JP2021103281A - Intermediate transfer body, method for manufacturing intermediate transfer body, image forming method, and image forming apparatus - Google Patents

Abstract

To provide an intermediate transfer body that has satisfactory toner transferability even when an environment changes and when it is used for a long period and a method for manufacturing the intermediate transfer body, and to provide an image forming method and an image forming apparatus using the intermediate transfer body.SOLUTION: An intermediate transfer body of the present invention contains at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu, and a ferroelectric substance B. The ferroelectric substance B preferably contains barium titanate.SELECTED DRAWING: None

Description

The present invention relates to an intermediate transfer body, a method for producing an intermediate transfer body, an image forming method, and an image forming apparatus, and more particularly to an intermediate transfer body having good toner transferability even during environmental changes and long-term use.

Conventionally, as an electrophotographic image forming apparatus using an intermediate transfer body (also referred to as an intermediate transfer belt), a toner image formed on a photoconductor is primaryly transferred to the intermediate transfer body, and the toner on the intermediate transfer body is transferred. It is known that an image is secondarily transferred to a transfer material such as transfer paper (recording paper). That is, after the toner image formed on the photoconductor, which is charged to a predetermined polarity, is transferred to the intermediate transfer body by using electrostatic force, the toner image of the intermediate transfer body is transferred by using electrostatic force. Transfer onto the material.

An image forming apparatus using such an intermediate transfer body sequentially superimposes toner images formed on each photoconductor on the intermediate transfer body by utilizing electrostatic force, and further, collectively superimposes the superimposed toner images on a transfer material. Since it can be transferred, it is widely used as a color image forming apparatus.

It is known that by increasing the dielectric constant of the intermediate transfer body, the voltage applied to the intermediate transfer body is reduced, and the voltage is applied to the toner by that amount to improve the electric field strength. In order to improve the dielectric constant of the intermediate transfer material, it is effective to add a highly dielectric material to the intermediate transfer material, and it is common to add a ferroelectric substance in particular.
For example, as disclosed in Patent Document 1, a technique of adding a ferroelectric substance to an intermediate transfer material to improve transferability is known.
However, it has been found that the relative permittivity of a ferroelectric substance of such a technique changes greatly depending on the temperature environment. It has also been found that the relative permittivity gradually decreases with time.

Japanese Unexamined Patent Publication No. 08-152759

The present invention has been made in view of the above problems and situations, and a problem to be solved thereof is to provide an intermediate transfer body and a method for producing an intermediate transfer body having good toner transferability even during environmental changes and long-term use. Is. Another object of the present invention is to provide an image forming method and an image forming apparatus using the intermediate transfer body.

In the process of investigating the cause of the above problem in order to solve the above problem, the present inventor contains a specific metal A and a ferroelectric substance B, so that the toner transferability even during environmental changes and long-term use We have found that it is possible to provide a good intermediate transcript and the like, and have arrived at the present invention.
That is, the above-mentioned problem according to the present invention is solved by the following means.

1. 1. An intermediate transfer material containing at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu and a ferroelectric substance B.

2. The intermediate transfer material according to item 1, wherein the ferroelectric substance B contains barium titanate.

3. 3. Item 1 or the above, which contains a calcined composition containing at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu and a ferroelectric substance B. The intermediate transcript according to item 2.

4. The metal A contains at least one metal A-1 selected from Mg, Sc, Tm, Yb and Lu and at least one metal A-2 selected from Y, Eu, Dy, Ho and Er.
The intermediate transfer material according to any one of items 1 to 3, wherein the ferroelectric substance B contains barium titanate.

5. The metal A contains at least one metal A-1-1 selected from Sc, Tm, Yb and Lu, at least one metal A-2 selected from Y, Eu, Dy, Ho and Er, and Mg. And
The intermediate transfer material according to any one of items 1 to 3, wherein the ferroelectric substance B contains barium titanate.

6. The item according to any one of items 1 to 5, wherein the metal A is contained in the range of 0.1 to 10 mol in terms of oxide with respect to 100 mol of the ferroelectric substance B. Intermediate transcript of.

7. The method for producing an intermediate transfer product according to any one of paragraphs 1 to 6, wherein the intermediate transfer product is produced.
An intermediate transfer product comprising a step of calcining at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu and a ferroelectric substance B at 1000 ° C. or higher. Manufacturing method.

8. A method for forming an image, which comprises using the intermediate transfer material according to any one of the items 1 to 6.

9. An image forming apparatus comprising the intermediate transfer member according to any one of items 1 to 6.

According to the above means of the present invention, it is possible to provide an intermediate transfer body and a method for producing an intermediate transfer body having good toner transferability even when the toner is used for a long period of time and changes in the environment. Further, it is possible to provide an image forming method and an image forming apparatus using the intermediate transfer body.
Although the mechanism of expression or mechanism of action of the effect of the present invention has not been clarified, it is inferred as follows.
Since the crystal structure is changed by adding a metal such as a rare earth element to the ferroelectric substance and firing it, it is possible to suppress the change in the crystal structure due to temperature and aging.
That is, as a ferroelectric substance, for example, the dielectric constant of barium titanate (BaTIO ₃ ) becomes a tetragonal system when the temperature drops again after being raised to the Curie temperature or higher, so that the distance between the bariums becomes vertically long. This is due to the electrical bias (polarization) caused by the displacement of the oxygen atom and titanium electron generated due to (the c / a ratio becomes higher), but when the temperature is further lowered, the crystal system becomes a tetragonal system. Instead, the dielectric constant drops below 5 ° C.
In addition, even at a temperature at which the tetragonal system is maintained, the capacitance is rearranged in a more stable form over time, and the capacitance decreases.
Therefore, as the ferroelectric substance B, titanium of barium titanate or a part of barium is defined as a specified metal (at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu). It is presumed that by replacing with, the Curie temperature can be shifted, the amount of change in the dielectric constant due to the temperature change can be changed, and the change in the crystal system over time can be suppressed.
Although the details of the mechanism have not been clarified, Mg, Sc, Tm, Yb, and Lu have ionic radii close to those of titanium, so they easily enter the titanium site, which is effective in changing the Curie temperature and flattening the temperature characteristics. In addition, Eu, Dy, Ho, and Er are presumed to be effective in suppressing changes in the crystal system over time because they easily enter the Ba site from the ionic radius. The size of the ionic radius tends to make it easier to enter the Ba site and titanium site, but it is presumed that some small ions may enter the barium site and large ions may enter the titanium site.

