent in an average of 5 to 15% by mass.

Images