JP2020197622A - Intermediate transfer body, manufacturing method for the same, and image forming apparatus including the same - Google Patents

Abstract

To provide an intermediate transfer body having a resin layer that transmits ultraviolet light, the intermediate transfer body preventing a reduction in both ultraviolet transmittance and tensile strength, a manufacturing method for the same, and an image forming apparatus provided with the same.SOLUTION: An intermediate transfer body of the present invention is an intermediate transfer body used for transferring an image to a recording medium, and the intermediate transfer body has a resin layer that transmits ultraviolet light. The resin layer contains an additive selected at least from a light stabilizer, an antioxidant, and an ultraviolet absorber.SELECTED DRAWING: Figure 1

Description

The present invention relates to an intermediate transfer body, a method for producing the same, and an image forming apparatus provided with the intermediate transfer body. More specifically, the present invention is an intermediate transfer body having a resin layer that transmits ultraviolet rays, and suppresses a decrease in ultraviolet transmittance and tensile strength. Regarding compatible intermediate transcripts and the like.

A technique is disclosed in which an intermediate transfer body that transmits ultraviolet rays is used to irradiate an intermediate transfer body with ultraviolet rays from a surface opposite to the surface to which the ink is applied to cure an image (for example, Patent Document). See 1.).

However, as the image formation is repeated, there is a problem that the transfer rate of the ink deteriorates as compared with the initial stage.

As a result of diligently examining the cause of the deterioration of the transfer rate of the ink, as a factor of the deterioration of the transfer rate of the ink, the tensile strength of the intermediate transfer body decreases as the irradiation with ultraviolet rays, and the tension of the transfer body decreases. It was found that the transfer rate was deteriorated.

Therefore, when an intermediate transfer material that transmits ultraviolet rays is used, an intermediate transfer material that has both an ultraviolet transmittance and suppression of a decrease in tensile strength due to ultraviolet rays is required, and Patent Document 1 states that the decrease in tensile strength due to ultraviolet rays is achieved. The technical idea of suppressing and improving the durability of the transfer image quality is not disclosed.

Japanese Unexamined Patent Publication No. 2014-8656

The present invention has been made in view of the above problems and situations, and the problem to be solved thereof is an intermediate transfer material having a resin layer that transmits ultraviolet rays, and is an intermediate that achieves both ultraviolet transmittance and suppression of decrease in tensile strength. The present invention provides a transfer body, a method for producing the same, and an image forming apparatus equipped with the transfer body.

In the process of examining the cause of the above problem in order to solve the above problems, the present inventor has an intermediate transfer material having a resin layer that transmits ultraviolet rays, and the resin layer further contains a specific additive. As a result, it has been found that an intermediate transfer material having both ultraviolet transmittance and suppression of decrease in tensile strength, a method for producing the intermediate transfer material, and an image forming apparatus equipped with the intermediate transfer material can be obtained.

That is, the above problem according to the present invention is solved by the following means.

1. 1. An intermediate transfer body used to transfer an image to a recording medium.
The intermediate transfer material has a resin layer that transmits ultraviolet rays,
An intermediate transfer product, wherein the resin layer contains at least an additive selected from a light stabilizer, an antioxidant, and an ultraviolet absorber.

2. 2. The intermediate transfer material according to item 1, wherein the resin layer contains a polyimide containing a polyamic acid.

3. 3. The first or second item, wherein the resin layer contains a light stabilizer or an antioxidant, and the content of the ultraviolet absorber in the resin layer is 1% by mass or less. Intermediate transcript.

4. The intermediate transfer product according to any one of items 1 to 3, wherein the thickness of the resin layer is in the range of 30 to 500 μm.

5. The intermediate transfer product according to any one of items 1 to 4, wherein the resin layer contains a filler having an average particle size in the range of 10 to 80 nm.

6. Items 1 to 5 are characterized in that the resin layer is a layer that transmits ultraviolet rays in the light wavelength range of 350 to 420 nm, and the light wavelength of the ultraviolet rays is in the range of 350 to 420 nm. The intermediate transcript according to any one of the items up to.

7. The intermediate transfer product according to any one of items 1 to 6, wherein the resin layer has an ultraviolet transmittance of 70% or more at a light wavelength of 395 nm.

8. The intermediate transfer product according to any one of items 1 to 7, wherein the tensile elastic modulus is 4 GPa or more.

9. The intermediate transfer body according to any one of items 1 to 8, wherein the intermediate transfer body is an intermediate transfer belt.

10. The intermediate transfer body according to any one of items 1 to 9, wherein the resin layer is a base material layer of the intermediate transfer body.

11. A method for producing an intermediate transcript according to any one of paragraphs 1 to 10, wherein the intermediate transcript is produced.
A method for producing an intermediate transcript, which comprises a step of adding at least an additive selected from a light stabilizer, an antioxidant, and an ultraviolet absorber to a resin composition containing a polyimide containing a polyamic acid. ..

12. An image forming apparatus comprising the intermediate transfer member according to any one of items 1 to 10.

13. An image forming apparatus according to item 12, wherein the image forming apparatus is an image forming apparatus for an inkjet.

By the above means of the present invention, an intermediate transfer body having a resin layer that transmits ultraviolet rays, which has both an ultraviolet transmittance and suppression of a decrease in tensile strength, a manufacturing method thereof, and an image forming apparatus provided with the intermediate transfer body. Can be provided.

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.

As described above, as a result of diligently examining the cause of the deterioration of the transfer rate of the ink, the irradiation of ultraviolet rays exposed to an intermediate transfer body (hereinafter, may be referred to as “transfer body”) that transmits ultraviolet rays causes. It was found that the transfer rate gradually deteriorated. As a result of further examination, it was found that the tensile strength of the intermediate transfer material decreased before and after irradiation with ultraviolet rays. Probably, the reason why the transfer rate deteriorates compared to the initial stage is that the tension of the transfer body set at the initial stage cannot be maintained due to the decrease in the tensile strength of the transfer material, and the transfer rate of the image deteriorates compared to the initial stage. It is inferred that.

The present invention is characterized in that an intermediate transfer material having a resin layer that transmits ultraviolet rays contains at least an additive selected from a light stabilizer, an antioxidant, and an ultraviolet absorber, and has an ultraviolet transmittance and tension. It is possible to suppress the decrease in strength at the same time, but the following mechanism is considered for this.

When the intermediate transfer material is exposed to ultraviolet rays, the generated active oxygen is quenched with a light stabilizer to prevent the molecular chains from being cleaved by the active oxygen. Since the breakage of the molecular chain causes a decrease in tensile strength, the decrease in tensile strength can be suppressed by preventing the breakage.

At the same time, by adding an antioxidant for suppressing oxidation by active oxygen, it is possible to suppress the oxidation and deterioration of the molecule, so that the decrease in tensile strength can also be suppressed by the antioxidant.

In particular, when polyimide is used as the resin for the resin layer, it is considered that the completion of the polyimideization reaction increases the rigidity of the base material, but the timing of adding the additive according to the present invention is up to amidation, which is a primary reaction. When the molecular chain was once formed in the state where the above was completed (polyimide-containing state), it was examined to add the above-mentioned additive. As a result, the reaction was carried out by adding the additive from the state of the varnish containing the polyamic acid. It was found that the inhibition of sexuality is reduced, and that the presence of a very small amount of polyimideic acid exerts an intermolecular force with the additive to have the effect of retaining the additive in the vicinity of the molecular chain. Since there is an additive in the vicinity of the molecular chain, it is presumed that the molecular chain is less likely to be cut by ultraviolet rays and that the decrease in tensile strength after irradiation with ultraviolet rays is suppressed.

Furthermore, by adding a small amount of UV absorber to the extent that it is not affected by the UV transmittance, the UV absorber absorbs the UV itself and converts it into heat, so that the UV can be suppressed from directly affecting the resin. Inferred.

Schematic cross-sectional view showing an example of the configuration of the intermediate transfer member of the present invention. An embodiment of an apparatus for producing an intermediate transcript of the present invention. Schematic configuration diagram showing an example of an image forming apparatus for an inkjet The figure which shows the internal structure of the image forming apparatus main body for electrophotographic system

The intermediate transfer body of the present invention is an intermediate transfer body used for transferring an image to a recording medium, and the intermediate transfer body has a resin layer that transmits ultraviolet rays, and the resin layer is at least light. It is characterized by containing an additive selected from a stabilizer, an antioxidant, and an ultraviolet absorber. This feature is a technical feature common to or corresponding to the following embodiments.

In an embodiment of the present invention, from the viewpoint of exhibiting the effect of the present invention, it is preferable that the resin layer contains a polyimide containing a polyamic acid because the dispersibility of the light stabilizer and the antioxidant is improved. It is preferable from the viewpoint that the deterioration suppressing effect due to ultraviolet rays can be exhibited. Further, as a method for producing the intermediate transcript, it is advantageous to add the additive from the state where the resin composition contains the polyamic acid because the reactivity is not hindered.

The resin layer contains a light stabilizer or an antioxidant, and the content of the ultraviolet absorber is 1% by mass or less, which can maintain ultraviolet transparency and suppress the influence of ultraviolet rays on the resin. Therefore, it is preferably 0.1% by mass or less.

The thickness of the resin layer is preferably in the range of 30 to 500 μm, preferably in the range of 50 to 100 μm from the viewpoint of suppressing the decrease in ultraviolet transmittance and tensile strength.

Further, it is preferable that the resin layer contains a filler having an average particle diameter in the range of 10 to 80 nm from the viewpoint of improving ultraviolet transparency and tensile strength. If a filler having a large particle size is added, the transmittance decreases, and if a filler having a small particle size is used, it tends to aggregate. Therefore, it is preferably within the above range, and more preferably within the range of 20 to 70 nm.