Conceptual cross-sectional view showing an example of the layer structure of the intermediate transfer member of the present invention. Schematic diagram showing the structure of the image forming apparatus of the present invention Block diagram showing the configuration of the image forming apparatus of the present invention Block diagram showing the configuration of the image forming apparatus of the present invention Schematic diagram for explaining the method of measuring the dielectric constant

The intermediate transfer material of the present invention is characterized by containing at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu, and a ferroelectric substance B.
This feature is a technical feature common to or corresponding to each of the following embodiments.

In an embodiment of the present invention, it is preferable that the ferroelectric substance B contains barium titanate from the viewpoint of environmental safety.

Further, the intermediate transfer material of the present invention contains a firing composition containing at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu and a ferroelectric substance B. This is preferable from the viewpoint of maintaining transferability for a long period of time or suppressing environmental changes.

Further, the metal A contains at least one metal A-1 selected from Mg, Sc, Tm, Yb and Lu, and at least one metal A-2 selected from Y, Eu, Dy, Ho and Er. It is preferable that the ferroelectric substance B contains barium titanate from the viewpoint of maintaining transferability for a long period of time and suppressing environmental fluctuations.

Further, the metal A includes at least one metal A-1-1 selected from Sc, Tm, Yb and Lu, at least one metal A-2 selected from Y, Eu, Dy, Ho and Er, and Mg. It is preferable that the ferroelectric substance B contains barium titanate from the viewpoints of environmental safety, maintenance of transferability for a long period of time, and suppression of environmental fluctuations.

When the metal A is contained in the range of 0.1 to 10 mol in terms of oxide with respect to 100 mol of the ferroelectric substance B, the sinterability is good, the dielectric constant is increased, and the transferability is improved. It is preferable in terms of improvement.

In the method for producing an intermediate transfer product of the present invention, at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu and a ferroelectric substance B are fired at 1000 ° C. or higher. It is preferable to have a process in that an intermediate transfer product having good transferability of the toner during environmental changes and long-term use can be obtained.

The image forming method of the present invention preferably uses the intermediate transfer material.
Further, the image forming apparatus of the present invention preferably includes the intermediate transfer body.

Hereinafter, the present invention, its constituent elements, and modes and modes for carrying out the present invention will be described. In the present application, "~" is used to mean that the numerical values described before and after the value are included as the lower limit value and the upper limit value.

[Overview of the intermediate transcript of the present invention]
The intermediate transfer material of the present invention is characterized by containing at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu, and a ferroelectric substance B.

<Metal A>
The metal A according to the present invention is at least one metal selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu.

<ferroelectric B>
In the present invention, the ferroelectric substance B is a kind of dielectric, and is a substance in which electric dipoles are aligned even if there is no electric field outside, and the direction of the dipoles can be changed by the electric field. Specifically, the ferroelectric substance B refers to a substance having a relative permittivity of 15 or more at a frequency of 1 MHz in an environment of a temperature of 23 ° C. and a humidity of 50% RH. Preferably, the relative permittivity is 20 or more, more preferably 100 or more. A higher dielectric constant is preferable from the viewpoint of exhibiting the effect of the present invention. The upper limit is constrained by the availability of materials.

Further, the state in which the electric dipole moments are spontaneously aligned in this way is called a ferroelectric state, and this property is called a ferroelectricity. _{Among the ferroelectric substances, in the present invention, barium titanate (BaTIO 3} ) and lead zirconate titanate (PZT:) are used as the ferroelectric substance B because of the load in the production process and the stability during aging. It is preferable to contain Pb (Zr, Ti) O ₃ ), lead lanthanate titanate (PLZT: (Pb, La) (Zr, Ti) O ₃ : La (lantern) dielectric ceramic, etc. It is particularly preferable to contain barium titanate from the viewpoint of environmental safety and improvement of transferability.

The intermediate transfer material of the present invention is a calcined composition containing at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu and a ferroelectric substance B (modification described later). (Also referred to as a ferroelectric substance) is preferable from the viewpoint of maintaining transferability for a long period of time or suppressing environmental fluctuations.
The firing composition, which will be described later, is obtained by firing the metal A and the ferroelectric substance B, for example, in the range of 1000 to 1400 ° C., more preferably in the range of 1200 to 1400 ° C.

(Detection method)
As a method for detecting the metal A and the strong dielectric B, an appropriate method such as a general-purpose cross-sectional cutter for preparing a scanning electron microscope (SEM) sample, ion milling, a microtome, or the like is used to thicken the intermediate transfer body (belt). EDS (energy dispersive X-ray spectroscopy) connected to the device by cutting in the direction and observing the cross section of the intermediate transfer body with a scanning electron microscope (SEM) to identify the metal A and the strong dielectric B. It can be confirmed by performing elemental analysis such as.

Further, in the intermediate transfer material of the present invention, the metal A is at least one metal A-1 selected from Mg, Sc, Tm, Yb and Lu, and at least one selected from Y, Eu, Dy, Ho and Er. It is preferable that the metal A-2 of the above material is contained and the ferroelectric substance B contains barium titanate from the viewpoint of maintaining transferability for a long period of time and suppressing environmental fluctuations.
Further, the metal A includes at least one metal A-1-1 selected from Sc, Tm, Yb and Lu, at least one metal A-2 selected from Y, Eu, Dy, Ho and Er, and Mg. It is more preferable that the ferroelectric substance B contains barium titanate from the viewpoint of maintaining transferability for a long period of time and suppressing environmental fluctuations.

The intermediate transfer material of the present invention preferably contains metal A in the range of 0.1 to 10 mol in terms of oxide with respect to 100 mol of the ferroelectric substance B. When it is 0.1 mol or more, a sufficient effect of the metal A is obtained, and when it is 10 mol or less, the sinterability is good, the dielectric constant is increased, and the transferability is good.

The intermediate transfer material of the present invention preferably contains a small amount of silicon oxide in addition to the metal A and the ferroelectric substance B. The inclusion of silicon oxide improves the sinterability of the metal A and the ferroelectric substance B. The content of silicon oxide is preferably in the range of 0.1 to 3 mol with respect to 100 mol of the ferroelectric substance B.

[Layer structure of intermediate transcript]
FIG. 1 is a conceptual cross-sectional view showing an example of the layer structure of the intermediate transfer member of the present invention.
The intermediate transfer body 1a of the present invention has at least a base material layer 2a. The intermediate transfer body 1a may have a single-layer structure composed of only the base material layer 2a, but if necessary, layers such as the elastic layer 3a or the surface layer 4a are placed on the base material layer 2a in this order. It is also possible to have a configuration having the above.
The metal A and the ferroelectric substance B may be contained in the base material layer 2a or in the elastic layer 3a.

The thickness of the intermediate transfer material can be appropriately determined depending on the intended use and the like, but is preferably in the range of 50 to 100 μm. The thinner the thickness, the lower the voltage required for transfer, the more the discharge is suppressed, and the transfer efficiency is improved. Therefore, 100 μm or less is preferable. Further, if the thickness is 50 μm or more, the strength of the intermediate transfer material can be sufficiently maintained.

Electrical resistance of the intermediate transfer body (the volume resistivity) ^is preferably in the range of 10 5 ~10 ¹¹ Ω · cm. The electric resistance value can be controlled by the content of the conductor described later.
As for the shape of the intermediate transfer body, the intermediate transfer body having an endless structure does not have a thickness change due to superposition, and an arbitrary part can be set as the rotation start position of the intermediate transfer body, and the control mechanism of the rotation start position can be omitted. It has advantages and is preferable.

The surface resistivity of the intermediate transfer member ^is preferably in the range of ¹⁰ 9 ~10 ¹² Ω · cm.
The breaking stress of the intermediate transfer material is preferably 100 MPa or more, more preferably 120 MPa or more, and the breaking elongation is preferably 20% or more, more preferably 40% or more. By setting the breaking stress and breaking elongation within the above ranges, high crack resistance and high wear resistance can be obtained.
The breaking stress and the breaking elongation were measured in accordance with JIS K7161.

<Base layer>
The base material layer preferably contains the metal A and the ferroelectric substance B.
Further, it is more preferable that the base material layer contains a conductor.

The method for producing barium titanate contained as the ferroelectric substance B is not particularly limited, and for example, it can be produced by the method described in paragraphs 0033 to 0044 of Japanese Patent No. 6368246.
Specifically, an aqueous solution containing barium and titanium hydroxide is prepared, and the aqueous solution is subjected to a hydrothermal reaction under high temperature and high pressure conditions.
The temperature of the hydrothermal reaction is 200 ° C. or higher, preferably 200 to 450 ° C., more preferably 250 to 400 ° C., and the total pressure is 2 MPa or higher, preferably 2 to 50 MPa, more preferably 10 to 40 MPa, usually 0.1. The reaction may be carried out for a minute or more, preferably 0.1 to 1 hour, more preferably 0.1 to 30 minutes. A hydrothermal reaction is carried out under such high temperature and high pressure conditions to control the particle morphology such as the ratio value (c / a) and the average primary particle size. Then, after filtering and washing with water, the particles are dried and crushed to obtain barium titanate particles.
As a means for setting the value of the ratio and the average primary particle size according to the present invention into the above range, the type of raw material in the aqueous solution containing barium and titanium hydroxide, the Ba / Ti ratio, the amount of alkali, and the reaction scale. , Reaction temperature, reaction pressure, reaction time, etc. can be controlled.

(Average primary particle size of ferroelectric B particles)
The average primary particle size of the ferroelectric substance B particles (referring to those in the fine particle state of the ferroelectric substance B) is preferably 300 nm or less in that the residual polarization can be reduced. The lower limit of the average primary particle size is 30 nm, more preferably 50 nm, and the optimum range is in the range of 90 to 110 nm.
For the measurement of the average primary particle size of the particles of the ferroelectric substance B, 200 or more particles were randomly measured using a transmission electron microscope (TEM) (manufactured by Hitachi High-Tech), and the average value was calculated. .. When the shape of the particles is not spherical, the average value of the major axis and the minor axis can be calculated as the diameter of each particle.

Further, the ferroelectric substance B according to the present invention preferably contains the ferroelectric substance B in the range of 5 to 30% by volume with respect to the entire base material layer. When it is 5% by volume or more, there is a high dielectricing effect of the intermediate transfer material, that is, an effect of improving transferability. When it is 30% by volume or less, it can have the required mechanical strength.