It is preferable that the resin layer is a layer that transmits ultraviolet rays having a light wavelength in the range of 350 to 420 nm, and the light wavelength of the ultraviolet rays is in the range of 350 to 420 nm. This is because ultraviolet rays having a wave shorter than 350 nm have a large degree of photodegradation of the intermediate transfer material due to the strong photon energy. Visible light occurs where the wave is longer than 420 nm, and the photon energy is too weak in visible light to cure the ink.

If the ultraviolet transmittance of the resin layer is low, sufficient curing energy cannot be given to the ink. Therefore, the ultraviolet transmittance at a light wavelength of 395 nm is preferably 70% or more, more preferably 90% or more. is there.

The tensile elastic modulus of the intermediate transfer material is preferably 4 GPa or more, more preferably 4 GPa or more, because when the tensile elastic modulus is low, the tension of the belt is weak and the transferability to a recording medium (paper, plastic film, etc.) is lowered. Is 6 GPa or more.

The intermediate transfer body is preferably an intermediate transfer belt. This is because the decrease in tensile strength occurs especially in the intermediate transfer belt.

The resin layer is preferably a base material layer of the intermediate transfer material. This may be because the surface layer of the intermediate transfer material may be the resin layer according to the present invention, but it is preferable to use it as the base material layer because the decrease in tensile strength occurs especially in the base material layer.

The intermediate transfer body of the present invention is suitably provided in an image forming apparatus, and is effectively used, for example, when applied to an image forming apparatus for electrophotographic photography and when a toner melted by light irradiation is used. It is more preferable that the image forming apparatus is applied to an image forming apparatus for an inkjet.

Hereinafter, the present invention, its constituent elements, and modes and modes for carrying out the present invention will be described in detail. 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.

<< Outline of the intermediate transcript of the present invention >>
The intermediate transfer body of the present invention is an intermediate transfer body used for transferring an image to a recording medium, and the intermediate transfer body has a resin layer that transmits ultraviolet rays, and the resin layer is at least light. It is characterized by containing an additive selected from a stabilizer, an antioxidant, and an ultraviolet absorber.

The intermediate transfer body of the present invention may have an endless belt shape or a roller shape. Hereinafter, an endless belt-shaped transfer body will be mainly described as an intermediate transfer body in which the effects of the present invention are more likely to be exhibited.

The intermediate transfer product of the present invention has at least a base material layer. In the case of a multi-layer endless belt shape, it is preferable to have a functional layer such as an elastic layer or a surface layer on the base material layer.

FIG. 1 is a schematic cross-sectional view showing an example of the configuration of the intermediate transfer member of the present invention.

The intermediate transfer body 1 shown in FIG. 1 is configured by laminating an elastic layer 3 and a surface layer 4 on the base material layer 2 in this order. The intermediate transfer material according to the present invention may have only the base material layer 2, but may have an elastic layer 3 and a surface layer 4 in order to improve transferability, durability and the like.

The resin layer that transmits ultraviolet rays according to the present invention is particularly preferably used as the base material layer 2. Further, the resin layer that transmits the ultraviolet rays may be applied to the functional layer such as the elastic layer 3 or the surface layer 4.

The thickness of the resin layer according to the present invention is preferably in the range of 30 to 500 μm, more preferably in the range of 50 to 100 μm from the viewpoint of suppressing the decrease in ultraviolet transmittance and tensile strength. The thickness of the resin layer can be measured by a film thickness meter.

For example, the thickness of the resin layer can be measured by using a film thickness meter with the following combination.

(Terminal, stand, reader)
Terminal: DIGIMICRO MH-15M (manufactured by NIKON)
Stand: DIGIMICRO STAND MS-5C (manufactured by NIKON)
Reader: DIGITAL READ OUT TC-101A (manufactured by NIKON)
Alternatively, an eddy current type film thickness measuring device (film thickness meter FMP30, Fisher) can also be used.

It is preferable that the resin layer is a layer that transmits ultraviolet rays in the light wavelength range of 350 to 460 nm, and the light wavelength of the ultraviolet rays is in the range of 380 to 420 nm.

The light wavelength of the ultraviolet rays can be determined, for example, by spectroscopic measurement using C10027-01 manufactured by Hamamatsu Photonics.

Further, if the ultraviolet transmittance of the resin layer is low, sufficient curing energy cannot be given to the ink. Therefore, the ultraviolet transmittance is preferably 70% or more, more preferably 90% at a light wavelength of 395 nm. That is all.

For the ultraviolet transmittance, for example, the spectral absorption spectrum of the intermediate transfer material is measured using a Spectrophotometer U-3200 (manufactured by Hitachi, Ltd.), and the transmittance (%) at a light wavelength of 395 nm is determined.

The tensile elastic modulus of the intermediate transfer member is preferably 4 GPa or more, more preferably 6 GPa or more, because the tension of the belt is weak and the transferability to paper is lowered when the tensile elastic modulus is low.

The tensile elastic modulus is measured by a tensile test using a section obtained by cutting an intermediate transfer material into a dumbbell shape by the method of JIS K6251 or JIS K7161.

Measuring equipment: Tensilon universal material testing machine RTC-1250 (manufactured by A & D Co., Ltd.)
Measurement conditions: Test piece for tensile test: Shape conforming to JIS K7161
Tensile speed: 1 mm / s
Distance between chucks: 115 mm
Distance between gauge points: 100 mm

[1] Details of Configuration of Intermediate Transfer Body (Multilayer Endless Belt) [1.1] Base Material Layer An embodiment in which the base material layer according to the present invention is formed of a resin will be described.

[resin]
Various resins can be used, but the strength and durability of polyimide (PI), polyamide (PA), polyamideimide (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.

Conventional polyimides are known to be absorptive in the near-ultraviolet region and therefore have a light brown tint. The coloring is caused by the tetracarboxylic dianhydride-derived unit and the diamine unit in the constituent polymer chains forming intramolecular and intermolecular CT complexes (Charge Transfer Complex) as acceptors and donors, respectively. There is. Generally, in the case of an aromatic polyimide skeleton, by forming a CT complex composed of an aromatic acid dianhydride and an aromatic diamine, it has spectral absorption on the short wavelength side up to around 400 nm, so that UV transparency is lowered. It is known that it will be stored.

From the viewpoint of suppressing coloration, the guideline for structural design is how to reduce the chromophore, block the conjugated structure, and suppress CT complexing. Specifically, (1) non-planar structure and (2) It is preferable to select a polyimide having a structure that satisfies non-aromaticization.

As a result of further studies, from the viewpoint of UV resistance, soluble polyimide with high solvent solubility has low UV resistance due to its small molecular weight and is not suitable, and the primary reaction between acid dianhydride and diamine has been completed. It was found that the one provided as a polyamic acid varnish and imidized by heating after forming the resin layer has higher ultraviolet resistance.

Furthermore, by adding the additive from the state of the polyamic acid varnish, the inhibition of reactivity is reduced, and the presence of a very small amount of polyamic acid exerts an intermolecular force with the additive to make the additive a molecular chain. Since it has the effect of keeping it in the vicinity, it was found that since the additive is present in the vicinity of the molecular chain, the molecular chain is less likely to be cut by ultraviolet rays, and the tensile strength after irradiation with ultraviolet rays can be increased.

From this point of view, preferred polyimides for the present invention include, for example, commercially available polyimide varnishes containing a polyimide precursor (polyamic acid) as a main component, such as TOMED-S, X (manufactured by IST), Spixeria HR003, GR003. (The above is manufactured by Somar), FLUPI (manufactured by NTT), Type HM (manufactured by Toyobo), Type-C (manufactured by Mitsui Chemicals), PI-100 (manufactured by Maruzen Chemicals), HDN-20D (New Japan Chemical Co., Ltd.) CBDA-6FDAC (manufactured by Central Glass Co., Ltd.), Q-VR-X-1655 (manufactured by PI Giken Co., Ltd.) and the like are examples of suitable resins for ultraviolet-transmissive polyimide. Among them, as a preferable ultraviolet-transmissive resin, Q-VR-X-1655 (manufactured by PI Giken Co., Ltd.) can be mentioned.

In the present invention, a resin other than polyimide can be further used as long as the effect of the present invention is not impaired, and polyamide, polyamideimide (PAI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), Examples thereof include triacetyl cellulose (TAC) and cycloolefin polymer (COP), and examples thereof include Uniamide (manufactured by Unitica), Lumirer T60 (manufactured by Toray), and Zeonex (manufactured by Zeon Japan). Among them, a preferable ultraviolet-transmitting resin is Uniamide EX-35 (manufactured by Unitika Ltd.), which is a polyamide.

[Light stabilizer]
A hindered amine-based light stabilizer is preferably used, and examples thereof include Chimasslob 944, Chimasslob 2020, and Tinuvin 622 (all manufactured by BASF Japan Ltd.). Preferred light stabilizers include Chimasslob 2020.

The light stabilizer is preferably contained in the resin layer in an amount of 1 to 10% by mass, more preferably 3 to 5% by mass. When analyzing the content of the corresponding component, after identifying the component, a calibration curve of high performance liquid chromatography (HPLC) is obtained for the substance, and it can be calculated from the area% of the component.

[Antioxidant]
A hindered phenolic antioxidant, a phosphorus-based antioxidant, or an amine-based antioxidant is preferably used, and examples thereof include Irganox 1076 and Irganox 1010 (all manufactured by BASF Japan Ltd.). Preferred antioxidants include Irganox 1010. The antioxidant is preferably contained in the resin layer in an amount of 1 to 10% by mass, more preferably 3 to 5% by mass. The analysis of the content of the relevant component is the same as above.