(conductor)
The base material layer used in the present invention preferably contains a conductor in addition to the metal A and the ferroelectric substance B.
In the present invention, the conductor is not particularly limited as long as it is a conductive substance. Specifically, as the conductor (conductive agent) used in the present invention, a known electronic conductive substance or ionic conductive substance can be used, and the conductor is carbon black, carbon nanotube, graphite or graphene. It is preferable that the intermediate transfer material has conductivity, and it is more preferable that the intermediate transfer material is made of carbon black, carbon nanotubes, or graphene in terms of ease of handling.
The amount of the conductor used in the present invention is preferably in the range of 0.1 to 20% by volume with respect to the entire base material layer. When it is 0.1% by volume or more, the toner is not contaminated on the surface of the base material layer, and when it is 20% by volume or less, the strength of the base material layer and the charge amount of the toner are not lowered, which is good. Is. More preferably, it is in the range of 0.5 to 15% by volume, and even more preferably, it is in the range of 1 to 10% by volume.

(Carbon black)
Examples of carbon black among the conductors include gas black, acetylene black, oil furnace black, thermal black, channel black, and Ketjen black. Effective methods for obtaining the desired conductivity with a smaller amount of mixing include Ketjen black, acetylene black and oil furnace black. Ketjen black is a contactive furnace type carbon black.

The average primary particle size of carbon black is preferably in the range of 10 to 50 nm. The average primary particle size can be measured by the method of FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.) using a photon counting method.

(carbon nanotube)
A carbon nanotube (hereinafter abbreviated as CNT) is a defect-free single-walled material having a structure in which a graphite hexagonal net plane is rolled into a tubular shape, or a multi-walled tubular material in which they are laminated in a nested manner. .. The average tube diameter of the CNTs contained in the intermediate transfer material of the present invention is preferably in the range of 10 to 150 nm, and the length of the CNTs is preferably in the range of 5 to 12 μm. By setting the diameter and length of the CNTs in the above ranges, appropriate conductivity can be imparted to the intermediate transfer material.

This CNT may be covalently bonded to a functional group, if necessary. For example, a strong acid treatment of CNT produces oxidized CNT in which a carboxylic acid is introduced on the surface, and the oxidized CNT is reacted with thionyl chloride and then reacted with an alkyl alcohol or the like to dissolve in an organic solvent. CNT can be generated. By using such chemically decorated CNTs, the CNTs can be uniformly dispersed in the resin. Further, by applying an electric field from the outside with the CNTs dispersed in the resin, the CNTs can be oriented in a desired direction, and the dielectric constant of the intermediate transfer material can be improved.

The average tube system and the length can be obtained from a scanning electron microscope (SEM) photograph of a cross section of the intermediate transfer material, and are adjusted by cutting (crushing) CNTs or mixing two or more types of CNTs. It is possible.

(Graphite)
As the graphite used in the present invention, both natural products and artificial synthetic products can be used. It is difficult to unambiguously define the preferable particle size of graphite because the shape of graphite is scaly and the shape changes during the dispersion step during the production of the toner carrier, but it is difficult to unambiguously define it. The width (in the direction of the graphite fracture surface) is preferably 100 μm or less. As a measuring method, the sample is directly observed with a microscope and measured.

(Graphene)
Graphene is a sheet-like substance consisting of a planar hexagonal lattice structure of carbon atoms. The graphene sheet is flat graphene and is usually a single layer. Graphene sheets are artificial and are available as flaky powders. For example, it can be produced by a chemical vapor deposition (CVD) method.

The graphene sheet does not have to be completely single layer, and may partially include two or more layers. For this reason, graphene sheets have, for example, less than two layers. Further, the size is preferably less than 2 μm, and the thickness is preferably 2 nm or less. The graphene sheet laminate preferably has, for example, two or more layers, a size of 5 to 25 μm, and a thickness of 12 nm or less.

Commercially available products can be used for the graphene sheet and its laminate. The number, size and thickness of the graphene sheet and its laminate can be measured, for example, by a transmission electron microscope (TEM).

(resin)
The base material layer according to the present invention preferably contains the metal A and the ferroelectric substance B in a dispersed state in the resin.
Various resins can be used as the resin according to the present invention, but the strength and durability of polyimide (PI), polyamide-imide (PAI), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), etc. Super engineering plastic with is desirable.

Of these, polyimide, polyamide and polyamideimide are preferred. Among them, polyimide is more preferable because it has excellent properties such as heat resistance, bending resistance, flexibility, and dimensional stability. Polyimide can be obtained, for example, by synthesizing a polyamic acid (polyimide precursor) from an acid anhydride and a diamine compound, and imidizing the polyamic acid by heat or a catalyst.

The acid anhydride used for the synthesis of polyimide is not particularly limited, and for example, biphenyltetracarboxylic acid dianhydride, terphenyltetracarboxylic acid dianhydride, benzophenone tetracarboxylic acid dianhydride, pyromellitic anhydride, and the like. Examples thereof include aromatic tetracarboxylic acid dianhydrides such as oxydiphthalic acid dianhydride, diphenylsulfone tetracarboxylic acid dianhydride, hexafluoroisopropyridene diphthalic acid dianhydride, and cyclobutane tetracarboxylic acid dianhydride.

The diamine compound used in the synthesis of polyimide is not particularly limited, but for example, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 4,4'-diaminodiphenylmethane, 4,4'. -Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 3,7 -Diamino-dimethyldibenzothiophene-5,5'-dioxide, 4,4'-diaminobenzophenone, 4,4'-bis (4-aminophenyl) sulfide, 4,4'-diaminobenzanilide, 1,4-bis Examples thereof include aromatic diamines such as (4-aminophenoxy) benzene.