[UV absorber]
Benzophenone-based UV absorbers, benzotriazole-based UV absorbers, benzoate-based UV absorbers, or triazine-based UV absorbers are preferably used, and examples thereof include Tinuvin 326, Tinuvin 329, and Tinuvin 234 (all manufactured by BASF Japan). Will be done. Preferred UV absorbers include Tinuvin 326. It is preferable that the ultraviolet absorber is contained in the resin layer in an amount of 1% by mass or less from the viewpoint that the ultraviolet transmittance can be maintained and the influence of ultraviolet rays is not exerted on the resin, and more preferably 0.1% by mass or less. The analysis of the content of the relevant component is the same as above.

[Filler]
It is preferable that the resin layer contains a filler having an average particle diameter in the range of 10 to 80 nm from the viewpoint of further improving the tensile strength. If a filler having a large particle size is added, the transmittance decreases, and if a filler having a small particle size is used, it tends to aggregate. Therefore, it is preferably within the above range, and more preferably within the range of 20 to 70 nm.

The resin layer containing the polyimide according to the present invention includes, for example, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, and silicate. It is preferable to contain inorganic fine particles such as magnesium and calcium phosphate and a matting agent such as a crosslinked polymer. Of these, silicon dioxide is preferable from the viewpoint of suppressing a decrease in transparency.

These fillers may be primary particles or secondary particles. To measure the average particle size of the filler, observe the particles with a transmission electron microscope (magnification: 500,000 to 2 million times), observe 100 particles, measure the particle size, and use the average value as the average particle size. To do.

Specific fillers include, for example, fine silica gel (silicon dioxide), silica RX-50 (70 nm), NAX-50 (30 nm), RM-50 (30 nm), or AEROSIL 50 (30 nm): manufactured by AEROSIL Japan. Etc. are preferable, and among them, AEROSIL50 is preferable.

The amount of the filler added is preferably 1 to 50% by mass, more preferably 5 to 40% by mass, and even more preferably 10 to 30% by mass in the resin layer. The analysis of the content of the relevant component is the same as above.

[1.2] Elastic layer The elastic layer is a layer having desired conductivity and elasticity formed on the outer peripheral surface of the base material.

The elastic layer refers to a layer that can be deformed by following an external force, and by providing this elastic layer, it is possible to follow a recording medium having irregularities and improve the transferability of ink. Examples of the recording medium having irregularities include embossed paper and rough paper. Embossed paper and rough paper have irregularities on the surface of the paper and are given a design property by the uneven shape to give features such as a sense of quality and improve the quality of the printed matter to which the ink image is transferred. For example, it is often used for greeting mails, certificates, high-class photographs, catalogs, DM, etc., and high-quality images are required. In order for the elastic layer to follow the unevenness of the paper, it is required to be deformed by an external force.

As described above, the elastic layer is required to be deformed by an external force and follow the unevenness, and the specifications required for this elastic layer include viscoelasticity, elastic modulus, hardness and the like. For convenience, it is preferably observed with a hardness tester. An MD-1 hardness tester is preferably used, and if the hardness observed by the MD-1 hardness tester is about 70 or less, it can be applied as an elastic layer. More preferably, the hardness is 55 or less.

The elastic layer is preferably made of a rubber material. The thickness of the elastic layer is, for example, in the range of 50 to 400 μm, preferably in the range of 200 to 300 μm. Examples of rubber materials include resins having rubber elasticity such as urethane rubber, chloroprene rubber and nitrile rubber. The rubber material preferably contains chloroprene rubber or nitrile butadiene rubber from the viewpoint of controlling the electrical resistance of the multilayer endless belt.

Further, the elastic layer is also required to be transparent, and KE2061-30A / B and KE153U (manufactured by Shin-Etsu Chemical Co., Ltd.), which are transparent silicone rubbers, are preferably used.

An additive selected from the light stabilizer, the antioxidant, and the ultraviolet absorber according to the present invention may be contained in the elastic layer, if necessary.

[1.3] Surface layer The surface layer can be formed on the outer peripheral surface of the elastic layer, if necessary. The surface layer protects the elastic layer, has moderate flexibility that deforms according to the deformation of the elastic layer, and has sufficient durability (mechanical strength, releasability, etc.) against contact with the recording medium during transfer. Have. The surface layer is composed of, for example, a cured product (resin) obtained by radical polymerization of a radically polymerizable composition containing a radically polymerizable monomer.

For example, known resins and additives are used for the surface layer. Further, it can be cured and used by using a conventionally known method. The surface layer is a metal oxide fine particle (A), a (meth) acrylate monomer (B) having a refractive index in the range of 1.6 to 1.8, and many other than the (meth) acrylate monomer (B). It is preferably obtained by irradiating a coating film of a coating liquid for forming a surface layer containing an active energy ray-curable composition containing a functional (meth) acrylate (C) with active energy rays and curing it. The durability of the multi-layer endless belt can be improved.

[2] Method for Producing Intermediate Transfer Body Next, a method for producing the intermediate transfer body (for example, a multilayer endless belt) will be described.

The method for producing an intermediate transfer material of the present invention preferably forms a coating film in the central region by using a nozzle that moves a coating liquid containing a polyimide resin precursor and an additive relative to the outer peripheral surface. After that, it is preferable to have a step of forming a coating film in both end regions to form the base material layer.

Further, the intermediate transfer material of the present invention forms a coating film in the central region by using a nozzle that moves a coating liquid containing acrylonitrile rubber, chloroprene rubber or silicone rubber relative to the surface of the base material layer. After that, it is preferable to have a step of forming a coating film on both end regions and forming the elastic layer.

By producing the base material layer and the elastic layer with a uniform layer thickness in this way, the intermediate transfer material of the present invention can be efficiently produced.

FIG. 2 shows an embodiment of an apparatus for manufacturing a multilayer endless belt of the present invention. As shown in FIG. 2, the coating device 1b includes a coating means 2b having a nozzle and a metal cylinder 5b. The coating means 2b atomizes the coating liquid having a desired composition, sprays the atomized coating liquid 3b on the metal cylinder 5b, and forms the coating film 4b on the metal cylinder 5b. The metal cylinder 5b is rotated at a desired speed in the direction of arrow 7b, and the coating means 2b is further moved in the direction of arrow 6b to form a uniform coating film while spreading the coating liquid from the nozzle.

According to a preferred embodiment, the base material layer can be produced by using a coating liquid containing a flame-retardant resin component, that is, a coating liquid containing a polyimide resin precursor.

While slowly rotating a cylindrical mold, for example, a cylindrical metal mold (mold drum: metal cylinder 5b), a coating liquid containing a flame-retardant resin component (for example, a coating containing a polyimide resin precursor). Liquid) is applied to the entire outer surface of the metal cylinder 5b so that the thickness after heat treatment (firing) treatment is the thickness of the central region using a liquid supply device (not shown) such as a nozzle or dispenser. To form a coating film by applying and casting in this way.

The number of rotations at this time is not particularly limited and can be appropriately set according to the size of the metal cylinder 5b and the like, but about 30 to 80 rpm is preferable. The solvent in the coating film is evaporated at a temperature of about 80 to 150 ° C. for about 30 to 90 minutes while gradually raising the temperature while rotating. In this process, it is preferable to efficiently circulate and remove atmospheric vapors (volatilized solvent, etc.). Next, a coating film of the same coating liquid as the central region is formed only in both end regions so that the thickness after the heating (firing) treatment is the thickness of both end regions. The thickness can be controlled by controlling the supply amount of the coating liquid.

When the self-supporting film is formed, the metal cylinder 5b is transferred to a heating furnace (firing furnace) capable of high temperature treatment, the temperature is gradually raised, and finally at a high temperature of about 250 to 450 ° C., 10 Heat treatment (calcination) is performed for about 90 minutes to sufficiently imidize the polyimide resin precursor to prepare a base material layer. After imidization is performed to prepare a base material layer and then sufficiently cooled, an elastic layer is subsequently laminated on the base material layer.

The elastic layer can be formed on the base material layer by injection molding, extrusion molding, etc., but here, a method of coating and forming on the base material layer using a thermosetting liquid elastomer material will be described. To do.

For example, a nozzle or a dispenser is applied to a coating liquid containing a liquid thermosetting elastomer material while slowly rotating a cylindrical metal mold (mold drum: metal cylinder 5b) in the same manner as in the case of a base material layer. A liquid supply device (not shown) such as the above is used to apply and cast (form a coating film) on a base material layer formed on the outer surface of a metal cylinder 5b.

The number of rotations at this time is not particularly limited and can be appropriately set according to the size of the metal cylinder 5b and the like, but about 30 to 80 rpm is preferable. However, at this time, it is preferable that the coating film in the central region is first formed, and then the coating film in both ends is formed to form the elastic layer. In this way, the thickness of both end regions and the center region can be controlled. The thickness can be controlled by controlling the supply amount of the coating liquid.

Then, while rotating the metal cylinder 5b, heat treatment is performed at a predetermined temperature and a predetermined time to cure the elastomer material and form an elastic layer. As the elastomer material, acrylonitrile rubber, chloroprene rubber or silicone rubber is preferable, and transparent silicone rubber is particularly preferable.

The specific temperature conditions are not particularly limited and can be appropriately selected depending on the type of coating liquid and the like, but as a guide, the temperature is about 35 to 70 ° C., and the time is about 10 to 90 minutes. When the self-supporting film is formed, the metal cylinder 5b is transferred to a heating furnace capable of high temperature treatment, the temperature is gradually raised, and finally the heat treatment is performed at about 130 to 180 ° C. for 10 to 90 minutes. (Vulcanization). After the elastic layer is prepared and cooled sufficiently, a surface layer obtained by radically polymerizing a radically polymerizable monomer may be laminated on the elastic layer, if necessary, using active energy rays.