The resin used in the present invention is preferably contained in the range of 50 to 95% by volume with respect to the entire base material layer. When it is 50% by volume or more, it can have the required mechanical strength. When it is 95% by volume or less, a space containing the metal A, the ferroelectric substance B and the conductor can be secured.

<Elastic layer>
The elastic layer used in the present invention is a layer having desired conductivity and elasticity that can be formed on the outer peripheral surface of the base material, if necessary.
The elastic layer is made of a rubber material. The thickness of the elastic layer is preferably within, for example, 50 to 400 μm.
Examples of rubber materials include resins having rubber elasticity such as urethane rubber, chloroprene rubber (CR) and acrylic nitrile rubber (NBR). The rubber material preferably contains chloroprene rubber or nitrile butadiene rubber from the viewpoint of controlling the electrical resistance of the intermediate transfer material.
The elastic layer may contain the metal A and the ferroelectric substance B according to the present invention.

<Surface layer>
If necessary, the surface layer (surface layer) is a layer that can be formed on the outer peripheral surface of the base material or on the outer peripheral surface of the elastic layer, and has an effect of improving transferability.
The surface layer can be provided with a surface layer used for a known intermediate transfer belt as long as the effect of the present invention is not impaired. The surface layer includes, for example, metal oxide fine particles (a), a (meth) acrylate monomer (b) having a refractive index nD in the range of 1.6 to 1.8, and the (meth) acrylate monomer (b). It can be obtained by irradiating a coating film of a coating liquid for forming a surface layer containing an active energy ray-curable composition containing a polyfunctional (meth) acrylate (c) other than the above with active energy rays and curing the coating liquid. It is not limited to this.

<Relative permittivity>
The intermediate transfer material of the present invention preferably has a relative permittivity at a frequency of 1 MHz in the range of 10 to 100 under an environment of a temperature of 23 ° C. and a humidity of 50% RH.
When the relative permittivity is 10 or more, it is easy to increase the transfer electric field, which is preferable. On the other hand, when the relative permittivity is 100 or less, the adhesive force between the toner and the intermediate transfer body is not too large, and the transfer efficiency does not decrease, which is preferable. The relative permittivity is more preferably in the range of 20 to 50, and particularly preferably in the range of 30 to 40.

The relative permittivity can be calculated by the following method.
The permittivity of the intermediate transfer material is measured. Specifically, as shown in FIG. 6, a thin film electrode 201 having a resistance of one digit Ω is formed on both sides of the intermediate transfer body 87a by sputtering or the like, and cut out with a mold of 10 mmφ to prepare a measurement sample, and an impedance analyzer “ Using a "12608W type" (manufactured by Solartron Analytical Co., Ltd.), the permittivity (F / m) was measured by the electrode contact method in an environment of a temperature of 23 ° C. and a humidity of 50% RH under the condition of a frequency of 1 Hz to 1 MHz. , Converted to relative permittivity.

[Manufacturing method of intermediate transcript]
Next, a method for producing the intermediate transcript of the present invention will be described. The following production method is an example, and any method capable of producing an intermediate transcript can be used.
In the method for producing an intermediate transfer product of the present invention, at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu and a ferroelectric substance B are fired at 1000 ° C. or higher. It is characterized by having a process.

Specifically, first, the metal A and the ferroelectric substance B are calcined at 1000 ° C. or higher to obtain a modified ferroelectric substance (calcination composition). At this time, in order to improve the sinterability of the metal A and the ferroelectric substance B, it is preferable to further add silicon oxide and fire. The content of silicon oxide is as described above.
Next, a dispersion liquid A in which the obtained modified ferroelectric particles are dispersed in a solvent is prepared. In addition, a dispersion liquid B in which the conductor is dispersed in a solvent is also prepared. Here, both the dispersion liquid A and the dispersion liquid B may use a dispersant to the extent that the dielectric constant and the mechanical properties are not affected.
The prepared dispersion liquid A and dispersion liquid B are mixed and dispersed with the resin of the polyimide varnish "Yupia-AT (U-varnish-A)" (manufactured by Ube Industries, Ltd.). At this time, the contents of the metal A, the ferroelectric substance B, and the conductor are appropriately adjusted so as to be in a preferable range. The mixing / dispersing operation can be performed using a mixer or the like. The metal A, the ferroelectric substance B, and the conductor may be mixed and dispersed in the polyimide varnish, if necessary, without preparing the dispersion liquid A and the dispersion liquid B.
A coating liquid for forming a base material layer can be prepared by the mixing / dispersing operation.

Next, while rotating the stainless steel cylindrical mold around the cylindrical shaft, the dispense nozzle is moved in the axial direction, and the coating liquid for forming the base material layer is discharged from the nozzle to discharge the coating liquid for forming the base material layer from the outer peripheral surface of the mold. It is applied spirally on top to form a coating that connects them.
Next, most of the solvent is volatilized by heating while rotating the cylindrical mold, and then by heating at 350 ° C. or higher for 1 hour, an endless belt-shaped base material layer can be formed. Then, this base material layer is processed to obtain an intermediate transfer material containing the metal A, the ferroelectric substance B, and the conductor in the resin.
The intermediate transfer body may be prepared using only the base material layer prepared by the above method, or the intermediate transfer body may be prepared by bonding the elastic layer and the surface layer to the base material layer. A known method may be used for forming the elastic layer and the surface layer, and the method is not particularly limited.

[Image forming device]
Next, an image forming apparatus including the intermediate transfer body of the present invention and an image forming method using the intermediate transfer body will be described.
The image forming apparatus (also referred to as an electrophotographic image forming apparatus) of the present invention has, for example, four colors of yellow (Y), magenta (M), cyan (C), and black (K), as shown in FIG. A tandem image forming apparatus in which photoconductor drums 83Y, 83M, 83C, and 83K as corresponding photoconductors are arranged in series in the traveling direction of the intermediate transfer body.