For details of the method for producing the intermediate transcript of the present invention, see, for example, JP-A-2011-118026, JP-A-2012-194551, JP-A-2013-007812, JP-A-2016-109965. Production of intermediate transcripts described in JP-A-2017-105049, JP-A-2018-405169, JP-A-2018-055052, JP-A-2018-072592, JP-A-2018-084815, etc. You can refer to the method.

[3] Applications The intermediate transfer body (multilayer endless belt) of the present invention is suitably used for an intermediate transfer belt of an image forming apparatus such as an electrophotographic copying machine, a printer, and a facsimile. In particular, it is preferably used in an image forming apparatus for an inkjet and an image forming apparatus for an electrophotographic photograph.

The recording medium used in the present invention is a support that holds an ink image or a toner image, and is usually called an image support, a transfer material, or a transfer paper. Preferred are various recording media such as plain paper from thin paper to thick paper, coated printing paper such as art paper and coated paper, commercially available Japanese paper and postcard paper, uneven paper, plastic film for OHP, and cloth. It can, but is not limited to these.

[3.1] Image Forming Device for Inkjet The intermediate transfer body of the present invention can be preferably applied to an intermediate transfer belt in an image forming device for inkjet. Hereinafter, an image forming apparatus for an inkjet using an active light-curing inkjet ink (hereinafter, also simply referred to as “gel ink”) that undergoes a sol-gel phase transition will be described as an example.

FIG. 3 is a side view showing the concept of an inkjet image forming apparatus using the intermediate transfer body (multilayer endless belt) of the present invention.

The image forming apparatus 5 shown in FIG. 3 is an intermediate transfer type image forming apparatus using an inkjet method. The image forming apparatus 5 includes an ink ejection unit 10, an intermediate transfer unit 20, a paper transport unit 30, a first light irradiation unit 40, a second light irradiation unit 50, and a control unit (not shown). .. The control unit (not shown) includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The CPU reads a program according to the processing content from the ROM, develops it in the RAM, and centrally controls the operation of each block of the image forming apparatus 5 in cooperation with the expanded program. In addition, a control unit (not shown) is provided as a notification means, and the permeation amount information of the low molecular weight component obtained by the measurement unit is returned to the user side.

As shown in FIG. 3, the ink ejection unit 10 ejects inkjet ink (also simply referred to as “ink”) to the intermediate transfer unit 20 to form an ink-based image (ink image). In the present invention, the ink is preferably an ultraviolet curable ink (UV ink) containing a monomer that is polymerized, crosslinked and cured by being irradiated with ultraviolet rays as a liquid component.

The image formed on the front surface of the intermediate transfer body 1 by the inkjet head 11 is the back surface of the intermediate transfer body (opposite to the surface on which the ink image is formed) by the first light irradiation unit 40 due to the rotation of the intermediate transfer body 1. It is pre-cured from the side) and transferred to the paper S transported by the paper transport unit 30. The image transferred to the paper S is finally cured by the second light irradiation unit 50.

The image forming apparatus and the image forming method of the present invention will be further described with reference to FIG.

As shown in FIG. 3, the ink ejection unit 10 includes inkjet heads 11Y, 11C, 11M, and 11K, and inks of each color of Y (yellow), M (magenta), C (cyan), and K (black). An ink image is formed by ejecting the ink to the intermediate transfer unit 20. Since the inkjet heads 11Y, 11C, 11M, and 11K have the same configuration, in the following description, Y, M, C, and K will be omitted for convenience and will be referred to as "injection head 11".

In the present invention, the ink ejected from each of the inkjet heads 11 is preferably a UV ink containing a monomer that is polymerized, crosslinked and cured by being irradiated with ultraviolet rays as a liquid component.

After the image forming step of forming an ink image on the intermediate transfer body 1 described above, the transfer step is performed in the intermediate transfer unit 20. The intermediate transfer unit 20 has an intermediate transfer body 1 of the present invention constituting the transfer unit and three support rollers 22, 23, and 24. The intermediate transfer body 1 is composed of an endless belt, and is stretched in an inverted triangular shape on three support rollers 22, 23, and 24. The intermediate transfer body 1 preferably has a base material layer made of a resin material such as polyimide and an elastic layer made of transparent silicone rubber or the like. As described above, the intermediate transfer body 1 can obtain strength and elasticity by having at least two or more layer structures including a surface layer and an elastic layer.

At least one of the three support rollers 22, 23, and 24 is a drive roller, which is driven under the control of the control unit. As a result, the intermediate transfer body 1 rotates in the A direction (clockwise direction in FIG. 3).

The portions of the intermediate transfer body 1 stretched over the support rollers 22 and 24 located at the left and right apex portions of the inverted triangle shape are the landing surfaces of the ink ejected from the inkjet head 11. The support roller 23 located at the lower apex portion of the inverted triangular shape in the intermediate transfer body 1 is a pressure roller that pressurizes the intermediate transfer body 1 toward the paper transport portion 30 by a predetermined nip pressure.

The paper transport unit 30 is composed of a metal drum, and is pressed against the support roller 23 to form a transfer nip. The paper transport unit 30 has a claw (not shown) for fixing the tip of the paper S. Under the control of the control unit, the paper transport unit 30 fixes the tip of the paper S to the claw and rotates it counterclockwise in FIG. 3, thereby transporting the paper S as an example of the recording medium to the transfer nip. To do.

The first light irradiation unit 40 irradiates light from the surface side of the intermediate transfer body 1 on the downstream side of the ink ejection unit 10 that faces the ink landing surface. The first light irradiation unit 40 irradiates the image formed on the intermediate transfer body 1 with light from the back surface of the intermediate transfer body 1 to pre-cure the image.

The second light irradiation unit 50 faces the portion of the paper transport unit 30 on the downstream side of the transfer nip, and irradiates the image on the paper S with light to actually cure the image.

From the above, the image formed on the surface of the intermediate transfer body 1 by the inkjet head 11 is pre-cured by the first light irradiation unit 40 as the intermediate transfer body 1 rotates, and the support roller 23 and the paper transport unit 30 It is transported to the transfer nip of. Then, the image conveyed to the transfer nip is transferred to the paper S conveyed by the paper conveying unit 30. The image transferred to the paper S is finally cured by the second light irradiation unit 50.

The cleaning unit 25 is located downstream of the transfer nip, and under the control of the control unit, removes the transfer residual image which is an image formed on the intermediate transfer body 1. The "transfer residual image" here means a transfer image that remains on the intermediate transfer body 1 without being transferred to the paper S.

The inkjet head used in the above image forming method may be an on-demand method or a continuous method. The discharge method includes an electric-mechanical conversion method (for example, single cavity type, double cavity type, bender type, piston type, shared mode type, shared wall type, etc.) and an electric-heat conversion method (for example, thermal). Specific examples include an inkjet type, a bubble jet (registered trademark) type, etc.), an electrostatic attraction method (for example, an electric field control type, a slit jet type, etc.), and a discharge method (for example, a spark jet type, etc.). However, any discharge method may be used. Further, as the printing method, a serial head method, a line head method, or the like can be used without limitation.

Examples of the inkjet head include JP2012-140017, JP2013-010227, 2014-058771, 2014-097644, 2015-142979, and 2015. It is described in JP-A-142980, JP-A-2016-002675, JP-A-2016-002682, JP-A-2016-107401, JP-A-2017-109476, JP-A-2017-177626, etc. An inkjet head having a configuration can be appropriately selected and applied.

Further, as means for irradiating ultraviolet rays having a wavelength range of 350 to 420 nm in the first light irradiation unit 40 and the second light irradiation unit 50, a fluorescent tube (for example, a low-pressure mercury lamp, a germicidal lamp, etc.), a cold cathode tube, and an ultraviolet laser , Low pressure, medium pressure, high pressure mercury lamps, metal halide lamps, LEDs and the like having an operating pressure of several hundred Pa to 1 MPa are included. From the viewpoint of curability, an ultraviolet irradiation means for irradiating ultraviolet rays having an illuminance of 100 mW / cm ² or more, specifically, a high-pressure mercury lamp, a metal halide lamp, an LED, or the like is preferable, and an LED is more preferable because it consumes less power. preferable. Specifically, RX-FIRE-FLEX (wavelength: 395 nm) manufactured by Phoseon Technology, and a water-cooled LED can be used.

[UV curable ink]
Hereinafter, each component of the ultraviolet curable ink (also referred to as UV ink) used in the present invention will be described.

(monomer)
The UV ink used in the present invention preferably contains at least a monomer having a function of being cured by ultraviolet rays.

The monomer may be a polymerizable oligomer, a prepolymer, or a mixture thereof. The molecular weight may meet the above range. Only one type of monomer may be contained in the ink according to the present invention, or two or more types of monomers may be contained.

Examples of the monomer include a radically polymerizable monomer and a cationically polymerizable monomer, and a radically polymerizable monomer is preferable.

The content of the monomer is preferably in the range of 1 to 97% by mass with respect to the total mass of the ink used in the present invention from the viewpoint of film physical properties such as curability and flexibility, and is 30 to 95% by mass. More preferably, it is in the range of%.

<Radical polymerizable monomer>
The radically polymerizable monomer applicable to the present invention is preferably an unsaturated carboxylic acid ester, more preferably a (meth) acrylate.

In the present invention, "(meth) acrylate" means acrylate or methacrylate, "(meth) acryloyl group" means acryloyl group or metaacryloyl group, and "(meth) acrylic" means acrylic. Or it means methacrylic.

Examples of (meth) acrylates include isoamyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, isomilstill (meth) acrylate, isostearyl (meth). Acrylate, 2-ethylhexyl-diglycol (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, Methoxydiethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, 2-hydroxyethyl (meth) ) Aacrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2 Monofunctional acrylates containing- (meth) acryloyloxyethyl-2-hydroxyethyl-phthalic acid and t-butylcyclohexyl (meth) acrylates, triethylene glycol di (meth) acrylates, tetraethylene glycol di (meth) acrylates, Polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1 , 9-Nonandiol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dimethylol-tricyclodecanedi (meth) acrylate, di (meth) acrylate having bisphenol A structure, neopentyl glycol di (hydroxypivalate) Bifunctional (meth) acrylates including meta) acrylates, polytetramethylene glycol di (meth) acrylates, polyethylene glycol diacrylates and tripropylene glycol diacrylates, as well as trimethylpropantri (meth) acrylates and pentaerythritol tri (meth). ) Acrylic, pe Trifunctional or higher (meth) acrylate including entaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, glycerin propoxytri (meth) acrylate and pentaerythritol ethoxytetra (meth) acrylate. ) Acrylate, an oligomer having a (meth) acryloyl group containing a polyester acrylate oligomer, and modified products thereof.

Examples of the modified product include ethylene oxide-modified (EO-modified) acrylate in which an ethylene oxide group is inserted, and propylene oxide-modified (PO-modified) acrylate in which a propylene oxide is inserted.

<Cationopolymerizable monomer>
Examples of the cationically polymerizable monomer applicable to the present invention include epoxy compounds, vinyl ether compounds and oxetane compounds.

Only one type of cationically polymerizable monomer may be contained in the ink, or two or more types may be contained in the ink.

The epoxy compound is an aromatic epoxide, an alicyclic epoxide, an aliphatic epoxide, or the like, and in order to enhance the curability, the aromatic epoxide and the alicyclic epoxide are preferable.

The aromatic epoxide can be a di or polyglycidyl ether obtained by reacting a polyhydric phenol or an alkylene oxide adduct thereof with epichlorohydrin.

Examples of the polyvalent phenol to be reacted or an alkylene oxide adduct thereof include bisphenol A or an alkylene oxide adduct thereof.

The alkylene oxide in the alkylene oxide adduct may be ethylene oxide, propylene oxide or the like.

The alicyclic epoxide can be a cycloalkane oxide-containing compound obtained by epoxidizing a cycloalkane-containing compound with an oxidizing agent such as hydrogen peroxide or peracid. The cycloalkane in the cycloalkane oxide-containing compound can be cyclohexene or cyclopentene.

The aliphatic epoxide can be a di or polyglycidyl ether obtained by reacting an aliphatic polyhydric alcohol or an alkylene oxide adduct thereof with epichlorohydrin.

Examples of the aliphatic polyhydric alcohol include ethylene glycol, propylene glycol, alkylene glycol such as 1,6-hexanediol and the like. The alkylene oxide in the alkylene oxide adduct may be ethylene oxide, propylene oxide or the like.

Examples of vinyl ether compounds include ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexanedimethanol monovinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, isopropenyl ether. Monovinyl ether compounds such as -o-propylene carbonate, dodecyl vinyl ether, diethylene glycol monovinyl ether, octadecyl vinyl ether;
Dipropylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, cyclohexanedimethanol divinyl ether, trimethylpropantrivinyl ether and the like. Alternatively, a trivinyl ether compound or the like is included. Among these vinyl ether compounds, di or trivinyl ether compounds are preferable in consideration of curability and adhesion.

The oxetane compound is a compound having an oxetane ring, and examples thereof include the oxetane compounds described in JP-A-2001-220526, JP-A-2001-310937, JP-A-2005-255821, and the like. .. Among them, the compound represented by the general formula (1) described in paragraph number (089) of JP-A-2005-255821 and the compound represented by the general formula (2) described in paragraph number (0092) of JP-A-2005-255821. Compounds, compounds represented by the general formula (7) described in paragraph number (0107) of the same issue, compounds represented by the general formula (8) described in paragraph number (0109) of the same issue, the same item. Examples thereof include compounds represented by the general formula (9) described in paragraph number (0116) of the publication.

(Gel agent)
The UV ink used in the present invention preferably contains a gelling agent.

The gelling agent has a function of temporarily fixing (pinning) the ink droplets that have landed on the intermediate transfer material in a gel state. When an ink containing a gelling agent is pinned in a gel state, the wet spread of the ink is suppressed and it becomes difficult for adjacent dots to coalesce, so that a higher-definition image can be formed.

Examples of gelling agents include aliphatic ketones, aliphatic esters, petroleum waxes, plant waxes, animal waxes, mineral waxes, hardened castor oil, modified waxes, higher fatty acids, higher alcohols, hydroxystearic acids, and N. -Includes fatty acid amides, including substituted fatty acid amides and specialty fatty acid amides, higher amines, esters of sucrose fatty acids, synthetic waxes, dibenzylidene sorbitol, dimer acid and dimer diols. Among them, aliphatic ketones, aliphatic esters, higher fatty acids, and higher alcohols having a hydrocarbon group in the range of 9 to 25 carbon atoms are preferable, and aliphatic ketones are particularly preferable, from the viewpoint of further enhancing the pinning property. Only one type of gelling agent may be contained in the ink, or two or more types may be contained in the ink.

Examples of aliphatic ketones include dilignoceryl ketone, dibehenyl ketone, distearyl ketone, diicosyl ketone, dipalmityl ketone, dilauryl ketone, dimyristyl ketone, myristyl palmitol ketone and palmityl stearyl ketone. Is done.

Examples of aliphatic esters are fatty acid esters of monoalcohols such as behenyl behenate, icosyl icosanoate, and oleyl palmitate; glycerin fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, ethylene glycol fatty acid esters and polyoxyethylene fatty acid esters. Etc. contains fatty acid esters of polyhydric alcohols.

Examples of commercial products of the above aliphatic esters include EMALEX series, manufactured by Nippon Emulsion Co., Ltd. (“EMALEX” is a registered trademark of the company), Rikemar series and Poem series, and manufactured by RIKEN Vitamin Co., Ltd. (“Rikemar” and “Poem”). Both are registered trademarks of the same company).

The content of the gelling agent is preferably in the range of 1.0 to 10.0% by mass with respect to the total mass of the ink.

(Photopolymerization initiator)
The UV ink containing the monomer contains a photopolymerization initiator. The photopolymerization initiator is a photoradical initiator when the monomer is a radically polymerizable monomer, and a photoacid generator when the monomer is a cationically polymerizable monomer.

Only one type of photopolymerization initiator may be contained in the ink, or two or more types may be contained in the ink. The photopolymerization initiator may be a combination of both a photoradical initiator and a photoacid generator.

Examples of the photoradical initiator include a cleavage type radical initiator and a hydrogen abstraction type radical initiator.

Examples of cleaved radical initiators include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-. Methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) Acetphenone-based initiators containing propane-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, benzoin-based initiators containing benzoin, benzoin methyl ether and benzoin isopropyl ether, Includes acylphosphine oxide-based initiators, including 2,4,6-trimethylbenzoindiphenylphosphine oxide, benzyl and methylphenylglycoesters.

Examples of hydrogen abstraction initiators include benzophenone, methyl-4-phenylbenzophenone o-benzoyl benzoate, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, acrylicization. Benzophenone-based initiators, including benzophenone, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone and 3,3'-dimethyl-4-methoxybenzophenone, 2-isopropylthioxanthone, 2,4- Thioxanthone-based initiators containing dimethylthioxanthone, 2,4-diethylthioxanthone and 2,4-dichlorothioxanthone, aminobenzophenone-based initiators containing Michler ketone and 4,4'-diethylaminobenzophenone, 10-butyl-2-chloroacry Includes dong, 2-ethylanthraquinone, 9,10-phenanthrene quinone and campharquinone.

Examples of photoacid generators include the compounds described in Organic Electronics Materials Study Group, "Organic Materials for Imaging", Bunshin Publishing (1993), pp. 187-192.

The content of the photopolymerization initiator may be in the range where the monomer can be sufficiently cured, and can be, for example, in the range of 0.01 to 10% by mass with respect to the total mass of the ink.

(Other additives)
The UV ink used in the present invention may further contain other components such as a photopolymerization initiator auxiliary agent, a polymerization inhibitor, a polymer dispersant, and a surfactant as long as the effects of the present invention can be obtained. ..

(Color material)
As a coloring material applicable to the UV ink used in the present invention, a dye or a pigment can be applied, and the pigment has good dispersibility with respect to the constituent components of the ink and is excellent in weather resistance. Is more preferable.

<dye>
As the dye, an oil-soluble dye or the like can be applied. Examples of the oil-soluble dye include the following various dyes. Examples of magenta dyes include MS Magenta VP, MS Magenta HM-1450, MS Magenta HSo-147 (all manufactured by Mitsui Toatsu Co., Ltd.), AIZENSOT Red-1, AIZEN SOT Red-2, AIZEN SOTRed-3, AIZEN SOT. Pink-1, SPIRON Red GEH SPECIAL (above, manufactured by Hodogaya Chemical Co., Ltd.), RESOLIN Red FB 200%, MACROLEX Red Violet R, MACROLEX ROT5B (above, manufactured by Bayer Japan), KAYASET Red B, KAYASET RED 802 (above, manufactured by Nippon Kayaku Co., Ltd.), PHLOXIN, ROSE BENGAL, ACID Red (above, manufactured by Daiwa Kasei Corp.), HSR-31, DIARESIN Red K (above, manufactured by Mitsubishi Kasei Corp.), Oil Red (manufactured by BASF Japan). ) Is included.