As shown in FIG. 3, the image forming apparatus 1 includes a control unit 10 composed of a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a memory such as a RAM (Random Access Memory) 13, and the like. A storage unit 20 composed of an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc., a network I / F unit 30 composed of a NIC (Network Interface Card), a modem, etc., and a touch panel or the like. A display operation unit 40, an image reading unit 50 composed of an ADF (Auto Memory Feeder) and a scanner, an image processing unit 60 composed of a RIP (Raster Image Processor), a transport unit 70, and an image forming unit. The image forming unit 80 that processes the paper conveyed from the conveying unit 70, including the 80 and the like, includes the intermediate transfer unit of the present embodiment.

As shown in FIG. 2, the transport unit 70 includes a paper feed device 71, a transport mechanism 72, a paper discharge device 73, and the like. The paper housed in the paper feeding device 71 is fed one by one from the uppermost portion, and is conveyed to the image forming unit 80 by a conveying mechanism 72 provided with a plurality of conveying rollers such as a resist roller. At this time, the resist portion on which the resist roller is arranged corrects the inclination of the fed paper and adjusts the transfer timing. Then, the paper on which the image is formed by the image forming unit 80 is discharged to the paper ejection tray outside the machine by the paper ejection device 73 provided with the paper ejection roller.

As shown in FIGS. 2 and 4, the image forming unit 80 includes an exposure apparatus 81 (81Y, 81M, 81C, 81K) and a developing apparatus 82 provided corresponding to different color components Y, M, C, and K. (82Y, 82M, 82C, 82K), Photoreceptor drum 83 (83Y, 83M, 83C, 83K), Charging device 84 (84Y, 84M, 84C, 84K), Cleaning device 85 (85Y, 85M, 85C, 85K), It is composed of a primary transfer roller 86 (86Y, 86M, 86C, 86K), an intermediate transfer unit 87, a fixing device 88, and the like. Each element will be outlined below. In the following description, symbols excluding Y, M, C, and K are used as necessary.

In the photoconductor drum 83 of each color component Y, M, C, K, an organic photoconductor layer (OPC) provided with an overcoat layer as a protective layer is formed on the outer peripheral surface of a cylindrical metal substrate made of an aluminum material. It is an image carrier. The photoconductor drum 83 is rotated counterclockwise in FIG. 3 by following the intermediate transfer body in a grounded state.

The charging device 84 for each of the color components Y, M, C, and K is a scorotron type, and is arranged close to the corresponding photoconductor drum 83 in a state in which the longitudinal direction thereof is along the rotation axis direction of the photoconductor drum 83. By corona discharge having the same polarity as the toner, a uniform potential is applied to the surface of the photoconductor drum 83.

The exposure apparatus 81 for each color component Y, M, C, K scans in parallel with the rotation axis of the photoconductor drum 83 by, for example, a polygon mirror, and is uniformly charged on the surface of the corresponding photoconductor drum 83. An electrostatic latent image is formed by performing image exposure based on the image data.

The developing device 82 for each of the color components Y, M, C, and K contains a two-component developer composed of a toner having a small particle size of the corresponding color component and a magnetic material, and the toner is applied to the surface of the photoconductor drum 83. The electrostatic latent image carried on the photoconductor drum 83 is visualized with toner.

The primary transfer roller 86 of each color component Y, M, C, K presses the intermediate transfer body of the present embodiment against the photoconductor drum 83, and sequentially superimposes each color toner image formed on the corresponding photoconductor drum 83 in the middle. Primary transfer to the transcript.

The cleaning device 85 for each of the color components Y, M, C, and K recovers the residual toner remaining on the corresponding photoconductor drum 83 after the primary transfer. Further, a lubricant application mechanism (not shown) is provided adjacent to the photoconductor drum 83 of the cleaning device 85 in the rotation direction, and the lubricant is applied to the photosensitive surface of the corresponding photoconductor drum 83. There is.

The intermediate transfer unit 87 includes an endless intermediate transfer body 87a to be transferred, a support roller 87b, a secondary transfer roller 87c, an intermediate transfer cleaning unit 87d, and the like, and the intermediate transfer body 87a is stretched on a plurality of support rollers 87b. It is constructed by being hung. When the intermediate transfer body 87a whose toner images of each color are first transferred by the primary transfer rollers 86Y, 86M, 86C, and 86K is pressed against the paper by the secondary transfer roller 87c, the intermediate transfer body 87a and the secondary transfer roller 87c are brought into contact with each other. The toner image is secondarily transferred to the paper by the electric field acting on the toner based on the transfer voltage between them, and sent to the fixing device 88. The intermediate transfer cleaning unit 87d has a belt cleaning blade that is slidably contacted with the surface of the intermediate transfer body 87a. The transfer residual toner remaining on the surface of the intermediate transfer body 87a after the secondary transfer is scraped off and removed by the belt cleaning blade.

The fixing device 88 includes a heating roller 88a and a fixing roller 88b as heat sources, a fixing belt 88c and a pressure roller 88d hung on the fixing roller 88b, and the pressure roller 88d is pressed against the fixing roller 88b via the fixing belt 88c. The pressure contact portion constitutes the nip portion. Then, the fixing belt 88c heated by the heating roller 88a and each roller heat and pressurize the paper passing through the nip portion to fix the unfixed toner image formed on the paper.

Then, the paper on which the toner image is fixed by the fixing device 88 is discharged to the paper ejection tray outside the machine by the paper ejection device 73 provided with the paper ejection roller.