Examples of cyan dyes include MS Cyan HM-1238, MS Cyan HSo-16, Cyan HSo-144, MS Cyan VPG (manufactured by Mitsui Toatsu Co., Ltd.), AIZEN SOT Blue-4 (manufactured by Hodogaya Chemical Co., Ltd.), RESOLIN BR. Blue BGLN 200%, MACROLEX Blue RR, CERES Blue GN, SIRIUS SUPRATURQ. Blue Z-BGL, SIRIUS SUPRA TURQ. Blue FB-LL 330% (above, manufactured by Bayer Japan), KAYASET Blue FR, KAYASET Blue N, KAYASET Blue 814, Turq. Blue GL-5 200, Light Blue BGL-5 200 (above, manufactured by Nippon Kayaku Co., Ltd.), DAIWA Blue 7000, Oleosol Fast Blue GL (above, manufactured by Daiwa Kasei Corp.), DIARESIN Blue P (manufactured by Mitsubishi Kasei Corp.), S. Includes Blue 670, NEOPEN Blue 808, ZAPON Blue 806 (all manufactured by BASF Japan Ltd.) and the like.

Examples of yellow dyes include MS Yellow HSm-41, Yellow KX-7, Yellow EX-27 (all manufactured by Mitsui Toatsu Co., Ltd.), AIZEN SOT Yellow-1, AIZEN SOT YellowW-3, AIZEN SOT Yellow-6 (Aizen SOT Yellow-6). (Manufactured by Hodogaya Chemical Co., Ltd.), MACROLEX Yellow 6G, MACROLEX FLUOR. Yellow 10GN (above, made by Bayer Japan), KAYASET Yellow SF-G, KAYASET Yellow2G, KAYASET Yellow AG, KAYASET Yellow EG (above, manufactured by Nippon Kayaku Co., Ltd.), DAIWA Yellow 330H , HSY-68 (manufactured by Mitsubishi Kasei Corp.), SUDAN Yellow 146, NEOPEN Yellow 075 (manufactured by BASF Japan Ltd.) and the like.

Examples of black dyes include MS Black VPC (manufactured by Mitsui Toatsu Co., Ltd.), AIZEN SOT Black-1, AIZEN SOT Black-5 (manufactured by Hodogaya Chemical Co., Ltd.), RESORIN Black GSN 200%, RESOLIN BlackBS (manufactured by Hodogaya Chemical Co., Ltd.). Bayer Japan), KAYASET Black A-N (Nippon Kayaku), DAIWA Black MSC (Daiwa Kasei), HSB-202 (Mitsubishi Kasei), NEPTUNE Black X60, NEOPEN Black X58 (above, BASF) Made by Japan), etc. are included.

<Pigment>
It is preferable to apply a pigment as a coloring material to the UV ink used in the present invention, and the pigment is not particularly limited, but for example, an organic pigment or an inorganic pigment having the following number described in the Color Index (CI). Can be mentioned.

Examples of red or magenta pigments include Pigment Red 3, 5, 19, 22, 31, 38, 43, 48: 1, 48: 2, 48: 3, 48: 4, 48: 5, 49: 1, 53. 1, 57: 1, 57: 2, 58: 4, 63: 1, 81, 81: 1, 81: 2, 81: 3, 81: 4, 88, 104, 108, 112, 122, 123, 144 , 146, 149, 166, 168, 169, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257, Pigment Violet 3, 19, 23, 29, 30, 37, 50, 88, Pigment Orange 13, 16, 20, 36 and the like are included. Examples of blue or cyan pigments include Pigment Blue 1, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17-1, 22, 27, 28, 29, 36. , 60 and the like are included. Examples of green pigments include Pigment Green 7, 26, 36, 50. Examples of yellow pigments include Pigment Yellow 1, 3, 12, 13, 14, 17, 34, 35, 37, 55, 74, 81, 83, 93, 94, 95, 97, 108, 109, 110, 137. 138, 139, 153, 154, 155, 157, 166, 167, 168, 180, 185, 193 and the like are included. Examples of black pigments include Pigment Black 7, 28, 26 and the like.

Examples of commercially available pigments include Chromofine Yellow 2080, 5900, 5930, AF-1300, 2700L, Chromofine Orange 3700L, 6730, Chromofine Scarlet 6750, Chromofine Magenta 6880, 6886, 6891N, 6790, 6887, Chromo. Fine Violet RE, Chromo Fine Red 6820, 6830, Chromo Fine Blue HS-3, 5187, 5108, 5197, 5085N, SR-5020, 5026, 5050, 4920, 4927, 4937, 4824, 4933GN-EP, 4940, 4973, 5205, 5208, 5214, 5221, 5000P, Chromo Fine Green 2GN, 2GO, 2G-550D, 5310, 5370, 6830, Chromo Fine Black A-1103, Seika Fast Yellow 10GH, A-3, 2035, 2054, 2200, 2270 , 2300, 2400 (B), 2500, 2600, ZAY-260, 2700 (B), 2770, Seika Fast Red 8040, C405 (F), CA120, LR-116, 1531B, 8060R, 1547, ZAW-262, 1537B , GY, 4R-4016, 3820, 3891, ZA-215, Seika Fast Carmine 6B1476T-7, 1843LT, 3840, 3870, Seika Fast Bordeaux 10B-430, Seika Light Rose R40, Seika Light Violet B800, 7805, Seika Fast Maroon 460N, Seika Fast Orange 900, 2900, Seika Light Blue C718, A612, Cyanine Blue 4933M, 4933GN-EP, 4940, 4973 (manufactured by Dainichiseika Kogyo Co., Ltd.);
KET Yellow 401, 402, 403, 404, 405, 406, 416, 424, KET Orange 501, KET Red 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 336, 337, 338, 346, KET Blue 101, 102, 103, 104, 105, 106, 111, 118, 124, KET Green 201 (manufactured by Dainippon Ink and Chemicals);
Colortex 1024, 314, 315, 316, P-624, 314, U10GN, U3GN, UNN, UA-414, U263, Finecol HELLOW T-13, T-05, Pigment 1024, Pigment Yellow1705, Colortex Orange 202, Color103 115, 116, D3B, P-625, 102, H-1024, 105C, UFN, UCN, UBN, U3BN, URN, UGN, UG276, U456, U457, 105C, USN, Colortex Maroon601, Colortex BrownB610N, Colortex BrownB610N, Col. Red 122, Colortex Blue516, 517,518,519, A818, P-908,510, Colortex Green402, 403, Colortex Black 702, U905 (manufactured by Sanyo Pigment);
Lionol Yellow1405G, Lionol Blue FG7330, FG7350, FG7400G, FG7405G, ES, ESP-S (manufactured by Toyo Ink Mfg. Co., Ltd.), Toner Magenta E02, Permanent Rubin F6B, Permanent Rubin F6B, Toner Yellow HG, Perman );
Novoperm P-HG, Hostaparm Pink E, Hostaparm Blue B2G (manufactured by Clariant);
Carbon Black # 2600, # 2400, # 2350, # 2200, # 1000, # 990, # 980, # 970, # 960, # 950, # 850, MCF88, # 750, # 650, MA600, MA7, MA8, MA11 , MA100, MA100R, MA77, # 52, # 50, # 47, # 45, # 45L, # 40, # 33, # 32, # 30, # 25, # 20, # 10, # 5, # 44, CF9 (Manufactured by Mitsubishi Chemical Corporation) and the like.

Moreover, titanium oxide (particularly rutile type titanium dioxide) can also be used as a white pigment.

The volume average particle size of the pigment is preferably 0.1 to 0.5 μm. The maximum particle size of the pigment is preferably 0.1 to 1.0 μm, more preferably 0.1 to 0.5 μm, and particularly preferably in the range of 0.2 to 0.5 μm. By adjusting the particle size of the pigment, clogging of the nozzle of the inkjet recording head can be suppressed, and the storage stability of the ink, the transparency of the ink, and the curing sensitivity can be maintained.

In the present invention, the amount of the coloring material contained in the UV ink is preferably in the range of 0.1 to 20% by mass, preferably in the range of 0.4 to 10% by mass with respect to the total mass of the ink. Is more preferable. This is because if the content of the pigment or dye is too small, the color of the obtained image is not sufficient, and if it is too large, the viscosity of the ink becomes high and the ejection property deteriorates.

[3.2] Electrophotographic image forming apparatus The intermediate transfer body of the present invention can also be preferably applied to an intermediate transfer belt in an electrophotographic image forming apparatus. When applied to an electrophotographic image forming apparatus, it is effectively used when a toner image melted or softened by light irradiation is used. The intermediate transfer body using the ultraviolet transmissive resin makes it possible to irradiate the toner image formed on the intermediate transfer body with light from the back surface and the front surface of the intermediate transfer body. For example, the toner image used for the decorative expression. Suitable for formation.

As the toner image used for the decorative expression, for example, by using a compound that melts or softens by changing the molecular structure by light absorption and a powder having a metallic luster, it depends on the amount of light irradiation (light amount). By controlling the state of the image surface, the orientation of the powder can be controlled, and the texture of the powder, particularly the reflection characteristics, can be variously changed. Therefore, by controlling the irradiation amount and irradiation range of light, it is possible to form images having different textures and glossiness with the same powder. "Compounds that photomelt or soften" include, for example, azobenzene derivatives that are isomerized compounds, azobenzene-containing polymer compounds and stilbene derivatives, and polymer compounds having a hexaarylimidazole group branched chain that cleaves the crosslinked structure by light absorption. It has been reported.

An example of a schematic configuration of the color tandem image forming apparatus 100 including the intermediate transfer member of the present invention will be described with reference to FIG. This image forming apparatus is a multifunction device 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. 4, the image forming apparatus 100 includes an annular intermediate transfer belt 108 wound around the two rollers 102 and 106 and moving in the circumferential direction at substantially the center of the main body casing 101.

Of the two rollers 102 and 106, one roller 102 is arranged on the left side in the drawing, and the other roller 106 is arranged on the right side in the drawing. The intermediate transfer belt 108 of the present invention is supported by these rollers 102 and 106 and is rotationally driven in the direction of arrow X.

Below the intermediate transfer belt 108, in order from the left side in the figure, image forming segments 110Y, 110M, 110C, 110K corresponding to each color toner of yellow (Y), magenta (M), cyan (C), and black (K). Are arranged side by side.