Note that FIGS. 2 and 4 are examples of the image forming apparatus 1 of the present invention, and the structure and configuration thereof can be appropriately changed as long as the intermediate transfer body 87a of the present invention can be used.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the following examples, the operation was performed at room temperature (25 ° C.) unless otherwise specified. Unless otherwise specified, "%" and "parts" mean "mass%" and "parts by mass", respectively.

[Preparation of modified ferroelectric substance B-1]
To 100 mol of barium titanate as the ferroelectric substance B, 3 mol of magnesium as metal A and _{0.1 mol of SiO 2} were added in terms of MgO, and the mixture was pulverized with water and a ball mill.
Then, water is evaporated at 120 ° C., calcined at 1250 ° C. for 2 hours in a reducing atmosphere, slowly cooled, recovered, and pulverized by a ball mill. I got 1.

[Preparation of ferroelectric particle dispersion liquid 1]
30 parts by mass of the obtained modified ferroelectric substance B-1 is mixed with 70 parts by mass of N-methyl-2-pyrrolidone (NMP) which is a dispersion medium, and the ferroelectric substance is subjected to ultrasonic dispersion treatment. Particle dispersion 1 was obtained.

[Preparation of modified ferroelectrics B-2 to B-17]
In the preparation of the modified ferroelectric B-1, the modified ferroelectrics B-2 to B17 were prepared in the same manner except that the type of the metal A and the molar ratio of the metal A were changed as shown in Table I below. did.

[Preparation of ferroelectric particle dispersion liquids 2 to 18]
In the preparation of the ferroelectric particle dispersion liquid 1, the ferroelectric particle dispersion liquids 2 to 17 were prepared in the same manner except that the modified ferroelectric substance B-1 was changed as shown in Table I below. As the ferroelectric particle dispersion liquid 18, a dispersion liquid was prepared by using unmodified barium titanate as it was.

[Preparation of conductor dispersion]
50 parts by mass of polyimide precursor (Yupia (registered trademark) -ST1001 (solid content 18% by mass) manufactured by Ube Kosan Co., Ltd.) and a fluorine-containing organic compound (manufactured by Mitsubishi Materials Co., Ltd., F-top) (Registered Trademark) EF-351) 0.1 part by mass and 50 parts by mass of N-methyl-2-pyrrolidone (NMP) were mixed and stirred to prepare a solution.
Next, 13 parts by mass of carbon black (manufactured by Evonik Degussa Japan Co., Ltd., NIPex® (registered trademark) 150 (pH = 4, volatile content: 10% by mass)), which is a conductor, was added to the obtained solution with a ball mill. A conductor dispersion was prepared by dispersing.

[Preparation of intermediate transcript 1]
100 parts by mass of polyimide precursor varnish (manufactured by Ube Industries, Ltd., Yupia (registered trademark) -ST1001 (solid content 18% by mass)), 150 parts by mass of the obtained ferroelectric dispersion liquid, and the above obtained. 20 parts by mass of the conductor dispersion liquid was mixed to obtain a coating liquid for forming a base material layer.
Next, after defoaming the coating liquid, the coating liquid was poured into the inner peripheral surface of the cylindrical mold in a state of being rotated at 1500 rpm so that the thickness after drying would be 60 μm via a dispenser, and then for 15 minutes. By rotating, a base material layer (coating layer) having a uniform thickness was formed.
Subsequently, while rotating the mold at 250 rpm, hot air at 60 ° C. was applied to the mold for 30 minutes from the outside of the mold, and then the mold was heated at 150 ° C. for 60 minutes.
Then, the mold was heated to 360 ° C. at a heating rate of 2 ° C./min, and further heated at 360 ° C. for 60 minutes. By blowing and heating such hot air, the evaporated solvent and water generated by dehydration ring closure were removed from the base material layer, and the imide conversion reaction in the base material layer was completed. In this way, an endless belt-shaped intermediate transfer body 1 containing a polyimide resin, a conductor, a metal A, and a ferroelectric substance B was obtained.

[Preparation of intermediate transcripts 2 to 18]
In the preparation of the intermediate transfer material 1, the intermediate transfer materials 2 to 18 were prepared in the same manner except that the ferroelectric dispersion liquid 1 was changed as shown in Table I below.

[Evaluation of transferability]
<Evaluation at temperature and humidity 20 ° C and 50% RH>
The "intermediate transfer member 1" prepared above was attached to an image forming apparatus (bizhub (registered trademark) PRESS C1100, manufactured by Konica Minolta KK) under a temperature and humidity of 20 ° C. and 50% RH. Using an evaluation machine, output 10 solid images of 100% blue, which is the secondary color of cyan and magenta, on embossed paper (special Tokai Paper Co., Ltd., Rezac paper A3 Y stitch 302 g / m ^2). did.
Next, the obtained individual solid images are digitized by a scanner, and the image density of each solid image is the highest by image processing using image editing / processing software (manufactured by Adobe Systems, Inc., Photoshop (registered trademark)). The concentration was determined.
The "average value of the maximum density of the initial temperature and humidity of 20 ° C. and 50%" was obtained from the maximum density of 10 images of each image. Subsequently, the area ratio (%) of the region having an image density of 90% or less of the "average value of the maximum density of the initial temperature and humidity of 20 ° C. and 50%" in each solid image was determined.
Then, in this individual solid image, the sum of the area ratios of the regions having an image density of 90% or less of the "average value of the maximum density of the initial temperature and humidity of 20 ° C. and 50%" is calculated, and the sum is calculated as the individual sum. By dividing by the total number of solid images, the average value (%) of the area ratio of the region having an image density of 90% or less of the above average value was further obtained. This value was defined as the area ratio (%) having an image density of 90% or less.