The image forming segments 110Y, 110M, 110C, and 110K are configured in the same manner as each other except for the difference in the toner colors handled by them.

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

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

At the time of image formation, the surface of the photoconductor drum 190 is first uniformly charged by the charging device 191 and then the surface of the photoconductor drum 190 is exposed by the exposure device 192 to form a latent image there. Next, the developing device 193 develops a latent image on the surface of the photoconductor drum 190 to obtain a toner image. This toner image is transferred to the intermediate transfer belt 108 by applying a voltage between the photoconductor drum 190 and the primary transfer roller 194. The transfer residual toner on the surface of the photoconductor drum 190 is cleaned by the cleaner device 195.

As the intermediate transfer belt 108 moves in the direction of the arrow X, the image forming segments 110Y, 110M, 110C, and 110K form a four-color toner image as an output image on the intermediate transfer belt 108. Next, the first light irradiation unit 40 irradiates light from the back surface side of the intermediate transfer belt 108, and the toner image is melted or softened and sent to the secondary transfer roller 112.

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

On the right side of the intermediate transfer belt 108, a secondary transfer roller 112 is provided with a transfer path 124 for the transfer material interposed therebetween. The 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 for detecting the toner pattern on the intermediate transfer belt 108 is provided.

A fixing device 130 for fixing the toner to the 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 drive unit that rotationally drives the fixing member, a pressure member, a pressure drive unit that rotationally drives the pressure member, and the fixing drive unit or the above. It has a drive control unit that controls the rotational drive of the pressurization drive unit.

The fixing device 130 includes a pair of fixing rollers, which are fixing members, and a pressure roller, which is a pressure member, extending perpendicularly to the paper surface in FIG. In FIG. 4, 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 unit (not shown) and a drive control unit (control unit 200 in FIG. 3), and control the rotational speeds of the rotationally driven heating roller 132 and the pressure roller 131. ..

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

When the transfer material 90 on which the toner image is transferred passes through the nip portion, the toner image is fixed on the transfer material 90. The temperatures of the pressurizing roller 131 and the heating roller 132 are detected by the temperature sensors 135 and 136, respectively.

At the lower part of the main body casing 101, paper feed cassettes 116A and 116B for accommodating the transfer material 90 are provided in two stages. FIG. 4 shows a state in which the transfer material 90 is housed 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 paper feed material that has been sent out.

Inside the main body casing 101, a control unit 200 including a CPU (Central Processing Unit) that controls the operation of the entire image forming apparatus is provided.

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

On the other hand, as described above, the toner images of four colors are superposed on the intermediate transfer belt 108 by the image forming segments 110Y, 110M, 110C, and 110K, and the transfer material 90 sent to the toner transfer position is formed. The four-color toner image on the intermediate transfer belt 108 is transferred by the secondary transfer roller 112.

Next, the toner image formed on the transfer material is irradiated with light by the second light irradiation unit 50 to be melted or softened.

The transfer material 90 to which the toner image is transferred is conveyed through a nip portion formed by the pressurizing roller 131 and the heating roller 132 of the fixing device 130 and is heated and pressurized. 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 ejection roller 121 to the paper ejection tray portion 122 provided on the upper surface of the main body casing 101 through the paper ejection path 127.

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

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

The embodiment to which the present invention can be applied is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.

Further, in the above description, the case where the fixing member is a heating roller and the pressure member is a pressure roller has been described as an example, but the fixing belt method can also be manufactured and used in the same manner. Further, the fixing belt referred to in the present specification is a fixing belt made of silicone rubber used when fixing toner to a transfer material in an image forming apparatus. Specifically, for example, it refers to a known fixing belt used in a fixing device described in JP-A-2017-194550, JP-A-2017-173445, JP-A-2017-97187, and the like.

Hereinafter, each typical step in image formation using the electrophotographic image forming apparatus of the present invention will be described.

The steps in image formation are preferably performed in steps used in general electrophotographic image forming methods, such as a charging step, an electrostatic latent image forming step, a developing step, a fixing step, and a cleaning step. ..

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

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

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

The formation of the electrostatic latent image is performed, for example, by uniformly charging the surface of the electrophotographic photosensitive member by a charging means and exposing the surface of the electrophotographic photosensitive member in an image manner by an exposure means. The electrostatic latent image is an image formed on the surface of the electrophotographic photosensitive member by such a charging means.

The charging means and the exposure means are not particularly limited, and those generally used in the electrophotographic method can be used.

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

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

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

(Transfer process)
In this step, the toner image is transferred to the recording medium.

The transfer of the toner image to the recording medium (transfer material) is performed by peeling and charging the toner image on the transfer material.

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

Further, in the transfer step, for example, an intermediate transfer body is used, the toner image is first transferred onto the intermediate transfer body, and then the toner image is secondarily transferred onto the transfer material. In addition, the toner image is transferred onto the electrophotographic photosensitive member. It can also be performed by a mode in which the formed toner image is directly transferred to a transfer material.

(Fixing process)
In this step, a transfer material to which an unfixed image (toner image) formed by using toner is transferred is passed between a heated fixing belt or fixing roller and a pressure roller which is a pressure member. Thereby, it has a step of fixing the unfixed image on the transfer material.

As a method of the fixing step, as described above, as a fixing belt or a fixing roller as a fixing rotating body and a pressurizing member provided in a state of being pressure-welded so as to form a fixing nip portion on the fixing belt or the fixing roller. A belt fixing method or a roller fixing method composed of the pressure rollers of the above can be mentioned.

(Cleaning process)
In this step, the developer that has not been used for image formation or remains untransferred on the developer carrier such as the photoconductor and the intermediate transfer member is removed from the developer carrier.

The cleaning method is not particularly limited, but it is preferable that a blade having a tip abutting against a cleaning object such as a photoconductor and scraping the surface of the photoconductor is used.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, the indication of "parts" or "%" is used, but unless otherwise specified, it indicates "parts by mass" or "% by mass".
(Material used)
[Polyimide for base material layer, polyamide]
・ Spixeria HR003 (manufactured by SOMAR)
・ Uniamide EX-35 (manufactured by Unitika Ltd.)
・ Q-VR-X-1655 (manufactured by PI Giken)
・ TOMED-S (manufactured by IST)
[Light stabilizer]
・ H-1: Chimassrov 2020 (manufactured by BASF Japan Ltd.)
・ H-2: Chimassrov 944 (manufactured by BASF Japan Ltd.)
・ H-3: Tinuvin622 (manufactured by BASF Japan Ltd.)
[Antioxidant]
-S-1: Irganox 1010 (manufactured by BASF Japan Ltd.)
・ S-2: Irganox 1076 (manufactured by BASF Japan Ltd.)
[Ultraviolet (UV) absorber]
-U-1: Tinuvin 326 (manufactured by BASF Japan Ltd.)
[Filler]
-Silica RX-50 (average particle size 70 nm, manufactured by AEROSIL Japan)
-Silica NAX-50 (average particle size 30 nm, manufactured by AEROSIL Japan)
[Transparent silicone rubber for elastic layer]
・ KE2061-30A / B (manufactured by Shin-Etsu Chemical Co., Ltd.)

<Preparation of intermediate transfer body (intermediate transfer belt)>
[Manufacturing of intermediate transcript 1]
<Formation of base material layer>
A leveling agent (KF-96 manufactured by Shin-Etsu Chemical Co., Ltd.) is added to a polyimide varnish (Spixeria HR003 (manufactured by Somar Corporation)) containing a polyimide resin precursor (polyamic acid) as a main component and having a solid content of 15% by mass with respect to the total weight of the polyimide varnish. A coating liquid for forming a substrate layer was prepared by adding 100 ppm and mixing using a mixer.

Next, a cylindrical stainless steel mold having a circumference of 2500 mm and a width of 800 mm on which a mold release agent is formed is rotated at 100 rpm around a cylindrical shaft, and the dispenser nozzle is moved in the direction of the cylindrical shaft to a total width of 700 mm after firing. A wet film was formed so that the thickness of the film was 750 μm.

Next, the solvent was volatilized by heating (calcining) at 100 ° C. for 2 hours using a far-infrared drying device while rotating the cylinder shaft at 100 rpm so that the base material layer did not flow down.

Finally, the mold was introduced into a heating furnace, heated stepwise, and heat-treated (baked) for 90 minutes while being held at 380 ° C. It was cooled sufficiently to obtain a polyimide base material layer having a thickness of 750 μm.

The thickness of the base material layer was measured using MMS manufactured by Fisher Instruments Co., Ltd.

<Formation of elastic layer>
The following components were dissolved in toluene in the following amounts so that the solid content concentration was 20% by mass, and then a coating liquid for forming an elastic layer was prepared.

(Coating liquid for forming elastic layer)
Matrix polymer: KE2061-30A / B (manufactured by Shin-Etsu Chemical Co., Ltd.)
) 100 parts by mass Organic flame retardant: trimethyl phosphate TPM (manufactured by Daihachi Chemical Industry Co., Ltd.) 30 parts by mass Resin cross-linking agent: Phenol novolac type epoxy resin N-770 (manufactured by DIC)
10 parts by mass Conductive agent: Tetrabutylammonium perchlorate QAP-01 (manufactured by Carlit Japan Co., Ltd.)
1 part by mass Next, using the polyimide base material layer formed on the outer peripheral surface of the mold, while rotating at 200 rpm around the cylindrical axis, while moving the dispenser nozzle in the direction of the cylindrical axis, the total width is 700 mm and the thickness after firing. The wet film was laminated so that the thickness was 300 μm.

Next, the mold was introduced into a heating furnace, and the temperature was gradually raised and the mold was heat-treated (vulcanized) for 60 minutes while being held at 180 ° C. After sufficiently cooling, an intermediate transfer body 1 which is a laminated belt of a base material layer (750 μm) and an elastic layer (300 μm) was obtained.

[Preparation of intermediate transcript 2]
<Formation of base material layer>
In the formation of the base material layer of the intermediate transfer material 1, the polyimide for the base material layer was changed from Spixeria HR003 (manufactured by Somar) to Uniamide EX-35 (manufactured by Unitica), which is a polyamide, and H-1: Chimassrov2020 as a light stabilizer. 5% by mass (BASF Japan), 4% by mass of S-1: Irganox1010 (BASF Japan) as an antioxidant, and 10% by mass of RX-50 (average particle size 70 nm, manufactured by AEROSIL Japan) as a filler. A polyamide substrate layer having a total width of 700 mm and a thickness of 35 μm after firing was obtained in the same manner except that% was added.

<Formation of elastic layer>
Similar to the formation of the elastic layer of the intermediate transfer body 1, an elastic layer having a thickness of 300 μm is formed on the base material layer, and the intermediate transfer body is a laminated belt of the base material layer (35 μm) and the elastic layer (300 μm). I got 2.

[Preparation of intermediate transcripts 3-9]
With the configurations shown in Table I, the type of polyimide resin, the type of light stabilizer, the type and amount of antioxidant, the type of filler and the layer thickness were changed to prepare a base material layer, and then the elasticity of the intermediate transfer material 1 was formed. An elastic layer having a thickness of 300 μm was formed on the base material layer in the same manner as in the formation of the layer, and intermediate transcripts 3 to 9 were prepared.

In the intermediate transfer material 3, a UV absorber was added to the elastic layer in an amount of 0.5% by mass.

《Evaluation》
The following evaluations were carried out using the intermediate transcripts 1 to 9 prepared above.

[1] Measurement of UV Transmittance The produced intermediate transfer material was subjected to a spectrophoto absorption spectrum using a Spectrophotometer U-3200 (manufactured by Hitachi, Ltd.) to determine the transmittance (%) at a light wavelength of 395 nm.

[2] Measurement of Tensile Elastic Modulus The tensile elastic modulus was measured by a tensile test using a section obtained by cutting an intermediate transfer material into a dumbbell shape by the method of JIS K7161.

Measuring equipment: Tensilon universal material testing machine RTC-1250 (manufactured by A & D Co., Ltd.)
Measurement conditions: Test piece for tensile test: Shape conforming to JIS K7161
Tensile speed: 1 mm / s
Distance between chucks: 115 mm
Distance between gauge points: 100 mm
For the intermediate transfer material, the tensile elastic modulus immediately after preparation and the tensile elastic modulus after irradiation with ultraviolet rays at 500 mW / cm ² for 100 hours were measured using a high-pressure mercury lamp.
For the intermediate transfer material 7, the tensile elastic modulus before and after the ultraviolet irradiation was measured under the condition of 500 mW / cm ² for 100 hours using PM50C-100A1 of Ushio Lighting.

[3] Transfer rate The transfer rate was tested by preparing the following inks and mounting the above-prepared intermediate transfer bodies on the image forming apparatus for an inkjet shown in FIG.

For the transfer rate, the intermediate transfer material after the transfer step was observed with an optical microscope, and the ink remaining area ratio of each intermediate image was evaluated according to the following criteria. When all the inks were transferred to the recording medium and no intermediate image remained, the transfer rate was 100%.
[Preparation of ink 1]
(Preparation of pigment dispersion)
The following components were formulated so as to have a total of 100 parts by mass. This was placed in a 200 cc polyethylene container with a lid together with 120 g of 0.5 mmφ zirconia beads, the lid was closed, and the mixture was dispersed with a paint conditioner for 3 hours. Then, the beads were separated to obtain a pigment dispersion liquid.

C. I. Pigment Blue 15: 3 (manufactured by DIC, TGR / no surface treatment)
20.0 parts by mass Tripropylene glycol diacrylate (photopolymerizable compound) 71.9 parts by mass Solspace 3000 (manufactured by Lubrizol, polymer dispersant)
8.0 parts by mass Irgastab UV-10 (manufactured by BASF, polymerization inhibitor) 0.1 parts by mass (preparation of ink)
While heating the obtained pigment dispersion liquid to 60 ° C., the following components were added in the following proportions to prepare ink 1.

Pigment dispersion 20.0% by mass
PO-modified neopentyl glycol diacrylate (photopolymerizable compound)
34.8% by mass
Polyethylene glycol # 400 diacrylate (photopolymerizable compound)
20.0% by mass
4EO-modified pentaerythritol tetraacrylate (photopolymerizable compound)
20.0% by mass
Irgacure819 (BASF, photopolymerization initiator) 3.0% by mass
Irgastab UV-10 (manufactured by BASF, photopolymerization inhibitor) 0.1% by mass
KF-352 (Surfactant manufactured by Shinetsu Silicone Co., Ltd.) 0.1% by mass
Kao Wax T-1 (Kao Corporation, gelling agent) 2.0% by mass
With the obtained ink, the intermediate transfer body 1 produced above as the intermediate transfer unit 20 was attached to the image forming apparatus shown in FIG. 3, and the UV curable ink prepared above was filled in the inkjet head 11K.

Next, a repetitive halftone image of 1-dot line-1 dot non-printing-1 dot line is printed on the intermediate transfer body 1 from an inkjet head at a printing speed of 600 mm / s (resolution 1200 × 1200 dpi, ink droplet size 10 pL). )did. Next, the first light irradiation unit 40 performed pre-curing using an ultraviolet LED light source having a wavelength of 395 nm and an irradiation intensity of 200 mW / cm ² .

Next, the formed image was transferred to embossed paper (Rezac 66 260 kg paper) as a recording medium with the pressure of the support roller 23 on the paper transport portion 30 being 20 kN / m.

Finally, the second light irradiation unit 50 performed the main curing using an ultraviolet LED light source having a wavelength of 395 nm and an irradiation intensity of 500 mW / cm ² , to produce printed matter 1. Further, 10,000 sheets of this halftone image were output.

The transfer rate was defined as the transfer rate immediately after the 10th halftone image was produced, and the transfer rate after the durability test was used for the 10000th image.

Table I shows the composition and evaluation results of the intermediate transcript as described above.

From the results in Table I, according to the configuration of the present invention, in the intermediate transfer material having a resin layer that transmits ultraviolet rays, the transferability is improved in the durability test by suppressing the decrease in tensile strength while maintaining the ultraviolet transmittance. We were able to obtain the system and the intermediate transcript applied to it.

By adding a filler to further increase the tensile strength, it is possible to increase the tensile elastic modulus and not decrease the ultraviolet transmittance, and the intermediate transfer material that achieves both the ultraviolet transmittance and the suppression of the decrease in tensile strength, and the intermediate transfer material thereof. It was possible to obtain an image forming apparatus equipped with the above.

1 Intermediate transfer member 2 Base material layer 3 Elastic layer 4 Surface layer 1b Coating device 2b Coating means with nozzle 3b Atomized coating liquid 4b Coating film 5b Metal cylinder,
6b arrow 26
7b arrow 27
5 Image forming device 6 Ink layer 10 Ink ejection part 11 Ink ejection head 20 Intermediate transfer part 22 Supporting roller 23 Supporting roller 24 Supporting roller 25 Cleaning part 30 Paper transporting part 40 First light irradiation part 50 Second light irradiation part 100 Image forming device 108 Intermediate transfer belt 110Y, 110M, 110C, 110K Image forming unit 130 Fixing device 131 Pressurizing roller 132 Heating roller 190 Photoreceptor drum 191 Charging device 192 Exposure device 193 Developing device 195 Cleaner device

Claims (13)

An intermediate transfer body used to transfer an image to a recording medium.
The intermediate transfer material has a resin layer that transmits ultraviolet rays,
An intermediate transfer product, wherein the resin layer contains at least an additive selected from a light stabilizer, an antioxidant, and an ultraviolet absorber. The intermediate transfer material according to claim 1, wherein the resin layer contains a polyimide containing a polyamic acid. The first or second aspect of the present invention, wherein the resin layer contains a light stabilizer or an antioxidant, and the content of the ultraviolet absorber in the resin layer is 1% by mass or less. Intermediate transcript. The intermediate transfer product according to any one of claims 1 to 3, wherein the thickness of the resin layer is in the range of 30 to 500 μm. The intermediate transfer product according to any one of claims 1 to 4, wherein the resin layer contains a filler having an average particle diameter in the range of 10 to 80 nm. Claims 1 to 5 are characterized in that the resin layer is a layer that transmits ultraviolet rays in the light wavelength range of 350 to 420 nm, and the light wavelength of the ultraviolet rays is in the range of 350 to 420 nm. The intermediate transcript according to any one of the above. The intermediate transfer product according to any one of claims 1 to 6, wherein the resin layer has an ultraviolet transmittance of 70% or more at a light wavelength of 395 nm. The intermediate transfer product according to any one of claims 1 to 7, wherein the tensile elastic modulus is 4 GPa or more. The intermediate transfer body according to any one of claims 1 to 8, wherein the intermediate transfer body is an intermediate transfer belt. The intermediate transfer body according to any one of claims 1 to 9, wherein the resin layer is a base material layer of the intermediate transfer body. A method for producing an intermediate transcript according to any one of claims 1 to 10, wherein the intermediate transcript is produced.
A method for producing an intermediate transcript, which comprises a step of adding at least an additive selected from a light stabilizer, an antioxidant, and an ultraviolet absorber to a resin composition containing a polyimide containing a polyamic acid. .. An image forming apparatus comprising the intermediate transfer member according to any one of claims 1 to 10. An image forming apparatus according to claim 12, wherein the image forming apparatus is an image forming apparatus for an inkjet.

Images