<Evaluation at temperature and humidity 30 ° C. 80% RH and 10 ° C. 20% RH>
Subsequently, the evaluator equipped with the "intermediate transfer material 1" was placed in an environment of temperature and humidity of 30 ° C. and 80% RH for 24 hours to control the temperature and humidity, and then similarly embossed paper (Tokushu Tokai Paper Co., Ltd.). Ten 100% solid images of blue, which is the secondary color of cyan and magenta, were output on each of the company-made Rezac paper A3 Y eyes 302 g / m ^2).
Next, the obtained solid images were digitized by a scanner, and image processing using image editing / processing software (Photoshop (registered trademark) manufactured by Adobe Systems Co., Ltd.) was performed to obtain the above "initial temperature and humidity". The sum of the area ratios of the regions having an image density of 90% or less with respect to the "average value of the maximum density of 20 ° C. and 50% RH" is calculated, and the sum is divided by the total number of individual solid images. The average value (%) of the area ratio of the region having an image density of 90% or less of the average value was further obtained. This value was defined as the area ratio (%) having an image density of 90% or less.
Similarly, after adjusting the temperature and humidity to an environment of 10 ° C. and 20% RH, the image density is 90% or less with respect to the "average value of the maximum concentrations of the initial temperature and humidity of 20 ° C. and 50% RH". By calculating the sum of the area ratios of the above and dividing the sum by the total number of individual solid images, the average value (%) of the area ratio of the area having an image density of 90% or less of the above average value was further obtained. .. This value was defined as the area ratio (%) having an image density of 90% or less.

<20 ° C 50% RH, evaluation after copying 1 million sheets (durability)>
After outputting 1 million sheets of full-color images with a printing rate of 5% using plain paper (J paper, manufactured by Konica Minolta) under a 20 ° C and 50% RH environment, embossed paper (manufactured by Tokai Paper Co., Ltd.) On Rezac paper A3 Y stitch 302 g / m ² ), 10 solid images of 100% blue, which is the secondary color of cyan and magenta, were output. Using image editing / processing software, calculate the total area ratio of the area with an image density of 90% or less with respect to the "average value of the maximum density of the initial temperature and humidity of 20 ° C. and 50%", and calculate the total sum. By dividing by the total number of solid images in the above, the average value (%) of the area ratio of the region having an image density of 90% or less of the above average value was further obtained. This value was defined as the area ratio (%) having an image density of 90% or less.
Each "area ratio (%) with an image density of 90% or less" was evaluated according to the following evaluation criteria, and all of them were evaluated as passing.

(Evaluation criteria)
⊚: Area ratio of image density 90% or less is less than 2% 〇: Area ratio of image density 90% or less is 2% or more and less than 6% Δ: Area ratio of image density 90% or less is 6% or more 10 Less than% ×: The area ratio with an image density of 90% or less is 10% or more.

As shown in the above results, it can be seen that the intermediate transcript of the present invention has better transferability during environmental changes and long-term use than the intermediate transcript of the comparative example.

1a Intermediate transfer body 2a Base material layer 3a Elastic layer 4a Surface layer 1 Image forming apparatus 10 Control unit 11 CPU
12 ROM
13 RAM
20 Storage unit 30 Network I / F unit 40 Display operation unit 50 Image reading unit 60 Image processing unit 70 Transport unit 71 Feeding device 72 Transport mechanism 73 Paper ejection device 80 Image forming unit 81, 81Y, 81M, 81C, 81K Exposure device 82, 82Y, 82M, 82C, 82K Developer 83, 83Y, 83M, 83C, 83K Photoreceptor drum 84, 84Y, 84M, 84C, 84K Charging device 85, 85Y, 85M, 85C, 85K Cleaning device 86, 86Y, 86M , 86C, 86K Primary transfer roller 87 Intermediate transfer unit 87a Intermediate transfer body 87b Support roller 87c Secondary transfer roller 87d Intermediate transfer cleaning unit 88 Fixing device 88a Heating roller 88b Fixing roller 88c Fixing belt 88d Pressurizing roller 201 Thin film electrode

Claims (9)

An intermediate transfer material containing at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu and a ferroelectric substance B. The intermediate transfer material according to claim 1, wherein the ferroelectric substance B contains barium titanate. 1 or claim 1, wherein the calcined composition containing at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu and a ferroelectric substance B is contained. The intermediate transfer product according to claim 2. The metal A contains at least one metal A-1 selected from Mg, Sc, Tm, Yb and Lu and at least one metal A-2 selected from Y, Eu, Dy, Ho and Er.
The intermediate transfer material according to any one of claims 1 to 3, wherein the ferroelectric substance B contains barium titanate. The metal A contains at least one metal A-1-1 selected from Sc, Tm, Yb and Lu, at least one metal A-2 selected from Y, Eu, Dy, Ho and Er, and Mg. And
The intermediate transfer material according to any one of claims 1 to 3, wherein the ferroelectric substance B contains barium titanate. The invention according to any one of claims 1 to 5, wherein the metal A is contained in the range of 0.1 to 10 mol in terms of oxide with respect to 100 mol of the ferroelectric substance B. Intermediate transcript of. A production method for producing an intermediate transcript according to any one of claims 1 to 6.
An intermediate transfer product comprising a step of calcining at least one metal A selected from Mg, Sc, Y, Er, Tm, Yb, Lu, Dy, Ho and Eu and a ferroelectric substance B at 1000 ° C. or higher. Manufacturing method. An image forming method comprising using the intermediate transfer material according to any one of claims 1 to 6. An image forming apparatus comprising the intermediate transfer member according to any one of claims 1 to 6.

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